xref: /linux/include/net/sock.h (revision a7ddedc84c59a645ef970b992f7cda5bffc70cc0)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the AF_INET socket handler.
8  *
9  * Version:	@(#)sock.h	1.0.4	05/13/93
10  *
11  * Authors:	Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
14  *		Florian La Roche <flla@stud.uni-sb.de>
15  *
16  * Fixes:
17  *		Alan Cox	:	Volatiles in skbuff pointers. See
18  *					skbuff comments. May be overdone,
19  *					better to prove they can be removed
20  *					than the reverse.
21  *		Alan Cox	:	Added a zapped field for tcp to note
22  *					a socket is reset and must stay shut up
23  *		Alan Cox	:	New fields for options
24  *	Pauline Middelink	:	identd support
25  *		Alan Cox	:	Eliminate low level recv/recvfrom
26  *		David S. Miller	:	New socket lookup architecture.
27  *              Steve Whitehouse:       Default routines for sock_ops
28  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
29  *              			protinfo be just a void pointer, as the
30  *              			protocol specific parts were moved to
31  *              			respective headers and ipv4/v6, etc now
32  *              			use private slabcaches for its socks
33  *              Pedro Hortas	:	New flags field for socket options
34  */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37 
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h>	/* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/rculist_nulls.h>
60 #include <linux/poll.h>
61 #include <linux/sockptr.h>
62 #include <linux/indirect_call_wrapper.h>
63 #include <linux/atomic.h>
64 #include <linux/refcount.h>
65 #include <linux/llist.h>
66 #include <net/dst.h>
67 #include <net/checksum.h>
68 #include <net/tcp_states.h>
69 #include <linux/net_tstamp.h>
70 #include <net/l3mdev.h>
71 #include <uapi/linux/socket.h>
72 
73 /*
74  * This structure really needs to be cleaned up.
75  * Most of it is for TCP, and not used by any of
76  * the other protocols.
77  */
78 
79 /* This is the per-socket lock.  The spinlock provides a synchronization
80  * between user contexts and software interrupt processing, whereas the
81  * mini-semaphore synchronizes multiple users amongst themselves.
82  */
83 typedef struct {
84 	spinlock_t		slock;
85 	int			owned;
86 	wait_queue_head_t	wq;
87 	/*
88 	 * We express the mutex-alike socket_lock semantics
89 	 * to the lock validator by explicitly managing
90 	 * the slock as a lock variant (in addition to
91 	 * the slock itself):
92 	 */
93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
94 	struct lockdep_map dep_map;
95 #endif
96 } socket_lock_t;
97 
98 struct sock;
99 struct proto;
100 struct net;
101 
102 typedef __u32 __bitwise __portpair;
103 typedef __u64 __bitwise __addrpair;
104 
105 struct socket_drop_counters {
106 	atomic_t	drops0 ____cacheline_aligned_in_smp;
107 	atomic_t	drops1 ____cacheline_aligned_in_smp;
108 };
109 
110 /**
111  *	struct sock_common - minimal network layer representation of sockets
112  *	@skc_daddr: Foreign IPv4 addr
113  *	@skc_rcv_saddr: Bound local IPv4 addr
114  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
115  *	@skc_hash: hash value used with various protocol lookup tables
116  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
117  *	@skc_dport: placeholder for inet_dport/tw_dport
118  *	@skc_num: placeholder for inet_num/tw_num
119  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
120  *	@skc_family: network address family
121  *	@skc_state: Connection state
122  *	@skc_reuse: %SO_REUSEADDR setting
123  *	@skc_reuseport: %SO_REUSEPORT setting
124  *	@skc_ipv6only: socket is IPV6 only
125  *	@skc_net_refcnt: socket is using net ref counting
126  *	@skc_bound_dev_if: bound device index if != 0
127  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
128  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
129  *	@skc_prot: protocol handlers inside a network family
130  *	@skc_net: reference to the network namespace of this socket
131  *	@skc_v6_daddr: IPV6 destination address
132  *	@skc_v6_rcv_saddr: IPV6 source address
133  *	@skc_cookie: socket's cookie value
134  *	@skc_node: main hash linkage for various protocol lookup tables
135  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
136  *	@skc_tx_queue_mapping: tx queue number for this connection
137  *	@skc_rx_queue_mapping: rx queue number for this connection
138  *	@skc_flags: place holder for sk_flags
139  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
140  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
141  *	@skc_listener: connection request listener socket (aka rsk_listener)
142  *		[union with @skc_flags]
143  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
144  *		[union with @skc_flags]
145  *	@skc_incoming_cpu: record/match cpu processing incoming packets
146  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
147  *		[union with @skc_incoming_cpu]
148  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
149  *		[union with @skc_incoming_cpu]
150  *	@skc_refcnt: reference count
151  *
152  *	This is the minimal network layer representation of sockets, the header
153  *	for struct sock and struct inet_timewait_sock.
154  */
155 struct sock_common {
156 	union {
157 		__addrpair	skc_addrpair;
158 		struct {
159 			__be32	skc_daddr;
160 			__be32	skc_rcv_saddr;
161 		};
162 	};
163 	union  {
164 		unsigned int	skc_hash;
165 		__u16		skc_u16hashes[2];
166 	};
167 	/* skc_dport && skc_num must be grouped as well */
168 	union {
169 		__portpair	skc_portpair;
170 		struct {
171 			__be16	skc_dport;
172 			__u16	skc_num;
173 		};
174 	};
175 
176 	unsigned short		skc_family;
177 	volatile unsigned char	skc_state;
178 	unsigned char		skc_reuse:4;
179 	unsigned char		skc_reuseport:1;
180 	unsigned char		skc_ipv6only:1;
181 	unsigned char		skc_net_refcnt:1;
182 	int			skc_bound_dev_if;
183 	union {
184 		struct hlist_node	skc_bind_node;
185 		struct hlist_node	skc_portaddr_node;
186 	};
187 	struct proto		*skc_prot;
188 	possible_net_t		skc_net;
189 
190 #if IS_ENABLED(CONFIG_IPV6)
191 	struct in6_addr		skc_v6_daddr;
192 	struct in6_addr		skc_v6_rcv_saddr;
193 #endif
194 
195 	atomic64_t		skc_cookie;
196 
197 	/* following fields are padding to force
198 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
199 	 * assuming IPV6 is enabled. We use this padding differently
200 	 * for different kind of 'sockets'
201 	 */
202 	union {
203 		unsigned long	skc_flags;
204 		struct sock	*skc_listener; /* request_sock */
205 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
206 	};
207 	/*
208 	 * fields between dontcopy_begin/dontcopy_end
209 	 * are not copied in sock_copy()
210 	 */
211 	/* private: */
212 	int			skc_dontcopy_begin[0];
213 	/* public: */
214 	union {
215 		struct hlist_node	skc_node;
216 		struct hlist_nulls_node skc_nulls_node;
217 	};
218 	unsigned short		skc_tx_queue_mapping;
219 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
220 	unsigned short		skc_rx_queue_mapping;
221 #endif
222 	union {
223 		int		skc_incoming_cpu;
224 		u32		skc_rcv_wnd;
225 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
226 	};
227 
228 	refcount_t		skc_refcnt;
229 	/* private: */
230 	int                     skc_dontcopy_end[0];
231 	union {
232 		u32		skc_rxhash;
233 		u32		skc_window_clamp;
234 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
235 	};
236 	/* public: */
237 };
238 
239 struct bpf_local_storage;
240 struct sk_filter;
241 
242 /**
243   *	struct sock - network layer representation of sockets
244   *	@__sk_common: shared layout with inet_timewait_sock
245   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
246   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
247   *	@sk_lock:	synchronizer
248   *	@sk_kern_sock: True if sock is using kernel lock classes
249   *	@sk_rcvbuf: size of receive buffer in bytes
250   *	@sk_wq: sock wait queue and async head
251   *	@sk_rx_dst: receive input route used by early demux
252   *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
253   *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
254   *	@sk_dst_cache: destination cache
255   *	@sk_dst_pending_confirm: need to confirm neighbour
256   *	@sk_policy: flow policy
257   *	@sk_receive_queue: incoming packets
258   *	@sk_wmem_alloc: transmit queue bytes committed
259   *	@sk_tsq_flags: TCP Small Queues flags
260   *	@sk_write_queue: Packet sending queue
261   *	@sk_omem_alloc: "o" is "option" or "other"
262   *	@sk_wmem_queued: persistent queue size
263   *	@sk_forward_alloc: space allocated forward
264   *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
265   *	@sk_napi_id: id of the last napi context to receive data for sk
266   *	@sk_ll_usec: usecs to busypoll when there is no data
267   *	@sk_allocation: allocation mode
268   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
269   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
270   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
271   *	@sk_sndbuf: size of send buffer in bytes
272   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
273   *	@sk_no_check_rx: allow zero checksum in RX packets
274   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
275   *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
276   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
277   *	@sk_gso_max_size: Maximum GSO segment size to build
278   *	@sk_gso_max_segs: Maximum number of GSO segments
279   *	@sk_pacing_shift: scaling factor for TCP Small Queues
280   *	@sk_lingertime: %SO_LINGER l_linger setting
281   *	@sk_backlog: always used with the per-socket spinlock held
282   *	@sk_callback_lock: used with the callbacks in the end of this struct
283   *	@sk_error_queue: rarely used
284   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
285   *			  IPV6_ADDRFORM for instance)
286   *	@sk_err: last error
287   *	@sk_err_soft: errors that don't cause failure but are the cause of a
288   *		      persistent failure not just 'timed out'
289   *	@sk_drops: raw/udp drops counter
290   *	@sk_drop_counters: optional pointer to socket_drop_counters
291   *	@sk_ack_backlog: current listen backlog
292   *	@sk_max_ack_backlog: listen backlog set in listen()
293   *	@sk_uid: user id of owner
294   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
295   *	@sk_busy_poll_budget: napi processing budget when busypolling
296   *	@sk_priority: %SO_PRIORITY setting
297   *	@sk_type: socket type (%SOCK_STREAM, etc)
298   *	@sk_protocol: which protocol this socket belongs in this network family
299   *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
300   *	@sk_peer_pid: &struct pid for this socket's peer
301   *	@sk_peer_cred: %SO_PEERCRED setting
302   *	@sk_rcvlowat: %SO_RCVLOWAT setting
303   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
304   *	@sk_sndtimeo: %SO_SNDTIMEO setting
305   *	@sk_txhash: computed flow hash for use on transmit
306   *	@sk_txrehash: enable TX hash rethink
307   *	@sk_filter: socket filtering instructions
308   *	@sk_timer: sock cleanup timer
309   *	@sk_stamp: time stamp of last packet received
310   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
311   *	@sk_tsflags: SO_TIMESTAMPING flags
312   *	@sk_bpf_cb_flags: used in bpf_setsockopt()
313   *	@sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
314   *			   Sockets that can be used under memory reclaim should
315   *			   set this to false.
316   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
317   *	              for timestamping
318   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
319   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
320   *	@sk_socket: Identd and reporting IO signals
321   *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
322   *	@sk_frag: cached page frag
323   *	@sk_peek_off: current peek_offset value
324   *	@sk_send_head: front of stuff to transmit
325   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
326   *	@sk_security: used by security modules
327   *	@sk_mark: generic packet mark
328   *	@sk_cgrp_data: cgroup data for this cgroup
329   *	@sk_memcg: this socket's memory cgroup association
330   *	@sk_write_pending: a write to stream socket waits to start
331   *	@sk_disconnects: number of disconnect operations performed on this sock
332   *	@sk_state_change: callback to indicate change in the state of the sock
333   *	@sk_data_ready: callback to indicate there is data to be processed
334   *	@sk_write_space: callback to indicate there is bf sending space available
335   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
336   *	@sk_backlog_rcv: callback to process the backlog
337   *	@sk_validate_xmit_skb: ptr to an optional validate function
338   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
339   *	@sk_reuseport_cb: reuseport group container
340   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
341   *	@sk_rcu: used during RCU grace period
342   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
343   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
344   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
345   *	@sk_txtime_unused: unused txtime flags
346   *	@sk_scm_recv_flags: all flags used by scm_recv()
347   *	@sk_scm_credentials: flagged by SO_PASSCRED to recv SCM_CREDENTIALS
348   *	@sk_scm_security: flagged by SO_PASSSEC to recv SCM_SECURITY
349   *	@sk_scm_pidfd: flagged by SO_PASSPIDFD to recv SCM_PIDFD
350   *	@sk_scm_rights: flagged by SO_PASSRIGHTS to recv SCM_RIGHTS
351   *	@sk_scm_unused: unused flags for scm_recv()
352   *	@ns_tracker: tracker for netns reference
353   *	@sk_user_frags: xarray of pages the user is holding a reference on.
354   *	@sk_owner: reference to the real owner of the socket that calls
355   *		   sock_lock_init_class_and_name().
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 	__cacheline_group_begin(sock_write_rx);
398 
399 	atomic_t		sk_drops;
400 	__s32			sk_peek_off;
401 	struct sk_buff_head	sk_error_queue;
402 	struct sk_buff_head	sk_receive_queue;
403 	/*
404 	 * The backlog queue is special, it is always used with
405 	 * the per-socket spinlock held and requires low latency
406 	 * access. Therefore we special case it's implementation.
407 	 * Note : rmem_alloc is in this structure to fill a hole
408 	 * on 64bit arches, not because its logically part of
409 	 * backlog.
410 	 */
411 	struct {
412 		atomic_t	rmem_alloc;
413 		int		len;
414 		struct sk_buff	*head;
415 		struct sk_buff	*tail;
416 	} sk_backlog;
417 #define sk_rmem_alloc sk_backlog.rmem_alloc
418 
419 	__cacheline_group_end(sock_write_rx);
420 
421 	__cacheline_group_begin(sock_read_rx);
422 	/* early demux fields */
423 	struct dst_entry __rcu	*sk_rx_dst;
424 	int			sk_rx_dst_ifindex;
425 	u32			sk_rx_dst_cookie;
426 
427 #ifdef CONFIG_NET_RX_BUSY_POLL
428 	unsigned int		sk_ll_usec;
429 	unsigned int		sk_napi_id;
430 	u16			sk_busy_poll_budget;
431 	u8			sk_prefer_busy_poll;
432 #endif
433 	u8			sk_userlocks;
434 	int			sk_rcvbuf;
435 
436 	struct sk_filter __rcu	*sk_filter;
437 	union {
438 		struct socket_wq __rcu	*sk_wq;
439 		/* private: */
440 		struct socket_wq	*sk_wq_raw;
441 		/* public: */
442 	};
443 
444 	void			(*sk_data_ready)(struct sock *sk);
445 	long			sk_rcvtimeo;
446 	int			sk_rcvlowat;
447 	__cacheline_group_end(sock_read_rx);
448 
449 	__cacheline_group_begin(sock_read_rxtx);
450 	int			sk_err;
451 	struct socket		*sk_socket;
452 #ifdef CONFIG_MEMCG
453 	struct mem_cgroup	*sk_memcg;
454 #endif
455 #ifdef CONFIG_XFRM
456 	struct xfrm_policy __rcu *sk_policy[2];
457 #endif
458 	struct socket_drop_counters *sk_drop_counters;
459 	__cacheline_group_end(sock_read_rxtx);
460 
461 	__cacheline_group_begin(sock_write_rxtx);
462 	socket_lock_t		sk_lock;
463 	u32			sk_reserved_mem;
464 	int			sk_forward_alloc;
465 	u32			sk_tsflags;
466 	__cacheline_group_end(sock_write_rxtx);
467 
468 	__cacheline_group_begin(sock_write_tx);
469 	int			sk_write_pending;
470 	atomic_t		sk_omem_alloc;
471 	int			sk_sndbuf;
472 
473 	int			sk_wmem_queued;
474 	refcount_t		sk_wmem_alloc;
475 	unsigned long		sk_tsq_flags;
476 	union {
477 		struct sk_buff	*sk_send_head;
478 		struct rb_root	tcp_rtx_queue;
479 	};
480 	struct sk_buff_head	sk_write_queue;
481 	u32			sk_dst_pending_confirm;
482 	u32			sk_pacing_status; /* see enum sk_pacing */
483 	struct page_frag	sk_frag;
484 	struct timer_list	sk_timer;
485 
486 	unsigned long		sk_pacing_rate; /* bytes per second */
487 	atomic_t		sk_zckey;
488 	atomic_t		sk_tskey;
489 	__cacheline_group_end(sock_write_tx);
490 
491 	__cacheline_group_begin(sock_read_tx);
492 	unsigned long		sk_max_pacing_rate;
493 	long			sk_sndtimeo;
494 	u32			sk_priority;
495 	u32			sk_mark;
496 	struct dst_entry __rcu	*sk_dst_cache;
497 	netdev_features_t	sk_route_caps;
498 #ifdef CONFIG_SOCK_VALIDATE_XMIT
499 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
500 							struct net_device *dev,
501 							struct sk_buff *skb);
502 #endif
503 	u16			sk_gso_type;
504 	u16			sk_gso_max_segs;
505 	unsigned int		sk_gso_max_size;
506 	gfp_t			sk_allocation;
507 	u32			sk_txhash;
508 	u8			sk_pacing_shift;
509 	bool			sk_use_task_frag;
510 	__cacheline_group_end(sock_read_tx);
511 
512 	/*
513 	 * Because of non atomicity rules, all
514 	 * changes are protected by socket lock.
515 	 */
516 	u8			sk_gso_disabled : 1,
517 				sk_kern_sock : 1,
518 				sk_no_check_tx : 1,
519 				sk_no_check_rx : 1;
520 	u8			sk_shutdown;
521 	u16			sk_type;
522 	u16			sk_protocol;
523 	unsigned long	        sk_lingertime;
524 	struct proto		*sk_prot_creator;
525 	rwlock_t		sk_callback_lock;
526 	int			sk_err_soft;
527 	u32			sk_ack_backlog;
528 	u32			sk_max_ack_backlog;
529 	kuid_t			sk_uid;
530 	spinlock_t		sk_peer_lock;
531 	int			sk_bind_phc;
532 	struct pid		*sk_peer_pid;
533 	const struct cred	*sk_peer_cred;
534 
535 	ktime_t			sk_stamp;
536 #if BITS_PER_LONG==32
537 	seqlock_t		sk_stamp_seq;
538 #endif
539 	int			sk_disconnects;
540 
541 	union {
542 		u8		sk_txrehash;
543 		u8		sk_scm_recv_flags;
544 		struct {
545 			u8	sk_scm_credentials : 1,
546 				sk_scm_security : 1,
547 				sk_scm_pidfd : 1,
548 				sk_scm_rights : 1,
549 				sk_scm_unused : 4;
550 		};
551 	};
552 	u8			sk_clockid;
553 	u8			sk_txtime_deadline_mode : 1,
554 				sk_txtime_report_errors : 1,
555 				sk_txtime_unused : 6;
556 #define SK_BPF_CB_FLAG_TEST(SK, FLAG) ((SK)->sk_bpf_cb_flags & (FLAG))
557 	u8			sk_bpf_cb_flags;
558 
559 	void			*sk_user_data;
560 #ifdef CONFIG_SECURITY
561 	void			*sk_security;
562 #endif
563 	struct sock_cgroup_data	sk_cgrp_data;
564 	void			(*sk_state_change)(struct sock *sk);
565 	void			(*sk_write_space)(struct sock *sk);
566 	void			(*sk_error_report)(struct sock *sk);
567 	int			(*sk_backlog_rcv)(struct sock *sk,
568 						  struct sk_buff *skb);
569 	void                    (*sk_destruct)(struct sock *sk);
570 	struct sock_reuseport __rcu	*sk_reuseport_cb;
571 #ifdef CONFIG_BPF_SYSCALL
572 	struct bpf_local_storage __rcu	*sk_bpf_storage;
573 #endif
574 	struct rcu_head		sk_rcu;
575 	netns_tracker		ns_tracker;
576 	struct xarray		sk_user_frags;
577 
578 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
579 	struct module		*sk_owner;
580 #endif
581 };
582 
583 struct sock_bh_locked {
584 	struct sock *sock;
585 	local_lock_t bh_lock;
586 };
587 
588 enum sk_pacing {
589 	SK_PACING_NONE		= 0,
590 	SK_PACING_NEEDED	= 1,
591 	SK_PACING_FQ		= 2,
592 };
593 
594 /* flag bits in sk_user_data
595  *
596  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
597  *   not be suitable for copying when cloning the socket. For instance,
598  *   it can point to a reference counted object. sk_user_data bottom
599  *   bit is set if pointer must not be copied.
600  *
601  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
602  *   managed/owned by a BPF reuseport array. This bit should be set
603  *   when sk_user_data's sk is added to the bpf's reuseport_array.
604  *
605  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
606  *   sk_user_data points to psock type. This bit should be set
607  *   when sk_user_data is assigned to a psock object.
608  */
609 #define SK_USER_DATA_NOCOPY	1UL
610 #define SK_USER_DATA_BPF	2UL
611 #define SK_USER_DATA_PSOCK	4UL
612 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
613 				  SK_USER_DATA_PSOCK)
614 
615 /**
616  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
617  * @sk: socket
618  */
619 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
620 {
621 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
622 }
623 
624 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
625 
626 /**
627  * __locked_read_sk_user_data_with_flags - return the pointer
628  * only if argument flags all has been set in sk_user_data. Otherwise
629  * return NULL
630  *
631  * @sk: socket
632  * @flags: flag bits
633  *
634  * The caller must be holding sk->sk_callback_lock.
635  */
636 static inline void *
637 __locked_read_sk_user_data_with_flags(const struct sock *sk,
638 				      uintptr_t flags)
639 {
640 	uintptr_t sk_user_data =
641 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
642 						 lockdep_is_held(&sk->sk_callback_lock));
643 
644 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
645 
646 	if ((sk_user_data & flags) == flags)
647 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
648 	return NULL;
649 }
650 
651 /**
652  * __rcu_dereference_sk_user_data_with_flags - return the pointer
653  * only if argument flags all has been set in sk_user_data. Otherwise
654  * return NULL
655  *
656  * @sk: socket
657  * @flags: flag bits
658  */
659 static inline void *
660 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
661 					  uintptr_t flags)
662 {
663 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
664 
665 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
666 
667 	if ((sk_user_data & flags) == flags)
668 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
669 	return NULL;
670 }
671 
672 #define rcu_dereference_sk_user_data(sk)				\
673 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
674 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
675 ({									\
676 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
677 		  __tmp2 = (uintptr_t)(flags);				\
678 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
679 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
680 	rcu_assign_pointer(__sk_user_data((sk)),			\
681 			   __tmp1 | __tmp2);				\
682 })
683 #define rcu_assign_sk_user_data(sk, ptr)				\
684 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
685 
686 static inline
687 struct net *sock_net(const struct sock *sk)
688 {
689 	return read_pnet(&sk->sk_net);
690 }
691 
692 static inline
693 void sock_net_set(struct sock *sk, struct net *net)
694 {
695 	write_pnet(&sk->sk_net, net);
696 }
697 
698 /*
699  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
700  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
701  * on a socket means that the socket will reuse everybody else's port
702  * without looking at the other's sk_reuse value.
703  */
704 
705 #define SK_NO_REUSE	0
706 #define SK_CAN_REUSE	1
707 #define SK_FORCE_REUSE	2
708 
709 int sk_set_peek_off(struct sock *sk, int val);
710 
711 static inline int sk_peek_offset(const struct sock *sk, int flags)
712 {
713 	if (unlikely(flags & MSG_PEEK)) {
714 		return READ_ONCE(sk->sk_peek_off);
715 	}
716 
717 	return 0;
718 }
719 
720 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
721 {
722 	s32 off = READ_ONCE(sk->sk_peek_off);
723 
724 	if (unlikely(off >= 0)) {
725 		off = max_t(s32, off - val, 0);
726 		WRITE_ONCE(sk->sk_peek_off, off);
727 	}
728 }
729 
730 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
731 {
732 	sk_peek_offset_bwd(sk, -val);
733 }
734 
735 /*
736  * Hashed lists helper routines
737  */
738 static inline struct sock *sk_entry(const struct hlist_node *node)
739 {
740 	return hlist_entry(node, struct sock, sk_node);
741 }
742 
743 static inline struct sock *__sk_head(const struct hlist_head *head)
744 {
745 	return hlist_entry(head->first, struct sock, sk_node);
746 }
747 
748 static inline struct sock *sk_head(const struct hlist_head *head)
749 {
750 	return hlist_empty(head) ? NULL : __sk_head(head);
751 }
752 
753 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
754 {
755 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
756 }
757 
758 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
759 {
760 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
761 }
762 
763 static inline struct sock *sk_next(const struct sock *sk)
764 {
765 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
766 }
767 
768 static inline struct sock *sk_nulls_next(const struct sock *sk)
769 {
770 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
771 		hlist_nulls_entry(sk->sk_nulls_node.next,
772 				  struct sock, sk_nulls_node) :
773 		NULL;
774 }
775 
776 static inline bool sk_unhashed(const struct sock *sk)
777 {
778 	return hlist_unhashed(&sk->sk_node);
779 }
780 
781 static inline bool sk_hashed(const struct sock *sk)
782 {
783 	return !sk_unhashed(sk);
784 }
785 
786 static inline void sk_node_init(struct hlist_node *node)
787 {
788 	node->pprev = NULL;
789 }
790 
791 static inline void __sk_del_node(struct sock *sk)
792 {
793 	__hlist_del(&sk->sk_node);
794 }
795 
796 /* NB: equivalent to hlist_del_init_rcu */
797 static inline bool __sk_del_node_init(struct sock *sk)
798 {
799 	if (sk_hashed(sk)) {
800 		__sk_del_node(sk);
801 		sk_node_init(&sk->sk_node);
802 		return true;
803 	}
804 	return false;
805 }
806 
807 /* Grab socket reference count. This operation is valid only
808    when sk is ALREADY grabbed f.e. it is found in hash table
809    or a list and the lookup is made under lock preventing hash table
810    modifications.
811  */
812 
813 static __always_inline void sock_hold(struct sock *sk)
814 {
815 	refcount_inc(&sk->sk_refcnt);
816 }
817 
818 /* Ungrab socket in the context, which assumes that socket refcnt
819    cannot hit zero, f.e. it is true in context of any socketcall.
820  */
821 static __always_inline void __sock_put(struct sock *sk)
822 {
823 	refcount_dec(&sk->sk_refcnt);
824 }
825 
826 static inline bool sk_del_node_init(struct sock *sk)
827 {
828 	bool rc = __sk_del_node_init(sk);
829 
830 	if (rc) {
831 		/* paranoid for a while -acme */
832 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
833 		__sock_put(sk);
834 	}
835 	return rc;
836 }
837 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
838 
839 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
840 {
841 	if (sk_hashed(sk)) {
842 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
843 		return true;
844 	}
845 	return false;
846 }
847 
848 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
849 {
850 	bool rc = __sk_nulls_del_node_init_rcu(sk);
851 
852 	if (rc) {
853 		/* paranoid for a while -acme */
854 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
855 		__sock_put(sk);
856 	}
857 	return rc;
858 }
859 
860 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
861 {
862 	hlist_add_head(&sk->sk_node, list);
863 }
864 
865 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
866 {
867 	sock_hold(sk);
868 	__sk_add_node(sk, list);
869 }
870 
871 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
872 {
873 	sock_hold(sk);
874 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
875 	    sk->sk_family == AF_INET6)
876 		hlist_add_tail_rcu(&sk->sk_node, list);
877 	else
878 		hlist_add_head_rcu(&sk->sk_node, list);
879 }
880 
881 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
882 {
883 	sock_hold(sk);
884 	hlist_add_tail_rcu(&sk->sk_node, list);
885 }
886 
887 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
888 {
889 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
890 }
891 
892 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
893 {
894 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
895 }
896 
897 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
898 {
899 	sock_hold(sk);
900 	__sk_nulls_add_node_rcu(sk, list);
901 }
902 
903 static inline void __sk_del_bind_node(struct sock *sk)
904 {
905 	__hlist_del(&sk->sk_bind_node);
906 }
907 
908 static inline void sk_add_bind_node(struct sock *sk,
909 					struct hlist_head *list)
910 {
911 	hlist_add_head(&sk->sk_bind_node, list);
912 }
913 
914 #define sk_for_each(__sk, list) \
915 	hlist_for_each_entry(__sk, list, sk_node)
916 #define sk_for_each_rcu(__sk, list) \
917 	hlist_for_each_entry_rcu(__sk, list, sk_node)
918 #define sk_nulls_for_each(__sk, node, list) \
919 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
920 #define sk_nulls_for_each_rcu(__sk, node, list) \
921 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
922 #define sk_for_each_from(__sk) \
923 	hlist_for_each_entry_from(__sk, sk_node)
924 #define sk_nulls_for_each_from(__sk, node) \
925 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
926 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
927 #define sk_for_each_safe(__sk, tmp, list) \
928 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
929 #define sk_for_each_bound(__sk, list) \
930 	hlist_for_each_entry(__sk, list, sk_bind_node)
931 #define sk_for_each_bound_safe(__sk, tmp, list) \
932 	hlist_for_each_entry_safe(__sk, tmp, list, sk_bind_node)
933 
934 /**
935  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
936  * @tpos:	the type * to use as a loop cursor.
937  * @pos:	the &struct hlist_node to use as a loop cursor.
938  * @head:	the head for your list.
939  * @offset:	offset of hlist_node within the struct.
940  *
941  */
942 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
943 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
944 	     pos != NULL &&						       \
945 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
946 	     pos = rcu_dereference(hlist_next_rcu(pos)))
947 
948 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
949 {
950 	/* Careful only use this in a context where these parameters
951 	 * can not change and must all be valid, such as recvmsg from
952 	 * userspace.
953 	 */
954 	return sk->sk_socket->file->f_cred->user_ns;
955 }
956 
957 /* Sock flags */
958 enum sock_flags {
959 	SOCK_DEAD,
960 	SOCK_DONE,
961 	SOCK_URGINLINE,
962 	SOCK_KEEPOPEN,
963 	SOCK_LINGER,
964 	SOCK_DESTROY,
965 	SOCK_BROADCAST,
966 	SOCK_TIMESTAMP,
967 	SOCK_ZAPPED,
968 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
969 	SOCK_DBG, /* %SO_DEBUG setting */
970 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
971 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
972 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
973 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
974 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
975 	SOCK_FASYNC, /* fasync() active */
976 	SOCK_RXQ_OVFL,
977 	SOCK_ZEROCOPY, /* buffers from userspace */
978 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
979 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
980 		     * Will use last 4 bytes of packet sent from
981 		     * user-space instead.
982 		     */
983 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
984 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
985 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
986 	SOCK_TXTIME,
987 	SOCK_XDP, /* XDP is attached */
988 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
989 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
990 	SOCK_RCVPRIORITY, /* Receive SO_PRIORITY ancillary data with packet */
991 	SOCK_TIMESTAMPING_ANY, /* Copy of sk_tsflags & TSFLAGS_ANY */
992 };
993 
994 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
995 /*
996  * The highest bit of sk_tsflags is reserved for kernel-internal
997  * SOCKCM_FLAG_TS_OPT_ID. There is a check in core/sock.c to control that
998  * SOF_TIMESTAMPING* values do not reach this reserved area
999  */
1000 #define SOCKCM_FLAG_TS_OPT_ID	BIT(31)
1001 
1002 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
1003 {
1004 	nsk->sk_flags = osk->sk_flags;
1005 }
1006 
1007 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
1008 {
1009 	__set_bit(flag, &sk->sk_flags);
1010 }
1011 
1012 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
1013 {
1014 	__clear_bit(flag, &sk->sk_flags);
1015 }
1016 
1017 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
1018 				     int valbool)
1019 {
1020 	if (valbool)
1021 		sock_set_flag(sk, bit);
1022 	else
1023 		sock_reset_flag(sk, bit);
1024 }
1025 
1026 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
1027 {
1028 	return test_bit(flag, &sk->sk_flags);
1029 }
1030 
1031 #ifdef CONFIG_NET
1032 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
1033 static inline int sk_memalloc_socks(void)
1034 {
1035 	return static_branch_unlikely(&memalloc_socks_key);
1036 }
1037 
1038 void __receive_sock(struct file *file);
1039 #else
1040 
1041 static inline int sk_memalloc_socks(void)
1042 {
1043 	return 0;
1044 }
1045 
1046 static inline void __receive_sock(struct file *file)
1047 { }
1048 #endif
1049 
1050 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1051 {
1052 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1053 }
1054 
1055 static inline void sk_acceptq_removed(struct sock *sk)
1056 {
1057 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1058 }
1059 
1060 static inline void sk_acceptq_added(struct sock *sk)
1061 {
1062 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1063 }
1064 
1065 /* Note: If you think the test should be:
1066  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1067  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1068  */
1069 static inline bool sk_acceptq_is_full(const struct sock *sk)
1070 {
1071 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1072 }
1073 
1074 /*
1075  * Compute minimal free write space needed to queue new packets.
1076  */
1077 static inline int sk_stream_min_wspace(const struct sock *sk)
1078 {
1079 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1080 }
1081 
1082 static inline int sk_stream_wspace(const struct sock *sk)
1083 {
1084 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1085 }
1086 
1087 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1088 {
1089 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1090 }
1091 
1092 static inline void sk_forward_alloc_add(struct sock *sk, int val)
1093 {
1094 	/* Paired with lockless reads of sk->sk_forward_alloc */
1095 	WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val);
1096 }
1097 
1098 void sk_stream_write_space(struct sock *sk);
1099 
1100 /* OOB backlog add */
1101 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1102 {
1103 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1104 	skb_dst_force(skb);
1105 
1106 	if (!sk->sk_backlog.tail)
1107 		WRITE_ONCE(sk->sk_backlog.head, skb);
1108 	else
1109 		sk->sk_backlog.tail->next = skb;
1110 
1111 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1112 	skb->next = NULL;
1113 }
1114 
1115 /*
1116  * Take into account size of receive queue and backlog queue
1117  * Do not take into account this skb truesize,
1118  * to allow even a single big packet to come.
1119  */
1120 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1121 {
1122 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1123 
1124 	return qsize > limit;
1125 }
1126 
1127 /* The per-socket spinlock must be held here. */
1128 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1129 					      unsigned int limit)
1130 {
1131 	if (sk_rcvqueues_full(sk, limit))
1132 		return -ENOBUFS;
1133 
1134 	/*
1135 	 * If the skb was allocated from pfmemalloc reserves, only
1136 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1137 	 * helping free memory
1138 	 */
1139 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1140 		return -ENOMEM;
1141 
1142 	__sk_add_backlog(sk, skb);
1143 	sk->sk_backlog.len += skb->truesize;
1144 	return 0;
1145 }
1146 
1147 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1148 
1149 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1150 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1151 
1152 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1153 {
1154 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1155 		return __sk_backlog_rcv(sk, skb);
1156 
1157 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1158 				  tcp_v6_do_rcv,
1159 				  tcp_v4_do_rcv,
1160 				  sk, skb);
1161 }
1162 
1163 static inline void sk_incoming_cpu_update(struct sock *sk)
1164 {
1165 	int cpu = raw_smp_processor_id();
1166 
1167 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1168 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1169 }
1170 
1171 
1172 static inline void sock_rps_save_rxhash(struct sock *sk,
1173 					const struct sk_buff *skb)
1174 {
1175 #ifdef CONFIG_RPS
1176 	/* The following WRITE_ONCE() is paired with the READ_ONCE()
1177 	 * here, and another one in sock_rps_record_flow().
1178 	 */
1179 	if (unlikely(READ_ONCE(sk->sk_rxhash) != skb->hash))
1180 		WRITE_ONCE(sk->sk_rxhash, skb->hash);
1181 #endif
1182 }
1183 
1184 static inline void sock_rps_reset_rxhash(struct sock *sk)
1185 {
1186 #ifdef CONFIG_RPS
1187 	/* Paired with READ_ONCE() in sock_rps_record_flow() */
1188 	WRITE_ONCE(sk->sk_rxhash, 0);
1189 #endif
1190 }
1191 
1192 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1193 	({	int __rc, __dis = __sk->sk_disconnects;			\
1194 		release_sock(__sk);					\
1195 		__rc = __condition;					\
1196 		if (!__rc) {						\
1197 			*(__timeo) = wait_woken(__wait,			\
1198 						TASK_INTERRUPTIBLE,	\
1199 						*(__timeo));		\
1200 		}							\
1201 		sched_annotate_sleep();					\
1202 		lock_sock(__sk);					\
1203 		__rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
1204 		__rc;							\
1205 	})
1206 
1207 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1208 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1209 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1210 int sk_stream_error(struct sock *sk, int flags, int err);
1211 void sk_stream_kill_queues(struct sock *sk);
1212 void sk_set_memalloc(struct sock *sk);
1213 void sk_clear_memalloc(struct sock *sk);
1214 
1215 void __sk_flush_backlog(struct sock *sk);
1216 
1217 static inline bool sk_flush_backlog(struct sock *sk)
1218 {
1219 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1220 		__sk_flush_backlog(sk);
1221 		return true;
1222 	}
1223 	return false;
1224 }
1225 
1226 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1227 
1228 struct request_sock_ops;
1229 struct timewait_sock_ops;
1230 struct inet_hashinfo;
1231 struct raw_hashinfo;
1232 struct smc_hashinfo;
1233 struct module;
1234 struct sk_psock;
1235 
1236 /*
1237  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1238  * un-modified. Special care is taken when initializing object to zero.
1239  */
1240 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1241 {
1242 	if (offsetof(struct sock, sk_node.next) != 0)
1243 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1244 	memset(&sk->sk_node.pprev, 0,
1245 	       size - offsetof(struct sock, sk_node.pprev));
1246 }
1247 
1248 struct proto_accept_arg {
1249 	int flags;
1250 	int err;
1251 	int is_empty;
1252 	bool kern;
1253 };
1254 
1255 /* Networking protocol blocks we attach to sockets.
1256  * socket layer -> transport layer interface
1257  */
1258 struct proto {
1259 	void			(*close)(struct sock *sk,
1260 					long timeout);
1261 	int			(*pre_connect)(struct sock *sk,
1262 					struct sockaddr *uaddr,
1263 					int addr_len);
1264 	int			(*connect)(struct sock *sk,
1265 					struct sockaddr *uaddr,
1266 					int addr_len);
1267 	int			(*disconnect)(struct sock *sk, int flags);
1268 
1269 	struct sock *		(*accept)(struct sock *sk,
1270 					  struct proto_accept_arg *arg);
1271 
1272 	int			(*ioctl)(struct sock *sk, int cmd,
1273 					 int *karg);
1274 	int			(*init)(struct sock *sk);
1275 	void			(*destroy)(struct sock *sk);
1276 	void			(*shutdown)(struct sock *sk, int how);
1277 	int			(*setsockopt)(struct sock *sk, int level,
1278 					int optname, sockptr_t optval,
1279 					unsigned int optlen);
1280 	int			(*getsockopt)(struct sock *sk, int level,
1281 					int optname, char __user *optval,
1282 					int __user *option);
1283 	void			(*keepalive)(struct sock *sk, int valbool);
1284 #ifdef CONFIG_COMPAT
1285 	int			(*compat_ioctl)(struct sock *sk,
1286 					unsigned int cmd, unsigned long arg);
1287 #endif
1288 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1289 					   size_t len);
1290 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1291 					   size_t len, int flags, int *addr_len);
1292 	void			(*splice_eof)(struct socket *sock);
1293 	int			(*bind)(struct sock *sk,
1294 					struct sockaddr *addr, int addr_len);
1295 	int			(*bind_add)(struct sock *sk,
1296 					struct sockaddr *addr, int addr_len);
1297 
1298 	int			(*backlog_rcv) (struct sock *sk,
1299 						struct sk_buff *skb);
1300 	bool			(*bpf_bypass_getsockopt)(int level,
1301 							 int optname);
1302 
1303 	void		(*release_cb)(struct sock *sk);
1304 
1305 	/* Keeping track of sk's, looking them up, and port selection methods. */
1306 	int			(*hash)(struct sock *sk);
1307 	void			(*unhash)(struct sock *sk);
1308 	void			(*rehash)(struct sock *sk);
1309 	int			(*get_port)(struct sock *sk, unsigned short snum);
1310 	void			(*put_port)(struct sock *sk);
1311 #ifdef CONFIG_BPF_SYSCALL
1312 	int			(*psock_update_sk_prot)(struct sock *sk,
1313 							struct sk_psock *psock,
1314 							bool restore);
1315 #endif
1316 
1317 	/* Keeping track of sockets in use */
1318 #ifdef CONFIG_PROC_FS
1319 	unsigned int		inuse_idx;
1320 #endif
1321 
1322 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1323 	bool			(*sock_is_readable)(struct sock *sk);
1324 	/* Memory pressure */
1325 	void			(*enter_memory_pressure)(struct sock *sk);
1326 	void			(*leave_memory_pressure)(struct sock *sk);
1327 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1328 	int  __percpu		*per_cpu_fw_alloc;
1329 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1330 
1331 	/*
1332 	 * Pressure flag: try to collapse.
1333 	 * Technical note: it is used by multiple contexts non atomically.
1334 	 * Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
1335 	 * All the __sk_mem_schedule() is of this nature: accounting
1336 	 * is strict, actions are advisory and have some latency.
1337 	 */
1338 	unsigned long		*memory_pressure;
1339 	long			*sysctl_mem;
1340 
1341 	int			*sysctl_wmem;
1342 	int			*sysctl_rmem;
1343 	u32			sysctl_wmem_offset;
1344 	u32			sysctl_rmem_offset;
1345 
1346 	int			max_header;
1347 	bool			no_autobind;
1348 
1349 	struct kmem_cache	*slab;
1350 	unsigned int		obj_size;
1351 	unsigned int		ipv6_pinfo_offset;
1352 	slab_flags_t		slab_flags;
1353 	unsigned int		useroffset;	/* Usercopy region offset */
1354 	unsigned int		usersize;	/* Usercopy region size */
1355 
1356 	struct request_sock_ops	*rsk_prot;
1357 	struct timewait_sock_ops *twsk_prot;
1358 
1359 	union {
1360 		struct inet_hashinfo	*hashinfo;
1361 		struct udp_table	*udp_table;
1362 		struct raw_hashinfo	*raw_hash;
1363 		struct smc_hashinfo	*smc_hash;
1364 	} h;
1365 
1366 	struct module		*owner;
1367 
1368 	char			name[32];
1369 
1370 	struct list_head	node;
1371 	int			(*diag_destroy)(struct sock *sk, int err);
1372 } __randomize_layout;
1373 
1374 int proto_register(struct proto *prot, int alloc_slab);
1375 void proto_unregister(struct proto *prot);
1376 int sock_load_diag_module(int family, int protocol);
1377 
1378 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1379 
1380 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1381 {
1382 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1383 		return false;
1384 
1385 	return sk->sk_prot->stream_memory_free ?
1386 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1387 				     tcp_stream_memory_free, sk, wake) : true;
1388 }
1389 
1390 static inline bool sk_stream_memory_free(const struct sock *sk)
1391 {
1392 	return __sk_stream_memory_free(sk, 0);
1393 }
1394 
1395 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1396 {
1397 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1398 	       __sk_stream_memory_free(sk, wake);
1399 }
1400 
1401 static inline bool sk_stream_is_writeable(const struct sock *sk)
1402 {
1403 	return __sk_stream_is_writeable(sk, 0);
1404 }
1405 
1406 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1407 					    struct cgroup *ancestor)
1408 {
1409 #ifdef CONFIG_SOCK_CGROUP_DATA
1410 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1411 				    ancestor);
1412 #else
1413 	return -ENOTSUPP;
1414 #endif
1415 }
1416 
1417 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1418 
1419 static inline void sk_sockets_allocated_dec(struct sock *sk)
1420 {
1421 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1422 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1423 }
1424 
1425 static inline void sk_sockets_allocated_inc(struct sock *sk)
1426 {
1427 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1428 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1429 }
1430 
1431 static inline u64
1432 sk_sockets_allocated_read_positive(struct sock *sk)
1433 {
1434 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1435 }
1436 
1437 static inline int
1438 proto_sockets_allocated_sum_positive(struct proto *prot)
1439 {
1440 	return percpu_counter_sum_positive(prot->sockets_allocated);
1441 }
1442 
1443 #ifdef CONFIG_PROC_FS
1444 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1445 struct prot_inuse {
1446 	int all;
1447 	int val[PROTO_INUSE_NR];
1448 };
1449 
1450 static inline void sock_prot_inuse_add(const struct net *net,
1451 				       const struct proto *prot, int val)
1452 {
1453 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1454 }
1455 
1456 static inline void sock_inuse_add(const struct net *net, int val)
1457 {
1458 	this_cpu_add(net->core.prot_inuse->all, val);
1459 }
1460 
1461 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1462 int sock_inuse_get(struct net *net);
1463 #else
1464 static inline void sock_prot_inuse_add(const struct net *net,
1465 				       const struct proto *prot, int val)
1466 {
1467 }
1468 
1469 static inline void sock_inuse_add(const struct net *net, int val)
1470 {
1471 }
1472 #endif
1473 
1474 
1475 /* With per-bucket locks this operation is not-atomic, so that
1476  * this version is not worse.
1477  */
1478 static inline int __sk_prot_rehash(struct sock *sk)
1479 {
1480 	sk->sk_prot->unhash(sk);
1481 	return sk->sk_prot->hash(sk);
1482 }
1483 
1484 /* About 10 seconds */
1485 #define SOCK_DESTROY_TIME (10*HZ)
1486 
1487 /* Sockets 0-1023 can't be bound to unless you are superuser */
1488 #define PROT_SOCK	1024
1489 
1490 #define SHUTDOWN_MASK	3
1491 #define RCV_SHUTDOWN	1
1492 #define SEND_SHUTDOWN	2
1493 
1494 #define SOCK_BINDADDR_LOCK	4
1495 #define SOCK_BINDPORT_LOCK	8
1496 
1497 struct socket_alloc {
1498 	struct socket socket;
1499 	struct inode vfs_inode;
1500 };
1501 
1502 static inline struct socket *SOCKET_I(struct inode *inode)
1503 {
1504 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1505 }
1506 
1507 static inline struct inode *SOCK_INODE(struct socket *socket)
1508 {
1509 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1510 }
1511 
1512 /*
1513  * Functions for memory accounting
1514  */
1515 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1516 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1517 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1518 void __sk_mem_reclaim(struct sock *sk, int amount);
1519 
1520 #define SK_MEM_SEND	0
1521 #define SK_MEM_RECV	1
1522 
1523 /* sysctl_mem values are in pages */
1524 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1525 {
1526 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1527 }
1528 
1529 static inline int sk_mem_pages(int amt)
1530 {
1531 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1532 }
1533 
1534 static inline bool sk_has_account(struct sock *sk)
1535 {
1536 	/* return true if protocol supports memory accounting */
1537 	return !!sk->sk_prot->memory_allocated;
1538 }
1539 
1540 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1541 {
1542 	int delta;
1543 
1544 	if (!sk_has_account(sk))
1545 		return true;
1546 	delta = size - sk->sk_forward_alloc;
1547 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1548 }
1549 
1550 static inline bool
1551 __sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)
1552 {
1553 	int delta;
1554 
1555 	if (!sk_has_account(sk))
1556 		return true;
1557 	delta = size - sk->sk_forward_alloc;
1558 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1559 	       pfmemalloc;
1560 }
1561 
1562 static inline bool
1563 sk_rmem_schedule(struct sock *sk, const struct sk_buff *skb, int size)
1564 {
1565 	return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));
1566 }
1567 
1568 static inline int sk_unused_reserved_mem(const struct sock *sk)
1569 {
1570 	int unused_mem;
1571 
1572 	if (likely(!sk->sk_reserved_mem))
1573 		return 0;
1574 
1575 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1576 			atomic_read(&sk->sk_rmem_alloc);
1577 
1578 	return unused_mem > 0 ? unused_mem : 0;
1579 }
1580 
1581 static inline void sk_mem_reclaim(struct sock *sk)
1582 {
1583 	int reclaimable;
1584 
1585 	if (!sk_has_account(sk))
1586 		return;
1587 
1588 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1589 
1590 	if (reclaimable >= (int)PAGE_SIZE)
1591 		__sk_mem_reclaim(sk, reclaimable);
1592 }
1593 
1594 static inline void sk_mem_reclaim_final(struct sock *sk)
1595 {
1596 	sk->sk_reserved_mem = 0;
1597 	sk_mem_reclaim(sk);
1598 }
1599 
1600 static inline void sk_mem_charge(struct sock *sk, int size)
1601 {
1602 	if (!sk_has_account(sk))
1603 		return;
1604 	sk_forward_alloc_add(sk, -size);
1605 }
1606 
1607 static inline void sk_mem_uncharge(struct sock *sk, int size)
1608 {
1609 	if (!sk_has_account(sk))
1610 		return;
1611 	sk_forward_alloc_add(sk, size);
1612 	sk_mem_reclaim(sk);
1613 }
1614 
1615 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
1616 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1617 {
1618 	__module_get(owner);
1619 	sk->sk_owner = owner;
1620 }
1621 
1622 static inline void sk_owner_clear(struct sock *sk)
1623 {
1624 	sk->sk_owner = NULL;
1625 }
1626 
1627 static inline void sk_owner_put(struct sock *sk)
1628 {
1629 	module_put(sk->sk_owner);
1630 }
1631 #else
1632 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1633 {
1634 }
1635 
1636 static inline void sk_owner_clear(struct sock *sk)
1637 {
1638 }
1639 
1640 static inline void sk_owner_put(struct sock *sk)
1641 {
1642 }
1643 #endif
1644 /*
1645  * Macro so as to not evaluate some arguments when
1646  * lockdep is not enabled.
1647  *
1648  * Mark both the sk_lock and the sk_lock.slock as a
1649  * per-address-family lock class.
1650  */
1651 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1652 do {									\
1653 	sk_owner_set(sk, THIS_MODULE);					\
1654 	sk->sk_lock.owned = 0;						\
1655 	init_waitqueue_head(&sk->sk_lock.wq);				\
1656 	spin_lock_init(&(sk)->sk_lock.slock);				\
1657 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1658 				   sizeof((sk)->sk_lock));		\
1659 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1660 				   (skey), (sname));			\
1661 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1662 } while (0)
1663 
1664 static inline bool lockdep_sock_is_held(const struct sock *sk)
1665 {
1666 	return lockdep_is_held(&sk->sk_lock) ||
1667 	       lockdep_is_held(&sk->sk_lock.slock);
1668 }
1669 
1670 void lock_sock_nested(struct sock *sk, int subclass);
1671 
1672 static inline void lock_sock(struct sock *sk)
1673 {
1674 	lock_sock_nested(sk, 0);
1675 }
1676 
1677 void __lock_sock(struct sock *sk);
1678 void __release_sock(struct sock *sk);
1679 void release_sock(struct sock *sk);
1680 
1681 /* BH context may only use the following locking interface. */
1682 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1683 #define bh_lock_sock_nested(__sk) \
1684 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1685 				SINGLE_DEPTH_NESTING)
1686 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1687 
1688 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1689 
1690 /**
1691  * lock_sock_fast - fast version of lock_sock
1692  * @sk: socket
1693  *
1694  * This version should be used for very small section, where process won't block
1695  * return false if fast path is taken:
1696  *
1697  *   sk_lock.slock locked, owned = 0, BH disabled
1698  *
1699  * return true if slow path is taken:
1700  *
1701  *   sk_lock.slock unlocked, owned = 1, BH enabled
1702  */
1703 static inline bool lock_sock_fast(struct sock *sk)
1704 {
1705 	/* The sk_lock has mutex_lock() semantics here. */
1706 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1707 
1708 	return __lock_sock_fast(sk);
1709 }
1710 
1711 /* fast socket lock variant for caller already holding a [different] socket lock */
1712 static inline bool lock_sock_fast_nested(struct sock *sk)
1713 {
1714 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1715 
1716 	return __lock_sock_fast(sk);
1717 }
1718 
1719 /**
1720  * unlock_sock_fast - complement of lock_sock_fast
1721  * @sk: socket
1722  * @slow: slow mode
1723  *
1724  * fast unlock socket for user context.
1725  * If slow mode is on, we call regular release_sock()
1726  */
1727 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1728 	__releases(&sk->sk_lock.slock)
1729 {
1730 	if (slow) {
1731 		release_sock(sk);
1732 		__release(&sk->sk_lock.slock);
1733 	} else {
1734 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1735 		spin_unlock_bh(&sk->sk_lock.slock);
1736 	}
1737 }
1738 
1739 void sockopt_lock_sock(struct sock *sk);
1740 void sockopt_release_sock(struct sock *sk);
1741 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1742 bool sockopt_capable(int cap);
1743 
1744 /* Used by processes to "lock" a socket state, so that
1745  * interrupts and bottom half handlers won't change it
1746  * from under us. It essentially blocks any incoming
1747  * packets, so that we won't get any new data or any
1748  * packets that change the state of the socket.
1749  *
1750  * While locked, BH processing will add new packets to
1751  * the backlog queue.  This queue is processed by the
1752  * owner of the socket lock right before it is released.
1753  *
1754  * Since ~2.3.5 it is also exclusive sleep lock serializing
1755  * accesses from user process context.
1756  */
1757 
1758 static inline void sock_owned_by_me(const struct sock *sk)
1759 {
1760 #ifdef CONFIG_LOCKDEP
1761 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1762 #endif
1763 }
1764 
1765 static inline void sock_not_owned_by_me(const struct sock *sk)
1766 {
1767 #ifdef CONFIG_LOCKDEP
1768 	WARN_ON_ONCE(lockdep_sock_is_held(sk) && debug_locks);
1769 #endif
1770 }
1771 
1772 static inline bool sock_owned_by_user(const struct sock *sk)
1773 {
1774 	sock_owned_by_me(sk);
1775 	return sk->sk_lock.owned;
1776 }
1777 
1778 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1779 {
1780 	return sk->sk_lock.owned;
1781 }
1782 
1783 static inline void sock_release_ownership(struct sock *sk)
1784 {
1785 	DEBUG_NET_WARN_ON_ONCE(!sock_owned_by_user_nocheck(sk));
1786 	sk->sk_lock.owned = 0;
1787 
1788 	/* The sk_lock has mutex_unlock() semantics: */
1789 	mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1790 }
1791 
1792 /* no reclassification while locks are held */
1793 static inline bool sock_allow_reclassification(const struct sock *csk)
1794 {
1795 	struct sock *sk = (struct sock *)csk;
1796 
1797 	return !sock_owned_by_user_nocheck(sk) &&
1798 		!spin_is_locked(&sk->sk_lock.slock);
1799 }
1800 
1801 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1802 		      struct proto *prot, int kern);
1803 void sk_free(struct sock *sk);
1804 void sk_net_refcnt_upgrade(struct sock *sk);
1805 void sk_destruct(struct sock *sk);
1806 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1807 
1808 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1809 			     gfp_t priority);
1810 void __sock_wfree(struct sk_buff *skb);
1811 void sock_wfree(struct sk_buff *skb);
1812 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1813 			     gfp_t priority);
1814 void skb_orphan_partial(struct sk_buff *skb);
1815 void sock_rfree(struct sk_buff *skb);
1816 void sock_efree(struct sk_buff *skb);
1817 #ifdef CONFIG_INET
1818 void sock_edemux(struct sk_buff *skb);
1819 void sock_pfree(struct sk_buff *skb);
1820 
1821 static inline void skb_set_owner_edemux(struct sk_buff *skb, struct sock *sk)
1822 {
1823 	skb_orphan(skb);
1824 	if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1825 		skb->sk = sk;
1826 		skb->destructor = sock_edemux;
1827 	}
1828 }
1829 #else
1830 #define sock_edemux sock_efree
1831 #endif
1832 
1833 int sk_setsockopt(struct sock *sk, int level, int optname,
1834 		  sockptr_t optval, unsigned int optlen);
1835 int sock_setsockopt(struct socket *sock, int level, int op,
1836 		    sockptr_t optval, unsigned int optlen);
1837 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
1838 		       int optname, sockptr_t optval, int optlen);
1839 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
1840 		       int optname, sockptr_t optval, sockptr_t optlen);
1841 
1842 int sk_getsockopt(struct sock *sk, int level, int optname,
1843 		  sockptr_t optval, sockptr_t optlen);
1844 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1845 		   bool timeval, bool time32);
1846 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1847 				     unsigned long data_len, int noblock,
1848 				     int *errcode, int max_page_order);
1849 
1850 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1851 						  unsigned long size,
1852 						  int noblock, int *errcode)
1853 {
1854 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1855 }
1856 
1857 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1858 void *sock_kmemdup(struct sock *sk, const void *src,
1859 		   int size, gfp_t priority);
1860 void sock_kfree_s(struct sock *sk, void *mem, int size);
1861 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1862 void sk_send_sigurg(struct sock *sk);
1863 
1864 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1865 {
1866 	if (sk->sk_socket)
1867 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1868 	WRITE_ONCE(sk->sk_prot, proto);
1869 }
1870 
1871 struct sockcm_cookie {
1872 	u64 transmit_time;
1873 	u32 mark;
1874 	u32 tsflags;
1875 	u32 ts_opt_id;
1876 	u32 priority;
1877 	u32 dmabuf_id;
1878 };
1879 
1880 static inline void sockcm_init(struct sockcm_cookie *sockc,
1881 			       const struct sock *sk)
1882 {
1883 	*sockc = (struct sockcm_cookie) {
1884 		.mark = READ_ONCE(sk->sk_mark),
1885 		.tsflags = READ_ONCE(sk->sk_tsflags),
1886 		.priority = READ_ONCE(sk->sk_priority),
1887 	};
1888 }
1889 
1890 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1891 		     struct sockcm_cookie *sockc);
1892 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1893 		   struct sockcm_cookie *sockc);
1894 
1895 /*
1896  * Functions to fill in entries in struct proto_ops when a protocol
1897  * does not implement a particular function.
1898  */
1899 int sock_no_bind(struct socket *, struct sockaddr *, int);
1900 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1901 int sock_no_socketpair(struct socket *, struct socket *);
1902 int sock_no_accept(struct socket *, struct socket *, struct proto_accept_arg *);
1903 int sock_no_getname(struct socket *, struct sockaddr *, int);
1904 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1905 int sock_no_listen(struct socket *, int);
1906 int sock_no_shutdown(struct socket *, int);
1907 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1908 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1909 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1910 int sock_no_mmap(struct file *file, struct socket *sock,
1911 		 struct vm_area_struct *vma);
1912 
1913 /*
1914  * Functions to fill in entries in struct proto_ops when a protocol
1915  * uses the inet style.
1916  */
1917 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1918 				  char __user *optval, int __user *optlen);
1919 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1920 			int flags);
1921 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1922 			   sockptr_t optval, unsigned int optlen);
1923 
1924 void sk_common_release(struct sock *sk);
1925 
1926 /*
1927  *	Default socket callbacks and setup code
1928  */
1929 
1930 /* Initialise core socket variables using an explicit uid. */
1931 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1932 
1933 /* Initialise core socket variables.
1934  * Assumes struct socket *sock is embedded in a struct socket_alloc.
1935  */
1936 void sock_init_data(struct socket *sock, struct sock *sk);
1937 
1938 /*
1939  * Socket reference counting postulates.
1940  *
1941  * * Each user of socket SHOULD hold a reference count.
1942  * * Each access point to socket (an hash table bucket, reference from a list,
1943  *   running timer, skb in flight MUST hold a reference count.
1944  * * When reference count hits 0, it means it will never increase back.
1945  * * When reference count hits 0, it means that no references from
1946  *   outside exist to this socket and current process on current CPU
1947  *   is last user and may/should destroy this socket.
1948  * * sk_free is called from any context: process, BH, IRQ. When
1949  *   it is called, socket has no references from outside -> sk_free
1950  *   may release descendant resources allocated by the socket, but
1951  *   to the time when it is called, socket is NOT referenced by any
1952  *   hash tables, lists etc.
1953  * * Packets, delivered from outside (from network or from another process)
1954  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1955  *   when they sit in queue. Otherwise, packets will leak to hole, when
1956  *   socket is looked up by one cpu and unhasing is made by another CPU.
1957  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1958  *   (leak to backlog). Packet socket does all the processing inside
1959  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1960  *   use separate SMP lock, so that they are prone too.
1961  */
1962 
1963 /* Ungrab socket and destroy it, if it was the last reference. */
1964 static inline void sock_put(struct sock *sk)
1965 {
1966 	if (refcount_dec_and_test(&sk->sk_refcnt))
1967 		sk_free(sk);
1968 }
1969 /* Generic version of sock_put(), dealing with all sockets
1970  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1971  */
1972 void sock_gen_put(struct sock *sk);
1973 
1974 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1975 		     unsigned int trim_cap, bool refcounted);
1976 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1977 				 const int nested)
1978 {
1979 	return __sk_receive_skb(sk, skb, nested, 1, true);
1980 }
1981 
1982 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1983 {
1984 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1985 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1986 		return;
1987 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
1988 	 * other WRITE_ONCE() because socket lock might be not held.
1989 	 */
1990 	WRITE_ONCE(sk->sk_tx_queue_mapping, tx_queue);
1991 }
1992 
1993 #define NO_QUEUE_MAPPING	USHRT_MAX
1994 
1995 static inline void sk_tx_queue_clear(struct sock *sk)
1996 {
1997 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
1998 	 * other WRITE_ONCE() because socket lock might be not held.
1999 	 */
2000 	WRITE_ONCE(sk->sk_tx_queue_mapping, NO_QUEUE_MAPPING);
2001 }
2002 
2003 static inline int sk_tx_queue_get(const struct sock *sk)
2004 {
2005 	if (sk) {
2006 		/* Paired with WRITE_ONCE() in sk_tx_queue_clear()
2007 		 * and sk_tx_queue_set().
2008 		 */
2009 		int val = READ_ONCE(sk->sk_tx_queue_mapping);
2010 
2011 		if (val != NO_QUEUE_MAPPING)
2012 			return val;
2013 	}
2014 	return -1;
2015 }
2016 
2017 static inline void __sk_rx_queue_set(struct sock *sk,
2018 				     const struct sk_buff *skb,
2019 				     bool force_set)
2020 {
2021 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2022 	if (skb_rx_queue_recorded(skb)) {
2023 		u16 rx_queue = skb_get_rx_queue(skb);
2024 
2025 		if (force_set ||
2026 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2027 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2028 	}
2029 #endif
2030 }
2031 
2032 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2033 {
2034 	__sk_rx_queue_set(sk, skb, true);
2035 }
2036 
2037 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2038 {
2039 	__sk_rx_queue_set(sk, skb, false);
2040 }
2041 
2042 static inline void sk_rx_queue_clear(struct sock *sk)
2043 {
2044 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2045 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2046 #endif
2047 }
2048 
2049 static inline int sk_rx_queue_get(const struct sock *sk)
2050 {
2051 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2052 	if (sk) {
2053 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2054 
2055 		if (res != NO_QUEUE_MAPPING)
2056 			return res;
2057 	}
2058 #endif
2059 
2060 	return -1;
2061 }
2062 
2063 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2064 {
2065 	sk->sk_socket = sock;
2066 }
2067 
2068 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2069 {
2070 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2071 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2072 }
2073 /* Detach socket from process context.
2074  * Announce socket dead, detach it from wait queue and inode.
2075  * Note that parent inode held reference count on this struct sock,
2076  * we do not release it in this function, because protocol
2077  * probably wants some additional cleanups or even continuing
2078  * to work with this socket (TCP).
2079  */
2080 static inline void sock_orphan(struct sock *sk)
2081 {
2082 	write_lock_bh(&sk->sk_callback_lock);
2083 	sock_set_flag(sk, SOCK_DEAD);
2084 	sk_set_socket(sk, NULL);
2085 	sk->sk_wq  = NULL;
2086 	/* Note: sk_uid is unchanged. */
2087 	write_unlock_bh(&sk->sk_callback_lock);
2088 }
2089 
2090 static inline void sock_graft(struct sock *sk, struct socket *parent)
2091 {
2092 	WARN_ON(parent->sk);
2093 	write_lock_bh(&sk->sk_callback_lock);
2094 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2095 	parent->sk = sk;
2096 	sk_set_socket(sk, parent);
2097 	WRITE_ONCE(sk->sk_uid, SOCK_INODE(parent)->i_uid);
2098 	security_sock_graft(sk, parent);
2099 	write_unlock_bh(&sk->sk_callback_lock);
2100 }
2101 
2102 static inline kuid_t sk_uid(const struct sock *sk)
2103 {
2104 	/* Paired with WRITE_ONCE() in sockfs_setattr() */
2105 	return READ_ONCE(sk->sk_uid);
2106 }
2107 
2108 unsigned long __sock_i_ino(struct sock *sk);
2109 unsigned long sock_i_ino(struct sock *sk);
2110 
2111 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2112 {
2113 	return sk ? sk_uid(sk) : make_kuid(net->user_ns, 0);
2114 }
2115 
2116 static inline u32 net_tx_rndhash(void)
2117 {
2118 	u32 v = get_random_u32();
2119 
2120 	return v ?: 1;
2121 }
2122 
2123 static inline void sk_set_txhash(struct sock *sk)
2124 {
2125 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2126 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2127 }
2128 
2129 static inline bool sk_rethink_txhash(struct sock *sk)
2130 {
2131 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2132 		sk_set_txhash(sk);
2133 		return true;
2134 	}
2135 	return false;
2136 }
2137 
2138 static inline struct dst_entry *
2139 __sk_dst_get(const struct sock *sk)
2140 {
2141 	return rcu_dereference_check(sk->sk_dst_cache,
2142 				     lockdep_sock_is_held(sk));
2143 }
2144 
2145 static inline struct dst_entry *
2146 sk_dst_get(const struct sock *sk)
2147 {
2148 	struct dst_entry *dst;
2149 
2150 	rcu_read_lock();
2151 	dst = rcu_dereference(sk->sk_dst_cache);
2152 	if (dst && !rcuref_get(&dst->__rcuref))
2153 		dst = NULL;
2154 	rcu_read_unlock();
2155 	return dst;
2156 }
2157 
2158 static inline void __dst_negative_advice(struct sock *sk)
2159 {
2160 	struct dst_entry *dst = __sk_dst_get(sk);
2161 
2162 	if (dst && dst->ops->negative_advice)
2163 		dst->ops->negative_advice(sk, dst);
2164 }
2165 
2166 static inline void dst_negative_advice(struct sock *sk)
2167 {
2168 	sk_rethink_txhash(sk);
2169 	__dst_negative_advice(sk);
2170 }
2171 
2172 static inline void
2173 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2174 {
2175 	struct dst_entry *old_dst;
2176 
2177 	sk_tx_queue_clear(sk);
2178 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2179 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2180 					    lockdep_sock_is_held(sk));
2181 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2182 	dst_release(old_dst);
2183 }
2184 
2185 static inline void
2186 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2187 {
2188 	struct dst_entry *old_dst;
2189 
2190 	sk_tx_queue_clear(sk);
2191 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2192 	old_dst = unrcu_pointer(xchg(&sk->sk_dst_cache, RCU_INITIALIZER(dst)));
2193 	dst_release(old_dst);
2194 }
2195 
2196 static inline void
2197 __sk_dst_reset(struct sock *sk)
2198 {
2199 	__sk_dst_set(sk, NULL);
2200 }
2201 
2202 static inline void
2203 sk_dst_reset(struct sock *sk)
2204 {
2205 	sk_dst_set(sk, NULL);
2206 }
2207 
2208 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2209 
2210 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2211 
2212 static inline void sk_dst_confirm(struct sock *sk)
2213 {
2214 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2215 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2216 }
2217 
2218 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2219 {
2220 	if (skb_get_dst_pending_confirm(skb)) {
2221 		struct sock *sk = skb->sk;
2222 
2223 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2224 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2225 		neigh_confirm(n);
2226 	}
2227 }
2228 
2229 bool sk_mc_loop(const struct sock *sk);
2230 
2231 static inline bool sk_can_gso(const struct sock *sk)
2232 {
2233 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2234 }
2235 
2236 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2237 
2238 static inline void sk_gso_disable(struct sock *sk)
2239 {
2240 	sk->sk_gso_disabled = 1;
2241 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2242 }
2243 
2244 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2245 					   struct iov_iter *from, char *to,
2246 					   int copy, int offset)
2247 {
2248 	if (skb->ip_summed == CHECKSUM_NONE) {
2249 		__wsum csum = 0;
2250 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2251 			return -EFAULT;
2252 		skb->csum = csum_block_add(skb->csum, csum, offset);
2253 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2254 		if (!copy_from_iter_full_nocache(to, copy, from))
2255 			return -EFAULT;
2256 	} else if (!copy_from_iter_full(to, copy, from))
2257 		return -EFAULT;
2258 
2259 	return 0;
2260 }
2261 
2262 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2263 				       struct iov_iter *from, int copy)
2264 {
2265 	int err, offset = skb->len;
2266 
2267 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2268 				       copy, offset);
2269 	if (err)
2270 		__skb_trim(skb, offset);
2271 
2272 	return err;
2273 }
2274 
2275 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2276 					   struct sk_buff *skb,
2277 					   struct page *page,
2278 					   int off, int copy)
2279 {
2280 	int err;
2281 
2282 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2283 				       copy, skb->len);
2284 	if (err)
2285 		return err;
2286 
2287 	skb_len_add(skb, copy);
2288 	sk_wmem_queued_add(sk, copy);
2289 	sk_mem_charge(sk, copy);
2290 	return 0;
2291 }
2292 
2293 /**
2294  * sk_wmem_alloc_get - returns write allocations
2295  * @sk: socket
2296  *
2297  * Return: sk_wmem_alloc minus initial offset of one
2298  */
2299 static inline int sk_wmem_alloc_get(const struct sock *sk)
2300 {
2301 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2302 }
2303 
2304 /**
2305  * sk_rmem_alloc_get - returns read allocations
2306  * @sk: socket
2307  *
2308  * Return: sk_rmem_alloc
2309  */
2310 static inline int sk_rmem_alloc_get(const struct sock *sk)
2311 {
2312 	return atomic_read(&sk->sk_rmem_alloc);
2313 }
2314 
2315 /**
2316  * sk_has_allocations - check if allocations are outstanding
2317  * @sk: socket
2318  *
2319  * Return: true if socket has write or read allocations
2320  */
2321 static inline bool sk_has_allocations(const struct sock *sk)
2322 {
2323 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2324 }
2325 
2326 /**
2327  * skwq_has_sleeper - check if there are any waiting processes
2328  * @wq: struct socket_wq
2329  *
2330  * Return: true if socket_wq has waiting processes
2331  *
2332  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2333  * barrier call. They were added due to the race found within the tcp code.
2334  *
2335  * Consider following tcp code paths::
2336  *
2337  *   CPU1                CPU2
2338  *   sys_select          receive packet
2339  *   ...                 ...
2340  *   __add_wait_queue    update tp->rcv_nxt
2341  *   ...                 ...
2342  *   tp->rcv_nxt check   sock_def_readable
2343  *   ...                 {
2344  *   schedule               rcu_read_lock();
2345  *                          wq = rcu_dereference(sk->sk_wq);
2346  *                          if (wq && waitqueue_active(&wq->wait))
2347  *                              wake_up_interruptible(&wq->wait)
2348  *                          ...
2349  *                       }
2350  *
2351  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2352  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2353  * could then endup calling schedule and sleep forever if there are no more
2354  * data on the socket.
2355  *
2356  */
2357 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2358 {
2359 	return wq && wq_has_sleeper(&wq->wait);
2360 }
2361 
2362 /**
2363  * sock_poll_wait - wrapper for the poll_wait call.
2364  * @filp:           file
2365  * @sock:           socket to wait on
2366  * @p:              poll_table
2367  *
2368  * See the comments in the wq_has_sleeper function.
2369  */
2370 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2371 				  poll_table *p)
2372 {
2373 	/* Provides a barrier we need to be sure we are in sync
2374 	 * with the socket flags modification.
2375 	 *
2376 	 * This memory barrier is paired in the wq_has_sleeper.
2377 	 */
2378 	poll_wait(filp, &sock->wq.wait, p);
2379 }
2380 
2381 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2382 {
2383 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2384 	u32 txhash = READ_ONCE(sk->sk_txhash);
2385 
2386 	if (txhash) {
2387 		skb->l4_hash = 1;
2388 		skb->hash = txhash;
2389 	}
2390 }
2391 
2392 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2393 
2394 /*
2395  *	Queue a received datagram if it will fit. Stream and sequenced
2396  *	protocols can't normally use this as they need to fit buffers in
2397  *	and play with them.
2398  *
2399  *	Inlined as it's very short and called for pretty much every
2400  *	packet ever received.
2401  */
2402 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2403 {
2404 	skb_orphan(skb);
2405 	skb->sk = sk;
2406 	skb->destructor = sock_rfree;
2407 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2408 	sk_mem_charge(sk, skb->truesize);
2409 }
2410 
2411 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2412 {
2413 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2414 		skb_orphan(skb);
2415 		skb->destructor = sock_efree;
2416 		skb->sk = sk;
2417 		return true;
2418 	}
2419 	return false;
2420 }
2421 
2422 static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2423 {
2424 	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2425 	if (skb) {
2426 		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2427 			skb_set_owner_r(skb, sk);
2428 			return skb;
2429 		}
2430 		__kfree_skb(skb);
2431 	}
2432 	return NULL;
2433 }
2434 
2435 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2436 {
2437 	if (skb->destructor != sock_wfree) {
2438 		skb_orphan(skb);
2439 		return;
2440 	}
2441 	skb->slow_gro = 1;
2442 }
2443 
2444 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2445 		    unsigned long expires);
2446 
2447 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2448 
2449 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2450 
2451 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2452 			struct sk_buff *skb, unsigned int flags,
2453 			void (*destructor)(struct sock *sk,
2454 					   struct sk_buff *skb));
2455 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2456 
2457 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2458 			      enum skb_drop_reason *reason);
2459 
2460 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2461 {
2462 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2463 }
2464 
2465 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2466 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2467 
2468 /*
2469  *	Recover an error report and clear atomically
2470  */
2471 
2472 static inline int sock_error(struct sock *sk)
2473 {
2474 	int err;
2475 
2476 	/* Avoid an atomic operation for the common case.
2477 	 * This is racy since another cpu/thread can change sk_err under us.
2478 	 */
2479 	if (likely(data_race(!sk->sk_err)))
2480 		return 0;
2481 
2482 	err = xchg(&sk->sk_err, 0);
2483 	return -err;
2484 }
2485 
2486 void sk_error_report(struct sock *sk);
2487 
2488 static inline unsigned long sock_wspace(struct sock *sk)
2489 {
2490 	int amt = 0;
2491 
2492 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2493 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2494 		if (amt < 0)
2495 			amt = 0;
2496 	}
2497 	return amt;
2498 }
2499 
2500 /* Note:
2501  *  We use sk->sk_wq_raw, from contexts knowing this
2502  *  pointer is not NULL and cannot disappear/change.
2503  */
2504 static inline void sk_set_bit(int nr, struct sock *sk)
2505 {
2506 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2507 	    !sock_flag(sk, SOCK_FASYNC))
2508 		return;
2509 
2510 	set_bit(nr, &sk->sk_wq_raw->flags);
2511 }
2512 
2513 static inline void sk_clear_bit(int nr, struct sock *sk)
2514 {
2515 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2516 	    !sock_flag(sk, SOCK_FASYNC))
2517 		return;
2518 
2519 	clear_bit(nr, &sk->sk_wq_raw->flags);
2520 }
2521 
2522 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2523 {
2524 	if (sock_flag(sk, SOCK_FASYNC)) {
2525 		rcu_read_lock();
2526 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2527 		rcu_read_unlock();
2528 	}
2529 }
2530 
2531 static inline void sk_wake_async_rcu(const struct sock *sk, int how, int band)
2532 {
2533 	if (unlikely(sock_flag(sk, SOCK_FASYNC)))
2534 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2535 }
2536 
2537 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2538  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2539  * Note: for send buffers, TCP works better if we can build two skbs at
2540  * minimum.
2541  */
2542 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2543 
2544 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2545 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2546 
2547 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2548 {
2549 	u32 val;
2550 
2551 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2552 		return;
2553 
2554 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2555 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2556 
2557 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2558 }
2559 
2560 /**
2561  * sk_page_frag - return an appropriate page_frag
2562  * @sk: socket
2563  *
2564  * Use the per task page_frag instead of the per socket one for
2565  * optimization when we know that we're in process context and own
2566  * everything that's associated with %current.
2567  *
2568  * Both direct reclaim and page faults can nest inside other
2569  * socket operations and end up recursing into sk_page_frag()
2570  * while it's already in use: explicitly avoid task page_frag
2571  * when users disable sk_use_task_frag.
2572  *
2573  * Return: a per task page_frag if context allows that,
2574  * otherwise a per socket one.
2575  */
2576 static inline struct page_frag *sk_page_frag(struct sock *sk)
2577 {
2578 	if (sk->sk_use_task_frag)
2579 		return &current->task_frag;
2580 
2581 	return &sk->sk_frag;
2582 }
2583 
2584 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2585 
2586 /*
2587  *	Default write policy as shown to user space via poll/select/SIGIO
2588  */
2589 static inline bool sock_writeable(const struct sock *sk)
2590 {
2591 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2592 }
2593 
2594 static inline gfp_t gfp_any(void)
2595 {
2596 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2597 }
2598 
2599 static inline gfp_t gfp_memcg_charge(void)
2600 {
2601 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2602 }
2603 
2604 #ifdef CONFIG_MEMCG
2605 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2606 {
2607 	return sk->sk_memcg;
2608 }
2609 
2610 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2611 {
2612 	return mem_cgroup_sockets_enabled && mem_cgroup_from_sk(sk);
2613 }
2614 
2615 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2616 {
2617 	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);
2618 
2619 #ifdef CONFIG_MEMCG_V1
2620 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
2621 		return !!memcg->tcpmem_pressure;
2622 #endif /* CONFIG_MEMCG_V1 */
2623 
2624 	do {
2625 		if (time_before64(get_jiffies_64(), mem_cgroup_get_socket_pressure(memcg)))
2626 			return true;
2627 	} while ((memcg = parent_mem_cgroup(memcg)));
2628 
2629 	return false;
2630 }
2631 #else
2632 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2633 {
2634 	return NULL;
2635 }
2636 
2637 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2638 {
2639 	return false;
2640 }
2641 
2642 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2643 {
2644 	return false;
2645 }
2646 #endif
2647 
2648 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2649 {
2650 	return noblock ? 0 : READ_ONCE(sk->sk_rcvtimeo);
2651 }
2652 
2653 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2654 {
2655 	return noblock ? 0 : READ_ONCE(sk->sk_sndtimeo);
2656 }
2657 
2658 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2659 {
2660 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2661 
2662 	return v ?: 1;
2663 }
2664 
2665 /* Alas, with timeout socket operations are not restartable.
2666  * Compare this to poll().
2667  */
2668 static inline int sock_intr_errno(long timeo)
2669 {
2670 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2671 }
2672 
2673 struct sock_skb_cb {
2674 	u32 dropcount;
2675 };
2676 
2677 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2678  * using skb->cb[] would keep using it directly and utilize its
2679  * alignment guarantee.
2680  */
2681 #define SOCK_SKB_CB_OFFSET (sizeof_field(struct sk_buff, cb) - \
2682 			    sizeof(struct sock_skb_cb))
2683 
2684 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2685 			    SOCK_SKB_CB_OFFSET))
2686 
2687 #define sock_skb_cb_check_size(size) \
2688 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2689 
2690 static inline void sk_drops_add(struct sock *sk, int segs)
2691 {
2692 	struct socket_drop_counters *sdc = sk->sk_drop_counters;
2693 
2694 	if (sdc) {
2695 		int n = numa_node_id() % 2;
2696 
2697 		if (n)
2698 			atomic_add(segs, &sdc->drops1);
2699 		else
2700 			atomic_add(segs, &sdc->drops0);
2701 	} else {
2702 		atomic_add(segs, &sk->sk_drops);
2703 	}
2704 }
2705 
2706 static inline void sk_drops_inc(struct sock *sk)
2707 {
2708 	sk_drops_add(sk, 1);
2709 }
2710 
2711 static inline int sk_drops_read(const struct sock *sk)
2712 {
2713 	const struct socket_drop_counters *sdc = sk->sk_drop_counters;
2714 
2715 	if (sdc) {
2716 		DEBUG_NET_WARN_ON_ONCE(atomic_read(&sk->sk_drops));
2717 		return atomic_read(&sdc->drops0) + atomic_read(&sdc->drops1);
2718 	}
2719 	return atomic_read(&sk->sk_drops);
2720 }
2721 
2722 static inline void sk_drops_reset(struct sock *sk)
2723 {
2724 	struct socket_drop_counters *sdc = sk->sk_drop_counters;
2725 
2726 	if (sdc) {
2727 		atomic_set(&sdc->drops0, 0);
2728 		atomic_set(&sdc->drops1, 0);
2729 	}
2730 	atomic_set(&sk->sk_drops, 0);
2731 }
2732 
2733 static inline void
2734 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2735 {
2736 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2737 						sk_drops_read(sk) : 0;
2738 }
2739 
2740 static inline void sk_drops_skbadd(struct sock *sk, const struct sk_buff *skb)
2741 {
2742 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2743 
2744 	sk_drops_add(sk, segs);
2745 }
2746 
2747 static inline ktime_t sock_read_timestamp(struct sock *sk)
2748 {
2749 #if BITS_PER_LONG==32
2750 	unsigned int seq;
2751 	ktime_t kt;
2752 
2753 	do {
2754 		seq = read_seqbegin(&sk->sk_stamp_seq);
2755 		kt = sk->sk_stamp;
2756 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2757 
2758 	return kt;
2759 #else
2760 	return READ_ONCE(sk->sk_stamp);
2761 #endif
2762 }
2763 
2764 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2765 {
2766 #if BITS_PER_LONG==32
2767 	write_seqlock(&sk->sk_stamp_seq);
2768 	sk->sk_stamp = kt;
2769 	write_sequnlock(&sk->sk_stamp_seq);
2770 #else
2771 	WRITE_ONCE(sk->sk_stamp, kt);
2772 #endif
2773 }
2774 
2775 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2776 			   struct sk_buff *skb);
2777 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2778 			     struct sk_buff *skb);
2779 
2780 bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk);
2781 int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
2782 			 struct timespec64 *ts);
2783 
2784 static inline void
2785 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2786 {
2787 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2788 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
2789 	ktime_t kt = skb->tstamp;
2790 	/*
2791 	 * generate control messages if
2792 	 * - receive time stamping in software requested
2793 	 * - software time stamp available and wanted
2794 	 * - hardware time stamps available and wanted
2795 	 */
2796 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2797 	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2798 	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2799 	    (hwtstamps->hwtstamp &&
2800 	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2801 		__sock_recv_timestamp(msg, sk, skb);
2802 	else
2803 		sock_write_timestamp(sk, kt);
2804 
2805 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb_wifi_acked_valid(skb))
2806 		__sock_recv_wifi_status(msg, sk, skb);
2807 }
2808 
2809 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2810 		       struct sk_buff *skb);
2811 
2812 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2813 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2814 				   struct sk_buff *skb)
2815 {
2816 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2817 			   (1UL << SOCK_RCVTSTAMP)			| \
2818 			   (1UL << SOCK_RCVMARK)			| \
2819 			   (1UL << SOCK_RCVPRIORITY)			| \
2820 			   (1UL << SOCK_TIMESTAMPING_ANY))
2821 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2822 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2823 
2824 	if (READ_ONCE(sk->sk_flags) & FLAGS_RECV_CMSGS)
2825 		__sock_recv_cmsgs(msg, sk, skb);
2826 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2827 		sock_write_timestamp(sk, skb->tstamp);
2828 	else if (unlikely(sock_read_timestamp(sk) == SK_DEFAULT_STAMP))
2829 		sock_write_timestamp(sk, 0);
2830 }
2831 
2832 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags);
2833 
2834 /**
2835  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2836  * @sk:		socket sending this packet
2837  * @sockc:	pointer to socket cmsg cookie to get timestamping info
2838  * @tx_flags:	completed with instructions for time stamping
2839  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2840  *
2841  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2842  */
2843 static inline void _sock_tx_timestamp(struct sock *sk,
2844 				      const struct sockcm_cookie *sockc,
2845 				      __u8 *tx_flags, __u32 *tskey)
2846 {
2847 	__u32 tsflags = sockc->tsflags;
2848 
2849 	if (unlikely(tsflags)) {
2850 		__sock_tx_timestamp(tsflags, tx_flags);
2851 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2852 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) {
2853 			if (tsflags & SOCKCM_FLAG_TS_OPT_ID)
2854 				*tskey = sockc->ts_opt_id;
2855 			else
2856 				*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2857 		}
2858 	}
2859 }
2860 
2861 static inline void sock_tx_timestamp(struct sock *sk,
2862 				     const struct sockcm_cookie *sockc,
2863 				     __u8 *tx_flags)
2864 {
2865 	_sock_tx_timestamp(sk, sockc, tx_flags, NULL);
2866 }
2867 
2868 static inline void skb_setup_tx_timestamp(struct sk_buff *skb,
2869 					  const struct sockcm_cookie *sockc)
2870 {
2871 	_sock_tx_timestamp(skb->sk, sockc, &skb_shinfo(skb)->tx_flags,
2872 			   &skb_shinfo(skb)->tskey);
2873 }
2874 
2875 static inline bool sk_is_inet(const struct sock *sk)
2876 {
2877 	int family = READ_ONCE(sk->sk_family);
2878 
2879 	return family == AF_INET || family == AF_INET6;
2880 }
2881 
2882 static inline bool sk_is_tcp(const struct sock *sk)
2883 {
2884 	return sk_is_inet(sk) &&
2885 	       sk->sk_type == SOCK_STREAM &&
2886 	       sk->sk_protocol == IPPROTO_TCP;
2887 }
2888 
2889 static inline bool sk_is_udp(const struct sock *sk)
2890 {
2891 	return sk_is_inet(sk) &&
2892 	       sk->sk_type == SOCK_DGRAM &&
2893 	       sk->sk_protocol == IPPROTO_UDP;
2894 }
2895 
2896 static inline bool sk_is_unix(const struct sock *sk)
2897 {
2898 	return sk->sk_family == AF_UNIX;
2899 }
2900 
2901 static inline bool sk_is_stream_unix(const struct sock *sk)
2902 {
2903 	return sk_is_unix(sk) && sk->sk_type == SOCK_STREAM;
2904 }
2905 
2906 static inline bool sk_is_vsock(const struct sock *sk)
2907 {
2908 	return sk->sk_family == AF_VSOCK;
2909 }
2910 
2911 static inline bool sk_may_scm_recv(const struct sock *sk)
2912 {
2913 	return (IS_ENABLED(CONFIG_UNIX) && sk->sk_family == AF_UNIX) ||
2914 		sk->sk_family == AF_NETLINK ||
2915 		(IS_ENABLED(CONFIG_BT) && sk->sk_family == AF_BLUETOOTH);
2916 }
2917 
2918 /**
2919  * sk_eat_skb - Release a skb if it is no longer needed
2920  * @sk: socket to eat this skb from
2921  * @skb: socket buffer to eat
2922  *
2923  * This routine must be called with interrupts disabled or with the socket
2924  * locked so that the sk_buff queue operation is ok.
2925 */
2926 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2927 {
2928 	__skb_unlink(skb, &sk->sk_receive_queue);
2929 	__kfree_skb(skb);
2930 }
2931 
2932 static inline bool
2933 skb_sk_is_prefetched(struct sk_buff *skb)
2934 {
2935 #ifdef CONFIG_INET
2936 	return skb->destructor == sock_pfree;
2937 #else
2938 	return false;
2939 #endif /* CONFIG_INET */
2940 }
2941 
2942 /* This helper checks if a socket is a full socket,
2943  * ie _not_ a timewait or request socket.
2944  */
2945 static inline bool sk_fullsock(const struct sock *sk)
2946 {
2947 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2948 }
2949 
2950 static inline bool
2951 sk_is_refcounted(struct sock *sk)
2952 {
2953 	/* Only full sockets have sk->sk_flags. */
2954 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2955 }
2956 
2957 static inline bool
2958 sk_requests_wifi_status(struct sock *sk)
2959 {
2960 	return sk && sk_fullsock(sk) && sock_flag(sk, SOCK_WIFI_STATUS);
2961 }
2962 
2963 /* Checks if this SKB belongs to an HW offloaded socket
2964  * and whether any SW fallbacks are required based on dev.
2965  * Check decrypted mark in case skb_orphan() cleared socket.
2966  */
2967 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2968 						   struct net_device *dev)
2969 {
2970 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2971 	struct sock *sk = skb->sk;
2972 
2973 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2974 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2975 	} else if (unlikely(skb_is_decrypted(skb))) {
2976 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2977 		kfree_skb(skb);
2978 		skb = NULL;
2979 	}
2980 #endif
2981 
2982 	return skb;
2983 }
2984 
2985 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2986  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2987  */
2988 static inline bool sk_listener(const struct sock *sk)
2989 {
2990 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2991 }
2992 
2993 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV or TIME_WAIT
2994  * TCP SYNACK messages can be attached to LISTEN or NEW_SYN_RECV (depending on SYNCOOKIE)
2995  * TCP RST and ACK can be attached to TIME_WAIT.
2996  */
2997 static inline bool sk_listener_or_tw(const struct sock *sk)
2998 {
2999 	return (1 << READ_ONCE(sk->sk_state)) &
3000 	       (TCPF_LISTEN | TCPF_NEW_SYN_RECV | TCPF_TIME_WAIT);
3001 }
3002 
3003 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
3004 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
3005 		       int type);
3006 
3007 bool sk_ns_capable(const struct sock *sk,
3008 		   struct user_namespace *user_ns, int cap);
3009 bool sk_capable(const struct sock *sk, int cap);
3010 bool sk_net_capable(const struct sock *sk, int cap);
3011 
3012 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
3013 
3014 /* Take into consideration the size of the struct sk_buff overhead in the
3015  * determination of these values, since that is non-constant across
3016  * platforms.  This makes socket queueing behavior and performance
3017  * not depend upon such differences.
3018  */
3019 #define _SK_MEM_PACKETS		256
3020 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
3021 #define SK_WMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3022 #define SK_RMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3023 
3024 extern __u32 sysctl_wmem_max;
3025 extern __u32 sysctl_rmem_max;
3026 
3027 extern __u32 sysctl_wmem_default;
3028 extern __u32 sysctl_rmem_default;
3029 
3030 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
3031 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3032 
3033 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
3034 {
3035 	/* Does this proto have per netns sysctl_wmem ? */
3036 	if (proto->sysctl_wmem_offset)
3037 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
3038 
3039 	return READ_ONCE(*proto->sysctl_wmem);
3040 }
3041 
3042 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
3043 {
3044 	/* Does this proto have per netns sysctl_rmem ? */
3045 	if (proto->sysctl_rmem_offset)
3046 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
3047 
3048 	return READ_ONCE(*proto->sysctl_rmem);
3049 }
3050 
3051 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
3052  * Some wifi drivers need to tweak it to get more chunks.
3053  * They can use this helper from their ndo_start_xmit()
3054  */
3055 static inline void sk_pacing_shift_update(struct sock *sk, int val)
3056 {
3057 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
3058 		return;
3059 	WRITE_ONCE(sk->sk_pacing_shift, val);
3060 }
3061 
3062 /* if a socket is bound to a device, check that the given device
3063  * index is either the same or that the socket is bound to an L3
3064  * master device and the given device index is also enslaved to
3065  * that L3 master
3066  */
3067 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
3068 {
3069 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
3070 	int mdif;
3071 
3072 	if (!bound_dev_if || bound_dev_if == dif)
3073 		return true;
3074 
3075 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
3076 	if (mdif && mdif == bound_dev_if)
3077 		return true;
3078 
3079 	return false;
3080 }
3081 
3082 void sock_def_readable(struct sock *sk);
3083 
3084 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
3085 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
3086 int sock_set_timestamping(struct sock *sk, int optname,
3087 			  struct so_timestamping timestamping);
3088 
3089 #if defined(CONFIG_CGROUP_BPF)
3090 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op);
3091 #else
3092 static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
3093 {
3094 }
3095 #endif
3096 void sock_no_linger(struct sock *sk);
3097 void sock_set_keepalive(struct sock *sk);
3098 void sock_set_priority(struct sock *sk, u32 priority);
3099 void sock_set_rcvbuf(struct sock *sk, int val);
3100 void sock_set_mark(struct sock *sk, u32 val);
3101 void sock_set_reuseaddr(struct sock *sk);
3102 void sock_set_reuseport(struct sock *sk);
3103 void sock_set_sndtimeo(struct sock *sk, s64 secs);
3104 
3105 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
3106 
3107 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
3108 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
3109 			   sockptr_t optval, int optlen, bool old_timeval);
3110 
3111 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
3112 		     void __user *arg, void *karg, size_t size);
3113 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
3114 static inline bool sk_is_readable(struct sock *sk)
3115 {
3116 	const struct proto *prot = READ_ONCE(sk->sk_prot);
3117 
3118 	if (prot->sock_is_readable)
3119 		return prot->sock_is_readable(sk);
3120 
3121 	return false;
3122 }
3123 #endif	/* _SOCK_H */
3124