~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.12 ] ~ [ linux-5.11.16 ] ~ [ linux-5.10.32 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.114 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.188 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.231 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.267 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.267 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  3  *              operating system.  INET is implemented using the  BSD Socket
  4  *              interface as the means of communication with the user level.
  5  *
  6  *              Definitions for the AF_INET socket handler.
  7  *
  8  * Version:     @(#)sock.h      1.0.4   05/13/93
  9  *
 10  * Authors:     Ross Biro
 11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 12  *              Corey Minyard <wf-rch!minyard@relay.EU.net>
 13  *              Florian La Roche <flla@stud.uni-sb.de>
 14  *
 15  * Fixes:
 16  *              Alan Cox        :       Volatiles in skbuff pointers. See
 17  *                                      skbuff comments. May be overdone,
 18  *                                      better to prove they can be removed
 19  *                                      than the reverse.
 20  *              Alan Cox        :       Added a zapped field for tcp to note
 21  *                                      a socket is reset and must stay shut up
 22  *              Alan Cox        :       New fields for options
 23  *      Pauline Middelink       :       identd support
 24  *              Alan Cox        :       Eliminate low level recv/recvfrom
 25  *              David S. Miller :       New socket lookup architecture.
 26  *              Steve Whitehouse:       Default routines for sock_ops
 27  *              Arnaldo C. Melo :       removed net_pinfo, tp_pinfo and made
 28  *                                      protinfo be just a void pointer, as the
 29  *                                      protocol specific parts were moved to
 30  *                                      respective headers and ipv4/v6, etc now
 31  *                                      use private slabcaches for its socks
 32  *              Pedro Hortas    :       New flags field for socket options
 33  *
 34  *
 35  *              This program is free software; you can redistribute it and/or
 36  *              modify it under the terms of the GNU General Public License
 37  *              as published by the Free Software Foundation; either version
 38  *              2 of the License, or (at your option) any later version.
 39  */
 40 #ifndef _SOCK_H
 41 #define _SOCK_H
 42 
 43 #include <linux/hardirq.h>
 44 #include <linux/kernel.h>
 45 #include <linux/list.h>
 46 #include <linux/list_nulls.h>
 47 #include <linux/timer.h>
 48 #include <linux/cache.h>
 49 #include <linux/bitops.h>
 50 #include <linux/lockdep.h>
 51 #include <linux/netdevice.h>
 52 #include <linux/skbuff.h>       /* struct sk_buff */
 53 #include <linux/mm.h>
 54 #include <linux/security.h>
 55 #include <linux/slab.h>
 56 #include <linux/uaccess.h>
 57 #include <linux/page_counter.h>
 58 #include <linux/memcontrol.h>
 59 #include <linux/static_key.h>
 60 #include <linux/sched.h>
 61 #include <linux/wait.h>
 62 #include <linux/cgroup-defs.h>
 63 
 64 #include <linux/filter.h>
 65 #include <linux/rculist_nulls.h>
 66 #include <linux/poll.h>
 67 
 68 #include <linux/atomic.h>
 69 #include <net/dst.h>
 70 #include <net/checksum.h>
 71 #include <net/tcp_states.h>
 72 #include <linux/net_tstamp.h>
 73 
 74 /*
 75  * This structure really needs to be cleaned up.
 76  * Most of it is for TCP, and not used by any of
 77  * the other protocols.
 78  */
 79 
 80 /* Define this to get the SOCK_DBG debugging facility. */
 81 #define SOCK_DEBUGGING
 82 #ifdef SOCK_DEBUGGING
 83 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
 84                                         printk(KERN_DEBUG msg); } while (0)
 85 #else
 86 /* Validate arguments and do nothing */
 87 static inline __printf(2, 3)
 88 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
 89 {
 90 }
 91 #endif
 92 
 93 /* This is the per-socket lock.  The spinlock provides a synchronization
 94  * between user contexts and software interrupt processing, whereas the
 95  * mini-semaphore synchronizes multiple users amongst themselves.
 96  */
 97 typedef struct {
 98         spinlock_t              slock;
 99         int                     owned;
100         wait_queue_head_t       wq;
101         /*
102          * We express the mutex-alike socket_lock semantics
103          * to the lock validator by explicitly managing
104          * the slock as a lock variant (in addition to
105          * the slock itself):
106          */
107 #ifdef CONFIG_DEBUG_LOCK_ALLOC
108         struct lockdep_map dep_map;
109 #endif
110 } socket_lock_t;
111 
112 struct sock;
113 struct proto;
114 struct net;
115 
116 typedef __u32 __bitwise __portpair;
117 typedef __u64 __bitwise __addrpair;
118 
119 /**
120  *      struct sock_common - minimal network layer representation of sockets
121  *      @skc_daddr: Foreign IPv4 addr
122  *      @skc_rcv_saddr: Bound local IPv4 addr
123  *      @skc_hash: hash value used with various protocol lookup tables
124  *      @skc_u16hashes: two u16 hash values used by UDP lookup tables
125  *      @skc_dport: placeholder for inet_dport/tw_dport
126  *      @skc_num: placeholder for inet_num/tw_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_bound_dev_if: bound device index if != 0
132  *      @skc_bind_node: bind hash linkage for various protocol lookup tables
133  *      @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
134  *      @skc_prot: protocol handlers inside a network family
135  *      @skc_net: reference to the network namespace of this socket
136  *      @skc_node: main hash linkage for various protocol lookup tables
137  *      @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
138  *      @skc_tx_queue_mapping: tx queue number for this connection
139  *      @skc_flags: place holder for sk_flags
140  *              %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
141  *              %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
142  *      @skc_incoming_cpu: record/match cpu processing incoming packets
143  *      @skc_refcnt: reference count
144  *
145  *      This is the minimal network layer representation of sockets, the header
146  *      for struct sock and struct inet_timewait_sock.
147  */
148 struct sock_common {
149         /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
150          * address on 64bit arches : cf INET_MATCH()
151          */
152         union {
153                 __addrpair      skc_addrpair;
154                 struct {
155                         __be32  skc_daddr;
156                         __be32  skc_rcv_saddr;
157                 };
158         };
159         union  {
160                 unsigned int    skc_hash;
161                 __u16           skc_u16hashes[2];
162         };
163         /* skc_dport && skc_num must be grouped as well */
164         union {
165                 __portpair      skc_portpair;
166                 struct {
167                         __be16  skc_dport;
168                         __u16   skc_num;
169                 };
170         };
171 
172         unsigned short          skc_family;
173         volatile unsigned char  skc_state;
174         unsigned char           skc_reuse:4;
175         unsigned char           skc_reuseport:1;
176         unsigned char           skc_ipv6only:1;
177         unsigned char           skc_net_refcnt:1;
178         int                     skc_bound_dev_if;
179         union {
180                 struct hlist_node       skc_bind_node;
181                 struct hlist_nulls_node skc_portaddr_node;
182         };
183         struct proto            *skc_prot;
184         possible_net_t          skc_net;
185 
186 #if IS_ENABLED(CONFIG_IPV6)
187         struct in6_addr         skc_v6_daddr;
188         struct in6_addr         skc_v6_rcv_saddr;
189 #endif
190 
191         atomic64_t              skc_cookie;
192 
193         /* following fields are padding to force
194          * offset(struct sock, sk_refcnt) == 128 on 64bit arches
195          * assuming IPV6 is enabled. We use this padding differently
196          * for different kind of 'sockets'
197          */
198         union {
199                 unsigned long   skc_flags;
200                 struct sock     *skc_listener; /* request_sock */
201                 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
202         };
203         /*
204          * fields between dontcopy_begin/dontcopy_end
205          * are not copied in sock_copy()
206          */
207         /* private: */
208         int                     skc_dontcopy_begin[0];
209         /* public: */
210         union {
211                 struct hlist_node       skc_node;
212                 struct hlist_nulls_node skc_nulls_node;
213         };
214         int                     skc_tx_queue_mapping;
215         union {
216                 int             skc_incoming_cpu;
217                 u32             skc_rcv_wnd;
218                 u32             skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
219         };
220 
221         atomic_t                skc_refcnt;
222         /* private: */
223         int                     skc_dontcopy_end[0];
224         union {
225                 u32             skc_rxhash;
226                 u32             skc_window_clamp;
227                 u32             skc_tw_snd_nxt; /* struct tcp_timewait_sock */
228         };
229         /* public: */
230 };
231 
232 /**
233   *     struct sock - network layer representation of sockets
234   *     @__sk_common: shared layout with inet_timewait_sock
235   *     @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
236   *     @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
237   *     @sk_lock:       synchronizer
238   *     @sk_rcvbuf: size of receive buffer in bytes
239   *     @sk_wq: sock wait queue and async head
240   *     @sk_rx_dst: receive input route used by early demux
241   *     @sk_dst_cache: destination cache
242   *     @sk_policy: flow policy
243   *     @sk_receive_queue: incoming packets
244   *     @sk_wmem_alloc: transmit queue bytes committed
245   *     @sk_write_queue: Packet sending queue
246   *     @sk_omem_alloc: "o" is "option" or "other"
247   *     @sk_wmem_queued: persistent queue size
248   *     @sk_forward_alloc: space allocated forward
249   *     @sk_napi_id: id of the last napi context to receive data for sk
250   *     @sk_ll_usec: usecs to busypoll when there is no data
251   *     @sk_allocation: allocation mode
252   *     @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
253   *     @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
254   *     @sk_sndbuf: size of send buffer in bytes
255   *     @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
256   *     @sk_no_check_rx: allow zero checksum in RX packets
257   *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
258   *     @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
259   *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
260   *     @sk_gso_max_size: Maximum GSO segment size to build
261   *     @sk_gso_max_segs: Maximum number of GSO segments
262   *     @sk_lingertime: %SO_LINGER l_linger setting
263   *     @sk_backlog: always used with the per-socket spinlock held
264   *     @sk_callback_lock: used with the callbacks in the end of this struct
265   *     @sk_error_queue: rarely used
266   *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
267   *                       IPV6_ADDRFORM for instance)
268   *     @sk_err: last error
269   *     @sk_err_soft: errors that don't cause failure but are the cause of a
270   *                   persistent failure not just 'timed out'
271   *     @sk_drops: raw/udp drops counter
272   *     @sk_ack_backlog: current listen backlog
273   *     @sk_max_ack_backlog: listen backlog set in listen()
274   *     @sk_priority: %SO_PRIORITY setting
275   *     @sk_type: socket type (%SOCK_STREAM, etc)
276   *     @sk_protocol: which protocol this socket belongs in this network family
277   *     @sk_peer_pid: &struct pid for this socket's peer
278   *     @sk_peer_cred: %SO_PEERCRED setting
279   *     @sk_rcvlowat: %SO_RCVLOWAT setting
280   *     @sk_rcvtimeo: %SO_RCVTIMEO setting
281   *     @sk_sndtimeo: %SO_SNDTIMEO setting
282   *     @sk_txhash: computed flow hash for use on transmit
283   *     @sk_filter: socket filtering instructions
284   *     @sk_timer: sock cleanup timer
285   *     @sk_stamp: time stamp of last packet received
286   *     @sk_tsflags: SO_TIMESTAMPING socket options
287   *     @sk_tskey: counter to disambiguate concurrent tstamp requests
288   *     @sk_socket: Identd and reporting IO signals
289   *     @sk_user_data: RPC layer private data
290   *     @sk_frag: cached page frag
291   *     @sk_peek_off: current peek_offset value
292   *     @sk_send_head: front of stuff to transmit
293   *     @sk_security: used by security modules
294   *     @sk_mark: generic packet mark
295   *     @sk_cgrp_data: cgroup data for this cgroup
296   *     @sk_memcg: this socket's memory cgroup association
297   *     @sk_write_pending: a write to stream socket waits to start
298   *     @sk_state_change: callback to indicate change in the state of the sock
299   *     @sk_data_ready: callback to indicate there is data to be processed
300   *     @sk_write_space: callback to indicate there is bf sending space available
301   *     @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
302   *     @sk_backlog_rcv: callback to process the backlog
303   *     @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
304   *     @sk_reuseport_cb: reuseport group container
305  */
306 struct sock {
307         /*
308          * Now struct inet_timewait_sock also uses sock_common, so please just
309          * don't add nothing before this first member (__sk_common) --acme
310          */
311         struct sock_common      __sk_common;
312 #define sk_node                 __sk_common.skc_node
313 #define sk_nulls_node           __sk_common.skc_nulls_node
314 #define sk_refcnt               __sk_common.skc_refcnt
315 #define sk_tx_queue_mapping     __sk_common.skc_tx_queue_mapping
316 
317 #define sk_dontcopy_begin       __sk_common.skc_dontcopy_begin
318 #define sk_dontcopy_end         __sk_common.skc_dontcopy_end
319 #define sk_hash                 __sk_common.skc_hash
320 #define sk_portpair             __sk_common.skc_portpair
321 #define sk_num                  __sk_common.skc_num
322 #define sk_dport                __sk_common.skc_dport
323 #define sk_addrpair             __sk_common.skc_addrpair
324 #define sk_daddr                __sk_common.skc_daddr
325 #define sk_rcv_saddr            __sk_common.skc_rcv_saddr
326 #define sk_family               __sk_common.skc_family
327 #define sk_state                __sk_common.skc_state
328 #define sk_reuse                __sk_common.skc_reuse
329 #define sk_reuseport            __sk_common.skc_reuseport
330 #define sk_ipv6only             __sk_common.skc_ipv6only
331 #define sk_net_refcnt           __sk_common.skc_net_refcnt
332 #define sk_bound_dev_if         __sk_common.skc_bound_dev_if
333 #define sk_bind_node            __sk_common.skc_bind_node
334 #define sk_prot                 __sk_common.skc_prot
335 #define sk_net                  __sk_common.skc_net
336 #define sk_v6_daddr             __sk_common.skc_v6_daddr
337 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
338 #define sk_cookie               __sk_common.skc_cookie
339 #define sk_incoming_cpu         __sk_common.skc_incoming_cpu
340 #define sk_flags                __sk_common.skc_flags
341 #define sk_rxhash               __sk_common.skc_rxhash
342 
343         socket_lock_t           sk_lock;
344         struct sk_buff_head     sk_receive_queue;
345         /*
346          * The backlog queue is special, it is always used with
347          * the per-socket spinlock held and requires low latency
348          * access. Therefore we special case it's implementation.
349          * Note : rmem_alloc is in this structure to fill a hole
350          * on 64bit arches, not because its logically part of
351          * backlog.
352          */
353         struct {
354                 atomic_t        rmem_alloc;
355                 int             len;
356                 struct sk_buff  *head;
357                 struct sk_buff  *tail;
358         } sk_backlog;
359 #define sk_rmem_alloc sk_backlog.rmem_alloc
360         int                     sk_forward_alloc;
361 
362         __u32                   sk_txhash;
363 #ifdef CONFIG_NET_RX_BUSY_POLL
364         unsigned int            sk_napi_id;
365         unsigned int            sk_ll_usec;
366 #endif
367         atomic_t                sk_drops;
368         int                     sk_rcvbuf;
369 
370         struct sk_filter __rcu  *sk_filter;
371         union {
372                 struct socket_wq __rcu  *sk_wq;
373                 struct socket_wq        *sk_wq_raw;
374         };
375 #ifdef CONFIG_XFRM
376         struct xfrm_policy __rcu *sk_policy[2];
377 #endif
378         struct dst_entry        *sk_rx_dst;
379         struct dst_entry __rcu  *sk_dst_cache;
380         /* Note: 32bit hole on 64bit arches */
381         atomic_t                sk_wmem_alloc;
382         atomic_t                sk_omem_alloc;
383         int                     sk_sndbuf;
384         struct sk_buff_head     sk_write_queue;
385         kmemcheck_bitfield_begin(flags);
386         unsigned int            sk_shutdown  : 2,
387                                 sk_no_check_tx : 1,
388                                 sk_no_check_rx : 1,
389                                 sk_userlocks : 4,
390                                 sk_protocol  : 8,
391                                 sk_type      : 16;
392 #define SK_PROTOCOL_MAX U8_MAX
393         kmemcheck_bitfield_end(flags);
394         int                     sk_wmem_queued;
395         gfp_t                   sk_allocation;
396         u32                     sk_pacing_rate; /* bytes per second */
397         u32                     sk_max_pacing_rate;
398         netdev_features_t       sk_route_caps;
399         netdev_features_t       sk_route_nocaps;
400         int                     sk_gso_type;
401         unsigned int            sk_gso_max_size;
402         u16                     sk_gso_max_segs;
403         int                     sk_rcvlowat;
404         unsigned long           sk_lingertime;
405         struct sk_buff_head     sk_error_queue;
406         struct proto            *sk_prot_creator;
407         rwlock_t                sk_callback_lock;
408         int                     sk_err,
409                                 sk_err_soft;
410         u32                     sk_ack_backlog;
411         u32                     sk_max_ack_backlog;
412         __u32                   sk_priority;
413         __u32                   sk_mark;
414         struct pid              *sk_peer_pid;
415         const struct cred       *sk_peer_cred;
416         long                    sk_rcvtimeo;
417         long                    sk_sndtimeo;
418         struct timer_list       sk_timer;
419         ktime_t                 sk_stamp;
420         u16                     sk_tsflags;
421         u32                     sk_tskey;
422         struct socket           *sk_socket;
423         void                    *sk_user_data;
424         struct page_frag        sk_frag;
425         struct sk_buff          *sk_send_head;
426         __s32                   sk_peek_off;
427         int                     sk_write_pending;
428 #ifdef CONFIG_SECURITY
429         void                    *sk_security;
430 #endif
431         struct sock_cgroup_data sk_cgrp_data;
432         struct mem_cgroup       *sk_memcg;
433         void                    (*sk_state_change)(struct sock *sk);
434         void                    (*sk_data_ready)(struct sock *sk);
435         void                    (*sk_write_space)(struct sock *sk);
436         void                    (*sk_error_report)(struct sock *sk);
437         int                     (*sk_backlog_rcv)(struct sock *sk,
438                                                   struct sk_buff *skb);
439         void                    (*sk_destruct)(struct sock *sk);
440         struct sock_reuseport __rcu     *sk_reuseport_cb;
441 };
442 
443 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
444 
445 #define rcu_dereference_sk_user_data(sk)        rcu_dereference(__sk_user_data((sk)))
446 #define rcu_assign_sk_user_data(sk, ptr)        rcu_assign_pointer(__sk_user_data((sk)), ptr)
447 
448 /*
449  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
450  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
451  * on a socket means that the socket will reuse everybody else's port
452  * without looking at the other's sk_reuse value.
453  */
454 
455 #define SK_NO_REUSE     0
456 #define SK_CAN_REUSE    1
457 #define SK_FORCE_REUSE  2
458 
459 static inline int sk_peek_offset(struct sock *sk, int flags)
460 {
461         if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
462                 return sk->sk_peek_off;
463         else
464                 return 0;
465 }
466 
467 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
468 {
469         if (sk->sk_peek_off >= 0) {
470                 if (sk->sk_peek_off >= val)
471                         sk->sk_peek_off -= val;
472                 else
473                         sk->sk_peek_off = 0;
474         }
475 }
476 
477 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
478 {
479         if (sk->sk_peek_off >= 0)
480                 sk->sk_peek_off += val;
481 }
482 
483 /*
484  * Hashed lists helper routines
485  */
486 static inline struct sock *sk_entry(const struct hlist_node *node)
487 {
488         return hlist_entry(node, struct sock, sk_node);
489 }
490 
491 static inline struct sock *__sk_head(const struct hlist_head *head)
492 {
493         return hlist_entry(head->first, struct sock, sk_node);
494 }
495 
496 static inline struct sock *sk_head(const struct hlist_head *head)
497 {
498         return hlist_empty(head) ? NULL : __sk_head(head);
499 }
500 
501 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
502 {
503         return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
504 }
505 
506 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
507 {
508         return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
509 }
510 
511 static inline struct sock *sk_next(const struct sock *sk)
512 {
513         return sk->sk_node.next ?
514                 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
515 }
516 
517 static inline struct sock *sk_nulls_next(const struct sock *sk)
518 {
519         return (!is_a_nulls(sk->sk_nulls_node.next)) ?
520                 hlist_nulls_entry(sk->sk_nulls_node.next,
521                                   struct sock, sk_nulls_node) :
522                 NULL;
523 }
524 
525 static inline bool sk_unhashed(const struct sock *sk)
526 {
527         return hlist_unhashed(&sk->sk_node);
528 }
529 
530 static inline bool sk_hashed(const struct sock *sk)
531 {
532         return !sk_unhashed(sk);
533 }
534 
535 static inline void sk_node_init(struct hlist_node *node)
536 {
537         node->pprev = NULL;
538 }
539 
540 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
541 {
542         node->pprev = NULL;
543 }
544 
545 static inline void __sk_del_node(struct sock *sk)
546 {
547         __hlist_del(&sk->sk_node);
548 }
549 
550 /* NB: equivalent to hlist_del_init_rcu */
551 static inline bool __sk_del_node_init(struct sock *sk)
552 {
553         if (sk_hashed(sk)) {
554                 __sk_del_node(sk);
555                 sk_node_init(&sk->sk_node);
556                 return true;
557         }
558         return false;
559 }
560 
561 /* Grab socket reference count. This operation is valid only
562    when sk is ALREADY grabbed f.e. it is found in hash table
563    or a list and the lookup is made under lock preventing hash table
564    modifications.
565  */
566 
567 static inline void sock_hold(struct sock *sk)
568 {
569         atomic_inc(&sk->sk_refcnt);
570 }
571 
572 /* Ungrab socket in the context, which assumes that socket refcnt
573    cannot hit zero, f.e. it is true in context of any socketcall.
574  */
575 static inline void __sock_put(struct sock *sk)
576 {
577         atomic_dec(&sk->sk_refcnt);
578 }
579 
580 static inline bool sk_del_node_init(struct sock *sk)
581 {
582         bool rc = __sk_del_node_init(sk);
583 
584         if (rc) {
585                 /* paranoid for a while -acme */
586                 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
587                 __sock_put(sk);
588         }
589         return rc;
590 }
591 #define sk_del_node_init_rcu(sk)        sk_del_node_init(sk)
592 
593 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
594 {
595         if (sk_hashed(sk)) {
596                 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
597                 return true;
598         }
599         return false;
600 }
601 
602 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
603 {
604         bool rc = __sk_nulls_del_node_init_rcu(sk);
605 
606         if (rc) {
607                 /* paranoid for a while -acme */
608                 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
609                 __sock_put(sk);
610         }
611         return rc;
612 }
613 
614 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
615 {
616         hlist_add_head(&sk->sk_node, list);
617 }
618 
619 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
620 {
621         sock_hold(sk);
622         __sk_add_node(sk, list);
623 }
624 
625 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
626 {
627         sock_hold(sk);
628         hlist_add_head_rcu(&sk->sk_node, list);
629 }
630 
631 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
632 {
633         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
634             sk->sk_family == AF_INET6)
635                 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
636         else
637                 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
638 }
639 
640 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
641 {
642         sock_hold(sk);
643         __sk_nulls_add_node_rcu(sk, list);
644 }
645 
646 static inline void __sk_del_bind_node(struct sock *sk)
647 {
648         __hlist_del(&sk->sk_bind_node);
649 }
650 
651 static inline void sk_add_bind_node(struct sock *sk,
652                                         struct hlist_head *list)
653 {
654         hlist_add_head(&sk->sk_bind_node, list);
655 }
656 
657 #define sk_for_each(__sk, list) \
658         hlist_for_each_entry(__sk, list, sk_node)
659 #define sk_for_each_rcu(__sk, list) \
660         hlist_for_each_entry_rcu(__sk, list, sk_node)
661 #define sk_nulls_for_each(__sk, node, list) \
662         hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
663 #define sk_nulls_for_each_rcu(__sk, node, list) \
664         hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
665 #define sk_for_each_from(__sk) \
666         hlist_for_each_entry_from(__sk, sk_node)
667 #define sk_nulls_for_each_from(__sk, node) \
668         if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
669                 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
670 #define sk_for_each_safe(__sk, tmp, list) \
671         hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
672 #define sk_for_each_bound(__sk, list) \
673         hlist_for_each_entry(__sk, list, sk_bind_node)
674 
675 /**
676  * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset
677  * @tpos:       the type * to use as a loop cursor.
678  * @pos:        the &struct hlist_node to use as a loop cursor.
679  * @head:       the head for your list.
680  * @offset:     offset of hlist_node within the struct.
681  *
682  */
683 #define sk_nulls_for_each_entry_offset(tpos, pos, head, offset)                \
684         for (pos = (head)->first;                                              \
685              (!is_a_nulls(pos)) &&                                             \
686                 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
687              pos = pos->next)
688 
689 static inline struct user_namespace *sk_user_ns(struct sock *sk)
690 {
691         /* Careful only use this in a context where these parameters
692          * can not change and must all be valid, such as recvmsg from
693          * userspace.
694          */
695         return sk->sk_socket->file->f_cred->user_ns;
696 }
697 
698 /* Sock flags */
699 enum sock_flags {
700         SOCK_DEAD,
701         SOCK_DONE,
702         SOCK_URGINLINE,
703         SOCK_KEEPOPEN,
704         SOCK_LINGER,
705         SOCK_DESTROY,
706         SOCK_BROADCAST,
707         SOCK_TIMESTAMP,
708         SOCK_ZAPPED,
709         SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
710         SOCK_DBG, /* %SO_DEBUG setting */
711         SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
712         SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
713         SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
714         SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
715         SOCK_MEMALLOC, /* VM depends on this socket for swapping */
716         SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
717         SOCK_FASYNC, /* fasync() active */
718         SOCK_RXQ_OVFL,
719         SOCK_ZEROCOPY, /* buffers from userspace */
720         SOCK_WIFI_STATUS, /* push wifi status to userspace */
721         SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
722                      * Will use last 4 bytes of packet sent from
723                      * user-space instead.
724                      */
725         SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
726         SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
727 };
728 
729 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
730 
731 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
732 {
733         nsk->sk_flags = osk->sk_flags;
734 }
735 
736 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
737 {
738         __set_bit(flag, &sk->sk_flags);
739 }
740 
741 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
742 {
743         __clear_bit(flag, &sk->sk_flags);
744 }
745 
746 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
747 {
748         return test_bit(flag, &sk->sk_flags);
749 }
750 
751 #ifdef CONFIG_NET
752 extern struct static_key memalloc_socks;
753 static inline int sk_memalloc_socks(void)
754 {
755         return static_key_false(&memalloc_socks);
756 }
757 #else
758 
759 static inline int sk_memalloc_socks(void)
760 {
761         return 0;
762 }
763 
764 #endif
765 
766 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
767 {
768         return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
769 }
770 
771 static inline void sk_acceptq_removed(struct sock *sk)
772 {
773         sk->sk_ack_backlog--;
774 }
775 
776 static inline void sk_acceptq_added(struct sock *sk)
777 {
778         sk->sk_ack_backlog++;
779 }
780 
781 static inline bool sk_acceptq_is_full(const struct sock *sk)
782 {
783         return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
784 }
785 
786 /*
787  * Compute minimal free write space needed to queue new packets.
788  */
789 static inline int sk_stream_min_wspace(const struct sock *sk)
790 {
791         return sk->sk_wmem_queued >> 1;
792 }
793 
794 static inline int sk_stream_wspace(const struct sock *sk)
795 {
796         return sk->sk_sndbuf - sk->sk_wmem_queued;
797 }
798 
799 void sk_stream_write_space(struct sock *sk);
800 
801 /* OOB backlog add */
802 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
803 {
804         /* dont let skb dst not refcounted, we are going to leave rcu lock */
805         skb_dst_force_safe(skb);
806 
807         if (!sk->sk_backlog.tail)
808                 sk->sk_backlog.head = skb;
809         else
810                 sk->sk_backlog.tail->next = skb;
811 
812         sk->sk_backlog.tail = skb;
813         skb->next = NULL;
814 }
815 
816 /*
817  * Take into account size of receive queue and backlog queue
818  * Do not take into account this skb truesize,
819  * to allow even a single big packet to come.
820  */
821 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
822 {
823         unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
824 
825         return qsize > limit;
826 }
827 
828 /* The per-socket spinlock must be held here. */
829 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
830                                               unsigned int limit)
831 {
832         if (sk_rcvqueues_full(sk, limit))
833                 return -ENOBUFS;
834 
835         /*
836          * If the skb was allocated from pfmemalloc reserves, only
837          * allow SOCK_MEMALLOC sockets to use it as this socket is
838          * helping free memory
839          */
840         if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
841                 return -ENOMEM;
842 
843         __sk_add_backlog(sk, skb);
844         sk->sk_backlog.len += skb->truesize;
845         return 0;
846 }
847 
848 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
849 
850 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
851 {
852         if (sk_memalloc_socks() && skb_pfmemalloc(skb))
853                 return __sk_backlog_rcv(sk, skb);
854 
855         return sk->sk_backlog_rcv(sk, skb);
856 }
857 
858 static inline void sk_incoming_cpu_update(struct sock *sk)
859 {
860         sk->sk_incoming_cpu = raw_smp_processor_id();
861 }
862 
863 static inline void sock_rps_record_flow_hash(__u32 hash)
864 {
865 #ifdef CONFIG_RPS
866         struct rps_sock_flow_table *sock_flow_table;
867 
868         rcu_read_lock();
869         sock_flow_table = rcu_dereference(rps_sock_flow_table);
870         rps_record_sock_flow(sock_flow_table, hash);
871         rcu_read_unlock();
872 #endif
873 }
874 
875 static inline void sock_rps_record_flow(const struct sock *sk)
876 {
877 #ifdef CONFIG_RPS
878         sock_rps_record_flow_hash(sk->sk_rxhash);
879 #endif
880 }
881 
882 static inline void sock_rps_save_rxhash(struct sock *sk,
883                                         const struct sk_buff *skb)
884 {
885 #ifdef CONFIG_RPS
886         if (unlikely(sk->sk_rxhash != skb->hash))
887                 sk->sk_rxhash = skb->hash;
888 #endif
889 }
890 
891 static inline void sock_rps_reset_rxhash(struct sock *sk)
892 {
893 #ifdef CONFIG_RPS
894         sk->sk_rxhash = 0;
895 #endif
896 }
897 
898 #define sk_wait_event(__sk, __timeo, __condition)                       \
899         ({      int __rc;                                               \
900                 release_sock(__sk);                                     \
901                 __rc = __condition;                                     \
902                 if (!__rc) {                                            \
903                         *(__timeo) = schedule_timeout(*(__timeo));      \
904                 }                                                       \
905                 sched_annotate_sleep();                                         \
906                 lock_sock(__sk);                                        \
907                 __rc = __condition;                                     \
908                 __rc;                                                   \
909         })
910 
911 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
912 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
913 void sk_stream_wait_close(struct sock *sk, long timeo_p);
914 int sk_stream_error(struct sock *sk, int flags, int err);
915 void sk_stream_kill_queues(struct sock *sk);
916 void sk_set_memalloc(struct sock *sk);
917 void sk_clear_memalloc(struct sock *sk);
918 
919 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
920 
921 struct request_sock_ops;
922 struct timewait_sock_ops;
923 struct inet_hashinfo;
924 struct raw_hashinfo;
925 struct module;
926 
927 /*
928  * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
929  * un-modified. Special care is taken when initializing object to zero.
930  */
931 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
932 {
933         if (offsetof(struct sock, sk_node.next) != 0)
934                 memset(sk, 0, offsetof(struct sock, sk_node.next));
935         memset(&sk->sk_node.pprev, 0,
936                size - offsetof(struct sock, sk_node.pprev));
937 }
938 
939 /* Networking protocol blocks we attach to sockets.
940  * socket layer -> transport layer interface
941  */
942 struct proto {
943         void                    (*close)(struct sock *sk,
944                                         long timeout);
945         int                     (*connect)(struct sock *sk,
946                                         struct sockaddr *uaddr,
947                                         int addr_len);
948         int                     (*disconnect)(struct sock *sk, int flags);
949 
950         struct sock *           (*accept)(struct sock *sk, int flags, int *err);
951 
952         int                     (*ioctl)(struct sock *sk, int cmd,
953                                          unsigned long arg);
954         int                     (*init)(struct sock *sk);
955         void                    (*destroy)(struct sock *sk);
956         void                    (*shutdown)(struct sock *sk, int how);
957         int                     (*setsockopt)(struct sock *sk, int level,
958                                         int optname, char __user *optval,
959                                         unsigned int optlen);
960         int                     (*getsockopt)(struct sock *sk, int level,
961                                         int optname, char __user *optval,
962                                         int __user *option);
963 #ifdef CONFIG_COMPAT
964         int                     (*compat_setsockopt)(struct sock *sk,
965                                         int level,
966                                         int optname, char __user *optval,
967                                         unsigned int optlen);
968         int                     (*compat_getsockopt)(struct sock *sk,
969                                         int level,
970                                         int optname, char __user *optval,
971                                         int __user *option);
972         int                     (*compat_ioctl)(struct sock *sk,
973                                         unsigned int cmd, unsigned long arg);
974 #endif
975         int                     (*sendmsg)(struct sock *sk, struct msghdr *msg,
976                                            size_t len);
977         int                     (*recvmsg)(struct sock *sk, struct msghdr *msg,
978                                            size_t len, int noblock, int flags,
979                                            int *addr_len);
980         int                     (*sendpage)(struct sock *sk, struct page *page,
981                                         int offset, size_t size, int flags);
982         int                     (*bind)(struct sock *sk,
983                                         struct sockaddr *uaddr, int addr_len);
984 
985         int                     (*backlog_rcv) (struct sock *sk,
986                                                 struct sk_buff *skb);
987 
988         void            (*release_cb)(struct sock *sk);
989 
990         /* Keeping track of sk's, looking them up, and port selection methods. */
991         int                     (*hash)(struct sock *sk);
992         void                    (*unhash)(struct sock *sk);
993         void                    (*rehash)(struct sock *sk);
994         int                     (*get_port)(struct sock *sk, unsigned short snum);
995         void                    (*clear_sk)(struct sock *sk, int size);
996 
997         /* Keeping track of sockets in use */
998 #ifdef CONFIG_PROC_FS
999         unsigned int            inuse_idx;
1000 #endif
1001 
1002         bool                    (*stream_memory_free)(const struct sock *sk);
1003         /* Memory pressure */
1004         void                    (*enter_memory_pressure)(struct sock *sk);
1005         atomic_long_t           *memory_allocated;      /* Current allocated memory. */
1006         struct percpu_counter   *sockets_allocated;     /* Current number of sockets. */
1007         /*
1008          * Pressure flag: try to collapse.
1009          * Technical note: it is used by multiple contexts non atomically.
1010          * All the __sk_mem_schedule() is of this nature: accounting
1011          * is strict, actions are advisory and have some latency.
1012          */
1013         int                     *memory_pressure;
1014         long                    *sysctl_mem;
1015         int                     *sysctl_wmem;
1016         int                     *sysctl_rmem;
1017         int                     max_header;
1018         bool                    no_autobind;
1019 
1020         struct kmem_cache       *slab;
1021         unsigned int            obj_size;
1022         int                     slab_flags;
1023 
1024         struct percpu_counter   *orphan_count;
1025 
1026         struct request_sock_ops *rsk_prot;
1027         struct timewait_sock_ops *twsk_prot;
1028 
1029         union {
1030                 struct inet_hashinfo    *hashinfo;
1031                 struct udp_table        *udp_table;
1032                 struct raw_hashinfo     *raw_hash;
1033         } h;
1034 
1035         struct module           *owner;
1036 
1037         char                    name[32];
1038 
1039         struct list_head        node;
1040 #ifdef SOCK_REFCNT_DEBUG
1041         atomic_t                socks;
1042 #endif
1043         int                     (*diag_destroy)(struct sock *sk, int err);
1044 };
1045 
1046 int proto_register(struct proto *prot, int alloc_slab);
1047 void proto_unregister(struct proto *prot);
1048 
1049 #ifdef SOCK_REFCNT_DEBUG
1050 static inline void sk_refcnt_debug_inc(struct sock *sk)
1051 {
1052         atomic_inc(&sk->sk_prot->socks);
1053 }
1054 
1055 static inline void sk_refcnt_debug_dec(struct sock *sk)
1056 {
1057         atomic_dec(&sk->sk_prot->socks);
1058         printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1059                sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1060 }
1061 
1062 static inline void sk_refcnt_debug_release(const struct sock *sk)
1063 {
1064         if (atomic_read(&sk->sk_refcnt) != 1)
1065                 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1066                        sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1067 }
1068 #else /* SOCK_REFCNT_DEBUG */
1069 #define sk_refcnt_debug_inc(sk) do { } while (0)
1070 #define sk_refcnt_debug_dec(sk) do { } while (0)
1071 #define sk_refcnt_debug_release(sk) do { } while (0)
1072 #endif /* SOCK_REFCNT_DEBUG */
1073 
1074 static inline bool sk_stream_memory_free(const struct sock *sk)
1075 {
1076         if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1077                 return false;
1078 
1079         return sk->sk_prot->stream_memory_free ?
1080                 sk->sk_prot->stream_memory_free(sk) : true;
1081 }
1082 
1083 static inline bool sk_stream_is_writeable(const struct sock *sk)
1084 {
1085         return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1086                sk_stream_memory_free(sk);
1087 }
1088 
1089 
1090 static inline bool sk_has_memory_pressure(const struct sock *sk)
1091 {
1092         return sk->sk_prot->memory_pressure != NULL;
1093 }
1094 
1095 static inline bool sk_under_memory_pressure(const struct sock *sk)
1096 {
1097         if (!sk->sk_prot->memory_pressure)
1098                 return false;
1099 
1100         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1101             mem_cgroup_under_socket_pressure(sk->sk_memcg))
1102                 return true;
1103 
1104         return !!*sk->sk_prot->memory_pressure;
1105 }
1106 
1107 static inline void sk_leave_memory_pressure(struct sock *sk)
1108 {
1109         int *memory_pressure = sk->sk_prot->memory_pressure;
1110 
1111         if (!memory_pressure)
1112                 return;
1113 
1114         if (*memory_pressure)
1115                 *memory_pressure = 0;
1116 }
1117 
1118 static inline void sk_enter_memory_pressure(struct sock *sk)
1119 {
1120         if (!sk->sk_prot->enter_memory_pressure)
1121                 return;
1122 
1123         sk->sk_prot->enter_memory_pressure(sk);
1124 }
1125 
1126 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1127 {
1128         return sk->sk_prot->sysctl_mem[index];
1129 }
1130 
1131 static inline long
1132 sk_memory_allocated(const struct sock *sk)
1133 {
1134         return atomic_long_read(sk->sk_prot->memory_allocated);
1135 }
1136 
1137 static inline long
1138 sk_memory_allocated_add(struct sock *sk, int amt)
1139 {
1140         return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1141 }
1142 
1143 static inline void
1144 sk_memory_allocated_sub(struct sock *sk, int amt)
1145 {
1146         atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1147 }
1148 
1149 static inline void sk_sockets_allocated_dec(struct sock *sk)
1150 {
1151         percpu_counter_dec(sk->sk_prot->sockets_allocated);
1152 }
1153 
1154 static inline void sk_sockets_allocated_inc(struct sock *sk)
1155 {
1156         percpu_counter_inc(sk->sk_prot->sockets_allocated);
1157 }
1158 
1159 static inline int
1160 sk_sockets_allocated_read_positive(struct sock *sk)
1161 {
1162         return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1163 }
1164 
1165 static inline int
1166 proto_sockets_allocated_sum_positive(struct proto *prot)
1167 {
1168         return percpu_counter_sum_positive(prot->sockets_allocated);
1169 }
1170 
1171 static inline long
1172 proto_memory_allocated(struct proto *prot)
1173 {
1174         return atomic_long_read(prot->memory_allocated);
1175 }
1176 
1177 static inline bool
1178 proto_memory_pressure(struct proto *prot)
1179 {
1180         if (!prot->memory_pressure)
1181                 return false;
1182         return !!*prot->memory_pressure;
1183 }
1184 
1185 
1186 #ifdef CONFIG_PROC_FS
1187 /* Called with local bh disabled */
1188 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1189 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1190 #else
1191 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1192                 int inc)
1193 {
1194 }
1195 #endif
1196 
1197 
1198 /* With per-bucket locks this operation is not-atomic, so that
1199  * this version is not worse.
1200  */
1201 static inline int __sk_prot_rehash(struct sock *sk)
1202 {
1203         sk->sk_prot->unhash(sk);
1204         return sk->sk_prot->hash(sk);
1205 }
1206 
1207 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1208 
1209 /* About 10 seconds */
1210 #define SOCK_DESTROY_TIME (10*HZ)
1211 
1212 /* Sockets 0-1023 can't be bound to unless you are superuser */
1213 #define PROT_SOCK       1024
1214 
1215 #define SHUTDOWN_MASK   3
1216 #define RCV_SHUTDOWN    1
1217 #define SEND_SHUTDOWN   2
1218 
1219 #define SOCK_SNDBUF_LOCK        1
1220 #define SOCK_RCVBUF_LOCK        2
1221 #define SOCK_BINDADDR_LOCK      4
1222 #define SOCK_BINDPORT_LOCK      8
1223 
1224 struct socket_alloc {
1225         struct socket socket;
1226         struct inode vfs_inode;
1227 };
1228 
1229 static inline struct socket *SOCKET_I(struct inode *inode)
1230 {
1231         return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1232 }
1233 
1234 static inline struct inode *SOCK_INODE(struct socket *socket)
1235 {
1236         return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1237 }
1238 
1239 /*
1240  * Functions for memory accounting
1241  */
1242 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1243 void __sk_mem_reclaim(struct sock *sk, int amount);
1244 
1245 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1246 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1247 #define SK_MEM_SEND     0
1248 #define SK_MEM_RECV     1
1249 
1250 static inline int sk_mem_pages(int amt)
1251 {
1252         return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1253 }
1254 
1255 static inline bool sk_has_account(struct sock *sk)
1256 {
1257         /* return true if protocol supports memory accounting */
1258         return !!sk->sk_prot->memory_allocated;
1259 }
1260 
1261 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1262 {
1263         if (!sk_has_account(sk))
1264                 return true;
1265         return size <= sk->sk_forward_alloc ||
1266                 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1267 }
1268 
1269 static inline bool
1270 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1271 {
1272         if (!sk_has_account(sk))
1273                 return true;
1274         return size<= sk->sk_forward_alloc ||
1275                 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1276                 skb_pfmemalloc(skb);
1277 }
1278 
1279 static inline void sk_mem_reclaim(struct sock *sk)
1280 {
1281         if (!sk_has_account(sk))
1282                 return;
1283         if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1284                 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1285 }
1286 
1287 static inline void sk_mem_reclaim_partial(struct sock *sk)
1288 {
1289         if (!sk_has_account(sk))
1290                 return;
1291         if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1292                 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1293 }
1294 
1295 static inline void sk_mem_charge(struct sock *sk, int size)
1296 {
1297         if (!sk_has_account(sk))
1298                 return;
1299         sk->sk_forward_alloc -= size;
1300 }
1301 
1302 static inline void sk_mem_uncharge(struct sock *sk, int size)
1303 {
1304         if (!sk_has_account(sk))
1305                 return;
1306         sk->sk_forward_alloc += size;
1307 }
1308 
1309 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1310 {
1311         sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1312         sk->sk_wmem_queued -= skb->truesize;
1313         sk_mem_uncharge(sk, skb->truesize);
1314         __kfree_skb(skb);
1315 }
1316 
1317 /* Used by processes to "lock" a socket state, so that
1318  * interrupts and bottom half handlers won't change it
1319  * from under us. It essentially blocks any incoming
1320  * packets, so that we won't get any new data or any
1321  * packets that change the state of the socket.
1322  *
1323  * While locked, BH processing will add new packets to
1324  * the backlog queue.  This queue is processed by the
1325  * owner of the socket lock right before it is released.
1326  *
1327  * Since ~2.3.5 it is also exclusive sleep lock serializing
1328  * accesses from user process context.
1329  */
1330 #define sock_owned_by_user(sk)  ((sk)->sk_lock.owned)
1331 
1332 static inline void sock_release_ownership(struct sock *sk)
1333 {
1334         sk->sk_lock.owned = 0;
1335 }
1336 
1337 /*
1338  * Macro so as to not evaluate some arguments when
1339  * lockdep is not enabled.
1340  *
1341  * Mark both the sk_lock and the sk_lock.slock as a
1342  * per-address-family lock class.
1343  */
1344 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
1345 do {                                                                    \
1346         sk->sk_lock.owned = 0;                                          \
1347         init_waitqueue_head(&sk->sk_lock.wq);                           \
1348         spin_lock_init(&(sk)->sk_lock.slock);                           \
1349         debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
1350                         sizeof((sk)->sk_lock));                         \
1351         lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
1352                                 (skey), (sname));                               \
1353         lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
1354 } while (0)
1355 
1356 void lock_sock_nested(struct sock *sk, int subclass);
1357 
1358 static inline void lock_sock(struct sock *sk)
1359 {
1360         lock_sock_nested(sk, 0);
1361 }
1362 
1363 void release_sock(struct sock *sk);
1364 
1365 /* BH context may only use the following locking interface. */
1366 #define bh_lock_sock(__sk)      spin_lock(&((__sk)->sk_lock.slock))
1367 #define bh_lock_sock_nested(__sk) \
1368                                 spin_lock_nested(&((__sk)->sk_lock.slock), \
1369                                 SINGLE_DEPTH_NESTING)
1370 #define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
1371 
1372 bool lock_sock_fast(struct sock *sk);
1373 /**
1374  * unlock_sock_fast - complement of lock_sock_fast
1375  * @sk: socket
1376  * @slow: slow mode
1377  *
1378  * fast unlock socket for user context.
1379  * If slow mode is on, we call regular release_sock()
1380  */
1381 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1382 {
1383         if (slow)
1384                 release_sock(sk);
1385         else
1386                 spin_unlock_bh(&sk->sk_lock.slock);
1387 }
1388 
1389 
1390 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1391                       struct proto *prot, int kern);
1392 void sk_free(struct sock *sk);
1393 void sk_destruct(struct sock *sk);
1394 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1395 
1396 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1397                              gfp_t priority);
1398 void sock_wfree(struct sk_buff *skb);
1399 void skb_orphan_partial(struct sk_buff *skb);
1400 void sock_rfree(struct sk_buff *skb);
1401 void sock_efree(struct sk_buff *skb);
1402 #ifdef CONFIG_INET
1403 void sock_edemux(struct sk_buff *skb);
1404 #else
1405 #define sock_edemux(skb) sock_efree(skb)
1406 #endif
1407 
1408 int sock_setsockopt(struct socket *sock, int level, int op,
1409                     char __user *optval, unsigned int optlen);
1410 
1411 int sock_getsockopt(struct socket *sock, int level, int op,
1412                     char __user *optval, int __user *optlen);
1413 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1414                                     int noblock, int *errcode);
1415 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1416                                      unsigned long data_len, int noblock,
1417                                      int *errcode, int max_page_order);
1418 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1419 void sock_kfree_s(struct sock *sk, void *mem, int size);
1420 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1421 void sk_send_sigurg(struct sock *sk);
1422 
1423 struct sockcm_cookie {
1424         u32 mark;
1425 };
1426 
1427 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1428                    struct sockcm_cookie *sockc);
1429 
1430 /*
1431  * Functions to fill in entries in struct proto_ops when a protocol
1432  * does not implement a particular function.
1433  */
1434 int sock_no_bind(struct socket *, struct sockaddr *, int);
1435 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1436 int sock_no_socketpair(struct socket *, struct socket *);
1437 int sock_no_accept(struct socket *, struct socket *, int);
1438 int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1439 unsigned int sock_no_poll(struct file *, struct socket *,
1440                           struct poll_table_struct *);
1441 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1442 int sock_no_listen(struct socket *, int);
1443 int sock_no_shutdown(struct socket *, int);
1444 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1445 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1446 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1447 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1448 int sock_no_mmap(struct file *file, struct socket *sock,
1449                  struct vm_area_struct *vma);
1450 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1451                          size_t size, int flags);
1452 
1453 /*
1454  * Functions to fill in entries in struct proto_ops when a protocol
1455  * uses the inet style.
1456  */
1457 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1458                                   char __user *optval, int __user *optlen);
1459 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1460                         int flags);
1461 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1462                                   char __user *optval, unsigned int optlen);
1463 int compat_sock_common_getsockopt(struct socket *sock, int level,
1464                 int optname, char __user *optval, int __user *optlen);
1465 int compat_sock_common_setsockopt(struct socket *sock, int level,
1466                 int optname, char __user *optval, unsigned int optlen);
1467 
1468 void sk_common_release(struct sock *sk);
1469 
1470 /*
1471  *      Default socket callbacks and setup code
1472  */
1473 
1474 /* Initialise core socket variables */
1475 void sock_init_data(struct socket *sock, struct sock *sk);
1476 
1477 /*
1478  * Socket reference counting postulates.
1479  *
1480  * * Each user of socket SHOULD hold a reference count.
1481  * * Each access point to socket (an hash table bucket, reference from a list,
1482  *   running timer, skb in flight MUST hold a reference count.
1483  * * When reference count hits 0, it means it will never increase back.
1484  * * When reference count hits 0, it means that no references from
1485  *   outside exist to this socket and current process on current CPU
1486  *   is last user and may/should destroy this socket.
1487  * * sk_free is called from any context: process, BH, IRQ. When
1488  *   it is called, socket has no references from outside -> sk_free
1489  *   may release descendant resources allocated by the socket, but
1490  *   to the time when it is called, socket is NOT referenced by any
1491  *   hash tables, lists etc.
1492  * * Packets, delivered from outside (from network or from another process)
1493  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1494  *   when they sit in queue. Otherwise, packets will leak to hole, when
1495  *   socket is looked up by one cpu and unhasing is made by another CPU.
1496  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1497  *   (leak to backlog). Packet socket does all the processing inside
1498  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1499  *   use separate SMP lock, so that they are prone too.
1500  */
1501 
1502 /* Ungrab socket and destroy it, if it was the last reference. */
1503 static inline void sock_put(struct sock *sk)
1504 {
1505         if (atomic_dec_and_test(&sk->sk_refcnt))
1506                 sk_free(sk);
1507 }
1508 /* Generic version of sock_put(), dealing with all sockets
1509  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1510  */
1511 void sock_gen_put(struct sock *sk);
1512 
1513 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
1514 
1515 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1516 {
1517         sk->sk_tx_queue_mapping = tx_queue;
1518 }
1519 
1520 static inline void sk_tx_queue_clear(struct sock *sk)
1521 {
1522         sk->sk_tx_queue_mapping = -1;
1523 }
1524 
1525 static inline int sk_tx_queue_get(const struct sock *sk)
1526 {
1527         return sk ? sk->sk_tx_queue_mapping : -1;
1528 }
1529 
1530 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1531 {
1532         sk_tx_queue_clear(sk);
1533         sk->sk_socket = sock;
1534 }
1535 
1536 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1537 {
1538         BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1539         return &rcu_dereference_raw(sk->sk_wq)->wait;
1540 }
1541 /* Detach socket from process context.
1542  * Announce socket dead, detach it from wait queue and inode.
1543  * Note that parent inode held reference count on this struct sock,
1544  * we do not release it in this function, because protocol
1545  * probably wants some additional cleanups or even continuing
1546  * to work with this socket (TCP).
1547  */
1548 static inline void sock_orphan(struct sock *sk)
1549 {
1550         write_lock_bh(&sk->sk_callback_lock);
1551         sock_set_flag(sk, SOCK_DEAD);
1552         sk_set_socket(sk, NULL);
1553         sk->sk_wq  = NULL;
1554         write_unlock_bh(&sk->sk_callback_lock);
1555 }
1556 
1557 static inline void sock_graft(struct sock *sk, struct socket *parent)
1558 {
1559         write_lock_bh(&sk->sk_callback_lock);
1560         sk->sk_wq = parent->wq;
1561         parent->sk = sk;
1562         sk_set_socket(sk, parent);
1563         security_sock_graft(sk, parent);
1564         write_unlock_bh(&sk->sk_callback_lock);
1565 }
1566 
1567 kuid_t sock_i_uid(struct sock *sk);
1568 unsigned long sock_i_ino(struct sock *sk);
1569 
1570 static inline u32 net_tx_rndhash(void)
1571 {
1572         u32 v = prandom_u32();
1573 
1574         return v ?: 1;
1575 }
1576 
1577 static inline void sk_set_txhash(struct sock *sk)
1578 {
1579         sk->sk_txhash = net_tx_rndhash();
1580 }
1581 
1582 static inline void sk_rethink_txhash(struct sock *sk)
1583 {
1584         if (sk->sk_txhash)
1585                 sk_set_txhash(sk);
1586 }
1587 
1588 static inline struct dst_entry *
1589 __sk_dst_get(struct sock *sk)
1590 {
1591         return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1592                                                        lockdep_is_held(&sk->sk_lock.slock));
1593 }
1594 
1595 static inline struct dst_entry *
1596 sk_dst_get(struct sock *sk)
1597 {
1598         struct dst_entry *dst;
1599 
1600         rcu_read_lock();
1601         dst = rcu_dereference(sk->sk_dst_cache);
1602         if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1603                 dst = NULL;
1604         rcu_read_unlock();
1605         return dst;
1606 }
1607 
1608 static inline void dst_negative_advice(struct sock *sk)
1609 {
1610         struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1611 
1612         sk_rethink_txhash(sk);
1613 
1614         if (dst && dst->ops->negative_advice) {
1615                 ndst = dst->ops->negative_advice(dst);
1616 
1617                 if (ndst != dst) {
1618                         rcu_assign_pointer(sk->sk_dst_cache, ndst);
1619                         sk_tx_queue_clear(sk);
1620                 }
1621         }
1622 }
1623 
1624 static inline void
1625 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1626 {
1627         struct dst_entry *old_dst;
1628 
1629         sk_tx_queue_clear(sk);
1630         /*
1631          * This can be called while sk is owned by the caller only,
1632          * with no state that can be checked in a rcu_dereference_check() cond
1633          */
1634         old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1635         rcu_assign_pointer(sk->sk_dst_cache, dst);
1636         dst_release(old_dst);
1637 }
1638 
1639 static inline void
1640 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1641 {
1642         struct dst_entry *old_dst;
1643 
1644         sk_tx_queue_clear(sk);
1645         old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1646         dst_release(old_dst);
1647 }
1648 
1649 static inline void
1650 __sk_dst_reset(struct sock *sk)
1651 {
1652         __sk_dst_set(sk, NULL);
1653 }
1654 
1655 static inline void
1656 sk_dst_reset(struct sock *sk)
1657 {
1658         sk_dst_set(sk, NULL);
1659 }
1660 
1661 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1662 
1663 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1664 
1665 bool sk_mc_loop(struct sock *sk);
1666 
1667 static inline bool sk_can_gso(const struct sock *sk)
1668 {
1669         return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1670 }
1671 
1672 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1673 
1674 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1675 {
1676         sk->sk_route_nocaps |= flags;
1677         sk->sk_route_caps &= ~flags;
1678 }
1679 
1680 static inline bool sk_check_csum_caps(struct sock *sk)
1681 {
1682         return (sk->sk_route_caps & NETIF_F_HW_CSUM) ||
1683                (sk->sk_family == PF_INET &&
1684                 (sk->sk_route_caps & NETIF_F_IP_CSUM)) ||
1685                (sk->sk_family == PF_INET6 &&
1686                 (sk->sk_route_caps & NETIF_F_IPV6_CSUM));
1687 }
1688 
1689 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1690                                            struct iov_iter *from, char *to,
1691                                            int copy, int offset)
1692 {
1693         if (skb->ip_summed == CHECKSUM_NONE) {
1694                 __wsum csum = 0;
1695                 if (csum_and_copy_from_iter(to, copy, &csum, from) != copy)
1696                         return -EFAULT;
1697                 skb->csum = csum_block_add(skb->csum, csum, offset);
1698         } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1699                 if (copy_from_iter_nocache(to, copy, from) != copy)
1700                         return -EFAULT;
1701         } else if (copy_from_iter(to, copy, from) != copy)
1702                 return -EFAULT;
1703 
1704         return 0;
1705 }
1706 
1707 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1708                                        struct iov_iter *from, int copy)
1709 {
1710         int err, offset = skb->len;
1711 
1712         err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1713                                        copy, offset);
1714         if (err)
1715                 __skb_trim(skb, offset);
1716 
1717         return err;
1718 }
1719 
1720 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
1721                                            struct sk_buff *skb,
1722                                            struct page *page,
1723                                            int off, int copy)
1724 {
1725         int err;
1726 
1727         err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1728                                        copy, skb->len);
1729         if (err)
1730                 return err;
1731 
1732         skb->len             += copy;
1733         skb->data_len        += copy;
1734         skb->truesize        += copy;
1735         sk->sk_wmem_queued   += copy;
1736         sk_mem_charge(sk, copy);
1737         return 0;
1738 }
1739 
1740 /**
1741  * sk_wmem_alloc_get - returns write allocations
1742  * @sk: socket
1743  *
1744  * Returns sk_wmem_alloc minus initial offset of one
1745  */
1746 static inline int sk_wmem_alloc_get(const struct sock *sk)
1747 {
1748         return atomic_read(&sk->sk_wmem_alloc) - 1;
1749 }
1750 
1751 /**
1752  * sk_rmem_alloc_get - returns read allocations
1753  * @sk: socket
1754  *
1755  * Returns sk_rmem_alloc
1756  */
1757 static inline int sk_rmem_alloc_get(const struct sock *sk)
1758 {
1759         return atomic_read(&sk->sk_rmem_alloc);
1760 }
1761 
1762 /**
1763  * sk_has_allocations - check if allocations are outstanding
1764  * @sk: socket
1765  *
1766  * Returns true if socket has write or read allocations
1767  */
1768 static inline bool sk_has_allocations(const struct sock *sk)
1769 {
1770         return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1771 }
1772 
1773 /**
1774  * skwq_has_sleeper - check if there are any waiting processes
1775  * @wq: struct socket_wq
1776  *
1777  * Returns true if socket_wq has waiting processes
1778  *
1779  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
1780  * barrier call. They were added due to the race found within the tcp code.
1781  *
1782  * Consider following tcp code paths:
1783  *
1784  * CPU1                  CPU2
1785  *
1786  * sys_select            receive packet
1787  *   ...                 ...
1788  *   __add_wait_queue    update tp->rcv_nxt
1789  *   ...                 ...
1790  *   tp->rcv_nxt check   sock_def_readable
1791  *   ...                 {
1792  *   schedule               rcu_read_lock();
1793  *                          wq = rcu_dereference(sk->sk_wq);
1794  *                          if (wq && waitqueue_active(&wq->wait))
1795  *                              wake_up_interruptible(&wq->wait)
1796  *                          ...
1797  *                       }
1798  *
1799  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1800  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
1801  * could then endup calling schedule and sleep forever if there are no more
1802  * data on the socket.
1803  *
1804  */
1805 static inline bool skwq_has_sleeper(struct socket_wq *wq)
1806 {
1807         return wq && wq_has_sleeper(&wq->wait);
1808 }
1809 
1810 /**
1811  * sock_poll_wait - place memory barrier behind the poll_wait call.
1812  * @filp:           file
1813  * @wait_address:   socket wait queue
1814  * @p:              poll_table
1815  *
1816  * See the comments in the wq_has_sleeper function.
1817  */
1818 static inline void sock_poll_wait(struct file *filp,
1819                 wait_queue_head_t *wait_address, poll_table *p)
1820 {
1821         if (!poll_does_not_wait(p) && wait_address) {
1822                 poll_wait(filp, wait_address, p);
1823                 /* We need to be sure we are in sync with the
1824                  * socket flags modification.
1825                  *
1826                  * This memory barrier is paired in the wq_has_sleeper.
1827                  */
1828                 smp_mb();
1829         }
1830 }
1831 
1832 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
1833 {
1834         if (sk->sk_txhash) {
1835                 skb->l4_hash = 1;
1836                 skb->hash = sk->sk_txhash;
1837         }
1838 }
1839 
1840 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
1841 
1842 /*
1843  *      Queue a received datagram if it will fit. Stream and sequenced
1844  *      protocols can't normally use this as they need to fit buffers in
1845  *      and play with them.
1846  *
1847  *      Inlined as it's very short and called for pretty much every
1848  *      packet ever received.
1849  */
1850 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1851 {
1852         skb_orphan(skb);
1853         skb->sk = sk;
1854         skb->destructor = sock_rfree;
1855         atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1856         sk_mem_charge(sk, skb->truesize);
1857 }
1858 
1859 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
1860                     unsigned long expires);
1861 
1862 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
1863 
1864 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1865 
1866 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1867 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
1868 
1869 /*
1870  *      Recover an error report and clear atomically
1871  */
1872 
1873 static inline int sock_error(struct sock *sk)
1874 {
1875         int err;
1876         if (likely(!sk->sk_err))
1877                 return 0;
1878         err = xchg(&sk->sk_err, 0);
1879         return -err;
1880 }
1881 
1882 static inline unsigned long sock_wspace(struct sock *sk)
1883 {
1884         int amt = 0;
1885 
1886         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1887                 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1888                 if (amt < 0)
1889                         amt = 0;
1890         }
1891         return amt;
1892 }
1893 
1894 /* Note:
1895  *  We use sk->sk_wq_raw, from contexts knowing this
1896  *  pointer is not NULL and cannot disappear/change.
1897  */
1898 static inline void sk_set_bit(int nr, struct sock *sk)
1899 {
1900         set_bit(nr, &sk->sk_wq_raw->flags);
1901 }
1902 
1903 static inline void sk_clear_bit(int nr, struct sock *sk)
1904 {
1905         clear_bit(nr, &sk->sk_wq_raw->flags);
1906 }
1907 
1908 static inline void sk_wake_async(const struct sock *sk, int how, int band)
1909 {
1910         if (sock_flag(sk, SOCK_FASYNC)) {
1911                 rcu_read_lock();
1912                 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
1913                 rcu_read_unlock();
1914         }
1915 }
1916 
1917 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
1918  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
1919  * Note: for send buffers, TCP works better if we can build two skbs at
1920  * minimum.
1921  */
1922 #define TCP_SKB_MIN_TRUESIZE    (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
1923 
1924 #define SOCK_MIN_SNDBUF         (TCP_SKB_MIN_TRUESIZE * 2)
1925 #define SOCK_MIN_RCVBUF          TCP_SKB_MIN_TRUESIZE
1926 
1927 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1928 {
1929         if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1930                 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1931                 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1932         }
1933 }
1934 
1935 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
1936                                     bool force_schedule);
1937 
1938 /**
1939  * sk_page_frag - return an appropriate page_frag
1940  * @sk: socket
1941  *
1942  * If socket allocation mode allows current thread to sleep, it means its
1943  * safe to use the per task page_frag instead of the per socket one.
1944  */
1945 static inline struct page_frag *sk_page_frag(struct sock *sk)
1946 {
1947         if (gfpflags_allow_blocking(sk->sk_allocation))
1948                 return &current->task_frag;
1949 
1950         return &sk->sk_frag;
1951 }
1952 
1953 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
1954 
1955 /*
1956  *      Default write policy as shown to user space via poll/select/SIGIO
1957  */
1958 static inline bool sock_writeable(const struct sock *sk)
1959 {
1960         return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
1961 }
1962 
1963 static inline gfp_t gfp_any(void)
1964 {
1965         return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1966 }
1967 
1968 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
1969 {
1970         return noblock ? 0 : sk->sk_rcvtimeo;
1971 }
1972 
1973 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
1974 {
1975         return noblock ? 0 : sk->sk_sndtimeo;
1976 }
1977 
1978 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1979 {
1980         return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1981 }
1982 
1983 /* Alas, with timeout socket operations are not restartable.
1984  * Compare this to poll().
1985  */
1986 static inline int sock_intr_errno(long timeo)
1987 {
1988         return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1989 }
1990 
1991 struct sock_skb_cb {
1992         u32 dropcount;
1993 };
1994 
1995 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
1996  * using skb->cb[] would keep using it directly and utilize its
1997  * alignement guarantee.
1998  */
1999 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2000                             sizeof(struct sock_skb_cb)))
2001 
2002 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2003                             SOCK_SKB_CB_OFFSET))
2004 
2005 #define sock_skb_cb_check_size(size) \
2006         BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2007 
2008 static inline void
2009 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2010 {
2011         SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops);
2012 }
2013 
2014 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2015                            struct sk_buff *skb);
2016 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2017                              struct sk_buff *skb);
2018 
2019 static inline void
2020 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2021 {
2022         ktime_t kt = skb->tstamp;
2023         struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2024 
2025         /*
2026          * generate control messages if
2027          * - receive time stamping in software requested
2028          * - software time stamp available and wanted
2029          * - hardware time stamps available and wanted
2030          */
2031         if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2032             (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2033             (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2034             (hwtstamps->hwtstamp.tv64 &&
2035              (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2036                 __sock_recv_timestamp(msg, sk, skb);
2037         else
2038                 sk->sk_stamp = kt;
2039 
2040         if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2041                 __sock_recv_wifi_status(msg, sk, skb);
2042 }
2043 
2044 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2045                               struct sk_buff *skb);
2046 
2047 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2048                                           struct sk_buff *skb)
2049 {
2050 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)                       | \
2051                            (1UL << SOCK_RCVTSTAMP))
2052 #define TSFLAGS_ANY       (SOF_TIMESTAMPING_SOFTWARE                    | \
2053                            SOF_TIMESTAMPING_RAW_HARDWARE)
2054 
2055         if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2056                 __sock_recv_ts_and_drops(msg, sk, skb);
2057         else
2058                 sk->sk_stamp = skb->tstamp;
2059 }
2060 
2061 void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags);
2062 
2063 /**
2064  * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2065  * @sk:         socket sending this packet
2066  * @tx_flags:   completed with instructions for time stamping
2067  *
2068  * Note : callers should take care of initial *tx_flags value (usually 0)
2069  */
2070 static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
2071 {
2072         if (unlikely(sk->sk_tsflags))
2073                 __sock_tx_timestamp(sk, tx_flags);
2074         if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2075                 *tx_flags |= SKBTX_WIFI_STATUS;
2076 }
2077 
2078 /**
2079  * sk_eat_skb - Release a skb if it is no longer needed
2080  * @sk: socket to eat this skb from
2081  * @skb: socket buffer to eat
2082  *
2083  * This routine must be called with interrupts disabled or with the socket
2084  * locked so that the sk_buff queue operation is ok.
2085 */
2086 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2087 {
2088         __skb_unlink(skb, &sk->sk_receive_queue);
2089         __kfree_skb(skb);
2090 }
2091 
2092 static inline
2093 struct net *sock_net(const struct sock *sk)
2094 {
2095         return read_pnet(&sk->sk_net);
2096 }
2097 
2098 static inline
2099 void sock_net_set(struct sock *sk, struct net *net)
2100 {
2101         write_pnet(&sk->sk_net, net);
2102 }
2103 
2104 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2105 {
2106         if (skb->sk) {
2107                 struct sock *sk = skb->sk;
2108 
2109                 skb->destructor = NULL;
2110                 skb->sk = NULL;
2111                 return sk;
2112         }
2113         return NULL;
2114 }
2115 
2116 /* This helper checks if a socket is a full socket,
2117  * ie _not_ a timewait or request socket.
2118  */
2119 static inline bool sk_fullsock(const struct sock *sk)
2120 {
2121         return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2122 }
2123 
2124 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2125  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2126  */
2127 static inline bool sk_listener(const struct sock *sk)
2128 {
2129         return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2130 }
2131 
2132 /**
2133  * sk_state_load - read sk->sk_state for lockless contexts
2134  * @sk: socket pointer
2135  *
2136  * Paired with sk_state_store(). Used in places we do not hold socket lock :
2137  * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
2138  */
2139 static inline int sk_state_load(const struct sock *sk)
2140 {
2141         return smp_load_acquire(&sk->sk_state);
2142 }
2143 
2144 /**
2145  * sk_state_store - update sk->sk_state
2146  * @sk: socket pointer
2147  * @newstate: new state
2148  *
2149  * Paired with sk_state_load(). Should be used in contexts where
2150  * state change might impact lockless readers.
2151  */
2152 static inline void sk_state_store(struct sock *sk, int newstate)
2153 {
2154         smp_store_release(&sk->sk_state, newstate);
2155 }
2156 
2157 void sock_enable_timestamp(struct sock *sk, int flag);
2158 int sock_get_timestamp(struct sock *, struct timeval __user *);
2159 int sock_get_timestampns(struct sock *, struct timespec __user *);
2160 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2161                        int type);
2162 
2163 bool sk_ns_capable(const struct sock *sk,
2164                    struct user_namespace *user_ns, int cap);
2165 bool sk_capable(const struct sock *sk, int cap);
2166 bool sk_net_capable(const struct sock *sk, int cap);
2167 
2168 extern __u32 sysctl_wmem_max;
2169 extern __u32 sysctl_rmem_max;
2170 
2171 extern int sysctl_tstamp_allow_data;
2172 extern int sysctl_optmem_max;
2173 
2174 extern __u32 sysctl_wmem_default;
2175 extern __u32 sysctl_rmem_default;
2176 
2177 #endif  /* _SOCK_H */
2178 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp