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TOMOYO Linux Cross Reference
Linux/include/net/sock.h

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  1 /* SPDX-License-Identifier: GPL-2.0-or-later */
  2 /*
  3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  4  *              operating system.  INET is implemented using the  BSD Socket
  5  *              interface as the means of communication with the user level.
  6  *
  7  *              Definitions for the AF_INET socket handler.
  8  *
  9  * Version:     @(#)sock.h      1.0.4   05/13/93
 10  *
 11  * Authors:     Ross Biro
 12  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 13  *              Corey Minyard <wf-rch!minyard@relay.EU.net>
 14  *              Florian La Roche <flla@stud.uni-sb.de>
 15  *
 16  * Fixes:
 17  *              Alan Cox        :       Volatiles in skbuff pointers. See
 18  *                                      skbuff comments. May be overdone,
 19  *                                      better to prove they can be removed
 20  *                                      than the reverse.
 21  *              Alan Cox        :       Added a zapped field for tcp to note
 22  *                                      a socket is reset and must stay shut up
 23  *              Alan Cox        :       New fields for options
 24  *      Pauline Middelink       :       identd support
 25  *              Alan Cox        :       Eliminate low level recv/recvfrom
 26  *              David S. Miller :       New socket lookup architecture.
 27  *              Steve Whitehouse:       Default routines for sock_ops
 28  *              Arnaldo C. Melo :       removed net_pinfo, tp_pinfo and made
 29  *                                      protinfo be just a void pointer, as the
 30  *                                      protocol specific parts were moved to
 31  *                                      respective headers and ipv4/v6, etc now
 32  *                                      use private slabcaches for its socks
 33  *              Pedro Hortas    :       New flags field for socket options
 34  */
 35 #ifndef _SOCK_H
 36 #define _SOCK_H
 37 
 38 #include <linux/hardirq.h>
 39 #include <linux/kernel.h>
 40 #include <linux/list.h>
 41 #include <linux/list_nulls.h>
 42 #include <linux/timer.h>
 43 #include <linux/cache.h>
 44 #include <linux/bitops.h>
 45 #include <linux/lockdep.h>
 46 #include <linux/netdevice.h>
 47 #include <linux/skbuff.h>       /* struct sk_buff */
 48 #include <linux/mm.h>
 49 #include <linux/security.h>
 50 #include <linux/slab.h>
 51 #include <linux/uaccess.h>
 52 #include <linux/page_counter.h>
 53 #include <linux/memcontrol.h>
 54 #include <linux/static_key.h>
 55 #include <linux/sched.h>
 56 #include <linux/wait.h>
 57 #include <linux/cgroup-defs.h>
 58 #include <linux/rbtree.h>
 59 #include <linux/filter.h>
 60 #include <linux/rculist_nulls.h>
 61 #include <linux/poll.h>
 62 #include <linux/sockptr.h>
 63 #include <linux/indirect_call_wrapper.h>
 64 #include <linux/atomic.h>
 65 #include <linux/refcount.h>
 66 #include <net/dst.h>
 67 #include <net/checksum.h>
 68 #include <net/tcp_states.h>
 69 #include <linux/net_tstamp.h>
 70 #include <net/l3mdev.h>
 71 
 72 /*
 73  * This structure really needs to be cleaned up.
 74  * Most of it is for TCP, and not used by any of
 75  * the other protocols.
 76  */
 77 
 78 /* Define this to get the SOCK_DBG debugging facility. */
 79 #define SOCK_DEBUGGING
 80 #ifdef SOCK_DEBUGGING
 81 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
 82                                         printk(KERN_DEBUG msg); } while (0)
 83 #else
 84 /* Validate arguments and do nothing */
 85 static inline __printf(2, 3)
 86 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
 87 {
 88 }
 89 #endif
 90 
 91 /* This is the per-socket lock.  The spinlock provides a synchronization
 92  * between user contexts and software interrupt processing, whereas the
 93  * mini-semaphore synchronizes multiple users amongst themselves.
 94  */
 95 typedef struct {
 96         spinlock_t              slock;
 97         int                     owned;
 98         wait_queue_head_t       wq;
 99         /*
100          * We express the mutex-alike socket_lock semantics
101          * to the lock validator by explicitly managing
102          * the slock as a lock variant (in addition to
103          * the slock itself):
104          */
105 #ifdef CONFIG_DEBUG_LOCK_ALLOC
106         struct lockdep_map dep_map;
107 #endif
108 } socket_lock_t;
109 
110 struct sock;
111 struct proto;
112 struct net;
113 
114 typedef __u32 __bitwise __portpair;
115 typedef __u64 __bitwise __addrpair;
116 
117 /**
118  *      struct sock_common - minimal network layer representation of sockets
119  *      @skc_daddr: Foreign IPv4 addr
120  *      @skc_rcv_saddr: Bound local IPv4 addr
121  *      @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
122  *      @skc_hash: hash value used with various protocol lookup tables
123  *      @skc_u16hashes: two u16 hash values used by UDP lookup tables
124  *      @skc_dport: placeholder for inet_dport/tw_dport
125  *      @skc_num: placeholder for inet_num/tw_num
126  *      @skc_portpair: __u32 union of @skc_dport & @skc_num
127  *      @skc_family: network address family
128  *      @skc_state: Connection state
129  *      @skc_reuse: %SO_REUSEADDR setting
130  *      @skc_reuseport: %SO_REUSEPORT setting
131  *      @skc_ipv6only: socket is IPV6 only
132  *      @skc_net_refcnt: socket is using net ref counting
133  *      @skc_bound_dev_if: bound device index if != 0
134  *      @skc_bind_node: bind hash linkage for various protocol lookup tables
135  *      @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
136  *      @skc_prot: protocol handlers inside a network family
137  *      @skc_net: reference to the network namespace of this socket
138  *      @skc_v6_daddr: IPV6 destination address
139  *      @skc_v6_rcv_saddr: IPV6 source address
140  *      @skc_cookie: socket's cookie value
141  *      @skc_node: main hash linkage for various protocol lookup tables
142  *      @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
143  *      @skc_tx_queue_mapping: tx queue number for this connection
144  *      @skc_rx_queue_mapping: rx queue number for this connection
145  *      @skc_flags: place holder for sk_flags
146  *              %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
147  *              %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
148  *      @skc_listener: connection request listener socket (aka rsk_listener)
149  *              [union with @skc_flags]
150  *      @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
151  *              [union with @skc_flags]
152  *      @skc_incoming_cpu: record/match cpu processing incoming packets
153  *      @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
154  *              [union with @skc_incoming_cpu]
155  *      @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
156  *              [union with @skc_incoming_cpu]
157  *      @skc_refcnt: reference count
158  *
159  *      This is the minimal network layer representation of sockets, the header
160  *      for struct sock and struct inet_timewait_sock.
161  */
162 struct sock_common {
163         /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
164          * address on 64bit arches : cf INET_MATCH()
165          */
166         union {
167                 __addrpair      skc_addrpair;
168                 struct {
169                         __be32  skc_daddr;
170                         __be32  skc_rcv_saddr;
171                 };
172         };
173         union  {
174                 unsigned int    skc_hash;
175                 __u16           skc_u16hashes[2];
176         };
177         /* skc_dport && skc_num must be grouped as well */
178         union {
179                 __portpair      skc_portpair;
180                 struct {
181                         __be16  skc_dport;
182                         __u16   skc_num;
183                 };
184         };
185 
186         unsigned short          skc_family;
187         volatile unsigned char  skc_state;
188         unsigned char           skc_reuse:4;
189         unsigned char           skc_reuseport:1;
190         unsigned char           skc_ipv6only:1;
191         unsigned char           skc_net_refcnt:1;
192         int                     skc_bound_dev_if;
193         union {
194                 struct hlist_node       skc_bind_node;
195                 struct hlist_node       skc_portaddr_node;
196         };
197         struct proto            *skc_prot;
198         possible_net_t          skc_net;
199 
200 #if IS_ENABLED(CONFIG_IPV6)
201         struct in6_addr         skc_v6_daddr;
202         struct in6_addr         skc_v6_rcv_saddr;
203 #endif
204 
205         atomic64_t              skc_cookie;
206 
207         /* following fields are padding to force
208          * offset(struct sock, sk_refcnt) == 128 on 64bit arches
209          * assuming IPV6 is enabled. We use this padding differently
210          * for different kind of 'sockets'
211          */
212         union {
213                 unsigned long   skc_flags;
214                 struct sock     *skc_listener; /* request_sock */
215                 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
216         };
217         /*
218          * fields between dontcopy_begin/dontcopy_end
219          * are not copied in sock_copy()
220          */
221         /* private: */
222         int                     skc_dontcopy_begin[0];
223         /* public: */
224         union {
225                 struct hlist_node       skc_node;
226                 struct hlist_nulls_node skc_nulls_node;
227         };
228         unsigned short          skc_tx_queue_mapping;
229 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
230         unsigned short          skc_rx_queue_mapping;
231 #endif
232         union {
233                 int             skc_incoming_cpu;
234                 u32             skc_rcv_wnd;
235                 u32             skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
236         };
237 
238         refcount_t              skc_refcnt;
239         /* private: */
240         int                     skc_dontcopy_end[0];
241         union {
242                 u32             skc_rxhash;
243                 u32             skc_window_clamp;
244                 u32             skc_tw_snd_nxt; /* struct tcp_timewait_sock */
245         };
246         /* public: */
247 };
248 
249 struct bpf_local_storage;
250 
251 /**
252   *     struct sock - network layer representation of sockets
253   *     @__sk_common: shared layout with inet_timewait_sock
254   *     @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
255   *     @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
256   *     @sk_lock:       synchronizer
257   *     @sk_kern_sock: True if sock is using kernel lock classes
258   *     @sk_rcvbuf: size of receive buffer in bytes
259   *     @sk_wq: sock wait queue and async head
260   *     @sk_rx_dst: receive input route used by early demux
261   *     @sk_dst_cache: destination cache
262   *     @sk_dst_pending_confirm: need to confirm neighbour
263   *     @sk_policy: flow policy
264   *     @sk_rx_skb_cache: cache copy of recently accessed RX skb
265   *     @sk_receive_queue: incoming packets
266   *     @sk_wmem_alloc: transmit queue bytes committed
267   *     @sk_tsq_flags: TCP Small Queues flags
268   *     @sk_write_queue: Packet sending queue
269   *     @sk_omem_alloc: "o" is "option" or "other"
270   *     @sk_wmem_queued: persistent queue size
271   *     @sk_forward_alloc: space allocated forward
272   *     @sk_napi_id: id of the last napi context to receive data for sk
273   *     @sk_ll_usec: usecs to busypoll when there is no data
274   *     @sk_allocation: allocation mode
275   *     @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
276   *     @sk_pacing_status: Pacing status (requested, handled by sch_fq)
277   *     @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
278   *     @sk_sndbuf: size of send buffer in bytes
279   *     @__sk_flags_offset: empty field used to determine location of bitfield
280   *     @sk_padding: unused element for alignment
281   *     @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
282   *     @sk_no_check_rx: allow zero checksum in RX packets
283   *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
284   *     @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
285   *     @sk_route_forced_caps: static, forced route capabilities
286   *             (set in tcp_init_sock())
287   *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
288   *     @sk_gso_max_size: Maximum GSO segment size to build
289   *     @sk_gso_max_segs: Maximum number of GSO segments
290   *     @sk_pacing_shift: scaling factor for TCP Small Queues
291   *     @sk_lingertime: %SO_LINGER l_linger setting
292   *     @sk_backlog: always used with the per-socket spinlock held
293   *     @sk_callback_lock: used with the callbacks in the end of this struct
294   *     @sk_error_queue: rarely used
295   *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
296   *                       IPV6_ADDRFORM for instance)
297   *     @sk_err: last error
298   *     @sk_err_soft: errors that don't cause failure but are the cause of a
299   *                   persistent failure not just 'timed out'
300   *     @sk_drops: raw/udp drops counter
301   *     @sk_ack_backlog: current listen backlog
302   *     @sk_max_ack_backlog: listen backlog set in listen()
303   *     @sk_uid: user id of owner
304   *     @sk_prefer_busy_poll: prefer busypolling over softirq processing
305   *     @sk_busy_poll_budget: napi processing budget when busypolling
306   *     @sk_priority: %SO_PRIORITY setting
307   *     @sk_type: socket type (%SOCK_STREAM, etc)
308   *     @sk_protocol: which protocol this socket belongs in this network family
309   *     @sk_peer_pid: &struct pid for this socket's peer
310   *     @sk_peer_cred: %SO_PEERCRED setting
311   *     @sk_rcvlowat: %SO_RCVLOWAT setting
312   *     @sk_rcvtimeo: %SO_RCVTIMEO setting
313   *     @sk_sndtimeo: %SO_SNDTIMEO setting
314   *     @sk_txhash: computed flow hash for use on transmit
315   *     @sk_filter: socket filtering instructions
316   *     @sk_timer: sock cleanup timer
317   *     @sk_stamp: time stamp of last packet received
318   *     @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
319   *     @sk_tsflags: SO_TIMESTAMPING socket options
320   *     @sk_tskey: counter to disambiguate concurrent tstamp requests
321   *     @sk_zckey: counter to order MSG_ZEROCOPY notifications
322   *     @sk_socket: Identd and reporting IO signals
323   *     @sk_user_data: RPC layer private data
324   *     @sk_frag: cached page frag
325   *     @sk_peek_off: current peek_offset value
326   *     @sk_send_head: front of stuff to transmit
327   *     @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
328   *     @sk_tx_skb_cache: cache copy of recently accessed TX skb
329   *     @sk_security: used by security modules
330   *     @sk_mark: generic packet mark
331   *     @sk_cgrp_data: cgroup data for this cgroup
332   *     @sk_memcg: this socket's memory cgroup association
333   *     @sk_write_pending: a write to stream socket waits to start
334   *     @sk_state_change: callback to indicate change in the state of the sock
335   *     @sk_data_ready: callback to indicate there is data to be processed
336   *     @sk_write_space: callback to indicate there is bf sending space available
337   *     @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
338   *     @sk_backlog_rcv: callback to process the backlog
339   *     @sk_validate_xmit_skb: ptr to an optional validate function
340   *     @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
341   *     @sk_reuseport_cb: reuseport group container
342   *     @sk_bpf_storage: ptr to cache and control for bpf_sk_storage
343   *     @sk_rcu: used during RCU grace period
344   *     @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
345   *     @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
346   *     @sk_txtime_report_errors: set report errors mode for SO_TXTIME
347   *     @sk_txtime_unused: unused txtime flags
348   */
349 struct sock {
350         /*
351          * Now struct inet_timewait_sock also uses sock_common, so please just
352          * don't add nothing before this first member (__sk_common) --acme
353          */
354         struct sock_common      __sk_common;
355 #define sk_node                 __sk_common.skc_node
356 #define sk_nulls_node           __sk_common.skc_nulls_node
357 #define sk_refcnt               __sk_common.skc_refcnt
358 #define sk_tx_queue_mapping     __sk_common.skc_tx_queue_mapping
359 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
360 #define sk_rx_queue_mapping     __sk_common.skc_rx_queue_mapping
361 #endif
362 
363 #define sk_dontcopy_begin       __sk_common.skc_dontcopy_begin
364 #define sk_dontcopy_end         __sk_common.skc_dontcopy_end
365 #define sk_hash                 __sk_common.skc_hash
366 #define sk_portpair             __sk_common.skc_portpair
367 #define sk_num                  __sk_common.skc_num
368 #define sk_dport                __sk_common.skc_dport
369 #define sk_addrpair             __sk_common.skc_addrpair
370 #define sk_daddr                __sk_common.skc_daddr
371 #define sk_rcv_saddr            __sk_common.skc_rcv_saddr
372 #define sk_family               __sk_common.skc_family
373 #define sk_state                __sk_common.skc_state
374 #define sk_reuse                __sk_common.skc_reuse
375 #define sk_reuseport            __sk_common.skc_reuseport
376 #define sk_ipv6only             __sk_common.skc_ipv6only
377 #define sk_net_refcnt           __sk_common.skc_net_refcnt
378 #define sk_bound_dev_if         __sk_common.skc_bound_dev_if
379 #define sk_bind_node            __sk_common.skc_bind_node
380 #define sk_prot                 __sk_common.skc_prot
381 #define sk_net                  __sk_common.skc_net
382 #define sk_v6_daddr             __sk_common.skc_v6_daddr
383 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
384 #define sk_cookie               __sk_common.skc_cookie
385 #define sk_incoming_cpu         __sk_common.skc_incoming_cpu
386 #define sk_flags                __sk_common.skc_flags
387 #define sk_rxhash               __sk_common.skc_rxhash
388 
389         socket_lock_t           sk_lock;
390         atomic_t                sk_drops;
391         int                     sk_rcvlowat;
392         struct sk_buff_head     sk_error_queue;
393         struct sk_buff          *sk_rx_skb_cache;
394         struct sk_buff_head     sk_receive_queue;
395         /*
396          * The backlog queue is special, it is always used with
397          * the per-socket spinlock held and requires low latency
398          * access. Therefore we special case it's implementation.
399          * Note : rmem_alloc is in this structure to fill a hole
400          * on 64bit arches, not because its logically part of
401          * backlog.
402          */
403         struct {
404                 atomic_t        rmem_alloc;
405                 int             len;
406                 struct sk_buff  *head;
407                 struct sk_buff  *tail;
408         } sk_backlog;
409 #define sk_rmem_alloc sk_backlog.rmem_alloc
410 
411         int                     sk_forward_alloc;
412 #ifdef CONFIG_NET_RX_BUSY_POLL
413         unsigned int            sk_ll_usec;
414         /* ===== mostly read cache line ===== */
415         unsigned int            sk_napi_id;
416 #endif
417         int                     sk_rcvbuf;
418 
419         struct sk_filter __rcu  *sk_filter;
420         union {
421                 struct socket_wq __rcu  *sk_wq;
422                 /* private: */
423                 struct socket_wq        *sk_wq_raw;
424                 /* public: */
425         };
426 #ifdef CONFIG_XFRM
427         struct xfrm_policy __rcu *sk_policy[2];
428 #endif
429         struct dst_entry        *sk_rx_dst;
430         struct dst_entry __rcu  *sk_dst_cache;
431         atomic_t                sk_omem_alloc;
432         int                     sk_sndbuf;
433 
434         /* ===== cache line for TX ===== */
435         int                     sk_wmem_queued;
436         refcount_t              sk_wmem_alloc;
437         unsigned long           sk_tsq_flags;
438         union {
439                 struct sk_buff  *sk_send_head;
440                 struct rb_root  tcp_rtx_queue;
441         };
442         struct sk_buff          *sk_tx_skb_cache;
443         struct sk_buff_head     sk_write_queue;
444         __s32                   sk_peek_off;
445         int                     sk_write_pending;
446         __u32                   sk_dst_pending_confirm;
447         u32                     sk_pacing_status; /* see enum sk_pacing */
448         long                    sk_sndtimeo;
449         struct timer_list       sk_timer;
450         __u32                   sk_priority;
451         __u32                   sk_mark;
452         unsigned long           sk_pacing_rate; /* bytes per second */
453         unsigned long           sk_max_pacing_rate;
454         struct page_frag        sk_frag;
455         netdev_features_t       sk_route_caps;
456         netdev_features_t       sk_route_nocaps;
457         netdev_features_t       sk_route_forced_caps;
458         int                     sk_gso_type;
459         unsigned int            sk_gso_max_size;
460         gfp_t                   sk_allocation;
461         __u32                   sk_txhash;
462 
463         /*
464          * Because of non atomicity rules, all
465          * changes are protected by socket lock.
466          */
467         u8                      sk_padding : 1,
468                                 sk_kern_sock : 1,
469                                 sk_no_check_tx : 1,
470                                 sk_no_check_rx : 1,
471                                 sk_userlocks : 4;
472         u8                      sk_pacing_shift;
473         u16                     sk_type;
474         u16                     sk_protocol;
475         u16                     sk_gso_max_segs;
476         unsigned long           sk_lingertime;
477         struct proto            *sk_prot_creator;
478         rwlock_t                sk_callback_lock;
479         int                     sk_err,
480                                 sk_err_soft;
481         u32                     sk_ack_backlog;
482         u32                     sk_max_ack_backlog;
483         kuid_t                  sk_uid;
484 #ifdef CONFIG_NET_RX_BUSY_POLL
485         u8                      sk_prefer_busy_poll;
486         u16                     sk_busy_poll_budget;
487 #endif
488         struct pid              *sk_peer_pid;
489         const struct cred       *sk_peer_cred;
490         long                    sk_rcvtimeo;
491         ktime_t                 sk_stamp;
492 #if BITS_PER_LONG==32
493         seqlock_t               sk_stamp_seq;
494 #endif
495         u16                     sk_tsflags;
496         u8                      sk_shutdown;
497         u32                     sk_tskey;
498         atomic_t                sk_zckey;
499 
500         u8                      sk_clockid;
501         u8                      sk_txtime_deadline_mode : 1,
502                                 sk_txtime_report_errors : 1,
503                                 sk_txtime_unused : 6;
504 
505         struct socket           *sk_socket;
506         void                    *sk_user_data;
507 #ifdef CONFIG_SECURITY
508         void                    *sk_security;
509 #endif
510         struct sock_cgroup_data sk_cgrp_data;
511         struct mem_cgroup       *sk_memcg;
512         void                    (*sk_state_change)(struct sock *sk);
513         void                    (*sk_data_ready)(struct sock *sk);
514         void                    (*sk_write_space)(struct sock *sk);
515         void                    (*sk_error_report)(struct sock *sk);
516         int                     (*sk_backlog_rcv)(struct sock *sk,
517                                                   struct sk_buff *skb);
518 #ifdef CONFIG_SOCK_VALIDATE_XMIT
519         struct sk_buff*         (*sk_validate_xmit_skb)(struct sock *sk,
520                                                         struct net_device *dev,
521                                                         struct sk_buff *skb);
522 #endif
523         void                    (*sk_destruct)(struct sock *sk);
524         struct sock_reuseport __rcu     *sk_reuseport_cb;
525 #ifdef CONFIG_BPF_SYSCALL
526         struct bpf_local_storage __rcu  *sk_bpf_storage;
527 #endif
528         struct rcu_head         sk_rcu;
529 };
530 
531 enum sk_pacing {
532         SK_PACING_NONE          = 0,
533         SK_PACING_NEEDED        = 1,
534         SK_PACING_FQ            = 2,
535 };
536 
537 /* Pointer stored in sk_user_data might not be suitable for copying
538  * when cloning the socket. For instance, it can point to a reference
539  * counted object. sk_user_data bottom bit is set if pointer must not
540  * be copied.
541  */
542 #define SK_USER_DATA_NOCOPY     1UL
543 #define SK_USER_DATA_BPF        2UL     /* Managed by BPF */
544 #define SK_USER_DATA_PTRMASK    ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
545 
546 /**
547  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
548  * @sk: socket
549  */
550 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
551 {
552         return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
553 }
554 
555 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
556 
557 #define rcu_dereference_sk_user_data(sk)                                \
558 ({                                                                      \
559         void *__tmp = rcu_dereference(__sk_user_data((sk)));            \
560         (void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);              \
561 })
562 #define rcu_assign_sk_user_data(sk, ptr)                                \
563 ({                                                                      \
564         uintptr_t __tmp = (uintptr_t)(ptr);                             \
565         WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);                    \
566         rcu_assign_pointer(__sk_user_data((sk)), __tmp);                \
567 })
568 #define rcu_assign_sk_user_data_nocopy(sk, ptr)                         \
569 ({                                                                      \
570         uintptr_t __tmp = (uintptr_t)(ptr);                             \
571         WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);                    \
572         rcu_assign_pointer(__sk_user_data((sk)),                        \
573                            __tmp | SK_USER_DATA_NOCOPY);                \
574 })
575 
576 /*
577  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
578  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
579  * on a socket means that the socket will reuse everybody else's port
580  * without looking at the other's sk_reuse value.
581  */
582 
583 #define SK_NO_REUSE     0
584 #define SK_CAN_REUSE    1
585 #define SK_FORCE_REUSE  2
586 
587 int sk_set_peek_off(struct sock *sk, int val);
588 
589 static inline int sk_peek_offset(struct sock *sk, int flags)
590 {
591         if (unlikely(flags & MSG_PEEK)) {
592                 return READ_ONCE(sk->sk_peek_off);
593         }
594 
595         return 0;
596 }
597 
598 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
599 {
600         s32 off = READ_ONCE(sk->sk_peek_off);
601 
602         if (unlikely(off >= 0)) {
603                 off = max_t(s32, off - val, 0);
604                 WRITE_ONCE(sk->sk_peek_off, off);
605         }
606 }
607 
608 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
609 {
610         sk_peek_offset_bwd(sk, -val);
611 }
612 
613 /*
614  * Hashed lists helper routines
615  */
616 static inline struct sock *sk_entry(const struct hlist_node *node)
617 {
618         return hlist_entry(node, struct sock, sk_node);
619 }
620 
621 static inline struct sock *__sk_head(const struct hlist_head *head)
622 {
623         return hlist_entry(head->first, struct sock, sk_node);
624 }
625 
626 static inline struct sock *sk_head(const struct hlist_head *head)
627 {
628         return hlist_empty(head) ? NULL : __sk_head(head);
629 }
630 
631 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
632 {
633         return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
634 }
635 
636 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
637 {
638         return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
639 }
640 
641 static inline struct sock *sk_next(const struct sock *sk)
642 {
643         return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
644 }
645 
646 static inline struct sock *sk_nulls_next(const struct sock *sk)
647 {
648         return (!is_a_nulls(sk->sk_nulls_node.next)) ?
649                 hlist_nulls_entry(sk->sk_nulls_node.next,
650                                   struct sock, sk_nulls_node) :
651                 NULL;
652 }
653 
654 static inline bool sk_unhashed(const struct sock *sk)
655 {
656         return hlist_unhashed(&sk->sk_node);
657 }
658 
659 static inline bool sk_hashed(const struct sock *sk)
660 {
661         return !sk_unhashed(sk);
662 }
663 
664 static inline void sk_node_init(struct hlist_node *node)
665 {
666         node->pprev = NULL;
667 }
668 
669 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
670 {
671         node->pprev = NULL;
672 }
673 
674 static inline void __sk_del_node(struct sock *sk)
675 {
676         __hlist_del(&sk->sk_node);
677 }
678 
679 /* NB: equivalent to hlist_del_init_rcu */
680 static inline bool __sk_del_node_init(struct sock *sk)
681 {
682         if (sk_hashed(sk)) {
683                 __sk_del_node(sk);
684                 sk_node_init(&sk->sk_node);
685                 return true;
686         }
687         return false;
688 }
689 
690 /* Grab socket reference count. This operation is valid only
691    when sk is ALREADY grabbed f.e. it is found in hash table
692    or a list and the lookup is made under lock preventing hash table
693    modifications.
694  */
695 
696 static __always_inline void sock_hold(struct sock *sk)
697 {
698         refcount_inc(&sk->sk_refcnt);
699 }
700 
701 /* Ungrab socket in the context, which assumes that socket refcnt
702    cannot hit zero, f.e. it is true in context of any socketcall.
703  */
704 static __always_inline void __sock_put(struct sock *sk)
705 {
706         refcount_dec(&sk->sk_refcnt);
707 }
708 
709 static inline bool sk_del_node_init(struct sock *sk)
710 {
711         bool rc = __sk_del_node_init(sk);
712 
713         if (rc) {
714                 /* paranoid for a while -acme */
715                 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
716                 __sock_put(sk);
717         }
718         return rc;
719 }
720 #define sk_del_node_init_rcu(sk)        sk_del_node_init(sk)
721 
722 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
723 {
724         if (sk_hashed(sk)) {
725                 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
726                 return true;
727         }
728         return false;
729 }
730 
731 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
732 {
733         bool rc = __sk_nulls_del_node_init_rcu(sk);
734 
735         if (rc) {
736                 /* paranoid for a while -acme */
737                 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
738                 __sock_put(sk);
739         }
740         return rc;
741 }
742 
743 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
744 {
745         hlist_add_head(&sk->sk_node, list);
746 }
747 
748 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
749 {
750         sock_hold(sk);
751         __sk_add_node(sk, list);
752 }
753 
754 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
755 {
756         sock_hold(sk);
757         if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
758             sk->sk_family == AF_INET6)
759                 hlist_add_tail_rcu(&sk->sk_node, list);
760         else
761                 hlist_add_head_rcu(&sk->sk_node, list);
762 }
763 
764 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
765 {
766         sock_hold(sk);
767         hlist_add_tail_rcu(&sk->sk_node, list);
768 }
769 
770 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
771 {
772         hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
773 }
774 
775 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
776 {
777         hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
778 }
779 
780 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
781 {
782         sock_hold(sk);
783         __sk_nulls_add_node_rcu(sk, list);
784 }
785 
786 static inline void __sk_del_bind_node(struct sock *sk)
787 {
788         __hlist_del(&sk->sk_bind_node);
789 }
790 
791 static inline void sk_add_bind_node(struct sock *sk,
792                                         struct hlist_head *list)
793 {
794         hlist_add_head(&sk->sk_bind_node, list);
795 }
796 
797 #define sk_for_each(__sk, list) \
798         hlist_for_each_entry(__sk, list, sk_node)
799 #define sk_for_each_rcu(__sk, list) \
800         hlist_for_each_entry_rcu(__sk, list, sk_node)
801 #define sk_nulls_for_each(__sk, node, list) \
802         hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
803 #define sk_nulls_for_each_rcu(__sk, node, list) \
804         hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
805 #define sk_for_each_from(__sk) \
806         hlist_for_each_entry_from(__sk, sk_node)
807 #define sk_nulls_for_each_from(__sk, node) \
808         if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
809                 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
810 #define sk_for_each_safe(__sk, tmp, list) \
811         hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
812 #define sk_for_each_bound(__sk, list) \
813         hlist_for_each_entry(__sk, list, sk_bind_node)
814 
815 /**
816  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
817  * @tpos:       the type * to use as a loop cursor.
818  * @pos:        the &struct hlist_node to use as a loop cursor.
819  * @head:       the head for your list.
820  * @offset:     offset of hlist_node within the struct.
821  *
822  */
823 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)                  \
824         for (pos = rcu_dereference(hlist_first_rcu(head));                     \
825              pos != NULL &&                                                    \
826                 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
827              pos = rcu_dereference(hlist_next_rcu(pos)))
828 
829 static inline struct user_namespace *sk_user_ns(struct sock *sk)
830 {
831         /* Careful only use this in a context where these parameters
832          * can not change and must all be valid, such as recvmsg from
833          * userspace.
834          */
835         return sk->sk_socket->file->f_cred->user_ns;
836 }
837 
838 /* Sock flags */
839 enum sock_flags {
840         SOCK_DEAD,
841         SOCK_DONE,
842         SOCK_URGINLINE,
843         SOCK_KEEPOPEN,
844         SOCK_LINGER,
845         SOCK_DESTROY,
846         SOCK_BROADCAST,
847         SOCK_TIMESTAMP,
848         SOCK_ZAPPED,
849         SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
850         SOCK_DBG, /* %SO_DEBUG setting */
851         SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
852         SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
853         SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
854         SOCK_MEMALLOC, /* VM depends on this socket for swapping */
855         SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
856         SOCK_FASYNC, /* fasync() active */
857         SOCK_RXQ_OVFL,
858         SOCK_ZEROCOPY, /* buffers from userspace */
859         SOCK_WIFI_STATUS, /* push wifi status to userspace */
860         SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
861                      * Will use last 4 bytes of packet sent from
862                      * user-space instead.
863                      */
864         SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
865         SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
866         SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
867         SOCK_TXTIME,
868         SOCK_XDP, /* XDP is attached */
869         SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
870 };
871 
872 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
873 
874 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
875 {
876         nsk->sk_flags = osk->sk_flags;
877 }
878 
879 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
880 {
881         __set_bit(flag, &sk->sk_flags);
882 }
883 
884 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
885 {
886         __clear_bit(flag, &sk->sk_flags);
887 }
888 
889 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
890                                      int valbool)
891 {
892         if (valbool)
893                 sock_set_flag(sk, bit);
894         else
895                 sock_reset_flag(sk, bit);
896 }
897 
898 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
899 {
900         return test_bit(flag, &sk->sk_flags);
901 }
902 
903 #ifdef CONFIG_NET
904 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
905 static inline int sk_memalloc_socks(void)
906 {
907         return static_branch_unlikely(&memalloc_socks_key);
908 }
909 
910 void __receive_sock(struct file *file);
911 #else
912 
913 static inline int sk_memalloc_socks(void)
914 {
915         return 0;
916 }
917 
918 static inline void __receive_sock(struct file *file)
919 { }
920 #endif
921 
922 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
923 {
924         return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
925 }
926 
927 static inline void sk_acceptq_removed(struct sock *sk)
928 {
929         WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
930 }
931 
932 static inline void sk_acceptq_added(struct sock *sk)
933 {
934         WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
935 }
936 
937 /* Note: If you think the test should be:
938  *      return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
939  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
940  */
941 static inline bool sk_acceptq_is_full(const struct sock *sk)
942 {
943         return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
944 }
945 
946 /*
947  * Compute minimal free write space needed to queue new packets.
948  */
949 static inline int sk_stream_min_wspace(const struct sock *sk)
950 {
951         return READ_ONCE(sk->sk_wmem_queued) >> 1;
952 }
953 
954 static inline int sk_stream_wspace(const struct sock *sk)
955 {
956         return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
957 }
958 
959 static inline void sk_wmem_queued_add(struct sock *sk, int val)
960 {
961         WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
962 }
963 
964 void sk_stream_write_space(struct sock *sk);
965 
966 /* OOB backlog add */
967 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
968 {
969         /* dont let skb dst not refcounted, we are going to leave rcu lock */
970         skb_dst_force(skb);
971 
972         if (!sk->sk_backlog.tail)
973                 WRITE_ONCE(sk->sk_backlog.head, skb);
974         else
975                 sk->sk_backlog.tail->next = skb;
976 
977         WRITE_ONCE(sk->sk_backlog.tail, skb);
978         skb->next = NULL;
979 }
980 
981 /*
982  * Take into account size of receive queue and backlog queue
983  * Do not take into account this skb truesize,
984  * to allow even a single big packet to come.
985  */
986 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
987 {
988         unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
989 
990         return qsize > limit;
991 }
992 
993 /* The per-socket spinlock must be held here. */
994 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
995                                               unsigned int limit)
996 {
997         if (sk_rcvqueues_full(sk, limit))
998                 return -ENOBUFS;
999 
1000         /*
1001          * If the skb was allocated from pfmemalloc reserves, only
1002          * allow SOCK_MEMALLOC sockets to use it as this socket is
1003          * helping free memory
1004          */
1005         if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1006                 return -ENOMEM;
1007 
1008         __sk_add_backlog(sk, skb);
1009         sk->sk_backlog.len += skb->truesize;
1010         return 0;
1011 }
1012 
1013 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1014 
1015 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1016 {
1017         if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1018                 return __sk_backlog_rcv(sk, skb);
1019 
1020         return sk->sk_backlog_rcv(sk, skb);
1021 }
1022 
1023 static inline void sk_incoming_cpu_update(struct sock *sk)
1024 {
1025         int cpu = raw_smp_processor_id();
1026 
1027         if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1028                 WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1029 }
1030 
1031 static inline void sock_rps_record_flow_hash(__u32 hash)
1032 {
1033 #ifdef CONFIG_RPS
1034         struct rps_sock_flow_table *sock_flow_table;
1035 
1036         rcu_read_lock();
1037         sock_flow_table = rcu_dereference(rps_sock_flow_table);
1038         rps_record_sock_flow(sock_flow_table, hash);
1039         rcu_read_unlock();
1040 #endif
1041 }
1042 
1043 static inline void sock_rps_record_flow(const struct sock *sk)
1044 {
1045 #ifdef CONFIG_RPS
1046         if (static_branch_unlikely(&rfs_needed)) {
1047                 /* Reading sk->sk_rxhash might incur an expensive cache line
1048                  * miss.
1049                  *
1050                  * TCP_ESTABLISHED does cover almost all states where RFS
1051                  * might be useful, and is cheaper [1] than testing :
1052                  *      IPv4: inet_sk(sk)->inet_daddr
1053                  *      IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1054                  * OR   an additional socket flag
1055                  * [1] : sk_state and sk_prot are in the same cache line.
1056                  */
1057                 if (sk->sk_state == TCP_ESTABLISHED)
1058                         sock_rps_record_flow_hash(sk->sk_rxhash);
1059         }
1060 #endif
1061 }
1062 
1063 static inline void sock_rps_save_rxhash(struct sock *sk,
1064                                         const struct sk_buff *skb)
1065 {
1066 #ifdef CONFIG_RPS
1067         if (unlikely(sk->sk_rxhash != skb->hash))
1068                 sk->sk_rxhash = skb->hash;
1069 #endif
1070 }
1071 
1072 static inline void sock_rps_reset_rxhash(struct sock *sk)
1073 {
1074 #ifdef CONFIG_RPS
1075         sk->sk_rxhash = 0;
1076 #endif
1077 }
1078 
1079 #define sk_wait_event(__sk, __timeo, __condition, __wait)               \
1080         ({      int __rc;                                               \
1081                 release_sock(__sk);                                     \
1082                 __rc = __condition;                                     \
1083                 if (!__rc) {                                            \
1084                         *(__timeo) = wait_woken(__wait,                 \
1085                                                 TASK_INTERRUPTIBLE,     \
1086                                                 *(__timeo));            \
1087                 }                                                       \
1088                 sched_annotate_sleep();                                 \
1089                 lock_sock(__sk);                                        \
1090                 __rc = __condition;                                     \
1091                 __rc;                                                   \
1092         })
1093 
1094 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1095 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1096 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1097 int sk_stream_error(struct sock *sk, int flags, int err);
1098 void sk_stream_kill_queues(struct sock *sk);
1099 void sk_set_memalloc(struct sock *sk);
1100 void sk_clear_memalloc(struct sock *sk);
1101 
1102 void __sk_flush_backlog(struct sock *sk);
1103 
1104 static inline bool sk_flush_backlog(struct sock *sk)
1105 {
1106         if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1107                 __sk_flush_backlog(sk);
1108                 return true;
1109         }
1110         return false;
1111 }
1112 
1113 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1114 
1115 struct request_sock_ops;
1116 struct timewait_sock_ops;
1117 struct inet_hashinfo;
1118 struct raw_hashinfo;
1119 struct smc_hashinfo;
1120 struct module;
1121 struct sk_psock;
1122 
1123 /*
1124  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1125  * un-modified. Special care is taken when initializing object to zero.
1126  */
1127 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1128 {
1129         if (offsetof(struct sock, sk_node.next) != 0)
1130                 memset(sk, 0, offsetof(struct sock, sk_node.next));
1131         memset(&sk->sk_node.pprev, 0,
1132                size - offsetof(struct sock, sk_node.pprev));
1133 }
1134 
1135 /* Networking protocol blocks we attach to sockets.
1136  * socket layer -> transport layer interface
1137  */
1138 struct proto {
1139         void                    (*close)(struct sock *sk,
1140                                         long timeout);
1141         int                     (*pre_connect)(struct sock *sk,
1142                                         struct sockaddr *uaddr,
1143                                         int addr_len);
1144         int                     (*connect)(struct sock *sk,
1145                                         struct sockaddr *uaddr,
1146                                         int addr_len);
1147         int                     (*disconnect)(struct sock *sk, int flags);
1148 
1149         struct sock *           (*accept)(struct sock *sk, int flags, int *err,
1150                                           bool kern);
1151 
1152         int                     (*ioctl)(struct sock *sk, int cmd,
1153                                          unsigned long arg);
1154         int                     (*init)(struct sock *sk);
1155         void                    (*destroy)(struct sock *sk);
1156         void                    (*shutdown)(struct sock *sk, int how);
1157         int                     (*setsockopt)(struct sock *sk, int level,
1158                                         int optname, sockptr_t optval,
1159                                         unsigned int optlen);
1160         int                     (*getsockopt)(struct sock *sk, int level,
1161                                         int optname, char __user *optval,
1162                                         int __user *option);
1163         void                    (*keepalive)(struct sock *sk, int valbool);
1164 #ifdef CONFIG_COMPAT
1165         int                     (*compat_ioctl)(struct sock *sk,
1166                                         unsigned int cmd, unsigned long arg);
1167 #endif
1168         int                     (*sendmsg)(struct sock *sk, struct msghdr *msg,
1169                                            size_t len);
1170         int                     (*recvmsg)(struct sock *sk, struct msghdr *msg,
1171                                            size_t len, int noblock, int flags,
1172                                            int *addr_len);
1173         int                     (*sendpage)(struct sock *sk, struct page *page,
1174                                         int offset, size_t size, int flags);
1175         int                     (*bind)(struct sock *sk,
1176                                         struct sockaddr *addr, int addr_len);
1177         int                     (*bind_add)(struct sock *sk,
1178                                         struct sockaddr *addr, int addr_len);
1179 
1180         int                     (*backlog_rcv) (struct sock *sk,
1181                                                 struct sk_buff *skb);
1182         bool                    (*bpf_bypass_getsockopt)(int level,
1183                                                          int optname);
1184 
1185         void            (*release_cb)(struct sock *sk);
1186 
1187         /* Keeping track of sk's, looking them up, and port selection methods. */
1188         int                     (*hash)(struct sock *sk);
1189         void                    (*unhash)(struct sock *sk);
1190         void                    (*rehash)(struct sock *sk);
1191         int                     (*get_port)(struct sock *sk, unsigned short snum);
1192 #ifdef CONFIG_BPF_SYSCALL
1193         int                     (*psock_update_sk_prot)(struct sock *sk,
1194                                                         struct sk_psock *psock,
1195                                                         bool restore);
1196 #endif
1197 
1198         /* Keeping track of sockets in use */
1199 #ifdef CONFIG_PROC_FS
1200         unsigned int            inuse_idx;
1201 #endif
1202 
1203         bool                    (*stream_memory_free)(const struct sock *sk, int wake);
1204         bool                    (*stream_memory_read)(const struct sock *sk);
1205         /* Memory pressure */
1206         void                    (*enter_memory_pressure)(struct sock *sk);
1207         void                    (*leave_memory_pressure)(struct sock *sk);
1208         atomic_long_t           *memory_allocated;      /* Current allocated memory. */
1209         struct percpu_counter   *sockets_allocated;     /* Current number of sockets. */
1210         /*
1211          * Pressure flag: try to collapse.
1212          * Technical note: it is used by multiple contexts non atomically.
1213          * All the __sk_mem_schedule() is of this nature: accounting
1214          * is strict, actions are advisory and have some latency.
1215          */
1216         unsigned long           *memory_pressure;
1217         long                    *sysctl_mem;
1218 
1219         int                     *sysctl_wmem;
1220         int                     *sysctl_rmem;
1221         u32                     sysctl_wmem_offset;
1222         u32                     sysctl_rmem_offset;
1223 
1224         int                     max_header;
1225         bool                    no_autobind;
1226 
1227         struct kmem_cache       *slab;
1228         unsigned int            obj_size;
1229         slab_flags_t            slab_flags;
1230         unsigned int            useroffset;     /* Usercopy region offset */
1231         unsigned int            usersize;       /* Usercopy region size */
1232 
1233         struct percpu_counter   *orphan_count;
1234 
1235         struct request_sock_ops *rsk_prot;
1236         struct timewait_sock_ops *twsk_prot;
1237 
1238         union {
1239                 struct inet_hashinfo    *hashinfo;
1240                 struct udp_table        *udp_table;
1241                 struct raw_hashinfo     *raw_hash;
1242                 struct smc_hashinfo     *smc_hash;
1243         } h;
1244 
1245         struct module           *owner;
1246 
1247         char                    name[32];
1248 
1249         struct list_head        node;
1250 #ifdef SOCK_REFCNT_DEBUG
1251         atomic_t                socks;
1252 #endif
1253         int                     (*diag_destroy)(struct sock *sk, int err);
1254 } __randomize_layout;
1255 
1256 int proto_register(struct proto *prot, int alloc_slab);
1257 void proto_unregister(struct proto *prot);
1258 int sock_load_diag_module(int family, int protocol);
1259 
1260 #ifdef SOCK_REFCNT_DEBUG
1261 static inline void sk_refcnt_debug_inc(struct sock *sk)
1262 {
1263         atomic_inc(&sk->sk_prot->socks);
1264 }
1265 
1266 static inline void sk_refcnt_debug_dec(struct sock *sk)
1267 {
1268         atomic_dec(&sk->sk_prot->socks);
1269         printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1270                sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1271 }
1272 
1273 static inline void sk_refcnt_debug_release(const struct sock *sk)
1274 {
1275         if (refcount_read(&sk->sk_refcnt) != 1)
1276                 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1277                        sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1278 }
1279 #else /* SOCK_REFCNT_DEBUG */
1280 #define sk_refcnt_debug_inc(sk) do { } while (0)
1281 #define sk_refcnt_debug_dec(sk) do { } while (0)
1282 #define sk_refcnt_debug_release(sk) do { } while (0)
1283 #endif /* SOCK_REFCNT_DEBUG */
1284 
1285 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1286 
1287 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1288 {
1289         if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1290                 return false;
1291 
1292 #ifdef CONFIG_INET
1293         return sk->sk_prot->stream_memory_free ?
1294                 INDIRECT_CALL_1(sk->sk_prot->stream_memory_free,
1295                                 tcp_stream_memory_free,
1296                                 sk, wake) : true;
1297 #else
1298         return sk->sk_prot->stream_memory_free ?
1299                 sk->sk_prot->stream_memory_free(sk, wake) : true;
1300 #endif
1301 }
1302 
1303 static inline bool sk_stream_memory_free(const struct sock *sk)
1304 {
1305         return __sk_stream_memory_free(sk, 0);
1306 }
1307 
1308 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1309 {
1310         return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1311                __sk_stream_memory_free(sk, wake);
1312 }
1313 
1314 static inline bool sk_stream_is_writeable(const struct sock *sk)
1315 {
1316         return __sk_stream_is_writeable(sk, 0);
1317 }
1318 
1319 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1320                                             struct cgroup *ancestor)
1321 {
1322 #ifdef CONFIG_SOCK_CGROUP_DATA
1323         return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1324                                     ancestor);
1325 #else
1326         return -ENOTSUPP;
1327 #endif
1328 }
1329 
1330 static inline bool sk_has_memory_pressure(const struct sock *sk)
1331 {
1332         return sk->sk_prot->memory_pressure != NULL;
1333 }
1334 
1335 static inline bool sk_under_memory_pressure(const struct sock *sk)
1336 {
1337         if (!sk->sk_prot->memory_pressure)
1338                 return false;
1339 
1340         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1341             mem_cgroup_under_socket_pressure(sk->sk_memcg))
1342                 return true;
1343 
1344         return !!*sk->sk_prot->memory_pressure;
1345 }
1346 
1347 static inline long
1348 sk_memory_allocated(const struct sock *sk)
1349 {
1350         return atomic_long_read(sk->sk_prot->memory_allocated);
1351 }
1352 
1353 static inline long
1354 sk_memory_allocated_add(struct sock *sk, int amt)
1355 {
1356         return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1357 }
1358 
1359 static inline void
1360 sk_memory_allocated_sub(struct sock *sk, int amt)
1361 {
1362         atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1363 }
1364 
1365 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1366 
1367 static inline void sk_sockets_allocated_dec(struct sock *sk)
1368 {
1369         percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1370                                  SK_ALLOC_PERCPU_COUNTER_BATCH);
1371 }
1372 
1373 static inline void sk_sockets_allocated_inc(struct sock *sk)
1374 {
1375         percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1376                                  SK_ALLOC_PERCPU_COUNTER_BATCH);
1377 }
1378 
1379 static inline u64
1380 sk_sockets_allocated_read_positive(struct sock *sk)
1381 {
1382         return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1383 }
1384 
1385 static inline int
1386 proto_sockets_allocated_sum_positive(struct proto *prot)
1387 {
1388         return percpu_counter_sum_positive(prot->sockets_allocated);
1389 }
1390 
1391 static inline long
1392 proto_memory_allocated(struct proto *prot)
1393 {
1394         return atomic_long_read(prot->memory_allocated);
1395 }
1396 
1397 static inline bool
1398 proto_memory_pressure(struct proto *prot)
1399 {
1400         if (!prot->memory_pressure)
1401                 return false;
1402         return !!*prot->memory_pressure;
1403 }
1404 
1405 
1406 #ifdef CONFIG_PROC_FS
1407 /* Called with local bh disabled */
1408 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1409 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1410 int sock_inuse_get(struct net *net);
1411 #else
1412 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1413                 int inc)
1414 {
1415 }
1416 #endif
1417 
1418 
1419 /* With per-bucket locks this operation is not-atomic, so that
1420  * this version is not worse.
1421  */
1422 static inline int __sk_prot_rehash(struct sock *sk)
1423 {
1424         sk->sk_prot->unhash(sk);
1425         return sk->sk_prot->hash(sk);
1426 }
1427 
1428 /* About 10 seconds */
1429 #define SOCK_DESTROY_TIME (10*HZ)
1430 
1431 /* Sockets 0-1023 can't be bound to unless you are superuser */
1432 #define PROT_SOCK       1024
1433 
1434 #define SHUTDOWN_MASK   3
1435 #define RCV_SHUTDOWN    1
1436 #define SEND_SHUTDOWN   2
1437 
1438 #define SOCK_SNDBUF_LOCK        1
1439 #define SOCK_RCVBUF_LOCK        2
1440 #define SOCK_BINDADDR_LOCK      4
1441 #define SOCK_BINDPORT_LOCK      8
1442 
1443 struct socket_alloc {
1444         struct socket socket;
1445         struct inode vfs_inode;
1446 };
1447 
1448 static inline struct socket *SOCKET_I(struct inode *inode)
1449 {
1450         return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1451 }
1452 
1453 static inline struct inode *SOCK_INODE(struct socket *socket)
1454 {
1455         return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1456 }
1457 
1458 /*
1459  * Functions for memory accounting
1460  */
1461 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1462 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1463 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1464 void __sk_mem_reclaim(struct sock *sk, int amount);
1465 
1466 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1467  * do not necessarily have 16x time more memory than 4KB ones.
1468  */
1469 #define SK_MEM_QUANTUM 4096
1470 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1471 #define SK_MEM_SEND     0
1472 #define SK_MEM_RECV     1
1473 
1474 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1475 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1476 {
1477         long val = sk->sk_prot->sysctl_mem[index];
1478 
1479 #if PAGE_SIZE > SK_MEM_QUANTUM
1480         val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1481 #elif PAGE_SIZE < SK_MEM_QUANTUM
1482         val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1483 #endif
1484         return val;
1485 }
1486 
1487 static inline int sk_mem_pages(int amt)
1488 {
1489         return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1490 }
1491 
1492 static inline bool sk_has_account(struct sock *sk)
1493 {
1494         /* return true if protocol supports memory accounting */
1495         return !!sk->sk_prot->memory_allocated;
1496 }
1497 
1498 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1499 {
1500         if (!sk_has_account(sk))
1501                 return true;
1502         return size <= sk->sk_forward_alloc ||
1503                 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1504 }
1505 
1506 static inline bool
1507 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1508 {
1509         if (!sk_has_account(sk))
1510                 return true;
1511         return size <= sk->sk_forward_alloc ||
1512                 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1513                 skb_pfmemalloc(skb);
1514 }
1515 
1516 static inline void sk_mem_reclaim(struct sock *sk)
1517 {
1518         if (!sk_has_account(sk))
1519                 return;
1520         if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1521                 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1522 }
1523 
1524 static inline void sk_mem_reclaim_partial(struct sock *sk)
1525 {
1526         if (!sk_has_account(sk))
1527                 return;
1528         if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1529                 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1530 }
1531 
1532 static inline void sk_mem_charge(struct sock *sk, int size)
1533 {
1534         if (!sk_has_account(sk))
1535                 return;
1536         sk->sk_forward_alloc -= size;
1537 }
1538 
1539 static inline void sk_mem_uncharge(struct sock *sk, int size)
1540 {
1541         if (!sk_has_account(sk))
1542                 return;
1543         sk->sk_forward_alloc += size;
1544 
1545         /* Avoid a possible overflow.
1546          * TCP send queues can make this happen, if sk_mem_reclaim()
1547          * is not called and more than 2 GBytes are released at once.
1548          *
1549          * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1550          * no need to hold that much forward allocation anyway.
1551          */
1552         if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1553                 __sk_mem_reclaim(sk, 1 << 20);
1554 }
1555 
1556 DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1557 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1558 {
1559         sk_wmem_queued_add(sk, -skb->truesize);
1560         sk_mem_uncharge(sk, skb->truesize);
1561         if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1562             !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1563                 skb_ext_reset(skb);
1564                 skb_zcopy_clear(skb, true);
1565                 sk->sk_tx_skb_cache = skb;
1566                 return;
1567         }
1568         __kfree_skb(skb);
1569 }
1570 
1571 static inline void sock_release_ownership(struct sock *sk)
1572 {
1573         if (sk->sk_lock.owned) {
1574                 sk->sk_lock.owned = 0;
1575 
1576                 /* The sk_lock has mutex_unlock() semantics: */
1577                 mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1578         }
1579 }
1580 
1581 /*
1582  * Macro so as to not evaluate some arguments when
1583  * lockdep is not enabled.
1584  *
1585  * Mark both the sk_lock and the sk_lock.slock as a
1586  * per-address-family lock class.
1587  */
1588 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
1589 do {                                                                    \
1590         sk->sk_lock.owned = 0;                                          \
1591         init_waitqueue_head(&sk->sk_lock.wq);                           \
1592         spin_lock_init(&(sk)->sk_lock.slock);                           \
1593         debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
1594                         sizeof((sk)->sk_lock));                         \
1595         lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
1596                                 (skey), (sname));                               \
1597         lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
1598 } while (0)
1599 
1600 static inline bool lockdep_sock_is_held(const struct sock *sk)
1601 {
1602         return lockdep_is_held(&sk->sk_lock) ||
1603                lockdep_is_held(&sk->sk_lock.slock);
1604 }
1605 
1606 void lock_sock_nested(struct sock *sk, int subclass);
1607 
1608 static inline void lock_sock(struct sock *sk)
1609 {
1610         lock_sock_nested(sk, 0);
1611 }
1612 
1613 void __lock_sock(struct sock *sk);
1614 void __release_sock(struct sock *sk);
1615 void release_sock(struct sock *sk);
1616 
1617 /* BH context may only use the following locking interface. */
1618 #define bh_lock_sock(__sk)      spin_lock(&((__sk)->sk_lock.slock))
1619 #define bh_lock_sock_nested(__sk) \
1620                                 spin_lock_nested(&((__sk)->sk_lock.slock), \
1621                                 SINGLE_DEPTH_NESTING)
1622 #define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
1623 
1624 bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1625 
1626 /**
1627  * unlock_sock_fast - complement of lock_sock_fast
1628  * @sk: socket
1629  * @slow: slow mode
1630  *
1631  * fast unlock socket for user context.
1632  * If slow mode is on, we call regular release_sock()
1633  */
1634 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1635         __releases(&sk->sk_lock.slock)
1636 {
1637         if (slow) {
1638                 release_sock(sk);
1639                 __release(&sk->sk_lock.slock);
1640         } else {
1641                 spin_unlock_bh(&sk->sk_lock.slock);
1642         }
1643 }
1644 
1645 /* Used by processes to "lock" a socket state, so that
1646  * interrupts and bottom half handlers won't change it
1647  * from under us. It essentially blocks any incoming
1648  * packets, so that we won't get any new data or any
1649  * packets that change the state of the socket.
1650  *
1651  * While locked, BH processing will add new packets to
1652  * the backlog queue.  This queue is processed by the
1653  * owner of the socket lock right before it is released.
1654  *
1655  * Since ~2.3.5 it is also exclusive sleep lock serializing
1656  * accesses from user process context.
1657  */
1658 
1659 static inline void sock_owned_by_me(const struct sock *sk)
1660 {
1661 #ifdef CONFIG_LOCKDEP
1662         WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1663 #endif
1664 }
1665 
1666 static inline bool sock_owned_by_user(const struct sock *sk)
1667 {
1668         sock_owned_by_me(sk);
1669         return sk->sk_lock.owned;
1670 }
1671 
1672 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1673 {
1674         return sk->sk_lock.owned;
1675 }
1676 
1677 /* no reclassification while locks are held */
1678 static inline bool sock_allow_reclassification(const struct sock *csk)
1679 {
1680         struct sock *sk = (struct sock *)csk;
1681 
1682         return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1683 }
1684 
1685 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1686                       struct proto *prot, int kern);
1687 void sk_free(struct sock *sk);
1688 void sk_destruct(struct sock *sk);
1689 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1690 void sk_free_unlock_clone(struct sock *sk);
1691 
1692 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1693                              gfp_t priority);
1694 void __sock_wfree(struct sk_buff *skb);
1695 void sock_wfree(struct sk_buff *skb);
1696 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1697                              gfp_t priority);
1698 void skb_orphan_partial(struct sk_buff *skb);
1699 void sock_rfree(struct sk_buff *skb);
1700 void sock_efree(struct sk_buff *skb);
1701 #ifdef CONFIG_INET
1702 void sock_edemux(struct sk_buff *skb);
1703 void sock_pfree(struct sk_buff *skb);
1704 #else
1705 #define sock_edemux sock_efree
1706 #endif
1707 
1708 int sock_setsockopt(struct socket *sock, int level, int op,
1709                     sockptr_t optval, unsigned int optlen);
1710 
1711 int sock_getsockopt(struct socket *sock, int level, int op,
1712                     char __user *optval, int __user *optlen);
1713 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1714                    bool timeval, bool time32);
1715 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1716                                     int noblock, int *errcode);
1717 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1718                                      unsigned long data_len, int noblock,
1719                                      int *errcode, int max_page_order);
1720 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1721 void sock_kfree_s(struct sock *sk, void *mem, int size);
1722 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1723 void sk_send_sigurg(struct sock *sk);
1724 
1725 struct sockcm_cookie {
1726         u64 transmit_time;
1727         u32 mark;
1728         u16 tsflags;
1729 };
1730 
1731 static inline void sockcm_init(struct sockcm_cookie *sockc,
1732                                const struct sock *sk)
1733 {
1734         *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1735 }
1736 
1737 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1738                      struct sockcm_cookie *sockc);
1739 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1740                    struct sockcm_cookie *sockc);
1741 
1742 /*
1743  * Functions to fill in entries in struct proto_ops when a protocol
1744  * does not implement a particular function.
1745  */
1746 int sock_no_bind(struct socket *, struct sockaddr *, int);
1747 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1748 int sock_no_socketpair(struct socket *, struct socket *);
1749 int sock_no_accept(struct socket *, struct socket *, int, bool);
1750 int sock_no_getname(struct socket *, struct sockaddr *, int);
1751 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1752 int sock_no_listen(struct socket *, int);
1753 int sock_no_shutdown(struct socket *, int);
1754 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1755 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1756 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1757 int sock_no_mmap(struct file *file, struct socket *sock,
1758                  struct vm_area_struct *vma);
1759 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1760                          size_t size, int flags);
1761 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1762                                 int offset, size_t size, int flags);
1763 
1764 /*
1765  * Functions to fill in entries in struct proto_ops when a protocol
1766  * uses the inet style.
1767  */
1768 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1769                                   char __user *optval, int __user *optlen);
1770 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1771                         int flags);
1772 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1773                            sockptr_t optval, unsigned int optlen);
1774 
1775 void sk_common_release(struct sock *sk);
1776 
1777 /*
1778  *      Default socket callbacks and setup code
1779  */
1780 
1781 /* Initialise core socket variables */
1782 void sock_init_data(struct socket *sock, struct sock *sk);
1783 
1784 /*
1785  * Socket reference counting postulates.
1786  *
1787  * * Each user of socket SHOULD hold a reference count.
1788  * * Each access point to socket (an hash table bucket, reference from a list,
1789  *   running timer, skb in flight MUST hold a reference count.
1790  * * When reference count hits 0, it means it will never increase back.
1791  * * When reference count hits 0, it means that no references from
1792  *   outside exist to this socket and current process on current CPU
1793  *   is last user and may/should destroy this socket.
1794  * * sk_free is called from any context: process, BH, IRQ. When
1795  *   it is called, socket has no references from outside -> sk_free
1796  *   may release descendant resources allocated by the socket, but
1797  *   to the time when it is called, socket is NOT referenced by any
1798  *   hash tables, lists etc.
1799  * * Packets, delivered from outside (from network or from another process)
1800  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1801  *   when they sit in queue. Otherwise, packets will leak to hole, when
1802  *   socket is looked up by one cpu and unhasing is made by another CPU.
1803  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1804  *   (leak to backlog). Packet socket does all the processing inside
1805  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1806  *   use separate SMP lock, so that they are prone too.
1807  */
1808 
1809 /* Ungrab socket and destroy it, if it was the last reference. */
1810 static inline void sock_put(struct sock *sk)
1811 {
1812         if (refcount_dec_and_test(&sk->sk_refcnt))
1813                 sk_free(sk);
1814 }
1815 /* Generic version of sock_put(), dealing with all sockets
1816  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1817  */
1818 void sock_gen_put(struct sock *sk);
1819 
1820 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1821                      unsigned int trim_cap, bool refcounted);
1822 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1823                                  const int nested)
1824 {
1825         return __sk_receive_skb(sk, skb, nested, 1, true);
1826 }
1827 
1828 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1829 {
1830         /* sk_tx_queue_mapping accept only upto a 16-bit value */
1831         if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1832                 return;
1833         sk->sk_tx_queue_mapping = tx_queue;
1834 }
1835 
1836 #define NO_QUEUE_MAPPING        USHRT_MAX
1837 
1838 static inline void sk_tx_queue_clear(struct sock *sk)
1839 {
1840         sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1841 }
1842 
1843 static inline int sk_tx_queue_get(const struct sock *sk)
1844 {
1845         if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1846                 return sk->sk_tx_queue_mapping;
1847 
1848         return -1;
1849 }
1850 
1851 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1852 {
1853 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1854         if (skb_rx_queue_recorded(skb)) {
1855                 u16 rx_queue = skb_get_rx_queue(skb);
1856 
1857                 if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1858                         return;
1859 
1860                 sk->sk_rx_queue_mapping = rx_queue;
1861         }
1862 #endif
1863 }
1864 
1865 static inline void sk_rx_queue_clear(struct sock *sk)
1866 {
1867 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1868         sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1869 #endif
1870 }
1871 
1872 static inline int sk_rx_queue_get(const struct sock *sk)
1873 {
1874 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1875         if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1876                 return sk->sk_rx_queue_mapping;
1877 #endif
1878 
1879         return -1;
1880 }
1881 
1882 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1883 {
1884         sk->sk_socket = sock;
1885 }
1886 
1887 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1888 {
1889         BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1890         return &rcu_dereference_raw(sk->sk_wq)->wait;
1891 }
1892 /* Detach socket from process context.
1893  * Announce socket dead, detach it from wait queue and inode.
1894  * Note that parent inode held reference count on this struct sock,
1895  * we do not release it in this function, because protocol
1896  * probably wants some additional cleanups or even continuing
1897  * to work with this socket (TCP).
1898  */
1899 static inline void sock_orphan(struct sock *sk)
1900 {
1901         write_lock_bh(&sk->sk_callback_lock);
1902         sock_set_flag(sk, SOCK_DEAD);
1903         sk_set_socket(sk, NULL);
1904         sk->sk_wq  = NULL;
1905         write_unlock_bh(&sk->sk_callback_lock);
1906 }
1907 
1908 static inline void sock_graft(struct sock *sk, struct socket *parent)
1909 {
1910         WARN_ON(parent->sk);
1911         write_lock_bh(&sk->sk_callback_lock);
1912         rcu_assign_pointer(sk->sk_wq, &parent->wq);
1913         parent->sk = sk;
1914         sk_set_socket(sk, parent);
1915         sk->sk_uid = SOCK_INODE(parent)->i_uid;
1916         security_sock_graft(sk, parent);
1917         write_unlock_bh(&sk->sk_callback_lock);
1918 }
1919 
1920 kuid_t sock_i_uid(struct sock *sk);
1921 unsigned long sock_i_ino(struct sock *sk);
1922 
1923 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1924 {
1925         return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1926 }
1927 
1928 static inline u32 net_tx_rndhash(void)
1929 {
1930         u32 v = prandom_u32();
1931 
1932         return v ?: 1;
1933 }
1934 
1935 static inline void sk_set_txhash(struct sock *sk)
1936 {
1937         sk->sk_txhash = net_tx_rndhash();
1938 }
1939 
1940 static inline bool sk_rethink_txhash(struct sock *sk)
1941 {
1942         if (sk->sk_txhash) {
1943                 sk_set_txhash(sk);
1944                 return true;
1945         }
1946         return false;
1947 }
1948 
1949 static inline struct dst_entry *
1950 __sk_dst_get(struct sock *sk)
1951 {
1952         return rcu_dereference_check(sk->sk_dst_cache,
1953                                      lockdep_sock_is_held(sk));
1954 }
1955 
1956 static inline struct dst_entry *
1957 sk_dst_get(struct sock *sk)
1958 {
1959         struct dst_entry *dst;
1960 
1961         rcu_read_lock();
1962         dst = rcu_dereference(sk->sk_dst_cache);
1963         if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1964                 dst = NULL;
1965         rcu_read_unlock();
1966         return dst;
1967 }
1968 
1969 static inline void __dst_negative_advice(struct sock *sk)
1970 {
1971         struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1972 
1973         if (dst && dst->ops->negative_advice) {
1974                 ndst = dst->ops->negative_advice(dst);
1975 
1976                 if (ndst != dst) {
1977                         rcu_assign_pointer(sk->sk_dst_cache, ndst);
1978                         sk_tx_queue_clear(sk);
1979                         sk->sk_dst_pending_confirm = 0;
1980                 }
1981         }
1982 }
1983 
1984 static inline void dst_negative_advice(struct sock *sk)
1985 {
1986         sk_rethink_txhash(sk);
1987         __dst_negative_advice(sk);
1988 }
1989 
1990 static inline void
1991 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1992 {
1993         struct dst_entry *old_dst;
1994 
1995         sk_tx_queue_clear(sk);
1996         sk->sk_dst_pending_confirm = 0;
1997         old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1998                                             lockdep_sock_is_held(sk));
1999         rcu_assign_pointer(sk->sk_dst_cache, dst);
2000         dst_release(old_dst);
2001 }
2002 
2003 static inline void
2004 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2005 {
2006         struct dst_entry *old_dst;
2007 
2008         sk_tx_queue_clear(sk);
2009         sk->sk_dst_pending_confirm = 0;
2010         old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2011         dst_release(old_dst);
2012 }
2013 
2014 static inline void
2015 __sk_dst_reset(struct sock *sk)
2016 {
2017         __sk_dst_set(sk, NULL);
2018 }
2019 
2020 static inline void
2021 sk_dst_reset(struct sock *sk)
2022 {
2023         sk_dst_set(sk, NULL);
2024 }
2025 
2026 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2027 
2028 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2029 
2030 static inline void sk_dst_confirm(struct sock *sk)
2031 {
2032         if (!READ_ONCE(sk->sk_dst_pending_confirm))
2033                 WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2034 }
2035 
2036 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2037 {
2038         if (skb_get_dst_pending_confirm(skb)) {
2039                 struct sock *sk = skb->sk;
2040                 unsigned long now = jiffies;
2041 
2042                 /* avoid dirtying neighbour */
2043                 if (READ_ONCE(n->confirmed) != now)
2044                         WRITE_ONCE(n->confirmed, now);
2045                 if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2046                         WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2047         }
2048 }
2049 
2050 bool sk_mc_loop(struct sock *sk);
2051 
2052 static inline bool sk_can_gso(const struct sock *sk)
2053 {
2054         return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2055 }
2056 
2057 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2058 
2059 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
2060 {
2061         sk->sk_route_nocaps |= flags;
2062         sk->sk_route_caps &= ~flags;
2063 }
2064 
2065 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2066                                            struct iov_iter *from, char *to,
2067                                            int copy, int offset)
2068 {
2069         if (skb->ip_summed == CHECKSUM_NONE) {
2070                 __wsum csum = 0;
2071                 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2072                         return -EFAULT;
2073                 skb->csum = csum_block_add(skb->csum, csum, offset);
2074         } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2075                 if (!copy_from_iter_full_nocache(to, copy, from))
2076                         return -EFAULT;
2077         } else if (!copy_from_iter_full(to, copy, from))
2078                 return -EFAULT;
2079 
2080         return 0;
2081 }
2082 
2083 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2084                                        struct iov_iter *from, int copy)
2085 {
2086         int err, offset = skb->len;
2087 
2088         err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2089                                        copy, offset);
2090         if (err)
2091                 __skb_trim(skb, offset);
2092 
2093         return err;
2094 }
2095 
2096 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2097                                            struct sk_buff *skb,
2098                                            struct page *page,
2099                                            int off, int copy)
2100 {
2101         int err;
2102 
2103         err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2104                                        copy, skb->len);
2105         if (err)
2106                 return err;
2107 
2108         skb->len             += copy;
2109         skb->data_len        += copy;
2110         skb->truesize        += copy;
2111         sk_wmem_queued_add(sk, copy);
2112         sk_mem_charge(sk, copy);
2113         return 0;
2114 }
2115 
2116 /**
2117  * sk_wmem_alloc_get - returns write allocations
2118  * @sk: socket
2119  *
2120  * Return: sk_wmem_alloc minus initial offset of one
2121  */
2122 static inline int sk_wmem_alloc_get(const struct sock *sk)
2123 {
2124         return refcount_read(&sk->sk_wmem_alloc) - 1;
2125 }
2126 
2127 /**
2128  * sk_rmem_alloc_get - returns read allocations
2129  * @sk: socket
2130  *
2131  * Return: sk_rmem_alloc
2132  */
2133 static inline int sk_rmem_alloc_get(const struct sock *sk)
2134 {
2135         return atomic_read(&sk->sk_rmem_alloc);
2136 }
2137 
2138 /**
2139  * sk_has_allocations - check if allocations are outstanding
2140  * @sk: socket
2141  *
2142  * Return: true if socket has write or read allocations
2143  */
2144 static inline bool sk_has_allocations(const struct sock *sk)
2145 {
2146         return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2147 }
2148 
2149 /**
2150  * skwq_has_sleeper - check if there are any waiting processes
2151  * @wq: struct socket_wq
2152  *
2153  * Return: true if socket_wq has waiting processes
2154  *
2155  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2156  * barrier call. They were added due to the race found within the tcp code.
2157  *
2158  * Consider following tcp code paths::
2159  *
2160  *   CPU1                CPU2
2161  *   sys_select          receive packet
2162  *   ...                 ...
2163  *   __add_wait_queue    update tp->rcv_nxt
2164  *   ...                 ...
2165  *   tp->rcv_nxt check   sock_def_readable
2166  *   ...                 {
2167  *   schedule               rcu_read_lock();
2168  *                          wq = rcu_dereference(sk->sk_wq);
2169  *                          if (wq && waitqueue_active(&wq->wait))
2170  *                              wake_up_interruptible(&wq->wait)
2171  *                          ...
2172  *                       }
2173  *
2174  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2175  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2176  * could then endup calling schedule and sleep forever if there are no more
2177  * data on the socket.
2178  *
2179  */
2180 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2181 {
2182         return wq && wq_has_sleeper(&wq->wait);
2183 }
2184 
2185 /**
2186  * sock_poll_wait - place memory barrier behind the poll_wait call.
2187  * @filp:           file
2188  * @sock:           socket to wait on
2189  * @p:              poll_table
2190  *
2191  * See the comments in the wq_has_sleeper function.
2192  */
2193 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2194                                   poll_table *p)
2195 {
2196         if (!poll_does_not_wait(p)) {
2197                 poll_wait(filp, &sock->wq.wait, p);
2198                 /* We need to be sure we are in sync with the
2199                  * socket flags modification.
2200                  *
2201                  * This memory barrier is paired in the wq_has_sleeper.
2202                  */
2203                 smp_mb();
2204         }
2205 }
2206 
2207 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2208 {
2209         if (sk->sk_txhash) {
2210                 skb->l4_hash = 1;
2211                 skb->hash = sk->sk_txhash;
2212         }
2213 }
2214 
2215 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2216 
2217 /*
2218  *      Queue a received datagram if it will fit. Stream and sequenced
2219  *      protocols can't normally use this as they need to fit buffers in
2220  *      and play with them.
2221  *
2222  *      Inlined as it's very short and called for pretty much every
2223  *      packet ever received.
2224  */
2225 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2226 {
2227         skb_orphan(skb);
2228         skb->sk = sk;
2229         skb->destructor = sock_rfree;
2230         atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2231         sk_mem_charge(sk, skb->truesize);
2232 }
2233 
2234 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2235 {
2236         if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2237                 skb_orphan(skb);
2238                 skb->destructor = sock_efree;
2239                 skb->sk = sk;
2240                 return true;
2241         }
2242         return false;
2243 }
2244 
2245 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2246                     unsigned long expires);
2247 
2248 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2249 
2250 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2251 
2252 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2253                         struct sk_buff *skb, unsigned int flags,
2254                         void (*destructor)(struct sock *sk,
2255                                            struct sk_buff *skb));
2256 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2257 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2258 
2259 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2260 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2261 
2262 /*
2263  *      Recover an error report and clear atomically
2264  */
2265 
2266 static inline int sock_error(struct sock *sk)
2267 {
2268         int err;
2269         if (likely(!sk->sk_err))
2270                 return 0;
2271         err = xchg(&sk->sk_err, 0);
2272         return -err;
2273 }
2274 
2275 static inline unsigned long sock_wspace(struct sock *sk)
2276 {
2277         int amt = 0;
2278 
2279         if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2280                 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2281                 if (amt < 0)
2282                         amt = 0;
2283         }
2284         return amt;
2285 }
2286 
2287 /* Note:
2288  *  We use sk->sk_wq_raw, from contexts knowing this
2289  *  pointer is not NULL and cannot disappear/change.
2290  */
2291 static inline void sk_set_bit(int nr, struct sock *sk)
2292 {
2293         if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2294             !sock_flag(sk, SOCK_FASYNC))
2295                 return;
2296 
2297         set_bit(nr, &sk->sk_wq_raw->flags);
2298 }
2299 
2300 static inline void sk_clear_bit(int nr, struct sock *sk)
2301 {
2302         if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2303             !sock_flag(sk, SOCK_FASYNC))
2304                 return;
2305 
2306         clear_bit(nr, &sk->sk_wq_raw->flags);
2307 }
2308 
2309 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2310 {
2311         if (sock_flag(sk, SOCK_FASYNC)) {
2312                 rcu_read_lock();
2313                 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2314                 rcu_read_unlock();
2315         }
2316 }
2317 
2318 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2319  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2320  * Note: for send buffers, TCP works better if we can build two skbs at
2321  * minimum.
2322  */
2323 #define TCP_SKB_MIN_TRUESIZE    (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2324 
2325 #define SOCK_MIN_SNDBUF         (TCP_SKB_MIN_TRUESIZE * 2)
2326 #define SOCK_MIN_RCVBUF          TCP_SKB_MIN_TRUESIZE
2327 
2328 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2329 {
2330         u32 val;
2331 
2332         if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2333                 return;
2334 
2335         val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2336 
2337         WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2338 }
2339 
2340 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2341                                     bool force_schedule);
2342 
2343 /**
2344  * sk_page_frag - return an appropriate page_frag
2345  * @sk: socket
2346  *
2347  * Use the per task page_frag instead of the per socket one for
2348  * optimization when we know that we're in the normal context and owns
2349  * everything that's associated with %current.
2350  *
2351  * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2352  * inside other socket operations and end up recursing into sk_page_frag()
2353  * while it's already in use.
2354  *
2355  * Return: a per task page_frag if context allows that,
2356  * otherwise a per socket one.
2357  */
2358 static inline struct page_frag *sk_page_frag(struct sock *sk)
2359 {
2360         if (gfpflags_normal_context(sk->sk_allocation))
2361                 return &current->task_frag;
2362 
2363         return &sk->sk_frag;
2364 }
2365 
2366 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2367 
2368 /*
2369  *      Default write policy as shown to user space via poll/select/SIGIO
2370  */
2371 static inline bool sock_writeable(const struct sock *sk)
2372 {
2373         return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2374 }
2375 
2376 static inline gfp_t gfp_any(void)
2377 {
2378         return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2379 }
2380 
2381 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2382 {
2383         return noblock ? 0 : sk->sk_rcvtimeo;
2384 }
2385 
2386 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2387 {
2388         return noblock ? 0 : sk->sk_sndtimeo;
2389 }
2390 
2391 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2392 {
2393         int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2394 
2395         return v ?: 1;
2396 }
2397 
2398 /* Alas, with timeout socket operations are not restartable.
2399  * Compare this to poll().
2400  */
2401 static inline int sock_intr_errno(long timeo)
2402 {
2403         return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2404 }
2405 
2406 struct sock_skb_cb {
2407         u32 dropcount;
2408 };
2409 
2410 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2411  * using skb->cb[] would keep using it directly and utilize its
2412  * alignement guarantee.
2413  */
2414 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2415                             sizeof(struct sock_skb_cb)))
2416 
2417 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2418                             SOCK_SKB_CB_OFFSET))
2419 
2420 #define sock_skb_cb_check_size(size) \
2421         BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2422 
2423 static inline void
2424 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2425 {
2426         SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2427                                                 atomic_read(&sk->sk_drops) : 0;
2428 }
2429 
2430 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2431 {
2432         int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2433 
2434         atomic_add(segs, &sk->sk_drops);
2435 }
2436 
2437 static inline ktime_t sock_read_timestamp(struct sock *sk)
2438 {
2439 #if BITS_PER_LONG==32
2440         unsigned int seq;
2441         ktime_t kt;
2442 
2443         do {
2444                 seq = read_seqbegin(&sk->sk_stamp_seq);
2445                 kt = sk->sk_stamp;
2446         } while (read_seqretry(&sk->sk_stamp_seq, seq));
2447 
2448         return kt;
2449 #else
2450         return READ_ONCE(sk->sk_stamp);
2451 #endif
2452 }
2453 
2454 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2455 {
2456 #if BITS_PER_LONG==32
2457         write_seqlock(&sk->sk_stamp_seq);
2458         sk->sk_stamp = kt;
2459         write_sequnlock(&sk->sk_stamp_seq);
2460 #else
2461         WRITE_ONCE(sk->sk_stamp, kt);
2462 #endif
2463 }
2464 
2465 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2466                            struct sk_buff *skb);
2467 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2468                              struct sk_buff *skb);
2469 
2470 static inline void
2471 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2472 {
2473         ktime_t kt = skb->tstamp;
2474         struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2475 
2476         /*
2477          * generate control messages if
2478          * - receive time stamping in software requested
2479          * - software time stamp available and wanted
2480          * - hardware time stamps available and wanted
2481          */
2482         if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2483             (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2484             (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2485             (hwtstamps->hwtstamp &&
2486              (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2487                 __sock_recv_timestamp(msg, sk, skb);
2488         else
2489                 sock_write_timestamp(sk, kt);
2490 
2491         if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2492                 __sock_recv_wifi_status(msg, sk, skb);
2493 }
2494 
2495 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2496                               struct sk_buff *skb);
2497 
2498 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2499 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2500                                           struct sk_buff *skb)
2501 {
2502 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)                       | \
2503                            (1UL << SOCK_RCVTSTAMP))
2504 #define TSFLAGS_ANY       (SOF_TIMESTAMPING_SOFTWARE                    | \
2505                            SOF_TIMESTAMPING_RAW_HARDWARE)
2506 
2507         if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2508                 __sock_recv_ts_and_drops(msg, sk, skb);
2509         else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2510                 sock_write_timestamp(sk, skb->tstamp);
2511         else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2512                 sock_write_timestamp(sk, 0);
2513 }
2514 
2515 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2516 
2517 /**
2518  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2519  * @sk:         socket sending this packet
2520  * @tsflags:    timestamping flags to use
2521  * @tx_flags:   completed with instructions for time stamping
2522  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2523  *
2524  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2525  */
2526 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2527                                       __u8 *tx_flags, __u32 *tskey)
2528 {
2529         if (unlikely(tsflags)) {
2530                 __sock_tx_timestamp(tsflags, tx_flags);
2531                 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2532                     tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2533                         *tskey = sk->sk_tskey++;
2534         }
2535         if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2536                 *tx_flags |= SKBTX_WIFI_STATUS;
2537 }
2538 
2539 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2540                                      __u8 *tx_flags)
2541 {
2542         _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2543 }
2544 
2545 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2546 {
2547         _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2548                            &skb_shinfo(skb)->tskey);
2549 }
2550 
2551 DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2552 /**
2553  * sk_eat_skb - Release a skb if it is no longer needed
2554  * @sk: socket to eat this skb from
2555  * @skb: socket buffer to eat
2556  *
2557  * This routine must be called with interrupts disabled or with the socket
2558  * locked so that the sk_buff queue operation is ok.
2559 */
2560 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2561 {
2562         __skb_unlink(skb, &sk->sk_receive_queue);
2563         if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2564             !sk->sk_rx_skb_cache) {
2565                 sk->sk_rx_skb_cache = skb;
2566                 skb_orphan(skb);
2567                 return;
2568         }
2569         __kfree_skb(skb);
2570 }
2571 
2572 static inline
2573 struct net *sock_net(const struct sock *sk)
2574 {
2575         return read_pnet(&sk->sk_net);
2576 }
2577 
2578 static inline
2579 void sock_net_set(struct sock *sk, struct net *net)
2580 {
2581         write_pnet(&sk->sk_net, net);
2582 }
2583 
2584 static inline bool
2585 skb_sk_is_prefetched(struct sk_buff *skb)
2586 {
2587 #ifdef CONFIG_INET
2588         return skb->destructor == sock_pfree;
2589 #else
2590         return false;
2591 #endif /* CONFIG_INET */
2592 }
2593 
2594 /* This helper checks if a socket is a full socket,
2595  * ie _not_ a timewait or request socket.
2596  */
2597 static inline bool sk_fullsock(const struct sock *sk)
2598 {
2599         return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2600 }
2601 
2602 static inline bool
2603 sk_is_refcounted(struct sock *sk)
2604 {
2605         /* Only full sockets have sk->sk_flags. */
2606         return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2607 }
2608 
2609 /**
2610  * skb_steal_sock - steal a socket from an sk_buff
2611  * @skb: sk_buff to steal the socket from
2612  * @refcounted: is set to true if the socket is reference-counted
2613  */
2614 static inline struct sock *
2615 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2616 {
2617         if (skb->sk) {
2618                 struct sock *sk = skb->sk;
2619 
2620                 *refcounted = true;
2621                 if (skb_sk_is_prefetched(skb))
2622                         *refcounted = sk_is_refcounted(sk);
2623                 skb->destructor = NULL;
2624                 skb->sk = NULL;
2625                 return sk;
2626         }
2627         *refcounted = false;
2628         return NULL;
2629 }
2630 
2631 /* Checks if this SKB belongs to an HW offloaded socket
2632  * and whether any SW fallbacks are required based on dev.
2633  * Check decrypted mark in case skb_orphan() cleared socket.
2634  */
2635 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2636                                                    struct net_device *dev)
2637 {
2638 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2639         struct sock *sk = skb->sk;
2640 
2641         if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2642                 skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2643 #ifdef CONFIG_TLS_DEVICE
2644         } else if (unlikely(skb->decrypted)) {
2645                 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2646                 kfree_skb(skb);
2647                 skb = NULL;
2648 #endif
2649         }
2650 #endif
2651 
2652         return skb;
2653 }
2654 
2655 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2656  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2657  */
2658 static inline bool sk_listener(const struct sock *sk)
2659 {
2660         return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2661 }
2662 
2663 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2664 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2665                        int type);
2666 
2667 bool sk_ns_capable(const struct sock *sk,
2668                    struct user_namespace *user_ns, int cap);
2669 bool sk_capable(const struct sock *sk, int cap);
2670 bool sk_net_capable(const struct sock *sk, int cap);
2671 
2672 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2673 
2674 /* Take into consideration the size of the struct sk_buff overhead in the
2675  * determination of these values, since that is non-constant across
2676  * platforms.  This makes socket queueing behavior and performance
2677  * not depend upon such differences.
2678  */
2679 #define _SK_MEM_PACKETS         256
2680 #define _SK_MEM_OVERHEAD        SKB_TRUESIZE(256)
2681 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2682 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2683 
2684 extern __u32 sysctl_wmem_max;
2685 extern __u32 sysctl_rmem_max;
2686 
2687 extern int sysctl_tstamp_allow_data;
2688 extern int sysctl_optmem_max;
2689 
2690 extern __u32 sysctl_wmem_default;
2691 extern __u32 sysctl_rmem_default;
2692 
2693 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2694 
2695 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2696 {
2697         /* Does this proto have per netns sysctl_wmem ? */
2698         if (proto->sysctl_wmem_offset)
2699                 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2700 
2701         return *proto->sysctl_wmem;
2702 }
2703 
2704 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2705 {
2706         /* Does this proto have per netns sysctl_rmem ? */
2707         if (proto->sysctl_rmem_offset)
2708                 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2709 
2710         return *proto->sysctl_rmem;
2711 }
2712 
2713 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2714  * Some wifi drivers need to tweak it to get more chunks.
2715  * They can use this helper from their ndo_start_xmit()
2716  */
2717 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2718 {
2719         if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2720                 return;
2721         WRITE_ONCE(sk->sk_pacing_shift, val);
2722 }
2723 
2724 /* if a socket is bound to a device, check that the given device
2725  * index is either the same or that the socket is bound to an L3
2726  * master device and the given device index is also enslaved to
2727  * that L3 master
2728  */
2729 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2730 {
2731         int mdif;
2732 
2733         if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2734                 return true;
2735 
2736         mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2737         if (mdif && mdif == sk->sk_bound_dev_if)
2738                 return true;
2739 
2740         return false;
2741 }
2742 
2743 void sock_def_readable(struct sock *sk);
2744 
2745 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2746 void sock_enable_timestamps(struct sock *sk);
2747 void sock_no_linger(struct sock *sk);
2748 void sock_set_keepalive(struct sock *sk);
2749 void sock_set_priority(struct sock *sk, u32 priority);
2750 void sock_set_rcvbuf(struct sock *sk, int val);
2751 void sock_set_mark(struct sock *sk, u32 val);
2752 void sock_set_reuseaddr(struct sock *sk);
2753 void sock_set_reuseport(struct sock *sk);
2754 void sock_set_sndtimeo(struct sock *sk, s64 secs);
2755 
2756 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2757 
2758 #endif  /* _SOCK_H */
2759 

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