source: lib/ftutil.c @ 7b40f17

/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  Utility functions for file transfer                                      *
*                                                                           *
*  Copyright 2008 Uli Meis <a.sporto+bee@gmail.com>                         *
*                                                                           *
*  This program is free software; you can redistribute it and/or modify     *
*  it under the terms of the GNU General Public License as published by     *
*  the Free Software Foundation; either version 2 of the License, or        *
*  (at your option) any later version.                                      *
*                                                                           *
*  This program is distributed in the hope that it will be useful,          *
*  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            *
*  GNU General Public License for more details.                             *
*                                                                           *
*  You should have received a copy of the GNU General Public License along  *
*  with this program; if not, write to the Free Software Foundation, Inc.,  *
*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              *
*                                                                           *
\***************************************************************************/

#define BITLBEE_CORE
#include "bitlbee.h"
#include <poll.h>
#include <netinet/tcp.h>
#include "lib/ftutil.h"

#define ASSERTSOCKOP(op, msg) \
        if( (op) == -1 ) {\
                g_snprintf( errmsg, sizeof( errmsg ), msg ": %s", strerror( errno ) ); \
                return -1; }

/*
 * Creates a listening socket and returns it in saddr_ptr.
 */
int ft_listen( struct sockaddr_storage *saddr_ptr, char *host, char *port, int copy_fd, int for_bitlbee_client, char **errptr )
{
        int fd, gret, saddrlen;
        struct addrinfo hints, *rp;
        socklen_t ssize = sizeof( struct sockaddr_storage );
        struct sockaddr_storage saddrs, *saddr = &saddrs;
        static char errmsg[1024];
        char *ftlisten = global.conf->ft_listen;

        if( errptr )
                *errptr = errmsg;

        strcpy( port, "0" );

        /* Format is <IP-A>[:<Port-A>];<IP-B>[:<Port-B>] where
         * A is for connections with the bitlbee client (DCC)
         * and B is for connections with IM peers.
         */
        if( ftlisten )
        {
                char *scolon = strchr( ftlisten, ';' );
                char *colon;

                if( scolon )
                {
                        if( for_bitlbee_client )
                        {
                                *scolon = '\0';
                                strncpy( host, ftlisten, HOST_NAME_MAX );
                                *scolon = ';';
                        }
                        else
                        {
                                strncpy( host, scolon + 1, HOST_NAME_MAX );
                        }
                }
                else
                {
                        strncpy( host, ftlisten, HOST_NAME_MAX );
                }

                if( ( colon = strchr( host, ':' ) ) )
                {
                        *colon = '\0';
                        strncpy( port, colon + 1, 5 );
                }
        }
        else if( copy_fd >= 0 && getsockname( copy_fd, (struct sockaddr*) &saddrs, &ssize ) == 0 &&
                 ( saddrs.ss_family == AF_INET || saddrs.ss_family == AF_INET6 ) &&
                 getnameinfo( (struct sockaddr*) &saddrs, ssize, host, HOST_NAME_MAX,
                              NULL, 0, NI_NUMERICHOST ) == 0 )
        {
                /* We just took our local address on copy_fd, which is likely to be a
                   sensible address from which we can do a file transfer now - the
                   most sensible we can get easily. */
        }
        else
        {
                ASSERTSOCKOP( gethostname( host, HOST_NAME_MAX + 1 ), "gethostname()" );
        }

        memset( &hints, 0, sizeof( struct addrinfo ) );
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_flags = AI_NUMERICSERV;

        if ( ( gret = getaddrinfo( host, port, &hints, &rp ) ) != 0 )
        {
                sprintf( errmsg, "getaddrinfo() failed: %s", gai_strerror( gret ) );
                return -1;
        }

        saddrlen = rp->ai_addrlen;

        memcpy( saddr, rp->ai_addr, saddrlen );

        freeaddrinfo( rp );

        ASSERTSOCKOP( fd = socket( saddr->ss_family, SOCK_STREAM, 0 ), "Opening socket" );
        ASSERTSOCKOP( bind( fd, ( struct sockaddr *)saddr, saddrlen ), "Binding socket" );
        ASSERTSOCKOP( listen( fd, 1 ), "Making socket listen" );

        if ( !inet_ntop( saddr->ss_family, saddr->ss_family == AF_INET ?
                        ( void * )&( ( struct sockaddr_in * ) saddr )->sin_addr.s_addr :
                        ( void * )&( ( struct sockaddr_in6 * ) saddr )->sin6_addr.s6_addr,
                        host, HOST_NAME_MAX ) )
        {
                strcpy( errmsg, "inet_ntop failed on listening socket" );
                return -1;
        }

        ssize = sizeof( struct sockaddr_storage );
        ASSERTSOCKOP( getsockname( fd, ( struct sockaddr *)saddr, &ssize ), "Getting socket name" );

        if( saddr->ss_family == AF_INET )
                g_snprintf( port, 6, "%d", ntohs( ( (struct sockaddr_in *) saddr )->sin_port ) );
        else
                g_snprintf( port, 6, "%d", ntohs( ( (struct sockaddr_in6 *) saddr )->sin6_port ) );

        if( saddr_ptr )
                memcpy( saddr_ptr, saddr, saddrlen );

        /* I hate static-length strings.. */
        host[HOST_NAME_MAX] = '\0';
        port[5] = '\0';
        
        return fd;
}