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