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.
6 * Definitions for the AF_INET socket handler.
8 * Version: @(#)sock.h 1.0.4 05/13/93
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>
16 * Alan Cox : Volatiles in skbuff pointers. See
17 * skbuff comments. May be overdone,
18 * better to prove they can be removed
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
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.
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 */
54 #include <linux/security.h>
55 #include <linux/slab.h>
56 #include <linux/uaccess.h>
57 #include <linux/memcontrol.h>
58 #include <linux/res_counter.h>
59 #include <linux/static_key.h>
60 #include <linux/aio.h>
61 #include <linux/sched.h>
63 #include <linux/filter.h>
64 #include <linux/rculist_nulls.h>
65 #include <linux/poll.h>
67 #include <linux/atomic.h>
69 #include <net/checksum.h>
74 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
75 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
78 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
83 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
88 * This structure really needs to be cleaned up.
89 * Most of it is for TCP, and not used by any of
90 * the other protocols.
93 /* Define this to get the SOCK_DBG debugging facility. */
94 #define SOCK_DEBUGGING
96 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
97 printk(KERN_DEBUG msg); } while (0)
99 /* Validate arguments and do nothing */
100 static inline __printf(2, 3)
101 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
106 /* This is the per-socket lock. The spinlock provides a synchronization
107 * between user contexts and software interrupt processing, whereas the
108 * mini-semaphore synchronizes multiple users amongst themselves.
113 wait_queue_head_t wq;
115 * We express the mutex-alike socket_lock semantics
116 * to the lock validator by explicitly managing
117 * the slock as a lock variant (in addition to
120 #ifdef CONFIG_DEBUG_LOCK_ALLOC
121 struct lockdep_map dep_map;
130 * struct sock_common - minimal network layer representation of sockets
131 * @skc_daddr: Foreign IPv4 addr
132 * @skc_rcv_saddr: Bound local IPv4 addr
133 * @skc_hash: hash value used with various protocol lookup tables
134 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
135 * @skc_family: network address family
136 * @skc_state: Connection state
137 * @skc_reuse: %SO_REUSEADDR setting
138 * @skc_bound_dev_if: bound device index if != 0
139 * @skc_bind_node: bind hash linkage for various protocol lookup tables
140 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
141 * @skc_prot: protocol handlers inside a network family
142 * @skc_net: reference to the network namespace of this socket
143 * @skc_node: main hash linkage for various protocol lookup tables
144 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
145 * @skc_tx_queue_mapping: tx queue number for this connection
146 * @skc_refcnt: reference count
148 * This is the minimal network layer representation of sockets, the header
149 * for struct sock and struct inet_timewait_sock.
152 /* skc_daddr and skc_rcv_saddr must be grouped :
153 * cf INET_MATCH() and INET_TW_MATCH()
156 __be32 skc_rcv_saddr;
159 unsigned int skc_hash;
160 __u16 skc_u16hashes[2];
162 unsigned short skc_family;
163 volatile unsigned char skc_state;
164 unsigned char skc_reuse;
165 int skc_bound_dev_if;
167 struct hlist_node skc_bind_node;
168 struct hlist_nulls_node skc_portaddr_node;
170 struct proto *skc_prot;
175 * fields between dontcopy_begin/dontcopy_end
176 * are not copied in sock_copy()
179 int skc_dontcopy_begin[0];
182 struct hlist_node skc_node;
183 struct hlist_nulls_node skc_nulls_node;
185 int skc_tx_queue_mapping;
188 int skc_dontcopy_end[0];
194 * struct sock - network layer representation of sockets
195 * @__sk_common: shared layout with inet_timewait_sock
196 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
197 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
198 * @sk_lock: synchronizer
199 * @sk_rcvbuf: size of receive buffer in bytes
200 * @sk_wq: sock wait queue and async head
201 * @sk_dst_cache: destination cache
202 * @sk_dst_lock: destination cache lock
203 * @sk_policy: flow policy
204 * @sk_receive_queue: incoming packets
205 * @sk_wmem_alloc: transmit queue bytes committed
206 * @sk_write_queue: Packet sending queue
207 * @sk_async_wait_queue: DMA copied packets
208 * @sk_omem_alloc: "o" is "option" or "other"
209 * @sk_wmem_queued: persistent queue size
210 * @sk_forward_alloc: space allocated forward
211 * @sk_allocation: allocation mode
212 * @sk_sndbuf: size of send buffer in bytes
213 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
214 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
215 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
216 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
217 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
218 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
219 * @sk_gso_max_size: Maximum GSO segment size to build
220 * @sk_lingertime: %SO_LINGER l_linger setting
221 * @sk_backlog: always used with the per-socket spinlock held
222 * @sk_callback_lock: used with the callbacks in the end of this struct
223 * @sk_error_queue: rarely used
224 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
225 * IPV6_ADDRFORM for instance)
226 * @sk_err: last error
227 * @sk_err_soft: errors that don't cause failure but are the cause of a
228 * persistent failure not just 'timed out'
229 * @sk_drops: raw/udp drops counter
230 * @sk_ack_backlog: current listen backlog
231 * @sk_max_ack_backlog: listen backlog set in listen()
232 * @sk_priority: %SO_PRIORITY setting
233 * @sk_cgrp_prioidx: socket group's priority map index
234 * @sk_type: socket type (%SOCK_STREAM, etc)
235 * @sk_protocol: which protocol this socket belongs in this network family
236 * @sk_peer_pid: &struct pid for this socket's peer
237 * @sk_peer_cred: %SO_PEERCRED setting
238 * @sk_rcvlowat: %SO_RCVLOWAT setting
239 * @sk_rcvtimeo: %SO_RCVTIMEO setting
240 * @sk_sndtimeo: %SO_SNDTIMEO setting
241 * @sk_rxhash: flow hash received from netif layer
242 * @sk_filter: socket filtering instructions
243 * @sk_protinfo: private area, net family specific, when not using slab
244 * @sk_timer: sock cleanup timer
245 * @sk_stamp: time stamp of last packet received
246 * @sk_socket: Identd and reporting IO signals
247 * @sk_user_data: RPC layer private data
248 * @sk_sndmsg_page: cached page for sendmsg
249 * @sk_sndmsg_off: cached offset for sendmsg
250 * @sk_peek_off: current peek_offset value
251 * @sk_send_head: front of stuff to transmit
252 * @sk_security: used by security modules
253 * @sk_mark: generic packet mark
254 * @sk_classid: this socket's cgroup classid
255 * @sk_cgrp: this socket's cgroup-specific proto data
256 * @sk_write_pending: a write to stream socket waits to start
257 * @sk_state_change: callback to indicate change in the state of the sock
258 * @sk_data_ready: callback to indicate there is data to be processed
259 * @sk_write_space: callback to indicate there is bf sending space available
260 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
261 * @sk_backlog_rcv: callback to process the backlog
262 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
266 * Now struct inet_timewait_sock also uses sock_common, so please just
267 * don't add nothing before this first member (__sk_common) --acme
269 struct sock_common __sk_common;
270 #define sk_node __sk_common.skc_node
271 #define sk_nulls_node __sk_common.skc_nulls_node
272 #define sk_refcnt __sk_common.skc_refcnt
273 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
275 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
276 #define sk_dontcopy_end __sk_common.skc_dontcopy_end
277 #define sk_hash __sk_common.skc_hash
278 #define sk_family __sk_common.skc_family
279 #define sk_state __sk_common.skc_state
280 #define sk_reuse __sk_common.skc_reuse
281 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
282 #define sk_bind_node __sk_common.skc_bind_node
283 #define sk_prot __sk_common.skc_prot
284 #define sk_net __sk_common.skc_net
285 socket_lock_t sk_lock;
286 struct sk_buff_head sk_receive_queue;
288 * The backlog queue is special, it is always used with
289 * the per-socket spinlock held and requires low latency
290 * access. Therefore we special case it's implementation.
291 * Note : rmem_alloc is in this structure to fill a hole
292 * on 64bit arches, not because its logically part of
298 struct sk_buff *head;
299 struct sk_buff *tail;
301 #define sk_rmem_alloc sk_backlog.rmem_alloc
302 int sk_forward_alloc;
309 struct sk_filter __rcu *sk_filter;
310 struct socket_wq __rcu *sk_wq;
312 #ifdef CONFIG_NET_DMA
313 struct sk_buff_head sk_async_wait_queue;
317 struct xfrm_policy *sk_policy[2];
319 unsigned long sk_flags;
320 struct dst_entry *sk_dst_cache;
321 spinlock_t sk_dst_lock;
322 struct dst_entry *sk_rx_dst;
323 atomic_t sk_wmem_alloc;
324 atomic_t sk_omem_alloc;
326 struct sk_buff_head sk_write_queue;
327 kmemcheck_bitfield_begin(flags);
328 unsigned int sk_shutdown : 2,
333 kmemcheck_bitfield_end(flags);
336 netdev_features_t sk_route_caps;
337 netdev_features_t sk_route_nocaps;
339 unsigned int sk_gso_max_size;
341 unsigned long sk_lingertime;
342 struct sk_buff_head sk_error_queue;
343 struct proto *sk_prot_creator;
344 rwlock_t sk_callback_lock;
347 unsigned short sk_ack_backlog;
348 unsigned short sk_max_ack_backlog;
350 #ifdef CONFIG_CGROUPS
351 __u32 sk_cgrp_prioidx;
353 struct pid *sk_peer_pid;
354 const struct cred *sk_peer_cred;
358 struct timer_list sk_timer;
360 struct socket *sk_socket;
362 struct page *sk_sndmsg_page;
363 struct sk_buff *sk_send_head;
366 int sk_write_pending;
367 #ifdef CONFIG_SECURITY
372 struct cg_proto *sk_cgrp;
373 void (*sk_state_change)(struct sock *sk);
374 void (*sk_data_ready)(struct sock *sk, int bytes);
375 void (*sk_write_space)(struct sock *sk);
376 void (*sk_error_report)(struct sock *sk);
377 int (*sk_backlog_rcv)(struct sock *sk,
378 struct sk_buff *skb);
379 void (*sk_destruct)(struct sock *sk);
383 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
384 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
385 * on a socket means that the socket will reuse everybody else's port
386 * without looking at the other's sk_reuse value.
389 #define SK_NO_REUSE 0
390 #define SK_CAN_REUSE 1
391 #define SK_FORCE_REUSE 2
393 static inline int sk_peek_offset(struct sock *sk, int flags)
395 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
396 return sk->sk_peek_off;
401 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
403 if (sk->sk_peek_off >= 0) {
404 if (sk->sk_peek_off >= val)
405 sk->sk_peek_off -= val;
411 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
413 if (sk->sk_peek_off >= 0)
414 sk->sk_peek_off += val;
418 * Hashed lists helper routines
420 static inline struct sock *sk_entry(const struct hlist_node *node)
422 return hlist_entry(node, struct sock, sk_node);
425 static inline struct sock *__sk_head(const struct hlist_head *head)
427 return hlist_entry(head->first, struct sock, sk_node);
430 static inline struct sock *sk_head(const struct hlist_head *head)
432 return hlist_empty(head) ? NULL : __sk_head(head);
435 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
437 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
440 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
442 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
445 static inline struct sock *sk_next(const struct sock *sk)
447 return sk->sk_node.next ?
448 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
451 static inline struct sock *sk_nulls_next(const struct sock *sk)
453 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
454 hlist_nulls_entry(sk->sk_nulls_node.next,
455 struct sock, sk_nulls_node) :
459 static inline bool sk_unhashed(const struct sock *sk)
461 return hlist_unhashed(&sk->sk_node);
464 static inline bool sk_hashed(const struct sock *sk)
466 return !sk_unhashed(sk);
469 static inline void sk_node_init(struct hlist_node *node)
474 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
479 static inline void __sk_del_node(struct sock *sk)
481 __hlist_del(&sk->sk_node);
484 /* NB: equivalent to hlist_del_init_rcu */
485 static inline bool __sk_del_node_init(struct sock *sk)
489 sk_node_init(&sk->sk_node);
495 /* Grab socket reference count. This operation is valid only
496 when sk is ALREADY grabbed f.e. it is found in hash table
497 or a list and the lookup is made under lock preventing hash table
501 static inline void sock_hold(struct sock *sk)
503 atomic_inc(&sk->sk_refcnt);
506 /* Ungrab socket in the context, which assumes that socket refcnt
507 cannot hit zero, f.e. it is true in context of any socketcall.
509 static inline void __sock_put(struct sock *sk)
511 atomic_dec(&sk->sk_refcnt);
514 static inline bool sk_del_node_init(struct sock *sk)
516 bool rc = __sk_del_node_init(sk);
519 /* paranoid for a while -acme */
520 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
525 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
527 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
530 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
536 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
538 bool rc = __sk_nulls_del_node_init_rcu(sk);
541 /* paranoid for a while -acme */
542 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
548 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
550 hlist_add_head(&sk->sk_node, list);
553 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
556 __sk_add_node(sk, list);
559 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
562 hlist_add_head_rcu(&sk->sk_node, list);
565 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
567 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
570 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
573 __sk_nulls_add_node_rcu(sk, list);
576 static inline void __sk_del_bind_node(struct sock *sk)
578 __hlist_del(&sk->sk_bind_node);
581 static inline void sk_add_bind_node(struct sock *sk,
582 struct hlist_head *list)
584 hlist_add_head(&sk->sk_bind_node, list);
587 #define sk_for_each(__sk, node, list) \
588 hlist_for_each_entry(__sk, node, list, sk_node)
589 #define sk_for_each_rcu(__sk, node, list) \
590 hlist_for_each_entry_rcu(__sk, node, list, sk_node)
591 #define sk_nulls_for_each(__sk, node, list) \
592 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
593 #define sk_nulls_for_each_rcu(__sk, node, list) \
594 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
595 #define sk_for_each_from(__sk, node) \
596 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
597 hlist_for_each_entry_from(__sk, node, sk_node)
598 #define sk_nulls_for_each_from(__sk, node) \
599 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
600 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
601 #define sk_for_each_safe(__sk, node, tmp, list) \
602 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
603 #define sk_for_each_bound(__sk, node, list) \
604 hlist_for_each_entry(__sk, node, list, sk_bind_node)
617 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
618 SOCK_DBG, /* %SO_DEBUG setting */
619 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
620 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
621 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
622 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
623 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
624 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
625 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
626 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
627 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
628 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
629 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
630 SOCK_FASYNC, /* fasync() active */
632 SOCK_ZEROCOPY, /* buffers from userspace */
633 SOCK_WIFI_STATUS, /* push wifi status to userspace */
634 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
635 * Will use last 4 bytes of packet sent from
636 * user-space instead.
640 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
642 nsk->sk_flags = osk->sk_flags;
645 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
647 __set_bit(flag, &sk->sk_flags);
650 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
652 __clear_bit(flag, &sk->sk_flags);
655 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
657 return test_bit(flag, &sk->sk_flags);
660 static inline void sk_acceptq_removed(struct sock *sk)
662 sk->sk_ack_backlog--;
665 static inline void sk_acceptq_added(struct sock *sk)
667 sk->sk_ack_backlog++;
670 static inline bool sk_acceptq_is_full(const struct sock *sk)
672 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
676 * Compute minimal free write space needed to queue new packets.
678 static inline int sk_stream_min_wspace(const struct sock *sk)
680 return sk->sk_wmem_queued >> 1;
683 static inline int sk_stream_wspace(const struct sock *sk)
685 return sk->sk_sndbuf - sk->sk_wmem_queued;
688 extern void sk_stream_write_space(struct sock *sk);
690 static inline bool sk_stream_memory_free(const struct sock *sk)
692 return sk->sk_wmem_queued < sk->sk_sndbuf;
695 /* OOB backlog add */
696 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
698 /* dont let skb dst not refcounted, we are going to leave rcu lock */
701 if (!sk->sk_backlog.tail)
702 sk->sk_backlog.head = skb;
704 sk->sk_backlog.tail->next = skb;
706 sk->sk_backlog.tail = skb;
711 * Take into account size of receive queue and backlog queue
712 * Do not take into account this skb truesize,
713 * to allow even a single big packet to come.
715 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
718 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
720 return qsize > limit;
723 /* The per-socket spinlock must be held here. */
724 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
727 if (sk_rcvqueues_full(sk, skb, limit))
730 __sk_add_backlog(sk, skb);
731 sk->sk_backlog.len += skb->truesize;
735 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
737 return sk->sk_backlog_rcv(sk, skb);
740 static inline void sock_rps_record_flow(const struct sock *sk)
743 struct rps_sock_flow_table *sock_flow_table;
746 sock_flow_table = rcu_dereference(rps_sock_flow_table);
747 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
752 static inline void sock_rps_reset_flow(const struct sock *sk)
755 struct rps_sock_flow_table *sock_flow_table;
758 sock_flow_table = rcu_dereference(rps_sock_flow_table);
759 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
764 static inline void sock_rps_save_rxhash(struct sock *sk,
765 const struct sk_buff *skb)
768 if (unlikely(sk->sk_rxhash != skb->rxhash)) {
769 sock_rps_reset_flow(sk);
770 sk->sk_rxhash = skb->rxhash;
775 static inline void sock_rps_reset_rxhash(struct sock *sk)
778 sock_rps_reset_flow(sk);
783 #define sk_wait_event(__sk, __timeo, __condition) \
785 release_sock(__sk); \
786 __rc = __condition; \
788 *(__timeo) = schedule_timeout(*(__timeo)); \
791 __rc = __condition; \
795 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
796 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
797 extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
798 extern int sk_stream_error(struct sock *sk, int flags, int err);
799 extern void sk_stream_kill_queues(struct sock *sk);
801 extern int sk_wait_data(struct sock *sk, long *timeo);
803 struct request_sock_ops;
804 struct timewait_sock_ops;
805 struct inet_hashinfo;
809 /* Networking protocol blocks we attach to sockets.
810 * socket layer -> transport layer interface
811 * transport -> network interface is defined by struct inet_proto
814 void (*close)(struct sock *sk,
816 int (*connect)(struct sock *sk,
817 struct sockaddr *uaddr,
819 int (*disconnect)(struct sock *sk, int flags);
821 struct sock * (*accept)(struct sock *sk, int flags, int *err);
823 int (*ioctl)(struct sock *sk, int cmd,
825 int (*init)(struct sock *sk);
826 void (*destroy)(struct sock *sk);
827 void (*shutdown)(struct sock *sk, int how);
828 int (*setsockopt)(struct sock *sk, int level,
829 int optname, char __user *optval,
830 unsigned int optlen);
831 int (*getsockopt)(struct sock *sk, int level,
832 int optname, char __user *optval,
835 int (*compat_setsockopt)(struct sock *sk,
837 int optname, char __user *optval,
838 unsigned int optlen);
839 int (*compat_getsockopt)(struct sock *sk,
841 int optname, char __user *optval,
843 int (*compat_ioctl)(struct sock *sk,
844 unsigned int cmd, unsigned long arg);
846 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
847 struct msghdr *msg, size_t len);
848 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
850 size_t len, int noblock, int flags,
852 int (*sendpage)(struct sock *sk, struct page *page,
853 int offset, size_t size, int flags);
854 int (*bind)(struct sock *sk,
855 struct sockaddr *uaddr, int addr_len);
857 int (*backlog_rcv) (struct sock *sk,
858 struct sk_buff *skb);
860 /* Keeping track of sk's, looking them up, and port selection methods. */
861 void (*hash)(struct sock *sk);
862 void (*unhash)(struct sock *sk);
863 void (*rehash)(struct sock *sk);
864 int (*get_port)(struct sock *sk, unsigned short snum);
865 void (*clear_sk)(struct sock *sk, int size);
867 /* Keeping track of sockets in use */
868 #ifdef CONFIG_PROC_FS
869 unsigned int inuse_idx;
872 /* Memory pressure */
873 void (*enter_memory_pressure)(struct sock *sk);
874 atomic_long_t *memory_allocated; /* Current allocated memory. */
875 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
877 * Pressure flag: try to collapse.
878 * Technical note: it is used by multiple contexts non atomically.
879 * All the __sk_mem_schedule() is of this nature: accounting
880 * is strict, actions are advisory and have some latency.
882 int *memory_pressure;
889 struct kmem_cache *slab;
890 unsigned int obj_size;
893 struct percpu_counter *orphan_count;
895 struct request_sock_ops *rsk_prot;
896 struct timewait_sock_ops *twsk_prot;
899 struct inet_hashinfo *hashinfo;
900 struct udp_table *udp_table;
901 struct raw_hashinfo *raw_hash;
904 struct module *owner;
908 struct list_head node;
909 #ifdef SOCK_REFCNT_DEBUG
912 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
914 * cgroup specific init/deinit functions. Called once for all
915 * protocols that implement it, from cgroups populate function.
916 * This function has to setup any files the protocol want to
917 * appear in the kmem cgroup filesystem.
919 int (*init_cgroup)(struct mem_cgroup *memcg,
920 struct cgroup_subsys *ss);
921 void (*destroy_cgroup)(struct mem_cgroup *memcg);
922 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg);
927 * Bits in struct cg_proto.flags
929 enum cg_proto_flags {
930 /* Currently active and new sockets should be assigned to cgroups */
932 /* It was ever activated; we must disarm static keys on destruction */
933 MEMCG_SOCK_ACTIVATED,
937 void (*enter_memory_pressure)(struct sock *sk);
938 struct res_counter *memory_allocated; /* Current allocated memory. */
939 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
940 int *memory_pressure;
944 * memcg field is used to find which memcg we belong directly
945 * Each memcg struct can hold more than one cg_proto, so container_of
948 * The elegant solution would be having an inverse function to
949 * proto_cgroup in struct proto, but that means polluting the structure
950 * for everybody, instead of just for memcg users.
952 struct mem_cgroup *memcg;
955 extern int proto_register(struct proto *prot, int alloc_slab);
956 extern void proto_unregister(struct proto *prot);
958 static inline bool memcg_proto_active(struct cg_proto *cg_proto)
960 return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
963 static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
965 return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
968 #ifdef SOCK_REFCNT_DEBUG
969 static inline void sk_refcnt_debug_inc(struct sock *sk)
971 atomic_inc(&sk->sk_prot->socks);
974 static inline void sk_refcnt_debug_dec(struct sock *sk)
976 atomic_dec(&sk->sk_prot->socks);
977 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
978 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
981 inline void sk_refcnt_debug_release(const struct sock *sk)
983 if (atomic_read(&sk->sk_refcnt) != 1)
984 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
985 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
987 #else /* SOCK_REFCNT_DEBUG */
988 #define sk_refcnt_debug_inc(sk) do { } while (0)
989 #define sk_refcnt_debug_dec(sk) do { } while (0)
990 #define sk_refcnt_debug_release(sk) do { } while (0)
991 #endif /* SOCK_REFCNT_DEBUG */
993 #if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_NET)
994 extern struct static_key memcg_socket_limit_enabled;
995 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
996 struct cg_proto *cg_proto)
998 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1000 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1002 #define mem_cgroup_sockets_enabled 0
1003 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1004 struct cg_proto *cg_proto)
1011 static inline bool sk_has_memory_pressure(const struct sock *sk)
1013 return sk->sk_prot->memory_pressure != NULL;
1016 static inline bool sk_under_memory_pressure(const struct sock *sk)
1018 if (!sk->sk_prot->memory_pressure)
1021 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1022 return !!*sk->sk_cgrp->memory_pressure;
1024 return !!*sk->sk_prot->memory_pressure;
1027 static inline void sk_leave_memory_pressure(struct sock *sk)
1029 int *memory_pressure = sk->sk_prot->memory_pressure;
1031 if (!memory_pressure)
1034 if (*memory_pressure)
1035 *memory_pressure = 0;
1037 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1038 struct cg_proto *cg_proto = sk->sk_cgrp;
1039 struct proto *prot = sk->sk_prot;
1041 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1042 if (*cg_proto->memory_pressure)
1043 *cg_proto->memory_pressure = 0;
1048 static inline void sk_enter_memory_pressure(struct sock *sk)
1050 if (!sk->sk_prot->enter_memory_pressure)
1053 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1054 struct cg_proto *cg_proto = sk->sk_cgrp;
1055 struct proto *prot = sk->sk_prot;
1057 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1058 cg_proto->enter_memory_pressure(sk);
1061 sk->sk_prot->enter_memory_pressure(sk);
1064 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1066 long *prot = sk->sk_prot->sysctl_mem;
1067 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1068 prot = sk->sk_cgrp->sysctl_mem;
1072 static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1076 struct res_counter *fail;
1079 ret = res_counter_charge_nofail(prot->memory_allocated,
1080 amt << PAGE_SHIFT, &fail);
1082 *parent_status = OVER_LIMIT;
1085 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1088 res_counter_uncharge(prot->memory_allocated, amt << PAGE_SHIFT);
1091 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1094 ret = res_counter_read_u64(prot->memory_allocated, RES_USAGE);
1095 return ret >> PAGE_SHIFT;
1099 sk_memory_allocated(const struct sock *sk)
1101 struct proto *prot = sk->sk_prot;
1102 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1103 return memcg_memory_allocated_read(sk->sk_cgrp);
1105 return atomic_long_read(prot->memory_allocated);
1109 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1111 struct proto *prot = sk->sk_prot;
1113 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1114 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1115 /* update the root cgroup regardless */
1116 atomic_long_add_return(amt, prot->memory_allocated);
1117 return memcg_memory_allocated_read(sk->sk_cgrp);
1120 return atomic_long_add_return(amt, prot->memory_allocated);
1124 sk_memory_allocated_sub(struct sock *sk, int amt)
1126 struct proto *prot = sk->sk_prot;
1128 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1129 memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1131 atomic_long_sub(amt, prot->memory_allocated);
1134 static inline void sk_sockets_allocated_dec(struct sock *sk)
1136 struct proto *prot = sk->sk_prot;
1138 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1139 struct cg_proto *cg_proto = sk->sk_cgrp;
1141 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1142 percpu_counter_dec(cg_proto->sockets_allocated);
1145 percpu_counter_dec(prot->sockets_allocated);
1148 static inline void sk_sockets_allocated_inc(struct sock *sk)
1150 struct proto *prot = sk->sk_prot;
1152 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1153 struct cg_proto *cg_proto = sk->sk_cgrp;
1155 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1156 percpu_counter_inc(cg_proto->sockets_allocated);
1159 percpu_counter_inc(prot->sockets_allocated);
1163 sk_sockets_allocated_read_positive(struct sock *sk)
1165 struct proto *prot = sk->sk_prot;
1167 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1168 return percpu_counter_read_positive(sk->sk_cgrp->sockets_allocated);
1170 return percpu_counter_read_positive(prot->sockets_allocated);
1174 proto_sockets_allocated_sum_positive(struct proto *prot)
1176 return percpu_counter_sum_positive(prot->sockets_allocated);
1180 proto_memory_allocated(struct proto *prot)
1182 return atomic_long_read(prot->memory_allocated);
1186 proto_memory_pressure(struct proto *prot)
1188 if (!prot->memory_pressure)
1190 return !!*prot->memory_pressure;
1194 #ifdef CONFIG_PROC_FS
1195 /* Called with local bh disabled */
1196 extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1197 extern int sock_prot_inuse_get(struct net *net, struct proto *proto);
1199 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1206 /* With per-bucket locks this operation is not-atomic, so that
1207 * this version is not worse.
1209 static inline void __sk_prot_rehash(struct sock *sk)
1211 sk->sk_prot->unhash(sk);
1212 sk->sk_prot->hash(sk);
1215 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1217 /* About 10 seconds */
1218 #define SOCK_DESTROY_TIME (10*HZ)
1220 /* Sockets 0-1023 can't be bound to unless you are superuser */
1221 #define PROT_SOCK 1024
1223 #define SHUTDOWN_MASK 3
1224 #define RCV_SHUTDOWN 1
1225 #define SEND_SHUTDOWN 2
1227 #define SOCK_SNDBUF_LOCK 1
1228 #define SOCK_RCVBUF_LOCK 2
1229 #define SOCK_BINDADDR_LOCK 4
1230 #define SOCK_BINDPORT_LOCK 8
1232 /* sock_iocb: used to kick off async processing of socket ios */
1234 struct list_head list;
1238 struct socket *sock;
1240 struct scm_cookie *scm;
1241 struct msghdr *msg, async_msg;
1242 struct kiocb *kiocb;
1245 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1247 return (struct sock_iocb *)iocb->private;
1250 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1255 struct socket_alloc {
1256 struct socket socket;
1257 struct inode vfs_inode;
1260 static inline struct socket *SOCKET_I(struct inode *inode)
1262 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1265 static inline struct inode *SOCK_INODE(struct socket *socket)
1267 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1271 * Functions for memory accounting
1273 extern int __sk_mem_schedule(struct sock *sk, int size, int kind);
1274 extern void __sk_mem_reclaim(struct sock *sk);
1276 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1277 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1278 #define SK_MEM_SEND 0
1279 #define SK_MEM_RECV 1
1281 static inline int sk_mem_pages(int amt)
1283 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1286 static inline bool sk_has_account(struct sock *sk)
1288 /* return true if protocol supports memory accounting */
1289 return !!sk->sk_prot->memory_allocated;
1292 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1294 if (!sk_has_account(sk))
1296 return size <= sk->sk_forward_alloc ||
1297 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1300 static inline bool sk_rmem_schedule(struct sock *sk, int size)
1302 if (!sk_has_account(sk))
1304 return size <= sk->sk_forward_alloc ||
1305 __sk_mem_schedule(sk, size, SK_MEM_RECV);
1308 static inline void sk_mem_reclaim(struct sock *sk)
1310 if (!sk_has_account(sk))
1312 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1313 __sk_mem_reclaim(sk);
1316 static inline void sk_mem_reclaim_partial(struct sock *sk)
1318 if (!sk_has_account(sk))
1320 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1321 __sk_mem_reclaim(sk);
1324 static inline void sk_mem_charge(struct sock *sk, int size)
1326 if (!sk_has_account(sk))
1328 sk->sk_forward_alloc -= size;
1331 static inline void sk_mem_uncharge(struct sock *sk, int size)
1333 if (!sk_has_account(sk))
1335 sk->sk_forward_alloc += size;
1338 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1340 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1341 sk->sk_wmem_queued -= skb->truesize;
1342 sk_mem_uncharge(sk, skb->truesize);
1346 /* Used by processes to "lock" a socket state, so that
1347 * interrupts and bottom half handlers won't change it
1348 * from under us. It essentially blocks any incoming
1349 * packets, so that we won't get any new data or any
1350 * packets that change the state of the socket.
1352 * While locked, BH processing will add new packets to
1353 * the backlog queue. This queue is processed by the
1354 * owner of the socket lock right before it is released.
1356 * Since ~2.3.5 it is also exclusive sleep lock serializing
1357 * accesses from user process context.
1359 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1362 * Macro so as to not evaluate some arguments when
1363 * lockdep is not enabled.
1365 * Mark both the sk_lock and the sk_lock.slock as a
1366 * per-address-family lock class.
1368 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1370 sk->sk_lock.owned = 0; \
1371 init_waitqueue_head(&sk->sk_lock.wq); \
1372 spin_lock_init(&(sk)->sk_lock.slock); \
1373 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1374 sizeof((sk)->sk_lock)); \
1375 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1377 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1380 extern void lock_sock_nested(struct sock *sk, int subclass);
1382 static inline void lock_sock(struct sock *sk)
1384 lock_sock_nested(sk, 0);
1387 extern void release_sock(struct sock *sk);
1389 /* BH context may only use the following locking interface. */
1390 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1391 #define bh_lock_sock_nested(__sk) \
1392 spin_lock_nested(&((__sk)->sk_lock.slock), \
1393 SINGLE_DEPTH_NESTING)
1394 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1396 extern bool lock_sock_fast(struct sock *sk);
1398 * unlock_sock_fast - complement of lock_sock_fast
1402 * fast unlock socket for user context.
1403 * If slow mode is on, we call regular release_sock()
1405 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1410 spin_unlock_bh(&sk->sk_lock.slock);
1414 extern struct sock *sk_alloc(struct net *net, int family,
1416 struct proto *prot);
1417 extern void sk_free(struct sock *sk);
1418 extern void sk_release_kernel(struct sock *sk);
1419 extern struct sock *sk_clone_lock(const struct sock *sk,
1420 const gfp_t priority);
1422 extern struct sk_buff *sock_wmalloc(struct sock *sk,
1423 unsigned long size, int force,
1425 extern struct sk_buff *sock_rmalloc(struct sock *sk,
1426 unsigned long size, int force,
1428 extern void sock_wfree(struct sk_buff *skb);
1429 extern void sock_rfree(struct sk_buff *skb);
1430 extern void sock_edemux(struct sk_buff *skb);
1432 extern int sock_setsockopt(struct socket *sock, int level,
1433 int op, char __user *optval,
1434 unsigned int optlen);
1436 extern int sock_getsockopt(struct socket *sock, int level,
1437 int op, char __user *optval,
1438 int __user *optlen);
1439 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1443 extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
1444 unsigned long header_len,
1445 unsigned long data_len,
1448 extern void *sock_kmalloc(struct sock *sk, int size,
1450 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
1451 extern void sk_send_sigurg(struct sock *sk);
1453 #ifdef CONFIG_CGROUPS
1454 extern void sock_update_classid(struct sock *sk);
1456 static inline void sock_update_classid(struct sock *sk)
1462 * Functions to fill in entries in struct proto_ops when a protocol
1463 * does not implement a particular function.
1465 extern int sock_no_bind(struct socket *,
1466 struct sockaddr *, int);
1467 extern int sock_no_connect(struct socket *,
1468 struct sockaddr *, int, int);
1469 extern int sock_no_socketpair(struct socket *,
1471 extern int sock_no_accept(struct socket *,
1472 struct socket *, int);
1473 extern int sock_no_getname(struct socket *,
1474 struct sockaddr *, int *, int);
1475 extern unsigned int sock_no_poll(struct file *, struct socket *,
1476 struct poll_table_struct *);
1477 extern int sock_no_ioctl(struct socket *, unsigned int,
1479 extern int sock_no_listen(struct socket *, int);
1480 extern int sock_no_shutdown(struct socket *, int);
1481 extern int sock_no_getsockopt(struct socket *, int , int,
1482 char __user *, int __user *);
1483 extern int sock_no_setsockopt(struct socket *, int, int,
1484 char __user *, unsigned int);
1485 extern int sock_no_sendmsg(struct kiocb *, struct socket *,
1486 struct msghdr *, size_t);
1487 extern int sock_no_recvmsg(struct kiocb *, struct socket *,
1488 struct msghdr *, size_t, int);
1489 extern int sock_no_mmap(struct file *file,
1490 struct socket *sock,
1491 struct vm_area_struct *vma);
1492 extern ssize_t sock_no_sendpage(struct socket *sock,
1494 int offset, size_t size,
1498 * Functions to fill in entries in struct proto_ops when a protocol
1499 * uses the inet style.
1501 extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
1502 char __user *optval, int __user *optlen);
1503 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1504 struct msghdr *msg, size_t size, int flags);
1505 extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
1506 char __user *optval, unsigned int optlen);
1507 extern int compat_sock_common_getsockopt(struct socket *sock, int level,
1508 int optname, char __user *optval, int __user *optlen);
1509 extern int compat_sock_common_setsockopt(struct socket *sock, int level,
1510 int optname, char __user *optval, unsigned int optlen);
1512 extern void sk_common_release(struct sock *sk);
1515 * Default socket callbacks and setup code
1518 /* Initialise core socket variables */
1519 extern void sock_init_data(struct socket *sock, struct sock *sk);
1521 extern void sk_filter_release_rcu(struct rcu_head *rcu);
1524 * sk_filter_release - release a socket filter
1525 * @fp: filter to remove
1527 * Remove a filter from a socket and release its resources.
1530 static inline void sk_filter_release(struct sk_filter *fp)
1532 if (atomic_dec_and_test(&fp->refcnt))
1533 call_rcu(&fp->rcu, sk_filter_release_rcu);
1536 static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
1538 unsigned int size = sk_filter_len(fp);
1540 atomic_sub(size, &sk->sk_omem_alloc);
1541 sk_filter_release(fp);
1544 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
1546 atomic_inc(&fp->refcnt);
1547 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
1551 * Socket reference counting postulates.
1553 * * Each user of socket SHOULD hold a reference count.
1554 * * Each access point to socket (an hash table bucket, reference from a list,
1555 * running timer, skb in flight MUST hold a reference count.
1556 * * When reference count hits 0, it means it will never increase back.
1557 * * When reference count hits 0, it means that no references from
1558 * outside exist to this socket and current process on current CPU
1559 * is last user and may/should destroy this socket.
1560 * * sk_free is called from any context: process, BH, IRQ. When
1561 * it is called, socket has no references from outside -> sk_free
1562 * may release descendant resources allocated by the socket, but
1563 * to the time when it is called, socket is NOT referenced by any
1564 * hash tables, lists etc.
1565 * * Packets, delivered from outside (from network or from another process)
1566 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1567 * when they sit in queue. Otherwise, packets will leak to hole, when
1568 * socket is looked up by one cpu and unhasing is made by another CPU.
1569 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1570 * (leak to backlog). Packet socket does all the processing inside
1571 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1572 * use separate SMP lock, so that they are prone too.
1575 /* Ungrab socket and destroy it, if it was the last reference. */
1576 static inline void sock_put(struct sock *sk)
1578 if (atomic_dec_and_test(&sk->sk_refcnt))
1582 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1585 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1587 sk->sk_tx_queue_mapping = tx_queue;
1590 static inline void sk_tx_queue_clear(struct sock *sk)
1592 sk->sk_tx_queue_mapping = -1;
1595 static inline int sk_tx_queue_get(const struct sock *sk)
1597 return sk ? sk->sk_tx_queue_mapping : -1;
1600 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1602 sk_tx_queue_clear(sk);
1603 sk->sk_socket = sock;
1606 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1608 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1609 return &rcu_dereference_raw(sk->sk_wq)->wait;
1611 /* Detach socket from process context.
1612 * Announce socket dead, detach it from wait queue and inode.
1613 * Note that parent inode held reference count on this struct sock,
1614 * we do not release it in this function, because protocol
1615 * probably wants some additional cleanups or even continuing
1616 * to work with this socket (TCP).
1618 static inline void sock_orphan(struct sock *sk)
1620 write_lock_bh(&sk->sk_callback_lock);
1621 sock_set_flag(sk, SOCK_DEAD);
1622 sk_set_socket(sk, NULL);
1624 write_unlock_bh(&sk->sk_callback_lock);
1627 static inline void sock_graft(struct sock *sk, struct socket *parent)
1629 write_lock_bh(&sk->sk_callback_lock);
1630 sk->sk_wq = parent->wq;
1632 sk_set_socket(sk, parent);
1633 security_sock_graft(sk, parent);
1634 write_unlock_bh(&sk->sk_callback_lock);
1637 extern int sock_i_uid(struct sock *sk);
1638 extern unsigned long sock_i_ino(struct sock *sk);
1640 static inline struct dst_entry *
1641 __sk_dst_get(struct sock *sk)
1643 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1644 lockdep_is_held(&sk->sk_lock.slock));
1647 static inline struct dst_entry *
1648 sk_dst_get(struct sock *sk)
1650 struct dst_entry *dst;
1653 dst = rcu_dereference(sk->sk_dst_cache);
1660 extern void sk_reset_txq(struct sock *sk);
1662 static inline void dst_negative_advice(struct sock *sk)
1664 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1666 if (dst && dst->ops->negative_advice) {
1667 ndst = dst->ops->negative_advice(dst);
1670 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1677 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1679 struct dst_entry *old_dst;
1681 sk_tx_queue_clear(sk);
1683 * This can be called while sk is owned by the caller only,
1684 * with no state that can be checked in a rcu_dereference_check() cond
1686 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1687 rcu_assign_pointer(sk->sk_dst_cache, dst);
1688 dst_release(old_dst);
1692 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1694 spin_lock(&sk->sk_dst_lock);
1695 __sk_dst_set(sk, dst);
1696 spin_unlock(&sk->sk_dst_lock);
1700 __sk_dst_reset(struct sock *sk)
1702 __sk_dst_set(sk, NULL);
1706 sk_dst_reset(struct sock *sk)
1708 spin_lock(&sk->sk_dst_lock);
1710 spin_unlock(&sk->sk_dst_lock);
1713 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1715 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1717 static inline bool sk_can_gso(const struct sock *sk)
1719 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1722 extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1724 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1726 sk->sk_route_nocaps |= flags;
1727 sk->sk_route_caps &= ~flags;
1730 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1731 char __user *from, char *to,
1732 int copy, int offset)
1734 if (skb->ip_summed == CHECKSUM_NONE) {
1736 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1739 skb->csum = csum_block_add(skb->csum, csum, offset);
1740 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1741 if (!access_ok(VERIFY_READ, from, copy) ||
1742 __copy_from_user_nocache(to, from, copy))
1744 } else if (copy_from_user(to, from, copy))
1750 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1751 char __user *from, int copy)
1753 int err, offset = skb->len;
1755 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1758 __skb_trim(skb, offset);
1763 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1764 struct sk_buff *skb,
1770 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1776 skb->data_len += copy;
1777 skb->truesize += copy;
1778 sk->sk_wmem_queued += copy;
1779 sk_mem_charge(sk, copy);
1783 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1784 struct sk_buff *skb, struct page *page,
1787 if (skb->ip_summed == CHECKSUM_NONE) {
1789 __wsum csum = csum_and_copy_from_user(from,
1790 page_address(page) + off,
1794 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1795 } else if (copy_from_user(page_address(page) + off, from, copy))
1799 skb->data_len += copy;
1800 skb->truesize += copy;
1801 sk->sk_wmem_queued += copy;
1802 sk_mem_charge(sk, copy);
1807 * sk_wmem_alloc_get - returns write allocations
1810 * Returns sk_wmem_alloc minus initial offset of one
1812 static inline int sk_wmem_alloc_get(const struct sock *sk)
1814 return atomic_read(&sk->sk_wmem_alloc) - 1;
1818 * sk_rmem_alloc_get - returns read allocations
1821 * Returns sk_rmem_alloc
1823 static inline int sk_rmem_alloc_get(const struct sock *sk)
1825 return atomic_read(&sk->sk_rmem_alloc);
1829 * sk_has_allocations - check if allocations are outstanding
1832 * Returns true if socket has write or read allocations
1834 static inline bool sk_has_allocations(const struct sock *sk)
1836 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1840 * wq_has_sleeper - check if there are any waiting processes
1841 * @wq: struct socket_wq
1843 * Returns true if socket_wq has waiting processes
1845 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1846 * barrier call. They were added due to the race found within the tcp code.
1848 * Consider following tcp code paths:
1852 * sys_select receive packet
1854 * __add_wait_queue update tp->rcv_nxt
1856 * tp->rcv_nxt check sock_def_readable
1858 * schedule rcu_read_lock();
1859 * wq = rcu_dereference(sk->sk_wq);
1860 * if (wq && waitqueue_active(&wq->wait))
1861 * wake_up_interruptible(&wq->wait)
1865 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1866 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1867 * could then endup calling schedule and sleep forever if there are no more
1868 * data on the socket.
1871 static inline bool wq_has_sleeper(struct socket_wq *wq)
1873 /* We need to be sure we are in sync with the
1874 * add_wait_queue modifications to the wait queue.
1876 * This memory barrier is paired in the sock_poll_wait.
1879 return wq && waitqueue_active(&wq->wait);
1883 * sock_poll_wait - place memory barrier behind the poll_wait call.
1885 * @wait_address: socket wait queue
1888 * See the comments in the wq_has_sleeper function.
1890 static inline void sock_poll_wait(struct file *filp,
1891 wait_queue_head_t *wait_address, poll_table *p)
1893 if (!poll_does_not_wait(p) && wait_address) {
1894 poll_wait(filp, wait_address, p);
1895 /* We need to be sure we are in sync with the
1896 * socket flags modification.
1898 * This memory barrier is paired in the wq_has_sleeper.
1905 * Queue a received datagram if it will fit. Stream and sequenced
1906 * protocols can't normally use this as they need to fit buffers in
1907 * and play with them.
1909 * Inlined as it's very short and called for pretty much every
1910 * packet ever received.
1913 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1917 skb->destructor = sock_wfree;
1919 * We used to take a refcount on sk, but following operation
1920 * is enough to guarantee sk_free() wont free this sock until
1921 * all in-flight packets are completed
1923 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1926 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1930 skb->destructor = sock_rfree;
1931 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1932 sk_mem_charge(sk, skb->truesize);
1935 extern void sk_reset_timer(struct sock *sk, struct timer_list *timer,
1936 unsigned long expires);
1938 extern void sk_stop_timer(struct sock *sk, struct timer_list *timer);
1940 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1942 extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1945 * Recover an error report and clear atomically
1948 static inline int sock_error(struct sock *sk)
1951 if (likely(!sk->sk_err))
1953 err = xchg(&sk->sk_err, 0);
1957 static inline unsigned long sock_wspace(struct sock *sk)
1961 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1962 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1969 static inline void sk_wake_async(struct sock *sk, int how, int band)
1971 if (sock_flag(sk, SOCK_FASYNC))
1972 sock_wake_async(sk->sk_socket, how, band);
1975 #define SOCK_MIN_SNDBUF 2048
1977 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
1978 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
1980 #define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
1982 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1984 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1985 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1986 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1990 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
1992 static inline struct page *sk_stream_alloc_page(struct sock *sk)
1994 struct page *page = NULL;
1996 page = alloc_pages(sk->sk_allocation, 0);
1998 sk_enter_memory_pressure(sk);
1999 sk_stream_moderate_sndbuf(sk);
2005 * Default write policy as shown to user space via poll/select/SIGIO
2007 static inline bool sock_writeable(const struct sock *sk)
2009 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2012 static inline gfp_t gfp_any(void)
2014 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2017 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2019 return noblock ? 0 : sk->sk_rcvtimeo;
2022 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2024 return noblock ? 0 : sk->sk_sndtimeo;
2027 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2029 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2032 /* Alas, with timeout socket operations are not restartable.
2033 * Compare this to poll().
2035 static inline int sock_intr_errno(long timeo)
2037 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2040 extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2041 struct sk_buff *skb);
2042 extern void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2043 struct sk_buff *skb);
2046 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2048 ktime_t kt = skb->tstamp;
2049 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2052 * generate control messages if
2053 * - receive time stamping in software requested (SOCK_RCVTSTAMP
2054 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
2055 * - software time stamp available and wanted
2056 * (SOCK_TIMESTAMPING_SOFTWARE)
2057 * - hardware time stamps available and wanted
2058 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
2059 * SOCK_TIMESTAMPING_RAW_HARDWARE)
2061 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2062 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
2063 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
2064 (hwtstamps->hwtstamp.tv64 &&
2065 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
2066 (hwtstamps->syststamp.tv64 &&
2067 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
2068 __sock_recv_timestamp(msg, sk, skb);
2072 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2073 __sock_recv_wifi_status(msg, sk, skb);
2076 extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2077 struct sk_buff *skb);
2079 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2080 struct sk_buff *skb)
2082 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2083 (1UL << SOCK_RCVTSTAMP) | \
2084 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
2085 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
2086 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
2087 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
2089 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
2090 __sock_recv_ts_and_drops(msg, sk, skb);
2092 sk->sk_stamp = skb->tstamp;
2096 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2097 * @sk: socket sending this packet
2098 * @tx_flags: filled with instructions for time stamping
2100 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
2101 * parameters are invalid.
2103 extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
2106 * sk_eat_skb - Release a skb if it is no longer needed
2107 * @sk: socket to eat this skb from
2108 * @skb: socket buffer to eat
2109 * @copied_early: flag indicating whether DMA operations copied this data early
2111 * This routine must be called with interrupts disabled or with the socket
2112 * locked so that the sk_buff queue operation is ok.
2114 #ifdef CONFIG_NET_DMA
2115 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2117 __skb_unlink(skb, &sk->sk_receive_queue);
2121 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
2124 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2126 __skb_unlink(skb, &sk->sk_receive_queue);
2132 struct net *sock_net(const struct sock *sk)
2134 return read_pnet(&sk->sk_net);
2138 void sock_net_set(struct sock *sk, struct net *net)
2140 write_pnet(&sk->sk_net, net);
2144 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2145 * They should not hold a reference to a namespace in order to allow
2147 * Sockets after sk_change_net should be released using sk_release_kernel
2149 static inline void sk_change_net(struct sock *sk, struct net *net)
2151 put_net(sock_net(sk));
2152 sock_net_set(sk, hold_net(net));
2155 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2157 if (unlikely(skb->sk)) {
2158 struct sock *sk = skb->sk;
2160 skb->destructor = NULL;
2167 extern void sock_enable_timestamp(struct sock *sk, int flag);
2168 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
2169 extern int sock_get_timestampns(struct sock *, struct timespec __user *);
2172 * Enable debug/info messages
2174 extern int net_msg_warn;
2175 #define NETDEBUG(fmt, args...) \
2176 do { if (net_msg_warn) printk(fmt,##args); } while (0)
2178 #define LIMIT_NETDEBUG(fmt, args...) \
2179 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
2181 extern __u32 sysctl_wmem_max;
2182 extern __u32 sysctl_rmem_max;
2184 extern void sk_init(void);
2186 extern int sysctl_optmem_max;
2188 extern __u32 sysctl_wmem_default;
2189 extern __u32 sysctl_rmem_default;
2191 #endif /* _SOCK_H */