xref: /linux/include/net/sock.h (revision ccde82e909467abdf098a8ee6f63e1ecf9a47ce5)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the AF_INET socket handler.
8  *
9  * Version:	@(#)sock.h	1.0.4	05/13/93
10  *
11  * Authors:	Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
14  *		Florian La Roche <flla@stud.uni-sb.de>
15  *
16  * Fixes:
17  *		Alan Cox	:	Volatiles in skbuff pointers. See
18  *					skbuff comments. May be overdone,
19  *					better to prove they can be removed
20  *					than the reverse.
21  *		Alan Cox	:	Added a zapped field for tcp to note
22  *					a socket is reset and must stay shut up
23  *		Alan Cox	:	New fields for options
24  *	Pauline Middelink	:	identd support
25  *		Alan Cox	:	Eliminate low level recv/recvfrom
26  *		David S. Miller	:	New socket lookup architecture.
27  *              Steve Whitehouse:       Default routines for sock_ops
28  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
29  *              			protinfo be just a void pointer, as the
30  *              			protocol specific parts were moved to
31  *              			respective headers and ipv4/v6, etc now
32  *              			use private slabcaches for its socks
33  *              Pedro Hortas	:	New flags field for socket options
34  */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37 
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h>	/* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/rculist_nulls.h>
60 #include <linux/poll.h>
61 #include <linux/sockptr.h>
62 #include <linux/indirect_call_wrapper.h>
63 #include <linux/atomic.h>
64 #include <linux/refcount.h>
65 #include <linux/llist.h>
66 #include <net/dst.h>
67 #include <net/checksum.h>
68 #include <net/tcp_states.h>
69 #include <linux/net_tstamp.h>
70 #include <net/l3mdev.h>
71 #include <uapi/linux/socket.h>
72 
73 /*
74  * This structure really needs to be cleaned up.
75  * Most of it is for TCP, and not used by any of
76  * the other protocols.
77  */
78 
79 /* This is the per-socket lock.  The spinlock provides a synchronization
80  * between user contexts and software interrupt processing, whereas the
81  * mini-semaphore synchronizes multiple users amongst themselves.
82  */
83 typedef struct {
84 	spinlock_t		slock;
85 	int			owned;
86 	wait_queue_head_t	wq;
87 	/*
88 	 * We express the mutex-alike socket_lock semantics
89 	 * to the lock validator by explicitly managing
90 	 * the slock as a lock variant (in addition to
91 	 * the slock itself):
92 	 */
93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
94 	struct lockdep_map dep_map;
95 #endif
96 } socket_lock_t;
97 
98 struct sock;
99 struct proto;
100 struct net;
101 
102 typedef __u32 __bitwise __portpair;
103 typedef __u64 __bitwise __addrpair;
104 
105 /**
106  *	struct sock_common - minimal network layer representation of sockets
107  *	@skc_daddr: Foreign IPv4 addr
108  *	@skc_rcv_saddr: Bound local IPv4 addr
109  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
110  *	@skc_hash: hash value used with various protocol lookup tables
111  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
112  *	@skc_dport: placeholder for inet_dport/tw_dport
113  *	@skc_num: placeholder for inet_num/tw_num
114  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
115  *	@skc_family: network address family
116  *	@skc_state: Connection state
117  *	@skc_reuse: %SO_REUSEADDR setting
118  *	@skc_reuseport: %SO_REUSEPORT setting
119  *	@skc_ipv6only: socket is IPV6 only
120  *	@skc_net_refcnt: socket is using net ref counting
121  *	@skc_bound_dev_if: bound device index if != 0
122  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
123  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
124  *	@skc_prot: protocol handlers inside a network family
125  *	@skc_net: reference to the network namespace of this socket
126  *	@skc_v6_daddr: IPV6 destination address
127  *	@skc_v6_rcv_saddr: IPV6 source address
128  *	@skc_cookie: socket's cookie value
129  *	@skc_node: main hash linkage for various protocol lookup tables
130  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
131  *	@skc_tx_queue_mapping: tx queue number for this connection
132  *	@skc_rx_queue_mapping: rx queue number for this connection
133  *	@skc_flags: place holder for sk_flags
134  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
135  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
136  *	@skc_listener: connection request listener socket (aka rsk_listener)
137  *		[union with @skc_flags]
138  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
139  *		[union with @skc_flags]
140  *	@skc_incoming_cpu: record/match cpu processing incoming packets
141  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
142  *		[union with @skc_incoming_cpu]
143  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
144  *		[union with @skc_incoming_cpu]
145  *	@skc_refcnt: reference count
146  *
147  *	This is the minimal network layer representation of sockets, the header
148  *	for struct sock and struct inet_timewait_sock.
149  */
150 struct sock_common {
151 	union {
152 		__addrpair	skc_addrpair;
153 		struct {
154 			__be32	skc_daddr;
155 			__be32	skc_rcv_saddr;
156 		};
157 	};
158 	union  {
159 		unsigned int	skc_hash;
160 		__u16		skc_u16hashes[2];
161 	};
162 	/* skc_dport && skc_num must be grouped as well */
163 	union {
164 		__portpair	skc_portpair;
165 		struct {
166 			__be16	skc_dport;
167 			__u16	skc_num;
168 		};
169 	};
170 
171 	unsigned short		skc_family;
172 	volatile unsigned char	skc_state;
173 	unsigned char		skc_reuse:4;
174 	unsigned char		skc_reuseport:1;
175 	unsigned char		skc_ipv6only:1;
176 	unsigned char		skc_net_refcnt:1;
177 	int			skc_bound_dev_if;
178 	union {
179 		struct hlist_node	skc_bind_node;
180 		struct hlist_node	skc_portaddr_node;
181 	};
182 	struct proto		*skc_prot;
183 	possible_net_t		skc_net;
184 
185 #if IS_ENABLED(CONFIG_IPV6)
186 	struct in6_addr		skc_v6_daddr;
187 	struct in6_addr		skc_v6_rcv_saddr;
188 #endif
189 
190 	atomic64_t		skc_cookie;
191 
192 	/* following fields are padding to force
193 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
194 	 * assuming IPV6 is enabled. We use this padding differently
195 	 * for different kind of 'sockets'
196 	 */
197 	union {
198 		unsigned long	skc_flags;
199 		struct sock	*skc_listener; /* request_sock */
200 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
201 	};
202 	/*
203 	 * fields between dontcopy_begin/dontcopy_end
204 	 * are not copied in sock_copy()
205 	 */
206 	/* private: */
207 	int			skc_dontcopy_begin[0];
208 	/* public: */
209 	union {
210 		struct hlist_node	skc_node;
211 		struct hlist_nulls_node skc_nulls_node;
212 	};
213 	unsigned short		skc_tx_queue_mapping;
214 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
215 	unsigned short		skc_rx_queue_mapping;
216 #endif
217 	union {
218 		int		skc_incoming_cpu;
219 		u32		skc_rcv_wnd;
220 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
221 	};
222 
223 	refcount_t		skc_refcnt;
224 	/* private: */
225 	int                     skc_dontcopy_end[0];
226 	union {
227 		u32		skc_rxhash;
228 		u32		skc_window_clamp;
229 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
230 	};
231 	/* public: */
232 };
233 
234 struct bpf_local_storage;
235 struct sk_filter;
236 
237 /**
238   *	struct sock - network layer representation of sockets
239   *	@__sk_common: shared layout with inet_timewait_sock
240   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
241   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
242   *	@sk_lock:	synchronizer
243   *	@sk_kern_sock: True if sock is using kernel lock classes
244   *	@sk_rcvbuf: size of receive buffer in bytes
245   *	@sk_wq: sock wait queue and async head
246   *	@sk_rx_dst: receive input route used by early demux
247   *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
248   *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
249   *	@sk_dst_cache: destination cache
250   *	@sk_dst_pending_confirm: need to confirm neighbour
251   *	@sk_policy: flow policy
252   *	@psp_assoc: PSP association, if socket is PSP-secured
253   *	@sk_receive_queue: incoming packets
254   *	@sk_wmem_alloc: transmit queue bytes committed
255   *	@sk_tsq_flags: TCP Small Queues flags
256   *	@sk_write_queue: Packet sending queue
257   *	@sk_omem_alloc: "o" is "option" or "other"
258   *	@sk_wmem_queued: persistent queue size
259   *	@sk_forward_alloc: space allocated forward
260   *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
261   *	@sk_napi_id: id of the last napi context to receive data for sk
262   *	@sk_ll_usec: usecs to busypoll when there is no data
263   *	@sk_allocation: allocation mode
264   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
265   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
266   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
267   *	@sk_sndbuf: size of send buffer in bytes
268   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
269   *	@sk_no_check_rx: allow zero checksum in RX packets
270   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
271   *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
272   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
273   *	@sk_gso_max_size: Maximum GSO segment size to build
274   *	@sk_gso_max_segs: Maximum number of GSO segments
275   *	@sk_pacing_shift: scaling factor for TCP Small Queues
276   *	@sk_lingertime: %SO_LINGER l_linger setting
277   *	@sk_backlog: always used with the per-socket spinlock held
278   *	@sk_callback_lock: used with the callbacks in the end of this struct
279   *	@sk_error_queue: rarely used
280   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
281   *			  IPV6_ADDRFORM for instance)
282   *	@sk_err: last error
283   *	@sk_err_soft: errors that don't cause failure but are the cause of a
284   *		      persistent failure not just 'timed out'
285   *	@sk_drops: raw/udp drops counter
286   *	@sk_drop_counters: optional pointer to numa_drop_counters
287   *	@sk_ack_backlog: current listen backlog
288   *	@sk_max_ack_backlog: listen backlog set in listen()
289   *	@sk_uid: user id of owner
290   *	@sk_ino: inode number (zero if orphaned)
291   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
292   *	@sk_busy_poll_budget: napi processing budget when busypolling
293   *	@sk_priority: %SO_PRIORITY setting
294   *	@sk_type: socket type (%SOCK_STREAM, etc)
295   *	@sk_protocol: which protocol this socket belongs in this network family
296   *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
297   *	@sk_peer_pid: &struct pid for this socket's peer
298   *	@sk_peer_cred: %SO_PEERCRED setting
299   *	@sk_rcvlowat: %SO_RCVLOWAT setting
300   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
301   *	@sk_sndtimeo: %SO_SNDTIMEO setting
302   *	@sk_txhash: computed flow hash for use on transmit
303   *	@sk_txrehash: enable TX hash rethink
304   *	@sk_filter: socket filtering instructions
305   *	@sk_timer: sock cleanup timer
306   *	@sk_stamp: time stamp of last packet received
307   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
308   *	@sk_tsflags: SO_TIMESTAMPING flags
309   *	@sk_bpf_cb_flags: used in bpf_setsockopt()
310   *	@sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
311   *			   Sockets that can be used under memory reclaim should
312   *			   set this to false.
313   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
314   *	              for timestamping
315   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
316   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
317   *	@sk_socket: Identd and reporting IO signals
318   *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
319   *	@sk_frag: cached page frag
320   *	@sk_peek_off: current peek_offset value
321   *	@sk_send_head: front of stuff to transmit
322   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
323   *	@sk_security: used by security modules
324   *	@sk_mark: generic packet mark
325   *	@sk_cgrp_data: cgroup data for this cgroup
326   *	@sk_memcg: this socket's memory cgroup association
327   *	@sk_write_pending: a write to stream socket waits to start
328   *	@sk_disconnects: number of disconnect operations performed on this sock
329   *	@sk_state_change: callback to indicate change in the state of the sock
330   *	@sk_data_ready: callback to indicate there is data to be processed
331   *	@sk_write_space: callback to indicate there is bf sending space available
332   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
333   *	@sk_backlog_rcv: callback to process the backlog
334   *	@sk_validate_xmit_skb: ptr to an optional validate function
335   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
336   *	@sk_reuseport_cb: reuseport group container
337   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
338   *	@sk_rcu: used during RCU grace period
339   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
340   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
341   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
342   *	@sk_txtime_unused: unused txtime flags
343   *	@sk_scm_recv_flags: all flags used by scm_recv()
344   *	@sk_scm_credentials: flagged by SO_PASSCRED to recv SCM_CREDENTIALS
345   *	@sk_scm_security: flagged by SO_PASSSEC to recv SCM_SECURITY
346   *	@sk_scm_pidfd: flagged by SO_PASSPIDFD to recv SCM_PIDFD
347   *	@sk_scm_rights: flagged by SO_PASSRIGHTS to recv SCM_RIGHTS
348   *	@sk_scm_unused: unused flags for scm_recv()
349   *	@ns_tracker: tracker for netns reference
350   *	@sk_user_frags: xarray of pages the user is holding a reference on.
351   *	@sk_owner: reference to the real owner of the socket that calls
352   *		   sock_lock_init_class_and_name().
353   */
354 struct sock {
355 	/*
356 	 * Now struct inet_timewait_sock also uses sock_common, so please just
357 	 * don't add nothing before this first member (__sk_common) --acme
358 	 */
359 	struct sock_common	__sk_common;
360 #define sk_node			__sk_common.skc_node
361 #define sk_nulls_node		__sk_common.skc_nulls_node
362 #define sk_refcnt		__sk_common.skc_refcnt
363 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
364 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
365 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
366 #endif
367 
368 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
369 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
370 #define sk_hash			__sk_common.skc_hash
371 #define sk_portpair		__sk_common.skc_portpair
372 #define sk_num			__sk_common.skc_num
373 #define sk_dport		__sk_common.skc_dport
374 #define sk_addrpair		__sk_common.skc_addrpair
375 #define sk_daddr		__sk_common.skc_daddr
376 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
377 #define sk_family		__sk_common.skc_family
378 #define sk_state		__sk_common.skc_state
379 #define sk_reuse		__sk_common.skc_reuse
380 #define sk_reuseport		__sk_common.skc_reuseport
381 #define sk_ipv6only		__sk_common.skc_ipv6only
382 #define sk_net_refcnt		__sk_common.skc_net_refcnt
383 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
384 #define sk_bind_node		__sk_common.skc_bind_node
385 #define sk_prot			__sk_common.skc_prot
386 #define sk_net			__sk_common.skc_net
387 #define sk_v6_daddr		__sk_common.skc_v6_daddr
388 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
389 #define sk_cookie		__sk_common.skc_cookie
390 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
391 #define sk_flags		__sk_common.skc_flags
392 #define sk_rxhash		__sk_common.skc_rxhash
393 
394 	__cacheline_group_begin(sock_write_rx);
395 
396 	atomic_t		sk_drops;
397 	__s32			sk_peek_off;
398 	struct sk_buff_head	sk_receive_queue;
399 	/*
400 	 * The backlog queue is special, it is always used with
401 	 * the per-socket spinlock held and requires low latency
402 	 * access. Therefore we special case it's implementation.
403 	 * Note : rmem_alloc is in this structure to fill a hole
404 	 * on 64bit arches, not because its logically part of
405 	 * backlog.
406 	 */
407 	struct {
408 		atomic_t	rmem_alloc;
409 		int		len;
410 		struct sk_buff	*head;
411 		struct sk_buff	*tail;
412 	} sk_backlog;
413 #define sk_rmem_alloc sk_backlog.rmem_alloc
414 
415 	struct sk_buff_head	sk_error_queue;
416 	__cacheline_group_end(sock_write_rx);
417 
418 	__cacheline_group_begin(sock_read_rx);
419 	/* early demux fields */
420 	struct dst_entry __rcu	*sk_rx_dst;
421 	int			sk_rx_dst_ifindex;
422 	u32			sk_rx_dst_cookie;
423 
424 #ifdef CONFIG_NET_RX_BUSY_POLL
425 	unsigned int		sk_ll_usec;
426 	unsigned int		sk_napi_id;
427 	u16			sk_busy_poll_budget;
428 	u8			sk_prefer_busy_poll;
429 #endif
430 	u8			sk_userlocks;
431 	int			sk_rcvbuf;
432 
433 	struct sk_filter __rcu	*sk_filter;
434 	union {
435 		struct socket_wq __rcu	*sk_wq;
436 		/* private: */
437 		struct socket_wq	*sk_wq_raw;
438 		/* public: */
439 	};
440 
441 	void			(*sk_data_ready)(struct sock *sk);
442 	long			sk_rcvtimeo;
443 	int			sk_rcvlowat;
444 	__cacheline_group_end(sock_read_rx);
445 
446 	__cacheline_group_begin(sock_read_rxtx);
447 	int			sk_err;
448 	struct socket		*sk_socket;
449 #ifdef CONFIG_MEMCG
450 	struct mem_cgroup	*sk_memcg;
451 #endif
452 #ifdef CONFIG_XFRM
453 	struct xfrm_policy __rcu *sk_policy[2];
454 #endif
455 #if IS_ENABLED(CONFIG_INET_PSP)
456 	struct psp_assoc __rcu	*psp_assoc;
457 #endif
458 	__cacheline_group_end(sock_read_rxtx);
459 
460 	__cacheline_group_begin(sock_write_rxtx);
461 	socket_lock_t		sk_lock;
462 	u32			sk_reserved_mem;
463 	int			sk_forward_alloc;
464 	u32			sk_tsflags;
465 	__cacheline_group_end(sock_write_rxtx);
466 
467 	__cacheline_group_begin(sock_write_tx);
468 	int			sk_write_pending;
469 	atomic_t		sk_omem_alloc;
470 	int			sk_sndbuf;
471 
472 	int			sk_wmem_queued;
473 	refcount_t		sk_wmem_alloc;
474 	unsigned long		sk_tsq_flags;
475 	union {
476 		struct sk_buff	*sk_send_head;
477 		struct rb_root	tcp_rtx_queue;
478 	};
479 	struct sk_buff_head	sk_write_queue;
480 	u32			sk_dst_pending_confirm;
481 	u32			sk_pacing_status; /* see enum sk_pacing */
482 	struct page_frag	sk_frag;
483 	struct timer_list	sk_timer;
484 
485 	unsigned long		sk_pacing_rate; /* bytes per second */
486 	atomic_t		sk_zckey;
487 	atomic_t		sk_tskey;
488 	__cacheline_group_end(sock_write_tx);
489 
490 	__cacheline_group_begin(sock_read_tx);
491 	unsigned long		sk_max_pacing_rate;
492 	long			sk_sndtimeo;
493 	u32			sk_priority;
494 	u32			sk_mark;
495 	struct dst_entry __rcu	*sk_dst_cache;
496 	netdev_features_t	sk_route_caps;
497 #ifdef CONFIG_SOCK_VALIDATE_XMIT
498 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
499 							struct net_device *dev,
500 							struct sk_buff *skb);
501 #endif
502 	u16			sk_gso_type;
503 	u16			sk_gso_max_segs;
504 	unsigned int		sk_gso_max_size;
505 	gfp_t			sk_allocation;
506 	u32			sk_txhash;
507 	u8			sk_pacing_shift;
508 	bool			sk_use_task_frag;
509 	__cacheline_group_end(sock_read_tx);
510 
511 	/*
512 	 * Because of non atomicity rules, all
513 	 * changes are protected by socket lock.
514 	 */
515 	u8			sk_gso_disabled : 1,
516 				sk_kern_sock : 1,
517 				sk_no_check_tx : 1,
518 				sk_no_check_rx : 1;
519 	u8			sk_shutdown;
520 	u16			sk_type;
521 	u16			sk_protocol;
522 	unsigned long	        sk_lingertime;
523 	struct proto		*sk_prot_creator;
524 	rwlock_t		sk_callback_lock;
525 	int			sk_err_soft;
526 	u32			sk_ack_backlog;
527 	u32			sk_max_ack_backlog;
528 	kuid_t			sk_uid;
529 	unsigned long		sk_ino;
530 	spinlock_t		sk_peer_lock;
531 	int			sk_bind_phc;
532 	struct pid		*sk_peer_pid;
533 	const struct cred	*sk_peer_cred;
534 
535 	ktime_t			sk_stamp;
536 #if BITS_PER_LONG==32
537 	seqlock_t		sk_stamp_seq;
538 #endif
539 	int			sk_disconnects;
540 
541 	union {
542 		u8		sk_txrehash;
543 		u8		sk_scm_recv_flags;
544 		struct {
545 			u8	sk_scm_credentials : 1,
546 				sk_scm_security : 1,
547 				sk_scm_pidfd : 1,
548 				sk_scm_rights : 1,
549 				sk_scm_unused : 4;
550 		};
551 	};
552 	u8			sk_clockid;
553 	u8			sk_txtime_deadline_mode : 1,
554 				sk_txtime_report_errors : 1,
555 				sk_txtime_unused : 6;
556 #define SK_BPF_CB_FLAG_TEST(SK, FLAG) ((SK)->sk_bpf_cb_flags & (FLAG))
557 	u8			sk_bpf_cb_flags;
558 
559 	void			*sk_user_data;
560 #ifdef CONFIG_SECURITY
561 	void			*sk_security;
562 #endif
563 	struct sock_cgroup_data	sk_cgrp_data;
564 	void			(*sk_state_change)(struct sock *sk);
565 	void			(*sk_write_space)(struct sock *sk);
566 	void			(*sk_error_report)(struct sock *sk);
567 	int			(*sk_backlog_rcv)(struct sock *sk,
568 						  struct sk_buff *skb);
569 	void                    (*sk_destruct)(struct sock *sk);
570 	struct sock_reuseport __rcu	*sk_reuseport_cb;
571 #ifdef CONFIG_BPF_SYSCALL
572 	struct bpf_local_storage __rcu	*sk_bpf_storage;
573 #endif
574 	struct numa_drop_counters *sk_drop_counters;
575 	struct rcu_head		sk_rcu;
576 	netns_tracker		ns_tracker;
577 	struct xarray		sk_user_frags;
578 
579 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
580 	struct module		*sk_owner;
581 #endif
582 };
583 
584 struct sock_bh_locked {
585 	struct sock *sock;
586 	local_lock_t bh_lock;
587 };
588 
589 enum sk_pacing {
590 	SK_PACING_NONE		= 0,
591 	SK_PACING_NEEDED	= 1,
592 	SK_PACING_FQ		= 2,
593 };
594 
595 /* flag bits in sk_user_data
596  *
597  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
598  *   not be suitable for copying when cloning the socket. For instance,
599  *   it can point to a reference counted object. sk_user_data bottom
600  *   bit is set if pointer must not be copied.
601  *
602  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
603  *   managed/owned by a BPF reuseport array. This bit should be set
604  *   when sk_user_data's sk is added to the bpf's reuseport_array.
605  *
606  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
607  *   sk_user_data points to psock type. This bit should be set
608  *   when sk_user_data is assigned to a psock object.
609  */
610 #define SK_USER_DATA_NOCOPY	1UL
611 #define SK_USER_DATA_BPF	2UL
612 #define SK_USER_DATA_PSOCK	4UL
613 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
614 				  SK_USER_DATA_PSOCK)
615 
616 /**
617  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
618  * @sk: socket
619  */
620 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
621 {
622 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
623 }
624 
625 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
626 
627 /**
628  * __locked_read_sk_user_data_with_flags - return the pointer
629  * only if argument flags all has been set in sk_user_data. Otherwise
630  * return NULL
631  *
632  * @sk: socket
633  * @flags: flag bits
634  *
635  * The caller must be holding sk->sk_callback_lock.
636  */
637 static inline void *
638 __locked_read_sk_user_data_with_flags(const struct sock *sk,
639 				      uintptr_t flags)
640 {
641 	uintptr_t sk_user_data =
642 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
643 						 lockdep_is_held(&sk->sk_callback_lock));
644 
645 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
646 
647 	if ((sk_user_data & flags) == flags)
648 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
649 	return NULL;
650 }
651 
652 /**
653  * __rcu_dereference_sk_user_data_with_flags - return the pointer
654  * only if argument flags all has been set in sk_user_data. Otherwise
655  * return NULL
656  *
657  * @sk: socket
658  * @flags: flag bits
659  */
660 static inline void *
661 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
662 					  uintptr_t flags)
663 {
664 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
665 
666 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
667 
668 	if ((sk_user_data & flags) == flags)
669 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
670 	return NULL;
671 }
672 
673 #define rcu_dereference_sk_user_data(sk)				\
674 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
675 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
676 ({									\
677 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
678 		  __tmp2 = (uintptr_t)(flags);				\
679 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
680 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
681 	rcu_assign_pointer(__sk_user_data((sk)),			\
682 			   __tmp1 | __tmp2);				\
683 })
684 #define rcu_assign_sk_user_data(sk, ptr)				\
685 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
686 
687 static inline
688 struct net *sock_net(const struct sock *sk)
689 {
690 	return read_pnet(&sk->sk_net);
691 }
692 
693 static inline
694 void sock_net_set(struct sock *sk, struct net *net)
695 {
696 	write_pnet(&sk->sk_net, net);
697 }
698 
699 /*
700  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
701  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
702  * on a socket means that the socket will reuse everybody else's port
703  * without looking at the other's sk_reuse value.
704  */
705 
706 #define SK_NO_REUSE	0
707 #define SK_CAN_REUSE	1
708 #define SK_FORCE_REUSE	2
709 
710 int sk_set_peek_off(struct sock *sk, int val);
711 
712 static inline int sk_peek_offset(const struct sock *sk, int flags)
713 {
714 	if (unlikely(flags & MSG_PEEK)) {
715 		return READ_ONCE(sk->sk_peek_off);
716 	}
717 
718 	return 0;
719 }
720 
721 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
722 {
723 	s32 off = READ_ONCE(sk->sk_peek_off);
724 
725 	if (unlikely(off >= 0)) {
726 		off = max_t(s32, off - val, 0);
727 		WRITE_ONCE(sk->sk_peek_off, off);
728 	}
729 }
730 
731 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
732 {
733 	sk_peek_offset_bwd(sk, -val);
734 }
735 
736 /*
737  * Hashed lists helper routines
738  */
739 static inline struct sock *sk_entry(const struct hlist_node *node)
740 {
741 	return hlist_entry(node, struct sock, sk_node);
742 }
743 
744 static inline struct sock *__sk_head(const struct hlist_head *head)
745 {
746 	return hlist_entry(head->first, struct sock, sk_node);
747 }
748 
749 static inline struct sock *sk_head(const struct hlist_head *head)
750 {
751 	return hlist_empty(head) ? NULL : __sk_head(head);
752 }
753 
754 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
755 {
756 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
757 }
758 
759 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
760 {
761 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
762 }
763 
764 static inline struct sock *sk_next(const struct sock *sk)
765 {
766 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
767 }
768 
769 static inline struct sock *sk_nulls_next(const struct sock *sk)
770 {
771 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
772 		hlist_nulls_entry(sk->sk_nulls_node.next,
773 				  struct sock, sk_nulls_node) :
774 		NULL;
775 }
776 
777 static inline bool sk_unhashed(const struct sock *sk)
778 {
779 	return hlist_unhashed(&sk->sk_node);
780 }
781 
782 static inline bool sk_hashed(const struct sock *sk)
783 {
784 	return !sk_unhashed(sk);
785 }
786 
787 static inline void sk_node_init(struct hlist_node *node)
788 {
789 	node->pprev = NULL;
790 }
791 
792 static inline void __sk_del_node(struct sock *sk)
793 {
794 	__hlist_del(&sk->sk_node);
795 }
796 
797 /* NB: equivalent to hlist_del_init_rcu */
798 static inline bool __sk_del_node_init(struct sock *sk)
799 {
800 	if (sk_hashed(sk)) {
801 		__sk_del_node(sk);
802 		sk_node_init(&sk->sk_node);
803 		return true;
804 	}
805 	return false;
806 }
807 
808 /* Grab socket reference count. This operation is valid only
809    when sk is ALREADY grabbed f.e. it is found in hash table
810    or a list and the lookup is made under lock preventing hash table
811    modifications.
812  */
813 
814 static __always_inline void sock_hold(struct sock *sk)
815 {
816 	refcount_inc(&sk->sk_refcnt);
817 }
818 
819 /* Ungrab socket in the context, which assumes that socket refcnt
820    cannot hit zero, f.e. it is true in context of any socketcall.
821  */
822 static __always_inline void __sock_put(struct sock *sk)
823 {
824 	refcount_dec(&sk->sk_refcnt);
825 }
826 
827 static inline bool sk_del_node_init(struct sock *sk)
828 {
829 	bool rc = __sk_del_node_init(sk);
830 
831 	if (rc) {
832 		/* paranoid for a while -acme */
833 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
834 		__sock_put(sk);
835 	}
836 	return rc;
837 }
838 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
839 
840 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
841 {
842 	if (sk_hashed(sk)) {
843 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
844 		return true;
845 	}
846 	return false;
847 }
848 
849 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
850 {
851 	bool rc = __sk_nulls_del_node_init_rcu(sk);
852 
853 	if (rc) {
854 		/* paranoid for a while -acme */
855 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
856 		__sock_put(sk);
857 	}
858 	return rc;
859 }
860 
861 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
862 {
863 	hlist_add_head(&sk->sk_node, list);
864 }
865 
866 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
867 {
868 	sock_hold(sk);
869 	__sk_add_node(sk, list);
870 }
871 
872 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
873 {
874 	sock_hold(sk);
875 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
876 	    sk->sk_family == AF_INET6)
877 		hlist_add_tail_rcu(&sk->sk_node, list);
878 	else
879 		hlist_add_head_rcu(&sk->sk_node, list);
880 }
881 
882 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
883 {
884 	sock_hold(sk);
885 	hlist_add_tail_rcu(&sk->sk_node, list);
886 }
887 
888 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
889 {
890 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
891 }
892 
893 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
894 {
895 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
896 }
897 
898 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
899 {
900 	sock_hold(sk);
901 	__sk_nulls_add_node_rcu(sk, list);
902 }
903 
904 static inline void __sk_del_bind_node(struct sock *sk)
905 {
906 	__hlist_del(&sk->sk_bind_node);
907 }
908 
909 static inline void sk_add_bind_node(struct sock *sk,
910 					struct hlist_head *list)
911 {
912 	hlist_add_head(&sk->sk_bind_node, list);
913 }
914 
915 #define sk_for_each(__sk, list) \
916 	hlist_for_each_entry(__sk, list, sk_node)
917 #define sk_for_each_rcu(__sk, list) \
918 	hlist_for_each_entry_rcu(__sk, list, sk_node)
919 #define sk_nulls_for_each(__sk, node, list) \
920 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
921 #define sk_nulls_for_each_rcu(__sk, node, list) \
922 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
923 #define sk_for_each_from(__sk) \
924 	hlist_for_each_entry_from(__sk, sk_node)
925 #define sk_nulls_for_each_from(__sk, node) \
926 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
927 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
928 #define sk_for_each_safe(__sk, tmp, list) \
929 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
930 #define sk_for_each_bound(__sk, list) \
931 	hlist_for_each_entry(__sk, list, sk_bind_node)
932 #define sk_for_each_bound_safe(__sk, tmp, list) \
933 	hlist_for_each_entry_safe(__sk, tmp, list, sk_bind_node)
934 
935 /**
936  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
937  * @tpos:	the type * to use as a loop cursor.
938  * @pos:	the &struct hlist_node to use as a loop cursor.
939  * @head:	the head for your list.
940  * @offset:	offset of hlist_node within the struct.
941  *
942  */
943 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
944 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
945 	     pos != NULL &&						       \
946 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
947 	     pos = rcu_dereference(hlist_next_rcu(pos)))
948 
949 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
950 {
951 	/* Careful only use this in a context where these parameters
952 	 * can not change and must all be valid, such as recvmsg from
953 	 * userspace.
954 	 */
955 	return sk->sk_socket->file->f_cred->user_ns;
956 }
957 
958 /* Sock flags */
959 enum sock_flags {
960 	SOCK_DEAD,
961 	SOCK_DONE,
962 	SOCK_URGINLINE,
963 	SOCK_KEEPOPEN,
964 	SOCK_LINGER,
965 	SOCK_DESTROY,
966 	SOCK_BROADCAST,
967 	SOCK_TIMESTAMP,
968 	SOCK_ZAPPED,
969 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
970 	SOCK_DBG, /* %SO_DEBUG setting */
971 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
972 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
973 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
974 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
975 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
976 	SOCK_FASYNC, /* fasync() active */
977 	SOCK_RXQ_OVFL,
978 	SOCK_ZEROCOPY, /* buffers from userspace */
979 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
980 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
981 		     * Will use last 4 bytes of packet sent from
982 		     * user-space instead.
983 		     */
984 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
985 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
986 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
987 	SOCK_TXTIME,
988 	SOCK_XDP, /* XDP is attached */
989 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
990 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
991 	SOCK_RCVPRIORITY, /* Receive SO_PRIORITY ancillary data with packet */
992 	SOCK_TIMESTAMPING_ANY, /* Copy of sk_tsflags & TSFLAGS_ANY */
993 };
994 
995 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
996 /*
997  * The highest bit of sk_tsflags is reserved for kernel-internal
998  * SOCKCM_FLAG_TS_OPT_ID. There is a check in core/sock.c to control that
999  * SOF_TIMESTAMPING* values do not reach this reserved area
1000  */
1001 #define SOCKCM_FLAG_TS_OPT_ID	BIT(31)
1002 
1003 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
1004 {
1005 	nsk->sk_flags = osk->sk_flags;
1006 }
1007 
1008 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
1009 {
1010 	__set_bit(flag, &sk->sk_flags);
1011 }
1012 
1013 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
1014 {
1015 	__clear_bit(flag, &sk->sk_flags);
1016 }
1017 
1018 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
1019 				     int valbool)
1020 {
1021 	if (valbool)
1022 		sock_set_flag(sk, bit);
1023 	else
1024 		sock_reset_flag(sk, bit);
1025 }
1026 
1027 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
1028 {
1029 	return test_bit(flag, &sk->sk_flags);
1030 }
1031 
1032 #ifdef CONFIG_NET
1033 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
1034 static inline int sk_memalloc_socks(void)
1035 {
1036 	return static_branch_unlikely(&memalloc_socks_key);
1037 }
1038 
1039 void __receive_sock(struct file *file);
1040 #else
1041 
1042 static inline int sk_memalloc_socks(void)
1043 {
1044 	return 0;
1045 }
1046 
1047 static inline void __receive_sock(struct file *file)
1048 { }
1049 #endif
1050 
1051 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1052 {
1053 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1054 }
1055 
1056 static inline void sk_acceptq_removed(struct sock *sk)
1057 {
1058 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1059 }
1060 
1061 static inline void sk_acceptq_added(struct sock *sk)
1062 {
1063 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1064 }
1065 
1066 /* Note: If you think the test should be:
1067  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1068  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1069  */
1070 static inline bool sk_acceptq_is_full(const struct sock *sk)
1071 {
1072 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1073 }
1074 
1075 /*
1076  * Compute minimal free write space needed to queue new packets.
1077  */
1078 static inline int sk_stream_min_wspace(const struct sock *sk)
1079 {
1080 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1081 }
1082 
1083 static inline int sk_stream_wspace(const struct sock *sk)
1084 {
1085 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1086 }
1087 
1088 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1089 {
1090 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1091 }
1092 
1093 static inline void sk_forward_alloc_add(struct sock *sk, int val)
1094 {
1095 	/* Paired with lockless reads of sk->sk_forward_alloc */
1096 	WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val);
1097 }
1098 
1099 void sk_stream_write_space(struct sock *sk);
1100 
1101 /* OOB backlog add */
1102 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1103 {
1104 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1105 	skb_dst_force(skb);
1106 
1107 	if (!sk->sk_backlog.tail)
1108 		WRITE_ONCE(sk->sk_backlog.head, skb);
1109 	else
1110 		sk->sk_backlog.tail->next = skb;
1111 
1112 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1113 	skb->next = NULL;
1114 }
1115 
1116 /*
1117  * Take into account size of receive queue and backlog queue
1118  * Do not take into account this skb truesize,
1119  * to allow even a single big packet to come.
1120  */
1121 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1122 {
1123 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1124 
1125 	return qsize > limit;
1126 }
1127 
1128 /* The per-socket spinlock must be held here. */
1129 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1130 					      unsigned int limit)
1131 {
1132 	if (sk_rcvqueues_full(sk, limit))
1133 		return -ENOBUFS;
1134 
1135 	/*
1136 	 * If the skb was allocated from pfmemalloc reserves, only
1137 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1138 	 * helping free memory
1139 	 */
1140 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1141 		return -ENOMEM;
1142 
1143 	__sk_add_backlog(sk, skb);
1144 	sk->sk_backlog.len += skb->truesize;
1145 	return 0;
1146 }
1147 
1148 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1149 
1150 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1151 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1152 
1153 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1154 {
1155 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1156 		return __sk_backlog_rcv(sk, skb);
1157 
1158 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1159 				  tcp_v6_do_rcv,
1160 				  tcp_v4_do_rcv,
1161 				  sk, skb);
1162 }
1163 
1164 static inline void sk_incoming_cpu_update(struct sock *sk)
1165 {
1166 	int cpu = raw_smp_processor_id();
1167 
1168 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1169 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1170 }
1171 
1172 
1173 static inline void sock_rps_save_rxhash(struct sock *sk,
1174 					const struct sk_buff *skb)
1175 {
1176 #ifdef CONFIG_RPS
1177 	/* The following WRITE_ONCE() is paired with the READ_ONCE()
1178 	 * here, and another one in sock_rps_record_flow().
1179 	 */
1180 	if (unlikely(READ_ONCE(sk->sk_rxhash) != skb->hash))
1181 		WRITE_ONCE(sk->sk_rxhash, skb->hash);
1182 #endif
1183 }
1184 
1185 static inline void sock_rps_reset_rxhash(struct sock *sk)
1186 {
1187 #ifdef CONFIG_RPS
1188 	/* Paired with READ_ONCE() in sock_rps_record_flow() */
1189 	WRITE_ONCE(sk->sk_rxhash, 0);
1190 #endif
1191 }
1192 
1193 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1194 	({	int __rc, __dis = __sk->sk_disconnects;			\
1195 		release_sock(__sk);					\
1196 		__rc = __condition;					\
1197 		if (!__rc) {						\
1198 			*(__timeo) = wait_woken(__wait,			\
1199 						TASK_INTERRUPTIBLE,	\
1200 						*(__timeo));		\
1201 		}							\
1202 		sched_annotate_sleep();					\
1203 		lock_sock(__sk);					\
1204 		__rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
1205 		__rc;							\
1206 	})
1207 
1208 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1209 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1210 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1211 int sk_stream_error(struct sock *sk, int flags, int err);
1212 void sk_stream_kill_queues(struct sock *sk);
1213 void sk_set_memalloc(struct sock *sk);
1214 void sk_clear_memalloc(struct sock *sk);
1215 
1216 void __sk_flush_backlog(struct sock *sk);
1217 
1218 static inline bool sk_flush_backlog(struct sock *sk)
1219 {
1220 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1221 		__sk_flush_backlog(sk);
1222 		return true;
1223 	}
1224 	return false;
1225 }
1226 
1227 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1228 
1229 struct request_sock_ops;
1230 struct timewait_sock_ops;
1231 struct inet_hashinfo;
1232 struct raw_hashinfo;
1233 struct smc_hashinfo;
1234 struct module;
1235 struct sk_psock;
1236 
1237 /*
1238  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1239  * un-modified. Special care is taken when initializing object to zero.
1240  */
1241 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1242 {
1243 	if (offsetof(struct sock, sk_node.next) != 0)
1244 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1245 	memset(&sk->sk_node.pprev, 0,
1246 	       size - offsetof(struct sock, sk_node.pprev));
1247 }
1248 
1249 struct proto_accept_arg {
1250 	int flags;
1251 	int err;
1252 	int is_empty;
1253 	bool kern;
1254 };
1255 
1256 /* Networking protocol blocks we attach to sockets.
1257  * socket layer -> transport layer interface
1258  */
1259 struct proto {
1260 	void			(*close)(struct sock *sk,
1261 					long timeout);
1262 	int			(*pre_connect)(struct sock *sk,
1263 					struct sockaddr *uaddr,
1264 					int addr_len);
1265 	int			(*connect)(struct sock *sk,
1266 					struct sockaddr *uaddr,
1267 					int addr_len);
1268 	int			(*disconnect)(struct sock *sk, int flags);
1269 
1270 	struct sock *		(*accept)(struct sock *sk,
1271 					  struct proto_accept_arg *arg);
1272 
1273 	int			(*ioctl)(struct sock *sk, int cmd,
1274 					 int *karg);
1275 	int			(*init)(struct sock *sk);
1276 	void			(*destroy)(struct sock *sk);
1277 	void			(*shutdown)(struct sock *sk, int how);
1278 	int			(*setsockopt)(struct sock *sk, int level,
1279 					int optname, sockptr_t optval,
1280 					unsigned int optlen);
1281 	int			(*getsockopt)(struct sock *sk, int level,
1282 					int optname, char __user *optval,
1283 					int __user *option);
1284 	void			(*keepalive)(struct sock *sk, int valbool);
1285 #ifdef CONFIG_COMPAT
1286 	int			(*compat_ioctl)(struct sock *sk,
1287 					unsigned int cmd, unsigned long arg);
1288 #endif
1289 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1290 					   size_t len);
1291 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1292 					   size_t len, int flags, int *addr_len);
1293 	void			(*splice_eof)(struct socket *sock);
1294 	int			(*bind)(struct sock *sk,
1295 					struct sockaddr *addr, int addr_len);
1296 	int			(*bind_add)(struct sock *sk,
1297 					struct sockaddr *addr, int addr_len);
1298 
1299 	int			(*backlog_rcv) (struct sock *sk,
1300 						struct sk_buff *skb);
1301 	bool			(*bpf_bypass_getsockopt)(int level,
1302 							 int optname);
1303 
1304 	void		(*release_cb)(struct sock *sk);
1305 
1306 	/* Keeping track of sk's, looking them up, and port selection methods. */
1307 	int			(*hash)(struct sock *sk);
1308 	void			(*unhash)(struct sock *sk);
1309 	void			(*rehash)(struct sock *sk);
1310 	int			(*get_port)(struct sock *sk, unsigned short snum);
1311 	void			(*put_port)(struct sock *sk);
1312 #ifdef CONFIG_BPF_SYSCALL
1313 	int			(*psock_update_sk_prot)(struct sock *sk,
1314 							struct sk_psock *psock,
1315 							bool restore);
1316 #endif
1317 
1318 	/* Keeping track of sockets in use */
1319 #ifdef CONFIG_PROC_FS
1320 	unsigned int		inuse_idx;
1321 #endif
1322 
1323 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1324 	bool			(*sock_is_readable)(struct sock *sk);
1325 	/* Memory pressure */
1326 	void			(*enter_memory_pressure)(struct sock *sk);
1327 	void			(*leave_memory_pressure)(struct sock *sk);
1328 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1329 	int  __percpu		*per_cpu_fw_alloc;
1330 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1331 
1332 	/*
1333 	 * Pressure flag: try to collapse.
1334 	 * Technical note: it is used by multiple contexts non atomically.
1335 	 * Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
1336 	 * All the __sk_mem_schedule() is of this nature: accounting
1337 	 * is strict, actions are advisory and have some latency.
1338 	 */
1339 	unsigned long		*memory_pressure;
1340 	long			*sysctl_mem;
1341 
1342 	int			*sysctl_wmem;
1343 	int			*sysctl_rmem;
1344 	u32			sysctl_wmem_offset;
1345 	u32			sysctl_rmem_offset;
1346 
1347 	int			max_header;
1348 	bool			no_autobind;
1349 
1350 	struct kmem_cache	*slab;
1351 	unsigned int		obj_size;
1352 	unsigned int		ipv6_pinfo_offset;
1353 	slab_flags_t		slab_flags;
1354 	unsigned int		useroffset;	/* Usercopy region offset */
1355 	unsigned int		usersize;	/* Usercopy region size */
1356 
1357 	struct request_sock_ops	*rsk_prot;
1358 	struct timewait_sock_ops *twsk_prot;
1359 
1360 	union {
1361 		struct inet_hashinfo	*hashinfo;
1362 		struct udp_table	*udp_table;
1363 		struct raw_hashinfo	*raw_hash;
1364 		struct smc_hashinfo	*smc_hash;
1365 	} h;
1366 
1367 	struct module		*owner;
1368 
1369 	char			name[32];
1370 
1371 	struct list_head	node;
1372 	int			(*diag_destroy)(struct sock *sk, int err);
1373 } __randomize_layout;
1374 
1375 int proto_register(struct proto *prot, int alloc_slab);
1376 void proto_unregister(struct proto *prot);
1377 int sock_load_diag_module(int family, int protocol);
1378 
1379 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1380 
1381 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1382 {
1383 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1384 		return false;
1385 
1386 	return sk->sk_prot->stream_memory_free ?
1387 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1388 				     tcp_stream_memory_free, sk, wake) : true;
1389 }
1390 
1391 static inline bool sk_stream_memory_free(const struct sock *sk)
1392 {
1393 	return __sk_stream_memory_free(sk, 0);
1394 }
1395 
1396 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1397 {
1398 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1399 	       __sk_stream_memory_free(sk, wake);
1400 }
1401 
1402 static inline bool sk_stream_is_writeable(const struct sock *sk)
1403 {
1404 	return __sk_stream_is_writeable(sk, 0);
1405 }
1406 
1407 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1408 					    struct cgroup *ancestor)
1409 {
1410 #ifdef CONFIG_SOCK_CGROUP_DATA
1411 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1412 				    ancestor);
1413 #else
1414 	return -ENOTSUPP;
1415 #endif
1416 }
1417 
1418 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1419 
1420 static inline void sk_sockets_allocated_dec(struct sock *sk)
1421 {
1422 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1423 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1424 }
1425 
1426 static inline void sk_sockets_allocated_inc(struct sock *sk)
1427 {
1428 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1429 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1430 }
1431 
1432 static inline u64
1433 sk_sockets_allocated_read_positive(struct sock *sk)
1434 {
1435 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1436 }
1437 
1438 static inline int
1439 proto_sockets_allocated_sum_positive(struct proto *prot)
1440 {
1441 	return percpu_counter_sum_positive(prot->sockets_allocated);
1442 }
1443 
1444 #ifdef CONFIG_PROC_FS
1445 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1446 struct prot_inuse {
1447 	int all;
1448 	int val[PROTO_INUSE_NR];
1449 };
1450 
1451 static inline void sock_prot_inuse_add(const struct net *net,
1452 				       const struct proto *prot, int val)
1453 {
1454 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1455 }
1456 
1457 static inline void sock_inuse_add(const struct net *net, int val)
1458 {
1459 	this_cpu_add(net->core.prot_inuse->all, val);
1460 }
1461 
1462 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1463 int sock_inuse_get(struct net *net);
1464 #else
1465 static inline void sock_prot_inuse_add(const struct net *net,
1466 				       const struct proto *prot, int val)
1467 {
1468 }
1469 
1470 static inline void sock_inuse_add(const struct net *net, int val)
1471 {
1472 }
1473 #endif
1474 
1475 
1476 /* With per-bucket locks this operation is not-atomic, so that
1477  * this version is not worse.
1478  */
1479 static inline int __sk_prot_rehash(struct sock *sk)
1480 {
1481 	sk->sk_prot->unhash(sk);
1482 	return sk->sk_prot->hash(sk);
1483 }
1484 
1485 /* About 10 seconds */
1486 #define SOCK_DESTROY_TIME (10*HZ)
1487 
1488 /* Sockets 0-1023 can't be bound to unless you are superuser */
1489 #define PROT_SOCK	1024
1490 
1491 #define SHUTDOWN_MASK	3
1492 #define RCV_SHUTDOWN	1
1493 #define SEND_SHUTDOWN	2
1494 
1495 #define SOCK_BINDADDR_LOCK	4
1496 #define SOCK_BINDPORT_LOCK	8
1497 
1498 struct socket_alloc {
1499 	struct socket socket;
1500 	struct inode vfs_inode;
1501 };
1502 
1503 static inline struct socket *SOCKET_I(struct inode *inode)
1504 {
1505 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1506 }
1507 
1508 static inline struct inode *SOCK_INODE(struct socket *socket)
1509 {
1510 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1511 }
1512 
1513 /*
1514  * Functions for memory accounting
1515  */
1516 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1517 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1518 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1519 void __sk_mem_reclaim(struct sock *sk, int amount);
1520 
1521 #define SK_MEM_SEND	0
1522 #define SK_MEM_RECV	1
1523 
1524 /* sysctl_mem values are in pages */
1525 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1526 {
1527 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1528 }
1529 
1530 static inline int sk_mem_pages(int amt)
1531 {
1532 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1533 }
1534 
1535 static inline bool sk_has_account(struct sock *sk)
1536 {
1537 	/* return true if protocol supports memory accounting */
1538 	return !!sk->sk_prot->memory_allocated;
1539 }
1540 
1541 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1542 {
1543 	int delta;
1544 
1545 	if (!sk_has_account(sk))
1546 		return true;
1547 	delta = size - sk->sk_forward_alloc;
1548 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1549 }
1550 
1551 static inline bool
1552 __sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)
1553 {
1554 	int delta;
1555 
1556 	if (!sk_has_account(sk))
1557 		return true;
1558 	delta = size - sk->sk_forward_alloc;
1559 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1560 	       pfmemalloc;
1561 }
1562 
1563 static inline bool
1564 sk_rmem_schedule(struct sock *sk, const struct sk_buff *skb, int size)
1565 {
1566 	return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));
1567 }
1568 
1569 static inline int sk_unused_reserved_mem(const struct sock *sk)
1570 {
1571 	int unused_mem;
1572 
1573 	if (likely(!sk->sk_reserved_mem))
1574 		return 0;
1575 
1576 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1577 			atomic_read(&sk->sk_rmem_alloc);
1578 
1579 	return unused_mem > 0 ? unused_mem : 0;
1580 }
1581 
1582 static inline void sk_mem_reclaim(struct sock *sk)
1583 {
1584 	int reclaimable;
1585 
1586 	if (!sk_has_account(sk))
1587 		return;
1588 
1589 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1590 
1591 	if (reclaimable >= (int)PAGE_SIZE)
1592 		__sk_mem_reclaim(sk, reclaimable);
1593 }
1594 
1595 static inline void sk_mem_reclaim_final(struct sock *sk)
1596 {
1597 	sk->sk_reserved_mem = 0;
1598 	sk_mem_reclaim(sk);
1599 }
1600 
1601 static inline void sk_mem_charge(struct sock *sk, int size)
1602 {
1603 	if (!sk_has_account(sk))
1604 		return;
1605 	sk_forward_alloc_add(sk, -size);
1606 }
1607 
1608 static inline void sk_mem_uncharge(struct sock *sk, int size)
1609 {
1610 	if (!sk_has_account(sk))
1611 		return;
1612 	sk_forward_alloc_add(sk, size);
1613 	sk_mem_reclaim(sk);
1614 }
1615 
1616 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
1617 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1618 {
1619 	__module_get(owner);
1620 	sk->sk_owner = owner;
1621 }
1622 
1623 static inline void sk_owner_clear(struct sock *sk)
1624 {
1625 	sk->sk_owner = NULL;
1626 }
1627 
1628 static inline void sk_owner_put(struct sock *sk)
1629 {
1630 	module_put(sk->sk_owner);
1631 }
1632 #else
1633 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1634 {
1635 }
1636 
1637 static inline void sk_owner_clear(struct sock *sk)
1638 {
1639 }
1640 
1641 static inline void sk_owner_put(struct sock *sk)
1642 {
1643 }
1644 #endif
1645 /*
1646  * Macro so as to not evaluate some arguments when
1647  * lockdep is not enabled.
1648  *
1649  * Mark both the sk_lock and the sk_lock.slock as a
1650  * per-address-family lock class.
1651  */
1652 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1653 do {									\
1654 	sk_owner_set(sk, THIS_MODULE);					\
1655 	sk->sk_lock.owned = 0;						\
1656 	init_waitqueue_head(&sk->sk_lock.wq);				\
1657 	spin_lock_init(&(sk)->sk_lock.slock);				\
1658 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1659 				   sizeof((sk)->sk_lock));		\
1660 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1661 				   (skey), (sname));			\
1662 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1663 } while (0)
1664 
1665 static inline bool lockdep_sock_is_held(const struct sock *sk)
1666 {
1667 	return lockdep_is_held(&sk->sk_lock) ||
1668 	       lockdep_is_held(&sk->sk_lock.slock);
1669 }
1670 
1671 void lock_sock_nested(struct sock *sk, int subclass);
1672 
1673 static inline void lock_sock(struct sock *sk)
1674 {
1675 	lock_sock_nested(sk, 0);
1676 }
1677 
1678 void __lock_sock(struct sock *sk);
1679 void __release_sock(struct sock *sk);
1680 void release_sock(struct sock *sk);
1681 
1682 /* BH context may only use the following locking interface. */
1683 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1684 #define bh_lock_sock_nested(__sk) \
1685 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1686 				SINGLE_DEPTH_NESTING)
1687 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1688 
1689 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1690 
1691 /**
1692  * lock_sock_fast - fast version of lock_sock
1693  * @sk: socket
1694  *
1695  * This version should be used for very small section, where process won't block
1696  * return false if fast path is taken:
1697  *
1698  *   sk_lock.slock locked, owned = 0, BH disabled
1699  *
1700  * return true if slow path is taken:
1701  *
1702  *   sk_lock.slock unlocked, owned = 1, BH enabled
1703  */
1704 static inline bool lock_sock_fast(struct sock *sk)
1705 {
1706 	/* The sk_lock has mutex_lock() semantics here. */
1707 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1708 
1709 	return __lock_sock_fast(sk);
1710 }
1711 
1712 /* fast socket lock variant for caller already holding a [different] socket lock */
1713 static inline bool lock_sock_fast_nested(struct sock *sk)
1714 {
1715 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1716 
1717 	return __lock_sock_fast(sk);
1718 }
1719 
1720 /**
1721  * unlock_sock_fast - complement of lock_sock_fast
1722  * @sk: socket
1723  * @slow: slow mode
1724  *
1725  * fast unlock socket for user context.
1726  * If slow mode is on, we call regular release_sock()
1727  */
1728 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1729 	__releases(&sk->sk_lock.slock)
1730 {
1731 	if (slow) {
1732 		release_sock(sk);
1733 		__release(&sk->sk_lock.slock);
1734 	} else {
1735 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1736 		spin_unlock_bh(&sk->sk_lock.slock);
1737 	}
1738 }
1739 
1740 void sockopt_lock_sock(struct sock *sk);
1741 void sockopt_release_sock(struct sock *sk);
1742 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1743 bool sockopt_capable(int cap);
1744 
1745 /* Used by processes to "lock" a socket state, so that
1746  * interrupts and bottom half handlers won't change it
1747  * from under us. It essentially blocks any incoming
1748  * packets, so that we won't get any new data or any
1749  * packets that change the state of the socket.
1750  *
1751  * While locked, BH processing will add new packets to
1752  * the backlog queue.  This queue is processed by the
1753  * owner of the socket lock right before it is released.
1754  *
1755  * Since ~2.3.5 it is also exclusive sleep lock serializing
1756  * accesses from user process context.
1757  */
1758 
1759 static inline void sock_owned_by_me(const struct sock *sk)
1760 {
1761 #ifdef CONFIG_LOCKDEP
1762 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1763 #endif
1764 }
1765 
1766 static inline void sock_not_owned_by_me(const struct sock *sk)
1767 {
1768 #ifdef CONFIG_LOCKDEP
1769 	WARN_ON_ONCE(lockdep_sock_is_held(sk) && debug_locks);
1770 #endif
1771 }
1772 
1773 static inline bool sock_owned_by_user(const struct sock *sk)
1774 {
1775 	sock_owned_by_me(sk);
1776 	return sk->sk_lock.owned;
1777 }
1778 
1779 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1780 {
1781 	return sk->sk_lock.owned;
1782 }
1783 
1784 static inline void sock_release_ownership(struct sock *sk)
1785 {
1786 	DEBUG_NET_WARN_ON_ONCE(!sock_owned_by_user_nocheck(sk));
1787 	sk->sk_lock.owned = 0;
1788 
1789 	/* The sk_lock has mutex_unlock() semantics: */
1790 	mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1791 }
1792 
1793 /* no reclassification while locks are held */
1794 static inline bool sock_allow_reclassification(const struct sock *csk)
1795 {
1796 	struct sock *sk = (struct sock *)csk;
1797 
1798 	return !sock_owned_by_user_nocheck(sk) &&
1799 		!spin_is_locked(&sk->sk_lock.slock);
1800 }
1801 
1802 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1803 		      struct proto *prot, int kern);
1804 void sk_free(struct sock *sk);
1805 void sk_net_refcnt_upgrade(struct sock *sk);
1806 void sk_destruct(struct sock *sk);
1807 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1808 
1809 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1810 			     gfp_t priority);
1811 void __sock_wfree(struct sk_buff *skb);
1812 void sock_wfree(struct sk_buff *skb);
1813 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1814 			     gfp_t priority);
1815 void skb_orphan_partial(struct sk_buff *skb);
1816 void sock_rfree(struct sk_buff *skb);
1817 void sock_efree(struct sk_buff *skb);
1818 #ifdef CONFIG_INET
1819 void sock_edemux(struct sk_buff *skb);
1820 void sock_pfree(struct sk_buff *skb);
1821 
1822 static inline void skb_set_owner_edemux(struct sk_buff *skb, struct sock *sk)
1823 {
1824 	skb_orphan(skb);
1825 	if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1826 		skb->sk = sk;
1827 		skb->destructor = sock_edemux;
1828 	}
1829 }
1830 #else
1831 #define sock_edemux sock_efree
1832 #endif
1833 
1834 int sk_setsockopt(struct sock *sk, int level, int optname,
1835 		  sockptr_t optval, unsigned int optlen);
1836 int sock_setsockopt(struct socket *sock, int level, int op,
1837 		    sockptr_t optval, unsigned int optlen);
1838 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
1839 		       int optname, sockptr_t optval, int optlen);
1840 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
1841 		       int optname, sockptr_t optval, sockptr_t optlen);
1842 
1843 int sk_getsockopt(struct sock *sk, int level, int optname,
1844 		  sockptr_t optval, sockptr_t optlen);
1845 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1846 		   bool timeval, bool time32);
1847 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1848 				     unsigned long data_len, int noblock,
1849 				     int *errcode, int max_page_order);
1850 
1851 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1852 						  unsigned long size,
1853 						  int noblock, int *errcode)
1854 {
1855 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1856 }
1857 
1858 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1859 void *sock_kmemdup(struct sock *sk, const void *src,
1860 		   int size, gfp_t priority);
1861 void sock_kfree_s(struct sock *sk, void *mem, int size);
1862 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1863 void sk_send_sigurg(struct sock *sk);
1864 
1865 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1866 {
1867 	if (sk->sk_socket)
1868 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1869 	WRITE_ONCE(sk->sk_prot, proto);
1870 }
1871 
1872 struct sockcm_cookie {
1873 	u64 transmit_time;
1874 	u32 mark;
1875 	u32 tsflags;
1876 	u32 ts_opt_id;
1877 	u32 priority;
1878 	u32 dmabuf_id;
1879 };
1880 
1881 static inline void sockcm_init(struct sockcm_cookie *sockc,
1882 			       const struct sock *sk)
1883 {
1884 	*sockc = (struct sockcm_cookie) {
1885 		.mark = READ_ONCE(sk->sk_mark),
1886 		.tsflags = READ_ONCE(sk->sk_tsflags),
1887 		.priority = READ_ONCE(sk->sk_priority),
1888 	};
1889 }
1890 
1891 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1892 		     struct sockcm_cookie *sockc);
1893 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1894 		   struct sockcm_cookie *sockc);
1895 
1896 /*
1897  * Functions to fill in entries in struct proto_ops when a protocol
1898  * does not implement a particular function.
1899  */
1900 int sock_no_bind(struct socket *, struct sockaddr *, int);
1901 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1902 int sock_no_socketpair(struct socket *, struct socket *);
1903 int sock_no_accept(struct socket *, struct socket *, struct proto_accept_arg *);
1904 int sock_no_getname(struct socket *, struct sockaddr *, int);
1905 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1906 int sock_no_listen(struct socket *, int);
1907 int sock_no_shutdown(struct socket *, int);
1908 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1909 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1910 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1911 int sock_no_mmap(struct file *file, struct socket *sock,
1912 		 struct vm_area_struct *vma);
1913 
1914 /*
1915  * Functions to fill in entries in struct proto_ops when a protocol
1916  * uses the inet style.
1917  */
1918 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1919 				  char __user *optval, int __user *optlen);
1920 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1921 			int flags);
1922 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1923 			   sockptr_t optval, unsigned int optlen);
1924 
1925 void sk_common_release(struct sock *sk);
1926 
1927 /*
1928  *	Default socket callbacks and setup code
1929  */
1930 
1931 /* Initialise core socket variables using an explicit uid. */
1932 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1933 
1934 /* Initialise core socket variables.
1935  * Assumes struct socket *sock is embedded in a struct socket_alloc.
1936  */
1937 void sock_init_data(struct socket *sock, struct sock *sk);
1938 
1939 /*
1940  * Socket reference counting postulates.
1941  *
1942  * * Each user of socket SHOULD hold a reference count.
1943  * * Each access point to socket (an hash table bucket, reference from a list,
1944  *   running timer, skb in flight MUST hold a reference count.
1945  * * When reference count hits 0, it means it will never increase back.
1946  * * When reference count hits 0, it means that no references from
1947  *   outside exist to this socket and current process on current CPU
1948  *   is last user and may/should destroy this socket.
1949  * * sk_free is called from any context: process, BH, IRQ. When
1950  *   it is called, socket has no references from outside -> sk_free
1951  *   may release descendant resources allocated by the socket, but
1952  *   to the time when it is called, socket is NOT referenced by any
1953  *   hash tables, lists etc.
1954  * * Packets, delivered from outside (from network or from another process)
1955  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1956  *   when they sit in queue. Otherwise, packets will leak to hole, when
1957  *   socket is looked up by one cpu and unhasing is made by another CPU.
1958  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1959  *   (leak to backlog). Packet socket does all the processing inside
1960  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1961  *   use separate SMP lock, so that they are prone too.
1962  */
1963 
1964 /* Ungrab socket and destroy it, if it was the last reference. */
1965 static inline void sock_put(struct sock *sk)
1966 {
1967 	if (refcount_dec_and_test(&sk->sk_refcnt))
1968 		sk_free(sk);
1969 }
1970 /* Generic version of sock_put(), dealing with all sockets
1971  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1972  */
1973 void sock_gen_put(struct sock *sk);
1974 
1975 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1976 		     unsigned int trim_cap, bool refcounted);
1977 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1978 				 const int nested)
1979 {
1980 	return __sk_receive_skb(sk, skb, nested, 1, true);
1981 }
1982 
1983 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1984 {
1985 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1986 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1987 		return;
1988 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
1989 	 * other WRITE_ONCE() because socket lock might be not held.
1990 	 */
1991 	WRITE_ONCE(sk->sk_tx_queue_mapping, tx_queue);
1992 }
1993 
1994 #define NO_QUEUE_MAPPING	USHRT_MAX
1995 
1996 static inline void sk_tx_queue_clear(struct sock *sk)
1997 {
1998 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
1999 	 * other WRITE_ONCE() because socket lock might be not held.
2000 	 */
2001 	WRITE_ONCE(sk->sk_tx_queue_mapping, NO_QUEUE_MAPPING);
2002 }
2003 
2004 static inline int sk_tx_queue_get(const struct sock *sk)
2005 {
2006 	if (sk) {
2007 		/* Paired with WRITE_ONCE() in sk_tx_queue_clear()
2008 		 * and sk_tx_queue_set().
2009 		 */
2010 		int val = READ_ONCE(sk->sk_tx_queue_mapping);
2011 
2012 		if (val != NO_QUEUE_MAPPING)
2013 			return val;
2014 	}
2015 	return -1;
2016 }
2017 
2018 static inline void __sk_rx_queue_set(struct sock *sk,
2019 				     const struct sk_buff *skb,
2020 				     bool force_set)
2021 {
2022 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2023 	if (skb_rx_queue_recorded(skb)) {
2024 		u16 rx_queue = skb_get_rx_queue(skb);
2025 
2026 		if (force_set ||
2027 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2028 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2029 	}
2030 #endif
2031 }
2032 
2033 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2034 {
2035 	__sk_rx_queue_set(sk, skb, true);
2036 }
2037 
2038 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2039 {
2040 	__sk_rx_queue_set(sk, skb, false);
2041 }
2042 
2043 static inline void sk_rx_queue_clear(struct sock *sk)
2044 {
2045 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2046 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2047 #endif
2048 }
2049 
2050 static inline int sk_rx_queue_get(const struct sock *sk)
2051 {
2052 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2053 	if (sk) {
2054 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2055 
2056 		if (res != NO_QUEUE_MAPPING)
2057 			return res;
2058 	}
2059 #endif
2060 
2061 	return -1;
2062 }
2063 
2064 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2065 {
2066 	sk->sk_socket = sock;
2067 	if (sock) {
2068 		WRITE_ONCE(sk->sk_uid, SOCK_INODE(sock)->i_uid);
2069 		WRITE_ONCE(sk->sk_ino, SOCK_INODE(sock)->i_ino);
2070 	} else {
2071 		/* Note: sk_uid is unchanged. */
2072 		WRITE_ONCE(sk->sk_ino, 0);
2073 	}
2074 }
2075 
2076 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2077 {
2078 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2079 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2080 }
2081 /* Detach socket from process context.
2082  * Announce socket dead, detach it from wait queue and inode.
2083  * Note that parent inode held reference count on this struct sock,
2084  * we do not release it in this function, because protocol
2085  * probably wants some additional cleanups or even continuing
2086  * to work with this socket (TCP).
2087  */
2088 static inline void sock_orphan(struct sock *sk)
2089 {
2090 	write_lock_bh(&sk->sk_callback_lock);
2091 	sock_set_flag(sk, SOCK_DEAD);
2092 	sk_set_socket(sk, NULL);
2093 	sk->sk_wq  = NULL;
2094 	write_unlock_bh(&sk->sk_callback_lock);
2095 }
2096 
2097 static inline void sock_graft(struct sock *sk, struct socket *parent)
2098 {
2099 	WARN_ON(parent->sk);
2100 	write_lock_bh(&sk->sk_callback_lock);
2101 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2102 	parent->sk = sk;
2103 	sk_set_socket(sk, parent);
2104 	security_sock_graft(sk, parent);
2105 	write_unlock_bh(&sk->sk_callback_lock);
2106 }
2107 
2108 static inline unsigned long sock_i_ino(const struct sock *sk)
2109 {
2110 	/* Paired with WRITE_ONCE() in sock_graft() and sock_orphan() */
2111 	return READ_ONCE(sk->sk_ino);
2112 }
2113 
2114 static inline kuid_t sk_uid(const struct sock *sk)
2115 {
2116 	/* Paired with WRITE_ONCE() in sockfs_setattr() */
2117 	return READ_ONCE(sk->sk_uid);
2118 }
2119 
2120 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2121 {
2122 	return sk ? sk_uid(sk) : make_kuid(net->user_ns, 0);
2123 }
2124 
2125 static inline u32 net_tx_rndhash(void)
2126 {
2127 	u32 v = get_random_u32();
2128 
2129 	return v ?: 1;
2130 }
2131 
2132 static inline void sk_set_txhash(struct sock *sk)
2133 {
2134 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2135 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2136 }
2137 
2138 static inline bool sk_rethink_txhash(struct sock *sk)
2139 {
2140 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2141 		sk_set_txhash(sk);
2142 		return true;
2143 	}
2144 	return false;
2145 }
2146 
2147 static inline struct dst_entry *
2148 __sk_dst_get(const struct sock *sk)
2149 {
2150 	return rcu_dereference_check(sk->sk_dst_cache,
2151 				     lockdep_sock_is_held(sk));
2152 }
2153 
2154 static inline struct dst_entry *
2155 sk_dst_get(const struct sock *sk)
2156 {
2157 	struct dst_entry *dst;
2158 
2159 	rcu_read_lock();
2160 	dst = rcu_dereference(sk->sk_dst_cache);
2161 	if (dst && !rcuref_get(&dst->__rcuref))
2162 		dst = NULL;
2163 	rcu_read_unlock();
2164 	return dst;
2165 }
2166 
2167 static inline void __dst_negative_advice(struct sock *sk)
2168 {
2169 	struct dst_entry *dst = __sk_dst_get(sk);
2170 
2171 	if (dst && dst->ops->negative_advice)
2172 		dst->ops->negative_advice(sk, dst);
2173 }
2174 
2175 static inline void dst_negative_advice(struct sock *sk)
2176 {
2177 	sk_rethink_txhash(sk);
2178 	__dst_negative_advice(sk);
2179 }
2180 
2181 static inline void
2182 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2183 {
2184 	struct dst_entry *old_dst;
2185 
2186 	sk_tx_queue_clear(sk);
2187 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2188 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2189 					    lockdep_sock_is_held(sk));
2190 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2191 	dst_release(old_dst);
2192 }
2193 
2194 static inline void
2195 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2196 {
2197 	struct dst_entry *old_dst;
2198 
2199 	sk_tx_queue_clear(sk);
2200 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2201 	old_dst = unrcu_pointer(xchg(&sk->sk_dst_cache, RCU_INITIALIZER(dst)));
2202 	dst_release(old_dst);
2203 }
2204 
2205 static inline void
2206 __sk_dst_reset(struct sock *sk)
2207 {
2208 	__sk_dst_set(sk, NULL);
2209 }
2210 
2211 static inline void
2212 sk_dst_reset(struct sock *sk)
2213 {
2214 	sk_dst_set(sk, NULL);
2215 }
2216 
2217 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2218 
2219 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2220 
2221 static inline void sk_dst_confirm(struct sock *sk)
2222 {
2223 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2224 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2225 }
2226 
2227 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2228 {
2229 	if (skb_get_dst_pending_confirm(skb)) {
2230 		struct sock *sk = skb->sk;
2231 
2232 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2233 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2234 		neigh_confirm(n);
2235 	}
2236 }
2237 
2238 bool sk_mc_loop(const struct sock *sk);
2239 
2240 static inline bool sk_can_gso(const struct sock *sk)
2241 {
2242 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2243 }
2244 
2245 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2246 
2247 static inline void sk_gso_disable(struct sock *sk)
2248 {
2249 	sk->sk_gso_disabled = 1;
2250 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2251 }
2252 
2253 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2254 					   struct iov_iter *from, char *to,
2255 					   int copy, int offset)
2256 {
2257 	if (skb->ip_summed == CHECKSUM_NONE) {
2258 		__wsum csum = 0;
2259 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2260 			return -EFAULT;
2261 		skb->csum = csum_block_add(skb->csum, csum, offset);
2262 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2263 		if (!copy_from_iter_full_nocache(to, copy, from))
2264 			return -EFAULT;
2265 	} else if (!copy_from_iter_full(to, copy, from))
2266 		return -EFAULT;
2267 
2268 	return 0;
2269 }
2270 
2271 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2272 				       struct iov_iter *from, int copy)
2273 {
2274 	int err, offset = skb->len;
2275 
2276 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2277 				       copy, offset);
2278 	if (err)
2279 		__skb_trim(skb, offset);
2280 
2281 	return err;
2282 }
2283 
2284 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2285 					   struct sk_buff *skb,
2286 					   struct page *page,
2287 					   int off, int copy)
2288 {
2289 	int err;
2290 
2291 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2292 				       copy, skb->len);
2293 	if (err)
2294 		return err;
2295 
2296 	skb_len_add(skb, copy);
2297 	sk_wmem_queued_add(sk, copy);
2298 	sk_mem_charge(sk, copy);
2299 	return 0;
2300 }
2301 
2302 /**
2303  * sk_wmem_alloc_get - returns write allocations
2304  * @sk: socket
2305  *
2306  * Return: sk_wmem_alloc minus initial offset of one
2307  */
2308 static inline int sk_wmem_alloc_get(const struct sock *sk)
2309 {
2310 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2311 }
2312 
2313 /**
2314  * sk_rmem_alloc_get - returns read allocations
2315  * @sk: socket
2316  *
2317  * Return: sk_rmem_alloc
2318  */
2319 static inline int sk_rmem_alloc_get(const struct sock *sk)
2320 {
2321 	return atomic_read(&sk->sk_rmem_alloc);
2322 }
2323 
2324 /**
2325  * sk_has_allocations - check if allocations are outstanding
2326  * @sk: socket
2327  *
2328  * Return: true if socket has write or read allocations
2329  */
2330 static inline bool sk_has_allocations(const struct sock *sk)
2331 {
2332 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2333 }
2334 
2335 /**
2336  * skwq_has_sleeper - check if there are any waiting processes
2337  * @wq: struct socket_wq
2338  *
2339  * Return: true if socket_wq has waiting processes
2340  *
2341  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2342  * barrier call. They were added due to the race found within the tcp code.
2343  *
2344  * Consider following tcp code paths::
2345  *
2346  *   CPU1                CPU2
2347  *   sys_select          receive packet
2348  *   ...                 ...
2349  *   __add_wait_queue    update tp->rcv_nxt
2350  *   ...                 ...
2351  *   tp->rcv_nxt check   sock_def_readable
2352  *   ...                 {
2353  *   schedule               rcu_read_lock();
2354  *                          wq = rcu_dereference(sk->sk_wq);
2355  *                          if (wq && waitqueue_active(&wq->wait))
2356  *                              wake_up_interruptible(&wq->wait)
2357  *                          ...
2358  *                       }
2359  *
2360  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2361  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2362  * could then endup calling schedule and sleep forever if there are no more
2363  * data on the socket.
2364  *
2365  */
2366 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2367 {
2368 	return wq && wq_has_sleeper(&wq->wait);
2369 }
2370 
2371 /**
2372  * sock_poll_wait - wrapper for the poll_wait call.
2373  * @filp:           file
2374  * @sock:           socket to wait on
2375  * @p:              poll_table
2376  *
2377  * See the comments in the wq_has_sleeper function.
2378  */
2379 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2380 				  poll_table *p)
2381 {
2382 	/* Provides a barrier we need to be sure we are in sync
2383 	 * with the socket flags modification.
2384 	 *
2385 	 * This memory barrier is paired in the wq_has_sleeper.
2386 	 */
2387 	poll_wait(filp, &sock->wq.wait, p);
2388 }
2389 
2390 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2391 {
2392 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2393 	u32 txhash = READ_ONCE(sk->sk_txhash);
2394 
2395 	if (txhash) {
2396 		skb->l4_hash = 1;
2397 		skb->hash = txhash;
2398 	}
2399 }
2400 
2401 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2402 
2403 /*
2404  *	Queue a received datagram if it will fit. Stream and sequenced
2405  *	protocols can't normally use this as they need to fit buffers in
2406  *	and play with them.
2407  *
2408  *	Inlined as it's very short and called for pretty much every
2409  *	packet ever received.
2410  */
2411 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2412 {
2413 	skb_orphan(skb);
2414 	skb->sk = sk;
2415 	skb->destructor = sock_rfree;
2416 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2417 	sk_mem_charge(sk, skb->truesize);
2418 }
2419 
2420 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2421 {
2422 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2423 		skb_orphan(skb);
2424 		skb->destructor = sock_efree;
2425 		skb->sk = sk;
2426 		return true;
2427 	}
2428 	return false;
2429 }
2430 
2431 static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2432 {
2433 	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2434 	if (skb) {
2435 		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2436 			skb_set_owner_r(skb, sk);
2437 			return skb;
2438 		}
2439 		__kfree_skb(skb);
2440 	}
2441 	return NULL;
2442 }
2443 
2444 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2445 {
2446 	if (skb->destructor != sock_wfree) {
2447 		skb_orphan(skb);
2448 		return;
2449 	}
2450 	skb->slow_gro = 1;
2451 }
2452 
2453 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2454 		    unsigned long expires);
2455 
2456 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2457 
2458 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2459 
2460 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2461 			struct sk_buff *skb, unsigned int flags,
2462 			void (*destructor)(struct sock *sk,
2463 					   struct sk_buff *skb));
2464 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2465 
2466 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2467 			      enum skb_drop_reason *reason);
2468 
2469 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2470 {
2471 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2472 }
2473 
2474 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2475 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2476 
2477 /*
2478  *	Recover an error report and clear atomically
2479  */
2480 
2481 static inline int sock_error(struct sock *sk)
2482 {
2483 	int err;
2484 
2485 	/* Avoid an atomic operation for the common case.
2486 	 * This is racy since another cpu/thread can change sk_err under us.
2487 	 */
2488 	if (likely(data_race(!sk->sk_err)))
2489 		return 0;
2490 
2491 	err = xchg(&sk->sk_err, 0);
2492 	return -err;
2493 }
2494 
2495 void sk_error_report(struct sock *sk);
2496 
2497 static inline unsigned long sock_wspace(struct sock *sk)
2498 {
2499 	int amt = 0;
2500 
2501 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2502 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2503 		if (amt < 0)
2504 			amt = 0;
2505 	}
2506 	return amt;
2507 }
2508 
2509 /* Note:
2510  *  We use sk->sk_wq_raw, from contexts knowing this
2511  *  pointer is not NULL and cannot disappear/change.
2512  */
2513 static inline void sk_set_bit(int nr, struct sock *sk)
2514 {
2515 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2516 	    !sock_flag(sk, SOCK_FASYNC))
2517 		return;
2518 
2519 	set_bit(nr, &sk->sk_wq_raw->flags);
2520 }
2521 
2522 static inline void sk_clear_bit(int nr, struct sock *sk)
2523 {
2524 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2525 	    !sock_flag(sk, SOCK_FASYNC))
2526 		return;
2527 
2528 	clear_bit(nr, &sk->sk_wq_raw->flags);
2529 }
2530 
2531 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2532 {
2533 	if (sock_flag(sk, SOCK_FASYNC)) {
2534 		rcu_read_lock();
2535 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2536 		rcu_read_unlock();
2537 	}
2538 }
2539 
2540 static inline void sk_wake_async_rcu(const struct sock *sk, int how, int band)
2541 {
2542 	if (unlikely(sock_flag(sk, SOCK_FASYNC)))
2543 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2544 }
2545 
2546 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2547  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2548  * Note: for send buffers, TCP works better if we can build two skbs at
2549  * minimum.
2550  */
2551 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2552 
2553 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2554 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2555 
2556 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2557 {
2558 	u32 val;
2559 
2560 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2561 		return;
2562 
2563 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2564 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2565 
2566 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2567 }
2568 
2569 /**
2570  * sk_page_frag - return an appropriate page_frag
2571  * @sk: socket
2572  *
2573  * Use the per task page_frag instead of the per socket one for
2574  * optimization when we know that we're in process context and own
2575  * everything that's associated with %current.
2576  *
2577  * Both direct reclaim and page faults can nest inside other
2578  * socket operations and end up recursing into sk_page_frag()
2579  * while it's already in use: explicitly avoid task page_frag
2580  * when users disable sk_use_task_frag.
2581  *
2582  * Return: a per task page_frag if context allows that,
2583  * otherwise a per socket one.
2584  */
2585 static inline struct page_frag *sk_page_frag(struct sock *sk)
2586 {
2587 	if (sk->sk_use_task_frag)
2588 		return &current->task_frag;
2589 
2590 	return &sk->sk_frag;
2591 }
2592 
2593 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2594 
2595 /*
2596  *	Default write policy as shown to user space via poll/select/SIGIO
2597  */
2598 static inline bool sock_writeable(const struct sock *sk)
2599 {
2600 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2601 }
2602 
2603 static inline gfp_t gfp_any(void)
2604 {
2605 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2606 }
2607 
2608 static inline gfp_t gfp_memcg_charge(void)
2609 {
2610 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2611 }
2612 
2613 #ifdef CONFIG_MEMCG
2614 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2615 {
2616 	return sk->sk_memcg;
2617 }
2618 
2619 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2620 {
2621 	return mem_cgroup_sockets_enabled && mem_cgroup_from_sk(sk);
2622 }
2623 
2624 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2625 {
2626 	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);
2627 
2628 #ifdef CONFIG_MEMCG_V1
2629 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
2630 		return !!memcg->tcpmem_pressure;
2631 #endif /* CONFIG_MEMCG_V1 */
2632 
2633 	do {
2634 		if (time_before64(get_jiffies_64(), mem_cgroup_get_socket_pressure(memcg)))
2635 			return true;
2636 	} while ((memcg = parent_mem_cgroup(memcg)));
2637 
2638 	return false;
2639 }
2640 #else
2641 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2642 {
2643 	return NULL;
2644 }
2645 
2646 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2647 {
2648 	return false;
2649 }
2650 
2651 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2652 {
2653 	return false;
2654 }
2655 #endif
2656 
2657 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2658 {
2659 	return noblock ? 0 : READ_ONCE(sk->sk_rcvtimeo);
2660 }
2661 
2662 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2663 {
2664 	return noblock ? 0 : READ_ONCE(sk->sk_sndtimeo);
2665 }
2666 
2667 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2668 {
2669 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2670 
2671 	return v ?: 1;
2672 }
2673 
2674 /* Alas, with timeout socket operations are not restartable.
2675  * Compare this to poll().
2676  */
2677 static inline int sock_intr_errno(long timeo)
2678 {
2679 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2680 }
2681 
2682 struct sock_skb_cb {
2683 	u32 dropcount;
2684 };
2685 
2686 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2687  * using skb->cb[] would keep using it directly and utilize its
2688  * alignment guarantee.
2689  */
2690 #define SOCK_SKB_CB_OFFSET (sizeof_field(struct sk_buff, cb) - \
2691 			    sizeof(struct sock_skb_cb))
2692 
2693 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2694 			    SOCK_SKB_CB_OFFSET))
2695 
2696 #define sock_skb_cb_check_size(size) \
2697 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2698 
2699 static inline void sk_drops_add(struct sock *sk, int segs)
2700 {
2701 	struct numa_drop_counters *ndc = sk->sk_drop_counters;
2702 
2703 	if (ndc)
2704 		numa_drop_add(ndc, segs);
2705 	else
2706 		atomic_add(segs, &sk->sk_drops);
2707 }
2708 
2709 static inline void sk_drops_inc(struct sock *sk)
2710 {
2711 	sk_drops_add(sk, 1);
2712 }
2713 
2714 static inline int sk_drops_read(const struct sock *sk)
2715 {
2716 	const struct numa_drop_counters *ndc = sk->sk_drop_counters;
2717 
2718 	if (ndc) {
2719 		DEBUG_NET_WARN_ON_ONCE(atomic_read(&sk->sk_drops));
2720 		return numa_drop_read(ndc);
2721 	}
2722 	return atomic_read(&sk->sk_drops);
2723 }
2724 
2725 static inline void sk_drops_reset(struct sock *sk)
2726 {
2727 	struct numa_drop_counters *ndc = sk->sk_drop_counters;
2728 
2729 	if (ndc)
2730 		numa_drop_reset(ndc);
2731 	atomic_set(&sk->sk_drops, 0);
2732 }
2733 
2734 static inline void
2735 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2736 {
2737 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2738 						sk_drops_read(sk) : 0;
2739 }
2740 
2741 static inline void sk_drops_skbadd(struct sock *sk, const struct sk_buff *skb)
2742 {
2743 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2744 
2745 	sk_drops_add(sk, segs);
2746 }
2747 
2748 static inline ktime_t sock_read_timestamp(struct sock *sk)
2749 {
2750 #if BITS_PER_LONG==32
2751 	unsigned int seq;
2752 	ktime_t kt;
2753 
2754 	do {
2755 		seq = read_seqbegin(&sk->sk_stamp_seq);
2756 		kt = sk->sk_stamp;
2757 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2758 
2759 	return kt;
2760 #else
2761 	return READ_ONCE(sk->sk_stamp);
2762 #endif
2763 }
2764 
2765 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2766 {
2767 #if BITS_PER_LONG==32
2768 	write_seqlock(&sk->sk_stamp_seq);
2769 	sk->sk_stamp = kt;
2770 	write_sequnlock(&sk->sk_stamp_seq);
2771 #else
2772 	WRITE_ONCE(sk->sk_stamp, kt);
2773 #endif
2774 }
2775 
2776 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2777 			   struct sk_buff *skb);
2778 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2779 			     struct sk_buff *skb);
2780 
2781 bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk);
2782 int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
2783 			 struct timespec64 *ts);
2784 
2785 static inline void
2786 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2787 {
2788 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2789 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
2790 	ktime_t kt = skb->tstamp;
2791 	/*
2792 	 * generate control messages if
2793 	 * - receive time stamping in software requested
2794 	 * - software time stamp available and wanted
2795 	 * - hardware time stamps available and wanted
2796 	 */
2797 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2798 	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2799 	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2800 	    (hwtstamps->hwtstamp &&
2801 	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2802 		__sock_recv_timestamp(msg, sk, skb);
2803 	else
2804 		sock_write_timestamp(sk, kt);
2805 
2806 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb_wifi_acked_valid(skb))
2807 		__sock_recv_wifi_status(msg, sk, skb);
2808 }
2809 
2810 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2811 		       struct sk_buff *skb);
2812 
2813 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2814 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2815 				   struct sk_buff *skb)
2816 {
2817 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2818 			   (1UL << SOCK_RCVTSTAMP)			| \
2819 			   (1UL << SOCK_RCVMARK)			| \
2820 			   (1UL << SOCK_RCVPRIORITY)			| \
2821 			   (1UL << SOCK_TIMESTAMPING_ANY))
2822 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2823 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2824 
2825 	if (READ_ONCE(sk->sk_flags) & FLAGS_RECV_CMSGS)
2826 		__sock_recv_cmsgs(msg, sk, skb);
2827 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2828 		sock_write_timestamp(sk, skb->tstamp);
2829 	else if (unlikely(sock_read_timestamp(sk) == SK_DEFAULT_STAMP))
2830 		sock_write_timestamp(sk, 0);
2831 }
2832 
2833 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags);
2834 
2835 /**
2836  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2837  * @sk:		socket sending this packet
2838  * @sockc:	pointer to socket cmsg cookie to get timestamping info
2839  * @tx_flags:	completed with instructions for time stamping
2840  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2841  *
2842  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2843  */
2844 static inline void _sock_tx_timestamp(struct sock *sk,
2845 				      const struct sockcm_cookie *sockc,
2846 				      __u8 *tx_flags, __u32 *tskey)
2847 {
2848 	__u32 tsflags = sockc->tsflags;
2849 
2850 	if (unlikely(tsflags)) {
2851 		__sock_tx_timestamp(tsflags, tx_flags);
2852 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2853 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) {
2854 			if (tsflags & SOCKCM_FLAG_TS_OPT_ID)
2855 				*tskey = sockc->ts_opt_id;
2856 			else
2857 				*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2858 		}
2859 	}
2860 }
2861 
2862 static inline void sock_tx_timestamp(struct sock *sk,
2863 				     const struct sockcm_cookie *sockc,
2864 				     __u8 *tx_flags)
2865 {
2866 	_sock_tx_timestamp(sk, sockc, tx_flags, NULL);
2867 }
2868 
2869 static inline void skb_setup_tx_timestamp(struct sk_buff *skb,
2870 					  const struct sockcm_cookie *sockc)
2871 {
2872 	_sock_tx_timestamp(skb->sk, sockc, &skb_shinfo(skb)->tx_flags,
2873 			   &skb_shinfo(skb)->tskey);
2874 }
2875 
2876 static inline bool sk_is_inet(const struct sock *sk)
2877 {
2878 	int family = READ_ONCE(sk->sk_family);
2879 
2880 	return family == AF_INET || family == AF_INET6;
2881 }
2882 
2883 static inline bool sk_is_tcp(const struct sock *sk)
2884 {
2885 	return sk_is_inet(sk) &&
2886 	       sk->sk_type == SOCK_STREAM &&
2887 	       sk->sk_protocol == IPPROTO_TCP;
2888 }
2889 
2890 static inline bool sk_is_udp(const struct sock *sk)
2891 {
2892 	return sk_is_inet(sk) &&
2893 	       sk->sk_type == SOCK_DGRAM &&
2894 	       sk->sk_protocol == IPPROTO_UDP;
2895 }
2896 
2897 static inline bool sk_is_unix(const struct sock *sk)
2898 {
2899 	return sk->sk_family == AF_UNIX;
2900 }
2901 
2902 static inline bool sk_is_stream_unix(const struct sock *sk)
2903 {
2904 	return sk_is_unix(sk) && sk->sk_type == SOCK_STREAM;
2905 }
2906 
2907 static inline bool sk_is_vsock(const struct sock *sk)
2908 {
2909 	return sk->sk_family == AF_VSOCK;
2910 }
2911 
2912 static inline bool sk_may_scm_recv(const struct sock *sk)
2913 {
2914 	return (IS_ENABLED(CONFIG_UNIX) && sk->sk_family == AF_UNIX) ||
2915 		sk->sk_family == AF_NETLINK ||
2916 		(IS_ENABLED(CONFIG_BT) && sk->sk_family == AF_BLUETOOTH);
2917 }
2918 
2919 /**
2920  * sk_eat_skb - Release a skb if it is no longer needed
2921  * @sk: socket to eat this skb from
2922  * @skb: socket buffer to eat
2923  *
2924  * This routine must be called with interrupts disabled or with the socket
2925  * locked so that the sk_buff queue operation is ok.
2926 */
2927 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2928 {
2929 	__skb_unlink(skb, &sk->sk_receive_queue);
2930 	__kfree_skb(skb);
2931 }
2932 
2933 static inline bool
2934 skb_sk_is_prefetched(struct sk_buff *skb)
2935 {
2936 #ifdef CONFIG_INET
2937 	return skb->destructor == sock_pfree;
2938 #else
2939 	return false;
2940 #endif /* CONFIG_INET */
2941 }
2942 
2943 /* This helper checks if a socket is a full socket,
2944  * ie _not_ a timewait or request socket.
2945  */
2946 static inline bool sk_fullsock(const struct sock *sk)
2947 {
2948 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2949 }
2950 
2951 static inline bool
2952 sk_is_refcounted(struct sock *sk)
2953 {
2954 	/* Only full sockets have sk->sk_flags. */
2955 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2956 }
2957 
2958 static inline bool
2959 sk_requests_wifi_status(struct sock *sk)
2960 {
2961 	return sk && sk_fullsock(sk) && sock_flag(sk, SOCK_WIFI_STATUS);
2962 }
2963 
2964 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2965  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2966  */
2967 static inline bool sk_listener(const struct sock *sk)
2968 {
2969 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2970 }
2971 
2972 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV or TIME_WAIT
2973  * TCP SYNACK messages can be attached to LISTEN or NEW_SYN_RECV (depending on SYNCOOKIE)
2974  * TCP RST and ACK can be attached to TIME_WAIT.
2975  */
2976 static inline bool sk_listener_or_tw(const struct sock *sk)
2977 {
2978 	return (1 << READ_ONCE(sk->sk_state)) &
2979 	       (TCPF_LISTEN | TCPF_NEW_SYN_RECV | TCPF_TIME_WAIT);
2980 }
2981 
2982 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2983 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2984 		       int type);
2985 
2986 bool sk_ns_capable(const struct sock *sk,
2987 		   struct user_namespace *user_ns, int cap);
2988 bool sk_capable(const struct sock *sk, int cap);
2989 bool sk_net_capable(const struct sock *sk, int cap);
2990 
2991 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2992 
2993 /* Take into consideration the size of the struct sk_buff overhead in the
2994  * determination of these values, since that is non-constant across
2995  * platforms.  This makes socket queueing behavior and performance
2996  * not depend upon such differences.
2997  */
2998 #define _SK_MEM_PACKETS		256
2999 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
3000 #define SK_WMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3001 #define SK_RMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3002 
3003 extern __u32 sysctl_wmem_max;
3004 extern __u32 sysctl_rmem_max;
3005 
3006 extern __u32 sysctl_wmem_default;
3007 extern __u32 sysctl_rmem_default;
3008 
3009 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
3010 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3011 
3012 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
3013 {
3014 	/* Does this proto have per netns sysctl_wmem ? */
3015 	if (proto->sysctl_wmem_offset)
3016 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
3017 
3018 	return READ_ONCE(*proto->sysctl_wmem);
3019 }
3020 
3021 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
3022 {
3023 	/* Does this proto have per netns sysctl_rmem ? */
3024 	if (proto->sysctl_rmem_offset)
3025 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
3026 
3027 	return READ_ONCE(*proto->sysctl_rmem);
3028 }
3029 
3030 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
3031  * Some wifi drivers need to tweak it to get more chunks.
3032  * They can use this helper from their ndo_start_xmit()
3033  */
3034 static inline void sk_pacing_shift_update(struct sock *sk, int val)
3035 {
3036 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
3037 		return;
3038 	WRITE_ONCE(sk->sk_pacing_shift, val);
3039 }
3040 
3041 /* if a socket is bound to a device, check that the given device
3042  * index is either the same or that the socket is bound to an L3
3043  * master device and the given device index is also enslaved to
3044  * that L3 master
3045  */
3046 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
3047 {
3048 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
3049 	int mdif;
3050 
3051 	if (!bound_dev_if || bound_dev_if == dif)
3052 		return true;
3053 
3054 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
3055 	if (mdif && mdif == bound_dev_if)
3056 		return true;
3057 
3058 	return false;
3059 }
3060 
3061 void sock_def_readable(struct sock *sk);
3062 
3063 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
3064 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
3065 int sock_set_timestamping(struct sock *sk, int optname,
3066 			  struct so_timestamping timestamping);
3067 
3068 #if defined(CONFIG_CGROUP_BPF)
3069 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op);
3070 #else
3071 static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
3072 {
3073 }
3074 #endif
3075 void sock_no_linger(struct sock *sk);
3076 void sock_set_keepalive(struct sock *sk);
3077 void sock_set_priority(struct sock *sk, u32 priority);
3078 void sock_set_rcvbuf(struct sock *sk, int val);
3079 void sock_set_mark(struct sock *sk, u32 val);
3080 void sock_set_reuseaddr(struct sock *sk);
3081 void sock_set_reuseport(struct sock *sk);
3082 void sock_set_sndtimeo(struct sock *sk, s64 secs);
3083 
3084 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
3085 
3086 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
3087 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
3088 			   sockptr_t optval, int optlen, bool old_timeval);
3089 
3090 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
3091 		     void __user *arg, void *karg, size_t size);
3092 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
3093 static inline bool sk_is_readable(struct sock *sk)
3094 {
3095 	const struct proto *prot = READ_ONCE(sk->sk_prot);
3096 
3097 	if (prot->sock_is_readable)
3098 		return prot->sock_is_readable(sk);
3099 
3100 	return false;
3101 }
3102 #endif	/* _SOCK_H */
3103