linux/net/socket.c
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   1/*
   2 * NET          An implementation of the SOCKET network access protocol.
   3 *
   4 * Version:     @(#)socket.c    1.1.93  18/02/95
   5 *
   6 * Authors:     Orest Zborowski, <obz@Kodak.COM>
   7 *              Ross Biro
   8 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   9 *
  10 * Fixes:
  11 *              Anonymous       :       NOTSOCK/BADF cleanup. Error fix in
  12 *                                      shutdown()
  13 *              Alan Cox        :       verify_area() fixes
  14 *              Alan Cox        :       Removed DDI
  15 *              Jonathan Kamens :       SOCK_DGRAM reconnect bug
  16 *              Alan Cox        :       Moved a load of checks to the very
  17 *                                      top level.
  18 *              Alan Cox        :       Move address structures to/from user
  19 *                                      mode above the protocol layers.
  20 *              Rob Janssen     :       Allow 0 length sends.
  21 *              Alan Cox        :       Asynchronous I/O support (cribbed from the
  22 *                                      tty drivers).
  23 *              Niibe Yutaka    :       Asynchronous I/O for writes (4.4BSD style)
  24 *              Jeff Uphoff     :       Made max number of sockets command-line
  25 *                                      configurable.
  26 *              Matti Aarnio    :       Made the number of sockets dynamic,
  27 *                                      to be allocated when needed, and mr.
  28 *                                      Uphoff's max is used as max to be
  29 *                                      allowed to allocate.
  30 *              Linus           :       Argh. removed all the socket allocation
  31 *                                      altogether: it's in the inode now.
  32 *              Alan Cox        :       Made sock_alloc()/sock_release() public
  33 *                                      for NetROM and future kernel nfsd type
  34 *                                      stuff.
  35 *              Alan Cox        :       sendmsg/recvmsg basics.
  36 *              Tom Dyas        :       Export net symbols.
  37 *              Marcin Dalecki  :       Fixed problems with CONFIG_NET="n".
  38 *              Alan Cox        :       Added thread locking to sys_* calls
  39 *                                      for sockets. May have errors at the
  40 *                                      moment.
  41 *              Kevin Buhr      :       Fixed the dumb errors in the above.
  42 *              Andi Kleen      :       Some small cleanups, optimizations,
  43 *                                      and fixed a copy_from_user() bug.
  44 *              Tigran Aivazian :       sys_send(args) calls sys_sendto(args, NULL, 0)
  45 *              Tigran Aivazian :       Made listen(2) backlog sanity checks
  46 *                                      protocol-independent
  47 *
  48 *
  49 *              This program is free software; you can redistribute it and/or
  50 *              modify it under the terms of the GNU General Public License
  51 *              as published by the Free Software Foundation; either version
  52 *              2 of the License, or (at your option) any later version.
  53 *
  54 *
  55 *      This module is effectively the top level interface to the BSD socket
  56 *      paradigm.
  57 *
  58 *      Based upon Swansea University Computer Society NET3.039
  59 */
  60
  61#include <linux/mm.h>
  62#include <linux/socket.h>
  63#include <linux/file.h>
  64#include <linux/net.h>
  65#include <linux/interrupt.h>
  66#include <linux/thread_info.h>
  67#include <linux/rcupdate.h>
  68#include <linux/netdevice.h>
  69#include <linux/proc_fs.h>
  70#include <linux/seq_file.h>
  71#include <linux/mutex.h>
  72#include <linux/wanrouter.h>
  73#include <linux/if_bridge.h>
  74#include <linux/if_frad.h>
  75#include <linux/if_vlan.h>
  76#include <linux/init.h>
  77#include <linux/poll.h>
  78#include <linux/cache.h>
  79#include <linux/module.h>
  80#include <linux/highmem.h>
  81#include <linux/mount.h>
  82#include <linux/security.h>
  83#include <linux/syscalls.h>
  84#include <linux/compat.h>
  85#include <linux/kmod.h>
  86#include <linux/audit.h>
  87#include <linux/wireless.h>
  88#include <linux/nsproxy.h>
  89
  90#include <asm/uaccess.h>
  91#include <asm/unistd.h>
  92
  93#include <net/compat.h>
  94#include <net/wext.h>
  95
  96#include <net/sock.h>
  97#include <linux/netfilter.h>
  98
  99static int sock_no_open(struct inode *irrelevant, struct file *dontcare);
 100static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
 101                         unsigned long nr_segs, loff_t pos);
 102static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
 103                          unsigned long nr_segs, loff_t pos);
 104static int sock_mmap(struct file *file, struct vm_area_struct *vma);
 105
 106static int sock_close(struct inode *inode, struct file *file);
 107static unsigned int sock_poll(struct file *file,
 108                              struct poll_table_struct *wait);
 109static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 110#ifdef CONFIG_COMPAT
 111static long compat_sock_ioctl(struct file *file,
 112                              unsigned int cmd, unsigned long arg);
 113#endif
 114static int sock_fasync(int fd, struct file *filp, int on);
 115static ssize_t sock_sendpage(struct file *file, struct page *page,
 116                             int offset, size_t size, loff_t *ppos, int more);
 117static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
 118                                struct pipe_inode_info *pipe, size_t len,
 119                                unsigned int flags);
 120
 121/*
 122 *      Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
 123 *      in the operation structures but are done directly via the socketcall() multiplexor.
 124 */
 125
 126static const struct file_operations socket_file_ops = {
 127        .owner =        THIS_MODULE,
 128        .llseek =       no_llseek,
 129        .aio_read =     sock_aio_read,
 130        .aio_write =    sock_aio_write,
 131        .poll =         sock_poll,
 132        .unlocked_ioctl = sock_ioctl,
 133#ifdef CONFIG_COMPAT
 134        .compat_ioctl = compat_sock_ioctl,
 135#endif
 136        .mmap =         sock_mmap,
 137        .open =         sock_no_open,   /* special open code to disallow open via /proc */
 138        .release =      sock_close,
 139        .fasync =       sock_fasync,
 140        .sendpage =     sock_sendpage,
 141        .splice_write = generic_splice_sendpage,
 142        .splice_read =  sock_splice_read,
 143};
 144
 145/*
 146 *      The protocol list. Each protocol is registered in here.
 147 */
 148
 149static DEFINE_SPINLOCK(net_family_lock);
 150static const struct net_proto_family *net_families[NPROTO] __read_mostly;
 151
 152/*
 153 *      Statistics counters of the socket lists
 154 */
 155
 156static DEFINE_PER_CPU(int, sockets_in_use) = 0;
 157
 158/*
 159 * Support routines.
 160 * Move socket addresses back and forth across the kernel/user
 161 * divide and look after the messy bits.
 162 */
 163
 164#define MAX_SOCK_ADDR   128             /* 108 for Unix domain -
 165                                           16 for IP, 16 for IPX,
 166                                           24 for IPv6,
 167                                           about 80 for AX.25
 168                                           must be at least one bigger than
 169                                           the AF_UNIX size (see net/unix/af_unix.c
 170                                           :unix_mkname()).
 171                                         */
 172
 173/**
 174 *      move_addr_to_kernel     -       copy a socket address into kernel space
 175 *      @uaddr: Address in user space
 176 *      @kaddr: Address in kernel space
 177 *      @ulen: Length in user space
 178 *
 179 *      The address is copied into kernel space. If the provided address is
 180 *      too long an error code of -EINVAL is returned. If the copy gives
 181 *      invalid addresses -EFAULT is returned. On a success 0 is returned.
 182 */
 183
 184int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr *kaddr)
 185{
 186        if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
 187                return -EINVAL;
 188        if (ulen == 0)
 189                return 0;
 190        if (copy_from_user(kaddr, uaddr, ulen))
 191                return -EFAULT;
 192        return audit_sockaddr(ulen, kaddr);
 193}
 194
 195/**
 196 *      move_addr_to_user       -       copy an address to user space
 197 *      @kaddr: kernel space address
 198 *      @klen: length of address in kernel
 199 *      @uaddr: user space address
 200 *      @ulen: pointer to user length field
 201 *
 202 *      The value pointed to by ulen on entry is the buffer length available.
 203 *      This is overwritten with the buffer space used. -EINVAL is returned
 204 *      if an overlong buffer is specified or a negative buffer size. -EFAULT
 205 *      is returned if either the buffer or the length field are not
 206 *      accessible.
 207 *      After copying the data up to the limit the user specifies, the true
 208 *      length of the data is written over the length limit the user
 209 *      specified. Zero is returned for a success.
 210 */
 211
 212int move_addr_to_user(struct sockaddr *kaddr, int klen, void __user *uaddr,
 213                      int __user *ulen)
 214{
 215        int err;
 216        int len;
 217
 218        err = get_user(len, ulen);
 219        if (err)
 220                return err;
 221        if (len > klen)
 222                len = klen;
 223        if (len < 0 || len > sizeof(struct sockaddr_storage))
 224                return -EINVAL;
 225        if (len) {
 226                if (audit_sockaddr(klen, kaddr))
 227                        return -ENOMEM;
 228                if (copy_to_user(uaddr, kaddr, len))
 229                        return -EFAULT;
 230        }
 231        /*
 232         *      "fromlen shall refer to the value before truncation.."
 233         *                      1003.1g
 234         */
 235        return __put_user(klen, ulen);
 236}
 237
 238#define SOCKFS_MAGIC 0x534F434B
 239
 240static struct kmem_cache *sock_inode_cachep __read_mostly;
 241
 242static struct inode *sock_alloc_inode(struct super_block *sb)
 243{
 244        struct socket_alloc *ei;
 245
 246        ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
 247        if (!ei)
 248                return NULL;
 249        init_waitqueue_head(&ei->socket.wait);
 250
 251        ei->socket.fasync_list = NULL;
 252        ei->socket.state = SS_UNCONNECTED;
 253        ei->socket.flags = 0;
 254        ei->socket.ops = NULL;
 255        ei->socket.sk = NULL;
 256        ei->socket.file = NULL;
 257
 258        return &ei->vfs_inode;
 259}
 260
 261static void sock_destroy_inode(struct inode *inode)
 262{
 263        kmem_cache_free(sock_inode_cachep,
 264                        container_of(inode, struct socket_alloc, vfs_inode));
 265}
 266
 267static void init_once(void *foo)
 268{
 269        struct socket_alloc *ei = (struct socket_alloc *)foo;
 270
 271        inode_init_once(&ei->vfs_inode);
 272}
 273
 274static int init_inodecache(void)
 275{
 276        sock_inode_cachep = kmem_cache_create("sock_inode_cache",
 277                                              sizeof(struct socket_alloc),
 278                                              0,
 279                                              (SLAB_HWCACHE_ALIGN |
 280                                               SLAB_RECLAIM_ACCOUNT |
 281                                               SLAB_MEM_SPREAD),
 282                                              init_once);
 283        if (sock_inode_cachep == NULL)
 284                return -ENOMEM;
 285        return 0;
 286}
 287
 288static struct super_operations sockfs_ops = {
 289        .alloc_inode =  sock_alloc_inode,
 290        .destroy_inode =sock_destroy_inode,
 291        .statfs =       simple_statfs,
 292};
 293
 294static int sockfs_get_sb(struct file_system_type *fs_type,
 295                         int flags, const char *dev_name, void *data,
 296                         struct vfsmount *mnt)
 297{
 298        return get_sb_pseudo(fs_type, "socket:", &sockfs_ops, SOCKFS_MAGIC,
 299                             mnt);
 300}
 301
 302static struct vfsmount *sock_mnt __read_mostly;
 303
 304static struct file_system_type sock_fs_type = {
 305        .name =         "sockfs",
 306        .get_sb =       sockfs_get_sb,
 307        .kill_sb =      kill_anon_super,
 308};
 309
 310static int sockfs_delete_dentry(struct dentry *dentry)
 311{
 312        /*
 313         * At creation time, we pretended this dentry was hashed
 314         * (by clearing DCACHE_UNHASHED bit in d_flags)
 315         * At delete time, we restore the truth : not hashed.
 316         * (so that dput() can proceed correctly)
 317         */
 318        dentry->d_flags |= DCACHE_UNHASHED;
 319        return 0;
 320}
 321
 322/*
 323 * sockfs_dname() is called from d_path().
 324 */
 325static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
 326{
 327        return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]",
 328                                dentry->d_inode->i_ino);
 329}
 330
 331static const struct dentry_operations sockfs_dentry_operations = {
 332        .d_delete = sockfs_delete_dentry,
 333        .d_dname  = sockfs_dname,
 334};
 335
 336/*
 337 *      Obtains the first available file descriptor and sets it up for use.
 338 *
 339 *      These functions create file structures and maps them to fd space
 340 *      of the current process. On success it returns file descriptor
 341 *      and file struct implicitly stored in sock->file.
 342 *      Note that another thread may close file descriptor before we return
 343 *      from this function. We use the fact that now we do not refer
 344 *      to socket after mapping. If one day we will need it, this
 345 *      function will increment ref. count on file by 1.
 346 *
 347 *      In any case returned fd MAY BE not valid!
 348 *      This race condition is unavoidable
 349 *      with shared fd spaces, we cannot solve it inside kernel,
 350 *      but we take care of internal coherence yet.
 351 */
 352
 353static int sock_alloc_fd(struct file **filep, int flags)
 354{
 355        int fd;
 356
 357        fd = get_unused_fd_flags(flags);
 358        if (likely(fd >= 0)) {
 359                struct file *file = get_empty_filp();
 360
 361                *filep = file;
 362                if (unlikely(!file)) {
 363                        put_unused_fd(fd);
 364                        return -ENFILE;
 365                }
 366        } else
 367                *filep = NULL;
 368        return fd;
 369}
 370
 371static int sock_attach_fd(struct socket *sock, struct file *file, int flags)
 372{
 373        struct dentry *dentry;
 374        struct qstr name = { .name = "" };
 375
 376        dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name);
 377        if (unlikely(!dentry))
 378                return -ENOMEM;
 379
 380        dentry->d_op = &sockfs_dentry_operations;
 381        /*
 382         * We dont want to push this dentry into global dentry hash table.
 383         * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
 384         * This permits a working /proc/$pid/fd/XXX on sockets
 385         */
 386        dentry->d_flags &= ~DCACHE_UNHASHED;
 387        d_instantiate(dentry, SOCK_INODE(sock));
 388
 389        sock->file = file;
 390        init_file(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE,
 391                  &socket_file_ops);
 392        SOCK_INODE(sock)->i_fop = &socket_file_ops;
 393        file->f_flags = O_RDWR | (flags & O_NONBLOCK);
 394        file->f_pos = 0;
 395        file->private_data = sock;
 396
 397        return 0;
 398}
 399
 400int sock_map_fd(struct socket *sock, int flags)
 401{
 402        struct file *newfile;
 403        int fd = sock_alloc_fd(&newfile, flags);
 404
 405        if (likely(fd >= 0)) {
 406                int err = sock_attach_fd(sock, newfile, flags);
 407
 408                if (unlikely(err < 0)) {
 409                        put_filp(newfile);
 410                        put_unused_fd(fd);
 411                        return err;
 412                }
 413                fd_install(fd, newfile);
 414        }
 415        return fd;
 416}
 417
 418static struct socket *sock_from_file(struct file *file, int *err)
 419{
 420        if (file->f_op == &socket_file_ops)
 421                return file->private_data;      /* set in sock_map_fd */
 422
 423        *err = -ENOTSOCK;
 424        return NULL;
 425}
 426
 427/**
 428 *      sockfd_lookup   -       Go from a file number to its socket slot
 429 *      @fd: file handle
 430 *      @err: pointer to an error code return
 431 *
 432 *      The file handle passed in is locked and the socket it is bound
 433 *      too is returned. If an error occurs the err pointer is overwritten
 434 *      with a negative errno code and NULL is returned. The function checks
 435 *      for both invalid handles and passing a handle which is not a socket.
 436 *
 437 *      On a success the socket object pointer is returned.
 438 */
 439
 440struct socket *sockfd_lookup(int fd, int *err)
 441{
 442        struct file *file;
 443        struct socket *sock;
 444
 445        file = fget(fd);
 446        if (!file) {
 447                *err = -EBADF;
 448                return NULL;
 449        }
 450
 451        sock = sock_from_file(file, err);
 452        if (!sock)
 453                fput(file);
 454        return sock;
 455}
 456
 457static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
 458{
 459        struct file *file;
 460        struct socket *sock;
 461
 462        *err = -EBADF;
 463        file = fget_light(fd, fput_needed);
 464        if (file) {
 465                sock = sock_from_file(file, err);
 466                if (sock)
 467                        return sock;
 468                fput_light(file, *fput_needed);
 469        }
 470        return NULL;
 471}
 472
 473/**
 474 *      sock_alloc      -       allocate a socket
 475 *
 476 *      Allocate a new inode and socket object. The two are bound together
 477 *      and initialised. The socket is then returned. If we are out of inodes
 478 *      NULL is returned.
 479 */
 480
 481static struct socket *sock_alloc(void)
 482{
 483        struct inode *inode;
 484        struct socket *sock;
 485
 486        inode = new_inode(sock_mnt->mnt_sb);
 487        if (!inode)
 488                return NULL;
 489
 490        sock = SOCKET_I(inode);
 491
 492        inode->i_mode = S_IFSOCK | S_IRWXUGO;
 493        inode->i_uid = current_fsuid();
 494        inode->i_gid = current_fsgid();
 495
 496        percpu_add(sockets_in_use, 1);
 497        return sock;
 498}
 499
 500/*
 501 *      In theory you can't get an open on this inode, but /proc provides
 502 *      a back door. Remember to keep it shut otherwise you'll let the
 503 *      creepy crawlies in.
 504 */
 505
 506static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
 507{
 508        return -ENXIO;
 509}
 510
 511const struct file_operations bad_sock_fops = {
 512        .owner = THIS_MODULE,
 513        .open = sock_no_open,
 514};
 515
 516/**
 517 *      sock_release    -       close a socket
 518 *      @sock: socket to close
 519 *
 520 *      The socket is released from the protocol stack if it has a release
 521 *      callback, and the inode is then released if the socket is bound to
 522 *      an inode not a file.
 523 */
 524
 525void sock_release(struct socket *sock)
 526{
 527        if (sock->ops) {
 528                struct module *owner = sock->ops->owner;
 529
 530                sock->ops->release(sock);
 531                sock->ops = NULL;
 532                module_put(owner);
 533        }
 534
 535        if (sock->fasync_list)
 536                printk(KERN_ERR "sock_release: fasync list not empty!\n");
 537
 538        percpu_sub(sockets_in_use, 1);
 539        if (!sock->file) {
 540                iput(SOCK_INODE(sock));
 541                return;
 542        }
 543        sock->file = NULL;
 544}
 545
 546int sock_tx_timestamp(struct msghdr *msg, struct sock *sk,
 547                      union skb_shared_tx *shtx)
 548{
 549        shtx->flags = 0;
 550        if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
 551                shtx->hardware = 1;
 552        if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
 553                shtx->software = 1;
 554        return 0;
 555}
 556EXPORT_SYMBOL(sock_tx_timestamp);
 557
 558static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
 559                                 struct msghdr *msg, size_t size)
 560{
 561        struct sock_iocb *si = kiocb_to_siocb(iocb);
 562        int err;
 563
 564        si->sock = sock;
 565        si->scm = NULL;
 566        si->msg = msg;
 567        si->size = size;
 568
 569        err = security_socket_sendmsg(sock, msg, size);
 570        if (err)
 571                return err;
 572
 573        return sock->ops->sendmsg(iocb, sock, msg, size);
 574}
 575
 576int sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 577{
 578        struct kiocb iocb;
 579        struct sock_iocb siocb;
 580        int ret;
 581
 582        init_sync_kiocb(&iocb, NULL);
 583        iocb.private = &siocb;
 584        ret = __sock_sendmsg(&iocb, sock, msg, size);
 585        if (-EIOCBQUEUED == ret)
 586                ret = wait_on_sync_kiocb(&iocb);
 587        return ret;
 588}
 589
 590int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 591                   struct kvec *vec, size_t num, size_t size)
 592{
 593        mm_segment_t oldfs = get_fs();
 594        int result;
 595
 596        set_fs(KERNEL_DS);
 597        /*
 598         * the following is safe, since for compiler definitions of kvec and
 599         * iovec are identical, yielding the same in-core layout and alignment
 600         */
 601        msg->msg_iov = (struct iovec *)vec;
 602        msg->msg_iovlen = num;
 603        result = sock_sendmsg(sock, msg, size);
 604        set_fs(oldfs);
 605        return result;
 606}
 607
 608static int ktime2ts(ktime_t kt, struct timespec *ts)
 609{
 610        if (kt.tv64) {
 611                *ts = ktime_to_timespec(kt);
 612                return 1;
 613        } else {
 614                return 0;
 615        }
 616}
 617
 618/*
 619 * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
 620 */
 621void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 622        struct sk_buff *skb)
 623{
 624        int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
 625        struct timespec ts[3];
 626        int empty = 1;
 627        struct skb_shared_hwtstamps *shhwtstamps =
 628                skb_hwtstamps(skb);
 629
 630        /* Race occurred between timestamp enabling and packet
 631           receiving.  Fill in the current time for now. */
 632        if (need_software_tstamp && skb->tstamp.tv64 == 0)
 633                __net_timestamp(skb);
 634
 635        if (need_software_tstamp) {
 636                if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
 637                        struct timeval tv;
 638                        skb_get_timestamp(skb, &tv);
 639                        put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
 640                                 sizeof(tv), &tv);
 641                } else {
 642                        struct timespec ts;
 643                        skb_get_timestampns(skb, &ts);
 644                        put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
 645                                 sizeof(ts), &ts);
 646                }
 647        }
 648
 649
 650        memset(ts, 0, sizeof(ts));
 651        if (skb->tstamp.tv64 &&
 652            sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) {
 653                skb_get_timestampns(skb, ts + 0);
 654                empty = 0;
 655        }
 656        if (shhwtstamps) {
 657                if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE) &&
 658                    ktime2ts(shhwtstamps->syststamp, ts + 1))
 659                        empty = 0;
 660                if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE) &&
 661                    ktime2ts(shhwtstamps->hwtstamp, ts + 2))
 662                        empty = 0;
 663        }
 664        if (!empty)
 665                put_cmsg(msg, SOL_SOCKET,
 666                         SCM_TIMESTAMPING, sizeof(ts), &ts);
 667}
 668
 669EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
 670
 671static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 672                                 struct msghdr *msg, size_t size, int flags)
 673{
 674        int err;
 675        struct sock_iocb *si = kiocb_to_siocb(iocb);
 676
 677        si->sock = sock;
 678        si->scm = NULL;
 679        si->msg = msg;
 680        si->size = size;
 681        si->flags = flags;
 682
 683        err = security_socket_recvmsg(sock, msg, size, flags);
 684        if (err)
 685                return err;
 686
 687        return sock->ops->recvmsg(iocb, sock, msg, size, flags);
 688}
 689
 690int sock_recvmsg(struct socket *sock, struct msghdr *msg,
 691                 size_t size, int flags)
 692{
 693        struct kiocb iocb;
 694        struct sock_iocb siocb;
 695        int ret;
 696
 697        init_sync_kiocb(&iocb, NULL);
 698        iocb.private = &siocb;
 699        ret = __sock_recvmsg(&iocb, sock, msg, size, flags);
 700        if (-EIOCBQUEUED == ret)
 701                ret = wait_on_sync_kiocb(&iocb);
 702        return ret;
 703}
 704
 705int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 706                   struct kvec *vec, size_t num, size_t size, int flags)
 707{
 708        mm_segment_t oldfs = get_fs();
 709        int result;
 710
 711        set_fs(KERNEL_DS);
 712        /*
 713         * the following is safe, since for compiler definitions of kvec and
 714         * iovec are identical, yielding the same in-core layout and alignment
 715         */
 716        msg->msg_iov = (struct iovec *)vec, msg->msg_iovlen = num;
 717        result = sock_recvmsg(sock, msg, size, flags);
 718        set_fs(oldfs);
 719        return result;
 720}
 721
 722static void sock_aio_dtor(struct kiocb *iocb)
 723{
 724        kfree(iocb->private);
 725}
 726
 727static ssize_t sock_sendpage(struct file *file, struct page *page,
 728                             int offset, size_t size, loff_t *ppos, int more)
 729{
 730        struct socket *sock;
 731        int flags;
 732
 733        sock = file->private_data;
 734
 735        flags = !(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
 736        if (more)
 737                flags |= MSG_MORE;
 738
 739        return sock->ops->sendpage(sock, page, offset, size, flags);
 740}
 741
 742static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
 743                                struct pipe_inode_info *pipe, size_t len,
 744                                unsigned int flags)
 745{
 746        struct socket *sock = file->private_data;
 747
 748        if (unlikely(!sock->ops->splice_read))
 749                return -EINVAL;
 750
 751        return sock->ops->splice_read(sock, ppos, pipe, len, flags);
 752}
 753
 754static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb,
 755                                         struct sock_iocb *siocb)
 756{
 757        if (!is_sync_kiocb(iocb)) {
 758                siocb = kmalloc(sizeof(*siocb), GFP_KERNEL);
 759                if (!siocb)
 760                        return NULL;
 761                iocb->ki_dtor = sock_aio_dtor;
 762        }
 763
 764        siocb->kiocb = iocb;
 765        iocb->private = siocb;
 766        return siocb;
 767}
 768
 769static ssize_t do_sock_read(struct msghdr *msg, struct kiocb *iocb,
 770                struct file *file, const struct iovec *iov,
 771                unsigned long nr_segs)
 772{
 773        struct socket *sock = file->private_data;
 774        size_t size = 0;
 775        int i;
 776
 777        for (i = 0; i < nr_segs; i++)
 778                size += iov[i].iov_len;
 779
 780        msg->msg_name = NULL;
 781        msg->msg_namelen = 0;
 782        msg->msg_control = NULL;
 783        msg->msg_controllen = 0;
 784        msg->msg_iov = (struct iovec *)iov;
 785        msg->msg_iovlen = nr_segs;
 786        msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
 787
 788        return __sock_recvmsg(iocb, sock, msg, size, msg->msg_flags);
 789}
 790
 791static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
 792                                unsigned long nr_segs, loff_t pos)
 793{
 794        struct sock_iocb siocb, *x;
 795
 796        if (pos != 0)
 797                return -ESPIPE;
 798
 799        if (iocb->ki_left == 0) /* Match SYS5 behaviour */
 800                return 0;
 801
 802
 803        x = alloc_sock_iocb(iocb, &siocb);
 804        if (!x)
 805                return -ENOMEM;
 806        return do_sock_read(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
 807}
 808
 809static ssize_t do_sock_write(struct msghdr *msg, struct kiocb *iocb,
 810                        struct file *file, const struct iovec *iov,
 811                        unsigned long nr_segs)
 812{
 813        struct socket *sock = file->private_data;
 814        size_t size = 0;
 815        int i;
 816
 817        for (i = 0; i < nr_segs; i++)
 818                size += iov[i].iov_len;
 819
 820        msg->msg_name = NULL;
 821        msg->msg_namelen = 0;
 822        msg->msg_control = NULL;
 823        msg->msg_controllen = 0;
 824        msg->msg_iov = (struct iovec *)iov;
 825        msg->msg_iovlen = nr_segs;
 826        msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
 827        if (sock->type == SOCK_SEQPACKET)
 828                msg->msg_flags |= MSG_EOR;
 829
 830        return __sock_sendmsg(iocb, sock, msg, size);
 831}
 832
 833static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
 834                          unsigned long nr_segs, loff_t pos)
 835{
 836        struct sock_iocb siocb, *x;
 837
 838        if (pos != 0)
 839                return -ESPIPE;
 840
 841        x = alloc_sock_iocb(iocb, &siocb);
 842        if (!x)
 843                return -ENOMEM;
 844
 845        return do_sock_write(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
 846}
 847
 848/*
 849 * Atomic setting of ioctl hooks to avoid race
 850 * with module unload.
 851 */
 852
 853static DEFINE_MUTEX(br_ioctl_mutex);
 854static int (*br_ioctl_hook) (struct net *, unsigned int cmd, void __user *arg) = NULL;
 855
 856void brioctl_set(int (*hook) (struct net *, unsigned int, void __user *))
 857{
 858        mutex_lock(&br_ioctl_mutex);
 859        br_ioctl_hook = hook;
 860        mutex_unlock(&br_ioctl_mutex);
 861}
 862
 863EXPORT_SYMBOL(brioctl_set);
 864
 865static DEFINE_MUTEX(vlan_ioctl_mutex);
 866static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
 867
 868void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
 869{
 870        mutex_lock(&vlan_ioctl_mutex);
 871        vlan_ioctl_hook = hook;
 872        mutex_unlock(&vlan_ioctl_mutex);
 873}
 874
 875EXPORT_SYMBOL(vlan_ioctl_set);
 876
 877static DEFINE_MUTEX(dlci_ioctl_mutex);
 878static int (*dlci_ioctl_hook) (unsigned int, void __user *);
 879
 880void dlci_ioctl_set(int (*hook) (unsigned int, void __user *))
 881{
 882        mutex_lock(&dlci_ioctl_mutex);
 883        dlci_ioctl_hook = hook;
 884        mutex_unlock(&dlci_ioctl_mutex);
 885}
 886
 887EXPORT_SYMBOL(dlci_ioctl_set);
 888
 889/*
 890 *      With an ioctl, arg may well be a user mode pointer, but we don't know
 891 *      what to do with it - that's up to the protocol still.
 892 */
 893
 894static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 895{
 896        struct socket *sock;
 897        struct sock *sk;
 898        void __user *argp = (void __user *)arg;
 899        int pid, err;
 900        struct net *net;
 901
 902        sock = file->private_data;
 903        sk = sock->sk;
 904        net = sock_net(sk);
 905        if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
 906                err = dev_ioctl(net, cmd, argp);
 907        } else
 908#ifdef CONFIG_WIRELESS_EXT
 909        if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
 910                err = dev_ioctl(net, cmd, argp);
 911        } else
 912#endif                          /* CONFIG_WIRELESS_EXT */
 913                switch (cmd) {
 914                case FIOSETOWN:
 915                case SIOCSPGRP:
 916                        err = -EFAULT;
 917                        if (get_user(pid, (int __user *)argp))
 918                                break;
 919                        err = f_setown(sock->file, pid, 1);
 920                        break;
 921                case FIOGETOWN:
 922                case SIOCGPGRP:
 923                        err = put_user(f_getown(sock->file),
 924                                       (int __user *)argp);
 925                        break;
 926                case SIOCGIFBR:
 927                case SIOCSIFBR:
 928                case SIOCBRADDBR:
 929                case SIOCBRDELBR:
 930                        err = -ENOPKG;
 931                        if (!br_ioctl_hook)
 932                                request_module("bridge");
 933
 934                        mutex_lock(&br_ioctl_mutex);
 935                        if (br_ioctl_hook)
 936                                err = br_ioctl_hook(net, cmd, argp);
 937                        mutex_unlock(&br_ioctl_mutex);
 938                        break;
 939                case SIOCGIFVLAN:
 940                case SIOCSIFVLAN:
 941                        err = -ENOPKG;
 942                        if (!vlan_ioctl_hook)
 943                                request_module("8021q");
 944
 945                        mutex_lock(&vlan_ioctl_mutex);
 946                        if (vlan_ioctl_hook)
 947                                err = vlan_ioctl_hook(net, argp);
 948                        mutex_unlock(&vlan_ioctl_mutex);
 949                        break;
 950                case SIOCADDDLCI:
 951                case SIOCDELDLCI:
 952                        err = -ENOPKG;
 953                        if (!dlci_ioctl_hook)
 954                                request_module("dlci");
 955
 956                        mutex_lock(&dlci_ioctl_mutex);
 957                        if (dlci_ioctl_hook)
 958                                err = dlci_ioctl_hook(cmd, argp);
 959                        mutex_unlock(&dlci_ioctl_mutex);
 960                        break;
 961                default:
 962                        err = sock->ops->ioctl(sock, cmd, arg);
 963
 964                        /*
 965                         * If this ioctl is unknown try to hand it down
 966                         * to the NIC driver.
 967                         */
 968                        if (err == -ENOIOCTLCMD)
 969                                err = dev_ioctl(net, cmd, argp);
 970                        break;
 971                }
 972        return err;
 973}
 974
 975int sock_create_lite(int family, int type, int protocol, struct socket **res)
 976{
 977        int err;
 978        struct socket *sock = NULL;
 979
 980        err = security_socket_create(family, type, protocol, 1);
 981        if (err)
 982                goto out;
 983
 984        sock = sock_alloc();
 985        if (!sock) {
 986                err = -ENOMEM;
 987                goto out;
 988        }
 989
 990        sock->type = type;
 991        err = security_socket_post_create(sock, family, type, protocol, 1);
 992        if (err)
 993                goto out_release;
 994
 995out:
 996        *res = sock;
 997        return err;
 998out_release:
 999        sock_release(sock);
1000        sock = NULL;
1001        goto out;
1002}
1003
1004/* No kernel lock held - perfect */
1005static unsigned int sock_poll(struct file *file, poll_table *wait)
1006{
1007        struct socket *sock;
1008
1009        /*
1010         *      We can't return errors to poll, so it's either yes or no.
1011         */
1012        sock = file->private_data;
1013        return sock->ops->poll(file, sock, wait);
1014}
1015
1016static int sock_mmap(struct file *file, struct vm_area_struct *vma)
1017{
1018        struct socket *sock = file->private_data;
1019
1020        return sock->ops->mmap(file, sock, vma);
1021}
1022
1023static int sock_close(struct inode *inode, struct file *filp)
1024{
1025        /*
1026         *      It was possible the inode is NULL we were
1027         *      closing an unfinished socket.
1028         */
1029
1030        if (!inode) {
1031                printk(KERN_DEBUG "sock_close: NULL inode\n");
1032                return 0;
1033        }
1034        sock_release(SOCKET_I(inode));
1035        return 0;
1036}
1037
1038/*
1039 *      Update the socket async list
1040 *
1041 *      Fasync_list locking strategy.
1042 *
1043 *      1. fasync_list is modified only under process context socket lock
1044 *         i.e. under semaphore.
1045 *      2. fasync_list is used under read_lock(&sk->sk_callback_lock)
1046 *         or under socket lock.
1047 *      3. fasync_list can be used from softirq context, so that
1048 *         modification under socket lock have to be enhanced with
1049 *         write_lock_bh(&sk->sk_callback_lock).
1050 *                                                      --ANK (990710)
1051 */
1052
1053static int sock_fasync(int fd, struct file *filp, int on)
1054{
1055        struct fasync_struct *fa, *fna = NULL, **prev;
1056        struct socket *sock;
1057        struct sock *sk;
1058
1059        if (on) {
1060                fna = kmalloc(sizeof(struct fasync_struct), GFP_KERNEL);
1061                if (fna == NULL)
1062                        return -ENOMEM;
1063        }
1064
1065        sock = filp->private_data;
1066
1067        sk = sock->sk;
1068        if (sk == NULL) {
1069                kfree(fna);
1070                return -EINVAL;
1071        }
1072
1073        lock_sock(sk);
1074
1075        spin_lock(&filp->f_lock);
1076        if (on)
1077                filp->f_flags |= FASYNC;
1078        else
1079                filp->f_flags &= ~FASYNC;
1080        spin_unlock(&filp->f_lock);
1081
1082        prev = &(sock->fasync_list);
1083
1084        for (fa = *prev; fa != NULL; prev = &fa->fa_next, fa = *prev)
1085                if (fa->fa_file == filp)
1086                        break;
1087
1088        if (on) {
1089                if (fa != NULL) {
1090                        write_lock_bh(&sk->sk_callback_lock);
1091                        fa->fa_fd = fd;
1092                        write_unlock_bh(&sk->sk_callback_lock);
1093
1094                        kfree(fna);
1095                        goto out;
1096                }
1097                fna->fa_file = filp;
1098                fna->fa_fd = fd;
1099                fna->magic = FASYNC_MAGIC;
1100                fna->fa_next = sock->fasync_list;
1101                write_lock_bh(&sk->sk_callback_lock);
1102                sock->fasync_list = fna;
1103                write_unlock_bh(&sk->sk_callback_lock);
1104        } else {
1105                if (fa != NULL) {
1106                        write_lock_bh(&sk->sk_callback_lock);
1107                        *prev = fa->fa_next;
1108                        write_unlock_bh(&sk->sk_callback_lock);
1109                        kfree(fa);
1110                }
1111        }
1112
1113out:
1114        release_sock(sock->sk);
1115        return 0;
1116}
1117
1118/* This function may be called only under socket lock or callback_lock */
1119
1120int sock_wake_async(struct socket *sock, int how, int band)
1121{
1122        if (!sock || !sock->fasync_list)
1123                return -1;
1124        switch (how) {
1125        case SOCK_WAKE_WAITD:
1126                if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
1127                        break;
1128                goto call_kill;
1129        case SOCK_WAKE_SPACE:
1130                if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
1131                        break;
1132                /* fall through */
1133        case SOCK_WAKE_IO:
1134call_kill:
1135                __kill_fasync(sock->fasync_list, SIGIO, band);
1136                break;
1137        case SOCK_WAKE_URG:
1138                __kill_fasync(sock->fasync_list, SIGURG, band);
1139        }
1140        return 0;
1141}
1142
1143static int __sock_create(struct net *net, int family, int type, int protocol,
1144                         struct socket **res, int kern)
1145{
1146        int err;
1147        struct socket *sock;
1148        const struct net_proto_family *pf;
1149
1150        /*
1151         *      Check protocol is in range
1152         */
1153        if (family < 0 || family >= NPROTO)
1154                return -EAFNOSUPPORT;
1155        if (type < 0 || type >= SOCK_MAX)
1156                return -EINVAL;
1157
1158        /* Compatibility.
1159
1160           This uglymoron is moved from INET layer to here to avoid
1161           deadlock in module load.
1162         */
1163        if (family == PF_INET && type == SOCK_PACKET) {
1164                static int warned;
1165                if (!warned) {
1166                        warned = 1;
1167                        printk(KERN_INFO "%s uses obsolete (PF_INET,SOCK_PACKET)\n",
1168                               current->comm);
1169                }
1170                family = PF_PACKET;
1171        }
1172
1173        err = security_socket_create(family, type, protocol, kern);
1174        if (err)
1175                return err;
1176
1177        /*
1178         *      Allocate the socket and allow the family to set things up. if
1179         *      the protocol is 0, the family is instructed to select an appropriate
1180         *      default.
1181         */
1182        sock = sock_alloc();
1183        if (!sock) {
1184                if (net_ratelimit())
1185                        printk(KERN_WARNING "socket: no more sockets\n");
1186                return -ENFILE; /* Not exactly a match, but its the
1187                                   closest posix thing */
1188        }
1189
1190        sock->type = type;
1191
1192#ifdef CONFIG_MODULES
1193        /* Attempt to load a protocol module if the find failed.
1194         *
1195         * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
1196         * requested real, full-featured networking support upon configuration.
1197         * Otherwise module support will break!
1198         */
1199        if (net_families[family] == NULL)
1200                request_module("net-pf-%d", family);
1201#endif
1202
1203        rcu_read_lock();
1204        pf = rcu_dereference(net_families[family]);
1205        err = -EAFNOSUPPORT;
1206        if (!pf)
1207                goto out_release;
1208
1209        /*
1210         * We will call the ->create function, that possibly is in a loadable
1211         * module, so we have to bump that loadable module refcnt first.
1212         */
1213        if (!try_module_get(pf->owner))
1214                goto out_release;
1215
1216        /* Now protected by module ref count */
1217        rcu_read_unlock();
1218
1219        err = pf->create(net, sock, protocol);
1220        if (err < 0)
1221                goto out_module_put;
1222
1223        /*
1224         * Now to bump the refcnt of the [loadable] module that owns this
1225         * socket at sock_release time we decrement its refcnt.
1226         */
1227        if (!try_module_get(sock->ops->owner))
1228                goto out_module_busy;
1229
1230        /*
1231         * Now that we're done with the ->create function, the [loadable]
1232         * module can have its refcnt decremented
1233         */
1234        module_put(pf->owner);
1235        err = security_socket_post_create(sock, family, type, protocol, kern);
1236        if (err)
1237                goto out_sock_release;
1238        *res = sock;
1239
1240        return 0;
1241
1242out_module_busy:
1243        err = -EAFNOSUPPORT;
1244out_module_put:
1245        sock->ops = NULL;
1246        module_put(pf->owner);
1247out_sock_release:
1248        sock_release(sock);
1249        return err;
1250
1251out_release:
1252        rcu_read_unlock();
1253        goto out_sock_release;
1254}
1255
1256int sock_create(int family, int type, int protocol, struct socket **res)
1257{
1258        return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
1259}
1260
1261int sock_create_kern(int family, int type, int protocol, struct socket **res)
1262{
1263        return __sock_create(&init_net, family, type, protocol, res, 1);
1264}
1265
1266SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
1267{
1268        int retval;
1269        struct socket *sock;
1270        int flags;
1271
1272        /* Check the SOCK_* constants for consistency.  */
1273        BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
1274        BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
1275        BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
1276        BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
1277
1278        flags = type & ~SOCK_TYPE_MASK;
1279        if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1280                return -EINVAL;
1281        type &= SOCK_TYPE_MASK;
1282
1283        if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1284                flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1285
1286        retval = sock_create(family, type, protocol, &sock);
1287        if (retval < 0)
1288                goto out;
1289
1290        retval = sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
1291        if (retval < 0)
1292                goto out_release;
1293
1294out:
1295        /* It may be already another descriptor 8) Not kernel problem. */
1296        return retval;
1297
1298out_release:
1299        sock_release(sock);
1300        return retval;
1301}
1302
1303/*
1304 *      Create a pair of connected sockets.
1305 */
1306
1307SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
1308                int __user *, usockvec)
1309{
1310        struct socket *sock1, *sock2;
1311        int fd1, fd2, err;
1312        struct file *newfile1, *newfile2;
1313        int flags;
1314
1315        flags = type & ~SOCK_TYPE_MASK;
1316        if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1317                return -EINVAL;
1318        type &= SOCK_TYPE_MASK;
1319
1320        if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1321                flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1322
1323        /*
1324         * Obtain the first socket and check if the underlying protocol
1325         * supports the socketpair call.
1326         */
1327
1328        err = sock_create(family, type, protocol, &sock1);
1329        if (err < 0)
1330                goto out;
1331
1332        err = sock_create(family, type, protocol, &sock2);
1333        if (err < 0)
1334                goto out_release_1;
1335
1336        err = sock1->ops->socketpair(sock1, sock2);
1337        if (err < 0)
1338                goto out_release_both;
1339
1340        fd1 = sock_alloc_fd(&newfile1, flags & O_CLOEXEC);
1341        if (unlikely(fd1 < 0)) {
1342                err = fd1;
1343                goto out_release_both;
1344        }
1345
1346        fd2 = sock_alloc_fd(&newfile2, flags & O_CLOEXEC);
1347        if (unlikely(fd2 < 0)) {
1348                err = fd2;
1349                put_filp(newfile1);
1350                put_unused_fd(fd1);
1351                goto out_release_both;
1352        }
1353
1354        err = sock_attach_fd(sock1, newfile1, flags & O_NONBLOCK);
1355        if (unlikely(err < 0)) {
1356                goto out_fd2;
1357        }
1358
1359        err = sock_attach_fd(sock2, newfile2, flags & O_NONBLOCK);
1360        if (unlikely(err < 0)) {
1361                fput(newfile1);
1362                goto out_fd1;
1363        }
1364
1365        audit_fd_pair(fd1, fd2);
1366        fd_install(fd1, newfile1);
1367        fd_install(fd2, newfile2);
1368        /* fd1 and fd2 may be already another descriptors.
1369         * Not kernel problem.
1370         */
1371
1372        err = put_user(fd1, &usockvec[0]);
1373        if (!err)
1374                err = put_user(fd2, &usockvec[1]);
1375        if (!err)
1376                return 0;
1377
1378        sys_close(fd2);
1379        sys_close(fd1);
1380        return err;
1381
1382out_release_both:
1383        sock_release(sock2);
1384out_release_1:
1385        sock_release(sock1);
1386out:
1387        return err;
1388
1389out_fd2:
1390        put_filp(newfile1);
1391        sock_release(sock1);
1392out_fd1:
1393        put_filp(newfile2);
1394        sock_release(sock2);
1395        put_unused_fd(fd1);
1396        put_unused_fd(fd2);
1397        goto out;
1398}
1399
1400/*
1401 *      Bind a name to a socket. Nothing much to do here since it's
1402 *      the protocol's responsibility to handle the local address.
1403 *
1404 *      We move the socket address to kernel space before we call
1405 *      the protocol layer (having also checked the address is ok).
1406 */
1407
1408SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
1409{
1410        struct socket *sock;
1411        struct sockaddr_storage address;
1412        int err, fput_needed;
1413
1414        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1415        if (sock) {
1416                err = move_addr_to_kernel(umyaddr, addrlen, (struct sockaddr *)&address);
1417                if (err >= 0) {
1418                        err = security_socket_bind(sock,
1419                                                   (struct sockaddr *)&address,
1420                                                   addrlen);
1421                        if (!err)
1422                                err = sock->ops->bind(sock,
1423                                                      (struct sockaddr *)
1424                                                      &address, addrlen);
1425                }
1426                fput_light(sock->file, fput_needed);
1427        }
1428        return err;
1429}
1430
1431/*
1432 *      Perform a listen. Basically, we allow the protocol to do anything
1433 *      necessary for a listen, and if that works, we mark the socket as
1434 *      ready for listening.
1435 */
1436
1437SYSCALL_DEFINE2(listen, int, fd, int, backlog)
1438{
1439        struct socket *sock;
1440        int err, fput_needed;
1441        int somaxconn;
1442
1443        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1444        if (sock) {
1445                somaxconn = sock_net(sock->sk)->core.sysctl_somaxconn;
1446                if ((unsigned)backlog > somaxconn)
1447                        backlog = somaxconn;
1448
1449                err = security_socket_listen(sock, backlog);
1450                if (!err)
1451                        err = sock->ops->listen(sock, backlog);
1452
1453                fput_light(sock->file, fput_needed);
1454        }
1455        return err;
1456}
1457
1458/*
1459 *      For accept, we attempt to create a new socket, set up the link
1460 *      with the client, wake up the client, then return the new
1461 *      connected fd. We collect the address of the connector in kernel
1462 *      space and move it to user at the very end. This is unclean because
1463 *      we open the socket then return an error.
1464 *
1465 *      1003.1g adds the ability to recvmsg() to query connection pending
1466 *      status to recvmsg. We need to add that support in a way thats
1467 *      clean when we restucture accept also.
1468 */
1469
1470SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
1471                int __user *, upeer_addrlen, int, flags)
1472{
1473        struct socket *sock, *newsock;
1474        struct file *newfile;
1475        int err, len, newfd, fput_needed;
1476        struct sockaddr_storage address;
1477
1478        if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1479                return -EINVAL;
1480
1481        if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1482                flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1483
1484        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1485        if (!sock)
1486                goto out;
1487
1488        err = -ENFILE;
1489        if (!(newsock = sock_alloc()))
1490                goto out_put;
1491
1492        newsock->type = sock->type;
1493        newsock->ops = sock->ops;
1494
1495        /*
1496         * We don't need try_module_get here, as the listening socket (sock)
1497         * has the protocol module (sock->ops->owner) held.
1498         */
1499        __module_get(newsock->ops->owner);
1500
1501        newfd = sock_alloc_fd(&newfile, flags & O_CLOEXEC);
1502        if (unlikely(newfd < 0)) {
1503                err = newfd;
1504                sock_release(newsock);
1505                goto out_put;
1506        }
1507
1508        err = sock_attach_fd(newsock, newfile, flags & O_NONBLOCK);
1509        if (err < 0)
1510                goto out_fd_simple;
1511
1512        err = security_socket_accept(sock, newsock);
1513        if (err)
1514                goto out_fd;
1515
1516        err = sock->ops->accept(sock, newsock, sock->file->f_flags);
1517        if (err < 0)
1518                goto out_fd;
1519
1520        if (upeer_sockaddr) {
1521                if (newsock->ops->getname(newsock, (struct sockaddr *)&address,
1522                                          &len, 2) < 0) {
1523                        err = -ECONNABORTED;
1524                        goto out_fd;
1525                }
1526                err = move_addr_to_user((struct sockaddr *)&address,
1527                                        len, upeer_sockaddr, upeer_addrlen);
1528                if (err < 0)
1529                        goto out_fd;
1530        }
1531
1532        /* File flags are not inherited via accept() unlike another OSes. */
1533
1534        fd_install(newfd, newfile);
1535        err = newfd;
1536
1537out_put:
1538        fput_light(sock->file, fput_needed);
1539out:
1540        return err;
1541out_fd_simple:
1542        sock_release(newsock);
1543        put_filp(newfile);
1544        put_unused_fd(newfd);
1545        goto out_put;
1546out_fd:
1547        fput(newfile);
1548        put_unused_fd(newfd);
1549        goto out_put;
1550}
1551
1552SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
1553                int __user *, upeer_addrlen)
1554{
1555        return sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
1556}
1557
1558/*
1559 *      Attempt to connect to a socket with the server address.  The address
1560 *      is in user space so we verify it is OK and move it to kernel space.
1561 *
1562 *      For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
1563 *      break bindings
1564 *
1565 *      NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
1566 *      other SEQPACKET protocols that take time to connect() as it doesn't
1567 *      include the -EINPROGRESS status for such sockets.
1568 */
1569
1570SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
1571                int, addrlen)
1572{
1573        struct socket *sock;
1574        struct sockaddr_storage address;
1575        int err, fput_needed;
1576
1577        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1578        if (!sock)
1579                goto out;
1580        err = move_addr_to_kernel(uservaddr, addrlen, (struct sockaddr *)&address);
1581        if (err < 0)
1582                goto out_put;
1583
1584        err =
1585            security_socket_connect(sock, (struct sockaddr *)&address, addrlen);
1586        if (err)
1587                goto out_put;
1588
1589        err = sock->ops->connect(sock, (struct sockaddr *)&address, addrlen,
1590                                 sock->file->f_flags);
1591out_put:
1592        fput_light(sock->file, fput_needed);
1593out:
1594        return err;
1595}
1596
1597/*
1598 *      Get the local address ('name') of a socket object. Move the obtained
1599 *      name to user space.
1600 */
1601
1602SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
1603                int __user *, usockaddr_len)
1604{
1605        struct socket *sock;
1606        struct sockaddr_storage address;
1607        int len, err, fput_needed;
1608
1609        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1610        if (!sock)
1611                goto out;
1612
1613        err = security_socket_getsockname(sock);
1614        if (err)
1615                goto out_put;
1616
1617        err = sock->ops->getname(sock, (struct sockaddr *)&address, &len, 0);
1618        if (err)
1619                goto out_put;
1620        err = move_addr_to_user((struct sockaddr *)&address, len, usockaddr, usockaddr_len);
1621
1622out_put:
1623        fput_light(sock->file, fput_needed);
1624out:
1625        return err;
1626}
1627
1628/*
1629 *      Get the remote address ('name') of a socket object. Move the obtained
1630 *      name to user space.
1631 */
1632
1633SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
1634                int __user *, usockaddr_len)
1635{
1636        struct socket *sock;
1637        struct sockaddr_storage address;
1638        int len, err, fput_needed;
1639
1640        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1641        if (sock != NULL) {
1642                err = security_socket_getpeername(sock);
1643                if (err) {
1644                        fput_light(sock->file, fput_needed);
1645                        return err;
1646                }
1647
1648                err =
1649                    sock->ops->getname(sock, (struct sockaddr *)&address, &len,
1650                                       1);
1651                if (!err)
1652                        err = move_addr_to_user((struct sockaddr *)&address, len, usockaddr,
1653                                                usockaddr_len);
1654                fput_light(sock->file, fput_needed);
1655        }
1656        return err;
1657}
1658
1659/*
1660 *      Send a datagram to a given address. We move the address into kernel
1661 *      space and check the user space data area is readable before invoking
1662 *      the protocol.
1663 */
1664
1665SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
1666                unsigned, flags, struct sockaddr __user *, addr,
1667                int, addr_len)
1668{
1669        struct socket *sock;
1670        struct sockaddr_storage address;
1671        int err;
1672        struct msghdr msg;
1673        struct iovec iov;
1674        int fput_needed;
1675
1676        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1677        if (!sock)
1678                goto out;
1679
1680        iov.iov_base = buff;
1681        iov.iov_len = len;
1682        msg.msg_name = NULL;
1683        msg.msg_iov = &iov;
1684        msg.msg_iovlen = 1;
1685        msg.msg_control = NULL;
1686        msg.msg_controllen = 0;
1687        msg.msg_namelen = 0;
1688        if (addr) {
1689                err = move_addr_to_kernel(addr, addr_len, (struct sockaddr *)&address);
1690                if (err < 0)
1691                        goto out_put;
1692                msg.msg_name = (struct sockaddr *)&address;
1693                msg.msg_namelen = addr_len;
1694        }
1695        if (sock->file->f_flags & O_NONBLOCK)
1696                flags |= MSG_DONTWAIT;
1697        msg.msg_flags = flags;
1698        err = sock_sendmsg(sock, &msg, len);
1699
1700out_put:
1701        fput_light(sock->file, fput_needed);
1702out:
1703        return err;
1704}
1705
1706/*
1707 *      Send a datagram down a socket.
1708 */
1709
1710SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
1711                unsigned, flags)
1712{
1713        return sys_sendto(fd, buff, len, flags, NULL, 0);
1714}
1715
1716/*
1717 *      Receive a frame from the socket and optionally record the address of the
1718 *      sender. We verify the buffers are writable and if needed move the
1719 *      sender address from kernel to user space.
1720 */
1721
1722SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
1723                unsigned, flags, struct sockaddr __user *, addr,
1724                int __user *, addr_len)
1725{
1726        struct socket *sock;
1727        struct iovec iov;
1728        struct msghdr msg;
1729        struct sockaddr_storage address;
1730        int err, err2;
1731        int fput_needed;
1732
1733        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1734        if (!sock)
1735                goto out;
1736
1737        msg.msg_control = NULL;
1738        msg.msg_controllen = 0;
1739        msg.msg_iovlen = 1;
1740        msg.msg_iov = &iov;
1741        iov.iov_len = size;
1742        iov.iov_base = ubuf;
1743        msg.msg_name = (struct sockaddr *)&address;
1744        msg.msg_namelen = sizeof(address);
1745        if (sock->file->f_flags & O_NONBLOCK)
1746                flags |= MSG_DONTWAIT;
1747        err = sock_recvmsg(sock, &msg, size, flags);
1748
1749        if (err >= 0 && addr != NULL) {
1750                err2 = move_addr_to_user((struct sockaddr *)&address,
1751                                         msg.msg_namelen, addr, addr_len);
1752                if (err2 < 0)
1753                        err = err2;
1754        }
1755
1756        fput_light(sock->file, fput_needed);
1757out:
1758        return err;
1759}
1760
1761/*
1762 *      Receive a datagram from a socket.
1763 */
1764
1765asmlinkage long sys_recv(int fd, void __user *ubuf, size_t size,
1766                         unsigned flags)
1767{
1768        return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
1769}
1770
1771/*
1772 *      Set a socket option. Because we don't know the option lengths we have
1773 *      to pass the user mode parameter for the protocols to sort out.
1774 */
1775
1776SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
1777                char __user *, optval, int, optlen)
1778{
1779        int err, fput_needed;
1780        struct socket *sock;
1781
1782        if (optlen < 0)
1783                return -EINVAL;
1784
1785        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1786        if (sock != NULL) {
1787                err = security_socket_setsockopt(sock, level, optname);
1788                if (err)
1789                        goto out_put;
1790
1791                if (level == SOL_SOCKET)
1792                        err =
1793                            sock_setsockopt(sock, level, optname, optval,
1794                                            optlen);
1795                else
1796                        err =
1797                            sock->ops->setsockopt(sock, level, optname, optval,
1798                                                  optlen);
1799out_put:
1800                fput_light(sock->file, fput_needed);
1801        }
1802        return err;
1803}
1804
1805/*
1806 *      Get a socket option. Because we don't know the option lengths we have
1807 *      to pass a user mode parameter for the protocols to sort out.
1808 */
1809
1810SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
1811                char __user *, optval, int __user *, optlen)
1812{
1813        int err, fput_needed;
1814        struct socket *sock;
1815
1816        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1817        if (sock != NULL) {
1818                err = security_socket_getsockopt(sock, level, optname);
1819                if (err)
1820                        goto out_put;
1821
1822                if (level == SOL_SOCKET)
1823                        err =
1824                            sock_getsockopt(sock, level, optname, optval,
1825                                            optlen);
1826                else
1827                        err =
1828                            sock->ops->getsockopt(sock, level, optname, optval,
1829                                                  optlen);
1830out_put:
1831                fput_light(sock->file, fput_needed);
1832        }
1833        return err;
1834}
1835
1836/*
1837 *      Shutdown a socket.
1838 */
1839
1840SYSCALL_DEFINE2(shutdown, int, fd, int, how)
1841{
1842        int err, fput_needed;
1843        struct socket *sock;
1844
1845        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1846        if (sock != NULL) {
1847                err = security_socket_shutdown(sock, how);
1848                if (!err)
1849                        err = sock->ops->shutdown(sock, how);
1850                fput_light(sock->file, fput_needed);
1851        }
1852        return err;
1853}
1854
1855/* A couple of helpful macros for getting the address of the 32/64 bit
1856 * fields which are the same type (int / unsigned) on our platforms.
1857 */
1858#define COMPAT_MSG(msg, member) ((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
1859#define COMPAT_NAMELEN(msg)     COMPAT_MSG(msg, msg_namelen)
1860#define COMPAT_FLAGS(msg)       COMPAT_MSG(msg, msg_flags)
1861
1862/*
1863 *      BSD sendmsg interface
1864 */
1865
1866SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned, flags)
1867{
1868        struct compat_msghdr __user *msg_compat =
1869            (struct compat_msghdr __user *)msg;
1870        struct socket *sock;
1871        struct sockaddr_storage address;
1872        struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1873        unsigned char ctl[sizeof(struct cmsghdr) + 20]
1874            __attribute__ ((aligned(sizeof(__kernel_size_t))));
1875        /* 20 is size of ipv6_pktinfo */
1876        unsigned char *ctl_buf = ctl;
1877        struct msghdr msg_sys;
1878        int err, ctl_len, iov_size, total_len;
1879        int fput_needed;
1880
1881        err = -EFAULT;
1882        if (MSG_CMSG_COMPAT & flags) {
1883                if (get_compat_msghdr(&msg_sys, msg_compat))
1884                        return -EFAULT;
1885        }
1886        else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
1887                return -EFAULT;
1888
1889        sock = sockfd_lookup_light(fd, &err, &fput_needed);
1890        if (!sock)
1891                goto out;
1892
1893        /* do not move before msg_sys is valid */
1894        err = -EMSGSIZE;
1895        if (msg_sys.msg_iovlen > UIO_MAXIOV)
1896                goto out_put;
1897
1898        /* Check whether to allocate the iovec area */
1899        err = -ENOMEM;
1900        iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
1901        if (msg_sys.msg_iovlen > UIO_FASTIOV) {
1902                iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
1903                if (!iov)
1904                        goto out_put;
1905        }
1906
1907        /* This will also move the address data into kernel space */
1908        if (MSG_CMSG_COMPAT & flags) {
1909                err = verify_compat_iovec(&msg_sys, iov,
1910                                          (struct sockaddr *)&address,
1911                                          VERIFY_READ);
1912        } else
1913                err = verify_iovec(&msg_sys, iov,
1914                                   (struct sockaddr *)&address,
1915                                   VERIFY_READ);
1916        if (err < 0)
1917                goto out_freeiov;
1918        total_len = err;
1919
1920        err = -ENOBUFS;
1921
1922        if (msg_sys.msg_controllen > INT_MAX)
1923                goto out_freeiov;
1924        ctl_len = msg_sys.msg_controllen;
1925        if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
1926                err =
1927                    cmsghdr_from_user_compat_to_kern(&msg_sys, sock->sk, ctl,
1928                                                     sizeof(ctl));
1929                if (err)
1930                        goto out_freeiov;
1931                ctl_buf = msg_sys.msg_control;
1932                ctl_len = msg_sys.msg_controllen;
1933        } else if (ctl_len) {
1934                if (ctl_len > sizeof(ctl)) {
1935                        ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
1936                        if (ctl_buf == NULL)
1937                                goto out_freeiov;
1938                }
1939                err = -EFAULT;
1940                /*
1941                 * Careful! Before this, msg_sys.msg_control contains a user pointer.
1942                 * Afterwards, it will be a kernel pointer. Thus the compiler-assisted
1943                 * checking falls down on this.
1944                 */
1945                if (copy_from_user(ctl_buf, (void __user *)msg_sys.msg_control,
1946                                   ctl_len))
1947                        goto out_freectl;
1948                msg_sys.msg_control = ctl_buf;
1949        }
1950        msg_sys.msg_flags = flags;
1951
1952        if (sock->file->f_flags & O_NONBLOCK)
1953                msg_sys.msg_flags |= MSG_DONTWAIT;
1954        err = sock_sendmsg(sock, &msg_sys, total_len);
1955
1956out_freectl:
1957        if (ctl_buf != ctl)
1958                sock_kfree_s(sock->sk, ctl_buf, ctl_len);
1959out_freeiov:
1960        if (iov != iovstack)
1961                sock_kfree_s(sock->sk, iov, iov_size);
1962out_put:
1963        fput_light(sock->file, fput_needed);
1964out:
1965        return err;
1966}
1967
1968/*
1969 *      BSD recvmsg interface
1970 */
1971
1972SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg,
1973                unsigned int, flags)
1974{
1975        struct compat_msghdr __user *msg_compat =
1976            (struct compat_msghdr __user *)msg;
1977        struct socket *sock;
1978        struct iovec iovstack[UIO_FASTIOV];
1979        struct iovec *iov = iovstack;
1980        struct msghdr msg_sys;
1981        unsigned long cmsg_ptr;
1982        int err, iov_size, total_len, len;
1983        int fput_needed;
1984
1985        /* kernel mode address */
1986        struct sockaddr_storage addr;
1987
1988        /* user mode address pointers */
1989        struct sockaddr __user *uaddr;
1990        int __user *uaddr_len;
1991
1992        if (MSG_CMSG_COMPAT & flags) {
1993                if (get_compat_msghdr(&msg_sys, msg_compat))
1994                        return -EFAULT;
1995        }
1996        else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
1997                return -EFAULT;
1998
1999        sock = sockfd_lookup_light(fd, &err, &fput_needed);
2000        if (!sock)
2001                goto out;
2002
2003        err = -EMSGSIZE;
2004        if (msg_sys.msg_iovlen > UIO_MAXIOV)
2005                goto out_put;
2006
2007        /* Check whether to allocate the iovec area */
2008        err = -ENOMEM;
2009        iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
2010        if (msg_sys.msg_iovlen > UIO_FASTIOV) {
2011                iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
2012                if (!iov)
2013                        goto out_put;
2014        }
2015
2016        /*
2017         *      Save the user-mode address (verify_iovec will change the
2018         *      kernel msghdr to use the kernel address space)
2019         */
2020
2021        uaddr = (__force void __user *)msg_sys.msg_name;
2022        uaddr_len = COMPAT_NAMELEN(msg);
2023        if (MSG_CMSG_COMPAT & flags) {
2024                err = verify_compat_iovec(&msg_sys, iov,
2025                                          (struct sockaddr *)&addr,
2026                                          VERIFY_WRITE);
2027        } else
2028                err = verify_iovec(&msg_sys, iov,
2029                                   (struct sockaddr *)&addr,
2030                                   VERIFY_WRITE);
2031        if (err < 0)
2032                goto out_freeiov;
2033        total_len = err;
2034
2035        cmsg_ptr = (unsigned long)msg_sys.msg_control;
2036        msg_sys.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
2037
2038        if (sock->file->f_flags & O_NONBLOCK)
2039                flags |= MSG_DONTWAIT;
2040        err = sock_recvmsg(sock, &msg_sys, total_len, flags);
2041        if (err < 0)
2042                goto out_freeiov;
2043        len = err;
2044
2045        if (uaddr != NULL) {
2046                err = move_addr_to_user((struct sockaddr *)&addr,
2047                                        msg_sys.msg_namelen, uaddr,
2048                                        uaddr_len);
2049                if (err < 0)
2050                        goto out_freeiov;
2051        }
2052        err = __put_user((msg_sys.msg_flags & ~MSG_CMSG_COMPAT),
2053                         COMPAT_FLAGS(msg));
2054        if (err)
2055                goto out_freeiov;
2056        if (MSG_CMSG_COMPAT & flags)
2057                err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr,
2058                                 &msg_compat->msg_controllen);
2059        else
2060                err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr,
2061                                 &msg->msg_controllen);
2062        if (err)
2063                goto out_freeiov;
2064        err = len;
2065
2066out_freeiov:
2067        if (iov != iovstack)
2068                sock_kfree_s(sock->sk, iov, iov_size);
2069out_put:
2070        fput_light(sock->file, fput_needed);
2071out:
2072        return err;
2073}
2074
2075#ifdef __ARCH_WANT_SYS_SOCKETCALL
2076
2077/* Argument list sizes for sys_socketcall */
2078#define AL(x) ((x) * sizeof(unsigned long))
2079static const unsigned char nargs[19]={
2080        AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
2081        AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
2082        AL(6),AL(2),AL(5),AL(5),AL(3),AL(3),
2083        AL(4)
2084};
2085
2086#undef AL
2087
2088/*
2089 *      System call vectors.
2090 *
2091 *      Argument checking cleaned up. Saved 20% in size.
2092 *  This function doesn't need to set the kernel lock because
2093 *  it is set by the callees.
2094 */
2095
2096SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
2097{
2098        unsigned long a[6];
2099        unsigned long a0, a1;
2100        int err;
2101
2102        if (call < 1 || call > SYS_ACCEPT4)
2103                return -EINVAL;
2104
2105        /* copy_from_user should be SMP safe. */
2106        if (copy_from_user(a, args, nargs[call]))
2107                return -EFAULT;
2108
2109        audit_socketcall(nargs[call] / sizeof(unsigned long), a);
2110
2111        a0 = a[0];
2112        a1 = a[1];
2113
2114        switch (call) {
2115        case SYS_SOCKET:
2116                err = sys_socket(a0, a1, a[2]);
2117                break;
2118        case SYS_BIND:
2119                err = sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
2120                break;
2121        case SYS_CONNECT:
2122                err = sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
2123                break;
2124        case SYS_LISTEN:
2125                err = sys_listen(a0, a1);
2126                break;
2127        case SYS_ACCEPT:
2128                err = sys_accept4(a0, (struct sockaddr __user *)a1,
2129                                  (int __user *)a[2], 0);
2130                break;
2131        case SYS_GETSOCKNAME:
2132                err =
2133                    sys_getsockname(a0, (struct sockaddr __user *)a1,
2134                                    (int __user *)a[2]);
2135                break;
2136        case SYS_GETPEERNAME:
2137                err =
2138                    sys_getpeername(a0, (struct sockaddr __user *)a1,
2139                                    (int __user *)a[2]);
2140                break;
2141        case SYS_SOCKETPAIR:
2142                err = sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
2143                break;
2144        case SYS_SEND:
2145                err = sys_send(a0, (void __user *)a1, a[2], a[3]);
2146                break;
2147        case SYS_SENDTO:
2148                err = sys_sendto(a0, (void __user *)a1, a[2], a[3],
2149                                 (struct sockaddr __user *)a[4], a[5]);
2150                break;
2151        case SYS_RECV:
2152                err = sys_recv(a0, (void __user *)a1, a[2], a[3]);
2153                break;
2154        case SYS_RECVFROM:
2155                err = sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
2156                                   (struct sockaddr __user *)a[4],
2157                                   (int __user *)a[5]);
2158                break;
2159        case SYS_SHUTDOWN:
2160                err = sys_shutdown(a0, a1);
2161                break;
2162        case SYS_SETSOCKOPT:
2163                err = sys_setsockopt(a0, a1, a[2], (char __user *)a[3], a[4]);
2164                break;
2165        case SYS_GETSOCKOPT:
2166                err =
2167                    sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
2168                                   (int __user *)a[4]);
2169                break;
2170        case SYS_SENDMSG:
2171                err = sys_sendmsg(a0, (struct msghdr __user *)a1, a[2]);
2172                break;
2173        case SYS_RECVMSG:
2174                err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]);
2175                break;
2176        case SYS_ACCEPT4:
2177                err = sys_accept4(a0, (struct sockaddr __user *)a1,
2178                                  (int __user *)a[2], a[3]);
2179                break;
2180        default:
2181                err = -EINVAL;
2182                break;
2183        }
2184        return err;
2185}
2186
2187#endif                          /* __ARCH_WANT_SYS_SOCKETCALL */
2188
2189/**
2190 *      sock_register - add a socket protocol handler
2191 *      @ops: description of protocol
2192 *
2193 *      This function is called by a protocol handler that wants to
2194 *      advertise its address family, and have it linked into the
2195 *      socket interface. The value ops->family coresponds to the
2196 *      socket system call protocol family.
2197 */
2198int sock_register(const struct net_proto_family *ops)
2199{
2200        int err;
2201
2202        if (ops->family >= NPROTO) {
2203                printk(KERN_CRIT "protocol %d >= NPROTO(%d)\n", ops->family,
2204                       NPROTO);
2205                return -ENOBUFS;
2206        }
2207
2208        spin_lock(&net_family_lock);
2209        if (net_families[ops->family])
2210                err = -EEXIST;
2211        else {
2212                net_families[ops->family] = ops;
2213                err = 0;
2214        }
2215        spin_unlock(&net_family_lock);
2216
2217        printk(KERN_INFO "NET: Registered protocol family %d\n", ops->family);
2218        return err;
2219}
2220
2221/**
2222 *      sock_unregister - remove a protocol handler
2223 *      @family: protocol family to remove
2224 *
2225 *      This function is called by a protocol handler that wants to
2226 *      remove its address family, and have it unlinked from the
2227 *      new socket creation.
2228 *
2229 *      If protocol handler is a module, then it can use module reference
2230 *      counts to protect against new references. If protocol handler is not
2231 *      a module then it needs to provide its own protection in
2232 *      the ops->create routine.
2233 */
2234void sock_unregister(int family)
2235{
2236        BUG_ON(family < 0 || family >= NPROTO);
2237
2238        spin_lock(&net_family_lock);
2239        net_families[family] = NULL;
2240        spin_unlock(&net_family_lock);
2241
2242        synchronize_rcu();
2243
2244        printk(KERN_INFO "NET: Unregistered protocol family %d\n", family);
2245}
2246
2247static int __init sock_init(void)
2248{
2249        /*
2250         *      Initialize sock SLAB cache.
2251         */
2252
2253        sk_init();
2254
2255        /*
2256         *      Initialize skbuff SLAB cache
2257         */
2258        skb_init();
2259
2260        /*
2261         *      Initialize the protocols module.
2262         */
2263
2264        init_inodecache();
2265        register_filesystem(&sock_fs_type);
2266        sock_mnt = kern_mount(&sock_fs_type);
2267
2268        /* The real protocol initialization is performed in later initcalls.
2269         */
2270
2271#ifdef CONFIG_NETFILTER
2272        netfilter_init();
2273#endif
2274
2275        return 0;
2276}
2277
2278core_initcall(sock_init);       /* early initcall */
2279
2280#ifdef CONFIG_PROC_FS
2281void socket_seq_show(struct seq_file *seq)
2282{
2283        int cpu;
2284        int counter = 0;
2285
2286        for_each_possible_cpu(cpu)
2287            counter += per_cpu(sockets_in_use, cpu);
2288
2289        /* It can be negative, by the way. 8) */
2290        if (counter < 0)
2291                counter = 0;
2292
2293        seq_printf(seq, "sockets: used %d\n", counter);
2294}
2295#endif                          /* CONFIG_PROC_FS */
2296
2297#ifdef CONFIG_COMPAT
2298static long compat_sock_ioctl(struct file *file, unsigned cmd,
2299                              unsigned long arg)
2300{
2301        struct socket *sock = file->private_data;
2302        int ret = -ENOIOCTLCMD;
2303        struct sock *sk;
2304        struct net *net;
2305
2306        sk = sock->sk;
2307        net = sock_net(sk);
2308
2309        if (sock->ops->compat_ioctl)
2310                ret = sock->ops->compat_ioctl(sock, cmd, arg);
2311
2312        if (ret == -ENOIOCTLCMD &&
2313            (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
2314                ret = compat_wext_handle_ioctl(net, cmd, arg);
2315
2316        return ret;
2317}
2318#endif
2319
2320int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
2321{
2322        return sock->ops->bind(sock, addr, addrlen);
2323}
2324
2325int kernel_listen(struct socket *sock, int backlog)
2326{
2327        return sock->ops->listen(sock, backlog);
2328}
2329
2330int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
2331{
2332        struct sock *sk = sock->sk;
2333        int err;
2334
2335        err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
2336                               newsock);
2337        if (err < 0)
2338                goto done;
2339
2340        err = sock->ops->accept(sock, *newsock, flags);
2341        if (err < 0) {
2342                sock_release(*newsock);
2343                *newsock = NULL;
2344                goto done;
2345        }
2346
2347        (*newsock)->ops = sock->ops;
2348        __module_get((*newsock)->ops->owner);
2349
2350done:
2351        return err;
2352}
2353
2354int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
2355                   int flags)
2356{
2357        return sock->ops->connect(sock, addr, addrlen, flags);
2358}
2359
2360int kernel_getsockname(struct socket *sock, struct sockaddr *addr,
2361                         int *addrlen)
2362{
2363        return sock->ops->getname(sock, addr, addrlen, 0);
2364}
2365
2366int kernel_getpeername(struct socket *sock, struct sockaddr *addr,
2367                         int *addrlen)
2368{
2369        return sock->ops->getname(sock, addr, addrlen, 1);
2370}
2371
2372int kernel_getsockopt(struct socket *sock, int level, int optname,
2373                        char *optval, int *optlen)
2374{
2375        mm_segment_t oldfs = get_fs();
2376        int err;
2377
2378        set_fs(KERNEL_DS);
2379        if (level == SOL_SOCKET)
2380                err = sock_getsockopt(sock, level, optname, optval, optlen);
2381        else
2382                err = sock->ops->getsockopt(sock, level, optname, optval,
2383                                            optlen);
2384        set_fs(oldfs);
2385        return err;
2386}
2387
2388int kernel_setsockopt(struct socket *sock, int level, int optname,
2389                        char *optval, int optlen)
2390{
2391        mm_segment_t oldfs = get_fs();
2392        int err;
2393
2394        set_fs(KERNEL_DS);
2395        if (level == SOL_SOCKET)
2396                err = sock_setsockopt(sock, level, optname, optval, optlen);
2397        else
2398                err = sock->ops->setsockopt(sock, level, optname, optval,
2399                                            optlen);
2400        set_fs(oldfs);
2401        return err;
2402}
2403
2404int kernel_sendpage(struct socket *sock, struct page *page, int offset,
2405                    size_t size, int flags)
2406{
2407        if (sock->ops->sendpage)
2408                return sock->ops->sendpage(sock, page, offset, size, flags);
2409
2410        return sock_no_sendpage(sock, page, offset, size, flags);
2411}
2412
2413int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg)
2414{
2415        mm_segment_t oldfs = get_fs();
2416        int err;
2417
2418        set_fs(KERNEL_DS);
2419        err = sock->ops->ioctl(sock, cmd, arg);
2420        set_fs(oldfs);
2421
2422        return err;
2423}
2424
2425int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
2426{
2427        return sock->ops->shutdown(sock, how);
2428}
2429
2430EXPORT_SYMBOL(sock_create);
2431EXPORT_SYMBOL(sock_create_kern);
2432EXPORT_SYMBOL(sock_create_lite);
2433EXPORT_SYMBOL(sock_map_fd);
2434EXPORT_SYMBOL(sock_recvmsg);
2435EXPORT_SYMBOL(sock_register);
2436EXPORT_SYMBOL(sock_release);
2437EXPORT_SYMBOL(sock_sendmsg);
2438EXPORT_SYMBOL(sock_unregister);
2439EXPORT_SYMBOL(sock_wake_async);
2440EXPORT_SYMBOL(sockfd_lookup);
2441EXPORT_SYMBOL(kernel_sendmsg);
2442EXPORT_SYMBOL(kernel_recvmsg);
2443EXPORT_SYMBOL(kernel_bind);
2444EXPORT_SYMBOL(kernel_listen);
2445EXPORT_SYMBOL(kernel_accept);
2446EXPORT_SYMBOL(kernel_connect);
2447EXPORT_SYMBOL(kernel_getsockname);
2448EXPORT_SYMBOL(kernel_getpeername);
2449EXPORT_SYMBOL(kernel_getsockopt);
2450EXPORT_SYMBOL(kernel_setsockopt);
2451EXPORT_SYMBOL(kernel_sendpage);
2452EXPORT_SYMBOL(kernel_sock_ioctl);
2453EXPORT_SYMBOL(kernel_sock_shutdown);
2454
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