xref: /openbmc/linux/include/net/sock.h (revision 0c874100)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for the AF_INET socket handler.
7  *
8  * Version:	@(#)sock.h	1.0.4	05/13/93
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
13  *		Florian La Roche <flla@stud.uni-sb.de>
14  *
15  * Fixes:
16  *		Alan Cox	:	Volatiles in skbuff pointers. See
17  *					skbuff comments. May be overdone,
18  *					better to prove they can be removed
19  *					than the reverse.
20  *		Alan Cox	:	Added a zapped field for tcp to note
21  *					a socket is reset and must stay shut up
22  *		Alan Cox	:	New fields for options
23  *	Pauline Middelink	:	identd support
24  *		Alan Cox	:	Eliminate low level recv/recvfrom
25  *		David S. Miller	:	New socket lookup architecture.
26  *              Steve Whitehouse:       Default routines for sock_ops
27  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
28  *              			protinfo be just a void pointer, as the
29  *              			protocol specific parts were moved to
30  *              			respective headers and ipv4/v6, etc now
31  *              			use private slabcaches for its socks
32  *              Pedro Hortas	:	New flags field for socket options
33  *
34  *
35  *		This program is free software; you can redistribute it and/or
36  *		modify it under the terms of the GNU General Public License
37  *		as published by the Free Software Foundation; either version
38  *		2 of the License, or (at your option) any later version.
39  */
40 #ifndef _SOCK_H
41 #define _SOCK_H
42 
43 #include <linux/hardirq.h>
44 #include <linux/kernel.h>
45 #include <linux/list.h>
46 #include <linux/list_nulls.h>
47 #include <linux/timer.h>
48 #include <linux/cache.h>
49 #include <linux/bitops.h>
50 #include <linux/lockdep.h>
51 #include <linux/netdevice.h>
52 #include <linux/skbuff.h>	/* struct sk_buff */
53 #include <linux/mm.h>
54 #include <linux/security.h>
55 #include <linux/slab.h>
56 #include <linux/uaccess.h>
57 #include <linux/page_counter.h>
58 #include <linux/memcontrol.h>
59 #include <linux/static_key.h>
60 #include <linux/sched.h>
61 #include <linux/wait.h>
62 #include <linux/cgroup-defs.h>
63 #include <linux/rbtree.h>
64 #include <linux/filter.h>
65 #include <linux/rculist_nulls.h>
66 #include <linux/poll.h>
67 
68 #include <linux/atomic.h>
69 #include <linux/refcount.h>
70 #include <net/dst.h>
71 #include <net/checksum.h>
72 #include <net/tcp_states.h>
73 #include <linux/net_tstamp.h>
74 #include <net/smc.h>
75 #include <net/l3mdev.h>
76 
77 /*
78  * This structure really needs to be cleaned up.
79  * Most of it is for TCP, and not used by any of
80  * the other protocols.
81  */
82 
83 /* Define this to get the SOCK_DBG debugging facility. */
84 #define SOCK_DEBUGGING
85 #ifdef SOCK_DEBUGGING
86 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
87 					printk(KERN_DEBUG msg); } while (0)
88 #else
89 /* Validate arguments and do nothing */
90 static inline __printf(2, 3)
91 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
92 {
93 }
94 #endif
95 
96 /* This is the per-socket lock.  The spinlock provides a synchronization
97  * between user contexts and software interrupt processing, whereas the
98  * mini-semaphore synchronizes multiple users amongst themselves.
99  */
100 typedef struct {
101 	spinlock_t		slock;
102 	int			owned;
103 	wait_queue_head_t	wq;
104 	/*
105 	 * We express the mutex-alike socket_lock semantics
106 	 * to the lock validator by explicitly managing
107 	 * the slock as a lock variant (in addition to
108 	 * the slock itself):
109 	 */
110 #ifdef CONFIG_DEBUG_LOCK_ALLOC
111 	struct lockdep_map dep_map;
112 #endif
113 } socket_lock_t;
114 
115 struct sock;
116 struct proto;
117 struct net;
118 
119 typedef __u32 __bitwise __portpair;
120 typedef __u64 __bitwise __addrpair;
121 
122 /**
123  *	struct sock_common - minimal network layer representation of sockets
124  *	@skc_daddr: Foreign IPv4 addr
125  *	@skc_rcv_saddr: Bound local IPv4 addr
126  *	@skc_hash: hash value used with various protocol lookup tables
127  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
128  *	@skc_dport: placeholder for inet_dport/tw_dport
129  *	@skc_num: placeholder for inet_num/tw_num
130  *	@skc_family: network address family
131  *	@skc_state: Connection state
132  *	@skc_reuse: %SO_REUSEADDR setting
133  *	@skc_reuseport: %SO_REUSEPORT setting
134  *	@skc_bound_dev_if: bound device index if != 0
135  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
136  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
137  *	@skc_prot: protocol handlers inside a network family
138  *	@skc_net: reference to the network namespace of this socket
139  *	@skc_node: main hash linkage for various protocol lookup tables
140  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
141  *	@skc_tx_queue_mapping: tx queue number for this connection
142  *	@skc_rx_queue_mapping: rx queue number for this connection
143  *	@skc_flags: place holder for sk_flags
144  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
145  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
146  *	@skc_incoming_cpu: record/match cpu processing incoming packets
147  *	@skc_refcnt: reference count
148  *
149  *	This is the minimal network layer representation of sockets, the header
150  *	for struct sock and struct inet_timewait_sock.
151  */
152 struct sock_common {
153 	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
154 	 * address on 64bit arches : cf INET_MATCH()
155 	 */
156 	union {
157 		__addrpair	skc_addrpair;
158 		struct {
159 			__be32	skc_daddr;
160 			__be32	skc_rcv_saddr;
161 		};
162 	};
163 	union  {
164 		unsigned int	skc_hash;
165 		__u16		skc_u16hashes[2];
166 	};
167 	/* skc_dport && skc_num must be grouped as well */
168 	union {
169 		__portpair	skc_portpair;
170 		struct {
171 			__be16	skc_dport;
172 			__u16	skc_num;
173 		};
174 	};
175 
176 	unsigned short		skc_family;
177 	volatile unsigned char	skc_state;
178 	unsigned char		skc_reuse:4;
179 	unsigned char		skc_reuseport:1;
180 	unsigned char		skc_ipv6only:1;
181 	unsigned char		skc_net_refcnt:1;
182 	int			skc_bound_dev_if;
183 	union {
184 		struct hlist_node	skc_bind_node;
185 		struct hlist_node	skc_portaddr_node;
186 	};
187 	struct proto		*skc_prot;
188 	possible_net_t		skc_net;
189 
190 #if IS_ENABLED(CONFIG_IPV6)
191 	struct in6_addr		skc_v6_daddr;
192 	struct in6_addr		skc_v6_rcv_saddr;
193 #endif
194 
195 	atomic64_t		skc_cookie;
196 
197 	/* following fields are padding to force
198 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
199 	 * assuming IPV6 is enabled. We use this padding differently
200 	 * for different kind of 'sockets'
201 	 */
202 	union {
203 		unsigned long	skc_flags;
204 		struct sock	*skc_listener; /* request_sock */
205 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
206 	};
207 	/*
208 	 * fields between dontcopy_begin/dontcopy_end
209 	 * are not copied in sock_copy()
210 	 */
211 	/* private: */
212 	int			skc_dontcopy_begin[0];
213 	/* public: */
214 	union {
215 		struct hlist_node	skc_node;
216 		struct hlist_nulls_node skc_nulls_node;
217 	};
218 	unsigned short		skc_tx_queue_mapping;
219 #ifdef CONFIG_XPS
220 	unsigned short		skc_rx_queue_mapping;
221 #endif
222 	union {
223 		int		skc_incoming_cpu;
224 		u32		skc_rcv_wnd;
225 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
226 	};
227 
228 	refcount_t		skc_refcnt;
229 	/* private: */
230 	int                     skc_dontcopy_end[0];
231 	union {
232 		u32		skc_rxhash;
233 		u32		skc_window_clamp;
234 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
235 	};
236 	/* public: */
237 };
238 
239 /**
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_dst_cache: destination cache
250   *	@sk_dst_pending_confirm: need to confirm neighbour
251   *	@sk_policy: flow policy
252   *	@sk_receive_queue: incoming packets
253   *	@sk_wmem_alloc: transmit queue bytes committed
254   *	@sk_tsq_flags: TCP Small Queues flags
255   *	@sk_write_queue: Packet sending queue
256   *	@sk_omem_alloc: "o" is "option" or "other"
257   *	@sk_wmem_queued: persistent queue size
258   *	@sk_forward_alloc: space allocated forward
259   *	@sk_napi_id: id of the last napi context to receive data for sk
260   *	@sk_ll_usec: usecs to busypoll when there is no data
261   *	@sk_allocation: allocation mode
262   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
263   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
264   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
265   *	@sk_sndbuf: size of send buffer in bytes
266   *	@__sk_flags_offset: empty field used to determine location of bitfield
267   *	@sk_padding: unused element for alignment
268   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
269   *	@sk_no_check_rx: allow zero checksum in RX packets
270   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
271   *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
272   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
273   *	@sk_gso_max_size: Maximum GSO segment size to build
274   *	@sk_gso_max_segs: Maximum number of GSO segments
275   *	@sk_pacing_shift: scaling factor for TCP Small Queues
276   *	@sk_lingertime: %SO_LINGER l_linger setting
277   *	@sk_backlog: always used with the per-socket spinlock held
278   *	@sk_callback_lock: used with the callbacks in the end of this struct
279   *	@sk_error_queue: rarely used
280   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
281   *			  IPV6_ADDRFORM for instance)
282   *	@sk_err: last error
283   *	@sk_err_soft: errors that don't cause failure but are the cause of a
284   *		      persistent failure not just 'timed out'
285   *	@sk_drops: raw/udp drops counter
286   *	@sk_ack_backlog: current listen backlog
287   *	@sk_max_ack_backlog: listen backlog set in listen()
288   *	@sk_uid: user id of owner
289   *	@sk_priority: %SO_PRIORITY setting
290   *	@sk_type: socket type (%SOCK_STREAM, etc)
291   *	@sk_protocol: which protocol this socket belongs in this network family
292   *	@sk_peer_pid: &struct pid for this socket's peer
293   *	@sk_peer_cred: %SO_PEERCRED setting
294   *	@sk_rcvlowat: %SO_RCVLOWAT setting
295   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
296   *	@sk_sndtimeo: %SO_SNDTIMEO setting
297   *	@sk_txhash: computed flow hash for use on transmit
298   *	@sk_filter: socket filtering instructions
299   *	@sk_timer: sock cleanup timer
300   *	@sk_stamp: time stamp of last packet received
301   *	@sk_tsflags: SO_TIMESTAMPING socket options
302   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
303   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
304   *	@sk_socket: Identd and reporting IO signals
305   *	@sk_user_data: RPC layer private data
306   *	@sk_frag: cached page frag
307   *	@sk_peek_off: current peek_offset value
308   *	@sk_send_head: front of stuff to transmit
309   *	@sk_security: used by security modules
310   *	@sk_mark: generic packet mark
311   *	@sk_cgrp_data: cgroup data for this cgroup
312   *	@sk_memcg: this socket's memory cgroup association
313   *	@sk_write_pending: a write to stream socket waits to start
314   *	@sk_state_change: callback to indicate change in the state of the sock
315   *	@sk_data_ready: callback to indicate there is data to be processed
316   *	@sk_write_space: callback to indicate there is bf sending space available
317   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
318   *	@sk_backlog_rcv: callback to process the backlog
319   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
320   *	@sk_reuseport_cb: reuseport group container
321   *	@sk_rcu: used during RCU grace period
322   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
323   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
324   *	@sk_txtime_unused: unused txtime flags
325   */
326 struct sock {
327 	/*
328 	 * Now struct inet_timewait_sock also uses sock_common, so please just
329 	 * don't add nothing before this first member (__sk_common) --acme
330 	 */
331 	struct sock_common	__sk_common;
332 #define sk_node			__sk_common.skc_node
333 #define sk_nulls_node		__sk_common.skc_nulls_node
334 #define sk_refcnt		__sk_common.skc_refcnt
335 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
336 #ifdef CONFIG_XPS
337 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
338 #endif
339 
340 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
341 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
342 #define sk_hash			__sk_common.skc_hash
343 #define sk_portpair		__sk_common.skc_portpair
344 #define sk_num			__sk_common.skc_num
345 #define sk_dport		__sk_common.skc_dport
346 #define sk_addrpair		__sk_common.skc_addrpair
347 #define sk_daddr		__sk_common.skc_daddr
348 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
349 #define sk_family		__sk_common.skc_family
350 #define sk_state		__sk_common.skc_state
351 #define sk_reuse		__sk_common.skc_reuse
352 #define sk_reuseport		__sk_common.skc_reuseport
353 #define sk_ipv6only		__sk_common.skc_ipv6only
354 #define sk_net_refcnt		__sk_common.skc_net_refcnt
355 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
356 #define sk_bind_node		__sk_common.skc_bind_node
357 #define sk_prot			__sk_common.skc_prot
358 #define sk_net			__sk_common.skc_net
359 #define sk_v6_daddr		__sk_common.skc_v6_daddr
360 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
361 #define sk_cookie		__sk_common.skc_cookie
362 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
363 #define sk_flags		__sk_common.skc_flags
364 #define sk_rxhash		__sk_common.skc_rxhash
365 
366 	socket_lock_t		sk_lock;
367 	atomic_t		sk_drops;
368 	int			sk_rcvlowat;
369 	struct sk_buff_head	sk_error_queue;
370 	struct sk_buff_head	sk_receive_queue;
371 	/*
372 	 * The backlog queue is special, it is always used with
373 	 * the per-socket spinlock held and requires low latency
374 	 * access. Therefore we special case it's implementation.
375 	 * Note : rmem_alloc is in this structure to fill a hole
376 	 * on 64bit arches, not because its logically part of
377 	 * backlog.
378 	 */
379 	struct {
380 		atomic_t	rmem_alloc;
381 		int		len;
382 		struct sk_buff	*head;
383 		struct sk_buff	*tail;
384 	} sk_backlog;
385 #define sk_rmem_alloc sk_backlog.rmem_alloc
386 
387 	int			sk_forward_alloc;
388 #ifdef CONFIG_NET_RX_BUSY_POLL
389 	unsigned int		sk_ll_usec;
390 	/* ===== mostly read cache line ===== */
391 	unsigned int		sk_napi_id;
392 #endif
393 	int			sk_rcvbuf;
394 
395 	struct sk_filter __rcu	*sk_filter;
396 	union {
397 		struct socket_wq __rcu	*sk_wq;
398 		struct socket_wq	*sk_wq_raw;
399 	};
400 #ifdef CONFIG_XFRM
401 	struct xfrm_policy __rcu *sk_policy[2];
402 #endif
403 	struct dst_entry	*sk_rx_dst;
404 	struct dst_entry __rcu	*sk_dst_cache;
405 	atomic_t		sk_omem_alloc;
406 	int			sk_sndbuf;
407 
408 	/* ===== cache line for TX ===== */
409 	int			sk_wmem_queued;
410 	refcount_t		sk_wmem_alloc;
411 	unsigned long		sk_tsq_flags;
412 	union {
413 		struct sk_buff	*sk_send_head;
414 		struct rb_root	tcp_rtx_queue;
415 	};
416 	struct sk_buff_head	sk_write_queue;
417 	__s32			sk_peek_off;
418 	int			sk_write_pending;
419 	__u32			sk_dst_pending_confirm;
420 	u32			sk_pacing_status; /* see enum sk_pacing */
421 	long			sk_sndtimeo;
422 	struct timer_list	sk_timer;
423 	__u32			sk_priority;
424 	__u32			sk_mark;
425 	unsigned long		sk_pacing_rate; /* bytes per second */
426 	unsigned long		sk_max_pacing_rate;
427 	struct page_frag	sk_frag;
428 	netdev_features_t	sk_route_caps;
429 	netdev_features_t	sk_route_nocaps;
430 	netdev_features_t	sk_route_forced_caps;
431 	int			sk_gso_type;
432 	unsigned int		sk_gso_max_size;
433 	gfp_t			sk_allocation;
434 	__u32			sk_txhash;
435 
436 	/*
437 	 * Because of non atomicity rules, all
438 	 * changes are protected by socket lock.
439 	 */
440 	unsigned int		__sk_flags_offset[0];
441 #ifdef __BIG_ENDIAN_BITFIELD
442 #define SK_FL_PROTO_SHIFT  16
443 #define SK_FL_PROTO_MASK   0x00ff0000
444 
445 #define SK_FL_TYPE_SHIFT   0
446 #define SK_FL_TYPE_MASK    0x0000ffff
447 #else
448 #define SK_FL_PROTO_SHIFT  8
449 #define SK_FL_PROTO_MASK   0x0000ff00
450 
451 #define SK_FL_TYPE_SHIFT   16
452 #define SK_FL_TYPE_MASK    0xffff0000
453 #endif
454 
455 	unsigned int		sk_padding : 1,
456 				sk_kern_sock : 1,
457 				sk_no_check_tx : 1,
458 				sk_no_check_rx : 1,
459 				sk_userlocks : 4,
460 				sk_protocol  : 8,
461 				sk_type      : 16;
462 #define SK_PROTOCOL_MAX U8_MAX
463 	u16			sk_gso_max_segs;
464 	u8			sk_pacing_shift;
465 	unsigned long	        sk_lingertime;
466 	struct proto		*sk_prot_creator;
467 	rwlock_t		sk_callback_lock;
468 	int			sk_err,
469 				sk_err_soft;
470 	u32			sk_ack_backlog;
471 	u32			sk_max_ack_backlog;
472 	kuid_t			sk_uid;
473 	struct pid		*sk_peer_pid;
474 	const struct cred	*sk_peer_cred;
475 	long			sk_rcvtimeo;
476 	ktime_t			sk_stamp;
477 	u16			sk_tsflags;
478 	u8			sk_shutdown;
479 	u32			sk_tskey;
480 	atomic_t		sk_zckey;
481 
482 	u8			sk_clockid;
483 	u8			sk_txtime_deadline_mode : 1,
484 				sk_txtime_report_errors : 1,
485 				sk_txtime_unused : 6;
486 
487 	struct socket		*sk_socket;
488 	void			*sk_user_data;
489 #ifdef CONFIG_SECURITY
490 	void			*sk_security;
491 #endif
492 	struct sock_cgroup_data	sk_cgrp_data;
493 	struct mem_cgroup	*sk_memcg;
494 	void			(*sk_state_change)(struct sock *sk);
495 	void			(*sk_data_ready)(struct sock *sk);
496 	void			(*sk_write_space)(struct sock *sk);
497 	void			(*sk_error_report)(struct sock *sk);
498 	int			(*sk_backlog_rcv)(struct sock *sk,
499 						  struct sk_buff *skb);
500 #ifdef CONFIG_SOCK_VALIDATE_XMIT
501 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
502 							struct net_device *dev,
503 							struct sk_buff *skb);
504 #endif
505 	void                    (*sk_destruct)(struct sock *sk);
506 	struct sock_reuseport __rcu	*sk_reuseport_cb;
507 	struct rcu_head		sk_rcu;
508 };
509 
510 enum sk_pacing {
511 	SK_PACING_NONE		= 0,
512 	SK_PACING_NEEDED	= 1,
513 	SK_PACING_FQ		= 2,
514 };
515 
516 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
517 
518 #define rcu_dereference_sk_user_data(sk)	rcu_dereference(__sk_user_data((sk)))
519 #define rcu_assign_sk_user_data(sk, ptr)	rcu_assign_pointer(__sk_user_data((sk)), ptr)
520 
521 /*
522  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
523  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
524  * on a socket means that the socket will reuse everybody else's port
525  * without looking at the other's sk_reuse value.
526  */
527 
528 #define SK_NO_REUSE	0
529 #define SK_CAN_REUSE	1
530 #define SK_FORCE_REUSE	2
531 
532 int sk_set_peek_off(struct sock *sk, int val);
533 
534 static inline int sk_peek_offset(struct sock *sk, int flags)
535 {
536 	if (unlikely(flags & MSG_PEEK)) {
537 		return READ_ONCE(sk->sk_peek_off);
538 	}
539 
540 	return 0;
541 }
542 
543 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
544 {
545 	s32 off = READ_ONCE(sk->sk_peek_off);
546 
547 	if (unlikely(off >= 0)) {
548 		off = max_t(s32, off - val, 0);
549 		WRITE_ONCE(sk->sk_peek_off, off);
550 	}
551 }
552 
553 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
554 {
555 	sk_peek_offset_bwd(sk, -val);
556 }
557 
558 /*
559  * Hashed lists helper routines
560  */
561 static inline struct sock *sk_entry(const struct hlist_node *node)
562 {
563 	return hlist_entry(node, struct sock, sk_node);
564 }
565 
566 static inline struct sock *__sk_head(const struct hlist_head *head)
567 {
568 	return hlist_entry(head->first, struct sock, sk_node);
569 }
570 
571 static inline struct sock *sk_head(const struct hlist_head *head)
572 {
573 	return hlist_empty(head) ? NULL : __sk_head(head);
574 }
575 
576 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
577 {
578 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
579 }
580 
581 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
582 {
583 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
584 }
585 
586 static inline struct sock *sk_next(const struct sock *sk)
587 {
588 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
589 }
590 
591 static inline struct sock *sk_nulls_next(const struct sock *sk)
592 {
593 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
594 		hlist_nulls_entry(sk->sk_nulls_node.next,
595 				  struct sock, sk_nulls_node) :
596 		NULL;
597 }
598 
599 static inline bool sk_unhashed(const struct sock *sk)
600 {
601 	return hlist_unhashed(&sk->sk_node);
602 }
603 
604 static inline bool sk_hashed(const struct sock *sk)
605 {
606 	return !sk_unhashed(sk);
607 }
608 
609 static inline void sk_node_init(struct hlist_node *node)
610 {
611 	node->pprev = NULL;
612 }
613 
614 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
615 {
616 	node->pprev = NULL;
617 }
618 
619 static inline void __sk_del_node(struct sock *sk)
620 {
621 	__hlist_del(&sk->sk_node);
622 }
623 
624 /* NB: equivalent to hlist_del_init_rcu */
625 static inline bool __sk_del_node_init(struct sock *sk)
626 {
627 	if (sk_hashed(sk)) {
628 		__sk_del_node(sk);
629 		sk_node_init(&sk->sk_node);
630 		return true;
631 	}
632 	return false;
633 }
634 
635 /* Grab socket reference count. This operation is valid only
636    when sk is ALREADY grabbed f.e. it is found in hash table
637    or a list and the lookup is made under lock preventing hash table
638    modifications.
639  */
640 
641 static __always_inline void sock_hold(struct sock *sk)
642 {
643 	refcount_inc(&sk->sk_refcnt);
644 }
645 
646 /* Ungrab socket in the context, which assumes that socket refcnt
647    cannot hit zero, f.e. it is true in context of any socketcall.
648  */
649 static __always_inline void __sock_put(struct sock *sk)
650 {
651 	refcount_dec(&sk->sk_refcnt);
652 }
653 
654 static inline bool sk_del_node_init(struct sock *sk)
655 {
656 	bool rc = __sk_del_node_init(sk);
657 
658 	if (rc) {
659 		/* paranoid for a while -acme */
660 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
661 		__sock_put(sk);
662 	}
663 	return rc;
664 }
665 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
666 
667 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
668 {
669 	if (sk_hashed(sk)) {
670 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
671 		return true;
672 	}
673 	return false;
674 }
675 
676 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
677 {
678 	bool rc = __sk_nulls_del_node_init_rcu(sk);
679 
680 	if (rc) {
681 		/* paranoid for a while -acme */
682 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
683 		__sock_put(sk);
684 	}
685 	return rc;
686 }
687 
688 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
689 {
690 	hlist_add_head(&sk->sk_node, list);
691 }
692 
693 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
694 {
695 	sock_hold(sk);
696 	__sk_add_node(sk, list);
697 }
698 
699 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
700 {
701 	sock_hold(sk);
702 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
703 	    sk->sk_family == AF_INET6)
704 		hlist_add_tail_rcu(&sk->sk_node, list);
705 	else
706 		hlist_add_head_rcu(&sk->sk_node, list);
707 }
708 
709 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
710 {
711 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
712 }
713 
714 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
715 {
716 	sock_hold(sk);
717 	__sk_nulls_add_node_rcu(sk, list);
718 }
719 
720 static inline void __sk_del_bind_node(struct sock *sk)
721 {
722 	__hlist_del(&sk->sk_bind_node);
723 }
724 
725 static inline void sk_add_bind_node(struct sock *sk,
726 					struct hlist_head *list)
727 {
728 	hlist_add_head(&sk->sk_bind_node, list);
729 }
730 
731 #define sk_for_each(__sk, list) \
732 	hlist_for_each_entry(__sk, list, sk_node)
733 #define sk_for_each_rcu(__sk, list) \
734 	hlist_for_each_entry_rcu(__sk, list, sk_node)
735 #define sk_nulls_for_each(__sk, node, list) \
736 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
737 #define sk_nulls_for_each_rcu(__sk, node, list) \
738 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
739 #define sk_for_each_from(__sk) \
740 	hlist_for_each_entry_from(__sk, sk_node)
741 #define sk_nulls_for_each_from(__sk, node) \
742 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
743 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
744 #define sk_for_each_safe(__sk, tmp, list) \
745 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
746 #define sk_for_each_bound(__sk, list) \
747 	hlist_for_each_entry(__sk, list, sk_bind_node)
748 
749 /**
750  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
751  * @tpos:	the type * to use as a loop cursor.
752  * @pos:	the &struct hlist_node to use as a loop cursor.
753  * @head:	the head for your list.
754  * @offset:	offset of hlist_node within the struct.
755  *
756  */
757 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
758 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
759 	     pos != NULL &&						       \
760 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
761 	     pos = rcu_dereference(hlist_next_rcu(pos)))
762 
763 static inline struct user_namespace *sk_user_ns(struct sock *sk)
764 {
765 	/* Careful only use this in a context where these parameters
766 	 * can not change and must all be valid, such as recvmsg from
767 	 * userspace.
768 	 */
769 	return sk->sk_socket->file->f_cred->user_ns;
770 }
771 
772 /* Sock flags */
773 enum sock_flags {
774 	SOCK_DEAD,
775 	SOCK_DONE,
776 	SOCK_URGINLINE,
777 	SOCK_KEEPOPEN,
778 	SOCK_LINGER,
779 	SOCK_DESTROY,
780 	SOCK_BROADCAST,
781 	SOCK_TIMESTAMP,
782 	SOCK_ZAPPED,
783 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
784 	SOCK_DBG, /* %SO_DEBUG setting */
785 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
786 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
787 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
788 	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
789 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
790 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
791 	SOCK_FASYNC, /* fasync() active */
792 	SOCK_RXQ_OVFL,
793 	SOCK_ZEROCOPY, /* buffers from userspace */
794 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
795 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
796 		     * Will use last 4 bytes of packet sent from
797 		     * user-space instead.
798 		     */
799 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
800 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
801 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
802 	SOCK_TXTIME,
803 	SOCK_XDP, /* XDP is attached */
804 };
805 
806 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
807 
808 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
809 {
810 	nsk->sk_flags = osk->sk_flags;
811 }
812 
813 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
814 {
815 	__set_bit(flag, &sk->sk_flags);
816 }
817 
818 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
819 {
820 	__clear_bit(flag, &sk->sk_flags);
821 }
822 
823 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
824 {
825 	return test_bit(flag, &sk->sk_flags);
826 }
827 
828 #ifdef CONFIG_NET
829 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
830 static inline int sk_memalloc_socks(void)
831 {
832 	return static_branch_unlikely(&memalloc_socks_key);
833 }
834 #else
835 
836 static inline int sk_memalloc_socks(void)
837 {
838 	return 0;
839 }
840 
841 #endif
842 
843 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
844 {
845 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
846 }
847 
848 static inline void sk_acceptq_removed(struct sock *sk)
849 {
850 	sk->sk_ack_backlog--;
851 }
852 
853 static inline void sk_acceptq_added(struct sock *sk)
854 {
855 	sk->sk_ack_backlog++;
856 }
857 
858 static inline bool sk_acceptq_is_full(const struct sock *sk)
859 {
860 	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
861 }
862 
863 /*
864  * Compute minimal free write space needed to queue new packets.
865  */
866 static inline int sk_stream_min_wspace(const struct sock *sk)
867 {
868 	return sk->sk_wmem_queued >> 1;
869 }
870 
871 static inline int sk_stream_wspace(const struct sock *sk)
872 {
873 	return sk->sk_sndbuf - sk->sk_wmem_queued;
874 }
875 
876 void sk_stream_write_space(struct sock *sk);
877 
878 /* OOB backlog add */
879 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
880 {
881 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
882 	skb_dst_force(skb);
883 
884 	if (!sk->sk_backlog.tail)
885 		sk->sk_backlog.head = skb;
886 	else
887 		sk->sk_backlog.tail->next = skb;
888 
889 	sk->sk_backlog.tail = skb;
890 	skb->next = NULL;
891 }
892 
893 /*
894  * Take into account size of receive queue and backlog queue
895  * Do not take into account this skb truesize,
896  * to allow even a single big packet to come.
897  */
898 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
899 {
900 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
901 
902 	return qsize > limit;
903 }
904 
905 /* The per-socket spinlock must be held here. */
906 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
907 					      unsigned int limit)
908 {
909 	if (sk_rcvqueues_full(sk, limit))
910 		return -ENOBUFS;
911 
912 	/*
913 	 * If the skb was allocated from pfmemalloc reserves, only
914 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
915 	 * helping free memory
916 	 */
917 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
918 		return -ENOMEM;
919 
920 	__sk_add_backlog(sk, skb);
921 	sk->sk_backlog.len += skb->truesize;
922 	return 0;
923 }
924 
925 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
926 
927 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
928 {
929 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
930 		return __sk_backlog_rcv(sk, skb);
931 
932 	return sk->sk_backlog_rcv(sk, skb);
933 }
934 
935 static inline void sk_incoming_cpu_update(struct sock *sk)
936 {
937 	int cpu = raw_smp_processor_id();
938 
939 	if (unlikely(sk->sk_incoming_cpu != cpu))
940 		sk->sk_incoming_cpu = cpu;
941 }
942 
943 static inline void sock_rps_record_flow_hash(__u32 hash)
944 {
945 #ifdef CONFIG_RPS
946 	struct rps_sock_flow_table *sock_flow_table;
947 
948 	rcu_read_lock();
949 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
950 	rps_record_sock_flow(sock_flow_table, hash);
951 	rcu_read_unlock();
952 #endif
953 }
954 
955 static inline void sock_rps_record_flow(const struct sock *sk)
956 {
957 #ifdef CONFIG_RPS
958 	if (static_key_false(&rfs_needed)) {
959 		/* Reading sk->sk_rxhash might incur an expensive cache line
960 		 * miss.
961 		 *
962 		 * TCP_ESTABLISHED does cover almost all states where RFS
963 		 * might be useful, and is cheaper [1] than testing :
964 		 *	IPv4: inet_sk(sk)->inet_daddr
965 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
966 		 * OR	an additional socket flag
967 		 * [1] : sk_state and sk_prot are in the same cache line.
968 		 */
969 		if (sk->sk_state == TCP_ESTABLISHED)
970 			sock_rps_record_flow_hash(sk->sk_rxhash);
971 	}
972 #endif
973 }
974 
975 static inline void sock_rps_save_rxhash(struct sock *sk,
976 					const struct sk_buff *skb)
977 {
978 #ifdef CONFIG_RPS
979 	if (unlikely(sk->sk_rxhash != skb->hash))
980 		sk->sk_rxhash = skb->hash;
981 #endif
982 }
983 
984 static inline void sock_rps_reset_rxhash(struct sock *sk)
985 {
986 #ifdef CONFIG_RPS
987 	sk->sk_rxhash = 0;
988 #endif
989 }
990 
991 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
992 	({	int __rc;						\
993 		release_sock(__sk);					\
994 		__rc = __condition;					\
995 		if (!__rc) {						\
996 			*(__timeo) = wait_woken(__wait,			\
997 						TASK_INTERRUPTIBLE,	\
998 						*(__timeo));		\
999 		}							\
1000 		sched_annotate_sleep();					\
1001 		lock_sock(__sk);					\
1002 		__rc = __condition;					\
1003 		__rc;							\
1004 	})
1005 
1006 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1007 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1008 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1009 int sk_stream_error(struct sock *sk, int flags, int err);
1010 void sk_stream_kill_queues(struct sock *sk);
1011 void sk_set_memalloc(struct sock *sk);
1012 void sk_clear_memalloc(struct sock *sk);
1013 
1014 void __sk_flush_backlog(struct sock *sk);
1015 
1016 static inline bool sk_flush_backlog(struct sock *sk)
1017 {
1018 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1019 		__sk_flush_backlog(sk);
1020 		return true;
1021 	}
1022 	return false;
1023 }
1024 
1025 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1026 
1027 struct request_sock_ops;
1028 struct timewait_sock_ops;
1029 struct inet_hashinfo;
1030 struct raw_hashinfo;
1031 struct smc_hashinfo;
1032 struct module;
1033 
1034 /*
1035  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1036  * un-modified. Special care is taken when initializing object to zero.
1037  */
1038 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1039 {
1040 	if (offsetof(struct sock, sk_node.next) != 0)
1041 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1042 	memset(&sk->sk_node.pprev, 0,
1043 	       size - offsetof(struct sock, sk_node.pprev));
1044 }
1045 
1046 /* Networking protocol blocks we attach to sockets.
1047  * socket layer -> transport layer interface
1048  */
1049 struct proto {
1050 	void			(*close)(struct sock *sk,
1051 					long timeout);
1052 	int			(*pre_connect)(struct sock *sk,
1053 					struct sockaddr *uaddr,
1054 					int addr_len);
1055 	int			(*connect)(struct sock *sk,
1056 					struct sockaddr *uaddr,
1057 					int addr_len);
1058 	int			(*disconnect)(struct sock *sk, int flags);
1059 
1060 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1061 					  bool kern);
1062 
1063 	int			(*ioctl)(struct sock *sk, int cmd,
1064 					 unsigned long arg);
1065 	int			(*init)(struct sock *sk);
1066 	void			(*destroy)(struct sock *sk);
1067 	void			(*shutdown)(struct sock *sk, int how);
1068 	int			(*setsockopt)(struct sock *sk, int level,
1069 					int optname, char __user *optval,
1070 					unsigned int optlen);
1071 	int			(*getsockopt)(struct sock *sk, int level,
1072 					int optname, char __user *optval,
1073 					int __user *option);
1074 	void			(*keepalive)(struct sock *sk, int valbool);
1075 #ifdef CONFIG_COMPAT
1076 	int			(*compat_setsockopt)(struct sock *sk,
1077 					int level,
1078 					int optname, char __user *optval,
1079 					unsigned int optlen);
1080 	int			(*compat_getsockopt)(struct sock *sk,
1081 					int level,
1082 					int optname, char __user *optval,
1083 					int __user *option);
1084 	int			(*compat_ioctl)(struct sock *sk,
1085 					unsigned int cmd, unsigned long arg);
1086 #endif
1087 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1088 					   size_t len);
1089 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1090 					   size_t len, int noblock, int flags,
1091 					   int *addr_len);
1092 	int			(*sendpage)(struct sock *sk, struct page *page,
1093 					int offset, size_t size, int flags);
1094 	int			(*bind)(struct sock *sk,
1095 					struct sockaddr *uaddr, int addr_len);
1096 
1097 	int			(*backlog_rcv) (struct sock *sk,
1098 						struct sk_buff *skb);
1099 
1100 	void		(*release_cb)(struct sock *sk);
1101 
1102 	/* Keeping track of sk's, looking them up, and port selection methods. */
1103 	int			(*hash)(struct sock *sk);
1104 	void			(*unhash)(struct sock *sk);
1105 	void			(*rehash)(struct sock *sk);
1106 	int			(*get_port)(struct sock *sk, unsigned short snum);
1107 
1108 	/* Keeping track of sockets in use */
1109 #ifdef CONFIG_PROC_FS
1110 	unsigned int		inuse_idx;
1111 #endif
1112 
1113 	bool			(*stream_memory_free)(const struct sock *sk);
1114 	bool			(*stream_memory_read)(const struct sock *sk);
1115 	/* Memory pressure */
1116 	void			(*enter_memory_pressure)(struct sock *sk);
1117 	void			(*leave_memory_pressure)(struct sock *sk);
1118 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1119 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1120 	/*
1121 	 * Pressure flag: try to collapse.
1122 	 * Technical note: it is used by multiple contexts non atomically.
1123 	 * All the __sk_mem_schedule() is of this nature: accounting
1124 	 * is strict, actions are advisory and have some latency.
1125 	 */
1126 	unsigned long		*memory_pressure;
1127 	long			*sysctl_mem;
1128 
1129 	int			*sysctl_wmem;
1130 	int			*sysctl_rmem;
1131 	u32			sysctl_wmem_offset;
1132 	u32			sysctl_rmem_offset;
1133 
1134 	int			max_header;
1135 	bool			no_autobind;
1136 
1137 	struct kmem_cache	*slab;
1138 	unsigned int		obj_size;
1139 	slab_flags_t		slab_flags;
1140 	unsigned int		useroffset;	/* Usercopy region offset */
1141 	unsigned int		usersize;	/* Usercopy region size */
1142 
1143 	struct percpu_counter	*orphan_count;
1144 
1145 	struct request_sock_ops	*rsk_prot;
1146 	struct timewait_sock_ops *twsk_prot;
1147 
1148 	union {
1149 		struct inet_hashinfo	*hashinfo;
1150 		struct udp_table	*udp_table;
1151 		struct raw_hashinfo	*raw_hash;
1152 		struct smc_hashinfo	*smc_hash;
1153 	} h;
1154 
1155 	struct module		*owner;
1156 
1157 	char			name[32];
1158 
1159 	struct list_head	node;
1160 #ifdef SOCK_REFCNT_DEBUG
1161 	atomic_t		socks;
1162 #endif
1163 	int			(*diag_destroy)(struct sock *sk, int err);
1164 } __randomize_layout;
1165 
1166 int proto_register(struct proto *prot, int alloc_slab);
1167 void proto_unregister(struct proto *prot);
1168 int sock_load_diag_module(int family, int protocol);
1169 
1170 #ifdef SOCK_REFCNT_DEBUG
1171 static inline void sk_refcnt_debug_inc(struct sock *sk)
1172 {
1173 	atomic_inc(&sk->sk_prot->socks);
1174 }
1175 
1176 static inline void sk_refcnt_debug_dec(struct sock *sk)
1177 {
1178 	atomic_dec(&sk->sk_prot->socks);
1179 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1180 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1181 }
1182 
1183 static inline void sk_refcnt_debug_release(const struct sock *sk)
1184 {
1185 	if (refcount_read(&sk->sk_refcnt) != 1)
1186 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1187 		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1188 }
1189 #else /* SOCK_REFCNT_DEBUG */
1190 #define sk_refcnt_debug_inc(sk) do { } while (0)
1191 #define sk_refcnt_debug_dec(sk) do { } while (0)
1192 #define sk_refcnt_debug_release(sk) do { } while (0)
1193 #endif /* SOCK_REFCNT_DEBUG */
1194 
1195 static inline bool sk_stream_memory_free(const struct sock *sk)
1196 {
1197 	if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1198 		return false;
1199 
1200 	return sk->sk_prot->stream_memory_free ?
1201 		sk->sk_prot->stream_memory_free(sk) : true;
1202 }
1203 
1204 static inline bool sk_stream_is_writeable(const struct sock *sk)
1205 {
1206 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1207 	       sk_stream_memory_free(sk);
1208 }
1209 
1210 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1211 					    struct cgroup *ancestor)
1212 {
1213 #ifdef CONFIG_SOCK_CGROUP_DATA
1214 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1215 				    ancestor);
1216 #else
1217 	return -ENOTSUPP;
1218 #endif
1219 }
1220 
1221 static inline bool sk_has_memory_pressure(const struct sock *sk)
1222 {
1223 	return sk->sk_prot->memory_pressure != NULL;
1224 }
1225 
1226 static inline bool sk_under_memory_pressure(const struct sock *sk)
1227 {
1228 	if (!sk->sk_prot->memory_pressure)
1229 		return false;
1230 
1231 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1232 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1233 		return true;
1234 
1235 	return !!*sk->sk_prot->memory_pressure;
1236 }
1237 
1238 static inline long
1239 sk_memory_allocated(const struct sock *sk)
1240 {
1241 	return atomic_long_read(sk->sk_prot->memory_allocated);
1242 }
1243 
1244 static inline long
1245 sk_memory_allocated_add(struct sock *sk, int amt)
1246 {
1247 	return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1248 }
1249 
1250 static inline void
1251 sk_memory_allocated_sub(struct sock *sk, int amt)
1252 {
1253 	atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1254 }
1255 
1256 static inline void sk_sockets_allocated_dec(struct sock *sk)
1257 {
1258 	percpu_counter_dec(sk->sk_prot->sockets_allocated);
1259 }
1260 
1261 static inline void sk_sockets_allocated_inc(struct sock *sk)
1262 {
1263 	percpu_counter_inc(sk->sk_prot->sockets_allocated);
1264 }
1265 
1266 static inline int
1267 sk_sockets_allocated_read_positive(struct sock *sk)
1268 {
1269 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1270 }
1271 
1272 static inline int
1273 proto_sockets_allocated_sum_positive(struct proto *prot)
1274 {
1275 	return percpu_counter_sum_positive(prot->sockets_allocated);
1276 }
1277 
1278 static inline long
1279 proto_memory_allocated(struct proto *prot)
1280 {
1281 	return atomic_long_read(prot->memory_allocated);
1282 }
1283 
1284 static inline bool
1285 proto_memory_pressure(struct proto *prot)
1286 {
1287 	if (!prot->memory_pressure)
1288 		return false;
1289 	return !!*prot->memory_pressure;
1290 }
1291 
1292 
1293 #ifdef CONFIG_PROC_FS
1294 /* Called with local bh disabled */
1295 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1296 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1297 int sock_inuse_get(struct net *net);
1298 #else
1299 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1300 		int inc)
1301 {
1302 }
1303 #endif
1304 
1305 
1306 /* With per-bucket locks this operation is not-atomic, so that
1307  * this version is not worse.
1308  */
1309 static inline int __sk_prot_rehash(struct sock *sk)
1310 {
1311 	sk->sk_prot->unhash(sk);
1312 	return sk->sk_prot->hash(sk);
1313 }
1314 
1315 /* About 10 seconds */
1316 #define SOCK_DESTROY_TIME (10*HZ)
1317 
1318 /* Sockets 0-1023 can't be bound to unless you are superuser */
1319 #define PROT_SOCK	1024
1320 
1321 #define SHUTDOWN_MASK	3
1322 #define RCV_SHUTDOWN	1
1323 #define SEND_SHUTDOWN	2
1324 
1325 #define SOCK_SNDBUF_LOCK	1
1326 #define SOCK_RCVBUF_LOCK	2
1327 #define SOCK_BINDADDR_LOCK	4
1328 #define SOCK_BINDPORT_LOCK	8
1329 
1330 struct socket_alloc {
1331 	struct socket socket;
1332 	struct inode vfs_inode;
1333 };
1334 
1335 static inline struct socket *SOCKET_I(struct inode *inode)
1336 {
1337 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1338 }
1339 
1340 static inline struct inode *SOCK_INODE(struct socket *socket)
1341 {
1342 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1343 }
1344 
1345 /*
1346  * Functions for memory accounting
1347  */
1348 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1349 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1350 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1351 void __sk_mem_reclaim(struct sock *sk, int amount);
1352 
1353 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1354  * do not necessarily have 16x time more memory than 4KB ones.
1355  */
1356 #define SK_MEM_QUANTUM 4096
1357 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1358 #define SK_MEM_SEND	0
1359 #define SK_MEM_RECV	1
1360 
1361 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1362 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1363 {
1364 	long val = sk->sk_prot->sysctl_mem[index];
1365 
1366 #if PAGE_SIZE > SK_MEM_QUANTUM
1367 	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1368 #elif PAGE_SIZE < SK_MEM_QUANTUM
1369 	val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1370 #endif
1371 	return val;
1372 }
1373 
1374 static inline int sk_mem_pages(int amt)
1375 {
1376 	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1377 }
1378 
1379 static inline bool sk_has_account(struct sock *sk)
1380 {
1381 	/* return true if protocol supports memory accounting */
1382 	return !!sk->sk_prot->memory_allocated;
1383 }
1384 
1385 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1386 {
1387 	if (!sk_has_account(sk))
1388 		return true;
1389 	return size <= sk->sk_forward_alloc ||
1390 		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1391 }
1392 
1393 static inline bool
1394 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1395 {
1396 	if (!sk_has_account(sk))
1397 		return true;
1398 	return size<= sk->sk_forward_alloc ||
1399 		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1400 		skb_pfmemalloc(skb);
1401 }
1402 
1403 static inline void sk_mem_reclaim(struct sock *sk)
1404 {
1405 	if (!sk_has_account(sk))
1406 		return;
1407 	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1408 		__sk_mem_reclaim(sk, sk->sk_forward_alloc);
1409 }
1410 
1411 static inline void sk_mem_reclaim_partial(struct sock *sk)
1412 {
1413 	if (!sk_has_account(sk))
1414 		return;
1415 	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1416 		__sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1417 }
1418 
1419 static inline void sk_mem_charge(struct sock *sk, int size)
1420 {
1421 	if (!sk_has_account(sk))
1422 		return;
1423 	sk->sk_forward_alloc -= size;
1424 }
1425 
1426 static inline void sk_mem_uncharge(struct sock *sk, int size)
1427 {
1428 	if (!sk_has_account(sk))
1429 		return;
1430 	sk->sk_forward_alloc += size;
1431 
1432 	/* Avoid a possible overflow.
1433 	 * TCP send queues can make this happen, if sk_mem_reclaim()
1434 	 * is not called and more than 2 GBytes are released at once.
1435 	 *
1436 	 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1437 	 * no need to hold that much forward allocation anyway.
1438 	 */
1439 	if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1440 		__sk_mem_reclaim(sk, 1 << 20);
1441 }
1442 
1443 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1444 {
1445 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1446 	sk->sk_wmem_queued -= skb->truesize;
1447 	sk_mem_uncharge(sk, skb->truesize);
1448 	__kfree_skb(skb);
1449 }
1450 
1451 static inline void sock_release_ownership(struct sock *sk)
1452 {
1453 	if (sk->sk_lock.owned) {
1454 		sk->sk_lock.owned = 0;
1455 
1456 		/* The sk_lock has mutex_unlock() semantics: */
1457 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1458 	}
1459 }
1460 
1461 /*
1462  * Macro so as to not evaluate some arguments when
1463  * lockdep is not enabled.
1464  *
1465  * Mark both the sk_lock and the sk_lock.slock as a
1466  * per-address-family lock class.
1467  */
1468 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1469 do {									\
1470 	sk->sk_lock.owned = 0;						\
1471 	init_waitqueue_head(&sk->sk_lock.wq);				\
1472 	spin_lock_init(&(sk)->sk_lock.slock);				\
1473 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1474 			sizeof((sk)->sk_lock));				\
1475 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1476 				(skey), (sname));				\
1477 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1478 } while (0)
1479 
1480 #ifdef CONFIG_LOCKDEP
1481 static inline bool lockdep_sock_is_held(const struct sock *sk)
1482 {
1483 	return lockdep_is_held(&sk->sk_lock) ||
1484 	       lockdep_is_held(&sk->sk_lock.slock);
1485 }
1486 #endif
1487 
1488 void lock_sock_nested(struct sock *sk, int subclass);
1489 
1490 static inline void lock_sock(struct sock *sk)
1491 {
1492 	lock_sock_nested(sk, 0);
1493 }
1494 
1495 void __release_sock(struct sock *sk);
1496 void release_sock(struct sock *sk);
1497 
1498 /* BH context may only use the following locking interface. */
1499 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1500 #define bh_lock_sock_nested(__sk) \
1501 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1502 				SINGLE_DEPTH_NESTING)
1503 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1504 
1505 bool lock_sock_fast(struct sock *sk);
1506 /**
1507  * unlock_sock_fast - complement of lock_sock_fast
1508  * @sk: socket
1509  * @slow: slow mode
1510  *
1511  * fast unlock socket for user context.
1512  * If slow mode is on, we call regular release_sock()
1513  */
1514 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1515 {
1516 	if (slow)
1517 		release_sock(sk);
1518 	else
1519 		spin_unlock_bh(&sk->sk_lock.slock);
1520 }
1521 
1522 /* Used by processes to "lock" a socket state, so that
1523  * interrupts and bottom half handlers won't change it
1524  * from under us. It essentially blocks any incoming
1525  * packets, so that we won't get any new data or any
1526  * packets that change the state of the socket.
1527  *
1528  * While locked, BH processing will add new packets to
1529  * the backlog queue.  This queue is processed by the
1530  * owner of the socket lock right before it is released.
1531  *
1532  * Since ~2.3.5 it is also exclusive sleep lock serializing
1533  * accesses from user process context.
1534  */
1535 
1536 static inline void sock_owned_by_me(const struct sock *sk)
1537 {
1538 #ifdef CONFIG_LOCKDEP
1539 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1540 #endif
1541 }
1542 
1543 static inline bool sock_owned_by_user(const struct sock *sk)
1544 {
1545 	sock_owned_by_me(sk);
1546 	return sk->sk_lock.owned;
1547 }
1548 
1549 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1550 {
1551 	return sk->sk_lock.owned;
1552 }
1553 
1554 /* no reclassification while locks are held */
1555 static inline bool sock_allow_reclassification(const struct sock *csk)
1556 {
1557 	struct sock *sk = (struct sock *)csk;
1558 
1559 	return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1560 }
1561 
1562 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1563 		      struct proto *prot, int kern);
1564 void sk_free(struct sock *sk);
1565 void sk_destruct(struct sock *sk);
1566 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1567 void sk_free_unlock_clone(struct sock *sk);
1568 
1569 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1570 			     gfp_t priority);
1571 void __sock_wfree(struct sk_buff *skb);
1572 void sock_wfree(struct sk_buff *skb);
1573 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1574 			     gfp_t priority);
1575 void skb_orphan_partial(struct sk_buff *skb);
1576 void sock_rfree(struct sk_buff *skb);
1577 void sock_efree(struct sk_buff *skb);
1578 #ifdef CONFIG_INET
1579 void sock_edemux(struct sk_buff *skb);
1580 #else
1581 #define sock_edemux sock_efree
1582 #endif
1583 
1584 int sock_setsockopt(struct socket *sock, int level, int op,
1585 		    char __user *optval, unsigned int optlen);
1586 
1587 int sock_getsockopt(struct socket *sock, int level, int op,
1588 		    char __user *optval, int __user *optlen);
1589 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1590 				    int noblock, int *errcode);
1591 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1592 				     unsigned long data_len, int noblock,
1593 				     int *errcode, int max_page_order);
1594 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1595 void sock_kfree_s(struct sock *sk, void *mem, int size);
1596 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1597 void sk_send_sigurg(struct sock *sk);
1598 
1599 struct sockcm_cookie {
1600 	u64 transmit_time;
1601 	u32 mark;
1602 	u16 tsflags;
1603 };
1604 
1605 static inline void sockcm_init(struct sockcm_cookie *sockc,
1606 			       const struct sock *sk)
1607 {
1608 	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1609 }
1610 
1611 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1612 		     struct sockcm_cookie *sockc);
1613 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1614 		   struct sockcm_cookie *sockc);
1615 
1616 /*
1617  * Functions to fill in entries in struct proto_ops when a protocol
1618  * does not implement a particular function.
1619  */
1620 int sock_no_bind(struct socket *, struct sockaddr *, int);
1621 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1622 int sock_no_socketpair(struct socket *, struct socket *);
1623 int sock_no_accept(struct socket *, struct socket *, int, bool);
1624 int sock_no_getname(struct socket *, struct sockaddr *, int);
1625 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1626 int sock_no_listen(struct socket *, int);
1627 int sock_no_shutdown(struct socket *, int);
1628 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1629 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1630 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1631 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1632 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1633 int sock_no_mmap(struct file *file, struct socket *sock,
1634 		 struct vm_area_struct *vma);
1635 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1636 			 size_t size, int flags);
1637 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1638 				int offset, size_t size, int flags);
1639 
1640 /*
1641  * Functions to fill in entries in struct proto_ops when a protocol
1642  * uses the inet style.
1643  */
1644 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1645 				  char __user *optval, int __user *optlen);
1646 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1647 			int flags);
1648 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1649 				  char __user *optval, unsigned int optlen);
1650 int compat_sock_common_getsockopt(struct socket *sock, int level,
1651 		int optname, char __user *optval, int __user *optlen);
1652 int compat_sock_common_setsockopt(struct socket *sock, int level,
1653 		int optname, char __user *optval, unsigned int optlen);
1654 
1655 void sk_common_release(struct sock *sk);
1656 
1657 /*
1658  *	Default socket callbacks and setup code
1659  */
1660 
1661 /* Initialise core socket variables */
1662 void sock_init_data(struct socket *sock, struct sock *sk);
1663 
1664 /*
1665  * Socket reference counting postulates.
1666  *
1667  * * Each user of socket SHOULD hold a reference count.
1668  * * Each access point to socket (an hash table bucket, reference from a list,
1669  *   running timer, skb in flight MUST hold a reference count.
1670  * * When reference count hits 0, it means it will never increase back.
1671  * * When reference count hits 0, it means that no references from
1672  *   outside exist to this socket and current process on current CPU
1673  *   is last user and may/should destroy this socket.
1674  * * sk_free is called from any context: process, BH, IRQ. When
1675  *   it is called, socket has no references from outside -> sk_free
1676  *   may release descendant resources allocated by the socket, but
1677  *   to the time when it is called, socket is NOT referenced by any
1678  *   hash tables, lists etc.
1679  * * Packets, delivered from outside (from network or from another process)
1680  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1681  *   when they sit in queue. Otherwise, packets will leak to hole, when
1682  *   socket is looked up by one cpu and unhasing is made by another CPU.
1683  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1684  *   (leak to backlog). Packet socket does all the processing inside
1685  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1686  *   use separate SMP lock, so that they are prone too.
1687  */
1688 
1689 /* Ungrab socket and destroy it, if it was the last reference. */
1690 static inline void sock_put(struct sock *sk)
1691 {
1692 	if (refcount_dec_and_test(&sk->sk_refcnt))
1693 		sk_free(sk);
1694 }
1695 /* Generic version of sock_put(), dealing with all sockets
1696  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1697  */
1698 void sock_gen_put(struct sock *sk);
1699 
1700 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1701 		     unsigned int trim_cap, bool refcounted);
1702 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1703 				 const int nested)
1704 {
1705 	return __sk_receive_skb(sk, skb, nested, 1, true);
1706 }
1707 
1708 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1709 {
1710 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1711 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1712 		return;
1713 	sk->sk_tx_queue_mapping = tx_queue;
1714 }
1715 
1716 #define NO_QUEUE_MAPPING	USHRT_MAX
1717 
1718 static inline void sk_tx_queue_clear(struct sock *sk)
1719 {
1720 	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1721 }
1722 
1723 static inline int sk_tx_queue_get(const struct sock *sk)
1724 {
1725 	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1726 		return sk->sk_tx_queue_mapping;
1727 
1728 	return -1;
1729 }
1730 
1731 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1732 {
1733 #ifdef CONFIG_XPS
1734 	if (skb_rx_queue_recorded(skb)) {
1735 		u16 rx_queue = skb_get_rx_queue(skb);
1736 
1737 		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1738 			return;
1739 
1740 		sk->sk_rx_queue_mapping = rx_queue;
1741 	}
1742 #endif
1743 }
1744 
1745 static inline void sk_rx_queue_clear(struct sock *sk)
1746 {
1747 #ifdef CONFIG_XPS
1748 	sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1749 #endif
1750 }
1751 
1752 #ifdef CONFIG_XPS
1753 static inline int sk_rx_queue_get(const struct sock *sk)
1754 {
1755 	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1756 		return sk->sk_rx_queue_mapping;
1757 
1758 	return -1;
1759 }
1760 #endif
1761 
1762 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1763 {
1764 	sk_tx_queue_clear(sk);
1765 	sk->sk_socket = sock;
1766 }
1767 
1768 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1769 {
1770 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1771 	return &rcu_dereference_raw(sk->sk_wq)->wait;
1772 }
1773 /* Detach socket from process context.
1774  * Announce socket dead, detach it from wait queue and inode.
1775  * Note that parent inode held reference count on this struct sock,
1776  * we do not release it in this function, because protocol
1777  * probably wants some additional cleanups or even continuing
1778  * to work with this socket (TCP).
1779  */
1780 static inline void sock_orphan(struct sock *sk)
1781 {
1782 	write_lock_bh(&sk->sk_callback_lock);
1783 	sock_set_flag(sk, SOCK_DEAD);
1784 	sk_set_socket(sk, NULL);
1785 	sk->sk_wq  = NULL;
1786 	write_unlock_bh(&sk->sk_callback_lock);
1787 }
1788 
1789 static inline void sock_graft(struct sock *sk, struct socket *parent)
1790 {
1791 	WARN_ON(parent->sk);
1792 	write_lock_bh(&sk->sk_callback_lock);
1793 	rcu_assign_pointer(sk->sk_wq, parent->wq);
1794 	parent->sk = sk;
1795 	sk_set_socket(sk, parent);
1796 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
1797 	security_sock_graft(sk, parent);
1798 	write_unlock_bh(&sk->sk_callback_lock);
1799 }
1800 
1801 kuid_t sock_i_uid(struct sock *sk);
1802 unsigned long sock_i_ino(struct sock *sk);
1803 
1804 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1805 {
1806 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1807 }
1808 
1809 static inline u32 net_tx_rndhash(void)
1810 {
1811 	u32 v = prandom_u32();
1812 
1813 	return v ?: 1;
1814 }
1815 
1816 static inline void sk_set_txhash(struct sock *sk)
1817 {
1818 	sk->sk_txhash = net_tx_rndhash();
1819 }
1820 
1821 static inline void sk_rethink_txhash(struct sock *sk)
1822 {
1823 	if (sk->sk_txhash)
1824 		sk_set_txhash(sk);
1825 }
1826 
1827 static inline struct dst_entry *
1828 __sk_dst_get(struct sock *sk)
1829 {
1830 	return rcu_dereference_check(sk->sk_dst_cache,
1831 				     lockdep_sock_is_held(sk));
1832 }
1833 
1834 static inline struct dst_entry *
1835 sk_dst_get(struct sock *sk)
1836 {
1837 	struct dst_entry *dst;
1838 
1839 	rcu_read_lock();
1840 	dst = rcu_dereference(sk->sk_dst_cache);
1841 	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1842 		dst = NULL;
1843 	rcu_read_unlock();
1844 	return dst;
1845 }
1846 
1847 static inline void dst_negative_advice(struct sock *sk)
1848 {
1849 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1850 
1851 	sk_rethink_txhash(sk);
1852 
1853 	if (dst && dst->ops->negative_advice) {
1854 		ndst = dst->ops->negative_advice(dst);
1855 
1856 		if (ndst != dst) {
1857 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1858 			sk_tx_queue_clear(sk);
1859 			sk->sk_dst_pending_confirm = 0;
1860 		}
1861 	}
1862 }
1863 
1864 static inline void
1865 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1866 {
1867 	struct dst_entry *old_dst;
1868 
1869 	sk_tx_queue_clear(sk);
1870 	sk->sk_dst_pending_confirm = 0;
1871 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1872 					    lockdep_sock_is_held(sk));
1873 	rcu_assign_pointer(sk->sk_dst_cache, dst);
1874 	dst_release(old_dst);
1875 }
1876 
1877 static inline void
1878 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1879 {
1880 	struct dst_entry *old_dst;
1881 
1882 	sk_tx_queue_clear(sk);
1883 	sk->sk_dst_pending_confirm = 0;
1884 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1885 	dst_release(old_dst);
1886 }
1887 
1888 static inline void
1889 __sk_dst_reset(struct sock *sk)
1890 {
1891 	__sk_dst_set(sk, NULL);
1892 }
1893 
1894 static inline void
1895 sk_dst_reset(struct sock *sk)
1896 {
1897 	sk_dst_set(sk, NULL);
1898 }
1899 
1900 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1901 
1902 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1903 
1904 static inline void sk_dst_confirm(struct sock *sk)
1905 {
1906 	if (!sk->sk_dst_pending_confirm)
1907 		sk->sk_dst_pending_confirm = 1;
1908 }
1909 
1910 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1911 {
1912 	if (skb_get_dst_pending_confirm(skb)) {
1913 		struct sock *sk = skb->sk;
1914 		unsigned long now = jiffies;
1915 
1916 		/* avoid dirtying neighbour */
1917 		if (n->confirmed != now)
1918 			n->confirmed = now;
1919 		if (sk && sk->sk_dst_pending_confirm)
1920 			sk->sk_dst_pending_confirm = 0;
1921 	}
1922 }
1923 
1924 bool sk_mc_loop(struct sock *sk);
1925 
1926 static inline bool sk_can_gso(const struct sock *sk)
1927 {
1928 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1929 }
1930 
1931 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1932 
1933 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1934 {
1935 	sk->sk_route_nocaps |= flags;
1936 	sk->sk_route_caps &= ~flags;
1937 }
1938 
1939 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1940 					   struct iov_iter *from, char *to,
1941 					   int copy, int offset)
1942 {
1943 	if (skb->ip_summed == CHECKSUM_NONE) {
1944 		__wsum csum = 0;
1945 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1946 			return -EFAULT;
1947 		skb->csum = csum_block_add(skb->csum, csum, offset);
1948 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1949 		if (!copy_from_iter_full_nocache(to, copy, from))
1950 			return -EFAULT;
1951 	} else if (!copy_from_iter_full(to, copy, from))
1952 		return -EFAULT;
1953 
1954 	return 0;
1955 }
1956 
1957 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1958 				       struct iov_iter *from, int copy)
1959 {
1960 	int err, offset = skb->len;
1961 
1962 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1963 				       copy, offset);
1964 	if (err)
1965 		__skb_trim(skb, offset);
1966 
1967 	return err;
1968 }
1969 
1970 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
1971 					   struct sk_buff *skb,
1972 					   struct page *page,
1973 					   int off, int copy)
1974 {
1975 	int err;
1976 
1977 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1978 				       copy, skb->len);
1979 	if (err)
1980 		return err;
1981 
1982 	skb->len	     += copy;
1983 	skb->data_len	     += copy;
1984 	skb->truesize	     += copy;
1985 	sk->sk_wmem_queued   += copy;
1986 	sk_mem_charge(sk, copy);
1987 	return 0;
1988 }
1989 
1990 /**
1991  * sk_wmem_alloc_get - returns write allocations
1992  * @sk: socket
1993  *
1994  * Returns sk_wmem_alloc minus initial offset of one
1995  */
1996 static inline int sk_wmem_alloc_get(const struct sock *sk)
1997 {
1998 	return refcount_read(&sk->sk_wmem_alloc) - 1;
1999 }
2000 
2001 /**
2002  * sk_rmem_alloc_get - returns read allocations
2003  * @sk: socket
2004  *
2005  * Returns sk_rmem_alloc
2006  */
2007 static inline int sk_rmem_alloc_get(const struct sock *sk)
2008 {
2009 	return atomic_read(&sk->sk_rmem_alloc);
2010 }
2011 
2012 /**
2013  * sk_has_allocations - check if allocations are outstanding
2014  * @sk: socket
2015  *
2016  * Returns true if socket has write or read allocations
2017  */
2018 static inline bool sk_has_allocations(const struct sock *sk)
2019 {
2020 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2021 }
2022 
2023 /**
2024  * skwq_has_sleeper - check if there are any waiting processes
2025  * @wq: struct socket_wq
2026  *
2027  * Returns true if socket_wq has waiting processes
2028  *
2029  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2030  * barrier call. They were added due to the race found within the tcp code.
2031  *
2032  * Consider following tcp code paths::
2033  *
2034  *   CPU1                CPU2
2035  *   sys_select          receive packet
2036  *   ...                 ...
2037  *   __add_wait_queue    update tp->rcv_nxt
2038  *   ...                 ...
2039  *   tp->rcv_nxt check   sock_def_readable
2040  *   ...                 {
2041  *   schedule               rcu_read_lock();
2042  *                          wq = rcu_dereference(sk->sk_wq);
2043  *                          if (wq && waitqueue_active(&wq->wait))
2044  *                              wake_up_interruptible(&wq->wait)
2045  *                          ...
2046  *                       }
2047  *
2048  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2049  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2050  * could then endup calling schedule and sleep forever if there are no more
2051  * data on the socket.
2052  *
2053  */
2054 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2055 {
2056 	return wq && wq_has_sleeper(&wq->wait);
2057 }
2058 
2059 /**
2060  * sock_poll_wait - place memory barrier behind the poll_wait call.
2061  * @filp:           file
2062  * @sock:           socket to wait on
2063  * @p:              poll_table
2064  *
2065  * See the comments in the wq_has_sleeper function.
2066  *
2067  * Do not derive sock from filp->private_data here. An SMC socket establishes
2068  * an internal TCP socket that is used in the fallback case. All socket
2069  * operations on the SMC socket are then forwarded to the TCP socket. In case of
2070  * poll, the filp->private_data pointer references the SMC socket because the
2071  * TCP socket has no file assigned.
2072  */
2073 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2074 				  poll_table *p)
2075 {
2076 	if (!poll_does_not_wait(p)) {
2077 		poll_wait(filp, &sock->wq->wait, p);
2078 		/* We need to be sure we are in sync with the
2079 		 * socket flags modification.
2080 		 *
2081 		 * This memory barrier is paired in the wq_has_sleeper.
2082 		 */
2083 		smp_mb();
2084 	}
2085 }
2086 
2087 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2088 {
2089 	if (sk->sk_txhash) {
2090 		skb->l4_hash = 1;
2091 		skb->hash = sk->sk_txhash;
2092 	}
2093 }
2094 
2095 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2096 
2097 /*
2098  *	Queue a received datagram if it will fit. Stream and sequenced
2099  *	protocols can't normally use this as they need to fit buffers in
2100  *	and play with them.
2101  *
2102  *	Inlined as it's very short and called for pretty much every
2103  *	packet ever received.
2104  */
2105 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2106 {
2107 	skb_orphan(skb);
2108 	skb->sk = sk;
2109 	skb->destructor = sock_rfree;
2110 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2111 	sk_mem_charge(sk, skb->truesize);
2112 }
2113 
2114 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2115 		    unsigned long expires);
2116 
2117 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2118 
2119 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2120 			struct sk_buff *skb, unsigned int flags,
2121 			void (*destructor)(struct sock *sk,
2122 					   struct sk_buff *skb));
2123 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2124 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2125 
2126 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2127 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2128 
2129 /*
2130  *	Recover an error report and clear atomically
2131  */
2132 
2133 static inline int sock_error(struct sock *sk)
2134 {
2135 	int err;
2136 	if (likely(!sk->sk_err))
2137 		return 0;
2138 	err = xchg(&sk->sk_err, 0);
2139 	return -err;
2140 }
2141 
2142 static inline unsigned long sock_wspace(struct sock *sk)
2143 {
2144 	int amt = 0;
2145 
2146 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2147 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2148 		if (amt < 0)
2149 			amt = 0;
2150 	}
2151 	return amt;
2152 }
2153 
2154 /* Note:
2155  *  We use sk->sk_wq_raw, from contexts knowing this
2156  *  pointer is not NULL and cannot disappear/change.
2157  */
2158 static inline void sk_set_bit(int nr, struct sock *sk)
2159 {
2160 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2161 	    !sock_flag(sk, SOCK_FASYNC))
2162 		return;
2163 
2164 	set_bit(nr, &sk->sk_wq_raw->flags);
2165 }
2166 
2167 static inline void sk_clear_bit(int nr, struct sock *sk)
2168 {
2169 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2170 	    !sock_flag(sk, SOCK_FASYNC))
2171 		return;
2172 
2173 	clear_bit(nr, &sk->sk_wq_raw->flags);
2174 }
2175 
2176 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2177 {
2178 	if (sock_flag(sk, SOCK_FASYNC)) {
2179 		rcu_read_lock();
2180 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2181 		rcu_read_unlock();
2182 	}
2183 }
2184 
2185 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2186  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2187  * Note: for send buffers, TCP works better if we can build two skbs at
2188  * minimum.
2189  */
2190 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2191 
2192 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2193 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2194 
2195 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2196 {
2197 	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2198 		sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2199 		sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2200 	}
2201 }
2202 
2203 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2204 				    bool force_schedule);
2205 
2206 /**
2207  * sk_page_frag - return an appropriate page_frag
2208  * @sk: socket
2209  *
2210  * If socket allocation mode allows current thread to sleep, it means its
2211  * safe to use the per task page_frag instead of the per socket one.
2212  */
2213 static inline struct page_frag *sk_page_frag(struct sock *sk)
2214 {
2215 	if (gfpflags_allow_blocking(sk->sk_allocation))
2216 		return &current->task_frag;
2217 
2218 	return &sk->sk_frag;
2219 }
2220 
2221 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2222 
2223 /*
2224  *	Default write policy as shown to user space via poll/select/SIGIO
2225  */
2226 static inline bool sock_writeable(const struct sock *sk)
2227 {
2228 	return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2229 }
2230 
2231 static inline gfp_t gfp_any(void)
2232 {
2233 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2234 }
2235 
2236 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2237 {
2238 	return noblock ? 0 : sk->sk_rcvtimeo;
2239 }
2240 
2241 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2242 {
2243 	return noblock ? 0 : sk->sk_sndtimeo;
2244 }
2245 
2246 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2247 {
2248 	return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2249 }
2250 
2251 /* Alas, with timeout socket operations are not restartable.
2252  * Compare this to poll().
2253  */
2254 static inline int sock_intr_errno(long timeo)
2255 {
2256 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2257 }
2258 
2259 struct sock_skb_cb {
2260 	u32 dropcount;
2261 };
2262 
2263 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2264  * using skb->cb[] would keep using it directly and utilize its
2265  * alignement guarantee.
2266  */
2267 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2268 			    sizeof(struct sock_skb_cb)))
2269 
2270 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2271 			    SOCK_SKB_CB_OFFSET))
2272 
2273 #define sock_skb_cb_check_size(size) \
2274 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2275 
2276 static inline void
2277 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2278 {
2279 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2280 						atomic_read(&sk->sk_drops) : 0;
2281 }
2282 
2283 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2284 {
2285 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2286 
2287 	atomic_add(segs, &sk->sk_drops);
2288 }
2289 
2290 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2291 			   struct sk_buff *skb);
2292 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2293 			     struct sk_buff *skb);
2294 
2295 static inline void
2296 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2297 {
2298 	ktime_t kt = skb->tstamp;
2299 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2300 
2301 	/*
2302 	 * generate control messages if
2303 	 * - receive time stamping in software requested
2304 	 * - software time stamp available and wanted
2305 	 * - hardware time stamps available and wanted
2306 	 */
2307 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2308 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2309 	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2310 	    (hwtstamps->hwtstamp &&
2311 	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2312 		__sock_recv_timestamp(msg, sk, skb);
2313 	else
2314 		sk->sk_stamp = kt;
2315 
2316 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2317 		__sock_recv_wifi_status(msg, sk, skb);
2318 }
2319 
2320 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2321 			      struct sk_buff *skb);
2322 
2323 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2324 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2325 					  struct sk_buff *skb)
2326 {
2327 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2328 			   (1UL << SOCK_RCVTSTAMP))
2329 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2330 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2331 
2332 	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2333 		__sock_recv_ts_and_drops(msg, sk, skb);
2334 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2335 		sk->sk_stamp = skb->tstamp;
2336 	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2337 		sk->sk_stamp = 0;
2338 }
2339 
2340 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2341 
2342 /**
2343  * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2344  * @sk:		socket sending this packet
2345  * @tsflags:	timestamping flags to use
2346  * @tx_flags:	completed with instructions for time stamping
2347  *
2348  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2349  */
2350 static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags,
2351 				     __u8 *tx_flags)
2352 {
2353 	if (unlikely(tsflags))
2354 		__sock_tx_timestamp(tsflags, tx_flags);
2355 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2356 		*tx_flags |= SKBTX_WIFI_STATUS;
2357 }
2358 
2359 /**
2360  * sk_eat_skb - Release a skb if it is no longer needed
2361  * @sk: socket to eat this skb from
2362  * @skb: socket buffer to eat
2363  *
2364  * This routine must be called with interrupts disabled or with the socket
2365  * locked so that the sk_buff queue operation is ok.
2366 */
2367 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2368 {
2369 	__skb_unlink(skb, &sk->sk_receive_queue);
2370 	__kfree_skb(skb);
2371 }
2372 
2373 static inline
2374 struct net *sock_net(const struct sock *sk)
2375 {
2376 	return read_pnet(&sk->sk_net);
2377 }
2378 
2379 static inline
2380 void sock_net_set(struct sock *sk, struct net *net)
2381 {
2382 	write_pnet(&sk->sk_net, net);
2383 }
2384 
2385 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2386 {
2387 	if (skb->sk) {
2388 		struct sock *sk = skb->sk;
2389 
2390 		skb->destructor = NULL;
2391 		skb->sk = NULL;
2392 		return sk;
2393 	}
2394 	return NULL;
2395 }
2396 
2397 /* This helper checks if a socket is a full socket,
2398  * ie _not_ a timewait or request socket.
2399  */
2400 static inline bool sk_fullsock(const struct sock *sk)
2401 {
2402 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2403 }
2404 
2405 /* Checks if this SKB belongs to an HW offloaded socket
2406  * and whether any SW fallbacks are required based on dev.
2407  */
2408 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2409 						   struct net_device *dev)
2410 {
2411 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2412 	struct sock *sk = skb->sk;
2413 
2414 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb)
2415 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2416 #endif
2417 
2418 	return skb;
2419 }
2420 
2421 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2422  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2423  */
2424 static inline bool sk_listener(const struct sock *sk)
2425 {
2426 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2427 }
2428 
2429 void sock_enable_timestamp(struct sock *sk, int flag);
2430 int sock_get_timestamp(struct sock *, struct timeval __user *);
2431 int sock_get_timestampns(struct sock *, struct timespec __user *);
2432 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2433 		       int type);
2434 
2435 bool sk_ns_capable(const struct sock *sk,
2436 		   struct user_namespace *user_ns, int cap);
2437 bool sk_capable(const struct sock *sk, int cap);
2438 bool sk_net_capable(const struct sock *sk, int cap);
2439 
2440 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2441 
2442 /* Take into consideration the size of the struct sk_buff overhead in the
2443  * determination of these values, since that is non-constant across
2444  * platforms.  This makes socket queueing behavior and performance
2445  * not depend upon such differences.
2446  */
2447 #define _SK_MEM_PACKETS		256
2448 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2449 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2450 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2451 
2452 extern __u32 sysctl_wmem_max;
2453 extern __u32 sysctl_rmem_max;
2454 
2455 extern int sysctl_tstamp_allow_data;
2456 extern int sysctl_optmem_max;
2457 
2458 extern __u32 sysctl_wmem_default;
2459 extern __u32 sysctl_rmem_default;
2460 
2461 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2462 {
2463 	/* Does this proto have per netns sysctl_wmem ? */
2464 	if (proto->sysctl_wmem_offset)
2465 		return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2466 
2467 	return *proto->sysctl_wmem;
2468 }
2469 
2470 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2471 {
2472 	/* Does this proto have per netns sysctl_rmem ? */
2473 	if (proto->sysctl_rmem_offset)
2474 		return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2475 
2476 	return *proto->sysctl_rmem;
2477 }
2478 
2479 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2480  * Some wifi drivers need to tweak it to get more chunks.
2481  * They can use this helper from their ndo_start_xmit()
2482  */
2483 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2484 {
2485 	if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
2486 		return;
2487 	sk->sk_pacing_shift = val;
2488 }
2489 
2490 /* if a socket is bound to a device, check that the given device
2491  * index is either the same or that the socket is bound to an L3
2492  * master device and the given device index is also enslaved to
2493  * that L3 master
2494  */
2495 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2496 {
2497 	int mdif;
2498 
2499 	if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2500 		return true;
2501 
2502 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2503 	if (mdif && mdif == sk->sk_bound_dev_if)
2504 		return true;
2505 
2506 	return false;
2507 }
2508 
2509 #endif	/* _SOCK_H */
2510