xref: /openbmc/linux/include/net/sock.h (revision 5af198c3)
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 /* Define this to get the SOCK_DBG debugging facility. */
80 #define SOCK_DEBUGGING
81 #ifdef SOCK_DEBUGGING
82 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
83 					printk(KERN_DEBUG msg); } while (0)
84 #else
85 /* Validate arguments and do nothing */
86 static inline __printf(2, 3)
87 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
88 {
89 }
90 #endif
91 
92 /* This is the per-socket lock.  The spinlock provides a synchronization
93  * between user contexts and software interrupt processing, whereas the
94  * mini-semaphore synchronizes multiple users amongst themselves.
95  */
96 typedef struct {
97 	spinlock_t		slock;
98 	int			owned;
99 	wait_queue_head_t	wq;
100 	/*
101 	 * We express the mutex-alike socket_lock semantics
102 	 * to the lock validator by explicitly managing
103 	 * the slock as a lock variant (in addition to
104 	 * the slock itself):
105 	 */
106 #ifdef CONFIG_DEBUG_LOCK_ALLOC
107 	struct lockdep_map dep_map;
108 #endif
109 } socket_lock_t;
110 
111 struct sock;
112 struct proto;
113 struct net;
114 
115 typedef __u32 __bitwise __portpair;
116 typedef __u64 __bitwise __addrpair;
117 
118 /**
119  *	struct sock_common - minimal network layer representation of sockets
120  *	@skc_daddr: Foreign IPv4 addr
121  *	@skc_rcv_saddr: Bound local IPv4 addr
122  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
123  *	@skc_hash: hash value used with various protocol lookup tables
124  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
125  *	@skc_dport: placeholder for inet_dport/tw_dport
126  *	@skc_num: placeholder for inet_num/tw_num
127  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
128  *	@skc_family: network address family
129  *	@skc_state: Connection state
130  *	@skc_reuse: %SO_REUSEADDR setting
131  *	@skc_reuseport: %SO_REUSEPORT setting
132  *	@skc_ipv6only: socket is IPV6 only
133  *	@skc_net_refcnt: socket is using net ref counting
134  *	@skc_bound_dev_if: bound device index if != 0
135  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
136  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
137  *	@skc_prot: protocol handlers inside a network family
138  *	@skc_net: reference to the network namespace of this socket
139  *	@skc_v6_daddr: IPV6 destination address
140  *	@skc_v6_rcv_saddr: IPV6 source address
141  *	@skc_cookie: socket's cookie value
142  *	@skc_node: main hash linkage for various protocol lookup tables
143  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
144  *	@skc_tx_queue_mapping: tx queue number for this connection
145  *	@skc_rx_queue_mapping: rx queue number for this connection
146  *	@skc_flags: place holder for sk_flags
147  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
148  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
149  *	@skc_listener: connection request listener socket (aka rsk_listener)
150  *		[union with @skc_flags]
151  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
152  *		[union with @skc_flags]
153  *	@skc_incoming_cpu: record/match cpu processing incoming packets
154  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
155  *		[union with @skc_incoming_cpu]
156  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
157  *		[union with @skc_incoming_cpu]
158  *	@skc_refcnt: reference count
159  *
160  *	This is the minimal network layer representation of sockets, the header
161  *	for struct sock and struct inet_timewait_sock.
162  */
163 struct sock_common {
164 	union {
165 		__addrpair	skc_addrpair;
166 		struct {
167 			__be32	skc_daddr;
168 			__be32	skc_rcv_saddr;
169 		};
170 	};
171 	union  {
172 		unsigned int	skc_hash;
173 		__u16		skc_u16hashes[2];
174 	};
175 	/* skc_dport && skc_num must be grouped as well */
176 	union {
177 		__portpair	skc_portpair;
178 		struct {
179 			__be16	skc_dport;
180 			__u16	skc_num;
181 		};
182 	};
183 
184 	unsigned short		skc_family;
185 	volatile unsigned char	skc_state;
186 	unsigned char		skc_reuse:4;
187 	unsigned char		skc_reuseport:1;
188 	unsigned char		skc_ipv6only:1;
189 	unsigned char		skc_net_refcnt:1;
190 	int			skc_bound_dev_if;
191 	union {
192 		struct hlist_node	skc_bind_node;
193 		struct hlist_node	skc_portaddr_node;
194 	};
195 	struct proto		*skc_prot;
196 	possible_net_t		skc_net;
197 
198 #if IS_ENABLED(CONFIG_IPV6)
199 	struct in6_addr		skc_v6_daddr;
200 	struct in6_addr		skc_v6_rcv_saddr;
201 #endif
202 
203 	atomic64_t		skc_cookie;
204 
205 	/* following fields are padding to force
206 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
207 	 * assuming IPV6 is enabled. We use this padding differently
208 	 * for different kind of 'sockets'
209 	 */
210 	union {
211 		unsigned long	skc_flags;
212 		struct sock	*skc_listener; /* request_sock */
213 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
214 	};
215 	/*
216 	 * fields between dontcopy_begin/dontcopy_end
217 	 * are not copied in sock_copy()
218 	 */
219 	/* private: */
220 	int			skc_dontcopy_begin[0];
221 	/* public: */
222 	union {
223 		struct hlist_node	skc_node;
224 		struct hlist_nulls_node skc_nulls_node;
225 	};
226 	unsigned short		skc_tx_queue_mapping;
227 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
228 	unsigned short		skc_rx_queue_mapping;
229 #endif
230 	union {
231 		int		skc_incoming_cpu;
232 		u32		skc_rcv_wnd;
233 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
234 	};
235 
236 	refcount_t		skc_refcnt;
237 	/* private: */
238 	int                     skc_dontcopy_end[0];
239 	union {
240 		u32		skc_rxhash;
241 		u32		skc_window_clamp;
242 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
243 	};
244 	/* public: */
245 };
246 
247 struct bpf_local_storage;
248 struct sk_filter;
249 
250 /**
251   *	struct sock - network layer representation of sockets
252   *	@__sk_common: shared layout with inet_timewait_sock
253   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
254   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
255   *	@sk_lock:	synchronizer
256   *	@sk_kern_sock: True if sock is using kernel lock classes
257   *	@sk_rcvbuf: size of receive buffer in bytes
258   *	@sk_wq: sock wait queue and async head
259   *	@sk_rx_dst: receive input route used by early demux
260   *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
261   *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
262   *	@sk_dst_cache: destination cache
263   *	@sk_dst_pending_confirm: need to confirm neighbour
264   *	@sk_policy: flow policy
265   *	@sk_receive_queue: incoming packets
266   *	@sk_wmem_alloc: transmit queue bytes committed
267   *	@sk_tsq_flags: TCP Small Queues flags
268   *	@sk_write_queue: Packet sending queue
269   *	@sk_omem_alloc: "o" is "option" or "other"
270   *	@sk_wmem_queued: persistent queue size
271   *	@sk_forward_alloc: space allocated forward
272   *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
273   *	@sk_napi_id: id of the last napi context to receive data for sk
274   *	@sk_ll_usec: usecs to busypoll when there is no data
275   *	@sk_allocation: allocation mode
276   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
277   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
278   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
279   *	@sk_sndbuf: size of send buffer in bytes
280   *	@__sk_flags_offset: empty field used to determine location of bitfield
281   *	@sk_padding: unused element for alignment
282   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
283   *	@sk_no_check_rx: allow zero checksum in RX packets
284   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
285   *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
286   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
287   *	@sk_gso_max_size: Maximum GSO segment size to build
288   *	@sk_gso_max_segs: Maximum number of GSO segments
289   *	@sk_pacing_shift: scaling factor for TCP Small Queues
290   *	@sk_lingertime: %SO_LINGER l_linger setting
291   *	@sk_backlog: always used with the per-socket spinlock held
292   *	@sk_callback_lock: used with the callbacks in the end of this struct
293   *	@sk_error_queue: rarely used
294   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
295   *			  IPV6_ADDRFORM for instance)
296   *	@sk_err: last error
297   *	@sk_err_soft: errors that don't cause failure but are the cause of a
298   *		      persistent failure not just 'timed out'
299   *	@sk_drops: raw/udp drops counter
300   *	@sk_ack_backlog: current listen backlog
301   *	@sk_max_ack_backlog: listen backlog set in listen()
302   *	@sk_uid: user id of owner
303   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
304   *	@sk_busy_poll_budget: napi processing budget when busypolling
305   *	@sk_priority: %SO_PRIORITY setting
306   *	@sk_type: socket type (%SOCK_STREAM, etc)
307   *	@sk_protocol: which protocol this socket belongs in this network family
308   *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
309   *	@sk_peer_pid: &struct pid for this socket's peer
310   *	@sk_peer_cred: %SO_PEERCRED setting
311   *	@sk_rcvlowat: %SO_RCVLOWAT setting
312   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
313   *	@sk_sndtimeo: %SO_SNDTIMEO setting
314   *	@sk_txhash: computed flow hash for use on transmit
315   *	@sk_txrehash: enable TX hash rethink
316   *	@sk_filter: socket filtering instructions
317   *	@sk_timer: sock cleanup timer
318   *	@sk_stamp: time stamp of last packet received
319   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
320   *	@sk_tsflags: SO_TIMESTAMPING flags
321   *	@sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
322   *			   Sockets that can be used under memory reclaim should
323   *			   set this to false.
324   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
325   *	              for timestamping
326   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
327   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
328   *	@sk_socket: Identd and reporting IO signals
329   *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
330   *	@sk_frag: cached page frag
331   *	@sk_peek_off: current peek_offset value
332   *	@sk_send_head: front of stuff to transmit
333   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
334   *	@sk_security: used by security modules
335   *	@sk_mark: generic packet mark
336   *	@sk_cgrp_data: cgroup data for this cgroup
337   *	@sk_memcg: this socket's memory cgroup association
338   *	@sk_write_pending: a write to stream socket waits to start
339   *	@sk_disconnects: number of disconnect operations performed on this sock
340   *	@sk_state_change: callback to indicate change in the state of the sock
341   *	@sk_data_ready: callback to indicate there is data to be processed
342   *	@sk_write_space: callback to indicate there is bf sending space available
343   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
344   *	@sk_backlog_rcv: callback to process the backlog
345   *	@sk_validate_xmit_skb: ptr to an optional validate function
346   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
347   *	@sk_reuseport_cb: reuseport group container
348   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
349   *	@sk_rcu: used during RCU grace period
350   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
351   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
352   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
353   *	@sk_txtime_unused: unused txtime flags
354   *	@ns_tracker: tracker for netns reference
355   *	@sk_bind2_node: bind node in the bhash2 table
356   */
357 struct sock {
358 	/*
359 	 * Now struct inet_timewait_sock also uses sock_common, so please just
360 	 * don't add nothing before this first member (__sk_common) --acme
361 	 */
362 	struct sock_common	__sk_common;
363 #define sk_node			__sk_common.skc_node
364 #define sk_nulls_node		__sk_common.skc_nulls_node
365 #define sk_refcnt		__sk_common.skc_refcnt
366 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
367 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
368 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
369 #endif
370 
371 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
372 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
373 #define sk_hash			__sk_common.skc_hash
374 #define sk_portpair		__sk_common.skc_portpair
375 #define sk_num			__sk_common.skc_num
376 #define sk_dport		__sk_common.skc_dport
377 #define sk_addrpair		__sk_common.skc_addrpair
378 #define sk_daddr		__sk_common.skc_daddr
379 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
380 #define sk_family		__sk_common.skc_family
381 #define sk_state		__sk_common.skc_state
382 #define sk_reuse		__sk_common.skc_reuse
383 #define sk_reuseport		__sk_common.skc_reuseport
384 #define sk_ipv6only		__sk_common.skc_ipv6only
385 #define sk_net_refcnt		__sk_common.skc_net_refcnt
386 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
387 #define sk_bind_node		__sk_common.skc_bind_node
388 #define sk_prot			__sk_common.skc_prot
389 #define sk_net			__sk_common.skc_net
390 #define sk_v6_daddr		__sk_common.skc_v6_daddr
391 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
392 #define sk_cookie		__sk_common.skc_cookie
393 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
394 #define sk_flags		__sk_common.skc_flags
395 #define sk_rxhash		__sk_common.skc_rxhash
396 
397 	/* early demux fields */
398 	struct dst_entry __rcu	*sk_rx_dst;
399 	int			sk_rx_dst_ifindex;
400 	u32			sk_rx_dst_cookie;
401 
402 	socket_lock_t		sk_lock;
403 	atomic_t		sk_drops;
404 	int			sk_rcvlowat;
405 	struct sk_buff_head	sk_error_queue;
406 	struct sk_buff_head	sk_receive_queue;
407 	/*
408 	 * The backlog queue is special, it is always used with
409 	 * the per-socket spinlock held and requires low latency
410 	 * access. Therefore we special case it's implementation.
411 	 * Note : rmem_alloc is in this structure to fill a hole
412 	 * on 64bit arches, not because its logically part of
413 	 * backlog.
414 	 */
415 	struct {
416 		atomic_t	rmem_alloc;
417 		int		len;
418 		struct sk_buff	*head;
419 		struct sk_buff	*tail;
420 	} sk_backlog;
421 
422 #define sk_rmem_alloc sk_backlog.rmem_alloc
423 
424 	int			sk_forward_alloc;
425 	u32			sk_reserved_mem;
426 #ifdef CONFIG_NET_RX_BUSY_POLL
427 	unsigned int		sk_ll_usec;
428 	/* ===== mostly read cache line ===== */
429 	unsigned int		sk_napi_id;
430 #endif
431 	int			sk_rcvbuf;
432 	int			sk_disconnects;
433 
434 	struct sk_filter __rcu	*sk_filter;
435 	union {
436 		struct socket_wq __rcu	*sk_wq;
437 		/* private: */
438 		struct socket_wq	*sk_wq_raw;
439 		/* public: */
440 	};
441 #ifdef CONFIG_XFRM
442 	struct xfrm_policy __rcu *sk_policy[2];
443 #endif
444 
445 	struct dst_entry __rcu	*sk_dst_cache;
446 	atomic_t		sk_omem_alloc;
447 	int			sk_sndbuf;
448 
449 	/* ===== cache line for TX ===== */
450 	int			sk_wmem_queued;
451 	refcount_t		sk_wmem_alloc;
452 	unsigned long		sk_tsq_flags;
453 	union {
454 		struct sk_buff	*sk_send_head;
455 		struct rb_root	tcp_rtx_queue;
456 	};
457 	struct sk_buff_head	sk_write_queue;
458 	__s32			sk_peek_off;
459 	int			sk_write_pending;
460 	__u32			sk_dst_pending_confirm;
461 	u32			sk_pacing_status; /* see enum sk_pacing */
462 	long			sk_sndtimeo;
463 	struct timer_list	sk_timer;
464 	__u32			sk_priority;
465 	__u32			sk_mark;
466 	unsigned long		sk_pacing_rate; /* bytes per second */
467 	unsigned long		sk_max_pacing_rate;
468 	struct page_frag	sk_frag;
469 	netdev_features_t	sk_route_caps;
470 	int			sk_gso_type;
471 	unsigned int		sk_gso_max_size;
472 	gfp_t			sk_allocation;
473 	__u32			sk_txhash;
474 
475 	/*
476 	 * Because of non atomicity rules, all
477 	 * changes are protected by socket lock.
478 	 */
479 	u8			sk_gso_disabled : 1,
480 				sk_kern_sock : 1,
481 				sk_no_check_tx : 1,
482 				sk_no_check_rx : 1,
483 				sk_userlocks : 4;
484 	u8			sk_pacing_shift;
485 	u16			sk_type;
486 	u16			sk_protocol;
487 	u16			sk_gso_max_segs;
488 	unsigned long	        sk_lingertime;
489 	struct proto		*sk_prot_creator;
490 	rwlock_t		sk_callback_lock;
491 	int			sk_err,
492 				sk_err_soft;
493 	u32			sk_ack_backlog;
494 	u32			sk_max_ack_backlog;
495 	kuid_t			sk_uid;
496 	u8			sk_txrehash;
497 #ifdef CONFIG_NET_RX_BUSY_POLL
498 	u8			sk_prefer_busy_poll;
499 	u16			sk_busy_poll_budget;
500 #endif
501 	spinlock_t		sk_peer_lock;
502 	int			sk_bind_phc;
503 	struct pid		*sk_peer_pid;
504 	const struct cred	*sk_peer_cred;
505 
506 	long			sk_rcvtimeo;
507 	ktime_t			sk_stamp;
508 #if BITS_PER_LONG==32
509 	seqlock_t		sk_stamp_seq;
510 #endif
511 	atomic_t		sk_tskey;
512 	atomic_t		sk_zckey;
513 	u32			sk_tsflags;
514 	u8			sk_shutdown;
515 
516 	u8			sk_clockid;
517 	u8			sk_txtime_deadline_mode : 1,
518 				sk_txtime_report_errors : 1,
519 				sk_txtime_unused : 6;
520 	bool			sk_use_task_frag;
521 
522 	struct socket		*sk_socket;
523 	void			*sk_user_data;
524 #ifdef CONFIG_SECURITY
525 	void			*sk_security;
526 #endif
527 	struct sock_cgroup_data	sk_cgrp_data;
528 	struct mem_cgroup	*sk_memcg;
529 	void			(*sk_state_change)(struct sock *sk);
530 	void			(*sk_data_ready)(struct sock *sk);
531 	void			(*sk_write_space)(struct sock *sk);
532 	void			(*sk_error_report)(struct sock *sk);
533 	int			(*sk_backlog_rcv)(struct sock *sk,
534 						  struct sk_buff *skb);
535 #ifdef CONFIG_SOCK_VALIDATE_XMIT
536 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
537 							struct net_device *dev,
538 							struct sk_buff *skb);
539 #endif
540 	void                    (*sk_destruct)(struct sock *sk);
541 	struct sock_reuseport __rcu	*sk_reuseport_cb;
542 #ifdef CONFIG_BPF_SYSCALL
543 	struct bpf_local_storage __rcu	*sk_bpf_storage;
544 #endif
545 	struct rcu_head		sk_rcu;
546 	netns_tracker		ns_tracker;
547 	struct hlist_node	sk_bind2_node;
548 };
549 
550 enum sk_pacing {
551 	SK_PACING_NONE		= 0,
552 	SK_PACING_NEEDED	= 1,
553 	SK_PACING_FQ		= 2,
554 };
555 
556 /* flag bits in sk_user_data
557  *
558  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
559  *   not be suitable for copying when cloning the socket. For instance,
560  *   it can point to a reference counted object. sk_user_data bottom
561  *   bit is set if pointer must not be copied.
562  *
563  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
564  *   managed/owned by a BPF reuseport array. This bit should be set
565  *   when sk_user_data's sk is added to the bpf's reuseport_array.
566  *
567  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
568  *   sk_user_data points to psock type. This bit should be set
569  *   when sk_user_data is assigned to a psock object.
570  */
571 #define SK_USER_DATA_NOCOPY	1UL
572 #define SK_USER_DATA_BPF	2UL
573 #define SK_USER_DATA_PSOCK	4UL
574 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
575 				  SK_USER_DATA_PSOCK)
576 
577 /**
578  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
579  * @sk: socket
580  */
581 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
582 {
583 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
584 }
585 
586 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
587 
588 /**
589  * __locked_read_sk_user_data_with_flags - return the pointer
590  * only if argument flags all has been set in sk_user_data. Otherwise
591  * return NULL
592  *
593  * @sk: socket
594  * @flags: flag bits
595  *
596  * The caller must be holding sk->sk_callback_lock.
597  */
598 static inline void *
599 __locked_read_sk_user_data_with_flags(const struct sock *sk,
600 				      uintptr_t flags)
601 {
602 	uintptr_t sk_user_data =
603 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
604 						 lockdep_is_held(&sk->sk_callback_lock));
605 
606 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
607 
608 	if ((sk_user_data & flags) == flags)
609 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
610 	return NULL;
611 }
612 
613 /**
614  * __rcu_dereference_sk_user_data_with_flags - return the pointer
615  * only if argument flags all has been set in sk_user_data. Otherwise
616  * return NULL
617  *
618  * @sk: socket
619  * @flags: flag bits
620  */
621 static inline void *
622 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
623 					  uintptr_t flags)
624 {
625 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
626 
627 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
628 
629 	if ((sk_user_data & flags) == flags)
630 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
631 	return NULL;
632 }
633 
634 #define rcu_dereference_sk_user_data(sk)				\
635 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
636 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
637 ({									\
638 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
639 		  __tmp2 = (uintptr_t)(flags);				\
640 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
641 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
642 	rcu_assign_pointer(__sk_user_data((sk)),			\
643 			   __tmp1 | __tmp2);				\
644 })
645 #define rcu_assign_sk_user_data(sk, ptr)				\
646 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
647 
648 static inline
649 struct net *sock_net(const struct sock *sk)
650 {
651 	return read_pnet(&sk->sk_net);
652 }
653 
654 static inline
655 void sock_net_set(struct sock *sk, struct net *net)
656 {
657 	write_pnet(&sk->sk_net, net);
658 }
659 
660 /*
661  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
662  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
663  * on a socket means that the socket will reuse everybody else's port
664  * without looking at the other's sk_reuse value.
665  */
666 
667 #define SK_NO_REUSE	0
668 #define SK_CAN_REUSE	1
669 #define SK_FORCE_REUSE	2
670 
671 int sk_set_peek_off(struct sock *sk, int val);
672 
673 static inline int sk_peek_offset(const struct sock *sk, int flags)
674 {
675 	if (unlikely(flags & MSG_PEEK)) {
676 		return READ_ONCE(sk->sk_peek_off);
677 	}
678 
679 	return 0;
680 }
681 
682 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
683 {
684 	s32 off = READ_ONCE(sk->sk_peek_off);
685 
686 	if (unlikely(off >= 0)) {
687 		off = max_t(s32, off - val, 0);
688 		WRITE_ONCE(sk->sk_peek_off, off);
689 	}
690 }
691 
692 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
693 {
694 	sk_peek_offset_bwd(sk, -val);
695 }
696 
697 /*
698  * Hashed lists helper routines
699  */
700 static inline struct sock *sk_entry(const struct hlist_node *node)
701 {
702 	return hlist_entry(node, struct sock, sk_node);
703 }
704 
705 static inline struct sock *__sk_head(const struct hlist_head *head)
706 {
707 	return hlist_entry(head->first, struct sock, sk_node);
708 }
709 
710 static inline struct sock *sk_head(const struct hlist_head *head)
711 {
712 	return hlist_empty(head) ? NULL : __sk_head(head);
713 }
714 
715 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
716 {
717 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
718 }
719 
720 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
721 {
722 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
723 }
724 
725 static inline struct sock *sk_next(const struct sock *sk)
726 {
727 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
728 }
729 
730 static inline struct sock *sk_nulls_next(const struct sock *sk)
731 {
732 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
733 		hlist_nulls_entry(sk->sk_nulls_node.next,
734 				  struct sock, sk_nulls_node) :
735 		NULL;
736 }
737 
738 static inline bool sk_unhashed(const struct sock *sk)
739 {
740 	return hlist_unhashed(&sk->sk_node);
741 }
742 
743 static inline bool sk_hashed(const struct sock *sk)
744 {
745 	return !sk_unhashed(sk);
746 }
747 
748 static inline void sk_node_init(struct hlist_node *node)
749 {
750 	node->pprev = NULL;
751 }
752 
753 static inline void __sk_del_node(struct sock *sk)
754 {
755 	__hlist_del(&sk->sk_node);
756 }
757 
758 /* NB: equivalent to hlist_del_init_rcu */
759 static inline bool __sk_del_node_init(struct sock *sk)
760 {
761 	if (sk_hashed(sk)) {
762 		__sk_del_node(sk);
763 		sk_node_init(&sk->sk_node);
764 		return true;
765 	}
766 	return false;
767 }
768 
769 /* Grab socket reference count. This operation is valid only
770    when sk is ALREADY grabbed f.e. it is found in hash table
771    or a list and the lookup is made under lock preventing hash table
772    modifications.
773  */
774 
775 static __always_inline void sock_hold(struct sock *sk)
776 {
777 	refcount_inc(&sk->sk_refcnt);
778 }
779 
780 /* Ungrab socket in the context, which assumes that socket refcnt
781    cannot hit zero, f.e. it is true in context of any socketcall.
782  */
783 static __always_inline void __sock_put(struct sock *sk)
784 {
785 	refcount_dec(&sk->sk_refcnt);
786 }
787 
788 static inline bool sk_del_node_init(struct sock *sk)
789 {
790 	bool rc = __sk_del_node_init(sk);
791 
792 	if (rc) {
793 		/* paranoid for a while -acme */
794 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
795 		__sock_put(sk);
796 	}
797 	return rc;
798 }
799 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
800 
801 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
802 {
803 	if (sk_hashed(sk)) {
804 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
805 		return true;
806 	}
807 	return false;
808 }
809 
810 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
811 {
812 	bool rc = __sk_nulls_del_node_init_rcu(sk);
813 
814 	if (rc) {
815 		/* paranoid for a while -acme */
816 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
817 		__sock_put(sk);
818 	}
819 	return rc;
820 }
821 
822 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
823 {
824 	hlist_add_head(&sk->sk_node, list);
825 }
826 
827 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
828 {
829 	sock_hold(sk);
830 	__sk_add_node(sk, list);
831 }
832 
833 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
834 {
835 	sock_hold(sk);
836 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
837 	    sk->sk_family == AF_INET6)
838 		hlist_add_tail_rcu(&sk->sk_node, list);
839 	else
840 		hlist_add_head_rcu(&sk->sk_node, list);
841 }
842 
843 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
844 {
845 	sock_hold(sk);
846 	hlist_add_tail_rcu(&sk->sk_node, list);
847 }
848 
849 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
850 {
851 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
852 }
853 
854 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
855 {
856 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
857 }
858 
859 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
860 {
861 	sock_hold(sk);
862 	__sk_nulls_add_node_rcu(sk, list);
863 }
864 
865 static inline void __sk_del_bind_node(struct sock *sk)
866 {
867 	__hlist_del(&sk->sk_bind_node);
868 }
869 
870 static inline void sk_add_bind_node(struct sock *sk,
871 					struct hlist_head *list)
872 {
873 	hlist_add_head(&sk->sk_bind_node, list);
874 }
875 
876 static inline void __sk_del_bind2_node(struct sock *sk)
877 {
878 	__hlist_del(&sk->sk_bind2_node);
879 }
880 
881 static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
882 {
883 	hlist_add_head(&sk->sk_bind2_node, list);
884 }
885 
886 #define sk_for_each(__sk, list) \
887 	hlist_for_each_entry(__sk, list, sk_node)
888 #define sk_for_each_rcu(__sk, list) \
889 	hlist_for_each_entry_rcu(__sk, list, sk_node)
890 #define sk_nulls_for_each(__sk, node, list) \
891 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
892 #define sk_nulls_for_each_rcu(__sk, node, list) \
893 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
894 #define sk_for_each_from(__sk) \
895 	hlist_for_each_entry_from(__sk, sk_node)
896 #define sk_nulls_for_each_from(__sk, node) \
897 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
898 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
899 #define sk_for_each_safe(__sk, tmp, list) \
900 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
901 #define sk_for_each_bound(__sk, list) \
902 	hlist_for_each_entry(__sk, list, sk_bind_node)
903 #define sk_for_each_bound_bhash2(__sk, list) \
904 	hlist_for_each_entry(__sk, list, sk_bind2_node)
905 
906 /**
907  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
908  * @tpos:	the type * to use as a loop cursor.
909  * @pos:	the &struct hlist_node to use as a loop cursor.
910  * @head:	the head for your list.
911  * @offset:	offset of hlist_node within the struct.
912  *
913  */
914 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
915 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
916 	     pos != NULL &&						       \
917 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
918 	     pos = rcu_dereference(hlist_next_rcu(pos)))
919 
920 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
921 {
922 	/* Careful only use this in a context where these parameters
923 	 * can not change and must all be valid, such as recvmsg from
924 	 * userspace.
925 	 */
926 	return sk->sk_socket->file->f_cred->user_ns;
927 }
928 
929 /* Sock flags */
930 enum sock_flags {
931 	SOCK_DEAD,
932 	SOCK_DONE,
933 	SOCK_URGINLINE,
934 	SOCK_KEEPOPEN,
935 	SOCK_LINGER,
936 	SOCK_DESTROY,
937 	SOCK_BROADCAST,
938 	SOCK_TIMESTAMP,
939 	SOCK_ZAPPED,
940 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
941 	SOCK_DBG, /* %SO_DEBUG setting */
942 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
943 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
944 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
945 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
946 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
947 	SOCK_FASYNC, /* fasync() active */
948 	SOCK_RXQ_OVFL,
949 	SOCK_ZEROCOPY, /* buffers from userspace */
950 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
951 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
952 		     * Will use last 4 bytes of packet sent from
953 		     * user-space instead.
954 		     */
955 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
956 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
957 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
958 	SOCK_TXTIME,
959 	SOCK_XDP, /* XDP is attached */
960 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
961 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
962 };
963 
964 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
965 
966 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
967 {
968 	nsk->sk_flags = osk->sk_flags;
969 }
970 
971 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
972 {
973 	__set_bit(flag, &sk->sk_flags);
974 }
975 
976 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
977 {
978 	__clear_bit(flag, &sk->sk_flags);
979 }
980 
981 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
982 				     int valbool)
983 {
984 	if (valbool)
985 		sock_set_flag(sk, bit);
986 	else
987 		sock_reset_flag(sk, bit);
988 }
989 
990 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
991 {
992 	return test_bit(flag, &sk->sk_flags);
993 }
994 
995 #ifdef CONFIG_NET
996 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
997 static inline int sk_memalloc_socks(void)
998 {
999 	return static_branch_unlikely(&memalloc_socks_key);
1000 }
1001 
1002 void __receive_sock(struct file *file);
1003 #else
1004 
1005 static inline int sk_memalloc_socks(void)
1006 {
1007 	return 0;
1008 }
1009 
1010 static inline void __receive_sock(struct file *file)
1011 { }
1012 #endif
1013 
1014 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1015 {
1016 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1017 }
1018 
1019 static inline void sk_acceptq_removed(struct sock *sk)
1020 {
1021 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1022 }
1023 
1024 static inline void sk_acceptq_added(struct sock *sk)
1025 {
1026 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1027 }
1028 
1029 /* Note: If you think the test should be:
1030  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1031  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1032  */
1033 static inline bool sk_acceptq_is_full(const struct sock *sk)
1034 {
1035 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1036 }
1037 
1038 /*
1039  * Compute minimal free write space needed to queue new packets.
1040  */
1041 static inline int sk_stream_min_wspace(const struct sock *sk)
1042 {
1043 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1044 }
1045 
1046 static inline int sk_stream_wspace(const struct sock *sk)
1047 {
1048 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1049 }
1050 
1051 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1052 {
1053 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1054 }
1055 
1056 static inline void sk_forward_alloc_add(struct sock *sk, int val)
1057 {
1058 	/* Paired with lockless reads of sk->sk_forward_alloc */
1059 	WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val);
1060 }
1061 
1062 void sk_stream_write_space(struct sock *sk);
1063 
1064 /* OOB backlog add */
1065 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1066 {
1067 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1068 	skb_dst_force(skb);
1069 
1070 	if (!sk->sk_backlog.tail)
1071 		WRITE_ONCE(sk->sk_backlog.head, skb);
1072 	else
1073 		sk->sk_backlog.tail->next = skb;
1074 
1075 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1076 	skb->next = NULL;
1077 }
1078 
1079 /*
1080  * Take into account size of receive queue and backlog queue
1081  * Do not take into account this skb truesize,
1082  * to allow even a single big packet to come.
1083  */
1084 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1085 {
1086 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1087 
1088 	return qsize > limit;
1089 }
1090 
1091 /* The per-socket spinlock must be held here. */
1092 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1093 					      unsigned int limit)
1094 {
1095 	if (sk_rcvqueues_full(sk, limit))
1096 		return -ENOBUFS;
1097 
1098 	/*
1099 	 * If the skb was allocated from pfmemalloc reserves, only
1100 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1101 	 * helping free memory
1102 	 */
1103 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1104 		return -ENOMEM;
1105 
1106 	__sk_add_backlog(sk, skb);
1107 	sk->sk_backlog.len += skb->truesize;
1108 	return 0;
1109 }
1110 
1111 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1112 
1113 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1114 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1115 
1116 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1117 {
1118 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1119 		return __sk_backlog_rcv(sk, skb);
1120 
1121 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1122 				  tcp_v6_do_rcv,
1123 				  tcp_v4_do_rcv,
1124 				  sk, skb);
1125 }
1126 
1127 static inline void sk_incoming_cpu_update(struct sock *sk)
1128 {
1129 	int cpu = raw_smp_processor_id();
1130 
1131 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1132 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1133 }
1134 
1135 static inline void sock_rps_record_flow_hash(__u32 hash)
1136 {
1137 #ifdef CONFIG_RPS
1138 	struct rps_sock_flow_table *sock_flow_table;
1139 
1140 	rcu_read_lock();
1141 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1142 	rps_record_sock_flow(sock_flow_table, hash);
1143 	rcu_read_unlock();
1144 #endif
1145 }
1146 
1147 static inline void sock_rps_record_flow(const struct sock *sk)
1148 {
1149 #ifdef CONFIG_RPS
1150 	if (static_branch_unlikely(&rfs_needed)) {
1151 		/* Reading sk->sk_rxhash might incur an expensive cache line
1152 		 * miss.
1153 		 *
1154 		 * TCP_ESTABLISHED does cover almost all states where RFS
1155 		 * might be useful, and is cheaper [1] than testing :
1156 		 *	IPv4: inet_sk(sk)->inet_daddr
1157 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1158 		 * OR	an additional socket flag
1159 		 * [1] : sk_state and sk_prot are in the same cache line.
1160 		 */
1161 		if (sk->sk_state == TCP_ESTABLISHED) {
1162 			/* This READ_ONCE() is paired with the WRITE_ONCE()
1163 			 * from sock_rps_save_rxhash() and sock_rps_reset_rxhash().
1164 			 */
1165 			sock_rps_record_flow_hash(READ_ONCE(sk->sk_rxhash));
1166 		}
1167 	}
1168 #endif
1169 }
1170 
1171 static inline void sock_rps_save_rxhash(struct sock *sk,
1172 					const struct sk_buff *skb)
1173 {
1174 #ifdef CONFIG_RPS
1175 	/* The following WRITE_ONCE() is paired with the READ_ONCE()
1176 	 * here, and another one in sock_rps_record_flow().
1177 	 */
1178 	if (unlikely(READ_ONCE(sk->sk_rxhash) != skb->hash))
1179 		WRITE_ONCE(sk->sk_rxhash, skb->hash);
1180 #endif
1181 }
1182 
1183 static inline void sock_rps_reset_rxhash(struct sock *sk)
1184 {
1185 #ifdef CONFIG_RPS
1186 	/* Paired with READ_ONCE() in sock_rps_record_flow() */
1187 	WRITE_ONCE(sk->sk_rxhash, 0);
1188 #endif
1189 }
1190 
1191 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1192 	({	int __rc, __dis = __sk->sk_disconnects;			\
1193 		release_sock(__sk);					\
1194 		__rc = __condition;					\
1195 		if (!__rc) {						\
1196 			*(__timeo) = wait_woken(__wait,			\
1197 						TASK_INTERRUPTIBLE,	\
1198 						*(__timeo));		\
1199 		}							\
1200 		sched_annotate_sleep();					\
1201 		lock_sock(__sk);					\
1202 		__rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
1203 		__rc;							\
1204 	})
1205 
1206 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1207 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1208 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1209 int sk_stream_error(struct sock *sk, int flags, int err);
1210 void sk_stream_kill_queues(struct sock *sk);
1211 void sk_set_memalloc(struct sock *sk);
1212 void sk_clear_memalloc(struct sock *sk);
1213 
1214 void __sk_flush_backlog(struct sock *sk);
1215 
1216 static inline bool sk_flush_backlog(struct sock *sk)
1217 {
1218 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1219 		__sk_flush_backlog(sk);
1220 		return true;
1221 	}
1222 	return false;
1223 }
1224 
1225 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1226 
1227 struct request_sock_ops;
1228 struct timewait_sock_ops;
1229 struct inet_hashinfo;
1230 struct raw_hashinfo;
1231 struct smc_hashinfo;
1232 struct module;
1233 struct sk_psock;
1234 
1235 /*
1236  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1237  * un-modified. Special care is taken when initializing object to zero.
1238  */
1239 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1240 {
1241 	if (offsetof(struct sock, sk_node.next) != 0)
1242 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1243 	memset(&sk->sk_node.pprev, 0,
1244 	       size - offsetof(struct sock, sk_node.pprev));
1245 }
1246 
1247 /* Networking protocol blocks we attach to sockets.
1248  * socket layer -> transport layer interface
1249  */
1250 struct proto {
1251 	void			(*close)(struct sock *sk,
1252 					long timeout);
1253 	int			(*pre_connect)(struct sock *sk,
1254 					struct sockaddr *uaddr,
1255 					int addr_len);
1256 	int			(*connect)(struct sock *sk,
1257 					struct sockaddr *uaddr,
1258 					int addr_len);
1259 	int			(*disconnect)(struct sock *sk, int flags);
1260 
1261 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1262 					  bool kern);
1263 
1264 	int			(*ioctl)(struct sock *sk, int cmd,
1265 					 int *karg);
1266 	int			(*init)(struct sock *sk);
1267 	void			(*destroy)(struct sock *sk);
1268 	void			(*shutdown)(struct sock *sk, int how);
1269 	int			(*setsockopt)(struct sock *sk, int level,
1270 					int optname, sockptr_t optval,
1271 					unsigned int optlen);
1272 	int			(*getsockopt)(struct sock *sk, int level,
1273 					int optname, char __user *optval,
1274 					int __user *option);
1275 	void			(*keepalive)(struct sock *sk, int valbool);
1276 #ifdef CONFIG_COMPAT
1277 	int			(*compat_ioctl)(struct sock *sk,
1278 					unsigned int cmd, unsigned long arg);
1279 #endif
1280 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1281 					   size_t len);
1282 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1283 					   size_t len, int flags, int *addr_len);
1284 	void			(*splice_eof)(struct socket *sock);
1285 	int			(*bind)(struct sock *sk,
1286 					struct sockaddr *addr, int addr_len);
1287 	int			(*bind_add)(struct sock *sk,
1288 					struct sockaddr *addr, int addr_len);
1289 
1290 	int			(*backlog_rcv) (struct sock *sk,
1291 						struct sk_buff *skb);
1292 	bool			(*bpf_bypass_getsockopt)(int level,
1293 							 int optname);
1294 
1295 	void		(*release_cb)(struct sock *sk);
1296 
1297 	/* Keeping track of sk's, looking them up, and port selection methods. */
1298 	int			(*hash)(struct sock *sk);
1299 	void			(*unhash)(struct sock *sk);
1300 	void			(*rehash)(struct sock *sk);
1301 	int			(*get_port)(struct sock *sk, unsigned short snum);
1302 	void			(*put_port)(struct sock *sk);
1303 #ifdef CONFIG_BPF_SYSCALL
1304 	int			(*psock_update_sk_prot)(struct sock *sk,
1305 							struct sk_psock *psock,
1306 							bool restore);
1307 #endif
1308 
1309 	/* Keeping track of sockets in use */
1310 #ifdef CONFIG_PROC_FS
1311 	unsigned int		inuse_idx;
1312 #endif
1313 
1314 #if IS_ENABLED(CONFIG_MPTCP)
1315 	int			(*forward_alloc_get)(const struct sock *sk);
1316 #endif
1317 
1318 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1319 	bool			(*sock_is_readable)(struct sock *sk);
1320 	/* Memory pressure */
1321 	void			(*enter_memory_pressure)(struct sock *sk);
1322 	void			(*leave_memory_pressure)(struct sock *sk);
1323 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1324 	int  __percpu		*per_cpu_fw_alloc;
1325 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1326 
1327 	/*
1328 	 * Pressure flag: try to collapse.
1329 	 * Technical note: it is used by multiple contexts non atomically.
1330 	 * Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
1331 	 * All the __sk_mem_schedule() is of this nature: accounting
1332 	 * is strict, actions are advisory and have some latency.
1333 	 */
1334 	unsigned long		*memory_pressure;
1335 	long			*sysctl_mem;
1336 
1337 	int			*sysctl_wmem;
1338 	int			*sysctl_rmem;
1339 	u32			sysctl_wmem_offset;
1340 	u32			sysctl_rmem_offset;
1341 
1342 	int			max_header;
1343 	bool			no_autobind;
1344 
1345 	struct kmem_cache	*slab;
1346 	unsigned int		obj_size;
1347 	unsigned int		ipv6_pinfo_offset;
1348 	slab_flags_t		slab_flags;
1349 	unsigned int		useroffset;	/* Usercopy region offset */
1350 	unsigned int		usersize;	/* Usercopy region size */
1351 
1352 	unsigned int __percpu	*orphan_count;
1353 
1354 	struct request_sock_ops	*rsk_prot;
1355 	struct timewait_sock_ops *twsk_prot;
1356 
1357 	union {
1358 		struct inet_hashinfo	*hashinfo;
1359 		struct udp_table	*udp_table;
1360 		struct raw_hashinfo	*raw_hash;
1361 		struct smc_hashinfo	*smc_hash;
1362 	} h;
1363 
1364 	struct module		*owner;
1365 
1366 	char			name[32];
1367 
1368 	struct list_head	node;
1369 	int			(*diag_destroy)(struct sock *sk, int err);
1370 } __randomize_layout;
1371 
1372 int proto_register(struct proto *prot, int alloc_slab);
1373 void proto_unregister(struct proto *prot);
1374 int sock_load_diag_module(int family, int protocol);
1375 
1376 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1377 
1378 static inline int sk_forward_alloc_get(const struct sock *sk)
1379 {
1380 #if IS_ENABLED(CONFIG_MPTCP)
1381 	if (sk->sk_prot->forward_alloc_get)
1382 		return sk->sk_prot->forward_alloc_get(sk);
1383 #endif
1384 	return READ_ONCE(sk->sk_forward_alloc);
1385 }
1386 
1387 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1388 {
1389 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1390 		return false;
1391 
1392 	return sk->sk_prot->stream_memory_free ?
1393 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1394 				     tcp_stream_memory_free, sk, wake) : true;
1395 }
1396 
1397 static inline bool sk_stream_memory_free(const struct sock *sk)
1398 {
1399 	return __sk_stream_memory_free(sk, 0);
1400 }
1401 
1402 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1403 {
1404 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1405 	       __sk_stream_memory_free(sk, wake);
1406 }
1407 
1408 static inline bool sk_stream_is_writeable(const struct sock *sk)
1409 {
1410 	return __sk_stream_is_writeable(sk, 0);
1411 }
1412 
1413 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1414 					    struct cgroup *ancestor)
1415 {
1416 #ifdef CONFIG_SOCK_CGROUP_DATA
1417 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1418 				    ancestor);
1419 #else
1420 	return -ENOTSUPP;
1421 #endif
1422 }
1423 
1424 static inline bool sk_has_memory_pressure(const struct sock *sk)
1425 {
1426 	return sk->sk_prot->memory_pressure != NULL;
1427 }
1428 
1429 static inline bool sk_under_global_memory_pressure(const struct sock *sk)
1430 {
1431 	return sk->sk_prot->memory_pressure &&
1432 		!!READ_ONCE(*sk->sk_prot->memory_pressure);
1433 }
1434 
1435 static inline bool sk_under_memory_pressure(const struct sock *sk)
1436 {
1437 	if (!sk->sk_prot->memory_pressure)
1438 		return false;
1439 
1440 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1441 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1442 		return true;
1443 
1444 	return !!READ_ONCE(*sk->sk_prot->memory_pressure);
1445 }
1446 
1447 static inline long
1448 proto_memory_allocated(const struct proto *prot)
1449 {
1450 	return max(0L, atomic_long_read(prot->memory_allocated));
1451 }
1452 
1453 static inline long
1454 sk_memory_allocated(const struct sock *sk)
1455 {
1456 	return proto_memory_allocated(sk->sk_prot);
1457 }
1458 
1459 /* 1 MB per cpu, in page units */
1460 #define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT))
1461 extern int sysctl_mem_pcpu_rsv;
1462 
1463 static inline void proto_memory_pcpu_drain(struct proto *proto)
1464 {
1465 	int val = this_cpu_xchg(*proto->per_cpu_fw_alloc, 0);
1466 
1467 	if (val)
1468 		atomic_long_add(val, proto->memory_allocated);
1469 }
1470 
1471 static inline void
1472 sk_memory_allocated_add(const struct sock *sk, int val)
1473 {
1474 	struct proto *proto = sk->sk_prot;
1475 
1476 	val = this_cpu_add_return(*proto->per_cpu_fw_alloc, val);
1477 
1478 	if (unlikely(val >= READ_ONCE(sysctl_mem_pcpu_rsv)))
1479 		proto_memory_pcpu_drain(proto);
1480 }
1481 
1482 static inline void
1483 sk_memory_allocated_sub(const struct sock *sk, int val)
1484 {
1485 	struct proto *proto = sk->sk_prot;
1486 
1487 	val = this_cpu_sub_return(*proto->per_cpu_fw_alloc, val);
1488 
1489 	if (unlikely(val <= -READ_ONCE(sysctl_mem_pcpu_rsv)))
1490 		proto_memory_pcpu_drain(proto);
1491 }
1492 
1493 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1494 
1495 static inline void sk_sockets_allocated_dec(struct sock *sk)
1496 {
1497 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1498 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1499 }
1500 
1501 static inline void sk_sockets_allocated_inc(struct sock *sk)
1502 {
1503 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1504 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1505 }
1506 
1507 static inline u64
1508 sk_sockets_allocated_read_positive(struct sock *sk)
1509 {
1510 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1511 }
1512 
1513 static inline int
1514 proto_sockets_allocated_sum_positive(struct proto *prot)
1515 {
1516 	return percpu_counter_sum_positive(prot->sockets_allocated);
1517 }
1518 
1519 static inline bool
1520 proto_memory_pressure(struct proto *prot)
1521 {
1522 	if (!prot->memory_pressure)
1523 		return false;
1524 	return !!READ_ONCE(*prot->memory_pressure);
1525 }
1526 
1527 
1528 #ifdef CONFIG_PROC_FS
1529 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1530 struct prot_inuse {
1531 	int all;
1532 	int val[PROTO_INUSE_NR];
1533 };
1534 
1535 static inline void sock_prot_inuse_add(const struct net *net,
1536 				       const struct proto *prot, int val)
1537 {
1538 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1539 }
1540 
1541 static inline void sock_inuse_add(const struct net *net, int val)
1542 {
1543 	this_cpu_add(net->core.prot_inuse->all, val);
1544 }
1545 
1546 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1547 int sock_inuse_get(struct net *net);
1548 #else
1549 static inline void sock_prot_inuse_add(const struct net *net,
1550 				       const struct proto *prot, int val)
1551 {
1552 }
1553 
1554 static inline void sock_inuse_add(const struct net *net, int val)
1555 {
1556 }
1557 #endif
1558 
1559 
1560 /* With per-bucket locks this operation is not-atomic, so that
1561  * this version is not worse.
1562  */
1563 static inline int __sk_prot_rehash(struct sock *sk)
1564 {
1565 	sk->sk_prot->unhash(sk);
1566 	return sk->sk_prot->hash(sk);
1567 }
1568 
1569 /* About 10 seconds */
1570 #define SOCK_DESTROY_TIME (10*HZ)
1571 
1572 /* Sockets 0-1023 can't be bound to unless you are superuser */
1573 #define PROT_SOCK	1024
1574 
1575 #define SHUTDOWN_MASK	3
1576 #define RCV_SHUTDOWN	1
1577 #define SEND_SHUTDOWN	2
1578 
1579 #define SOCK_BINDADDR_LOCK	4
1580 #define SOCK_BINDPORT_LOCK	8
1581 
1582 struct socket_alloc {
1583 	struct socket socket;
1584 	struct inode vfs_inode;
1585 };
1586 
1587 static inline struct socket *SOCKET_I(struct inode *inode)
1588 {
1589 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1590 }
1591 
1592 static inline struct inode *SOCK_INODE(struct socket *socket)
1593 {
1594 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1595 }
1596 
1597 /*
1598  * Functions for memory accounting
1599  */
1600 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1601 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1602 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1603 void __sk_mem_reclaim(struct sock *sk, int amount);
1604 
1605 #define SK_MEM_SEND	0
1606 #define SK_MEM_RECV	1
1607 
1608 /* sysctl_mem values are in pages */
1609 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1610 {
1611 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1612 }
1613 
1614 static inline int sk_mem_pages(int amt)
1615 {
1616 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1617 }
1618 
1619 static inline bool sk_has_account(struct sock *sk)
1620 {
1621 	/* return true if protocol supports memory accounting */
1622 	return !!sk->sk_prot->memory_allocated;
1623 }
1624 
1625 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1626 {
1627 	int delta;
1628 
1629 	if (!sk_has_account(sk))
1630 		return true;
1631 	delta = size - sk->sk_forward_alloc;
1632 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1633 }
1634 
1635 static inline bool
1636 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1637 {
1638 	int delta;
1639 
1640 	if (!sk_has_account(sk))
1641 		return true;
1642 	delta = size - sk->sk_forward_alloc;
1643 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1644 		skb_pfmemalloc(skb);
1645 }
1646 
1647 static inline int sk_unused_reserved_mem(const struct sock *sk)
1648 {
1649 	int unused_mem;
1650 
1651 	if (likely(!sk->sk_reserved_mem))
1652 		return 0;
1653 
1654 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1655 			atomic_read(&sk->sk_rmem_alloc);
1656 
1657 	return unused_mem > 0 ? unused_mem : 0;
1658 }
1659 
1660 static inline void sk_mem_reclaim(struct sock *sk)
1661 {
1662 	int reclaimable;
1663 
1664 	if (!sk_has_account(sk))
1665 		return;
1666 
1667 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1668 
1669 	if (reclaimable >= (int)PAGE_SIZE)
1670 		__sk_mem_reclaim(sk, reclaimable);
1671 }
1672 
1673 static inline void sk_mem_reclaim_final(struct sock *sk)
1674 {
1675 	sk->sk_reserved_mem = 0;
1676 	sk_mem_reclaim(sk);
1677 }
1678 
1679 static inline void sk_mem_charge(struct sock *sk, int size)
1680 {
1681 	if (!sk_has_account(sk))
1682 		return;
1683 	sk_forward_alloc_add(sk, -size);
1684 }
1685 
1686 static inline void sk_mem_uncharge(struct sock *sk, int size)
1687 {
1688 	if (!sk_has_account(sk))
1689 		return;
1690 	sk_forward_alloc_add(sk, size);
1691 	sk_mem_reclaim(sk);
1692 }
1693 
1694 /*
1695  * Macro so as to not evaluate some arguments when
1696  * lockdep is not enabled.
1697  *
1698  * Mark both the sk_lock and the sk_lock.slock as a
1699  * per-address-family lock class.
1700  */
1701 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1702 do {									\
1703 	sk->sk_lock.owned = 0;						\
1704 	init_waitqueue_head(&sk->sk_lock.wq);				\
1705 	spin_lock_init(&(sk)->sk_lock.slock);				\
1706 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1707 			sizeof((sk)->sk_lock));				\
1708 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1709 				(skey), (sname));				\
1710 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1711 } while (0)
1712 
1713 static inline bool lockdep_sock_is_held(const struct sock *sk)
1714 {
1715 	return lockdep_is_held(&sk->sk_lock) ||
1716 	       lockdep_is_held(&sk->sk_lock.slock);
1717 }
1718 
1719 void lock_sock_nested(struct sock *sk, int subclass);
1720 
1721 static inline void lock_sock(struct sock *sk)
1722 {
1723 	lock_sock_nested(sk, 0);
1724 }
1725 
1726 void __lock_sock(struct sock *sk);
1727 void __release_sock(struct sock *sk);
1728 void release_sock(struct sock *sk);
1729 
1730 /* BH context may only use the following locking interface. */
1731 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1732 #define bh_lock_sock_nested(__sk) \
1733 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1734 				SINGLE_DEPTH_NESTING)
1735 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1736 
1737 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1738 
1739 /**
1740  * lock_sock_fast - fast version of lock_sock
1741  * @sk: socket
1742  *
1743  * This version should be used for very small section, where process wont block
1744  * return false if fast path is taken:
1745  *
1746  *   sk_lock.slock locked, owned = 0, BH disabled
1747  *
1748  * return true if slow path is taken:
1749  *
1750  *   sk_lock.slock unlocked, owned = 1, BH enabled
1751  */
1752 static inline bool lock_sock_fast(struct sock *sk)
1753 {
1754 	/* The sk_lock has mutex_lock() semantics here. */
1755 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1756 
1757 	return __lock_sock_fast(sk);
1758 }
1759 
1760 /* fast socket lock variant for caller already holding a [different] socket lock */
1761 static inline bool lock_sock_fast_nested(struct sock *sk)
1762 {
1763 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1764 
1765 	return __lock_sock_fast(sk);
1766 }
1767 
1768 /**
1769  * unlock_sock_fast - complement of lock_sock_fast
1770  * @sk: socket
1771  * @slow: slow mode
1772  *
1773  * fast unlock socket for user context.
1774  * If slow mode is on, we call regular release_sock()
1775  */
1776 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1777 	__releases(&sk->sk_lock.slock)
1778 {
1779 	if (slow) {
1780 		release_sock(sk);
1781 		__release(&sk->sk_lock.slock);
1782 	} else {
1783 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1784 		spin_unlock_bh(&sk->sk_lock.slock);
1785 	}
1786 }
1787 
1788 void sockopt_lock_sock(struct sock *sk);
1789 void sockopt_release_sock(struct sock *sk);
1790 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1791 bool sockopt_capable(int cap);
1792 
1793 /* Used by processes to "lock" a socket state, so that
1794  * interrupts and bottom half handlers won't change it
1795  * from under us. It essentially blocks any incoming
1796  * packets, so that we won't get any new data or any
1797  * packets that change the state of the socket.
1798  *
1799  * While locked, BH processing will add new packets to
1800  * the backlog queue.  This queue is processed by the
1801  * owner of the socket lock right before it is released.
1802  *
1803  * Since ~2.3.5 it is also exclusive sleep lock serializing
1804  * accesses from user process context.
1805  */
1806 
1807 static inline void sock_owned_by_me(const struct sock *sk)
1808 {
1809 #ifdef CONFIG_LOCKDEP
1810 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1811 #endif
1812 }
1813 
1814 static inline void sock_not_owned_by_me(const struct sock *sk)
1815 {
1816 #ifdef CONFIG_LOCKDEP
1817 	WARN_ON_ONCE(lockdep_sock_is_held(sk) && debug_locks);
1818 #endif
1819 }
1820 
1821 static inline bool sock_owned_by_user(const struct sock *sk)
1822 {
1823 	sock_owned_by_me(sk);
1824 	return sk->sk_lock.owned;
1825 }
1826 
1827 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1828 {
1829 	return sk->sk_lock.owned;
1830 }
1831 
1832 static inline void sock_release_ownership(struct sock *sk)
1833 {
1834 	if (sock_owned_by_user_nocheck(sk)) {
1835 		sk->sk_lock.owned = 0;
1836 
1837 		/* The sk_lock has mutex_unlock() semantics: */
1838 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1839 	}
1840 }
1841 
1842 /* no reclassification while locks are held */
1843 static inline bool sock_allow_reclassification(const struct sock *csk)
1844 {
1845 	struct sock *sk = (struct sock *)csk;
1846 
1847 	return !sock_owned_by_user_nocheck(sk) &&
1848 		!spin_is_locked(&sk->sk_lock.slock);
1849 }
1850 
1851 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1852 		      struct proto *prot, int kern);
1853 void sk_free(struct sock *sk);
1854 void sk_destruct(struct sock *sk);
1855 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1856 void sk_free_unlock_clone(struct sock *sk);
1857 
1858 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1859 			     gfp_t priority);
1860 void __sock_wfree(struct sk_buff *skb);
1861 void sock_wfree(struct sk_buff *skb);
1862 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1863 			     gfp_t priority);
1864 void skb_orphan_partial(struct sk_buff *skb);
1865 void sock_rfree(struct sk_buff *skb);
1866 void sock_efree(struct sk_buff *skb);
1867 #ifdef CONFIG_INET
1868 void sock_edemux(struct sk_buff *skb);
1869 void sock_pfree(struct sk_buff *skb);
1870 #else
1871 #define sock_edemux sock_efree
1872 #endif
1873 
1874 int sk_setsockopt(struct sock *sk, int level, int optname,
1875 		  sockptr_t optval, unsigned int optlen);
1876 int sock_setsockopt(struct socket *sock, int level, int op,
1877 		    sockptr_t optval, unsigned int optlen);
1878 
1879 int sk_getsockopt(struct sock *sk, int level, int optname,
1880 		  sockptr_t optval, sockptr_t optlen);
1881 int sock_getsockopt(struct socket *sock, int level, int op,
1882 		    char __user *optval, int __user *optlen);
1883 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1884 		   bool timeval, bool time32);
1885 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1886 				     unsigned long data_len, int noblock,
1887 				     int *errcode, int max_page_order);
1888 
1889 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1890 						  unsigned long size,
1891 						  int noblock, int *errcode)
1892 {
1893 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1894 }
1895 
1896 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1897 void sock_kfree_s(struct sock *sk, void *mem, int size);
1898 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1899 void sk_send_sigurg(struct sock *sk);
1900 
1901 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1902 {
1903 	if (sk->sk_socket)
1904 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1905 	WRITE_ONCE(sk->sk_prot, proto);
1906 }
1907 
1908 struct sockcm_cookie {
1909 	u64 transmit_time;
1910 	u32 mark;
1911 	u32 tsflags;
1912 };
1913 
1914 static inline void sockcm_init(struct sockcm_cookie *sockc,
1915 			       const struct sock *sk)
1916 {
1917 	*sockc = (struct sockcm_cookie) {
1918 		.tsflags = READ_ONCE(sk->sk_tsflags)
1919 	};
1920 }
1921 
1922 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1923 		     struct sockcm_cookie *sockc);
1924 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1925 		   struct sockcm_cookie *sockc);
1926 
1927 /*
1928  * Functions to fill in entries in struct proto_ops when a protocol
1929  * does not implement a particular function.
1930  */
1931 int sock_no_bind(struct socket *, struct sockaddr *, int);
1932 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1933 int sock_no_socketpair(struct socket *, struct socket *);
1934 int sock_no_accept(struct socket *, struct socket *, int, bool);
1935 int sock_no_getname(struct socket *, struct sockaddr *, int);
1936 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1937 int sock_no_listen(struct socket *, int);
1938 int sock_no_shutdown(struct socket *, int);
1939 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1940 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1941 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1942 int sock_no_mmap(struct file *file, struct socket *sock,
1943 		 struct vm_area_struct *vma);
1944 
1945 /*
1946  * Functions to fill in entries in struct proto_ops when a protocol
1947  * uses the inet style.
1948  */
1949 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1950 				  char __user *optval, int __user *optlen);
1951 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1952 			int flags);
1953 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1954 			   sockptr_t optval, unsigned int optlen);
1955 
1956 void sk_common_release(struct sock *sk);
1957 
1958 /*
1959  *	Default socket callbacks and setup code
1960  */
1961 
1962 /* Initialise core socket variables using an explicit uid. */
1963 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1964 
1965 /* Initialise core socket variables.
1966  * Assumes struct socket *sock is embedded in a struct socket_alloc.
1967  */
1968 void sock_init_data(struct socket *sock, struct sock *sk);
1969 
1970 /*
1971  * Socket reference counting postulates.
1972  *
1973  * * Each user of socket SHOULD hold a reference count.
1974  * * Each access point to socket (an hash table bucket, reference from a list,
1975  *   running timer, skb in flight MUST hold a reference count.
1976  * * When reference count hits 0, it means it will never increase back.
1977  * * When reference count hits 0, it means that no references from
1978  *   outside exist to this socket and current process on current CPU
1979  *   is last user and may/should destroy this socket.
1980  * * sk_free is called from any context: process, BH, IRQ. When
1981  *   it is called, socket has no references from outside -> sk_free
1982  *   may release descendant resources allocated by the socket, but
1983  *   to the time when it is called, socket is NOT referenced by any
1984  *   hash tables, lists etc.
1985  * * Packets, delivered from outside (from network or from another process)
1986  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1987  *   when they sit in queue. Otherwise, packets will leak to hole, when
1988  *   socket is looked up by one cpu and unhasing is made by another CPU.
1989  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1990  *   (leak to backlog). Packet socket does all the processing inside
1991  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1992  *   use separate SMP lock, so that they are prone too.
1993  */
1994 
1995 /* Ungrab socket and destroy it, if it was the last reference. */
1996 static inline void sock_put(struct sock *sk)
1997 {
1998 	if (refcount_dec_and_test(&sk->sk_refcnt))
1999 		sk_free(sk);
2000 }
2001 /* Generic version of sock_put(), dealing with all sockets
2002  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
2003  */
2004 void sock_gen_put(struct sock *sk);
2005 
2006 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
2007 		     unsigned int trim_cap, bool refcounted);
2008 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
2009 				 const int nested)
2010 {
2011 	return __sk_receive_skb(sk, skb, nested, 1, true);
2012 }
2013 
2014 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
2015 {
2016 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
2017 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
2018 		return;
2019 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2020 	 * other WRITE_ONCE() because socket lock might be not held.
2021 	 */
2022 	WRITE_ONCE(sk->sk_tx_queue_mapping, tx_queue);
2023 }
2024 
2025 #define NO_QUEUE_MAPPING	USHRT_MAX
2026 
2027 static inline void sk_tx_queue_clear(struct sock *sk)
2028 {
2029 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2030 	 * other WRITE_ONCE() because socket lock might be not held.
2031 	 */
2032 	WRITE_ONCE(sk->sk_tx_queue_mapping, NO_QUEUE_MAPPING);
2033 }
2034 
2035 static inline int sk_tx_queue_get(const struct sock *sk)
2036 {
2037 	if (sk) {
2038 		/* Paired with WRITE_ONCE() in sk_tx_queue_clear()
2039 		 * and sk_tx_queue_set().
2040 		 */
2041 		int val = READ_ONCE(sk->sk_tx_queue_mapping);
2042 
2043 		if (val != NO_QUEUE_MAPPING)
2044 			return val;
2045 	}
2046 	return -1;
2047 }
2048 
2049 static inline void __sk_rx_queue_set(struct sock *sk,
2050 				     const struct sk_buff *skb,
2051 				     bool force_set)
2052 {
2053 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2054 	if (skb_rx_queue_recorded(skb)) {
2055 		u16 rx_queue = skb_get_rx_queue(skb);
2056 
2057 		if (force_set ||
2058 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2059 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2060 	}
2061 #endif
2062 }
2063 
2064 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2065 {
2066 	__sk_rx_queue_set(sk, skb, true);
2067 }
2068 
2069 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2070 {
2071 	__sk_rx_queue_set(sk, skb, false);
2072 }
2073 
2074 static inline void sk_rx_queue_clear(struct sock *sk)
2075 {
2076 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2077 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2078 #endif
2079 }
2080 
2081 static inline int sk_rx_queue_get(const struct sock *sk)
2082 {
2083 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2084 	if (sk) {
2085 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2086 
2087 		if (res != NO_QUEUE_MAPPING)
2088 			return res;
2089 	}
2090 #endif
2091 
2092 	return -1;
2093 }
2094 
2095 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2096 {
2097 	sk->sk_socket = sock;
2098 }
2099 
2100 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2101 {
2102 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2103 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2104 }
2105 /* Detach socket from process context.
2106  * Announce socket dead, detach it from wait queue and inode.
2107  * Note that parent inode held reference count on this struct sock,
2108  * we do not release it in this function, because protocol
2109  * probably wants some additional cleanups or even continuing
2110  * to work with this socket (TCP).
2111  */
2112 static inline void sock_orphan(struct sock *sk)
2113 {
2114 	write_lock_bh(&sk->sk_callback_lock);
2115 	sock_set_flag(sk, SOCK_DEAD);
2116 	sk_set_socket(sk, NULL);
2117 	sk->sk_wq  = NULL;
2118 	write_unlock_bh(&sk->sk_callback_lock);
2119 }
2120 
2121 static inline void sock_graft(struct sock *sk, struct socket *parent)
2122 {
2123 	WARN_ON(parent->sk);
2124 	write_lock_bh(&sk->sk_callback_lock);
2125 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2126 	parent->sk = sk;
2127 	sk_set_socket(sk, parent);
2128 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
2129 	security_sock_graft(sk, parent);
2130 	write_unlock_bh(&sk->sk_callback_lock);
2131 }
2132 
2133 kuid_t sock_i_uid(struct sock *sk);
2134 unsigned long __sock_i_ino(struct sock *sk);
2135 unsigned long sock_i_ino(struct sock *sk);
2136 
2137 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2138 {
2139 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
2140 }
2141 
2142 static inline u32 net_tx_rndhash(void)
2143 {
2144 	u32 v = get_random_u32();
2145 
2146 	return v ?: 1;
2147 }
2148 
2149 static inline void sk_set_txhash(struct sock *sk)
2150 {
2151 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2152 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2153 }
2154 
2155 static inline bool sk_rethink_txhash(struct sock *sk)
2156 {
2157 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2158 		sk_set_txhash(sk);
2159 		return true;
2160 	}
2161 	return false;
2162 }
2163 
2164 static inline struct dst_entry *
2165 __sk_dst_get(const struct sock *sk)
2166 {
2167 	return rcu_dereference_check(sk->sk_dst_cache,
2168 				     lockdep_sock_is_held(sk));
2169 }
2170 
2171 static inline struct dst_entry *
2172 sk_dst_get(const struct sock *sk)
2173 {
2174 	struct dst_entry *dst;
2175 
2176 	rcu_read_lock();
2177 	dst = rcu_dereference(sk->sk_dst_cache);
2178 	if (dst && !rcuref_get(&dst->__rcuref))
2179 		dst = NULL;
2180 	rcu_read_unlock();
2181 	return dst;
2182 }
2183 
2184 static inline void __dst_negative_advice(struct sock *sk)
2185 {
2186 	struct dst_entry *dst = __sk_dst_get(sk);
2187 
2188 	if (dst && dst->ops->negative_advice)
2189 		dst->ops->negative_advice(sk, dst);
2190 }
2191 
2192 static inline void dst_negative_advice(struct sock *sk)
2193 {
2194 	sk_rethink_txhash(sk);
2195 	__dst_negative_advice(sk);
2196 }
2197 
2198 static inline void
2199 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2200 {
2201 	struct dst_entry *old_dst;
2202 
2203 	sk_tx_queue_clear(sk);
2204 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2205 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2206 					    lockdep_sock_is_held(sk));
2207 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2208 	dst_release(old_dst);
2209 }
2210 
2211 static inline void
2212 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2213 {
2214 	struct dst_entry *old_dst;
2215 
2216 	sk_tx_queue_clear(sk);
2217 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2218 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2219 	dst_release(old_dst);
2220 }
2221 
2222 static inline void
2223 __sk_dst_reset(struct sock *sk)
2224 {
2225 	__sk_dst_set(sk, NULL);
2226 }
2227 
2228 static inline void
2229 sk_dst_reset(struct sock *sk)
2230 {
2231 	sk_dst_set(sk, NULL);
2232 }
2233 
2234 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2235 
2236 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2237 
2238 static inline void sk_dst_confirm(struct sock *sk)
2239 {
2240 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2241 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2242 }
2243 
2244 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2245 {
2246 	if (skb_get_dst_pending_confirm(skb)) {
2247 		struct sock *sk = skb->sk;
2248 
2249 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2250 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2251 		neigh_confirm(n);
2252 	}
2253 }
2254 
2255 bool sk_mc_loop(struct sock *sk);
2256 
2257 static inline bool sk_can_gso(const struct sock *sk)
2258 {
2259 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2260 }
2261 
2262 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2263 
2264 static inline void sk_gso_disable(struct sock *sk)
2265 {
2266 	sk->sk_gso_disabled = 1;
2267 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2268 }
2269 
2270 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2271 					   struct iov_iter *from, char *to,
2272 					   int copy, int offset)
2273 {
2274 	if (skb->ip_summed == CHECKSUM_NONE) {
2275 		__wsum csum = 0;
2276 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2277 			return -EFAULT;
2278 		skb->csum = csum_block_add(skb->csum, csum, offset);
2279 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2280 		if (!copy_from_iter_full_nocache(to, copy, from))
2281 			return -EFAULT;
2282 	} else if (!copy_from_iter_full(to, copy, from))
2283 		return -EFAULT;
2284 
2285 	return 0;
2286 }
2287 
2288 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2289 				       struct iov_iter *from, int copy)
2290 {
2291 	int err, offset = skb->len;
2292 
2293 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2294 				       copy, offset);
2295 	if (err)
2296 		__skb_trim(skb, offset);
2297 
2298 	return err;
2299 }
2300 
2301 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2302 					   struct sk_buff *skb,
2303 					   struct page *page,
2304 					   int off, int copy)
2305 {
2306 	int err;
2307 
2308 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2309 				       copy, skb->len);
2310 	if (err)
2311 		return err;
2312 
2313 	skb_len_add(skb, copy);
2314 	sk_wmem_queued_add(sk, copy);
2315 	sk_mem_charge(sk, copy);
2316 	return 0;
2317 }
2318 
2319 /**
2320  * sk_wmem_alloc_get - returns write allocations
2321  * @sk: socket
2322  *
2323  * Return: sk_wmem_alloc minus initial offset of one
2324  */
2325 static inline int sk_wmem_alloc_get(const struct sock *sk)
2326 {
2327 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2328 }
2329 
2330 /**
2331  * sk_rmem_alloc_get - returns read allocations
2332  * @sk: socket
2333  *
2334  * Return: sk_rmem_alloc
2335  */
2336 static inline int sk_rmem_alloc_get(const struct sock *sk)
2337 {
2338 	return atomic_read(&sk->sk_rmem_alloc);
2339 }
2340 
2341 /**
2342  * sk_has_allocations - check if allocations are outstanding
2343  * @sk: socket
2344  *
2345  * Return: true if socket has write or read allocations
2346  */
2347 static inline bool sk_has_allocations(const struct sock *sk)
2348 {
2349 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2350 }
2351 
2352 /**
2353  * skwq_has_sleeper - check if there are any waiting processes
2354  * @wq: struct socket_wq
2355  *
2356  * Return: true if socket_wq has waiting processes
2357  *
2358  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2359  * barrier call. They were added due to the race found within the tcp code.
2360  *
2361  * Consider following tcp code paths::
2362  *
2363  *   CPU1                CPU2
2364  *   sys_select          receive packet
2365  *   ...                 ...
2366  *   __add_wait_queue    update tp->rcv_nxt
2367  *   ...                 ...
2368  *   tp->rcv_nxt check   sock_def_readable
2369  *   ...                 {
2370  *   schedule               rcu_read_lock();
2371  *                          wq = rcu_dereference(sk->sk_wq);
2372  *                          if (wq && waitqueue_active(&wq->wait))
2373  *                              wake_up_interruptible(&wq->wait)
2374  *                          ...
2375  *                       }
2376  *
2377  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2378  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2379  * could then endup calling schedule and sleep forever if there are no more
2380  * data on the socket.
2381  *
2382  */
2383 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2384 {
2385 	return wq && wq_has_sleeper(&wq->wait);
2386 }
2387 
2388 /**
2389  * sock_poll_wait - place memory barrier behind the poll_wait call.
2390  * @filp:           file
2391  * @sock:           socket to wait on
2392  * @p:              poll_table
2393  *
2394  * See the comments in the wq_has_sleeper function.
2395  */
2396 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2397 				  poll_table *p)
2398 {
2399 	if (!poll_does_not_wait(p)) {
2400 		poll_wait(filp, &sock->wq.wait, p);
2401 		/* We need to be sure we are in sync with the
2402 		 * socket flags modification.
2403 		 *
2404 		 * This memory barrier is paired in the wq_has_sleeper.
2405 		 */
2406 		smp_mb();
2407 	}
2408 }
2409 
2410 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2411 {
2412 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2413 	u32 txhash = READ_ONCE(sk->sk_txhash);
2414 
2415 	if (txhash) {
2416 		skb->l4_hash = 1;
2417 		skb->hash = txhash;
2418 	}
2419 }
2420 
2421 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2422 
2423 /*
2424  *	Queue a received datagram if it will fit. Stream and sequenced
2425  *	protocols can't normally use this as they need to fit buffers in
2426  *	and play with them.
2427  *
2428  *	Inlined as it's very short and called for pretty much every
2429  *	packet ever received.
2430  */
2431 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2432 {
2433 	skb_orphan(skb);
2434 	skb->sk = sk;
2435 	skb->destructor = sock_rfree;
2436 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2437 	sk_mem_charge(sk, skb->truesize);
2438 }
2439 
2440 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2441 {
2442 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2443 		skb_orphan(skb);
2444 		skb->destructor = sock_efree;
2445 		skb->sk = sk;
2446 		return true;
2447 	}
2448 	return false;
2449 }
2450 
2451 static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2452 {
2453 	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2454 	if (skb) {
2455 		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2456 			skb_set_owner_r(skb, sk);
2457 			return skb;
2458 		}
2459 		__kfree_skb(skb);
2460 	}
2461 	return NULL;
2462 }
2463 
2464 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2465 {
2466 	if (skb->destructor != sock_wfree) {
2467 		skb_orphan(skb);
2468 		return;
2469 	}
2470 	skb->slow_gro = 1;
2471 }
2472 
2473 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2474 		    unsigned long expires);
2475 
2476 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2477 
2478 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2479 
2480 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2481 			struct sk_buff *skb, unsigned int flags,
2482 			void (*destructor)(struct sock *sk,
2483 					   struct sk_buff *skb));
2484 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2485 
2486 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2487 			      enum skb_drop_reason *reason);
2488 
2489 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2490 {
2491 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2492 }
2493 
2494 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2495 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2496 
2497 /*
2498  *	Recover an error report and clear atomically
2499  */
2500 
2501 static inline int sock_error(struct sock *sk)
2502 {
2503 	int err;
2504 
2505 	/* Avoid an atomic operation for the common case.
2506 	 * This is racy since another cpu/thread can change sk_err under us.
2507 	 */
2508 	if (likely(data_race(!sk->sk_err)))
2509 		return 0;
2510 
2511 	err = xchg(&sk->sk_err, 0);
2512 	return -err;
2513 }
2514 
2515 void sk_error_report(struct sock *sk);
2516 
2517 static inline unsigned long sock_wspace(struct sock *sk)
2518 {
2519 	int amt = 0;
2520 
2521 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2522 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2523 		if (amt < 0)
2524 			amt = 0;
2525 	}
2526 	return amt;
2527 }
2528 
2529 /* Note:
2530  *  We use sk->sk_wq_raw, from contexts knowing this
2531  *  pointer is not NULL and cannot disappear/change.
2532  */
2533 static inline void sk_set_bit(int nr, struct sock *sk)
2534 {
2535 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2536 	    !sock_flag(sk, SOCK_FASYNC))
2537 		return;
2538 
2539 	set_bit(nr, &sk->sk_wq_raw->flags);
2540 }
2541 
2542 static inline void sk_clear_bit(int nr, struct sock *sk)
2543 {
2544 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2545 	    !sock_flag(sk, SOCK_FASYNC))
2546 		return;
2547 
2548 	clear_bit(nr, &sk->sk_wq_raw->flags);
2549 }
2550 
2551 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2552 {
2553 	if (sock_flag(sk, SOCK_FASYNC)) {
2554 		rcu_read_lock();
2555 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2556 		rcu_read_unlock();
2557 	}
2558 }
2559 
2560 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2561  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2562  * Note: for send buffers, TCP works better if we can build two skbs at
2563  * minimum.
2564  */
2565 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2566 
2567 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2568 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2569 
2570 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2571 {
2572 	u32 val;
2573 
2574 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2575 		return;
2576 
2577 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2578 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2579 
2580 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2581 }
2582 
2583 /**
2584  * sk_page_frag - return an appropriate page_frag
2585  * @sk: socket
2586  *
2587  * Use the per task page_frag instead of the per socket one for
2588  * optimization when we know that we're in process context and own
2589  * everything that's associated with %current.
2590  *
2591  * Both direct reclaim and page faults can nest inside other
2592  * socket operations and end up recursing into sk_page_frag()
2593  * while it's already in use: explicitly avoid task page_frag
2594  * when users disable sk_use_task_frag.
2595  *
2596  * Return: a per task page_frag if context allows that,
2597  * otherwise a per socket one.
2598  */
2599 static inline struct page_frag *sk_page_frag(struct sock *sk)
2600 {
2601 	if (sk->sk_use_task_frag)
2602 		return &current->task_frag;
2603 
2604 	return &sk->sk_frag;
2605 }
2606 
2607 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2608 
2609 /*
2610  *	Default write policy as shown to user space via poll/select/SIGIO
2611  */
2612 static inline bool sock_writeable(const struct sock *sk)
2613 {
2614 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2615 }
2616 
2617 static inline gfp_t gfp_any(void)
2618 {
2619 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2620 }
2621 
2622 static inline gfp_t gfp_memcg_charge(void)
2623 {
2624 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2625 }
2626 
2627 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2628 {
2629 	return noblock ? 0 : sk->sk_rcvtimeo;
2630 }
2631 
2632 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2633 {
2634 	return noblock ? 0 : sk->sk_sndtimeo;
2635 }
2636 
2637 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2638 {
2639 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2640 
2641 	return v ?: 1;
2642 }
2643 
2644 /* Alas, with timeout socket operations are not restartable.
2645  * Compare this to poll().
2646  */
2647 static inline int sock_intr_errno(long timeo)
2648 {
2649 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2650 }
2651 
2652 struct sock_skb_cb {
2653 	u32 dropcount;
2654 };
2655 
2656 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2657  * using skb->cb[] would keep using it directly and utilize its
2658  * alignement guarantee.
2659  */
2660 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2661 			    sizeof(struct sock_skb_cb)))
2662 
2663 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2664 			    SOCK_SKB_CB_OFFSET))
2665 
2666 #define sock_skb_cb_check_size(size) \
2667 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2668 
2669 static inline void
2670 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2671 {
2672 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2673 						atomic_read(&sk->sk_drops) : 0;
2674 }
2675 
2676 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2677 {
2678 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2679 
2680 	atomic_add(segs, &sk->sk_drops);
2681 }
2682 
2683 static inline ktime_t sock_read_timestamp(struct sock *sk)
2684 {
2685 #if BITS_PER_LONG==32
2686 	unsigned int seq;
2687 	ktime_t kt;
2688 
2689 	do {
2690 		seq = read_seqbegin(&sk->sk_stamp_seq);
2691 		kt = sk->sk_stamp;
2692 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2693 
2694 	return kt;
2695 #else
2696 	return READ_ONCE(sk->sk_stamp);
2697 #endif
2698 }
2699 
2700 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2701 {
2702 #if BITS_PER_LONG==32
2703 	write_seqlock(&sk->sk_stamp_seq);
2704 	sk->sk_stamp = kt;
2705 	write_sequnlock(&sk->sk_stamp_seq);
2706 #else
2707 	WRITE_ONCE(sk->sk_stamp, kt);
2708 #endif
2709 }
2710 
2711 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2712 			   struct sk_buff *skb);
2713 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2714 			     struct sk_buff *skb);
2715 
2716 static inline void
2717 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2718 {
2719 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2720 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
2721 	ktime_t kt = skb->tstamp;
2722 	/*
2723 	 * generate control messages if
2724 	 * - receive time stamping in software requested
2725 	 * - software time stamp available and wanted
2726 	 * - hardware time stamps available and wanted
2727 	 */
2728 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2729 	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2730 	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2731 	    (hwtstamps->hwtstamp &&
2732 	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2733 		__sock_recv_timestamp(msg, sk, skb);
2734 	else
2735 		sock_write_timestamp(sk, kt);
2736 
2737 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb_wifi_acked_valid(skb))
2738 		__sock_recv_wifi_status(msg, sk, skb);
2739 }
2740 
2741 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2742 		       struct sk_buff *skb);
2743 
2744 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2745 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2746 				   struct sk_buff *skb)
2747 {
2748 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2749 			   (1UL << SOCK_RCVTSTAMP)			| \
2750 			   (1UL << SOCK_RCVMARK))
2751 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2752 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2753 
2754 	if (sk->sk_flags & FLAGS_RECV_CMSGS ||
2755 	    READ_ONCE(sk->sk_tsflags) & TSFLAGS_ANY)
2756 		__sock_recv_cmsgs(msg, sk, skb);
2757 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2758 		sock_write_timestamp(sk, skb->tstamp);
2759 	else if (unlikely(sock_read_timestamp(sk) == SK_DEFAULT_STAMP))
2760 		sock_write_timestamp(sk, 0);
2761 }
2762 
2763 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2764 
2765 /**
2766  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2767  * @sk:		socket sending this packet
2768  * @tsflags:	timestamping flags to use
2769  * @tx_flags:	completed with instructions for time stamping
2770  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2771  *
2772  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2773  */
2774 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2775 				      __u8 *tx_flags, __u32 *tskey)
2776 {
2777 	if (unlikely(tsflags)) {
2778 		__sock_tx_timestamp(tsflags, tx_flags);
2779 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2780 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2781 			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2782 	}
2783 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2784 		*tx_flags |= SKBTX_WIFI_STATUS;
2785 }
2786 
2787 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2788 				     __u8 *tx_flags)
2789 {
2790 	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2791 }
2792 
2793 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2794 {
2795 	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2796 			   &skb_shinfo(skb)->tskey);
2797 }
2798 
2799 static inline bool sk_is_inet(const struct sock *sk)
2800 {
2801 	int family = READ_ONCE(sk->sk_family);
2802 
2803 	return family == AF_INET || family == AF_INET6;
2804 }
2805 
2806 static inline bool sk_is_tcp(const struct sock *sk)
2807 {
2808 	return sk_is_inet(sk) &&
2809 	       sk->sk_type == SOCK_STREAM &&
2810 	       sk->sk_protocol == IPPROTO_TCP;
2811 }
2812 
2813 static inline bool sk_is_udp(const struct sock *sk)
2814 {
2815 	return sk_is_inet(sk) &&
2816 	       sk->sk_type == SOCK_DGRAM &&
2817 	       sk->sk_protocol == IPPROTO_UDP;
2818 }
2819 
2820 static inline bool sk_is_stream_unix(const struct sock *sk)
2821 {
2822 	return sk->sk_family == AF_UNIX && sk->sk_type == SOCK_STREAM;
2823 }
2824 
2825 /**
2826  * sk_eat_skb - Release a skb if it is no longer needed
2827  * @sk: socket to eat this skb from
2828  * @skb: socket buffer to eat
2829  *
2830  * This routine must be called with interrupts disabled or with the socket
2831  * locked so that the sk_buff queue operation is ok.
2832 */
2833 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2834 {
2835 	__skb_unlink(skb, &sk->sk_receive_queue);
2836 	__kfree_skb(skb);
2837 }
2838 
2839 static inline bool
2840 skb_sk_is_prefetched(struct sk_buff *skb)
2841 {
2842 #ifdef CONFIG_INET
2843 	return skb->destructor == sock_pfree;
2844 #else
2845 	return false;
2846 #endif /* CONFIG_INET */
2847 }
2848 
2849 /* This helper checks if a socket is a full socket,
2850  * ie _not_ a timewait or request socket.
2851  */
2852 static inline bool sk_fullsock(const struct sock *sk)
2853 {
2854 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2855 }
2856 
2857 static inline bool
2858 sk_is_refcounted(struct sock *sk)
2859 {
2860 	/* Only full sockets have sk->sk_flags. */
2861 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2862 }
2863 
2864 /**
2865  * skb_steal_sock - steal a socket from an sk_buff
2866  * @skb: sk_buff to steal the socket from
2867  * @refcounted: is set to true if the socket is reference-counted
2868  * @prefetched: is set to true if the socket was assigned from bpf
2869  */
2870 static inline struct sock *
2871 skb_steal_sock(struct sk_buff *skb, bool *refcounted, bool *prefetched)
2872 {
2873 	if (skb->sk) {
2874 		struct sock *sk = skb->sk;
2875 
2876 		*refcounted = true;
2877 		*prefetched = skb_sk_is_prefetched(skb);
2878 		if (*prefetched)
2879 			*refcounted = sk_is_refcounted(sk);
2880 		skb->destructor = NULL;
2881 		skb->sk = NULL;
2882 		return sk;
2883 	}
2884 	*prefetched = false;
2885 	*refcounted = false;
2886 	return NULL;
2887 }
2888 
2889 /* Checks if this SKB belongs to an HW offloaded socket
2890  * and whether any SW fallbacks are required based on dev.
2891  * Check decrypted mark in case skb_orphan() cleared socket.
2892  */
2893 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2894 						   struct net_device *dev)
2895 {
2896 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2897 	struct sock *sk = skb->sk;
2898 
2899 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2900 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2901 #ifdef CONFIG_TLS_DEVICE
2902 	} else if (unlikely(skb->decrypted)) {
2903 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2904 		kfree_skb(skb);
2905 		skb = NULL;
2906 #endif
2907 	}
2908 #endif
2909 
2910 	return skb;
2911 }
2912 
2913 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2914  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2915  */
2916 static inline bool sk_listener(const struct sock *sk)
2917 {
2918 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2919 }
2920 
2921 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2922 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2923 		       int type);
2924 
2925 bool sk_ns_capable(const struct sock *sk,
2926 		   struct user_namespace *user_ns, int cap);
2927 bool sk_capable(const struct sock *sk, int cap);
2928 bool sk_net_capable(const struct sock *sk, int cap);
2929 
2930 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2931 
2932 /* Take into consideration the size of the struct sk_buff overhead in the
2933  * determination of these values, since that is non-constant across
2934  * platforms.  This makes socket queueing behavior and performance
2935  * not depend upon such differences.
2936  */
2937 #define _SK_MEM_PACKETS		256
2938 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2939 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2940 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2941 
2942 extern __u32 sysctl_wmem_max;
2943 extern __u32 sysctl_rmem_max;
2944 
2945 extern int sysctl_tstamp_allow_data;
2946 extern int sysctl_optmem_max;
2947 
2948 extern __u32 sysctl_wmem_default;
2949 extern __u32 sysctl_rmem_default;
2950 
2951 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2952 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2953 
2954 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2955 {
2956 	/* Does this proto have per netns sysctl_wmem ? */
2957 	if (proto->sysctl_wmem_offset)
2958 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
2959 
2960 	return READ_ONCE(*proto->sysctl_wmem);
2961 }
2962 
2963 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2964 {
2965 	/* Does this proto have per netns sysctl_rmem ? */
2966 	if (proto->sysctl_rmem_offset)
2967 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
2968 
2969 	return READ_ONCE(*proto->sysctl_rmem);
2970 }
2971 
2972 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2973  * Some wifi drivers need to tweak it to get more chunks.
2974  * They can use this helper from their ndo_start_xmit()
2975  */
2976 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2977 {
2978 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2979 		return;
2980 	WRITE_ONCE(sk->sk_pacing_shift, val);
2981 }
2982 
2983 /* if a socket is bound to a device, check that the given device
2984  * index is either the same or that the socket is bound to an L3
2985  * master device and the given device index is also enslaved to
2986  * that L3 master
2987  */
2988 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2989 {
2990 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
2991 	int mdif;
2992 
2993 	if (!bound_dev_if || bound_dev_if == dif)
2994 		return true;
2995 
2996 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2997 	if (mdif && mdif == bound_dev_if)
2998 		return true;
2999 
3000 	return false;
3001 }
3002 
3003 void sock_def_readable(struct sock *sk);
3004 
3005 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
3006 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
3007 int sock_set_timestamping(struct sock *sk, int optname,
3008 			  struct so_timestamping timestamping);
3009 
3010 void sock_enable_timestamps(struct sock *sk);
3011 void sock_no_linger(struct sock *sk);
3012 void sock_set_keepalive(struct sock *sk);
3013 void sock_set_priority(struct sock *sk, u32 priority);
3014 void sock_set_rcvbuf(struct sock *sk, int val);
3015 void sock_set_mark(struct sock *sk, u32 val);
3016 void sock_set_reuseaddr(struct sock *sk);
3017 void sock_set_reuseport(struct sock *sk);
3018 void sock_set_sndtimeo(struct sock *sk, s64 secs);
3019 
3020 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
3021 
3022 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
3023 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
3024 			   sockptr_t optval, int optlen, bool old_timeval);
3025 
3026 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
3027 		     void __user *arg, void *karg, size_t size);
3028 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
3029 static inline bool sk_is_readable(struct sock *sk)
3030 {
3031 	if (sk->sk_prot->sock_is_readable)
3032 		return sk->sk_prot->sock_is_readable(sk);
3033 	return false;
3034 }
3035 #endif	/* _SOCK_H */
3036