xref: /openbmc/linux/include/net/sock.h (revision b4e18b29)
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/filter.h>
60 #include <linux/rculist_nulls.h>
61 #include <linux/poll.h>
62 #include <linux/sockptr.h>
63 #include <linux/indirect_call_wrapper.h>
64 #include <linux/atomic.h>
65 #include <linux/refcount.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 
72 /*
73  * This structure really needs to be cleaned up.
74  * Most of it is for TCP, and not used by any of
75  * the other protocols.
76  */
77 
78 /* Define this to get the SOCK_DBG debugging facility. */
79 #define SOCK_DEBUGGING
80 #ifdef SOCK_DEBUGGING
81 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
82 					printk(KERN_DEBUG msg); } while (0)
83 #else
84 /* Validate arguments and do nothing */
85 static inline __printf(2, 3)
86 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
87 {
88 }
89 #endif
90 
91 /* This is the per-socket lock.  The spinlock provides a synchronization
92  * between user contexts and software interrupt processing, whereas the
93  * mini-semaphore synchronizes multiple users amongst themselves.
94  */
95 typedef struct {
96 	spinlock_t		slock;
97 	int			owned;
98 	wait_queue_head_t	wq;
99 	/*
100 	 * We express the mutex-alike socket_lock semantics
101 	 * to the lock validator by explicitly managing
102 	 * the slock as a lock variant (in addition to
103 	 * the slock itself):
104 	 */
105 #ifdef CONFIG_DEBUG_LOCK_ALLOC
106 	struct lockdep_map dep_map;
107 #endif
108 } socket_lock_t;
109 
110 struct sock;
111 struct proto;
112 struct net;
113 
114 typedef __u32 __bitwise __portpair;
115 typedef __u64 __bitwise __addrpair;
116 
117 /**
118  *	struct sock_common - minimal network layer representation of sockets
119  *	@skc_daddr: Foreign IPv4 addr
120  *	@skc_rcv_saddr: Bound local IPv4 addr
121  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
122  *	@skc_hash: hash value used with various protocol lookup tables
123  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
124  *	@skc_dport: placeholder for inet_dport/tw_dport
125  *	@skc_num: placeholder for inet_num/tw_num
126  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
127  *	@skc_family: network address family
128  *	@skc_state: Connection state
129  *	@skc_reuse: %SO_REUSEADDR setting
130  *	@skc_reuseport: %SO_REUSEPORT setting
131  *	@skc_ipv6only: socket is IPV6 only
132  *	@skc_net_refcnt: socket is using net ref counting
133  *	@skc_bound_dev_if: bound device index if != 0
134  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
135  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
136  *	@skc_prot: protocol handlers inside a network family
137  *	@skc_net: reference to the network namespace of this socket
138  *	@skc_v6_daddr: IPV6 destination address
139  *	@skc_v6_rcv_saddr: IPV6 source address
140  *	@skc_cookie: socket's cookie value
141  *	@skc_node: main hash linkage for various protocol lookup tables
142  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
143  *	@skc_tx_queue_mapping: tx queue number for this connection
144  *	@skc_rx_queue_mapping: rx queue number for this connection
145  *	@skc_flags: place holder for sk_flags
146  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
147  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
148  *	@skc_listener: connection request listener socket (aka rsk_listener)
149  *		[union with @skc_flags]
150  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
151  *		[union with @skc_flags]
152  *	@skc_incoming_cpu: record/match cpu processing incoming packets
153  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
154  *		[union with @skc_incoming_cpu]
155  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
156  *		[union with @skc_incoming_cpu]
157  *	@skc_refcnt: reference count
158  *
159  *	This is the minimal network layer representation of sockets, the header
160  *	for struct sock and struct inet_timewait_sock.
161  */
162 struct sock_common {
163 	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
164 	 * address on 64bit arches : cf INET_MATCH()
165 	 */
166 	union {
167 		__addrpair	skc_addrpair;
168 		struct {
169 			__be32	skc_daddr;
170 			__be32	skc_rcv_saddr;
171 		};
172 	};
173 	union  {
174 		unsigned int	skc_hash;
175 		__u16		skc_u16hashes[2];
176 	};
177 	/* skc_dport && skc_num must be grouped as well */
178 	union {
179 		__portpair	skc_portpair;
180 		struct {
181 			__be16	skc_dport;
182 			__u16	skc_num;
183 		};
184 	};
185 
186 	unsigned short		skc_family;
187 	volatile unsigned char	skc_state;
188 	unsigned char		skc_reuse:4;
189 	unsigned char		skc_reuseport:1;
190 	unsigned char		skc_ipv6only:1;
191 	unsigned char		skc_net_refcnt:1;
192 	int			skc_bound_dev_if;
193 	union {
194 		struct hlist_node	skc_bind_node;
195 		struct hlist_node	skc_portaddr_node;
196 	};
197 	struct proto		*skc_prot;
198 	possible_net_t		skc_net;
199 
200 #if IS_ENABLED(CONFIG_IPV6)
201 	struct in6_addr		skc_v6_daddr;
202 	struct in6_addr		skc_v6_rcv_saddr;
203 #endif
204 
205 	atomic64_t		skc_cookie;
206 
207 	/* following fields are padding to force
208 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
209 	 * assuming IPV6 is enabled. We use this padding differently
210 	 * for different kind of 'sockets'
211 	 */
212 	union {
213 		unsigned long	skc_flags;
214 		struct sock	*skc_listener; /* request_sock */
215 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
216 	};
217 	/*
218 	 * fields between dontcopy_begin/dontcopy_end
219 	 * are not copied in sock_copy()
220 	 */
221 	/* private: */
222 	int			skc_dontcopy_begin[0];
223 	/* public: */
224 	union {
225 		struct hlist_node	skc_node;
226 		struct hlist_nulls_node skc_nulls_node;
227 	};
228 	unsigned short		skc_tx_queue_mapping;
229 #ifdef CONFIG_XPS
230 	unsigned short		skc_rx_queue_mapping;
231 #endif
232 	union {
233 		int		skc_incoming_cpu;
234 		u32		skc_rcv_wnd;
235 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
236 	};
237 
238 	refcount_t		skc_refcnt;
239 	/* private: */
240 	int                     skc_dontcopy_end[0];
241 	union {
242 		u32		skc_rxhash;
243 		u32		skc_window_clamp;
244 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
245 	};
246 	/* public: */
247 };
248 
249 struct bpf_local_storage;
250 
251 /**
252   *	struct sock - network layer representation of sockets
253   *	@__sk_common: shared layout with inet_timewait_sock
254   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
255   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
256   *	@sk_lock:	synchronizer
257   *	@sk_kern_sock: True if sock is using kernel lock classes
258   *	@sk_rcvbuf: size of receive buffer in bytes
259   *	@sk_wq: sock wait queue and async head
260   *	@sk_rx_dst: receive input route used by early demux
261   *	@sk_dst_cache: destination cache
262   *	@sk_dst_pending_confirm: need to confirm neighbour
263   *	@sk_policy: flow policy
264   *	@sk_rx_skb_cache: cache copy of recently accessed RX skb
265   *	@sk_receive_queue: incoming packets
266   *	@sk_wmem_alloc: transmit queue bytes committed
267   *	@sk_tsq_flags: TCP Small Queues flags
268   *	@sk_write_queue: Packet sending queue
269   *	@sk_omem_alloc: "o" is "option" or "other"
270   *	@sk_wmem_queued: persistent queue size
271   *	@sk_forward_alloc: space allocated forward
272   *	@sk_napi_id: id of the last napi context to receive data for sk
273   *	@sk_ll_usec: usecs to busypoll when there is no data
274   *	@sk_allocation: allocation mode
275   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
276   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
277   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
278   *	@sk_sndbuf: size of send buffer in bytes
279   *	@__sk_flags_offset: empty field used to determine location of bitfield
280   *	@sk_padding: unused element for alignment
281   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
282   *	@sk_no_check_rx: allow zero checksum in RX packets
283   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
284   *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
285   *	@sk_route_forced_caps: static, forced route capabilities
286   *		(set in tcp_init_sock())
287   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
288   *	@sk_gso_max_size: Maximum GSO segment size to build
289   *	@sk_gso_max_segs: Maximum number of GSO segments
290   *	@sk_pacing_shift: scaling factor for TCP Small Queues
291   *	@sk_lingertime: %SO_LINGER l_linger setting
292   *	@sk_backlog: always used with the per-socket spinlock held
293   *	@sk_callback_lock: used with the callbacks in the end of this struct
294   *	@sk_error_queue: rarely used
295   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
296   *			  IPV6_ADDRFORM for instance)
297   *	@sk_err: last error
298   *	@sk_err_soft: errors that don't cause failure but are the cause of a
299   *		      persistent failure not just 'timed out'
300   *	@sk_drops: raw/udp drops counter
301   *	@sk_ack_backlog: current listen backlog
302   *	@sk_max_ack_backlog: listen backlog set in listen()
303   *	@sk_uid: user id of owner
304   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
305   *	@sk_busy_poll_budget: napi processing budget when busypolling
306   *	@sk_priority: %SO_PRIORITY setting
307   *	@sk_type: socket type (%SOCK_STREAM, etc)
308   *	@sk_protocol: which protocol this socket belongs in this network family
309   *	@sk_peer_pid: &struct pid for this socket's peer
310   *	@sk_peer_cred: %SO_PEERCRED setting
311   *	@sk_rcvlowat: %SO_RCVLOWAT setting
312   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
313   *	@sk_sndtimeo: %SO_SNDTIMEO setting
314   *	@sk_txhash: computed flow hash for use on transmit
315   *	@sk_filter: socket filtering instructions
316   *	@sk_timer: sock cleanup timer
317   *	@sk_stamp: time stamp of last packet received
318   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
319   *	@sk_tsflags: SO_TIMESTAMPING socket options
320   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
321   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
322   *	@sk_socket: Identd and reporting IO signals
323   *	@sk_user_data: RPC layer private data
324   *	@sk_frag: cached page frag
325   *	@sk_peek_off: current peek_offset value
326   *	@sk_send_head: front of stuff to transmit
327   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
328   *	@sk_tx_skb_cache: cache copy of recently accessed TX skb
329   *	@sk_security: used by security modules
330   *	@sk_mark: generic packet mark
331   *	@sk_cgrp_data: cgroup data for this cgroup
332   *	@sk_memcg: this socket's memory cgroup association
333   *	@sk_write_pending: a write to stream socket waits to start
334   *	@sk_state_change: callback to indicate change in the state of the sock
335   *	@sk_data_ready: callback to indicate there is data to be processed
336   *	@sk_write_space: callback to indicate there is bf sending space available
337   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
338   *	@sk_backlog_rcv: callback to process the backlog
339   *	@sk_validate_xmit_skb: ptr to an optional validate function
340   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
341   *	@sk_reuseport_cb: reuseport group container
342   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
343   *	@sk_rcu: used during RCU grace period
344   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
345   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
346   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
347   *	@sk_txtime_unused: unused txtime flags
348   */
349 struct sock {
350 	/*
351 	 * Now struct inet_timewait_sock also uses sock_common, so please just
352 	 * don't add nothing before this first member (__sk_common) --acme
353 	 */
354 	struct sock_common	__sk_common;
355 #define sk_node			__sk_common.skc_node
356 #define sk_nulls_node		__sk_common.skc_nulls_node
357 #define sk_refcnt		__sk_common.skc_refcnt
358 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
359 #ifdef CONFIG_XPS
360 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
361 #endif
362 
363 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
364 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
365 #define sk_hash			__sk_common.skc_hash
366 #define sk_portpair		__sk_common.skc_portpair
367 #define sk_num			__sk_common.skc_num
368 #define sk_dport		__sk_common.skc_dport
369 #define sk_addrpair		__sk_common.skc_addrpair
370 #define sk_daddr		__sk_common.skc_daddr
371 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
372 #define sk_family		__sk_common.skc_family
373 #define sk_state		__sk_common.skc_state
374 #define sk_reuse		__sk_common.skc_reuse
375 #define sk_reuseport		__sk_common.skc_reuseport
376 #define sk_ipv6only		__sk_common.skc_ipv6only
377 #define sk_net_refcnt		__sk_common.skc_net_refcnt
378 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
379 #define sk_bind_node		__sk_common.skc_bind_node
380 #define sk_prot			__sk_common.skc_prot
381 #define sk_net			__sk_common.skc_net
382 #define sk_v6_daddr		__sk_common.skc_v6_daddr
383 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
384 #define sk_cookie		__sk_common.skc_cookie
385 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
386 #define sk_flags		__sk_common.skc_flags
387 #define sk_rxhash		__sk_common.skc_rxhash
388 
389 	socket_lock_t		sk_lock;
390 	atomic_t		sk_drops;
391 	int			sk_rcvlowat;
392 	struct sk_buff_head	sk_error_queue;
393 	struct sk_buff		*sk_rx_skb_cache;
394 	struct sk_buff_head	sk_receive_queue;
395 	/*
396 	 * The backlog queue is special, it is always used with
397 	 * the per-socket spinlock held and requires low latency
398 	 * access. Therefore we special case it's implementation.
399 	 * Note : rmem_alloc is in this structure to fill a hole
400 	 * on 64bit arches, not because its logically part of
401 	 * backlog.
402 	 */
403 	struct {
404 		atomic_t	rmem_alloc;
405 		int		len;
406 		struct sk_buff	*head;
407 		struct sk_buff	*tail;
408 	} sk_backlog;
409 #define sk_rmem_alloc sk_backlog.rmem_alloc
410 
411 	int			sk_forward_alloc;
412 #ifdef CONFIG_NET_RX_BUSY_POLL
413 	unsigned int		sk_ll_usec;
414 	/* ===== mostly read cache line ===== */
415 	unsigned int		sk_napi_id;
416 #endif
417 	int			sk_rcvbuf;
418 
419 	struct sk_filter __rcu	*sk_filter;
420 	union {
421 		struct socket_wq __rcu	*sk_wq;
422 		/* private: */
423 		struct socket_wq	*sk_wq_raw;
424 		/* public: */
425 	};
426 #ifdef CONFIG_XFRM
427 	struct xfrm_policy __rcu *sk_policy[2];
428 #endif
429 	struct dst_entry	*sk_rx_dst;
430 	struct dst_entry __rcu	*sk_dst_cache;
431 	atomic_t		sk_omem_alloc;
432 	int			sk_sndbuf;
433 
434 	/* ===== cache line for TX ===== */
435 	int			sk_wmem_queued;
436 	refcount_t		sk_wmem_alloc;
437 	unsigned long		sk_tsq_flags;
438 	union {
439 		struct sk_buff	*sk_send_head;
440 		struct rb_root	tcp_rtx_queue;
441 	};
442 	struct sk_buff		*sk_tx_skb_cache;
443 	struct sk_buff_head	sk_write_queue;
444 	__s32			sk_peek_off;
445 	int			sk_write_pending;
446 	__u32			sk_dst_pending_confirm;
447 	u32			sk_pacing_status; /* see enum sk_pacing */
448 	long			sk_sndtimeo;
449 	struct timer_list	sk_timer;
450 	__u32			sk_priority;
451 	__u32			sk_mark;
452 	unsigned long		sk_pacing_rate; /* bytes per second */
453 	unsigned long		sk_max_pacing_rate;
454 	struct page_frag	sk_frag;
455 	netdev_features_t	sk_route_caps;
456 	netdev_features_t	sk_route_nocaps;
457 	netdev_features_t	sk_route_forced_caps;
458 	int			sk_gso_type;
459 	unsigned int		sk_gso_max_size;
460 	gfp_t			sk_allocation;
461 	__u32			sk_txhash;
462 
463 	/*
464 	 * Because of non atomicity rules, all
465 	 * changes are protected by socket lock.
466 	 */
467 	u8			sk_padding : 1,
468 				sk_kern_sock : 1,
469 				sk_no_check_tx : 1,
470 				sk_no_check_rx : 1,
471 				sk_userlocks : 4;
472 	u8			sk_pacing_shift;
473 	u16			sk_type;
474 	u16			sk_protocol;
475 	u16			sk_gso_max_segs;
476 	unsigned long	        sk_lingertime;
477 	struct proto		*sk_prot_creator;
478 	rwlock_t		sk_callback_lock;
479 	int			sk_err,
480 				sk_err_soft;
481 	u32			sk_ack_backlog;
482 	u32			sk_max_ack_backlog;
483 	kuid_t			sk_uid;
484 #ifdef CONFIG_NET_RX_BUSY_POLL
485 	u8			sk_prefer_busy_poll;
486 	u16			sk_busy_poll_budget;
487 #endif
488 	struct pid		*sk_peer_pid;
489 	const struct cred	*sk_peer_cred;
490 	long			sk_rcvtimeo;
491 	ktime_t			sk_stamp;
492 #if BITS_PER_LONG==32
493 	seqlock_t		sk_stamp_seq;
494 #endif
495 	u16			sk_tsflags;
496 	u8			sk_shutdown;
497 	u32			sk_tskey;
498 	atomic_t		sk_zckey;
499 
500 	u8			sk_clockid;
501 	u8			sk_txtime_deadline_mode : 1,
502 				sk_txtime_report_errors : 1,
503 				sk_txtime_unused : 6;
504 
505 	struct socket		*sk_socket;
506 	void			*sk_user_data;
507 #ifdef CONFIG_SECURITY
508 	void			*sk_security;
509 #endif
510 	struct sock_cgroup_data	sk_cgrp_data;
511 	struct mem_cgroup	*sk_memcg;
512 	void			(*sk_state_change)(struct sock *sk);
513 	void			(*sk_data_ready)(struct sock *sk);
514 	void			(*sk_write_space)(struct sock *sk);
515 	void			(*sk_error_report)(struct sock *sk);
516 	int			(*sk_backlog_rcv)(struct sock *sk,
517 						  struct sk_buff *skb);
518 #ifdef CONFIG_SOCK_VALIDATE_XMIT
519 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
520 							struct net_device *dev,
521 							struct sk_buff *skb);
522 #endif
523 	void                    (*sk_destruct)(struct sock *sk);
524 	struct sock_reuseport __rcu	*sk_reuseport_cb;
525 #ifdef CONFIG_BPF_SYSCALL
526 	struct bpf_local_storage __rcu	*sk_bpf_storage;
527 #endif
528 	struct rcu_head		sk_rcu;
529 };
530 
531 enum sk_pacing {
532 	SK_PACING_NONE		= 0,
533 	SK_PACING_NEEDED	= 1,
534 	SK_PACING_FQ		= 2,
535 };
536 
537 /* Pointer stored in sk_user_data might not be suitable for copying
538  * when cloning the socket. For instance, it can point to a reference
539  * counted object. sk_user_data bottom bit is set if pointer must not
540  * be copied.
541  */
542 #define SK_USER_DATA_NOCOPY	1UL
543 #define SK_USER_DATA_BPF	2UL	/* Managed by BPF */
544 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
545 
546 /**
547  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
548  * @sk: socket
549  */
550 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
551 {
552 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
553 }
554 
555 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
556 
557 #define rcu_dereference_sk_user_data(sk)				\
558 ({									\
559 	void *__tmp = rcu_dereference(__sk_user_data((sk)));		\
560 	(void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);		\
561 })
562 #define rcu_assign_sk_user_data(sk, ptr)				\
563 ({									\
564 	uintptr_t __tmp = (uintptr_t)(ptr);				\
565 	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
566 	rcu_assign_pointer(__sk_user_data((sk)), __tmp);		\
567 })
568 #define rcu_assign_sk_user_data_nocopy(sk, ptr)				\
569 ({									\
570 	uintptr_t __tmp = (uintptr_t)(ptr);				\
571 	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
572 	rcu_assign_pointer(__sk_user_data((sk)),			\
573 			   __tmp | SK_USER_DATA_NOCOPY);		\
574 })
575 
576 /*
577  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
578  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
579  * on a socket means that the socket will reuse everybody else's port
580  * without looking at the other's sk_reuse value.
581  */
582 
583 #define SK_NO_REUSE	0
584 #define SK_CAN_REUSE	1
585 #define SK_FORCE_REUSE	2
586 
587 int sk_set_peek_off(struct sock *sk, int val);
588 
589 static inline int sk_peek_offset(struct sock *sk, int flags)
590 {
591 	if (unlikely(flags & MSG_PEEK)) {
592 		return READ_ONCE(sk->sk_peek_off);
593 	}
594 
595 	return 0;
596 }
597 
598 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
599 {
600 	s32 off = READ_ONCE(sk->sk_peek_off);
601 
602 	if (unlikely(off >= 0)) {
603 		off = max_t(s32, off - val, 0);
604 		WRITE_ONCE(sk->sk_peek_off, off);
605 	}
606 }
607 
608 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
609 {
610 	sk_peek_offset_bwd(sk, -val);
611 }
612 
613 /*
614  * Hashed lists helper routines
615  */
616 static inline struct sock *sk_entry(const struct hlist_node *node)
617 {
618 	return hlist_entry(node, struct sock, sk_node);
619 }
620 
621 static inline struct sock *__sk_head(const struct hlist_head *head)
622 {
623 	return hlist_entry(head->first, struct sock, sk_node);
624 }
625 
626 static inline struct sock *sk_head(const struct hlist_head *head)
627 {
628 	return hlist_empty(head) ? NULL : __sk_head(head);
629 }
630 
631 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
632 {
633 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
634 }
635 
636 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
637 {
638 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
639 }
640 
641 static inline struct sock *sk_next(const struct sock *sk)
642 {
643 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
644 }
645 
646 static inline struct sock *sk_nulls_next(const struct sock *sk)
647 {
648 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
649 		hlist_nulls_entry(sk->sk_nulls_node.next,
650 				  struct sock, sk_nulls_node) :
651 		NULL;
652 }
653 
654 static inline bool sk_unhashed(const struct sock *sk)
655 {
656 	return hlist_unhashed(&sk->sk_node);
657 }
658 
659 static inline bool sk_hashed(const struct sock *sk)
660 {
661 	return !sk_unhashed(sk);
662 }
663 
664 static inline void sk_node_init(struct hlist_node *node)
665 {
666 	node->pprev = NULL;
667 }
668 
669 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
670 {
671 	node->pprev = NULL;
672 }
673 
674 static inline void __sk_del_node(struct sock *sk)
675 {
676 	__hlist_del(&sk->sk_node);
677 }
678 
679 /* NB: equivalent to hlist_del_init_rcu */
680 static inline bool __sk_del_node_init(struct sock *sk)
681 {
682 	if (sk_hashed(sk)) {
683 		__sk_del_node(sk);
684 		sk_node_init(&sk->sk_node);
685 		return true;
686 	}
687 	return false;
688 }
689 
690 /* Grab socket reference count. This operation is valid only
691    when sk is ALREADY grabbed f.e. it is found in hash table
692    or a list and the lookup is made under lock preventing hash table
693    modifications.
694  */
695 
696 static __always_inline void sock_hold(struct sock *sk)
697 {
698 	refcount_inc(&sk->sk_refcnt);
699 }
700 
701 /* Ungrab socket in the context, which assumes that socket refcnt
702    cannot hit zero, f.e. it is true in context of any socketcall.
703  */
704 static __always_inline void __sock_put(struct sock *sk)
705 {
706 	refcount_dec(&sk->sk_refcnt);
707 }
708 
709 static inline bool sk_del_node_init(struct sock *sk)
710 {
711 	bool rc = __sk_del_node_init(sk);
712 
713 	if (rc) {
714 		/* paranoid for a while -acme */
715 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
716 		__sock_put(sk);
717 	}
718 	return rc;
719 }
720 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
721 
722 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
723 {
724 	if (sk_hashed(sk)) {
725 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
726 		return true;
727 	}
728 	return false;
729 }
730 
731 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
732 {
733 	bool rc = __sk_nulls_del_node_init_rcu(sk);
734 
735 	if (rc) {
736 		/* paranoid for a while -acme */
737 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
738 		__sock_put(sk);
739 	}
740 	return rc;
741 }
742 
743 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
744 {
745 	hlist_add_head(&sk->sk_node, list);
746 }
747 
748 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
749 {
750 	sock_hold(sk);
751 	__sk_add_node(sk, list);
752 }
753 
754 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
755 {
756 	sock_hold(sk);
757 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
758 	    sk->sk_family == AF_INET6)
759 		hlist_add_tail_rcu(&sk->sk_node, list);
760 	else
761 		hlist_add_head_rcu(&sk->sk_node, list);
762 }
763 
764 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
765 {
766 	sock_hold(sk);
767 	hlist_add_tail_rcu(&sk->sk_node, list);
768 }
769 
770 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
771 {
772 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
773 }
774 
775 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
776 {
777 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
778 }
779 
780 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
781 {
782 	sock_hold(sk);
783 	__sk_nulls_add_node_rcu(sk, list);
784 }
785 
786 static inline void __sk_del_bind_node(struct sock *sk)
787 {
788 	__hlist_del(&sk->sk_bind_node);
789 }
790 
791 static inline void sk_add_bind_node(struct sock *sk,
792 					struct hlist_head *list)
793 {
794 	hlist_add_head(&sk->sk_bind_node, list);
795 }
796 
797 #define sk_for_each(__sk, list) \
798 	hlist_for_each_entry(__sk, list, sk_node)
799 #define sk_for_each_rcu(__sk, list) \
800 	hlist_for_each_entry_rcu(__sk, list, sk_node)
801 #define sk_nulls_for_each(__sk, node, list) \
802 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
803 #define sk_nulls_for_each_rcu(__sk, node, list) \
804 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
805 #define sk_for_each_from(__sk) \
806 	hlist_for_each_entry_from(__sk, sk_node)
807 #define sk_nulls_for_each_from(__sk, node) \
808 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
809 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
810 #define sk_for_each_safe(__sk, tmp, list) \
811 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
812 #define sk_for_each_bound(__sk, list) \
813 	hlist_for_each_entry(__sk, list, sk_bind_node)
814 
815 /**
816  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
817  * @tpos:	the type * to use as a loop cursor.
818  * @pos:	the &struct hlist_node to use as a loop cursor.
819  * @head:	the head for your list.
820  * @offset:	offset of hlist_node within the struct.
821  *
822  */
823 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
824 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
825 	     pos != NULL &&						       \
826 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
827 	     pos = rcu_dereference(hlist_next_rcu(pos)))
828 
829 static inline struct user_namespace *sk_user_ns(struct sock *sk)
830 {
831 	/* Careful only use this in a context where these parameters
832 	 * can not change and must all be valid, such as recvmsg from
833 	 * userspace.
834 	 */
835 	return sk->sk_socket->file->f_cred->user_ns;
836 }
837 
838 /* Sock flags */
839 enum sock_flags {
840 	SOCK_DEAD,
841 	SOCK_DONE,
842 	SOCK_URGINLINE,
843 	SOCK_KEEPOPEN,
844 	SOCK_LINGER,
845 	SOCK_DESTROY,
846 	SOCK_BROADCAST,
847 	SOCK_TIMESTAMP,
848 	SOCK_ZAPPED,
849 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
850 	SOCK_DBG, /* %SO_DEBUG setting */
851 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
852 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
853 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
854 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
855 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
856 	SOCK_FASYNC, /* fasync() active */
857 	SOCK_RXQ_OVFL,
858 	SOCK_ZEROCOPY, /* buffers from userspace */
859 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
860 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
861 		     * Will use last 4 bytes of packet sent from
862 		     * user-space instead.
863 		     */
864 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
865 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
866 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
867 	SOCK_TXTIME,
868 	SOCK_XDP, /* XDP is attached */
869 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
870 };
871 
872 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
873 
874 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
875 {
876 	nsk->sk_flags = osk->sk_flags;
877 }
878 
879 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
880 {
881 	__set_bit(flag, &sk->sk_flags);
882 }
883 
884 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
885 {
886 	__clear_bit(flag, &sk->sk_flags);
887 }
888 
889 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
890 				     int valbool)
891 {
892 	if (valbool)
893 		sock_set_flag(sk, bit);
894 	else
895 		sock_reset_flag(sk, bit);
896 }
897 
898 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
899 {
900 	return test_bit(flag, &sk->sk_flags);
901 }
902 
903 #ifdef CONFIG_NET
904 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
905 static inline int sk_memalloc_socks(void)
906 {
907 	return static_branch_unlikely(&memalloc_socks_key);
908 }
909 
910 void __receive_sock(struct file *file);
911 #else
912 
913 static inline int sk_memalloc_socks(void)
914 {
915 	return 0;
916 }
917 
918 static inline void __receive_sock(struct file *file)
919 { }
920 #endif
921 
922 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
923 {
924 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
925 }
926 
927 static inline void sk_acceptq_removed(struct sock *sk)
928 {
929 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
930 }
931 
932 static inline void sk_acceptq_added(struct sock *sk)
933 {
934 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
935 }
936 
937 static inline bool sk_acceptq_is_full(const struct sock *sk)
938 {
939 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
940 }
941 
942 /*
943  * Compute minimal free write space needed to queue new packets.
944  */
945 static inline int sk_stream_min_wspace(const struct sock *sk)
946 {
947 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
948 }
949 
950 static inline int sk_stream_wspace(const struct sock *sk)
951 {
952 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
953 }
954 
955 static inline void sk_wmem_queued_add(struct sock *sk, int val)
956 {
957 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
958 }
959 
960 void sk_stream_write_space(struct sock *sk);
961 
962 /* OOB backlog add */
963 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
964 {
965 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
966 	skb_dst_force(skb);
967 
968 	if (!sk->sk_backlog.tail)
969 		WRITE_ONCE(sk->sk_backlog.head, skb);
970 	else
971 		sk->sk_backlog.tail->next = skb;
972 
973 	WRITE_ONCE(sk->sk_backlog.tail, skb);
974 	skb->next = NULL;
975 }
976 
977 /*
978  * Take into account size of receive queue and backlog queue
979  * Do not take into account this skb truesize,
980  * to allow even a single big packet to come.
981  */
982 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
983 {
984 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
985 
986 	return qsize > limit;
987 }
988 
989 /* The per-socket spinlock must be held here. */
990 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
991 					      unsigned int limit)
992 {
993 	if (sk_rcvqueues_full(sk, limit))
994 		return -ENOBUFS;
995 
996 	/*
997 	 * If the skb was allocated from pfmemalloc reserves, only
998 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
999 	 * helping free memory
1000 	 */
1001 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1002 		return -ENOMEM;
1003 
1004 	__sk_add_backlog(sk, skb);
1005 	sk->sk_backlog.len += skb->truesize;
1006 	return 0;
1007 }
1008 
1009 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1010 
1011 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1012 {
1013 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1014 		return __sk_backlog_rcv(sk, skb);
1015 
1016 	return sk->sk_backlog_rcv(sk, skb);
1017 }
1018 
1019 static inline void sk_incoming_cpu_update(struct sock *sk)
1020 {
1021 	int cpu = raw_smp_processor_id();
1022 
1023 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1024 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1025 }
1026 
1027 static inline void sock_rps_record_flow_hash(__u32 hash)
1028 {
1029 #ifdef CONFIG_RPS
1030 	struct rps_sock_flow_table *sock_flow_table;
1031 
1032 	rcu_read_lock();
1033 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1034 	rps_record_sock_flow(sock_flow_table, hash);
1035 	rcu_read_unlock();
1036 #endif
1037 }
1038 
1039 static inline void sock_rps_record_flow(const struct sock *sk)
1040 {
1041 #ifdef CONFIG_RPS
1042 	if (static_branch_unlikely(&rfs_needed)) {
1043 		/* Reading sk->sk_rxhash might incur an expensive cache line
1044 		 * miss.
1045 		 *
1046 		 * TCP_ESTABLISHED does cover almost all states where RFS
1047 		 * might be useful, and is cheaper [1] than testing :
1048 		 *	IPv4: inet_sk(sk)->inet_daddr
1049 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1050 		 * OR	an additional socket flag
1051 		 * [1] : sk_state and sk_prot are in the same cache line.
1052 		 */
1053 		if (sk->sk_state == TCP_ESTABLISHED)
1054 			sock_rps_record_flow_hash(sk->sk_rxhash);
1055 	}
1056 #endif
1057 }
1058 
1059 static inline void sock_rps_save_rxhash(struct sock *sk,
1060 					const struct sk_buff *skb)
1061 {
1062 #ifdef CONFIG_RPS
1063 	if (unlikely(sk->sk_rxhash != skb->hash))
1064 		sk->sk_rxhash = skb->hash;
1065 #endif
1066 }
1067 
1068 static inline void sock_rps_reset_rxhash(struct sock *sk)
1069 {
1070 #ifdef CONFIG_RPS
1071 	sk->sk_rxhash = 0;
1072 #endif
1073 }
1074 
1075 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1076 	({	int __rc;						\
1077 		release_sock(__sk);					\
1078 		__rc = __condition;					\
1079 		if (!__rc) {						\
1080 			*(__timeo) = wait_woken(__wait,			\
1081 						TASK_INTERRUPTIBLE,	\
1082 						*(__timeo));		\
1083 		}							\
1084 		sched_annotate_sleep();					\
1085 		lock_sock(__sk);					\
1086 		__rc = __condition;					\
1087 		__rc;							\
1088 	})
1089 
1090 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1091 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1092 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1093 int sk_stream_error(struct sock *sk, int flags, int err);
1094 void sk_stream_kill_queues(struct sock *sk);
1095 void sk_set_memalloc(struct sock *sk);
1096 void sk_clear_memalloc(struct sock *sk);
1097 
1098 void __sk_flush_backlog(struct sock *sk);
1099 
1100 static inline bool sk_flush_backlog(struct sock *sk)
1101 {
1102 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1103 		__sk_flush_backlog(sk);
1104 		return true;
1105 	}
1106 	return false;
1107 }
1108 
1109 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1110 
1111 struct request_sock_ops;
1112 struct timewait_sock_ops;
1113 struct inet_hashinfo;
1114 struct raw_hashinfo;
1115 struct smc_hashinfo;
1116 struct module;
1117 
1118 /*
1119  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1120  * un-modified. Special care is taken when initializing object to zero.
1121  */
1122 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1123 {
1124 	if (offsetof(struct sock, sk_node.next) != 0)
1125 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1126 	memset(&sk->sk_node.pprev, 0,
1127 	       size - offsetof(struct sock, sk_node.pprev));
1128 }
1129 
1130 /* Networking protocol blocks we attach to sockets.
1131  * socket layer -> transport layer interface
1132  */
1133 struct proto {
1134 	void			(*close)(struct sock *sk,
1135 					long timeout);
1136 	int			(*pre_connect)(struct sock *sk,
1137 					struct sockaddr *uaddr,
1138 					int addr_len);
1139 	int			(*connect)(struct sock *sk,
1140 					struct sockaddr *uaddr,
1141 					int addr_len);
1142 	int			(*disconnect)(struct sock *sk, int flags);
1143 
1144 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1145 					  bool kern);
1146 
1147 	int			(*ioctl)(struct sock *sk, int cmd,
1148 					 unsigned long arg);
1149 	int			(*init)(struct sock *sk);
1150 	void			(*destroy)(struct sock *sk);
1151 	void			(*shutdown)(struct sock *sk, int how);
1152 	int			(*setsockopt)(struct sock *sk, int level,
1153 					int optname, sockptr_t optval,
1154 					unsigned int optlen);
1155 	int			(*getsockopt)(struct sock *sk, int level,
1156 					int optname, char __user *optval,
1157 					int __user *option);
1158 	void			(*keepalive)(struct sock *sk, int valbool);
1159 #ifdef CONFIG_COMPAT
1160 	int			(*compat_ioctl)(struct sock *sk,
1161 					unsigned int cmd, unsigned long arg);
1162 #endif
1163 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1164 					   size_t len);
1165 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1166 					   size_t len, int noblock, int flags,
1167 					   int *addr_len);
1168 	int			(*sendpage)(struct sock *sk, struct page *page,
1169 					int offset, size_t size, int flags);
1170 	int			(*bind)(struct sock *sk,
1171 					struct sockaddr *addr, int addr_len);
1172 	int			(*bind_add)(struct sock *sk,
1173 					struct sockaddr *addr, int addr_len);
1174 
1175 	int			(*backlog_rcv) (struct sock *sk,
1176 						struct sk_buff *skb);
1177 
1178 	void		(*release_cb)(struct sock *sk);
1179 
1180 	/* Keeping track of sk's, looking them up, and port selection methods. */
1181 	int			(*hash)(struct sock *sk);
1182 	void			(*unhash)(struct sock *sk);
1183 	void			(*rehash)(struct sock *sk);
1184 	int			(*get_port)(struct sock *sk, unsigned short snum);
1185 
1186 	/* Keeping track of sockets in use */
1187 #ifdef CONFIG_PROC_FS
1188 	unsigned int		inuse_idx;
1189 #endif
1190 
1191 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1192 	bool			(*stream_memory_read)(const struct sock *sk);
1193 	/* Memory pressure */
1194 	void			(*enter_memory_pressure)(struct sock *sk);
1195 	void			(*leave_memory_pressure)(struct sock *sk);
1196 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1197 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1198 	/*
1199 	 * Pressure flag: try to collapse.
1200 	 * Technical note: it is used by multiple contexts non atomically.
1201 	 * All the __sk_mem_schedule() is of this nature: accounting
1202 	 * is strict, actions are advisory and have some latency.
1203 	 */
1204 	unsigned long		*memory_pressure;
1205 	long			*sysctl_mem;
1206 
1207 	int			*sysctl_wmem;
1208 	int			*sysctl_rmem;
1209 	u32			sysctl_wmem_offset;
1210 	u32			sysctl_rmem_offset;
1211 
1212 	int			max_header;
1213 	bool			no_autobind;
1214 
1215 	struct kmem_cache	*slab;
1216 	unsigned int		obj_size;
1217 	slab_flags_t		slab_flags;
1218 	unsigned int		useroffset;	/* Usercopy region offset */
1219 	unsigned int		usersize;	/* Usercopy region size */
1220 
1221 	struct percpu_counter	*orphan_count;
1222 
1223 	struct request_sock_ops	*rsk_prot;
1224 	struct timewait_sock_ops *twsk_prot;
1225 
1226 	union {
1227 		struct inet_hashinfo	*hashinfo;
1228 		struct udp_table	*udp_table;
1229 		struct raw_hashinfo	*raw_hash;
1230 		struct smc_hashinfo	*smc_hash;
1231 	} h;
1232 
1233 	struct module		*owner;
1234 
1235 	char			name[32];
1236 
1237 	struct list_head	node;
1238 #ifdef SOCK_REFCNT_DEBUG
1239 	atomic_t		socks;
1240 #endif
1241 	int			(*diag_destroy)(struct sock *sk, int err);
1242 } __randomize_layout;
1243 
1244 int proto_register(struct proto *prot, int alloc_slab);
1245 void proto_unregister(struct proto *prot);
1246 int sock_load_diag_module(int family, int protocol);
1247 
1248 #ifdef SOCK_REFCNT_DEBUG
1249 static inline void sk_refcnt_debug_inc(struct sock *sk)
1250 {
1251 	atomic_inc(&sk->sk_prot->socks);
1252 }
1253 
1254 static inline void sk_refcnt_debug_dec(struct sock *sk)
1255 {
1256 	atomic_dec(&sk->sk_prot->socks);
1257 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1258 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1259 }
1260 
1261 static inline void sk_refcnt_debug_release(const struct sock *sk)
1262 {
1263 	if (refcount_read(&sk->sk_refcnt) != 1)
1264 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1265 		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1266 }
1267 #else /* SOCK_REFCNT_DEBUG */
1268 #define sk_refcnt_debug_inc(sk) do { } while (0)
1269 #define sk_refcnt_debug_dec(sk) do { } while (0)
1270 #define sk_refcnt_debug_release(sk) do { } while (0)
1271 #endif /* SOCK_REFCNT_DEBUG */
1272 
1273 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1274 
1275 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1276 {
1277 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1278 		return false;
1279 
1280 #ifdef CONFIG_INET
1281 	return sk->sk_prot->stream_memory_free ?
1282 		INDIRECT_CALL_1(sk->sk_prot->stream_memory_free,
1283 			        tcp_stream_memory_free,
1284 				sk, wake) : true;
1285 #else
1286 	return sk->sk_prot->stream_memory_free ?
1287 		sk->sk_prot->stream_memory_free(sk, wake) : true;
1288 #endif
1289 }
1290 
1291 static inline bool sk_stream_memory_free(const struct sock *sk)
1292 {
1293 	return __sk_stream_memory_free(sk, 0);
1294 }
1295 
1296 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1297 {
1298 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1299 	       __sk_stream_memory_free(sk, wake);
1300 }
1301 
1302 static inline bool sk_stream_is_writeable(const struct sock *sk)
1303 {
1304 	return __sk_stream_is_writeable(sk, 0);
1305 }
1306 
1307 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1308 					    struct cgroup *ancestor)
1309 {
1310 #ifdef CONFIG_SOCK_CGROUP_DATA
1311 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1312 				    ancestor);
1313 #else
1314 	return -ENOTSUPP;
1315 #endif
1316 }
1317 
1318 static inline bool sk_has_memory_pressure(const struct sock *sk)
1319 {
1320 	return sk->sk_prot->memory_pressure != NULL;
1321 }
1322 
1323 static inline bool sk_under_memory_pressure(const struct sock *sk)
1324 {
1325 	if (!sk->sk_prot->memory_pressure)
1326 		return false;
1327 
1328 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1329 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1330 		return true;
1331 
1332 	return !!*sk->sk_prot->memory_pressure;
1333 }
1334 
1335 static inline long
1336 sk_memory_allocated(const struct sock *sk)
1337 {
1338 	return atomic_long_read(sk->sk_prot->memory_allocated);
1339 }
1340 
1341 static inline long
1342 sk_memory_allocated_add(struct sock *sk, int amt)
1343 {
1344 	return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1345 }
1346 
1347 static inline void
1348 sk_memory_allocated_sub(struct sock *sk, int amt)
1349 {
1350 	atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1351 }
1352 
1353 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1354 
1355 static inline void sk_sockets_allocated_dec(struct sock *sk)
1356 {
1357 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1358 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1359 }
1360 
1361 static inline void sk_sockets_allocated_inc(struct sock *sk)
1362 {
1363 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1364 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1365 }
1366 
1367 static inline u64
1368 sk_sockets_allocated_read_positive(struct sock *sk)
1369 {
1370 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1371 }
1372 
1373 static inline int
1374 proto_sockets_allocated_sum_positive(struct proto *prot)
1375 {
1376 	return percpu_counter_sum_positive(prot->sockets_allocated);
1377 }
1378 
1379 static inline long
1380 proto_memory_allocated(struct proto *prot)
1381 {
1382 	return atomic_long_read(prot->memory_allocated);
1383 }
1384 
1385 static inline bool
1386 proto_memory_pressure(struct proto *prot)
1387 {
1388 	if (!prot->memory_pressure)
1389 		return false;
1390 	return !!*prot->memory_pressure;
1391 }
1392 
1393 
1394 #ifdef CONFIG_PROC_FS
1395 /* Called with local bh disabled */
1396 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1397 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1398 int sock_inuse_get(struct net *net);
1399 #else
1400 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1401 		int inc)
1402 {
1403 }
1404 #endif
1405 
1406 
1407 /* With per-bucket locks this operation is not-atomic, so that
1408  * this version is not worse.
1409  */
1410 static inline int __sk_prot_rehash(struct sock *sk)
1411 {
1412 	sk->sk_prot->unhash(sk);
1413 	return sk->sk_prot->hash(sk);
1414 }
1415 
1416 /* About 10 seconds */
1417 #define SOCK_DESTROY_TIME (10*HZ)
1418 
1419 /* Sockets 0-1023 can't be bound to unless you are superuser */
1420 #define PROT_SOCK	1024
1421 
1422 #define SHUTDOWN_MASK	3
1423 #define RCV_SHUTDOWN	1
1424 #define SEND_SHUTDOWN	2
1425 
1426 #define SOCK_SNDBUF_LOCK	1
1427 #define SOCK_RCVBUF_LOCK	2
1428 #define SOCK_BINDADDR_LOCK	4
1429 #define SOCK_BINDPORT_LOCK	8
1430 
1431 struct socket_alloc {
1432 	struct socket socket;
1433 	struct inode vfs_inode;
1434 };
1435 
1436 static inline struct socket *SOCKET_I(struct inode *inode)
1437 {
1438 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1439 }
1440 
1441 static inline struct inode *SOCK_INODE(struct socket *socket)
1442 {
1443 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1444 }
1445 
1446 /*
1447  * Functions for memory accounting
1448  */
1449 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1450 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1451 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1452 void __sk_mem_reclaim(struct sock *sk, int amount);
1453 
1454 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1455  * do not necessarily have 16x time more memory than 4KB ones.
1456  */
1457 #define SK_MEM_QUANTUM 4096
1458 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1459 #define SK_MEM_SEND	0
1460 #define SK_MEM_RECV	1
1461 
1462 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1463 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1464 {
1465 	long val = sk->sk_prot->sysctl_mem[index];
1466 
1467 #if PAGE_SIZE > SK_MEM_QUANTUM
1468 	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1469 #elif PAGE_SIZE < SK_MEM_QUANTUM
1470 	val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1471 #endif
1472 	return val;
1473 }
1474 
1475 static inline int sk_mem_pages(int amt)
1476 {
1477 	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1478 }
1479 
1480 static inline bool sk_has_account(struct sock *sk)
1481 {
1482 	/* return true if protocol supports memory accounting */
1483 	return !!sk->sk_prot->memory_allocated;
1484 }
1485 
1486 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1487 {
1488 	if (!sk_has_account(sk))
1489 		return true;
1490 	return size <= sk->sk_forward_alloc ||
1491 		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1492 }
1493 
1494 static inline bool
1495 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1496 {
1497 	if (!sk_has_account(sk))
1498 		return true;
1499 	return size <= sk->sk_forward_alloc ||
1500 		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1501 		skb_pfmemalloc(skb);
1502 }
1503 
1504 static inline void sk_mem_reclaim(struct sock *sk)
1505 {
1506 	if (!sk_has_account(sk))
1507 		return;
1508 	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1509 		__sk_mem_reclaim(sk, sk->sk_forward_alloc);
1510 }
1511 
1512 static inline void sk_mem_reclaim_partial(struct sock *sk)
1513 {
1514 	if (!sk_has_account(sk))
1515 		return;
1516 	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1517 		__sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1518 }
1519 
1520 static inline void sk_mem_charge(struct sock *sk, int size)
1521 {
1522 	if (!sk_has_account(sk))
1523 		return;
1524 	sk->sk_forward_alloc -= size;
1525 }
1526 
1527 static inline void sk_mem_uncharge(struct sock *sk, int size)
1528 {
1529 	if (!sk_has_account(sk))
1530 		return;
1531 	sk->sk_forward_alloc += size;
1532 
1533 	/* Avoid a possible overflow.
1534 	 * TCP send queues can make this happen, if sk_mem_reclaim()
1535 	 * is not called and more than 2 GBytes are released at once.
1536 	 *
1537 	 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1538 	 * no need to hold that much forward allocation anyway.
1539 	 */
1540 	if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1541 		__sk_mem_reclaim(sk, 1 << 20);
1542 }
1543 
1544 DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1545 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1546 {
1547 	sk_wmem_queued_add(sk, -skb->truesize);
1548 	sk_mem_uncharge(sk, skb->truesize);
1549 	if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1550 	    !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1551 		skb_ext_reset(skb);
1552 		skb_zcopy_clear(skb, true);
1553 		sk->sk_tx_skb_cache = skb;
1554 		return;
1555 	}
1556 	__kfree_skb(skb);
1557 }
1558 
1559 static inline void sock_release_ownership(struct sock *sk)
1560 {
1561 	if (sk->sk_lock.owned) {
1562 		sk->sk_lock.owned = 0;
1563 
1564 		/* The sk_lock has mutex_unlock() semantics: */
1565 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1566 	}
1567 }
1568 
1569 /*
1570  * Macro so as to not evaluate some arguments when
1571  * lockdep is not enabled.
1572  *
1573  * Mark both the sk_lock and the sk_lock.slock as a
1574  * per-address-family lock class.
1575  */
1576 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1577 do {									\
1578 	sk->sk_lock.owned = 0;						\
1579 	init_waitqueue_head(&sk->sk_lock.wq);				\
1580 	spin_lock_init(&(sk)->sk_lock.slock);				\
1581 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1582 			sizeof((sk)->sk_lock));				\
1583 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1584 				(skey), (sname));				\
1585 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1586 } while (0)
1587 
1588 static inline bool lockdep_sock_is_held(const struct sock *sk)
1589 {
1590 	return lockdep_is_held(&sk->sk_lock) ||
1591 	       lockdep_is_held(&sk->sk_lock.slock);
1592 }
1593 
1594 void lock_sock_nested(struct sock *sk, int subclass);
1595 
1596 static inline void lock_sock(struct sock *sk)
1597 {
1598 	lock_sock_nested(sk, 0);
1599 }
1600 
1601 void __lock_sock(struct sock *sk);
1602 void __release_sock(struct sock *sk);
1603 void release_sock(struct sock *sk);
1604 
1605 /* BH context may only use the following locking interface. */
1606 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1607 #define bh_lock_sock_nested(__sk) \
1608 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1609 				SINGLE_DEPTH_NESTING)
1610 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1611 
1612 bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1613 
1614 /**
1615  * unlock_sock_fast - complement of lock_sock_fast
1616  * @sk: socket
1617  * @slow: slow mode
1618  *
1619  * fast unlock socket for user context.
1620  * If slow mode is on, we call regular release_sock()
1621  */
1622 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1623 	__releases(&sk->sk_lock.slock)
1624 {
1625 	if (slow) {
1626 		release_sock(sk);
1627 		__release(&sk->sk_lock.slock);
1628 	} else {
1629 		spin_unlock_bh(&sk->sk_lock.slock);
1630 	}
1631 }
1632 
1633 /* Used by processes to "lock" a socket state, so that
1634  * interrupts and bottom half handlers won't change it
1635  * from under us. It essentially blocks any incoming
1636  * packets, so that we won't get any new data or any
1637  * packets that change the state of the socket.
1638  *
1639  * While locked, BH processing will add new packets to
1640  * the backlog queue.  This queue is processed by the
1641  * owner of the socket lock right before it is released.
1642  *
1643  * Since ~2.3.5 it is also exclusive sleep lock serializing
1644  * accesses from user process context.
1645  */
1646 
1647 static inline void sock_owned_by_me(const struct sock *sk)
1648 {
1649 #ifdef CONFIG_LOCKDEP
1650 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1651 #endif
1652 }
1653 
1654 static inline bool sock_owned_by_user(const struct sock *sk)
1655 {
1656 	sock_owned_by_me(sk);
1657 	return sk->sk_lock.owned;
1658 }
1659 
1660 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1661 {
1662 	return sk->sk_lock.owned;
1663 }
1664 
1665 /* no reclassification while locks are held */
1666 static inline bool sock_allow_reclassification(const struct sock *csk)
1667 {
1668 	struct sock *sk = (struct sock *)csk;
1669 
1670 	return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1671 }
1672 
1673 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1674 		      struct proto *prot, int kern);
1675 void sk_free(struct sock *sk);
1676 void sk_destruct(struct sock *sk);
1677 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1678 void sk_free_unlock_clone(struct sock *sk);
1679 
1680 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1681 			     gfp_t priority);
1682 void __sock_wfree(struct sk_buff *skb);
1683 void sock_wfree(struct sk_buff *skb);
1684 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1685 			     gfp_t priority);
1686 void skb_orphan_partial(struct sk_buff *skb);
1687 void sock_rfree(struct sk_buff *skb);
1688 void sock_efree(struct sk_buff *skb);
1689 #ifdef CONFIG_INET
1690 void sock_edemux(struct sk_buff *skb);
1691 void sock_pfree(struct sk_buff *skb);
1692 #else
1693 #define sock_edemux sock_efree
1694 #endif
1695 
1696 int sock_setsockopt(struct socket *sock, int level, int op,
1697 		    sockptr_t optval, unsigned int optlen);
1698 
1699 int sock_getsockopt(struct socket *sock, int level, int op,
1700 		    char __user *optval, int __user *optlen);
1701 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1702 		   bool timeval, bool time32);
1703 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1704 				    int noblock, int *errcode);
1705 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1706 				     unsigned long data_len, int noblock,
1707 				     int *errcode, int max_page_order);
1708 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1709 void sock_kfree_s(struct sock *sk, void *mem, int size);
1710 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1711 void sk_send_sigurg(struct sock *sk);
1712 
1713 struct sockcm_cookie {
1714 	u64 transmit_time;
1715 	u32 mark;
1716 	u16 tsflags;
1717 };
1718 
1719 static inline void sockcm_init(struct sockcm_cookie *sockc,
1720 			       const struct sock *sk)
1721 {
1722 	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1723 }
1724 
1725 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1726 		     struct sockcm_cookie *sockc);
1727 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1728 		   struct sockcm_cookie *sockc);
1729 
1730 /*
1731  * Functions to fill in entries in struct proto_ops when a protocol
1732  * does not implement a particular function.
1733  */
1734 int sock_no_bind(struct socket *, struct sockaddr *, int);
1735 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1736 int sock_no_socketpair(struct socket *, struct socket *);
1737 int sock_no_accept(struct socket *, struct socket *, int, bool);
1738 int sock_no_getname(struct socket *, struct sockaddr *, int);
1739 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1740 int sock_no_listen(struct socket *, int);
1741 int sock_no_shutdown(struct socket *, int);
1742 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1743 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1744 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1745 int sock_no_mmap(struct file *file, struct socket *sock,
1746 		 struct vm_area_struct *vma);
1747 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1748 			 size_t size, int flags);
1749 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1750 				int offset, size_t size, int flags);
1751 
1752 /*
1753  * Functions to fill in entries in struct proto_ops when a protocol
1754  * uses the inet style.
1755  */
1756 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1757 				  char __user *optval, int __user *optlen);
1758 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1759 			int flags);
1760 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1761 			   sockptr_t optval, unsigned int optlen);
1762 
1763 void sk_common_release(struct sock *sk);
1764 
1765 /*
1766  *	Default socket callbacks and setup code
1767  */
1768 
1769 /* Initialise core socket variables */
1770 void sock_init_data(struct socket *sock, struct sock *sk);
1771 
1772 /*
1773  * Socket reference counting postulates.
1774  *
1775  * * Each user of socket SHOULD hold a reference count.
1776  * * Each access point to socket (an hash table bucket, reference from a list,
1777  *   running timer, skb in flight MUST hold a reference count.
1778  * * When reference count hits 0, it means it will never increase back.
1779  * * When reference count hits 0, it means that no references from
1780  *   outside exist to this socket and current process on current CPU
1781  *   is last user and may/should destroy this socket.
1782  * * sk_free is called from any context: process, BH, IRQ. When
1783  *   it is called, socket has no references from outside -> sk_free
1784  *   may release descendant resources allocated by the socket, but
1785  *   to the time when it is called, socket is NOT referenced by any
1786  *   hash tables, lists etc.
1787  * * Packets, delivered from outside (from network or from another process)
1788  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1789  *   when they sit in queue. Otherwise, packets will leak to hole, when
1790  *   socket is looked up by one cpu and unhasing is made by another CPU.
1791  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1792  *   (leak to backlog). Packet socket does all the processing inside
1793  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1794  *   use separate SMP lock, so that they are prone too.
1795  */
1796 
1797 /* Ungrab socket and destroy it, if it was the last reference. */
1798 static inline void sock_put(struct sock *sk)
1799 {
1800 	if (refcount_dec_and_test(&sk->sk_refcnt))
1801 		sk_free(sk);
1802 }
1803 /* Generic version of sock_put(), dealing with all sockets
1804  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1805  */
1806 void sock_gen_put(struct sock *sk);
1807 
1808 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1809 		     unsigned int trim_cap, bool refcounted);
1810 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1811 				 const int nested)
1812 {
1813 	return __sk_receive_skb(sk, skb, nested, 1, true);
1814 }
1815 
1816 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1817 {
1818 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1819 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1820 		return;
1821 	sk->sk_tx_queue_mapping = tx_queue;
1822 }
1823 
1824 #define NO_QUEUE_MAPPING	USHRT_MAX
1825 
1826 static inline void sk_tx_queue_clear(struct sock *sk)
1827 {
1828 	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1829 }
1830 
1831 static inline int sk_tx_queue_get(const struct sock *sk)
1832 {
1833 	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1834 		return sk->sk_tx_queue_mapping;
1835 
1836 	return -1;
1837 }
1838 
1839 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1840 {
1841 #ifdef CONFIG_XPS
1842 	if (skb_rx_queue_recorded(skb)) {
1843 		u16 rx_queue = skb_get_rx_queue(skb);
1844 
1845 		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1846 			return;
1847 
1848 		sk->sk_rx_queue_mapping = rx_queue;
1849 	}
1850 #endif
1851 }
1852 
1853 static inline void sk_rx_queue_clear(struct sock *sk)
1854 {
1855 #ifdef CONFIG_XPS
1856 	sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1857 #endif
1858 }
1859 
1860 #ifdef CONFIG_XPS
1861 static inline int sk_rx_queue_get(const struct sock *sk)
1862 {
1863 	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1864 		return sk->sk_rx_queue_mapping;
1865 
1866 	return -1;
1867 }
1868 #endif
1869 
1870 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1871 {
1872 	sk->sk_socket = sock;
1873 }
1874 
1875 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1876 {
1877 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1878 	return &rcu_dereference_raw(sk->sk_wq)->wait;
1879 }
1880 /* Detach socket from process context.
1881  * Announce socket dead, detach it from wait queue and inode.
1882  * Note that parent inode held reference count on this struct sock,
1883  * we do not release it in this function, because protocol
1884  * probably wants some additional cleanups or even continuing
1885  * to work with this socket (TCP).
1886  */
1887 static inline void sock_orphan(struct sock *sk)
1888 {
1889 	write_lock_bh(&sk->sk_callback_lock);
1890 	sock_set_flag(sk, SOCK_DEAD);
1891 	sk_set_socket(sk, NULL);
1892 	sk->sk_wq  = NULL;
1893 	write_unlock_bh(&sk->sk_callback_lock);
1894 }
1895 
1896 static inline void sock_graft(struct sock *sk, struct socket *parent)
1897 {
1898 	WARN_ON(parent->sk);
1899 	write_lock_bh(&sk->sk_callback_lock);
1900 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
1901 	parent->sk = sk;
1902 	sk_set_socket(sk, parent);
1903 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
1904 	security_sock_graft(sk, parent);
1905 	write_unlock_bh(&sk->sk_callback_lock);
1906 }
1907 
1908 kuid_t sock_i_uid(struct sock *sk);
1909 unsigned long sock_i_ino(struct sock *sk);
1910 
1911 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1912 {
1913 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1914 }
1915 
1916 static inline u32 net_tx_rndhash(void)
1917 {
1918 	u32 v = prandom_u32();
1919 
1920 	return v ?: 1;
1921 }
1922 
1923 static inline void sk_set_txhash(struct sock *sk)
1924 {
1925 	sk->sk_txhash = net_tx_rndhash();
1926 }
1927 
1928 static inline bool sk_rethink_txhash(struct sock *sk)
1929 {
1930 	if (sk->sk_txhash) {
1931 		sk_set_txhash(sk);
1932 		return true;
1933 	}
1934 	return false;
1935 }
1936 
1937 static inline struct dst_entry *
1938 __sk_dst_get(struct sock *sk)
1939 {
1940 	return rcu_dereference_check(sk->sk_dst_cache,
1941 				     lockdep_sock_is_held(sk));
1942 }
1943 
1944 static inline struct dst_entry *
1945 sk_dst_get(struct sock *sk)
1946 {
1947 	struct dst_entry *dst;
1948 
1949 	rcu_read_lock();
1950 	dst = rcu_dereference(sk->sk_dst_cache);
1951 	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1952 		dst = NULL;
1953 	rcu_read_unlock();
1954 	return dst;
1955 }
1956 
1957 static inline void __dst_negative_advice(struct sock *sk)
1958 {
1959 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1960 
1961 	if (dst && dst->ops->negative_advice) {
1962 		ndst = dst->ops->negative_advice(dst);
1963 
1964 		if (ndst != dst) {
1965 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1966 			sk_tx_queue_clear(sk);
1967 			sk->sk_dst_pending_confirm = 0;
1968 		}
1969 	}
1970 }
1971 
1972 static inline void dst_negative_advice(struct sock *sk)
1973 {
1974 	sk_rethink_txhash(sk);
1975 	__dst_negative_advice(sk);
1976 }
1977 
1978 static inline void
1979 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1980 {
1981 	struct dst_entry *old_dst;
1982 
1983 	sk_tx_queue_clear(sk);
1984 	sk->sk_dst_pending_confirm = 0;
1985 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1986 					    lockdep_sock_is_held(sk));
1987 	rcu_assign_pointer(sk->sk_dst_cache, dst);
1988 	dst_release(old_dst);
1989 }
1990 
1991 static inline void
1992 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1993 {
1994 	struct dst_entry *old_dst;
1995 
1996 	sk_tx_queue_clear(sk);
1997 	sk->sk_dst_pending_confirm = 0;
1998 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1999 	dst_release(old_dst);
2000 }
2001 
2002 static inline void
2003 __sk_dst_reset(struct sock *sk)
2004 {
2005 	__sk_dst_set(sk, NULL);
2006 }
2007 
2008 static inline void
2009 sk_dst_reset(struct sock *sk)
2010 {
2011 	sk_dst_set(sk, NULL);
2012 }
2013 
2014 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2015 
2016 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2017 
2018 static inline void sk_dst_confirm(struct sock *sk)
2019 {
2020 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2021 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2022 }
2023 
2024 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2025 {
2026 	if (skb_get_dst_pending_confirm(skb)) {
2027 		struct sock *sk = skb->sk;
2028 		unsigned long now = jiffies;
2029 
2030 		/* avoid dirtying neighbour */
2031 		if (READ_ONCE(n->confirmed) != now)
2032 			WRITE_ONCE(n->confirmed, now);
2033 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2034 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2035 	}
2036 }
2037 
2038 bool sk_mc_loop(struct sock *sk);
2039 
2040 static inline bool sk_can_gso(const struct sock *sk)
2041 {
2042 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2043 }
2044 
2045 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2046 
2047 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
2048 {
2049 	sk->sk_route_nocaps |= flags;
2050 	sk->sk_route_caps &= ~flags;
2051 }
2052 
2053 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2054 					   struct iov_iter *from, char *to,
2055 					   int copy, int offset)
2056 {
2057 	if (skb->ip_summed == CHECKSUM_NONE) {
2058 		__wsum csum = 0;
2059 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2060 			return -EFAULT;
2061 		skb->csum = csum_block_add(skb->csum, csum, offset);
2062 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2063 		if (!copy_from_iter_full_nocache(to, copy, from))
2064 			return -EFAULT;
2065 	} else if (!copy_from_iter_full(to, copy, from))
2066 		return -EFAULT;
2067 
2068 	return 0;
2069 }
2070 
2071 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2072 				       struct iov_iter *from, int copy)
2073 {
2074 	int err, offset = skb->len;
2075 
2076 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2077 				       copy, offset);
2078 	if (err)
2079 		__skb_trim(skb, offset);
2080 
2081 	return err;
2082 }
2083 
2084 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2085 					   struct sk_buff *skb,
2086 					   struct page *page,
2087 					   int off, int copy)
2088 {
2089 	int err;
2090 
2091 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2092 				       copy, skb->len);
2093 	if (err)
2094 		return err;
2095 
2096 	skb->len	     += copy;
2097 	skb->data_len	     += copy;
2098 	skb->truesize	     += copy;
2099 	sk_wmem_queued_add(sk, copy);
2100 	sk_mem_charge(sk, copy);
2101 	return 0;
2102 }
2103 
2104 /**
2105  * sk_wmem_alloc_get - returns write allocations
2106  * @sk: socket
2107  *
2108  * Return: sk_wmem_alloc minus initial offset of one
2109  */
2110 static inline int sk_wmem_alloc_get(const struct sock *sk)
2111 {
2112 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2113 }
2114 
2115 /**
2116  * sk_rmem_alloc_get - returns read allocations
2117  * @sk: socket
2118  *
2119  * Return: sk_rmem_alloc
2120  */
2121 static inline int sk_rmem_alloc_get(const struct sock *sk)
2122 {
2123 	return atomic_read(&sk->sk_rmem_alloc);
2124 }
2125 
2126 /**
2127  * sk_has_allocations - check if allocations are outstanding
2128  * @sk: socket
2129  *
2130  * Return: true if socket has write or read allocations
2131  */
2132 static inline bool sk_has_allocations(const struct sock *sk)
2133 {
2134 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2135 }
2136 
2137 /**
2138  * skwq_has_sleeper - check if there are any waiting processes
2139  * @wq: struct socket_wq
2140  *
2141  * Return: true if socket_wq has waiting processes
2142  *
2143  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2144  * barrier call. They were added due to the race found within the tcp code.
2145  *
2146  * Consider following tcp code paths::
2147  *
2148  *   CPU1                CPU2
2149  *   sys_select          receive packet
2150  *   ...                 ...
2151  *   __add_wait_queue    update tp->rcv_nxt
2152  *   ...                 ...
2153  *   tp->rcv_nxt check   sock_def_readable
2154  *   ...                 {
2155  *   schedule               rcu_read_lock();
2156  *                          wq = rcu_dereference(sk->sk_wq);
2157  *                          if (wq && waitqueue_active(&wq->wait))
2158  *                              wake_up_interruptible(&wq->wait)
2159  *                          ...
2160  *                       }
2161  *
2162  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2163  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2164  * could then endup calling schedule and sleep forever if there are no more
2165  * data on the socket.
2166  *
2167  */
2168 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2169 {
2170 	return wq && wq_has_sleeper(&wq->wait);
2171 }
2172 
2173 /**
2174  * sock_poll_wait - place memory barrier behind the poll_wait call.
2175  * @filp:           file
2176  * @sock:           socket to wait on
2177  * @p:              poll_table
2178  *
2179  * See the comments in the wq_has_sleeper function.
2180  */
2181 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2182 				  poll_table *p)
2183 {
2184 	if (!poll_does_not_wait(p)) {
2185 		poll_wait(filp, &sock->wq.wait, p);
2186 		/* We need to be sure we are in sync with the
2187 		 * socket flags modification.
2188 		 *
2189 		 * This memory barrier is paired in the wq_has_sleeper.
2190 		 */
2191 		smp_mb();
2192 	}
2193 }
2194 
2195 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2196 {
2197 	if (sk->sk_txhash) {
2198 		skb->l4_hash = 1;
2199 		skb->hash = sk->sk_txhash;
2200 	}
2201 }
2202 
2203 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2204 
2205 /*
2206  *	Queue a received datagram if it will fit. Stream and sequenced
2207  *	protocols can't normally use this as they need to fit buffers in
2208  *	and play with them.
2209  *
2210  *	Inlined as it's very short and called for pretty much every
2211  *	packet ever received.
2212  */
2213 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2214 {
2215 	skb_orphan(skb);
2216 	skb->sk = sk;
2217 	skb->destructor = sock_rfree;
2218 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2219 	sk_mem_charge(sk, skb->truesize);
2220 }
2221 
2222 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2223 		    unsigned long expires);
2224 
2225 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2226 
2227 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2228 
2229 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2230 			struct sk_buff *skb, unsigned int flags,
2231 			void (*destructor)(struct sock *sk,
2232 					   struct sk_buff *skb));
2233 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2234 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2235 
2236 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2237 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2238 
2239 /*
2240  *	Recover an error report and clear atomically
2241  */
2242 
2243 static inline int sock_error(struct sock *sk)
2244 {
2245 	int err;
2246 	if (likely(!sk->sk_err))
2247 		return 0;
2248 	err = xchg(&sk->sk_err, 0);
2249 	return -err;
2250 }
2251 
2252 static inline unsigned long sock_wspace(struct sock *sk)
2253 {
2254 	int amt = 0;
2255 
2256 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2257 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2258 		if (amt < 0)
2259 			amt = 0;
2260 	}
2261 	return amt;
2262 }
2263 
2264 /* Note:
2265  *  We use sk->sk_wq_raw, from contexts knowing this
2266  *  pointer is not NULL and cannot disappear/change.
2267  */
2268 static inline void sk_set_bit(int nr, struct sock *sk)
2269 {
2270 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2271 	    !sock_flag(sk, SOCK_FASYNC))
2272 		return;
2273 
2274 	set_bit(nr, &sk->sk_wq_raw->flags);
2275 }
2276 
2277 static inline void sk_clear_bit(int nr, struct sock *sk)
2278 {
2279 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2280 	    !sock_flag(sk, SOCK_FASYNC))
2281 		return;
2282 
2283 	clear_bit(nr, &sk->sk_wq_raw->flags);
2284 }
2285 
2286 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2287 {
2288 	if (sock_flag(sk, SOCK_FASYNC)) {
2289 		rcu_read_lock();
2290 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2291 		rcu_read_unlock();
2292 	}
2293 }
2294 
2295 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2296  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2297  * Note: for send buffers, TCP works better if we can build two skbs at
2298  * minimum.
2299  */
2300 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2301 
2302 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2303 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2304 
2305 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2306 {
2307 	u32 val;
2308 
2309 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2310 		return;
2311 
2312 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2313 
2314 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2315 }
2316 
2317 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2318 				    bool force_schedule);
2319 
2320 /**
2321  * sk_page_frag - return an appropriate page_frag
2322  * @sk: socket
2323  *
2324  * Use the per task page_frag instead of the per socket one for
2325  * optimization when we know that we're in the normal context and owns
2326  * everything that's associated with %current.
2327  *
2328  * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2329  * inside other socket operations and end up recursing into sk_page_frag()
2330  * while it's already in use.
2331  *
2332  * Return: a per task page_frag if context allows that,
2333  * otherwise a per socket one.
2334  */
2335 static inline struct page_frag *sk_page_frag(struct sock *sk)
2336 {
2337 	if (gfpflags_normal_context(sk->sk_allocation))
2338 		return &current->task_frag;
2339 
2340 	return &sk->sk_frag;
2341 }
2342 
2343 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2344 
2345 /*
2346  *	Default write policy as shown to user space via poll/select/SIGIO
2347  */
2348 static inline bool sock_writeable(const struct sock *sk)
2349 {
2350 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2351 }
2352 
2353 static inline gfp_t gfp_any(void)
2354 {
2355 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2356 }
2357 
2358 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2359 {
2360 	return noblock ? 0 : sk->sk_rcvtimeo;
2361 }
2362 
2363 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2364 {
2365 	return noblock ? 0 : sk->sk_sndtimeo;
2366 }
2367 
2368 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2369 {
2370 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2371 
2372 	return v ?: 1;
2373 }
2374 
2375 /* Alas, with timeout socket operations are not restartable.
2376  * Compare this to poll().
2377  */
2378 static inline int sock_intr_errno(long timeo)
2379 {
2380 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2381 }
2382 
2383 struct sock_skb_cb {
2384 	u32 dropcount;
2385 };
2386 
2387 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2388  * using skb->cb[] would keep using it directly and utilize its
2389  * alignement guarantee.
2390  */
2391 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2392 			    sizeof(struct sock_skb_cb)))
2393 
2394 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2395 			    SOCK_SKB_CB_OFFSET))
2396 
2397 #define sock_skb_cb_check_size(size) \
2398 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2399 
2400 static inline void
2401 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2402 {
2403 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2404 						atomic_read(&sk->sk_drops) : 0;
2405 }
2406 
2407 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2408 {
2409 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2410 
2411 	atomic_add(segs, &sk->sk_drops);
2412 }
2413 
2414 static inline ktime_t sock_read_timestamp(struct sock *sk)
2415 {
2416 #if BITS_PER_LONG==32
2417 	unsigned int seq;
2418 	ktime_t kt;
2419 
2420 	do {
2421 		seq = read_seqbegin(&sk->sk_stamp_seq);
2422 		kt = sk->sk_stamp;
2423 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2424 
2425 	return kt;
2426 #else
2427 	return READ_ONCE(sk->sk_stamp);
2428 #endif
2429 }
2430 
2431 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2432 {
2433 #if BITS_PER_LONG==32
2434 	write_seqlock(&sk->sk_stamp_seq);
2435 	sk->sk_stamp = kt;
2436 	write_sequnlock(&sk->sk_stamp_seq);
2437 #else
2438 	WRITE_ONCE(sk->sk_stamp, kt);
2439 #endif
2440 }
2441 
2442 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2443 			   struct sk_buff *skb);
2444 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2445 			     struct sk_buff *skb);
2446 
2447 static inline void
2448 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2449 {
2450 	ktime_t kt = skb->tstamp;
2451 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2452 
2453 	/*
2454 	 * generate control messages if
2455 	 * - receive time stamping in software requested
2456 	 * - software time stamp available and wanted
2457 	 * - hardware time stamps available and wanted
2458 	 */
2459 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2460 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2461 	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2462 	    (hwtstamps->hwtstamp &&
2463 	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2464 		__sock_recv_timestamp(msg, sk, skb);
2465 	else
2466 		sock_write_timestamp(sk, kt);
2467 
2468 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2469 		__sock_recv_wifi_status(msg, sk, skb);
2470 }
2471 
2472 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2473 			      struct sk_buff *skb);
2474 
2475 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2476 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2477 					  struct sk_buff *skb)
2478 {
2479 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2480 			   (1UL << SOCK_RCVTSTAMP))
2481 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2482 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2483 
2484 	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2485 		__sock_recv_ts_and_drops(msg, sk, skb);
2486 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2487 		sock_write_timestamp(sk, skb->tstamp);
2488 	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2489 		sock_write_timestamp(sk, 0);
2490 }
2491 
2492 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2493 
2494 /**
2495  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2496  * @sk:		socket sending this packet
2497  * @tsflags:	timestamping flags to use
2498  * @tx_flags:	completed with instructions for time stamping
2499  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2500  *
2501  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2502  */
2503 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2504 				      __u8 *tx_flags, __u32 *tskey)
2505 {
2506 	if (unlikely(tsflags)) {
2507 		__sock_tx_timestamp(tsflags, tx_flags);
2508 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2509 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2510 			*tskey = sk->sk_tskey++;
2511 	}
2512 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2513 		*tx_flags |= SKBTX_WIFI_STATUS;
2514 }
2515 
2516 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2517 				     __u8 *tx_flags)
2518 {
2519 	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2520 }
2521 
2522 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2523 {
2524 	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2525 			   &skb_shinfo(skb)->tskey);
2526 }
2527 
2528 DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2529 /**
2530  * sk_eat_skb - Release a skb if it is no longer needed
2531  * @sk: socket to eat this skb from
2532  * @skb: socket buffer to eat
2533  *
2534  * This routine must be called with interrupts disabled or with the socket
2535  * locked so that the sk_buff queue operation is ok.
2536 */
2537 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2538 {
2539 	__skb_unlink(skb, &sk->sk_receive_queue);
2540 	if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2541 	    !sk->sk_rx_skb_cache) {
2542 		sk->sk_rx_skb_cache = skb;
2543 		skb_orphan(skb);
2544 		return;
2545 	}
2546 	__kfree_skb(skb);
2547 }
2548 
2549 static inline
2550 struct net *sock_net(const struct sock *sk)
2551 {
2552 	return read_pnet(&sk->sk_net);
2553 }
2554 
2555 static inline
2556 void sock_net_set(struct sock *sk, struct net *net)
2557 {
2558 	write_pnet(&sk->sk_net, net);
2559 }
2560 
2561 static inline bool
2562 skb_sk_is_prefetched(struct sk_buff *skb)
2563 {
2564 #ifdef CONFIG_INET
2565 	return skb->destructor == sock_pfree;
2566 #else
2567 	return false;
2568 #endif /* CONFIG_INET */
2569 }
2570 
2571 /* This helper checks if a socket is a full socket,
2572  * ie _not_ a timewait or request socket.
2573  */
2574 static inline bool sk_fullsock(const struct sock *sk)
2575 {
2576 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2577 }
2578 
2579 static inline bool
2580 sk_is_refcounted(struct sock *sk)
2581 {
2582 	/* Only full sockets have sk->sk_flags. */
2583 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2584 }
2585 
2586 /**
2587  * skb_steal_sock - steal a socket from an sk_buff
2588  * @skb: sk_buff to steal the socket from
2589  * @refcounted: is set to true if the socket is reference-counted
2590  */
2591 static inline struct sock *
2592 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2593 {
2594 	if (skb->sk) {
2595 		struct sock *sk = skb->sk;
2596 
2597 		*refcounted = true;
2598 		if (skb_sk_is_prefetched(skb))
2599 			*refcounted = sk_is_refcounted(sk);
2600 		skb->destructor = NULL;
2601 		skb->sk = NULL;
2602 		return sk;
2603 	}
2604 	*refcounted = false;
2605 	return NULL;
2606 }
2607 
2608 /* Checks if this SKB belongs to an HW offloaded socket
2609  * and whether any SW fallbacks are required based on dev.
2610  * Check decrypted mark in case skb_orphan() cleared socket.
2611  */
2612 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2613 						   struct net_device *dev)
2614 {
2615 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2616 	struct sock *sk = skb->sk;
2617 
2618 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2619 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2620 #ifdef CONFIG_TLS_DEVICE
2621 	} else if (unlikely(skb->decrypted)) {
2622 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2623 		kfree_skb(skb);
2624 		skb = NULL;
2625 #endif
2626 	}
2627 #endif
2628 
2629 	return skb;
2630 }
2631 
2632 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2633  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2634  */
2635 static inline bool sk_listener(const struct sock *sk)
2636 {
2637 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2638 }
2639 
2640 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2641 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2642 		       int type);
2643 
2644 bool sk_ns_capable(const struct sock *sk,
2645 		   struct user_namespace *user_ns, int cap);
2646 bool sk_capable(const struct sock *sk, int cap);
2647 bool sk_net_capable(const struct sock *sk, int cap);
2648 
2649 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2650 
2651 /* Take into consideration the size of the struct sk_buff overhead in the
2652  * determination of these values, since that is non-constant across
2653  * platforms.  This makes socket queueing behavior and performance
2654  * not depend upon such differences.
2655  */
2656 #define _SK_MEM_PACKETS		256
2657 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2658 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2659 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2660 
2661 extern __u32 sysctl_wmem_max;
2662 extern __u32 sysctl_rmem_max;
2663 
2664 extern int sysctl_tstamp_allow_data;
2665 extern int sysctl_optmem_max;
2666 
2667 extern __u32 sysctl_wmem_default;
2668 extern __u32 sysctl_rmem_default;
2669 
2670 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2671 
2672 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2673 {
2674 	/* Does this proto have per netns sysctl_wmem ? */
2675 	if (proto->sysctl_wmem_offset)
2676 		return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2677 
2678 	return *proto->sysctl_wmem;
2679 }
2680 
2681 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2682 {
2683 	/* Does this proto have per netns sysctl_rmem ? */
2684 	if (proto->sysctl_rmem_offset)
2685 		return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2686 
2687 	return *proto->sysctl_rmem;
2688 }
2689 
2690 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2691  * Some wifi drivers need to tweak it to get more chunks.
2692  * They can use this helper from their ndo_start_xmit()
2693  */
2694 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2695 {
2696 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2697 		return;
2698 	WRITE_ONCE(sk->sk_pacing_shift, val);
2699 }
2700 
2701 /* if a socket is bound to a device, check that the given device
2702  * index is either the same or that the socket is bound to an L3
2703  * master device and the given device index is also enslaved to
2704  * that L3 master
2705  */
2706 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2707 {
2708 	int mdif;
2709 
2710 	if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2711 		return true;
2712 
2713 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2714 	if (mdif && mdif == sk->sk_bound_dev_if)
2715 		return true;
2716 
2717 	return false;
2718 }
2719 
2720 void sock_def_readable(struct sock *sk);
2721 
2722 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2723 void sock_enable_timestamps(struct sock *sk);
2724 void sock_no_linger(struct sock *sk);
2725 void sock_set_keepalive(struct sock *sk);
2726 void sock_set_priority(struct sock *sk, u32 priority);
2727 void sock_set_rcvbuf(struct sock *sk, int val);
2728 void sock_set_mark(struct sock *sk, u32 val);
2729 void sock_set_reuseaddr(struct sock *sk);
2730 void sock_set_reuseport(struct sock *sk);
2731 void sock_set_sndtimeo(struct sock *sk, s64 secs);
2732 
2733 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2734 
2735 #endif	/* _SOCK_H */
2736