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_use_task_frag: allow sk_page_frag() to use current->task_frag.
322   *			   Sockets that can be used under memory reclaim should
323   *			   set this to false.
324   *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
325   *	              for timestamping
326   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
327   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
328   *	@sk_socket: Identd and reporting IO signals
329   *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
330   *	@sk_frag: cached page frag
331   *	@sk_peek_off: current peek_offset value
332   *	@sk_send_head: front of stuff to transmit
333   *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
334   *	@sk_security: used by security modules
335   *	@sk_mark: generic packet mark
336   *	@sk_cgrp_data: cgroup data for this cgroup
337   *	@sk_memcg: this socket's memory cgroup association
338   *	@sk_write_pending: a write to stream socket waits to start
339   *	@sk_disconnects: number of disconnect operations performed on this sock
340   *	@sk_state_change: callback to indicate change in the state of the sock
341   *	@sk_data_ready: callback to indicate there is data to be processed
342   *	@sk_write_space: callback to indicate there is bf sending space available
343   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
344   *	@sk_backlog_rcv: callback to process the backlog
345   *	@sk_validate_xmit_skb: ptr to an optional validate function
346   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
347   *	@sk_reuseport_cb: reuseport group container
348   *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
349   *	@sk_rcu: used during RCU grace period
350   *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
351   *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
352   *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
353   *	@sk_txtime_unused: unused txtime flags
354   *	@ns_tracker: tracker for netns reference
355   *	@sk_bind2_node: bind node in the bhash2 table
356   */
357 struct sock {
358 	/*
359 	 * Now struct inet_timewait_sock also uses sock_common, so please just
360 	 * don't add nothing before this first member (__sk_common) --acme
361 	 */
362 	struct sock_common	__sk_common;
363 #define sk_node			__sk_common.skc_node
364 #define sk_nulls_node		__sk_common.skc_nulls_node
365 #define sk_refcnt		__sk_common.skc_refcnt
366 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
367 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
368 #define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
369 #endif
370 
371 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
372 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
373 #define sk_hash			__sk_common.skc_hash
374 #define sk_portpair		__sk_common.skc_portpair
375 #define sk_num			__sk_common.skc_num
376 #define sk_dport		__sk_common.skc_dport
377 #define sk_addrpair		__sk_common.skc_addrpair
378 #define sk_daddr		__sk_common.skc_daddr
379 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
380 #define sk_family		__sk_common.skc_family
381 #define sk_state		__sk_common.skc_state
382 #define sk_reuse		__sk_common.skc_reuse
383 #define sk_reuseport		__sk_common.skc_reuseport
384 #define sk_ipv6only		__sk_common.skc_ipv6only
385 #define sk_net_refcnt		__sk_common.skc_net_refcnt
386 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
387 #define sk_bind_node		__sk_common.skc_bind_node
388 #define sk_prot			__sk_common.skc_prot
389 #define sk_net			__sk_common.skc_net
390 #define sk_v6_daddr		__sk_common.skc_v6_daddr
391 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
392 #define sk_cookie		__sk_common.skc_cookie
393 #define sk_incoming_cpu		__sk_common.skc_incoming_cpu
394 #define sk_flags		__sk_common.skc_flags
395 #define sk_rxhash		__sk_common.skc_rxhash
396 
397 	/* early demux fields */
398 	struct dst_entry __rcu	*sk_rx_dst;
399 	int			sk_rx_dst_ifindex;
400 	u32			sk_rx_dst_cookie;
401 
402 	socket_lock_t		sk_lock;
403 	atomic_t		sk_drops;
404 	int			sk_rcvlowat;
405 	struct sk_buff_head	sk_error_queue;
406 	struct sk_buff_head	sk_receive_queue;
407 	/*
408 	 * The backlog queue is special, it is always used with
409 	 * the per-socket spinlock held and requires low latency
410 	 * access. Therefore we special case it's implementation.
411 	 * Note : rmem_alloc is in this structure to fill a hole
412 	 * on 64bit arches, not because its logically part of
413 	 * backlog.
414 	 */
415 	struct {
416 		atomic_t	rmem_alloc;
417 		int		len;
418 		struct sk_buff	*head;
419 		struct sk_buff	*tail;
420 	} sk_backlog;
421 
422 #define sk_rmem_alloc sk_backlog.rmem_alloc
423 
424 	int			sk_forward_alloc;
425 	u32			sk_reserved_mem;
426 #ifdef CONFIG_NET_RX_BUSY_POLL
427 	unsigned int		sk_ll_usec;
428 	/* ===== mostly read cache line ===== */
429 	unsigned int		sk_napi_id;
430 #endif
431 	int			sk_rcvbuf;
432 	int			sk_disconnects;
433 
434 	struct sk_filter __rcu	*sk_filter;
435 	union {
436 		struct socket_wq __rcu	*sk_wq;
437 		/* private: */
438 		struct socket_wq	*sk_wq_raw;
439 		/* public: */
440 	};
441 #ifdef CONFIG_XFRM
442 	struct xfrm_policy __rcu *sk_policy[2];
443 #endif
444 
445 	struct dst_entry __rcu	*sk_dst_cache;
446 	atomic_t		sk_omem_alloc;
447 	int			sk_sndbuf;
448 
449 	/* ===== cache line for TX ===== */
450 	int			sk_wmem_queued;
451 	refcount_t		sk_wmem_alloc;
452 	unsigned long		sk_tsq_flags;
453 	union {
454 		struct sk_buff	*sk_send_head;
455 		struct rb_root	tcp_rtx_queue;
456 	};
457 	struct sk_buff_head	sk_write_queue;
458 	__s32			sk_peek_off;
459 	int			sk_write_pending;
460 	__u32			sk_dst_pending_confirm;
461 	u32			sk_pacing_status; /* see enum sk_pacing */
462 	long			sk_sndtimeo;
463 	struct timer_list	sk_timer;
464 	__u32			sk_priority;
465 	__u32			sk_mark;
466 	unsigned long		sk_pacing_rate; /* bytes per second */
467 	unsigned long		sk_max_pacing_rate;
468 	struct page_frag	sk_frag;
469 	netdev_features_t	sk_route_caps;
470 	int			sk_gso_type;
471 	unsigned int		sk_gso_max_size;
472 	gfp_t			sk_allocation;
473 	__u32			sk_txhash;
474 
475 	/*
476 	 * Because of non atomicity rules, all
477 	 * changes are protected by socket lock.
478 	 */
479 	u8			sk_gso_disabled : 1,
480 				sk_kern_sock : 1,
481 				sk_no_check_tx : 1,
482 				sk_no_check_rx : 1,
483 				sk_userlocks : 4;
484 	u8			sk_pacing_shift;
485 	u16			sk_type;
486 	u16			sk_protocol;
487 	u16			sk_gso_max_segs;
488 	unsigned long	        sk_lingertime;
489 	struct proto		*sk_prot_creator;
490 	rwlock_t		sk_callback_lock;
491 	int			sk_err,
492 				sk_err_soft;
493 	u32			sk_ack_backlog;
494 	u32			sk_max_ack_backlog;
495 	kuid_t			sk_uid;
496 	u8			sk_txrehash;
497 #ifdef CONFIG_NET_RX_BUSY_POLL
498 	u8			sk_prefer_busy_poll;
499 	u16			sk_busy_poll_budget;
500 #endif
501 	spinlock_t		sk_peer_lock;
502 	int			sk_bind_phc;
503 	struct pid		*sk_peer_pid;
504 	const struct cred	*sk_peer_cred;
505 
506 	long			sk_rcvtimeo;
507 	ktime_t			sk_stamp;
508 #if BITS_PER_LONG==32
509 	seqlock_t		sk_stamp_seq;
510 #endif
511 	atomic_t		sk_tskey;
512 	atomic_t		sk_zckey;
513 	u32			sk_tsflags;
514 	u8			sk_shutdown;
515 
516 	u8			sk_clockid;
517 	u8			sk_txtime_deadline_mode : 1,
518 				sk_txtime_report_errors : 1,
519 				sk_txtime_unused : 6;
520 	bool			sk_use_task_frag;
521 
522 	struct socket		*sk_socket;
523 	void			*sk_user_data;
524 #ifdef CONFIG_SECURITY
525 	void			*sk_security;
526 #endif
527 	struct sock_cgroup_data	sk_cgrp_data;
528 	struct mem_cgroup	*sk_memcg;
529 	void			(*sk_state_change)(struct sock *sk);
530 	void			(*sk_data_ready)(struct sock *sk);
531 	void			(*sk_write_space)(struct sock *sk);
532 	void			(*sk_error_report)(struct sock *sk);
533 	int			(*sk_backlog_rcv)(struct sock *sk,
534 						  struct sk_buff *skb);
535 #ifdef CONFIG_SOCK_VALIDATE_XMIT
536 	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
537 							struct net_device *dev,
538 							struct sk_buff *skb);
539 #endif
540 	void                    (*sk_destruct)(struct sock *sk);
541 	struct sock_reuseport __rcu	*sk_reuseport_cb;
542 #ifdef CONFIG_BPF_SYSCALL
543 	struct bpf_local_storage __rcu	*sk_bpf_storage;
544 #endif
545 	struct rcu_head		sk_rcu;
546 	netns_tracker		ns_tracker;
547 	struct hlist_node	sk_bind2_node;
548 };
549 
550 enum sk_pacing {
551 	SK_PACING_NONE		= 0,
552 	SK_PACING_NEEDED	= 1,
553 	SK_PACING_FQ		= 2,
554 };
555 
556 /* flag bits in sk_user_data
557  *
558  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
559  *   not be suitable for copying when cloning the socket. For instance,
560  *   it can point to a reference counted object. sk_user_data bottom
561  *   bit is set if pointer must not be copied.
562  *
563  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
564  *   managed/owned by a BPF reuseport array. This bit should be set
565  *   when sk_user_data's sk is added to the bpf's reuseport_array.
566  *
567  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
568  *   sk_user_data points to psock type. This bit should be set
569  *   when sk_user_data is assigned to a psock object.
570  */
571 #define SK_USER_DATA_NOCOPY	1UL
572 #define SK_USER_DATA_BPF	2UL
573 #define SK_USER_DATA_PSOCK	4UL
574 #define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
575 				  SK_USER_DATA_PSOCK)
576 
577 /**
578  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
579  * @sk: socket
580  */
sk_user_data_is_nocopy(const struct sock * sk)581 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
582 {
583 	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
584 }
585 
586 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
587 
588 /**
589  * __locked_read_sk_user_data_with_flags - return the pointer
590  * only if argument flags all has been set in sk_user_data. Otherwise
591  * return NULL
592  *
593  * @sk: socket
594  * @flags: flag bits
595  *
596  * The caller must be holding sk->sk_callback_lock.
597  */
598 static inline void *
__locked_read_sk_user_data_with_flags(const struct sock * sk,uintptr_t flags)599 __locked_read_sk_user_data_with_flags(const struct sock *sk,
600 				      uintptr_t flags)
601 {
602 	uintptr_t sk_user_data =
603 		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
604 						 lockdep_is_held(&sk->sk_callback_lock));
605 
606 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
607 
608 	if ((sk_user_data & flags) == flags)
609 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
610 	return NULL;
611 }
612 
613 /**
614  * __rcu_dereference_sk_user_data_with_flags - return the pointer
615  * only if argument flags all has been set in sk_user_data. Otherwise
616  * return NULL
617  *
618  * @sk: socket
619  * @flags: flag bits
620  */
621 static inline void *
__rcu_dereference_sk_user_data_with_flags(const struct sock * sk,uintptr_t flags)622 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
623 					  uintptr_t flags)
624 {
625 	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
626 
627 	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
628 
629 	if ((sk_user_data & flags) == flags)
630 		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
631 	return NULL;
632 }
633 
634 #define rcu_dereference_sk_user_data(sk)				\
635 	__rcu_dereference_sk_user_data_with_flags(sk, 0)
636 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
637 ({									\
638 	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
639 		  __tmp2 = (uintptr_t)(flags);				\
640 	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
641 	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
642 	rcu_assign_pointer(__sk_user_data((sk)),			\
643 			   __tmp1 | __tmp2);				\
644 })
645 #define rcu_assign_sk_user_data(sk, ptr)				\
646 	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
647 
648 static inline
sock_net(const struct sock * sk)649 struct net *sock_net(const struct sock *sk)
650 {
651 	return read_pnet(&sk->sk_net);
652 }
653 
654 static inline
sock_net_set(struct sock * sk,struct net * net)655 void sock_net_set(struct sock *sk, struct net *net)
656 {
657 	write_pnet(&sk->sk_net, net);
658 }
659 
660 /*
661  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
662  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
663  * on a socket means that the socket will reuse everybody else's port
664  * without looking at the other's sk_reuse value.
665  */
666 
667 #define SK_NO_REUSE	0
668 #define SK_CAN_REUSE	1
669 #define SK_FORCE_REUSE	2
670 
671 int sk_set_peek_off(struct sock *sk, int val);
672 
sk_peek_offset(const struct sock * sk,int flags)673 static inline int sk_peek_offset(const struct sock *sk, int flags)
674 {
675 	if (unlikely(flags & MSG_PEEK)) {
676 		return READ_ONCE(sk->sk_peek_off);
677 	}
678 
679 	return 0;
680 }
681 
sk_peek_offset_bwd(struct sock * sk,int val)682 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
683 {
684 	s32 off = READ_ONCE(sk->sk_peek_off);
685 
686 	if (unlikely(off >= 0)) {
687 		off = max_t(s32, off - val, 0);
688 		WRITE_ONCE(sk->sk_peek_off, off);
689 	}
690 }
691 
sk_peek_offset_fwd(struct sock * sk,int val)692 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
693 {
694 	sk_peek_offset_bwd(sk, -val);
695 }
696 
697 /*
698  * Hashed lists helper routines
699  */
sk_entry(const struct hlist_node * node)700 static inline struct sock *sk_entry(const struct hlist_node *node)
701 {
702 	return hlist_entry(node, struct sock, sk_node);
703 }
704 
__sk_head(const struct hlist_head * head)705 static inline struct sock *__sk_head(const struct hlist_head *head)
706 {
707 	return hlist_entry(head->first, struct sock, sk_node);
708 }
709 
sk_head(const struct hlist_head * head)710 static inline struct sock *sk_head(const struct hlist_head *head)
711 {
712 	return hlist_empty(head) ? NULL : __sk_head(head);
713 }
714 
__sk_nulls_head(const struct hlist_nulls_head * head)715 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
716 {
717 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
718 }
719 
sk_nulls_head(const struct hlist_nulls_head * head)720 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
721 {
722 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
723 }
724 
sk_next(const struct sock * sk)725 static inline struct sock *sk_next(const struct sock *sk)
726 {
727 	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
728 }
729 
sk_nulls_next(const struct sock * sk)730 static inline struct sock *sk_nulls_next(const struct sock *sk)
731 {
732 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
733 		hlist_nulls_entry(sk->sk_nulls_node.next,
734 				  struct sock, sk_nulls_node) :
735 		NULL;
736 }
737 
sk_unhashed(const struct sock * sk)738 static inline bool sk_unhashed(const struct sock *sk)
739 {
740 	return hlist_unhashed(&sk->sk_node);
741 }
742 
sk_hashed(const struct sock * sk)743 static inline bool sk_hashed(const struct sock *sk)
744 {
745 	return !sk_unhashed(sk);
746 }
747 
sk_node_init(struct hlist_node * node)748 static inline void sk_node_init(struct hlist_node *node)
749 {
750 	node->pprev = NULL;
751 }
752 
__sk_del_node(struct sock * sk)753 static inline void __sk_del_node(struct sock *sk)
754 {
755 	__hlist_del(&sk->sk_node);
756 }
757 
758 /* NB: equivalent to hlist_del_init_rcu */
__sk_del_node_init(struct sock * sk)759 static inline bool __sk_del_node_init(struct sock *sk)
760 {
761 	if (sk_hashed(sk)) {
762 		__sk_del_node(sk);
763 		sk_node_init(&sk->sk_node);
764 		return true;
765 	}
766 	return false;
767 }
768 
769 /* Grab socket reference count. This operation is valid only
770    when sk is ALREADY grabbed f.e. it is found in hash table
771    or a list and the lookup is made under lock preventing hash table
772    modifications.
773  */
774 
sock_hold(struct sock * sk)775 static __always_inline void sock_hold(struct sock *sk)
776 {
777 	refcount_inc(&sk->sk_refcnt);
778 }
779 
780 /* Ungrab socket in the context, which assumes that socket refcnt
781    cannot hit zero, f.e. it is true in context of any socketcall.
782  */
__sock_put(struct sock * sk)783 static __always_inline void __sock_put(struct sock *sk)
784 {
785 	refcount_dec(&sk->sk_refcnt);
786 }
787 
sk_del_node_init(struct sock * sk)788 static inline bool sk_del_node_init(struct sock *sk)
789 {
790 	bool rc = __sk_del_node_init(sk);
791 
792 	if (rc) {
793 		/* paranoid for a while -acme */
794 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
795 		__sock_put(sk);
796 	}
797 	return rc;
798 }
799 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
800 
__sk_nulls_del_node_init_rcu(struct sock * sk)801 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
802 {
803 	if (sk_hashed(sk)) {
804 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
805 		return true;
806 	}
807 	return false;
808 }
809 
sk_nulls_del_node_init_rcu(struct sock * sk)810 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
811 {
812 	bool rc = __sk_nulls_del_node_init_rcu(sk);
813 
814 	if (rc) {
815 		/* paranoid for a while -acme */
816 		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
817 		__sock_put(sk);
818 	}
819 	return rc;
820 }
821 
__sk_add_node(struct sock * sk,struct hlist_head * list)822 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
823 {
824 	hlist_add_head(&sk->sk_node, list);
825 }
826 
sk_add_node(struct sock * sk,struct hlist_head * list)827 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
828 {
829 	sock_hold(sk);
830 	__sk_add_node(sk, list);
831 }
832 
sk_add_node_rcu(struct sock * sk,struct hlist_head * list)833 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
834 {
835 	sock_hold(sk);
836 	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
837 	    sk->sk_family == AF_INET6)
838 		hlist_add_tail_rcu(&sk->sk_node, list);
839 	else
840 		hlist_add_head_rcu(&sk->sk_node, list);
841 }
842 
sk_add_node_tail_rcu(struct sock * sk,struct hlist_head * list)843 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
844 {
845 	sock_hold(sk);
846 	hlist_add_tail_rcu(&sk->sk_node, list);
847 }
848 
__sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)849 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
850 {
851 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
852 }
853 
__sk_nulls_add_node_tail_rcu(struct sock * sk,struct hlist_nulls_head * list)854 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
855 {
856 	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
857 }
858 
sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)859 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
860 {
861 	sock_hold(sk);
862 	__sk_nulls_add_node_rcu(sk, list);
863 }
864 
__sk_del_bind_node(struct sock * sk)865 static inline void __sk_del_bind_node(struct sock *sk)
866 {
867 	__hlist_del(&sk->sk_bind_node);
868 }
869 
sk_add_bind_node(struct sock * sk,struct hlist_head * list)870 static inline void sk_add_bind_node(struct sock *sk,
871 					struct hlist_head *list)
872 {
873 	hlist_add_head(&sk->sk_bind_node, list);
874 }
875 
__sk_del_bind2_node(struct sock * sk)876 static inline void __sk_del_bind2_node(struct sock *sk)
877 {
878 	__hlist_del(&sk->sk_bind2_node);
879 }
880 
sk_add_bind2_node(struct sock * sk,struct hlist_head * list)881 static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
882 {
883 	hlist_add_head(&sk->sk_bind2_node, list);
884 }
885 
886 #define sk_for_each(__sk, list) \
887 	hlist_for_each_entry(__sk, list, sk_node)
888 #define sk_for_each_rcu(__sk, list) \
889 	hlist_for_each_entry_rcu(__sk, list, sk_node)
890 #define sk_nulls_for_each(__sk, node, list) \
891 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
892 #define sk_nulls_for_each_rcu(__sk, node, list) \
893 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
894 #define sk_for_each_from(__sk) \
895 	hlist_for_each_entry_from(__sk, sk_node)
896 #define sk_nulls_for_each_from(__sk, node) \
897 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
898 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
899 #define sk_for_each_safe(__sk, tmp, list) \
900 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
901 #define sk_for_each_bound(__sk, list) \
902 	hlist_for_each_entry(__sk, list, sk_bind_node)
903 #define sk_for_each_bound_bhash2(__sk, list) \
904 	hlist_for_each_entry(__sk, list, sk_bind2_node)
905 
906 /**
907  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
908  * @tpos:	the type * to use as a loop cursor.
909  * @pos:	the &struct hlist_node to use as a loop cursor.
910  * @head:	the head for your list.
911  * @offset:	offset of hlist_node within the struct.
912  *
913  */
914 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
915 	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
916 	     pos != NULL &&						       \
917 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
918 	     pos = rcu_dereference(hlist_next_rcu(pos)))
919 
sk_user_ns(const struct sock * sk)920 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
921 {
922 	/* Careful only use this in a context where these parameters
923 	 * can not change and must all be valid, such as recvmsg from
924 	 * userspace.
925 	 */
926 	return sk->sk_socket->file->f_cred->user_ns;
927 }
928 
929 /* Sock flags */
930 enum sock_flags {
931 	SOCK_DEAD,
932 	SOCK_DONE,
933 	SOCK_URGINLINE,
934 	SOCK_KEEPOPEN,
935 	SOCK_LINGER,
936 	SOCK_DESTROY,
937 	SOCK_BROADCAST,
938 	SOCK_TIMESTAMP,
939 	SOCK_ZAPPED,
940 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
941 	SOCK_DBG, /* %SO_DEBUG setting */
942 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
943 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
944 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
945 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
946 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
947 	SOCK_FASYNC, /* fasync() active */
948 	SOCK_RXQ_OVFL,
949 	SOCK_ZEROCOPY, /* buffers from userspace */
950 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
951 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
952 		     * Will use last 4 bytes of packet sent from
953 		     * user-space instead.
954 		     */
955 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
956 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
957 	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
958 	SOCK_TXTIME,
959 	SOCK_XDP, /* XDP is attached */
960 	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
961 	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
962 };
963 
964 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
965 
sock_copy_flags(struct sock * nsk,const struct sock * osk)966 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
967 {
968 	nsk->sk_flags = osk->sk_flags;
969 }
970 
sock_set_flag(struct sock * sk,enum sock_flags flag)971 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
972 {
973 	__set_bit(flag, &sk->sk_flags);
974 }
975 
sock_reset_flag(struct sock * sk,enum sock_flags flag)976 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
977 {
978 	__clear_bit(flag, &sk->sk_flags);
979 }
980 
sock_valbool_flag(struct sock * sk,enum sock_flags bit,int valbool)981 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
982 				     int valbool)
983 {
984 	if (valbool)
985 		sock_set_flag(sk, bit);
986 	else
987 		sock_reset_flag(sk, bit);
988 }
989 
sock_flag(const struct sock * sk,enum sock_flags flag)990 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
991 {
992 	return test_bit(flag, &sk->sk_flags);
993 }
994 
995 #ifdef CONFIG_NET
996 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
sk_memalloc_socks(void)997 static inline int sk_memalloc_socks(void)
998 {
999 	return static_branch_unlikely(&memalloc_socks_key);
1000 }
1001 
1002 void __receive_sock(struct file *file);
1003 #else
1004 
sk_memalloc_socks(void)1005 static inline int sk_memalloc_socks(void)
1006 {
1007 	return 0;
1008 }
1009 
__receive_sock(struct file * file)1010 static inline void __receive_sock(struct file *file)
1011 { }
1012 #endif
1013 
sk_gfp_mask(const struct sock * sk,gfp_t gfp_mask)1014 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1015 {
1016 	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1017 }
1018 
sk_acceptq_removed(struct sock * sk)1019 static inline void sk_acceptq_removed(struct sock *sk)
1020 {
1021 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1022 }
1023 
sk_acceptq_added(struct sock * sk)1024 static inline void sk_acceptq_added(struct sock *sk)
1025 {
1026 	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1027 }
1028 
1029 /* Note: If you think the test should be:
1030  *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1031  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1032  */
sk_acceptq_is_full(const struct sock * sk)1033 static inline bool sk_acceptq_is_full(const struct sock *sk)
1034 {
1035 	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1036 }
1037 
1038 /*
1039  * Compute minimal free write space needed to queue new packets.
1040  */
sk_stream_min_wspace(const struct sock * sk)1041 static inline int sk_stream_min_wspace(const struct sock *sk)
1042 {
1043 	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1044 }
1045 
sk_stream_wspace(const struct sock * sk)1046 static inline int sk_stream_wspace(const struct sock *sk)
1047 {
1048 	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1049 }
1050 
sk_wmem_queued_add(struct sock * sk,int val)1051 static inline void sk_wmem_queued_add(struct sock *sk, int val)
1052 {
1053 	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1054 }
1055 
sk_forward_alloc_add(struct sock * sk,int val)1056 static inline void sk_forward_alloc_add(struct sock *sk, int val)
1057 {
1058 	/* Paired with lockless reads of sk->sk_forward_alloc */
1059 	WRITE_ONCE(sk->sk_forward_alloc, sk->sk_forward_alloc + val);
1060 }
1061 
1062 void sk_stream_write_space(struct sock *sk);
1063 
1064 /* OOB backlog add */
__sk_add_backlog(struct sock * sk,struct sk_buff * skb)1065 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1066 {
1067 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1068 	skb_dst_force(skb);
1069 
1070 	if (!sk->sk_backlog.tail)
1071 		WRITE_ONCE(sk->sk_backlog.head, skb);
1072 	else
1073 		sk->sk_backlog.tail->next = skb;
1074 
1075 	WRITE_ONCE(sk->sk_backlog.tail, skb);
1076 	skb->next = NULL;
1077 }
1078 
1079 /*
1080  * Take into account size of receive queue and backlog queue
1081  * Do not take into account this skb truesize,
1082  * to allow even a single big packet to come.
1083  */
sk_rcvqueues_full(const struct sock * sk,unsigned int limit)1084 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1085 {
1086 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1087 
1088 	return qsize > limit;
1089 }
1090 
1091 /* The per-socket spinlock must be held here. */
sk_add_backlog(struct sock * sk,struct sk_buff * skb,unsigned int limit)1092 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1093 					      unsigned int limit)
1094 {
1095 	if (sk_rcvqueues_full(sk, limit))
1096 		return -ENOBUFS;
1097 
1098 	/*
1099 	 * If the skb was allocated from pfmemalloc reserves, only
1100 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1101 	 * helping free memory
1102 	 */
1103 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1104 		return -ENOMEM;
1105 
1106 	__sk_add_backlog(sk, skb);
1107 	sk->sk_backlog.len += skb->truesize;
1108 	return 0;
1109 }
1110 
1111 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1112 
1113 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1114 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1115 
sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)1116 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1117 {
1118 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1119 		return __sk_backlog_rcv(sk, skb);
1120 
1121 	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1122 				  tcp_v6_do_rcv,
1123 				  tcp_v4_do_rcv,
1124 				  sk, skb);
1125 }
1126 
sk_incoming_cpu_update(struct sock * sk)1127 static inline void sk_incoming_cpu_update(struct sock *sk)
1128 {
1129 	int cpu = raw_smp_processor_id();
1130 
1131 	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1132 		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1133 }
1134 
sock_rps_record_flow_hash(__u32 hash)1135 static inline void sock_rps_record_flow_hash(__u32 hash)
1136 {
1137 #ifdef CONFIG_RPS
1138 	struct rps_sock_flow_table *sock_flow_table;
1139 
1140 	rcu_read_lock();
1141 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1142 	rps_record_sock_flow(sock_flow_table, hash);
1143 	rcu_read_unlock();
1144 #endif
1145 }
1146 
sock_rps_record_flow(const struct sock * sk)1147 static inline void sock_rps_record_flow(const struct sock *sk)
1148 {
1149 #ifdef CONFIG_RPS
1150 	if (static_branch_unlikely(&rfs_needed)) {
1151 		/* Reading sk->sk_rxhash might incur an expensive cache line
1152 		 * miss.
1153 		 *
1154 		 * TCP_ESTABLISHED does cover almost all states where RFS
1155 		 * might be useful, and is cheaper [1] than testing :
1156 		 *	IPv4: inet_sk(sk)->inet_daddr
1157 		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1158 		 * OR	an additional socket flag
1159 		 * [1] : sk_state and sk_prot are in the same cache line.
1160 		 */
1161 		if (sk->sk_state == TCP_ESTABLISHED) {
1162 			/* This READ_ONCE() is paired with the WRITE_ONCE()
1163 			 * from sock_rps_save_rxhash() and sock_rps_reset_rxhash().
1164 			 */
1165 			sock_rps_record_flow_hash(READ_ONCE(sk->sk_rxhash));
1166 		}
1167 	}
1168 #endif
1169 }
1170 
sock_rps_save_rxhash(struct sock * sk,const struct sk_buff * skb)1171 static inline void sock_rps_save_rxhash(struct sock *sk,
1172 					const struct sk_buff *skb)
1173 {
1174 #ifdef CONFIG_RPS
1175 	/* The following WRITE_ONCE() is paired with the READ_ONCE()
1176 	 * here, and another one in sock_rps_record_flow().
1177 	 */
1178 	if (unlikely(READ_ONCE(sk->sk_rxhash) != skb->hash))
1179 		WRITE_ONCE(sk->sk_rxhash, skb->hash);
1180 #endif
1181 }
1182 
sock_rps_reset_rxhash(struct sock * sk)1183 static inline void sock_rps_reset_rxhash(struct sock *sk)
1184 {
1185 #ifdef CONFIG_RPS
1186 	/* Paired with READ_ONCE() in sock_rps_record_flow() */
1187 	WRITE_ONCE(sk->sk_rxhash, 0);
1188 #endif
1189 }
1190 
1191 #define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1192 	({	int __rc, __dis = __sk->sk_disconnects;			\
1193 		release_sock(__sk);					\
1194 		__rc = __condition;					\
1195 		if (!__rc) {						\
1196 			*(__timeo) = wait_woken(__wait,			\
1197 						TASK_INTERRUPTIBLE,	\
1198 						*(__timeo));		\
1199 		}							\
1200 		sched_annotate_sleep();					\
1201 		lock_sock(__sk);					\
1202 		__rc = __dis == __sk->sk_disconnects ? __condition : -EPIPE; \
1203 		__rc;							\
1204 	})
1205 
1206 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1207 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1208 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1209 int sk_stream_error(struct sock *sk, int flags, int err);
1210 void sk_stream_kill_queues(struct sock *sk);
1211 void sk_set_memalloc(struct sock *sk);
1212 void sk_clear_memalloc(struct sock *sk);
1213 
1214 void __sk_flush_backlog(struct sock *sk);
1215 
sk_flush_backlog(struct sock * sk)1216 static inline bool sk_flush_backlog(struct sock *sk)
1217 {
1218 	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1219 		__sk_flush_backlog(sk);
1220 		return true;
1221 	}
1222 	return false;
1223 }
1224 
1225 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1226 
1227 struct request_sock_ops;
1228 struct timewait_sock_ops;
1229 struct inet_hashinfo;
1230 struct raw_hashinfo;
1231 struct smc_hashinfo;
1232 struct module;
1233 struct sk_psock;
1234 
1235 /*
1236  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1237  * un-modified. Special care is taken when initializing object to zero.
1238  */
sk_prot_clear_nulls(struct sock * sk,int size)1239 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1240 {
1241 	if (offsetof(struct sock, sk_node.next) != 0)
1242 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1243 	memset(&sk->sk_node.pprev, 0,
1244 	       size - offsetof(struct sock, sk_node.pprev));
1245 }
1246 
1247 /* Networking protocol blocks we attach to sockets.
1248  * socket layer -> transport layer interface
1249  */
1250 struct proto {
1251 	void			(*close)(struct sock *sk,
1252 					long timeout);
1253 	int			(*pre_connect)(struct sock *sk,
1254 					struct sockaddr *uaddr,
1255 					int addr_len);
1256 	int			(*connect)(struct sock *sk,
1257 					struct sockaddr *uaddr,
1258 					int addr_len);
1259 	int			(*disconnect)(struct sock *sk, int flags);
1260 
1261 	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1262 					  bool kern);
1263 
1264 	int			(*ioctl)(struct sock *sk, int cmd,
1265 					 int *karg);
1266 	int			(*init)(struct sock *sk);
1267 	void			(*destroy)(struct sock *sk);
1268 	void			(*shutdown)(struct sock *sk, int how);
1269 	int			(*setsockopt)(struct sock *sk, int level,
1270 					int optname, sockptr_t optval,
1271 					unsigned int optlen);
1272 	int			(*getsockopt)(struct sock *sk, int level,
1273 					int optname, char __user *optval,
1274 					int __user *option);
1275 	void			(*keepalive)(struct sock *sk, int valbool);
1276 #ifdef CONFIG_COMPAT
1277 	int			(*compat_ioctl)(struct sock *sk,
1278 					unsigned int cmd, unsigned long arg);
1279 #endif
1280 	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1281 					   size_t len);
1282 	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1283 					   size_t len, int flags, int *addr_len);
1284 	void			(*splice_eof)(struct socket *sock);
1285 	int			(*bind)(struct sock *sk,
1286 					struct sockaddr *addr, int addr_len);
1287 	int			(*bind_add)(struct sock *sk,
1288 					struct sockaddr *addr, int addr_len);
1289 
1290 	int			(*backlog_rcv) (struct sock *sk,
1291 						struct sk_buff *skb);
1292 	bool			(*bpf_bypass_getsockopt)(int level,
1293 							 int optname);
1294 
1295 	void		(*release_cb)(struct sock *sk);
1296 
1297 	/* Keeping track of sk's, looking them up, and port selection methods. */
1298 	int			(*hash)(struct sock *sk);
1299 	void			(*unhash)(struct sock *sk);
1300 	void			(*rehash)(struct sock *sk);
1301 	int			(*get_port)(struct sock *sk, unsigned short snum);
1302 	void			(*put_port)(struct sock *sk);
1303 #ifdef CONFIG_BPF_SYSCALL
1304 	int			(*psock_update_sk_prot)(struct sock *sk,
1305 							struct sk_psock *psock,
1306 							bool restore);
1307 #endif
1308 
1309 	/* Keeping track of sockets in use */
1310 #ifdef CONFIG_PROC_FS
1311 	unsigned int		inuse_idx;
1312 #endif
1313 
1314 #if IS_ENABLED(CONFIG_MPTCP)
1315 	int			(*forward_alloc_get)(const struct sock *sk);
1316 #endif
1317 
1318 	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1319 	bool			(*sock_is_readable)(struct sock *sk);
1320 	/* Memory pressure */
1321 	void			(*enter_memory_pressure)(struct sock *sk);
1322 	void			(*leave_memory_pressure)(struct sock *sk);
1323 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1324 	int  __percpu		*per_cpu_fw_alloc;
1325 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1326 
1327 	/*
1328 	 * Pressure flag: try to collapse.
1329 	 * Technical note: it is used by multiple contexts non atomically.
1330 	 * Make sure to use READ_ONCE()/WRITE_ONCE() for all reads/writes.
1331 	 * All the __sk_mem_schedule() is of this nature: accounting
1332 	 * is strict, actions are advisory and have some latency.
1333 	 */
1334 	unsigned long		*memory_pressure;
1335 	long			*sysctl_mem;
1336 
1337 	int			*sysctl_wmem;
1338 	int			*sysctl_rmem;
1339 	u32			sysctl_wmem_offset;
1340 	u32			sysctl_rmem_offset;
1341 
1342 	int			max_header;
1343 	bool			no_autobind;
1344 
1345 	struct kmem_cache	*slab;
1346 	unsigned int		obj_size;
1347 	unsigned int		ipv6_pinfo_offset;
1348 	slab_flags_t		slab_flags;
1349 	unsigned int		useroffset;	/* Usercopy region offset */
1350 	unsigned int		usersize;	/* Usercopy region size */
1351 
1352 	unsigned int __percpu	*orphan_count;
1353 
1354 	struct request_sock_ops	*rsk_prot;
1355 	struct timewait_sock_ops *twsk_prot;
1356 
1357 	union {
1358 		struct inet_hashinfo	*hashinfo;
1359 		struct udp_table	*udp_table;
1360 		struct raw_hashinfo	*raw_hash;
1361 		struct smc_hashinfo	*smc_hash;
1362 	} h;
1363 
1364 	struct module		*owner;
1365 
1366 	char			name[32];
1367 
1368 	struct list_head	node;
1369 	int			(*diag_destroy)(struct sock *sk, int err);
1370 } __randomize_layout;
1371 
1372 int proto_register(struct proto *prot, int alloc_slab);
1373 void proto_unregister(struct proto *prot);
1374 int sock_load_diag_module(int family, int protocol);
1375 
1376 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1377 
sk_forward_alloc_get(const struct sock * sk)1378 static inline int sk_forward_alloc_get(const struct sock *sk)
1379 {
1380 #if IS_ENABLED(CONFIG_MPTCP)
1381 	if (sk->sk_prot->forward_alloc_get)
1382 		return sk->sk_prot->forward_alloc_get(sk);
1383 #endif
1384 	return READ_ONCE(sk->sk_forward_alloc);
1385 }
1386 
__sk_stream_memory_free(const struct sock * sk,int wake)1387 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1388 {
1389 	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1390 		return false;
1391 
1392 	return sk->sk_prot->stream_memory_free ?
1393 		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1394 				     tcp_stream_memory_free, sk, wake) : true;
1395 }
1396 
sk_stream_memory_free(const struct sock * sk)1397 static inline bool sk_stream_memory_free(const struct sock *sk)
1398 {
1399 	return __sk_stream_memory_free(sk, 0);
1400 }
1401 
__sk_stream_is_writeable(const struct sock * sk,int wake)1402 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1403 {
1404 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1405 	       __sk_stream_memory_free(sk, wake);
1406 }
1407 
sk_stream_is_writeable(const struct sock * sk)1408 static inline bool sk_stream_is_writeable(const struct sock *sk)
1409 {
1410 	return __sk_stream_is_writeable(sk, 0);
1411 }
1412 
sk_under_cgroup_hierarchy(struct sock * sk,struct cgroup * ancestor)1413 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1414 					    struct cgroup *ancestor)
1415 {
1416 #ifdef CONFIG_SOCK_CGROUP_DATA
1417 	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1418 				    ancestor);
1419 #else
1420 	return -ENOTSUPP;
1421 #endif
1422 }
1423 
sk_has_memory_pressure(const struct sock * sk)1424 static inline bool sk_has_memory_pressure(const struct sock *sk)
1425 {
1426 	return sk->sk_prot->memory_pressure != NULL;
1427 }
1428 
sk_under_global_memory_pressure(const struct sock * sk)1429 static inline bool sk_under_global_memory_pressure(const struct sock *sk)
1430 {
1431 	return sk->sk_prot->memory_pressure &&
1432 		!!READ_ONCE(*sk->sk_prot->memory_pressure);
1433 }
1434 
sk_under_memory_pressure(const struct sock * sk)1435 static inline bool sk_under_memory_pressure(const struct sock *sk)
1436 {
1437 	if (!sk->sk_prot->memory_pressure)
1438 		return false;
1439 
1440 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1441 	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1442 		return true;
1443 
1444 	return !!READ_ONCE(*sk->sk_prot->memory_pressure);
1445 }
1446 
1447 static inline long
proto_memory_allocated(const struct proto * prot)1448 proto_memory_allocated(const struct proto *prot)
1449 {
1450 	return max(0L, atomic_long_read(prot->memory_allocated));
1451 }
1452 
1453 static inline long
sk_memory_allocated(const struct sock * sk)1454 sk_memory_allocated(const struct sock *sk)
1455 {
1456 	return proto_memory_allocated(sk->sk_prot);
1457 }
1458 
1459 /* 1 MB per cpu, in page units */
1460 #define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT))
1461 
1462 static inline void
sk_memory_allocated_add(struct sock * sk,int amt)1463 sk_memory_allocated_add(struct sock *sk, int amt)
1464 {
1465 	int local_reserve;
1466 
1467 	preempt_disable();
1468 	local_reserve = __this_cpu_add_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1469 	if (local_reserve >= SK_MEMORY_PCPU_RESERVE) {
1470 		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1471 		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1472 	}
1473 	preempt_enable();
1474 }
1475 
1476 static inline void
sk_memory_allocated_sub(struct sock * sk,int amt)1477 sk_memory_allocated_sub(struct sock *sk, int amt)
1478 {
1479 	int local_reserve;
1480 
1481 	preempt_disable();
1482 	local_reserve = __this_cpu_sub_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1483 	if (local_reserve <= -SK_MEMORY_PCPU_RESERVE) {
1484 		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1485 		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1486 	}
1487 	preempt_enable();
1488 }
1489 
1490 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1491 
sk_sockets_allocated_dec(struct sock * sk)1492 static inline void sk_sockets_allocated_dec(struct sock *sk)
1493 {
1494 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1495 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1496 }
1497 
sk_sockets_allocated_inc(struct sock * sk)1498 static inline void sk_sockets_allocated_inc(struct sock *sk)
1499 {
1500 	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1501 				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1502 }
1503 
1504 static inline u64
sk_sockets_allocated_read_positive(struct sock * sk)1505 sk_sockets_allocated_read_positive(struct sock *sk)
1506 {
1507 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1508 }
1509 
1510 static inline int
proto_sockets_allocated_sum_positive(struct proto * prot)1511 proto_sockets_allocated_sum_positive(struct proto *prot)
1512 {
1513 	return percpu_counter_sum_positive(prot->sockets_allocated);
1514 }
1515 
1516 static inline bool
proto_memory_pressure(struct proto * prot)1517 proto_memory_pressure(struct proto *prot)
1518 {
1519 	if (!prot->memory_pressure)
1520 		return false;
1521 	return !!READ_ONCE(*prot->memory_pressure);
1522 }
1523 
1524 
1525 #ifdef CONFIG_PROC_FS
1526 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1527 struct prot_inuse {
1528 	int all;
1529 	int val[PROTO_INUSE_NR];
1530 };
1531 
sock_prot_inuse_add(const struct net * net,const struct proto * prot,int val)1532 static inline void sock_prot_inuse_add(const struct net *net,
1533 				       const struct proto *prot, int val)
1534 {
1535 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1536 }
1537 
sock_inuse_add(const struct net * net,int val)1538 static inline void sock_inuse_add(const struct net *net, int val)
1539 {
1540 	this_cpu_add(net->core.prot_inuse->all, val);
1541 }
1542 
1543 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1544 int sock_inuse_get(struct net *net);
1545 #else
sock_prot_inuse_add(const struct net * net,const struct proto * prot,int val)1546 static inline void sock_prot_inuse_add(const struct net *net,
1547 				       const struct proto *prot, int val)
1548 {
1549 }
1550 
sock_inuse_add(const struct net * net,int val)1551 static inline void sock_inuse_add(const struct net *net, int val)
1552 {
1553 }
1554 #endif
1555 
1556 
1557 /* With per-bucket locks this operation is not-atomic, so that
1558  * this version is not worse.
1559  */
__sk_prot_rehash(struct sock * sk)1560 static inline int __sk_prot_rehash(struct sock *sk)
1561 {
1562 	sk->sk_prot->unhash(sk);
1563 	return sk->sk_prot->hash(sk);
1564 }
1565 
1566 /* About 10 seconds */
1567 #define SOCK_DESTROY_TIME (10*HZ)
1568 
1569 /* Sockets 0-1023 can't be bound to unless you are superuser */
1570 #define PROT_SOCK	1024
1571 
1572 #define SHUTDOWN_MASK	3
1573 #define RCV_SHUTDOWN	1
1574 #define SEND_SHUTDOWN	2
1575 
1576 #define SOCK_BINDADDR_LOCK	4
1577 #define SOCK_BINDPORT_LOCK	8
1578 
1579 struct socket_alloc {
1580 	struct socket socket;
1581 	struct inode vfs_inode;
1582 };
1583 
SOCKET_I(struct inode * inode)1584 static inline struct socket *SOCKET_I(struct inode *inode)
1585 {
1586 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1587 }
1588 
SOCK_INODE(struct socket * socket)1589 static inline struct inode *SOCK_INODE(struct socket *socket)
1590 {
1591 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1592 }
1593 
1594 /*
1595  * Functions for memory accounting
1596  */
1597 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1598 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1599 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1600 void __sk_mem_reclaim(struct sock *sk, int amount);
1601 
1602 #define SK_MEM_SEND	0
1603 #define SK_MEM_RECV	1
1604 
1605 /* sysctl_mem values are in pages */
sk_prot_mem_limits(const struct sock * sk,int index)1606 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1607 {
1608 	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1609 }
1610 
sk_mem_pages(int amt)1611 static inline int sk_mem_pages(int amt)
1612 {
1613 	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1614 }
1615 
sk_has_account(struct sock * sk)1616 static inline bool sk_has_account(struct sock *sk)
1617 {
1618 	/* return true if protocol supports memory accounting */
1619 	return !!sk->sk_prot->memory_allocated;
1620 }
1621 
sk_wmem_schedule(struct sock * sk,int size)1622 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1623 {
1624 	int delta;
1625 
1626 	if (!sk_has_account(sk))
1627 		return true;
1628 	delta = size - sk->sk_forward_alloc;
1629 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1630 }
1631 
1632 static inline bool
sk_rmem_schedule(struct sock * sk,struct sk_buff * skb,int size)1633 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1634 {
1635 	int delta;
1636 
1637 	if (!sk_has_account(sk))
1638 		return true;
1639 	delta = size - sk->sk_forward_alloc;
1640 	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1641 		skb_pfmemalloc(skb);
1642 }
1643 
sk_unused_reserved_mem(const struct sock * sk)1644 static inline int sk_unused_reserved_mem(const struct sock *sk)
1645 {
1646 	int unused_mem;
1647 
1648 	if (likely(!sk->sk_reserved_mem))
1649 		return 0;
1650 
1651 	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1652 			atomic_read(&sk->sk_rmem_alloc);
1653 
1654 	return unused_mem > 0 ? unused_mem : 0;
1655 }
1656 
sk_mem_reclaim(struct sock * sk)1657 static inline void sk_mem_reclaim(struct sock *sk)
1658 {
1659 	int reclaimable;
1660 
1661 	if (!sk_has_account(sk))
1662 		return;
1663 
1664 	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1665 
1666 	if (reclaimable >= (int)PAGE_SIZE)
1667 		__sk_mem_reclaim(sk, reclaimable);
1668 }
1669 
sk_mem_reclaim_final(struct sock * sk)1670 static inline void sk_mem_reclaim_final(struct sock *sk)
1671 {
1672 	sk->sk_reserved_mem = 0;
1673 	sk_mem_reclaim(sk);
1674 }
1675 
sk_mem_charge(struct sock * sk,int size)1676 static inline void sk_mem_charge(struct sock *sk, int size)
1677 {
1678 	if (!sk_has_account(sk))
1679 		return;
1680 	sk_forward_alloc_add(sk, -size);
1681 }
1682 
sk_mem_uncharge(struct sock * sk,int size)1683 static inline void sk_mem_uncharge(struct sock *sk, int size)
1684 {
1685 	if (!sk_has_account(sk))
1686 		return;
1687 	sk_forward_alloc_add(sk, size);
1688 	sk_mem_reclaim(sk);
1689 }
1690 
1691 /*
1692  * Macro so as to not evaluate some arguments when
1693  * lockdep is not enabled.
1694  *
1695  * Mark both the sk_lock and the sk_lock.slock as a
1696  * per-address-family lock class.
1697  */
1698 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1699 do {									\
1700 	sk->sk_lock.owned = 0;						\
1701 	init_waitqueue_head(&sk->sk_lock.wq);				\
1702 	spin_lock_init(&(sk)->sk_lock.slock);				\
1703 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1704 			sizeof((sk)->sk_lock));				\
1705 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1706 				(skey), (sname));				\
1707 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1708 } while (0)
1709 
lockdep_sock_is_held(const struct sock * sk)1710 static inline bool lockdep_sock_is_held(const struct sock *sk)
1711 {
1712 	return lockdep_is_held(&sk->sk_lock) ||
1713 	       lockdep_is_held(&sk->sk_lock.slock);
1714 }
1715 
1716 void lock_sock_nested(struct sock *sk, int subclass);
1717 
lock_sock(struct sock * sk)1718 static inline void lock_sock(struct sock *sk)
1719 {
1720 	lock_sock_nested(sk, 0);
1721 }
1722 
1723 void __lock_sock(struct sock *sk);
1724 void __release_sock(struct sock *sk);
1725 void release_sock(struct sock *sk);
1726 
1727 /* BH context may only use the following locking interface. */
1728 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1729 #define bh_lock_sock_nested(__sk) \
1730 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1731 				SINGLE_DEPTH_NESTING)
1732 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1733 
1734 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1735 
1736 /**
1737  * lock_sock_fast - fast version of lock_sock
1738  * @sk: socket
1739  *
1740  * This version should be used for very small section, where process wont block
1741  * return false if fast path is taken:
1742  *
1743  *   sk_lock.slock locked, owned = 0, BH disabled
1744  *
1745  * return true if slow path is taken:
1746  *
1747  *   sk_lock.slock unlocked, owned = 1, BH enabled
1748  */
lock_sock_fast(struct sock * sk)1749 static inline bool lock_sock_fast(struct sock *sk)
1750 {
1751 	/* The sk_lock has mutex_lock() semantics here. */
1752 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1753 
1754 	return __lock_sock_fast(sk);
1755 }
1756 
1757 /* fast socket lock variant for caller already holding a [different] socket lock */
lock_sock_fast_nested(struct sock * sk)1758 static inline bool lock_sock_fast_nested(struct sock *sk)
1759 {
1760 	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1761 
1762 	return __lock_sock_fast(sk);
1763 }
1764 
1765 /**
1766  * unlock_sock_fast - complement of lock_sock_fast
1767  * @sk: socket
1768  * @slow: slow mode
1769  *
1770  * fast unlock socket for user context.
1771  * If slow mode is on, we call regular release_sock()
1772  */
unlock_sock_fast(struct sock * sk,bool slow)1773 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1774 	__releases(&sk->sk_lock.slock)
1775 {
1776 	if (slow) {
1777 		release_sock(sk);
1778 		__release(&sk->sk_lock.slock);
1779 	} else {
1780 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1781 		spin_unlock_bh(&sk->sk_lock.slock);
1782 	}
1783 }
1784 
1785 void sockopt_lock_sock(struct sock *sk);
1786 void sockopt_release_sock(struct sock *sk);
1787 bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1788 bool sockopt_capable(int cap);
1789 
1790 /* Used by processes to "lock" a socket state, so that
1791  * interrupts and bottom half handlers won't change it
1792  * from under us. It essentially blocks any incoming
1793  * packets, so that we won't get any new data or any
1794  * packets that change the state of the socket.
1795  *
1796  * While locked, BH processing will add new packets to
1797  * the backlog queue.  This queue is processed by the
1798  * owner of the socket lock right before it is released.
1799  *
1800  * Since ~2.3.5 it is also exclusive sleep lock serializing
1801  * accesses from user process context.
1802  */
1803 
sock_owned_by_me(const struct sock * sk)1804 static inline void sock_owned_by_me(const struct sock *sk)
1805 {
1806 #ifdef CONFIG_LOCKDEP
1807 	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1808 #endif
1809 }
1810 
sock_owned_by_user(const struct sock * sk)1811 static inline bool sock_owned_by_user(const struct sock *sk)
1812 {
1813 	sock_owned_by_me(sk);
1814 	return sk->sk_lock.owned;
1815 }
1816 
sock_owned_by_user_nocheck(const struct sock * sk)1817 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1818 {
1819 	return sk->sk_lock.owned;
1820 }
1821 
sock_release_ownership(struct sock * sk)1822 static inline void sock_release_ownership(struct sock *sk)
1823 {
1824 	if (sock_owned_by_user_nocheck(sk)) {
1825 		sk->sk_lock.owned = 0;
1826 
1827 		/* The sk_lock has mutex_unlock() semantics: */
1828 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1829 	}
1830 }
1831 
1832 /* no reclassification while locks are held */
sock_allow_reclassification(const struct sock * csk)1833 static inline bool sock_allow_reclassification(const struct sock *csk)
1834 {
1835 	struct sock *sk = (struct sock *)csk;
1836 
1837 	return !sock_owned_by_user_nocheck(sk) &&
1838 		!spin_is_locked(&sk->sk_lock.slock);
1839 }
1840 
1841 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1842 		      struct proto *prot, int kern);
1843 void sk_free(struct sock *sk);
1844 void sk_destruct(struct sock *sk);
1845 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1846 void sk_free_unlock_clone(struct sock *sk);
1847 
1848 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1849 			     gfp_t priority);
1850 void __sock_wfree(struct sk_buff *skb);
1851 void sock_wfree(struct sk_buff *skb);
1852 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1853 			     gfp_t priority);
1854 void skb_orphan_partial(struct sk_buff *skb);
1855 void sock_rfree(struct sk_buff *skb);
1856 void sock_efree(struct sk_buff *skb);
1857 #ifdef CONFIG_INET
1858 void sock_edemux(struct sk_buff *skb);
1859 void sock_pfree(struct sk_buff *skb);
1860 #else
1861 #define sock_edemux sock_efree
1862 #endif
1863 
1864 int sk_setsockopt(struct sock *sk, int level, int optname,
1865 		  sockptr_t optval, unsigned int optlen);
1866 int sock_setsockopt(struct socket *sock, int level, int op,
1867 		    sockptr_t optval, unsigned int optlen);
1868 
1869 int sk_getsockopt(struct sock *sk, int level, int optname,
1870 		  sockptr_t optval, sockptr_t optlen);
1871 int sock_getsockopt(struct socket *sock, int level, int op,
1872 		    char __user *optval, int __user *optlen);
1873 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1874 		   bool timeval, bool time32);
1875 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1876 				     unsigned long data_len, int noblock,
1877 				     int *errcode, int max_page_order);
1878 
sock_alloc_send_skb(struct sock * sk,unsigned long size,int noblock,int * errcode)1879 static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1880 						  unsigned long size,
1881 						  int noblock, int *errcode)
1882 {
1883 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1884 }
1885 
1886 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1887 void sock_kfree_s(struct sock *sk, void *mem, int size);
1888 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1889 void sk_send_sigurg(struct sock *sk);
1890 
sock_replace_proto(struct sock * sk,struct proto * proto)1891 static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1892 {
1893 	if (sk->sk_socket)
1894 		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1895 	WRITE_ONCE(sk->sk_prot, proto);
1896 }
1897 
1898 struct sockcm_cookie {
1899 	u64 transmit_time;
1900 	u32 mark;
1901 	u32 tsflags;
1902 };
1903 
sockcm_init(struct sockcm_cookie * sockc,const struct sock * sk)1904 static inline void sockcm_init(struct sockcm_cookie *sockc,
1905 			       const struct sock *sk)
1906 {
1907 	*sockc = (struct sockcm_cookie) {
1908 		.tsflags = READ_ONCE(sk->sk_tsflags)
1909 	};
1910 }
1911 
1912 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1913 		     struct sockcm_cookie *sockc);
1914 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1915 		   struct sockcm_cookie *sockc);
1916 
1917 /*
1918  * Functions to fill in entries in struct proto_ops when a protocol
1919  * does not implement a particular function.
1920  */
1921 int sock_no_bind(struct socket *, struct sockaddr *, int);
1922 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1923 int sock_no_socketpair(struct socket *, struct socket *);
1924 int sock_no_accept(struct socket *, struct socket *, int, bool);
1925 int sock_no_getname(struct socket *, struct sockaddr *, int);
1926 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1927 int sock_no_listen(struct socket *, int);
1928 int sock_no_shutdown(struct socket *, int);
1929 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1930 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1931 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1932 int sock_no_mmap(struct file *file, struct socket *sock,
1933 		 struct vm_area_struct *vma);
1934 
1935 /*
1936  * Functions to fill in entries in struct proto_ops when a protocol
1937  * uses the inet style.
1938  */
1939 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1940 				  char __user *optval, int __user *optlen);
1941 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1942 			int flags);
1943 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1944 			   sockptr_t optval, unsigned int optlen);
1945 
1946 void sk_common_release(struct sock *sk);
1947 
1948 /*
1949  *	Default socket callbacks and setup code
1950  */
1951 
1952 /* Initialise core socket variables using an explicit uid. */
1953 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1954 
1955 /* Initialise core socket variables.
1956  * Assumes struct socket *sock is embedded in a struct socket_alloc.
1957  */
1958 void sock_init_data(struct socket *sock, struct sock *sk);
1959 
1960 /*
1961  * Socket reference counting postulates.
1962  *
1963  * * Each user of socket SHOULD hold a reference count.
1964  * * Each access point to socket (an hash table bucket, reference from a list,
1965  *   running timer, skb in flight MUST hold a reference count.
1966  * * When reference count hits 0, it means it will never increase back.
1967  * * When reference count hits 0, it means that no references from
1968  *   outside exist to this socket and current process on current CPU
1969  *   is last user and may/should destroy this socket.
1970  * * sk_free is called from any context: process, BH, IRQ. When
1971  *   it is called, socket has no references from outside -> sk_free
1972  *   may release descendant resources allocated by the socket, but
1973  *   to the time when it is called, socket is NOT referenced by any
1974  *   hash tables, lists etc.
1975  * * Packets, delivered from outside (from network or from another process)
1976  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1977  *   when they sit in queue. Otherwise, packets will leak to hole, when
1978  *   socket is looked up by one cpu and unhasing is made by another CPU.
1979  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1980  *   (leak to backlog). Packet socket does all the processing inside
1981  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1982  *   use separate SMP lock, so that they are prone too.
1983  */
1984 
1985 /* Ungrab socket and destroy it, if it was the last reference. */
sock_put(struct sock * sk)1986 static inline void sock_put(struct sock *sk)
1987 {
1988 	if (refcount_dec_and_test(&sk->sk_refcnt))
1989 		sk_free(sk);
1990 }
1991 /* Generic version of sock_put(), dealing with all sockets
1992  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1993  */
1994 void sock_gen_put(struct sock *sk);
1995 
1996 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1997 		     unsigned int trim_cap, bool refcounted);
sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested)1998 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1999 				 const int nested)
2000 {
2001 	return __sk_receive_skb(sk, skb, nested, 1, true);
2002 }
2003 
sk_tx_queue_set(struct sock * sk,int tx_queue)2004 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
2005 {
2006 	/* sk_tx_queue_mapping accept only upto a 16-bit value */
2007 	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
2008 		return;
2009 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2010 	 * other WRITE_ONCE() because socket lock might be not held.
2011 	 */
2012 	WRITE_ONCE(sk->sk_tx_queue_mapping, tx_queue);
2013 }
2014 
2015 #define NO_QUEUE_MAPPING	USHRT_MAX
2016 
sk_tx_queue_clear(struct sock * sk)2017 static inline void sk_tx_queue_clear(struct sock *sk)
2018 {
2019 	/* Paired with READ_ONCE() in sk_tx_queue_get() and
2020 	 * other WRITE_ONCE() because socket lock might be not held.
2021 	 */
2022 	WRITE_ONCE(sk->sk_tx_queue_mapping, NO_QUEUE_MAPPING);
2023 }
2024 
sk_tx_queue_get(const struct sock * sk)2025 static inline int sk_tx_queue_get(const struct sock *sk)
2026 {
2027 	if (sk) {
2028 		/* Paired with WRITE_ONCE() in sk_tx_queue_clear()
2029 		 * and sk_tx_queue_set().
2030 		 */
2031 		int val = READ_ONCE(sk->sk_tx_queue_mapping);
2032 
2033 		if (val != NO_QUEUE_MAPPING)
2034 			return val;
2035 	}
2036 	return -1;
2037 }
2038 
__sk_rx_queue_set(struct sock * sk,const struct sk_buff * skb,bool force_set)2039 static inline void __sk_rx_queue_set(struct sock *sk,
2040 				     const struct sk_buff *skb,
2041 				     bool force_set)
2042 {
2043 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2044 	if (skb_rx_queue_recorded(skb)) {
2045 		u16 rx_queue = skb_get_rx_queue(skb);
2046 
2047 		if (force_set ||
2048 		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2049 			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
2050 	}
2051 #endif
2052 }
2053 
sk_rx_queue_set(struct sock * sk,const struct sk_buff * skb)2054 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2055 {
2056 	__sk_rx_queue_set(sk, skb, true);
2057 }
2058 
sk_rx_queue_update(struct sock * sk,const struct sk_buff * skb)2059 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2060 {
2061 	__sk_rx_queue_set(sk, skb, false);
2062 }
2063 
sk_rx_queue_clear(struct sock * sk)2064 static inline void sk_rx_queue_clear(struct sock *sk)
2065 {
2066 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2067 	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2068 #endif
2069 }
2070 
sk_rx_queue_get(const struct sock * sk)2071 static inline int sk_rx_queue_get(const struct sock *sk)
2072 {
2073 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2074 	if (sk) {
2075 		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2076 
2077 		if (res != NO_QUEUE_MAPPING)
2078 			return res;
2079 	}
2080 #endif
2081 
2082 	return -1;
2083 }
2084 
sk_set_socket(struct sock * sk,struct socket * sock)2085 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2086 {
2087 	sk->sk_socket = sock;
2088 }
2089 
sk_sleep(struct sock * sk)2090 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2091 {
2092 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2093 	return &rcu_dereference_raw(sk->sk_wq)->wait;
2094 }
2095 /* Detach socket from process context.
2096  * Announce socket dead, detach it from wait queue and inode.
2097  * Note that parent inode held reference count on this struct sock,
2098  * we do not release it in this function, because protocol
2099  * probably wants some additional cleanups or even continuing
2100  * to work with this socket (TCP).
2101  */
sock_orphan(struct sock * sk)2102 static inline void sock_orphan(struct sock *sk)
2103 {
2104 	write_lock_bh(&sk->sk_callback_lock);
2105 	sock_set_flag(sk, SOCK_DEAD);
2106 	sk_set_socket(sk, NULL);
2107 	sk->sk_wq  = NULL;
2108 	write_unlock_bh(&sk->sk_callback_lock);
2109 }
2110 
sock_graft(struct sock * sk,struct socket * parent)2111 static inline void sock_graft(struct sock *sk, struct socket *parent)
2112 {
2113 	WARN_ON(parent->sk);
2114 	write_lock_bh(&sk->sk_callback_lock);
2115 	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2116 	parent->sk = sk;
2117 	sk_set_socket(sk, parent);
2118 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
2119 	security_sock_graft(sk, parent);
2120 	write_unlock_bh(&sk->sk_callback_lock);
2121 }
2122 
2123 kuid_t sock_i_uid(struct sock *sk);
2124 unsigned long __sock_i_ino(struct sock *sk);
2125 unsigned long sock_i_ino(struct sock *sk);
2126 
sock_net_uid(const struct net * net,const struct sock * sk)2127 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2128 {
2129 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
2130 }
2131 
net_tx_rndhash(void)2132 static inline u32 net_tx_rndhash(void)
2133 {
2134 	u32 v = get_random_u32();
2135 
2136 	return v ?: 1;
2137 }
2138 
sk_set_txhash(struct sock * sk)2139 static inline void sk_set_txhash(struct sock *sk)
2140 {
2141 	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2142 	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2143 }
2144 
sk_rethink_txhash(struct sock * sk)2145 static inline bool sk_rethink_txhash(struct sock *sk)
2146 {
2147 	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2148 		sk_set_txhash(sk);
2149 		return true;
2150 	}
2151 	return false;
2152 }
2153 
2154 static inline struct dst_entry *
__sk_dst_get(const struct sock * sk)2155 __sk_dst_get(const struct sock *sk)
2156 {
2157 	return rcu_dereference_check(sk->sk_dst_cache,
2158 				     lockdep_sock_is_held(sk));
2159 }
2160 
2161 static inline struct dst_entry *
sk_dst_get(const struct sock * sk)2162 sk_dst_get(const struct sock *sk)
2163 {
2164 	struct dst_entry *dst;
2165 
2166 	rcu_read_lock();
2167 	dst = rcu_dereference(sk->sk_dst_cache);
2168 	if (dst && !rcuref_get(&dst->__rcuref))
2169 		dst = NULL;
2170 	rcu_read_unlock();
2171 	return dst;
2172 }
2173 
__dst_negative_advice(struct sock * sk)2174 static inline void __dst_negative_advice(struct sock *sk)
2175 {
2176 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
2177 
2178 	if (dst && dst->ops->negative_advice) {
2179 		ndst = dst->ops->negative_advice(dst);
2180 
2181 		if (ndst != dst) {
2182 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
2183 			sk_tx_queue_clear(sk);
2184 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2185 		}
2186 	}
2187 }
2188 
dst_negative_advice(struct sock * sk)2189 static inline void dst_negative_advice(struct sock *sk)
2190 {
2191 	sk_rethink_txhash(sk);
2192 	__dst_negative_advice(sk);
2193 }
2194 
2195 static inline void
__sk_dst_set(struct sock * sk,struct dst_entry * dst)2196 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2197 {
2198 	struct dst_entry *old_dst;
2199 
2200 	sk_tx_queue_clear(sk);
2201 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2202 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2203 					    lockdep_sock_is_held(sk));
2204 	rcu_assign_pointer(sk->sk_dst_cache, dst);
2205 	dst_release(old_dst);
2206 }
2207 
2208 static inline void
sk_dst_set(struct sock * sk,struct dst_entry * dst)2209 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2210 {
2211 	struct dst_entry *old_dst;
2212 
2213 	sk_tx_queue_clear(sk);
2214 	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2215 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2216 	dst_release(old_dst);
2217 }
2218 
2219 static inline void
__sk_dst_reset(struct sock * sk)2220 __sk_dst_reset(struct sock *sk)
2221 {
2222 	__sk_dst_set(sk, NULL);
2223 }
2224 
2225 static inline void
sk_dst_reset(struct sock * sk)2226 sk_dst_reset(struct sock *sk)
2227 {
2228 	sk_dst_set(sk, NULL);
2229 }
2230 
2231 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2232 
2233 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2234 
sk_dst_confirm(struct sock * sk)2235 static inline void sk_dst_confirm(struct sock *sk)
2236 {
2237 	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2238 		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2239 }
2240 
sock_confirm_neigh(struct sk_buff * skb,struct neighbour * n)2241 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2242 {
2243 	if (skb_get_dst_pending_confirm(skb)) {
2244 		struct sock *sk = skb->sk;
2245 
2246 		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2247 			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2248 		neigh_confirm(n);
2249 	}
2250 }
2251 
2252 bool sk_mc_loop(struct sock *sk);
2253 
sk_can_gso(const struct sock * sk)2254 static inline bool sk_can_gso(const struct sock *sk)
2255 {
2256 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2257 }
2258 
2259 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2260 
sk_gso_disable(struct sock * sk)2261 static inline void sk_gso_disable(struct sock *sk)
2262 {
2263 	sk->sk_gso_disabled = 1;
2264 	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2265 }
2266 
skb_do_copy_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,char * to,int copy,int offset)2267 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2268 					   struct iov_iter *from, char *to,
2269 					   int copy, int offset)
2270 {
2271 	if (skb->ip_summed == CHECKSUM_NONE) {
2272 		__wsum csum = 0;
2273 		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2274 			return -EFAULT;
2275 		skb->csum = csum_block_add(skb->csum, csum, offset);
2276 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2277 		if (!copy_from_iter_full_nocache(to, copy, from))
2278 			return -EFAULT;
2279 	} else if (!copy_from_iter_full(to, copy, from))
2280 		return -EFAULT;
2281 
2282 	return 0;
2283 }
2284 
skb_add_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,int copy)2285 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2286 				       struct iov_iter *from, int copy)
2287 {
2288 	int err, offset = skb->len;
2289 
2290 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2291 				       copy, offset);
2292 	if (err)
2293 		__skb_trim(skb, offset);
2294 
2295 	return err;
2296 }
2297 
skb_copy_to_page_nocache(struct sock * sk,struct iov_iter * from,struct sk_buff * skb,struct page * page,int off,int copy)2298 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2299 					   struct sk_buff *skb,
2300 					   struct page *page,
2301 					   int off, int copy)
2302 {
2303 	int err;
2304 
2305 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2306 				       copy, skb->len);
2307 	if (err)
2308 		return err;
2309 
2310 	skb_len_add(skb, copy);
2311 	sk_wmem_queued_add(sk, copy);
2312 	sk_mem_charge(sk, copy);
2313 	return 0;
2314 }
2315 
2316 /**
2317  * sk_wmem_alloc_get - returns write allocations
2318  * @sk: socket
2319  *
2320  * Return: sk_wmem_alloc minus initial offset of one
2321  */
sk_wmem_alloc_get(const struct sock * sk)2322 static inline int sk_wmem_alloc_get(const struct sock *sk)
2323 {
2324 	return refcount_read(&sk->sk_wmem_alloc) - 1;
2325 }
2326 
2327 /**
2328  * sk_rmem_alloc_get - returns read allocations
2329  * @sk: socket
2330  *
2331  * Return: sk_rmem_alloc
2332  */
sk_rmem_alloc_get(const struct sock * sk)2333 static inline int sk_rmem_alloc_get(const struct sock *sk)
2334 {
2335 	return atomic_read(&sk->sk_rmem_alloc);
2336 }
2337 
2338 /**
2339  * sk_has_allocations - check if allocations are outstanding
2340  * @sk: socket
2341  *
2342  * Return: true if socket has write or read allocations
2343  */
sk_has_allocations(const struct sock * sk)2344 static inline bool sk_has_allocations(const struct sock *sk)
2345 {
2346 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2347 }
2348 
2349 /**
2350  * skwq_has_sleeper - check if there are any waiting processes
2351  * @wq: struct socket_wq
2352  *
2353  * Return: true if socket_wq has waiting processes
2354  *
2355  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2356  * barrier call. They were added due to the race found within the tcp code.
2357  *
2358  * Consider following tcp code paths::
2359  *
2360  *   CPU1                CPU2
2361  *   sys_select          receive packet
2362  *   ...                 ...
2363  *   __add_wait_queue    update tp->rcv_nxt
2364  *   ...                 ...
2365  *   tp->rcv_nxt check   sock_def_readable
2366  *   ...                 {
2367  *   schedule               rcu_read_lock();
2368  *                          wq = rcu_dereference(sk->sk_wq);
2369  *                          if (wq && waitqueue_active(&wq->wait))
2370  *                              wake_up_interruptible(&wq->wait)
2371  *                          ...
2372  *                       }
2373  *
2374  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2375  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2376  * could then endup calling schedule and sleep forever if there are no more
2377  * data on the socket.
2378  *
2379  */
skwq_has_sleeper(struct socket_wq * wq)2380 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2381 {
2382 	return wq && wq_has_sleeper(&wq->wait);
2383 }
2384 
2385 /**
2386  * sock_poll_wait - place memory barrier behind the poll_wait call.
2387  * @filp:           file
2388  * @sock:           socket to wait on
2389  * @p:              poll_table
2390  *
2391  * See the comments in the wq_has_sleeper function.
2392  */
sock_poll_wait(struct file * filp,struct socket * sock,poll_table * p)2393 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2394 				  poll_table *p)
2395 {
2396 	if (!poll_does_not_wait(p)) {
2397 		poll_wait(filp, &sock->wq.wait, p);
2398 		/* We need to be sure we are in sync with the
2399 		 * socket flags modification.
2400 		 *
2401 		 * This memory barrier is paired in the wq_has_sleeper.
2402 		 */
2403 		smp_mb();
2404 	}
2405 }
2406 
skb_set_hash_from_sk(struct sk_buff * skb,struct sock * sk)2407 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2408 {
2409 	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2410 	u32 txhash = READ_ONCE(sk->sk_txhash);
2411 
2412 	if (txhash) {
2413 		skb->l4_hash = 1;
2414 		skb->hash = txhash;
2415 	}
2416 }
2417 
2418 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2419 
2420 /*
2421  *	Queue a received datagram if it will fit. Stream and sequenced
2422  *	protocols can't normally use this as they need to fit buffers in
2423  *	and play with them.
2424  *
2425  *	Inlined as it's very short and called for pretty much every
2426  *	packet ever received.
2427  */
skb_set_owner_r(struct sk_buff * skb,struct sock * sk)2428 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2429 {
2430 	skb_orphan(skb);
2431 	skb->sk = sk;
2432 	skb->destructor = sock_rfree;
2433 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2434 	sk_mem_charge(sk, skb->truesize);
2435 }
2436 
skb_set_owner_sk_safe(struct sk_buff * skb,struct sock * sk)2437 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2438 {
2439 	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2440 		skb_orphan(skb);
2441 		skb->destructor = sock_efree;
2442 		skb->sk = sk;
2443 		return true;
2444 	}
2445 	return false;
2446 }
2447 
skb_clone_and_charge_r(struct sk_buff * skb,struct sock * sk)2448 static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2449 {
2450 	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2451 	if (skb) {
2452 		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2453 			skb_set_owner_r(skb, sk);
2454 			return skb;
2455 		}
2456 		__kfree_skb(skb);
2457 	}
2458 	return NULL;
2459 }
2460 
skb_prepare_for_gro(struct sk_buff * skb)2461 static inline void skb_prepare_for_gro(struct sk_buff *skb)
2462 {
2463 	if (skb->destructor != sock_wfree) {
2464 		skb_orphan(skb);
2465 		return;
2466 	}
2467 	skb->slow_gro = 1;
2468 }
2469 
2470 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2471 		    unsigned long expires);
2472 
2473 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2474 
2475 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2476 
2477 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2478 			struct sk_buff *skb, unsigned int flags,
2479 			void (*destructor)(struct sock *sk,
2480 					   struct sk_buff *skb));
2481 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2482 
2483 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2484 			      enum skb_drop_reason *reason);
2485 
sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)2486 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2487 {
2488 	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2489 }
2490 
2491 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2492 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2493 
2494 /*
2495  *	Recover an error report and clear atomically
2496  */
2497 
sock_error(struct sock * sk)2498 static inline int sock_error(struct sock *sk)
2499 {
2500 	int err;
2501 
2502 	/* Avoid an atomic operation for the common case.
2503 	 * This is racy since another cpu/thread can change sk_err under us.
2504 	 */
2505 	if (likely(data_race(!sk->sk_err)))
2506 		return 0;
2507 
2508 	err = xchg(&sk->sk_err, 0);
2509 	return -err;
2510 }
2511 
2512 void sk_error_report(struct sock *sk);
2513 
sock_wspace(struct sock * sk)2514 static inline unsigned long sock_wspace(struct sock *sk)
2515 {
2516 	int amt = 0;
2517 
2518 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2519 		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2520 		if (amt < 0)
2521 			amt = 0;
2522 	}
2523 	return amt;
2524 }
2525 
2526 /* Note:
2527  *  We use sk->sk_wq_raw, from contexts knowing this
2528  *  pointer is not NULL and cannot disappear/change.
2529  */
sk_set_bit(int nr,struct sock * sk)2530 static inline void sk_set_bit(int nr, struct sock *sk)
2531 {
2532 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2533 	    !sock_flag(sk, SOCK_FASYNC))
2534 		return;
2535 
2536 	set_bit(nr, &sk->sk_wq_raw->flags);
2537 }
2538 
sk_clear_bit(int nr,struct sock * sk)2539 static inline void sk_clear_bit(int nr, struct sock *sk)
2540 {
2541 	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2542 	    !sock_flag(sk, SOCK_FASYNC))
2543 		return;
2544 
2545 	clear_bit(nr, &sk->sk_wq_raw->flags);
2546 }
2547 
sk_wake_async(const struct sock * sk,int how,int band)2548 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2549 {
2550 	if (sock_flag(sk, SOCK_FASYNC)) {
2551 		rcu_read_lock();
2552 		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2553 		rcu_read_unlock();
2554 	}
2555 }
2556 
2557 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2558  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2559  * Note: for send buffers, TCP works better if we can build two skbs at
2560  * minimum.
2561  */
2562 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2563 
2564 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2565 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2566 
sk_stream_moderate_sndbuf(struct sock * sk)2567 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2568 {
2569 	u32 val;
2570 
2571 	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2572 		return;
2573 
2574 	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2575 	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2576 
2577 	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2578 }
2579 
2580 /**
2581  * sk_page_frag - return an appropriate page_frag
2582  * @sk: socket
2583  *
2584  * Use the per task page_frag instead of the per socket one for
2585  * optimization when we know that we're in process context and own
2586  * everything that's associated with %current.
2587  *
2588  * Both direct reclaim and page faults can nest inside other
2589  * socket operations and end up recursing into sk_page_frag()
2590  * while it's already in use: explicitly avoid task page_frag
2591  * when users disable sk_use_task_frag.
2592  *
2593  * Return: a per task page_frag if context allows that,
2594  * otherwise a per socket one.
2595  */
sk_page_frag(struct sock * sk)2596 static inline struct page_frag *sk_page_frag(struct sock *sk)
2597 {
2598 	if (sk->sk_use_task_frag)
2599 		return &current->task_frag;
2600 
2601 	return &sk->sk_frag;
2602 }
2603 
2604 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2605 
2606 /*
2607  *	Default write policy as shown to user space via poll/select/SIGIO
2608  */
sock_writeable(const struct sock * sk)2609 static inline bool sock_writeable(const struct sock *sk)
2610 {
2611 	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2612 }
2613 
gfp_any(void)2614 static inline gfp_t gfp_any(void)
2615 {
2616 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2617 }
2618 
gfp_memcg_charge(void)2619 static inline gfp_t gfp_memcg_charge(void)
2620 {
2621 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2622 }
2623 
sock_rcvtimeo(const struct sock * sk,bool noblock)2624 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2625 {
2626 	return noblock ? 0 : sk->sk_rcvtimeo;
2627 }
2628 
sock_sndtimeo(const struct sock * sk,bool noblock)2629 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2630 {
2631 	return noblock ? 0 : sk->sk_sndtimeo;
2632 }
2633 
sock_rcvlowat(const struct sock * sk,int waitall,int len)2634 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2635 {
2636 	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2637 
2638 	return v ?: 1;
2639 }
2640 
2641 /* Alas, with timeout socket operations are not restartable.
2642  * Compare this to poll().
2643  */
sock_intr_errno(long timeo)2644 static inline int sock_intr_errno(long timeo)
2645 {
2646 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2647 }
2648 
2649 struct sock_skb_cb {
2650 	u32 dropcount;
2651 };
2652 
2653 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2654  * using skb->cb[] would keep using it directly and utilize its
2655  * alignement guarantee.
2656  */
2657 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2658 			    sizeof(struct sock_skb_cb)))
2659 
2660 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2661 			    SOCK_SKB_CB_OFFSET))
2662 
2663 #define sock_skb_cb_check_size(size) \
2664 	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2665 
2666 static inline void
sock_skb_set_dropcount(const struct sock * sk,struct sk_buff * skb)2667 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2668 {
2669 	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2670 						atomic_read(&sk->sk_drops) : 0;
2671 }
2672 
sk_drops_add(struct sock * sk,const struct sk_buff * skb)2673 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2674 {
2675 	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2676 
2677 	atomic_add(segs, &sk->sk_drops);
2678 }
2679 
sock_read_timestamp(struct sock * sk)2680 static inline ktime_t sock_read_timestamp(struct sock *sk)
2681 {
2682 #if BITS_PER_LONG==32
2683 	unsigned int seq;
2684 	ktime_t kt;
2685 
2686 	do {
2687 		seq = read_seqbegin(&sk->sk_stamp_seq);
2688 		kt = sk->sk_stamp;
2689 	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2690 
2691 	return kt;
2692 #else
2693 	return READ_ONCE(sk->sk_stamp);
2694 #endif
2695 }
2696 
sock_write_timestamp(struct sock * sk,ktime_t kt)2697 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2698 {
2699 #if BITS_PER_LONG==32
2700 	write_seqlock(&sk->sk_stamp_seq);
2701 	sk->sk_stamp = kt;
2702 	write_sequnlock(&sk->sk_stamp_seq);
2703 #else
2704 	WRITE_ONCE(sk->sk_stamp, kt);
2705 #endif
2706 }
2707 
2708 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2709 			   struct sk_buff *skb);
2710 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2711 			     struct sk_buff *skb);
2712 
2713 static inline void
sock_recv_timestamp(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2714 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2715 {
2716 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2717 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
2718 	ktime_t kt = skb->tstamp;
2719 	/*
2720 	 * generate control messages if
2721 	 * - receive time stamping in software requested
2722 	 * - software time stamp available and wanted
2723 	 * - hardware time stamps available and wanted
2724 	 */
2725 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2726 	    (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2727 	    (kt && tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2728 	    (hwtstamps->hwtstamp &&
2729 	     (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2730 		__sock_recv_timestamp(msg, sk, skb);
2731 	else
2732 		sock_write_timestamp(sk, kt);
2733 
2734 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb_wifi_acked_valid(skb))
2735 		__sock_recv_wifi_status(msg, sk, skb);
2736 }
2737 
2738 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2739 		       struct sk_buff *skb);
2740 
2741 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
sock_recv_cmsgs(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2742 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2743 				   struct sk_buff *skb)
2744 {
2745 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2746 			   (1UL << SOCK_RCVTSTAMP)			| \
2747 			   (1UL << SOCK_RCVMARK))
2748 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2749 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2750 
2751 	if (sk->sk_flags & FLAGS_RECV_CMSGS ||
2752 	    READ_ONCE(sk->sk_tsflags) & TSFLAGS_ANY)
2753 		__sock_recv_cmsgs(msg, sk, skb);
2754 	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2755 		sock_write_timestamp(sk, skb->tstamp);
2756 	else if (unlikely(sock_read_timestamp(sk) == SK_DEFAULT_STAMP))
2757 		sock_write_timestamp(sk, 0);
2758 }
2759 
2760 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2761 
2762 /**
2763  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2764  * @sk:		socket sending this packet
2765  * @tsflags:	timestamping flags to use
2766  * @tx_flags:	completed with instructions for time stamping
2767  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2768  *
2769  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2770  */
_sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags,__u32 * tskey)2771 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2772 				      __u8 *tx_flags, __u32 *tskey)
2773 {
2774 	if (unlikely(tsflags)) {
2775 		__sock_tx_timestamp(tsflags, tx_flags);
2776 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2777 		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2778 			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2779 	}
2780 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2781 		*tx_flags |= SKBTX_WIFI_STATUS;
2782 }
2783 
sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags)2784 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2785 				     __u8 *tx_flags)
2786 {
2787 	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2788 }
2789 
skb_setup_tx_timestamp(struct sk_buff * skb,__u16 tsflags)2790 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2791 {
2792 	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2793 			   &skb_shinfo(skb)->tskey);
2794 }
2795 
sk_is_inet(const struct sock * sk)2796 static inline bool sk_is_inet(const struct sock *sk)
2797 {
2798 	int family = READ_ONCE(sk->sk_family);
2799 
2800 	return family == AF_INET || family == AF_INET6;
2801 }
2802 
sk_is_tcp(const struct sock * sk)2803 static inline bool sk_is_tcp(const struct sock *sk)
2804 {
2805 	return sk_is_inet(sk) &&
2806 	       sk->sk_type == SOCK_STREAM &&
2807 	       sk->sk_protocol == IPPROTO_TCP;
2808 }
2809 
sk_is_udp(const struct sock * sk)2810 static inline bool sk_is_udp(const struct sock *sk)
2811 {
2812 	return sk_is_inet(sk) &&
2813 	       sk->sk_type == SOCK_DGRAM &&
2814 	       sk->sk_protocol == IPPROTO_UDP;
2815 }
2816 
sk_is_stream_unix(const struct sock * sk)2817 static inline bool sk_is_stream_unix(const struct sock *sk)
2818 {
2819 	return sk->sk_family == AF_UNIX && sk->sk_type == SOCK_STREAM;
2820 }
2821 
2822 /**
2823  * sk_eat_skb - Release a skb if it is no longer needed
2824  * @sk: socket to eat this skb from
2825  * @skb: socket buffer to eat
2826  *
2827  * This routine must be called with interrupts disabled or with the socket
2828  * locked so that the sk_buff queue operation is ok.
2829 */
sk_eat_skb(struct sock * sk,struct sk_buff * skb)2830 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2831 {
2832 	__skb_unlink(skb, &sk->sk_receive_queue);
2833 	__kfree_skb(skb);
2834 }
2835 
2836 static inline bool
skb_sk_is_prefetched(struct sk_buff * skb)2837 skb_sk_is_prefetched(struct sk_buff *skb)
2838 {
2839 #ifdef CONFIG_INET
2840 	return skb->destructor == sock_pfree;
2841 #else
2842 	return false;
2843 #endif /* CONFIG_INET */
2844 }
2845 
2846 /* This helper checks if a socket is a full socket,
2847  * ie _not_ a timewait or request socket.
2848  */
sk_fullsock(const struct sock * sk)2849 static inline bool sk_fullsock(const struct sock *sk)
2850 {
2851 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2852 }
2853 
2854 static inline bool
sk_is_refcounted(struct sock * sk)2855 sk_is_refcounted(struct sock *sk)
2856 {
2857 	/* Only full sockets have sk->sk_flags. */
2858 	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2859 }
2860 
2861 /**
2862  * skb_steal_sock - steal a socket from an sk_buff
2863  * @skb: sk_buff to steal the socket from
2864  * @refcounted: is set to true if the socket is reference-counted
2865  * @prefetched: is set to true if the socket was assigned from bpf
2866  */
2867 static inline struct sock *
skb_steal_sock(struct sk_buff * skb,bool * refcounted,bool * prefetched)2868 skb_steal_sock(struct sk_buff *skb, bool *refcounted, bool *prefetched)
2869 {
2870 	if (skb->sk) {
2871 		struct sock *sk = skb->sk;
2872 
2873 		*refcounted = true;
2874 		*prefetched = skb_sk_is_prefetched(skb);
2875 		if (*prefetched)
2876 			*refcounted = sk_is_refcounted(sk);
2877 		skb->destructor = NULL;
2878 		skb->sk = NULL;
2879 		return sk;
2880 	}
2881 	*prefetched = false;
2882 	*refcounted = false;
2883 	return NULL;
2884 }
2885 
2886 /* Checks if this SKB belongs to an HW offloaded socket
2887  * and whether any SW fallbacks are required based on dev.
2888  * Check decrypted mark in case skb_orphan() cleared socket.
2889  */
sk_validate_xmit_skb(struct sk_buff * skb,struct net_device * dev)2890 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2891 						   struct net_device *dev)
2892 {
2893 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2894 	struct sock *sk = skb->sk;
2895 
2896 	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2897 		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2898 #ifdef CONFIG_TLS_DEVICE
2899 	} else if (unlikely(skb->decrypted)) {
2900 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2901 		kfree_skb(skb);
2902 		skb = NULL;
2903 #endif
2904 	}
2905 #endif
2906 
2907 	return skb;
2908 }
2909 
2910 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2911  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2912  */
sk_listener(const struct sock * sk)2913 static inline bool sk_listener(const struct sock *sk)
2914 {
2915 	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2916 }
2917 
2918 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2919 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2920 		       int type);
2921 
2922 bool sk_ns_capable(const struct sock *sk,
2923 		   struct user_namespace *user_ns, int cap);
2924 bool sk_capable(const struct sock *sk, int cap);
2925 bool sk_net_capable(const struct sock *sk, int cap);
2926 
2927 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2928 
2929 /* Take into consideration the size of the struct sk_buff overhead in the
2930  * determination of these values, since that is non-constant across
2931  * platforms.  This makes socket queueing behavior and performance
2932  * not depend upon such differences.
2933  */
2934 #define _SK_MEM_PACKETS		256
2935 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2936 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2937 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2938 
2939 extern __u32 sysctl_wmem_max;
2940 extern __u32 sysctl_rmem_max;
2941 
2942 extern int sysctl_tstamp_allow_data;
2943 extern int sysctl_optmem_max;
2944 
2945 extern __u32 sysctl_wmem_default;
2946 extern __u32 sysctl_rmem_default;
2947 
2948 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2949 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2950 
sk_get_wmem0(const struct sock * sk,const struct proto * proto)2951 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2952 {
2953 	/* Does this proto have per netns sysctl_wmem ? */
2954 	if (proto->sysctl_wmem_offset)
2955 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
2956 
2957 	return READ_ONCE(*proto->sysctl_wmem);
2958 }
2959 
sk_get_rmem0(const struct sock * sk,const struct proto * proto)2960 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2961 {
2962 	/* Does this proto have per netns sysctl_rmem ? */
2963 	if (proto->sysctl_rmem_offset)
2964 		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
2965 
2966 	return READ_ONCE(*proto->sysctl_rmem);
2967 }
2968 
2969 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2970  * Some wifi drivers need to tweak it to get more chunks.
2971  * They can use this helper from their ndo_start_xmit()
2972  */
sk_pacing_shift_update(struct sock * sk,int val)2973 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2974 {
2975 	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2976 		return;
2977 	WRITE_ONCE(sk->sk_pacing_shift, val);
2978 }
2979 
2980 /* if a socket is bound to a device, check that the given device
2981  * index is either the same or that the socket is bound to an L3
2982  * master device and the given device index is also enslaved to
2983  * that L3 master
2984  */
sk_dev_equal_l3scope(struct sock * sk,int dif)2985 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2986 {
2987 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
2988 	int mdif;
2989 
2990 	if (!bound_dev_if || bound_dev_if == dif)
2991 		return true;
2992 
2993 	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2994 	if (mdif && mdif == bound_dev_if)
2995 		return true;
2996 
2997 	return false;
2998 }
2999 
3000 void sock_def_readable(struct sock *sk);
3001 
3002 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
3003 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
3004 int sock_set_timestamping(struct sock *sk, int optname,
3005 			  struct so_timestamping timestamping);
3006 
3007 void sock_enable_timestamps(struct sock *sk);
3008 void sock_no_linger(struct sock *sk);
3009 void sock_set_keepalive(struct sock *sk);
3010 void sock_set_priority(struct sock *sk, u32 priority);
3011 void sock_set_rcvbuf(struct sock *sk, int val);
3012 void sock_set_mark(struct sock *sk, u32 val);
3013 void sock_set_reuseaddr(struct sock *sk);
3014 void sock_set_reuseport(struct sock *sk);
3015 void sock_set_sndtimeo(struct sock *sk, s64 secs);
3016 
3017 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
3018 
3019 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
3020 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
3021 			   sockptr_t optval, int optlen, bool old_timeval);
3022 
3023 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
3024 		     void __user *arg, void *karg, size_t size);
3025 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
sk_is_readable(struct sock * sk)3026 static inline bool sk_is_readable(struct sock *sk)
3027 {
3028 	if (sk->sk_prot->sock_is_readable)
3029 		return sk->sk_prot->sock_is_readable(sk);
3030 	return false;
3031 }
3032 #endif	/* _SOCK_H */
3033