linux/include/net/sock.h
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   1/*
   2 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3 *              operating system.  INET is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              Definitions for the AF_INET socket handler.
   7 *
   8 * Version:     @(#)sock.h      1.0.4   05/13/93
   9 *
  10 * Authors:     Ross Biro
  11 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 *              Corey Minyard <wf-rch!minyard@relay.EU.net>
  13 *              Florian La Roche <flla@stud.uni-sb.de>
  14 *
  15 * Fixes:
  16 *              Alan Cox        :       Volatiles in skbuff pointers. See
  17 *                                      skbuff comments. May be overdone,
  18 *                                      better to prove they can be removed
  19 *                                      than the reverse.
  20 *              Alan Cox        :       Added a zapped field for tcp to note
  21 *                                      a socket is reset and must stay shut up
  22 *              Alan Cox        :       New fields for options
  23 *      Pauline Middelink       :       identd support
  24 *              Alan Cox        :       Eliminate low level recv/recvfrom
  25 *              David S. Miller :       New socket lookup architecture.
  26 *              Steve Whitehouse:       Default routines for sock_ops
  27 *              Arnaldo C. Melo :       removed net_pinfo, tp_pinfo and made
  28 *                                      protinfo be just a void pointer, as the
  29 *                                      protocol specific parts were moved to
  30 *                                      respective headers and ipv4/v6, etc now
  31 *                                      use private slabcaches for its socks
  32 *              Pedro Hortas    :       New flags field for socket options
  33 *
  34 *
  35 *              This program is free software; you can redistribute it and/or
  36 *              modify it under the terms of the GNU General Public License
  37 *              as published by the Free Software Foundation; either version
  38 *              2 of the License, or (at your option) any later version.
  39 */
  40#ifndef _SOCK_H
  41#define _SOCK_H
  42
  43#include <linux/hardirq.h>
  44#include <linux/kernel.h>
  45#include <linux/list.h>
  46#include <linux/list_nulls.h>
  47#include <linux/timer.h>
  48#include <linux/cache.h>
  49#include <linux/lockdep.h>
  50#include <linux/netdevice.h>
  51#include <linux/skbuff.h>       /* struct sk_buff */
  52#include <linux/mm.h>
  53#include <linux/security.h>
  54#include <linux/slab.h>
  55#include <linux/uaccess.h>
  56
  57#include <linux/filter.h>
  58#include <linux/rculist_nulls.h>
  59#include <linux/poll.h>
  60
  61#include <linux/atomic.h>
  62#include <net/dst.h>
  63#include <net/checksum.h>
  64
  65/*
  66 * This structure really needs to be cleaned up.
  67 * Most of it is for TCP, and not used by any of
  68 * the other protocols.
  69 */
  70
  71/* Define this to get the SOCK_DBG debugging facility. */
  72#define SOCK_DEBUGGING
  73#ifdef SOCK_DEBUGGING
  74#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
  75                                        printk(KERN_DEBUG msg); } while (0)
  76#else
  77/* Validate arguments and do nothing */
  78static inline __printf(2, 3)
  79void SOCK_DEBUG(struct sock *sk, const char *msg, ...)
  80{
  81}
  82#endif
  83
  84/* This is the per-socket lock.  The spinlock provides a synchronization
  85 * between user contexts and software interrupt processing, whereas the
  86 * mini-semaphore synchronizes multiple users amongst themselves.
  87 */
  88typedef struct {
  89        spinlock_t              slock;
  90        int                     owned;
  91        wait_queue_head_t       wq;
  92        /*
  93         * We express the mutex-alike socket_lock semantics
  94         * to the lock validator by explicitly managing
  95         * the slock as a lock variant (in addition to
  96         * the slock itself):
  97         */
  98#ifdef CONFIG_DEBUG_LOCK_ALLOC
  99        struct lockdep_map dep_map;
 100#endif
 101} socket_lock_t;
 102
 103struct sock;
 104struct proto;
 105struct net;
 106
 107/**
 108 *      struct sock_common - minimal network layer representation of sockets
 109 *      @skc_daddr: Foreign IPv4 addr
 110 *      @skc_rcv_saddr: Bound local IPv4 addr
 111 *      @skc_hash: hash value used with various protocol lookup tables
 112 *      @skc_u16hashes: two u16 hash values used by UDP lookup tables
 113 *      @skc_family: network address family
 114 *      @skc_state: Connection state
 115 *      @skc_reuse: %SO_REUSEADDR setting
 116 *      @skc_bound_dev_if: bound device index if != 0
 117 *      @skc_bind_node: bind hash linkage for various protocol lookup tables
 118 *      @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
 119 *      @skc_prot: protocol handlers inside a network family
 120 *      @skc_net: reference to the network namespace of this socket
 121 *      @skc_node: main hash linkage for various protocol lookup tables
 122 *      @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
 123 *      @skc_tx_queue_mapping: tx queue number for this connection
 124 *      @skc_refcnt: reference count
 125 *
 126 *      This is the minimal network layer representation of sockets, the header
 127 *      for struct sock and struct inet_timewait_sock.
 128 */
 129struct sock_common {
 130        /* skc_daddr and skc_rcv_saddr must be grouped :
 131         * cf INET_MATCH() and INET_TW_MATCH()
 132         */
 133        __be32                  skc_daddr;
 134        __be32                  skc_rcv_saddr;
 135
 136        union  {
 137                unsigned int    skc_hash;
 138                __u16           skc_u16hashes[2];
 139        };
 140        unsigned short          skc_family;
 141        volatile unsigned char  skc_state;
 142        unsigned char           skc_reuse;
 143        int                     skc_bound_dev_if;
 144        union {
 145                struct hlist_node       skc_bind_node;
 146                struct hlist_nulls_node skc_portaddr_node;
 147        };
 148        struct proto            *skc_prot;
 149#ifdef CONFIG_NET_NS
 150        struct net              *skc_net;
 151#endif
 152        /*
 153         * fields between dontcopy_begin/dontcopy_end
 154         * are not copied in sock_copy()
 155         */
 156        /* private: */
 157        int                     skc_dontcopy_begin[0];
 158        /* public: */
 159        union {
 160                struct hlist_node       skc_node;
 161                struct hlist_nulls_node skc_nulls_node;
 162        };
 163        int                     skc_tx_queue_mapping;
 164        atomic_t                skc_refcnt;
 165        /* private: */
 166        int                     skc_dontcopy_end[0];
 167        /* public: */
 168};
 169
 170/**
 171  *     struct sock - network layer representation of sockets
 172  *     @__sk_common: shared layout with inet_timewait_sock
 173  *     @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
 174  *     @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
 175  *     @sk_lock:       synchronizer
 176  *     @sk_rcvbuf: size of receive buffer in bytes
 177  *     @sk_wq: sock wait queue and async head
 178  *     @sk_dst_cache: destination cache
 179  *     @sk_dst_lock: destination cache lock
 180  *     @sk_policy: flow policy
 181  *     @sk_receive_queue: incoming packets
 182  *     @sk_wmem_alloc: transmit queue bytes committed
 183  *     @sk_write_queue: Packet sending queue
 184  *     @sk_async_wait_queue: DMA copied packets
 185  *     @sk_omem_alloc: "o" is "option" or "other"
 186  *     @sk_wmem_queued: persistent queue size
 187  *     @sk_forward_alloc: space allocated forward
 188  *     @sk_allocation: allocation mode
 189  *     @sk_sndbuf: size of send buffer in bytes
 190  *     @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
 191  *                %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
 192  *     @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
 193  *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
 194  *     @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
 195  *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
 196  *     @sk_gso_max_size: Maximum GSO segment size to build
 197  *     @sk_lingertime: %SO_LINGER l_linger setting
 198  *     @sk_backlog: always used with the per-socket spinlock held
 199  *     @sk_callback_lock: used with the callbacks in the end of this struct
 200  *     @sk_error_queue: rarely used
 201  *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
 202  *                       IPV6_ADDRFORM for instance)
 203  *     @sk_err: last error
 204  *     @sk_err_soft: errors that don't cause failure but are the cause of a
 205  *                   persistent failure not just 'timed out'
 206  *     @sk_drops: raw/udp drops counter
 207  *     @sk_ack_backlog: current listen backlog
 208  *     @sk_max_ack_backlog: listen backlog set in listen()
 209  *     @sk_priority: %SO_PRIORITY setting
 210  *     @sk_type: socket type (%SOCK_STREAM, etc)
 211  *     @sk_protocol: which protocol this socket belongs in this network family
 212  *     @sk_peer_pid: &struct pid for this socket's peer
 213  *     @sk_peer_cred: %SO_PEERCRED setting
 214  *     @sk_rcvlowat: %SO_RCVLOWAT setting
 215  *     @sk_rcvtimeo: %SO_RCVTIMEO setting
 216  *     @sk_sndtimeo: %SO_SNDTIMEO setting
 217  *     @sk_rxhash: flow hash received from netif layer
 218  *     @sk_filter: socket filtering instructions
 219  *     @sk_protinfo: private area, net family specific, when not using slab
 220  *     @sk_timer: sock cleanup timer
 221  *     @sk_stamp: time stamp of last packet received
 222  *     @sk_socket: Identd and reporting IO signals
 223  *     @sk_user_data: RPC layer private data
 224  *     @sk_sndmsg_page: cached page for sendmsg
 225  *     @sk_sndmsg_off: cached offset for sendmsg
 226  *     @sk_send_head: front of stuff to transmit
 227  *     @sk_security: used by security modules
 228  *     @sk_mark: generic packet mark
 229  *     @sk_classid: this socket's cgroup classid
 230  *     @sk_write_pending: a write to stream socket waits to start
 231  *     @sk_state_change: callback to indicate change in the state of the sock
 232  *     @sk_data_ready: callback to indicate there is data to be processed
 233  *     @sk_write_space: callback to indicate there is bf sending space available
 234  *     @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
 235  *     @sk_backlog_rcv: callback to process the backlog
 236  *     @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
 237 */
 238struct sock {
 239        /*
 240         * Now struct inet_timewait_sock also uses sock_common, so please just
 241         * don't add nothing before this first member (__sk_common) --acme
 242         */
 243        struct sock_common      __sk_common;
 244#define sk_node                 __sk_common.skc_node
 245#define sk_nulls_node           __sk_common.skc_nulls_node
 246#define sk_refcnt               __sk_common.skc_refcnt
 247#define sk_tx_queue_mapping     __sk_common.skc_tx_queue_mapping
 248
 249#define sk_dontcopy_begin       __sk_common.skc_dontcopy_begin
 250#define sk_dontcopy_end         __sk_common.skc_dontcopy_end
 251#define sk_hash                 __sk_common.skc_hash
 252#define sk_family               __sk_common.skc_family
 253#define sk_state                __sk_common.skc_state
 254#define sk_reuse                __sk_common.skc_reuse
 255#define sk_bound_dev_if         __sk_common.skc_bound_dev_if
 256#define sk_bind_node            __sk_common.skc_bind_node
 257#define sk_prot                 __sk_common.skc_prot
 258#define sk_net                  __sk_common.skc_net
 259        socket_lock_t           sk_lock;
 260        struct sk_buff_head     sk_receive_queue;
 261        /*
 262         * The backlog queue is special, it is always used with
 263         * the per-socket spinlock held and requires low latency
 264         * access. Therefore we special case it's implementation.
 265         * Note : rmem_alloc is in this structure to fill a hole
 266         * on 64bit arches, not because its logically part of
 267         * backlog.
 268         */
 269        struct {
 270                atomic_t        rmem_alloc;
 271                int             len;
 272                struct sk_buff  *head;
 273                struct sk_buff  *tail;
 274        } sk_backlog;
 275#define sk_rmem_alloc sk_backlog.rmem_alloc
 276        int                     sk_forward_alloc;
 277#ifdef CONFIG_RPS
 278        __u32                   sk_rxhash;
 279#endif
 280        atomic_t                sk_drops;
 281        int                     sk_rcvbuf;
 282
 283        struct sk_filter __rcu  *sk_filter;
 284        struct socket_wq __rcu  *sk_wq;
 285
 286#ifdef CONFIG_NET_DMA
 287        struct sk_buff_head     sk_async_wait_queue;
 288#endif
 289
 290#ifdef CONFIG_XFRM
 291        struct xfrm_policy      *sk_policy[2];
 292#endif
 293        unsigned long           sk_flags;
 294        struct dst_entry        *sk_dst_cache;
 295        spinlock_t              sk_dst_lock;
 296        atomic_t                sk_wmem_alloc;
 297        atomic_t                sk_omem_alloc;
 298        int                     sk_sndbuf;
 299        struct sk_buff_head     sk_write_queue;
 300        kmemcheck_bitfield_begin(flags);
 301        unsigned int            sk_shutdown  : 2,
 302                                sk_no_check  : 2,
 303                                sk_userlocks : 4,
 304                                sk_protocol  : 8,
 305                                sk_type      : 16;
 306        kmemcheck_bitfield_end(flags);
 307        int                     sk_wmem_queued;
 308        gfp_t                   sk_allocation;
 309        int                     sk_route_caps;
 310        int                     sk_route_nocaps;
 311        int                     sk_gso_type;
 312        unsigned int            sk_gso_max_size;
 313        int                     sk_rcvlowat;
 314        unsigned long           sk_lingertime;
 315        struct sk_buff_head     sk_error_queue;
 316        struct proto            *sk_prot_creator;
 317        rwlock_t                sk_callback_lock;
 318        int                     sk_err,
 319                                sk_err_soft;
 320        unsigned short          sk_ack_backlog;
 321        unsigned short          sk_max_ack_backlog;
 322        __u32                   sk_priority;
 323        struct pid              *sk_peer_pid;
 324        const struct cred       *sk_peer_cred;
 325        long                    sk_rcvtimeo;
 326        long                    sk_sndtimeo;
 327        void                    *sk_protinfo;
 328        struct timer_list       sk_timer;
 329        ktime_t                 sk_stamp;
 330        struct socket           *sk_socket;
 331        void                    *sk_user_data;
 332        struct page             *sk_sndmsg_page;
 333        struct sk_buff          *sk_send_head;
 334        __u32                   sk_sndmsg_off;
 335        int                     sk_write_pending;
 336#ifdef CONFIG_SECURITY
 337        void                    *sk_security;
 338#endif
 339        __u32                   sk_mark;
 340        u32                     sk_classid;
 341        void                    (*sk_state_change)(struct sock *sk);
 342        void                    (*sk_data_ready)(struct sock *sk, int bytes);
 343        void                    (*sk_write_space)(struct sock *sk);
 344        void                    (*sk_error_report)(struct sock *sk);
 345        int                     (*sk_backlog_rcv)(struct sock *sk,
 346                                                  struct sk_buff *skb);  
 347        void                    (*sk_destruct)(struct sock *sk);
 348};
 349
 350/*
 351 * Hashed lists helper routines
 352 */
 353static inline struct sock *sk_entry(const struct hlist_node *node)
 354{
 355        return hlist_entry(node, struct sock, sk_node);
 356}
 357
 358static inline struct sock *__sk_head(const struct hlist_head *head)
 359{
 360        return hlist_entry(head->first, struct sock, sk_node);
 361}
 362
 363static inline struct sock *sk_head(const struct hlist_head *head)
 364{
 365        return hlist_empty(head) ? NULL : __sk_head(head);
 366}
 367
 368static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
 369{
 370        return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
 371}
 372
 373static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 374{
 375        return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
 376}
 377
 378static inline struct sock *sk_next(const struct sock *sk)
 379{
 380        return sk->sk_node.next ?
 381                hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
 382}
 383
 384static inline struct sock *sk_nulls_next(const struct sock *sk)
 385{
 386        return (!is_a_nulls(sk->sk_nulls_node.next)) ?
 387                hlist_nulls_entry(sk->sk_nulls_node.next,
 388                                  struct sock, sk_nulls_node) :
 389                NULL;
 390}
 391
 392static inline int sk_unhashed(const struct sock *sk)
 393{
 394        return hlist_unhashed(&sk->sk_node);
 395}
 396
 397static inline int sk_hashed(const struct sock *sk)
 398{
 399        return !sk_unhashed(sk);
 400}
 401
 402static __inline__ void sk_node_init(struct hlist_node *node)
 403{
 404        node->pprev = NULL;
 405}
 406
 407static __inline__ void sk_nulls_node_init(struct hlist_nulls_node *node)
 408{
 409        node->pprev = NULL;
 410}
 411
 412static __inline__ void __sk_del_node(struct sock *sk)
 413{
 414        __hlist_del(&sk->sk_node);
 415}
 416
 417/* NB: equivalent to hlist_del_init_rcu */
 418static __inline__ int __sk_del_node_init(struct sock *sk)
 419{
 420        if (sk_hashed(sk)) {
 421                __sk_del_node(sk);
 422                sk_node_init(&sk->sk_node);
 423                return 1;
 424        }
 425        return 0;
 426}
 427
 428/* Grab socket reference count. This operation is valid only
 429   when sk is ALREADY grabbed f.e. it is found in hash table
 430   or a list and the lookup is made under lock preventing hash table
 431   modifications.
 432 */
 433
 434static inline void sock_hold(struct sock *sk)
 435{
 436        atomic_inc(&sk->sk_refcnt);
 437}
 438
 439/* Ungrab socket in the context, which assumes that socket refcnt
 440   cannot hit zero, f.e. it is true in context of any socketcall.
 441 */
 442static inline void __sock_put(struct sock *sk)
 443{
 444        atomic_dec(&sk->sk_refcnt);
 445}
 446
 447static __inline__ int sk_del_node_init(struct sock *sk)
 448{
 449        int rc = __sk_del_node_init(sk);
 450
 451        if (rc) {
 452                /* paranoid for a while -acme */
 453                WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
 454                __sock_put(sk);
 455        }
 456        return rc;
 457}
 458#define sk_del_node_init_rcu(sk)        sk_del_node_init(sk)
 459
 460static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk)
 461{
 462        if (sk_hashed(sk)) {
 463                hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
 464                return 1;
 465        }
 466        return 0;
 467}
 468
 469static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk)
 470{
 471        int rc = __sk_nulls_del_node_init_rcu(sk);
 472
 473        if (rc) {
 474                /* paranoid for a while -acme */
 475                WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
 476                __sock_put(sk);
 477        }
 478        return rc;
 479}
 480
 481static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
 482{
 483        hlist_add_head(&sk->sk_node, list);
 484}
 485
 486static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
 487{
 488        sock_hold(sk);
 489        __sk_add_node(sk, list);
 490}
 491
 492static __inline__ void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 493{
 494        sock_hold(sk);
 495        hlist_add_head_rcu(&sk->sk_node, list);
 496}
 497
 498static __inline__ void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 499{
 500        hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 501}
 502
 503static __inline__ void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 504{
 505        sock_hold(sk);
 506        __sk_nulls_add_node_rcu(sk, list);
 507}
 508
 509static __inline__ void __sk_del_bind_node(struct sock *sk)
 510{
 511        __hlist_del(&sk->sk_bind_node);
 512}
 513
 514static __inline__ void sk_add_bind_node(struct sock *sk,
 515                                        struct hlist_head *list)
 516{
 517        hlist_add_head(&sk->sk_bind_node, list);
 518}
 519
 520#define sk_for_each(__sk, node, list) \
 521        hlist_for_each_entry(__sk, node, list, sk_node)
 522#define sk_for_each_rcu(__sk, node, list) \
 523        hlist_for_each_entry_rcu(__sk, node, list, sk_node)
 524#define sk_nulls_for_each(__sk, node, list) \
 525        hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
 526#define sk_nulls_for_each_rcu(__sk, node, list) \
 527        hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
 528#define sk_for_each_from(__sk, node) \
 529        if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
 530                hlist_for_each_entry_from(__sk, node, sk_node)
 531#define sk_nulls_for_each_from(__sk, node) \
 532        if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
 533                hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
 534#define sk_for_each_safe(__sk, node, tmp, list) \
 535        hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
 536#define sk_for_each_bound(__sk, node, list) \
 537        hlist_for_each_entry(__sk, node, list, sk_bind_node)
 538
 539/* Sock flags */
 540enum sock_flags {
 541        SOCK_DEAD,
 542        SOCK_DONE,
 543        SOCK_URGINLINE,
 544        SOCK_KEEPOPEN,
 545        SOCK_LINGER,
 546        SOCK_DESTROY,
 547        SOCK_BROADCAST,
 548        SOCK_TIMESTAMP,
 549        SOCK_ZAPPED,
 550        SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
 551        SOCK_DBG, /* %SO_DEBUG setting */
 552        SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
 553        SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
 554        SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
 555        SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
 556        SOCK_TIMESTAMPING_TX_HARDWARE,  /* %SOF_TIMESTAMPING_TX_HARDWARE */
 557        SOCK_TIMESTAMPING_TX_SOFTWARE,  /* %SOF_TIMESTAMPING_TX_SOFTWARE */
 558        SOCK_TIMESTAMPING_RX_HARDWARE,  /* %SOF_TIMESTAMPING_RX_HARDWARE */
 559        SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
 560        SOCK_TIMESTAMPING_SOFTWARE,     /* %SOF_TIMESTAMPING_SOFTWARE */
 561        SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
 562        SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
 563        SOCK_FASYNC, /* fasync() active */
 564        SOCK_RXQ_OVFL,
 565        SOCK_ZEROCOPY, /* buffers from userspace */
 566};
 567
 568static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
 569{
 570        nsk->sk_flags = osk->sk_flags;
 571}
 572
 573static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 574{
 575        __set_bit(flag, &sk->sk_flags);
 576}
 577
 578static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 579{
 580        __clear_bit(flag, &sk->sk_flags);
 581}
 582
 583static inline int sock_flag(struct sock *sk, enum sock_flags flag)
 584{
 585        return test_bit(flag, &sk->sk_flags);
 586}
 587
 588static inline void sk_acceptq_removed(struct sock *sk)
 589{
 590        sk->sk_ack_backlog--;
 591}
 592
 593static inline void sk_acceptq_added(struct sock *sk)
 594{
 595        sk->sk_ack_backlog++;
 596}
 597
 598static inline int sk_acceptq_is_full(struct sock *sk)
 599{
 600        return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
 601}
 602
 603/*
 604 * Compute minimal free write space needed to queue new packets.
 605 */
 606static inline int sk_stream_min_wspace(struct sock *sk)
 607{
 608        return sk->sk_wmem_queued >> 1;
 609}
 610
 611static inline int sk_stream_wspace(struct sock *sk)
 612{
 613        return sk->sk_sndbuf - sk->sk_wmem_queued;
 614}
 615
 616extern void sk_stream_write_space(struct sock *sk);
 617
 618static inline int sk_stream_memory_free(struct sock *sk)
 619{
 620        return sk->sk_wmem_queued < sk->sk_sndbuf;
 621}
 622
 623/* OOB backlog add */
 624static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 625{
 626        /* dont let skb dst not refcounted, we are going to leave rcu lock */
 627        skb_dst_force(skb);
 628
 629        if (!sk->sk_backlog.tail)
 630                sk->sk_backlog.head = skb;
 631        else
 632                sk->sk_backlog.tail->next = skb;
 633
 634        sk->sk_backlog.tail = skb;
 635        skb->next = NULL;
 636}
 637
 638/*
 639 * Take into account size of receive queue and backlog queue
 640 * Do not take into account this skb truesize,
 641 * to allow even a single big packet to come.
 642 */
 643static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb)
 644{
 645        unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
 646
 647        return qsize > sk->sk_rcvbuf;
 648}
 649
 650/* The per-socket spinlock must be held here. */
 651static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 652{
 653        if (sk_rcvqueues_full(sk, skb))
 654                return -ENOBUFS;
 655
 656        __sk_add_backlog(sk, skb);
 657        sk->sk_backlog.len += skb->truesize;
 658        return 0;
 659}
 660
 661static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 662{
 663        return sk->sk_backlog_rcv(sk, skb);
 664}
 665
 666static inline void sock_rps_record_flow(const struct sock *sk)
 667{
 668#ifdef CONFIG_RPS
 669        struct rps_sock_flow_table *sock_flow_table;
 670
 671        rcu_read_lock();
 672        sock_flow_table = rcu_dereference(rps_sock_flow_table);
 673        rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
 674        rcu_read_unlock();
 675#endif
 676}
 677
 678static inline void sock_rps_reset_flow(const struct sock *sk)
 679{
 680#ifdef CONFIG_RPS
 681        struct rps_sock_flow_table *sock_flow_table;
 682
 683        rcu_read_lock();
 684        sock_flow_table = rcu_dereference(rps_sock_flow_table);
 685        rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
 686        rcu_read_unlock();
 687#endif
 688}
 689
 690static inline void sock_rps_save_rxhash(struct sock *sk,
 691                                        const struct sk_buff *skb)
 692{
 693#ifdef CONFIG_RPS
 694        if (unlikely(sk->sk_rxhash != skb->rxhash)) {
 695                sock_rps_reset_flow(sk);
 696                sk->sk_rxhash = skb->rxhash;
 697        }
 698#endif
 699}
 700
 701static inline void sock_rps_reset_rxhash(struct sock *sk)
 702{
 703#ifdef CONFIG_RPS
 704        sock_rps_reset_flow(sk);
 705        sk->sk_rxhash = 0;
 706#endif
 707}
 708
 709#define sk_wait_event(__sk, __timeo, __condition)                       \
 710        ({      int __rc;                                               \
 711                release_sock(__sk);                                     \
 712                __rc = __condition;                                     \
 713                if (!__rc) {                                            \
 714                        *(__timeo) = schedule_timeout(*(__timeo));      \
 715                }                                                       \
 716                lock_sock(__sk);                                        \
 717                __rc = __condition;                                     \
 718                __rc;                                                   \
 719        })
 720
 721extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
 722extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
 723extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
 724extern int sk_stream_error(struct sock *sk, int flags, int err);
 725extern void sk_stream_kill_queues(struct sock *sk);
 726
 727extern int sk_wait_data(struct sock *sk, long *timeo);
 728
 729struct request_sock_ops;
 730struct timewait_sock_ops;
 731struct inet_hashinfo;
 732struct raw_hashinfo;
 733struct module;
 734
 735/* Networking protocol blocks we attach to sockets.
 736 * socket layer -> transport layer interface
 737 * transport -> network interface is defined by struct inet_proto
 738 */
 739struct proto {
 740        void                    (*close)(struct sock *sk, 
 741                                        long timeout);
 742        int                     (*connect)(struct sock *sk,
 743                                        struct sockaddr *uaddr, 
 744                                        int addr_len);
 745        int                     (*disconnect)(struct sock *sk, int flags);
 746
 747        struct sock *           (*accept) (struct sock *sk, int flags, int *err);
 748
 749        int                     (*ioctl)(struct sock *sk, int cmd,
 750                                         unsigned long arg);
 751        int                     (*init)(struct sock *sk);
 752        void                    (*destroy)(struct sock *sk);
 753        void                    (*shutdown)(struct sock *sk, int how);
 754        int                     (*setsockopt)(struct sock *sk, int level, 
 755                                        int optname, char __user *optval,
 756                                        unsigned int optlen);
 757        int                     (*getsockopt)(struct sock *sk, int level, 
 758                                        int optname, char __user *optval, 
 759                                        int __user *option);     
 760#ifdef CONFIG_COMPAT
 761        int                     (*compat_setsockopt)(struct sock *sk,
 762                                        int level,
 763                                        int optname, char __user *optval,
 764                                        unsigned int optlen);
 765        int                     (*compat_getsockopt)(struct sock *sk,
 766                                        int level,
 767                                        int optname, char __user *optval,
 768                                        int __user *option);
 769        int                     (*compat_ioctl)(struct sock *sk,
 770                                        unsigned int cmd, unsigned long arg);
 771#endif
 772        int                     (*sendmsg)(struct kiocb *iocb, struct sock *sk,
 773                                           struct msghdr *msg, size_t len);
 774        int                     (*recvmsg)(struct kiocb *iocb, struct sock *sk,
 775                                           struct msghdr *msg,
 776                                        size_t len, int noblock, int flags, 
 777                                        int *addr_len);
 778        int                     (*sendpage)(struct sock *sk, struct page *page,
 779                                        int offset, size_t size, int flags);
 780        int                     (*bind)(struct sock *sk, 
 781                                        struct sockaddr *uaddr, int addr_len);
 782
 783        int                     (*backlog_rcv) (struct sock *sk, 
 784                                                struct sk_buff *skb);
 785
 786        /* Keeping track of sk's, looking them up, and port selection methods. */
 787        void                    (*hash)(struct sock *sk);
 788        void                    (*unhash)(struct sock *sk);
 789        void                    (*rehash)(struct sock *sk);
 790        int                     (*get_port)(struct sock *sk, unsigned short snum);
 791        void                    (*clear_sk)(struct sock *sk, int size);
 792
 793        /* Keeping track of sockets in use */
 794#ifdef CONFIG_PROC_FS
 795        unsigned int            inuse_idx;
 796#endif
 797
 798        /* Memory pressure */
 799        void                    (*enter_memory_pressure)(struct sock *sk);
 800        atomic_long_t           *memory_allocated;      /* Current allocated memory. */
 801        struct percpu_counter   *sockets_allocated;     /* Current number of sockets. */
 802        /*
 803         * Pressure flag: try to collapse.
 804         * Technical note: it is used by multiple contexts non atomically.
 805         * All the __sk_mem_schedule() is of this nature: accounting
 806         * is strict, actions are advisory and have some latency.
 807         */
 808        int                     *memory_pressure;
 809        long                    *sysctl_mem;
 810        int                     *sysctl_wmem;
 811        int                     *sysctl_rmem;
 812        int                     max_header;
 813        bool                    no_autobind;
 814
 815        struct kmem_cache       *slab;
 816        unsigned int            obj_size;
 817        int                     slab_flags;
 818
 819        struct percpu_counter   *orphan_count;
 820
 821        struct request_sock_ops *rsk_prot;
 822        struct timewait_sock_ops *twsk_prot;
 823
 824        union {
 825                struct inet_hashinfo    *hashinfo;
 826                struct udp_table        *udp_table;
 827                struct raw_hashinfo     *raw_hash;
 828        } h;
 829
 830        struct module           *owner;
 831
 832        char                    name[32];
 833
 834        struct list_head        node;
 835#ifdef SOCK_REFCNT_DEBUG
 836        atomic_t                socks;
 837#endif
 838};
 839
 840extern int proto_register(struct proto *prot, int alloc_slab);
 841extern void proto_unregister(struct proto *prot);
 842
 843#ifdef SOCK_REFCNT_DEBUG
 844static inline void sk_refcnt_debug_inc(struct sock *sk)
 845{
 846        atomic_inc(&sk->sk_prot->socks);
 847}
 848
 849static inline void sk_refcnt_debug_dec(struct sock *sk)
 850{
 851        atomic_dec(&sk->sk_prot->socks);
 852        printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
 853               sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
 854}
 855
 856static inline void sk_refcnt_debug_release(const struct sock *sk)
 857{
 858        if (atomic_read(&sk->sk_refcnt) != 1)
 859                printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
 860                       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
 861}
 862#else /* SOCK_REFCNT_DEBUG */
 863#define sk_refcnt_debug_inc(sk) do { } while (0)
 864#define sk_refcnt_debug_dec(sk) do { } while (0)
 865#define sk_refcnt_debug_release(sk) do { } while (0)
 866#endif /* SOCK_REFCNT_DEBUG */
 867
 868
 869#ifdef CONFIG_PROC_FS
 870/* Called with local bh disabled */
 871extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
 872extern int sock_prot_inuse_get(struct net *net, struct proto *proto);
 873#else
 874static void inline sock_prot_inuse_add(struct net *net, struct proto *prot,
 875                int inc)
 876{
 877}
 878#endif
 879
 880
 881/* With per-bucket locks this operation is not-atomic, so that
 882 * this version is not worse.
 883 */
 884static inline void __sk_prot_rehash(struct sock *sk)
 885{
 886        sk->sk_prot->unhash(sk);
 887        sk->sk_prot->hash(sk);
 888}
 889
 890void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
 891
 892/* About 10 seconds */
 893#define SOCK_DESTROY_TIME (10*HZ)
 894
 895/* Sockets 0-1023 can't be bound to unless you are superuser */
 896#define PROT_SOCK       1024
 897
 898#define SHUTDOWN_MASK   3
 899#define RCV_SHUTDOWN    1
 900#define SEND_SHUTDOWN   2
 901
 902#define SOCK_SNDBUF_LOCK        1
 903#define SOCK_RCVBUF_LOCK        2
 904#define SOCK_BINDADDR_LOCK      4
 905#define SOCK_BINDPORT_LOCK      8
 906
 907/* sock_iocb: used to kick off async processing of socket ios */
 908struct sock_iocb {
 909        struct list_head        list;
 910
 911        int                     flags;
 912        int                     size;
 913        struct socket           *sock;
 914        struct sock             *sk;
 915        struct scm_cookie       *scm;
 916        struct msghdr           *msg, async_msg;
 917        struct kiocb            *kiocb;
 918};
 919
 920static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
 921{
 922        return (struct sock_iocb *)iocb->private;
 923}
 924
 925static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
 926{
 927        return si->kiocb;
 928}
 929
 930struct socket_alloc {
 931        struct socket socket;
 932        struct inode vfs_inode;
 933};
 934
 935static inline struct socket *SOCKET_I(struct inode *inode)
 936{
 937        return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
 938}
 939
 940static inline struct inode *SOCK_INODE(struct socket *socket)
 941{
 942        return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
 943}
 944
 945/*
 946 * Functions for memory accounting
 947 */
 948extern int __sk_mem_schedule(struct sock *sk, int size, int kind);
 949extern void __sk_mem_reclaim(struct sock *sk);
 950
 951#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
 952#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
 953#define SK_MEM_SEND     0
 954#define SK_MEM_RECV     1
 955
 956static inline int sk_mem_pages(int amt)
 957{
 958        return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
 959}
 960
 961static inline int sk_has_account(struct sock *sk)
 962{
 963        /* return true if protocol supports memory accounting */
 964        return !!sk->sk_prot->memory_allocated;
 965}
 966
 967static inline int sk_wmem_schedule(struct sock *sk, int size)
 968{
 969        if (!sk_has_account(sk))
 970                return 1;
 971        return size <= sk->sk_forward_alloc ||
 972                __sk_mem_schedule(sk, size, SK_MEM_SEND);
 973}
 974
 975static inline int sk_rmem_schedule(struct sock *sk, int size)
 976{
 977        if (!sk_has_account(sk))
 978                return 1;
 979        return size <= sk->sk_forward_alloc ||
 980                __sk_mem_schedule(sk, size, SK_MEM_RECV);
 981}
 982
 983static inline void sk_mem_reclaim(struct sock *sk)
 984{
 985        if (!sk_has_account(sk))
 986                return;
 987        if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
 988                __sk_mem_reclaim(sk);
 989}
 990
 991static inline void sk_mem_reclaim_partial(struct sock *sk)
 992{
 993        if (!sk_has_account(sk))
 994                return;
 995        if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
 996                __sk_mem_reclaim(sk);
 997}
 998
 999static inline void sk_mem_charge(struct sock *sk, int size)
1000{
1001        if (!sk_has_account(sk))
1002                return;
1003        sk->sk_forward_alloc -= size;
1004}
1005
1006static inline void sk_mem_uncharge(struct sock *sk, int size)
1007{
1008        if (!sk_has_account(sk))
1009                return;
1010        sk->sk_forward_alloc += size;
1011}
1012
1013static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1014{
1015        sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1016        sk->sk_wmem_queued -= skb->truesize;
1017        sk_mem_uncharge(sk, skb->truesize);
1018        __kfree_skb(skb);
1019}
1020
1021/* Used by processes to "lock" a socket state, so that
1022 * interrupts and bottom half handlers won't change it
1023 * from under us. It essentially blocks any incoming
1024 * packets, so that we won't get any new data or any
1025 * packets that change the state of the socket.
1026 *
1027 * While locked, BH processing will add new packets to
1028 * the backlog queue.  This queue is processed by the
1029 * owner of the socket lock right before it is released.
1030 *
1031 * Since ~2.3.5 it is also exclusive sleep lock serializing
1032 * accesses from user process context.
1033 */
1034#define sock_owned_by_user(sk)  ((sk)->sk_lock.owned)
1035
1036/*
1037 * Macro so as to not evaluate some arguments when
1038 * lockdep is not enabled.
1039 *
1040 * Mark both the sk_lock and the sk_lock.slock as a
1041 * per-address-family lock class.
1042 */
1043#define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
1044do {                                                                    \
1045        sk->sk_lock.owned = 0;                                          \
1046        init_waitqueue_head(&sk->sk_lock.wq);                           \
1047        spin_lock_init(&(sk)->sk_lock.slock);                           \
1048        debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
1049                        sizeof((sk)->sk_lock));                         \
1050        lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
1051                        (skey), (sname));                               \
1052        lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
1053} while (0)
1054
1055extern void lock_sock_nested(struct sock *sk, int subclass);
1056
1057static inline void lock_sock(struct sock *sk)
1058{
1059        lock_sock_nested(sk, 0);
1060}
1061
1062extern void release_sock(struct sock *sk);
1063
1064/* BH context may only use the following locking interface. */
1065#define bh_lock_sock(__sk)      spin_lock(&((__sk)->sk_lock.slock))
1066#define bh_lock_sock_nested(__sk) \
1067                                spin_lock_nested(&((__sk)->sk_lock.slock), \
1068                                SINGLE_DEPTH_NESTING)
1069#define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
1070
1071extern bool lock_sock_fast(struct sock *sk);
1072/**
1073 * unlock_sock_fast - complement of lock_sock_fast
1074 * @sk: socket
1075 * @slow: slow mode
1076 *
1077 * fast unlock socket for user context.
1078 * If slow mode is on, we call regular release_sock()
1079 */
1080static inline void unlock_sock_fast(struct sock *sk, bool slow)
1081{
1082        if (slow)
1083                release_sock(sk);
1084        else
1085                spin_unlock_bh(&sk->sk_lock.slock);
1086}
1087
1088
1089extern struct sock              *sk_alloc(struct net *net, int family,
1090                                          gfp_t priority,
1091                                          struct proto *prot);
1092extern void                     sk_free(struct sock *sk);
1093extern void                     sk_release_kernel(struct sock *sk);
1094extern struct sock              *sk_clone(const struct sock *sk,
1095                                          const gfp_t priority);
1096
1097extern struct sk_buff           *sock_wmalloc(struct sock *sk,
1098                                              unsigned long size, int force,
1099                                              gfp_t priority);
1100extern struct sk_buff           *sock_rmalloc(struct sock *sk,
1101                                              unsigned long size, int force,
1102                                              gfp_t priority);
1103extern void                     sock_wfree(struct sk_buff *skb);
1104extern void                     sock_rfree(struct sk_buff *skb);
1105
1106extern int                      sock_setsockopt(struct socket *sock, int level,
1107                                                int op, char __user *optval,
1108                                                unsigned int optlen);
1109
1110extern int                      sock_getsockopt(struct socket *sock, int level,
1111                                                int op, char __user *optval, 
1112                                                int __user *optlen);
1113extern struct sk_buff           *sock_alloc_send_skb(struct sock *sk,
1114                                                     unsigned long size,
1115                                                     int noblock,
1116                                                     int *errcode);
1117extern struct sk_buff           *sock_alloc_send_pskb(struct sock *sk,
1118                                                      unsigned long header_len,
1119                                                      unsigned long data_len,
1120                                                      int noblock,
1121                                                      int *errcode);
1122extern void *sock_kmalloc(struct sock *sk, int size,
1123                          gfp_t priority);
1124extern void sock_kfree_s(struct sock *sk, void *mem, int size);
1125extern void sk_send_sigurg(struct sock *sk);
1126
1127#ifdef CONFIG_CGROUPS
1128extern void sock_update_classid(struct sock *sk);
1129#else
1130static inline void sock_update_classid(struct sock *sk)
1131{
1132}
1133#endif
1134
1135/*
1136 * Functions to fill in entries in struct proto_ops when a protocol
1137 * does not implement a particular function.
1138 */
1139extern int                      sock_no_bind(struct socket *, 
1140                                             struct sockaddr *, int);
1141extern int                      sock_no_connect(struct socket *,
1142                                                struct sockaddr *, int, int);
1143extern int                      sock_no_socketpair(struct socket *,
1144                                                   struct socket *);
1145extern int                      sock_no_accept(struct socket *,
1146                                               struct socket *, int);
1147extern int                      sock_no_getname(struct socket *,
1148                                                struct sockaddr *, int *, int);
1149extern unsigned int             sock_no_poll(struct file *, struct socket *,
1150                                             struct poll_table_struct *);
1151extern int                      sock_no_ioctl(struct socket *, unsigned int,
1152                                              unsigned long);
1153extern int                      sock_no_listen(struct socket *, int);
1154extern int                      sock_no_shutdown(struct socket *, int);
1155extern int                      sock_no_getsockopt(struct socket *, int , int,
1156                                                   char __user *, int __user *);
1157extern int                      sock_no_setsockopt(struct socket *, int, int,
1158                                                   char __user *, unsigned int);
1159extern int                      sock_no_sendmsg(struct kiocb *, struct socket *,
1160                                                struct msghdr *, size_t);
1161extern int                      sock_no_recvmsg(struct kiocb *, struct socket *,
1162                                                struct msghdr *, size_t, int);
1163extern int                      sock_no_mmap(struct file *file,
1164                                             struct socket *sock,
1165                                             struct vm_area_struct *vma);
1166extern ssize_t                  sock_no_sendpage(struct socket *sock,
1167                                                struct page *page,
1168                                                int offset, size_t size, 
1169                                                int flags);
1170
1171/*
1172 * Functions to fill in entries in struct proto_ops when a protocol
1173 * uses the inet style.
1174 */
1175extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
1176                                  char __user *optval, int __user *optlen);
1177extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1178                               struct msghdr *msg, size_t size, int flags);
1179extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
1180                                  char __user *optval, unsigned int optlen);
1181extern int compat_sock_common_getsockopt(struct socket *sock, int level,
1182                int optname, char __user *optval, int __user *optlen);
1183extern int compat_sock_common_setsockopt(struct socket *sock, int level,
1184                int optname, char __user *optval, unsigned int optlen);
1185
1186extern void sk_common_release(struct sock *sk);
1187
1188/*
1189 *      Default socket callbacks and setup code
1190 */
1191 
1192/* Initialise core socket variables */
1193extern void sock_init_data(struct socket *sock, struct sock *sk);
1194
1195extern void sk_filter_release_rcu(struct rcu_head *rcu);
1196
1197/**
1198 *      sk_filter_release - release a socket filter
1199 *      @fp: filter to remove
1200 *
1201 *      Remove a filter from a socket and release its resources.
1202 */
1203
1204static inline void sk_filter_release(struct sk_filter *fp)
1205{
1206        if (atomic_dec_and_test(&fp->refcnt))
1207                call_rcu(&fp->rcu, sk_filter_release_rcu);
1208}
1209
1210static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
1211{
1212        unsigned int size = sk_filter_len(fp);
1213
1214        atomic_sub(size, &sk->sk_omem_alloc);
1215        sk_filter_release(fp);
1216}
1217
1218static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
1219{
1220        atomic_inc(&fp->refcnt);
1221        atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
1222}
1223
1224/*
1225 * Socket reference counting postulates.
1226 *
1227 * * Each user of socket SHOULD hold a reference count.
1228 * * Each access point to socket (an hash table bucket, reference from a list,
1229 *   running timer, skb in flight MUST hold a reference count.
1230 * * When reference count hits 0, it means it will never increase back.
1231 * * When reference count hits 0, it means that no references from
1232 *   outside exist to this socket and current process on current CPU
1233 *   is last user and may/should destroy this socket.
1234 * * sk_free is called from any context: process, BH, IRQ. When
1235 *   it is called, socket has no references from outside -> sk_free
1236 *   may release descendant resources allocated by the socket, but
1237 *   to the time when it is called, socket is NOT referenced by any
1238 *   hash tables, lists etc.
1239 * * Packets, delivered from outside (from network or from another process)
1240 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1241 *   when they sit in queue. Otherwise, packets will leak to hole, when
1242 *   socket is looked up by one cpu and unhasing is made by another CPU.
1243 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1244 *   (leak to backlog). Packet socket does all the processing inside
1245 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1246 *   use separate SMP lock, so that they are prone too.
1247 */
1248
1249/* Ungrab socket and destroy it, if it was the last reference. */
1250static inline void sock_put(struct sock *sk)
1251{
1252        if (atomic_dec_and_test(&sk->sk_refcnt))
1253                sk_free(sk);
1254}
1255
1256extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1257                          const int nested);
1258
1259static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1260{
1261        sk->sk_tx_queue_mapping = tx_queue;
1262}
1263
1264static inline void sk_tx_queue_clear(struct sock *sk)
1265{
1266        sk->sk_tx_queue_mapping = -1;
1267}
1268
1269static inline int sk_tx_queue_get(const struct sock *sk)
1270{
1271        return sk ? sk->sk_tx_queue_mapping : -1;
1272}
1273
1274static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1275{
1276        sk_tx_queue_clear(sk);
1277        sk->sk_socket = sock;
1278}
1279
1280static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1281{
1282        BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1283        return &rcu_dereference_raw(sk->sk_wq)->wait;
1284}
1285/* Detach socket from process context.
1286 * Announce socket dead, detach it from wait queue and inode.
1287 * Note that parent inode held reference count on this struct sock,
1288 * we do not release it in this function, because protocol
1289 * probably wants some additional cleanups or even continuing
1290 * to work with this socket (TCP).
1291 */
1292static inline void sock_orphan(struct sock *sk)
1293{
1294        write_lock_bh(&sk->sk_callback_lock);
1295        sock_set_flag(sk, SOCK_DEAD);
1296        sk_set_socket(sk, NULL);
1297        sk->sk_wq  = NULL;
1298        write_unlock_bh(&sk->sk_callback_lock);
1299}
1300
1301static inline void sock_graft(struct sock *sk, struct socket *parent)
1302{
1303        write_lock_bh(&sk->sk_callback_lock);
1304        sk->sk_wq = parent->wq;
1305        parent->sk = sk;
1306        sk_set_socket(sk, parent);
1307        security_sock_graft(sk, parent);
1308        write_unlock_bh(&sk->sk_callback_lock);
1309}
1310
1311extern int sock_i_uid(struct sock *sk);
1312extern unsigned long sock_i_ino(struct sock *sk);
1313
1314static inline struct dst_entry *
1315__sk_dst_get(struct sock *sk)
1316{
1317        return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1318                                                       lockdep_is_held(&sk->sk_lock.slock));
1319}
1320
1321static inline struct dst_entry *
1322sk_dst_get(struct sock *sk)
1323{
1324        struct dst_entry *dst;
1325
1326        rcu_read_lock();
1327        dst = rcu_dereference(sk->sk_dst_cache);
1328        if (dst)
1329                dst_hold(dst);
1330        rcu_read_unlock();
1331        return dst;
1332}
1333
1334extern void sk_reset_txq(struct sock *sk);
1335
1336static inline void dst_negative_advice(struct sock *sk)
1337{
1338        struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1339
1340        if (dst && dst->ops->negative_advice) {
1341                ndst = dst->ops->negative_advice(dst);
1342
1343                if (ndst != dst) {
1344                        rcu_assign_pointer(sk->sk_dst_cache, ndst);
1345                        sk_reset_txq(sk);
1346                }
1347        }
1348}
1349
1350static inline void
1351__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1352{
1353        struct dst_entry *old_dst;
1354
1355        sk_tx_queue_clear(sk);
1356        /*
1357         * This can be called while sk is owned by the caller only,
1358         * with no state that can be checked in a rcu_dereference_check() cond
1359         */
1360        old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1361        rcu_assign_pointer(sk->sk_dst_cache, dst);
1362        dst_release(old_dst);
1363}
1364
1365static inline void
1366sk_dst_set(struct sock *sk, struct dst_entry *dst)
1367{
1368        spin_lock(&sk->sk_dst_lock);
1369        __sk_dst_set(sk, dst);
1370        spin_unlock(&sk->sk_dst_lock);
1371}
1372
1373static inline void
1374__sk_dst_reset(struct sock *sk)
1375{
1376        __sk_dst_set(sk, NULL);
1377}
1378
1379static inline void
1380sk_dst_reset(struct sock *sk)
1381{
1382        spin_lock(&sk->sk_dst_lock);
1383        __sk_dst_reset(sk);
1384        spin_unlock(&sk->sk_dst_lock);
1385}
1386
1387extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1388
1389extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1390
1391static inline int sk_can_gso(const struct sock *sk)
1392{
1393        return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1394}
1395
1396extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1397
1398static inline void sk_nocaps_add(struct sock *sk, int flags)
1399{
1400        sk->sk_route_nocaps |= flags;
1401        sk->sk_route_caps &= ~flags;
1402}
1403
1404static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1405                                           char __user *from, char *to,
1406                                           int copy, int offset)
1407{
1408        if (skb->ip_summed == CHECKSUM_NONE) {
1409                int err = 0;
1410                __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1411                if (err)
1412                        return err;
1413                skb->csum = csum_block_add(skb->csum, csum, offset);
1414        } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1415                if (!access_ok(VERIFY_READ, from, copy) ||
1416                    __copy_from_user_nocache(to, from, copy))
1417                        return -EFAULT;
1418        } else if (copy_from_user(to, from, copy))
1419                return -EFAULT;
1420
1421        return 0;
1422}
1423
1424static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1425                                       char __user *from, int copy)
1426{
1427        int err, offset = skb->len;
1428
1429        err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1430                                       copy, offset);
1431        if (err)
1432                __skb_trim(skb, offset);
1433
1434        return err;
1435}
1436
1437static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1438                                           struct sk_buff *skb,
1439                                           struct page *page,
1440                                           int off, int copy)
1441{
1442        int err;
1443
1444        err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1445                                       copy, skb->len);
1446        if (err)
1447                return err;
1448
1449        skb->len             += copy;
1450        skb->data_len        += copy;
1451        skb->truesize        += copy;
1452        sk->sk_wmem_queued   += copy;
1453        sk_mem_charge(sk, copy);
1454        return 0;
1455}
1456
1457static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1458                                   struct sk_buff *skb, struct page *page,
1459                                   int off, int copy)
1460{
1461        if (skb->ip_summed == CHECKSUM_NONE) {
1462                int err = 0;
1463                __wsum csum = csum_and_copy_from_user(from,
1464                                                     page_address(page) + off,
1465                                                            copy, 0, &err);
1466                if (err)
1467                        return err;
1468                skb->csum = csum_block_add(skb->csum, csum, skb->len);
1469        } else if (copy_from_user(page_address(page) + off, from, copy))
1470                return -EFAULT;
1471
1472        skb->len             += copy;
1473        skb->data_len        += copy;
1474        skb->truesize        += copy;
1475        sk->sk_wmem_queued   += copy;
1476        sk_mem_charge(sk, copy);
1477        return 0;
1478}
1479
1480/**
1481 * sk_wmem_alloc_get - returns write allocations
1482 * @sk: socket
1483 *
1484 * Returns sk_wmem_alloc minus initial offset of one
1485 */
1486static inline int sk_wmem_alloc_get(const struct sock *sk)
1487{
1488        return atomic_read(&sk->sk_wmem_alloc) - 1;
1489}
1490
1491/**
1492 * sk_rmem_alloc_get - returns read allocations
1493 * @sk: socket
1494 *
1495 * Returns sk_rmem_alloc
1496 */
1497static inline int sk_rmem_alloc_get(const struct sock *sk)
1498{
1499        return atomic_read(&sk->sk_rmem_alloc);
1500}
1501
1502/**
1503 * sk_has_allocations - check if allocations are outstanding
1504 * @sk: socket
1505 *
1506 * Returns true if socket has write or read allocations
1507 */
1508static inline int sk_has_allocations(const struct sock *sk)
1509{
1510        return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1511}
1512
1513/**
1514 * wq_has_sleeper - check if there are any waiting processes
1515 * @wq: struct socket_wq
1516 *
1517 * Returns true if socket_wq has waiting processes
1518 *
1519 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1520 * barrier call. They were added due to the race found within the tcp code.
1521 *
1522 * Consider following tcp code paths:
1523 *
1524 * CPU1                  CPU2
1525 *
1526 * sys_select            receive packet
1527 *   ...                 ...
1528 *   __add_wait_queue    update tp->rcv_nxt
1529 *   ...                 ...
1530 *   tp->rcv_nxt check   sock_def_readable
1531 *   ...                 {
1532 *   schedule               rcu_read_lock();
1533 *                          wq = rcu_dereference(sk->sk_wq);
1534 *                          if (wq && waitqueue_active(&wq->wait))
1535 *                              wake_up_interruptible(&wq->wait)
1536 *                          ...
1537 *                       }
1538 *
1539 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1540 * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
1541 * could then endup calling schedule and sleep forever if there are no more
1542 * data on the socket.
1543 *
1544 */
1545static inline bool wq_has_sleeper(struct socket_wq *wq)
1546{
1547
1548        /*
1549         * We need to be sure we are in sync with the
1550         * add_wait_queue modifications to the wait queue.
1551         *
1552         * This memory barrier is paired in the sock_poll_wait.
1553         */
1554        smp_mb();
1555        return wq && waitqueue_active(&wq->wait);
1556}
1557
1558/**
1559 * sock_poll_wait - place memory barrier behind the poll_wait call.
1560 * @filp:           file
1561 * @wait_address:   socket wait queue
1562 * @p:              poll_table
1563 *
1564 * See the comments in the wq_has_sleeper function.
1565 */
1566static inline void sock_poll_wait(struct file *filp,
1567                wait_queue_head_t *wait_address, poll_table *p)
1568{
1569        if (p && wait_address) {
1570                poll_wait(filp, wait_address, p);
1571                /*
1572                 * We need to be sure we are in sync with the
1573                 * socket flags modification.
1574                 *
1575                 * This memory barrier is paired in the wq_has_sleeper.
1576                */
1577                smp_mb();
1578        }
1579}
1580
1581/*
1582 *      Queue a received datagram if it will fit. Stream and sequenced
1583 *      protocols can't normally use this as they need to fit buffers in
1584 *      and play with them.
1585 *
1586 *      Inlined as it's very short and called for pretty much every
1587 *      packet ever received.
1588 */
1589
1590static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1591{
1592        skb_orphan(skb);
1593        skb->sk = sk;
1594        skb->destructor = sock_wfree;
1595        /*
1596         * We used to take a refcount on sk, but following operation
1597         * is enough to guarantee sk_free() wont free this sock until
1598         * all in-flight packets are completed
1599         */
1600        atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1601}
1602
1603static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1604{
1605        skb_orphan(skb);
1606        skb->sk = sk;
1607        skb->destructor = sock_rfree;
1608        atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1609        sk_mem_charge(sk, skb->truesize);
1610}
1611
1612extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1613                           unsigned long expires);
1614
1615extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1616
1617extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1618
1619extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1620
1621/*
1622 *      Recover an error report and clear atomically
1623 */
1624 
1625static inline int sock_error(struct sock *sk)
1626{
1627        int err;
1628        if (likely(!sk->sk_err))
1629                return 0;
1630        err = xchg(&sk->sk_err, 0);
1631        return -err;
1632}
1633
1634static inline unsigned long sock_wspace(struct sock *sk)
1635{
1636        int amt = 0;
1637
1638        if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1639                amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1640                if (amt < 0) 
1641                        amt = 0;
1642        }
1643        return amt;
1644}
1645
1646static inline void sk_wake_async(struct sock *sk, int how, int band)
1647{
1648        if (sock_flag(sk, SOCK_FASYNC))
1649                sock_wake_async(sk->sk_socket, how, band);
1650}
1651
1652#define SOCK_MIN_SNDBUF 2048
1653/*
1654 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
1655 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
1656 */
1657#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
1658
1659static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1660{
1661        if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1662                sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1663                sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1664        }
1665}
1666
1667struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
1668
1669static inline struct page *sk_stream_alloc_page(struct sock *sk)
1670{
1671        struct page *page = NULL;
1672
1673        page = alloc_pages(sk->sk_allocation, 0);
1674        if (!page) {
1675                sk->sk_prot->enter_memory_pressure(sk);
1676                sk_stream_moderate_sndbuf(sk);
1677        }
1678        return page;
1679}
1680
1681/*
1682 *      Default write policy as shown to user space via poll/select/SIGIO
1683 */
1684static inline int sock_writeable(const struct sock *sk) 
1685{
1686        return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
1687}
1688
1689static inline gfp_t gfp_any(void)
1690{
1691        return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1692}
1693
1694static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1695{
1696        return noblock ? 0 : sk->sk_rcvtimeo;
1697}
1698
1699static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1700{
1701        return noblock ? 0 : sk->sk_sndtimeo;
1702}
1703
1704static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1705{
1706        return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1707}
1708
1709/* Alas, with timeout socket operations are not restartable.
1710 * Compare this to poll().
1711 */
1712static inline int sock_intr_errno(long timeo)
1713{
1714        return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1715}
1716
1717extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
1718        struct sk_buff *skb);
1719
1720static __inline__ void
1721sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1722{
1723        ktime_t kt = skb->tstamp;
1724        struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
1725
1726        /*
1727         * generate control messages if
1728         * - receive time stamping in software requested (SOCK_RCVTSTAMP
1729         *   or SOCK_TIMESTAMPING_RX_SOFTWARE)
1730         * - software time stamp available and wanted
1731         *   (SOCK_TIMESTAMPING_SOFTWARE)
1732         * - hardware time stamps available and wanted
1733         *   (SOCK_TIMESTAMPING_SYS_HARDWARE or
1734         *   SOCK_TIMESTAMPING_RAW_HARDWARE)
1735         */
1736        if (sock_flag(sk, SOCK_RCVTSTAMP) ||
1737            sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
1738            (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
1739            (hwtstamps->hwtstamp.tv64 &&
1740             sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
1741            (hwtstamps->syststamp.tv64 &&
1742             sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
1743                __sock_recv_timestamp(msg, sk, skb);
1744        else
1745                sk->sk_stamp = kt;
1746}
1747
1748extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1749                                     struct sk_buff *skb);
1750
1751static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1752                                          struct sk_buff *skb)
1753{
1754#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)                       | \
1755                           (1UL << SOCK_RCVTSTAMP)                      | \
1756                           (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)       | \
1757                           (1UL << SOCK_TIMESTAMPING_SOFTWARE)          | \
1758                           (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE)      | \
1759                           (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
1760
1761        if (sk->sk_flags & FLAGS_TS_OR_DROPS)
1762                __sock_recv_ts_and_drops(msg, sk, skb);
1763        else
1764                sk->sk_stamp = skb->tstamp;
1765}
1766
1767/**
1768 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
1769 * @sk:         socket sending this packet
1770 * @tx_flags:   filled with instructions for time stamping
1771 *
1772 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
1773 * parameters are invalid.
1774 */
1775extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
1776
1777/**
1778 * sk_eat_skb - Release a skb if it is no longer needed
1779 * @sk: socket to eat this skb from
1780 * @skb: socket buffer to eat
1781 * @copied_early: flag indicating whether DMA operations copied this data early
1782 *
1783 * This routine must be called with interrupts disabled or with the socket
1784 * locked so that the sk_buff queue operation is ok.
1785*/
1786#ifdef CONFIG_NET_DMA
1787static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1788{
1789        __skb_unlink(skb, &sk->sk_receive_queue);
1790        if (!copied_early)
1791                __kfree_skb(skb);
1792        else
1793                __skb_queue_tail(&sk->sk_async_wait_queue, skb);
1794}
1795#else
1796static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1797{
1798        __skb_unlink(skb, &sk->sk_receive_queue);
1799        __kfree_skb(skb);
1800}
1801#endif
1802
1803static inline
1804struct net *sock_net(const struct sock *sk)
1805{
1806        return read_pnet(&sk->sk_net);
1807}
1808
1809static inline
1810void sock_net_set(struct sock *sk, struct net *net)
1811{
1812        write_pnet(&sk->sk_net, net);
1813}
1814
1815/*
1816 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
1817 * They should not hold a reference to a namespace in order to allow
1818 * to stop it.
1819 * Sockets after sk_change_net should be released using sk_release_kernel
1820 */
1821static inline void sk_change_net(struct sock *sk, struct net *net)
1822{
1823        put_net(sock_net(sk));
1824        sock_net_set(sk, hold_net(net));
1825}
1826
1827static inline struct sock *skb_steal_sock(struct sk_buff *skb)
1828{
1829        if (unlikely(skb->sk)) {
1830                struct sock *sk = skb->sk;
1831
1832                skb->destructor = NULL;
1833                skb->sk = NULL;
1834                return sk;
1835        }
1836        return NULL;
1837}
1838
1839extern void sock_enable_timestamp(struct sock *sk, int flag);
1840extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1841extern int sock_get_timestampns(struct sock *, struct timespec __user *);
1842
1843/* 
1844 *      Enable debug/info messages 
1845 */
1846extern int net_msg_warn;
1847#define NETDEBUG(fmt, args...) \
1848        do { if (net_msg_warn) printk(fmt,##args); } while (0)
1849
1850#define LIMIT_NETDEBUG(fmt, args...) \
1851        do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
1852
1853extern __u32 sysctl_wmem_max;
1854extern __u32 sysctl_rmem_max;
1855
1856extern void sk_init(void);
1857
1858extern int sysctl_optmem_max;
1859
1860extern __u32 sysctl_wmem_default;
1861extern __u32 sysctl_rmem_default;
1862
1863#endif  /* _SOCK_H */
1864
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