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;
129 typedef __u32 __bitwise __portpair;
130 typedef __u64 __bitwise __addrpair;
133 * struct sock_common - minimal network layer representation of sockets
134 * @skc_daddr: Foreign IPv4 addr
135 * @skc_rcv_saddr: Bound local IPv4 addr
136 * @skc_hash: hash value used with various protocol lookup tables
137 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
138 * @skc_dport: placeholder for inet_dport/tw_dport
139 * @skc_num: placeholder for inet_num/tw_num
140 * @skc_family: network address family
141 * @skc_state: Connection state
142 * @skc_reuse: %SO_REUSEADDR setting
143 * @skc_reuseport: %SO_REUSEPORT setting
144 * @skc_bound_dev_if: bound device index if != 0
145 * @skc_bind_node: bind hash linkage for various protocol lookup tables
146 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
147 * @skc_prot: protocol handlers inside a network family
148 * @skc_net: reference to the network namespace of this socket
149 * @skc_node: main hash linkage for various protocol lookup tables
150 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
151 * @skc_tx_queue_mapping: tx queue number for this connection
152 * @skc_refcnt: reference count
154 * This is the minimal network layer representation of sockets, the header
155 * for struct sock and struct inet_timewait_sock.
158 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
159 * address on 64bit arches : cf INET_MATCH()
162 __addrpair skc_addrpair;
165 __be32 skc_rcv_saddr;
169 unsigned int skc_hash;
170 __u16 skc_u16hashes[2];
172 /* skc_dport && skc_num must be grouped as well */
174 __portpair skc_portpair;
181 unsigned short skc_family;
182 volatile unsigned char skc_state;
183 unsigned char skc_reuse:4;
184 unsigned char skc_reuseport:1;
185 unsigned char skc_ipv6only:1;
186 int skc_bound_dev_if;
188 struct hlist_node skc_bind_node;
189 struct hlist_nulls_node skc_portaddr_node;
191 struct proto *skc_prot;
196 #if IS_ENABLED(CONFIG_IPV6)
197 struct in6_addr skc_v6_daddr;
198 struct in6_addr skc_v6_rcv_saddr;
202 * fields between dontcopy_begin/dontcopy_end
203 * are not copied in sock_copy()
206 int skc_dontcopy_begin[0];
209 struct hlist_node skc_node;
210 struct hlist_nulls_node skc_nulls_node;
212 int skc_tx_queue_mapping;
215 int skc_dontcopy_end[0];
221 * struct sock - network layer representation of sockets
222 * @__sk_common: shared layout with inet_timewait_sock
223 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
224 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
225 * @sk_lock: synchronizer
226 * @sk_rcvbuf: size of receive buffer in bytes
227 * @sk_wq: sock wait queue and async head
228 * @sk_rx_dst: receive input route used by early demux
229 * @sk_dst_cache: destination cache
230 * @sk_dst_lock: destination cache lock
231 * @sk_policy: flow policy
232 * @sk_receive_queue: incoming packets
233 * @sk_wmem_alloc: transmit queue bytes committed
234 * @sk_write_queue: Packet sending queue
235 * @sk_async_wait_queue: DMA copied packets
236 * @sk_omem_alloc: "o" is "option" or "other"
237 * @sk_wmem_queued: persistent queue size
238 * @sk_forward_alloc: space allocated forward
239 * @sk_napi_id: id of the last napi context to receive data for sk
240 * @sk_ll_usec: usecs to busypoll when there is no data
241 * @sk_allocation: allocation mode
242 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
243 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
244 * @sk_sndbuf: size of send buffer in bytes
245 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
246 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
247 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
248 * @sk_no_check_rx: allow zero checksum in RX packets
249 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
250 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
251 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
252 * @sk_gso_max_size: Maximum GSO segment size to build
253 * @sk_gso_max_segs: Maximum number of GSO segments
254 * @sk_lingertime: %SO_LINGER l_linger setting
255 * @sk_backlog: always used with the per-socket spinlock held
256 * @sk_callback_lock: used with the callbacks in the end of this struct
257 * @sk_error_queue: rarely used
258 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
259 * IPV6_ADDRFORM for instance)
260 * @sk_err: last error
261 * @sk_err_soft: errors that don't cause failure but are the cause of a
262 * persistent failure not just 'timed out'
263 * @sk_drops: raw/udp drops counter
264 * @sk_ack_backlog: current listen backlog
265 * @sk_max_ack_backlog: listen backlog set in listen()
266 * @sk_priority: %SO_PRIORITY setting
267 * @sk_cgrp_prioidx: socket group's priority map index
268 * @sk_type: socket type (%SOCK_STREAM, etc)
269 * @sk_protocol: which protocol this socket belongs in this network family
270 * @sk_peer_pid: &struct pid for this socket's peer
271 * @sk_peer_cred: %SO_PEERCRED setting
272 * @sk_rcvlowat: %SO_RCVLOWAT setting
273 * @sk_rcvtimeo: %SO_RCVTIMEO setting
274 * @sk_sndtimeo: %SO_SNDTIMEO setting
275 * @sk_rxhash: flow hash received from netif layer
276 * @sk_txhash: computed flow hash for use on transmit
277 * @sk_filter: socket filtering instructions
278 * @sk_protinfo: private area, net family specific, when not using slab
279 * @sk_timer: sock cleanup timer
280 * @sk_stamp: time stamp of last packet received
281 * @sk_socket: Identd and reporting IO signals
282 * @sk_user_data: RPC layer private data
283 * @sk_frag: cached page frag
284 * @sk_peek_off: current peek_offset value
285 * @sk_send_head: front of stuff to transmit
286 * @sk_security: used by security modules
287 * @sk_mark: generic packet mark
288 * @sk_classid: this socket's cgroup classid
289 * @sk_cgrp: this socket's cgroup-specific proto data
290 * @sk_write_pending: a write to stream socket waits to start
291 * @sk_state_change: callback to indicate change in the state of the sock
292 * @sk_data_ready: callback to indicate there is data to be processed
293 * @sk_write_space: callback to indicate there is bf sending space available
294 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
295 * @sk_backlog_rcv: callback to process the backlog
296 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
300 * Now struct inet_timewait_sock also uses sock_common, so please just
301 * don't add nothing before this first member (__sk_common) --acme
303 struct sock_common __sk_common;
304 #define sk_node __sk_common.skc_node
305 #define sk_nulls_node __sk_common.skc_nulls_node
306 #define sk_refcnt __sk_common.skc_refcnt
307 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
309 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
310 #define sk_dontcopy_end __sk_common.skc_dontcopy_end
311 #define sk_hash __sk_common.skc_hash
312 #define sk_portpair __sk_common.skc_portpair
313 #define sk_num __sk_common.skc_num
314 #define sk_dport __sk_common.skc_dport
315 #define sk_addrpair __sk_common.skc_addrpair
316 #define sk_daddr __sk_common.skc_daddr
317 #define sk_rcv_saddr __sk_common.skc_rcv_saddr
318 #define sk_family __sk_common.skc_family
319 #define sk_state __sk_common.skc_state
320 #define sk_reuse __sk_common.skc_reuse
321 #define sk_reuseport __sk_common.skc_reuseport
322 #define sk_ipv6only __sk_common.skc_ipv6only
323 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
324 #define sk_bind_node __sk_common.skc_bind_node
325 #define sk_prot __sk_common.skc_prot
326 #define sk_net __sk_common.skc_net
327 #define sk_v6_daddr __sk_common.skc_v6_daddr
328 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
330 socket_lock_t sk_lock;
331 struct sk_buff_head sk_receive_queue;
333 * The backlog queue is special, it is always used with
334 * the per-socket spinlock held and requires low latency
335 * access. Therefore we special case it's implementation.
336 * Note : rmem_alloc is in this structure to fill a hole
337 * on 64bit arches, not because its logically part of
343 struct sk_buff *head;
344 struct sk_buff *tail;
346 #define sk_rmem_alloc sk_backlog.rmem_alloc
347 int sk_forward_alloc;
352 #ifdef CONFIG_NET_RX_BUSY_POLL
353 unsigned int sk_napi_id;
354 unsigned int sk_ll_usec;
359 struct sk_filter __rcu *sk_filter;
360 struct socket_wq __rcu *sk_wq;
362 #ifdef CONFIG_NET_DMA
363 struct sk_buff_head sk_async_wait_queue;
367 struct xfrm_policy *sk_policy[2];
369 unsigned long sk_flags;
370 struct dst_entry *sk_rx_dst;
371 struct dst_entry __rcu *sk_dst_cache;
372 spinlock_t sk_dst_lock;
373 atomic_t sk_wmem_alloc;
374 atomic_t sk_omem_alloc;
376 struct sk_buff_head sk_write_queue;
377 kmemcheck_bitfield_begin(flags);
378 unsigned int sk_shutdown : 2,
384 kmemcheck_bitfield_end(flags);
387 u32 sk_pacing_rate; /* bytes per second */
388 u32 sk_max_pacing_rate;
389 netdev_features_t sk_route_caps;
390 netdev_features_t sk_route_nocaps;
392 unsigned int sk_gso_max_size;
395 unsigned long sk_lingertime;
396 struct sk_buff_head sk_error_queue;
397 struct proto *sk_prot_creator;
398 rwlock_t sk_callback_lock;
401 unsigned short sk_ack_backlog;
402 unsigned short sk_max_ack_backlog;
404 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
405 __u32 sk_cgrp_prioidx;
407 struct pid *sk_peer_pid;
408 const struct cred *sk_peer_cred;
412 struct timer_list sk_timer;
414 struct socket *sk_socket;
416 struct page_frag sk_frag;
417 struct sk_buff *sk_send_head;
419 int sk_write_pending;
420 #ifdef CONFIG_SECURITY
425 struct cg_proto *sk_cgrp;
426 void (*sk_state_change)(struct sock *sk);
427 void (*sk_data_ready)(struct sock *sk);
428 void (*sk_write_space)(struct sock *sk);
429 void (*sk_error_report)(struct sock *sk);
430 int (*sk_backlog_rcv)(struct sock *sk,
431 struct sk_buff *skb);
432 void (*sk_destruct)(struct sock *sk);
435 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
437 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
438 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
441 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
442 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
443 * on a socket means that the socket will reuse everybody else's port
444 * without looking at the other's sk_reuse value.
447 #define SK_NO_REUSE 0
448 #define SK_CAN_REUSE 1
449 #define SK_FORCE_REUSE 2
451 static inline int sk_peek_offset(struct sock *sk, int flags)
453 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
454 return sk->sk_peek_off;
459 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
461 if (sk->sk_peek_off >= 0) {
462 if (sk->sk_peek_off >= val)
463 sk->sk_peek_off -= val;
469 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
471 if (sk->sk_peek_off >= 0)
472 sk->sk_peek_off += val;
476 * Hashed lists helper routines
478 static inline struct sock *sk_entry(const struct hlist_node *node)
480 return hlist_entry(node, struct sock, sk_node);
483 static inline struct sock *__sk_head(const struct hlist_head *head)
485 return hlist_entry(head->first, struct sock, sk_node);
488 static inline struct sock *sk_head(const struct hlist_head *head)
490 return hlist_empty(head) ? NULL : __sk_head(head);
493 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
495 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
498 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
500 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
503 static inline struct sock *sk_next(const struct sock *sk)
505 return sk->sk_node.next ?
506 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
509 static inline struct sock *sk_nulls_next(const struct sock *sk)
511 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
512 hlist_nulls_entry(sk->sk_nulls_node.next,
513 struct sock, sk_nulls_node) :
517 static inline bool sk_unhashed(const struct sock *sk)
519 return hlist_unhashed(&sk->sk_node);
522 static inline bool sk_hashed(const struct sock *sk)
524 return !sk_unhashed(sk);
527 static inline void sk_node_init(struct hlist_node *node)
532 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
537 static inline void __sk_del_node(struct sock *sk)
539 __hlist_del(&sk->sk_node);
542 /* NB: equivalent to hlist_del_init_rcu */
543 static inline bool __sk_del_node_init(struct sock *sk)
547 sk_node_init(&sk->sk_node);
553 /* Grab socket reference count. This operation is valid only
554 when sk is ALREADY grabbed f.e. it is found in hash table
555 or a list and the lookup is made under lock preventing hash table
559 static inline void sock_hold(struct sock *sk)
561 atomic_inc(&sk->sk_refcnt);
564 /* Ungrab socket in the context, which assumes that socket refcnt
565 cannot hit zero, f.e. it is true in context of any socketcall.
567 static inline void __sock_put(struct sock *sk)
569 atomic_dec(&sk->sk_refcnt);
572 static inline bool sk_del_node_init(struct sock *sk)
574 bool rc = __sk_del_node_init(sk);
577 /* paranoid for a while -acme */
578 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
583 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
585 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
588 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
594 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
596 bool rc = __sk_nulls_del_node_init_rcu(sk);
599 /* paranoid for a while -acme */
600 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
606 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
608 hlist_add_head(&sk->sk_node, list);
611 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
614 __sk_add_node(sk, list);
617 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
620 hlist_add_head_rcu(&sk->sk_node, list);
623 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
625 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
628 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
631 __sk_nulls_add_node_rcu(sk, list);
634 static inline void __sk_del_bind_node(struct sock *sk)
636 __hlist_del(&sk->sk_bind_node);
639 static inline void sk_add_bind_node(struct sock *sk,
640 struct hlist_head *list)
642 hlist_add_head(&sk->sk_bind_node, list);
645 #define sk_for_each(__sk, list) \
646 hlist_for_each_entry(__sk, list, sk_node)
647 #define sk_for_each_rcu(__sk, list) \
648 hlist_for_each_entry_rcu(__sk, list, sk_node)
649 #define sk_nulls_for_each(__sk, node, list) \
650 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
651 #define sk_nulls_for_each_rcu(__sk, node, list) \
652 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
653 #define sk_for_each_from(__sk) \
654 hlist_for_each_entry_from(__sk, sk_node)
655 #define sk_nulls_for_each_from(__sk, node) \
656 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
657 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
658 #define sk_for_each_safe(__sk, tmp, list) \
659 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
660 #define sk_for_each_bound(__sk, list) \
661 hlist_for_each_entry(__sk, list, sk_bind_node)
663 static inline struct user_namespace *sk_user_ns(struct sock *sk)
665 /* Careful only use this in a context where these parameters
666 * can not change and must all be valid, such as recvmsg from
669 return sk->sk_socket->file->f_cred->user_ns;
683 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
684 SOCK_DBG, /* %SO_DEBUG setting */
685 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
686 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
687 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
688 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
689 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
690 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
691 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
692 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
693 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
694 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
695 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
696 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
697 SOCK_FASYNC, /* fasync() active */
699 SOCK_ZEROCOPY, /* buffers from userspace */
700 SOCK_WIFI_STATUS, /* push wifi status to userspace */
701 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
702 * Will use last 4 bytes of packet sent from
703 * user-space instead.
705 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
706 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
709 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
711 nsk->sk_flags = osk->sk_flags;
714 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
716 __set_bit(flag, &sk->sk_flags);
719 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
721 __clear_bit(flag, &sk->sk_flags);
724 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
726 return test_bit(flag, &sk->sk_flags);
730 extern struct static_key memalloc_socks;
731 static inline int sk_memalloc_socks(void)
733 return static_key_false(&memalloc_socks);
737 static inline int sk_memalloc_socks(void)
744 static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
746 return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
749 static inline void sk_acceptq_removed(struct sock *sk)
751 sk->sk_ack_backlog--;
754 static inline void sk_acceptq_added(struct sock *sk)
756 sk->sk_ack_backlog++;
759 static inline bool sk_acceptq_is_full(const struct sock *sk)
761 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
765 * Compute minimal free write space needed to queue new packets.
767 static inline int sk_stream_min_wspace(const struct sock *sk)
769 return sk->sk_wmem_queued >> 1;
772 static inline int sk_stream_wspace(const struct sock *sk)
774 return sk->sk_sndbuf - sk->sk_wmem_queued;
777 void sk_stream_write_space(struct sock *sk);
779 /* OOB backlog add */
780 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
782 /* dont let skb dst not refcounted, we are going to leave rcu lock */
785 if (!sk->sk_backlog.tail)
786 sk->sk_backlog.head = skb;
788 sk->sk_backlog.tail->next = skb;
790 sk->sk_backlog.tail = skb;
795 * Take into account size of receive queue and backlog queue
796 * Do not take into account this skb truesize,
797 * to allow even a single big packet to come.
799 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
802 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
804 return qsize > limit;
807 /* The per-socket spinlock must be held here. */
808 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
811 if (sk_rcvqueues_full(sk, skb, limit))
814 __sk_add_backlog(sk, skb);
815 sk->sk_backlog.len += skb->truesize;
819 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
821 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
823 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
824 return __sk_backlog_rcv(sk, skb);
826 return sk->sk_backlog_rcv(sk, skb);
829 static inline void sock_rps_record_flow_hash(__u32 hash)
832 struct rps_sock_flow_table *sock_flow_table;
835 sock_flow_table = rcu_dereference(rps_sock_flow_table);
836 rps_record_sock_flow(sock_flow_table, hash);
841 static inline void sock_rps_reset_flow_hash(__u32 hash)
844 struct rps_sock_flow_table *sock_flow_table;
847 sock_flow_table = rcu_dereference(rps_sock_flow_table);
848 rps_reset_sock_flow(sock_flow_table, hash);
853 static inline void sock_rps_record_flow(const struct sock *sk)
856 sock_rps_record_flow_hash(sk->sk_rxhash);
860 static inline void sock_rps_reset_flow(const struct sock *sk)
863 sock_rps_reset_flow_hash(sk->sk_rxhash);
867 static inline void sock_rps_save_rxhash(struct sock *sk,
868 const struct sk_buff *skb)
871 if (unlikely(sk->sk_rxhash != skb->hash)) {
872 sock_rps_reset_flow(sk);
873 sk->sk_rxhash = skb->hash;
878 static inline void sock_rps_reset_rxhash(struct sock *sk)
881 sock_rps_reset_flow(sk);
886 #define sk_wait_event(__sk, __timeo, __condition) \
888 release_sock(__sk); \
889 __rc = __condition; \
891 *(__timeo) = schedule_timeout(*(__timeo)); \
894 __rc = __condition; \
898 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
899 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
900 void sk_stream_wait_close(struct sock *sk, long timeo_p);
901 int sk_stream_error(struct sock *sk, int flags, int err);
902 void sk_stream_kill_queues(struct sock *sk);
903 void sk_set_memalloc(struct sock *sk);
904 void sk_clear_memalloc(struct sock *sk);
906 int sk_wait_data(struct sock *sk, long *timeo);
908 struct request_sock_ops;
909 struct timewait_sock_ops;
910 struct inet_hashinfo;
915 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
916 * un-modified. Special care is taken when initializing object to zero.
918 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
920 if (offsetof(struct sock, sk_node.next) != 0)
921 memset(sk, 0, offsetof(struct sock, sk_node.next));
922 memset(&sk->sk_node.pprev, 0,
923 size - offsetof(struct sock, sk_node.pprev));
926 /* Networking protocol blocks we attach to sockets.
927 * socket layer -> transport layer interface
928 * transport -> network interface is defined by struct inet_proto
931 void (*close)(struct sock *sk,
933 int (*connect)(struct sock *sk,
934 struct sockaddr *uaddr,
936 int (*disconnect)(struct sock *sk, int flags);
938 struct sock * (*accept)(struct sock *sk, int flags, int *err);
940 int (*ioctl)(struct sock *sk, int cmd,
942 int (*init)(struct sock *sk);
943 void (*destroy)(struct sock *sk);
944 void (*shutdown)(struct sock *sk, int how);
945 int (*setsockopt)(struct sock *sk, int level,
946 int optname, char __user *optval,
947 unsigned int optlen);
948 int (*getsockopt)(struct sock *sk, int level,
949 int optname, char __user *optval,
952 int (*compat_setsockopt)(struct sock *sk,
954 int optname, char __user *optval,
955 unsigned int optlen);
956 int (*compat_getsockopt)(struct sock *sk,
958 int optname, char __user *optval,
960 int (*compat_ioctl)(struct sock *sk,
961 unsigned int cmd, unsigned long arg);
963 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
964 struct msghdr *msg, size_t len);
965 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
967 size_t len, int noblock, int flags,
969 int (*sendpage)(struct sock *sk, struct page *page,
970 int offset, size_t size, int flags);
971 int (*bind)(struct sock *sk,
972 struct sockaddr *uaddr, int addr_len);
974 int (*backlog_rcv) (struct sock *sk,
975 struct sk_buff *skb);
977 void (*release_cb)(struct sock *sk);
978 void (*mtu_reduced)(struct sock *sk);
980 /* Keeping track of sk's, looking them up, and port selection methods. */
981 void (*hash)(struct sock *sk);
982 void (*unhash)(struct sock *sk);
983 void (*rehash)(struct sock *sk);
984 int (*get_port)(struct sock *sk, unsigned short snum);
985 void (*clear_sk)(struct sock *sk, int size);
987 /* Keeping track of sockets in use */
988 #ifdef CONFIG_PROC_FS
989 unsigned int inuse_idx;
992 bool (*stream_memory_free)(const struct sock *sk);
993 /* Memory pressure */
994 void (*enter_memory_pressure)(struct sock *sk);
995 atomic_long_t *memory_allocated; /* Current allocated memory. */
996 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
998 * Pressure flag: try to collapse.
999 * Technical note: it is used by multiple contexts non atomically.
1000 * All the __sk_mem_schedule() is of this nature: accounting
1001 * is strict, actions are advisory and have some latency.
1003 int *memory_pressure;
1010 struct kmem_cache *slab;
1011 unsigned int obj_size;
1014 struct percpu_counter *orphan_count;
1016 struct request_sock_ops *rsk_prot;
1017 struct timewait_sock_ops *twsk_prot;
1020 struct inet_hashinfo *hashinfo;
1021 struct udp_table *udp_table;
1022 struct raw_hashinfo *raw_hash;
1025 struct module *owner;
1029 struct list_head node;
1030 #ifdef SOCK_REFCNT_DEBUG
1033 #ifdef CONFIG_MEMCG_KMEM
1035 * cgroup specific init/deinit functions. Called once for all
1036 * protocols that implement it, from cgroups populate function.
1037 * This function has to setup any files the protocol want to
1038 * appear in the kmem cgroup filesystem.
1040 int (*init_cgroup)(struct mem_cgroup *memcg,
1041 struct cgroup_subsys *ss);
1042 void (*destroy_cgroup)(struct mem_cgroup *memcg);
1043 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg);
1048 * Bits in struct cg_proto.flags
1050 enum cg_proto_flags {
1051 /* Currently active and new sockets should be assigned to cgroups */
1053 /* It was ever activated; we must disarm static keys on destruction */
1054 MEMCG_SOCK_ACTIVATED,
1058 struct res_counter memory_allocated; /* Current allocated memory. */
1059 struct percpu_counter sockets_allocated; /* Current number of sockets. */
1060 int memory_pressure;
1062 unsigned long flags;
1064 * memcg field is used to find which memcg we belong directly
1065 * Each memcg struct can hold more than one cg_proto, so container_of
1068 * The elegant solution would be having an inverse function to
1069 * proto_cgroup in struct proto, but that means polluting the structure
1070 * for everybody, instead of just for memcg users.
1072 struct mem_cgroup *memcg;
1075 int proto_register(struct proto *prot, int alloc_slab);
1076 void proto_unregister(struct proto *prot);
1078 static inline bool memcg_proto_active(struct cg_proto *cg_proto)
1080 return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
1083 static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
1085 return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
1088 #ifdef SOCK_REFCNT_DEBUG
1089 static inline void sk_refcnt_debug_inc(struct sock *sk)
1091 atomic_inc(&sk->sk_prot->socks);
1094 static inline void sk_refcnt_debug_dec(struct sock *sk)
1096 atomic_dec(&sk->sk_prot->socks);
1097 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1098 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1101 static inline void sk_refcnt_debug_release(const struct sock *sk)
1103 if (atomic_read(&sk->sk_refcnt) != 1)
1104 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1105 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1107 #else /* SOCK_REFCNT_DEBUG */
1108 #define sk_refcnt_debug_inc(sk) do { } while (0)
1109 #define sk_refcnt_debug_dec(sk) do { } while (0)
1110 #define sk_refcnt_debug_release(sk) do { } while (0)
1111 #endif /* SOCK_REFCNT_DEBUG */
1113 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET)
1114 extern struct static_key memcg_socket_limit_enabled;
1115 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1116 struct cg_proto *cg_proto)
1118 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1120 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1122 #define mem_cgroup_sockets_enabled 0
1123 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1124 struct cg_proto *cg_proto)
1130 static inline bool sk_stream_memory_free(const struct sock *sk)
1132 if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1135 return sk->sk_prot->stream_memory_free ?
1136 sk->sk_prot->stream_memory_free(sk) : true;
1139 static inline bool sk_stream_is_writeable(const struct sock *sk)
1141 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1142 sk_stream_memory_free(sk);
1146 static inline bool sk_has_memory_pressure(const struct sock *sk)
1148 return sk->sk_prot->memory_pressure != NULL;
1151 static inline bool sk_under_memory_pressure(const struct sock *sk)
1153 if (!sk->sk_prot->memory_pressure)
1156 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1157 return !!sk->sk_cgrp->memory_pressure;
1159 return !!*sk->sk_prot->memory_pressure;
1162 static inline void sk_leave_memory_pressure(struct sock *sk)
1164 int *memory_pressure = sk->sk_prot->memory_pressure;
1166 if (!memory_pressure)
1169 if (*memory_pressure)
1170 *memory_pressure = 0;
1172 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1173 struct cg_proto *cg_proto = sk->sk_cgrp;
1174 struct proto *prot = sk->sk_prot;
1176 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1177 cg_proto->memory_pressure = 0;
1182 static inline void sk_enter_memory_pressure(struct sock *sk)
1184 if (!sk->sk_prot->enter_memory_pressure)
1187 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1188 struct cg_proto *cg_proto = sk->sk_cgrp;
1189 struct proto *prot = sk->sk_prot;
1191 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1192 cg_proto->memory_pressure = 1;
1195 sk->sk_prot->enter_memory_pressure(sk);
1198 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1200 long *prot = sk->sk_prot->sysctl_mem;
1201 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1202 prot = sk->sk_cgrp->sysctl_mem;
1206 static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1210 struct res_counter *fail;
1213 ret = res_counter_charge_nofail(&prot->memory_allocated,
1214 amt << PAGE_SHIFT, &fail);
1216 *parent_status = OVER_LIMIT;
1219 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1222 res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
1225 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1228 ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
1229 return ret >> PAGE_SHIFT;
1233 sk_memory_allocated(const struct sock *sk)
1235 struct proto *prot = sk->sk_prot;
1236 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1237 return memcg_memory_allocated_read(sk->sk_cgrp);
1239 return atomic_long_read(prot->memory_allocated);
1243 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1245 struct proto *prot = sk->sk_prot;
1247 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1248 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1249 /* update the root cgroup regardless */
1250 atomic_long_add_return(amt, prot->memory_allocated);
1251 return memcg_memory_allocated_read(sk->sk_cgrp);
1254 return atomic_long_add_return(amt, prot->memory_allocated);
1258 sk_memory_allocated_sub(struct sock *sk, int amt)
1260 struct proto *prot = sk->sk_prot;
1262 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1263 memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1265 atomic_long_sub(amt, prot->memory_allocated);
1268 static inline void sk_sockets_allocated_dec(struct sock *sk)
1270 struct proto *prot = sk->sk_prot;
1272 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1273 struct cg_proto *cg_proto = sk->sk_cgrp;
1275 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1276 percpu_counter_dec(&cg_proto->sockets_allocated);
1279 percpu_counter_dec(prot->sockets_allocated);
1282 static inline void sk_sockets_allocated_inc(struct sock *sk)
1284 struct proto *prot = sk->sk_prot;
1286 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1287 struct cg_proto *cg_proto = sk->sk_cgrp;
1289 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1290 percpu_counter_inc(&cg_proto->sockets_allocated);
1293 percpu_counter_inc(prot->sockets_allocated);
1297 sk_sockets_allocated_read_positive(struct sock *sk)
1299 struct proto *prot = sk->sk_prot;
1301 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1302 return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
1304 return percpu_counter_read_positive(prot->sockets_allocated);
1308 proto_sockets_allocated_sum_positive(struct proto *prot)
1310 return percpu_counter_sum_positive(prot->sockets_allocated);
1314 proto_memory_allocated(struct proto *prot)
1316 return atomic_long_read(prot->memory_allocated);
1320 proto_memory_pressure(struct proto *prot)
1322 if (!prot->memory_pressure)
1324 return !!*prot->memory_pressure;
1328 #ifdef CONFIG_PROC_FS
1329 /* Called with local bh disabled */
1330 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1331 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1333 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1340 /* With per-bucket locks this operation is not-atomic, so that
1341 * this version is not worse.
1343 static inline void __sk_prot_rehash(struct sock *sk)
1345 sk->sk_prot->unhash(sk);
1346 sk->sk_prot->hash(sk);
1349 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1351 /* About 10 seconds */
1352 #define SOCK_DESTROY_TIME (10*HZ)
1354 /* Sockets 0-1023 can't be bound to unless you are superuser */
1355 #define PROT_SOCK 1024
1357 #define SHUTDOWN_MASK 3
1358 #define RCV_SHUTDOWN 1
1359 #define SEND_SHUTDOWN 2
1361 #define SOCK_SNDBUF_LOCK 1
1362 #define SOCK_RCVBUF_LOCK 2
1363 #define SOCK_BINDADDR_LOCK 4
1364 #define SOCK_BINDPORT_LOCK 8
1366 /* sock_iocb: used to kick off async processing of socket ios */
1368 struct list_head list;
1372 struct socket *sock;
1374 struct scm_cookie *scm;
1375 struct msghdr *msg, async_msg;
1376 struct kiocb *kiocb;
1379 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1381 return (struct sock_iocb *)iocb->private;
1384 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1389 struct socket_alloc {
1390 struct socket socket;
1391 struct inode vfs_inode;
1394 static inline struct socket *SOCKET_I(struct inode *inode)
1396 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1399 static inline struct inode *SOCK_INODE(struct socket *socket)
1401 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1405 * Functions for memory accounting
1407 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1408 void __sk_mem_reclaim(struct sock *sk);
1410 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1411 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1412 #define SK_MEM_SEND 0
1413 #define SK_MEM_RECV 1
1415 static inline int sk_mem_pages(int amt)
1417 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1420 static inline bool sk_has_account(struct sock *sk)
1422 /* return true if protocol supports memory accounting */
1423 return !!sk->sk_prot->memory_allocated;
1426 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1428 if (!sk_has_account(sk))
1430 return size <= sk->sk_forward_alloc ||
1431 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1435 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1437 if (!sk_has_account(sk))
1439 return size<= sk->sk_forward_alloc ||
1440 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1441 skb_pfmemalloc(skb);
1444 static inline void sk_mem_reclaim(struct sock *sk)
1446 if (!sk_has_account(sk))
1448 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1449 __sk_mem_reclaim(sk);
1452 static inline void sk_mem_reclaim_partial(struct sock *sk)
1454 if (!sk_has_account(sk))
1456 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1457 __sk_mem_reclaim(sk);
1460 static inline void sk_mem_charge(struct sock *sk, int size)
1462 if (!sk_has_account(sk))
1464 sk->sk_forward_alloc -= size;
1467 static inline void sk_mem_uncharge(struct sock *sk, int size)
1469 if (!sk_has_account(sk))
1471 sk->sk_forward_alloc += size;
1474 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1476 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1477 sk->sk_wmem_queued -= skb->truesize;
1478 sk_mem_uncharge(sk, skb->truesize);
1482 /* Used by processes to "lock" a socket state, so that
1483 * interrupts and bottom half handlers won't change it
1484 * from under us. It essentially blocks any incoming
1485 * packets, so that we won't get any new data or any
1486 * packets that change the state of the socket.
1488 * While locked, BH processing will add new packets to
1489 * the backlog queue. This queue is processed by the
1490 * owner of the socket lock right before it is released.
1492 * Since ~2.3.5 it is also exclusive sleep lock serializing
1493 * accesses from user process context.
1495 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1497 static inline void sock_release_ownership(struct sock *sk)
1499 sk->sk_lock.owned = 0;
1503 * Macro so as to not evaluate some arguments when
1504 * lockdep is not enabled.
1506 * Mark both the sk_lock and the sk_lock.slock as a
1507 * per-address-family lock class.
1509 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1511 sk->sk_lock.owned = 0; \
1512 init_waitqueue_head(&sk->sk_lock.wq); \
1513 spin_lock_init(&(sk)->sk_lock.slock); \
1514 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1515 sizeof((sk)->sk_lock)); \
1516 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1518 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1521 void lock_sock_nested(struct sock *sk, int subclass);
1523 static inline void lock_sock(struct sock *sk)
1525 lock_sock_nested(sk, 0);
1528 void release_sock(struct sock *sk);
1530 /* BH context may only use the following locking interface. */
1531 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1532 #define bh_lock_sock_nested(__sk) \
1533 spin_lock_nested(&((__sk)->sk_lock.slock), \
1534 SINGLE_DEPTH_NESTING)
1535 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1537 bool lock_sock_fast(struct sock *sk);
1539 * unlock_sock_fast - complement of lock_sock_fast
1543 * fast unlock socket for user context.
1544 * If slow mode is on, we call regular release_sock()
1546 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1551 spin_unlock_bh(&sk->sk_lock.slock);
1555 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1556 struct proto *prot);
1557 void sk_free(struct sock *sk);
1558 void sk_release_kernel(struct sock *sk);
1559 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1561 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1563 void sock_wfree(struct sk_buff *skb);
1564 void skb_orphan_partial(struct sk_buff *skb);
1565 void sock_rfree(struct sk_buff *skb);
1566 void sock_edemux(struct sk_buff *skb);
1568 int sock_setsockopt(struct socket *sock, int level, int op,
1569 char __user *optval, unsigned int optlen);
1571 int sock_getsockopt(struct socket *sock, int level, int op,
1572 char __user *optval, int __user *optlen);
1573 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1574 int noblock, int *errcode);
1575 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1576 unsigned long data_len, int noblock,
1577 int *errcode, int max_page_order);
1578 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1579 void sock_kfree_s(struct sock *sk, void *mem, int size);
1580 void sk_send_sigurg(struct sock *sk);
1583 * Functions to fill in entries in struct proto_ops when a protocol
1584 * does not implement a particular function.
1586 int sock_no_bind(struct socket *, struct sockaddr *, int);
1587 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1588 int sock_no_socketpair(struct socket *, struct socket *);
1589 int sock_no_accept(struct socket *, struct socket *, int);
1590 int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1591 unsigned int sock_no_poll(struct file *, struct socket *,
1592 struct poll_table_struct *);
1593 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1594 int sock_no_listen(struct socket *, int);
1595 int sock_no_shutdown(struct socket *, int);
1596 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1597 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1598 int sock_no_sendmsg(struct kiocb *, struct socket *, struct msghdr *, size_t);
1599 int sock_no_recvmsg(struct kiocb *, struct socket *, struct msghdr *, size_t,
1601 int sock_no_mmap(struct file *file, struct socket *sock,
1602 struct vm_area_struct *vma);
1603 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1604 size_t size, int flags);
1607 * Functions to fill in entries in struct proto_ops when a protocol
1608 * uses the inet style.
1610 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1611 char __user *optval, int __user *optlen);
1612 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1613 struct msghdr *msg, size_t size, int flags);
1614 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1615 char __user *optval, unsigned int optlen);
1616 int compat_sock_common_getsockopt(struct socket *sock, int level,
1617 int optname, char __user *optval, int __user *optlen);
1618 int compat_sock_common_setsockopt(struct socket *sock, int level,
1619 int optname, char __user *optval, unsigned int optlen);
1621 void sk_common_release(struct sock *sk);
1624 * Default socket callbacks and setup code
1627 /* Initialise core socket variables */
1628 void sock_init_data(struct socket *sock, struct sock *sk);
1631 * Socket reference counting postulates.
1633 * * Each user of socket SHOULD hold a reference count.
1634 * * Each access point to socket (an hash table bucket, reference from a list,
1635 * running timer, skb in flight MUST hold a reference count.
1636 * * When reference count hits 0, it means it will never increase back.
1637 * * When reference count hits 0, it means that no references from
1638 * outside exist to this socket and current process on current CPU
1639 * is last user and may/should destroy this socket.
1640 * * sk_free is called from any context: process, BH, IRQ. When
1641 * it is called, socket has no references from outside -> sk_free
1642 * may release descendant resources allocated by the socket, but
1643 * to the time when it is called, socket is NOT referenced by any
1644 * hash tables, lists etc.
1645 * * Packets, delivered from outside (from network or from another process)
1646 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1647 * when they sit in queue. Otherwise, packets will leak to hole, when
1648 * socket is looked up by one cpu and unhasing is made by another CPU.
1649 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1650 * (leak to backlog). Packet socket does all the processing inside
1651 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1652 * use separate SMP lock, so that they are prone too.
1655 /* Ungrab socket and destroy it, if it was the last reference. */
1656 static inline void sock_put(struct sock *sk)
1658 if (atomic_dec_and_test(&sk->sk_refcnt))
1661 /* Generic version of sock_put(), dealing with all sockets
1662 * (TCP_TIMEWAIT, ESTABLISHED...)
1664 void sock_gen_put(struct sock *sk);
1666 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
1668 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1670 sk->sk_tx_queue_mapping = tx_queue;
1673 static inline void sk_tx_queue_clear(struct sock *sk)
1675 sk->sk_tx_queue_mapping = -1;
1678 static inline int sk_tx_queue_get(const struct sock *sk)
1680 return sk ? sk->sk_tx_queue_mapping : -1;
1683 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1685 sk_tx_queue_clear(sk);
1686 sk->sk_socket = sock;
1689 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1691 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1692 return &rcu_dereference_raw(sk->sk_wq)->wait;
1694 /* Detach socket from process context.
1695 * Announce socket dead, detach it from wait queue and inode.
1696 * Note that parent inode held reference count on this struct sock,
1697 * we do not release it in this function, because protocol
1698 * probably wants some additional cleanups or even continuing
1699 * to work with this socket (TCP).
1701 static inline void sock_orphan(struct sock *sk)
1703 write_lock_bh(&sk->sk_callback_lock);
1704 sock_set_flag(sk, SOCK_DEAD);
1705 sk_set_socket(sk, NULL);
1707 write_unlock_bh(&sk->sk_callback_lock);
1710 static inline void sock_graft(struct sock *sk, struct socket *parent)
1712 write_lock_bh(&sk->sk_callback_lock);
1713 sk->sk_wq = parent->wq;
1715 sk_set_socket(sk, parent);
1716 security_sock_graft(sk, parent);
1717 write_unlock_bh(&sk->sk_callback_lock);
1720 kuid_t sock_i_uid(struct sock *sk);
1721 unsigned long sock_i_ino(struct sock *sk);
1723 static inline struct dst_entry *
1724 __sk_dst_get(struct sock *sk)
1726 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1727 lockdep_is_held(&sk->sk_lock.slock));
1730 static inline struct dst_entry *
1731 sk_dst_get(struct sock *sk)
1733 struct dst_entry *dst;
1736 dst = rcu_dereference(sk->sk_dst_cache);
1737 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1743 static inline void dst_negative_advice(struct sock *sk)
1745 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1747 if (dst && dst->ops->negative_advice) {
1748 ndst = dst->ops->negative_advice(dst);
1751 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1752 sk_tx_queue_clear(sk);
1758 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1760 struct dst_entry *old_dst;
1762 sk_tx_queue_clear(sk);
1764 * This can be called while sk is owned by the caller only,
1765 * with no state that can be checked in a rcu_dereference_check() cond
1767 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1768 rcu_assign_pointer(sk->sk_dst_cache, dst);
1769 dst_release(old_dst);
1773 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1775 spin_lock(&sk->sk_dst_lock);
1776 __sk_dst_set(sk, dst);
1777 spin_unlock(&sk->sk_dst_lock);
1781 __sk_dst_reset(struct sock *sk)
1783 __sk_dst_set(sk, NULL);
1787 sk_dst_reset(struct sock *sk)
1789 spin_lock(&sk->sk_dst_lock);
1791 spin_unlock(&sk->sk_dst_lock);
1794 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1796 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1798 static inline bool sk_can_gso(const struct sock *sk)
1800 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1803 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1805 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1807 sk->sk_route_nocaps |= flags;
1808 sk->sk_route_caps &= ~flags;
1811 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1812 char __user *from, char *to,
1813 int copy, int offset)
1815 if (skb->ip_summed == CHECKSUM_NONE) {
1817 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1820 skb->csum = csum_block_add(skb->csum, csum, offset);
1821 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1822 if (!access_ok(VERIFY_READ, from, copy) ||
1823 __copy_from_user_nocache(to, from, copy))
1825 } else if (copy_from_user(to, from, copy))
1831 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1832 char __user *from, int copy)
1834 int err, offset = skb->len;
1836 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1839 __skb_trim(skb, offset);
1844 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1845 struct sk_buff *skb,
1851 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1857 skb->data_len += copy;
1858 skb->truesize += copy;
1859 sk->sk_wmem_queued += copy;
1860 sk_mem_charge(sk, copy);
1864 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1865 struct sk_buff *skb, struct page *page,
1868 if (skb->ip_summed == CHECKSUM_NONE) {
1870 __wsum csum = csum_and_copy_from_user(from,
1871 page_address(page) + off,
1875 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1876 } else if (copy_from_user(page_address(page) + off, from, copy))
1880 skb->data_len += copy;
1881 skb->truesize += copy;
1882 sk->sk_wmem_queued += copy;
1883 sk_mem_charge(sk, copy);
1888 * sk_wmem_alloc_get - returns write allocations
1891 * Returns sk_wmem_alloc minus initial offset of one
1893 static inline int sk_wmem_alloc_get(const struct sock *sk)
1895 return atomic_read(&sk->sk_wmem_alloc) - 1;
1899 * sk_rmem_alloc_get - returns read allocations
1902 * Returns sk_rmem_alloc
1904 static inline int sk_rmem_alloc_get(const struct sock *sk)
1906 return atomic_read(&sk->sk_rmem_alloc);
1910 * sk_has_allocations - check if allocations are outstanding
1913 * Returns true if socket has write or read allocations
1915 static inline bool sk_has_allocations(const struct sock *sk)
1917 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1921 * wq_has_sleeper - check if there are any waiting processes
1922 * @wq: struct socket_wq
1924 * Returns true if socket_wq has waiting processes
1926 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1927 * barrier call. They were added due to the race found within the tcp code.
1929 * Consider following tcp code paths:
1933 * sys_select receive packet
1935 * __add_wait_queue update tp->rcv_nxt
1937 * tp->rcv_nxt check sock_def_readable
1939 * schedule rcu_read_lock();
1940 * wq = rcu_dereference(sk->sk_wq);
1941 * if (wq && waitqueue_active(&wq->wait))
1942 * wake_up_interruptible(&wq->wait)
1946 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1947 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1948 * could then endup calling schedule and sleep forever if there are no more
1949 * data on the socket.
1952 static inline bool wq_has_sleeper(struct socket_wq *wq)
1954 /* We need to be sure we are in sync with the
1955 * add_wait_queue modifications to the wait queue.
1957 * This memory barrier is paired in the sock_poll_wait.
1960 return wq && waitqueue_active(&wq->wait);
1964 * sock_poll_wait - place memory barrier behind the poll_wait call.
1966 * @wait_address: socket wait queue
1969 * See the comments in the wq_has_sleeper function.
1971 static inline void sock_poll_wait(struct file *filp,
1972 wait_queue_head_t *wait_address, poll_table *p)
1974 if (!poll_does_not_wait(p) && wait_address) {
1975 poll_wait(filp, wait_address, p);
1976 /* We need to be sure we are in sync with the
1977 * socket flags modification.
1979 * This memory barrier is paired in the wq_has_sleeper.
1985 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
1987 if (sk->sk_txhash) {
1989 skb->hash = sk->sk_txhash;
1994 * Queue a received datagram if it will fit. Stream and sequenced
1995 * protocols can't normally use this as they need to fit buffers in
1996 * and play with them.
1998 * Inlined as it's very short and called for pretty much every
1999 * packet ever received.
2002 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2006 skb->destructor = sock_wfree;
2007 skb_set_hash_from_sk(skb, sk);
2009 * We used to take a refcount on sk, but following operation
2010 * is enough to guarantee sk_free() wont free this sock until
2011 * all in-flight packets are completed
2013 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
2016 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2020 skb->destructor = sock_rfree;
2021 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2022 sk_mem_charge(sk, skb->truesize);
2025 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2026 unsigned long expires);
2028 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2030 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2032 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2035 * Recover an error report and clear atomically
2038 static inline int sock_error(struct sock *sk)
2041 if (likely(!sk->sk_err))
2043 err = xchg(&sk->sk_err, 0);
2047 static inline unsigned long sock_wspace(struct sock *sk)
2051 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2052 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
2059 static inline void sk_wake_async(struct sock *sk, int how, int band)
2061 if (sock_flag(sk, SOCK_FASYNC))
2062 sock_wake_async(sk->sk_socket, how, band);
2065 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2066 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2067 * Note: for send buffers, TCP works better if we can build two skbs at
2070 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2072 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2073 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2075 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2077 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2078 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2079 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2083 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
2086 * sk_page_frag - return an appropriate page_frag
2089 * If socket allocation mode allows current thread to sleep, it means its
2090 * safe to use the per task page_frag instead of the per socket one.
2092 static inline struct page_frag *sk_page_frag(struct sock *sk)
2094 if (sk->sk_allocation & __GFP_WAIT)
2095 return ¤t->task_frag;
2097 return &sk->sk_frag;
2100 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2103 * Default write policy as shown to user space via poll/select/SIGIO
2105 static inline bool sock_writeable(const struct sock *sk)
2107 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2110 static inline gfp_t gfp_any(void)
2112 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2115 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2117 return noblock ? 0 : sk->sk_rcvtimeo;
2120 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2122 return noblock ? 0 : sk->sk_sndtimeo;
2125 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2127 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2130 /* Alas, with timeout socket operations are not restartable.
2131 * Compare this to poll().
2133 static inline int sock_intr_errno(long timeo)
2135 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2138 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2139 struct sk_buff *skb);
2140 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2141 struct sk_buff *skb);
2144 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2146 ktime_t kt = skb->tstamp;
2147 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2150 * generate control messages if
2151 * - receive time stamping in software requested (SOCK_RCVTSTAMP
2152 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
2153 * - software time stamp available and wanted
2154 * (SOCK_TIMESTAMPING_SOFTWARE)
2155 * - hardware time stamps available and wanted
2156 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
2157 * SOCK_TIMESTAMPING_RAW_HARDWARE)
2159 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2160 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
2161 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
2162 (hwtstamps->hwtstamp.tv64 &&
2163 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
2164 (hwtstamps->syststamp.tv64 &&
2165 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
2166 __sock_recv_timestamp(msg, sk, skb);
2170 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2171 __sock_recv_wifi_status(msg, sk, skb);
2174 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2175 struct sk_buff *skb);
2177 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2178 struct sk_buff *skb)
2180 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2181 (1UL << SOCK_RCVTSTAMP) | \
2182 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
2183 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
2184 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
2186 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
2187 __sock_recv_ts_and_drops(msg, sk, skb);
2189 sk->sk_stamp = skb->tstamp;
2193 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2194 * @sk: socket sending this packet
2195 * @tx_flags: filled with instructions for time stamping
2197 * Currently only depends on SOCK_TIMESTAMPING* flags.
2199 void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
2202 * sk_eat_skb - Release a skb if it is no longer needed
2203 * @sk: socket to eat this skb from
2204 * @skb: socket buffer to eat
2205 * @copied_early: flag indicating whether DMA operations copied this data early
2207 * This routine must be called with interrupts disabled or with the socket
2208 * locked so that the sk_buff queue operation is ok.
2210 #ifdef CONFIG_NET_DMA
2211 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2213 __skb_unlink(skb, &sk->sk_receive_queue);
2217 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
2220 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2222 __skb_unlink(skb, &sk->sk_receive_queue);
2228 struct net *sock_net(const struct sock *sk)
2230 return read_pnet(&sk->sk_net);
2234 void sock_net_set(struct sock *sk, struct net *net)
2236 write_pnet(&sk->sk_net, net);
2240 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2241 * They should not hold a reference to a namespace in order to allow
2243 * Sockets after sk_change_net should be released using sk_release_kernel
2245 static inline void sk_change_net(struct sock *sk, struct net *net)
2247 struct net *current_net = sock_net(sk);
2249 if (!net_eq(current_net, net)) {
2250 put_net(current_net);
2251 sock_net_set(sk, hold_net(net));
2255 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2258 struct sock *sk = skb->sk;
2260 skb->destructor = NULL;
2267 void sock_enable_timestamp(struct sock *sk, int flag);
2268 int sock_get_timestamp(struct sock *, struct timeval __user *);
2269 int sock_get_timestampns(struct sock *, struct timespec __user *);
2270 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2273 bool sk_ns_capable(const struct sock *sk,
2274 struct user_namespace *user_ns, int cap);
2275 bool sk_capable(const struct sock *sk, int cap);
2276 bool sk_net_capable(const struct sock *sk, int cap);
2279 * Enable debug/info messages
2281 extern int net_msg_warn;
2282 #define NETDEBUG(fmt, args...) \
2283 do { if (net_msg_warn) printk(fmt,##args); } while (0)
2285 #define LIMIT_NETDEBUG(fmt, args...) \
2286 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
2288 extern __u32 sysctl_wmem_max;
2289 extern __u32 sysctl_rmem_max;
2291 extern int sysctl_optmem_max;
2293 extern __u32 sysctl_wmem_default;
2294 extern __u32 sysctl_rmem_default;
2296 #endif /* _SOCK_H */