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TOMOYO Linux Cross Reference
Linux/include/linux/skbuff.h

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  1 /* SPDX-License-Identifier: GPL-2.0-or-later */
  2 /*
  3  *      Definitions for the 'struct sk_buff' memory handlers.
  4  *
  5  *      Authors:
  6  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  7  *              Florian La Roche, <rzsfl@rz.uni-sb.de>
  8  */
  9 
 10 #ifndef _LINUX_SKBUFF_H
 11 #define _LINUX_SKBUFF_H
 12 
 13 #include <linux/kernel.h>
 14 #include <linux/compiler.h>
 15 #include <linux/time.h>
 16 #include <linux/bug.h>
 17 #include <linux/bvec.h>
 18 #include <linux/cache.h>
 19 #include <linux/rbtree.h>
 20 #include <linux/socket.h>
 21 #include <linux/refcount.h>
 22 
 23 #include <linux/atomic.h>
 24 #include <asm/types.h>
 25 #include <linux/spinlock.h>
 26 #include <linux/net.h>
 27 #include <linux/textsearch.h>
 28 #include <net/checksum.h>
 29 #include <linux/rcupdate.h>
 30 #include <linux/hrtimer.h>
 31 #include <linux/dma-mapping.h>
 32 #include <linux/netdev_features.h>
 33 #include <linux/sched.h>
 34 #include <linux/sched/clock.h>
 35 #include <net/flow_dissector.h>
 36 #include <linux/splice.h>
 37 #include <linux/in6.h>
 38 #include <linux/if_packet.h>
 39 #include <net/flow.h>
 40 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 41 #include <linux/netfilter/nf_conntrack_common.h>
 42 #endif
 43 
 44 /* The interface for checksum offload between the stack and networking drivers
 45  * is as follows...
 46  *
 47  * A. IP checksum related features
 48  *
 49  * Drivers advertise checksum offload capabilities in the features of a device.
 50  * From the stack's point of view these are capabilities offered by the driver.
 51  * A driver typically only advertises features that it is capable of offloading
 52  * to its device.
 53  *
 54  * The checksum related features are:
 55  *
 56  *      NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
 57  *                        IP (one's complement) checksum for any combination
 58  *                        of protocols or protocol layering. The checksum is
 59  *                        computed and set in a packet per the CHECKSUM_PARTIAL
 60  *                        interface (see below).
 61  *
 62  *      NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
 63  *                        TCP or UDP packets over IPv4. These are specifically
 64  *                        unencapsulated packets of the form IPv4|TCP or
 65  *                        IPv4|UDP where the Protocol field in the IPv4 header
 66  *                        is TCP or UDP. The IPv4 header may contain IP options.
 67  *                        This feature cannot be set in features for a device
 68  *                        with NETIF_F_HW_CSUM also set. This feature is being
 69  *                        DEPRECATED (see below).
 70  *
 71  *      NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
 72  *                        TCP or UDP packets over IPv6. These are specifically
 73  *                        unencapsulated packets of the form IPv6|TCP or
 74  *                        IPv6|UDP where the Next Header field in the IPv6
 75  *                        header is either TCP or UDP. IPv6 extension headers
 76  *                        are not supported with this feature. This feature
 77  *                        cannot be set in features for a device with
 78  *                        NETIF_F_HW_CSUM also set. This feature is being
 79  *                        DEPRECATED (see below).
 80  *
 81  *      NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
 82  *                       This flag is only used to disable the RX checksum
 83  *                       feature for a device. The stack will accept receive
 84  *                       checksum indication in packets received on a device
 85  *                       regardless of whether NETIF_F_RXCSUM is set.
 86  *
 87  * B. Checksumming of received packets by device. Indication of checksum
 88  *    verification is set in skb->ip_summed. Possible values are:
 89  *
 90  * CHECKSUM_NONE:
 91  *
 92  *   Device did not checksum this packet e.g. due to lack of capabilities.
 93  *   The packet contains full (though not verified) checksum in packet but
 94  *   not in skb->csum. Thus, skb->csum is undefined in this case.
 95  *
 96  * CHECKSUM_UNNECESSARY:
 97  *
 98  *   The hardware you're dealing with doesn't calculate the full checksum
 99  *   (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
100  *   for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
101  *   if their checksums are okay. skb->csum is still undefined in this case
102  *   though. A driver or device must never modify the checksum field in the
103  *   packet even if checksum is verified.
104  *
105  *   CHECKSUM_UNNECESSARY is applicable to following protocols:
106  *     TCP: IPv6 and IPv4.
107  *     UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
108  *       zero UDP checksum for either IPv4 or IPv6, the networking stack
109  *       may perform further validation in this case.
110  *     GRE: only if the checksum is present in the header.
111  *     SCTP: indicates the CRC in SCTP header has been validated.
112  *     FCOE: indicates the CRC in FC frame has been validated.
113  *
114  *   skb->csum_level indicates the number of consecutive checksums found in
115  *   the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
116  *   For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
117  *   and a device is able to verify the checksums for UDP (possibly zero),
118  *   GRE (checksum flag is set) and TCP, skb->csum_level would be set to
119  *   two. If the device were only able to verify the UDP checksum and not
120  *   GRE, either because it doesn't support GRE checksum or because GRE
121  *   checksum is bad, skb->csum_level would be set to zero (TCP checksum is
122  *   not considered in this case).
123  *
124  * CHECKSUM_COMPLETE:
125  *
126  *   This is the most generic way. The device supplied checksum of the _whole_
127  *   packet as seen by netif_rx() and fills in skb->csum. This means the
128  *   hardware doesn't need to parse L3/L4 headers to implement this.
129  *
130  *   Notes:
131  *   - Even if device supports only some protocols, but is able to produce
132  *     skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
133  *   - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
134  *
135  * CHECKSUM_PARTIAL:
136  *
137  *   A checksum is set up to be offloaded to a device as described in the
138  *   output description for CHECKSUM_PARTIAL. This may occur on a packet
139  *   received directly from another Linux OS, e.g., a virtualized Linux kernel
140  *   on the same host, or it may be set in the input path in GRO or remote
141  *   checksum offload. For the purposes of checksum verification, the checksum
142  *   referred to by skb->csum_start + skb->csum_offset and any preceding
143  *   checksums in the packet are considered verified. Any checksums in the
144  *   packet that are after the checksum being offloaded are not considered to
145  *   be verified.
146  *
147  * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
148  *    in the skb->ip_summed for a packet. Values are:
149  *
150  * CHECKSUM_PARTIAL:
151  *
152  *   The driver is required to checksum the packet as seen by hard_start_xmit()
153  *   from skb->csum_start up to the end, and to record/write the checksum at
154  *   offset skb->csum_start + skb->csum_offset. A driver may verify that the
155  *   csum_start and csum_offset values are valid values given the length and
156  *   offset of the packet, but it should not attempt to validate that the
157  *   checksum refers to a legitimate transport layer checksum -- it is the
158  *   purview of the stack to validate that csum_start and csum_offset are set
159  *   correctly.
160  *
161  *   When the stack requests checksum offload for a packet, the driver MUST
162  *   ensure that the checksum is set correctly. A driver can either offload the
163  *   checksum calculation to the device, or call skb_checksum_help (in the case
164  *   that the device does not support offload for a particular checksum).
165  *
166  *   NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
167  *   NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
168  *   checksum offload capability.
169  *   skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
170  *   on network device checksumming capabilities: if a packet does not match
171  *   them, skb_checksum_help or skb_crc32c_help (depending on the value of
172  *   csum_not_inet, see item D.) is called to resolve the checksum.
173  *
174  * CHECKSUM_NONE:
175  *
176  *   The skb was already checksummed by the protocol, or a checksum is not
177  *   required.
178  *
179  * CHECKSUM_UNNECESSARY:
180  *
181  *   This has the same meaning as CHECKSUM_NONE for checksum offload on
182  *   output.
183  *
184  * CHECKSUM_COMPLETE:
185  *   Not used in checksum output. If a driver observes a packet with this value
186  *   set in skbuff, it should treat the packet as if CHECKSUM_NONE were set.
187  *
188  * D. Non-IP checksum (CRC) offloads
189  *
190  *   NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
191  *     offloading the SCTP CRC in a packet. To perform this offload the stack
192  *     will set csum_start and csum_offset accordingly, set ip_summed to
193  *     CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
194  *     the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
195  *     A driver that supports both IP checksum offload and SCTP CRC32c offload
196  *     must verify which offload is configured for a packet by testing the
197  *     value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
198  *     CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
199  *
200  *   NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
201  *     offloading the FCOE CRC in a packet. To perform this offload the stack
202  *     will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
203  *     accordingly. Note that there is no indication in the skbuff that the
204  *     CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
205  *     both IP checksum offload and FCOE CRC offload must verify which offload
206  *     is configured for a packet, presumably by inspecting packet headers.
207  *
208  * E. Checksumming on output with GSO.
209  *
210  * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
211  * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
212  * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
213  * part of the GSO operation is implied. If a checksum is being offloaded
214  * with GSO then ip_summed is CHECKSUM_PARTIAL, and both csum_start and
215  * csum_offset are set to refer to the outermost checksum being offloaded
216  * (two offloaded checksums are possible with UDP encapsulation).
217  */
218 
219 /* Don't change this without changing skb_csum_unnecessary! */
220 #define CHECKSUM_NONE           0
221 #define CHECKSUM_UNNECESSARY    1
222 #define CHECKSUM_COMPLETE       2
223 #define CHECKSUM_PARTIAL        3
224 
225 /* Maximum value in skb->csum_level */
226 #define SKB_MAX_CSUM_LEVEL      3
227 
228 #define SKB_DATA_ALIGN(X)       ALIGN(X, SMP_CACHE_BYTES)
229 #define SKB_WITH_OVERHEAD(X)    \
230         ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
231 #define SKB_MAX_ORDER(X, ORDER) \
232         SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
233 #define SKB_MAX_HEAD(X)         (SKB_MAX_ORDER((X), 0))
234 #define SKB_MAX_ALLOC           (SKB_MAX_ORDER(0, 2))
235 
236 /* return minimum truesize of one skb containing X bytes of data */
237 #define SKB_TRUESIZE(X) ((X) +                                          \
238                          SKB_DATA_ALIGN(sizeof(struct sk_buff)) +       \
239                          SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
240 
241 struct ahash_request;
242 struct net_device;
243 struct scatterlist;
244 struct pipe_inode_info;
245 struct iov_iter;
246 struct napi_struct;
247 struct bpf_prog;
248 union bpf_attr;
249 struct skb_ext;
250 
251 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
252 struct nf_bridge_info {
253         enum {
254                 BRNF_PROTO_UNCHANGED,
255                 BRNF_PROTO_8021Q,
256                 BRNF_PROTO_PPPOE
257         } orig_proto:8;
258         u8                      pkt_otherhost:1;
259         u8                      in_prerouting:1;
260         u8                      bridged_dnat:1;
261         __u16                   frag_max_size;
262         struct net_device       *physindev;
263 
264         /* always valid & non-NULL from FORWARD on, for physdev match */
265         struct net_device       *physoutdev;
266         union {
267                 /* prerouting: detect dnat in orig/reply direction */
268                 __be32          ipv4_daddr;
269                 struct in6_addr ipv6_daddr;
270 
271                 /* after prerouting + nat detected: store original source
272                  * mac since neigh resolution overwrites it, only used while
273                  * skb is out in neigh layer.
274                  */
275                 char neigh_header[8];
276         };
277 };
278 #endif
279 
280 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
281 /* Chain in tc_skb_ext will be used to share the tc chain with
282  * ovs recirc_id. It will be set to the current chain by tc
283  * and read by ovs to recirc_id.
284  */
285 struct tc_skb_ext {
286         __u32 chain;
287         __u16 mru;
288         bool post_ct;
289 };
290 #endif
291 
292 struct sk_buff_head {
293         /* These two members must be first. */
294         struct sk_buff  *next;
295         struct sk_buff  *prev;
296 
297         __u32           qlen;
298         spinlock_t      lock;
299 };
300 
301 struct sk_buff;
302 
303 /* To allow 64K frame to be packed as single skb without frag_list we
304  * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
305  * buffers which do not start on a page boundary.
306  *
307  * Since GRO uses frags we allocate at least 16 regardless of page
308  * size.
309  */
310 #if (65536/PAGE_SIZE + 1) < 16
311 #define MAX_SKB_FRAGS 16UL
312 #else
313 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
314 #endif
315 extern int sysctl_max_skb_frags;
316 
317 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
318  * segment using its current segmentation instead.
319  */
320 #define GSO_BY_FRAGS    0xFFFF
321 
322 typedef struct bio_vec skb_frag_t;
323 
324 /**
325  * skb_frag_size() - Returns the size of a skb fragment
326  * @frag: skb fragment
327  */
328 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
329 {
330         return frag->bv_len;
331 }
332 
333 /**
334  * skb_frag_size_set() - Sets the size of a skb fragment
335  * @frag: skb fragment
336  * @size: size of fragment
337  */
338 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
339 {
340         frag->bv_len = size;
341 }
342 
343 /**
344  * skb_frag_size_add() - Increments the size of a skb fragment by @delta
345  * @frag: skb fragment
346  * @delta: value to add
347  */
348 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
349 {
350         frag->bv_len += delta;
351 }
352 
353 /**
354  * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
355  * @frag: skb fragment
356  * @delta: value to subtract
357  */
358 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
359 {
360         frag->bv_len -= delta;
361 }
362 
363 /**
364  * skb_frag_must_loop - Test if %p is a high memory page
365  * @p: fragment's page
366  */
367 static inline bool skb_frag_must_loop(struct page *p)
368 {
369 #if defined(CONFIG_HIGHMEM)
370         if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
371                 return true;
372 #endif
373         return false;
374 }
375 
376 /**
377  *      skb_frag_foreach_page - loop over pages in a fragment
378  *
379  *      @f:             skb frag to operate on
380  *      @f_off:         offset from start of f->bv_page
381  *      @f_len:         length from f_off to loop over
382  *      @p:             (temp var) current page
383  *      @p_off:         (temp var) offset from start of current page,
384  *                                 non-zero only on first page.
385  *      @p_len:         (temp var) length in current page,
386  *                                 < PAGE_SIZE only on first and last page.
387  *      @copied:        (temp var) length so far, excluding current p_len.
388  *
389  *      A fragment can hold a compound page, in which case per-page
390  *      operations, notably kmap_atomic, must be called for each
391  *      regular page.
392  */
393 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
394         for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT),            \
395              p_off = (f_off) & (PAGE_SIZE - 1),                         \
396              p_len = skb_frag_must_loop(p) ?                            \
397              min_t(u32, f_len, PAGE_SIZE - p_off) : f_len,              \
398              copied = 0;                                                \
399              copied < f_len;                                            \
400              copied += p_len, p++, p_off = 0,                           \
401              p_len = min_t(u32, f_len - copied, PAGE_SIZE))             \
402 
403 #define HAVE_HW_TIME_STAMP
404 
405 /**
406  * struct skb_shared_hwtstamps - hardware time stamps
407  * @hwtstamp:   hardware time stamp transformed into duration
408  *              since arbitrary point in time
409  *
410  * Software time stamps generated by ktime_get_real() are stored in
411  * skb->tstamp.
412  *
413  * hwtstamps can only be compared against other hwtstamps from
414  * the same device.
415  *
416  * This structure is attached to packets as part of the
417  * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
418  */
419 struct skb_shared_hwtstamps {
420         ktime_t hwtstamp;
421 };
422 
423 /* Definitions for tx_flags in struct skb_shared_info */
424 enum {
425         /* generate hardware time stamp */
426         SKBTX_HW_TSTAMP = 1 << 0,
427 
428         /* generate software time stamp when queueing packet to NIC */
429         SKBTX_SW_TSTAMP = 1 << 1,
430 
431         /* device driver is going to provide hardware time stamp */
432         SKBTX_IN_PROGRESS = 1 << 2,
433 
434         /* generate wifi status information (where possible) */
435         SKBTX_WIFI_STATUS = 1 << 4,
436 
437         /* generate software time stamp when entering packet scheduling */
438         SKBTX_SCHED_TSTAMP = 1 << 6,
439 };
440 
441 #define SKBTX_ANY_SW_TSTAMP     (SKBTX_SW_TSTAMP    | \
442                                  SKBTX_SCHED_TSTAMP)
443 #define SKBTX_ANY_TSTAMP        (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
444 
445 /* Definitions for flags in struct skb_shared_info */
446 enum {
447         /* use zcopy routines */
448         SKBFL_ZEROCOPY_ENABLE = BIT(0),
449 
450         /* This indicates at least one fragment might be overwritten
451          * (as in vmsplice(), sendfile() ...)
452          * If we need to compute a TX checksum, we'll need to copy
453          * all frags to avoid possible bad checksum
454          */
455         SKBFL_SHARED_FRAG = BIT(1),
456 };
457 
458 #define SKBFL_ZEROCOPY_FRAG     (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
459 
460 /*
461  * The callback notifies userspace to release buffers when skb DMA is done in
462  * lower device, the skb last reference should be 0 when calling this.
463  * The zerocopy_success argument is true if zero copy transmit occurred,
464  * false on data copy or out of memory error caused by data copy attempt.
465  * The ctx field is used to track device context.
466  * The desc field is used to track userspace buffer index.
467  */
468 struct ubuf_info {
469         void (*callback)(struct sk_buff *, struct ubuf_info *,
470                          bool zerocopy_success);
471         union {
472                 struct {
473                         unsigned long desc;
474                         void *ctx;
475                 };
476                 struct {
477                         u32 id;
478                         u16 len;
479                         u16 zerocopy:1;
480                         u32 bytelen;
481                 };
482         };
483         refcount_t refcnt;
484         u8 flags;
485 
486         struct mmpin {
487                 struct user_struct *user;
488                 unsigned int num_pg;
489         } mmp;
490 };
491 
492 #define skb_uarg(SKB)   ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
493 
494 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
495 void mm_unaccount_pinned_pages(struct mmpin *mmp);
496 
497 struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size);
498 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
499                                        struct ubuf_info *uarg);
500 
501 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
502 
503 void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
504                            bool success);
505 
506 int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len);
507 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
508                              struct msghdr *msg, int len,
509                              struct ubuf_info *uarg);
510 
511 /* This data is invariant across clones and lives at
512  * the end of the header data, ie. at skb->end.
513  */
514 struct skb_shared_info {
515         __u8            flags;
516         __u8            meta_len;
517         __u8            nr_frags;
518         __u8            tx_flags;
519         unsigned short  gso_size;
520         /* Warning: this field is not always filled in (UFO)! */
521         unsigned short  gso_segs;
522         struct sk_buff  *frag_list;
523         struct skb_shared_hwtstamps hwtstamps;
524         unsigned int    gso_type;
525         u32             tskey;
526 
527         /*
528          * Warning : all fields before dataref are cleared in __alloc_skb()
529          */
530         atomic_t        dataref;
531 
532         /* Intermediate layers must ensure that destructor_arg
533          * remains valid until skb destructor */
534         void *          destructor_arg;
535 
536         /* must be last field, see pskb_expand_head() */
537         skb_frag_t      frags[MAX_SKB_FRAGS];
538 };
539 
540 /* We divide dataref into two halves.  The higher 16 bits hold references
541  * to the payload part of skb->data.  The lower 16 bits hold references to
542  * the entire skb->data.  A clone of a headerless skb holds the length of
543  * the header in skb->hdr_len.
544  *
545  * All users must obey the rule that the skb->data reference count must be
546  * greater than or equal to the payload reference count.
547  *
548  * Holding a reference to the payload part means that the user does not
549  * care about modifications to the header part of skb->data.
550  */
551 #define SKB_DATAREF_SHIFT 16
552 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
553 
554 
555 enum {
556         SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
557         SKB_FCLONE_ORIG,        /* orig skb (from fclone_cache) */
558         SKB_FCLONE_CLONE,       /* companion fclone skb (from fclone_cache) */
559 };
560 
561 enum {
562         SKB_GSO_TCPV4 = 1 << 0,
563 
564         /* This indicates the skb is from an untrusted source. */
565         SKB_GSO_DODGY = 1 << 1,
566 
567         /* This indicates the tcp segment has CWR set. */
568         SKB_GSO_TCP_ECN = 1 << 2,
569 
570         SKB_GSO_TCP_FIXEDID = 1 << 3,
571 
572         SKB_GSO_TCPV6 = 1 << 4,
573 
574         SKB_GSO_FCOE = 1 << 5,
575 
576         SKB_GSO_GRE = 1 << 6,
577 
578         SKB_GSO_GRE_CSUM = 1 << 7,
579 
580         SKB_GSO_IPXIP4 = 1 << 8,
581 
582         SKB_GSO_IPXIP6 = 1 << 9,
583 
584         SKB_GSO_UDP_TUNNEL = 1 << 10,
585 
586         SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
587 
588         SKB_GSO_PARTIAL = 1 << 12,
589 
590         SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
591 
592         SKB_GSO_SCTP = 1 << 14,
593 
594         SKB_GSO_ESP = 1 << 15,
595 
596         SKB_GSO_UDP = 1 << 16,
597 
598         SKB_GSO_UDP_L4 = 1 << 17,
599 
600         SKB_GSO_FRAGLIST = 1 << 18,
601 };
602 
603 #if BITS_PER_LONG > 32
604 #define NET_SKBUFF_DATA_USES_OFFSET 1
605 #endif
606 
607 #ifdef NET_SKBUFF_DATA_USES_OFFSET
608 typedef unsigned int sk_buff_data_t;
609 #else
610 typedef unsigned char *sk_buff_data_t;
611 #endif
612 
613 /**
614  *      struct sk_buff - socket buffer
615  *      @next: Next buffer in list
616  *      @prev: Previous buffer in list
617  *      @tstamp: Time we arrived/left
618  *      @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
619  *              for retransmit timer
620  *      @rbnode: RB tree node, alternative to next/prev for netem/tcp
621  *      @list: queue head
622  *      @sk: Socket we are owned by
623  *      @ip_defrag_offset: (aka @sk) alternate use of @sk, used in
624  *              fragmentation management
625  *      @dev: Device we arrived on/are leaving by
626  *      @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
627  *      @cb: Control buffer. Free for use by every layer. Put private vars here
628  *      @_skb_refdst: destination entry (with norefcount bit)
629  *      @sp: the security path, used for xfrm
630  *      @len: Length of actual data
631  *      @data_len: Data length
632  *      @mac_len: Length of link layer header
633  *      @hdr_len: writable header length of cloned skb
634  *      @csum: Checksum (must include start/offset pair)
635  *      @csum_start: Offset from skb->head where checksumming should start
636  *      @csum_offset: Offset from csum_start where checksum should be stored
637  *      @priority: Packet queueing priority
638  *      @ignore_df: allow local fragmentation
639  *      @cloned: Head may be cloned (check refcnt to be sure)
640  *      @ip_summed: Driver fed us an IP checksum
641  *      @nohdr: Payload reference only, must not modify header
642  *      @pkt_type: Packet class
643  *      @fclone: skbuff clone status
644  *      @ipvs_property: skbuff is owned by ipvs
645  *      @inner_protocol_type: whether the inner protocol is
646  *              ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
647  *      @remcsum_offload: remote checksum offload is enabled
648  *      @offload_fwd_mark: Packet was L2-forwarded in hardware
649  *      @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
650  *      @tc_skip_classify: do not classify packet. set by IFB device
651  *      @tc_at_ingress: used within tc_classify to distinguish in/egress
652  *      @redirected: packet was redirected by packet classifier
653  *      @from_ingress: packet was redirected from the ingress path
654  *      @peeked: this packet has been seen already, so stats have been
655  *              done for it, don't do them again
656  *      @nf_trace: netfilter packet trace flag
657  *      @protocol: Packet protocol from driver
658  *      @destructor: Destruct function
659  *      @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
660  *      @_sk_redir: socket redirection information for skmsg
661  *      @_nfct: Associated connection, if any (with nfctinfo bits)
662  *      @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
663  *      @skb_iif: ifindex of device we arrived on
664  *      @tc_index: Traffic control index
665  *      @hash: the packet hash
666  *      @queue_mapping: Queue mapping for multiqueue devices
667  *      @head_frag: skb was allocated from page fragments,
668  *              not allocated by kmalloc() or vmalloc().
669  *      @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
670  *      @active_extensions: active extensions (skb_ext_id types)
671  *      @ndisc_nodetype: router type (from link layer)
672  *      @ooo_okay: allow the mapping of a socket to a queue to be changed
673  *      @l4_hash: indicate hash is a canonical 4-tuple hash over transport
674  *              ports.
675  *      @sw_hash: indicates hash was computed in software stack
676  *      @wifi_acked_valid: wifi_acked was set
677  *      @wifi_acked: whether frame was acked on wifi or not
678  *      @no_fcs:  Request NIC to treat last 4 bytes as Ethernet FCS
679  *      @encapsulation: indicates the inner headers in the skbuff are valid
680  *      @encap_hdr_csum: software checksum is needed
681  *      @csum_valid: checksum is already valid
682  *      @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
683  *      @csum_complete_sw: checksum was completed by software
684  *      @csum_level: indicates the number of consecutive checksums found in
685  *              the packet minus one that have been verified as
686  *              CHECKSUM_UNNECESSARY (max 3)
687  *      @dst_pending_confirm: need to confirm neighbour
688  *      @decrypted: Decrypted SKB
689  *      @napi_id: id of the NAPI struct this skb came from
690  *      @sender_cpu: (aka @napi_id) source CPU in XPS
691  *      @secmark: security marking
692  *      @mark: Generic packet mark
693  *      @reserved_tailroom: (aka @mark) number of bytes of free space available
694  *              at the tail of an sk_buff
695  *      @vlan_present: VLAN tag is present
696  *      @vlan_proto: vlan encapsulation protocol
697  *      @vlan_tci: vlan tag control information
698  *      @inner_protocol: Protocol (encapsulation)
699  *      @inner_ipproto: (aka @inner_protocol) stores ipproto when
700  *              skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
701  *      @inner_transport_header: Inner transport layer header (encapsulation)
702  *      @inner_network_header: Network layer header (encapsulation)
703  *      @inner_mac_header: Link layer header (encapsulation)
704  *      @transport_header: Transport layer header
705  *      @network_header: Network layer header
706  *      @mac_header: Link layer header
707  *      @kcov_handle: KCOV remote handle for remote coverage collection
708  *      @tail: Tail pointer
709  *      @end: End pointer
710  *      @head: Head of buffer
711  *      @data: Data head pointer
712  *      @truesize: Buffer size
713  *      @users: User count - see {datagram,tcp}.c
714  *      @extensions: allocated extensions, valid if active_extensions is nonzero
715  */
716 
717 struct sk_buff {
718         union {
719                 struct {
720                         /* These two members must be first. */
721                         struct sk_buff          *next;
722                         struct sk_buff          *prev;
723 
724                         union {
725                                 struct net_device       *dev;
726                                 /* Some protocols might use this space to store information,
727                                  * while device pointer would be NULL.
728                                  * UDP receive path is one user.
729                                  */
730                                 unsigned long           dev_scratch;
731                         };
732                 };
733                 struct rb_node          rbnode; /* used in netem, ip4 defrag, and tcp stack */
734                 struct list_head        list;
735         };
736 
737         union {
738                 struct sock             *sk;
739                 int                     ip_defrag_offset;
740         };
741 
742         union {
743                 ktime_t         tstamp;
744                 u64             skb_mstamp_ns; /* earliest departure time */
745         };
746         /*
747          * This is the control buffer. It is free to use for every
748          * layer. Please put your private variables there. If you
749          * want to keep them across layers you have to do a skb_clone()
750          * first. This is owned by whoever has the skb queued ATM.
751          */
752         char                    cb[48] __aligned(8);
753 
754         union {
755                 struct {
756                         unsigned long   _skb_refdst;
757                         void            (*destructor)(struct sk_buff *skb);
758                 };
759                 struct list_head        tcp_tsorted_anchor;
760 #ifdef CONFIG_NET_SOCK_MSG
761                 unsigned long           _sk_redir;
762 #endif
763         };
764 
765 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
766         unsigned long            _nfct;
767 #endif
768         unsigned int            len,
769                                 data_len;
770         __u16                   mac_len,
771                                 hdr_len;
772 
773         /* Following fields are _not_ copied in __copy_skb_header()
774          * Note that queue_mapping is here mostly to fill a hole.
775          */
776         __u16                   queue_mapping;
777 
778 /* if you move cloned around you also must adapt those constants */
779 #ifdef __BIG_ENDIAN_BITFIELD
780 #define CLONED_MASK     (1 << 7)
781 #else
782 #define CLONED_MASK     1
783 #endif
784 #define CLONED_OFFSET()         offsetof(struct sk_buff, __cloned_offset)
785 
786         /* private: */
787         __u8                    __cloned_offset[0];
788         /* public: */
789         __u8                    cloned:1,
790                                 nohdr:1,
791                                 fclone:2,
792                                 peeked:1,
793                                 head_frag:1,
794                                 pfmemalloc:1;
795 #ifdef CONFIG_SKB_EXTENSIONS
796         __u8                    active_extensions;
797 #endif
798         /* fields enclosed in headers_start/headers_end are copied
799          * using a single memcpy() in __copy_skb_header()
800          */
801         /* private: */
802         __u32                   headers_start[0];
803         /* public: */
804 
805 /* if you move pkt_type around you also must adapt those constants */
806 #ifdef __BIG_ENDIAN_BITFIELD
807 #define PKT_TYPE_MAX    (7 << 5)
808 #else
809 #define PKT_TYPE_MAX    7
810 #endif
811 #define PKT_TYPE_OFFSET()       offsetof(struct sk_buff, __pkt_type_offset)
812 
813         /* private: */
814         __u8                    __pkt_type_offset[0];
815         /* public: */
816         __u8                    pkt_type:3;
817         __u8                    ignore_df:1;
818         __u8                    nf_trace:1;
819         __u8                    ip_summed:2;
820         __u8                    ooo_okay:1;
821 
822         __u8                    l4_hash:1;
823         __u8                    sw_hash:1;
824         __u8                    wifi_acked_valid:1;
825         __u8                    wifi_acked:1;
826         __u8                    no_fcs:1;
827         /* Indicates the inner headers are valid in the skbuff. */
828         __u8                    encapsulation:1;
829         __u8                    encap_hdr_csum:1;
830         __u8                    csum_valid:1;
831 
832 #ifdef __BIG_ENDIAN_BITFIELD
833 #define PKT_VLAN_PRESENT_BIT    7
834 #else
835 #define PKT_VLAN_PRESENT_BIT    0
836 #endif
837 #define PKT_VLAN_PRESENT_OFFSET()       offsetof(struct sk_buff, __pkt_vlan_present_offset)
838         /* private: */
839         __u8                    __pkt_vlan_present_offset[0];
840         /* public: */
841         __u8                    vlan_present:1;
842         __u8                    csum_complete_sw:1;
843         __u8                    csum_level:2;
844         __u8                    csum_not_inet:1;
845         __u8                    dst_pending_confirm:1;
846 #ifdef CONFIG_IPV6_NDISC_NODETYPE
847         __u8                    ndisc_nodetype:2;
848 #endif
849 
850         __u8                    ipvs_property:1;
851         __u8                    inner_protocol_type:1;
852         __u8                    remcsum_offload:1;
853 #ifdef CONFIG_NET_SWITCHDEV
854         __u8                    offload_fwd_mark:1;
855         __u8                    offload_l3_fwd_mark:1;
856 #endif
857 #ifdef CONFIG_NET_CLS_ACT
858         __u8                    tc_skip_classify:1;
859         __u8                    tc_at_ingress:1;
860 #endif
861 #ifdef CONFIG_NET_REDIRECT
862         __u8                    redirected:1;
863         __u8                    from_ingress:1;
864 #endif
865 #ifdef CONFIG_TLS_DEVICE
866         __u8                    decrypted:1;
867 #endif
868 
869 #ifdef CONFIG_NET_SCHED
870         __u16                   tc_index;       /* traffic control index */
871 #endif
872 
873         union {
874                 __wsum          csum;
875                 struct {
876                         __u16   csum_start;
877                         __u16   csum_offset;
878                 };
879         };
880         __u32                   priority;
881         int                     skb_iif;
882         __u32                   hash;
883         __be16                  vlan_proto;
884         __u16                   vlan_tci;
885 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
886         union {
887                 unsigned int    napi_id;
888                 unsigned int    sender_cpu;
889         };
890 #endif
891 #ifdef CONFIG_NETWORK_SECMARK
892         __u32           secmark;
893 #endif
894 
895         union {
896                 __u32           mark;
897                 __u32           reserved_tailroom;
898         };
899 
900         union {
901                 __be16          inner_protocol;
902                 __u8            inner_ipproto;
903         };
904 
905         __u16                   inner_transport_header;
906         __u16                   inner_network_header;
907         __u16                   inner_mac_header;
908 
909         __be16                  protocol;
910         __u16                   transport_header;
911         __u16                   network_header;
912         __u16                   mac_header;
913 
914 #ifdef CONFIG_KCOV
915         u64                     kcov_handle;
916 #endif
917 
918         /* private: */
919         __u32                   headers_end[0];
920         /* public: */
921 
922         /* These elements must be at the end, see alloc_skb() for details.  */
923         sk_buff_data_t          tail;
924         sk_buff_data_t          end;
925         unsigned char           *head,
926                                 *data;
927         unsigned int            truesize;
928         refcount_t              users;
929 
930 #ifdef CONFIG_SKB_EXTENSIONS
931         /* only useable after checking ->active_extensions != 0 */
932         struct skb_ext          *extensions;
933 #endif
934 };
935 
936 #ifdef __KERNEL__
937 /*
938  *      Handling routines are only of interest to the kernel
939  */
940 
941 #define SKB_ALLOC_FCLONE        0x01
942 #define SKB_ALLOC_RX            0x02
943 #define SKB_ALLOC_NAPI          0x04
944 
945 /**
946  * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
947  * @skb: buffer
948  */
949 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
950 {
951         return unlikely(skb->pfmemalloc);
952 }
953 
954 /*
955  * skb might have a dst pointer attached, refcounted or not.
956  * _skb_refdst low order bit is set if refcount was _not_ taken
957  */
958 #define SKB_DST_NOREF   1UL
959 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
960 
961 /**
962  * skb_dst - returns skb dst_entry
963  * @skb: buffer
964  *
965  * Returns skb dst_entry, regardless of reference taken or not.
966  */
967 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
968 {
969         /* If refdst was not refcounted, check we still are in a
970          * rcu_read_lock section
971          */
972         WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
973                 !rcu_read_lock_held() &&
974                 !rcu_read_lock_bh_held());
975         return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
976 }
977 
978 /**
979  * skb_dst_set - sets skb dst
980  * @skb: buffer
981  * @dst: dst entry
982  *
983  * Sets skb dst, assuming a reference was taken on dst and should
984  * be released by skb_dst_drop()
985  */
986 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
987 {
988         skb->_skb_refdst = (unsigned long)dst;
989 }
990 
991 /**
992  * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
993  * @skb: buffer
994  * @dst: dst entry
995  *
996  * Sets skb dst, assuming a reference was not taken on dst.
997  * If dst entry is cached, we do not take reference and dst_release
998  * will be avoided by refdst_drop. If dst entry is not cached, we take
999  * reference, so that last dst_release can destroy the dst immediately.
1000  */
1001 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1002 {
1003         WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1004         skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1005 }
1006 
1007 /**
1008  * skb_dst_is_noref - Test if skb dst isn't refcounted
1009  * @skb: buffer
1010  */
1011 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1012 {
1013         return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1014 }
1015 
1016 /**
1017  * skb_rtable - Returns the skb &rtable
1018  * @skb: buffer
1019  */
1020 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
1021 {
1022         return (struct rtable *)skb_dst(skb);
1023 }
1024 
1025 /* For mangling skb->pkt_type from user space side from applications
1026  * such as nft, tc, etc, we only allow a conservative subset of
1027  * possible pkt_types to be set.
1028 */
1029 static inline bool skb_pkt_type_ok(u32 ptype)
1030 {
1031         return ptype <= PACKET_OTHERHOST;
1032 }
1033 
1034 /**
1035  * skb_napi_id - Returns the skb's NAPI id
1036  * @skb: buffer
1037  */
1038 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1039 {
1040 #ifdef CONFIG_NET_RX_BUSY_POLL
1041         return skb->napi_id;
1042 #else
1043         return 0;
1044 #endif
1045 }
1046 
1047 /**
1048  * skb_unref - decrement the skb's reference count
1049  * @skb: buffer
1050  *
1051  * Returns true if we can free the skb.
1052  */
1053 static inline bool skb_unref(struct sk_buff *skb)
1054 {
1055         if (unlikely(!skb))
1056                 return false;
1057         if (likely(refcount_read(&skb->users) == 1))
1058                 smp_rmb();
1059         else if (likely(!refcount_dec_and_test(&skb->users)))
1060                 return false;
1061 
1062         return true;
1063 }
1064 
1065 void skb_release_head_state(struct sk_buff *skb);
1066 void kfree_skb(struct sk_buff *skb);
1067 void kfree_skb_list(struct sk_buff *segs);
1068 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1069 void skb_tx_error(struct sk_buff *skb);
1070 
1071 #ifdef CONFIG_TRACEPOINTS
1072 void consume_skb(struct sk_buff *skb);
1073 #else
1074 static inline void consume_skb(struct sk_buff *skb)
1075 {
1076         return kfree_skb(skb);
1077 }
1078 #endif
1079 
1080 void __consume_stateless_skb(struct sk_buff *skb);
1081 void  __kfree_skb(struct sk_buff *skb);
1082 extern struct kmem_cache *skbuff_head_cache;
1083 
1084 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1085 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1086                       bool *fragstolen, int *delta_truesize);
1087 
1088 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1089                             int node);
1090 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1091 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1092 struct sk_buff *build_skb_around(struct sk_buff *skb,
1093                                  void *data, unsigned int frag_size);
1094 
1095 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1096 
1097 /**
1098  * alloc_skb - allocate a network buffer
1099  * @size: size to allocate
1100  * @priority: allocation mask
1101  *
1102  * This function is a convenient wrapper around __alloc_skb().
1103  */
1104 static inline struct sk_buff *alloc_skb(unsigned int size,
1105                                         gfp_t priority)
1106 {
1107         return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1108 }
1109 
1110 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1111                                      unsigned long data_len,
1112                                      int max_page_order,
1113                                      int *errcode,
1114                                      gfp_t gfp_mask);
1115 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1116 
1117 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1118 struct sk_buff_fclones {
1119         struct sk_buff  skb1;
1120 
1121         struct sk_buff  skb2;
1122 
1123         refcount_t      fclone_ref;
1124 };
1125 
1126 /**
1127  *      skb_fclone_busy - check if fclone is busy
1128  *      @sk: socket
1129  *      @skb: buffer
1130  *
1131  * Returns true if skb is a fast clone, and its clone is not freed.
1132  * Some drivers call skb_orphan() in their ndo_start_xmit(),
1133  * so we also check that this didnt happen.
1134  */
1135 static inline bool skb_fclone_busy(const struct sock *sk,
1136                                    const struct sk_buff *skb)
1137 {
1138         const struct sk_buff_fclones *fclones;
1139 
1140         fclones = container_of(skb, struct sk_buff_fclones, skb1);
1141 
1142         return skb->fclone == SKB_FCLONE_ORIG &&
1143                refcount_read(&fclones->fclone_ref) > 1 &&
1144                READ_ONCE(fclones->skb2.sk) == sk;
1145 }
1146 
1147 /**
1148  * alloc_skb_fclone - allocate a network buffer from fclone cache
1149  * @size: size to allocate
1150  * @priority: allocation mask
1151  *
1152  * This function is a convenient wrapper around __alloc_skb().
1153  */
1154 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1155                                                gfp_t priority)
1156 {
1157         return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1158 }
1159 
1160 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1161 void skb_headers_offset_update(struct sk_buff *skb, int off);
1162 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1163 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1164 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1165 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1166 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1167                                    gfp_t gfp_mask, bool fclone);
1168 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1169                                           gfp_t gfp_mask)
1170 {
1171         return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1172 }
1173 
1174 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1175 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1176                                      unsigned int headroom);
1177 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1178                                 int newtailroom, gfp_t priority);
1179 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1180                                      int offset, int len);
1181 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1182                               int offset, int len);
1183 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1184 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1185 
1186 /**
1187  *      skb_pad                 -       zero pad the tail of an skb
1188  *      @skb: buffer to pad
1189  *      @pad: space to pad
1190  *
1191  *      Ensure that a buffer is followed by a padding area that is zero
1192  *      filled. Used by network drivers which may DMA or transfer data
1193  *      beyond the buffer end onto the wire.
1194  *
1195  *      May return error in out of memory cases. The skb is freed on error.
1196  */
1197 static inline int skb_pad(struct sk_buff *skb, int pad)
1198 {
1199         return __skb_pad(skb, pad, true);
1200 }
1201 #define dev_kfree_skb(a)        consume_skb(a)
1202 
1203 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1204                          int offset, size_t size);
1205 
1206 struct skb_seq_state {
1207         __u32           lower_offset;
1208         __u32           upper_offset;
1209         __u32           frag_idx;
1210         __u32           stepped_offset;
1211         struct sk_buff  *root_skb;
1212         struct sk_buff  *cur_skb;
1213         __u8            *frag_data;
1214         __u32           frag_off;
1215 };
1216 
1217 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1218                           unsigned int to, struct skb_seq_state *st);
1219 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1220                           struct skb_seq_state *st);
1221 void skb_abort_seq_read(struct skb_seq_state *st);
1222 
1223 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1224                            unsigned int to, struct ts_config *config);
1225 
1226 /*
1227  * Packet hash types specify the type of hash in skb_set_hash.
1228  *
1229  * Hash types refer to the protocol layer addresses which are used to
1230  * construct a packet's hash. The hashes are used to differentiate or identify
1231  * flows of the protocol layer for the hash type. Hash types are either
1232  * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1233  *
1234  * Properties of hashes:
1235  *
1236  * 1) Two packets in different flows have different hash values
1237  * 2) Two packets in the same flow should have the same hash value
1238  *
1239  * A hash at a higher layer is considered to be more specific. A driver should
1240  * set the most specific hash possible.
1241  *
1242  * A driver cannot indicate a more specific hash than the layer at which a hash
1243  * was computed. For instance an L3 hash cannot be set as an L4 hash.
1244  *
1245  * A driver may indicate a hash level which is less specific than the
1246  * actual layer the hash was computed on. For instance, a hash computed
1247  * at L4 may be considered an L3 hash. This should only be done if the
1248  * driver can't unambiguously determine that the HW computed the hash at
1249  * the higher layer. Note that the "should" in the second property above
1250  * permits this.
1251  */
1252 enum pkt_hash_types {
1253         PKT_HASH_TYPE_NONE,     /* Undefined type */
1254         PKT_HASH_TYPE_L2,       /* Input: src_MAC, dest_MAC */
1255         PKT_HASH_TYPE_L3,       /* Input: src_IP, dst_IP */
1256         PKT_HASH_TYPE_L4,       /* Input: src_IP, dst_IP, src_port, dst_port */
1257 };
1258 
1259 static inline void skb_clear_hash(struct sk_buff *skb)
1260 {
1261         skb->hash = 0;
1262         skb->sw_hash = 0;
1263         skb->l4_hash = 0;
1264 }
1265 
1266 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1267 {
1268         if (!skb->l4_hash)
1269                 skb_clear_hash(skb);
1270 }
1271 
1272 static inline void
1273 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1274 {
1275         skb->l4_hash = is_l4;
1276         skb->sw_hash = is_sw;
1277         skb->hash = hash;
1278 }
1279 
1280 static inline void
1281 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1282 {
1283         /* Used by drivers to set hash from HW */
1284         __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1285 }
1286 
1287 static inline void
1288 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1289 {
1290         __skb_set_hash(skb, hash, true, is_l4);
1291 }
1292 
1293 void __skb_get_hash(struct sk_buff *skb);
1294 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1295 u32 skb_get_poff(const struct sk_buff *skb);
1296 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1297                    const struct flow_keys_basic *keys, int hlen);
1298 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1299                             const void *data, int hlen_proto);
1300 
1301 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1302                                         int thoff, u8 ip_proto)
1303 {
1304         return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1305 }
1306 
1307 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1308                              const struct flow_dissector_key *key,
1309                              unsigned int key_count);
1310 
1311 struct bpf_flow_dissector;
1312 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1313                       __be16 proto, int nhoff, int hlen, unsigned int flags);
1314 
1315 bool __skb_flow_dissect(const struct net *net,
1316                         const struct sk_buff *skb,
1317                         struct flow_dissector *flow_dissector,
1318                         void *target_container, const void *data,
1319                         __be16 proto, int nhoff, int hlen, unsigned int flags);
1320 
1321 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1322                                     struct flow_dissector *flow_dissector,
1323                                     void *target_container, unsigned int flags)
1324 {
1325         return __skb_flow_dissect(NULL, skb, flow_dissector,
1326                                   target_container, NULL, 0, 0, 0, flags);
1327 }
1328 
1329 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1330                                               struct flow_keys *flow,
1331                                               unsigned int flags)
1332 {
1333         memset(flow, 0, sizeof(*flow));
1334         return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1335                                   flow, NULL, 0, 0, 0, flags);
1336 }
1337 
1338 static inline bool
1339 skb_flow_dissect_flow_keys_basic(const struct net *net,
1340                                  const struct sk_buff *skb,
1341                                  struct flow_keys_basic *flow,
1342                                  const void *data, __be16 proto,
1343                                  int nhoff, int hlen, unsigned int flags)
1344 {
1345         memset(flow, 0, sizeof(*flow));
1346         return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1347                                   data, proto, nhoff, hlen, flags);
1348 }
1349 
1350 void skb_flow_dissect_meta(const struct sk_buff *skb,
1351                            struct flow_dissector *flow_dissector,
1352                            void *target_container);
1353 
1354 /* Gets a skb connection tracking info, ctinfo map should be a
1355  * map of mapsize to translate enum ip_conntrack_info states
1356  * to user states.
1357  */
1358 void
1359 skb_flow_dissect_ct(const struct sk_buff *skb,
1360                     struct flow_dissector *flow_dissector,
1361                     void *target_container,
1362                     u16 *ctinfo_map, size_t mapsize,
1363                     bool post_ct);
1364 void
1365 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1366                              struct flow_dissector *flow_dissector,
1367                              void *target_container);
1368 
1369 void skb_flow_dissect_hash(const struct sk_buff *skb,
1370                            struct flow_dissector *flow_dissector,
1371                            void *target_container);
1372 
1373 static inline __u32 skb_get_hash(struct sk_buff *skb)
1374 {
1375         if (!skb->l4_hash && !skb->sw_hash)
1376                 __skb_get_hash(skb);
1377 
1378         return skb->hash;
1379 }
1380 
1381 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1382 {
1383         if (!skb->l4_hash && !skb->sw_hash) {
1384                 struct flow_keys keys;
1385                 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1386 
1387                 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1388         }
1389 
1390         return skb->hash;
1391 }
1392 
1393 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1394                            const siphash_key_t *perturb);
1395 
1396 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1397 {
1398         return skb->hash;
1399 }
1400 
1401 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1402 {
1403         to->hash = from->hash;
1404         to->sw_hash = from->sw_hash;
1405         to->l4_hash = from->l4_hash;
1406 };
1407 
1408 static inline void skb_copy_decrypted(struct sk_buff *to,
1409                                       const struct sk_buff *from)
1410 {
1411 #ifdef CONFIG_TLS_DEVICE
1412         to->decrypted = from->decrypted;
1413 #endif
1414 }
1415 
1416 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1417 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1418 {
1419         return skb->head + skb->end;
1420 }
1421 
1422 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1423 {
1424         return skb->end;
1425 }
1426 #else
1427 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1428 {
1429         return skb->end;
1430 }
1431 
1432 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1433 {
1434         return skb->end - skb->head;
1435 }
1436 #endif
1437 
1438 /* Internal */
1439 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1440 
1441 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1442 {
1443         return &skb_shinfo(skb)->hwtstamps;
1444 }
1445 
1446 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1447 {
1448         bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1449 
1450         return is_zcopy ? skb_uarg(skb) : NULL;
1451 }
1452 
1453 static inline void net_zcopy_get(struct ubuf_info *uarg)
1454 {
1455         refcount_inc(&uarg->refcnt);
1456 }
1457 
1458 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1459 {
1460         skb_shinfo(skb)->destructor_arg = uarg;
1461         skb_shinfo(skb)->flags |= uarg->flags;
1462 }
1463 
1464 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1465                                  bool *have_ref)
1466 {
1467         if (skb && uarg && !skb_zcopy(skb)) {
1468                 if (unlikely(have_ref && *have_ref))
1469                         *have_ref = false;
1470                 else
1471                         net_zcopy_get(uarg);
1472                 skb_zcopy_init(skb, uarg);
1473         }
1474 }
1475 
1476 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1477 {
1478         skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1479         skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1480 }
1481 
1482 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1483 {
1484         return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1485 }
1486 
1487 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1488 {
1489         return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1490 }
1491 
1492 static inline void net_zcopy_put(struct ubuf_info *uarg)
1493 {
1494         if (uarg)
1495                 uarg->callback(NULL, uarg, true);
1496 }
1497 
1498 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1499 {
1500         if (uarg) {
1501                 if (uarg->callback == msg_zerocopy_callback)
1502                         msg_zerocopy_put_abort(uarg, have_uref);
1503                 else if (have_uref)
1504                         net_zcopy_put(uarg);
1505         }
1506 }
1507 
1508 /* Release a reference on a zerocopy structure */
1509 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1510 {
1511         struct ubuf_info *uarg = skb_zcopy(skb);
1512 
1513         if (uarg) {
1514                 if (!skb_zcopy_is_nouarg(skb))
1515                         uarg->callback(skb, uarg, zerocopy_success);
1516 
1517                 skb_shinfo(skb)->flags &= ~SKBFL_ZEROCOPY_FRAG;
1518         }
1519 }
1520 
1521 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1522 {
1523         skb->next = NULL;
1524 }
1525 
1526 /* Iterate through singly-linked GSO fragments of an skb. */
1527 #define skb_list_walk_safe(first, skb, next_skb)                               \
1528         for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb);  \
1529              (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1530 
1531 static inline void skb_list_del_init(struct sk_buff *skb)
1532 {
1533         __list_del_entry(&skb->list);
1534         skb_mark_not_on_list(skb);
1535 }
1536 
1537 /**
1538  *      skb_queue_empty - check if a queue is empty
1539  *      @list: queue head
1540  *
1541  *      Returns true if the queue is empty, false otherwise.
1542  */
1543 static inline int skb_queue_empty(const struct sk_buff_head *list)
1544 {
1545         return list->next == (const struct sk_buff *) list;
1546 }
1547 
1548 /**
1549  *      skb_queue_empty_lockless - check if a queue is empty
1550  *      @list: queue head
1551  *
1552  *      Returns true if the queue is empty, false otherwise.
1553  *      This variant can be used in lockless contexts.
1554  */
1555 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1556 {
1557         return READ_ONCE(list->next) == (const struct sk_buff *) list;
1558 }
1559 
1560 
1561 /**
1562  *      skb_queue_is_last - check if skb is the last entry in the queue
1563  *      @list: queue head
1564  *      @skb: buffer
1565  *
1566  *      Returns true if @skb is the last buffer on the list.
1567  */
1568 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1569                                      const struct sk_buff *skb)
1570 {
1571         return skb->next == (const struct sk_buff *) list;
1572 }
1573 
1574 /**
1575  *      skb_queue_is_first - check if skb is the first entry in the queue
1576  *      @list: queue head
1577  *      @skb: buffer
1578  *
1579  *      Returns true if @skb is the first buffer on the list.
1580  */
1581 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1582                                       const struct sk_buff *skb)
1583 {
1584         return skb->prev == (const struct sk_buff *) list;
1585 }
1586 
1587 /**
1588  *      skb_queue_next - return the next packet in the queue
1589  *      @list: queue head
1590  *      @skb: current buffer
1591  *
1592  *      Return the next packet in @list after @skb.  It is only valid to
1593  *      call this if skb_queue_is_last() evaluates to false.
1594  */
1595 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1596                                              const struct sk_buff *skb)
1597 {
1598         /* This BUG_ON may seem severe, but if we just return then we
1599          * are going to dereference garbage.
1600          */
1601         BUG_ON(skb_queue_is_last(list, skb));
1602         return skb->next;
1603 }
1604 
1605 /**
1606  *      skb_queue_prev - return the prev packet in the queue
1607  *      @list: queue head
1608  *      @skb: current buffer
1609  *
1610  *      Return the prev packet in @list before @skb.  It is only valid to
1611  *      call this if skb_queue_is_first() evaluates to false.
1612  */
1613 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1614                                              const struct sk_buff *skb)
1615 {
1616         /* This BUG_ON may seem severe, but if we just return then we
1617          * are going to dereference garbage.
1618          */
1619         BUG_ON(skb_queue_is_first(list, skb));
1620         return skb->prev;
1621 }
1622 
1623 /**
1624  *      skb_get - reference buffer
1625  *      @skb: buffer to reference
1626  *
1627  *      Makes another reference to a socket buffer and returns a pointer
1628  *      to the buffer.
1629  */
1630 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1631 {
1632         refcount_inc(&skb->users);
1633         return skb;
1634 }
1635 
1636 /*
1637  * If users == 1, we are the only owner and can avoid redundant atomic changes.
1638  */
1639 
1640 /**
1641  *      skb_cloned - is the buffer a clone
1642  *      @skb: buffer to check
1643  *
1644  *      Returns true if the buffer was generated with skb_clone() and is
1645  *      one of multiple shared copies of the buffer. Cloned buffers are
1646  *      shared data so must not be written to under normal circumstances.
1647  */
1648 static inline int skb_cloned(const struct sk_buff *skb)
1649 {
1650         return skb->cloned &&
1651                (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1652 }
1653 
1654 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1655 {
1656         might_sleep_if(gfpflags_allow_blocking(pri));
1657 
1658         if (skb_cloned(skb))
1659                 return pskb_expand_head(skb, 0, 0, pri);
1660 
1661         return 0;
1662 }
1663 
1664 /**
1665  *      skb_header_cloned - is the header a clone
1666  *      @skb: buffer to check
1667  *
1668  *      Returns true if modifying the header part of the buffer requires
1669  *      the data to be copied.
1670  */
1671 static inline int skb_header_cloned(const struct sk_buff *skb)
1672 {
1673         int dataref;
1674 
1675         if (!skb->cloned)
1676                 return 0;
1677 
1678         dataref = atomic_read(&skb_shinfo(skb)->dataref);
1679         dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1680         return dataref != 1;
1681 }
1682 
1683 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1684 {
1685         might_sleep_if(gfpflags_allow_blocking(pri));
1686 
1687         if (skb_header_cloned(skb))
1688                 return pskb_expand_head(skb, 0, 0, pri);
1689 
1690         return 0;
1691 }
1692 
1693 /**
1694  *      __skb_header_release - release reference to header
1695  *      @skb: buffer to operate on
1696  */
1697 static inline void __skb_header_release(struct sk_buff *skb)
1698 {
1699         skb->nohdr = 1;
1700         atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1701 }
1702 
1703 
1704 /**
1705  *      skb_shared - is the buffer shared
1706  *      @skb: buffer to check
1707  *
1708  *      Returns true if more than one person has a reference to this
1709  *      buffer.
1710  */
1711 static inline int skb_shared(const struct sk_buff *skb)
1712 {
1713         return refcount_read(&skb->users) != 1;
1714 }
1715 
1716 /**
1717  *      skb_share_check - check if buffer is shared and if so clone it
1718  *      @skb: buffer to check
1719  *      @pri: priority for memory allocation
1720  *
1721  *      If the buffer is shared the buffer is cloned and the old copy
1722  *      drops a reference. A new clone with a single reference is returned.
1723  *      If the buffer is not shared the original buffer is returned. When
1724  *      being called from interrupt status or with spinlocks held pri must
1725  *      be GFP_ATOMIC.
1726  *
1727  *      NULL is returned on a memory allocation failure.
1728  */
1729 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1730 {
1731         might_sleep_if(gfpflags_allow_blocking(pri));
1732         if (skb_shared(skb)) {
1733                 struct sk_buff *nskb = skb_clone(skb, pri);
1734 
1735                 if (likely(nskb))
1736                         consume_skb(skb);
1737                 else
1738                         kfree_skb(skb);
1739                 skb = nskb;
1740         }
1741         return skb;
1742 }
1743 
1744 /*
1745  *      Copy shared buffers into a new sk_buff. We effectively do COW on
1746  *      packets to handle cases where we have a local reader and forward
1747  *      and a couple of other messy ones. The normal one is tcpdumping
1748  *      a packet thats being forwarded.
1749  */
1750 
1751 /**
1752  *      skb_unshare - make a copy of a shared buffer
1753  *      @skb: buffer to check
1754  *      @pri: priority for memory allocation
1755  *
1756  *      If the socket buffer is a clone then this function creates a new
1757  *      copy of the data, drops a reference count on the old copy and returns
1758  *      the new copy with the reference count at 1. If the buffer is not a clone
1759  *      the original buffer is returned. When called with a spinlock held or
1760  *      from interrupt state @pri must be %GFP_ATOMIC
1761  *
1762  *      %NULL is returned on a memory allocation failure.
1763  */
1764 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1765                                           gfp_t pri)
1766 {
1767         might_sleep_if(gfpflags_allow_blocking(pri));
1768         if (skb_cloned(skb)) {
1769                 struct sk_buff *nskb = skb_copy(skb, pri);
1770 
1771                 /* Free our shared copy */
1772                 if (likely(nskb))
1773                         consume_skb(skb);
1774                 else
1775                         kfree_skb(skb);
1776                 skb = nskb;
1777         }
1778         return skb;
1779 }
1780 
1781 /**
1782  *      skb_peek - peek at the head of an &sk_buff_head
1783  *      @list_: list to peek at
1784  *
1785  *      Peek an &sk_buff. Unlike most other operations you _MUST_
1786  *      be careful with this one. A peek leaves the buffer on the
1787  *      list and someone else may run off with it. You must hold
1788  *      the appropriate locks or have a private queue to do this.
1789  *
1790  *      Returns %NULL for an empty list or a pointer to the head element.
1791  *      The reference count is not incremented and the reference is therefore
1792  *      volatile. Use with caution.
1793  */
1794 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1795 {
1796         struct sk_buff *skb = list_->next;
1797 
1798         if (skb == (struct sk_buff *)list_)
1799                 skb = NULL;
1800         return skb;
1801 }
1802 
1803 /**
1804  *      __skb_peek - peek at the head of a non-empty &sk_buff_head
1805  *      @list_: list to peek at
1806  *
1807  *      Like skb_peek(), but the caller knows that the list is not empty.
1808  */
1809 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
1810 {
1811         return list_->next;
1812 }
1813 
1814 /**
1815  *      skb_peek_next - peek skb following the given one from a queue
1816  *      @skb: skb to start from
1817  *      @list_: list to peek at
1818  *
1819  *      Returns %NULL when the end of the list is met or a pointer to the
1820  *      next element. The reference count is not incremented and the
1821  *      reference is therefore volatile. Use with caution.
1822  */
1823 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1824                 const struct sk_buff_head *list_)
1825 {
1826         struct sk_buff *next = skb->next;
1827 
1828         if (next == (struct sk_buff *)list_)
1829                 next = NULL;
1830         return next;
1831 }
1832 
1833 /**
1834  *      skb_peek_tail - peek at the tail of an &sk_buff_head
1835  *      @list_: list to peek at
1836  *
1837  *      Peek an &sk_buff. Unlike most other operations you _MUST_
1838  *      be careful with this one. A peek leaves the buffer on the
1839  *      list and someone else may run off with it. You must hold
1840  *      the appropriate locks or have a private queue to do this.
1841  *
1842  *      Returns %NULL for an empty list or a pointer to the tail element.
1843  *      The reference count is not incremented and the reference is therefore
1844  *      volatile. Use with caution.
1845  */
1846 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1847 {
1848         struct sk_buff *skb = READ_ONCE(list_->prev);
1849 
1850         if (skb == (struct sk_buff *)list_)
1851                 skb = NULL;
1852         return skb;
1853 
1854 }
1855 
1856 /**
1857  *      skb_queue_len   - get queue length
1858  *      @list_: list to measure
1859  *
1860  *      Return the length of an &sk_buff queue.
1861  */
1862 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1863 {
1864         return list_->qlen;
1865 }
1866 
1867 /**
1868  *      skb_queue_len_lockless  - get queue length
1869  *      @list_: list to measure
1870  *
1871  *      Return the length of an &sk_buff queue.
1872  *      This variant can be used in lockless contexts.
1873  */
1874 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
1875 {
1876         return READ_ONCE(list_->qlen);
1877 }
1878 
1879 /**
1880  *      __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1881  *      @list: queue to initialize
1882  *
1883  *      This initializes only the list and queue length aspects of
1884  *      an sk_buff_head object.  This allows to initialize the list
1885  *      aspects of an sk_buff_head without reinitializing things like
1886  *      the spinlock.  It can also be used for on-stack sk_buff_head
1887  *      objects where the spinlock is known to not be used.
1888  */
1889 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1890 {
1891         list->prev = list->next = (struct sk_buff *)list;
1892         list->qlen = 0;
1893 }
1894 
1895 /*
1896  * This function creates a split out lock class for each invocation;
1897  * this is needed for now since a whole lot of users of the skb-queue
1898  * infrastructure in drivers have different locking usage (in hardirq)
1899  * than the networking core (in softirq only). In the long run either the
1900  * network layer or drivers should need annotation to consolidate the
1901  * main types of usage into 3 classes.
1902  */
1903 static inline void skb_queue_head_init(struct sk_buff_head *list)
1904 {
1905         spin_lock_init(&list->lock);
1906         __skb_queue_head_init(list);
1907 }
1908 
1909 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1910                 struct lock_class_key *class)
1911 {
1912         skb_queue_head_init(list);
1913         lockdep_set_class(&list->lock, class);
1914 }
1915 
1916 /*
1917  *      Insert an sk_buff on a list.
1918  *
1919  *      The "__skb_xxxx()" functions are the non-atomic ones that
1920  *      can only be called with interrupts disabled.
1921  */
1922 static inline void __skb_insert(struct sk_buff *newsk,
1923                                 struct sk_buff *prev, struct sk_buff *next,
1924                                 struct sk_buff_head *list)
1925 {
1926         /* See skb_queue_empty_lockless() and skb_peek_tail()
1927          * for the opposite READ_ONCE()
1928          */
1929         WRITE_ONCE(newsk->next, next);
1930         WRITE_ONCE(newsk->prev, prev);
1931         WRITE_ONCE(next->prev, newsk);
1932         WRITE_ONCE(prev->next, newsk);
1933         list->qlen++;
1934 }
1935 
1936 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1937                                       struct sk_buff *prev,
1938                                       struct sk_buff *next)
1939 {
1940         struct sk_buff *first = list->next;
1941         struct sk_buff *last = list->prev;
1942 
1943         WRITE_ONCE(first->prev, prev);
1944         WRITE_ONCE(prev->next, first);
1945 
1946         WRITE_ONCE(last->next, next);
1947         WRITE_ONCE(next->prev, last);
1948 }
1949 
1950 /**
1951  *      skb_queue_splice - join two skb lists, this is designed for stacks
1952  *      @list: the new list to add
1953  *      @head: the place to add it in the first list
1954  */
1955 static inline void skb_queue_splice(const struct sk_buff_head *list,
1956                                     struct sk_buff_head *head)
1957 {
1958         if (!skb_queue_empty(list)) {
1959                 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1960                 head->qlen += list->qlen;
1961         }
1962 }
1963 
1964 /**
1965  *      skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1966  *      @list: the new list to add
1967  *      @head: the place to add it in the first list
1968  *
1969  *      The list at @list is reinitialised
1970  */
1971 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1972                                          struct sk_buff_head *head)
1973 {
1974         if (!skb_queue_empty(list)) {
1975                 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1976                 head->qlen += list->qlen;
1977                 __skb_queue_head_init(list);
1978         }
1979 }
1980 
1981 /**
1982  *      skb_queue_splice_tail - join two skb lists, each list being a queue
1983  *      @list: the new list to add
1984  *      @head: the place to add it in the first list
1985  */
1986 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1987                                          struct sk_buff_head *head)
1988 {
1989         if (!skb_queue_empty(list)) {
1990                 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1991                 head->qlen += list->qlen;
1992         }
1993 }
1994 
1995 /**
1996  *      skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1997  *      @list: the new list to add
1998  *      @head: the place to add it in the first list
1999  *
2000  *      Each of the lists is a queue.
2001  *      The list at @list is reinitialised
2002  */
2003 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2004                                               struct sk_buff_head *head)
2005 {
2006         if (!skb_queue_empty(list)) {
2007                 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2008                 head->qlen += list->qlen;
2009                 __skb_queue_head_init(list);
2010         }
2011 }
2012 
2013 /**
2014  *      __skb_queue_after - queue a buffer at the list head
2015  *      @list: list to use
2016  *      @prev: place after this buffer
2017  *      @newsk: buffer to queue
2018  *
2019  *      Queue a buffer int the middle of a list. This function takes no locks
2020  *      and you must therefore hold required locks before calling it.
2021  *
2022  *      A buffer cannot be placed on two lists at the same time.
2023  */
2024 static inline void __skb_queue_after(struct sk_buff_head *list,
2025                                      struct sk_buff *prev,
2026                                      struct sk_buff *newsk)
2027 {
2028         __skb_insert(newsk, prev, prev->next, list);
2029 }
2030 
2031 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2032                 struct sk_buff_head *list);
2033 
2034 static inline void __skb_queue_before(struct sk_buff_head *list,
2035                                       struct sk_buff *next,
2036                                       struct sk_buff *newsk)
2037 {
2038         __skb_insert(newsk, next->prev, next, list);
2039 }
2040 
2041 /**
2042  *      __skb_queue_head - queue a buffer at the list head
2043  *      @list: list to use
2044  *      @newsk: buffer to queue
2045  *
2046  *      Queue a buffer at the start of a list. This function takes no locks
2047  *      and you must therefore hold required locks before calling it.
2048  *
2049  *      A buffer cannot be placed on two lists at the same time.
2050  */
2051 static inline void __skb_queue_head(struct sk_buff_head *list,
2052                                     struct sk_buff *newsk)
2053 {
2054         __skb_queue_after(list, (struct sk_buff *)list, newsk);
2055 }
2056 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2057 
2058 /**
2059  *      __skb_queue_tail - queue a buffer at the list tail
2060  *      @list: list to use
2061  *      @newsk: buffer to queue
2062  *
2063  *      Queue a buffer at the end of a list. This function takes no locks
2064  *      and you must therefore hold required locks before calling it.
2065  *
2066  *      A buffer cannot be placed on two lists at the same time.
2067  */
2068 static inline void __skb_queue_tail(struct sk_buff_head *list,
2069                                    struct sk_buff *newsk)
2070 {
2071         __skb_queue_before(list, (struct sk_buff *)list, newsk);
2072 }
2073 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2074 
2075 /*
2076  * remove sk_buff from list. _Must_ be called atomically, and with
2077  * the list known..
2078  */
2079 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
2080 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2081 {
2082         struct sk_buff *next, *prev;
2083 
2084         WRITE_ONCE(list->qlen, list->qlen - 1);
2085         next       = skb->next;
2086         prev       = skb->prev;
2087         skb->next  = skb->prev = NULL;
2088         WRITE_ONCE(next->prev, prev);
2089         WRITE_ONCE(prev->next, next);
2090 }
2091 
2092 /**
2093  *      __skb_dequeue - remove from the head of the queue
2094  *      @list: list to dequeue from
2095  *
2096  *      Remove the head of the list. This function does not take any locks
2097  *      so must be used with appropriate locks held only. The head item is
2098  *      returned or %NULL if the list is empty.
2099  */
2100 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2101 {
2102         struct sk_buff *skb = skb_peek(list);
2103         if (skb)
2104                 __skb_unlink(skb, list);
2105         return skb;
2106 }
2107 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2108 
2109 /**
2110  *      __skb_dequeue_tail - remove from the tail of the queue
2111  *      @list: list to dequeue from
2112  *
2113  *      Remove the tail of the list. This function does not take any locks
2114  *      so must be used with appropriate locks held only. The tail item is
2115  *      returned or %NULL if the list is empty.
2116  */
2117 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2118 {
2119         struct sk_buff *skb = skb_peek_tail(list);
2120         if (skb)
2121                 __skb_unlink(skb, list);
2122         return skb;
2123 }
2124 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2125 
2126 
2127 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2128 {
2129         return skb->data_len;
2130 }
2131 
2132 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2133 {
2134         return skb->len - skb->data_len;
2135 }
2136 
2137 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2138 {
2139         unsigned int i, len = 0;
2140 
2141         for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2142                 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2143         return len;
2144 }
2145 
2146 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2147 {
2148         return skb_headlen(skb) + __skb_pagelen(skb);
2149 }
2150 
2151 /**
2152  * __skb_fill_page_desc - initialise a paged fragment in an skb
2153  * @skb: buffer containing fragment to be initialised
2154  * @i: paged fragment index to initialise
2155  * @page: the page to use for this fragment
2156  * @off: the offset to the data with @page
2157  * @size: the length of the data
2158  *
2159  * Initialises the @i'th fragment of @skb to point to &size bytes at
2160  * offset @off within @page.
2161  *
2162  * Does not take any additional reference on the fragment.
2163  */
2164 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2165                                         struct page *page, int off, int size)
2166 {
2167         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2168 
2169         /*
2170          * Propagate page pfmemalloc to the skb if we can. The problem is
2171          * that not all callers have unique ownership of the page but rely
2172          * on page_is_pfmemalloc doing the right thing(tm).
2173          */
2174         frag->bv_page             = page;
2175         frag->bv_offset           = off;
2176         skb_frag_size_set(frag, size);
2177 
2178         page = compound_head(page);
2179         if (page_is_pfmemalloc(page))
2180                 skb->pfmemalloc = true;
2181 }
2182 
2183 /**
2184  * skb_fill_page_desc - initialise a paged fragment in an skb
2185  * @skb: buffer containing fragment to be initialised
2186  * @i: paged fragment index to initialise
2187  * @page: the page to use for this fragment
2188  * @off: the offset to the data with @page
2189  * @size: the length of the data
2190  *
2191  * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2192  * @skb to point to @size bytes at offset @off within @page. In
2193  * addition updates @skb such that @i is the last fragment.
2194  *
2195  * Does not take any additional reference on the fragment.
2196  */
2197 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2198                                       struct page *page, int off, int size)
2199 {
2200         __skb_fill_page_desc(skb, i, page, off, size);
2201         skb_shinfo(skb)->nr_frags = i + 1;
2202 }
2203 
2204 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
2205                      int size, unsigned int truesize);
2206 
2207 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2208                           unsigned int truesize);
2209 
2210 #define SKB_LINEAR_ASSERT(skb)  BUG_ON(skb_is_nonlinear(skb))
2211 
2212 #ifdef NET_SKBUFF_DATA_USES_OFFSET
2213 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2214 {
2215         return skb->head + skb->tail;
2216 }
2217 
2218 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2219 {
2220         skb->tail = skb->data - skb->head;
2221 }
2222 
2223 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2224 {
2225         skb_reset_tail_pointer(skb);
2226         skb->tail += offset;
2227 }
2228 
2229 #else /* NET_SKBUFF_DATA_USES_OFFSET */
2230 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2231 {
2232         return skb->tail;
2233 }
2234 
2235 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2236 {
2237         skb->tail = skb->data;
2238 }
2239 
2240 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2241 {
2242         skb->tail = skb->data + offset;
2243 }
2244 
2245 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2246 
2247 /*
2248  *      Add data to an sk_buff
2249  */
2250 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2251 void *skb_put(struct sk_buff *skb, unsigned int len);
2252 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2253 {
2254         void *tmp = skb_tail_pointer(skb);
2255         SKB_LINEAR_ASSERT(skb);
2256         skb->tail += len;
2257         skb->len  += len;
2258         return tmp;
2259 }
2260 
2261 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2262 {
2263         void *tmp = __skb_put(skb, len);
2264 
2265         memset(tmp, 0, len);
2266         return tmp;
2267 }
2268 
2269 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2270                                    unsigned int len)
2271 {
2272         void *tmp = __skb_put(skb, len);
2273 
2274         memcpy(tmp, data, len);
2275         return tmp;
2276 }
2277 
2278 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2279 {
2280         *(u8 *)__skb_put(skb, 1) = val;
2281 }
2282 
2283 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2284 {
2285         void *tmp = skb_put(skb, len);
2286 
2287         memset(tmp, 0, len);
2288 
2289         return tmp;
2290 }
2291 
2292 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2293                                  unsigned int len)
2294 {
2295         void *tmp = skb_put(skb, len);
2296 
2297         memcpy(tmp, data, len);
2298 
2299         return tmp;
2300 }
2301 
2302 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2303 {
2304         *(u8 *)skb_put(skb, 1) = val;
2305 }
2306 
2307 void *skb_push(struct sk_buff *skb, unsigned int len);
2308 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2309 {
2310         skb->data -= len;
2311         skb->len  += len;
2312         return skb->data;
2313 }
2314 
2315 void *skb_pull(struct sk_buff *skb, unsigned int len);
2316 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2317 {
2318         skb->len -= len;
2319         BUG_ON(skb->len < skb->data_len);
2320         return skb->data += len;
2321 }
2322 
2323 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2324 {
2325         return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2326 }
2327 
2328 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2329 
2330 static inline void *__pskb_pull(struct sk_buff *skb, unsigned int len)
2331 {
2332         if (len > skb_headlen(skb) &&
2333             !__pskb_pull_tail(skb, len - skb_headlen(skb)))
2334                 return NULL;
2335         skb->len -= len;
2336         return skb->data += len;
2337 }
2338 
2339 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2340 {
2341         return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
2342 }
2343 
2344 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2345 {
2346         if (likely(len <= skb_headlen(skb)))
2347                 return true;
2348         if (unlikely(len > skb->len))
2349                 return false;
2350         return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
2351 }
2352 
2353 void skb_condense(struct sk_buff *skb);
2354 
2355 /**
2356  *      skb_headroom - bytes at buffer head
2357  *      @skb: buffer to check
2358  *
2359  *      Return the number of bytes of free space at the head of an &sk_buff.
2360  */
2361 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2362 {
2363         return skb->data - skb->head;
2364 }
2365 
2366 /**
2367  *      skb_tailroom - bytes at buffer end
2368  *      @skb: buffer to check
2369  *
2370  *      Return the number of bytes of free space at the tail of an sk_buff
2371  */
2372 static inline int skb_tailroom(const struct sk_buff *skb)
2373 {
2374         return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2375 }
2376 
2377 /**
2378  *      skb_availroom - bytes at buffer end
2379  *      @skb: buffer to check
2380  *
2381  *      Return the number of bytes of free space at the tail of an sk_buff
2382  *      allocated by sk_stream_alloc()
2383  */
2384 static inline int skb_availroom(const struct sk_buff *skb)
2385 {
2386         if (skb_is_nonlinear(skb))
2387                 return 0;
2388 
2389         return skb->end - skb->tail - skb->reserved_tailroom;
2390 }
2391 
2392 /**
2393  *      skb_reserve - adjust headroom
2394  *      @skb: buffer to alter
2395  *      @len: bytes to move
2396  *
2397  *      Increase the headroom of an empty &sk_buff by reducing the tail
2398  *      room. This is only allowed for an empty buffer.
2399  */
2400 static inline void skb_reserve(struct sk_buff *skb, int len)
2401 {
2402         skb->data += len;
2403         skb->tail += len;
2404 }
2405 
2406 /**
2407  *      skb_tailroom_reserve - adjust reserved_tailroom
2408  *      @skb: buffer to alter
2409  *      @mtu: maximum amount of headlen permitted
2410  *      @needed_tailroom: minimum amount of reserved_tailroom
2411  *
2412  *      Set reserved_tailroom so that headlen can be as large as possible but
2413  *      not larger than mtu and tailroom cannot be smaller than
2414  *      needed_tailroom.
2415  *      The required headroom should already have been reserved before using
2416  *      this function.
2417  */
2418 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2419                                         unsigned int needed_tailroom)
2420 {
2421         SKB_LINEAR_ASSERT(skb);
2422         if (mtu < skb_tailroom(skb) - needed_tailroom)
2423                 /* use at most mtu */
2424                 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2425         else
2426                 /* use up to all available space */
2427                 skb->reserved_tailroom = needed_tailroom;
2428 }
2429 
2430 #define ENCAP_TYPE_ETHER        0
2431 #define ENCAP_TYPE_IPPROTO      1
2432 
2433 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2434                                           __be16 protocol)
2435 {
2436         skb->inner_protocol = protocol;
2437         skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2438 }
2439 
2440 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2441                                          __u8 ipproto)
2442 {
2443         skb->inner_ipproto = ipproto;
2444         skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2445 }
2446 
2447 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2448 {
2449         skb->inner_mac_header = skb->mac_header;
2450         skb->inner_network_header = skb->network_header;
2451         skb->inner_transport_header = skb->transport_header;
2452 }
2453 
2454 static inline void skb_reset_mac_len(struct sk_buff *skb)
2455 {
2456         skb->mac_len = skb->network_header - skb->mac_header;
2457 }
2458 
2459 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2460                                                         *skb)
2461 {
2462         return skb->head + skb->inner_transport_header;
2463 }
2464 
2465 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2466 {
2467         return skb_inner_transport_header(skb) - skb->data;
2468 }
2469 
2470 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2471 {
2472         skb->inner_transport_header = skb->data - skb->head;
2473 }
2474 
2475 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2476                                                    const int offset)
2477 {
2478         skb_reset_inner_transport_header(skb);
2479         skb->inner_transport_header += offset;
2480 }
2481 
2482 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2483 {
2484         return skb->head + skb->inner_network_header;
2485 }
2486 
2487 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2488 {
2489         skb->inner_network_header = skb->data - skb->head;
2490 }
2491 
2492 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2493                                                 const int offset)
2494 {
2495         skb_reset_inner_network_header(skb);
2496         skb->inner_network_header += offset;
2497 }
2498 
2499 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2500 {
2501         return skb->head + skb->inner_mac_header;
2502 }
2503 
2504 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2505 {
2506         skb->inner_mac_header = skb->data - skb->head;
2507 }
2508 
2509 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2510                                             const int offset)
2511 {
2512         skb_reset_inner_mac_header(skb);
2513         skb->inner_mac_header += offset;
2514 }
2515 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2516 {
2517         return skb->transport_header != (typeof(skb->transport_header))~0U;
2518 }
2519 
2520 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2521 {
2522         return skb->head + skb->transport_header;
2523 }
2524 
2525 static inline void skb_reset_transport_header(struct sk_buff *skb)
2526 {
2527         skb->transport_header = skb->data - skb->head;
2528 }
2529 
2530 static inline void skb_set_transport_header(struct sk_buff *skb,
2531                                             const int offset)
2532 {
2533         skb_reset_transport_header(skb);
2534         skb->transport_header += offset;
2535 }
2536 
2537 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2538 {
2539         return skb->head + skb->network_header;
2540 }
2541 
2542 static inline void skb_reset_network_header(struct sk_buff *skb)
2543 {
2544         skb->network_header = skb->data - skb->head;
2545 }
2546 
2547 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2548 {
2549         skb_reset_network_header(skb);
2550         skb->network_header += offset;
2551 }
2552 
2553 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2554 {
2555         return skb->head + skb->mac_header;
2556 }
2557 
2558 static inline int skb_mac_offset(const struct sk_buff *skb)
2559 {
2560         return skb_mac_header(skb) - skb->data;
2561 }
2562 
2563 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2564 {
2565         return skb->network_header - skb->mac_header;
2566 }
2567 
2568 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2569 {
2570         return skb->mac_header != (typeof(skb->mac_header))~0U;
2571 }
2572 
2573 static inline void skb_unset_mac_header(struct sk_buff *skb)
2574 {
2575         skb->mac_header = (typeof(skb->mac_header))~0U;
2576 }
2577 
2578 static inline void skb_reset_mac_header(struct sk_buff *skb)
2579 {
2580         skb->mac_header = skb->data - skb->head;
2581 }
2582 
2583 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
2584 {
2585         skb_reset_mac_header(skb);
2586         skb->mac_header += offset;
2587 }
2588 
2589 static inline void skb_pop_mac_header(struct sk_buff *skb)
2590 {
2591         skb->mac_header = skb->network_header;
2592 }
2593 
2594 static inline void skb_probe_transport_header(struct sk_buff *skb)
2595 {
2596         struct flow_keys_basic keys;
2597 
2598         if (skb_transport_header_was_set(skb))
2599                 return;
2600 
2601         if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
2602                                              NULL, 0, 0, 0, 0))
2603                 skb_set_transport_header(skb, keys.control.thoff);
2604 }
2605 
2606 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
2607 {
2608         if (skb_mac_header_was_set(skb)) {
2609                 const unsigned char *old_mac = skb_mac_header(skb);
2610 
2611                 skb_set_mac_header(skb, -skb->mac_len);
2612                 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
2613         }
2614 }
2615 
2616 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
2617 {
2618         return skb->csum_start - skb_headroom(skb);
2619 }
2620 
2621 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
2622 {
2623         return skb->head + skb->csum_start;
2624 }
2625 
2626 static inline int skb_transport_offset(const struct sk_buff *skb)
2627 {
2628         return skb_transport_header(skb) - skb->data;
2629 }
2630 
2631 static inline u32 skb_network_header_len(const struct sk_buff *skb)
2632 {
2633         return skb->transport_header - skb->network_header;
2634 }
2635 
2636 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
2637 {
2638         return skb->inner_transport_header - skb->inner_network_header;
2639 }
2640 
2641 static inline int skb_network_offset(const struct sk_buff *skb)
2642 {
2643         return skb_network_header(skb) - skb->data;
2644 }
2645 
2646 static inline int skb_inner_network_offset(const struct sk_buff *skb)
2647 {
2648         return skb_inner_network_header(skb) - skb->data;
2649 }
2650 
2651 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
2652 {
2653         return pskb_may_pull(skb, skb_network_offset(skb) + len);
2654 }
2655 
2656 /*
2657  * CPUs often take a performance hit when accessing unaligned memory
2658  * locations. The actual performance hit varies, it can be small if the
2659  * hardware handles it or large if we have to take an exception and fix it
2660  * in software.
2661  *
2662  * Since an ethernet header is 14 bytes network drivers often end up with
2663  * the IP header at an unaligned offset. The IP header can be aligned by
2664  * shifting the start of the packet by 2 bytes. Drivers should do this
2665  * with:
2666  *
2667  * skb_reserve(skb, NET_IP_ALIGN);
2668  *
2669  * The downside to this alignment of the IP header is that the DMA is now
2670  * unaligned. On some architectures the cost of an unaligned DMA is high
2671  * and this cost outweighs the gains made by aligning the IP header.
2672  *
2673  * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2674  * to be overridden.
2675  */
2676 #ifndef NET_IP_ALIGN
2677 #define NET_IP_ALIGN    2
2678 #endif
2679 
2680 /*
2681  * The networking layer reserves some headroom in skb data (via
2682  * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2683  * the header has to grow. In the default case, if the header has to grow
2684  * 32 bytes or less we avoid the reallocation.
2685  *
2686  * Unfortunately this headroom changes the DMA alignment of the resulting
2687  * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2688  * on some architectures. An architecture can override this value,
2689  * perhaps setting it to a cacheline in size (since that will maintain
2690  * cacheline alignment of the DMA). It must be a power of 2.
2691  *
2692  * Various parts of the networking layer expect at least 32 bytes of
2693  * headroom, you should not reduce this.
2694  *
2695  * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2696  * to reduce average number of cache lines per packet.
2697  * get_rps_cpu() for example only access one 64 bytes aligned block :
2698  * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2699  */
2700 #ifndef NET_SKB_PAD
2701 #define NET_SKB_PAD     max(32, L1_CACHE_BYTES)
2702 #endif
2703 
2704 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
2705 
2706 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
2707 {
2708         if (WARN_ON(skb_is_nonlinear(skb)))
2709                 return;
2710         skb->len = len;
2711         skb_set_tail_pointer(skb, len);
2712 }
2713 
2714 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
2715 {
2716         __skb_set_length(skb, len);
2717 }
2718 
2719 void skb_trim(struct sk_buff *skb, unsigned int len);
2720 
2721 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
2722 {
2723         if (skb->data_len)
2724                 return ___pskb_trim(skb, len);
2725         __skb_trim(skb, len);
2726         return 0;
2727 }
2728 
2729 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
2730 {
2731         return (len < skb->len) ? __pskb_trim(skb, len) : 0;
2732 }
2733 
2734 /**
2735  *      pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2736  *      @skb: buffer to alter
2737  *      @len: new length
2738  *
2739  *      This is identical to pskb_trim except that the caller knows that
2740  *      the skb is not cloned so we should never get an error due to out-
2741  *      of-memory.
2742  */
2743 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
2744 {
2745         int err = pskb_trim(skb, len);
2746         BUG_ON(err);
2747 }
2748 
2749 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
2750 {
2751         unsigned int diff = len - skb->len;
2752 
2753         if (skb_tailroom(skb) < diff) {
2754                 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
2755                                            GFP_ATOMIC);
2756                 if (ret)
2757                         return ret;
2758         }
2759         __skb_set_length(skb, len);
2760         return 0;
2761 }
2762 
2763 /**
2764  *      skb_orphan - orphan a buffer
2765  *      @skb: buffer to orphan
2766  *
2767  *      If a buffer currently has an owner then we call the owner's
2768  *      destructor function and make the @skb unowned. The buffer continues
2769  *      to exist but is no longer charged to its former owner.
2770  */
2771 static inline void skb_orphan(struct sk_buff *skb)
2772 {
2773         if (skb->destructor) {
2774                 skb->destructor(skb);
2775                 skb->destructor = NULL;
2776                 skb->sk         = NULL;
2777         } else {
2778                 BUG_ON(skb->sk);
2779         }
2780 }
2781 
2782 /**
2783  *      skb_orphan_frags - orphan the frags contained in a buffer
2784  *      @skb: buffer to orphan frags from
2785  *      @gfp_mask: allocation mask for replacement pages
2786  *
2787  *      For each frag in the SKB which needs a destructor (i.e. has an
2788  *      owner) create a copy of that frag and release the original
2789  *      page by calling the destructor.
2790  */
2791 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2792 {
2793         if (likely(!skb_zcopy(skb)))
2794                 return 0;
2795         if (!skb_zcopy_is_nouarg(skb) &&
2796             skb_uarg(skb)->callback == msg_zerocopy_callback)
2797                 return 0;
2798         return skb_copy_ubufs(skb, gfp_mask);
2799 }
2800 
2801 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
2802 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
2803 {
2804         if (likely(!skb_zcopy(skb)))
2805                 return 0;
2806         return skb_copy_ubufs(skb, gfp_mask);
2807 }
2808 
2809 /**
2810  *      __skb_queue_purge - empty a list
2811  *      @list: list to empty
2812  *
2813  *      Delete all buffers on an &sk_buff list. Each buffer is removed from
2814  *      the list and one reference dropped. This function does not take the
2815  *      list lock and the caller must hold the relevant locks to use it.
2816  */
2817 static inline void __skb_queue_purge(struct sk_buff_head *list)
2818 {
2819         struct sk_buff *skb;
2820         while ((skb = __skb_dequeue(list)) != NULL)
2821                 kfree_skb(skb);
2822 }
2823 void skb_queue_purge(struct sk_buff_head *list);
2824 
2825 unsigned int skb_rbtree_purge(struct rb_root *root);
2826 
2827 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
2828 
2829 /**
2830  * netdev_alloc_frag - allocate a page fragment
2831  * @fragsz: fragment size
2832  *
2833  * Allocates a frag from a page for receive buffer.
2834  * Uses GFP_ATOMIC allocations.
2835  */
2836 static inline void *netdev_alloc_frag(unsigned int fragsz)
2837 {
2838         return __netdev_alloc_frag_align(fragsz, ~0u);
2839 }
2840 
2841 static inline void *netdev_alloc_frag_align(unsigned int fragsz,
2842                                             unsigned int align)
2843 {
2844         WARN_ON_ONCE(!is_power_of_2(align));
2845         return __netdev_alloc_frag_align(fragsz, -align);
2846 }
2847 
2848 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2849                                    gfp_t gfp_mask);
2850 
2851 /**
2852  *      netdev_alloc_skb - allocate an skbuff for rx on a specific device
2853  *      @dev: network device to receive on
2854  *      @length: length to allocate
2855  *
2856  *      Allocate a new &sk_buff and assign it a usage count of one. The
2857  *      buffer has unspecified headroom built in. Users should allocate
2858  *      the headroom they think they need without accounting for the
2859  *      built in space. The built in space is used for optimisations.
2860  *
2861  *      %NULL is returned if there is no free memory. Although this function
2862  *      allocates memory it can be called from an interrupt.
2863  */
2864 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2865                                                unsigned int length)
2866 {
2867         return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2868 }
2869 
2870 /* legacy helper around __netdev_alloc_skb() */
2871 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2872                                               gfp_t gfp_mask)
2873 {
2874         return __netdev_alloc_skb(NULL, length, gfp_mask);
2875 }
2876 
2877 /* legacy helper around netdev_alloc_skb() */
2878 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2879 {
2880         return netdev_alloc_skb(NULL, length);
2881 }
2882 
2883 
2884 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2885                 unsigned int length, gfp_t gfp)
2886 {
2887         struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2888 
2889         if (NET_IP_ALIGN && skb)
2890                 skb_reserve(skb, NET_IP_ALIGN);
2891         return skb;
2892 }
2893 
2894 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2895                 unsigned int length)
2896 {
2897         return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2898 }
2899 
2900 static inline void skb_free_frag(void *addr)
2901 {
2902         page_frag_free(addr);
2903 }
2904 
2905 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
2906 
2907 static inline void *napi_alloc_frag(unsigned int fragsz)
2908 {
2909         return __napi_alloc_frag_align(fragsz, ~0u);
2910 }
2911 
2912 static inline void *napi_alloc_frag_align(unsigned int fragsz,
2913                                           unsigned int align)
2914 {
2915         WARN_ON_ONCE(!is_power_of_2(align));
2916         return __napi_alloc_frag_align(fragsz, -align);
2917 }
2918 
2919 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
2920                                  unsigned int length, gfp_t gfp_mask);
2921 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
2922                                              unsigned int length)
2923 {
2924         return __napi_alloc_skb(napi, length, GFP_ATOMIC);
2925 }
2926 void napi_consume_skb(struct sk_buff *skb, int budget);
2927 
2928 void napi_skb_free_stolen_head(struct sk_buff *skb);
2929 void __kfree_skb_defer(struct sk_buff *skb);
2930 
2931 /**
2932  * __dev_alloc_pages - allocate page for network Rx
2933  * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2934  * @order: size of the allocation
2935  *
2936  * Allocate a new page.
2937  *
2938  * %NULL is returned if there is no free memory.
2939 */
2940 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
2941                                              unsigned int order)
2942 {
2943         /* This piece of code contains several assumptions.
2944          * 1.  This is for device Rx, therefor a cold page is preferred.
2945          * 2.  The expectation is the user wants a compound page.
2946          * 3.  If requesting a order 0 page it will not be compound
2947          *     due to the check to see if order has a value in prep_new_page
2948          * 4.  __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2949          *     code in gfp_to_alloc_flags that should be enforcing this.
2950          */
2951         gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
2952 
2953         return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2954 }
2955 
2956 static inline struct page *dev_alloc_pages(unsigned int order)
2957 {
2958         return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order);
2959 }
2960 
2961 /**
2962  * __dev_alloc_page - allocate a page for network Rx
2963  * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2964  *
2965  * Allocate a new page.
2966  *
2967  * %NULL is returned if there is no free memory.
2968  */
2969 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
2970 {
2971         return __dev_alloc_pages(gfp_mask, 0);
2972 }
2973 
2974 static inline struct page *dev_alloc_page(void)
2975 {
2976         return dev_alloc_pages(0);
2977 }
2978 
2979 /**
2980  * dev_page_is_reusable - check whether a page can be reused for network Rx
2981  * @page: the page to test
2982  *
2983  * A page shouldn't be considered for reusing/recycling if it was allocated
2984  * under memory pressure or at a distant memory node.
2985  *
2986  * Returns false if this page should be returned to page allocator, true
2987  * otherwise.
2988  */
2989 static inline bool dev_page_is_reusable(const struct page *page)
2990 {
2991         return likely(page_to_nid(page) == numa_mem_id() &&
2992                       !page_is_pfmemalloc(page));
2993 }
2994 
2995 /**
2996  *      skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2997  *      @page: The page that was allocated from skb_alloc_page
2998  *      @skb: The skb that may need pfmemalloc set
2999  */
3000 static inline void skb_propagate_pfmemalloc(const struct page *page,
3001                                             struct sk_buff *skb)
3002 {
3003         if (page_is_pfmemalloc(page))
3004                 skb->pfmemalloc = true;
3005 }
3006 
3007 /**
3008  * skb_frag_off() - Returns the offset of a skb fragment
3009  * @frag: the paged fragment
3010  */
3011 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3012 {
3013         return frag->bv_offset;
3014 }
3015 
3016 /**
3017  * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3018  * @frag: skb fragment
3019  * @delta: value to add
3020  */
3021 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3022 {
3023         frag->bv_offset += delta;
3024 }
3025 
3026 /**
3027  * skb_frag_off_set() - Sets the offset of a skb fragment
3028  * @frag: skb fragment
3029  * @offset: offset of fragment
3030  */
3031 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3032 {
3033         frag->bv_offset = offset;
3034 }
3035 
3036 /**
3037  * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3038  * @fragto: skb fragment where offset is set
3039  * @fragfrom: skb fragment offset is copied from
3040  */
3041 static inline void skb_frag_off_copy(skb_frag_t *fragto,
3042                                      const skb_frag_t *fragfrom)
3043 {
3044         fragto->bv_offset = fragfrom->bv_offset;
3045 }
3046 
3047 /**
3048  * skb_frag_page - retrieve the page referred to by a paged fragment
3049  * @frag: the paged fragment
3050  *
3051  * Returns the &struct page associated with @frag.
3052  */
3053 static inline struct page *skb_frag_page(const skb_frag_t *frag)
3054 {
3055         return frag->bv_page;
3056 }
3057 
3058 /**
3059  * __skb_frag_ref - take an addition reference on a paged fragment.
3060  * @frag: the paged fragment
3061  *
3062  * Takes an additional reference on the paged fragment @frag.
3063  */
3064 static inline void __skb_frag_ref(skb_frag_t *frag)
3065 {
3066         get_page(skb_frag_page(frag));
3067 }
3068 
3069 /**
3070  * skb_frag_ref - take an addition reference on a paged fragment of an skb.
3071  * @skb: the buffer
3072  * @f: the fragment offset.
3073  *
3074  * Takes an additional reference on the @f'th paged fragment of @skb.
3075  */
3076 static inline void skb_frag_ref(struct sk_buff *skb, int f)
3077 {
3078         __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3079 }
3080 
3081 /**
3082  * __skb_frag_unref - release a reference on a paged fragment.
3083  * @frag: the paged fragment
3084  *
3085  * Releases a reference on the paged fragment @frag.
3086  */
3087 static inline void __skb_frag_unref(skb_frag_t *frag)
3088 {
3089         put_page(skb_frag_page(frag));
3090 }
3091 
3092 /**
3093  * skb_frag_unref - release a reference on a paged fragment of an skb.
3094  * @skb: the buffer
3095  * @f: the fragment offset
3096  *
3097  * Releases a reference on the @f'th paged fragment of @skb.
3098  */
3099 static inline void skb_frag_unref(struct sk_buff *skb, int f)
3100 {
3101         __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
3102 }
3103 
3104 /**
3105  * skb_frag_address - gets the address of the data contained in a paged fragment
3106  * @frag: the paged fragment buffer
3107  *
3108  * Returns the address of the data within @frag. The page must already
3109  * be mapped.
3110  */
3111 static inline void *skb_frag_address(const skb_frag_t *frag)
3112 {
3113         return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3114 }
3115 
3116 /**
3117  * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3118  * @frag: the paged fragment buffer
3119  *
3120  * Returns the address of the data within @frag. Checks that the page
3121  * is mapped and returns %NULL otherwise.
3122  */
3123 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3124 {
3125         void *ptr = page_address(skb_frag_page(frag));
3126         if (unlikely(!ptr))
3127                 return NULL;
3128 
3129         return ptr + skb_frag_off(frag);
3130 }
3131 
3132 /**
3133  * skb_frag_page_copy() - sets the page in a fragment from another fragment
3134  * @fragto: skb fragment where page is set
3135  * @fragfrom: skb fragment page is copied from
3136  */
3137 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3138                                       const skb_frag_t *fragfrom)
3139 {
3140         fragto->bv_page = fragfrom->bv_page;
3141 }
3142 
3143 /**
3144  * __skb_frag_set_page - sets the page contained in a paged fragment
3145  * @frag: the paged fragment
3146  * @page: the page to set
3147  *
3148  * Sets the fragment @frag to contain @page.
3149  */
3150 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
3151 {
3152         frag->bv_page = page;
3153 }
3154 
3155 /**
3156  * skb_frag_set_page - sets the page contained in a paged fragment of an skb
3157  * @skb: the buffer
3158  * @f: the fragment offset
3159  * @page: the page to set
3160  *
3161  * Sets the @f'th fragment of @skb to contain @page.
3162  */
3163 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
3164                                      struct page *page)
3165 {
3166         __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
3167 }
3168 
3169 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3170 
3171 /**
3172  * skb_frag_dma_map - maps a paged fragment via the DMA API
3173  * @dev: the device to map the fragment to
3174  * @frag: the paged fragment to map
3175  * @offset: the offset within the fragment (starting at the
3176  *          fragment's own offset)
3177  * @size: the number of bytes to map
3178  * @dir: the direction of the mapping (``PCI_DMA_*``)
3179  *
3180  * Maps the page associated with @frag to @device.
3181  */
3182 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3183                                           const skb_frag_t *frag,
3184                                           size_t offset, size_t size,
3185                                           enum dma_data_direction dir)
3186 {
3187         return dma_map_page(dev, skb_frag_page(frag),
3188                             skb_frag_off(frag) + offset, size, dir);
3189 }
3190 
3191 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3192                                         gfp_t gfp_mask)
3193 {
3194         return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3195 }
3196 
3197 
3198 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3199                                                   gfp_t gfp_mask)
3200 {
3201         return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3202 }
3203 
3204 
3205 /**
3206  *      skb_clone_writable - is the header of a clone writable
3207  *      @skb: buffer to check
3208  *      @len: length up to which to write
3209  *
3210  *      Returns true if modifying the header part of the cloned buffer
3211  *      does not requires the data to be copied.
3212  */
3213 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3214 {
3215         return !skb_header_cloned(skb) &&
3216                skb_headroom(skb) + len <= skb->hdr_len;
3217 }
3218 
3219 static inline int skb_try_make_writable(struct sk_buff *skb,
3220                                         unsigned int write_len)
3221 {
3222         return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3223                pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3224 }
3225 
3226 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3227                             int cloned)
3228 {
3229         int delta = 0;
3230 
3231         if (headroom > skb_headroom(skb))
3232                 delta = headroom - skb_headroom(skb);
3233 
3234         if (delta || cloned)
3235                 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3236                                         GFP_ATOMIC);
3237         return 0;
3238 }
3239 
3240 /**
3241  *      skb_cow - copy header of skb when it is required
3242  *      @skb: buffer to cow
3243  *      @headroom: needed headroom
3244  *
3245  *      If the skb passed lacks sufficient headroom or its data part
3246  *      is shared, data is reallocated. If reallocation fails, an error
3247  *      is returned and original skb is not changed.
3248  *
3249  *      The result is skb with writable area skb->head...skb->tail
3250  *      and at least @headroom of space at head.
3251  */
3252 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3253 {
3254         return __skb_cow(skb, headroom, skb_cloned(skb));
3255 }
3256 
3257 /**
3258  *      skb_cow_head - skb_cow but only making the head writable
3259  *      @skb: buffer to cow
3260  *      @headroom: needed headroom
3261  *
3262  *      This function is identical to skb_cow except that we replace the
3263  *      skb_cloned check by skb_header_cloned.  It should be used when
3264  *      you only need to push on some header and do not need to modify
3265  *      the data.
3266  */
3267 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3268 {
3269         return __skb_cow(skb, headroom, skb_header_cloned(skb));
3270 }
3271 
3272 /**
3273  *      skb_padto       - pad an skbuff up to a minimal size
3274  *      @skb: buffer to pad
3275  *      @len: minimal length
3276  *
3277  *      Pads up a buffer to ensure the trailing bytes exist and are
3278  *      blanked. If the buffer already contains sufficient data it
3279  *      is untouched. Otherwise it is extended. Returns zero on
3280  *      success. The skb is freed on error.
3281  */
3282 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3283 {
3284         unsigned int size = skb->len;
3285         if (likely(size >= len))
3286                 return 0;
3287         return skb_pad(skb, len - size);
3288 }
3289 
3290 /**
3291  *      __skb_put_padto - increase size and pad an skbuff up to a minimal size
3292  *      @skb: buffer to pad
3293  *      @len: minimal length
3294  *      @free_on_error: free buffer on error
3295  *
3296  *      Pads up a buffer to ensure the trailing bytes exist and are
3297  *      blanked. If the buffer already contains sufficient data it
3298  *      is untouched. Otherwise it is extended. Returns zero on
3299  *      success. The skb is freed on error if @free_on_error is true.
3300  */
3301 static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3302                                                unsigned int len,
3303                                                bool free_on_error)
3304 {
3305         unsigned int size = skb->len;
3306 
3307         if (unlikely(size < len)) {
3308                 len -= size;
3309                 if (__skb_pad(skb, len, free_on_error))
3310                         return -ENOMEM;
3311                 __skb_put(skb, len);
3312         }
3313         return 0;
3314 }
3315 
3316 /**
3317  *      skb_put_padto - increase size and pad an skbuff up to a minimal size
3318  *      @skb: buffer to pad
3319  *      @len: minimal length
3320  *
3321  *      Pads up a buffer to ensure the trailing bytes exist and are
3322  *      blanked. If the buffer already contains sufficient data it
3323  *      is untouched. Otherwise it is extended. Returns zero on
3324  *      success. The skb is freed on error.
3325  */
3326 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3327 {
3328         return __skb_put_padto(skb, len, true);
3329 }
3330 
3331 static inline int skb_add_data(struct sk_buff *skb,
3332                                struct iov_iter *from, int copy)
3333 {
3334         const int off = skb->len;
3335 
3336         if (skb->ip_summed == CHECKSUM_NONE) {
3337                 __wsum csum = 0;
3338                 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3339                                                  &csum, from)) {
3340                         skb->csum = csum_block_add(skb->csum, csum, off);
3341                         return 0;
3342                 }
3343         } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3344                 return 0;
3345 
3346         __skb_trim(skb, off);
3347         return -EFAULT;
3348 }
3349 
3350 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3351                                     const struct page *page, int off)
3352 {
3353         if (skb_zcopy(skb))
3354                 return false;
3355         if (i) {
3356                 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3357 
3358                 return page == skb_frag_page(frag) &&
3359                        off == skb_frag_off(frag) + skb_frag_size(frag);
3360         }
3361         return false;
3362 }
3363 
3364 static inline int __skb_linearize(struct sk_buff *skb)
3365 {
3366         return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3367 }
3368 
3369 /**
3370  *      skb_linearize - convert paged skb to linear one
3371  *      @skb: buffer to linarize
3372  *
3373  *      If there is no free memory -ENOMEM is returned, otherwise zero
3374  *      is returned and the old skb data released.
3375  */
3376 static inline int skb_linearize(struct sk_buff *skb)
3377 {
3378         return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3379 }
3380 
3381 /**
3382  * skb_has_shared_frag - can any frag be overwritten
3383  * @skb: buffer to test
3384  *
3385  * Return true if the skb has at least one frag that might be modified
3386  * by an external entity (as in vmsplice()/sendfile())
3387  */
3388 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3389 {
3390         return skb_is_nonlinear(skb) &&
3391                skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3392 }
3393 
3394 /**
3395  *      skb_linearize_cow - make sure skb is linear and writable
3396  *      @skb: buffer to process
3397  *
3398  *      If there is no free memory -ENOMEM is returned, otherwise zero
3399  *      is returned and the old skb data released.
3400  */
3401 static inline int skb_linearize_cow(struct sk_buff *skb)
3402 {
3403         return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3404                __skb_linearize(skb) : 0;
3405 }
3406 
3407 static __always_inline void
3408 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3409                      unsigned int off)
3410 {
3411         if (skb->ip_summed == CHECKSUM_COMPLETE)
3412                 skb->csum = csum_block_sub(skb->csum,
3413                                            csum_partial(start, len, 0), off);
3414         else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3415                  skb_checksum_start_offset(skb) < 0)
3416                 skb->ip_summed = CHECKSUM_NONE;
3417 }
3418 
3419 /**
3420  *      skb_postpull_rcsum - update checksum for received skb after pull
3421  *      @skb: buffer to update
3422  *      @start: start of data before pull
3423  *      @len: length of data pulled
3424  *
3425  *      After doing a pull on a received packet, you need to call this to
3426  *      update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3427  *      CHECKSUM_NONE so that it can be recomputed from scratch.
3428  */
3429 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3430                                       const void *start, unsigned int len)
3431 {
3432         __skb_postpull_rcsum(skb, start, len, 0);
3433 }
3434 
3435 static __always_inline void
3436 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3437                      unsigned int off)
3438 {
3439         if (skb->ip_summed == CHECKSUM_COMPLETE)
3440                 skb->csum = csum_block_add(skb->csum,
3441                                            csum_partial(start, len, 0), off);
3442 }
3443 
3444 /**
3445  *      skb_postpush_rcsum - update checksum for received skb after push
3446  *      @skb: buffer to update
3447  *      @start: start of data after push
3448  *      @len: length of data pushed
3449  *
3450  *      After doing a push on a received packet, you need to call this to
3451  *      update the CHECKSUM_COMPLETE checksum.
3452  */
3453 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3454                                       const void *start, unsigned int len)
3455 {
3456         __skb_postpush_rcsum(skb, start, len, 0);
3457 }
3458 
3459 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3460 
3461 /**
3462  *      skb_push_rcsum - push skb and update receive checksum
3463  *      @skb: buffer to update
3464  *      @len: length of data pulled
3465  *
3466  *      This function performs an skb_push on the packet and updates
3467  *      the CHECKSUM_COMPLETE checksum.  It should be used on
3468  *      receive path processing instead of skb_push unless you know
3469  *      that the checksum difference is zero (e.g., a valid IP header)
3470  *      or you are setting ip_summed to CHECKSUM_NONE.
3471  */
3472 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3473 {
3474         skb_push(skb, len);
3475         skb_postpush_rcsum(skb, skb->data, len);
3476         return skb->data;
3477 }
3478 
3479 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3480 /**
3481  *      pskb_trim_rcsum - trim received skb and update checksum
3482  *      @skb: buffer to trim
3483  *      @len: new length
3484  *
3485  *      This is exactly the same as pskb_trim except that it ensures the
3486  *      checksum of received packets are still valid after the operation.
3487  *      It can change skb pointers.
3488  */
3489 
3490 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3491 {
3492         if (likely(len >= skb->len))
3493                 return 0;
3494         return pskb_trim_rcsum_slow(skb, len);
3495 }
3496 
3497 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3498 {
3499         if (skb->ip_summed == CHECKSUM_COMPLETE)
3500                 skb->ip_summed = CHECKSUM_NONE;
3501         __skb_trim(skb, len);
3502         return 0;
3503 }
3504 
3505 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3506 {
3507         if (skb->ip_summed == CHECKSUM_COMPLETE)
3508                 skb->ip_summed = CHECKSUM_NONE;
3509         return __skb_grow(skb, len);
3510 }
3511 
3512 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3513 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3514 #define skb_rb_last(root)  rb_to_skb(rb_last(root))
3515 #define skb_rb_next(skb)   rb_to_skb(rb_next(&(skb)->rbnode))
3516 #define skb_rb_prev(skb)   rb_to_skb(rb_prev(&(skb)->rbnode))
3517 
3518 #define skb_queue_walk(queue, skb) \
3519                 for (skb = (queue)->next;                                       \
3520                      skb != (struct sk_buff *)(queue);                          \
3521                      skb = skb->next)
3522 
3523 #define skb_queue_walk_safe(queue, skb, tmp)                                    \
3524                 for (skb = (queue)->next, tmp = skb->next;                      \
3525                      skb != (struct sk_buff *)(queue);                          \
3526                      skb = tmp, tmp = skb->next)
3527 
3528 #define skb_queue_walk_from(queue, skb)                                         \
3529                 for (; skb != (struct sk_buff *)(queue);                        \
3530                      skb = skb->next)
3531 
3532 #define skb_rbtree_walk(skb, root)                                              \
3533                 for (skb = skb_rb_first(root); skb != NULL;                     \
3534                      skb = skb_rb_next(skb))
3535 
3536 #define skb_rbtree_walk_from(skb)                                               \
3537                 for (; skb != NULL;                                             \
3538                      skb = skb_rb_next(skb))
3539 
3540 #define skb_rbtree_walk_from_safe(skb, tmp)                                     \
3541                 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL);      \
3542                      skb = tmp)
3543 
3544 #define skb_queue_walk_from_safe(queue, skb, tmp)                               \
3545                 for (tmp = skb->next;                                           \
3546                      skb != (struct sk_buff *)(queue);                          \
3547                      skb = tmp, tmp = skb->next)
3548 
3549 #define skb_queue_reverse_walk(queue, skb) \
3550                 for (skb = (queue)->prev;                                       \
3551                      skb != (struct sk_buff *)(queue);                          \
3552                      skb = skb->prev)
3553 
3554 #define skb_queue_reverse_walk_safe(queue, skb, tmp)                            \
3555                 for (skb = (queue)->prev, tmp = skb->prev;                      \
3556                      skb != (struct sk_buff *)(queue);                          \
3557                      skb = tmp, tmp = skb->prev)
3558 
3559 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp)                       \
3560                 for (tmp = skb->prev;                                           \
3561                      skb != (struct sk_buff *)(queue);                          \
3562                      skb = tmp, tmp = skb->prev)
3563 
3564 static inline bool skb_has_frag_list(const struct sk_buff *skb)
3565 {
3566         return skb_shinfo(skb)->frag_list != NULL;
3567 }
3568 
3569 static inline void skb_frag_list_init(struct sk_buff *skb)
3570 {
3571         skb_shinfo(skb)->frag_list = NULL;
3572 }
3573 
3574 #define skb_walk_frags(skb, iter)       \
3575         for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3576 
3577 
3578 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
3579                                 int *err, long *timeo_p,
3580                                 const struct sk_buff *skb);
3581 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
3582                                           struct sk_buff_head *queue,
3583                                           unsigned int flags,
3584                                           int *off, int *err,
3585                                           struct sk_buff **last);
3586 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
3587                                         struct sk_buff_head *queue,
3588                                         unsigned int flags, int *off, int *err,
3589                                         struct sk_buff **last);
3590 struct sk_buff *__skb_recv_datagram(struct sock *sk,
3591                                     struct sk_buff_head *sk_queue,
3592                                     unsigned int flags, int *off, int *err);
3593 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
3594                                   int *err);
3595 __poll_t datagram_poll(struct file *file, struct socket *sock,
3596                            struct poll_table_struct *wait);
3597 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
3598                            struct iov_iter *to, int size);
3599 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
3600                                         struct msghdr *msg, int size)
3601 {
3602         return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3603 }
3604 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
3605                                    struct msghdr *msg);
3606 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
3607                            struct iov_iter *to, int len,
3608                            struct ahash_request *hash);
3609 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
3610                                  struct iov_iter *from, int len);
3611 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
3612 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
3613 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
3614 static inline void skb_free_datagram_locked(struct sock *sk,
3615                                             struct sk_buff *skb)
3616 {
3617         __skb_free_datagram_locked(sk, skb, 0);
3618 }
3619 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
3620 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
3621 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
3622 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
3623                               int len);
3624 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
3625                     struct pipe_inode_info *pipe, unsigned int len,
3626                     unsigned int flags);
3627 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
3628                          int len);
3629 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
3630 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
3631 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
3632 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
3633                  int len, int hlen);
3634 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
3635 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
3636 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
3637 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
3638 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
3639 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
3640 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
3641                                  unsigned int offset);
3642 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
3643 int skb_ensure_writable(struct sk_buff *skb, int write_len);
3644 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
3645 int skb_vlan_pop(struct sk_buff *skb);
3646 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
3647 int skb_eth_pop(struct sk_buff *skb);
3648 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
3649                  const unsigned char *src);
3650 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
3651                   int mac_len, bool ethernet);
3652 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
3653                  bool ethernet);
3654 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
3655 int skb_mpls_dec_ttl(struct sk_buff *skb);
3656 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
3657                              gfp_t gfp);
3658 
3659 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
3660 {
3661         return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
3662 }
3663 
3664 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
3665 {
3666         return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
3667 }
3668 
3669 struct skb_checksum_ops {
3670         __wsum (*update)(const void *mem, int len, __wsum wsum);
3671         __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
3672 };
3673 
3674 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
3675 
3676 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
3677                       __wsum csum, const struct skb_checksum_ops *ops);
3678 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
3679                     __wsum csum);
3680 
3681 static inline void * __must_check
3682 __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
3683                      const void *data, int hlen, void *buffer)
3684 {
3685         if (likely(hlen - offset >= len))
3686                 return (void *)data + offset;
3687 
3688         if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
3689                 return NULL;
3690 
3691         return buffer;
3692 }
3693 
3694 static inline void * __must_check
3695 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
3696 {
3697         return __skb_header_pointer(skb, offset, len, skb->data,
3698                                     skb_headlen(skb), buffer);
3699 }
3700 
3701 /**
3702  *      skb_needs_linearize - check if we need to linearize a given skb
3703  *                            depending on the given device features.
3704  *      @skb: socket buffer to check
3705  *      @features: net device features
3706  *
3707  *      Returns true if either:
3708  *      1. skb has frag_list and the device doesn't support FRAGLIST, or
3709  *      2. skb is fragmented and the device does not support SG.
3710  */
3711 static inline bool skb_needs_linearize(struct sk_buff *skb,
3712                                        netdev_features_t features)
3713 {
3714         return skb_is_nonlinear(skb) &&
3715                ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
3716                 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
3717 }
3718 
3719 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
3720                                              void *to,
3721                                              const unsigned int len)
3722 {
3723         memcpy(to, skb->data, len);
3724 }
3725 
3726 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
3727                                                     const int offset, void *to,
3728                                                     const unsigned int len)
3729 {
3730         memcpy(to, skb->data + offset, len);
3731 }
3732 
3733 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
3734                                            const void *from,
3735                                            const unsigned int len)
3736 {
3737         memcpy(skb->data, from, len);
3738 }
3739 
3740 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
3741                                                   const int offset,
3742                                                   const void *from,
3743                                                   const unsigned int len)
3744 {
3745         memcpy(skb->data + offset, from, len);
3746 }
3747 
3748 void skb_init(void);
3749 
3750 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
3751 {
3752         return skb->tstamp;
3753 }
3754 
3755 /**
3756  *      skb_get_timestamp - get timestamp from a skb
3757  *      @skb: skb to get stamp from
3758  *      @stamp: pointer to struct __kernel_old_timeval to store stamp in
3759  *
3760  *      Timestamps are stored in the skb as offsets to a base timestamp.
3761  *      This function converts the offset back to a struct timeval and stores
3762  *      it in stamp.
3763  */
3764 static inline void skb_get_timestamp(const struct sk_buff *skb,
3765                                      struct __kernel_old_timeval *stamp)
3766 {
3767         *stamp = ns_to_kernel_old_timeval(skb->tstamp);
3768 }
3769 
3770 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
3771                                          struct __kernel_sock_timeval *stamp)
3772 {
3773         struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3774 
3775         stamp->tv_sec = ts.tv_sec;
3776         stamp->tv_usec = ts.tv_nsec / 1000;
3777 }
3778 
3779 static inline void skb_get_timestampns(const struct sk_buff *skb,
3780                                        struct __kernel_old_timespec *stamp)
3781 {
3782         struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3783 
3784         stamp->tv_sec = ts.tv_sec;
3785         stamp->tv_nsec = ts.tv_nsec;
3786 }
3787 
3788 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
3789                                            struct __kernel_timespec *stamp)
3790 {
3791         struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3792 
3793         stamp->tv_sec = ts.tv_sec;
3794         stamp->tv_nsec = ts.tv_nsec;
3795 }
3796 
3797 static inline void __net_timestamp(struct sk_buff *skb)
3798 {
3799         skb->tstamp = ktime_get_real();
3800 }
3801 
3802 static inline ktime_t net_timedelta(ktime_t t)
3803 {
3804         return ktime_sub(ktime_get_real(), t);
3805 }
3806 
3807 static inline ktime_t net_invalid_timestamp(void)
3808 {
3809         return 0;
3810 }
3811 
3812 static inline u8 skb_metadata_len(const struct sk_buff *skb)
3813 {
3814         return skb_shinfo(skb)->meta_len;
3815 }
3816 
3817 static inline void *skb_metadata_end(const struct sk_buff *skb)
3818 {
3819         return skb_mac_header(skb);
3820 }
3821 
3822 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
3823                                           const struct sk_buff *skb_b,
3824                                           u8 meta_len)
3825 {
3826         const void *a = skb_metadata_end(skb_a);
3827         const void *b = skb_metadata_end(skb_b);
3828         /* Using more efficient varaiant than plain call to memcmp(). */
3829 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
3830         u64 diffs = 0;
3831 
3832         switch (meta_len) {
3833 #define __it(x, op) (x -= sizeof(u##op))
3834 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
3835         case 32: diffs |= __it_diff(a, b, 64);
3836                 fallthrough;
3837         case 24: diffs |= __it_diff(a, b, 64);
3838                 fallthrough;
3839         case 16: diffs |= __it_diff(a, b, 64);
3840                 fallthrough;
3841         case  8: diffs |= __it_diff(a, b, 64);
3842                 break;
3843         case 28: diffs |= __it_diff(a, b, 64);
3844                 fallthrough;
3845         case 20: diffs |= __it_diff(a, b, 64);
3846                 fallthrough;
3847         case 12: diffs |= __it_diff(a, b, 64);
3848                 fallthrough;
3849         case  4: diffs |= __it_diff(a, b, 32);
3850                 break;
3851         }
3852         return diffs;
3853 #else
3854         return memcmp(a - meta_len, b - meta_len, meta_len);
3855 #endif
3856 }
3857 
3858 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
3859                                         const struct sk_buff *skb_b)
3860 {
3861         u8 len_a = skb_metadata_len(skb_a);
3862         u8 len_b = skb_metadata_len(skb_b);
3863 
3864         if (!(len_a | len_b))
3865                 return false;
3866 
3867         return len_a != len_b ?
3868                true : __skb_metadata_differs(skb_a, skb_b, len_a);
3869 }
3870 
3871 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
3872 {
3873         skb_shinfo(skb)->meta_len = meta_len;
3874 }
3875 
3876 static inline void skb_metadata_clear(struct sk_buff *skb)
3877 {
3878         skb_metadata_set(skb, 0);
3879 }
3880 
3881 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
3882 
3883 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3884 
3885 void skb_clone_tx_timestamp(struct sk_buff *skb);
3886 bool skb_defer_rx_timestamp(struct sk_buff *skb);
3887 
3888 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3889 
3890 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
3891 {
3892 }
3893 
3894 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
3895 {
3896         return false;
3897 }
3898 
3899 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3900 
3901 /**
3902  * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3903  *
3904  * PHY drivers may accept clones of transmitted packets for
3905  * timestamping via their phy_driver.txtstamp method. These drivers
3906  * must call this function to return the skb back to the stack with a
3907  * timestamp.
3908  *
3909  * @skb: clone of the original outgoing packet
3910  * @hwtstamps: hardware time stamps
3911  *
3912  */
3913 void skb_complete_tx_timestamp(struct sk_buff *skb,
3914                                struct skb_shared_hwtstamps *hwtstamps);
3915 
3916 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
3917                      struct skb_shared_hwtstamps *hwtstamps,
3918                      struct sock *sk, int tstype);
3919 
3920 /**
3921  * skb_tstamp_tx - queue clone of skb with send time stamps
3922  * @orig_skb:   the original outgoing packet
3923  * @hwtstamps:  hardware time stamps, may be NULL if not available
3924  *
3925  * If the skb has a socket associated, then this function clones the
3926  * skb (thus sharing the actual data and optional structures), stores
3927  * the optional hardware time stamping information (if non NULL) or
3928  * generates a software time stamp (otherwise), then queues the clone
3929  * to the error queue of the socket.  Errors are silently ignored.
3930  */
3931 void skb_tstamp_tx(struct sk_buff *orig_skb,
3932                    struct skb_shared_hwtstamps *hwtstamps);
3933 
3934 /**
3935  * skb_tx_timestamp() - Driver hook for transmit timestamping
3936  *
3937  * Ethernet MAC Drivers should call this function in their hard_xmit()
3938  * function immediately before giving the sk_buff to the MAC hardware.
3939  *
3940  * Specifically, one should make absolutely sure that this function is
3941  * called before TX completion of this packet can trigger.  Otherwise
3942  * the packet could potentially already be freed.
3943  *
3944  * @skb: A socket buffer.
3945  */
3946 static inline void skb_tx_timestamp(struct sk_buff *skb)
3947 {
3948         skb_clone_tx_timestamp(skb);
3949         if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
3950                 skb_tstamp_tx(skb, NULL);
3951 }
3952 
3953 /**
3954  * skb_complete_wifi_ack - deliver skb with wifi status
3955  *
3956  * @skb: the original outgoing packet
3957  * @acked: ack status
3958  *
3959  */
3960 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
3961 
3962 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
3963 __sum16 __skb_checksum_complete(struct sk_buff *skb);
3964 
3965 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
3966 {
3967         return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
3968                 skb->csum_valid ||
3969                 (skb->ip_summed == CHECKSUM_PARTIAL &&
3970                  skb_checksum_start_offset(skb) >= 0));
3971 }
3972 
3973 /**
3974  *      skb_checksum_complete - Calculate checksum of an entire packet
3975  *      @skb: packet to process
3976  *
3977  *      This function calculates the checksum over the entire packet plus
3978  *      the value of skb->csum.  The latter can be used to supply the
3979  *      checksum of a pseudo header as used by TCP/UDP.  It returns the
3980  *      checksum.
3981  *
3982  *      For protocols that contain complete checksums such as ICMP/TCP/UDP,
3983  *      this function can be used to verify that checksum on received
3984  *      packets.  In that case the function should return zero if the
3985  *      checksum is correct.  In particular, this function will return zero
3986  *      if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3987  *      hardware has already verified the correctness of the checksum.
3988  */
3989 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
3990 {
3991         return skb_csum_unnecessary(skb) ?
3992                0 : __skb_checksum_complete(skb);
3993 }
3994 
3995 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
3996 {
3997         if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3998                 if (skb->csum_level == 0)
3999                         skb->ip_summed = CHECKSUM_NONE;
4000                 else
4001                         skb->csum_level--;
4002         }
4003 }
4004 
4005 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4006 {
4007         if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4008                 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4009                         skb->csum_level++;
4010         } else if (skb->ip_summed == CHECKSUM_NONE) {
4011                 skb->ip_summed = CHECKSUM_UNNECESSARY;
4012                 skb->csum_level = 0;
4013         }
4014 }
4015 
4016 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4017 {
4018         if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4019                 skb->ip_summed = CHECKSUM_NONE;
4020                 skb->csum_level = 0;
4021         }
4022 }
4023 
4024 /* Check if we need to perform checksum complete validation.
4025  *
4026  * Returns true if checksum complete is needed, false otherwise
4027  * (either checksum is unnecessary or zero checksum is allowed).
4028  */
4029 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4030                                                   bool zero_okay,
4031                                                   __sum16 check)
4032 {
4033         if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4034                 skb->csum_valid = 1;
4035                 __skb_decr_checksum_unnecessary(skb);
4036                 return false;
4037         }
4038 
4039         return true;
4040 }
4041 
4042 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4043  * in checksum_init.
4044  */
4045 #define CHECKSUM_BREAK 76
4046 
4047 /* Unset checksum-complete
4048  *
4049  * Unset checksum complete can be done when packet is being modified
4050  * (uncompressed for instance) and checksum-complete value is
4051  * invalidated.
4052  */
4053 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4054 {
4055         if (skb->ip_summed == CHECKSUM_COMPLETE)
4056                 skb->ip_summed = CHECKSUM_NONE;
4057 }
4058 
4059 /* Validate (init) checksum based on checksum complete.
4060  *
4061  * Return values:
4062  *   0: checksum is validated or try to in skb_checksum_complete. In the latter
4063  *      case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4064  *      checksum is stored in skb->csum for use in __skb_checksum_complete
4065  *   non-zero: value of invalid checksum
4066  *
4067  */
4068 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4069                                                        bool complete,
4070                                                        __wsum psum)
4071 {
4072         if (skb->ip_summed == CHECKSUM_COMPLETE) {
4073                 if (!csum_fold(csum_add(psum, skb->csum))) {
4074                         skb->csum_valid = 1;
4075                         return 0;
4076                 }
4077         }
4078 
4079         skb->csum = psum;
4080 
4081         if (complete || skb->len <= CHECKSUM_BREAK) {
4082                 __sum16 csum;
4083 
4084                 csum = __skb_checksum_complete(skb);
4085                 skb->csum_valid = !csum;
4086                 return csum;
4087         }
4088 
4089         return 0;
4090 }
4091 
4092 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4093 {
4094         return 0;
4095 }
4096 
4097 /* Perform checksum validate (init). Note that this is a macro since we only
4098  * want to calculate the pseudo header which is an input function if necessary.
4099  * First we try to validate without any computation (checksum unnecessary) and
4100  * then calculate based on checksum complete calling the function to compute
4101  * pseudo header.
4102  *
4103  * Return values:
4104  *   0: checksum is validated or try to in skb_checksum_complete
4105  *   non-zero: value of invalid checksum
4106  */
4107 #define __skb_checksum_validate(skb, proto, complete,                   \
4108                                 zero_okay, check, compute_pseudo)       \
4109 ({                                                                      \
4110         __sum16 __ret = 0;                                              \
4111         skb->csum_valid = 0;                                            \
4112         if (__skb_checksum_validate_needed(skb, zero_okay, check))      \
4113                 __ret = __skb_checksum_validate_complete(skb,           \
4114                                 complete, compute_pseudo(skb, proto));  \
4115         __ret;                                                          \
4116 })
4117 
4118 #define skb_checksum_init(skb, proto, compute_pseudo)                   \
4119         __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4120 
4121 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4122         __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4123 
4124 #define skb_checksum_validate(skb, proto, compute_pseudo)               \
4125         __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4126 
4127 #define skb_checksum_validate_zero_check(skb, proto, check,             \
4128                                          compute_pseudo)                \
4129         __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4130 
4131 #define skb_checksum_simple_validate(skb)                               \
4132         __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4133 
4134 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4135 {
4136         return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4137 }
4138 
4139 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4140 {
4141         skb->csum = ~pseudo;
4142         skb->ip_summed = CHECKSUM_COMPLETE;
4143 }
4144 
4145 #define skb_checksum_try_convert(skb, proto, compute_pseudo)    \
4146 do {                                                                    \
4147         if (__skb_checksum_convert_check(skb))                          \
4148                 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4149 } while (0)
4150 
4151 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4152                                               u16 start, u16 offset)
4153 {
4154         skb->ip_summed = CHECKSUM_PARTIAL;
4155         skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4156         skb->csum_offset = offset - start;
4157 }
4158 
4159 /* Update skbuf and packet to reflect the remote checksum offload operation.
4160  * When called, ptr indicates the starting point for skb->csum when
4161  * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4162  * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4163  */
4164 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4165                                        int start, int offset, bool nopartial)
4166 {
4167         __wsum delta;
4168 
4169         if (!nopartial) {
4170                 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4171                 return;
4172         }
4173 
4174          if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4175                 __skb_checksum_complete(skb);
4176                 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4177         }
4178 
4179         delta = remcsum_adjust(ptr, skb->csum, start, offset);
4180 
4181         /* Adjust skb->csum since we changed the packet */
4182         skb->csum = csum_add(skb->csum, delta);
4183 }
4184 
4185 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4186 {
4187 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4188         return (void *)(skb->_nfct & NFCT_PTRMASK);
4189 #else
4190         return NULL;
4191 #endif
4192 }
4193 
4194 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4195 {
4196 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4197         return skb->_nfct;
4198 #else
4199         return 0UL;
4200 #endif
4201 }
4202 
4203 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4204 {
4205 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4206         skb->_nfct = nfct;
4207 #endif
4208 }
4209 
4210 #ifdef CONFIG_SKB_EXTENSIONS
4211 enum skb_ext_id {
4212 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4213         SKB_EXT_BRIDGE_NF,
4214 #endif
4215 #ifdef CONFIG_XFRM
4216         SKB_EXT_SEC_PATH,
4217 #endif
4218 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4219         TC_SKB_EXT,
4220 #endif
4221 #if IS_ENABLED(CONFIG_MPTCP)
4222         SKB_EXT_MPTCP,
4223 #endif
4224         SKB_EXT_NUM, /* must be last */
4225 };
4226 
4227 /**
4228  *      struct skb_ext - sk_buff extensions
4229  *      @refcnt: 1 on allocation, deallocated on 0
4230  *      @offset: offset to add to @data to obtain extension address
4231  *      @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4232  *      @data: start of extension data, variable sized
4233  *
4234  *      Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4235  *      to use 'u8' types while allowing up to 2kb worth of extension data.
4236  */
4237 struct skb_ext {
4238         refcount_t refcnt;
4239         u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4240         u8 chunks;              /* same */
4241         char data[] __aligned(8);
4242 };
4243 
4244 struct skb_ext *__skb_ext_alloc(gfp_t flags);
4245 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4246                     struct skb_ext *ext);
4247 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4248 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4249 void __skb_ext_put(struct skb_ext *ext);
4250 
4251 static inline void skb_ext_put(struct sk_buff *skb)
4252 {
4253         if (skb->active_extensions)
4254                 __skb_ext_put(skb->extensions);
4255 }
4256 
4257 static inline void __skb_ext_copy(struct sk_buff *dst,
4258                                   const struct sk_buff *src)
4259 {
4260         dst->active_extensions = src->active_extensions;
4261 
4262         if (src->active_extensions) {
4263                 struct skb_ext *ext = src->extensions;
4264 
4265                 refcount_inc(&ext->refcnt);
4266                 dst->extensions = ext;
4267         }
4268 }
4269 
4270 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4271 {
4272         skb_ext_put(dst);
4273         __skb_ext_copy(dst, src);
4274 }
4275 
4276 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4277 {
4278         return !!ext->offset[i];
4279 }
4280 
4281 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4282 {
4283         return skb->active_extensions & (1 << id);
4284 }
4285 
4286 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4287 {
4288         if (skb_ext_exist(skb, id))
4289                 __skb_ext_del(skb, id);
4290 }
4291 
4292 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4293 {
4294         if (skb_ext_exist(skb, id)) {
4295                 struct skb_ext *ext = skb->extensions;
4296 
4297                 return (void *)ext + (ext->offset[id] << 3);
4298         }
4299 
4300         return NULL;
4301 }
4302 
4303 static inline void skb_ext_reset(struct sk_buff *skb)
4304 {
4305         if (unlikely(skb->active_extensions)) {
4306                 __skb_ext_put(skb->extensions);
4307                 skb->active_extensions = 0;
4308         }
4309 }
4310 
4311 static inline bool skb_has_extensions(struct sk_buff *skb)
4312 {
4313         return unlikely(skb->active_extensions);
4314 }
4315 #else
4316 static inline void skb_ext_put(struct sk_buff *skb) {}
4317 static inline void skb_ext_reset(struct sk_buff *skb) {}
4318 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
4319 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
4320 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
4321 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4322 #endif /* CONFIG_SKB_EXTENSIONS */
4323 
4324 static inline void nf_reset_ct(struct sk_buff *skb)
4325 {
4326 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4327         nf_conntrack_put(skb_nfct(skb));
4328         skb->_nfct = 0;
4329 #endif
4330 }
4331 
4332 static inline void nf_reset_trace(struct sk_buff *skb)
4333 {
4334 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4335         skb->nf_trace = 0;
4336 #endif
4337 }
4338 
4339 static inline void ipvs_reset(struct sk_buff *skb)
4340 {
4341 #if IS_ENABLED(CONFIG_IP_VS)
4342         skb->ipvs_property = 0;
4343 #endif
4344 }
4345 
4346 /* Note: This doesn't put any conntrack info in dst. */
4347 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4348                              bool copy)
4349 {
4350 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4351         dst->_nfct = src->_nfct;
4352         nf_conntrack_get(skb_nfct(src));
4353 #endif
4354 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4355         if (copy)
4356                 dst->nf_trace = src->nf_trace;
4357 #endif
4358 }
4359 
4360 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4361 {
4362 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4363         nf_conntrack_put(skb_nfct(dst));
4364 #endif
4365         __nf_copy(dst, src, true);
4366 }
4367 
4368 #ifdef CONFIG_NETWORK_SECMARK
4369 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4370 {
4371         to->secmark = from->secmark;
4372 }
4373 
4374 static inline void skb_init_secmark(struct sk_buff *skb)
4375 {
4376         skb->secmark = 0;
4377 }
4378 #else
4379 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4380 { }
4381 
4382 static inline void skb_init_secmark(struct sk_buff *skb)
4383 { }
4384 #endif
4385 
4386 static inline int secpath_exists(const struct sk_buff *skb)
4387 {
4388 #ifdef CONFIG_XFRM
4389         return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4390 #else
4391         return 0;
4392 #endif
4393 }
4394 
4395 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4396 {
4397         return !skb->destructor &&
4398                 !secpath_exists(skb) &&
4399                 !skb_nfct(skb) &&
4400                 !skb->_skb_refdst &&
4401                 !skb_has_frag_list(skb);
4402 }
4403 
4404 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4405 {
4406         skb->queue_mapping = queue_mapping;
4407 }
4408 
4409 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4410 {
4411         return skb->queue_mapping;
4412 }
4413 
4414 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4415 {
4416         to->queue_mapping = from->queue_mapping;
4417 }
4418 
4419 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4420 {
4421         skb->queue_mapping = rx_queue + 1;
4422 }
4423 
4424 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4425 {
4426         return skb->queue_mapping - 1;
4427 }
4428 
4429 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4430 {
4431         return skb->queue_mapping != 0;
4432 }
4433 
4434 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4435 {
4436         skb->dst_pending_confirm = val;
4437 }
4438 
4439 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4440 {
4441         return skb->dst_pending_confirm != 0;
4442 }
4443 
4444 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4445 {
4446 #ifdef CONFIG_XFRM
4447         return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4448 #else
4449         return NULL;
4450 #endif
4451 }
4452 
4453 /* Keeps track of mac header offset relative to skb->head.
4454  * It is useful for TSO of Tunneling protocol. e.g. GRE.
4455  * For non-tunnel skb it points to skb_mac_header() and for
4456  * tunnel skb it points to outer mac header.
4457  * Keeps track of level of encapsulation of network headers.
4458  */
4459 struct skb_gso_cb {
4460         union {
4461                 int     mac_offset;
4462                 int     data_offset;
4463         };
4464         int     encap_level;
4465         __wsum  csum;
4466         __u16   csum_start;
4467 };
4468 #define SKB_GSO_CB_OFFSET       32
4469 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET))
4470 
4471 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
4472 {
4473         return (skb_mac_header(inner_skb) - inner_skb->head) -
4474                 SKB_GSO_CB(inner_skb)->mac_offset;
4475 }
4476 
4477 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
4478 {
4479         int new_headroom, headroom;
4480         int ret;
4481 
4482         headroom = skb_headroom(skb);
4483         ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
4484         if (ret)
4485                 return ret;
4486 
4487         new_headroom = skb_headroom(skb);
4488         SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
4489         return 0;
4490 }
4491 
4492 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
4493 {
4494         /* Do not update partial checksums if remote checksum is enabled. */
4495         if (skb->remcsum_offload)
4496                 return;
4497 
4498         SKB_GSO_CB(skb)->csum = res;
4499         SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head;
4500 }
4501 
4502 /* Compute the checksum for a gso segment. First compute the checksum value
4503  * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
4504  * then add in skb->csum (checksum from csum_start to end of packet).
4505  * skb->csum and csum_start are then updated to reflect the checksum of the
4506  * resultant packet starting from the transport header-- the resultant checksum
4507  * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
4508  * header.
4509  */
4510 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
4511 {
4512         unsigned char *csum_start = skb_transport_header(skb);
4513         int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start;
4514         __wsum partial = SKB_GSO_CB(skb)->csum;
4515 
4516         SKB_GSO_CB(skb)->csum = res;
4517         SKB_GSO_CB(skb)->csum_start = csum_start - skb->head;
4518 
4519         return csum_fold(csum_partial(csum_start, plen, partial));
4520 }
4521 
4522 static inline bool skb_is_gso(const struct sk_buff *skb)
4523 {
4524         return skb_shinfo(skb)->gso_size;
4525 }
4526 
4527 /* Note: Should be called only if skb_is_gso(skb) is true */
4528 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4529 {
4530         return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4531 }
4532 
4533 /* Note: Should be called only if skb_is_gso(skb) is true */
4534 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4535 {
4536         return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4537 }
4538 
4539 /* Note: Should be called only if skb_is_gso(skb) is true */
4540 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4541 {
4542         return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
4543 }
4544 
4545 static inline void skb_gso_reset(struct sk_buff *skb)
4546 {
4547         skb_shinfo(skb)->gso_size = 0;
4548         skb_shinfo(skb)->gso_segs = 0;
4549         skb_shinfo(skb)->gso_type = 0;
4550 }
4551 
4552 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
4553                                          u16 increment)
4554 {
4555         if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4556                 return;
4557         shinfo->gso_size += increment;
4558 }
4559 
4560 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
4561                                          u16 decrement)
4562 {
4563         if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4564                 return;
4565         shinfo->gso_size -= decrement;
4566 }
4567 
4568 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
4569 
4570 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
4571 {
4572         /* LRO sets gso_size but not gso_type, whereas if GSO is really
4573          * wanted then gso_type will be set. */
4574         const struct skb_shared_info *shinfo = skb_shinfo(skb);
4575 
4576         if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
4577             unlikely(shinfo->gso_type == 0)) {
4578                 __skb_warn_lro_forwarding(skb);
4579                 return true;
4580         }
4581         return false;
4582 }
4583 
4584 static inline void skb_forward_csum(struct sk_buff *skb)
4585 {
4586         /* Unfortunately we don't support this one.  Any brave souls? */
4587         if (skb->ip_summed == CHECKSUM_COMPLETE)
4588                 skb->ip_summed = CHECKSUM_NONE;
4589 }
4590 
4591 /**
4592  * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4593  * @skb: skb to check
4594  *
4595  * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4596  * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4597  * use this helper, to document places where we make this assertion.
4598  */
4599 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
4600 {
4601 #ifdef DEBUG
4602         BUG_ON(skb->ip_summed != CHECKSUM_NONE);
4603 #endif
4604 }
4605 
4606 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
4607 
4608 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
4609 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
4610                                      unsigned int transport_len,
4611                                      __sum16(*skb_chkf)(struct sk_buff *skb));
4612 
4613 /**
4614  * skb_head_is_locked - Determine if the skb->head is locked down
4615  * @skb: skb to check
4616  *
4617  * The head on skbs build around a head frag can be removed if they are
4618  * not cloned.  This function returns true if the skb head is locked down
4619  * due to either being allocated via kmalloc, or by being a clone with
4620  * multiple references to the head.
4621  */
4622 static inline bool skb_head_is_locked(const struct sk_buff *skb)
4623 {
4624         return !skb->head_frag || skb_cloned(skb);
4625 }
4626 
4627 /* Local Checksum Offload.
4628  * Compute outer checksum based on the assumption that the
4629  * inner checksum will be offloaded later.
4630  * See Documentation/networking/checksum-offloads.rst for
4631  * explanation of how this works.
4632  * Fill in outer checksum adjustment (e.g. with sum of outer
4633  * pseudo-header) before calling.
4634  * Also ensure that inner checksum is in linear data area.
4635  */
4636 static inline __wsum lco_csum(struct sk_buff *skb)
4637 {
4638         unsigned char *csum_start = skb_checksum_start(skb);
4639         unsigned char *l4_hdr = skb_transport_header(skb);
4640         __wsum partial;
4641 
4642         /* Start with complement of inner checksum adjustment */
4643         partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
4644                                                     skb->csum_offset));
4645 
4646         /* Add in checksum of our headers (incl. outer checksum
4647          * adjustment filled in by caller) and return result.
4648          */
4649         return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
4650 }
4651 
4652 static inline bool skb_is_redirected(const struct sk_buff *skb)
4653 {
4654 #ifdef CONFIG_NET_REDIRECT
4655         return skb->redirected;
4656 #else
4657         return false;
4658 #endif
4659 }
4660 
4661 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
4662 {
4663 #ifdef CONFIG_NET_REDIRECT
4664         skb->redirected = 1;
4665         skb->from_ingress = from_ingress;
4666         if (skb->from_ingress)
4667                 skb->tstamp = 0;
4668 #endif
4669 }
4670 
4671 static inline void skb_reset_redirect(struct sk_buff *skb)
4672 {
4673 #ifdef CONFIG_NET_REDIRECT
4674         skb->redirected = 0;
4675 #endif
4676 }
4677 
4678 static inline bool skb_csum_is_sctp(struct sk_buff *skb)
4679 {
4680         return skb->csum_not_inet;
4681 }
4682 
4683 static inline void skb_set_kcov_handle(struct sk_buff *skb,
4684                                        const u64 kcov_handle)
4685 {
4686 #ifdef CONFIG_KCOV
4687         skb->kcov_handle = kcov_handle;
4688 #endif
4689 }
4690 
4691 static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
4692 {
4693 #ifdef CONFIG_KCOV
4694         return skb->kcov_handle;
4695 #else
4696         return 0;
4697 #endif
4698 }
4699 
4700 #endif  /* __KERNEL__ */
4701 #endif  /* _LINUX_SKBUFF_H */
4702 

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