1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the AF_INET socket handler.
8  *
9  * Version:	@(#)sock.h	1.0.4	05/13/93
10  *
11  * Authors:	Ross Biro
12  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
14  *		Florian La Roche <flla@stud.uni-sb.de>
15  *
16  * Fixes:
17  *		Alan Cox	:	Volatiles in skbuff pointers. See
18  *					skbuff comments. May be overdone,
19  *					better to prove they can be removed
20  *					than the reverse.
21  *		Alan Cox	:	Added a zapped field for tcp to note
22  *					a socket is reset and must stay shut up
23  *		Alan Cox	:	New fields for options
24  *	Pauline Middelink	:	identd support
25  *		Alan Cox	:	Eliminate low level recv/recvfrom
26  *		David S. Miller	:	New socket lookup architecture.
27  *              Steve Whitehouse:       Default routines for sock_ops
28  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
29  *              			protinfo be just a void pointer, as the
30  *              			protocol specific parts were moved to
31  *              			respective headers and ipv4/v6, etc now
32  *              			use private slabcaches for its socks
33  *              Pedro Hortas	:	New flags field for socket options
34  */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37 
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h>	/* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/rculist_nulls.h>
60 #include <linux/poll.h>
61 #include <linux/sockptr.h>
62 #include <linux/indirect_call_wrapper.h>
63 #include <linux/atomic.h>
64 #include <linux/refcount.h>
65 #include <linux/llist.h>
66 #include <net/dst.h>
67 #include <net/checksum.h>
68 #include <net/tcp_states.h>
69 #include <linux/net_tstamp.h>
70 #include <net/l3mdev.h>
71 #include <uapi/linux/socket.h>
72 
73 /*
74  * This structure really needs to be cleaned up.
75  * Most of it is for TCP, and not used by any of
76  * the other protocols.
77  */
78 
79 /* Define this to get the SOCK_DBG debugging facility. */
80 #define SOCK_DEBUGGING
81 #ifdef SOCK_DEBUGGING
82 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
83 					printk(KERN_DEBUG msg); } while (0)
84 #else
85 /* Validate arguments and do nothing */
86 static inline __printf(2, 3)
SOCK_DEBUG(const struct sock * sk,const char * msg,...)87 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
88 {
89 }
90 #endif
91 
92 /* This is the per-socket lock.  The spinlock provides a synchronization
93  * between user contexts and software interrupt processing, whereas the
94  * mini-semaphore synchronizes multiple users amongst themselves.
95  */
96 typedef struct {
97 	spinlock_t		slock;
98 	int			owned;
99 	wait_queue_head_t	wq;
100 	/*
101 	 * We express the mutex-alike socket_lock semantics
102 	 * to the lock validator by explicitly managing
103 	 * the slock as a lock variant (in addition to
104 	 * the slock itself):
105 	 */
106 #ifdef CONFIG_DEBUG_LOCK_ALLOC
107 	struct lockdep_map dep_map;
108 #endif
109 } socket_lock_t;
110 
111 struct sock;
112 struct proto;
113 struct net;
114 
115 typedef __u32 __bitwise __portpair;
116 typedef __u64 __bitwise __addrpair;
117 
118 /**
119  *	struct sock_common - minimal network layer representation of sockets
120  *	@skc_daddr: Foreign IPv4 addr
121  *	@skc_rcv_saddr: Bound local IPv4 addr
122  *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
123  *	@skc_hash: hash value used with various protocol lookup tables
124  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
125  *	@skc_dport: placeholder for inet_dport/tw_dport
126  *	@skc_num: placeholder for inet_num/tw_num
127  *	@skc_portpair: __u32 union of @skc_dport & @skc_num
128  *	@skc_family: network address family
129  *	@skc_state: Connection state
130  *	@skc_reuse: %SO_REUSEADDR setting
131  *	@skc_reuseport: %SO_REUSEPORT setting
132  *	@skc_ipv6only: socket is IPV6 only
133  *	@skc_net_refcnt: socket is using net ref counting
134  *	@skc_bound_dev_if: bound device index if != 0
135  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
136  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
137  *	@skc_prot: protocol handlers inside a network family
138  *	@skc_net: reference to the network namespace of this socket
139  *	@skc_v6_daddr: IPV6 destination address
140  *	@skc_v6_rcv_saddr: IPV6 source address
141  *	@skc_cookie: socket's cookie value
142  *	@skc_node: main hash linkage for various protocol lookup tables
143  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
144  *	@skc_tx_queue_mapping: tx queue number for this connection
145  *	@skc_rx_queue_mapping: rx queue number for this connection
146  *	@skc_flags: place holder for sk_flags
147  *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
148  *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
149  *	@skc_listener: connection request listener socket (aka rsk_listener)
150  *		[union with @skc_flags]
151  *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
152  *		[union with @skc_flags]
153  *	@skc_incoming_cpu: record/match cpu processing incoming packets
154  *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
155  *		[union with @skc_incoming_cpu]
156  *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
157  *		[union with @skc_incoming_cpu]
158  *	@skc_refcnt: reference count
159  *
160  *	This is the minimal network layer representation of sockets, the header
161  *	for struct sock and struct inet_timewait_sock.
162  */
163 struct sock_common {
164 	union {
165 		__addrpair	skc_addrpair;
166 		struct {
167 			__be32	skc_daddr;
168 			__be32	skc_rcv_saddr;
169 		};
170 	};
171 	union  {
172 		unsigned int	skc_hash;
173 		__u16		skc_u16hashes[2];
174 	};
175 	/* skc_dport && skc_num must be grouped as well */
176 	union {
177 		__portpair	skc_portpair;
178 		struct {
179 			__be16	skc_dport;
180 			__u16	skc_num;
181 		};
182 	};
183 
184 	unsigned short		skc_family;
185 	volatile unsigned char	skc_state;
186 	unsigned char		skc_reuse:4;
187 	unsigned char		skc_reuseport:1;
188 	unsigned char		skc_ipv6only:1;
189 	unsigned char		skc_net_refcnt:1;
190 	int			skc_bound_dev_if;
191 	union {
192 		struct hlist_node	skc_bind_node;
193 		struct hlist_node	skc_portaddr_node;
194 	};
195 	struct proto		*skc_prot;
196 	possible_net_t		skc_net;
197 
198 #if IS_ENABLED(CONFIG_IPV6)
199 	struct in6_addr		skc_v6_daddr;
200 	struct in6_addr		skc_v6_rcv_saddr;
201 #endif
202 
203 	atomic64_t		skc_cookie;
204 
205 	/* following fields are padding to force
206 	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
207 	 * assuming IPV6 is enabled. We use this padding differently
208 	 * for different kind of 'sockets'
209 	 */
210 	union {
211 		unsigned long	skc_flags;
212 		struct sock	*skc_listener; /* request_sock */
213 		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
214 	};
215 	/*
216 	 * fields between dontcopy_begin/dontcopy_end
217 	 * are not copied in sock_copy()
218 	 */
219 	/* private: */
220 	int			skc_dontcopy_begin[0];
221 	/* public: */
222 	union {
223 		struct hlist_node	skc_node;
224 		struct hlist_nulls_node skc_nulls_node;
225 	};
226 	unsigned short		skc_tx_queue_mapping;
227 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
228 	unsigned short		skc_rx_queue_mapping;
229 #endif
230 	union {
231 		int		skc_incoming_cpu;
232 		u32		skc_rcv_wnd;
233 		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
234 	};
235 
236 	refcount_t		skc_refcnt;
237 	/* private: */
238 	int                     skc_dontcopy_end[0];
239 	union {
240 		u32		skc_rxhash;
241 		u32		skc_window_clamp;
242 		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
243 	};
244 	/* public: */
245 };
246 
247 struct bpf_local_storage;
248 struct sk_filter;
249 
250 /**
251   *	struct sock - network layer representation of sockets
252   *	@__sk_common: shared layout with inet_timewait_sock
253   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
254   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
255   *	@sk_lock:	synchronizer
256   *	@sk_kern_sock: True if sock is using kernel lock classes
257   *	@sk_rcvbuf: size of receive buffer in bytes
258   *	@sk_wq: sock wait queue and async head
259   *	@sk_rx_dst: receive input route used by early demux
260   *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
261   *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
262   *	@sk_dst_cache: destination cache
263   *	@sk_dst_pending_confirm: need to confirm neighbour
264   *	@sk_policy: flow policy
265   *	@sk_receive_queue: incoming packets
266   *	@sk_wmem_alloc: transmit queue bytes committed
267   *	@sk_tsq_flags: TCP Small Queues flags
268   *	@sk_write_queue: Packet sending queue
269   *	@sk_omem_alloc: "o" is "option" or "other"
270   *	@sk_wmem_queued: persistent queue size
271   *	@sk_forward_alloc: space allocated forward
272   *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
273   *	@sk_napi_id: id of the last napi context to receive data for sk
274   *	@sk_ll_usec: usecs to busypoll when there is no data
275   *	@sk_allocation: allocation mode
276   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
277   *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
278   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
279   *	@sk_sndbuf: size of send buffer in bytes
280   *	@__sk_flags_offset: empty field used to determine location of bitfield
281   *	@sk_padding: unused element for alignment
282   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
283   *	@sk_no_check_rx: allow zero checksum in RX packets
284   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
285   *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
286   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
287   *	@sk_gso_max_size: Maximum GSO segment size to build
288   *	@sk_gso_max_segs: Maximum number of GSO segments
289   *	@sk_pacing_shift: scaling factor for TCP Small Queues
290   *	@sk_lingertime: %SO_LINGER l_linger setting
291   *	@sk_backlog: always used with the per-socket spinlock held
292   *	@sk_callback_lock: used with the callbacks in the end of this struct
293   *	@sk_error_queue: rarely used
294   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
295   *			  IPV6_ADDRFORM for instance)
296   *	@sk_err: last error
297   *	@sk_err_soft: errors that don't cause failure but are the cause of a
298   *		      persistent failure not just 'timed out'
299   *	@sk_drops: raw/udp drops counter
300   *	@sk_ack_backlog: current listen backlog
301   *	@sk_max_ack_backlog: listen backlog set in listen()
302   *	@sk_uid: user id of owner
303   *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
304   *	@sk_busy_poll_budget: napi processing budget when busypolling
305   *	@sk_priority: %SO_PRIORITY setting
306   *	@sk_type: socket type (%SOCK_STREAM, etc)
307   *	@sk_protocol: which protocol this socket belongs in this network family
308   *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
309   *	@sk_peer_pid: &struct pid for this socket's peer
310   *	@sk_peer_cred: %SO_PEERCRED setting
311   *	@sk_rcvlowat: %SO_RCVLOWAT setting
312   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
313   *	@sk_sndtimeo: %SO_SNDTIMEO setting
314   *	@sk_txhash: computed flow hash for use on transmit
315   *	@sk_txrehash: enable TX hash rethink
316   *	@sk_filter: socket filtering instructions
317   *	@sk_timer: sock cleanup timer
318   *	@sk_stamp: time stamp of last packet received
319   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
320   *	@sk_tsflags: SO_TIMESTAMPING flags
321   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
322   *	              for timestamping
323   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
324   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
325   *	@sk_socket: Identd and reporting IO signals
326   *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
327   *	@sk_frag: cached page frag
328   *	@sk_peek_off: current peek_offset value
329   *	@sk_send_head: front of stuff to transmit
330   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
331   *	@sk_security: used by security modules
332   *	@sk_mark: generic packet mark
333   *	@sk_cgrp_data: cgroup data for this cgroup
334   *	@sk_memcg: this socket's memory cgroup association
335   *	@sk_write_pending: a write to stream socket waits to start
336   *	@sk_state_change: callback to indicate change in the state of the sock
337   *	@sk_data_ready: callback to indicate there is data to be processed
338   *	@sk_write_space: callback to indicate there is bf sending space available
339   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
340   *	@sk_backlog_rcv: callback to process the backlog
341   *	@sk_validate_xmit_skb: ptr to an optional validate function
342   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
343   *	@sk_reuseport_cb: reuseport group container
344   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
345   *	@sk_rcu: used during RCU grace period
346   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
347   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
348   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
349   *	@sk_txtime_unused: unused txtime flags
350   *	@ns_tracker: tracker for netns reference
351   *	@sk_bind2_node: bind node in the bhash2 table
352   */
353 struct sock {
354 	/*
355 	 * Now struct inet_timewait_sock also uses sock_common, so please just
356 	 * don't add nothing before this first member (__sk_common) --acme
357 	 */
358 	struct sock_common	__sk_common;
359 #define sk_node			__sk_common.skc_node
360 #define sk_nulls_node		__sk_common.skc_nulls_node
361 #define sk_refcnt		__sk_common.skc_refcnt
362 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
363 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
364 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
365 #endif
366 
367 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
368 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
369 #define sk_hash			__sk_common.skc_hash
370 #define sk_portpair		__sk_common.skc_portpair
371 #define sk_num			__sk_common.skc_num
372 #define sk_dport		__sk_common.skc_dport
373 #define sk_addrpair		__sk_common.skc_addrpair
374 #define sk_daddr		__sk_common.skc_daddr
375 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
376 #define sk_family		__sk_common.skc_family
377 #define sk_state		__sk_common.skc_state
378 #define sk_reuse		__sk_common.skc_reuse
379 #define sk_reuseport		__sk_common.skc_reuseport
380 #define sk_ipv6only		__sk_common.skc_ipv6only
381 #define sk_net_refcnt		__sk_common.skc_net_refcnt
382 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
383 #define sk_bind_node		__sk_common.skc_bind_node
384 #define sk_prot			__sk_common.skc_prot
385 #define sk_net			__sk_common.skc_net
386 #define sk_v6_daddr		__sk_common.skc_v6_daddr
387 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
388 #define sk_cookie		__sk_common.skc_cookie
389 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
390 #define sk_flags		__sk_common.skc_flags
391 #define sk_rxhash		__sk_common.skc_rxhash
392 
393 	/* early demux fields */
394 	struct dst_entry __rcu	*sk_rx_dst;
395 	int			sk_rx_dst_ifindex;
396 	u32			sk_rx_dst_cookie;
397 
398 	socket_lock_t		sk_lock;
399 	atomic_t		sk_drops;
400 	int			sk_rcvlowat;
401 	struct sk_buff_head	sk_error_queue;
402 	struct sk_buff_head	sk_receive_queue;
403 	/*
404 	 * The backlog queue is special, it is always used with
405 	 * the per-socket spinlock held and requires low latency
406 	 * access. Therefore we special case it's implementation.
407 	 * Note : rmem_alloc is in this structure to fill a hole
408 	 * on 64bit arches, not because its logically part of
409 	 * backlog.
410 	 */
411 	struct {
412 		atomic_t	rmem_alloc;
413 		int		len;
414 		struct sk_buff	*head;
415 		struct sk_buff	*tail;
416 	} sk_backlog;
417 
418 #define sk_rmem_alloc sk_backlog.rmem_alloc
419 
420 	int			sk_forward_alloc;
421 	u32			sk_reserved_mem;
422 #ifdef CONFIG_NET_RX_BUSY_POLL
423 	unsigned int		sk_ll_usec;
424 	/* ===== mostly read cache line ===== */
425 	unsigned int		sk_napi_id;
426 #endif
427 	int			sk_rcvbuf;
428 
429 	struct sk_filter __rcu	*sk_filter;
430 	union {
431 		struct socket_wq __rcu	*sk_wq;
432 		/* private: */
433 		struct socket_wq	*sk_wq_raw;
434 		/* public: */
435 	};
436 #ifdef CONFIG_XFRM
437 	struct xfrm_policy __rcu *sk_policy[2];
438 #endif
439 
440 	struct dst_entry __rcu	*sk_dst_cache;
441 	atomic_t		sk_omem_alloc;
442 	int			sk_sndbuf;
443 
444 	/* ===== cache line for TX ===== */
445 	int			sk_wmem_queued;
446 	refcount_t		sk_wmem_alloc;
447 	unsigned long		sk_tsq_flags;
448 	union {
449 		struct sk_buff	*sk_send_head;
450 		struct rb_root	tcp_rtx_queue;
451 	};
452 	struct sk_buff_head	sk_write_queue;
453 	__s32			sk_peek_off;
454 	int			sk_write_pending;
455 	__u32			sk_dst_pending_confirm;
456 	u32			sk_pacing_status; /* see enum sk_pacing */
457 	long			sk_sndtimeo;
458 	struct timer_list	sk_timer;
459 	__u32			sk_priority;
460 	__u32			sk_mark;
461 	unsigned long		sk_pacing_rate; /* bytes per second */
462 	unsigned long		sk_max_pacing_rate;
463 	struct page_frag	sk_frag;
464 	netdev_features_t	sk_route_caps;
465 	int			sk_gso_type;
466 	unsigned int		sk_gso_max_size;
467 	gfp_t			sk_allocation;
468 	__u32			sk_txhash;
469 
470 	/*
471 	 * Because of non atomicity rules, all
472 	 * changes are protected by socket lock.
473 	 */
474 	u8			sk_gso_disabled : 1,
475 				sk_kern_sock : 1,
476 				sk_no_check_tx : 1,
477 				sk_no_check_rx : 1,
478 				sk_userlocks : 4;
479 	u8			sk_pacing_shift;
480 	u16			sk_type;
481 	u16			sk_protocol;
482 	u16			sk_gso_max_segs;
483 	unsigned long	        sk_lingertime;
484 	struct proto		*sk_prot_creator;
485 	rwlock_t		sk_callback_lock;
486 	int			sk_err,
487 				sk_err_soft;
488 	u32			sk_ack_backlog;
489 	u32			sk_max_ack_backlog;
490 	kuid_t			sk_uid;
491 	u8			sk_txrehash;
492 #ifdef CONFIG_NET_RX_BUSY_POLL
493 	u8			sk_prefer_busy_poll;
494 	u16			sk_busy_poll_budget;
495 #endif
496 	spinlock_t		sk_peer_lock;
497 	int			sk_bind_phc;
498 	struct pid		*sk_peer_pid;
499 	const struct cred	*sk_peer_cred;
500 
501 	long			sk_rcvtimeo;
502 	ktime_t			sk_stamp;
503 #if BITS_PER_LONG==32
504 	seqlock_t		sk_stamp_seq;
505 #endif
506 	u16			sk_tsflags;
507 	u8			sk_shutdown;
508 	atomic_t		sk_tskey;
509 	atomic_t		sk_zckey;
510 
511 	u8			sk_clockid;
512 	u8			sk_txtime_deadline_mode : 1,
513 				sk_txtime_report_errors : 1,
514 				sk_txtime_unused : 6;
515 
516 	struct socket		*sk_socket;
517 	void			*sk_user_data;
518 #ifdef CONFIG_SECURITY
519 	void			*sk_security;
520 #endif
521 	struct sock_cgroup_data	sk_cgrp_data;
522 	struct mem_cgroup	*sk_memcg;
523 	void			(*sk_state_change)(struct sock *sk);
524 	void			(*sk_data_ready)(struct sock *sk);
525 	void			(*sk_write_space)(struct sock *sk);
526 	void			(*sk_error_report)(struct sock *sk);
527 	int			(*sk_backlog_rcv)(struct sock *sk,
528 						  struct sk_buff *skb);
529 #ifdef CONFIG_SOCK_VALIDATE_XMIT
530 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
531 							struct net_device *dev,
532 							struct sk_buff *skb);
533 #endif
534 	void                    (*sk_destruct)(struct sock *sk);
535 	struct sock_reuseport __rcu	*sk_reuseport_cb;
536 #ifdef CONFIG_BPF_SYSCALL
537 	struct bpf_local_storage __rcu	*sk_bpf_storage;
538 #endif
539 	struct rcu_head		sk_rcu;
540 	netns_tracker		ns_tracker;
541 	struct hlist_node	sk_bind2_node;
542 };
543 
544 enum sk_pacing {
545 	SK_PACING_NONE		= 0,
546 	SK_PACING_NEEDED	= 1,
547 	SK_PACING_FQ		= 2,
548 };
549 
550 /* flag bits in sk_user_data
551  *
552  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
553  *   not be suitable for copying when cloning the socket. For instance,
554  *   it can point to a reference counted object. sk_user_data bottom
555  *   bit is set if pointer must not be copied.
556  *
557  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
558  *   managed/owned by a BPF reuseport array. This bit should be set
559  *   when sk_user_data's sk is added to the bpf's reuseport_array.
560  *
561  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
562  *   sk_user_data points to psock type. This bit should be set
563  *   when sk_user_data is assigned to a psock object.
564  */
565 #define SK_USER_DATA_NOCOPY	1UL
566 #define SK_USER_DATA_BPF	2UL
567 #define SK_USER_DATA_PSOCK	4UL
568 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
569 				  SK_USER_DATA_PSOCK)
570 
571 /**
572  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
573  * @sk: socket
574  */
sk_user_data_is_nocopy(const struct sock * sk)575 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
576 {
577 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
578 }
579 
580 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
581 
582 /**
583  * __locked_read_sk_user_data_with_flags - return the pointer
584  * only if argument flags all has been set in sk_user_data. Otherwise
585  * return NULL
586  *
587  * @sk: socket
588  * @flags: flag bits
589  *
590  * The caller must be holding sk->sk_callback_lock.
591  */
592 static inline void *
__locked_read_sk_user_data_with_flags(const struct sock * sk,uintptr_t flags)593 __locked_read_sk_user_data_with_flags(const struct sock *sk,
594 				      uintptr_t flags)
595 {
596 	uintptr_t sk_user_data =
597 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
598 						 lockdep_is_held(&sk->sk_callback_lock));
599 
600 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
601 
602 	if ((sk_user_data & flags) == flags)
603 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
604 	return NULL;
605 }
606 
607 /**
608  * __rcu_dereference_sk_user_data_with_flags - return the pointer
609  * only if argument flags all has been set in sk_user_data. Otherwise
610  * return NULL
611  *
612  * @sk: socket
613  * @flags: flag bits
614  */
615 static inline void *
__rcu_dereference_sk_user_data_with_flags(const struct sock * sk,uintptr_t flags)616 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
617 					  uintptr_t flags)
618 {
619 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
620 
621 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
622 
623 	if ((sk_user_data & flags) == flags)
624 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
625 	return NULL;
626 }
627 
628 #define rcu_dereference_sk_user_data(sk)				\
629 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
630 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
631 ({									\
632 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
633 		  __tmp2 = (uintptr_t)(flags);				\
634 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
635 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
636 	rcu_assign_pointer(__sk_user_data((sk)),			\
637 			   __tmp1 | __tmp2);				\
638 })
639 #define rcu_assign_sk_user_data(sk, ptr)				\
640 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
641 
642 static inline
sock_net(const struct sock * sk)643 struct net *sock_net(const struct sock *sk)
644 {
645 	return read_pnet(&sk->sk_net);
646 }
647 
648 static inline
sock_net_set(struct sock * sk,struct net * net)649 void sock_net_set(struct sock *sk, struct net *net)
650 {
651 	write_pnet(&sk->sk_net, net);
652 }
653 
654 /*
655  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
656  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
657  * on a socket means that the socket will reuse everybody else's port
658  * without looking at the other's sk_reuse value.
659  */
660 
661 #define SK_NO_REUSE	0
662 #define SK_CAN_REUSE	1
663 #define SK_FORCE_REUSE	2
664 
665 int sk_set_peek_off(struct sock *sk, int val);
666 
sk_peek_offset(const struct sock * sk,int flags)667 static inline int sk_peek_offset(const struct sock *sk, int flags)
668 {
669 	if (unlikely(flags & MSG_PEEK)) {
670 		return READ_ONCE(sk->sk_peek_off);
671 	}
672 
673 	return 0;
674 }
675 
sk_peek_offset_bwd(struct sock * sk,int val)676 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
677 {
678 	s32 off = READ_ONCE(sk->sk_peek_off);
679 
680 	if (unlikely(off >= 0)) {
681 		off = max_t(s32, off - val, 0);
682 		WRITE_ONCE(sk->sk_peek_off, off);
683 	}
684 }
685 
sk_peek_offset_fwd(struct sock * sk,int val)686 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
687 {
688 	sk_peek_offset_bwd(sk, -val);
689 }
690 
691 /*
692  * Hashed lists helper routines
693  */
sk_entry(const struct hlist_node * node)694 static inline struct sock *sk_entry(const struct hlist_node *node)
695 {
696 	return hlist_entry(node, struct sock, sk_node);
697 }
698 
__sk_head(const struct hlist_head * head)699 static inline struct sock *__sk_head(const struct hlist_head *head)
700 {
701 	return hlist_entry(head->first, struct sock, sk_node);
702 }
703 
sk_head(const struct hlist_head * head)704 static inline struct sock *sk_head(const struct hlist_head *head)
705 {
706 	return hlist_empty(head) ? NULL : __sk_head(head);
707 }
708 
__sk_nulls_head(const struct hlist_nulls_head * head)709 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
710 {
711 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
712 }
713 
sk_nulls_head(const struct hlist_nulls_head * head)714 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
715 {
716 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
717 }
718 
sk_next(const struct sock * sk)719 static inline struct sock *sk_next(const struct sock *sk)
720 {
721 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
722 }
723 
sk_nulls_next(const struct sock * sk)724 static inline struct sock *sk_nulls_next(const struct sock *sk)
725 {
726 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
727 		hlist_nulls_entry(sk->sk_nulls_node.next,
728 				  struct sock, sk_nulls_node) :
729 		NULL;
730 }
731 
sk_unhashed(const struct sock * sk)732 static inline bool sk_unhashed(const struct sock *sk)
733 {
734 	return hlist_unhashed(&sk->sk_node);
735 }
736 
sk_hashed(const struct sock * sk)737 static inline bool sk_hashed(const struct sock *sk)
738 {
739 	return !sk_unhashed(sk);
740 }
741 
sk_node_init(struct hlist_node * node)742 static inline void sk_node_init(struct hlist_node *node)
743 {
744 	node->pprev = NULL;
745 }
746 
__sk_del_node(struct sock * sk)747 static inline void __sk_del_node(struct sock *sk)
748 {
749 	__hlist_del(&sk->sk_node);
750 }
751 
752 /* NB: equivalent to hlist_del_init_rcu */
__sk_del_node_init(struct sock * sk)753 static inline bool __sk_del_node_init(struct sock *sk)
754 {
755 	if (sk_hashed(sk)) {
756 		__sk_del_node(sk);
757 		sk_node_init(&sk->sk_node);
758 		return true;
759 	}
760 	return false;
761 }
762 
763 /* Grab socket reference count. This operation is valid only
764    when sk is ALREADY grabbed f.e. it is found in hash table
765    or a list and the lookup is made under lock preventing hash table
766    modifications.
767  */
768 
sock_hold(struct sock * sk)769 static __always_inline void sock_hold(struct sock *sk)
770 {
771 	refcount_inc(&sk->sk_refcnt);
772 }
773 
774 /* Ungrab socket in the context, which assumes that socket refcnt
775    cannot hit zero, f.e. it is true in context of any socketcall.
776  */
__sock_put(struct sock * sk)777 static __always_inline void __sock_put(struct sock *sk)
778 {
779 	refcount_dec(&sk->sk_refcnt);
780 }
781 
sk_del_node_init(struct sock * sk)782 static inline bool sk_del_node_init(struct sock *sk)
783 {
784 	bool rc = __sk_del_node_init(sk);
785 
786 	if (rc) {
787 		/* paranoid for a while -acme */
788 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
789 		__sock_put(sk);
790 	}
791 	return rc;
792 }
793 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
794 
__sk_nulls_del_node_init_rcu(struct sock * sk)795 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
796 {
797 	if (sk_hashed(sk)) {
798 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
799 		return true;
800 	}
801 	return false;
802 }
803 
sk_nulls_del_node_init_rcu(struct sock * sk)804 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
805 {
806 	bool rc = __sk_nulls_del_node_init_rcu(sk);
807 
808 	if (rc) {
809 		/* paranoid for a while -acme */
810 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
811 		__sock_put(sk);
812 	}
813 	return rc;
814 }
815 
__sk_add_node(struct sock * sk,struct hlist_head * list)816 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
817 {
818 	hlist_add_head(&sk->sk_node, list);
819 }
820 
sk_add_node(struct sock * sk,struct hlist_head * list)821 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
822 {
823 	sock_hold(sk);
824 	__sk_add_node(sk, list);
825 }
826 
sk_add_node_rcu(struct sock * sk,struct hlist_head * list)827 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
828 {
829 	sock_hold(sk);
830 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
831 	    sk->sk_family == AF_INET6)
832 		hlist_add_tail_rcu(&sk->sk_node, list);
833 	else
834 		hlist_add_head_rcu(&sk->sk_node, list);
835 }
836 
sk_add_node_tail_rcu(struct sock * sk,struct hlist_head * list)837 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
838 {
839 	sock_hold(sk);
840 	hlist_add_tail_rcu(&sk->sk_node, list);
841 }
842 
__sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)843 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
844 {
845 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
846 }
847 
__sk_nulls_add_node_tail_rcu(struct sock * sk,struct hlist_nulls_head * list)848 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
849 {
850 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
851 }
852 
sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)853 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
854 {
855 	sock_hold(sk);
856 	__sk_nulls_add_node_rcu(sk, list);
857 }
858 
__sk_del_bind_node(struct sock * sk)859 static inline void __sk_del_bind_node(struct sock *sk)
860 {
861 	__hlist_del(&sk->sk_bind_node);
862 }
863 
sk_add_bind_node(struct sock * sk,struct hlist_head * list)864 static inline void sk_add_bind_node(struct sock *sk,
865 					struct hlist_head *list)
866 {
867 	hlist_add_head(&sk->sk_bind_node, list);
868 }
869 
__sk_del_bind2_node(struct sock * sk)870 static inline void __sk_del_bind2_node(struct sock *sk)
871 {
872 	__hlist_del(&sk->sk_bind2_node);
873 }
874 
sk_add_bind2_node(struct sock * sk,struct hlist_head * list)875 static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
876 {
877 	hlist_add_head(&sk->sk_bind2_node, list);
878 }
879 
880 #define sk_for_each(__sk, list) \
881 	hlist_for_each_entry(__sk, list, sk_node)
882 #define sk_for_each_rcu(__sk, list) \
883 	hlist_for_each_entry_rcu(__sk, list, sk_node)
884 #define sk_nulls_for_each(__sk, node, list) \
885 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
886 #define sk_nulls_for_each_rcu(__sk, node, list) \
887 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
888 #define sk_for_each_from(__sk) \
889 	hlist_for_each_entry_from(__sk, sk_node)
890 #define sk_nulls_for_each_from(__sk, node) \
891 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
892 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
893 #define sk_for_each_safe(__sk, tmp, list) \
894 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
895 #define sk_for_each_bound(__sk, list) \
896 	hlist_for_each_entry(__sk, list, sk_bind_node)
897 #define sk_for_each_bound_bhash2(__sk, list) \
898 	hlist_for_each_entry(__sk, list, sk_bind2_node)
899 
900 /**
901  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
902  * @tpos:	the type * to use as a loop cursor.
903  * @pos:	the &struct hlist_node to use as a loop cursor.
904  * @head:	the head for your list.
905  * @offset:	offset of hlist_node within the struct.
906  *
907  */
908 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
909 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
910 	     pos != NULL &&						       \
911 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
912 	     pos = rcu_dereference(hlist_next_rcu(pos)))
913 
sk_user_ns(const struct sock * sk)914 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
915 {
916 	/* Careful only use this in a context where these parameters
917 	 * can not change and must all be valid, such as recvmsg from
918 	 * userspace.
919 	 */
920 	return sk->sk_socket->file->f_cred->user_ns;
921 }
922 
923 /* Sock flags */
924 enum sock_flags {
925 	SOCK_DEAD,
926 	SOCK_DONE,
927 	SOCK_URGINLINE,
928 	SOCK_KEEPOPEN,
929 	SOCK_LINGER,
930 	SOCK_DESTROY,
931 	SOCK_BROADCAST,
932 	SOCK_TIMESTAMP,
933 	SOCK_ZAPPED,
934 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
935 	SOCK_DBG, /* %SO_DEBUG setting */
936 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
937 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
938 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
939 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
940 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
941 	SOCK_FASYNC, /* fasync() active */
942 	SOCK_RXQ_OVFL,
943 	SOCK_ZEROCOPY, /* buffers from userspace */
944 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
945 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
946 		     * Will use last 4 bytes of packet sent from
947 		     * user-space instead.
948 		     */
949 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
950 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
951 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
952 	SOCK_TXTIME,
953 	SOCK_XDP, /* XDP is attached */
954 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
955 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
956 };
957 
958 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
959 
sock_copy_flags(struct sock * nsk,const struct sock * osk)960 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
961 {
962 	nsk->sk_flags = osk->sk_flags;
963 }
964 
sock_set_flag(struct sock * sk,enum sock_flags flag)965 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
966 {
967 	__set_bit(flag, &sk->sk_flags);
968 }
969 
sock_reset_flag(struct sock * sk,enum sock_flags flag)970 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
971 {
972 	__clear_bit(flag, &sk->sk_flags);
973 }
974 
sock_valbool_flag(struct sock * sk,enum sock_flags bit,int valbool)975 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
976 				     int valbool)
977 {
978 	if (valbool)
979 		sock_set_flag(sk, bit);
980 	else
981 		sock_reset_flag(sk, bit);
982 }
983 
sock_flag(const struct sock * sk,enum sock_flags flag)984 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
985 {
986 	return test_bit(flag, &sk->sk_flags);
987 }
988 
989 #ifdef CONFIG_NET
990 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
sk_memalloc_socks(void)991 static inline int sk_memalloc_socks(void)
992 {
993 	return static_branch_unlikely(&memalloc_socks_key);
994 }
995 
996 void __receive_sock(struct file *file);
997 #else
998 
sk_memalloc_socks(void)999 static inline int sk_memalloc_socks(void)
1000 {
1001 	return 0;
1002 }
1003 
__receive_sock(struct file * file)1004 static inline void __receive_sock(struct file *file)
1005 { }
1006 #endif
1007 
sk_gfp_mask(const struct sock * sk,gfp_t gfp_mask)1008 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1009 {
1010 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1011 }
1012 
sk_acceptq_removed(struct sock * sk)1013 static inline void sk_acceptq_removed(struct sock *sk)
1014 {
1015 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1016 }
1017 
sk_acceptq_added(struct sock * sk)1018 static inline void sk_acceptq_added(struct sock *sk)
1019 {
1020 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1021 }
1022 
1023 /* Note: If you think the test should be:
1024  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1025  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1026  */
sk_acceptq_is_full(const struct sock * sk)1027 static inline bool sk_acceptq_is_full(const struct sock *sk)
1028 {
1029 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1030 }
1031 
1032 /*
1033  * Compute minimal free write space needed to queue new packets.
1034  */
sk_stream_min_wspace(const struct sock * sk)1035 static inline int sk_stream_min_wspace(const struct sock *sk)
1036 {
1037 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1038 }
1039 
sk_stream_wspace(const struct sock * sk)1040 static inline int sk_stream_wspace(const struct sock *sk)
1041 {
1042 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1043 }
1044 
sk_wmem_queued_add(struct sock * sk,int val)1045 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1046 {
1047 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1048 }
1049 
1050 void sk_stream_write_space(struct sock *sk);
1051 
1052 /* OOB backlog add */
__sk_add_backlog(struct sock * sk,struct sk_buff * skb)1053 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1054 {
1055 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1056 	skb_dst_force(skb);
1057 
1058 	if (!sk->sk_backlog.tail)
1059 		WRITE_ONCE(sk->sk_backlog.head, skb);
1060 	else
1061 		sk->sk_backlog.tail->next = skb;
1062 
1063 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1064 	skb->next = NULL;
1065 }
1066 
1067 /*
1068  * Take into account size of receive queue and backlog queue
1069  * Do not take into account this skb truesize,
1070  * to allow even a single big packet to come.
1071  */
sk_rcvqueues_full(const struct sock * sk,unsigned int limit)1072 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1073 {
1074 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1075 
1076 	return qsize > limit;
1077 }
1078 
1079 /* The per-socket spinlock must be held here. */
sk_add_backlog(struct sock * sk,struct sk_buff * skb,unsigned int limit)1080 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1081 					      unsigned int limit)
1082 {
1083 	if (sk_rcvqueues_full(sk, limit))
1084 		return -ENOBUFS;
1085 
1086 	/*
1087 	 * If the skb was allocated from pfmemalloc reserves, only
1088 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1089 	 * helping free memory
1090 	 */
1091 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1092 		return -ENOMEM;
1093 
1094 	__sk_add_backlog(sk, skb);
1095 	sk->sk_backlog.len += skb->truesize;
1096 	return 0;
1097 }
1098 
1099 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1100 
1101 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1102 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1103 
sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)1104 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1105 {
1106 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1107 		return __sk_backlog_rcv(sk, skb);
1108 
1109 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1110 				  tcp_v6_do_rcv,
1111 				  tcp_v4_do_rcv,
1112 				  sk, skb);
1113 }
1114 
sk_incoming_cpu_update(struct sock * sk)1115 static inline void sk_incoming_cpu_update(struct sock *sk)
1116 {
1117 	int cpu = raw_smp_processor_id();
1118 
1119 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1120 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1121 }
1122 
sock_rps_record_flow_hash(__u32 hash)1123 static inline void sock_rps_record_flow_hash(__u32 hash)
1124 {
1125 #ifdef CONFIG_RPS
1126 	struct rps_sock_flow_table *sock_flow_table;
1127 
1128 	rcu_read_lock();
1129 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1130 	rps_record_sock_flow(sock_flow_table, hash);
1131 	rcu_read_unlock();
1132 #endif
1133 }
1134 
sock_rps_record_flow(const struct sock * sk)1135 static inline void sock_rps_record_flow(const struct sock *sk)
1136 {
1137 #ifdef CONFIG_RPS
1138 	if (static_branch_unlikely(&rfs_needed)) {
1139 		/* Reading sk->sk_rxhash might incur an expensive cache line
1140 		 * miss.
1141 		 *
1142 		 * TCP_ESTABLISHED does cover almost all states where RFS
1143 		 * might be useful, and is cheaper [1] than testing :
1144 		 *	IPv4: inet_sk(sk)->inet_daddr
1145 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1146 		 * OR	an additional socket flag
1147 		 * [1] : sk_state and sk_prot are in the same cache line.
1148 		 */
1149 		if (sk->sk_state == TCP_ESTABLISHED)
1150 			sock_rps_record_flow_hash(sk->sk_rxhash);
1151 	}
1152 #endif
1153 }
1154 
sock_rps_save_rxhash(struct sock * sk,const struct sk_buff * skb)1155 static inline void sock_rps_save_rxhash(struct sock *sk,
1156 					const struct sk_buff *skb)
1157 {
1158 #ifdef CONFIG_RPS
1159 	if (unlikely(sk->sk_rxhash != skb->hash))
1160 		sk->sk_rxhash = skb->hash;
1161 #endif
1162 }
1163 
sock_rps_reset_rxhash(struct sock * sk)1164 static inline void sock_rps_reset_rxhash(struct sock *sk)
1165 {
1166 #ifdef CONFIG_RPS
1167 	sk->sk_rxhash = 0;
1168 #endif
1169 }
1170 
1171 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1172 	({	int __rc;						\
1173 		release_sock(__sk);					\
1174 		__rc = __condition;					\
1175 		if (!__rc) {						\
1176 			*(__timeo) = wait_woken(__wait,			\
1177 						TASK_INTERRUPTIBLE,	\
1178 						*(__timeo));		\
1179 		}							\
1180 		sched_annotate_sleep();					\
1181 		lock_sock(__sk);					\
1182 		__rc = __condition;					\
1183 		__rc;							\
1184 	})
1185 
1186 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1187 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1188 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1189 int sk_stream_error(struct sock *sk, int flags, int err);
1190 void sk_stream_kill_queues(struct sock *sk);
1191 void sk_set_memalloc(struct sock *sk);
1192 void sk_clear_memalloc(struct sock *sk);
1193 
1194 void __sk_flush_backlog(struct sock *sk);
1195 
sk_flush_backlog(struct sock * sk)1196 static inline bool sk_flush_backlog(struct sock *sk)
1197 {
1198 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1199 		__sk_flush_backlog(sk);
1200 		return true;
1201 	}
1202 	return false;
1203 }
1204 
1205 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1206 
1207 struct request_sock_ops;
1208 struct timewait_sock_ops;
1209 struct inet_hashinfo;
1210 struct raw_hashinfo;
1211 struct smc_hashinfo;
1212 struct module;
1213 struct sk_psock;
1214 
1215 /*
1216  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1217  * un-modified. Special care is taken when initializing object to zero.
1218  */
sk_prot_clear_nulls(struct sock * sk,int size)1219 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1220 {
1221 	if (offsetof(struct sock, sk_node.next) != 0)
1222 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1223 	memset(&sk->sk_node.pprev, 0,
1224 	       size - offsetof(struct sock, sk_node.pprev));
1225 }
1226 
1227 /* Networking protocol blocks we attach to sockets.
1228  * socket layer -> transport layer interface
1229  */
1230 struct proto {
1231 	void			(*close)(struct sock *sk,
1232 					long timeout);
1233 	int			(*pre_connect)(struct sock *sk,
1234 					struct sockaddr *uaddr,
1235 					int addr_len);
1236 	int			(*connect)(struct sock *sk,
1237 					struct sockaddr *uaddr,
1238 					int addr_len);
1239 	int			(*disconnect)(struct sock *sk, int flags);
1240 
1241 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1242 					  bool kern);
1243 
1244 	int			(*ioctl)(struct sock *sk, int cmd,
1245 					 unsigned long arg);
1246 	int			(*init)(struct sock *sk);
1247 	void			(*destroy)(struct sock *sk);
1248 	void			(*shutdown)(struct sock *sk, int how);
1249 	int			(*setsockopt)(struct sock *sk, int level,
1250 					int optname, sockptr_t optval,
1251 					unsigned int optlen);
1252 	int			(*getsockopt)(struct sock *sk, int level,
1253 					int optname, char __user *optval,
1254 					int __user *option);
1255 	void			(*keepalive)(struct sock *sk, int valbool);
1256 #ifdef CONFIG_COMPAT
1257 	int			(*compat_ioctl)(struct sock *sk,
1258 					unsigned int cmd, unsigned long arg);
1259 #endif
1260 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1261 					   size_t len);
1262 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1263 					   size_t len, int flags, int *addr_len);
1264 	int			(*sendpage)(struct sock *sk, struct page *page,
1265 					int offset, size_t size, int flags);
1266 	int			(*bind)(struct sock *sk,
1267 					struct sockaddr *addr, int addr_len);
1268 	int			(*bind_add)(struct sock *sk,
1269 					struct sockaddr *addr, int addr_len);
1270 
1271 	int			(*backlog_rcv) (struct sock *sk,
1272 						struct sk_buff *skb);
1273 	bool			(*bpf_bypass_getsockopt)(int level,
1274 							 int optname);
1275 
1276 	void		(*release_cb)(struct sock *sk);
1277 
1278 	/* Keeping track of sk's, looking them up, and port selection methods. */
1279 	int			(*hash)(struct sock *sk);
1280 	void			(*unhash)(struct sock *sk);
1281 	void			(*rehash)(struct sock *sk);
1282 	int			(*get_port)(struct sock *sk, unsigned short snum);
1283 	void			(*put_port)(struct sock *sk);
1284 #ifdef CONFIG_BPF_SYSCALL
1285 	int			(*psock_update_sk_prot)(struct sock *sk,
1286 							struct sk_psock *psock,
1287 							bool restore);
1288 #endif
1289 
1290 	/* Keeping track of sockets in use */
1291 #ifdef CONFIG_PROC_FS
1292 	unsigned int		inuse_idx;
1293 #endif
1294 
1295 #if IS_ENABLED(CONFIG_MPTCP)
1296 	int			(*forward_alloc_get)(const struct sock *sk);
1297 #endif
1298 
1299 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1300 	bool			(*sock_is_readable)(struct sock *sk);
1301 	/* Memory pressure */
1302 	void			(*enter_memory_pressure)(struct sock *sk);
1303 	void			(*leave_memory_pressure)(struct sock *sk);
1304 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1305 	int  __percpu		*per_cpu_fw_alloc;
1306 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1307 
1308 	/*
1309 	 * Pressure flag: try to collapse.
1310 	 * Technical note: it is used by multiple contexts non atomically.
1311 	 * All the __sk_mem_schedule() is of this nature: accounting
1312 	 * is strict, actions are advisory and have some latency.
1313 	 */
1314 	unsigned long		*memory_pressure;
1315 	long			*sysctl_mem;
1316 
1317 	int			*sysctl_wmem;
1318 	int			*sysctl_rmem;
1319 	u32			sysctl_wmem_offset;
1320 	u32			sysctl_rmem_offset;
1321 
1322 	int			max_header;
1323 	bool			no_autobind;
1324 
1325 	struct kmem_cache	*slab;
1326 	unsigned int		obj_size;
1327 	slab_flags_t		slab_flags;
1328 	unsigned int		useroffset;	/* Usercopy region offset */
1329 	unsigned int		usersize;	/* Usercopy region size */
1330 
1331 	unsigned int __percpu	*orphan_count;
1332 
1333 	struct request_sock_ops	*rsk_prot;
1334 	struct timewait_sock_ops *twsk_prot;
1335 
1336 	union {
1337 		struct inet_hashinfo	*hashinfo;
1338 		struct udp_table	*udp_table;
1339 		struct raw_hashinfo	*raw_hash;
1340 		struct smc_hashinfo	*smc_hash;
1341 	} h;
1342 
1343 	struct module		*owner;
1344 
1345 	char			name[32];
1346 
1347 	struct list_head	node;
1348 #ifdef SOCK_REFCNT_DEBUG
1349 	atomic_t		socks;
1350 #endif
1351 	int			(*diag_destroy)(struct sock *sk, int err);
1352 } __randomize_layout;
1353 
1354 int proto_register(struct proto *prot, int alloc_slab);
1355 void proto_unregister(struct proto *prot);
1356 int sock_load_diag_module(int family, int protocol);
1357 
1358 #ifdef SOCK_REFCNT_DEBUG
sk_refcnt_debug_inc(struct sock * sk)1359 static inline void sk_refcnt_debug_inc(struct sock *sk)
1360 {
1361 	atomic_inc(&sk->sk_prot->socks);
1362 }
1363 
sk_refcnt_debug_dec(struct sock * sk)1364 static inline void sk_refcnt_debug_dec(struct sock *sk)
1365 {
1366 	atomic_dec(&sk->sk_prot->socks);
1367 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1368 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1369 }
1370 
sk_refcnt_debug_release(const struct sock * sk)1371 static inline void sk_refcnt_debug_release(const struct sock *sk)
1372 {
1373 	if (refcount_read(&sk->sk_refcnt) != 1)
1374 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1375 		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1376 }
1377 #else /* SOCK_REFCNT_DEBUG */
1378 #define sk_refcnt_debug_inc(sk) do { } while (0)
1379 #define sk_refcnt_debug_dec(sk) do { } while (0)
1380 #define sk_refcnt_debug_release(sk) do { } while (0)
1381 #endif /* SOCK_REFCNT_DEBUG */
1382 
1383 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1384 
sk_forward_alloc_get(const struct sock * sk)1385 static inline int sk_forward_alloc_get(const struct sock *sk)
1386 {
1387 #if IS_ENABLED(CONFIG_MPTCP)
1388 	if (sk->sk_prot->forward_alloc_get)
1389 		return sk->sk_prot->forward_alloc_get(sk);
1390 #endif
1391 	return sk->sk_forward_alloc;
1392 }
1393 
__sk_stream_memory_free(const struct sock * sk,int wake)1394 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1395 {
1396 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1397 		return false;
1398 
1399 	return sk->sk_prot->stream_memory_free ?
1400 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1401 				     tcp_stream_memory_free, sk, wake) : true;
1402 }
1403 
sk_stream_memory_free(const struct sock * sk)1404 static inline bool sk_stream_memory_free(const struct sock *sk)
1405 {
1406 	return __sk_stream_memory_free(sk, 0);
1407 }
1408 
__sk_stream_is_writeable(const struct sock * sk,int wake)1409 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1410 {
1411 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1412 	       __sk_stream_memory_free(sk, wake);
1413 }
1414 
sk_stream_is_writeable(const struct sock * sk)1415 static inline bool sk_stream_is_writeable(const struct sock *sk)
1416 {
1417 	return __sk_stream_is_writeable(sk, 0);
1418 }
1419 
sk_under_cgroup_hierarchy(struct sock * sk,struct cgroup * ancestor)1420 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1421 					    struct cgroup *ancestor)
1422 {
1423 #ifdef CONFIG_SOCK_CGROUP_DATA
1424 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1425 				    ancestor);
1426 #else
1427 	return -ENOTSUPP;
1428 #endif
1429 }
1430 
sk_has_memory_pressure(const struct sock * sk)1431 static inline bool sk_has_memory_pressure(const struct sock *sk)
1432 {
1433 	return sk->sk_prot->memory_pressure != NULL;
1434 }
1435 
sk_under_memory_pressure(const struct sock * sk)1436 static inline bool sk_under_memory_pressure(const struct sock *sk)
1437 {
1438 	if (!sk->sk_prot->memory_pressure)
1439 		return false;
1440 
1441 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1442 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1443 		return true;
1444 
1445 	return !!*sk->sk_prot->memory_pressure;
1446 }
1447 
1448 static inline long
proto_memory_allocated(const struct proto * prot)1449 proto_memory_allocated(const struct proto *prot)
1450 {
1451 	return max(0L, atomic_long_read(prot->memory_allocated));
1452 }
1453 
1454 static inline long
sk_memory_allocated(const struct sock * sk)1455 sk_memory_allocated(const struct sock *sk)
1456 {
1457 	return proto_memory_allocated(sk->sk_prot);
1458 }
1459 
1460 /* 1 MB per cpu, in page units */
1461 #define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT))
1462 
1463 static inline void
sk_memory_allocated_add(struct sock * sk,int amt)1464 sk_memory_allocated_add(struct sock *sk, int amt)
1465 {
1466 	int local_reserve;
1467 
1468 	preempt_disable();
1469 	local_reserve = __this_cpu_add_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1470 	if (local_reserve >= SK_MEMORY_PCPU_RESERVE) {
1471 		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1472 		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1473 	}
1474 	preempt_enable();
1475 }
1476 
1477 static inline void
sk_memory_allocated_sub(struct sock * sk,int amt)1478 sk_memory_allocated_sub(struct sock *sk, int amt)
1479 {
1480 	int local_reserve;
1481 
1482 	preempt_disable();
1483 	local_reserve = __this_cpu_sub_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1484 	if (local_reserve <= -SK_MEMORY_PCPU_RESERVE) {
1485 		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1486 		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1487 	}
1488 	preempt_enable();
1489 }
1490 
1491 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1492 
sk_sockets_allocated_dec(struct sock * sk)1493 static inline void sk_sockets_allocated_dec(struct sock *sk)
1494 {
1495 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1496 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1497 }
1498 
sk_sockets_allocated_inc(struct sock * sk)1499 static inline void sk_sockets_allocated_inc(struct sock *sk)
1500 {
1501 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1502 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1503 }
1504 
1505 static inline u64
sk_sockets_allocated_read_positive(struct sock * sk)1506 sk_sockets_allocated_read_positive(struct sock *sk)
1507 {
1508 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1509 }
1510 
1511 static inline int
proto_sockets_allocated_sum_positive(struct proto * prot)1512 proto_sockets_allocated_sum_positive(struct proto *prot)
1513 {
1514 	return percpu_counter_sum_positive(prot->sockets_allocated);
1515 }
1516 
1517 static inline bool
proto_memory_pressure(struct proto * prot)1518 proto_memory_pressure(struct proto *prot)
1519 {
1520 	if (!prot->memory_pressure)
1521 		return false;
1522 	return !!*prot->memory_pressure;
1523 }
1524 
1525 
1526 #ifdef CONFIG_PROC_FS
1527 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1528 struct prot_inuse {
1529 	int all;
1530 	int val[PROTO_INUSE_NR];
1531 };
1532 
sock_prot_inuse_add(const struct net * net,const struct proto * prot,int val)1533 static inline void sock_prot_inuse_add(const struct net *net,
1534 				       const struct proto *prot, int val)
1535 {
1536 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1537 }
1538 
sock_inuse_add(const struct net * net,int val)1539 static inline void sock_inuse_add(const struct net *net, int val)
1540 {
1541 	this_cpu_add(net->core.prot_inuse->all, val);
1542 }
1543 
1544 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1545 int sock_inuse_get(struct net *net);
1546 #else
sock_prot_inuse_add(const struct net * net,const struct proto * prot,int val)1547 static inline void sock_prot_inuse_add(const struct net *net,
1548 				       const struct proto *prot, int val)
1549 {
1550 }
1551 
sock_inuse_add(const struct net * net,int val)1552 static inline void sock_inuse_add(const struct net *net, int val)
1553 {
1554 }
1555 #endif
1556 
1557 
1558 /* With per-bucket locks this operation is not-atomic, so that
1559  * this version is not worse.
1560  */
__sk_prot_rehash(struct sock * sk)1561 static inline int __sk_prot_rehash(struct sock *sk)
1562 {
1563 	sk->sk_prot->unhash(sk);
1564 	return sk->sk_prot->hash(sk);
1565 }
1566 
1567 /* About 10 seconds */
1568 #define SOCK_DESTROY_TIME (10*HZ)
1569 
1570 /* Sockets 0-1023 can't be bound to unless you are superuser */
1571 #define PROT_SOCK	1024
1572 
1573 #define SHUTDOWN_MASK	3
1574 #define RCV_SHUTDOWN	1
1575 #define SEND_SHUTDOWN	2
1576 
1577 #define SOCK_BINDADDR_LOCK	4
1578 #define SOCK_BINDPORT_LOCK	8
1579 
1580 struct socket_alloc {
1581 	struct socket socket;
1582 	struct inode vfs_inode;
1583 };
1584 
SOCKET_I(struct inode * inode)1585 static inline struct socket *SOCKET_I(struct inode *inode)
1586 {
1587 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1588 }
1589 
SOCK_INODE(struct socket * socket)1590 static inline struct inode *SOCK_INODE(struct socket *socket)
1591 {
1592 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1593 }
1594 
1595 /*
1596  * Functions for memory accounting
1597  */
1598 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1599 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1600 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1601 void __sk_mem_reclaim(struct sock *sk, int amount);
1602 
1603 #define SK_MEM_SEND	0
1604 #define SK_MEM_RECV	1
1605 
1606 /* sysctl_mem values are in pages */
sk_prot_mem_limits(const struct sock * sk,int index)1607 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1608 {
1609 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1610 }
1611 
sk_mem_pages(int amt)1612 static inline int sk_mem_pages(int amt)
1613 {
1614 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1615 }
1616 
sk_has_account(struct sock * sk)1617 static inline bool sk_has_account(struct sock *sk)
1618 {
1619 	/* return true if protocol supports memory accounting */
1620 	return !!sk->sk_prot->memory_allocated;
1621 }
1622 
sk_wmem_schedule(struct sock * sk,int size)1623 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1624 {
1625 	int delta;
1626 
1627 	if (!sk_has_account(sk))
1628 		return true;
1629 	delta = size - sk->sk_forward_alloc;
1630 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1631 }
1632 
1633 static inline bool
sk_rmem_schedule(struct sock * sk,struct sk_buff * skb,int size)1634 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1635 {
1636 	int delta;
1637 
1638 	if (!sk_has_account(sk))
1639 		return true;
1640 	delta = size - sk->sk_forward_alloc;
1641 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1642 		skb_pfmemalloc(skb);
1643 }
1644 
sk_unused_reserved_mem(const struct sock * sk)1645 static inline int sk_unused_reserved_mem(const struct sock *sk)
1646 {
1647 	int unused_mem;
1648 
1649 	if (likely(!sk->sk_reserved_mem))
1650 		return 0;
1651 
1652 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1653 			atomic_read(&sk->sk_rmem_alloc);
1654 
1655 	return unused_mem > 0 ? unused_mem : 0;
1656 }
1657 
sk_mem_reclaim(struct sock * sk)1658 static inline void sk_mem_reclaim(struct sock *sk)
1659 {
1660 	int reclaimable;
1661 
1662 	if (!sk_has_account(sk))
1663 		return;
1664 
1665 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1666 
1667 	if (reclaimable >= (int)PAGE_SIZE)
1668 		__sk_mem_reclaim(sk, reclaimable);
1669 }
1670 
sk_mem_reclaim_final(struct sock * sk)1671 static inline void sk_mem_reclaim_final(struct sock *sk)
1672 {
1673 	sk->sk_reserved_mem = 0;
1674 	sk_mem_reclaim(sk);
1675 }
1676 
sk_mem_charge(struct sock * sk,int size)1677 static inline void sk_mem_charge(struct sock *sk, int size)
1678 {
1679 	if (!sk_has_account(sk))
1680 		return;
1681 	sk->sk_forward_alloc -= size;
1682 }
1683 
sk_mem_uncharge(struct sock * sk,int size)1684 static inline void sk_mem_uncharge(struct sock *sk, int size)
1685 {
1686 	if (!sk_has_account(sk))
1687 		return;
1688 	sk->sk_forward_alloc += size;
1689 	sk_mem_reclaim(sk);
1690 }
1691 
1692 /*
1693  * Macro so as to not evaluate some arguments when
1694  * lockdep is not enabled.
1695  *
1696  * Mark both the sk_lock and the sk_lock.slock as a
1697  * per-address-family lock class.
1698  */
1699 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1700 do {									\
1701 	sk->sk_lock.owned = 0;						\
1702 	init_waitqueue_head(&sk->sk_lock.wq);				\
1703 	spin_lock_init(&(sk)->sk_lock.slock);				\
1704 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1705 			sizeof((sk)->sk_lock));				\
1706 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1707 				(skey), (sname));				\
1708 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1709 } while (0)
1710 
lockdep_sock_is_held(const struct sock * sk)1711 static inline bool lockdep_sock_is_held(const struct sock *sk)
1712 {
1713 	return lockdep_is_held(&sk->sk_lock) ||
1714 	       lockdep_is_held(&sk->sk_lock.slock);
1715 }
1716 
1717 void lock_sock_nested(struct sock *sk, int subclass);
1718 
lock_sock(struct sock * sk)1719 static inline void lock_sock(struct sock *sk)
1720 {
1721 	lock_sock_nested(sk, 0);
1722 }
1723 
1724 void __lock_sock(struct sock *sk);
1725 void __release_sock(struct sock *sk);
1726 void release_sock(struct sock *sk);
1727 
1728 /* BH context may only use the following locking interface. */
1729 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1730 #define bh_lock_sock_nested(__sk) \
1731 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1732 				SINGLE_DEPTH_NESTING)
1733 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1734 
1735 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1736 
1737 /**
1738  * lock_sock_fast - fast version of lock_sock
1739  * @sk: socket
1740  *
1741  * This version should be used for very small section, where process wont block
1742  * return false if fast path is taken:
1743  *
1744  *   sk_lock.slock locked, owned = 0, BH disabled
1745  *
1746  * return true if slow path is taken:
1747  *
1748  *   sk_lock.slock unlocked, owned = 1, BH enabled
1749  */
lock_sock_fast(struct sock * sk)1750 static inline bool lock_sock_fast(struct sock *sk)
1751 {
1752 	/* The sk_lock has mutex_lock() semantics here. */
1753 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1754 
1755 	return __lock_sock_fast(sk);
1756 }
1757 
1758 /* fast socket lock variant for caller already holding a [different] socket lock */
lock_sock_fast_nested(struct sock * sk)1759 static inline bool lock_sock_fast_nested(struct sock *sk)
1760 {
1761 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1762 
1763 	return __lock_sock_fast(sk);
1764 }
1765 
1766 /**
1767  * unlock_sock_fast - complement of lock_sock_fast
1768  * @sk: socket
1769  * @slow: slow mode
1770  *
1771  * fast unlock socket for user context.
1772  * If slow mode is on, we call regular release_sock()
1773  */
unlock_sock_fast(struct sock * sk,bool slow)1774 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1775 	__releases(&sk->sk_lock.slock)
1776 {
1777 	if (slow) {
1778 		release_sock(sk);
1779 		__release(&sk->sk_lock.slock);
1780 	} else {
1781 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1782 		spin_unlock_bh(&sk->sk_lock.slock);
1783 	}
1784 }
1785 
1786 void sockopt_lock_sock(struct sock *sk);
1787 void sockopt_release_sock(struct sock *sk);
1788 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1789 bool sockopt_capable(int cap);
1790 
1791 /* Used by processes to "lock" a socket state, so that
1792  * interrupts and bottom half handlers won't change it
1793  * from under us. It essentially blocks any incoming
1794  * packets, so that we won't get any new data or any
1795  * packets that change the state of the socket.
1796  *
1797  * While locked, BH processing will add new packets to
1798  * the backlog queue.  This queue is processed by the
1799  * owner of the socket lock right before it is released.
1800  *
1801  * Since ~2.3.5 it is also exclusive sleep lock serializing
1802  * accesses from user process context.
1803  */
1804 
sock_owned_by_me(const struct sock * sk)1805 static inline void sock_owned_by_me(const struct sock *sk)
1806 {
1807 #ifdef CONFIG_LOCKDEP
1808 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1809 #endif
1810 }
1811 
sock_owned_by_user(const struct sock * sk)1812 static inline bool sock_owned_by_user(const struct sock *sk)
1813 {
1814 	sock_owned_by_me(sk);
1815 	return sk->sk_lock.owned;
1816 }
1817 
sock_owned_by_user_nocheck(const struct sock * sk)1818 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1819 {
1820 	return sk->sk_lock.owned;
1821 }
1822 
sock_release_ownership(struct sock * sk)1823 static inline void sock_release_ownership(struct sock *sk)
1824 {
1825 	if (sock_owned_by_user_nocheck(sk)) {
1826 		sk->sk_lock.owned = 0;
1827 
1828 		/* The sk_lock has mutex_unlock() semantics: */
1829 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1830 	}
1831 }
1832 
1833 /* no reclassification while locks are held */
sock_allow_reclassification(const struct sock * csk)1834 static inline bool sock_allow_reclassification(const struct sock *csk)
1835 {
1836 	struct sock *sk = (struct sock *)csk;
1837 
1838 	return !sock_owned_by_user_nocheck(sk) &&
1839 		!spin_is_locked(&sk->sk_lock.slock);
1840 }
1841 
1842 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1843 		      struct proto *prot, int kern);
1844 void sk_free(struct sock *sk);
1845 void sk_destruct(struct sock *sk);
1846 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1847 void sk_free_unlock_clone(struct sock *sk);
1848 
1849 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1850 			     gfp_t priority);
1851 void __sock_wfree(struct sk_buff *skb);
1852 void sock_wfree(struct sk_buff *skb);
1853 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1854 			     gfp_t priority);
1855 void skb_orphan_partial(struct sk_buff *skb);
1856 void sock_rfree(struct sk_buff *skb);
1857 void sock_efree(struct sk_buff *skb);
1858 #ifdef CONFIG_INET
1859 void sock_edemux(struct sk_buff *skb);
1860 void sock_pfree(struct sk_buff *skb);
1861 #else
1862 #define sock_edemux sock_efree
1863 #endif
1864 
1865 int sk_setsockopt(struct sock *sk, int level, int optname,
1866 		  sockptr_t optval, unsigned int optlen);
1867 int sock_setsockopt(struct socket *sock, int level, int op,
1868 		    sockptr_t optval, unsigned int optlen);
1869 
1870 int sk_getsockopt(struct sock *sk, int level, int optname,
1871 		  sockptr_t optval, sockptr_t optlen);
1872 int sock_getsockopt(struct socket *sock, int level, int op,
1873 		    char __user *optval, int __user *optlen);
1874 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1875 		   bool timeval, bool time32);
1876 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1877 				     unsigned long data_len, int noblock,
1878 				     int *errcode, int max_page_order);
1879 
sock_alloc_send_skb(struct sock * sk,unsigned long size,int noblock,int * errcode)1880 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1881 						  unsigned long size,
1882 						  int noblock, int *errcode)
1883 {
1884 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1885 }
1886 
1887 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1888 void sock_kfree_s(struct sock *sk, void *mem, int size);
1889 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1890 void sk_send_sigurg(struct sock *sk);
1891 
sock_replace_proto(struct sock * sk,struct proto * proto)1892 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1893 {
1894 	if (sk->sk_socket)
1895 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1896 	WRITE_ONCE(sk->sk_prot, proto);
1897 }
1898 
1899 struct sockcm_cookie {
1900 	u64 transmit_time;
1901 	u32 mark;
1902 	u16 tsflags;
1903 };
1904 
sockcm_init(struct sockcm_cookie * sockc,const struct sock * sk)1905 static inline void sockcm_init(struct sockcm_cookie *sockc,
1906 			       const struct sock *sk)
1907 {
1908 	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1909 }
1910 
1911 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1912 		     struct sockcm_cookie *sockc);
1913 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1914 		   struct sockcm_cookie *sockc);
1915 
1916 /*
1917  * Functions to fill in entries in struct proto_ops when a protocol
1918  * does not implement a particular function.
1919  */
1920 int sock_no_bind(struct socket *, struct sockaddr *, int);
1921 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1922 int sock_no_socketpair(struct socket *, struct socket *);
1923 int sock_no_accept(struct socket *, struct socket *, int, bool);
1924 int sock_no_getname(struct socket *, struct sockaddr *, int);
1925 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1926 int sock_no_listen(struct socket *, int);
1927 int sock_no_shutdown(struct socket *, int);
1928 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1929 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1930 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1931 int sock_no_mmap(struct file *file, struct socket *sock,
1932 		 struct vm_area_struct *vma);
1933 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1934 			 size_t size, int flags);
1935 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1936 				int offset, size_t size, int flags);
1937 
1938 /*
1939  * Functions to fill in entries in struct proto_ops when a protocol
1940  * uses the inet style.
1941  */
1942 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1943 				  char __user *optval, int __user *optlen);
1944 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1945 			int flags);
1946 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1947 			   sockptr_t optval, unsigned int optlen);
1948 
1949 void sk_common_release(struct sock *sk);
1950 
1951 /*
1952  *	Default socket callbacks and setup code
1953  */
1954 
1955 /* Initialise core socket variables */
1956 void sock_init_data(struct socket *sock, struct sock *sk);
1957 
1958 /*
1959  * Socket reference counting postulates.
1960  *
1961  * * Each user of socket SHOULD hold a reference count.
1962  * * Each access point to socket (an hash table bucket, reference from a list,
1963  *   running timer, skb in flight MUST hold a reference count.
1964  * * When reference count hits 0, it means it will never increase back.
1965  * * When reference count hits 0, it means that no references from
1966  *   outside exist to this socket and current process on current CPU
1967  *   is last user and may/should destroy this socket.
1968  * * sk_free is called from any context: process, BH, IRQ. When
1969  *   it is called, socket has no references from outside -> sk_free
1970  *   may release descendant resources allocated by the socket, but
1971  *   to the time when it is called, socket is NOT referenced by any
1972  *   hash tables, lists etc.
1973  * * Packets, delivered from outside (from network or from another process)
1974  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1975  *   when they sit in queue. Otherwise, packets will leak to hole, when
1976  *   socket is looked up by one cpu and unhasing is made by another CPU.
1977  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1978  *   (leak to backlog). Packet socket does all the processing inside
1979  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1980  *   use separate SMP lock, so that they are prone too.
1981  */
1982 
1983 /* Ungrab socket and destroy it, if it was the last reference. */
sock_put(struct sock * sk)1984 static inline void sock_put(struct sock *sk)
1985 {
1986 	if (refcount_dec_and_test(&sk->sk_refcnt))
1987 		sk_free(sk);
1988 }
1989 /* Generic version of sock_put(), dealing with all sockets
1990  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1991  */
1992 void sock_gen_put(struct sock *sk);
1993 
1994 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1995 		     unsigned int trim_cap, bool refcounted);
sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested)1996 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1997 				 const int nested)
1998 {
1999 	return __sk_receive_skb(sk, skb, nested, 1, true);
2000 }
2001 
sk_tx_queue_set(struct sock * sk,int tx_queue)2002 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
2003 {
2004 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
2005 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
2006 		return;
2007 	sk->sk_tx_queue_mapping = tx_queue;
2008 }
2009 
2010 #define NO_QUEUE_MAPPING	USHRT_MAX
2011 
sk_tx_queue_clear(struct sock * sk)2012 static inline void sk_tx_queue_clear(struct sock *sk)
2013 {
2014 	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
2015 }
2016 
sk_tx_queue_get(const struct sock * sk)2017 static inline int sk_tx_queue_get(const struct sock *sk)
2018 {
2019 	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
2020 		return sk->sk_tx_queue_mapping;
2021 
2022 	return -1;
2023 }
2024 
__sk_rx_queue_set(struct sock * sk,const struct sk_buff * skb,bool force_set)2025 static inline void __sk_rx_queue_set(struct sock *sk,
2026 				     const struct sk_buff *skb,
2027 				     bool force_set)
2028 {
2029 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2030 	if (skb_rx_queue_recorded(skb)) {
2031 		u16 rx_queue = skb_get_rx_queue(skb);
2032 
2033 		if (force_set ||
2034 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2035 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2036 	}
2037 #endif
2038 }
2039 
sk_rx_queue_set(struct sock * sk,const struct sk_buff * skb)2040 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2041 {
2042 	__sk_rx_queue_set(sk, skb, true);
2043 }
2044 
sk_rx_queue_update(struct sock * sk,const struct sk_buff * skb)2045 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2046 {
2047 	__sk_rx_queue_set(sk, skb, false);
2048 }
2049 
sk_rx_queue_clear(struct sock * sk)2050 static inline void sk_rx_queue_clear(struct sock *sk)
2051 {
2052 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2053 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2054 #endif
2055 }
2056 
sk_rx_queue_get(const struct sock * sk)2057 static inline int sk_rx_queue_get(const struct sock *sk)
2058 {
2059 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2060 	if (sk) {
2061 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2062 
2063 		if (res != NO_QUEUE_MAPPING)
2064 			return res;
2065 	}
2066 #endif
2067 
2068 	return -1;
2069 }
2070 
sk_set_socket(struct sock * sk,struct socket * sock)2071 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2072 {
2073 	sk->sk_socket = sock;
2074 }
2075 
sk_sleep(struct sock * sk)2076 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2077 {
2078 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2079 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2080 }
2081 /* Detach socket from process context.
2082  * Announce socket dead, detach it from wait queue and inode.
2083  * Note that parent inode held reference count on this struct sock,
2084  * we do not release it in this function, because protocol
2085  * probably wants some additional cleanups or even continuing
2086  * to work with this socket (TCP).
2087  */
sock_orphan(struct sock * sk)2088 static inline void sock_orphan(struct sock *sk)
2089 {
2090 	write_lock_bh(&sk->sk_callback_lock);
2091 	sock_set_flag(sk, SOCK_DEAD);
2092 	sk_set_socket(sk, NULL);
2093 	sk->sk_wq  = NULL;
2094 	write_unlock_bh(&sk->sk_callback_lock);
2095 }
2096 
sock_graft(struct sock * sk,struct socket * parent)2097 static inline void sock_graft(struct sock *sk, struct socket *parent)
2098 {
2099 	WARN_ON(parent->sk);
2100 	write_lock_bh(&sk->sk_callback_lock);
2101 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2102 	parent->sk = sk;
2103 	sk_set_socket(sk, parent);
2104 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
2105 	security_sock_graft(sk, parent);
2106 	write_unlock_bh(&sk->sk_callback_lock);
2107 }
2108 
2109 kuid_t sock_i_uid(struct sock *sk);
2110 unsigned long sock_i_ino(struct sock *sk);
2111 
sock_net_uid(const struct net * net,const struct sock * sk)2112 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2113 {
2114 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
2115 }
2116 
net_tx_rndhash(void)2117 static inline u32 net_tx_rndhash(void)
2118 {
2119 	u32 v = get_random_u32();
2120 
2121 	return v ?: 1;
2122 }
2123 
sk_set_txhash(struct sock * sk)2124 static inline void sk_set_txhash(struct sock *sk)
2125 {
2126 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2127 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2128 }
2129 
sk_rethink_txhash(struct sock * sk)2130 static inline bool sk_rethink_txhash(struct sock *sk)
2131 {
2132 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2133 		sk_set_txhash(sk);
2134 		return true;
2135 	}
2136 	return false;
2137 }
2138 
2139 static inline struct dst_entry *
__sk_dst_get(struct sock * sk)2140 __sk_dst_get(struct sock *sk)
2141 {
2142 	return rcu_dereference_check(sk->sk_dst_cache,
2143 				     lockdep_sock_is_held(sk));
2144 }
2145 
2146 static inline struct dst_entry *
sk_dst_get(struct sock * sk)2147 sk_dst_get(struct sock *sk)
2148 {
2149 	struct dst_entry *dst;
2150 
2151 	rcu_read_lock();
2152 	dst = rcu_dereference(sk->sk_dst_cache);
2153 	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
2154 		dst = NULL;
2155 	rcu_read_unlock();
2156 	return dst;
2157 }
2158 
__dst_negative_advice(struct sock * sk)2159 static inline void __dst_negative_advice(struct sock *sk)
2160 {
2161 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
2162 
2163 	if (dst && dst->ops->negative_advice) {
2164 		ndst = dst->ops->negative_advice(dst);
2165 
2166 		if (ndst != dst) {
2167 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
2168 			sk_tx_queue_clear(sk);
2169 			sk->sk_dst_pending_confirm = 0;
2170 		}
2171 	}
2172 }
2173 
dst_negative_advice(struct sock * sk)2174 static inline void dst_negative_advice(struct sock *sk)
2175 {
2176 	sk_rethink_txhash(sk);
2177 	__dst_negative_advice(sk);
2178 }
2179 
2180 static inline void
__sk_dst_set(struct sock * sk,struct dst_entry * dst)2181 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2182 {
2183 	struct dst_entry *old_dst;
2184 
2185 	sk_tx_queue_clear(sk);
2186 	sk->sk_dst_pending_confirm = 0;
2187 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2188 					    lockdep_sock_is_held(sk));
2189 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2190 	dst_release(old_dst);
2191 }
2192 
2193 static inline void
sk_dst_set(struct sock * sk,struct dst_entry * dst)2194 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2195 {
2196 	struct dst_entry *old_dst;
2197 
2198 	sk_tx_queue_clear(sk);
2199 	sk->sk_dst_pending_confirm = 0;
2200 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2201 	dst_release(old_dst);
2202 }
2203 
2204 static inline void
__sk_dst_reset(struct sock * sk)2205 __sk_dst_reset(struct sock *sk)
2206 {
2207 	__sk_dst_set(sk, NULL);
2208 }
2209 
2210 static inline void
sk_dst_reset(struct sock * sk)2211 sk_dst_reset(struct sock *sk)
2212 {
2213 	sk_dst_set(sk, NULL);
2214 }
2215 
2216 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2217 
2218 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2219 
sk_dst_confirm(struct sock * sk)2220 static inline void sk_dst_confirm(struct sock *sk)
2221 {
2222 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2223 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2224 }
2225 
sock_confirm_neigh(struct sk_buff * skb,struct neighbour * n)2226 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2227 {
2228 	if (skb_get_dst_pending_confirm(skb)) {
2229 		struct sock *sk = skb->sk;
2230 
2231 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2232 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2233 		neigh_confirm(n);
2234 	}
2235 }
2236 
2237 bool sk_mc_loop(struct sock *sk);
2238 
sk_can_gso(const struct sock * sk)2239 static inline bool sk_can_gso(const struct sock *sk)
2240 {
2241 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2242 }
2243 
2244 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2245 
sk_gso_disable(struct sock * sk)2246 static inline void sk_gso_disable(struct sock *sk)
2247 {
2248 	sk->sk_gso_disabled = 1;
2249 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2250 }
2251 
skb_do_copy_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,char * to,int copy,int offset)2252 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2253 					   struct iov_iter *from, char *to,
2254 					   int copy, int offset)
2255 {
2256 	if (skb->ip_summed == CHECKSUM_NONE) {
2257 		__wsum csum = 0;
2258 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2259 			return -EFAULT;
2260 		skb->csum = csum_block_add(skb->csum, csum, offset);
2261 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2262 		if (!copy_from_iter_full_nocache(to, copy, from))
2263 			return -EFAULT;
2264 	} else if (!copy_from_iter_full(to, copy, from))
2265 		return -EFAULT;
2266 
2267 	return 0;
2268 }
2269 
skb_add_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,int copy)2270 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2271 				       struct iov_iter *from, int copy)
2272 {
2273 	int err, offset = skb->len;
2274 
2275 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2276 				       copy, offset);
2277 	if (err)
2278 		__skb_trim(skb, offset);
2279 
2280 	return err;
2281 }
2282 
skb_copy_to_page_nocache(struct sock * sk,struct iov_iter * from,struct sk_buff * skb,struct page * page,int off,int copy)2283 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2284 					   struct sk_buff *skb,
2285 					   struct page *page,
2286 					   int off, int copy)
2287 {
2288 	int err;
2289 
2290 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2291 				       copy, skb->len);
2292 	if (err)
2293 		return err;
2294 
2295 	skb_len_add(skb, copy);
2296 	sk_wmem_queued_add(sk, copy);
2297 	sk_mem_charge(sk, copy);
2298 	return 0;
2299 }
2300 
2301 /**
2302  * sk_wmem_alloc_get - returns write allocations
2303  * @sk: socket
2304  *
2305  * Return: sk_wmem_alloc minus initial offset of one
2306  */
sk_wmem_alloc_get(const struct sock * sk)2307 static inline int sk_wmem_alloc_get(const struct sock *sk)
2308 {
2309 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2310 }
2311 
2312 /**
2313  * sk_rmem_alloc_get - returns read allocations
2314  * @sk: socket
2315  *
2316  * Return: sk_rmem_alloc
2317  */
sk_rmem_alloc_get(const struct sock * sk)2318 static inline int sk_rmem_alloc_get(const struct sock *sk)
2319 {
2320 	return atomic_read(&sk->sk_rmem_alloc);
2321 }
2322 
2323 /**
2324  * sk_has_allocations - check if allocations are outstanding
2325  * @sk: socket
2326  *
2327  * Return: true if socket has write or read allocations
2328  */
sk_has_allocations(const struct sock * sk)2329 static inline bool sk_has_allocations(const struct sock *sk)
2330 {
2331 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2332 }
2333 
2334 /**
2335  * skwq_has_sleeper - check if there are any waiting processes
2336  * @wq: struct socket_wq
2337  *
2338  * Return: true if socket_wq has waiting processes
2339  *
2340  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2341  * barrier call. They were added due to the race found within the tcp code.
2342  *
2343  * Consider following tcp code paths::
2344  *
2345  *   CPU1                CPU2
2346  *   sys_select          receive packet
2347  *   ...                 ...
2348  *   __add_wait_queue    update tp->rcv_nxt
2349  *   ...                 ...
2350  *   tp->rcv_nxt check   sock_def_readable
2351  *   ...                 {
2352  *   schedule               rcu_read_lock();
2353  *                          wq = rcu_dereference(sk->sk_wq);
2354  *                          if (wq && waitqueue_active(&wq->wait))
2355  *                              wake_up_interruptible(&wq->wait)
2356  *                          ...
2357  *                       }
2358  *
2359  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2360  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2361  * could then endup calling schedule and sleep forever if there are no more
2362  * data on the socket.
2363  *
2364  */
skwq_has_sleeper(struct socket_wq * wq)2365 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2366 {
2367 	return wq && wq_has_sleeper(&wq->wait);
2368 }
2369 
2370 /**
2371  * sock_poll_wait - place memory barrier behind the poll_wait call.
2372  * @filp:           file
2373  * @sock:           socket to wait on
2374  * @p:              poll_table
2375  *
2376  * See the comments in the wq_has_sleeper function.
2377  */
sock_poll_wait(struct file * filp,struct socket * sock,poll_table * p)2378 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2379 				  poll_table *p)
2380 {
2381 	if (!poll_does_not_wait(p)) {
2382 		poll_wait(filp, &sock->wq.wait, p);
2383 		/* We need to be sure we are in sync with the
2384 		 * socket flags modification.
2385 		 *
2386 		 * This memory barrier is paired in the wq_has_sleeper.
2387 		 */
2388 		smp_mb();
2389 	}
2390 }
2391 
skb_set_hash_from_sk(struct sk_buff * skb,struct sock * sk)2392 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2393 {
2394 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2395 	u32 txhash = READ_ONCE(sk->sk_txhash);
2396 
2397 	if (txhash) {
2398 		skb->l4_hash = 1;
2399 		skb->hash = txhash;
2400 	}
2401 }
2402 
2403 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2404 
2405 /*
2406  *	Queue a received datagram if it will fit. Stream and sequenced
2407  *	protocols can't normally use this as they need to fit buffers in
2408  *	and play with them.
2409  *
2410  *	Inlined as it's very short and called for pretty much every
2411  *	packet ever received.
2412  */
skb_set_owner_r(struct sk_buff * skb,struct sock * sk)2413 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2414 {
2415 	skb_orphan(skb);
2416 	skb->sk = sk;
2417 	skb->destructor = sock_rfree;
2418 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2419 	sk_mem_charge(sk, skb->truesize);
2420 }
2421 
skb_set_owner_sk_safe(struct sk_buff * skb,struct sock * sk)2422 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2423 {
2424 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2425 		skb_orphan(skb);
2426 		skb->destructor = sock_efree;
2427 		skb->sk = sk;
2428 		return true;
2429 	}
2430 	return false;
2431 }
2432 
skb_prepare_for_gro(struct sk_buff * skb)2433 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2434 {
2435 	if (skb->destructor != sock_wfree) {
2436 		skb_orphan(skb);
2437 		return;
2438 	}
2439 	skb->slow_gro = 1;
2440 }
2441 
2442 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2443 		    unsigned long expires);
2444 
2445 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2446 
2447 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2448 
2449 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2450 			struct sk_buff *skb, unsigned int flags,
2451 			void (*destructor)(struct sock *sk,
2452 					   struct sk_buff *skb));
2453 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2454 
2455 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2456 			      enum skb_drop_reason *reason);
2457 
sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)2458 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2459 {
2460 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2461 }
2462 
2463 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2464 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2465 
2466 /*
2467  *	Recover an error report and clear atomically
2468  */
2469 
sock_error(struct sock * sk)2470 static inline int sock_error(struct sock *sk)
2471 {
2472 	int err;
2473 
2474 	/* Avoid an atomic operation for the common case.
2475 	 * This is racy since another cpu/thread can change sk_err under us.
2476 	 */
2477 	if (likely(data_race(!sk->sk_err)))
2478 		return 0;
2479 
2480 	err = xchg(&sk->sk_err, 0);
2481 	return -err;
2482 }
2483 
2484 void sk_error_report(struct sock *sk);
2485 
sock_wspace(struct sock * sk)2486 static inline unsigned long sock_wspace(struct sock *sk)
2487 {
2488 	int amt = 0;
2489 
2490 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2491 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2492 		if (amt < 0)
2493 			amt = 0;
2494 	}
2495 	return amt;
2496 }
2497 
2498 /* Note:
2499  *  We use sk->sk_wq_raw, from contexts knowing this
2500  *  pointer is not NULL and cannot disappear/change.
2501  */
sk_set_bit(int nr,struct sock * sk)2502 static inline void sk_set_bit(int nr, struct sock *sk)
2503 {
2504 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2505 	    !sock_flag(sk, SOCK_FASYNC))
2506 		return;
2507 
2508 	set_bit(nr, &sk->sk_wq_raw->flags);
2509 }
2510 
sk_clear_bit(int nr,struct sock * sk)2511 static inline void sk_clear_bit(int nr, struct sock *sk)
2512 {
2513 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2514 	    !sock_flag(sk, SOCK_FASYNC))
2515 		return;
2516 
2517 	clear_bit(nr, &sk->sk_wq_raw->flags);
2518 }
2519 
sk_wake_async(const struct sock * sk,int how,int band)2520 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2521 {
2522 	if (sock_flag(sk, SOCK_FASYNC)) {
2523 		rcu_read_lock();
2524 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2525 		rcu_read_unlock();
2526 	}
2527 }
2528 
2529 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2530  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2531  * Note: for send buffers, TCP works better if we can build two skbs at
2532  * minimum.
2533  */
2534 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2535 
2536 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2537 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2538 
sk_stream_moderate_sndbuf(struct sock * sk)2539 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2540 {
2541 	u32 val;
2542 
2543 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2544 		return;
2545 
2546 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2547 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2548 
2549 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2550 }
2551 
2552 /**
2553  * sk_page_frag - return an appropriate page_frag
2554  * @sk: socket
2555  *
2556  * Use the per task page_frag instead of the per socket one for
2557  * optimization when we know that we're in process context and own
2558  * everything that's associated with %current.
2559  *
2560  * Both direct reclaim and page faults can nest inside other
2561  * socket operations and end up recursing into sk_page_frag()
2562  * while it's already in use: explicitly avoid task page_frag
2563  * usage if the caller is potentially doing any of them.
2564  * This assumes that page fault handlers use the GFP_NOFS flags.
2565  *
2566  * Return: a per task page_frag if context allows that,
2567  * otherwise a per socket one.
2568  */
sk_page_frag(struct sock * sk)2569 static inline struct page_frag *sk_page_frag(struct sock *sk)
2570 {
2571 	if ((sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC | __GFP_FS)) ==
2572 	    (__GFP_DIRECT_RECLAIM | __GFP_FS))
2573 		return &current->task_frag;
2574 
2575 	return &sk->sk_frag;
2576 }
2577 
2578 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2579 
2580 /*
2581  *	Default write policy as shown to user space via poll/select/SIGIO
2582  */
sock_writeable(const struct sock * sk)2583 static inline bool sock_writeable(const struct sock *sk)
2584 {
2585 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2586 }
2587 
gfp_any(void)2588 static inline gfp_t gfp_any(void)
2589 {
2590 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2591 }
2592 
gfp_memcg_charge(void)2593 static inline gfp_t gfp_memcg_charge(void)
2594 {
2595 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2596 }
2597 
sock_rcvtimeo(const struct sock * sk,bool noblock)2598 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2599 {
2600 	return noblock ? 0 : sk->sk_rcvtimeo;
2601 }
2602 
sock_sndtimeo(const struct sock * sk,bool noblock)2603 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2604 {
2605 	return noblock ? 0 : sk->sk_sndtimeo;
2606 }
2607 
sock_rcvlowat(const struct sock * sk,int waitall,int len)2608 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2609 {
2610 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2611 
2612 	return v ?: 1;
2613 }
2614 
2615 /* Alas, with timeout socket operations are not restartable.
2616  * Compare this to poll().
2617  */
sock_intr_errno(long timeo)2618 static inline int sock_intr_errno(long timeo)
2619 {
2620 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2621 }
2622 
2623 struct sock_skb_cb {
2624 	u32 dropcount;
2625 };
2626 
2627 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2628  * using skb->cb[] would keep using it directly and utilize its
2629  * alignement guarantee.
2630  */
2631 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2632 			    sizeof(struct sock_skb_cb)))
2633 
2634 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2635 			    SOCK_SKB_CB_OFFSET))
2636 
2637 #define sock_skb_cb_check_size(size) \
2638 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2639 
2640 static inline void
sock_skb_set_dropcount(const struct sock * sk,struct sk_buff * skb)2641 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2642 {
2643 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2644 						atomic_read(&sk->sk_drops) : 0;
2645 }
2646 
sk_drops_add(struct sock * sk,const struct sk_buff * skb)2647 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2648 {
2649 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2650 
2651 	atomic_add(segs, &sk->sk_drops);
2652 }
2653 
sock_read_timestamp(struct sock * sk)2654 static inline ktime_t sock_read_timestamp(struct sock *sk)
2655 {
2656 #if BITS_PER_LONG==32
2657 	unsigned int seq;
2658 	ktime_t kt;
2659 
2660 	do {
2661 		seq = read_seqbegin(&sk->sk_stamp_seq);
2662 		kt = sk->sk_stamp;
2663 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2664 
2665 	return kt;
2666 #else
2667 	return READ_ONCE(sk->sk_stamp);
2668 #endif
2669 }
2670 
sock_write_timestamp(struct sock * sk,ktime_t kt)2671 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2672 {
2673 #if BITS_PER_LONG==32
2674 	write_seqlock(&sk->sk_stamp_seq);
2675 	sk->sk_stamp = kt;
2676 	write_sequnlock(&sk->sk_stamp_seq);
2677 #else
2678 	WRITE_ONCE(sk->sk_stamp, kt);
2679 #endif
2680 }
2681 
2682 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2683 			   struct sk_buff *skb);
2684 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2685 			     struct sk_buff *skb);
2686 
2687 static inline void
sock_recv_timestamp(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2688 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2689 {
2690 	ktime_t kt = skb->tstamp;
2691 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2692 
2693 	/*
2694 	 * generate control messages if
2695 	 * - receive time stamping in software requested
2696 	 * - software time stamp available and wanted
2697 	 * - hardware time stamps available and wanted
2698 	 */
2699 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2700 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2701 	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2702 	    (hwtstamps->hwtstamp &&
2703 	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2704 		__sock_recv_timestamp(msg, sk, skb);
2705 	else
2706 		sock_write_timestamp(sk, kt);
2707 
2708 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2709 		__sock_recv_wifi_status(msg, sk, skb);
2710 }
2711 
2712 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2713 		       struct sk_buff *skb);
2714 
2715 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
sock_recv_cmsgs(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2716 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2717 				   struct sk_buff *skb)
2718 {
2719 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2720 			   (1UL << SOCK_RCVTSTAMP)			| \
2721 			   (1UL << SOCK_RCVMARK))
2722 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2723 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2724 
2725 	if (sk->sk_flags & FLAGS_RECV_CMSGS || sk->sk_tsflags & TSFLAGS_ANY)
2726 		__sock_recv_cmsgs(msg, sk, skb);
2727 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2728 		sock_write_timestamp(sk, skb->tstamp);
2729 	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2730 		sock_write_timestamp(sk, 0);
2731 }
2732 
2733 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2734 
2735 /**
2736  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2737  * @sk:		socket sending this packet
2738  * @tsflags:	timestamping flags to use
2739  * @tx_flags:	completed with instructions for time stamping
2740  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2741  *
2742  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2743  */
_sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags,__u32 * tskey)2744 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2745 				      __u8 *tx_flags, __u32 *tskey)
2746 {
2747 	if (unlikely(tsflags)) {
2748 		__sock_tx_timestamp(tsflags, tx_flags);
2749 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2750 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2751 			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2752 	}
2753 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2754 		*tx_flags |= SKBTX_WIFI_STATUS;
2755 }
2756 
sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags)2757 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2758 				     __u8 *tx_flags)
2759 {
2760 	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2761 }
2762 
skb_setup_tx_timestamp(struct sk_buff * skb,__u16 tsflags)2763 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2764 {
2765 	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2766 			   &skb_shinfo(skb)->tskey);
2767 }
2768 
sk_is_tcp(const struct sock * sk)2769 static inline bool sk_is_tcp(const struct sock *sk)
2770 {
2771 	return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
2772 }
2773 
2774 /**
2775  * sk_eat_skb - Release a skb if it is no longer needed
2776  * @sk: socket to eat this skb from
2777  * @skb: socket buffer to eat
2778  *
2779  * This routine must be called with interrupts disabled or with the socket
2780  * locked so that the sk_buff queue operation is ok.
2781 */
sk_eat_skb(struct sock * sk,struct sk_buff * skb)2782 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2783 {
2784 	__skb_unlink(skb, &sk->sk_receive_queue);
2785 	__kfree_skb(skb);
2786 }
2787 
2788 static inline bool
skb_sk_is_prefetched(struct sk_buff * skb)2789 skb_sk_is_prefetched(struct sk_buff *skb)
2790 {
2791 #ifdef CONFIG_INET
2792 	return skb->destructor == sock_pfree;
2793 #else
2794 	return false;
2795 #endif /* CONFIG_INET */
2796 }
2797 
2798 /* This helper checks if a socket is a full socket,
2799  * ie _not_ a timewait or request socket.
2800  */
sk_fullsock(const struct sock * sk)2801 static inline bool sk_fullsock(const struct sock *sk)
2802 {
2803 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2804 }
2805 
2806 static inline bool
sk_is_refcounted(struct sock * sk)2807 sk_is_refcounted(struct sock *sk)
2808 {
2809 	/* Only full sockets have sk->sk_flags. */
2810 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2811 }
2812 
2813 /**
2814  * skb_steal_sock - steal a socket from an sk_buff
2815  * @skb: sk_buff to steal the socket from
2816  * @refcounted: is set to true if the socket is reference-counted
2817  */
2818 static inline struct sock *
skb_steal_sock(struct sk_buff * skb,bool * refcounted)2819 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2820 {
2821 	if (skb->sk) {
2822 		struct sock *sk = skb->sk;
2823 
2824 		*refcounted = true;
2825 		if (skb_sk_is_prefetched(skb))
2826 			*refcounted = sk_is_refcounted(sk);
2827 		skb->destructor = NULL;
2828 		skb->sk = NULL;
2829 		return sk;
2830 	}
2831 	*refcounted = false;
2832 	return NULL;
2833 }
2834 
2835 /* Checks if this SKB belongs to an HW offloaded socket
2836  * and whether any SW fallbacks are required based on dev.
2837  * Check decrypted mark in case skb_orphan() cleared socket.
2838  */
sk_validate_xmit_skb(struct sk_buff * skb,struct net_device * dev)2839 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2840 						   struct net_device *dev)
2841 {
2842 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2843 	struct sock *sk = skb->sk;
2844 
2845 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2846 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2847 #ifdef CONFIG_TLS_DEVICE
2848 	} else if (unlikely(skb->decrypted)) {
2849 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2850 		kfree_skb(skb);
2851 		skb = NULL;
2852 #endif
2853 	}
2854 #endif
2855 
2856 	return skb;
2857 }
2858 
2859 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2860  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2861  */
sk_listener(const struct sock * sk)2862 static inline bool sk_listener(const struct sock *sk)
2863 {
2864 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2865 }
2866 
2867 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2868 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2869 		       int type);
2870 
2871 bool sk_ns_capable(const struct sock *sk,
2872 		   struct user_namespace *user_ns, int cap);
2873 bool sk_capable(const struct sock *sk, int cap);
2874 bool sk_net_capable(const struct sock *sk, int cap);
2875 
2876 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2877 
2878 /* Take into consideration the size of the struct sk_buff overhead in the
2879  * determination of these values, since that is non-constant across
2880  * platforms.  This makes socket queueing behavior and performance
2881  * not depend upon such differences.
2882  */
2883 #define _SK_MEM_PACKETS		256
2884 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2885 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2886 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2887 
2888 extern __u32 sysctl_wmem_max;
2889 extern __u32 sysctl_rmem_max;
2890 
2891 extern int sysctl_tstamp_allow_data;
2892 extern int sysctl_optmem_max;
2893 
2894 extern __u32 sysctl_wmem_default;
2895 extern __u32 sysctl_rmem_default;
2896 
2897 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2898 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2899 
sk_get_wmem0(const struct sock * sk,const struct proto * proto)2900 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2901 {
2902 	/* Does this proto have per netns sysctl_wmem ? */
2903 	if (proto->sysctl_wmem_offset)
2904 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
2905 
2906 	return READ_ONCE(*proto->sysctl_wmem);
2907 }
2908 
sk_get_rmem0(const struct sock * sk,const struct proto * proto)2909 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2910 {
2911 	/* Does this proto have per netns sysctl_rmem ? */
2912 	if (proto->sysctl_rmem_offset)
2913 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
2914 
2915 	return READ_ONCE(*proto->sysctl_rmem);
2916 }
2917 
2918 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2919  * Some wifi drivers need to tweak it to get more chunks.
2920  * They can use this helper from their ndo_start_xmit()
2921  */
sk_pacing_shift_update(struct sock * sk,int val)2922 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2923 {
2924 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2925 		return;
2926 	WRITE_ONCE(sk->sk_pacing_shift, val);
2927 }
2928 
2929 /* if a socket is bound to a device, check that the given device
2930  * index is either the same or that the socket is bound to an L3
2931  * master device and the given device index is also enslaved to
2932  * that L3 master
2933  */
sk_dev_equal_l3scope(struct sock * sk,int dif)2934 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2935 {
2936 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
2937 	int mdif;
2938 
2939 	if (!bound_dev_if || bound_dev_if == dif)
2940 		return true;
2941 
2942 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2943 	if (mdif && mdif == bound_dev_if)
2944 		return true;
2945 
2946 	return false;
2947 }
2948 
2949 void sock_def_readable(struct sock *sk);
2950 
2951 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2952 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
2953 int sock_set_timestamping(struct sock *sk, int optname,
2954 			  struct so_timestamping timestamping);
2955 
2956 void sock_enable_timestamps(struct sock *sk);
2957 void sock_no_linger(struct sock *sk);
2958 void sock_set_keepalive(struct sock *sk);
2959 void sock_set_priority(struct sock *sk, u32 priority);
2960 void sock_set_rcvbuf(struct sock *sk, int val);
2961 void sock_set_mark(struct sock *sk, u32 val);
2962 void sock_set_reuseaddr(struct sock *sk);
2963 void sock_set_reuseport(struct sock *sk);
2964 void sock_set_sndtimeo(struct sock *sk, s64 secs);
2965 
2966 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2967 
2968 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
2969 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
2970 			   sockptr_t optval, int optlen, bool old_timeval);
2971 
sk_is_readable(struct sock * sk)2972 static inline bool sk_is_readable(struct sock *sk)
2973 {
2974 	if (sk->sk_prot->sock_is_readable)
2975 		return sk->sk_prot->sock_is_readable(sk);
2976 	return false;
2977 }
2978 #endif	/* _SOCK_H */
2979