src/network/io.c

   1 /*****************************************************************************
   2  * io.c: network I/O functions
   3  *****************************************************************************
   4  * Copyright (C) 2004-2005, 2007 VLC authors and VideoLAN
   5  * Copyright © 2005-2006 Rémi Denis-Courmont
   6  * $Id$
   7  *
   8  * Authors: Laurent Aimar <fenrir@videolan.org>
   9  *          Rémi Denis-Courmont <rem # videolan.org>
  10  *          Christophe Mutricy <xtophe at videolan dot org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU Lesser General Public License as published by
  14  * the Free Software Foundation; either version 2.1 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc_common.h>
  36
  37 #include <stdlib.h>
  38 #include <stdio.h>
  39 #include <limits.h>
  40
  41 #include <errno.h>
  42 #include <assert.h>
  43
  44 #include <fcntl.h>
  45 #ifdef HAVE_UNISTD_H
  46 #   include <unistd.h>
  47 #endif
  48 #ifdef HAVE_POLL
  49 #   include <poll.h>
  50 #endif
  51
  52 #include <vlc_network.h>
  53
  54 #ifndef INADDR_ANY
  55 #   define INADDR_ANY  0x00000000
  56 #endif
  57 #ifndef INADDR_NONE
  58 #   define INADDR_NONE 0xFFFFFFFF
  59 #endif
  60
  61 #if defined(WIN32) || defined(UNDER_CE)
  62 # undef EAFNOSUPPORT
  63 # define EAFNOSUPPORT WSAEAFNOSUPPORT
  64 #endif
  65
  66 #ifdef HAVE_LINUX_DCCP_H
  67 /* TODO: use glibc instead of linux-kernel headers */
  68 # include <linux/dccp.h>
  69 # define SOL_DCCP 269
  70 #endif
  71
  72 #include "libvlc.h" /* vlc_object_waitpipe */
  73
  74 extern int rootwrap_bind (int family, int socktype, int protocol,
  75                           const struct sockaddr *addr, size_t alen);
  76
  77 int net_Socket (vlc_object_t *p_this, int family, int socktype,
  78                 int protocol)
  79 {
  80     int fd = vlc_socket (family, socktype, protocol, true);
  81     if (fd == -1)
  82     {
  83         if (net_errno != EAFNOSUPPORT)
  84             msg_Err (p_this, "cannot create socket: %m");
  85         return -1;
  86     }
  87
  88     setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof (int));
  89
  90 #ifdef IPV6_V6ONLY
  91     /*
  92      * Accepts only IPv6 connections on IPv6 sockets.
  93      * If possible, we should open two sockets, but it is not always possible.
  94      */
  95     if (family == AF_INET6)
  96         setsockopt (fd, IPPROTO_IPV6, IPV6_V6ONLY, &(int){ 1 }, sizeof (int));
  97 #endif
  98
  99 #if defined (WIN32) || defined (UNDER_CE)
 100 # ifndef IPV6_PROTECTION_LEVEL
 101 #  warning Please update your C library headers.
 102 #  define IPV6_PROTECTION_LEVEL 23
 103 #  define PROTECTION_LEVEL_UNRESTRICTED 10
 104 # endif
 105     if (family == AF_INET6)
 106         setsockopt (fd, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL,
 107                     &(int){ PROTECTION_LEVEL_UNRESTRICTED }, sizeof (int));
 108 #endif
 109
 110 #ifdef DCCP_SOCKOPT_SERVICE
 111     if (socktype == SOL_DCCP)
 112     {
 113         char *dccps = var_InheritString (p_this, "dccp-service");
 114         if (dccps != NULL)
 115         {
 116             setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE, dccps,
 117                         (strlen (dccps) + 3) & ~3);
 118             free (dccps);
 119         }
 120     }
 121 #endif
 122
 123     return fd;
 124 }
 125
 126
 127 int *net_Listen (vlc_object_t *p_this, const char *psz_host,
 128                  int i_port, int type, int protocol)
 129 {
 130     struct addrinfo hints, *res;
 131
 132     memset (&hints, 0, sizeof( hints ));
 133     hints.ai_socktype = type;
 134     hints.ai_protocol = protocol;
 135     hints.ai_flags = AI_PASSIVE;
 136
 137     msg_Dbg (p_this, "net: listening to %s port %d",
 138              (psz_host != NULL) ? psz_host : "*", i_port);
 139
 140     int i_val = vlc_getaddrinfo (p_this, psz_host, i_port, &hints, &res);
 141     if (i_val)
 142     {
 143         msg_Err (p_this, "Cannot resolve %s port %d : %s",
 144                  (psz_host != NULL) ? psz_host : "", i_port,
 145                  gai_strerror (i_val));
 146         return NULL;
 147     }
 148
 149     int *sockv = NULL;
 150     unsigned sockc = 0;
 151
 152     for (struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
 153     {
 154         int fd = net_Socket (p_this, ptr->ai_family, ptr->ai_socktype,
 155                              ptr->ai_protocol);
 156         if (fd == -1)
 157         {
 158             msg_Dbg (p_this, "socket error: %m");
 159             continue;
 160         }
 161
 162         /* Bind the socket */
 163 #if defined (WIN32) || defined (UNDER_CE)
 164         /*
 165          * Under Win32 and for multicasting, we bind to INADDR_ANY.
 166          * This is of course a severe bug, since the socket would logically
 167          * receive unicast traffic, and multicast traffic of groups subscribed
 168          * to via other sockets.
 169          */
 170         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
 171          && (sizeof (struct sockaddr_storage) >= ptr->ai_addrlen))
 172         {
 173             // This works for IPv4 too - don't worry!
 174             struct sockaddr_in6 dumb =
 175             {
 176                 .sin6_family = ptr->ai_addr->sa_family,
 177                 .sin6_port =  ((struct sockaddr_in *)(ptr->ai_addr))->sin_port
 178             };
 179
 180             bind (fd, (struct sockaddr *)&dumb, ptr->ai_addrlen);
 181         }
 182         else
 183 #endif
 184         if (bind (fd, ptr->ai_addr, ptr->ai_addrlen))
 185         {
 186             net_Close (fd);
 187 #if !defined(WIN32) && !defined(UNDER_CE)
 188             fd = rootwrap_bind (ptr->ai_family, ptr->ai_socktype,
 189                                 ptr->ai_protocol,
 190                                 ptr->ai_addr, ptr->ai_addrlen);
 191             if (fd != -1)
 192             {
 193                 msg_Dbg (p_this, "got socket %d from rootwrap", fd);
 194             }
 195             else
 196 #endif
 197             {
 198                 msg_Err (p_this, "socket bind error (%m)");
 199                 continue;
 200             }
 201         }
 202
 203         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen))
 204         {
 205             if (net_Subscribe (p_this, fd, ptr->ai_addr, ptr->ai_addrlen))
 206             {
 207                 net_Close (fd);
 208                 continue;
 209             }
 210         }
 211
 212         /* Listen */
 213         switch (ptr->ai_socktype)
 214         {
 215             case SOCK_STREAM:
 216             case SOCK_RDM:
 217             case SOCK_SEQPACKET:
 218 #ifdef SOCK_DCCP
 219             case SOCK_DCCP:
 220 #endif
 221                 if (listen (fd, INT_MAX))
 222                 {
 223                     msg_Err (p_this, "socket listen error (%m)");
 224                     net_Close (fd);
 225                     continue;
 226                 }
 227         }
 228
 229         int *nsockv = (int *)realloc (sockv, (sockc + 2) * sizeof (int));
 230         if (nsockv != NULL)
 231         {
 232             nsockv[sockc++] = fd;
 233             sockv = nsockv;
 234         }
 235         else
 236             net_Close (fd);
 237     }
 238
 239     freeaddrinfo (res);
 240
 241     if (sockv != NULL)
 242         sockv[sockc] = -1;
 243
 244     return sockv;
 245 }
 246
 247 #undef net_Read
 248 /*****************************************************************************
 249  * net_Read:
 250  *****************************************************************************
 251  * Reads from a network socket. Cancellation point.
 252  * If waitall is true, then we repeat until we have read the right amount of
 253  * data; in that case, a short count means EOF has been reached or the VLC
 254  * object has been signaled.
 255  *****************************************************************************/
 256 ssize_t
 257 net_Read (vlc_object_t *restrict p_this, int fd, const v_socket_t *vs,
 258           void *restrict p_buf, size_t i_buflen, bool waitall)
 259 {
 260     size_t i_total = 0;
 261     struct pollfd ufd[2] = {
 262         { .fd = fd,                           .events = POLLIN },
 263         { .fd = vlc_object_waitpipe (p_this), .events = POLLIN },
 264     };
 265
 266     if (ufd[1].fd == -1)
 267         return -1; /* vlc_object_waitpipe() sets errno */
 268
 269     while (i_buflen > 0)
 270     {
 271         ufd[0].revents = ufd[1].revents = 0;
 272
 273         if (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1) < 0)
 274         {
 275             if (errno != EINTR)
 276                 goto error;
 277             continue;
 278         }
 279
 280 #ifndef POLLRDHUP /* This is nice but non-portable */
 281 # define POLLRDHUP 0
 282 #endif
 283         if (i_total > 0)
 284         {
 285             /* Errors (-1) and EOF (0) will be returned on next call,
 286              * otherwise we'd "hide" the error from the caller, which is a
 287              * bad idea™. */
 288             if (ufd[0].revents & (POLLERR|POLLNVAL|POLLRDHUP))
 289                 break;
 290             if (ufd[1].revents)
 291                 break;
 292         }
 293         else
 294         {
 295             if (ufd[1].revents)
 296             {
 297                 assert (p_this->b_die);
 298                 msg_Dbg (p_this, "socket %d polling interrupted", fd);
 299 #if defined(WIN32) || defined(UNDER_CE)
 300                 WSASetLastError (WSAEINTR);
 301 #else
 302                 errno = EINTR;
 303 #endif
 304                 goto silent;
 305             }
 306         }
 307
 308         assert (ufd[0].revents);
 309
 310         ssize_t n;
 311 #if defined(WIN32) || defined(UNDER_CE)
 312         int error;
 313 #endif
 314         if (vs != NULL)
 315         {
 316             int canc = vlc_savecancel ();
 317             n = vs->pf_recv (vs->p_sys, p_buf, i_buflen);
 318 #if defined(WIN32) || defined(UNDER_CE)
 319             /* We must read last error immediately, because vlc_restorecancel()
 320              * access thread local storage, and TlsGetValue() will call
 321              * SetLastError() to indicate that the function succeeded, thus
 322              * overwriting the error code coming from pf_recv().
 323              * WSAGetLastError is just an alias for GetLastError these days.
 324              */
 325             error = WSAGetLastError();
 326 #endif
 327             vlc_restorecancel (canc);
 328         }
 329         else
 330         {
 331 #ifdef WIN32
 332             n = recv (fd, p_buf, i_buflen, 0);
 333             error = WSAGetLastError();
 334 #else
 335             n = read (fd, p_buf, i_buflen);
 336 #endif
 337         }
 338
 339         if (n == -1)
 340         {
 341 #if defined(WIN32) || defined(UNDER_CE)
 342             switch (error)
 343             {
 344                 case WSAEWOULDBLOCK:
 345                 case WSAEINTR:
 346                 /* only happens with vs != NULL (TLS) - not really an error */
 347                     continue;
 348
 349                 case WSAEMSGSIZE:
 350                 /* For UDP only */
 351                 /* On Win32, recv() fails if the datagram doesn't fit inside
 352                  * the passed buffer, even though the buffer will be filled
 353                  * with the first part of the datagram. */
 354                     msg_Err (p_this, "Receive error: "
 355                                      "Increase the mtu size (--mtu option)");
 356                     n = i_buflen;
 357                     break;
 358             }
 359 #else
 360             switch (errno)
 361             {
 362                 case EAGAIN: /* spurious wakeup or no TLS data */
 363 #if (EAGAIN != EWOULDBLOCK)
 364                 case EWOULDBLOCK:
 365 #endif
 366                 case EINTR:  /* asynchronous signal */
 367                     continue;
 368             }
 369 #endif
 370             goto error;
 371         }
 372
 373         if (n == 0)
 374             /* For streams, this means end of file, and there will not be any
 375              * further data ever on the stream. For datagram sockets, this
 376              * means empty datagram, and there could be more data coming.
 377              * However, it makes no sense to set <waitall> with datagrams in the
 378              * first place.
 379              */
 380             break; // EOF
 381
 382         i_total += n;
 383         p_buf = (char *)p_buf + n;
 384         i_buflen -= n;
 385
 386         if (!waitall)
 387             break;
 388     }
 389
 390     return i_total;
 391
 392 error:
 393     msg_Err (p_this, "Read error: %m");
 394 silent:
 395     return -1;
 396 }
 397
 398 #undef net_Write
 399 /**
 400  * Writes data to a file descriptor.
 401  * This blocks until all data is written or an error occurs.
 402  *
 403  * This function is a cancellation point if p_vs is NULL.
 404  * This function is not cancellation-safe if p_vs is not NULL.
 405  *
 406  * @return the total number of bytes written, or -1 if an error occurs
 407  * before any data is written.
 408  */
 409 ssize_t net_Write( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 410                    const void *restrict p_data, size_t i_data )
 411 {
 412     size_t i_total = 0;
 413     struct pollfd ufd[2] = {
 414         { .fd = fd,                           .events = POLLOUT },
 415         { .fd = vlc_object_waitpipe (p_this), .events = POLLIN  },
 416     };
 417
 418     if (unlikely(ufd[1].fd == -1))
 419     {
 420         vlc_testcancel ();
 421         return -1;
 422     }
 423
 424     while( i_data > 0 )
 425     {
 426         ssize_t val;
 427
 428         ufd[0].revents = ufd[1].revents = 0;
 429
 430         if (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1) == -1)
 431         {
 432             if (errno == EINTR)
 433                 continue;
 434             msg_Err (p_this, "Polling error: %m");
 435             return -1;
 436         }
 437
 438         if (i_total > 0)
 439         {   /* If POLLHUP resp. POLLERR|POLLNVAL occurs while we have already
 440              * read some data, it is important that we first return the number
 441              * of bytes read, and then return 0 resp. -1 on the NEXT call. */
 442             if (ufd[0].revents & (POLLHUP|POLLERR|POLLNVAL))
 443                 break;
 444             if (ufd[1].revents) /* VLC object signaled */
 445                 break;
 446         }
 447         else
 448         {
 449             if (ufd[1].revents)
 450             {
 451                 assert (p_this->b_die);
 452                 errno = EINTR;
 453                 goto error;
 454             }
 455         }
 456
 457         if (p_vs != NULL)
 458             val = p_vs->pf_send (p_vs->p_sys, p_data, i_data);
 459         else
 460 #ifdef WIN32
 461             val = send (fd, p_data, i_data, 0);
 462 #else
 463             val = write (fd, p_data, i_data);
 464 #endif
 465
 466         if (val == -1)
 467         {
 468             if (errno == EINTR)
 469                 continue;
 470             msg_Err (p_this, "Write error: %m");
 471             break;
 472         }
 473
 474         p_data = (const char *)p_data + val;
 475         i_data -= val;
 476         i_total += val;
 477     }
 478
 479     if (unlikely(i_data == 0))
 480         vlc_testcancel (); /* corner case */
 481
 482     if ((i_total > 0) || (i_data == 0))
 483         return i_total;
 484
 485 error:
 486     return -1;
 487 }
 488
 489 #undef net_Gets
 490 /**
 491  * Reads a line from a file descriptor.
 492  * This function is not thread-safe; the same file descriptor I/O cannot be
 493  * read by another thread at the same time (although it can be written to).
 494  *
 495  * @return nul-terminated heap-allocated string, or NULL on I/O error.
 496  */
 497 char *net_Gets( vlc_object_t *p_this, int fd, const v_socket_t *p_vs )
 498 {
 499     char *psz_line = NULL, *ptr = NULL;
 500     size_t  i_line = 0, i_max = 0;
 501
 502
 503     for( ;; )
 504     {
 505         if( i_line == i_max )
 506         {
 507             i_max += 1024;
 508             psz_line = xrealloc( psz_line, i_max );
 509             ptr = psz_line + i_line;
 510         }
 511
 512         if( net_Read( p_this, fd, p_vs, ptr, 1, true ) != 1 )
 513         {
 514             if( i_line == 0 )
 515             {
 516                 free( psz_line );
 517                 return NULL;
 518             }
 519             break;
 520         }
 521
 522         if ( *ptr == '\n' )
 523             break;
 524
 525         i_line++;
 526         ptr++;
 527     }
 528
 529     *ptr-- = '\0';
 530
 531     if( ( ptr >= psz_line ) && ( *ptr == '\r' ) )
 532         *ptr = '\0';
 533
 534     return psz_line;
 535 }
 536
 537 #undef net_Printf
 538 ssize_t net_Printf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 539                     const char *psz_fmt, ... )
 540 {
 541     int i_ret;
 542     va_list args;
 543     va_start( args, psz_fmt );
 544     i_ret = net_vaPrintf( p_this, fd, p_vs, psz_fmt, args );
 545     va_end( args );
 546
 547     return i_ret;
 548 }
 549
 550 #undef net_vaPrintf
 551 ssize_t net_vaPrintf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 552                       const char *psz_fmt, va_list args )
 553 {
 554     char    *psz;
 555     int      i_ret;
 556
 557     int i_size = vasprintf( &psz, psz_fmt, args );
 558     if( i_size == -1 )
 559         return -1;
 560     i_ret = net_Write( p_this, fd, p_vs, psz, i_size ) < i_size
 561         ? -1 : i_size;
 562     free( psz );
 563
 564     return i_ret;
 565 }