xref: /linux/include/net/sock.h (revision c99ebb6132595b4b288a413981197eb076547c5a)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the AF_INET socket handler.
8  *
9  * Version:	@(#)sock.h	1.0.4	05/13/93
10  *
11  * Authors:	Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
14  *		Florian La Roche <flla@stud.uni-sb.de>
15  *
16  * Fixes:
17  *		Alan Cox	:	Volatiles in skbuff pointers. See
18  *					skbuff comments. May be overdone,
19  *					better to prove they can be removed
20  *					than the reverse.
21  *		Alan Cox	:	Added a zapped field for tcp to note
22  *					a socket is reset and must stay shut up
23  *		Alan Cox	:	New fields for options
24  *	Pauline Middelink	:	identd support
25  *		Alan Cox	:	Eliminate low level recv/recvfrom
26  *		David S. Miller	:	New socket lookup architecture.
27  *              Steve Whitehouse:       Default routines for sock_ops
28  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
29  *              			protinfo be just a void pointer, as the
30  *              			protocol specific parts were moved to
31  *              			respective headers and ipv4/v6, etc now
32  *              			use private slabcaches for its socks
33  *              Pedro Hortas	:	New flags field for socket options
34  */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37 
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h>	/* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/rculist_nulls.h>
60 #include <linux/poll.h>
61 #include <linux/sockptr.h>
62 #include <linux/indirect_call_wrapper.h>
63 #include <linux/atomic.h>
64 #include <linux/refcount.h>
65 #include <linux/llist.h>
66 #include <net/dst.h>
67 #include <net/checksum.h>
68 #include <net/tcp_states.h>
69 #include <linux/net_tstamp.h>
70 #include <net/l3mdev.h>
71 #include <uapi/linux/socket.h>
72 
73 /*
74  * This structure really needs to be cleaned up.
75  * Most of it is for TCP, and not used by any of
76  * the other protocols.
77  */
78 
79 /* This is the per-socket lock.  The spinlock provides a synchronization
80  * between user contexts and software interrupt processing, whereas the
81  * mini-semaphore synchronizes multiple users amongst themselves.
82  */
83 typedef struct {
84 	spinlock_t		slock;
85 	int			owned;
86 	wait_queue_head_t	wq;
87 	/*
88 	 * We express the mutex-alike socket_lock semantics
89 	 * to the lock validator by explicitly managing
90 	 * the slock as a lock variant (in addition to
91 	 * the slock itself):
92 	 */
93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
94 	struct lockdep_map dep_map;
95 #endif
96 } socket_lock_t;
97 
98 struct sock;
99 struct proto;
100 struct net;
101 
102 typedef __u32 __bitwise __portpair;
103 typedef __u64 __bitwise __addrpair;
104 
105 /**
106  *	struct sock_common - minimal network layer representation of sockets
107  *	@skc_daddr: Foreign IPv4 addr
108  *	@skc_rcv_saddr: Bound local IPv4 addr
109  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
110  *	@skc_hash: hash value used with various protocol lookup tables
111  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
112  *	@skc_dport: placeholder for inet_dport/tw_dport
113  *	@skc_num: placeholder for inet_num/tw_num
114  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
115  *	@skc_family: network address family
116  *	@skc_state: Connection state
117  *	@skc_reuse: %SO_REUSEADDR setting
118  *	@skc_reuseport: %SO_REUSEPORT setting
119  *	@skc_ipv6only: socket is IPV6 only
120  *	@skc_net_refcnt: socket is using net ref counting
121  *	@skc_bypass_prot_mem: bypass the per-protocol memory accounting for skb
122  *	@skc_bound_dev_if: bound device index if != 0
123  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
124  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
125  *	@skc_prot: protocol handlers inside a network family
126  *	@skc_net: reference to the network namespace of this socket
127  *	@skc_v6_daddr: IPV6 destination address
128  *	@skc_v6_rcv_saddr: IPV6 source address
129  *	@skc_cookie: socket's cookie value
130  *	@skc_node: main hash linkage for various protocol lookup tables
131  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
132  *	@skc_tx_queue_mapping: tx queue number for this connection
133  *	@skc_rx_queue_mapping: rx queue number for this connection
134  *	@skc_flags: place holder for sk_flags
135  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
136  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
137  *	@skc_listener: connection request listener socket (aka rsk_listener)
138  *		[union with @skc_flags]
139  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
140  *		[union with @skc_flags]
141  *	@skc_incoming_cpu: record/match cpu processing incoming packets
142  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
143  *		[union with @skc_incoming_cpu]
144  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
145  *		[union with @skc_incoming_cpu]
146  *	@skc_refcnt: reference count
147  *
148  *	This is the minimal network layer representation of sockets, the header
149  *	for struct sock and struct inet_timewait_sock.
150  */
151 struct sock_common {
152 	union {
153 		__addrpair	skc_addrpair;
154 		struct {
155 			__be32	skc_daddr;
156 			__be32	skc_rcv_saddr;
157 		};
158 	};
159 	union  {
160 		unsigned int	skc_hash;
161 		__u16		skc_u16hashes[2];
162 	};
163 	/* skc_dport && skc_num must be grouped as well */
164 	union {
165 		__portpair	skc_portpair;
166 		struct {
167 			__be16	skc_dport;
168 			__u16	skc_num;
169 		};
170 	};
171 
172 	unsigned short		skc_family;
173 	volatile unsigned char	skc_state;
174 	unsigned char		skc_reuse:4;
175 	unsigned char		skc_reuseport:1;
176 	unsigned char		skc_ipv6only:1;
177 	unsigned char		skc_net_refcnt:1;
178 	unsigned char		skc_bypass_prot_mem:1;
179 	int			skc_bound_dev_if;
180 	union {
181 		struct hlist_node	skc_bind_node;
182 		struct hlist_node	skc_portaddr_node;
183 	};
184 	struct proto		*skc_prot;
185 	possible_net_t		skc_net;
186 
187 #if IS_ENABLED(CONFIG_IPV6)
188 	struct in6_addr		skc_v6_daddr;
189 	struct in6_addr		skc_v6_rcv_saddr;
190 #endif
191 
192 	atomic64_t		skc_cookie;
193 
194 	/* following fields are padding to force
195 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
196 	 * assuming IPV6 is enabled. We use this padding differently
197 	 * for different kind of 'sockets'
198 	 */
199 	union {
200 		unsigned long	skc_flags;
201 		struct sock	*skc_listener; /* request_sock */
202 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
203 	};
204 	/*
205 	 * fields between dontcopy_begin/dontcopy_end
206 	 * are not copied in sock_copy()
207 	 */
208 	/* private: */
209 	int			skc_dontcopy_begin[0];
210 	/* public: */
211 	union {
212 		struct hlist_node	skc_node;
213 		struct hlist_nulls_node skc_nulls_node;
214 	};
215 	unsigned short		skc_tx_queue_mapping;
216 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
217 	unsigned short		skc_rx_queue_mapping;
218 #endif
219 	union {
220 		int		skc_incoming_cpu;
221 		u32		skc_rcv_wnd;
222 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
223 	};
224 
225 	refcount_t		skc_refcnt;
226 	/* private: */
227 	int                     skc_dontcopy_end[0];
228 	union {
229 		u32		skc_rxhash;
230 		u32		skc_window_clamp;
231 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
232 	};
233 	/* public: */
234 };
235 
236 struct bpf_local_storage;
237 struct sk_filter;
238 
239 /**
240   *	struct sock - network layer representation of sockets
241   *	@__sk_common: shared layout with inet_timewait_sock
242   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
243   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
244   *	@sk_lock:	synchronizer
245   *	@sk_kern_sock: True if sock is using kernel lock classes
246   *	@sk_rcvbuf: size of receive buffer in bytes
247   *	@sk_wq: sock wait queue and async head
248   *	@sk_rx_dst: receive input route used by early demux
249   *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
250   *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
251   *	@sk_dst_cache: destination cache
252   *	@sk_dst_pending_confirm: need to confirm neighbour
253   *	@sk_policy: flow policy
254   *	@psp_assoc: PSP association, if socket is PSP-secured
255   *	@sk_receive_queue: incoming packets
256   *	@sk_wmem_alloc: transmit queue bytes committed
257   *	@sk_tsq_flags: TCP Small Queues flags
258   *	@sk_write_queue: Packet sending queue
259   *	@sk_omem_alloc: "o" is "option" or "other"
260   *	@sk_wmem_queued: persistent queue size
261   *	@sk_forward_alloc: space allocated forward
262   *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
263   *	@sk_napi_id: id of the last napi context to receive data for sk
264   *	@sk_ll_usec: usecs to busypoll when there is no data
265   *	@sk_allocation: allocation mode
266   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
267   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
268   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
269   *	@sk_sndbuf: size of send buffer in bytes
270   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
271   *	@sk_no_check_rx: allow zero checksum in RX packets
272   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
273   *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
274   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
275   *	@sk_gso_max_size: Maximum GSO segment size to build
276   *	@sk_gso_max_segs: Maximum number of GSO segments
277   *	@sk_pacing_shift: scaling factor for TCP Small Queues
278   *	@sk_lingertime: %SO_LINGER l_linger setting
279   *	@sk_backlog: always used with the per-socket spinlock held
280   *	@sk_callback_lock: used with the callbacks in the end of this struct
281   *	@sk_error_queue: rarely used
282   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
283   *			  IPV6_ADDRFORM for instance)
284   *	@sk_err: last error
285   *	@sk_err_soft: errors that don't cause failure but are the cause of a
286   *		      persistent failure not just 'timed out'
287   *	@sk_drops: raw/udp drops counter
288   *	@sk_drop_counters: optional pointer to numa_drop_counters
289   *	@sk_ack_backlog: current listen backlog
290   *	@sk_max_ack_backlog: listen backlog set in listen()
291   *	@sk_uid: user id of owner
292   *	@sk_ino: inode number (zero if orphaned)
293   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
294   *	@sk_busy_poll_budget: napi processing budget when busypolling
295   *	@sk_priority: %SO_PRIORITY setting
296   *	@sk_type: socket type (%SOCK_STREAM, etc)
297   *	@sk_protocol: which protocol this socket belongs in this network family
298   *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
299   *	@sk_peer_pid: &struct pid for this socket's peer
300   *	@sk_peer_cred: %SO_PEERCRED setting
301   *	@sk_rcvlowat: %SO_RCVLOWAT setting
302   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
303   *	@sk_sndtimeo: %SO_SNDTIMEO setting
304   *	@sk_txhash: computed flow hash for use on transmit
305   *	@sk_txrehash: enable TX hash rethink
306   *	@sk_filter: socket filtering instructions
307   *	@sk_timer: sock cleanup timer
308   *	@sk_stamp: time stamp of last packet received
309   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
310   *	@sk_tsflags: SO_TIMESTAMPING flags
311   *	@sk_bpf_cb_flags: used in bpf_setsockopt()
312   *	@sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
313   *			   Sockets that can be used under memory reclaim should
314   *			   set this to false.
315   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
316   *	              for timestamping
317   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
318   *	@sk_tx_queue_mapping_jiffies: time in jiffies of last @sk_tx_queue_mapping refresh.
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_bypass_prot_mem	__sk_common.skc_bypass_prot_mem
387 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
388 #define sk_bind_node		__sk_common.skc_bind_node
389 #define sk_prot			__sk_common.skc_prot
390 #define sk_net			__sk_common.skc_net
391 #define sk_v6_daddr		__sk_common.skc_v6_daddr
392 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
393 #define sk_cookie		__sk_common.skc_cookie
394 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
395 #define sk_flags		__sk_common.skc_flags
396 #define sk_rxhash		__sk_common.skc_rxhash
397 
398 	__cacheline_group_begin(sock_write_rx);
399 
400 	atomic_t		sk_drops;
401 	__s32			sk_peek_off;
402 	struct sk_buff_head	sk_error_queue;
403 	struct sk_buff_head	sk_receive_queue;
404 	/*
405 	 * The backlog queue is special, it is always used with
406 	 * the per-socket spinlock held and requires low latency
407 	 * access. Therefore we special case it's implementation.
408 	 * Note : rmem_alloc is in this structure to fill a hole
409 	 * on 64bit arches, not because its logically part of
410 	 * backlog.
411 	 */
412 	struct {
413 		atomic_t	rmem_alloc;
414 		int		len;
415 		struct sk_buff	*head;
416 		struct sk_buff	*tail;
417 	} sk_backlog;
418 #define sk_rmem_alloc sk_backlog.rmem_alloc
419 
420 	__cacheline_group_end(sock_write_rx);
421 
422 	__cacheline_group_begin(sock_read_rx);
423 	/* early demux fields */
424 	struct dst_entry __rcu	*sk_rx_dst;
425 	int			sk_rx_dst_ifindex;
426 	u32			sk_rx_dst_cookie;
427 
428 #ifdef CONFIG_NET_RX_BUSY_POLL
429 	unsigned int		sk_ll_usec;
430 	unsigned int		sk_napi_id;
431 	u16			sk_busy_poll_budget;
432 	u8			sk_prefer_busy_poll;
433 #endif
434 	u8			sk_userlocks;
435 	int			sk_rcvbuf;
436 
437 	struct sk_filter __rcu	*sk_filter;
438 	union {
439 		struct socket_wq __rcu	*sk_wq;
440 		/* private: */
441 		struct socket_wq	*sk_wq_raw;
442 		/* public: */
443 	};
444 
445 	void			(*sk_data_ready)(struct sock *sk);
446 	long			sk_rcvtimeo;
447 	int			sk_rcvlowat;
448 	__cacheline_group_end(sock_read_rx);
449 
450 	__cacheline_group_begin(sock_read_rxtx);
451 	int			sk_err;
452 	struct socket		*sk_socket;
453 #ifdef CONFIG_MEMCG
454 	struct mem_cgroup	*sk_memcg;
455 #endif
456 #ifdef CONFIG_XFRM
457 	struct xfrm_policy __rcu *sk_policy[2];
458 #endif
459 #if IS_ENABLED(CONFIG_INET_PSP)
460 	struct psp_assoc __rcu	*psp_assoc;
461 #endif
462 	__cacheline_group_end(sock_read_rxtx);
463 
464 	__cacheline_group_begin(sock_write_rxtx);
465 	socket_lock_t		sk_lock;
466 	u32			sk_reserved_mem;
467 	int			sk_forward_alloc;
468 	u32			sk_tsflags;
469 	__cacheline_group_end(sock_write_rxtx);
470 
471 	__cacheline_group_begin(sock_write_tx);
472 	int			sk_write_pending;
473 	atomic_t		sk_omem_alloc;
474 	int			sk_err_soft;
475 
476 	int			sk_wmem_queued;
477 	refcount_t		sk_wmem_alloc;
478 	unsigned long		sk_tsq_flags;
479 	union {
480 		struct sk_buff	*sk_send_head;
481 		struct rb_root	tcp_rtx_queue;
482 	};
483 	struct sk_buff_head	sk_write_queue;
484 	u32			sk_dst_pending_confirm;
485 	u32			sk_pacing_status; /* see enum sk_pacing */
486 	struct page_frag	sk_frag;
487 	struct timer_list	sk_timer;
488 
489 	unsigned long		sk_pacing_rate; /* bytes per second */
490 	atomic_t		sk_zckey;
491 	atomic_t		sk_tskey;
492 	unsigned long		sk_tx_queue_mapping_jiffies;
493 	__cacheline_group_end(sock_write_tx);
494 
495 	__cacheline_group_begin(sock_read_tx);
496 	unsigned long		sk_max_pacing_rate;
497 	long			sk_sndtimeo;
498 	u32			sk_priority;
499 	u32			sk_mark;
500 	kuid_t			sk_uid;
501 	u16			sk_protocol;
502 	u16			sk_type;
503 	struct dst_entry __rcu	*sk_dst_cache;
504 	netdev_features_t	sk_route_caps;
505 #ifdef CONFIG_SOCK_VALIDATE_XMIT
506 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
507 							struct net_device *dev,
508 							struct sk_buff *skb);
509 #endif
510 	u16			sk_gso_type;
511 	u16			sk_gso_max_segs;
512 	unsigned int		sk_gso_max_size;
513 	gfp_t			sk_allocation;
514 	u32			sk_txhash;
515 	int			sk_sndbuf;
516 	u8			sk_pacing_shift;
517 	bool			sk_use_task_frag;
518 	__cacheline_group_end(sock_read_tx);
519 
520 	/*
521 	 * Because of non atomicity rules, all
522 	 * changes are protected by socket lock.
523 	 */
524 	u8			sk_gso_disabled : 1,
525 				sk_kern_sock : 1,
526 				sk_no_check_tx : 1,
527 				sk_no_check_rx : 1;
528 	u8			sk_shutdown;
529 	unsigned long	        sk_lingertime;
530 	struct proto		*sk_prot_creator;
531 	rwlock_t		sk_callback_lock;
532 	u32			sk_ack_backlog;
533 	u32			sk_max_ack_backlog;
534 	unsigned long		sk_ino;
535 	spinlock_t		sk_peer_lock;
536 	int			sk_bind_phc;
537 	struct pid		*sk_peer_pid;
538 	const struct cred	*sk_peer_cred;
539 
540 	ktime_t			sk_stamp;
541 #if BITS_PER_LONG==32
542 	seqlock_t		sk_stamp_seq;
543 #endif
544 	int			sk_disconnects;
545 
546 	union {
547 		u8		sk_txrehash;
548 		u8		sk_scm_recv_flags;
549 		struct {
550 			u8	sk_scm_credentials : 1,
551 				sk_scm_security : 1,
552 				sk_scm_pidfd : 1,
553 				sk_scm_rights : 1,
554 				sk_scm_unused : 4;
555 		};
556 	};
557 	u8			sk_clockid;
558 	u8			sk_txtime_deadline_mode : 1,
559 				sk_txtime_report_errors : 1,
560 				sk_txtime_unused : 6;
561 #define SK_BPF_CB_FLAG_TEST(SK, FLAG) ((SK)->sk_bpf_cb_flags & (FLAG))
562 	u8			sk_bpf_cb_flags;
563 
564 	void			*sk_user_data;
565 #ifdef CONFIG_SECURITY
566 	void			*sk_security;
567 #endif
568 	struct sock_cgroup_data	sk_cgrp_data;
569 	void			(*sk_state_change)(struct sock *sk);
570 	void			(*sk_write_space)(struct sock *sk);
571 	void			(*sk_error_report)(struct sock *sk);
572 	int			(*sk_backlog_rcv)(struct sock *sk,
573 						  struct sk_buff *skb);
574 	void                    (*sk_destruct)(struct sock *sk);
575 	struct sock_reuseport __rcu	*sk_reuseport_cb;
576 #ifdef CONFIG_BPF_SYSCALL
577 	struct bpf_local_storage __rcu	*sk_bpf_storage;
578 #endif
579 	struct numa_drop_counters *sk_drop_counters;
580 	struct rcu_head		sk_rcu;
581 	netns_tracker		ns_tracker;
582 	struct xarray		sk_user_frags;
583 
584 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
585 	struct module		*sk_owner;
586 #endif
587 };
588 
589 struct sock_bh_locked {
590 	struct sock *sock;
591 	local_lock_t bh_lock;
592 };
593 
594 enum sk_pacing {
595 	SK_PACING_NONE		= 0,
596 	SK_PACING_NEEDED	= 1,
597 	SK_PACING_FQ		= 2,
598 };
599 
600 /* flag bits in sk_user_data
601  *
602  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
603  *   not be suitable for copying when cloning the socket. For instance,
604  *   it can point to a reference counted object. sk_user_data bottom
605  *   bit is set if pointer must not be copied.
606  *
607  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
608  *   managed/owned by a BPF reuseport array. This bit should be set
609  *   when sk_user_data's sk is added to the bpf's reuseport_array.
610  *
611  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
612  *   sk_user_data points to psock type. This bit should be set
613  *   when sk_user_data is assigned to a psock object.
614  */
615 #define SK_USER_DATA_NOCOPY	1UL
616 #define SK_USER_DATA_BPF	2UL
617 #define SK_USER_DATA_PSOCK	4UL
618 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
619 				  SK_USER_DATA_PSOCK)
620 
621 /**
622  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
623  * @sk: socket
624  */
625 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
626 {
627 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
628 }
629 
630 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
631 
632 /**
633  * __locked_read_sk_user_data_with_flags - return the pointer
634  * only if argument flags all has been set in sk_user_data. Otherwise
635  * return NULL
636  *
637  * @sk: socket
638  * @flags: flag bits
639  *
640  * The caller must be holding sk->sk_callback_lock.
641  */
642 static inline void *
643 __locked_read_sk_user_data_with_flags(const struct sock *sk,
644 				      uintptr_t flags)
645 {
646 	uintptr_t sk_user_data =
647 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
648 						 lockdep_is_held(&sk->sk_callback_lock));
649 
650 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
651 
652 	if ((sk_user_data & flags) == flags)
653 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
654 	return NULL;
655 }
656 
657 /**
658  * __rcu_dereference_sk_user_data_with_flags - return the pointer
659  * only if argument flags all has been set in sk_user_data. Otherwise
660  * return NULL
661  *
662  * @sk: socket
663  * @flags: flag bits
664  */
665 static inline void *
666 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
667 					  uintptr_t flags)
668 {
669 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
670 
671 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
672 
673 	if ((sk_user_data & flags) == flags)
674 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
675 	return NULL;
676 }
677 
678 #define rcu_dereference_sk_user_data(sk)				\
679 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
680 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
681 ({									\
682 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
683 		  __tmp2 = (uintptr_t)(flags);				\
684 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
685 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
686 	rcu_assign_pointer(__sk_user_data((sk)),			\
687 			   __tmp1 | __tmp2);				\
688 })
689 #define rcu_assign_sk_user_data(sk, ptr)				\
690 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
691 
692 static inline
693 struct net *sock_net(const struct sock *sk)
694 {
695 	return read_pnet(&sk->sk_net);
696 }
697 
698 static inline
699 void sock_net_set(struct sock *sk, struct net *net)
700 {
701 	write_pnet(&sk->sk_net, net);
702 }
703 
704 /*
705  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
706  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
707  * on a socket means that the socket will reuse everybody else's port
708  * without looking at the other's sk_reuse value.
709  */
710 
711 #define SK_NO_REUSE	0
712 #define SK_CAN_REUSE	1
713 #define SK_FORCE_REUSE	2
714 
715 int sk_set_peek_off(struct sock *sk, int val);
716 
717 static inline int sk_peek_offset(const struct sock *sk, int flags)
718 {
719 	if (unlikely(flags & MSG_PEEK)) {
720 		return READ_ONCE(sk->sk_peek_off);
721 	}
722 
723 	return 0;
724 }
725 
726 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
727 {
728 	s32 off = READ_ONCE(sk->sk_peek_off);
729 
730 	if (unlikely(off >= 0)) {
731 		off = max_t(s32, off - val, 0);
732 		WRITE_ONCE(sk->sk_peek_off, off);
733 	}
734 }
735 
736 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
737 {
738 	sk_peek_offset_bwd(sk, -val);
739 }
740 
741 /*
742  * Hashed lists helper routines
743  */
744 static inline struct sock *sk_entry(const struct hlist_node *node)
745 {
746 	return hlist_entry(node, struct sock, sk_node);
747 }
748 
749 static inline struct sock *__sk_head(const struct hlist_head *head)
750 {
751 	return hlist_entry(head->first, struct sock, sk_node);
752 }
753 
754 static inline struct sock *sk_head(const struct hlist_head *head)
755 {
756 	return hlist_empty(head) ? NULL : __sk_head(head);
757 }
758 
759 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
760 {
761 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
762 }
763 
764 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
765 {
766 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
767 }
768 
769 static inline struct sock *sk_next(const struct sock *sk)
770 {
771 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
772 }
773 
774 static inline struct sock *sk_nulls_next(const struct sock *sk)
775 {
776 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
777 		hlist_nulls_entry(sk->sk_nulls_node.next,
778 				  struct sock, sk_nulls_node) :
779 		NULL;
780 }
781 
782 static inline bool sk_unhashed(const struct sock *sk)
783 {
784 	return hlist_unhashed(&sk->sk_node);
785 }
786 
787 static inline bool sk_hashed(const struct sock *sk)
788 {
789 	return !sk_unhashed(sk);
790 }
791 
792 static inline void sk_node_init(struct hlist_node *node)
793 {
794 	node->pprev = NULL;
795 }
796 
797 static inline void __sk_del_node(struct sock *sk)
798 {
799 	__hlist_del(&sk->sk_node);
800 }
801 
802 /* NB: equivalent to hlist_del_init_rcu */
803 static inline bool __sk_del_node_init(struct sock *sk)
804 {
805 	if (sk_hashed(sk)) {
806 		__sk_del_node(sk);
807 		sk_node_init(&sk->sk_node);
808 		return true;
809 	}
810 	return false;
811 }
812 
813 /* Grab socket reference count. This operation is valid only
814    when sk is ALREADY grabbed f.e. it is found in hash table
815    or a list and the lookup is made under lock preventing hash table
816    modifications.
817  */
818 
819 static __always_inline void sock_hold(struct sock *sk)
820 {
821 	refcount_inc(&sk->sk_refcnt);
822 }
823 
824 /* Ungrab socket in the context, which assumes that socket refcnt
825    cannot hit zero, f.e. it is true in context of any socketcall.
826  */
827 static __always_inline void __sock_put(struct sock *sk)
828 {
829 	refcount_dec(&sk->sk_refcnt);
830 }
831 
832 static inline bool sk_del_node_init(struct sock *sk)
833 {
834 	bool rc = __sk_del_node_init(sk);
835 
836 	if (rc)
837 		__sock_put(sk);
838 
839 	return rc;
840 }
841 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
842 
843 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
844 {
845 	if (sk_hashed(sk)) {
846 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
847 		return true;
848 	}
849 	return false;
850 }
851 
852 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
853 {
854 	bool rc = __sk_nulls_del_node_init_rcu(sk);
855 
856 	if (rc)
857 		__sock_put(sk);
858 
859 	return rc;
860 }
861 
862 static inline bool sk_nulls_replace_node_init_rcu(struct sock *old,
863 						  struct sock *new)
864 {
865 	if (sk_hashed(old)) {
866 		hlist_nulls_replace_init_rcu(&old->sk_nulls_node,
867 					     &new->sk_nulls_node);
868 		__sock_put(old);
869 		return true;
870 	}
871 
872 	return false;
873 }
874 
875 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
876 {
877 	hlist_add_head(&sk->sk_node, list);
878 }
879 
880 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
881 {
882 	sock_hold(sk);
883 	__sk_add_node(sk, list);
884 }
885 
886 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
887 {
888 	sock_hold(sk);
889 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
890 	    sk->sk_family == AF_INET6)
891 		hlist_add_tail_rcu(&sk->sk_node, list);
892 	else
893 		hlist_add_head_rcu(&sk->sk_node, list);
894 }
895 
896 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
897 {
898 	sock_hold(sk);
899 	hlist_add_tail_rcu(&sk->sk_node, list);
900 }
901 
902 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
903 {
904 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
905 }
906 
907 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
908 {
909 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
910 }
911 
912 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
913 {
914 	sock_hold(sk);
915 	__sk_nulls_add_node_rcu(sk, list);
916 }
917 
918 static inline void __sk_del_bind_node(struct sock *sk)
919 {
920 	__hlist_del(&sk->sk_bind_node);
921 }
922 
923 static inline void sk_add_bind_node(struct sock *sk,
924 					struct hlist_head *list)
925 {
926 	hlist_add_head(&sk->sk_bind_node, list);
927 }
928 
929 #define sk_for_each(__sk, list) \
930 	hlist_for_each_entry(__sk, list, sk_node)
931 #define sk_for_each_rcu(__sk, list) \
932 	hlist_for_each_entry_rcu(__sk, list, sk_node)
933 #define sk_nulls_for_each(__sk, node, list) \
934 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
935 #define sk_nulls_for_each_rcu(__sk, node, list) \
936 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
937 #define sk_for_each_from(__sk) \
938 	hlist_for_each_entry_from(__sk, sk_node)
939 #define sk_nulls_for_each_from(__sk, node) \
940 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
941 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
942 #define sk_for_each_safe(__sk, tmp, list) \
943 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
944 #define sk_for_each_bound(__sk, list) \
945 	hlist_for_each_entry(__sk, list, sk_bind_node)
946 #define sk_for_each_bound_safe(__sk, tmp, list) \
947 	hlist_for_each_entry_safe(__sk, tmp, list, sk_bind_node)
948 
949 /**
950  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
951  * @tpos:	the type * to use as a loop cursor.
952  * @pos:	the &struct hlist_node to use as a loop cursor.
953  * @head:	the head for your list.
954  * @offset:	offset of hlist_node within the struct.
955  *
956  */
957 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
958 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
959 	     pos != NULL &&						       \
960 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
961 	     pos = rcu_dereference(hlist_next_rcu(pos)))
962 
963 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
964 {
965 	/* Careful only use this in a context where these parameters
966 	 * can not change and must all be valid, such as recvmsg from
967 	 * userspace.
968 	 */
969 	return sk->sk_socket->file->f_cred->user_ns;
970 }
971 
972 /* Sock flags */
973 enum sock_flags {
974 	SOCK_DEAD,
975 	SOCK_DONE,
976 	SOCK_URGINLINE,
977 	SOCK_KEEPOPEN,
978 	SOCK_LINGER,
979 	SOCK_DESTROY,
980 	SOCK_BROADCAST,
981 	SOCK_TIMESTAMP,
982 	SOCK_ZAPPED,
983 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
984 	SOCK_DBG, /* %SO_DEBUG setting */
985 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
986 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
987 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
988 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
989 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
990 	SOCK_FASYNC, /* fasync() active */
991 	SOCK_RXQ_OVFL,
992 	SOCK_ZEROCOPY, /* buffers from userspace */
993 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
994 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
995 		     * Will use last 4 bytes of packet sent from
996 		     * user-space instead.
997 		     */
998 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
999 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
1000 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
1001 	SOCK_TXTIME,
1002 	SOCK_XDP, /* XDP is attached */
1003 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
1004 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
1005 	SOCK_RCVPRIORITY, /* Receive SO_PRIORITY ancillary data with packet */
1006 	SOCK_TIMESTAMPING_ANY, /* Copy of sk_tsflags & TSFLAGS_ANY */
1007 };
1008 
1009 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
1010 /*
1011  * The highest bit of sk_tsflags is reserved for kernel-internal
1012  * SOCKCM_FLAG_TS_OPT_ID. There is a check in core/sock.c to control that
1013  * SOF_TIMESTAMPING* values do not reach this reserved area
1014  */
1015 #define SOCKCM_FLAG_TS_OPT_ID	BIT(31)
1016 
1017 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
1018 {
1019 	nsk->sk_flags = osk->sk_flags;
1020 }
1021 
1022 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
1023 {
1024 	__set_bit(flag, &sk->sk_flags);
1025 }
1026 
1027 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
1028 {
1029 	__clear_bit(flag, &sk->sk_flags);
1030 }
1031 
1032 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
1033 				     int valbool)
1034 {
1035 	if (valbool)
1036 		sock_set_flag(sk, bit);
1037 	else
1038 		sock_reset_flag(sk, bit);
1039 }
1040 
1041 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
1042 {
1043 	return test_bit(flag, &sk->sk_flags);
1044 }
1045 
1046 #ifdef CONFIG_NET
1047 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
1048 static inline int sk_memalloc_socks(void)
1049 {
1050 	return static_branch_unlikely(&memalloc_socks_key);
1051 }
1052 
1053 void __receive_sock(struct file *file);
1054 #else
1055 
1056 static inline int sk_memalloc_socks(void)
1057 {
1058 	return 0;
1059 }
1060 
1061 static inline void __receive_sock(struct file *file)
1062 { }
1063 #endif
1064 
1065 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1066 {
1067 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1068 }
1069 
1070 static inline void sk_acceptq_removed(struct sock *sk)
1071 {
1072 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1073 }
1074 
1075 static inline void sk_acceptq_added(struct sock *sk)
1076 {
1077 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1078 }
1079 
1080 /* Note: If you think the test should be:
1081  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1082  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1083  */
1084 static inline bool sk_acceptq_is_full(const struct sock *sk)
1085 {
1086 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1087 }
1088 
1089 /*
1090  * Compute minimal free write space needed to queue new packets.
1091  */
1092 static inline int sk_stream_min_wspace(const struct sock *sk)
1093 {
1094 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1095 }
1096 
1097 static inline int sk_stream_wspace(const struct sock *sk)
1098 {
1099 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1100 }
1101 
1102 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1103 {
1104 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1105 }
1106 
1107 static inline void sk_forward_alloc_add(struct sock *sk, int val)
1108 {
1109 	/* Paired with lockless reads of sk->sk_forward_alloc */
1110 	WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val);
1111 }
1112 
1113 void sk_stream_write_space(struct sock *sk);
1114 
1115 /* OOB backlog add */
1116 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1117 {
1118 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1119 	skb_dst_force(skb);
1120 
1121 	if (!sk->sk_backlog.tail)
1122 		WRITE_ONCE(sk->sk_backlog.head, skb);
1123 	else
1124 		sk->sk_backlog.tail->next = skb;
1125 
1126 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1127 	skb->next = NULL;
1128 }
1129 
1130 /*
1131  * Take into account size of receive queue and backlog queue
1132  * Do not take into account this skb truesize,
1133  * to allow even a single big packet to come.
1134  */
1135 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1136 {
1137 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1138 
1139 	return qsize > limit;
1140 }
1141 
1142 /* The per-socket spinlock must be held here. */
1143 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1144 					      unsigned int limit)
1145 {
1146 	if (sk_rcvqueues_full(sk, limit))
1147 		return -ENOBUFS;
1148 
1149 	/*
1150 	 * If the skb was allocated from pfmemalloc reserves, only
1151 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1152 	 * helping free memory
1153 	 */
1154 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1155 		return -ENOMEM;
1156 
1157 	__sk_add_backlog(sk, skb);
1158 	sk->sk_backlog.len += skb->truesize;
1159 	return 0;
1160 }
1161 
1162 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1163 
1164 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1165 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1166 
1167 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1168 {
1169 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1170 		return __sk_backlog_rcv(sk, skb);
1171 
1172 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1173 				  tcp_v6_do_rcv,
1174 				  tcp_v4_do_rcv,
1175 				  sk, skb);
1176 }
1177 
1178 static inline void sk_incoming_cpu_update(struct sock *sk)
1179 {
1180 	int cpu = raw_smp_processor_id();
1181 
1182 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1183 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1184 }
1185 
1186 
1187 static inline void sock_rps_save_rxhash(struct sock *sk,
1188 					const struct sk_buff *skb)
1189 {
1190 #ifdef CONFIG_RPS
1191 	/* The following WRITE_ONCE() is paired with the READ_ONCE()
1192 	 * here, and another one in sock_rps_record_flow().
1193 	 */
1194 	if (unlikely(READ_ONCE(sk->sk_rxhash) != skb->hash))
1195 		WRITE_ONCE(sk->sk_rxhash, skb->hash);
1196 #endif
1197 }
1198 
1199 static inline void sock_rps_reset_rxhash(struct sock *sk)
1200 {
1201 #ifdef CONFIG_RPS
1202 	/* Paired with READ_ONCE() in sock_rps_record_flow() */
1203 	WRITE_ONCE(sk->sk_rxhash, 0);
1204 #endif
1205 }
1206 
1207 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1208 	({	int __rc, __dis = __sk->sk_disconnects;			\
1209 		release_sock(__sk);					\
1210 		__rc = __condition;					\
1211 		if (!__rc) {						\
1212 			*(__timeo) = wait_woken(__wait,			\
1213 						TASK_INTERRUPTIBLE,	\
1214 						*(__timeo));		\
1215 		}							\
1216 		sched_annotate_sleep();					\
1217 		lock_sock(__sk);					\
1218 		__rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
1219 		__rc;							\
1220 	})
1221 
1222 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1223 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1224 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1225 int sk_stream_error(struct sock *sk, int flags, int err);
1226 void sk_stream_kill_queues(struct sock *sk);
1227 void sk_set_memalloc(struct sock *sk);
1228 void sk_clear_memalloc(struct sock *sk);
1229 
1230 void __sk_flush_backlog(struct sock *sk);
1231 
1232 static inline bool sk_flush_backlog(struct sock *sk)
1233 {
1234 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1235 		__sk_flush_backlog(sk);
1236 		return true;
1237 	}
1238 	return false;
1239 }
1240 
1241 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1242 
1243 struct request_sock_ops;
1244 struct timewait_sock_ops;
1245 struct inet_hashinfo;
1246 struct raw_hashinfo;
1247 struct smc_hashinfo;
1248 struct module;
1249 struct sk_psock;
1250 
1251 /*
1252  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1253  * un-modified. Special care is taken when initializing object to zero.
1254  */
1255 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1256 {
1257 	if (offsetof(struct sock, sk_node.next) != 0)
1258 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1259 	memset(&sk->sk_node.pprev, 0,
1260 	       size - offsetof(struct sock, sk_node.pprev));
1261 }
1262 
1263 struct proto_accept_arg {
1264 	int flags;
1265 	int err;
1266 	int is_empty;
1267 	bool kern;
1268 };
1269 
1270 /* Networking protocol blocks we attach to sockets.
1271  * socket layer -> transport layer interface
1272  */
1273 struct proto {
1274 	void			(*close)(struct sock *sk,
1275 					long timeout);
1276 	int			(*pre_connect)(struct sock *sk,
1277 					struct sockaddr_unsized *uaddr,
1278 					int addr_len);
1279 	int			(*connect)(struct sock *sk,
1280 					struct sockaddr_unsized *uaddr,
1281 					int addr_len);
1282 	int			(*disconnect)(struct sock *sk, int flags);
1283 
1284 	struct sock *		(*accept)(struct sock *sk,
1285 					  struct proto_accept_arg *arg);
1286 
1287 	int			(*ioctl)(struct sock *sk, int cmd,
1288 					 int *karg);
1289 	int			(*init)(struct sock *sk);
1290 	void			(*destroy)(struct sock *sk);
1291 	void			(*shutdown)(struct sock *sk, int how);
1292 	int			(*setsockopt)(struct sock *sk, int level,
1293 					int optname, sockptr_t optval,
1294 					unsigned int optlen);
1295 	int			(*getsockopt)(struct sock *sk, int level,
1296 					int optname, char __user *optval,
1297 					int __user *option);
1298 	void			(*keepalive)(struct sock *sk, int valbool);
1299 #ifdef CONFIG_COMPAT
1300 	int			(*compat_ioctl)(struct sock *sk,
1301 					unsigned int cmd, unsigned long arg);
1302 #endif
1303 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1304 					   size_t len);
1305 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1306 					   size_t len, int flags, int *addr_len);
1307 	void			(*splice_eof)(struct socket *sock);
1308 	int			(*bind)(struct sock *sk,
1309 					struct sockaddr_unsized *addr, int addr_len);
1310 	int			(*bind_add)(struct sock *sk,
1311 					struct sockaddr_unsized *addr, int addr_len);
1312 
1313 	int			(*backlog_rcv) (struct sock *sk,
1314 						struct sk_buff *skb);
1315 	bool			(*bpf_bypass_getsockopt)(int level,
1316 							 int optname);
1317 
1318 	void		(*release_cb)(struct sock *sk);
1319 
1320 	/* Keeping track of sk's, looking them up, and port selection methods. */
1321 	int			(*hash)(struct sock *sk);
1322 	void			(*unhash)(struct sock *sk);
1323 	void			(*rehash)(struct sock *sk);
1324 	int			(*get_port)(struct sock *sk, unsigned short snum);
1325 	void			(*put_port)(struct sock *sk);
1326 #ifdef CONFIG_BPF_SYSCALL
1327 	int			(*psock_update_sk_prot)(struct sock *sk,
1328 							struct sk_psock *psock,
1329 							bool restore);
1330 #endif
1331 
1332 	/* Keeping track of sockets in use */
1333 #ifdef CONFIG_PROC_FS
1334 	unsigned int		inuse_idx;
1335 #endif
1336 
1337 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1338 	bool			(*sock_is_readable)(struct sock *sk);
1339 	/* Memory pressure */
1340 	void			(*enter_memory_pressure)(struct sock *sk);
1341 	void			(*leave_memory_pressure)(struct sock *sk);
1342 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1343 	int  __percpu		*per_cpu_fw_alloc;
1344 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1345 
1346 	/*
1347 	 * Pressure flag: try to collapse.
1348 	 * Technical note: it is used by multiple contexts non atomically.
1349 	 * Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
1350 	 * All the __sk_mem_schedule() is of this nature: accounting
1351 	 * is strict, actions are advisory and have some latency.
1352 	 */
1353 	unsigned long		*memory_pressure;
1354 	long			*sysctl_mem;
1355 
1356 	int			*sysctl_wmem;
1357 	int			*sysctl_rmem;
1358 	u32			sysctl_wmem_offset;
1359 	u32			sysctl_rmem_offset;
1360 
1361 	int			max_header;
1362 	bool			no_autobind;
1363 
1364 	struct kmem_cache	*slab;
1365 	unsigned int		obj_size;
1366 	unsigned int		ipv6_pinfo_offset;
1367 	slab_flags_t		slab_flags;
1368 	unsigned int		useroffset;	/* Usercopy region offset */
1369 	unsigned int		usersize;	/* Usercopy region size */
1370 
1371 	struct request_sock_ops	*rsk_prot;
1372 	struct timewait_sock_ops *twsk_prot;
1373 
1374 	union {
1375 		struct inet_hashinfo	*hashinfo;
1376 		struct udp_table	*udp_table;
1377 		struct raw_hashinfo	*raw_hash;
1378 		struct smc_hashinfo	*smc_hash;
1379 	} h;
1380 
1381 	struct module		*owner;
1382 
1383 	char			name[32];
1384 
1385 	struct list_head	node;
1386 	int			(*diag_destroy)(struct sock *sk, int err);
1387 } __randomize_layout;
1388 
1389 int proto_register(struct proto *prot, int alloc_slab);
1390 void proto_unregister(struct proto *prot);
1391 int sock_load_diag_module(int family, int protocol);
1392 
1393 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1394 
1395 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1396 {
1397 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1398 		return false;
1399 
1400 	return sk->sk_prot->stream_memory_free ?
1401 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1402 				     tcp_stream_memory_free, sk, wake) : true;
1403 }
1404 
1405 static inline bool sk_stream_memory_free(const struct sock *sk)
1406 {
1407 	return __sk_stream_memory_free(sk, 0);
1408 }
1409 
1410 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1411 {
1412 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1413 	       __sk_stream_memory_free(sk, wake);
1414 }
1415 
1416 static inline bool sk_stream_is_writeable(const struct sock *sk)
1417 {
1418 	return __sk_stream_is_writeable(sk, 0);
1419 }
1420 
1421 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1422 					    struct cgroup *ancestor)
1423 {
1424 #ifdef CONFIG_SOCK_CGROUP_DATA
1425 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1426 				    ancestor);
1427 #else
1428 	return -ENOTSUPP;
1429 #endif
1430 }
1431 
1432 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1433 
1434 static inline void sk_sockets_allocated_dec(struct sock *sk)
1435 {
1436 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1437 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1438 }
1439 
1440 static inline void sk_sockets_allocated_inc(struct sock *sk)
1441 {
1442 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1443 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1444 }
1445 
1446 static inline u64
1447 sk_sockets_allocated_read_positive(struct sock *sk)
1448 {
1449 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1450 }
1451 
1452 static inline int
1453 proto_sockets_allocated_sum_positive(struct proto *prot)
1454 {
1455 	return percpu_counter_sum_positive(prot->sockets_allocated);
1456 }
1457 
1458 #ifdef CONFIG_PROC_FS
1459 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1460 struct prot_inuse {
1461 	int all;
1462 	int val[PROTO_INUSE_NR];
1463 };
1464 
1465 static inline void sock_prot_inuse_add(const struct net *net,
1466 				       const struct proto *prot, int val)
1467 {
1468 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1469 }
1470 
1471 static inline void sock_inuse_add(const struct net *net, int val)
1472 {
1473 	this_cpu_add(net->core.prot_inuse->all, val);
1474 }
1475 
1476 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1477 int sock_inuse_get(struct net *net);
1478 #else
1479 static inline void sock_prot_inuse_add(const struct net *net,
1480 				       const struct proto *prot, int val)
1481 {
1482 }
1483 
1484 static inline void sock_inuse_add(const struct net *net, int val)
1485 {
1486 }
1487 #endif
1488 
1489 
1490 /* With per-bucket locks this operation is not-atomic, so that
1491  * this version is not worse.
1492  */
1493 static inline int __sk_prot_rehash(struct sock *sk)
1494 {
1495 	sk->sk_prot->unhash(sk);
1496 	return sk->sk_prot->hash(sk);
1497 }
1498 
1499 /* About 10 seconds */
1500 #define SOCK_DESTROY_TIME (10*HZ)
1501 
1502 /* Sockets 0-1023 can't be bound to unless you are superuser */
1503 #define PROT_SOCK	1024
1504 
1505 #define SHUTDOWN_MASK	3
1506 #define RCV_SHUTDOWN	1
1507 #define SEND_SHUTDOWN	2
1508 
1509 #define SOCK_BINDADDR_LOCK	4
1510 #define SOCK_BINDPORT_LOCK	8
1511 /**
1512  * define SOCK_CONNECT_BIND - &sock->sk_userlocks flag for auto-bind at connect() time
1513  */
1514 #define SOCK_CONNECT_BIND	16
1515 
1516 struct socket_alloc {
1517 	struct socket socket;
1518 	struct inode vfs_inode;
1519 };
1520 
1521 static inline struct socket *SOCKET_I(struct inode *inode)
1522 {
1523 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1524 }
1525 
1526 static inline struct inode *SOCK_INODE(struct socket *socket)
1527 {
1528 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1529 }
1530 
1531 /*
1532  * Functions for memory accounting
1533  */
1534 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1535 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1536 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1537 void __sk_mem_reclaim(struct sock *sk, int amount);
1538 
1539 #define SK_MEM_SEND	0
1540 #define SK_MEM_RECV	1
1541 
1542 /* sysctl_mem values are in pages */
1543 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1544 {
1545 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1546 }
1547 
1548 static inline int sk_mem_pages(int amt)
1549 {
1550 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1551 }
1552 
1553 static inline bool sk_has_account(struct sock *sk)
1554 {
1555 	/* return true if protocol supports memory accounting */
1556 	return !!sk->sk_prot->memory_allocated;
1557 }
1558 
1559 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1560 {
1561 	int delta;
1562 
1563 	if (!sk_has_account(sk))
1564 		return true;
1565 	delta = size - sk->sk_forward_alloc;
1566 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1567 }
1568 
1569 static inline bool
1570 __sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)
1571 {
1572 	int delta;
1573 
1574 	if (!sk_has_account(sk))
1575 		return true;
1576 	delta = size - sk->sk_forward_alloc;
1577 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1578 	       pfmemalloc;
1579 }
1580 
1581 static inline bool
1582 sk_rmem_schedule(struct sock *sk, const struct sk_buff *skb, int size)
1583 {
1584 	return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));
1585 }
1586 
1587 static inline int sk_unused_reserved_mem(const struct sock *sk)
1588 {
1589 	int unused_mem;
1590 
1591 	if (likely(!sk->sk_reserved_mem))
1592 		return 0;
1593 
1594 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1595 			atomic_read(&sk->sk_rmem_alloc);
1596 
1597 	return unused_mem > 0 ? unused_mem : 0;
1598 }
1599 
1600 static inline void sk_mem_reclaim(struct sock *sk)
1601 {
1602 	int reclaimable;
1603 
1604 	if (!sk_has_account(sk))
1605 		return;
1606 
1607 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1608 
1609 	if (reclaimable >= (int)PAGE_SIZE)
1610 		__sk_mem_reclaim(sk, reclaimable);
1611 }
1612 
1613 static inline void sk_mem_reclaim_final(struct sock *sk)
1614 {
1615 	sk->sk_reserved_mem = 0;
1616 	sk_mem_reclaim(sk);
1617 }
1618 
1619 static inline void sk_mem_charge(struct sock *sk, int size)
1620 {
1621 	if (!sk_has_account(sk))
1622 		return;
1623 	sk_forward_alloc_add(sk, -size);
1624 }
1625 
1626 static inline void sk_mem_uncharge(struct sock *sk, int size)
1627 {
1628 	if (!sk_has_account(sk))
1629 		return;
1630 	sk_forward_alloc_add(sk, size);
1631 	sk_mem_reclaim(sk);
1632 }
1633 
1634 #if IS_ENABLED(CONFIG_PROVE_LOCKING) && IS_ENABLED(CONFIG_MODULES)
1635 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1636 {
1637 	__module_get(owner);
1638 	sk->sk_owner = owner;
1639 }
1640 
1641 static inline void sk_owner_clear(struct sock *sk)
1642 {
1643 	sk->sk_owner = NULL;
1644 }
1645 
1646 static inline void sk_owner_put(struct sock *sk)
1647 {
1648 	module_put(sk->sk_owner);
1649 }
1650 #else
1651 static inline void sk_owner_set(struct sock *sk, struct module *owner)
1652 {
1653 }
1654 
1655 static inline void sk_owner_clear(struct sock *sk)
1656 {
1657 }
1658 
1659 static inline void sk_owner_put(struct sock *sk)
1660 {
1661 }
1662 #endif
1663 /*
1664  * Macro so as to not evaluate some arguments when
1665  * lockdep is not enabled.
1666  *
1667  * Mark both the sk_lock and the sk_lock.slock as a
1668  * per-address-family lock class.
1669  */
1670 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1671 do {									\
1672 	sk_owner_set(sk, THIS_MODULE);					\
1673 	sk->sk_lock.owned = 0;						\
1674 	init_waitqueue_head(&sk->sk_lock.wq);				\
1675 	spin_lock_init(&(sk)->sk_lock.slock);				\
1676 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1677 				   sizeof((sk)->sk_lock));		\
1678 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1679 				   (skey), (sname));			\
1680 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1681 } while (0)
1682 
1683 static inline bool lockdep_sock_is_held(const struct sock *sk)
1684 {
1685 	return lockdep_is_held(&sk->sk_lock) ||
1686 	       lockdep_is_held(&sk->sk_lock.slock);
1687 }
1688 
1689 void lock_sock_nested(struct sock *sk, int subclass);
1690 
1691 static inline void lock_sock(struct sock *sk)
1692 {
1693 	lock_sock_nested(sk, 0);
1694 }
1695 
1696 void __lock_sock(struct sock *sk);
1697 void __release_sock(struct sock *sk);
1698 void release_sock(struct sock *sk);
1699 
1700 /* BH context may only use the following locking interface. */
1701 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1702 #define bh_lock_sock_nested(__sk) \
1703 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1704 				SINGLE_DEPTH_NESTING)
1705 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1706 
1707 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1708 
1709 /**
1710  * lock_sock_fast - fast version of lock_sock
1711  * @sk: socket
1712  *
1713  * This version should be used for very small section, where process won't block
1714  * return false if fast path is taken:
1715  *
1716  *   sk_lock.slock locked, owned = 0, BH disabled
1717  *
1718  * return true if slow path is taken:
1719  *
1720  *   sk_lock.slock unlocked, owned = 1, BH enabled
1721  */
1722 static inline bool lock_sock_fast(struct sock *sk)
1723 {
1724 	/* The sk_lock has mutex_lock() semantics here. */
1725 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1726 
1727 	return __lock_sock_fast(sk);
1728 }
1729 
1730 /* fast socket lock variant for caller already holding a [different] socket lock */
1731 static inline bool lock_sock_fast_nested(struct sock *sk)
1732 {
1733 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1734 
1735 	return __lock_sock_fast(sk);
1736 }
1737 
1738 /**
1739  * unlock_sock_fast - complement of lock_sock_fast
1740  * @sk: socket
1741  * @slow: slow mode
1742  *
1743  * fast unlock socket for user context.
1744  * If slow mode is on, we call regular release_sock()
1745  */
1746 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1747 	__releases(&sk->sk_lock.slock)
1748 {
1749 	if (slow) {
1750 		release_sock(sk);
1751 		__release(&sk->sk_lock.slock);
1752 	} else {
1753 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1754 		spin_unlock_bh(&sk->sk_lock.slock);
1755 	}
1756 }
1757 
1758 void sockopt_lock_sock(struct sock *sk);
1759 void sockopt_release_sock(struct sock *sk);
1760 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1761 bool sockopt_capable(int cap);
1762 
1763 /* Used by processes to "lock" a socket state, so that
1764  * interrupts and bottom half handlers won't change it
1765  * from under us. It essentially blocks any incoming
1766  * packets, so that we won't get any new data or any
1767  * packets that change the state of the socket.
1768  *
1769  * While locked, BH processing will add new packets to
1770  * the backlog queue.  This queue is processed by the
1771  * owner of the socket lock right before it is released.
1772  *
1773  * Since ~2.3.5 it is also exclusive sleep lock serializing
1774  * accesses from user process context.
1775  */
1776 
1777 static inline void sock_owned_by_me(const struct sock *sk)
1778 {
1779 #ifdef CONFIG_LOCKDEP
1780 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1781 #endif
1782 }
1783 
1784 static inline void sock_not_owned_by_me(const struct sock *sk)
1785 {
1786 #ifdef CONFIG_LOCKDEP
1787 	WARN_ON_ONCE(lockdep_sock_is_held(sk) && debug_locks);
1788 #endif
1789 }
1790 
1791 static inline bool sock_owned_by_user(const struct sock *sk)
1792 {
1793 	sock_owned_by_me(sk);
1794 	return sk->sk_lock.owned;
1795 }
1796 
1797 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1798 {
1799 	return sk->sk_lock.owned;
1800 }
1801 
1802 static inline void sock_release_ownership(struct sock *sk)
1803 {
1804 	DEBUG_NET_WARN_ON_ONCE(!sock_owned_by_user_nocheck(sk));
1805 	sk->sk_lock.owned = 0;
1806 
1807 	/* The sk_lock has mutex_unlock() semantics: */
1808 	mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1809 }
1810 
1811 /* no reclassification while locks are held */
1812 static inline bool sock_allow_reclassification(const struct sock *csk)
1813 {
1814 	struct sock *sk = (struct sock *)csk;
1815 
1816 	return !sock_owned_by_user_nocheck(sk) &&
1817 		!spin_is_locked(&sk->sk_lock.slock);
1818 }
1819 
1820 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1821 		      struct proto *prot, int kern);
1822 void sk_free(struct sock *sk);
1823 void sk_net_refcnt_upgrade(struct sock *sk);
1824 void sk_destruct(struct sock *sk);
1825 struct sock *sk_clone(const struct sock *sk, const gfp_t priority, bool lock);
1826 
1827 static inline struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1828 {
1829 	return sk_clone(sk, priority, true);
1830 }
1831 
1832 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1833 			     gfp_t priority);
1834 void __sock_wfree(struct sk_buff *skb);
1835 void sock_wfree(struct sk_buff *skb);
1836 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1837 			     gfp_t priority);
1838 void skb_orphan_partial(struct sk_buff *skb);
1839 void sock_rfree(struct sk_buff *skb);
1840 void sock_efree(struct sk_buff *skb);
1841 #ifdef CONFIG_INET
1842 void sock_edemux(struct sk_buff *skb);
1843 void sock_pfree(struct sk_buff *skb);
1844 
1845 static inline void skb_set_owner_edemux(struct sk_buff *skb, struct sock *sk)
1846 {
1847 	skb_orphan(skb);
1848 	if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1849 		skb->sk = sk;
1850 		skb->destructor = sock_edemux;
1851 	}
1852 }
1853 #else
1854 #define sock_edemux sock_efree
1855 #endif
1856 
1857 int sk_setsockopt(struct sock *sk, int level, int optname,
1858 		  sockptr_t optval, unsigned int optlen);
1859 int sock_setsockopt(struct socket *sock, int level, int op,
1860 		    sockptr_t optval, unsigned int optlen);
1861 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
1862 		       int optname, sockptr_t optval, int optlen);
1863 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
1864 		       int optname, sockptr_t optval, sockptr_t optlen);
1865 
1866 int sk_getsockopt(struct sock *sk, int level, int optname,
1867 		  sockptr_t optval, sockptr_t optlen);
1868 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1869 		   bool timeval, bool time32);
1870 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1871 				     unsigned long data_len, int noblock,
1872 				     int *errcode, int max_page_order);
1873 
1874 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1875 						  unsigned long size,
1876 						  int noblock, int *errcode)
1877 {
1878 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1879 }
1880 
1881 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1882 void *sock_kmemdup(struct sock *sk, const void *src,
1883 		   int size, gfp_t priority);
1884 void sock_kfree_s(struct sock *sk, void *mem, int size);
1885 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1886 void sk_send_sigurg(struct sock *sk);
1887 
1888 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1889 {
1890 	if (sk->sk_socket)
1891 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1892 	WRITE_ONCE(sk->sk_prot, proto);
1893 }
1894 
1895 struct sockcm_cookie {
1896 	u64 transmit_time;
1897 	u32 mark;
1898 	u32 tsflags;
1899 	u32 ts_opt_id;
1900 	u32 priority;
1901 	u32 dmabuf_id;
1902 };
1903 
1904 static inline void sockcm_init(struct sockcm_cookie *sockc,
1905 			       const struct sock *sk)
1906 {
1907 	*sockc = (struct sockcm_cookie) {
1908 		.mark = READ_ONCE(sk->sk_mark),
1909 		.tsflags = READ_ONCE(sk->sk_tsflags),
1910 		.priority = READ_ONCE(sk->sk_priority),
1911 	};
1912 }
1913 
1914 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1915 		     struct sockcm_cookie *sockc);
1916 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1917 		   struct sockcm_cookie *sockc);
1918 
1919 /*
1920  * Functions to fill in entries in struct proto_ops when a protocol
1921  * does not implement a particular function.
1922  */
1923 int sock_no_bind(struct socket *sock, struct sockaddr_unsized *saddr, int len);
1924 int sock_no_connect(struct socket *sock, struct sockaddr_unsized *saddr, int len, int flags);
1925 int sock_no_socketpair(struct socket *, struct socket *);
1926 int sock_no_accept(struct socket *, struct socket *, struct proto_accept_arg *);
1927 int sock_no_getname(struct socket *, struct sockaddr *, int);
1928 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1929 int sock_no_listen(struct socket *, int);
1930 int sock_no_shutdown(struct socket *, int);
1931 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1932 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1933 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1934 int sock_no_mmap(struct file *file, struct socket *sock,
1935 		 struct vm_area_struct *vma);
1936 
1937 /*
1938  * Functions to fill in entries in struct proto_ops when a protocol
1939  * uses the inet style.
1940  */
1941 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1942 				  char __user *optval, int __user *optlen);
1943 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1944 			int flags);
1945 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1946 			   sockptr_t optval, unsigned int optlen);
1947 
1948 void sk_common_release(struct sock *sk);
1949 
1950 /*
1951  *	Default socket callbacks and setup code
1952  */
1953 
1954 /* Initialise core socket variables using an explicit uid. */
1955 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1956 
1957 /* Initialise core socket variables.
1958  * Assumes struct socket *sock is embedded in a struct socket_alloc.
1959  */
1960 void sock_init_data(struct socket *sock, struct sock *sk);
1961 
1962 /*
1963  * Socket reference counting postulates.
1964  *
1965  * * Each user of socket SHOULD hold a reference count.
1966  * * Each access point to socket (an hash table bucket, reference from a list,
1967  *   running timer, skb in flight MUST hold a reference count.
1968  * * When reference count hits 0, it means it will never increase back.
1969  * * When reference count hits 0, it means that no references from
1970  *   outside exist to this socket and current process on current CPU
1971  *   is last user and may/should destroy this socket.
1972  * * sk_free is called from any context: process, BH, IRQ. When
1973  *   it is called, socket has no references from outside -> sk_free
1974  *   may release descendant resources allocated by the socket, but
1975  *   to the time when it is called, socket is NOT referenced by any
1976  *   hash tables, lists etc.
1977  * * Packets, delivered from outside (from network or from another process)
1978  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1979  *   when they sit in queue. Otherwise, packets will leak to hole, when
1980  *   socket is looked up by one cpu and unhasing is made by another CPU.
1981  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1982  *   (leak to backlog). Packet socket does all the processing inside
1983  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1984  *   use separate SMP lock, so that they are prone too.
1985  */
1986 
1987 /* Ungrab socket and destroy it, if it was the last reference. */
1988 static inline void sock_put(struct sock *sk)
1989 {
1990 	if (refcount_dec_and_test(&sk->sk_refcnt))
1991 		sk_free(sk);
1992 }
1993 /* Generic version of sock_put(), dealing with all sockets
1994  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1995  */
1996 void sock_gen_put(struct sock *sk);
1997 
1998 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1999 		     unsigned int trim_cap, bool refcounted);
2000 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
2001 				 const int nested)
2002 {
2003 	return __sk_receive_skb(sk, skb, nested, 1, true);
2004 }
2005 
2006 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
2007 {
2008 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
2009 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
2010 		return;
2011 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2012 	 * other WRITE_ONCE() because socket lock might be not held.
2013 	 */
2014 	if (READ_ONCE(sk->sk_tx_queue_mapping) != tx_queue) {
2015 		WRITE_ONCE(sk->sk_tx_queue_mapping, tx_queue);
2016 		WRITE_ONCE(sk->sk_tx_queue_mapping_jiffies, jiffies);
2017 		return;
2018 	}
2019 
2020 	/* Refresh sk_tx_queue_mapping_jiffies if too old. */
2021 	if (time_is_before_jiffies(READ_ONCE(sk->sk_tx_queue_mapping_jiffies) + HZ))
2022 		WRITE_ONCE(sk->sk_tx_queue_mapping_jiffies, jiffies);
2023 }
2024 
2025 #define NO_QUEUE_MAPPING	USHRT_MAX
2026 
2027 static inline void sk_tx_queue_clear(struct sock *sk)
2028 {
2029 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2030 	 * other WRITE_ONCE() because socket lock might be not held.
2031 	 */
2032 	WRITE_ONCE(sk->sk_tx_queue_mapping, NO_QUEUE_MAPPING);
2033 }
2034 
2035 int sk_tx_queue_get(const struct sock *sk);
2036 
2037 static inline void __sk_rx_queue_set(struct sock *sk,
2038 				     const struct sk_buff *skb,
2039 				     bool force_set)
2040 {
2041 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2042 	if (skb_rx_queue_recorded(skb)) {
2043 		u16 rx_queue = skb_get_rx_queue(skb);
2044 
2045 		if (force_set ||
2046 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2047 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2048 	}
2049 #endif
2050 }
2051 
2052 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2053 {
2054 	__sk_rx_queue_set(sk, skb, true);
2055 }
2056 
2057 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2058 {
2059 	__sk_rx_queue_set(sk, skb, false);
2060 }
2061 
2062 static inline void sk_rx_queue_clear(struct sock *sk)
2063 {
2064 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2065 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2066 #endif
2067 }
2068 
2069 static inline int sk_rx_queue_get(const struct sock *sk)
2070 {
2071 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2072 	if (sk) {
2073 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2074 
2075 		if (res != NO_QUEUE_MAPPING)
2076 			return res;
2077 	}
2078 #endif
2079 
2080 	return -1;
2081 }
2082 
2083 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2084 {
2085 	sk->sk_socket = sock;
2086 	if (sock) {
2087 		WRITE_ONCE(sk->sk_uid, SOCK_INODE(sock)->i_uid);
2088 		WRITE_ONCE(sk->sk_ino, SOCK_INODE(sock)->i_ino);
2089 	} else {
2090 		/* Note: sk_uid is unchanged. */
2091 		WRITE_ONCE(sk->sk_ino, 0);
2092 	}
2093 }
2094 
2095 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2096 {
2097 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2098 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2099 }
2100 /* Detach socket from process context.
2101  * Announce socket dead, detach it from wait queue and inode.
2102  * Note that parent inode held reference count on this struct sock,
2103  * we do not release it in this function, because protocol
2104  * probably wants some additional cleanups or even continuing
2105  * to work with this socket (TCP).
2106  */
2107 static inline void sock_orphan(struct sock *sk)
2108 {
2109 	write_lock_bh(&sk->sk_callback_lock);
2110 	sock_set_flag(sk, SOCK_DEAD);
2111 	sk_set_socket(sk, NULL);
2112 	sk->sk_wq  = NULL;
2113 	write_unlock_bh(&sk->sk_callback_lock);
2114 }
2115 
2116 static inline void sock_graft(struct sock *sk, struct socket *parent)
2117 {
2118 	WARN_ON(parent->sk);
2119 	write_lock_bh(&sk->sk_callback_lock);
2120 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2121 	parent->sk = sk;
2122 	sk_set_socket(sk, parent);
2123 	security_sock_graft(sk, parent);
2124 	write_unlock_bh(&sk->sk_callback_lock);
2125 }
2126 
2127 static inline unsigned long sock_i_ino(const struct sock *sk)
2128 {
2129 	/* Paired with WRITE_ONCE() in sock_graft() and sock_orphan() */
2130 	return READ_ONCE(sk->sk_ino);
2131 }
2132 
2133 static inline kuid_t sk_uid(const struct sock *sk)
2134 {
2135 	/* Paired with WRITE_ONCE() in sockfs_setattr() */
2136 	return READ_ONCE(sk->sk_uid);
2137 }
2138 
2139 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2140 {
2141 	return sk ? sk_uid(sk) : make_kuid(net->user_ns, 0);
2142 }
2143 
2144 static inline u32 net_tx_rndhash(void)
2145 {
2146 	u32 v = get_random_u32();
2147 
2148 	return v ?: 1;
2149 }
2150 
2151 static inline void sk_set_txhash(struct sock *sk)
2152 {
2153 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2154 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2155 }
2156 
2157 static inline bool sk_rethink_txhash(struct sock *sk)
2158 {
2159 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2160 		sk_set_txhash(sk);
2161 		return true;
2162 	}
2163 	return false;
2164 }
2165 
2166 static inline struct dst_entry *
2167 __sk_dst_get(const struct sock *sk)
2168 {
2169 	return rcu_dereference_check(sk->sk_dst_cache,
2170 				     lockdep_sock_is_held(sk));
2171 }
2172 
2173 static inline struct dst_entry *
2174 sk_dst_get(const struct sock *sk)
2175 {
2176 	struct dst_entry *dst;
2177 
2178 	rcu_read_lock();
2179 	dst = rcu_dereference(sk->sk_dst_cache);
2180 	if (dst && !rcuref_get(&dst->__rcuref))
2181 		dst = NULL;
2182 	rcu_read_unlock();
2183 	return dst;
2184 }
2185 
2186 static inline void __dst_negative_advice(struct sock *sk)
2187 {
2188 	struct dst_entry *dst = __sk_dst_get(sk);
2189 
2190 	if (dst && dst->ops->negative_advice)
2191 		dst->ops->negative_advice(sk, dst);
2192 }
2193 
2194 static inline void dst_negative_advice(struct sock *sk)
2195 {
2196 	sk_rethink_txhash(sk);
2197 	__dst_negative_advice(sk);
2198 }
2199 
2200 static inline void
2201 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2202 {
2203 	struct dst_entry *old_dst;
2204 
2205 	sk_tx_queue_clear(sk);
2206 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2207 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2208 					    lockdep_sock_is_held(sk));
2209 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2210 	dst_release(old_dst);
2211 }
2212 
2213 static inline void
2214 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2215 {
2216 	struct dst_entry *old_dst;
2217 
2218 	sk_tx_queue_clear(sk);
2219 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2220 	old_dst = unrcu_pointer(xchg(&sk->sk_dst_cache, RCU_INITIALIZER(dst)));
2221 	dst_release(old_dst);
2222 }
2223 
2224 static inline void
2225 __sk_dst_reset(struct sock *sk)
2226 {
2227 	__sk_dst_set(sk, NULL);
2228 }
2229 
2230 static inline void
2231 sk_dst_reset(struct sock *sk)
2232 {
2233 	sk_dst_set(sk, NULL);
2234 }
2235 
2236 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2237 
2238 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2239 
2240 static inline void sk_dst_confirm(struct sock *sk)
2241 {
2242 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2243 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2244 }
2245 
2246 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2247 {
2248 	if (skb_get_dst_pending_confirm(skb)) {
2249 		struct sock *sk = skb->sk;
2250 
2251 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2252 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2253 		neigh_confirm(n);
2254 	}
2255 }
2256 
2257 bool sk_mc_loop(const struct sock *sk);
2258 
2259 static inline bool sk_can_gso(const struct sock *sk)
2260 {
2261 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2262 }
2263 
2264 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2265 
2266 static inline void sk_gso_disable(struct sock *sk)
2267 {
2268 	sk->sk_gso_disabled = 1;
2269 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2270 }
2271 
2272 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2273 					   struct iov_iter *from, char *to,
2274 					   int copy, int offset)
2275 {
2276 	if (skb->ip_summed == CHECKSUM_NONE) {
2277 		__wsum csum = 0;
2278 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2279 			return -EFAULT;
2280 		skb->csum = csum_block_add(skb->csum, csum, offset);
2281 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2282 		if (!copy_from_iter_full_nocache(to, copy, from))
2283 			return -EFAULT;
2284 	} else if (!copy_from_iter_full(to, copy, from))
2285 		return -EFAULT;
2286 
2287 	return 0;
2288 }
2289 
2290 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2291 				       struct iov_iter *from, int copy)
2292 {
2293 	int err, offset = skb->len;
2294 
2295 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2296 				       copy, offset);
2297 	if (err)
2298 		__skb_trim(skb, offset);
2299 
2300 	return err;
2301 }
2302 
2303 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2304 					   struct sk_buff *skb,
2305 					   struct page *page,
2306 					   int off, int copy)
2307 {
2308 	int err;
2309 
2310 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2311 				       copy, skb->len);
2312 	if (err)
2313 		return err;
2314 
2315 	skb_len_add(skb, copy);
2316 	sk_wmem_queued_add(sk, copy);
2317 	sk_mem_charge(sk, copy);
2318 	return 0;
2319 }
2320 
2321 #define SK_WMEM_ALLOC_BIAS 1
2322 /**
2323  * sk_wmem_alloc_get - returns write allocations
2324  * @sk: socket
2325  *
2326  * Return: sk_wmem_alloc minus initial offset of one
2327  */
2328 static inline int sk_wmem_alloc_get(const struct sock *sk)
2329 {
2330 	return refcount_read(&sk->sk_wmem_alloc) - SK_WMEM_ALLOC_BIAS;
2331 }
2332 
2333 /**
2334  * sk_rmem_alloc_get - returns read allocations
2335  * @sk: socket
2336  *
2337  * Return: sk_rmem_alloc
2338  */
2339 static inline int sk_rmem_alloc_get(const struct sock *sk)
2340 {
2341 	return atomic_read(&sk->sk_rmem_alloc);
2342 }
2343 
2344 /**
2345  * sk_has_allocations - check if allocations are outstanding
2346  * @sk: socket
2347  *
2348  * Return: true if socket has write or read allocations
2349  */
2350 static inline bool sk_has_allocations(const struct sock *sk)
2351 {
2352 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2353 }
2354 
2355 /**
2356  * skwq_has_sleeper - check if there are any waiting processes
2357  * @wq: struct socket_wq
2358  *
2359  * Return: true if socket_wq has waiting processes
2360  *
2361  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2362  * barrier call. They were added due to the race found within the tcp code.
2363  *
2364  * Consider following tcp code paths::
2365  *
2366  *   CPU1                CPU2
2367  *   sys_select          receive packet
2368  *   ...                 ...
2369  *   __add_wait_queue    update tp->rcv_nxt
2370  *   ...                 ...
2371  *   tp->rcv_nxt check   sock_def_readable
2372  *   ...                 {
2373  *   schedule               rcu_read_lock();
2374  *                          wq = rcu_dereference(sk->sk_wq);
2375  *                          if (wq && waitqueue_active(&wq->wait))
2376  *                              wake_up_interruptible(&wq->wait)
2377  *                          ...
2378  *                       }
2379  *
2380  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2381  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2382  * could then endup calling schedule and sleep forever if there are no more
2383  * data on the socket.
2384  *
2385  */
2386 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2387 {
2388 	return wq && wq_has_sleeper(&wq->wait);
2389 }
2390 
2391 /**
2392  * sock_poll_wait - wrapper for the poll_wait call.
2393  * @filp:           file
2394  * @sock:           socket to wait on
2395  * @p:              poll_table
2396  *
2397  * See the comments in the wq_has_sleeper function.
2398  */
2399 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2400 				  poll_table *p)
2401 {
2402 	/* Provides a barrier we need to be sure we are in sync
2403 	 * with the socket flags modification.
2404 	 *
2405 	 * This memory barrier is paired in the wq_has_sleeper.
2406 	 */
2407 	poll_wait(filp, &sock->wq.wait, p);
2408 }
2409 
2410 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2411 {
2412 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2413 	u32 txhash = READ_ONCE(sk->sk_txhash);
2414 
2415 	if (txhash) {
2416 		skb->l4_hash = 1;
2417 		skb->hash = txhash;
2418 	}
2419 }
2420 
2421 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2422 
2423 /*
2424  *	Queue a received datagram if it will fit. Stream and sequenced
2425  *	protocols can't normally use this as they need to fit buffers in
2426  *	and play with them.
2427  *
2428  *	Inlined as it's very short and called for pretty much every
2429  *	packet ever received.
2430  */
2431 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2432 {
2433 	skb_orphan(skb);
2434 	skb->sk = sk;
2435 	skb->destructor = sock_rfree;
2436 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2437 	sk_mem_charge(sk, skb->truesize);
2438 }
2439 
2440 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2441 {
2442 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2443 		skb_orphan(skb);
2444 		skb->destructor = sock_efree;
2445 		skb->sk = sk;
2446 		return true;
2447 	}
2448 	return false;
2449 }
2450 
2451 static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2452 {
2453 	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2454 	if (skb) {
2455 		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2456 			skb_set_owner_r(skb, sk);
2457 			return skb;
2458 		}
2459 		__kfree_skb(skb);
2460 	}
2461 	return NULL;
2462 }
2463 
2464 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2465 {
2466 	if (skb->destructor != sock_wfree) {
2467 		skb_orphan(skb);
2468 		return;
2469 	}
2470 	skb->slow_gro = 1;
2471 }
2472 
2473 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2474 		    unsigned long expires);
2475 
2476 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2477 
2478 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2479 
2480 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2481 			struct sk_buff *skb, unsigned int flags,
2482 			void (*destructor)(struct sock *sk,
2483 					   struct sk_buff *skb));
2484 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2485 
2486 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2487 			      enum skb_drop_reason *reason);
2488 
2489 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2490 {
2491 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2492 }
2493 
2494 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2495 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2496 
2497 /*
2498  *	Recover an error report and clear atomically
2499  */
2500 
2501 static inline int sock_error(struct sock *sk)
2502 {
2503 	int err;
2504 
2505 	/* Avoid an atomic operation for the common case.
2506 	 * This is racy since another cpu/thread can change sk_err under us.
2507 	 */
2508 	if (likely(data_race(!sk->sk_err)))
2509 		return 0;
2510 
2511 	err = xchg(&sk->sk_err, 0);
2512 	return -err;
2513 }
2514 
2515 void sk_error_report(struct sock *sk);
2516 
2517 static inline unsigned long sock_wspace(struct sock *sk)
2518 {
2519 	int amt = 0;
2520 
2521 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2522 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2523 		if (amt < 0)
2524 			amt = 0;
2525 	}
2526 	return amt;
2527 }
2528 
2529 /* Note:
2530  *  We use sk->sk_wq_raw, from contexts knowing this
2531  *  pointer is not NULL and cannot disappear/change.
2532  */
2533 static inline void sk_set_bit(int nr, struct sock *sk)
2534 {
2535 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2536 	    !sock_flag(sk, SOCK_FASYNC))
2537 		return;
2538 
2539 	set_bit(nr, &sk->sk_wq_raw->flags);
2540 }
2541 
2542 static inline void sk_clear_bit(int nr, struct sock *sk)
2543 {
2544 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2545 	    !sock_flag(sk, SOCK_FASYNC))
2546 		return;
2547 
2548 	clear_bit(nr, &sk->sk_wq_raw->flags);
2549 }
2550 
2551 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2552 {
2553 	if (sock_flag(sk, SOCK_FASYNC)) {
2554 		rcu_read_lock();
2555 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2556 		rcu_read_unlock();
2557 	}
2558 }
2559 
2560 static inline void sk_wake_async_rcu(const struct sock *sk, int how, int band)
2561 {
2562 	if (unlikely(sock_flag(sk, SOCK_FASYNC)))
2563 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2564 }
2565 
2566 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2567  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2568  * Note: for send buffers, TCP works better if we can build two skbs at
2569  * minimum.
2570  */
2571 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2572 
2573 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2574 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2575 
2576 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2577 {
2578 	u32 val;
2579 
2580 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2581 		return;
2582 
2583 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2584 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2585 
2586 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2587 }
2588 
2589 /**
2590  * sk_page_frag - return an appropriate page_frag
2591  * @sk: socket
2592  *
2593  * Use the per task page_frag instead of the per socket one for
2594  * optimization when we know that we're in process context and own
2595  * everything that's associated with %current.
2596  *
2597  * Both direct reclaim and page faults can nest inside other
2598  * socket operations and end up recursing into sk_page_frag()
2599  * while it's already in use: explicitly avoid task page_frag
2600  * when users disable sk_use_task_frag.
2601  *
2602  * Return: a per task page_frag if context allows that,
2603  * otherwise a per socket one.
2604  */
2605 static inline struct page_frag *sk_page_frag(struct sock *sk)
2606 {
2607 	if (sk->sk_use_task_frag)
2608 		return &current->task_frag;
2609 
2610 	return &sk->sk_frag;
2611 }
2612 
2613 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2614 
2615 static inline bool __sock_writeable(const struct sock *sk, int wmem_alloc)
2616 {
2617 	return wmem_alloc < (READ_ONCE(sk->sk_sndbuf) >> 1);
2618 }
2619 /*
2620  *	Default write policy as shown to user space via poll/select/SIGIO
2621  */
2622 static inline bool sock_writeable(const struct sock *sk)
2623 {
2624 	return __sock_writeable(sk, refcount_read(&sk->sk_wmem_alloc));
2625 }
2626 
2627 static inline gfp_t gfp_any(void)
2628 {
2629 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2630 }
2631 
2632 static inline gfp_t gfp_memcg_charge(void)
2633 {
2634 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2635 }
2636 
2637 #ifdef CONFIG_MEMCG
2638 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2639 {
2640 	return sk->sk_memcg;
2641 }
2642 
2643 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2644 {
2645 	return mem_cgroup_sockets_enabled && mem_cgroup_from_sk(sk);
2646 }
2647 
2648 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2649 {
2650 	struct mem_cgroup *memcg = mem_cgroup_from_sk(sk);
2651 
2652 #ifdef CONFIG_MEMCG_V1
2653 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
2654 		return !!memcg->tcpmem_pressure;
2655 #endif /* CONFIG_MEMCG_V1 */
2656 
2657 	do {
2658 		if (time_before64(get_jiffies_64(), mem_cgroup_get_socket_pressure(memcg)))
2659 			return true;
2660 	} while ((memcg = parent_mem_cgroup(memcg)));
2661 
2662 	return false;
2663 }
2664 #else
2665 static inline struct mem_cgroup *mem_cgroup_from_sk(const struct sock *sk)
2666 {
2667 	return NULL;
2668 }
2669 
2670 static inline bool mem_cgroup_sk_enabled(const struct sock *sk)
2671 {
2672 	return false;
2673 }
2674 
2675 static inline bool mem_cgroup_sk_under_memory_pressure(const struct sock *sk)
2676 {
2677 	return false;
2678 }
2679 #endif
2680 
2681 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2682 {
2683 	return noblock ? 0 : READ_ONCE(sk->sk_rcvtimeo);
2684 }
2685 
2686 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2687 {
2688 	return noblock ? 0 : READ_ONCE(sk->sk_sndtimeo);
2689 }
2690 
2691 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2692 {
2693 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2694 
2695 	return v ?: 1;
2696 }
2697 
2698 /* Alas, with timeout socket operations are not restartable.
2699  * Compare this to poll().
2700  */
2701 static inline int sock_intr_errno(long timeo)
2702 {
2703 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2704 }
2705 
2706 struct sock_skb_cb {
2707 	u32 dropcount;
2708 };
2709 
2710 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2711  * using skb->cb[] would keep using it directly and utilize its
2712  * alignment guarantee.
2713  */
2714 #define SOCK_SKB_CB_OFFSET (sizeof_field(struct sk_buff, cb) - \
2715 			    sizeof(struct sock_skb_cb))
2716 
2717 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2718 			    SOCK_SKB_CB_OFFSET))
2719 
2720 #define sock_skb_cb_check_size(size) \
2721 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2722 
2723 static inline void sk_drops_add(struct sock *sk, int segs)
2724 {
2725 	struct numa_drop_counters *ndc = sk->sk_drop_counters;
2726 
2727 	if (ndc)
2728 		numa_drop_add(ndc, segs);
2729 	else
2730 		atomic_add(segs, &sk->sk_drops);
2731 }
2732 
2733 static inline void sk_drops_inc(struct sock *sk)
2734 {
2735 	sk_drops_add(sk, 1);
2736 }
2737 
2738 static inline int sk_drops_read(const struct sock *sk)
2739 {
2740 	const struct numa_drop_counters *ndc = sk->sk_drop_counters;
2741 
2742 	if (ndc) {
2743 		DEBUG_NET_WARN_ON_ONCE(atomic_read(&sk->sk_drops));
2744 		return numa_drop_read(ndc);
2745 	}
2746 	return atomic_read(&sk->sk_drops);
2747 }
2748 
2749 static inline void sk_drops_reset(struct sock *sk)
2750 {
2751 	struct numa_drop_counters *ndc = sk->sk_drop_counters;
2752 
2753 	if (ndc)
2754 		numa_drop_reset(ndc);
2755 	atomic_set(&sk->sk_drops, 0);
2756 }
2757 
2758 static inline void
2759 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2760 {
2761 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2762 						sk_drops_read(sk) : 0;
2763 }
2764 
2765 static inline void sk_drops_skbadd(struct sock *sk, const struct sk_buff *skb)
2766 {
2767 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2768 
2769 	sk_drops_add(sk, segs);
2770 }
2771 
2772 static inline ktime_t sock_read_timestamp(struct sock *sk)
2773 {
2774 #if BITS_PER_LONG==32
2775 	unsigned int seq;
2776 	ktime_t kt;
2777 
2778 	do {
2779 		seq = read_seqbegin(&sk->sk_stamp_seq);
2780 		kt = sk->sk_stamp;
2781 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2782 
2783 	return kt;
2784 #else
2785 	return READ_ONCE(sk->sk_stamp);
2786 #endif
2787 }
2788 
2789 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2790 {
2791 #if BITS_PER_LONG==32
2792 	write_seqlock(&sk->sk_stamp_seq);
2793 	sk->sk_stamp = kt;
2794 	write_sequnlock(&sk->sk_stamp_seq);
2795 #else
2796 	WRITE_ONCE(sk->sk_stamp, kt);
2797 #endif
2798 }
2799 
2800 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2801 			   struct sk_buff *skb);
2802 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2803 			     struct sk_buff *skb);
2804 
2805 bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk);
2806 int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
2807 			 struct timespec64 *ts);
2808 
2809 static inline void
2810 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2811 {
2812 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2813 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
2814 	ktime_t kt = skb->tstamp;
2815 	/*
2816 	 * generate control messages if
2817 	 * - receive time stamping in software requested
2818 	 * - software time stamp available and wanted
2819 	 * - hardware time stamps available and wanted
2820 	 */
2821 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2822 	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2823 	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2824 	    (hwtstamps->hwtstamp &&
2825 	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2826 		__sock_recv_timestamp(msg, sk, skb);
2827 	else
2828 		sock_write_timestamp(sk, kt);
2829 
2830 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb_wifi_acked_valid(skb))
2831 		__sock_recv_wifi_status(msg, sk, skb);
2832 }
2833 
2834 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2835 		       struct sk_buff *skb);
2836 
2837 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2838 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2839 				   struct sk_buff *skb)
2840 {
2841 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2842 			   (1UL << SOCK_RCVTSTAMP)			| \
2843 			   (1UL << SOCK_RCVMARK)			| \
2844 			   (1UL << SOCK_RCVPRIORITY)			| \
2845 			   (1UL << SOCK_TIMESTAMPING_ANY))
2846 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2847 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2848 
2849 	if (READ_ONCE(sk->sk_flags) & FLAGS_RECV_CMSGS)
2850 		__sock_recv_cmsgs(msg, sk, skb);
2851 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2852 		sock_write_timestamp(sk, skb->tstamp);
2853 	else if (unlikely(sock_read_timestamp(sk) == SK_DEFAULT_STAMP))
2854 		sock_write_timestamp(sk, 0);
2855 }
2856 
2857 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags);
2858 
2859 /**
2860  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2861  * @sk:		socket sending this packet
2862  * @sockc:	pointer to socket cmsg cookie to get timestamping info
2863  * @tx_flags:	completed with instructions for time stamping
2864  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2865  *
2866  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2867  */
2868 static inline void _sock_tx_timestamp(struct sock *sk,
2869 				      const struct sockcm_cookie *sockc,
2870 				      __u8 *tx_flags, __u32 *tskey)
2871 {
2872 	__u32 tsflags = sockc->tsflags;
2873 
2874 	if (unlikely(tsflags)) {
2875 		__sock_tx_timestamp(tsflags, tx_flags);
2876 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2877 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) {
2878 			if (tsflags & SOCKCM_FLAG_TS_OPT_ID)
2879 				*tskey = sockc->ts_opt_id;
2880 			else
2881 				*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2882 		}
2883 	}
2884 }
2885 
2886 static inline void sock_tx_timestamp(struct sock *sk,
2887 				     const struct sockcm_cookie *sockc,
2888 				     __u8 *tx_flags)
2889 {
2890 	_sock_tx_timestamp(sk, sockc, tx_flags, NULL);
2891 }
2892 
2893 static inline void skb_setup_tx_timestamp(struct sk_buff *skb,
2894 					  const struct sockcm_cookie *sockc)
2895 {
2896 	_sock_tx_timestamp(skb->sk, sockc, &skb_shinfo(skb)->tx_flags,
2897 			   &skb_shinfo(skb)->tskey);
2898 }
2899 
2900 static inline bool sk_is_inet(const struct sock *sk)
2901 {
2902 	int family = READ_ONCE(sk->sk_family);
2903 
2904 	return family == AF_INET || family == AF_INET6;
2905 }
2906 
2907 static inline bool sk_is_tcp(const struct sock *sk)
2908 {
2909 	return sk_is_inet(sk) &&
2910 	       sk->sk_type == SOCK_STREAM &&
2911 	       sk->sk_protocol == IPPROTO_TCP;
2912 }
2913 
2914 static inline bool sk_is_udp(const struct sock *sk)
2915 {
2916 	return sk_is_inet(sk) &&
2917 	       sk->sk_type == SOCK_DGRAM &&
2918 	       sk->sk_protocol == IPPROTO_UDP;
2919 }
2920 
2921 static inline bool sk_is_unix(const struct sock *sk)
2922 {
2923 	return sk->sk_family == AF_UNIX;
2924 }
2925 
2926 static inline bool sk_is_stream_unix(const struct sock *sk)
2927 {
2928 	return sk_is_unix(sk) && sk->sk_type == SOCK_STREAM;
2929 }
2930 
2931 static inline bool sk_is_vsock(const struct sock *sk)
2932 {
2933 	return sk->sk_family == AF_VSOCK;
2934 }
2935 
2936 static inline bool sk_may_scm_recv(const struct sock *sk)
2937 {
2938 	return (IS_ENABLED(CONFIG_UNIX) && sk->sk_family == AF_UNIX) ||
2939 		sk->sk_family == AF_NETLINK ||
2940 		(IS_ENABLED(CONFIG_BT) && sk->sk_family == AF_BLUETOOTH);
2941 }
2942 
2943 /**
2944  * sk_eat_skb - Release a skb if it is no longer needed
2945  * @sk: socket to eat this skb from
2946  * @skb: socket buffer to eat
2947  *
2948  * This routine must be called with interrupts disabled or with the socket
2949  * locked so that the sk_buff queue operation is ok.
2950 */
2951 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2952 {
2953 	__skb_unlink(skb, &sk->sk_receive_queue);
2954 	__kfree_skb(skb);
2955 }
2956 
2957 static inline bool
2958 skb_sk_is_prefetched(struct sk_buff *skb)
2959 {
2960 #ifdef CONFIG_INET
2961 	return skb->destructor == sock_pfree;
2962 #else
2963 	return false;
2964 #endif /* CONFIG_INET */
2965 }
2966 
2967 /* This helper checks if a socket is a full socket,
2968  * ie _not_ a timewait or request socket.
2969  */
2970 static inline bool sk_fullsock(const struct sock *sk)
2971 {
2972 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2973 }
2974 
2975 static inline bool
2976 sk_is_refcounted(struct sock *sk)
2977 {
2978 	/* Only full sockets have sk->sk_flags. */
2979 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2980 }
2981 
2982 static inline bool
2983 sk_requests_wifi_status(struct sock *sk)
2984 {
2985 	return sk && sk_fullsock(sk) && sock_flag(sk, SOCK_WIFI_STATUS);
2986 }
2987 
2988 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2989  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2990  */
2991 static inline bool sk_listener(const struct sock *sk)
2992 {
2993 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2994 }
2995 
2996 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV or TIME_WAIT
2997  * TCP SYNACK messages can be attached to LISTEN or NEW_SYN_RECV (depending on SYNCOOKIE)
2998  * TCP RST and ACK can be attached to TIME_WAIT.
2999  */
3000 static inline bool sk_listener_or_tw(const struct sock *sk)
3001 {
3002 	return (1 << READ_ONCE(sk->sk_state)) &
3003 	       (TCPF_LISTEN | TCPF_NEW_SYN_RECV | TCPF_TIME_WAIT);
3004 }
3005 
3006 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
3007 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
3008 		       int type);
3009 
3010 bool sk_ns_capable(const struct sock *sk,
3011 		   struct user_namespace *user_ns, int cap);
3012 bool sk_capable(const struct sock *sk, int cap);
3013 bool sk_net_capable(const struct sock *sk, int cap);
3014 
3015 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
3016 
3017 /* Take into consideration the size of the struct sk_buff overhead in the
3018  * determination of these values, since that is non-constant across
3019  * platforms.  This makes socket queueing behavior and performance
3020  * not depend upon such differences.
3021  */
3022 #define _SK_MEM_PACKETS		256
3023 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
3024 #define SK_WMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3025 #define SK_RMEM_DEFAULT		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
3026 
3027 extern __u32 sysctl_wmem_max;
3028 extern __u32 sysctl_rmem_max;
3029 
3030 extern __u32 sysctl_wmem_default;
3031 extern __u32 sysctl_rmem_default;
3032 
3033 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
3034 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3035 
3036 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
3037 {
3038 	/* Does this proto have per netns sysctl_wmem ? */
3039 	if (proto->sysctl_wmem_offset)
3040 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
3041 
3042 	return READ_ONCE(*proto->sysctl_wmem);
3043 }
3044 
3045 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
3046 {
3047 	/* Does this proto have per netns sysctl_rmem ? */
3048 	if (proto->sysctl_rmem_offset)
3049 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
3050 
3051 	return READ_ONCE(*proto->sysctl_rmem);
3052 }
3053 
3054 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
3055  * Some wifi drivers need to tweak it to get more chunks.
3056  * They can use this helper from their ndo_start_xmit()
3057  */
3058 static inline void sk_pacing_shift_update(struct sock *sk, int val)
3059 {
3060 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
3061 		return;
3062 	WRITE_ONCE(sk->sk_pacing_shift, val);
3063 }
3064 
3065 /* if a socket is bound to a device, check that the given device
3066  * index is either the same or that the socket is bound to an L3
3067  * master device and the given device index is also enslaved to
3068  * that L3 master
3069  */
3070 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
3071 {
3072 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
3073 	int mdif;
3074 
3075 	if (!bound_dev_if || bound_dev_if == dif)
3076 		return true;
3077 
3078 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
3079 	if (mdif && mdif == bound_dev_if)
3080 		return true;
3081 
3082 	return false;
3083 }
3084 
3085 void sock_def_readable(struct sock *sk);
3086 
3087 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
3088 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
3089 int sock_set_timestamping(struct sock *sk, int optname,
3090 			  struct so_timestamping timestamping);
3091 
3092 #if defined(CONFIG_CGROUP_BPF)
3093 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op);
3094 #else
3095 static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
3096 {
3097 }
3098 #endif
3099 void sock_no_linger(struct sock *sk);
3100 void sock_set_keepalive(struct sock *sk);
3101 void sock_set_priority(struct sock *sk, u32 priority);
3102 void sock_set_rcvbuf(struct sock *sk, int val);
3103 void sock_set_mark(struct sock *sk, u32 val);
3104 void sock_set_reuseaddr(struct sock *sk);
3105 void sock_set_reuseport(struct sock *sk);
3106 void sock_set_sndtimeo(struct sock *sk, s64 secs);
3107 
3108 int sock_bind_add(struct sock *sk, struct sockaddr_unsized *addr, int addr_len);
3109 
3110 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
3111 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
3112 			   sockptr_t optval, int optlen, bool old_timeval);
3113 
3114 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
3115 		     void __user *arg, void *karg, size_t size);
3116 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
3117 static inline bool sk_is_readable(struct sock *sk)
3118 {
3119 	const struct proto *prot = READ_ONCE(sk->sk_prot);
3120 
3121 	if (prot->sock_is_readable)
3122 		return prot->sock_is_readable(sk);
3123 
3124 	return false;
3125 }
3126 #endif	/* _SOCK_H */
3127