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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/module.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
58#include <linux/filter.h>
59#include <linux/rculist_nulls.h>
60#include <linux/poll.h>
61
62#include <linux/atomic.h>
63#include <net/dst.h>
64#include <net/checksum.h>
65
66/*
67 * This structure really needs to be cleaned up.
68 * Most of it is for TCP, and not used by any of
69 * the other protocols.
70 */
71
72/* Define this to get the SOCK_DBG debugging facility. */
73#define SOCK_DEBUGGING
74#ifdef SOCK_DEBUGGING
75#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
76 printk(KERN_DEBUG msg); } while (0)
77#else
78/* Validate arguments and do nothing */
79static inline void __attribute__ ((format (printf, 2, 3)))
80SOCK_DEBUG(struct sock *sk, const char *msg, ...)
81{
82}
83#endif
84
85/* This is the per-socket lock. The spinlock provides a synchronization
86 * between user contexts and software interrupt processing, whereas the
87 * mini-semaphore synchronizes multiple users amongst themselves.
88 */
89typedef struct {
90 spinlock_t slock;
91 int owned;
92 wait_queue_head_t wq;
93 /*
94 * We express the mutex-alike socket_lock semantics
95 * to the lock validator by explicitly managing
96 * the slock as a lock variant (in addition to
97 * the slock itself):
98 */
99#ifdef CONFIG_DEBUG_LOCK_ALLOC
100 struct lockdep_map dep_map;
101#endif
102} socket_lock_t;
103
104struct sock;
105struct proto;
106struct net;
107
108/**
109 * struct sock_common - minimal network layer representation of sockets
110 * @skc_daddr: Foreign IPv4 addr
111 * @skc_rcv_saddr: Bound local IPv4 addr
112 * @skc_hash: hash value used with various protocol lookup tables
113 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
114 * @skc_family: network address family
115 * @skc_state: Connection state
116 * @skc_reuse: %SO_REUSEADDR setting
117 * @skc_bound_dev_if: bound device index if != 0
118 * @skc_bind_node: bind hash linkage for various protocol lookup tables
119 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
120 * @skc_prot: protocol handlers inside a network family
121 * @skc_net: reference to the network namespace of this socket
122 * @skc_node: main hash linkage for various protocol lookup tables
123 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
124 * @skc_tx_queue_mapping: tx queue number for this connection
125 * @skc_refcnt: reference count
126 *
127 * This is the minimal network layer representation of sockets, the header
128 * for struct sock and struct inet_timewait_sock.
129 */
130struct sock_common {
131 /* skc_daddr and skc_rcv_saddr must be grouped :
132 * cf INET_MATCH() and INET_TW_MATCH()
133 */
134 __be32 skc_daddr;
135 __be32 skc_rcv_saddr;
136
137 union {
138 unsigned int skc_hash;
139 __u16 skc_u16hashes[2];
140 };
141 unsigned short skc_family;
142 volatile unsigned char skc_state;
143 unsigned char skc_reuse;
144 int skc_bound_dev_if;
145 union {
146 struct hlist_node skc_bind_node;
147 struct hlist_nulls_node skc_portaddr_node;
148 };
149 struct proto *skc_prot;
150#ifdef CONFIG_NET_NS
151 struct net *skc_net;
152#endif
153 /*
154 * fields between dontcopy_begin/dontcopy_end
155 * are not copied in sock_copy()
156 */
157 /* private: */
158 int skc_dontcopy_begin[0];
159 /* public: */
160 union {
161 struct hlist_node skc_node;
162 struct hlist_nulls_node skc_nulls_node;
163 };
164 int skc_tx_queue_mapping;
165 atomic_t skc_refcnt;
166 /* private: */
167 int skc_dontcopy_end[0];
168 /* public: */
169};
170
171/**
172 * struct sock - network layer representation of sockets
173 * @__sk_common: shared layout with inet_timewait_sock
174 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
175 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
176 * @sk_lock: synchronizer
177 * @sk_rcvbuf: size of receive buffer in bytes
178 * @sk_wq: sock wait queue and async head
179 * @sk_dst_cache: destination cache
180 * @sk_dst_lock: destination cache lock
181 * @sk_policy: flow policy
182 * @sk_receive_queue: incoming packets
183 * @sk_wmem_alloc: transmit queue bytes committed
184 * @sk_write_queue: Packet sending queue
185 * @sk_async_wait_queue: DMA copied packets
186 * @sk_omem_alloc: "o" is "option" or "other"
187 * @sk_wmem_queued: persistent queue size
188 * @sk_forward_alloc: space allocated forward
189 * @sk_allocation: allocation mode
190 * @sk_sndbuf: size of send buffer in bytes
191 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
192 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
193 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
194 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
195 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
196 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
197 * @sk_gso_max_size: Maximum GSO segment size to build
198 * @sk_lingertime: %SO_LINGER l_linger setting
199 * @sk_backlog: always used with the per-socket spinlock held
200 * @sk_callback_lock: used with the callbacks in the end of this struct
201 * @sk_error_queue: rarely used
202 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
203 * IPV6_ADDRFORM for instance)
204 * @sk_err: last error
205 * @sk_err_soft: errors that don't cause failure but are the cause of a
206 * persistent failure not just 'timed out'
207 * @sk_drops: raw/udp drops counter
208 * @sk_ack_backlog: current listen backlog
209 * @sk_max_ack_backlog: listen backlog set in listen()
210 * @sk_priority: %SO_PRIORITY setting
211 * @sk_type: socket type (%SOCK_STREAM, etc)
212 * @sk_protocol: which protocol this socket belongs in this network family
213 * @sk_peer_pid: &struct pid for this socket's peer
214 * @sk_peer_cred: %SO_PEERCRED setting
215 * @sk_rcvlowat: %SO_RCVLOWAT setting
216 * @sk_rcvtimeo: %SO_RCVTIMEO setting
217 * @sk_sndtimeo: %SO_SNDTIMEO setting
218 * @sk_rxhash: flow hash received from netif layer
219 * @sk_filter: socket filtering instructions
220 * @sk_protinfo: private area, net family specific, when not using slab
221 * @sk_timer: sock cleanup timer
222 * @sk_stamp: time stamp of last packet received
223 * @sk_socket: Identd and reporting IO signals
224 * @sk_user_data: RPC layer private data
225 * @sk_sndmsg_page: cached page for sendmsg
226 * @sk_sndmsg_off: cached offset for sendmsg
227 * @sk_send_head: front of stuff to transmit
228 * @sk_security: used by security modules
229 * @sk_mark: generic packet mark
230 * @sk_classid: this socket's cgroup classid
231 * @sk_write_pending: a write to stream socket waits to start
232 * @sk_state_change: callback to indicate change in the state of the sock
233 * @sk_data_ready: callback to indicate there is data to be processed
234 * @sk_write_space: callback to indicate there is bf sending space available
235 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
236 * @sk_backlog_rcv: callback to process the backlog
237 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
238 */
239struct sock {
240 /*
241 * Now struct inet_timewait_sock also uses sock_common, so please just
242 * don't add nothing before this first member (__sk_common) --acme
243 */
244 struct sock_common __sk_common;
245#define sk_node __sk_common.skc_node
246#define sk_nulls_node __sk_common.skc_nulls_node
247#define sk_refcnt __sk_common.skc_refcnt
248#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
249
250#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
251#define sk_dontcopy_end __sk_common.skc_dontcopy_end
252#define sk_hash __sk_common.skc_hash
253#define sk_family __sk_common.skc_family
254#define sk_state __sk_common.skc_state
255#define sk_reuse __sk_common.skc_reuse
256#define sk_bound_dev_if __sk_common.skc_bound_dev_if
257#define sk_bind_node __sk_common.skc_bind_node
258#define sk_prot __sk_common.skc_prot
259#define sk_net __sk_common.skc_net
260 socket_lock_t sk_lock;
261 struct sk_buff_head sk_receive_queue;
262 /*
263 * The backlog queue is special, it is always used with
264 * the per-socket spinlock held and requires low latency
265 * access. Therefore we special case it's implementation.
266 * Note : rmem_alloc is in this structure to fill a hole
267 * on 64bit arches, not because its logically part of
268 * backlog.
269 */
270 struct {
271 atomic_t rmem_alloc;
272 int len;
273 struct sk_buff *head;
274 struct sk_buff *tail;
275 } sk_backlog;
276#define sk_rmem_alloc sk_backlog.rmem_alloc
277 int sk_forward_alloc;
278#ifdef CONFIG_RPS
279 __u32 sk_rxhash;
280#endif
281 atomic_t sk_drops;
282 int sk_rcvbuf;
283
284 struct sk_filter __rcu *sk_filter;
285 struct socket_wq __rcu *sk_wq;
286
287#ifdef CONFIG_NET_DMA
288 struct sk_buff_head sk_async_wait_queue;
289#endif
290
291#ifdef CONFIG_XFRM
292 struct xfrm_policy *sk_policy[2];
293#endif
294 unsigned long sk_flags;
295 struct dst_entry *sk_dst_cache;
296 spinlock_t sk_dst_lock;
297 atomic_t sk_wmem_alloc;
298 atomic_t sk_omem_alloc;
299 int sk_sndbuf;
300 struct sk_buff_head sk_write_queue;
301 kmemcheck_bitfield_begin(flags);
302 unsigned int sk_shutdown : 2,
303 sk_no_check : 2,
304 sk_userlocks : 4,
305 sk_protocol : 8,
306 sk_type : 16;
307 kmemcheck_bitfield_end(flags);
308 int sk_wmem_queued;
309 gfp_t sk_allocation;
310 int sk_route_caps;
311 int sk_route_nocaps;
312 int sk_gso_type;
313 unsigned int sk_gso_max_size;
314 int sk_rcvlowat;
315 unsigned long sk_lingertime;
316 struct sk_buff_head sk_error_queue;
317 struct proto *sk_prot_creator;
318 rwlock_t sk_callback_lock;
319 int sk_err,
320 sk_err_soft;
321 unsigned short sk_ack_backlog;
322 unsigned short sk_max_ack_backlog;
323 __u32 sk_priority;
324 struct pid *sk_peer_pid;
325 const struct cred *sk_peer_cred;
326 long sk_rcvtimeo;
327 long sk_sndtimeo;
328 void *sk_protinfo;
329 struct timer_list sk_timer;
330 ktime_t sk_stamp;
331 struct socket *sk_socket;
332 void *sk_user_data;
333 struct page *sk_sndmsg_page;
334 struct sk_buff *sk_send_head;
335 __u32 sk_sndmsg_off;
336 int sk_write_pending;
337#ifdef CONFIG_SECURITY
338 void *sk_security;
339#endif
340 __u32 sk_mark;
341 u32 sk_classid;
342 void (*sk_state_change)(struct sock *sk);
343 void (*sk_data_ready)(struct sock *sk, int bytes);
344 void (*sk_write_space)(struct sock *sk);
345 void (*sk_error_report)(struct sock *sk);
346 int (*sk_backlog_rcv)(struct sock *sk,
347 struct sk_buff *skb);
348 void (*sk_destruct)(struct sock *sk);
349};
350
351/*
352 * Hashed lists helper routines
353 */
354static inline struct sock *sk_entry(const struct hlist_node *node)
355{
356 return hlist_entry(node, struct sock, sk_node);
357}
358
359static inline struct sock *__sk_head(const struct hlist_head *head)
360{
361 return hlist_entry(head->first, struct sock, sk_node);
362}
363
364static inline struct sock *sk_head(const struct hlist_head *head)
365{
366 return hlist_empty(head) ? NULL : __sk_head(head);
367}
368
369static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
370{
371 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
372}
373
374static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
375{
376 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
377}
378
379static inline struct sock *sk_next(const struct sock *sk)
380{
381 return sk->sk_node.next ?
382 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
383}
384
385static inline struct sock *sk_nulls_next(const struct sock *sk)
386{
387 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
388 hlist_nulls_entry(sk->sk_nulls_node.next,
389 struct sock, sk_nulls_node) :
390 NULL;
391}
392
393static inline int sk_unhashed(const struct sock *sk)
394{
395 return hlist_unhashed(&sk->sk_node);
396}
397
398static inline int sk_hashed(const struct sock *sk)
399{
400 return !sk_unhashed(sk);
401}
402
403static __inline__ void sk_node_init(struct hlist_node *node)
404{
405 node->pprev = NULL;
406}
407
408static __inline__ void sk_nulls_node_init(struct hlist_nulls_node *node)
409{
410 node->pprev = NULL;
411}
412
413static __inline__ void __sk_del_node(struct sock *sk)
414{
415 __hlist_del(&sk->sk_node);
416}
417
418/* NB: equivalent to hlist_del_init_rcu */
419static __inline__ int __sk_del_node_init(struct sock *sk)
420{
421 if (sk_hashed(sk)) {
422 __sk_del_node(sk);
423 sk_node_init(&sk->sk_node);
424 return 1;
425 }
426 return 0;
427}
428
429/* Grab socket reference count. This operation is valid only
430 when sk is ALREADY grabbed f.e. it is found in hash table
431 or a list and the lookup is made under lock preventing hash table
432 modifications.
433 */
434
435static inline void sock_hold(struct sock *sk)
436{
437 atomic_inc(&sk->sk_refcnt);
438}
439
440/* Ungrab socket in the context, which assumes that socket refcnt
441 cannot hit zero, f.e. it is true in context of any socketcall.
442 */
443static inline void __sock_put(struct sock *sk)
444{
445 atomic_dec(&sk->sk_refcnt);
446}
447
448static __inline__ int sk_del_node_init(struct sock *sk)
449{
450 int rc = __sk_del_node_init(sk);
451
452 if (rc) {
453 /* paranoid for a while -acme */
454 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
455 __sock_put(sk);
456 }
457 return rc;
458}
459#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
460
461static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk)
462{
463 if (sk_hashed(sk)) {
464 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
465 return 1;
466 }
467 return 0;
468}
469
470static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk)
471{
472 int rc = __sk_nulls_del_node_init_rcu(sk);
473
474 if (rc) {
475 /* paranoid for a while -acme */
476 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
477 __sock_put(sk);
478 }
479 return rc;
480}
481
482static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
483{
484 hlist_add_head(&sk->sk_node, list);
485}
486
487static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
488{
489 sock_hold(sk);
490 __sk_add_node(sk, list);
491}
492
493static __inline__ void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
494{
495 sock_hold(sk);
496 hlist_add_head_rcu(&sk->sk_node, list);
497}
498
499static __inline__ void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
500{
501 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
502}
503
504static __inline__ void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
505{
506 sock_hold(sk);
507 __sk_nulls_add_node_rcu(sk, list);
508}
509
510static __inline__ void __sk_del_bind_node(struct sock *sk)
511{
512 __hlist_del(&sk->sk_bind_node);
513}
514
515static __inline__ void sk_add_bind_node(struct sock *sk,
516 struct hlist_head *list)
517{
518 hlist_add_head(&sk->sk_bind_node, list);
519}
520
521#define sk_for_each(__sk, node, list) \
522 hlist_for_each_entry(__sk, node, list, sk_node)
523#define sk_for_each_rcu(__sk, node, list) \
524 hlist_for_each_entry_rcu(__sk, node, list, sk_node)
525#define sk_nulls_for_each(__sk, node, list) \
526 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
527#define sk_nulls_for_each_rcu(__sk, node, list) \
528 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
529#define sk_for_each_from(__sk, node) \
530 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
531 hlist_for_each_entry_from(__sk, node, sk_node)
532#define sk_nulls_for_each_from(__sk, node) \
533 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
534 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
535#define sk_for_each_safe(__sk, node, tmp, list) \
536 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
537#define sk_for_each_bound(__sk, node, list) \
538 hlist_for_each_entry(__sk, node, list, sk_bind_node)
539
540/* Sock flags */
541enum sock_flags {
542 SOCK_DEAD,
543 SOCK_DONE,
544 SOCK_URGINLINE,
545 SOCK_KEEPOPEN,
546 SOCK_LINGER,
547 SOCK_DESTROY,
548 SOCK_BROADCAST,
549 SOCK_TIMESTAMP,
550 SOCK_ZAPPED,
551 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
552 SOCK_DBG, /* %SO_DEBUG setting */
553 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
554 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
555 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
556 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
557 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
558 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
559 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
560 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
561 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
562 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
563 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
564 SOCK_FASYNC, /* fasync() active */
565 SOCK_RXQ_OVFL,
566 SOCK_ZEROCOPY, /* buffers from userspace */
567};
568
569static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
570{
571 nsk->sk_flags = osk->sk_flags;
572}
573
574static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
575{
576 __set_bit(flag, &sk->sk_flags);
577}
578
579static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
580{
581 __clear_bit(flag, &sk->sk_flags);
582}
583
584static inline int sock_flag(struct sock *sk, enum sock_flags flag)
585{
586 return test_bit(flag, &sk->sk_flags);
587}
588
589static inline void sk_acceptq_removed(struct sock *sk)
590{
591 sk->sk_ack_backlog--;
592}
593
594static inline void sk_acceptq_added(struct sock *sk)
595{
596 sk->sk_ack_backlog++;
597}
598
599static inline int sk_acceptq_is_full(struct sock *sk)
600{
601 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
602}
603
604/*
605 * Compute minimal free write space needed to queue new packets.
606 */
607static inline int sk_stream_min_wspace(struct sock *sk)
608{
609 return sk->sk_wmem_queued >> 1;
610}
611
612static inline int sk_stream_wspace(struct sock *sk)
613{
614 return sk->sk_sndbuf - sk->sk_wmem_queued;
615}
616
617extern void sk_stream_write_space(struct sock *sk);
618
619static inline int sk_stream_memory_free(struct sock *sk)
620{
621 return sk->sk_wmem_queued < sk->sk_sndbuf;
622}
623
624/* OOB backlog add */
625static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
626{
627 /* dont let skb dst not refcounted, we are going to leave rcu lock */
628 skb_dst_force(skb);
629
630 if (!sk->sk_backlog.tail)
631 sk->sk_backlog.head = skb;
632 else
633 sk->sk_backlog.tail->next = skb;
634
635 sk->sk_backlog.tail = skb;
636 skb->next = NULL;
637}
638
639/*
640 * Take into account size of receive queue and backlog queue
641 */
642static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb)
643{
644 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
645
646 return qsize + skb->truesize > sk->sk_rcvbuf;
647}
648
649/* The per-socket spinlock must be held here. */
650static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb)
651{
652 if (sk_rcvqueues_full(sk, skb))
653 return -ENOBUFS;
654
655 __sk_add_backlog(sk, skb);
656 sk->sk_backlog.len += skb->truesize;
657 return 0;
658}
659
660static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
661{
662 return sk->sk_backlog_rcv(sk, skb);
663}
664
665static inline void sock_rps_record_flow(const struct sock *sk)
666{
667#ifdef CONFIG_RPS
668 struct rps_sock_flow_table *sock_flow_table;
669
670 rcu_read_lock();
671 sock_flow_table = rcu_dereference(rps_sock_flow_table);
672 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
673 rcu_read_unlock();
674#endif
675}
676
677static inline void sock_rps_reset_flow(const struct sock *sk)
678{
679#ifdef CONFIG_RPS
680 struct rps_sock_flow_table *sock_flow_table;
681
682 rcu_read_lock();
683 sock_flow_table = rcu_dereference(rps_sock_flow_table);
684 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
685 rcu_read_unlock();
686#endif
687}
688
689static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash)
690{
691#ifdef CONFIG_RPS
692 if (unlikely(sk->sk_rxhash != rxhash)) {
693 sock_rps_reset_flow(sk);
694 sk->sk_rxhash = rxhash;
695 }
696#endif
697}
698
699#define sk_wait_event(__sk, __timeo, __condition) \
700 ({ int __rc; \
701 release_sock(__sk); \
702 __rc = __condition; \
703 if (!__rc) { \
704 *(__timeo) = schedule_timeout(*(__timeo)); \
705 } \
706 lock_sock(__sk); \
707 __rc = __condition; \
708 __rc; \
709 })
710
711extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
712extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
713extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
714extern int sk_stream_error(struct sock *sk, int flags, int err);
715extern void sk_stream_kill_queues(struct sock *sk);
716
717extern int sk_wait_data(struct sock *sk, long *timeo);
718
719struct request_sock_ops;
720struct timewait_sock_ops;
721struct inet_hashinfo;
722struct raw_hashinfo;
723
724/* Networking protocol blocks we attach to sockets.
725 * socket layer -> transport layer interface
726 * transport -> network interface is defined by struct inet_proto
727 */
728struct proto {
729 void (*close)(struct sock *sk,
730 long timeout);
731 int (*connect)(struct sock *sk,
732 struct sockaddr *uaddr,
733 int addr_len);
734 int (*disconnect)(struct sock *sk, int flags);
735
736 struct sock * (*accept) (struct sock *sk, int flags, int *err);
737
738 int (*ioctl)(struct sock *sk, int cmd,
739 unsigned long arg);
740 int (*init)(struct sock *sk);
741 void (*destroy)(struct sock *sk);
742 void (*shutdown)(struct sock *sk, int how);
743 int (*setsockopt)(struct sock *sk, int level,
744 int optname, char __user *optval,
745 unsigned int optlen);
746 int (*getsockopt)(struct sock *sk, int level,
747 int optname, char __user *optval,
748 int __user *option);
749#ifdef CONFIG_COMPAT
750 int (*compat_setsockopt)(struct sock *sk,
751 int level,
752 int optname, char __user *optval,
753 unsigned int optlen);
754 int (*compat_getsockopt)(struct sock *sk,
755 int level,
756 int optname, char __user *optval,
757 int __user *option);
758 int (*compat_ioctl)(struct sock *sk,
759 unsigned int cmd, unsigned long arg);
760#endif
761 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
762 struct msghdr *msg, size_t len);
763 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
764 struct msghdr *msg,
765 size_t len, int noblock, int flags,
766 int *addr_len);
767 int (*sendpage)(struct sock *sk, struct page *page,
768 int offset, size_t size, int flags);
769 int (*bind)(struct sock *sk,
770 struct sockaddr *uaddr, int addr_len);
771
772 int (*backlog_rcv) (struct sock *sk,
773 struct sk_buff *skb);
774
775 /* Keeping track of sk's, looking them up, and port selection methods. */
776 void (*hash)(struct sock *sk);
777 void (*unhash)(struct sock *sk);
778 void (*rehash)(struct sock *sk);
779 int (*get_port)(struct sock *sk, unsigned short snum);
780 void (*clear_sk)(struct sock *sk, int size);
781
782 /* Keeping track of sockets in use */
783#ifdef CONFIG_PROC_FS
784 unsigned int inuse_idx;
785#endif
786
787 /* Memory pressure */
788 void (*enter_memory_pressure)(struct sock *sk);
789 atomic_long_t *memory_allocated; /* Current allocated memory. */
790 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
791 /*
792 * Pressure flag: try to collapse.
793 * Technical note: it is used by multiple contexts non atomically.
794 * All the __sk_mem_schedule() is of this nature: accounting
795 * is strict, actions are advisory and have some latency.
796 */
797 int *memory_pressure;
798 long *sysctl_mem;
799 int *sysctl_wmem;
800 int *sysctl_rmem;
801 int max_header;
802 bool no_autobind;
803
804 struct kmem_cache *slab;
805 unsigned int obj_size;
806 int slab_flags;
807
808 struct percpu_counter *orphan_count;
809
810 struct request_sock_ops *rsk_prot;
811 struct timewait_sock_ops *twsk_prot;
812
813 union {
814 struct inet_hashinfo *hashinfo;
815 struct udp_table *udp_table;
816 struct raw_hashinfo *raw_hash;
817 } h;
818
819 struct module *owner;
820
821 char name[32];
822
823 struct list_head node;
824#ifdef SOCK_REFCNT_DEBUG
825 atomic_t socks;
826#endif
827};
828
829extern int proto_register(struct proto *prot, int alloc_slab);
830extern void proto_unregister(struct proto *prot);
831
832#ifdef SOCK_REFCNT_DEBUG
833static inline void sk_refcnt_debug_inc(struct sock *sk)
834{
835 atomic_inc(&sk->sk_prot->socks);
836}
837
838static inline void sk_refcnt_debug_dec(struct sock *sk)
839{
840 atomic_dec(&sk->sk_prot->socks);
841 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
842 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
843}
844
845static inline void sk_refcnt_debug_release(const struct sock *sk)
846{
847 if (atomic_read(&sk->sk_refcnt) != 1)
848 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
849 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
850}
851#else /* SOCK_REFCNT_DEBUG */
852#define sk_refcnt_debug_inc(sk) do { } while (0)
853#define sk_refcnt_debug_dec(sk) do { } while (0)
854#define sk_refcnt_debug_release(sk) do { } while (0)
855#endif /* SOCK_REFCNT_DEBUG */
856
857
858#ifdef CONFIG_PROC_FS
859/* Called with local bh disabled */
860extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
861extern int sock_prot_inuse_get(struct net *net, struct proto *proto);
862#else
863static void inline sock_prot_inuse_add(struct net *net, struct proto *prot,
864 int inc)
865{
866}
867#endif
868
869
870/* With per-bucket locks this operation is not-atomic, so that
871 * this version is not worse.
872 */
873static inline void __sk_prot_rehash(struct sock *sk)
874{
875 sk->sk_prot->unhash(sk);
876 sk->sk_prot->hash(sk);
877}
878
879void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
880
881/* About 10 seconds */
882#define SOCK_DESTROY_TIME (10*HZ)
883
884/* Sockets 0-1023 can't be bound to unless you are superuser */
885#define PROT_SOCK 1024
886
887#define SHUTDOWN_MASK 3
888#define RCV_SHUTDOWN 1
889#define SEND_SHUTDOWN 2
890
891#define SOCK_SNDBUF_LOCK 1
892#define SOCK_RCVBUF_LOCK 2
893#define SOCK_BINDADDR_LOCK 4
894#define SOCK_BINDPORT_LOCK 8
895
896/* sock_iocb: used to kick off async processing of socket ios */
897struct sock_iocb {
898 struct list_head list;
899
900 int flags;
901 int size;
902 struct socket *sock;
903 struct sock *sk;
904 struct scm_cookie *scm;
905 struct msghdr *msg, async_msg;
906 struct kiocb *kiocb;
907};
908
909static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
910{
911 return (struct sock_iocb *)iocb->private;
912}
913
914static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
915{
916 return si->kiocb;
917}
918
919struct socket_alloc {
920 struct socket socket;
921 struct inode vfs_inode;
922};
923
924static inline struct socket *SOCKET_I(struct inode *inode)
925{
926 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
927}
928
929static inline struct inode *SOCK_INODE(struct socket *socket)
930{
931 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
932}
933
934/*
935 * Functions for memory accounting
936 */
937extern int __sk_mem_schedule(struct sock *sk, int size, int kind);
938extern void __sk_mem_reclaim(struct sock *sk);
939
940#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
941#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
942#define SK_MEM_SEND 0
943#define SK_MEM_RECV 1
944
945static inline int sk_mem_pages(int amt)
946{
947 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
948}
949
950static inline int sk_has_account(struct sock *sk)
951{
952 /* return true if protocol supports memory accounting */
953 return !!sk->sk_prot->memory_allocated;
954}
955
956static inline int sk_wmem_schedule(struct sock *sk, int size)
957{
958 if (!sk_has_account(sk))
959 return 1;
960 return size <= sk->sk_forward_alloc ||
961 __sk_mem_schedule(sk, size, SK_MEM_SEND);
962}
963
964static inline int sk_rmem_schedule(struct sock *sk, int size)
965{
966 if (!sk_has_account(sk))
967 return 1;
968 return size <= sk->sk_forward_alloc ||
969 __sk_mem_schedule(sk, size, SK_MEM_RECV);
970}
971
972static inline void sk_mem_reclaim(struct sock *sk)
973{
974 if (!sk_has_account(sk))
975 return;
976 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
977 __sk_mem_reclaim(sk);
978}
979
980static inline void sk_mem_reclaim_partial(struct sock *sk)
981{
982 if (!sk_has_account(sk))
983 return;
984 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
985 __sk_mem_reclaim(sk);
986}
987
988static inline void sk_mem_charge(struct sock *sk, int size)
989{
990 if (!sk_has_account(sk))
991 return;
992 sk->sk_forward_alloc -= size;
993}
994
995static inline void sk_mem_uncharge(struct sock *sk, int size)
996{
997 if (!sk_has_account(sk))
998 return;
999 sk->sk_forward_alloc += size;
1000}
1001
1002static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1003{
1004 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1005 sk->sk_wmem_queued -= skb->truesize;
1006 sk_mem_uncharge(sk, skb->truesize);
1007 __kfree_skb(skb);
1008}
1009
1010/* Used by processes to "lock" a socket state, so that
1011 * interrupts and bottom half handlers won't change it
1012 * from under us. It essentially blocks any incoming
1013 * packets, so that we won't get any new data or any
1014 * packets that change the state of the socket.
1015 *
1016 * While locked, BH processing will add new packets to
1017 * the backlog queue. This queue is processed by the
1018 * owner of the socket lock right before it is released.
1019 *
1020 * Since ~2.3.5 it is also exclusive sleep lock serializing
1021 * accesses from user process context.
1022 */
1023#define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1024
1025/*
1026 * Macro so as to not evaluate some arguments when
1027 * lockdep is not enabled.
1028 *
1029 * Mark both the sk_lock and the sk_lock.slock as a
1030 * per-address-family lock class.
1031 */
1032#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1033do { \
1034 sk->sk_lock.owned = 0; \
1035 init_waitqueue_head(&sk->sk_lock.wq); \
1036 spin_lock_init(&(sk)->sk_lock.slock); \
1037 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1038 sizeof((sk)->sk_lock)); \
1039 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1040 (skey), (sname)); \
1041 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1042} while (0)
1043
1044extern void lock_sock_nested(struct sock *sk, int subclass);
1045
1046static inline void lock_sock(struct sock *sk)
1047{
1048 lock_sock_nested(sk, 0);
1049}
1050
1051extern void release_sock(struct sock *sk);
1052
1053/* BH context may only use the following locking interface. */
1054#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1055#define bh_lock_sock_nested(__sk) \
1056 spin_lock_nested(&((__sk)->sk_lock.slock), \
1057 SINGLE_DEPTH_NESTING)
1058#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1059
1060extern bool lock_sock_fast(struct sock *sk);
1061/**
1062 * unlock_sock_fast - complement of lock_sock_fast
1063 * @sk: socket
1064 * @slow: slow mode
1065 *
1066 * fast unlock socket for user context.
1067 * If slow mode is on, we call regular release_sock()
1068 */
1069static inline void unlock_sock_fast(struct sock *sk, bool slow)
1070{
1071 if (slow)
1072 release_sock(sk);
1073 else
1074 spin_unlock_bh(&sk->sk_lock.slock);
1075}
1076
1077
1078extern struct sock *sk_alloc(struct net *net, int family,
1079 gfp_t priority,
1080 struct proto *prot);
1081extern void sk_free(struct sock *sk);
1082extern void sk_release_kernel(struct sock *sk);
1083extern struct sock *sk_clone(const struct sock *sk,
1084 const gfp_t priority);
1085
1086extern struct sk_buff *sock_wmalloc(struct sock *sk,
1087 unsigned long size, int force,
1088 gfp_t priority);
1089extern struct sk_buff *sock_rmalloc(struct sock *sk,
1090 unsigned long size, int force,
1091 gfp_t priority);
1092extern void sock_wfree(struct sk_buff *skb);
1093extern void sock_rfree(struct sk_buff *skb);
1094
1095extern int sock_setsockopt(struct socket *sock, int level,
1096 int op, char __user *optval,
1097 unsigned int optlen);
1098
1099extern int sock_getsockopt(struct socket *sock, int level,
1100 int op, char __user *optval,
1101 int __user *optlen);
1102extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1103 unsigned long size,
1104 int noblock,
1105 int *errcode);
1106extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
1107 unsigned long header_len,
1108 unsigned long data_len,
1109 int noblock,
1110 int *errcode);
1111extern void *sock_kmalloc(struct sock *sk, int size,
1112 gfp_t priority);
1113extern void sock_kfree_s(struct sock *sk, void *mem, int size);
1114extern void sk_send_sigurg(struct sock *sk);
1115
1116#ifdef CONFIG_CGROUPS
1117extern void sock_update_classid(struct sock *sk);
1118#else
1119static inline void sock_update_classid(struct sock *sk)
1120{
1121}
1122#endif
1123
1124/*
1125 * Functions to fill in entries in struct proto_ops when a protocol
1126 * does not implement a particular function.
1127 */
1128extern int sock_no_bind(struct socket *,
1129 struct sockaddr *, int);
1130extern int sock_no_connect(struct socket *,
1131 struct sockaddr *, int, int);
1132extern int sock_no_socketpair(struct socket *,
1133 struct socket *);
1134extern int sock_no_accept(struct socket *,
1135 struct socket *, int);
1136extern int sock_no_getname(struct socket *,
1137 struct sockaddr *, int *, int);
1138extern unsigned int sock_no_poll(struct file *, struct socket *,
1139 struct poll_table_struct *);
1140extern int sock_no_ioctl(struct socket *, unsigned int,
1141 unsigned long);
1142extern int sock_no_listen(struct socket *, int);
1143extern int sock_no_shutdown(struct socket *, int);
1144extern int sock_no_getsockopt(struct socket *, int , int,
1145 char __user *, int __user *);
1146extern int sock_no_setsockopt(struct socket *, int, int,
1147 char __user *, unsigned int);
1148extern int sock_no_sendmsg(struct kiocb *, struct socket *,
1149 struct msghdr *, size_t);
1150extern int sock_no_recvmsg(struct kiocb *, struct socket *,
1151 struct msghdr *, size_t, int);
1152extern int sock_no_mmap(struct file *file,
1153 struct socket *sock,
1154 struct vm_area_struct *vma);
1155extern ssize_t sock_no_sendpage(struct socket *sock,
1156 struct page *page,
1157 int offset, size_t size,
1158 int flags);
1159
1160/*
1161 * Functions to fill in entries in struct proto_ops when a protocol
1162 * uses the inet style.
1163 */
1164extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
1165 char __user *optval, int __user *optlen);
1166extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1167 struct msghdr *msg, size_t size, int flags);
1168extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
1169 char __user *optval, unsigned int optlen);
1170extern int compat_sock_common_getsockopt(struct socket *sock, int level,
1171 int optname, char __user *optval, int __user *optlen);
1172extern int compat_sock_common_setsockopt(struct socket *sock, int level,
1173 int optname, char __user *optval, unsigned int optlen);
1174
1175extern void sk_common_release(struct sock *sk);
1176
1177/*
1178 * Default socket callbacks and setup code
1179 */
1180
1181/* Initialise core socket variables */
1182extern void sock_init_data(struct socket *sock, struct sock *sk);
1183
1184extern void sk_filter_release_rcu(struct rcu_head *rcu);
1185
1186/**
1187 * sk_filter_release - release a socket filter
1188 * @fp: filter to remove
1189 *
1190 * Remove a filter from a socket and release its resources.
1191 */
1192
1193static inline void sk_filter_release(struct sk_filter *fp)
1194{
1195 if (atomic_dec_and_test(&fp->refcnt))
1196 call_rcu(&fp->rcu, sk_filter_release_rcu);
1197}
1198
1199static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
1200{
1201 unsigned int size = sk_filter_len(fp);
1202
1203 atomic_sub(size, &sk->sk_omem_alloc);
1204 sk_filter_release(fp);
1205}
1206
1207static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
1208{
1209 atomic_inc(&fp->refcnt);
1210 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
1211}
1212
1213/*
1214 * Socket reference counting postulates.
1215 *
1216 * * Each user of socket SHOULD hold a reference count.
1217 * * Each access point to socket (an hash table bucket, reference from a list,
1218 * running timer, skb in flight MUST hold a reference count.
1219 * * When reference count hits 0, it means it will never increase back.
1220 * * When reference count hits 0, it means that no references from
1221 * outside exist to this socket and current process on current CPU
1222 * is last user and may/should destroy this socket.
1223 * * sk_free is called from any context: process, BH, IRQ. When
1224 * it is called, socket has no references from outside -> sk_free
1225 * may release descendant resources allocated by the socket, but
1226 * to the time when it is called, socket is NOT referenced by any
1227 * hash tables, lists etc.
1228 * * Packets, delivered from outside (from network or from another process)
1229 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1230 * when they sit in queue. Otherwise, packets will leak to hole, when
1231 * socket is looked up by one cpu and unhasing is made by another CPU.
1232 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1233 * (leak to backlog). Packet socket does all the processing inside
1234 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1235 * use separate SMP lock, so that they are prone too.
1236 */
1237
1238/* Ungrab socket and destroy it, if it was the last reference. */
1239static inline void sock_put(struct sock *sk)
1240{
1241 if (atomic_dec_and_test(&sk->sk_refcnt))
1242 sk_free(sk);
1243}
1244
1245extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1246 const int nested);
1247
1248static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1249{
1250 sk->sk_tx_queue_mapping = tx_queue;
1251}
1252
1253static inline void sk_tx_queue_clear(struct sock *sk)
1254{
1255 sk->sk_tx_queue_mapping = -1;
1256}
1257
1258static inline int sk_tx_queue_get(const struct sock *sk)
1259{
1260 return sk ? sk->sk_tx_queue_mapping : -1;
1261}
1262
1263static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1264{
1265 sk_tx_queue_clear(sk);
1266 sk->sk_socket = sock;
1267}
1268
1269static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1270{
1271 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1272 return &rcu_dereference_raw(sk->sk_wq)->wait;
1273}
1274/* Detach socket from process context.
1275 * Announce socket dead, detach it from wait queue and inode.
1276 * Note that parent inode held reference count on this struct sock,
1277 * we do not release it in this function, because protocol
1278 * probably wants some additional cleanups or even continuing
1279 * to work with this socket (TCP).
1280 */
1281static inline void sock_orphan(struct sock *sk)
1282{
1283 write_lock_bh(&sk->sk_callback_lock);
1284 sock_set_flag(sk, SOCK_DEAD);
1285 sk_set_socket(sk, NULL);
1286 sk->sk_wq = NULL;
1287 write_unlock_bh(&sk->sk_callback_lock);
1288}
1289
1290static inline void sock_graft(struct sock *sk, struct socket *parent)
1291{
1292 write_lock_bh(&sk->sk_callback_lock);
1293 sk->sk_wq = parent->wq;
1294 parent->sk = sk;
1295 sk_set_socket(sk, parent);
1296 security_sock_graft(sk, parent);
1297 write_unlock_bh(&sk->sk_callback_lock);
1298}
1299
1300extern int sock_i_uid(struct sock *sk);
1301extern unsigned long sock_i_ino(struct sock *sk);
1302
1303static inline struct dst_entry *
1304__sk_dst_get(struct sock *sk)
1305{
1306 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1307 lockdep_is_held(&sk->sk_lock.slock));
1308}
1309
1310static inline struct dst_entry *
1311sk_dst_get(struct sock *sk)
1312{
1313 struct dst_entry *dst;
1314
1315 rcu_read_lock();
1316 dst = rcu_dereference(sk->sk_dst_cache);
1317 if (dst)
1318 dst_hold(dst);
1319 rcu_read_unlock();
1320 return dst;
1321}
1322
1323extern void sk_reset_txq(struct sock *sk);
1324
1325static inline void dst_negative_advice(struct sock *sk)
1326{
1327 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1328
1329 if (dst && dst->ops->negative_advice) {
1330 ndst = dst->ops->negative_advice(dst);
1331
1332 if (ndst != dst) {
1333 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1334 sk_reset_txq(sk);
1335 }
1336 }
1337}
1338
1339static inline void
1340__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1341{
1342 struct dst_entry *old_dst;
1343
1344 sk_tx_queue_clear(sk);
1345 /*
1346 * This can be called while sk is owned by the caller only,
1347 * with no state that can be checked in a rcu_dereference_check() cond
1348 */
1349 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1350 rcu_assign_pointer(sk->sk_dst_cache, dst);
1351 dst_release(old_dst);
1352}
1353
1354static inline void
1355sk_dst_set(struct sock *sk, struct dst_entry *dst)
1356{
1357 spin_lock(&sk->sk_dst_lock);
1358 __sk_dst_set(sk, dst);
1359 spin_unlock(&sk->sk_dst_lock);
1360}
1361
1362static inline void
1363__sk_dst_reset(struct sock *sk)
1364{
1365 __sk_dst_set(sk, NULL);
1366}
1367
1368static inline void
1369sk_dst_reset(struct sock *sk)
1370{
1371 spin_lock(&sk->sk_dst_lock);
1372 __sk_dst_reset(sk);
1373 spin_unlock(&sk->sk_dst_lock);
1374}
1375
1376extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1377
1378extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1379
1380static inline int sk_can_gso(const struct sock *sk)
1381{
1382 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1383}
1384
1385extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1386
1387static inline void sk_nocaps_add(struct sock *sk, int flags)
1388{
1389 sk->sk_route_nocaps |= flags;
1390 sk->sk_route_caps &= ~flags;
1391}
1392
1393static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1394 char __user *from, char *to,
1395 int copy, int offset)
1396{
1397 if (skb->ip_summed == CHECKSUM_NONE) {
1398 int err = 0;
1399 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1400 if (err)
1401 return err;
1402 skb->csum = csum_block_add(skb->csum, csum, offset);
1403 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1404 if (!access_ok(VERIFY_READ, from, copy) ||
1405 __copy_from_user_nocache(to, from, copy))
1406 return -EFAULT;
1407 } else if (copy_from_user(to, from, copy))
1408 return -EFAULT;
1409
1410 return 0;
1411}
1412
1413static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1414 char __user *from, int copy)
1415{
1416 int err, offset = skb->len;
1417
1418 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1419 copy, offset);
1420 if (err)
1421 __skb_trim(skb, offset);
1422
1423 return err;
1424}
1425
1426static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1427 struct sk_buff *skb,
1428 struct page *page,
1429 int off, int copy)
1430{
1431 int err;
1432
1433 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1434 copy, skb->len);
1435 if (err)
1436 return err;
1437
1438 skb->len += copy;
1439 skb->data_len += copy;
1440 skb->truesize += copy;
1441 sk->sk_wmem_queued += copy;
1442 sk_mem_charge(sk, copy);
1443 return 0;
1444}
1445
1446static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1447 struct sk_buff *skb, struct page *page,
1448 int off, int copy)
1449{
1450 if (skb->ip_summed == CHECKSUM_NONE) {
1451 int err = 0;
1452 __wsum csum = csum_and_copy_from_user(from,
1453 page_address(page) + off,
1454 copy, 0, &err);
1455 if (err)
1456 return err;
1457 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1458 } else if (copy_from_user(page_address(page) + off, from, copy))
1459 return -EFAULT;
1460
1461 skb->len += copy;
1462 skb->data_len += copy;
1463 skb->truesize += copy;
1464 sk->sk_wmem_queued += copy;
1465 sk_mem_charge(sk, copy);
1466 return 0;
1467}
1468
1469/**
1470 * sk_wmem_alloc_get - returns write allocations
1471 * @sk: socket
1472 *
1473 * Returns sk_wmem_alloc minus initial offset of one
1474 */
1475static inline int sk_wmem_alloc_get(const struct sock *sk)
1476{
1477 return atomic_read(&sk->sk_wmem_alloc) - 1;
1478}
1479
1480/**
1481 * sk_rmem_alloc_get - returns read allocations
1482 * @sk: socket
1483 *
1484 * Returns sk_rmem_alloc
1485 */
1486static inline int sk_rmem_alloc_get(const struct sock *sk)
1487{
1488 return atomic_read(&sk->sk_rmem_alloc);
1489}
1490
1491/**
1492 * sk_has_allocations - check if allocations are outstanding
1493 * @sk: socket
1494 *
1495 * Returns true if socket has write or read allocations
1496 */
1497static inline int sk_has_allocations(const struct sock *sk)
1498{
1499 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1500}
1501
1502/**
1503 * wq_has_sleeper - check if there are any waiting processes
1504 * @wq: struct socket_wq
1505 *
1506 * Returns true if socket_wq has waiting processes
1507 *
1508 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1509 * barrier call. They were added due to the race found within the tcp code.
1510 *
1511 * Consider following tcp code paths:
1512 *
1513 * CPU1 CPU2
1514 *
1515 * sys_select receive packet
1516 * ... ...
1517 * __add_wait_queue update tp->rcv_nxt
1518 * ... ...
1519 * tp->rcv_nxt check sock_def_readable
1520 * ... {
1521 * schedule rcu_read_lock();
1522 * wq = rcu_dereference(sk->sk_wq);
1523 * if (wq && waitqueue_active(&wq->wait))
1524 * wake_up_interruptible(&wq->wait)
1525 * ...
1526 * }
1527 *
1528 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1529 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1530 * could then endup calling schedule and sleep forever if there are no more
1531 * data on the socket.
1532 *
1533 */
1534static inline bool wq_has_sleeper(struct socket_wq *wq)
1535{
1536
1537 /*
1538 * We need to be sure we are in sync with the
1539 * add_wait_queue modifications to the wait queue.
1540 *
1541 * This memory barrier is paired in the sock_poll_wait.
1542 */
1543 smp_mb();
1544 return wq && waitqueue_active(&wq->wait);
1545}
1546
1547/**
1548 * sock_poll_wait - place memory barrier behind the poll_wait call.
1549 * @filp: file
1550 * @wait_address: socket wait queue
1551 * @p: poll_table
1552 *
1553 * See the comments in the wq_has_sleeper function.
1554 */
1555static inline void sock_poll_wait(struct file *filp,
1556 wait_queue_head_t *wait_address, poll_table *p)
1557{
1558 if (p && wait_address) {
1559 poll_wait(filp, wait_address, p);
1560 /*
1561 * We need to be sure we are in sync with the
1562 * socket flags modification.
1563 *
1564 * This memory barrier is paired in the wq_has_sleeper.
1565 */
1566 smp_mb();
1567 }
1568}
1569
1570/*
1571 * Queue a received datagram if it will fit. Stream and sequenced
1572 * protocols can't normally use this as they need to fit buffers in
1573 * and play with them.
1574 *
1575 * Inlined as it's very short and called for pretty much every
1576 * packet ever received.
1577 */
1578
1579static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1580{
1581 skb_orphan(skb);
1582 skb->sk = sk;
1583 skb->destructor = sock_wfree;
1584 /*
1585 * We used to take a refcount on sk, but following operation
1586 * is enough to guarantee sk_free() wont free this sock until
1587 * all in-flight packets are completed
1588 */
1589 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1590}
1591
1592static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1593{
1594 skb_orphan(skb);
1595 skb->sk = sk;
1596 skb->destructor = sock_rfree;
1597 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1598 sk_mem_charge(sk, skb->truesize);
1599}
1600
1601extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1602 unsigned long expires);
1603
1604extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1605
1606extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1607
1608extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1609
1610/*
1611 * Recover an error report and clear atomically
1612 */
1613
1614static inline int sock_error(struct sock *sk)
1615{
1616 int err;
1617 if (likely(!sk->sk_err))
1618 return 0;
1619 err = xchg(&sk->sk_err, 0);
1620 return -err;
1621}
1622
1623static inline unsigned long sock_wspace(struct sock *sk)
1624{
1625 int amt = 0;
1626
1627 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1628 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1629 if (amt < 0)
1630 amt = 0;
1631 }
1632 return amt;
1633}
1634
1635static inline void sk_wake_async(struct sock *sk, int how, int band)
1636{
1637 if (sock_flag(sk, SOCK_FASYNC))
1638 sock_wake_async(sk->sk_socket, how, band);
1639}
1640
1641#define SOCK_MIN_SNDBUF 2048
1642/*
1643 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
1644 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
1645 */
1646#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
1647
1648static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1649{
1650 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1651 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1652 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1653 }
1654}
1655
1656struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
1657
1658static inline struct page *sk_stream_alloc_page(struct sock *sk)
1659{
1660 struct page *page = NULL;
1661
1662 page = alloc_pages(sk->sk_allocation, 0);
1663 if (!page) {
1664 sk->sk_prot->enter_memory_pressure(sk);
1665 sk_stream_moderate_sndbuf(sk);
1666 }
1667 return page;
1668}
1669
1670/*
1671 * Default write policy as shown to user space via poll/select/SIGIO
1672 */
1673static inline int sock_writeable(const struct sock *sk)
1674{
1675 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
1676}
1677
1678static inline gfp_t gfp_any(void)
1679{
1680 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1681}
1682
1683static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1684{
1685 return noblock ? 0 : sk->sk_rcvtimeo;
1686}
1687
1688static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1689{
1690 return noblock ? 0 : sk->sk_sndtimeo;
1691}
1692
1693static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1694{
1695 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1696}
1697
1698/* Alas, with timeout socket operations are not restartable.
1699 * Compare this to poll().
1700 */
1701static inline int sock_intr_errno(long timeo)
1702{
1703 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1704}
1705
1706extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
1707 struct sk_buff *skb);
1708
1709static __inline__ void
1710sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1711{
1712 ktime_t kt = skb->tstamp;
1713 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
1714
1715 /*
1716 * generate control messages if
1717 * - receive time stamping in software requested (SOCK_RCVTSTAMP
1718 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
1719 * - software time stamp available and wanted
1720 * (SOCK_TIMESTAMPING_SOFTWARE)
1721 * - hardware time stamps available and wanted
1722 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
1723 * SOCK_TIMESTAMPING_RAW_HARDWARE)
1724 */
1725 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
1726 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
1727 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
1728 (hwtstamps->hwtstamp.tv64 &&
1729 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
1730 (hwtstamps->syststamp.tv64 &&
1731 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
1732 __sock_recv_timestamp(msg, sk, skb);
1733 else
1734 sk->sk_stamp = kt;
1735}
1736
1737extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1738 struct sk_buff *skb);
1739
1740static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1741 struct sk_buff *skb)
1742{
1743#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
1744 (1UL << SOCK_RCVTSTAMP) | \
1745 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
1746 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
1747 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
1748 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
1749
1750 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
1751 __sock_recv_ts_and_drops(msg, sk, skb);
1752 else
1753 sk->sk_stamp = skb->tstamp;
1754}
1755
1756/**
1757 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
1758 * @sk: socket sending this packet
1759 * @tx_flags: filled with instructions for time stamping
1760 *
1761 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
1762 * parameters are invalid.
1763 */
1764extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
1765
1766/**
1767 * sk_eat_skb - Release a skb if it is no longer needed
1768 * @sk: socket to eat this skb from
1769 * @skb: socket buffer to eat
1770 * @copied_early: flag indicating whether DMA operations copied this data early
1771 *
1772 * This routine must be called with interrupts disabled or with the socket
1773 * locked so that the sk_buff queue operation is ok.
1774*/
1775#ifdef CONFIG_NET_DMA
1776static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1777{
1778 __skb_unlink(skb, &sk->sk_receive_queue);
1779 if (!copied_early)
1780 __kfree_skb(skb);
1781 else
1782 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
1783}
1784#else
1785static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1786{
1787 __skb_unlink(skb, &sk->sk_receive_queue);
1788 __kfree_skb(skb);
1789}
1790#endif
1791
1792static inline
1793struct net *sock_net(const struct sock *sk)
1794{
1795 return read_pnet(&sk->sk_net);
1796}
1797
1798static inline
1799void sock_net_set(struct sock *sk, struct net *net)
1800{
1801 write_pnet(&sk->sk_net, net);
1802}
1803
1804/*
1805 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
1806 * They should not hold a reference to a namespace in order to allow
1807 * to stop it.
1808 * Sockets after sk_change_net should be released using sk_release_kernel
1809 */
1810static inline void sk_change_net(struct sock *sk, struct net *net)
1811{
1812 put_net(sock_net(sk));
1813 sock_net_set(sk, hold_net(net));
1814}
1815
1816static inline struct sock *skb_steal_sock(struct sk_buff *skb)
1817{
1818 if (unlikely(skb->sk)) {
1819 struct sock *sk = skb->sk;
1820
1821 skb->destructor = NULL;
1822 skb->sk = NULL;
1823 return sk;
1824 }
1825 return NULL;
1826}
1827
1828extern void sock_enable_timestamp(struct sock *sk, int flag);
1829extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1830extern int sock_get_timestampns(struct sock *, struct timespec __user *);
1831
1832/*
1833 * Enable debug/info messages
1834 */
1835extern int net_msg_warn;
1836#define NETDEBUG(fmt, args...) \
1837 do { if (net_msg_warn) printk(fmt,##args); } while (0)
1838
1839#define LIMIT_NETDEBUG(fmt, args...) \
1840 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
1841
1842extern __u32 sysctl_wmem_max;
1843extern __u32 sysctl_rmem_max;
1844
1845extern void sk_init(void);
1846
1847extern int sysctl_optmem_max;
1848
1849extern __u32 sysctl_wmem_default;
1850extern __u32 sysctl_rmem_default;
1851
1852#endif /* _SOCK_H */
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 */
87static inline __printf(2, 3)
88void 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 */
97typedef 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
112struct sock;
113struct proto;
114struct net;
115
116typedef __u32 __bitwise __portpair;
117typedef __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 */
148struct 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 */
306struct 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
459static 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
467static 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
477static 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 */
486static inline struct sock *sk_entry(const struct hlist_node *node)
487{
488 return hlist_entry(node, struct sock, sk_node);
489}
490
491static inline struct sock *__sk_head(const struct hlist_head *head)
492{
493 return hlist_entry(head->first, struct sock, sk_node);
494}
495
496static inline struct sock *sk_head(const struct hlist_head *head)
497{
498 return hlist_empty(head) ? NULL : __sk_head(head);
499}
500
501static 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
506static 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
511static 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
517static 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
525static inline bool sk_unhashed(const struct sock *sk)
526{
527 return hlist_unhashed(&sk->sk_node);
528}
529
530static inline bool sk_hashed(const struct sock *sk)
531{
532 return !sk_unhashed(sk);
533}
534
535static inline void sk_node_init(struct hlist_node *node)
536{
537 node->pprev = NULL;
538}
539
540static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
541{
542 node->pprev = NULL;
543}
544
545static 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 */
551static 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
567static 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 */
575static inline void __sock_put(struct sock *sk)
576{
577 atomic_dec(&sk->sk_refcnt);
578}
579
580static 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
593static 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
602static 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
614static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
615{
616 hlist_add_head(&sk->sk_node, list);
617}
618
619static 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
625static 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
631static 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
640static 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
646static inline void __sk_del_bind_node(struct sock *sk)
647{
648 __hlist_del(&sk->sk_bind_node);
649}
650
651static 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
689static 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 */
699enum 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
731static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
732{
733 nsk->sk_flags = osk->sk_flags;
734}
735
736static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
737{
738 __set_bit(flag, &sk->sk_flags);
739}
740
741static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
742{
743 __clear_bit(flag, &sk->sk_flags);
744}
745
746static 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
752extern struct static_key memalloc_socks;
753static inline int sk_memalloc_socks(void)
754{
755 return static_key_false(&memalloc_socks);
756}
757#else
758
759static inline int sk_memalloc_socks(void)
760{
761 return 0;
762}
763
764#endif
765
766static 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
771static inline void sk_acceptq_removed(struct sock *sk)
772{
773 sk->sk_ack_backlog--;
774}
775
776static inline void sk_acceptq_added(struct sock *sk)
777{
778 sk->sk_ack_backlog++;
779}
780
781static 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 */
789static inline int sk_stream_min_wspace(const struct sock *sk)
790{
791 return sk->sk_wmem_queued >> 1;
792}
793
794static inline int sk_stream_wspace(const struct sock *sk)
795{
796 return sk->sk_sndbuf - sk->sk_wmem_queued;
797}
798
799void sk_stream_write_space(struct sock *sk);
800
801/* OOB backlog add */
802static 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 */
821static 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. */
829static 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
848int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
849
850static 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
858static inline void sk_incoming_cpu_update(struct sock *sk)
859{
860 sk->sk_incoming_cpu = raw_smp_processor_id();
861}
862
863static 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
875static 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
882static 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
891static 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
911int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
912int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
913void sk_stream_wait_close(struct sock *sk, long timeo_p);
914int sk_stream_error(struct sock *sk, int flags, int err);
915void sk_stream_kill_queues(struct sock *sk);
916void sk_set_memalloc(struct sock *sk);
917void sk_clear_memalloc(struct sock *sk);
918
919int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
920
921struct request_sock_ops;
922struct timewait_sock_ops;
923struct inet_hashinfo;
924struct raw_hashinfo;
925struct 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 */
931static 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 */
942struct 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
1046int proto_register(struct proto *prot, int alloc_slab);
1047void proto_unregister(struct proto *prot);
1048
1049#ifdef SOCK_REFCNT_DEBUG
1050static inline void sk_refcnt_debug_inc(struct sock *sk)
1051{
1052 atomic_inc(&sk->sk_prot->socks);
1053}
1054
1055static 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
1062static 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
1074static 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
1083static 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
1090static inline bool sk_has_memory_pressure(const struct sock *sk)
1091{
1092 return sk->sk_prot->memory_pressure != NULL;
1093}
1094
1095static 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
1107static 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
1118static 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
1126static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1127{
1128 return sk->sk_prot->sysctl_mem[index];
1129}
1130
1131static inline long
1132sk_memory_allocated(const struct sock *sk)
1133{
1134 return atomic_long_read(sk->sk_prot->memory_allocated);
1135}
1136
1137static inline long
1138sk_memory_allocated_add(struct sock *sk, int amt)
1139{
1140 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1141}
1142
1143static inline void
1144sk_memory_allocated_sub(struct sock *sk, int amt)
1145{
1146 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1147}
1148
1149static inline void sk_sockets_allocated_dec(struct sock *sk)
1150{
1151 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1152}
1153
1154static inline void sk_sockets_allocated_inc(struct sock *sk)
1155{
1156 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1157}
1158
1159static inline int
1160sk_sockets_allocated_read_positive(struct sock *sk)
1161{
1162 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1163}
1164
1165static inline int
1166proto_sockets_allocated_sum_positive(struct proto *prot)
1167{
1168 return percpu_counter_sum_positive(prot->sockets_allocated);
1169}
1170
1171static inline long
1172proto_memory_allocated(struct proto *prot)
1173{
1174 return atomic_long_read(prot->memory_allocated);
1175}
1176
1177static inline bool
1178proto_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 */
1188void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1189int sock_prot_inuse_get(struct net *net, struct proto *proto);
1190#else
1191static 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 */
1201static inline int __sk_prot_rehash(struct sock *sk)
1202{
1203 sk->sk_prot->unhash(sk);
1204 return sk->sk_prot->hash(sk);
1205}
1206
1207void 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
1224struct socket_alloc {
1225 struct socket socket;
1226 struct inode vfs_inode;
1227};
1228
1229static inline struct socket *SOCKET_I(struct inode *inode)
1230{
1231 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1232}
1233
1234static 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 */
1242int __sk_mem_schedule(struct sock *sk, int size, int kind);
1243void __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
1250static inline int sk_mem_pages(int amt)
1251{
1252 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1253}
1254
1255static 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
1261static 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
1269static inline bool
1270sk_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
1279static 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
1287static 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
1295static 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
1302static 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
1309static 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
1332static 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) \
1345do { \
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
1356void lock_sock_nested(struct sock *sk, int subclass);
1357
1358static inline void lock_sock(struct sock *sk)
1359{
1360 lock_sock_nested(sk, 0);
1361}
1362
1363void 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
1372bool 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 */
1381static 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
1390struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1391 struct proto *prot, int kern);
1392void sk_free(struct sock *sk);
1393void sk_destruct(struct sock *sk);
1394struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1395
1396struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1397 gfp_t priority);
1398void sock_wfree(struct sk_buff *skb);
1399void skb_orphan_partial(struct sk_buff *skb);
1400void sock_rfree(struct sk_buff *skb);
1401void sock_efree(struct sk_buff *skb);
1402#ifdef CONFIG_INET
1403void sock_edemux(struct sk_buff *skb);
1404#else
1405#define sock_edemux(skb) sock_efree(skb)
1406#endif
1407
1408int sock_setsockopt(struct socket *sock, int level, int op,
1409 char __user *optval, unsigned int optlen);
1410
1411int sock_getsockopt(struct socket *sock, int level, int op,
1412 char __user *optval, int __user *optlen);
1413struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1414 int noblock, int *errcode);
1415struct 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);
1418void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1419void sock_kfree_s(struct sock *sk, void *mem, int size);
1420void sock_kzfree_s(struct sock *sk, void *mem, int size);
1421void sk_send_sigurg(struct sock *sk);
1422
1423struct sockcm_cookie {
1424 u32 mark;
1425};
1426
1427int 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 */
1434int sock_no_bind(struct socket *, struct sockaddr *, int);
1435int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1436int sock_no_socketpair(struct socket *, struct socket *);
1437int sock_no_accept(struct socket *, struct socket *, int);
1438int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1439unsigned int sock_no_poll(struct file *, struct socket *,
1440 struct poll_table_struct *);
1441int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1442int sock_no_listen(struct socket *, int);
1443int sock_no_shutdown(struct socket *, int);
1444int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1445int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1446int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1447int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1448int sock_no_mmap(struct file *file, struct socket *sock,
1449 struct vm_area_struct *vma);
1450ssize_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 */
1457int sock_common_getsockopt(struct socket *sock, int level, int optname,
1458 char __user *optval, int __user *optlen);
1459int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1460 int flags);
1461int sock_common_setsockopt(struct socket *sock, int level, int optname,
1462 char __user *optval, unsigned int optlen);
1463int compat_sock_common_getsockopt(struct socket *sock, int level,
1464 int optname, char __user *optval, int __user *optlen);
1465int compat_sock_common_setsockopt(struct socket *sock, int level,
1466 int optname, char __user *optval, unsigned int optlen);
1467
1468void sk_common_release(struct sock *sk);
1469
1470/*
1471 * Default socket callbacks and setup code
1472 */
1473
1474/* Initialise core socket variables */
1475void 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. */
1503static 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 */
1511void sock_gen_put(struct sock *sk);
1512
1513int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
1514
1515static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1516{
1517 sk->sk_tx_queue_mapping = tx_queue;
1518}
1519
1520static inline void sk_tx_queue_clear(struct sock *sk)
1521{
1522 sk->sk_tx_queue_mapping = -1;
1523}
1524
1525static inline int sk_tx_queue_get(const struct sock *sk)
1526{
1527 return sk ? sk->sk_tx_queue_mapping : -1;
1528}
1529
1530static 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
1536static 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 */
1548static 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
1557static 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
1567kuid_t sock_i_uid(struct sock *sk);
1568unsigned long sock_i_ino(struct sock *sk);
1569
1570static inline u32 net_tx_rndhash(void)
1571{
1572 u32 v = prandom_u32();
1573
1574 return v ?: 1;
1575}
1576
1577static inline void sk_set_txhash(struct sock *sk)
1578{
1579 sk->sk_txhash = net_tx_rndhash();
1580}
1581
1582static inline void sk_rethink_txhash(struct sock *sk)
1583{
1584 if (sk->sk_txhash)
1585 sk_set_txhash(sk);
1586}
1587
1588static 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
1595static inline struct dst_entry *
1596sk_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
1608static 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
1624static 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
1639static inline void
1640sk_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
1649static inline void
1650__sk_dst_reset(struct sock *sk)
1651{
1652 __sk_dst_set(sk, NULL);
1653}
1654
1655static inline void
1656sk_dst_reset(struct sock *sk)
1657{
1658 sk_dst_set(sk, NULL);
1659}
1660
1661struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1662
1663struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1664
1665bool sk_mc_loop(struct sock *sk);
1666
1667static 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
1672void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1673
1674static 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
1680static 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
1689static 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
1707static 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
1720static 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 */
1746static 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 */
1757static 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 */
1768static 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 */
1805static 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 */
1818static 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
1832static 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
1840void 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 */
1850static 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
1859void sk_reset_timer(struct sock *sk, struct timer_list *timer,
1860 unsigned long expires);
1861
1862void sk_stop_timer(struct sock *sk, struct timer_list *timer);
1863
1864int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1865
1866int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1867struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
1868
1869/*
1870 * Recover an error report and clear atomically
1871 */
1872
1873static 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
1882static 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 */
1898static inline void sk_set_bit(int nr, struct sock *sk)
1899{
1900 set_bit(nr, &sk->sk_wq_raw->flags);
1901}
1902
1903static inline void sk_clear_bit(int nr, struct sock *sk)
1904{
1905 clear_bit(nr, &sk->sk_wq_raw->flags);
1906}
1907
1908static 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
1927static 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
1935struct 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 */
1945static inline struct page_frag *sk_page_frag(struct sock *sk)
1946{
1947 if (gfpflags_allow_blocking(sk->sk_allocation))
1948 return ¤t->task_frag;
1949
1950 return &sk->sk_frag;
1951}
1952
1953bool 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 */
1958static inline bool sock_writeable(const struct sock *sk)
1959{
1960 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
1961}
1962
1963static inline gfp_t gfp_any(void)
1964{
1965 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1966}
1967
1968static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
1969{
1970 return noblock ? 0 : sk->sk_rcvtimeo;
1971}
1972
1973static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
1974{
1975 return noblock ? 0 : sk->sk_sndtimeo;
1976}
1977
1978static 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 */
1986static inline int sock_intr_errno(long timeo)
1987{
1988 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1989}
1990
1991struct 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
2008static inline void
2009sock_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
2014void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2015 struct sk_buff *skb);
2016void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2017 struct sk_buff *skb);
2018
2019static inline void
2020sock_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
2044void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2045 struct sk_buff *skb);
2046
2047static 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
2061void __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 */
2070static 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*/
2086static 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
2092static inline
2093struct net *sock_net(const struct sock *sk)
2094{
2095 return read_pnet(&sk->sk_net);
2096}
2097
2098static inline
2099void sock_net_set(struct sock *sk, struct net *net)
2100{
2101 write_pnet(&sk->sk_net, net);
2102}
2103
2104static 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 */
2119static 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 */
2127static 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 */
2139static 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 */
2152static inline void sk_state_store(struct sock *sk, int newstate)
2153{
2154 smp_store_release(&sk->sk_state, newstate);
2155}
2156
2157void sock_enable_timestamp(struct sock *sk, int flag);
2158int sock_get_timestamp(struct sock *, struct timeval __user *);
2159int sock_get_timestampns(struct sock *, struct timespec __user *);
2160int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2161 int type);
2162
2163bool sk_ns_capable(const struct sock *sk,
2164 struct user_namespace *user_ns, int cap);
2165bool sk_capable(const struct sock *sk, int cap);
2166bool sk_net_capable(const struct sock *sk, int cap);
2167
2168extern __u32 sysctl_wmem_max;
2169extern __u32 sysctl_rmem_max;
2170
2171extern int sysctl_tstamp_allow_data;
2172extern int sysctl_optmem_max;
2173
2174extern __u32 sysctl_wmem_default;
2175extern __u32 sysctl_rmem_default;
2176
2177#endif /* _SOCK_H */