lib/ftutil.c

   1 /***************************************************************************\
   2 *                                                                           *
   3 *  BitlBee - An IRC to IM gateway                                           *
   4 *  Utility functions for file transfer                                      *
   5 *                                                                           *
   6 *  Copyright 2008 Uli Meis <a.sporto+bee@gmail.com>                         *
   7 *                                                                           *
   8 *  This program is free software; you can redistribute it and/or modify     *
   9 *  it under the terms of the GNU General Public License as published by     *
  10 *  the Free Software Foundation; either version 2 of the License, or        *
  11 *  (at your option) any later version.                                      *
  12 *                                                                           *
  13 *  This program is distributed in the hope that it will be useful,          *
  14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
  15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            *
  16 *  GNU General Public License for more details.                             *
  17 *                                                                           *
  18 *  You should have received a copy of the GNU General Public License along  *
  19 *  with this program; if not, write to the Free Software Foundation, Inc.,  *
  20 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              *
  21 *                                                                           *
  22 \***************************************************************************/
  23
  24 #define BITLBEE_CORE
  25 #include "bitlbee.h"
  26 #include <poll.h>
  27 #include <netinet/tcp.h>
  28 #include "lib/ftutil.h"
  29
  30 #define ASSERTSOCKOP(op, msg) \
  31         if( (op) == -1 ) {\
  32                 g_snprintf( errmsg, sizeof( errmsg ), msg ": %s", strerror( errno ) ); \
  33                 return -1; }
  34
  35 /*
  36  * Creates a listening socket and returns it in saddr_ptr.
  37  */
  38 int ft_listen( struct sockaddr_storage *saddr_ptr, char *host, char *port, int copy_fd, int for_bitlbee_client, char **errptr )
  39 {
  40         int fd, gret, saddrlen;
  41         struct addrinfo hints, *rp;
  42         socklen_t ssize = sizeof( struct sockaddr_storage );
  43         struct sockaddr_storage saddrs, *saddr = &saddrs;
  44         static char errmsg[1024];
  45         char *ftlisten = global.conf->ft_listen;
  46
  47         if( errptr )
  48                 *errptr = errmsg;
  49
  50         strcpy( port, "0" );
  51
  52         /* Format is <IP-A>[:<Port-A>];<IP-B>[:<Port-B>] where
  53          * A is for connections with the bitlbee client (DCC)
  54          * and B is for connections with IM peers.
  55          */
  56         if( ftlisten )
  57         {
  58                 char *scolon = strchr( ftlisten, ';' );
  59                 char *colon;
  60
  61                 if( scolon )
  62                 {
  63                         if( for_bitlbee_client )
  64                         {
  65                                 *scolon = '\0';
  66                                 strncpy( host, ftlisten, HOST_NAME_MAX );
  67                                 *scolon = ';';
  68                         }
  69                         else
  70                         {
  71                                 strncpy( host, scolon + 1, HOST_NAME_MAX );
  72                         }
  73                 }
  74                 else
  75                 {
  76                         strncpy( host, ftlisten, HOST_NAME_MAX );
  77                 }
  78
  79                 if( ( colon = strchr( host, ':' ) ) )
  80                 {
  81                         *colon = '\0';
  82                         strncpy( port, colon + 1, 5 );
  83                 }
  84         }
  85         else if( copy_fd >= 0 && getsockname( copy_fd, (struct sockaddr*) &saddrs, &ssize ) == 0 &&
  86                  ( saddrs.ss_family == AF_INET || saddrs.ss_family == AF_INET6 ) &&
  87                  getnameinfo( (struct sockaddr*) &saddrs, ssize, host, HOST_NAME_MAX,
  88                               NULL, 0, NI_NUMERICHOST ) == 0 )
  89         {
  90                 /* We just took our local address on copy_fd, which is likely to be a
  91                    sensible address from which we can do a file transfer now - the
  92                    most sensible we can get easily. */
  93         }
  94         else
  95         {
  96                 ASSERTSOCKOP( gethostname( host, HOST_NAME_MAX + 1 ), "gethostname()" );
  97         }
  98
  99         memset( &hints, 0, sizeof( struct addrinfo ) );
 100         hints.ai_socktype = SOCK_STREAM;
 101         hints.ai_flags = AI_NUMERICSERV;
 102
 103         if ( ( gret = getaddrinfo( host, port, &hints, &rp ) ) != 0 )
 104         {
 105                 sprintf( errmsg, "getaddrinfo() failed: %s", gai_strerror( gret ) );
 106                 return -1;
 107         }
 108
 109         saddrlen = rp->ai_addrlen;
 110
 111         memcpy( saddr, rp->ai_addr, saddrlen );
 112
 113         freeaddrinfo( rp );
 114
 115         ASSERTSOCKOP( fd = socket( saddr->ss_family, SOCK_STREAM, 0 ), "Opening socket" );
 116         ASSERTSOCKOP( bind( fd, ( struct sockaddr *)saddr, saddrlen ), "Binding socket" );
 117         ASSERTSOCKOP( listen( fd, 1 ), "Making socket listen" );
 118
 119         if ( !inet_ntop( saddr->ss_family, saddr->ss_family == AF_INET ?
 120                         ( void * )&( ( struct sockaddr_in * ) saddr )->sin_addr.s_addr :
 121                         ( void * )&( ( struct sockaddr_in6 * ) saddr )->sin6_addr.s6_addr,
 122                         host, HOST_NAME_MAX ) )
 123         {
 124                 strcpy( errmsg, "inet_ntop failed on listening socket" );
 125                 return -1;
 126         }
 127
 128         ssize = sizeof( struct sockaddr_storage );
 129         ASSERTSOCKOP( getsockname( fd, ( struct sockaddr *)saddr, &ssize ), "Getting socket name" );
 130
 131         if( saddr->ss_family == AF_INET )
 132                 g_snprintf( port, 6, "%d", ntohs( ( (struct sockaddr_in *) saddr )->sin_port ) );
 133         else
 134                 g_snprintf( port, 6, "%d", ntohs( ( (struct sockaddr_in6 *) saddr )->sin6_port ) );
 135
 136         if( saddr_ptr )
 137                 memcpy( saddr_ptr, saddr, saddrlen );
 138
 139         /* I hate static-length strings.. */
 140         host[HOST_NAME_MAX] = '\0';
 141         port[5] = '\0';
 142
 143         return fd;
 144 }