src/network/io.c

   1 /*****************************************************************************
   2  * io.c: network I/O functions
   3  *****************************************************************************
   4  * Copyright (C) 2004-2005, 2007 the VideoLAN team
   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
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 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 General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, 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_CreateGetNonEmptyString (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", psz_host, i_port);
 140
 141     int i_val = vlc_getaddrinfo (p_this, psz_host, i_port, &hints, &res);
 142     if (i_val)
 143     {
 144         msg_Err (p_this, "Cannot resolve %s port %d : %s", 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 (vs != NULL)
 312         {
 313             int canc = vlc_savecancel ();
 314             n = vs->pf_recv (vs->p_sys, p_buf, i_buflen);
 315             vlc_restorecancel (canc);
 316         }
 317         else
 318         {
 319 #ifdef WIN32
 320             n = recv (fd, p_buf, i_buflen, 0);
 321 #else
 322             n = read (fd, p_buf, i_buflen);
 323 #endif
 324         }
 325
 326         if (n == -1)
 327         {
 328 #if defined(WIN32) || defined(UNDER_CE)
 329             switch (WSAGetLastError ())
 330             {
 331                 case WSAEWOULDBLOCK:
 332                 case WSAEINTR:
 333                 /* only happens with vs != NULL (TLS) - not really an error */
 334                     continue;
 335
 336                 case WSAEMSGSIZE:
 337                 /* For UDP only */
 338                 /* On Win32, recv() fails if the datagram doesn't fit inside
 339                  * the passed buffer, even though the buffer will be filled
 340                  * with the first part of the datagram. */
 341                     msg_Err (p_this, "Receive error: "
 342                                      "Increase the mtu size (--mtu option)");
 343                     n = i_buflen;
 344                     break;
 345             }
 346 #else
 347             switch (errno)
 348             {
 349                 case EAGAIN: /* spurious wakeup or no TLS data */
 350 #if (EAGAIN != EWOULDBLOCK)
 351                 case EWOULDBLOCK:
 352 #endif
 353                 case EINTR:  /* asynchronous signal */
 354                     continue;
 355             }
 356 #endif
 357             goto error;
 358         }
 359
 360         if (n == 0)
 361             /* For streams, this means end of file, and there will not be any
 362              * further data ever on the stream. For datagram sockets, this
 363              * means empty datagram, and there could be more data coming.
 364              * However, it makes no sense to set <waitall> with datagrams in the
 365              * first place.
 366              */
 367             break; // EOF
 368
 369         i_total += n;
 370         p_buf = (char *)p_buf + n;
 371         i_buflen -= n;
 372
 373         if (!waitall)
 374             break;
 375     }
 376
 377     return i_total;
 378
 379 error:
 380     msg_Err (p_this, "Read error: %m");
 381 silent:
 382     return -1;
 383 }
 384
 385 #undef net_Write
 386 /**
 387  * Writes data to a file descriptor.
 388  * This blocks until all data is written or an error occurs.
 389  *
 390  * This function is a cancellation point if p_vs is NULL.
 391  * This function is not cancellation-safe if p_vs is not NULL.
 392  *
 393  * @return the total number of bytes written, or -1 if an error occurs
 394  * before any data is written.
 395  */
 396 ssize_t net_Write( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 397                    const void *restrict p_data, size_t i_data )
 398 {
 399     size_t i_total = 0;
 400     struct pollfd ufd[2] = {
 401         { .fd = fd,                           .events = POLLOUT },
 402         { .fd = vlc_object_waitpipe (p_this), .events = POLLIN  },
 403     };
 404
 405     if (unlikely(ufd[1].fd == -1))
 406     {
 407         vlc_testcancel ();
 408         return -1;
 409     }
 410
 411     while( i_data > 0 )
 412     {
 413         ssize_t val;
 414
 415         ufd[0].revents = ufd[1].revents = 0;
 416
 417         if (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1) == -1)
 418         {
 419             if (errno == EINTR)
 420                 continue;
 421             msg_Err (p_this, "Polling error: %m");
 422             return -1;
 423         }
 424
 425         if (i_total > 0)
 426         {   /* If POLLHUP resp. POLLERR|POLLNVAL occurs while we have already
 427              * read some data, it is important that we first return the number
 428              * of bytes read, and then return 0 resp. -1 on the NEXT call. */
 429             if (ufd[0].revents & (POLLHUP|POLLERR|POLLNVAL))
 430                 break;
 431             if (ufd[1].revents) /* VLC object signaled */
 432                 break;
 433         }
 434         else
 435         {
 436             if (ufd[1].revents)
 437             {
 438                 assert (p_this->b_die);
 439                 errno = EINTR;
 440                 goto error;
 441             }
 442         }
 443
 444         if (p_vs != NULL)
 445             val = p_vs->pf_send (p_vs->p_sys, p_data, i_data);
 446         else
 447 #ifdef WIN32
 448             val = send (fd, p_data, i_data, 0);
 449 #else
 450             val = write (fd, p_data, i_data);
 451 #endif
 452
 453         if (val == -1)
 454         {
 455             if (errno == EINTR)
 456                 continue;
 457             msg_Err (p_this, "Write error: %m");
 458             break;
 459         }
 460
 461         p_data = (const char *)p_data + val;
 462         i_data -= val;
 463         i_total += val;
 464     }
 465
 466     if (unlikely(i_data == 0))
 467         vlc_testcancel (); /* corner case */
 468
 469     if ((i_total > 0) || (i_data == 0))
 470         return i_total;
 471
 472 error:
 473     return -1;
 474 }
 475
 476 #undef net_Gets
 477 /**
 478  * Reads a line from a file descriptor.
 479  * This function is not thread-safe; the same file descriptor I/O cannot be
 480  * read by another thread at the same time (although it can be written to).
 481  *
 482  * @return nul-terminated heap-allocated string, or NULL on I/O error.
 483  */
 484 char *net_Gets( vlc_object_t *p_this, int fd, const v_socket_t *p_vs )
 485 {
 486     char *psz_line = NULL, *ptr = NULL;
 487     size_t  i_line = 0, i_max = 0;
 488
 489
 490     for( ;; )
 491     {
 492         if( i_line == i_max )
 493         {
 494             i_max += 1024;
 495             psz_line = xrealloc( psz_line, i_max );
 496             ptr = psz_line + i_line;
 497         }
 498
 499         if( net_Read( p_this, fd, p_vs, ptr, 1, true ) != 1 )
 500         {
 501             if( i_line == 0 )
 502             {
 503                 free( psz_line );
 504                 return NULL;
 505             }
 506             break;
 507         }
 508
 509         if ( *ptr == '\n' )
 510             break;
 511
 512         i_line++;
 513         ptr++;
 514     }
 515
 516     *ptr-- = '\0';
 517
 518     if( ( ptr >= psz_line ) && ( *ptr == '\r' ) )
 519         *ptr = '\0';
 520
 521     return psz_line;
 522 }
 523
 524 #undef net_Printf
 525 ssize_t net_Printf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 526                     const char *psz_fmt, ... )
 527 {
 528     int i_ret;
 529     va_list args;
 530     va_start( args, psz_fmt );
 531     i_ret = net_vaPrintf( p_this, fd, p_vs, psz_fmt, args );
 532     va_end( args );
 533
 534     return i_ret;
 535 }
 536
 537 #undef net_vaPrintf
 538 ssize_t net_vaPrintf( vlc_object_t *p_this, int fd, const v_socket_t *p_vs,
 539                       const char *psz_fmt, va_list args )
 540 {
 541     char    *psz;
 542     int      i_ret;
 543
 544     int i_size = vasprintf( &psz, psz_fmt, args );
 545     if( i_size == -1 )
 546         return -1;
 547     i_ret = net_Write( p_this, fd, p_vs, psz, i_size ) < i_size
 548         ? -1 : i_size;
 549     free( psz );
 550
 551     return i_ret;
 552 }