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/list.h>
  44#include <linux/timer.h>
  45#include <linux/cache.h>
  46#include <linux/module.h>
  47#include <linux/lockdep.h>
  48#include <linux/netdevice.h>
  49#include <linux/skbuff.h>       /* struct sk_buff */
  50#include <linux/mm.h>
  51#include <linux/security.h>
  52
  53#include <linux/filter.h>
  54
  55#include <asm/atomic.h>
  56#include <net/dst.h>
  57#include <net/checksum.h>
  58
  59/*
  60 * This structure really needs to be cleaned up.
  61 * Most of it is for TCP, and not used by any of
  62 * the other protocols.
  63 */
  64
  65/* Define this to get the SOCK_DBG debugging facility. */
  66#define SOCK_DEBUGGING
  67#ifdef SOCK_DEBUGGING
  68#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
  69                                        printk(KERN_DEBUG msg); } while (0)
  70#else
  71#define SOCK_DEBUG(sk, msg...) do { } while (0)
  72#endif
  73
  74/* This is the per-socket lock.  The spinlock provides a synchronization
  75 * between user contexts and software interrupt processing, whereas the
  76 * mini-semaphore synchronizes multiple users amongst themselves.
  77 */
  78struct sock_iocb;
  79typedef struct {
  80        spinlock_t              slock;
  81        struct sock_iocb        *owner;
  82        wait_queue_head_t       wq;
  83        /*
  84         * We express the mutex-alike socket_lock semantics
  85         * to the lock validator by explicitly managing
  86         * the slock as a lock variant (in addition to
  87         * the slock itself):
  88         */
  89#ifdef CONFIG_DEBUG_LOCK_ALLOC
  90        struct lockdep_map dep_map;
  91#endif
  92} socket_lock_t;
  93
  94struct sock;
  95struct proto;
  96
  97/**
  98 *      struct sock_common - minimal network layer representation of sockets
  99 *      @skc_family: network address family
 100 *      @skc_state: Connection state
 101 *      @skc_reuse: %SO_REUSEADDR setting
 102 *      @skc_bound_dev_if: bound device index if != 0
 103 *      @skc_node: main hash linkage for various protocol lookup tables
 104 *      @skc_bind_node: bind hash linkage for various protocol lookup tables
 105 *      @skc_refcnt: reference count
 106 *      @skc_hash: hash value used with various protocol lookup tables
 107 *      @skc_prot: protocol handlers inside a network family
 108 *
 109 *      This is the minimal network layer representation of sockets, the header
 110 *      for struct sock and struct inet_timewait_sock.
 111 */
 112struct sock_common {
 113        unsigned short          skc_family;
 114        volatile unsigned char  skc_state;
 115        unsigned char           skc_reuse;
 116        int                     skc_bound_dev_if;
 117        struct hlist_node       skc_node;
 118        struct hlist_node       skc_bind_node;
 119        atomic_t                skc_refcnt;
 120        unsigned int            skc_hash;
 121        struct proto            *skc_prot;
 122};
 123
 124/**
 125  *     struct sock - network layer representation of sockets
 126  *     @__sk_common: shared layout with inet_timewait_sock
 127  *     @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
 128  *     @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
 129  *     @sk_lock:       synchronizer
 130  *     @sk_rcvbuf: size of receive buffer in bytes
 131  *     @sk_sleep: sock wait queue
 132  *     @sk_dst_cache: destination cache
 133  *     @sk_dst_lock: destination cache lock
 134  *     @sk_policy: flow policy
 135  *     @sk_rmem_alloc: receive queue bytes committed
 136  *     @sk_receive_queue: incoming packets
 137  *     @sk_wmem_alloc: transmit queue bytes committed
 138  *     @sk_write_queue: Packet sending queue
 139  *     @sk_async_wait_queue: DMA copied packets
 140  *     @sk_omem_alloc: "o" is "option" or "other"
 141  *     @sk_wmem_queued: persistent queue size
 142  *     @sk_forward_alloc: space allocated forward
 143  *     @sk_allocation: allocation mode
 144  *     @sk_sndbuf: size of send buffer in bytes
 145  *     @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings
 146  *     @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
 147  *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
 148  *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
 149  *     @sk_lingertime: %SO_LINGER l_linger setting
 150  *     @sk_backlog: always used with the per-socket spinlock held
 151  *     @sk_callback_lock: used with the callbacks in the end of this struct
 152  *     @sk_error_queue: rarely used
 153  *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
 154  *     @sk_err: last error
 155  *     @sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
 156  *     @sk_ack_backlog: current listen backlog
 157  *     @sk_max_ack_backlog: listen backlog set in listen()
 158  *     @sk_priority: %SO_PRIORITY setting
 159  *     @sk_type: socket type (%SOCK_STREAM, etc)
 160  *     @sk_protocol: which protocol this socket belongs in this network family
 161  *     @sk_peercred: %SO_PEERCRED setting
 162  *     @sk_rcvlowat: %SO_RCVLOWAT setting
 163  *     @sk_rcvtimeo: %SO_RCVTIMEO setting
 164  *     @sk_sndtimeo: %SO_SNDTIMEO setting
 165  *     @sk_filter: socket filtering instructions
 166  *     @sk_protinfo: private area, net family specific, when not using slab
 167  *     @sk_timer: sock cleanup timer
 168  *     @sk_stamp: time stamp of last packet received
 169  *     @sk_socket: Identd and reporting IO signals
 170  *     @sk_user_data: RPC layer private data
 171  *     @sk_sndmsg_page: cached page for sendmsg
 172  *     @sk_sndmsg_off: cached offset for sendmsg
 173  *     @sk_send_head: front of stuff to transmit
 174  *     @sk_security: used by security modules
 175  *     @sk_write_pending: a write to stream socket waits to start
 176  *     @sk_state_change: callback to indicate change in the state of the sock
 177  *     @sk_data_ready: callback to indicate there is data to be processed
 178  *     @sk_write_space: callback to indicate there is bf sending space available
 179  *     @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
 180  *     @sk_backlog_rcv: callback to process the backlog
 181  *     @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
 182 */
 183struct sock {
 184        /*
 185         * Now struct inet_timewait_sock also uses sock_common, so please just
 186         * don't add nothing before this first member (__sk_common) --acme
 187         */
 188        struct sock_common      __sk_common;
 189#define sk_family               __sk_common.skc_family
 190#define sk_state                __sk_common.skc_state
 191#define sk_reuse                __sk_common.skc_reuse
 192#define sk_bound_dev_if         __sk_common.skc_bound_dev_if
 193#define sk_node                 __sk_common.skc_node
 194#define sk_bind_node            __sk_common.skc_bind_node
 195#define sk_refcnt               __sk_common.skc_refcnt
 196#define sk_hash                 __sk_common.skc_hash
 197#define sk_prot                 __sk_common.skc_prot
 198        unsigned char           sk_shutdown : 2,
 199                                sk_no_check : 2,
 200                                sk_userlocks : 4;
 201        unsigned char           sk_protocol;
 202        unsigned short          sk_type;
 203        int                     sk_rcvbuf;
 204        socket_lock_t           sk_lock;
 205        wait_queue_head_t       *sk_sleep;
 206        struct dst_entry        *sk_dst_cache;
 207        struct xfrm_policy      *sk_policy[2];
 208        rwlock_t                sk_dst_lock;
 209        atomic_t                sk_rmem_alloc;
 210        atomic_t                sk_wmem_alloc;
 211        atomic_t                sk_omem_alloc;
 212        struct sk_buff_head     sk_receive_queue;
 213        struct sk_buff_head     sk_write_queue;
 214        struct sk_buff_head     sk_async_wait_queue;
 215        int                     sk_wmem_queued;
 216        int                     sk_forward_alloc;
 217        gfp_t                   sk_allocation;
 218        int                     sk_sndbuf;
 219        int                     sk_route_caps;
 220        int                     sk_gso_type;
 221        int                     sk_rcvlowat;
 222        unsigned long           sk_flags;
 223        unsigned long           sk_lingertime;
 224        /*
 225         * The backlog queue is special, it is always used with
 226         * the per-socket spinlock held and requires low latency
 227         * access. Therefore we special case it's implementation.
 228         */
 229        struct {
 230                struct sk_buff *head;
 231                struct sk_buff *tail;
 232        } sk_backlog;
 233        struct sk_buff_head     sk_error_queue;
 234        struct proto            *sk_prot_creator;
 235        rwlock_t                sk_callback_lock;
 236        int                     sk_err,
 237                                sk_err_soft;
 238        unsigned short          sk_ack_backlog;
 239        unsigned short          sk_max_ack_backlog;
 240        __u32                   sk_priority;
 241        struct ucred            sk_peercred;
 242        long                    sk_rcvtimeo;
 243        long                    sk_sndtimeo;
 244        struct sk_filter        *sk_filter;
 245        void                    *sk_protinfo;
 246        struct timer_list       sk_timer;
 247        struct timeval          sk_stamp;
 248        struct socket           *sk_socket;
 249        void                    *sk_user_data;
 250        struct page             *sk_sndmsg_page;
 251        struct sk_buff          *sk_send_head;
 252        __u32                   sk_sndmsg_off;
 253        int                     sk_write_pending;
 254        void                    *sk_security;
 255        void                    (*sk_state_change)(struct sock *sk);
 256        void                    (*sk_data_ready)(struct sock *sk, int bytes);
 257        void                    (*sk_write_space)(struct sock *sk);
 258        void                    (*sk_error_report)(struct sock *sk);
 259        int                     (*sk_backlog_rcv)(struct sock *sk,
 260                                                  struct sk_buff *skb);  
 261        void                    (*sk_destruct)(struct sock *sk);
 262};
 263
 264/*
 265 * Hashed lists helper routines
 266 */
 267static inline struct sock *__sk_head(const struct hlist_head *head)
 268{
 269        return hlist_entry(head->first, struct sock, sk_node);
 270}
 271
 272static inline struct sock *sk_head(const struct hlist_head *head)
 273{
 274        return hlist_empty(head) ? NULL : __sk_head(head);
 275}
 276
 277static inline struct sock *sk_next(const struct sock *sk)
 278{
 279        return sk->sk_node.next ?
 280                hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
 281}
 282
 283static inline int sk_unhashed(const struct sock *sk)
 284{
 285        return hlist_unhashed(&sk->sk_node);
 286}
 287
 288static inline int sk_hashed(const struct sock *sk)
 289{
 290        return !sk_unhashed(sk);
 291}
 292
 293static __inline__ void sk_node_init(struct hlist_node *node)
 294{
 295        node->pprev = NULL;
 296}
 297
 298static __inline__ void __sk_del_node(struct sock *sk)
 299{
 300        __hlist_del(&sk->sk_node);
 301}
 302
 303static __inline__ int __sk_del_node_init(struct sock *sk)
 304{
 305        if (sk_hashed(sk)) {
 306                __sk_del_node(sk);
 307                sk_node_init(&sk->sk_node);
 308                return 1;
 309        }
 310        return 0;
 311}
 312
 313/* Grab socket reference count. This operation is valid only
 314   when sk is ALREADY grabbed f.e. it is found in hash table
 315   or a list and the lookup is made under lock preventing hash table
 316   modifications.
 317 */
 318
 319static inline void sock_hold(struct sock *sk)
 320{
 321        atomic_inc(&sk->sk_refcnt);
 322}
 323
 324/* Ungrab socket in the context, which assumes that socket refcnt
 325   cannot hit zero, f.e. it is true in context of any socketcall.
 326 */
 327static inline void __sock_put(struct sock *sk)
 328{
 329        atomic_dec(&sk->sk_refcnt);
 330}
 331
 332static __inline__ int sk_del_node_init(struct sock *sk)
 333{
 334        int rc = __sk_del_node_init(sk);
 335
 336        if (rc) {
 337                /* paranoid for a while -acme */
 338                WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
 339                __sock_put(sk);
 340        }
 341        return rc;
 342}
 343
 344static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
 345{
 346        hlist_add_head(&sk->sk_node, list);
 347}
 348
 349static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
 350{
 351        sock_hold(sk);
 352        __sk_add_node(sk, list);
 353}
 354
 355static __inline__ void __sk_del_bind_node(struct sock *sk)
 356{
 357        __hlist_del(&sk->sk_bind_node);
 358}
 359
 360static __inline__ void sk_add_bind_node(struct sock *sk,
 361                                        struct hlist_head *list)
 362{
 363        hlist_add_head(&sk->sk_bind_node, list);
 364}
 365
 366#define sk_for_each(__sk, node, list) \
 367        hlist_for_each_entry(__sk, node, list, sk_node)
 368#define sk_for_each_from(__sk, node) \
 369        if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
 370                hlist_for_each_entry_from(__sk, node, sk_node)
 371#define sk_for_each_continue(__sk, node) \
 372        if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
 373                hlist_for_each_entry_continue(__sk, node, sk_node)
 374#define sk_for_each_safe(__sk, node, tmp, list) \
 375        hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
 376#define sk_for_each_bound(__sk, node, list) \
 377        hlist_for_each_entry(__sk, node, list, sk_bind_node)
 378
 379/* Sock flags */
 380enum sock_flags {
 381        SOCK_DEAD,
 382        SOCK_DONE,
 383        SOCK_URGINLINE,
 384        SOCK_KEEPOPEN,
 385        SOCK_LINGER,
 386        SOCK_DESTROY,
 387        SOCK_BROADCAST,
 388        SOCK_TIMESTAMP,
 389        SOCK_ZAPPED,
 390        SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
 391        SOCK_DBG, /* %SO_DEBUG setting */
 392        SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
 393        SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
 394        SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
 395};
 396
 397static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
 398{
 399        nsk->sk_flags = osk->sk_flags;
 400}
 401
 402static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 403{
 404        __set_bit(flag, &sk->sk_flags);
 405}
 406
 407static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 408{
 409        __clear_bit(flag, &sk->sk_flags);
 410}
 411
 412static inline int sock_flag(struct sock *sk, enum sock_flags flag)
 413{
 414        return test_bit(flag, &sk->sk_flags);
 415}
 416
 417static inline void sk_acceptq_removed(struct sock *sk)
 418{
 419        sk->sk_ack_backlog--;
 420}
 421
 422static inline void sk_acceptq_added(struct sock *sk)
 423{
 424        sk->sk_ack_backlog++;
 425}
 426
 427static inline int sk_acceptq_is_full(struct sock *sk)
 428{
 429        return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
 430}
 431
 432/*
 433 * Compute minimal free write space needed to queue new packets.
 434 */
 435static inline int sk_stream_min_wspace(struct sock *sk)
 436{
 437        return sk->sk_wmem_queued / 2;
 438}
 439
 440static inline int sk_stream_wspace(struct sock *sk)
 441{
 442        return sk->sk_sndbuf - sk->sk_wmem_queued;
 443}
 444
 445extern void sk_stream_write_space(struct sock *sk);
 446
 447static inline int sk_stream_memory_free(struct sock *sk)
 448{
 449        return sk->sk_wmem_queued < sk->sk_sndbuf;
 450}
 451
 452extern void sk_stream_rfree(struct sk_buff *skb);
 453
 454static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk)
 455{
 456        skb->sk = sk;
 457        skb->destructor = sk_stream_rfree;
 458        atomic_add(skb->truesize, &sk->sk_rmem_alloc);
 459        sk->sk_forward_alloc -= skb->truesize;
 460}
 461
 462static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
 463{
 464        skb_truesize_check(skb);
 465        sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
 466        sk->sk_wmem_queued   -= skb->truesize;
 467        sk->sk_forward_alloc += skb->truesize;
 468        __kfree_skb(skb);
 469}
 470
 471/* The per-socket spinlock must be held here. */
 472static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 473{
 474        if (!sk->sk_backlog.tail) {
 475                sk->sk_backlog.head = sk->sk_backlog.tail = skb;
 476        } else {
 477                sk->sk_backlog.tail->next = skb;
 478                sk->sk_backlog.tail = skb;
 479        }
 480        skb->next = NULL;
 481}
 482
 483#define sk_wait_event(__sk, __timeo, __condition)               \
 484({      int rc;                                                 \
 485        release_sock(__sk);                                     \
 486        rc = __condition;                                       \
 487        if (!rc) {                                              \
 488                *(__timeo) = schedule_timeout(*(__timeo));      \
 489        }                                                       \
 490        lock_sock(__sk);                                        \
 491        rc = __condition;                                       \
 492        rc;                                                     \
 493})
 494
 495extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
 496extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
 497extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
 498extern int sk_stream_error(struct sock *sk, int flags, int err);
 499extern void sk_stream_kill_queues(struct sock *sk);
 500
 501extern int sk_wait_data(struct sock *sk, long *timeo);
 502
 503struct request_sock_ops;
 504struct timewait_sock_ops;
 505
 506/* Networking protocol blocks we attach to sockets.
 507 * socket layer -> transport layer interface
 508 * transport -> network interface is defined by struct inet_proto
 509 */
 510struct proto {
 511        void                    (*close)(struct sock *sk, 
 512                                        long timeout);
 513        int                     (*connect)(struct sock *sk,
 514                                        struct sockaddr *uaddr, 
 515                                        int addr_len);
 516        int                     (*disconnect)(struct sock *sk, int flags);
 517
 518        struct sock *           (*accept) (struct sock *sk, int flags, int *err);
 519
 520        int                     (*ioctl)(struct sock *sk, int cmd,
 521                                         unsigned long arg);
 522        int                     (*init)(struct sock *sk);
 523        int                     (*destroy)(struct sock *sk);
 524        void                    (*shutdown)(struct sock *sk, int how);
 525        int                     (*setsockopt)(struct sock *sk, int level, 
 526                                        int optname, char __user *optval,
 527                                        int optlen);
 528        int                     (*getsockopt)(struct sock *sk, int level, 
 529                                        int optname, char __user *optval, 
 530                                        int __user *option);     
 531        int                     (*compat_setsockopt)(struct sock *sk,
 532                                        int level,
 533                                        int optname, char __user *optval,
 534                                        int optlen);
 535        int                     (*compat_getsockopt)(struct sock *sk,
 536                                        int level,
 537                                        int optname, char __user *optval,
 538                                        int __user *option);
 539        int                     (*sendmsg)(struct kiocb *iocb, struct sock *sk,
 540                                           struct msghdr *msg, size_t len);
 541        int                     (*recvmsg)(struct kiocb *iocb, struct sock *sk,
 542                                           struct msghdr *msg,
 543                                        size_t len, int noblock, int flags, 
 544                                        int *addr_len);
 545        int                     (*sendpage)(struct sock *sk, struct page *page,
 546                                        int offset, size_t size, int flags);
 547        int                     (*bind)(struct sock *sk, 
 548                                        struct sockaddr *uaddr, int addr_len);
 549
 550        int                     (*backlog_rcv) (struct sock *sk, 
 551                                                struct sk_buff *skb);
 552
 553        /* Keeping track of sk's, looking them up, and port selection methods. */
 554        void                    (*hash)(struct sock *sk);
 555        void                    (*unhash)(struct sock *sk);
 556        int                     (*get_port)(struct sock *sk, unsigned short snum);
 557
 558        /* Memory pressure */
 559        void                    (*enter_memory_pressure)(void);
 560        atomic_t                *memory_allocated;      /* Current allocated memory. */
 561        atomic_t                *sockets_allocated;     /* Current number of sockets. */
 562        /*
 563         * Pressure flag: try to collapse.
 564         * Technical note: it is used by multiple contexts non atomically.
 565         * All the sk_stream_mem_schedule() is of this nature: accounting
 566         * is strict, actions are advisory and have some latency.
 567         */
 568        int                     *memory_pressure;
 569        int                     *sysctl_mem;
 570        int                     *sysctl_wmem;
 571        int                     *sysctl_rmem;
 572        int                     max_header;
 573
 574        struct kmem_cache               *slab;
 575        unsigned int            obj_size;
 576
 577        atomic_t                *orphan_count;
 578
 579        struct request_sock_ops *rsk_prot;
 580        struct timewait_sock_ops *twsk_prot;
 581
 582        struct module           *owner;
 583
 584        char                    name[32];
 585
 586        struct list_head        node;
 587#ifdef SOCK_REFCNT_DEBUG
 588        atomic_t                socks;
 589#endif
 590        struct {
 591                int inuse;
 592                u8  __pad[SMP_CACHE_BYTES - sizeof(int)];
 593        } stats[NR_CPUS];
 594};
 595
 596extern int proto_register(struct proto *prot, int alloc_slab);
 597extern void proto_unregister(struct proto *prot);
 598
 599#ifdef SOCK_REFCNT_DEBUG
 600static inline void sk_refcnt_debug_inc(struct sock *sk)
 601{
 602        atomic_inc(&sk->sk_prot->socks);
 603}
 604
 605static inline void sk_refcnt_debug_dec(struct sock *sk)
 606{
 607        atomic_dec(&sk->sk_prot->socks);
 608        printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
 609               sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
 610}
 611
 612static inline void sk_refcnt_debug_release(const struct sock *sk)
 613{
 614        if (atomic_read(&sk->sk_refcnt) != 1)
 615                printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
 616                       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
 617}
 618#else /* SOCK_REFCNT_DEBUG */
 619#define sk_refcnt_debug_inc(sk) do { } while (0)
 620#define sk_refcnt_debug_dec(sk) do { } while (0)
 621#define sk_refcnt_debug_release(sk) do { } while (0)
 622#endif /* SOCK_REFCNT_DEBUG */
 623
 624/* Called with local bh disabled */
 625static __inline__ void sock_prot_inc_use(struct proto *prot)
 626{
 627        prot->stats[smp_processor_id()].inuse++;
 628}
 629
 630static __inline__ void sock_prot_dec_use(struct proto *prot)
 631{
 632        prot->stats[smp_processor_id()].inuse--;
 633}
 634
 635/* With per-bucket locks this operation is not-atomic, so that
 636 * this version is not worse.
 637 */
 638static inline void __sk_prot_rehash(struct sock *sk)
 639{
 640        sk->sk_prot->unhash(sk);
 641        sk->sk_prot->hash(sk);
 642}
 643
 644/* About 10 seconds */
 645#define SOCK_DESTROY_TIME (10*HZ)
 646
 647/* Sockets 0-1023 can't be bound to unless you are superuser */
 648#define PROT_SOCK       1024
 649
 650#define SHUTDOWN_MASK   3
 651#define RCV_SHUTDOWN    1
 652#define SEND_SHUTDOWN   2
 653
 654#define SOCK_SNDBUF_LOCK        1
 655#define SOCK_RCVBUF_LOCK        2
 656#define SOCK_BINDADDR_LOCK      4
 657#define SOCK_BINDPORT_LOCK      8
 658
 659/* sock_iocb: used to kick off async processing of socket ios */
 660struct sock_iocb {
 661        struct list_head        list;
 662
 663        int                     flags;
 664        int                     size;
 665        struct socket           *sock;
 666        struct sock             *sk;
 667        struct scm_cookie       *scm;
 668        struct msghdr           *msg, async_msg;
 669        struct kiocb            *kiocb;
 670};
 671
 672static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
 673{
 674        return (struct sock_iocb *)iocb->private;
 675}
 676
 677static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
 678{
 679        return si->kiocb;
 680}
 681
 682struct socket_alloc {
 683        struct socket socket;
 684        struct inode vfs_inode;
 685};
 686
 687static inline struct socket *SOCKET_I(struct inode *inode)
 688{
 689        return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
 690}
 691
 692static inline struct inode *SOCK_INODE(struct socket *socket)
 693{
 694        return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
 695}
 696
 697extern void __sk_stream_mem_reclaim(struct sock *sk);
 698extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind);
 699
 700#define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE)
 701
 702static inline int sk_stream_pages(int amt)
 703{
 704        return (amt + SK_STREAM_MEM_QUANTUM - 1) / SK_STREAM_MEM_QUANTUM;
 705}
 706
 707static inline void sk_stream_mem_reclaim(struct sock *sk)
 708{
 709        if (sk->sk_forward_alloc >= SK_STREAM_MEM_QUANTUM)
 710                __sk_stream_mem_reclaim(sk);
 711}
 712
 713static inline void sk_stream_writequeue_purge(struct sock *sk)
 714{
 715        struct sk_buff *skb;
 716
 717        while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
 718                sk_stream_free_skb(sk, skb);
 719        sk_stream_mem_reclaim(sk);
 720}
 721
 722static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb)
 723{
 724        return (int)skb->truesize <= sk->sk_forward_alloc ||
 725                sk_stream_mem_schedule(sk, skb->truesize, 1);
 726}
 727
 728static inline int sk_stream_wmem_schedule(struct sock *sk, int size)
 729{
 730        return size <= sk->sk_forward_alloc ||
 731               sk_stream_mem_schedule(sk, size, 0);
 732}
 733
 734/* Used by processes to "lock" a socket state, so that
 735 * interrupts and bottom half handlers won't change it
 736 * from under us. It essentially blocks any incoming
 737 * packets, so that we won't get any new data or any
 738 * packets that change the state of the socket.
 739 *
 740 * While locked, BH processing will add new packets to
 741 * the backlog queue.  This queue is processed by the
 742 * owner of the socket lock right before it is released.
 743 *
 744 * Since ~2.3.5 it is also exclusive sleep lock serializing
 745 * accesses from user process context.
 746 */
 747#define sock_owned_by_user(sk)  ((sk)->sk_lock.owner)
 748
 749/*
 750 * Macro so as to not evaluate some arguments when
 751 * lockdep is not enabled.
 752 *
 753 * Mark both the sk_lock and the sk_lock.slock as a
 754 * per-address-family lock class.
 755 */
 756#define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
 757do {                                                                    \
 758        sk->sk_lock.owner = NULL;                                       \
 759        init_waitqueue_head(&sk->sk_lock.wq);                           \
 760        spin_lock_init(&(sk)->sk_lock.slock);                           \
 761        debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
 762                        sizeof((sk)->sk_lock));                         \
 763        lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
 764                        (skey), (sname));                               \
 765        lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
 766} while (0)
 767
 768extern void FASTCALL(lock_sock_nested(struct sock *sk, int subclass));
 769
 770static inline void lock_sock(struct sock *sk)
 771{
 772        lock_sock_nested(sk, 0);
 773}
 774
 775extern void FASTCALL(release_sock(struct sock *sk));
 776
 777/* BH context may only use the following locking interface. */
 778#define bh_lock_sock(__sk)      spin_lock(&((__sk)->sk_lock.slock))
 779#define bh_lock_sock_nested(__sk) \
 780                                spin_lock_nested(&((__sk)->sk_lock.slock), \
 781                                SINGLE_DEPTH_NESTING)
 782#define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
 783
 784extern struct sock              *sk_alloc(int family,
 785                                          gfp_t priority,
 786                                          struct proto *prot, int zero_it);
 787extern void                     sk_free(struct sock *sk);
 788extern struct sock              *sk_clone(const struct sock *sk,
 789                                          const gfp_t priority);
 790
 791extern struct sk_buff           *sock_wmalloc(struct sock *sk,
 792                                              unsigned long size, int force,
 793                                              gfp_t priority);
 794extern struct sk_buff           *sock_rmalloc(struct sock *sk,
 795                                              unsigned long size, int force,
 796                                              gfp_t priority);
 797extern void                     sock_wfree(struct sk_buff *skb);
 798extern void                     sock_rfree(struct sk_buff *skb);
 799
 800extern int                      sock_setsockopt(struct socket *sock, int level,
 801                                                int op, char __user *optval,
 802                                                int optlen);
 803
 804extern int                      sock_getsockopt(struct socket *sock, int level,
 805                                                int op, char __user *optval, 
 806                                                int __user *optlen);
 807extern struct sk_buff           *sock_alloc_send_skb(struct sock *sk,
 808                                                     unsigned long size,
 809                                                     int noblock,
 810                                                     int *errcode);
 811extern void *sock_kmalloc(struct sock *sk, int size,
 812                          gfp_t priority);
 813extern void sock_kfree_s(struct sock *sk, void *mem, int size);
 814extern void sk_send_sigurg(struct sock *sk);
 815
 816/*
 817 * Functions to fill in entries in struct proto_ops when a protocol
 818 * does not implement a particular function.
 819 */
 820extern int                      sock_no_bind(struct socket *, 
 821                                             struct sockaddr *, int);
 822extern int                      sock_no_connect(struct socket *,
 823                                                struct sockaddr *, int, int);
 824extern int                      sock_no_socketpair(struct socket *,
 825                                                   struct socket *);
 826extern int                      sock_no_accept(struct socket *,
 827                                               struct socket *, int);
 828extern int                      sock_no_getname(struct socket *,
 829                                                struct sockaddr *, int *, int);
 830extern unsigned int             sock_no_poll(struct file *, struct socket *,
 831                                             struct poll_table_struct *);
 832extern int                      sock_no_ioctl(struct socket *, unsigned int,
 833                                              unsigned long);
 834extern int                      sock_no_listen(struct socket *, int);
 835extern int                      sock_no_shutdown(struct socket *, int);
 836extern int                      sock_no_getsockopt(struct socket *, int , int,
 837                                                   char __user *, int __user *);
 838extern int                      sock_no_setsockopt(struct socket *, int, int,
 839                                                   char __user *, int);
 840extern int                      sock_no_sendmsg(struct kiocb *, struct socket *,
 841                                                struct msghdr *, size_t);
 842extern int                      sock_no_recvmsg(struct kiocb *, struct socket *,
 843                                                struct msghdr *, size_t, int);
 844extern int                      sock_no_mmap(struct file *file,
 845                                             struct socket *sock,
 846                                             struct vm_area_struct *vma);
 847extern ssize_t                  sock_no_sendpage(struct socket *sock,
 848                                                struct page *page,
 849                                                int offset, size_t size, 
 850                                                int flags);
 851
 852/*
 853 * Functions to fill in entries in struct proto_ops when a protocol
 854 * uses the inet style.
 855 */
 856extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
 857                                  char __user *optval, int __user *optlen);
 858extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
 859                               struct msghdr *msg, size_t size, int flags);
 860extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
 861                                  char __user *optval, int optlen);
 862extern int compat_sock_common_getsockopt(struct socket *sock, int level,
 863                int optname, char __user *optval, int __user *optlen);
 864extern int compat_sock_common_setsockopt(struct socket *sock, int level,
 865                int optname, char __user *optval, int optlen);
 866
 867extern void sk_common_release(struct sock *sk);
 868
 869/*
 870 *      Default socket callbacks and setup code
 871 */
 872 
 873/* Initialise core socket variables */
 874extern void sock_init_data(struct socket *sock, struct sock *sk);
 875
 876/**
 877 *      sk_filter - run a packet through a socket filter
 878 *      @sk: sock associated with &sk_buff
 879 *      @skb: buffer to filter
 880 *      @needlock: set to 1 if the sock is not locked by caller.
 881 *
 882 * Run the filter code and then cut skb->data to correct size returned by
 883 * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller
 884 * than pkt_len we keep whole skb->data. This is the socket level
 885 * wrapper to sk_run_filter. It returns 0 if the packet should
 886 * be accepted or -EPERM if the packet should be tossed.
 887 *
 888 */
 889
 890static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
 891{
 892        int err;
 893        struct sk_filter *filter;
 894        
 895        err = security_sock_rcv_skb(sk, skb);
 896        if (err)
 897                return err;
 898        
 899        rcu_read_lock_bh();
 900        filter = sk->sk_filter;
 901        if (filter) {
 902                unsigned int pkt_len = sk_run_filter(skb, filter->insns,
 903                                filter->len);
 904                err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
 905        }
 906        rcu_read_unlock_bh();
 907
 908        return err;
 909}
 910
 911/**
 912 *      sk_filter_rcu_free: Free a socket filter
 913 *      @rcu: rcu_head that contains the sk_filter to free
 914 */
 915static inline void sk_filter_rcu_free(struct rcu_head *rcu)
 916{
 917        struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
 918        kfree(fp);
 919}
 920
 921/**
 922 *      sk_filter_release: Release a socket filter
 923 *      @sk: socket
 924 *      @fp: filter to remove
 925 *
 926 *      Remove a filter from a socket and release its resources.
 927 */
 928
 929static inline void sk_filter_release(struct sock *sk, struct sk_filter *fp)
 930{
 931        unsigned int size = sk_filter_len(fp);
 932
 933        atomic_sub(size, &sk->sk_omem_alloc);
 934
 935        if (atomic_dec_and_test(&fp->refcnt))
 936                call_rcu_bh(&fp->rcu, sk_filter_rcu_free);
 937}
 938
 939static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
 940{
 941        atomic_inc(&fp->refcnt);
 942        atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
 943}
 944
 945/*
 946 * Socket reference counting postulates.
 947 *
 948 * * Each user of socket SHOULD hold a reference count.
 949 * * Each access point to socket (an hash table bucket, reference from a list,
 950 *   running timer, skb in flight MUST hold a reference count.
 951 * * When reference count hits 0, it means it will never increase back.
 952 * * When reference count hits 0, it means that no references from
 953 *   outside exist to this socket and current process on current CPU
 954 *   is last user and may/should destroy this socket.
 955 * * sk_free is called from any context: process, BH, IRQ. When
 956 *   it is called, socket has no references from outside -> sk_free
 957 *   may release descendant resources allocated by the socket, but
 958 *   to the time when it is called, socket is NOT referenced by any
 959 *   hash tables, lists etc.
 960 * * Packets, delivered from outside (from network or from another process)
 961 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
 962 *   when they sit in queue. Otherwise, packets will leak to hole, when
 963 *   socket is looked up by one cpu and unhasing is made by another CPU.
 964 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
 965 *   (leak to backlog). Packet socket does all the processing inside
 966 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
 967 *   use separate SMP lock, so that they are prone too.
 968 */
 969
 970/* Ungrab socket and destroy it, if it was the last reference. */
 971static inline void sock_put(struct sock *sk)
 972{
 973        if (atomic_dec_and_test(&sk->sk_refcnt))
 974                sk_free(sk);
 975}
 976
 977extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
 978                          const int nested);
 979
 980/* Detach socket from process context.
 981 * Announce socket dead, detach it from wait queue and inode.
 982 * Note that parent inode held reference count on this struct sock,
 983 * we do not release it in this function, because protocol
 984 * probably wants some additional cleanups or even continuing
 985 * to work with this socket (TCP).
 986 */
 987static inline void sock_orphan(struct sock *sk)
 988{
 989        write_lock_bh(&sk->sk_callback_lock);
 990        sock_set_flag(sk, SOCK_DEAD);
 991        sk->sk_socket = NULL;
 992        sk->sk_sleep  = NULL;
 993        write_unlock_bh(&sk->sk_callback_lock);
 994}
 995
 996static inline void sock_graft(struct sock *sk, struct socket *parent)
 997{
 998        write_lock_bh(&sk->sk_callback_lock);
 999        sk->sk_sleep = &parent->wait;
1000        parent->sk = sk;
1001        sk->sk_socket = parent;
1002        security_sock_graft(sk, parent);
1003        write_unlock_bh(&sk->sk_callback_lock);
1004}
1005
1006static inline void sock_copy(struct sock *nsk, const struct sock *osk)
1007{
1008#ifdef CONFIG_SECURITY_NETWORK
1009        void *sptr = nsk->sk_security;
1010#endif
1011
1012        memcpy(nsk, osk, osk->sk_prot->obj_size);
1013#ifdef CONFIG_SECURITY_NETWORK
1014        nsk->sk_security = sptr;
1015        security_sk_clone(osk, nsk);
1016#endif
1017}
1018
1019extern int sock_i_uid(struct sock *sk);
1020extern unsigned long sock_i_ino(struct sock *sk);
1021
1022static inline struct dst_entry *
1023__sk_dst_get(struct sock *sk)
1024{
1025        return sk->sk_dst_cache;
1026}
1027
1028static inline struct dst_entry *
1029sk_dst_get(struct sock *sk)
1030{
1031        struct dst_entry *dst;
1032
1033        read_lock(&sk->sk_dst_lock);
1034        dst = sk->sk_dst_cache;
1035        if (dst)
1036                dst_hold(dst);
1037        read_unlock(&sk->sk_dst_lock);
1038        return dst;
1039}
1040
1041static inline void
1042__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1043{
1044        struct dst_entry *old_dst;
1045
1046        old_dst = sk->sk_dst_cache;
1047        sk->sk_dst_cache = dst;
1048        dst_release(old_dst);
1049}
1050
1051static inline void
1052sk_dst_set(struct sock *sk, struct dst_entry *dst)
1053{
1054        write_lock(&sk->sk_dst_lock);
1055        __sk_dst_set(sk, dst);
1056        write_unlock(&sk->sk_dst_lock);
1057}
1058
1059static inline void
1060__sk_dst_reset(struct sock *sk)
1061{
1062        struct dst_entry *old_dst;
1063
1064        old_dst = sk->sk_dst_cache;
1065        sk->sk_dst_cache = NULL;
1066        dst_release(old_dst);
1067}
1068
1069static inline void
1070sk_dst_reset(struct sock *sk)
1071{
1072        write_lock(&sk->sk_dst_lock);
1073        __sk_dst_reset(sk);
1074        write_unlock(&sk->sk_dst_lock);
1075}
1076
1077extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1078
1079extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1080
1081static inline int sk_can_gso(const struct sock *sk)
1082{
1083        return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1084}
1085
1086static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1087{
1088        __sk_dst_set(sk, dst);
1089        sk->sk_route_caps = dst->dev->features;
1090        if (sk->sk_route_caps & NETIF_F_GSO)
1091                sk->sk_route_caps |= NETIF_F_GSO_MASK;
1092        if (sk_can_gso(sk)) {
1093                if (dst->header_len)
1094                        sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1095                else 
1096                        sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1097        }
1098}
1099
1100static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
1101{
1102        sk->sk_wmem_queued   += skb->truesize;
1103        sk->sk_forward_alloc -= skb->truesize;
1104}
1105
1106static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1107                                   struct sk_buff *skb, struct page *page,
1108                                   int off, int copy)
1109{
1110        if (skb->ip_summed == CHECKSUM_NONE) {
1111                int err = 0;
1112                __wsum csum = csum_and_copy_from_user(from,
1113                                                     page_address(page) + off,
1114                                                            copy, 0, &err);
1115                if (err)
1116                        return err;
1117                skb->csum = csum_block_add(skb->csum, csum, skb->len);
1118        } else if (copy_from_user(page_address(page) + off, from, copy))
1119                return -EFAULT;
1120
1121        skb->len             += copy;
1122        skb->data_len        += copy;
1123        skb->truesize        += copy;
1124        sk->sk_wmem_queued   += copy;
1125        sk->sk_forward_alloc -= copy;
1126        return 0;
1127}
1128
1129/*
1130 *      Queue a received datagram if it will fit. Stream and sequenced
1131 *      protocols can't normally use this as they need to fit buffers in
1132 *      and play with them.
1133 *
1134 *      Inlined as it's very short and called for pretty much every
1135 *      packet ever received.
1136 */
1137
1138static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1139{
1140        sock_hold(sk);
1141        skb->sk = sk;
1142        skb->destructor = sock_wfree;
1143        atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1144}
1145
1146static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1147{
1148        skb->sk = sk;
1149        skb->destructor = sock_rfree;
1150        atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1151}
1152
1153extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1154                           unsigned long expires);
1155
1156extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1157
1158extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1159
1160static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
1161{
1162        /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1163           number of warnings when compiling with -W --ANK
1164         */
1165        if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
1166            (unsigned)sk->sk_rcvbuf)
1167                return -ENOMEM;
1168        skb_set_owner_r(skb, sk);
1169        skb_queue_tail(&sk->sk_error_queue, skb);
1170        if (!sock_flag(sk, SOCK_DEAD))
1171                sk->sk_data_ready(sk, skb->len);
1172        return 0;
1173}
1174
1175/*
1176 *      Recover an error report and clear atomically
1177 */
1178 
1179static inline int sock_error(struct sock *sk)
1180{
1181        int err;
1182        if (likely(!sk->sk_err))
1183                return 0;
1184        err = xchg(&sk->sk_err, 0);
1185        return -err;
1186}
1187
1188static inline unsigned long sock_wspace(struct sock *sk)
1189{
1190        int amt = 0;
1191
1192        if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1193                amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1194                if (amt < 0) 
1195                        amt = 0;
1196        }
1197        return amt;
1198}
1199
1200static inline void sk_wake_async(struct sock *sk, int how, int band)
1201{
1202        if (sk->sk_socket && sk->sk_socket->fasync_list)
1203                sock_wake_async(sk->sk_socket, how, band);
1204}
1205
1206#define SOCK_MIN_SNDBUF 2048
1207#define SOCK_MIN_RCVBUF 256
1208
1209static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1210{
1211        if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1212                sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued / 2);
1213                sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1214        }
1215}
1216
1217static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
1218                                                   int size, int mem,
1219                                                   gfp_t gfp)
1220{
1221        struct sk_buff *skb;
1222        int hdr_len;
1223
1224        hdr_len = SKB_DATA_ALIGN(sk->sk_prot->max_header);
1225        skb = alloc_skb_fclone(size + hdr_len, gfp);
1226        if (skb) {
1227                skb->truesize += mem;
1228                if (sk_stream_wmem_schedule(sk, skb->truesize)) {
1229                        skb_reserve(skb, hdr_len);
1230                        return skb;
1231                }
1232                __kfree_skb(skb);
1233        } else {
1234                sk->sk_prot->enter_memory_pressure();
1235                sk_stream_moderate_sndbuf(sk);
1236        }
1237        return NULL;
1238}
1239
1240static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
1241                                                  int size,
1242                                                  gfp_t gfp)
1243{
1244        return sk_stream_alloc_pskb(sk, size, 0, gfp);
1245}
1246
1247static inline struct page *sk_stream_alloc_page(struct sock *sk)
1248{
1249        struct page *page = NULL;
1250
1251        page = alloc_pages(sk->sk_allocation, 0);
1252        if (!page) {
1253                sk->sk_prot->enter_memory_pressure();
1254                sk_stream_moderate_sndbuf(sk);
1255        }
1256        return page;
1257}
1258
1259#define sk_stream_for_retrans_queue(skb, sk)                            \
1260                for (skb = (sk)->sk_write_queue.next;                   \
1261                     (skb != (sk)->sk_send_head) &&                     \
1262                     (skb != (struct sk_buff *)&(sk)->sk_write_queue);  \
1263                     skb = skb->next)
1264
1265/*from STCP for fast SACK Process*/
1266#define sk_stream_for_retrans_queue_from(skb, sk)                       \
1267                for (; (skb != (sk)->sk_send_head) &&                   \
1268                     (skb != (struct sk_buff *)&(sk)->sk_write_queue);  \
1269                     skb = skb->next)
1270
1271/*
1272 *      Default write policy as shown to user space via poll/select/SIGIO
1273 */
1274static inline int sock_writeable(const struct sock *sk) 
1275{
1276        return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf / 2);
1277}
1278
1279static inline gfp_t gfp_any(void)
1280{
1281        return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1282}
1283
1284static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1285{
1286        return noblock ? 0 : sk->sk_rcvtimeo;
1287}
1288
1289static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1290{
1291        return noblock ? 0 : sk->sk_sndtimeo;
1292}
1293
1294static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1295{
1296        return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1297}
1298
1299/* Alas, with timeout socket operations are not restartable.
1300 * Compare this to poll().
1301 */
1302static inline int sock_intr_errno(long timeo)
1303{
1304        return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1305}
1306
1307static __inline__ void
1308sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1309{
1310        struct timeval stamp;
1311
1312        skb_get_timestamp(skb, &stamp);
1313        if (sock_flag(sk, SOCK_RCVTSTAMP)) {
1314                /* Race occurred between timestamp enabling and packet
1315                   receiving.  Fill in the current time for now. */
1316                if (stamp.tv_sec == 0)
1317                        do_gettimeofday(&stamp);
1318                skb_set_timestamp(skb, &stamp);
1319                put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval),
1320                         &stamp);
1321        } else
1322                sk->sk_stamp = stamp;
1323}
1324
1325/**
1326 * sk_eat_skb - Release a skb if it is no longer needed
1327 * @sk: socket to eat this skb from
1328 * @skb: socket buffer to eat
1329 * @copied_early: flag indicating whether DMA operations copied this data early
1330 *
1331 * This routine must be called with interrupts disabled or with the socket
1332 * locked so that the sk_buff queue operation is ok.
1333*/
1334#ifdef CONFIG_NET_DMA
1335static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1336{
1337        __skb_unlink(skb, &sk->sk_receive_queue);
1338        if (!copied_early)
1339                __kfree_skb(skb);
1340        else
1341                __skb_queue_tail(&sk->sk_async_wait_queue, skb);
1342}
1343#else
1344static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1345{
1346        __skb_unlink(skb, &sk->sk_receive_queue);
1347        __kfree_skb(skb);
1348}
1349#endif
1350
1351extern void sock_enable_timestamp(struct sock *sk);
1352extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1353
1354/* 
1355 *      Enable debug/info messages 
1356 */
1357
1358#ifdef CONFIG_NETDEBUG
1359#define NETDEBUG(fmt, args...)  printk(fmt,##args)
1360#define LIMIT_NETDEBUG(fmt, args...) do { if (net_ratelimit()) printk(fmt,##args); } while(0)
1361#else
1362#define NETDEBUG(fmt, args...)  do { } while (0)
1363#define LIMIT_NETDEBUG(fmt, args...) do { } while(0)
1364#endif
1365
1366/*
1367 * Macros for sleeping on a socket. Use them like this:
1368 *
1369 * SOCK_SLEEP_PRE(sk)
1370 * if (condition)
1371 *      schedule();
1372 * SOCK_SLEEP_POST(sk)
1373 *
1374 * N.B. These are now obsolete and were, afaik, only ever used in DECnet
1375 * and when the last use of them in DECnet has gone, I'm intending to
1376 * remove them.
1377 */
1378
1379#define SOCK_SLEEP_PRE(sk)      { struct task_struct *tsk = current; \
1380                                DECLARE_WAITQUEUE(wait, tsk); \
1381                                tsk->state = TASK_INTERRUPTIBLE; \
1382                                add_wait_queue((sk)->sk_sleep, &wait); \
1383                                release_sock(sk);
1384
1385#define SOCK_SLEEP_POST(sk)     tsk->state = TASK_RUNNING; \
1386                                remove_wait_queue((sk)->sk_sleep, &wait); \
1387                                lock_sock(sk); \
1388                                }
1389
1390static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
1391{
1392        if (valbool)
1393                sock_set_flag(sk, bit);
1394        else
1395                sock_reset_flag(sk, bit);
1396}
1397
1398extern __u32 sysctl_wmem_max;
1399extern __u32 sysctl_rmem_max;
1400
1401#ifdef CONFIG_NET
1402int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg);
1403#else
1404static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
1405{
1406        return -ENODEV;
1407}
1408#endif
1409
1410extern void sk_init(void);
1411
1412#ifdef CONFIG_SYSCTL
1413extern struct ctl_table core_table[];
1414#endif
1415
1416extern int sysctl_optmem_max;
1417
1418extern __u32 sysctl_wmem_default;
1419extern __u32 sysctl_rmem_default;
1420
1421#endif  /* _SOCK_H */
1422
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