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 #ifdef HAVE_FCNTL_H
  45 #   include <fcntl.h>
  46 #endif
  47 #ifdef HAVE_UNISTD_H
  48 #   include <unistd.h>
  49 #endif
  50 #ifdef HAVE_POLL
  51 #   include <poll.h>
  52 #endif
  53
  54 #include <vlc_network.h>
  55
  56 #ifndef INADDR_ANY
  57 #   define INADDR_ANY  0x00000000
  58 #endif
  59 #ifndef INADDR_NONE
  60 #   define INADDR_NONE 0xFFFFFFFF
  61 #endif
  62
  63 #if defined(WIN32) || defined(UNDER_CE)
  64 # undef EAFNOSUPPORT
  65 # define EAFNOSUPPORT WSAEAFNOSUPPORT
  66 #endif
  67
  68 #ifdef HAVE_LINUX_DCCP_H
  69 /* TODO: use glibc instead of linux-kernel headers */
  70 # include <linux/dccp.h>
  71 # define SOL_DCCP 269
  72 #endif
  73
  74 #include "libvlc.h" /* vlc_object_waitpipe */
  75
  76 extern int rootwrap_bind (int family, int socktype, int protocol,
  77                           const struct sockaddr *addr, size_t alen);
  78
  79 int net_Socket (vlc_object_t *p_this, int family, int socktype,
  80                 int protocol)
  81 {
  82     int fd = vlc_socket (family, socktype, protocol, true);
  83     if (fd == -1)
  84     {
  85         if (net_errno != EAFNOSUPPORT)
  86             msg_Err (p_this, "cannot create socket: %m");
  87         return -1;
  88     }
  89
  90     setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof (int));
  91
  92 #ifdef IPV6_V6ONLY
  93     /*
  94      * Accepts only IPv6 connections on IPv6 sockets.
  95      * If possible, we should open two sockets, but it is not always possible.
  96      */
  97     if (family == AF_INET6)
  98         setsockopt (fd, IPPROTO_IPV6, IPV6_V6ONLY, &(int){ 1 }, sizeof (int));
  99 #endif
 100
 101 #if defined (WIN32) || defined (UNDER_CE)
 102 # ifndef IPV6_PROTECTION_LEVEL
 103 #  warning Please update your C library headers.
 104 #  define IPV6_PROTECTION_LEVEL 23
 105 #  define PROTECTION_LEVEL_UNRESTRICTED 10
 106 # endif
 107     if (family == AF_INET6)
 108         setsockopt (fd, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL,
 109                     &(int){ PROTECTION_LEVEL_UNRESTRICTED }, sizeof (int));
 110 #endif
 111
 112 #ifdef DCCP_SOCKOPT_SERVICE
 113     if (socktype == SOL_DCCP)
 114     {
 115         char *dccps = var_InheritString (p_this, "dccp-service");
 116         if (dccps != NULL)
 117         {
 118             setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE, dccps,
 119                         (strlen (dccps) + 3) & ~3);
 120             free (dccps);
 121         }
 122     }
 123 #endif
 124
 125     return fd;
 126 }
 127
 128
 129 int *net_Listen (vlc_object_t *p_this, const char *psz_host,
 130                  int i_port, int type, int protocol)
 131 {
 132     struct addrinfo hints, *res;
 133
 134     memset (&hints, 0, sizeof( hints ));
 135     hints.ai_socktype = type;
 136     hints.ai_protocol = protocol;
 137     hints.ai_flags = AI_PASSIVE;
 138
 139     msg_Dbg (p_this, "net: listening to %s port %d",
 140              (psz_host != NULL) ? psz_host : "*", i_port);
 141
 142     int i_val = vlc_getaddrinfo (p_this, psz_host, i_port, &hints, &res);
 143     if (i_val)
 144     {
 145         msg_Err (p_this, "Cannot resolve %s port %d : %s",
 146                  (psz_host != NULL) ? psz_host : "", i_port,
 147                  gai_strerror (i_val));
 148         return NULL;
 149     }
 150
 151     int *sockv = NULL;
 152     unsigned sockc = 0;
 153
 154     for (struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
 155     {
 156         int fd = net_Socket (p_this, ptr->ai_family, ptr->ai_socktype,
 157                              ptr->ai_protocol);
 158         if (fd == -1)
 159         {
 160             msg_Dbg (p_this, "socket error: %m");
 161             continue;
 162         }
 163
 164         /* Bind the socket */
 165 #if defined (WIN32) || defined (UNDER_CE)
 166         /*
 167          * Under Win32 and for multicasting, we bind to INADDR_ANY.
 168          * This is of course a severe bug, since the socket would logically
 169          * receive unicast traffic, and multicast traffic of groups subscribed
 170          * to via other sockets.
 171          */
 172         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
 173          && (sizeof (struct sockaddr_storage) >= ptr->ai_addrlen))
 174         {
 175             // This works for IPv4 too - don't worry!
 176             struct sockaddr_in6 dumb =
 177             {
 178                 .sin6_family = ptr->ai_addr->sa_family,
 179                 .sin6_port =  ((struct sockaddr_in *)(ptr->ai_addr))->sin_port
 180             };
 181
 182             bind (fd, (struct sockaddr *)&dumb, ptr->ai_addrlen);
 183         }
 184         else
 185 #endif
 186         if (bind (fd, ptr->ai_addr, ptr->ai_addrlen))
 187         {
 188             net_Close (fd);
 189 #if !defined(WIN32) && !defined(UNDER_CE)
 190             fd = rootwrap_bind (ptr->ai_family, ptr->ai_socktype,
 191                                 ptr->ai_protocol,
 192                                 ptr->ai_addr, ptr->ai_addrlen);
 193             if (fd != -1)
 194             {
 195                 msg_Dbg (p_this, "got socket %d from rootwrap", fd);
 196             }
 197             else
 198 #endif
 199             {
 200                 msg_Err (p_this, "socket bind error (%m)");
 201                 continue;
 202             }
 203         }
 204
 205         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen))
 206         {
 207             if (net_Subscribe (p_this, fd, ptr->ai_addr, ptr->ai_addrlen))
 208             {
 209                 net_Close (fd);
 210                 continue;
 211             }
 212         }
 213
 214         /* Listen */
 215         switch (ptr->ai_socktype)
 216         {
 217             case SOCK_STREAM:
 218             case SOCK_RDM:
 219             case SOCK_SEQPACKET:
 220 #ifdef SOCK_DCCP
 221             case SOCK_DCCP:
 222 #endif
 223                 if (listen (fd, INT_MAX))
 224                 {
 225                     msg_Err (p_this, "socket listen error (%m)");
 226                     net_Close (fd);
 227                     continue;
 228                 }
 229         }
 230
 231         int *nsockv = (int *)realloc (sockv, (sockc + 2) * sizeof (int));
 232         if (nsockv != NULL)
 233         {
 234             nsockv[sockc++] = fd;
 235             sockv = nsockv;
 236         }
 237         else
 238             net_Close (fd);
 239     }
 240
 241     freeaddrinfo (res);
 242
 243     if (sockv != NULL)
 244         sockv[sockc] = -1;
 245
 246     return sockv;
 247 }
 248
 249 #undef net_Read
 250 /*****************************************************************************
 251  * net_Read:
 252  *****************************************************************************
 253  * Reads from a network socket. Cancellation point.
 254  * If waitall is true, then we repeat until we have read the right amount of
 255  * data; in that case, a short count means EOF has been reached or the VLC
 256  * object has been signaled.
 257  *****************************************************************************/
 258 ssize_t
 259 net_Read (vlc_object_t *restrict p_this, int fd, const v_socket_t *vs,
 260           void *restrict p_buf, size_t i_buflen, bool waitall)
 261 {
 262     size_t i_total = 0;
 263     struct pollfd ufd[2] = {
 264         { .fd = fd,                           .events = POLLIN },
 265         { .fd = vlc_object_waitpipe (p_this), .events = POLLIN },
 266     };
 267
 268     if (ufd[1].fd == -1)
 269         return -1; /* vlc_object_waitpipe() sets errno */
 270
 271     while (i_buflen > 0)
 272     {
 273         ufd[0].revents = ufd[1].revents = 0;
 274
 275         if (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1) < 0)
 276         {
 277             if (errno != EINTR)
 278                 goto error;
 279             continue;
 280         }
 281
 282 #ifndef POLLRDHUP /* This is nice but non-portable */
 283 # define POLLRDHUP 0
 284 #endif
 285         if (i_total > 0)
 286         {
 287             /* Errors (-1) and EOF (0) will be returned on next call,
 288              * otherwise we'd "hide" the error from the caller, which is a
 289              * bad idea™. */
 290             if (ufd[0].revents & (POLLERR|POLLNVAL|POLLRDHUP))
 291                 break;
 292             if (ufd[1].revents)
 293                 break;
 294         }
 295         else
 296         {
 297             if (ufd[1].revents)
 298             {
 299                 assert (p_this->b_die);
 300                 msg_Dbg (p_this, "socket %d polling interrupted", fd);
 301 #if defined(WIN32) || defined(UNDER_CE)
 302                 WSASetLastError (WSAEINTR);
 303 #else
 304                 errno = EINTR;
 305 #endif
 306                 goto silent;
 307             }
 308         }
 309
 310         assert (ufd[0].revents);
 311
 312         ssize_t n;
 313 #if defined(WIN32) || defined(UNDER_CE)
 314         int error;
 315 #endif
 316         if (vs != NULL)
 317         {
 318             int canc = vlc_savecancel ();
 319             n = vs->pf_recv (vs->p_sys, p_buf, i_buflen);
 320 #if defined(WIN32) || defined(UNDER_CE)
 321             /* We must read last error immediately, because vlc_restorecancel()
 322              * access thread local storage, and TlsGetValue() will call
 323              * SetLastError() to indicate that the function succeeded, thus
 324              * overwriting the error code coming from pf_recv().
 325              * WSAGetLastError is just an alias for GetLastError these days.
 326              */
 327             error = WSAGetLastError();
 328 #endif
 329             vlc_restorecancel (canc);
 330         }
 331         else
 332         {
 333 #ifdef WIN32
 334             n = recv (fd, p_buf, i_buflen, 0);
 335             error = WSAGetLastError();
 336 #else
 337             n = read (fd, p_buf, i_buflen);
 338 #endif
 339         }
 340
 341         if (n == -1)
 342         {
 343 #if defined(WIN32) || defined(UNDER_CE)
 344             switch (error)
 345             {
 346                 case WSAEWOULDBLOCK:
 347                 case WSAEINTR:
 348                 /* only happens with vs != NULL (TLS) - not really an error */
 349                     continue;
 350
 351                 case WSAEMSGSIZE:
 352                 /* For UDP only */
 353                 /* On Win32, recv() fails if the datagram doesn't fit inside
 354                  * the passed buffer, even though the buffer will be filled
 355                  * with the first part of the datagram. */
 356                     msg_Err (p_this, "Receive error: "
 357                                      "Increase the mtu size (--mtu option)");
 358                     n = i_buflen;
 359                     break;
 360             }
 361 #else
 362             switch (errno)
 363             {
 364                 case EAGAIN: /* spurious wakeup or no TLS data */
 365 #if (EAGAIN != EWOULDBLOCK)
 366                 case EWOULDBLOCK:
 367 #endif
 368                 case EINTR:  /* asynchronous signal */
 369                     continue;
 370             }
 371 #endif
 372             goto error;
 373         }
 374
 375         if (n == 0)
 376             /* For streams, this means end of file, and there will not be any
 377              * further data ever on the stream. For datagram sockets, this
 378              * means empty datagram, and there could be more data coming.
 379              * However, it makes no sense to set <waitall> with datagrams in the
 380              * first place.
 381              */
 382             break; // EOF
 383
 384         i_total += n;
 385         p_buf = (char *)p_buf + n;
 386         i_buflen -= n;
 387
 388         if (!waitall)
 389             break;
 390     }
 391
 392     return i_total;
 393
 394 error:
 395     msg_Err (p_this, "Read error: %m");
 396 silent:
 397     return -1;
 398 }
 399
 400 #undef net_Write
 401 /**
 402  * Writes data to a file descriptor.
 403  * This blocks until all data is written or an error occurs.
 404  *
 405  * This function is a cancellation point if p_vs is NULL.
 406  * This function is not cancellation-safe if p_vs is not NULL.
 407  *
 408  * @return the total number of bytes written, or -1 if an error occurs
 409  * before any data is written.
 410  */
 411 ssize_t net_Write( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 412                    const void *restrict p_data, size_t i_data )
 413 {
 414     size_t i_total = 0;
 415     struct pollfd ufd[2] = {
 416         { .fd = fd,                           .events = POLLOUT },
 417         { .fd = vlc_object_waitpipe (p_this), .events = POLLIN  },
 418     };
 419
 420     if (unlikely(ufd[1].fd == -1))
 421     {
 422         vlc_testcancel ();
 423         return -1;
 424     }
 425
 426     while( i_data > 0 )
 427     {
 428         ssize_t val;
 429
 430         ufd[0].revents = ufd[1].revents = 0;
 431
 432         if (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1) == -1)
 433         {
 434             if (errno == EINTR)
 435                 continue;
 436             msg_Err (p_this, "Polling error: %m");
 437             return -1;
 438         }
 439
 440         if (i_total > 0)
 441         {   /* If POLLHUP resp. POLLERR|POLLNVAL occurs while we have already
 442              * read some data, it is important that we first return the number
 443              * of bytes read, and then return 0 resp. -1 on the NEXT call. */
 444             if (ufd[0].revents & (POLLHUP|POLLERR|POLLNVAL))
 445                 break;
 446             if (ufd[1].revents) /* VLC object signaled */
 447                 break;
 448         }
 449         else
 450         {
 451             if (ufd[1].revents)
 452             {
 453                 assert (p_this->b_die);
 454                 errno = EINTR;
 455                 goto error;
 456             }
 457         }
 458
 459         if (p_vs != NULL)
 460             val = p_vs->pf_send (p_vs->p_sys, p_data, i_data);
 461         else
 462 #ifdef WIN32
 463             val = send (fd, p_data, i_data, 0);
 464 #else
 465             val = write (fd, p_data, i_data);
 466 #endif
 467
 468         if (val == -1)
 469         {
 470             if (errno == EINTR)
 471                 continue;
 472             msg_Err (p_this, "Write error: %m");
 473             break;
 474         }
 475
 476         p_data = (const char *)p_data + val;
 477         i_data -= val;
 478         i_total += val;
 479     }
 480
 481     if (unlikely(i_data == 0))
 482         vlc_testcancel (); /* corner case */
 483
 484     if ((i_total > 0) || (i_data == 0))
 485         return i_total;
 486
 487 error:
 488     return -1;
 489 }
 490
 491 #undef net_Gets
 492 /**
 493  * Reads a line from a file descriptor.
 494  * This function is not thread-safe; the same file descriptor I/O cannot be
 495  * read by another thread at the same time (although it can be written to).
 496  *
 497  * @return nul-terminated heap-allocated string, or NULL on I/O error.
 498  */
 499 char *net_Gets( vlc_object_t *p_this, int fd, const v_socket_t *p_vs )
 500 {
 501     char *psz_line = NULL, *ptr = NULL;
 502     size_t  i_line = 0, i_max = 0;
 503
 504
 505     for( ;; )
 506     {
 507         if( i_line == i_max )
 508         {
 509             i_max += 1024;
 510             psz_line = xrealloc( psz_line, i_max );
 511             ptr = psz_line + i_line;
 512         }
 513
 514         if( net_Read( p_this, fd, p_vs, ptr, 1, true ) != 1 )
 515         {
 516             if( i_line == 0 )
 517             {
 518                 free( psz_line );
 519                 return NULL;
 520             }
 521             break;
 522         }
 523
 524         if ( *ptr == '\n' )
 525             break;
 526
 527         i_line++;
 528         ptr++;
 529     }
 530
 531     *ptr-- = '\0';
 532
 533     if( ( ptr >= psz_line ) && ( *ptr == '\r' ) )
 534         *ptr = '\0';
 535
 536     return psz_line;
 537 }
 538
 539 #undef net_Printf
 540 ssize_t net_Printf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 541                     const char *psz_fmt, ... )
 542 {
 543     int i_ret;
 544     va_list args;
 545     va_start( args, psz_fmt );
 546     i_ret = net_vaPrintf( p_this, fd, p_vs, psz_fmt, args );
 547     va_end( args );
 548
 549     return i_ret;
 550 }
 551
 552 #undef net_vaPrintf
 553 ssize_t net_vaPrintf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 554                       const char *psz_fmt, va_list args )
 555 {
 556     char    *psz;
 557     int      i_ret;
 558
 559     int i_size = vasprintf( &psz, psz_fmt, args );
 560     if( i_size == -1 )
 561         return -1;
 562     i_ret = net_Write( p_this, fd, p_vs, psz, i_size ) < i_size
 563         ? -1 : i_size;
 564     free( psz );
 565
 566     return i_ret;
 567 }