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TOMOYO Linux Cross Reference
Linux/include/net/sock.h

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  1 /* SPDX-License-Identifier: GPL-2.0-or-later */
  2 /*
  3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  4  *              operating system.  INET is implemented using the  BSD Socket
  5  *              interface as the means of communication with the user level.
  6  *
  7  *              Definitions for the AF_INET socket handler.
  8  *
  9  * Version:     @(#)sock.h      1.0.4   05/13/93
 10  *
 11  * Authors:     Ross Biro
 12  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 13  *              Corey Minyard <wf-rch!minyard@relay.EU.net>
 14  *              Florian La Roche <flla@stud.uni-sb.de>
 15  *
 16  * Fixes:
 17  *              Alan Cox        :       Volatiles in skbuff pointers. See
 18  *                                      skbuff comments. May be overdone,
 19  *                                      better to prove they can be removed
 20  *                                      than the reverse.
 21  *              Alan Cox        :       Added a zapped field for tcp to note
 22  *                                      a socket is reset and must stay shut up
 23  *              Alan Cox        :       New fields for options
 24  *      Pauline Middelink       :       identd support
 25  *              Alan Cox        :       Eliminate low level recv/recvfrom
 26  *              David S. Miller :       New socket lookup architecture.
 27  *              Steve Whitehouse:       Default routines for sock_ops
 28  *              Arnaldo C. Melo :       removed net_pinfo, tp_pinfo and made
 29  *                                      protinfo be just a void pointer, as the
 30  *                                      protocol specific parts were moved to
 31  *                                      respective headers and ipv4/v6, etc now
 32  *                                      use private slabcaches for its socks
 33  *              Pedro Hortas    :       New flags field for socket options
 34  */
 35 #ifndef _SOCK_H
 36 #define _SOCK_H
 37 
 38 #include <linux/hardirq.h>
 39 #include <linux/kernel.h>
 40 #include <linux/list.h>
 41 #include <linux/list_nulls.h>
 42 #include <linux/timer.h>
 43 #include <linux/cache.h>
 44 #include <linux/bitops.h>
 45 #include <linux/lockdep.h>
 46 #include <linux/netdevice.h>
 47 #include <linux/skbuff.h>       /* struct sk_buff */
 48 #include <linux/mm.h>
 49 #include <linux/security.h>
 50 #include <linux/slab.h>
 51 #include <linux/uaccess.h>
 52 #include <linux/page_counter.h>
 53 #include <linux/memcontrol.h>
 54 #include <linux/static_key.h>
 55 #include <linux/sched.h>
 56 #include <linux/wait.h>
 57 #include <linux/cgroup-defs.h>
 58 #include <linux/rbtree.h>
 59 #include <linux/filter.h>
 60 #include <linux/rculist_nulls.h>
 61 #include <linux/poll.h>
 62 #include <linux/sockptr.h>
 63 
 64 #include <linux/atomic.h>
 65 #include <linux/refcount.h>
 66 #include <net/dst.h>
 67 #include <net/checksum.h>
 68 #include <net/tcp_states.h>
 69 #include <linux/net_tstamp.h>
 70 #include <net/l3mdev.h>
 71 
 72 /*
 73  * This structure really needs to be cleaned up.
 74  * Most of it is for TCP, and not used by any of
 75  * the other protocols.
 76  */
 77 
 78 /* Define this to get the SOCK_DBG debugging facility. */
 79 #define SOCK_DEBUGGING
 80 #ifdef SOCK_DEBUGGING
 81 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
 82                                         printk(KERN_DEBUG msg); } while (0)
 83 #else
 84 /* Validate arguments and do nothing */
 85 static inline __printf(2, 3)
 86 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
 87 {
 88 }
 89 #endif
 90 
 91 /* This is the per-socket lock.  The spinlock provides a synchronization
 92  * between user contexts and software interrupt processing, whereas the
 93  * mini-semaphore synchronizes multiple users amongst themselves.
 94  */
 95 typedef struct {
 96         spinlock_t              slock;
 97         int                     owned;
 98         wait_queue_head_t       wq;
 99         /*
100          * We express the mutex-alike socket_lock semantics
101          * to the lock validator by explicitly managing
102          * the slock as a lock variant (in addition to
103          * the slock itself):
104          */
105 #ifdef CONFIG_DEBUG_LOCK_ALLOC
106         struct lockdep_map dep_map;
107 #endif
108 } socket_lock_t;
109 
110 struct sock;
111 struct proto;
112 struct net;
113 
114 typedef __u32 __bitwise __portpair;
115 typedef __u64 __bitwise __addrpair;
116 
117 /**
118  *      struct sock_common - minimal network layer representation of sockets
119  *      @skc_daddr: Foreign IPv4 addr
120  *      @skc_rcv_saddr: Bound local IPv4 addr
121  *      @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
122  *      @skc_hash: hash value used with various protocol lookup tables
123  *      @skc_u16hashes: two u16 hash values used by UDP lookup tables
124  *      @skc_dport: placeholder for inet_dport/tw_dport
125  *      @skc_num: placeholder for inet_num/tw_num
126  *      @skc_portpair: __u32 union of @skc_dport & @skc_num
127  *      @skc_family: network address family
128  *      @skc_state: Connection state
129  *      @skc_reuse: %SO_REUSEADDR setting
130  *      @skc_reuseport: %SO_REUSEPORT setting
131  *      @skc_ipv6only: socket is IPV6 only
132  *      @skc_net_refcnt: socket is using net ref counting
133  *      @skc_bound_dev_if: bound device index if != 0
134  *      @skc_bind_node: bind hash linkage for various protocol lookup tables
135  *      @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
136  *      @skc_prot: protocol handlers inside a network family
137  *      @skc_net: reference to the network namespace of this socket
138  *      @skc_v6_daddr: IPV6 destination address
139  *      @skc_v6_rcv_saddr: IPV6 source address
140  *      @skc_cookie: socket's cookie value
141  *      @skc_node: main hash linkage for various protocol lookup tables
142  *      @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
143  *      @skc_tx_queue_mapping: tx queue number for this connection
144  *      @skc_rx_queue_mapping: rx queue number for this connection
145  *      @skc_flags: place holder for sk_flags
146  *              %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
147  *              %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
148  *      @skc_listener: connection request listener socket (aka rsk_listener)
149  *              [union with @skc_flags]
150  *      @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
151  *              [union with @skc_flags]
152  *      @skc_incoming_cpu: record/match cpu processing incoming packets
153  *      @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
154  *              [union with @skc_incoming_cpu]
155  *      @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
156  *              [union with @skc_incoming_cpu]
157  *      @skc_refcnt: reference count
158  *
159  *      This is the minimal network layer representation of sockets, the header
160  *      for struct sock and struct inet_timewait_sock.
161  */
162 struct sock_common {
163         /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
164          * address on 64bit arches : cf INET_MATCH()
165          */
166         union {
167                 __addrpair      skc_addrpair;
168                 struct {
169                         __be32  skc_daddr;
170                         __be32  skc_rcv_saddr;
171                 };
172         };
173         union  {
174                 unsigned int    skc_hash;
175                 __u16           skc_u16hashes[2];
176         };
177         /* skc_dport && skc_num must be grouped as well */
178         union {
179                 __portpair      skc_portpair;
180                 struct {
181                         __be16  skc_dport;
182                         __u16   skc_num;
183                 };
184         };
185 
186         unsigned short          skc_family;
187         volatile unsigned char  skc_state;
188         unsigned char           skc_reuse:4;
189         unsigned char           skc_reuseport:1;
190         unsigned char           skc_ipv6only:1;
191         unsigned char           skc_net_refcnt:1;
192         int                     skc_bound_dev_if;
193         union {
194                 struct hlist_node       skc_bind_node;
195                 struct hlist_node       skc_portaddr_node;
196         };
197         struct proto            *skc_prot;
198         possible_net_t          skc_net;
199 
200 #if IS_ENABLED(CONFIG_IPV6)
201         struct in6_addr         skc_v6_daddr;
202         struct in6_addr         skc_v6_rcv_saddr;
203 #endif
204 
205         atomic64_t              skc_cookie;
206 
207         /* following fields are padding to force
208          * offset(struct sock, sk_refcnt) == 128 on 64bit arches
209          * assuming IPV6 is enabled. We use this padding differently
210          * for different kind of 'sockets'
211          */
212         union {
213                 unsigned long   skc_flags;
214                 struct sock     *skc_listener; /* request_sock */
215                 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
216         };
217         /*
218          * fields between dontcopy_begin/dontcopy_end
219          * are not copied in sock_copy()
220          */
221         /* private: */
222         int                     skc_dontcopy_begin[0];
223         /* public: */
224         union {
225                 struct hlist_node       skc_node;
226                 struct hlist_nulls_node skc_nulls_node;
227         };
228         unsigned short          skc_tx_queue_mapping;
229 #ifdef CONFIG_XPS
230         unsigned short          skc_rx_queue_mapping;
231 #endif
232         union {
233                 int             skc_incoming_cpu;
234                 u32             skc_rcv_wnd;
235                 u32             skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
236         };
237 
238         refcount_t              skc_refcnt;
239         /* private: */
240         int                     skc_dontcopy_end[0];
241         union {
242                 u32             skc_rxhash;
243                 u32             skc_window_clamp;
244                 u32             skc_tw_snd_nxt; /* struct tcp_timewait_sock */
245         };
246         /* public: */
247 };
248 
249 struct bpf_sk_storage;
250 
251 /**
252   *     struct sock - network layer representation of sockets
253   *     @__sk_common: shared layout with inet_timewait_sock
254   *     @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
255   *     @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
256   *     @sk_lock:       synchronizer
257   *     @sk_kern_sock: True if sock is using kernel lock classes
258   *     @sk_rcvbuf: size of receive buffer in bytes
259   *     @sk_wq: sock wait queue and async head
260   *     @sk_rx_dst: receive input route used by early demux
261   *     @sk_dst_cache: destination cache
262   *     @sk_dst_pending_confirm: need to confirm neighbour
263   *     @sk_policy: flow policy
264   *     @sk_rx_skb_cache: cache copy of recently accessed RX skb
265   *     @sk_receive_queue: incoming packets
266   *     @sk_wmem_alloc: transmit queue bytes committed
267   *     @sk_tsq_flags: TCP Small Queues flags
268   *     @sk_write_queue: Packet sending queue
269   *     @sk_omem_alloc: "o" is "option" or "other"
270   *     @sk_wmem_queued: persistent queue size
271   *     @sk_forward_alloc: space allocated forward
272   *     @sk_napi_id: id of the last napi context to receive data for sk
273   *     @sk_ll_usec: usecs to busypoll when there is no data
274   *     @sk_allocation: allocation mode
275   *     @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
276   *     @sk_pacing_status: Pacing status (requested, handled by sch_fq)
277   *     @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
278   *     @sk_sndbuf: size of send buffer in bytes
279   *     @__sk_flags_offset: empty field used to determine location of bitfield
280   *     @sk_padding: unused element for alignment
281   *     @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
282   *     @sk_no_check_rx: allow zero checksum in RX packets
283   *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
284   *     @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
285   *     @sk_route_forced_caps: static, forced route capabilities
286   *             (set in tcp_init_sock())
287   *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
288   *     @sk_gso_max_size: Maximum GSO segment size to build
289   *     @sk_gso_max_segs: Maximum number of GSO segments
290   *     @sk_pacing_shift: scaling factor for TCP Small Queues
291   *     @sk_lingertime: %SO_LINGER l_linger setting
292   *     @sk_backlog: always used with the per-socket spinlock held
293   *     @sk_callback_lock: used with the callbacks in the end of this struct
294   *     @sk_error_queue: rarely used
295   *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
296   *                       IPV6_ADDRFORM for instance)
297   *     @sk_err: last error
298   *     @sk_err_soft: errors that don't cause failure but are the cause of a
299   *                   persistent failure not just 'timed out'
300   *     @sk_drops: raw/udp drops counter
301   *     @sk_ack_backlog: current listen backlog
302   *     @sk_max_ack_backlog: listen backlog set in listen()
303   *     @sk_uid: user id of owner
304   *     @sk_priority: %SO_PRIORITY setting
305   *     @sk_type: socket type (%SOCK_STREAM, etc)
306   *     @sk_protocol: which protocol this socket belongs in this network family
307   *     @sk_peer_pid: &struct pid for this socket's peer
308   *     @sk_peer_cred: %SO_PEERCRED setting
309   *     @sk_rcvlowat: %SO_RCVLOWAT setting
310   *     @sk_rcvtimeo: %SO_RCVTIMEO setting
311   *     @sk_sndtimeo: %SO_SNDTIMEO setting
312   *     @sk_txhash: computed flow hash for use on transmit
313   *     @sk_filter: socket filtering instructions
314   *     @sk_timer: sock cleanup timer
315   *     @sk_stamp: time stamp of last packet received
316   *     @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
317   *     @sk_tsflags: SO_TIMESTAMPING socket options
318   *     @sk_tskey: counter to disambiguate concurrent tstamp requests
319   *     @sk_zckey: counter to order MSG_ZEROCOPY notifications
320   *     @sk_socket: Identd and reporting IO signals
321   *     @sk_user_data: RPC layer private data
322   *     @sk_frag: cached page frag
323   *     @sk_peek_off: current peek_offset value
324   *     @sk_send_head: front of stuff to transmit
325   *     @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
326   *     @sk_tx_skb_cache: cache copy of recently accessed TX skb
327   *     @sk_security: used by security modules
328   *     @sk_mark: generic packet mark
329   *     @sk_cgrp_data: cgroup data for this cgroup
330   *     @sk_memcg: this socket's memory cgroup association
331   *     @sk_write_pending: a write to stream socket waits to start
332   *     @sk_state_change: callback to indicate change in the state of the sock
333   *     @sk_data_ready: callback to indicate there is data to be processed
334   *     @sk_write_space: callback to indicate there is bf sending space available
335   *     @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
336   *     @sk_backlog_rcv: callback to process the backlog
337   *     @sk_validate_xmit_skb: ptr to an optional validate function
338   *     @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
339   *     @sk_reuseport_cb: reuseport group container
340   *     @sk_bpf_storage: ptr to cache and control for bpf_sk_storage
341   *     @sk_rcu: used during RCU grace period
342   *     @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
343   *     @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
344   *     @sk_txtime_report_errors: set report errors mode for SO_TXTIME
345   *     @sk_txtime_unused: unused txtime flags
346   */
347 struct sock {
348         /*
349          * Now struct inet_timewait_sock also uses sock_common, so please just
350          * don't add nothing before this first member (__sk_common) --acme
351          */
352         struct sock_common      __sk_common;
353 #define sk_node                 __sk_common.skc_node
354 #define sk_nulls_node           __sk_common.skc_nulls_node
355 #define sk_refcnt               __sk_common.skc_refcnt
356 #define sk_tx_queue_mapping     __sk_common.skc_tx_queue_mapping
357 #ifdef CONFIG_XPS
358 #define sk_rx_queue_mapping     __sk_common.skc_rx_queue_mapping
359 #endif
360 
361 #define sk_dontcopy_begin       __sk_common.skc_dontcopy_begin
362 #define sk_dontcopy_end         __sk_common.skc_dontcopy_end
363 #define sk_hash                 __sk_common.skc_hash
364 #define sk_portpair             __sk_common.skc_portpair
365 #define sk_num                  __sk_common.skc_num
366 #define sk_dport                __sk_common.skc_dport
367 #define sk_addrpair             __sk_common.skc_addrpair
368 #define sk_daddr                __sk_common.skc_daddr
369 #define sk_rcv_saddr            __sk_common.skc_rcv_saddr
370 #define sk_family               __sk_common.skc_family
371 #define sk_state                __sk_common.skc_state
372 #define sk_reuse                __sk_common.skc_reuse
373 #define sk_reuseport            __sk_common.skc_reuseport
374 #define sk_ipv6only             __sk_common.skc_ipv6only
375 #define sk_net_refcnt           __sk_common.skc_net_refcnt
376 #define sk_bound_dev_if         __sk_common.skc_bound_dev_if
377 #define sk_bind_node            __sk_common.skc_bind_node
378 #define sk_prot                 __sk_common.skc_prot
379 #define sk_net                  __sk_common.skc_net
380 #define sk_v6_daddr             __sk_common.skc_v6_daddr
381 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
382 #define sk_cookie               __sk_common.skc_cookie
383 #define sk_incoming_cpu         __sk_common.skc_incoming_cpu
384 #define sk_flags                __sk_common.skc_flags
385 #define sk_rxhash               __sk_common.skc_rxhash
386 
387         socket_lock_t           sk_lock;
388         atomic_t                sk_drops;
389         int                     sk_rcvlowat;
390         struct sk_buff_head     sk_error_queue;
391         struct sk_buff          *sk_rx_skb_cache;
392         struct sk_buff_head     sk_receive_queue;
393         /*
394          * The backlog queue is special, it is always used with
395          * the per-socket spinlock held and requires low latency
396          * access. Therefore we special case it's implementation.
397          * Note : rmem_alloc is in this structure to fill a hole
398          * on 64bit arches, not because its logically part of
399          * backlog.
400          */
401         struct {
402                 atomic_t        rmem_alloc;
403                 int             len;
404                 struct sk_buff  *head;
405                 struct sk_buff  *tail;
406         } sk_backlog;
407 #define sk_rmem_alloc sk_backlog.rmem_alloc
408 
409         int                     sk_forward_alloc;
410 #ifdef CONFIG_NET_RX_BUSY_POLL
411         unsigned int            sk_ll_usec;
412         /* ===== mostly read cache line ===== */
413         unsigned int            sk_napi_id;
414 #endif
415         int                     sk_rcvbuf;
416 
417         struct sk_filter __rcu  *sk_filter;
418         union {
419                 struct socket_wq __rcu  *sk_wq;
420                 /* private: */
421                 struct socket_wq        *sk_wq_raw;
422                 /* public: */
423         };
424 #ifdef CONFIG_XFRM
425         struct xfrm_policy __rcu *sk_policy[2];
426 #endif
427         struct dst_entry        *sk_rx_dst;
428         struct dst_entry __rcu  *sk_dst_cache;
429         atomic_t                sk_omem_alloc;
430         int                     sk_sndbuf;
431 
432         /* ===== cache line for TX ===== */
433         int                     sk_wmem_queued;
434         refcount_t              sk_wmem_alloc;
435         unsigned long           sk_tsq_flags;
436         union {
437                 struct sk_buff  *sk_send_head;
438                 struct rb_root  tcp_rtx_queue;
439         };
440         struct sk_buff          *sk_tx_skb_cache;
441         struct sk_buff_head     sk_write_queue;
442         __s32                   sk_peek_off;
443         int                     sk_write_pending;
444         __u32                   sk_dst_pending_confirm;
445         u32                     sk_pacing_status; /* see enum sk_pacing */
446         long                    sk_sndtimeo;
447         struct timer_list       sk_timer;
448         __u32                   sk_priority;
449         __u32                   sk_mark;
450         unsigned long           sk_pacing_rate; /* bytes per second */
451         unsigned long           sk_max_pacing_rate;
452         struct page_frag        sk_frag;
453         netdev_features_t       sk_route_caps;
454         netdev_features_t       sk_route_nocaps;
455         netdev_features_t       sk_route_forced_caps;
456         int                     sk_gso_type;
457         unsigned int            sk_gso_max_size;
458         gfp_t                   sk_allocation;
459         __u32                   sk_txhash;
460 
461         /*
462          * Because of non atomicity rules, all
463          * changes are protected by socket lock.
464          */
465         u8                      sk_padding : 1,
466                                 sk_kern_sock : 1,
467                                 sk_no_check_tx : 1,
468                                 sk_no_check_rx : 1,
469                                 sk_userlocks : 4;
470         u8                      sk_pacing_shift;
471         u16                     sk_type;
472         u16                     sk_protocol;
473         u16                     sk_gso_max_segs;
474         unsigned long           sk_lingertime;
475         struct proto            *sk_prot_creator;
476         rwlock_t                sk_callback_lock;
477         int                     sk_err,
478                                 sk_err_soft;
479         u32                     sk_ack_backlog;
480         u32                     sk_max_ack_backlog;
481         kuid_t                  sk_uid;
482         struct pid              *sk_peer_pid;
483         const struct cred       *sk_peer_cred;
484         long                    sk_rcvtimeo;
485         ktime_t                 sk_stamp;
486 #if BITS_PER_LONG==32
487         seqlock_t               sk_stamp_seq;
488 #endif
489         u16                     sk_tsflags;
490         u8                      sk_shutdown;
491         u32                     sk_tskey;
492         atomic_t                sk_zckey;
493 
494         u8                      sk_clockid;
495         u8                      sk_txtime_deadline_mode : 1,
496                                 sk_txtime_report_errors : 1,
497                                 sk_txtime_unused : 6;
498 
499         struct socket           *sk_socket;
500         void                    *sk_user_data;
501 #ifdef CONFIG_SECURITY
502         void                    *sk_security;
503 #endif
504         struct sock_cgroup_data sk_cgrp_data;
505         struct mem_cgroup       *sk_memcg;
506         void                    (*sk_state_change)(struct sock *sk);
507         void                    (*sk_data_ready)(struct sock *sk);
508         void                    (*sk_write_space)(struct sock *sk);
509         void                    (*sk_error_report)(struct sock *sk);
510         int                     (*sk_backlog_rcv)(struct sock *sk,
511                                                   struct sk_buff *skb);
512 #ifdef CONFIG_SOCK_VALIDATE_XMIT
513         struct sk_buff*         (*sk_validate_xmit_skb)(struct sock *sk,
514                                                         struct net_device *dev,
515                                                         struct sk_buff *skb);
516 #endif
517         void                    (*sk_destruct)(struct sock *sk);
518         struct sock_reuseport __rcu     *sk_reuseport_cb;
519 #ifdef CONFIG_BPF_SYSCALL
520         struct bpf_sk_storage __rcu     *sk_bpf_storage;
521 #endif
522         struct rcu_head         sk_rcu;
523 };
524 
525 enum sk_pacing {
526         SK_PACING_NONE          = 0,
527         SK_PACING_NEEDED        = 1,
528         SK_PACING_FQ            = 2,
529 };
530 
531 /* Pointer stored in sk_user_data might not be suitable for copying
532  * when cloning the socket. For instance, it can point to a reference
533  * counted object. sk_user_data bottom bit is set if pointer must not
534  * be copied.
535  */
536 #define SK_USER_DATA_NOCOPY     1UL
537 #define SK_USER_DATA_BPF        2UL     /* Managed by BPF */
538 #define SK_USER_DATA_PTRMASK    ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
539 
540 /**
541  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
542  * @sk: socket
543  */
544 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
545 {
546         return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
547 }
548 
549 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
550 
551 #define rcu_dereference_sk_user_data(sk)                                \
552 ({                                                                      \
553         void *__tmp = rcu_dereference(__sk_user_data((sk)));            \
554         (void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);              \
555 })
556 #define rcu_assign_sk_user_data(sk, ptr)                                \
557 ({                                                                      \
558         uintptr_t __tmp = (uintptr_t)(ptr);                             \
559         WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);                    \
560         rcu_assign_pointer(__sk_user_data((sk)), __tmp);                \
561 })
562 #define rcu_assign_sk_user_data_nocopy(sk, ptr)                         \
563 ({                                                                      \
564         uintptr_t __tmp = (uintptr_t)(ptr);                             \
565         WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);                    \
566         rcu_assign_pointer(__sk_user_data((sk)),                        \
567                            __tmp | SK_USER_DATA_NOCOPY);                \
568 })
569 
570 /*
571  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
572  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
573  * on a socket means that the socket will reuse everybody else's port
574  * without looking at the other's sk_reuse value.
575  */
576 
577 #define SK_NO_REUSE     0
578 #define SK_CAN_REUSE    1
579 #define SK_FORCE_REUSE  2
580 
581 int sk_set_peek_off(struct sock *sk, int val);
582 
583 static inline int sk_peek_offset(struct sock *sk, int flags)
584 {
585         if (unlikely(flags & MSG_PEEK)) {
586                 return READ_ONCE(sk->sk_peek_off);
587         }
588 
589         return 0;
590 }
591 
592 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
593 {
594         s32 off = READ_ONCE(sk->sk_peek_off);
595 
596         if (unlikely(off >= 0)) {
597                 off = max_t(s32, off - val, 0);
598                 WRITE_ONCE(sk->sk_peek_off, off);
599         }
600 }
601 
602 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
603 {
604         sk_peek_offset_bwd(sk, -val);
605 }
606 
607 /*
608  * Hashed lists helper routines
609  */
610 static inline struct sock *sk_entry(const struct hlist_node *node)
611 {
612         return hlist_entry(node, struct sock, sk_node);
613 }
614 
615 static inline struct sock *__sk_head(const struct hlist_head *head)
616 {
617         return hlist_entry(head->first, struct sock, sk_node);
618 }
619 
620 static inline struct sock *sk_head(const struct hlist_head *head)
621 {
622         return hlist_empty(head) ? NULL : __sk_head(head);
623 }
624 
625 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
626 {
627         return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
628 }
629 
630 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
631 {
632         return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
633 }
634 
635 static inline struct sock *sk_next(const struct sock *sk)
636 {
637         return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
638 }
639 
640 static inline struct sock *sk_nulls_next(const struct sock *sk)
641 {
642         return (!is_a_nulls(sk->sk_nulls_node.next)) ?
643                 hlist_nulls_entry(sk->sk_nulls_node.next,
644                                   struct sock, sk_nulls_node) :
645                 NULL;
646 }
647 
648 static inline bool sk_unhashed(const struct sock *sk)
649 {
650         return hlist_unhashed(&sk->sk_node);
651 }
652 
653 static inline bool sk_hashed(const struct sock *sk)
654 {
655         return !sk_unhashed(sk);
656 }
657 
658 static inline void sk_node_init(struct hlist_node *node)
659 {
660         node->pprev = NULL;
661 }
662 
663 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
664 {
665         node->pprev = NULL;
666 }
667 
668 static inline void __sk_del_node(struct sock *sk)
669 {
670         __hlist_del(&sk->sk_node);
671 }
672 
673 /* NB: equivalent to hlist_del_init_rcu */
674 static inline bool __sk_del_node_init(struct sock *sk)
675 {
676         if (sk_hashed(sk)) {
677                 __sk_del_node(sk);
678                 sk_node_init(&sk->sk_node);
679                 return true;
680         }
681         return false;
682 }
683 
684 /* Grab socket reference count. This operation is valid only
685    when sk is ALREADY grabbed f.e. it is found in hash table
686    or a list and the lookup is made under lock preventing hash table
687    modifications.
688  */
689 
690 static __always_inline void sock_hold(struct sock *sk)
691 {
692         refcount_inc(&sk->sk_refcnt);
693 }
694 
695 /* Ungrab socket in the context, which assumes that socket refcnt
696    cannot hit zero, f.e. it is true in context of any socketcall.
697  */
698 static __always_inline void __sock_put(struct sock *sk)
699 {
700         refcount_dec(&sk->sk_refcnt);
701 }
702 
703 static inline bool sk_del_node_init(struct sock *sk)
704 {
705         bool rc = __sk_del_node_init(sk);
706 
707         if (rc) {
708                 /* paranoid for a while -acme */
709                 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
710                 __sock_put(sk);
711         }
712         return rc;
713 }
714 #define sk_del_node_init_rcu(sk)        sk_del_node_init(sk)
715 
716 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
717 {
718         if (sk_hashed(sk)) {
719                 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
720                 return true;
721         }
722         return false;
723 }
724 
725 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
726 {
727         bool rc = __sk_nulls_del_node_init_rcu(sk);
728 
729         if (rc) {
730                 /* paranoid for a while -acme */
731                 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
732                 __sock_put(sk);
733         }
734         return rc;
735 }
736 
737 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
738 {
739         hlist_add_head(&sk->sk_node, list);
740 }
741 
742 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
743 {
744         sock_hold(sk);
745         __sk_add_node(sk, list);
746 }
747 
748 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
749 {
750         sock_hold(sk);
751         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
752             sk->sk_family == AF_INET6)
753                 hlist_add_tail_rcu(&sk->sk_node, list);
754         else
755                 hlist_add_head_rcu(&sk->sk_node, list);
756 }
757 
758 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
759 {
760         sock_hold(sk);
761         hlist_add_tail_rcu(&sk->sk_node, list);
762 }
763 
764 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
765 {
766         hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
767 }
768 
769 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
770 {
771         hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
772 }
773 
774 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
775 {
776         sock_hold(sk);
777         __sk_nulls_add_node_rcu(sk, list);
778 }
779 
780 static inline void __sk_del_bind_node(struct sock *sk)
781 {
782         __hlist_del(&sk->sk_bind_node);
783 }
784 
785 static inline void sk_add_bind_node(struct sock *sk,
786                                         struct hlist_head *list)
787 {
788         hlist_add_head(&sk->sk_bind_node, list);
789 }
790 
791 #define sk_for_each(__sk, list) \
792         hlist_for_each_entry(__sk, list, sk_node)
793 #define sk_for_each_rcu(__sk, list) \
794         hlist_for_each_entry_rcu(__sk, list, sk_node)
795 #define sk_nulls_for_each(__sk, node, list) \
796         hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
797 #define sk_nulls_for_each_rcu(__sk, node, list) \
798         hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
799 #define sk_for_each_from(__sk) \
800         hlist_for_each_entry_from(__sk, sk_node)
801 #define sk_nulls_for_each_from(__sk, node) \
802         if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
803                 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
804 #define sk_for_each_safe(__sk, tmp, list) \
805         hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
806 #define sk_for_each_bound(__sk, list) \
807         hlist_for_each_entry(__sk, list, sk_bind_node)
808 
809 /**
810  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
811  * @tpos:       the type * to use as a loop cursor.
812  * @pos:        the &struct hlist_node to use as a loop cursor.
813  * @head:       the head for your list.
814  * @offset:     offset of hlist_node within the struct.
815  *
816  */
817 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)                  \
818         for (pos = rcu_dereference(hlist_first_rcu(head));                     \
819              pos != NULL &&                                                    \
820                 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
821              pos = rcu_dereference(hlist_next_rcu(pos)))
822 
823 static inline struct user_namespace *sk_user_ns(struct sock *sk)
824 {
825         /* Careful only use this in a context where these parameters
826          * can not change and must all be valid, such as recvmsg from
827          * userspace.
828          */
829         return sk->sk_socket->file->f_cred->user_ns;
830 }
831 
832 /* Sock flags */
833 enum sock_flags {
834         SOCK_DEAD,
835         SOCK_DONE,
836         SOCK_URGINLINE,
837         SOCK_KEEPOPEN,
838         SOCK_LINGER,
839         SOCK_DESTROY,
840         SOCK_BROADCAST,
841         SOCK_TIMESTAMP,
842         SOCK_ZAPPED,
843         SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
844         SOCK_DBG, /* %SO_DEBUG setting */
845         SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
846         SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
847         SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
848         SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
849         SOCK_MEMALLOC, /* VM depends on this socket for swapping */
850         SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
851         SOCK_FASYNC, /* fasync() active */
852         SOCK_RXQ_OVFL,
853         SOCK_ZEROCOPY, /* buffers from userspace */
854         SOCK_WIFI_STATUS, /* push wifi status to userspace */
855         SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
856                      * Will use last 4 bytes of packet sent from
857                      * user-space instead.
858                      */
859         SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
860         SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
861         SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
862         SOCK_TXTIME,
863         SOCK_XDP, /* XDP is attached */
864         SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
865 };
866 
867 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
868 
869 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
870 {
871         nsk->sk_flags = osk->sk_flags;
872 }
873 
874 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
875 {
876         __set_bit(flag, &sk->sk_flags);
877 }
878 
879 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
880 {
881         __clear_bit(flag, &sk->sk_flags);
882 }
883 
884 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
885                                      int valbool)
886 {
887         if (valbool)
888                 sock_set_flag(sk, bit);
889         else
890                 sock_reset_flag(sk, bit);
891 }
892 
893 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
894 {
895         return test_bit(flag, &sk->sk_flags);
896 }
897 
898 #ifdef CONFIG_NET
899 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
900 static inline int sk_memalloc_socks(void)
901 {
902         return static_branch_unlikely(&memalloc_socks_key);
903 }
904 
905 void __receive_sock(struct file *file);
906 #else
907 
908 static inline int sk_memalloc_socks(void)
909 {
910         return 0;
911 }
912 
913 static inline void __receive_sock(struct file *file)
914 { }
915 #endif
916 
917 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
918 {
919         return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
920 }
921 
922 static inline void sk_acceptq_removed(struct sock *sk)
923 {
924         WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
925 }
926 
927 static inline void sk_acceptq_added(struct sock *sk)
928 {
929         WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
930 }
931 
932 static inline bool sk_acceptq_is_full(const struct sock *sk)
933 {
934         return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
935 }
936 
937 /*
938  * Compute minimal free write space needed to queue new packets.
939  */
940 static inline int sk_stream_min_wspace(const struct sock *sk)
941 {
942         return READ_ONCE(sk->sk_wmem_queued) >> 1;
943 }
944 
945 static inline int sk_stream_wspace(const struct sock *sk)
946 {
947         return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
948 }
949 
950 static inline void sk_wmem_queued_add(struct sock *sk, int val)
951 {
952         WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
953 }
954 
955 void sk_stream_write_space(struct sock *sk);
956 
957 /* OOB backlog add */
958 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
959 {
960         /* dont let skb dst not refcounted, we are going to leave rcu lock */
961         skb_dst_force(skb);
962 
963         if (!sk->sk_backlog.tail)
964                 WRITE_ONCE(sk->sk_backlog.head, skb);
965         else
966                 sk->sk_backlog.tail->next = skb;
967 
968         WRITE_ONCE(sk->sk_backlog.tail, skb);
969         skb->next = NULL;
970 }
971 
972 /*
973  * Take into account size of receive queue and backlog queue
974  * Do not take into account this skb truesize,
975  * to allow even a single big packet to come.
976  */
977 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
978 {
979         unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
980 
981         return qsize > limit;
982 }
983 
984 /* The per-socket spinlock must be held here. */
985 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
986                                               unsigned int limit)
987 {
988         if (sk_rcvqueues_full(sk, limit))
989                 return -ENOBUFS;
990 
991         /*
992          * If the skb was allocated from pfmemalloc reserves, only
993          * allow SOCK_MEMALLOC sockets to use it as this socket is
994          * helping free memory
995          */
996         if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
997                 return -ENOMEM;
998 
999         __sk_add_backlog(sk, skb);
1000         sk->sk_backlog.len += skb->truesize;
1001         return 0;
1002 }
1003 
1004 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1005 
1006 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1007 {
1008         if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1009                 return __sk_backlog_rcv(sk, skb);
1010 
1011         return sk->sk_backlog_rcv(sk, skb);
1012 }
1013 
1014 static inline void sk_incoming_cpu_update(struct sock *sk)
1015 {
1016         int cpu = raw_smp_processor_id();
1017 
1018         if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1019                 WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1020 }
1021 
1022 static inline void sock_rps_record_flow_hash(__u32 hash)
1023 {
1024 #ifdef CONFIG_RPS
1025         struct rps_sock_flow_table *sock_flow_table;
1026 
1027         rcu_read_lock();
1028         sock_flow_table = rcu_dereference(rps_sock_flow_table);
1029         rps_record_sock_flow(sock_flow_table, hash);
1030         rcu_read_unlock();
1031 #endif
1032 }
1033 
1034 static inline void sock_rps_record_flow(const struct sock *sk)
1035 {
1036 #ifdef CONFIG_RPS
1037         if (static_branch_unlikely(&rfs_needed)) {
1038                 /* Reading sk->sk_rxhash might incur an expensive cache line
1039                  * miss.
1040                  *
1041                  * TCP_ESTABLISHED does cover almost all states where RFS
1042                  * might be useful, and is cheaper [1] than testing :
1043                  *      IPv4: inet_sk(sk)->inet_daddr
1044                  *      IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1045                  * OR   an additional socket flag
1046                  * [1] : sk_state and sk_prot are in the same cache line.
1047                  */
1048                 if (sk->sk_state == TCP_ESTABLISHED)
1049                         sock_rps_record_flow_hash(sk->sk_rxhash);
1050         }
1051 #endif
1052 }
1053 
1054 static inline void sock_rps_save_rxhash(struct sock *sk,
1055                                         const struct sk_buff *skb)
1056 {
1057 #ifdef CONFIG_RPS
1058         if (unlikely(sk->sk_rxhash != skb->hash))
1059                 sk->sk_rxhash = skb->hash;
1060 #endif
1061 }
1062 
1063 static inline void sock_rps_reset_rxhash(struct sock *sk)
1064 {
1065 #ifdef CONFIG_RPS
1066         sk->sk_rxhash = 0;
1067 #endif
1068 }
1069 
1070 #define sk_wait_event(__sk, __timeo, __condition, __wait)               \
1071         ({      int __rc;                                               \
1072                 release_sock(__sk);                                     \
1073                 __rc = __condition;                                     \
1074                 if (!__rc) {                                            \
1075                         *(__timeo) = wait_woken(__wait,                 \
1076                                                 TASK_INTERRUPTIBLE,     \
1077                                                 *(__timeo));            \
1078                 }                                                       \
1079                 sched_annotate_sleep();                                 \
1080                 lock_sock(__sk);                                        \
1081                 __rc = __condition;                                     \
1082                 __rc;                                                   \
1083         })
1084 
1085 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1086 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1087 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1088 int sk_stream_error(struct sock *sk, int flags, int err);
1089 void sk_stream_kill_queues(struct sock *sk);
1090 void sk_set_memalloc(struct sock *sk);
1091 void sk_clear_memalloc(struct sock *sk);
1092 
1093 void __sk_flush_backlog(struct sock *sk);
1094 
1095 static inline bool sk_flush_backlog(struct sock *sk)
1096 {
1097         if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1098                 __sk_flush_backlog(sk);
1099                 return true;
1100         }
1101         return false;
1102 }
1103 
1104 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1105 
1106 struct request_sock_ops;
1107 struct timewait_sock_ops;
1108 struct inet_hashinfo;
1109 struct raw_hashinfo;
1110 struct smc_hashinfo;
1111 struct module;
1112 
1113 /*
1114  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1115  * un-modified. Special care is taken when initializing object to zero.
1116  */
1117 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1118 {
1119         if (offsetof(struct sock, sk_node.next) != 0)
1120                 memset(sk, 0, offsetof(struct sock, sk_node.next));
1121         memset(&sk->sk_node.pprev, 0,
1122                size - offsetof(struct sock, sk_node.pprev));
1123 }
1124 
1125 /* Networking protocol blocks we attach to sockets.
1126  * socket layer -> transport layer interface
1127  */
1128 struct proto {
1129         void                    (*close)(struct sock *sk,
1130                                         long timeout);
1131         int                     (*pre_connect)(struct sock *sk,
1132                                         struct sockaddr *uaddr,
1133                                         int addr_len);
1134         int                     (*connect)(struct sock *sk,
1135                                         struct sockaddr *uaddr,
1136                                         int addr_len);
1137         int                     (*disconnect)(struct sock *sk, int flags);
1138 
1139         struct sock *           (*accept)(struct sock *sk, int flags, int *err,
1140                                           bool kern);
1141 
1142         int                     (*ioctl)(struct sock *sk, int cmd,
1143                                          unsigned long arg);
1144         int                     (*init)(struct sock *sk);
1145         void                    (*destroy)(struct sock *sk);
1146         void                    (*shutdown)(struct sock *sk, int how);
1147         int                     (*setsockopt)(struct sock *sk, int level,
1148                                         int optname, sockptr_t optval,
1149                                         unsigned int optlen);
1150         int                     (*getsockopt)(struct sock *sk, int level,
1151                                         int optname, char __user *optval,
1152                                         int __user *option);
1153         void                    (*keepalive)(struct sock *sk, int valbool);
1154 #ifdef CONFIG_COMPAT
1155         int                     (*compat_ioctl)(struct sock *sk,
1156                                         unsigned int cmd, unsigned long arg);
1157 #endif
1158         int                     (*sendmsg)(struct sock *sk, struct msghdr *msg,
1159                                            size_t len);
1160         int                     (*recvmsg)(struct sock *sk, struct msghdr *msg,
1161                                            size_t len, int noblock, int flags,
1162                                            int *addr_len);
1163         int                     (*sendpage)(struct sock *sk, struct page *page,
1164                                         int offset, size_t size, int flags);
1165         int                     (*bind)(struct sock *sk,
1166                                         struct sockaddr *addr, int addr_len);
1167         int                     (*bind_add)(struct sock *sk,
1168                                         struct sockaddr *addr, int addr_len);
1169 
1170         int                     (*backlog_rcv) (struct sock *sk,
1171                                                 struct sk_buff *skb);
1172 
1173         void            (*release_cb)(struct sock *sk);
1174 
1175         /* Keeping track of sk's, looking them up, and port selection methods. */
1176         int                     (*hash)(struct sock *sk);
1177         void                    (*unhash)(struct sock *sk);
1178         void                    (*rehash)(struct sock *sk);
1179         int                     (*get_port)(struct sock *sk, unsigned short snum);
1180 
1181         /* Keeping track of sockets in use */
1182 #ifdef CONFIG_PROC_FS
1183         unsigned int            inuse_idx;
1184 #endif
1185 
1186         bool                    (*stream_memory_free)(const struct sock *sk, int wake);
1187         bool                    (*stream_memory_read)(const struct sock *sk);
1188         /* Memory pressure */
1189         void                    (*enter_memory_pressure)(struct sock *sk);
1190         void                    (*leave_memory_pressure)(struct sock *sk);
1191         atomic_long_t           *memory_allocated;      /* Current allocated memory. */
1192         struct percpu_counter   *sockets_allocated;     /* Current number of sockets. */
1193         /*
1194          * Pressure flag: try to collapse.
1195          * Technical note: it is used by multiple contexts non atomically.
1196          * All the __sk_mem_schedule() is of this nature: accounting
1197          * is strict, actions are advisory and have some latency.
1198          */
1199         unsigned long           *memory_pressure;
1200         long                    *sysctl_mem;
1201 
1202         int                     *sysctl_wmem;
1203         int                     *sysctl_rmem;
1204         u32                     sysctl_wmem_offset;
1205         u32                     sysctl_rmem_offset;
1206 
1207         int                     max_header;
1208         bool                    no_autobind;
1209 
1210         struct kmem_cache       *slab;
1211         unsigned int            obj_size;
1212         slab_flags_t            slab_flags;
1213         unsigned int            useroffset;     /* Usercopy region offset */
1214         unsigned int            usersize;       /* Usercopy region size */
1215 
1216         struct percpu_counter   *orphan_count;
1217 
1218         struct request_sock_ops *rsk_prot;
1219         struct timewait_sock_ops *twsk_prot;
1220 
1221         union {
1222                 struct inet_hashinfo    *hashinfo;
1223                 struct udp_table        *udp_table;
1224                 struct raw_hashinfo     *raw_hash;
1225                 struct smc_hashinfo     *smc_hash;
1226         } h;
1227 
1228         struct module           *owner;
1229 
1230         char                    name[32];
1231 
1232         struct list_head        node;
1233 #ifdef SOCK_REFCNT_DEBUG
1234         atomic_t                socks;
1235 #endif
1236         int                     (*diag_destroy)(struct sock *sk, int err);
1237 } __randomize_layout;
1238 
1239 int proto_register(struct proto *prot, int alloc_slab);
1240 void proto_unregister(struct proto *prot);
1241 int sock_load_diag_module(int family, int protocol);
1242 
1243 #ifdef SOCK_REFCNT_DEBUG
1244 static inline void sk_refcnt_debug_inc(struct sock *sk)
1245 {
1246         atomic_inc(&sk->sk_prot->socks);
1247 }
1248 
1249 static inline void sk_refcnt_debug_dec(struct sock *sk)
1250 {
1251         atomic_dec(&sk->sk_prot->socks);
1252         printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1253                sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1254 }
1255 
1256 static inline void sk_refcnt_debug_release(const struct sock *sk)
1257 {
1258         if (refcount_read(&sk->sk_refcnt) != 1)
1259                 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1260                        sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1261 }
1262 #else /* SOCK_REFCNT_DEBUG */
1263 #define sk_refcnt_debug_inc(sk) do { } while (0)
1264 #define sk_refcnt_debug_dec(sk) do { } while (0)
1265 #define sk_refcnt_debug_release(sk) do { } while (0)
1266 #endif /* SOCK_REFCNT_DEBUG */
1267 
1268 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1269 {
1270         if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1271                 return false;
1272 
1273         return sk->sk_prot->stream_memory_free ?
1274                 sk->sk_prot->stream_memory_free(sk, wake) : true;
1275 }
1276 
1277 static inline bool sk_stream_memory_free(const struct sock *sk)
1278 {
1279         return __sk_stream_memory_free(sk, 0);
1280 }
1281 
1282 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1283 {
1284         return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1285                __sk_stream_memory_free(sk, wake);
1286 }
1287 
1288 static inline bool sk_stream_is_writeable(const struct sock *sk)
1289 {
1290         return __sk_stream_is_writeable(sk, 0);
1291 }
1292 
1293 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1294                                             struct cgroup *ancestor)
1295 {
1296 #ifdef CONFIG_SOCK_CGROUP_DATA
1297         return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1298                                     ancestor);
1299 #else
1300         return -ENOTSUPP;
1301 #endif
1302 }
1303 
1304 static inline bool sk_has_memory_pressure(const struct sock *sk)
1305 {
1306         return sk->sk_prot->memory_pressure != NULL;
1307 }
1308 
1309 static inline bool sk_under_memory_pressure(const struct sock *sk)
1310 {
1311         if (!sk->sk_prot->memory_pressure)
1312                 return false;
1313 
1314         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1315             mem_cgroup_under_socket_pressure(sk->sk_memcg))
1316                 return true;
1317 
1318         return !!*sk->sk_prot->memory_pressure;
1319 }
1320 
1321 static inline long
1322 sk_memory_allocated(const struct sock *sk)
1323 {
1324         return atomic_long_read(sk->sk_prot->memory_allocated);
1325 }
1326 
1327 static inline long
1328 sk_memory_allocated_add(struct sock *sk, int amt)
1329 {
1330         return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1331 }
1332 
1333 static inline void
1334 sk_memory_allocated_sub(struct sock *sk, int amt)
1335 {
1336         atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1337 }
1338 
1339 static inline void sk_sockets_allocated_dec(struct sock *sk)
1340 {
1341         percpu_counter_dec(sk->sk_prot->sockets_allocated);
1342 }
1343 
1344 static inline void sk_sockets_allocated_inc(struct sock *sk)
1345 {
1346         percpu_counter_inc(sk->sk_prot->sockets_allocated);
1347 }
1348 
1349 static inline u64
1350 sk_sockets_allocated_read_positive(struct sock *sk)
1351 {
1352         return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1353 }
1354 
1355 static inline int
1356 proto_sockets_allocated_sum_positive(struct proto *prot)
1357 {
1358         return percpu_counter_sum_positive(prot->sockets_allocated);
1359 }
1360 
1361 static inline long
1362 proto_memory_allocated(struct proto *prot)
1363 {
1364         return atomic_long_read(prot->memory_allocated);
1365 }
1366 
1367 static inline bool
1368 proto_memory_pressure(struct proto *prot)
1369 {
1370         if (!prot->memory_pressure)
1371                 return false;
1372         return !!*prot->memory_pressure;
1373 }
1374 
1375 
1376 #ifdef CONFIG_PROC_FS
1377 /* Called with local bh disabled */
1378 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1379 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1380 int sock_inuse_get(struct net *net);
1381 #else
1382 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1383                 int inc)
1384 {
1385 }
1386 #endif
1387 
1388 
1389 /* With per-bucket locks this operation is not-atomic, so that
1390  * this version is not worse.
1391  */
1392 static inline int __sk_prot_rehash(struct sock *sk)
1393 {
1394         sk->sk_prot->unhash(sk);
1395         return sk->sk_prot->hash(sk);
1396 }
1397 
1398 /* About 10 seconds */
1399 #define SOCK_DESTROY_TIME (10*HZ)
1400 
1401 /* Sockets 0-1023 can't be bound to unless you are superuser */
1402 #define PROT_SOCK       1024
1403 
1404 #define SHUTDOWN_MASK   3
1405 #define RCV_SHUTDOWN    1
1406 #define SEND_SHUTDOWN   2
1407 
1408 #define SOCK_SNDBUF_LOCK        1
1409 #define SOCK_RCVBUF_LOCK        2
1410 #define SOCK_BINDADDR_LOCK      4
1411 #define SOCK_BINDPORT_LOCK      8
1412 
1413 struct socket_alloc {
1414         struct socket socket;
1415         struct inode vfs_inode;
1416 };
1417 
1418 static inline struct socket *SOCKET_I(struct inode *inode)
1419 {
1420         return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1421 }
1422 
1423 static inline struct inode *SOCK_INODE(struct socket *socket)
1424 {
1425         return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1426 }
1427 
1428 /*
1429  * Functions for memory accounting
1430  */
1431 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1432 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1433 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1434 void __sk_mem_reclaim(struct sock *sk, int amount);
1435 
1436 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1437  * do not necessarily have 16x time more memory than 4KB ones.
1438  */
1439 #define SK_MEM_QUANTUM 4096
1440 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1441 #define SK_MEM_SEND     0
1442 #define SK_MEM_RECV     1
1443 
1444 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1445 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1446 {
1447         long val = sk->sk_prot->sysctl_mem[index];
1448 
1449 #if PAGE_SIZE > SK_MEM_QUANTUM
1450         val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1451 #elif PAGE_SIZE < SK_MEM_QUANTUM
1452         val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1453 #endif
1454         return val;
1455 }
1456 
1457 static inline int sk_mem_pages(int amt)
1458 {
1459         return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1460 }
1461 
1462 static inline bool sk_has_account(struct sock *sk)
1463 {
1464         /* return true if protocol supports memory accounting */
1465         return !!sk->sk_prot->memory_allocated;
1466 }
1467 
1468 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1469 {
1470         if (!sk_has_account(sk))
1471                 return true;
1472         return size <= sk->sk_forward_alloc ||
1473                 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1474 }
1475 
1476 static inline bool
1477 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1478 {
1479         if (!sk_has_account(sk))
1480                 return true;
1481         return size<= sk->sk_forward_alloc ||
1482                 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1483                 skb_pfmemalloc(skb);
1484 }
1485 
1486 static inline void sk_mem_reclaim(struct sock *sk)
1487 {
1488         if (!sk_has_account(sk))
1489                 return;
1490         if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1491                 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1492 }
1493 
1494 static inline void sk_mem_reclaim_partial(struct sock *sk)
1495 {
1496         if (!sk_has_account(sk))
1497                 return;
1498         if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1499                 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1500 }
1501 
1502 static inline void sk_mem_charge(struct sock *sk, int size)
1503 {
1504         if (!sk_has_account(sk))
1505                 return;
1506         sk->sk_forward_alloc -= size;
1507 }
1508 
1509 static inline void sk_mem_uncharge(struct sock *sk, int size)
1510 {
1511         if (!sk_has_account(sk))
1512                 return;
1513         sk->sk_forward_alloc += size;
1514 
1515         /* Avoid a possible overflow.
1516          * TCP send queues can make this happen, if sk_mem_reclaim()
1517          * is not called and more than 2 GBytes are released at once.
1518          *
1519          * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1520          * no need to hold that much forward allocation anyway.
1521          */
1522         if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1523                 __sk_mem_reclaim(sk, 1 << 20);
1524 }
1525 
1526 DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1527 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1528 {
1529         sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1530         sk_wmem_queued_add(sk, -skb->truesize);
1531         sk_mem_uncharge(sk, skb->truesize);
1532         if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1533             !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1534                 skb_ext_reset(skb);
1535                 skb_zcopy_clear(skb, true);
1536                 sk->sk_tx_skb_cache = skb;
1537                 return;
1538         }
1539         __kfree_skb(skb);
1540 }
1541 
1542 static inline void sock_release_ownership(struct sock *sk)
1543 {
1544         if (sk->sk_lock.owned) {
1545                 sk->sk_lock.owned = 0;
1546 
1547                 /* The sk_lock has mutex_unlock() semantics: */
1548                 mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1549         }
1550 }
1551 
1552 /*
1553  * Macro so as to not evaluate some arguments when
1554  * lockdep is not enabled.
1555  *
1556  * Mark both the sk_lock and the sk_lock.slock as a
1557  * per-address-family lock class.
1558  */
1559 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
1560 do {                                                                    \
1561         sk->sk_lock.owned = 0;                                          \
1562         init_waitqueue_head(&sk->sk_lock.wq);                           \
1563         spin_lock_init(&(sk)->sk_lock.slock);                           \
1564         debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
1565                         sizeof((sk)->sk_lock));                         \
1566         lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
1567                                 (skey), (sname));                               \
1568         lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
1569 } while (0)
1570 
1571 #ifdef CONFIG_LOCKDEP
1572 static inline bool lockdep_sock_is_held(const struct sock *sk)
1573 {
1574         return lockdep_is_held(&sk->sk_lock) ||
1575                lockdep_is_held(&sk->sk_lock.slock);
1576 }
1577 #endif
1578 
1579 void lock_sock_nested(struct sock *sk, int subclass);
1580 
1581 static inline void lock_sock(struct sock *sk)
1582 {
1583         lock_sock_nested(sk, 0);
1584 }
1585 
1586 void __release_sock(struct sock *sk);
1587 void release_sock(struct sock *sk);
1588 
1589 /* BH context may only use the following locking interface. */
1590 #define bh_lock_sock(__sk)      spin_lock(&((__sk)->sk_lock.slock))
1591 #define bh_lock_sock_nested(__sk) \
1592                                 spin_lock_nested(&((__sk)->sk_lock.slock), \
1593                                 SINGLE_DEPTH_NESTING)
1594 #define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
1595 
1596 bool lock_sock_fast(struct sock *sk);
1597 /**
1598  * unlock_sock_fast - complement of lock_sock_fast
1599  * @sk: socket
1600  * @slow: slow mode
1601  *
1602  * fast unlock socket for user context.
1603  * If slow mode is on, we call regular release_sock()
1604  */
1605 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1606 {
1607         if (slow)
1608                 release_sock(sk);
1609         else
1610                 spin_unlock_bh(&sk->sk_lock.slock);
1611 }
1612 
1613 /* Used by processes to "lock" a socket state, so that
1614  * interrupts and bottom half handlers won't change it
1615  * from under us. It essentially blocks any incoming
1616  * packets, so that we won't get any new data or any
1617  * packets that change the state of the socket.
1618  *
1619  * While locked, BH processing will add new packets to
1620  * the backlog queue.  This queue is processed by the
1621  * owner of the socket lock right before it is released.
1622  *
1623  * Since ~2.3.5 it is also exclusive sleep lock serializing
1624  * accesses from user process context.
1625  */
1626 
1627 static inline void sock_owned_by_me(const struct sock *sk)
1628 {
1629 #ifdef CONFIG_LOCKDEP
1630         WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1631 #endif
1632 }
1633 
1634 static inline bool sock_owned_by_user(const struct sock *sk)
1635 {
1636         sock_owned_by_me(sk);
1637         return sk->sk_lock.owned;
1638 }
1639 
1640 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1641 {
1642         return sk->sk_lock.owned;
1643 }
1644 
1645 /* no reclassification while locks are held */
1646 static inline bool sock_allow_reclassification(const struct sock *csk)
1647 {
1648         struct sock *sk = (struct sock *)csk;
1649 
1650         return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1651 }
1652 
1653 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1654                       struct proto *prot, int kern);
1655 void sk_free(struct sock *sk);
1656 void sk_destruct(struct sock *sk);
1657 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1658 void sk_free_unlock_clone(struct sock *sk);
1659 
1660 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1661                              gfp_t priority);
1662 void __sock_wfree(struct sk_buff *skb);
1663 void sock_wfree(struct sk_buff *skb);
1664 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1665                              gfp_t priority);
1666 void skb_orphan_partial(struct sk_buff *skb);
1667 void sock_rfree(struct sk_buff *skb);
1668 void sock_efree(struct sk_buff *skb);
1669 #ifdef CONFIG_INET
1670 void sock_edemux(struct sk_buff *skb);
1671 void sock_pfree(struct sk_buff *skb);
1672 #else
1673 #define sock_edemux sock_efree
1674 #endif
1675 
1676 int sock_setsockopt(struct socket *sock, int level, int op,
1677                     sockptr_t optval, unsigned int optlen);
1678 
1679 int sock_getsockopt(struct socket *sock, int level, int op,
1680                     char __user *optval, int __user *optlen);
1681 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1682                    bool timeval, bool time32);
1683 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1684                                     int noblock, int *errcode);
1685 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1686                                      unsigned long data_len, int noblock,
1687                                      int *errcode, int max_page_order);
1688 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1689 void sock_kfree_s(struct sock *sk, void *mem, int size);
1690 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1691 void sk_send_sigurg(struct sock *sk);
1692 
1693 struct sockcm_cookie {
1694         u64 transmit_time;
1695         u32 mark;
1696         u16 tsflags;
1697 };
1698 
1699 static inline void sockcm_init(struct sockcm_cookie *sockc,
1700                                const struct sock *sk)
1701 {
1702         *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1703 }
1704 
1705 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1706                      struct sockcm_cookie *sockc);
1707 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1708                    struct sockcm_cookie *sockc);
1709 
1710 /*
1711  * Functions to fill in entries in struct proto_ops when a protocol
1712  * does not implement a particular function.
1713  */
1714 int sock_no_bind(struct socket *, struct sockaddr *, int);
1715 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1716 int sock_no_socketpair(struct socket *, struct socket *);
1717 int sock_no_accept(struct socket *, struct socket *, int, bool);
1718 int sock_no_getname(struct socket *, struct sockaddr *, int);
1719 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1720 int sock_no_listen(struct socket *, int);
1721 int sock_no_shutdown(struct socket *, int);
1722 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1723 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1724 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1725 int sock_no_mmap(struct file *file, struct socket *sock,
1726                  struct vm_area_struct *vma);
1727 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1728                          size_t size, int flags);
1729 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1730                                 int offset, size_t size, int flags);
1731 
1732 /*
1733  * Functions to fill in entries in struct proto_ops when a protocol
1734  * uses the inet style.
1735  */
1736 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1737                                   char __user *optval, int __user *optlen);
1738 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1739                         int flags);
1740 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1741                            sockptr_t optval, unsigned int optlen);
1742 
1743 void sk_common_release(struct sock *sk);
1744 
1745 /*
1746  *      Default socket callbacks and setup code
1747  */
1748 
1749 /* Initialise core socket variables */
1750 void sock_init_data(struct socket *sock, struct sock *sk);
1751 
1752 /*
1753  * Socket reference counting postulates.
1754  *
1755  * * Each user of socket SHOULD hold a reference count.
1756  * * Each access point to socket (an hash table bucket, reference from a list,
1757  *   running timer, skb in flight MUST hold a reference count.
1758  * * When reference count hits 0, it means it will never increase back.
1759  * * When reference count hits 0, it means that no references from
1760  *   outside exist to this socket and current process on current CPU
1761  *   is last user and may/should destroy this socket.
1762  * * sk_free is called from any context: process, BH, IRQ. When
1763  *   it is called, socket has no references from outside -> sk_free
1764  *   may release descendant resources allocated by the socket, but
1765  *   to the time when it is called, socket is NOT referenced by any
1766  *   hash tables, lists etc.
1767  * * Packets, delivered from outside (from network or from another process)
1768  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1769  *   when they sit in queue. Otherwise, packets will leak to hole, when
1770  *   socket is looked up by one cpu and unhasing is made by another CPU.
1771  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1772  *   (leak to backlog). Packet socket does all the processing inside
1773  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1774  *   use separate SMP lock, so that they are prone too.
1775  */
1776 
1777 /* Ungrab socket and destroy it, if it was the last reference. */
1778 static inline void sock_put(struct sock *sk)
1779 {
1780         if (refcount_dec_and_test(&sk->sk_refcnt))
1781                 sk_free(sk);
1782 }
1783 /* Generic version of sock_put(), dealing with all sockets
1784  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1785  */
1786 void sock_gen_put(struct sock *sk);
1787 
1788 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1789                      unsigned int trim_cap, bool refcounted);
1790 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1791                                  const int nested)
1792 {
1793         return __sk_receive_skb(sk, skb, nested, 1, true);
1794 }
1795 
1796 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1797 {
1798         /* sk_tx_queue_mapping accept only upto a 16-bit value */
1799         if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1800                 return;
1801         sk->sk_tx_queue_mapping = tx_queue;
1802 }
1803 
1804 #define NO_QUEUE_MAPPING        USHRT_MAX
1805 
1806 static inline void sk_tx_queue_clear(struct sock *sk)
1807 {
1808         sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1809 }
1810 
1811 static inline int sk_tx_queue_get(const struct sock *sk)
1812 {
1813         if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1814                 return sk->sk_tx_queue_mapping;
1815 
1816         return -1;
1817 }
1818 
1819 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1820 {
1821 #ifdef CONFIG_XPS
1822         if (skb_rx_queue_recorded(skb)) {
1823                 u16 rx_queue = skb_get_rx_queue(skb);
1824 
1825                 if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1826                         return;
1827 
1828                 sk->sk_rx_queue_mapping = rx_queue;
1829         }
1830 #endif
1831 }
1832 
1833 static inline void sk_rx_queue_clear(struct sock *sk)
1834 {
1835 #ifdef CONFIG_XPS
1836         sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1837 #endif
1838 }
1839 
1840 #ifdef CONFIG_XPS
1841 static inline int sk_rx_queue_get(const struct sock *sk)
1842 {
1843         if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1844                 return sk->sk_rx_queue_mapping;
1845 
1846         return -1;
1847 }
1848 #endif
1849 
1850 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1851 {
1852         sk->sk_socket = sock;
1853 }
1854 
1855 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1856 {
1857         BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1858         return &rcu_dereference_raw(sk->sk_wq)->wait;
1859 }
1860 /* Detach socket from process context.
1861  * Announce socket dead, detach it from wait queue and inode.
1862  * Note that parent inode held reference count on this struct sock,
1863  * we do not release it in this function, because protocol
1864  * probably wants some additional cleanups or even continuing
1865  * to work with this socket (TCP).
1866  */
1867 static inline void sock_orphan(struct sock *sk)
1868 {
1869         write_lock_bh(&sk->sk_callback_lock);
1870         sock_set_flag(sk, SOCK_DEAD);
1871         sk_set_socket(sk, NULL);
1872         sk->sk_wq  = NULL;
1873         write_unlock_bh(&sk->sk_callback_lock);
1874 }
1875 
1876 static inline void sock_graft(struct sock *sk, struct socket *parent)
1877 {
1878         WARN_ON(parent->sk);
1879         write_lock_bh(&sk->sk_callback_lock);
1880         rcu_assign_pointer(sk->sk_wq, &parent->wq);
1881         parent->sk = sk;
1882         sk_set_socket(sk, parent);
1883         sk->sk_uid = SOCK_INODE(parent)->i_uid;
1884         security_sock_graft(sk, parent);
1885         write_unlock_bh(&sk->sk_callback_lock);
1886 }
1887 
1888 kuid_t sock_i_uid(struct sock *sk);
1889 unsigned long sock_i_ino(struct sock *sk);
1890 
1891 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1892 {
1893         return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1894 }
1895 
1896 static inline u32 net_tx_rndhash(void)
1897 {
1898         u32 v = prandom_u32();
1899 
1900         return v ?: 1;
1901 }
1902 
1903 static inline void sk_set_txhash(struct sock *sk)
1904 {
1905         sk->sk_txhash = net_tx_rndhash();
1906 }
1907 
1908 static inline void sk_rethink_txhash(struct sock *sk)
1909 {
1910         if (sk->sk_txhash)
1911                 sk_set_txhash(sk);
1912 }
1913 
1914 static inline struct dst_entry *
1915 __sk_dst_get(struct sock *sk)
1916 {
1917         return rcu_dereference_check(sk->sk_dst_cache,
1918                                      lockdep_sock_is_held(sk));
1919 }
1920 
1921 static inline struct dst_entry *
1922 sk_dst_get(struct sock *sk)
1923 {
1924         struct dst_entry *dst;
1925 
1926         rcu_read_lock();
1927         dst = rcu_dereference(sk->sk_dst_cache);
1928         if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1929                 dst = NULL;
1930         rcu_read_unlock();
1931         return dst;
1932 }
1933 
1934 static inline void dst_negative_advice(struct sock *sk)
1935 {
1936         struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1937 
1938         sk_rethink_txhash(sk);
1939 
1940         if (dst && dst->ops->negative_advice) {
1941                 ndst = dst->ops->negative_advice(dst);
1942 
1943                 if (ndst != dst) {
1944                         rcu_assign_pointer(sk->sk_dst_cache, ndst);
1945                         sk_tx_queue_clear(sk);
1946                         sk->sk_dst_pending_confirm = 0;
1947                 }
1948         }
1949 }
1950 
1951 static inline void
1952 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1953 {
1954         struct dst_entry *old_dst;
1955 
1956         sk_tx_queue_clear(sk);
1957         sk->sk_dst_pending_confirm = 0;
1958         old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1959                                             lockdep_sock_is_held(sk));
1960         rcu_assign_pointer(sk->sk_dst_cache, dst);
1961         dst_release(old_dst);
1962 }
1963 
1964 static inline void
1965 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1966 {
1967         struct dst_entry *old_dst;
1968 
1969         sk_tx_queue_clear(sk);
1970         sk->sk_dst_pending_confirm = 0;
1971         old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1972         dst_release(old_dst);
1973 }
1974 
1975 static inline void
1976 __sk_dst_reset(struct sock *sk)
1977 {
1978         __sk_dst_set(sk, NULL);
1979 }
1980 
1981 static inline void
1982 sk_dst_reset(struct sock *sk)
1983 {
1984         sk_dst_set(sk, NULL);
1985 }
1986 
1987 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1988 
1989 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1990 
1991 static inline void sk_dst_confirm(struct sock *sk)
1992 {
1993         if (!READ_ONCE(sk->sk_dst_pending_confirm))
1994                 WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
1995 }
1996 
1997 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1998 {
1999         if (skb_get_dst_pending_confirm(skb)) {
2000                 struct sock *sk = skb->sk;
2001                 unsigned long now = jiffies;
2002 
2003                 /* avoid dirtying neighbour */
2004                 if (READ_ONCE(n->confirmed) != now)
2005                         WRITE_ONCE(n->confirmed, now);
2006                 if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2007                         WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2008         }
2009 }
2010 
2011 bool sk_mc_loop(struct sock *sk);
2012 
2013 static inline bool sk_can_gso(const struct sock *sk)
2014 {
2015         return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2016 }
2017 
2018 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2019 
2020 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
2021 {
2022         sk->sk_route_nocaps |= flags;
2023         sk->sk_route_caps &= ~flags;
2024 }
2025 
2026 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2027                                            struct iov_iter *from, char *to,
2028                                            int copy, int offset)
2029 {
2030         if (skb->ip_summed == CHECKSUM_NONE) {
2031                 __wsum csum = 0;
2032                 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2033                         return -EFAULT;
2034                 skb->csum = csum_block_add(skb->csum, csum, offset);
2035         } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2036                 if (!copy_from_iter_full_nocache(to, copy, from))
2037                         return -EFAULT;
2038         } else if (!copy_from_iter_full(to, copy, from))
2039                 return -EFAULT;
2040 
2041         return 0;
2042 }
2043 
2044 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2045                                        struct iov_iter *from, int copy)
2046 {
2047         int err, offset = skb->len;
2048 
2049         err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2050                                        copy, offset);
2051         if (err)
2052                 __skb_trim(skb, offset);
2053 
2054         return err;
2055 }
2056 
2057 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2058                                            struct sk_buff *skb,
2059                                            struct page *page,
2060                                            int off, int copy)
2061 {
2062         int err;
2063 
2064         err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2065                                        copy, skb->len);
2066         if (err)
2067                 return err;
2068 
2069         skb->len             += copy;
2070         skb->data_len        += copy;
2071         skb->truesize        += copy;
2072         sk_wmem_queued_add(sk, copy);
2073         sk_mem_charge(sk, copy);
2074         return 0;
2075 }
2076 
2077 /**
2078  * sk_wmem_alloc_get - returns write allocations
2079  * @sk: socket
2080  *
2081  * Return: sk_wmem_alloc minus initial offset of one
2082  */
2083 static inline int sk_wmem_alloc_get(const struct sock *sk)
2084 {
2085         return refcount_read(&sk->sk_wmem_alloc) - 1;
2086 }
2087 
2088 /**
2089  * sk_rmem_alloc_get - returns read allocations
2090  * @sk: socket
2091  *
2092  * Return: sk_rmem_alloc
2093  */
2094 static inline int sk_rmem_alloc_get(const struct sock *sk)
2095 {
2096         return atomic_read(&sk->sk_rmem_alloc);
2097 }
2098 
2099 /**
2100  * sk_has_allocations - check if allocations are outstanding
2101  * @sk: socket
2102  *
2103  * Return: true if socket has write or read allocations
2104  */
2105 static inline bool sk_has_allocations(const struct sock *sk)
2106 {
2107         return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2108 }
2109 
2110 /**
2111  * skwq_has_sleeper - check if there are any waiting processes
2112  * @wq: struct socket_wq
2113  *
2114  * Return: true if socket_wq has waiting processes
2115  *
2116  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2117  * barrier call. They were added due to the race found within the tcp code.
2118  *
2119  * Consider following tcp code paths::
2120  *
2121  *   CPU1                CPU2
2122  *   sys_select          receive packet
2123  *   ...                 ...
2124  *   __add_wait_queue    update tp->rcv_nxt
2125  *   ...                 ...
2126  *   tp->rcv_nxt check   sock_def_readable
2127  *   ...                 {
2128  *   schedule               rcu_read_lock();
2129  *                          wq = rcu_dereference(sk->sk_wq);
2130  *                          if (wq && waitqueue_active(&wq->wait))
2131  *                              wake_up_interruptible(&wq->wait)
2132  *                          ...
2133  *                       }
2134  *
2135  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2136  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2137  * could then endup calling schedule and sleep forever if there are no more
2138  * data on the socket.
2139  *
2140  */
2141 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2142 {
2143         return wq && wq_has_sleeper(&wq->wait);
2144 }
2145 
2146 /**
2147  * sock_poll_wait - place memory barrier behind the poll_wait call.
2148  * @filp:           file
2149  * @sock:           socket to wait on
2150  * @p:              poll_table
2151  *
2152  * See the comments in the wq_has_sleeper function.
2153  */
2154 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2155                                   poll_table *p)
2156 {
2157         if (!poll_does_not_wait(p)) {
2158                 poll_wait(filp, &sock->wq.wait, p);
2159                 /* We need to be sure we are in sync with the
2160                  * socket flags modification.
2161                  *
2162                  * This memory barrier is paired in the wq_has_sleeper.
2163                  */
2164                 smp_mb();
2165         }
2166 }
2167 
2168 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2169 {
2170         if (sk->sk_txhash) {
2171                 skb->l4_hash = 1;
2172                 skb->hash = sk->sk_txhash;
2173         }
2174 }
2175 
2176 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2177 
2178 /*
2179  *      Queue a received datagram if it will fit. Stream and sequenced
2180  *      protocols can't normally use this as they need to fit buffers in
2181  *      and play with them.
2182  *
2183  *      Inlined as it's very short and called for pretty much every
2184  *      packet ever received.
2185  */
2186 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2187 {
2188         skb_orphan(skb);
2189         skb->sk = sk;
2190         skb->destructor = sock_rfree;
2191         atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2192         sk_mem_charge(sk, skb->truesize);
2193 }
2194 
2195 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2196                     unsigned long expires);
2197 
2198 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2199 
2200 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2201                         struct sk_buff *skb, unsigned int flags,
2202                         void (*destructor)(struct sock *sk,
2203                                            struct sk_buff *skb));
2204 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2205 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2206 
2207 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2208 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2209 
2210 /*
2211  *      Recover an error report and clear atomically
2212  */
2213 
2214 static inline int sock_error(struct sock *sk)
2215 {
2216         int err;
2217         if (likely(!sk->sk_err))
2218                 return 0;
2219         err = xchg(&sk->sk_err, 0);
2220         return -err;
2221 }
2222 
2223 static inline unsigned long sock_wspace(struct sock *sk)
2224 {
2225         int amt = 0;
2226 
2227         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2228                 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2229                 if (amt < 0)
2230                         amt = 0;
2231         }
2232         return amt;
2233 }
2234 
2235 /* Note:
2236  *  We use sk->sk_wq_raw, from contexts knowing this
2237  *  pointer is not NULL and cannot disappear/change.
2238  */
2239 static inline void sk_set_bit(int nr, struct sock *sk)
2240 {
2241         if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2242             !sock_flag(sk, SOCK_FASYNC))
2243                 return;
2244 
2245         set_bit(nr, &sk->sk_wq_raw->flags);
2246 }
2247 
2248 static inline void sk_clear_bit(int nr, struct sock *sk)
2249 {
2250         if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2251             !sock_flag(sk, SOCK_FASYNC))
2252                 return;
2253 
2254         clear_bit(nr, &sk->sk_wq_raw->flags);
2255 }
2256 
2257 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2258 {
2259         if (sock_flag(sk, SOCK_FASYNC)) {
2260                 rcu_read_lock();
2261                 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2262                 rcu_read_unlock();
2263         }
2264 }
2265 
2266 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2267  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2268  * Note: for send buffers, TCP works better if we can build two skbs at
2269  * minimum.
2270  */
2271 #define TCP_SKB_MIN_TRUESIZE    (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2272 
2273 #define SOCK_MIN_SNDBUF         (TCP_SKB_MIN_TRUESIZE * 2)
2274 #define SOCK_MIN_RCVBUF          TCP_SKB_MIN_TRUESIZE
2275 
2276 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2277 {
2278         u32 val;
2279 
2280         if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2281                 return;
2282 
2283         val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2284 
2285         WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2286 }
2287 
2288 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2289                                     bool force_schedule);
2290 
2291 /**
2292  * sk_page_frag - return an appropriate page_frag
2293  * @sk: socket
2294  *
2295  * Use the per task page_frag instead of the per socket one for
2296  * optimization when we know that we're in the normal context and owns
2297  * everything that's associated with %current.
2298  *
2299  * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2300  * inside other socket operations and end up recursing into sk_page_frag()
2301  * while it's already in use.
2302  *
2303  * Return: a per task page_frag if context allows that,
2304  * otherwise a per socket one.
2305  */
2306 static inline struct page_frag *sk_page_frag(struct sock *sk)
2307 {
2308         if (gfpflags_normal_context(sk->sk_allocation))
2309                 return &current->task_frag;
2310 
2311         return &sk->sk_frag;
2312 }
2313 
2314 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2315 
2316 /*
2317  *      Default write policy as shown to user space via poll/select/SIGIO
2318  */
2319 static inline bool sock_writeable(const struct sock *sk)
2320 {
2321         return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2322 }
2323 
2324 static inline gfp_t gfp_any(void)
2325 {
2326         return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2327 }
2328 
2329 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2330 {
2331         return noblock ? 0 : sk->sk_rcvtimeo;
2332 }
2333 
2334 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2335 {
2336         return noblock ? 0 : sk->sk_sndtimeo;
2337 }
2338 
2339 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2340 {
2341         int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2342 
2343         return v ?: 1;
2344 }
2345 
2346 /* Alas, with timeout socket operations are not restartable.
2347  * Compare this to poll().
2348  */
2349 static inline int sock_intr_errno(long timeo)
2350 {
2351         return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2352 }
2353 
2354 struct sock_skb_cb {
2355         u32 dropcount;
2356 };
2357 
2358 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2359  * using skb->cb[] would keep using it directly and utilize its
2360  * alignement guarantee.
2361  */
2362 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2363                             sizeof(struct sock_skb_cb)))
2364 
2365 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2366                             SOCK_SKB_CB_OFFSET))
2367 
2368 #define sock_skb_cb_check_size(size) \
2369         BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2370 
2371 static inline void
2372 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2373 {
2374         SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2375                                                 atomic_read(&sk->sk_drops) : 0;
2376 }
2377 
2378 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2379 {
2380         int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2381 
2382         atomic_add(segs, &sk->sk_drops);
2383 }
2384 
2385 static inline ktime_t sock_read_timestamp(struct sock *sk)
2386 {
2387 #if BITS_PER_LONG==32
2388         unsigned int seq;
2389         ktime_t kt;
2390 
2391         do {
2392                 seq = read_seqbegin(&sk->sk_stamp_seq);
2393                 kt = sk->sk_stamp;
2394         } while (read_seqretry(&sk->sk_stamp_seq, seq));
2395 
2396         return kt;
2397 #else
2398         return READ_ONCE(sk->sk_stamp);
2399 #endif
2400 }
2401 
2402 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2403 {
2404 #if BITS_PER_LONG==32
2405         write_seqlock(&sk->sk_stamp_seq);
2406         sk->sk_stamp = kt;
2407         write_sequnlock(&sk->sk_stamp_seq);
2408 #else
2409         WRITE_ONCE(sk->sk_stamp, kt);
2410 #endif
2411 }
2412 
2413 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2414                            struct sk_buff *skb);
2415 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2416                              struct sk_buff *skb);
2417 
2418 static inline void
2419 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2420 {
2421         ktime_t kt = skb->tstamp;
2422         struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2423 
2424         /*
2425          * generate control messages if
2426          * - receive time stamping in software requested
2427          * - software time stamp available and wanted
2428          * - hardware time stamps available and wanted
2429          */
2430         if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2431             (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2432             (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2433             (hwtstamps->hwtstamp &&
2434              (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2435                 __sock_recv_timestamp(msg, sk, skb);
2436         else
2437                 sock_write_timestamp(sk, kt);
2438 
2439         if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2440                 __sock_recv_wifi_status(msg, sk, skb);
2441 }
2442 
2443 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2444                               struct sk_buff *skb);
2445 
2446 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2447 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2448                                           struct sk_buff *skb)
2449 {
2450 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)                       | \
2451                            (1UL << SOCK_RCVTSTAMP))
2452 #define TSFLAGS_ANY       (SOF_TIMESTAMPING_SOFTWARE                    | \
2453                            SOF_TIMESTAMPING_RAW_HARDWARE)
2454 
2455         if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2456                 __sock_recv_ts_and_drops(msg, sk, skb);
2457         else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2458                 sock_write_timestamp(sk, skb->tstamp);
2459         else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2460                 sock_write_timestamp(sk, 0);
2461 }
2462 
2463 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2464 
2465 /**
2466  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2467  * @sk:         socket sending this packet
2468  * @tsflags:    timestamping flags to use
2469  * @tx_flags:   completed with instructions for time stamping
2470  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2471  *
2472  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2473  */
2474 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2475                                       __u8 *tx_flags, __u32 *tskey)
2476 {
2477         if (unlikely(tsflags)) {
2478                 __sock_tx_timestamp(tsflags, tx_flags);
2479                 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2480                     tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2481                         *tskey = sk->sk_tskey++;
2482         }
2483         if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2484                 *tx_flags |= SKBTX_WIFI_STATUS;
2485 }
2486 
2487 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2488                                      __u8 *tx_flags)
2489 {
2490         _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2491 }
2492 
2493 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2494 {
2495         _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2496                            &skb_shinfo(skb)->tskey);
2497 }
2498 
2499 DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2500 /**
2501  * sk_eat_skb - Release a skb if it is no longer needed
2502  * @sk: socket to eat this skb from
2503  * @skb: socket buffer to eat
2504  *
2505  * This routine must be called with interrupts disabled or with the socket
2506  * locked so that the sk_buff queue operation is ok.
2507 */
2508 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2509 {
2510         __skb_unlink(skb, &sk->sk_receive_queue);
2511         if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2512             !sk->sk_rx_skb_cache) {
2513                 sk->sk_rx_skb_cache = skb;
2514                 skb_orphan(skb);
2515                 return;
2516         }
2517         __kfree_skb(skb);
2518 }
2519 
2520 static inline
2521 struct net *sock_net(const struct sock *sk)
2522 {
2523         return read_pnet(&sk->sk_net);
2524 }
2525 
2526 static inline
2527 void sock_net_set(struct sock *sk, struct net *net)
2528 {
2529         write_pnet(&sk->sk_net, net);
2530 }
2531 
2532 static inline bool
2533 skb_sk_is_prefetched(struct sk_buff *skb)
2534 {
2535 #ifdef CONFIG_INET
2536         return skb->destructor == sock_pfree;
2537 #else
2538         return false;
2539 #endif /* CONFIG_INET */
2540 }
2541 
2542 /* This helper checks if a socket is a full socket,
2543  * ie _not_ a timewait or request socket.
2544  */
2545 static inline bool sk_fullsock(const struct sock *sk)
2546 {
2547         return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2548 }
2549 
2550 static inline bool
2551 sk_is_refcounted(struct sock *sk)
2552 {
2553         /* Only full sockets have sk->sk_flags. */
2554         return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2555 }
2556 
2557 /**
2558  * skb_steal_sock - steal a socket from an sk_buff
2559  * @skb: sk_buff to steal the socket from
2560  * @refcounted: is set to true if the socket is reference-counted
2561  */
2562 static inline struct sock *
2563 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2564 {
2565         if (skb->sk) {
2566                 struct sock *sk = skb->sk;
2567 
2568                 *refcounted = true;
2569                 if (skb_sk_is_prefetched(skb))
2570                         *refcounted = sk_is_refcounted(sk);
2571                 skb->destructor = NULL;
2572                 skb->sk = NULL;
2573                 return sk;
2574         }
2575         *refcounted = false;
2576         return NULL;
2577 }
2578 
2579 /* Checks if this SKB belongs to an HW offloaded socket
2580  * and whether any SW fallbacks are required based on dev.
2581  * Check decrypted mark in case skb_orphan() cleared socket.
2582  */
2583 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2584                                                    struct net_device *dev)
2585 {
2586 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2587         struct sock *sk = skb->sk;
2588 
2589         if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2590                 skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2591 #ifdef CONFIG_TLS_DEVICE
2592         } else if (unlikely(skb->decrypted)) {
2593                 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2594                 kfree_skb(skb);
2595                 skb = NULL;
2596 #endif
2597         }
2598 #endif
2599 
2600         return skb;
2601 }
2602 
2603 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2604  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2605  */
2606 static inline bool sk_listener(const struct sock *sk)
2607 {
2608         return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2609 }
2610 
2611 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2612 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2613                        int type);
2614 
2615 bool sk_ns_capable(const struct sock *sk,
2616                    struct user_namespace *user_ns, int cap);
2617 bool sk_capable(const struct sock *sk, int cap);
2618 bool sk_net_capable(const struct sock *sk, int cap);
2619 
2620 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2621 
2622 /* Take into consideration the size of the struct sk_buff overhead in the
2623  * determination of these values, since that is non-constant across
2624  * platforms.  This makes socket queueing behavior and performance
2625  * not depend upon such differences.
2626  */
2627 #define _SK_MEM_PACKETS         256
2628 #define _SK_MEM_OVERHEAD        SKB_TRUESIZE(256)
2629 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2630 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2631 
2632 extern __u32 sysctl_wmem_max;
2633 extern __u32 sysctl_rmem_max;
2634 
2635 extern int sysctl_tstamp_allow_data;
2636 extern int sysctl_optmem_max;
2637 
2638 extern __u32 sysctl_wmem_default;
2639 extern __u32 sysctl_rmem_default;
2640 
2641 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2642 
2643 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2644 {
2645         /* Does this proto have per netns sysctl_wmem ? */
2646         if (proto->sysctl_wmem_offset)
2647                 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2648 
2649         return *proto->sysctl_wmem;
2650 }
2651 
2652 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2653 {
2654         /* Does this proto have per netns sysctl_rmem ? */
2655         if (proto->sysctl_rmem_offset)
2656                 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2657 
2658         return *proto->sysctl_rmem;
2659 }
2660 
2661 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2662  * Some wifi drivers need to tweak it to get more chunks.
2663  * They can use this helper from their ndo_start_xmit()
2664  */
2665 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2666 {
2667         if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2668                 return;
2669         WRITE_ONCE(sk->sk_pacing_shift, val);
2670 }
2671 
2672 /* if a socket is bound to a device, check that the given device
2673  * index is either the same or that the socket is bound to an L3
2674  * master device and the given device index is also enslaved to
2675  * that L3 master
2676  */
2677 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2678 {
2679         int mdif;
2680 
2681         if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2682                 return true;
2683 
2684         mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2685         if (mdif && mdif == sk->sk_bound_dev_if)
2686                 return true;
2687 
2688         return false;
2689 }
2690 
2691 void sock_def_readable(struct sock *sk);
2692 
2693 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2694 void sock_enable_timestamps(struct sock *sk);
2695 void sock_no_linger(struct sock *sk);
2696 void sock_set_keepalive(struct sock *sk);
2697 void sock_set_priority(struct sock *sk, u32 priority);
2698 void sock_set_rcvbuf(struct sock *sk, int val);
2699 void sock_set_mark(struct sock *sk, u32 val);
2700 void sock_set_reuseaddr(struct sock *sk);
2701 void sock_set_reuseport(struct sock *sk);
2702 void sock_set_sndtimeo(struct sock *sk, s64 secs);
2703 
2704 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2705 
2706 #endif  /* _SOCK_H */
2707 

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