/***************************************************************************\ * * * BitlBee - An IRC to IM gateway * * Jabber module - SOCKS5 Bytestreams ( XEP-0065 ) * * * * Copyright 2007 Uli Meis * * * * 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. * * * \***************************************************************************/ #include "jabber.h" #include "sha1.h" #include "lib/ftutil.h" #include struct bs_transfer { struct jabber_transfer *tf; jabber_streamhost_t *sh; GSList *streamhosts; enum { BS_PHASE_CONNECT, BS_PHASE_CONNECTED, BS_PHASE_REQUEST, BS_PHASE_REPLY } phase; /* SHA1( SID + Initiator JID + Target JID) */ char *pseudoadr; gint connect_timeout; char peek_buf[64]; int peek_buf_len; }; struct socks5_message { unsigned char ver; union { unsigned char cmd; unsigned char rep; } cmdrep; unsigned char rsv; unsigned char atyp; unsigned char addrlen; unsigned char address[40]; in_port_t port; } __attribute__ ((packed)); char *socks5_reply_code[] = { "succeeded", "general SOCKS server failure", "connection not allowed by ruleset", "Network unreachable", "Host unreachable", "Connection refused", "TTL expired", "Command not supported", "Address type not supported", "unassigned"}; /* connect() timeout in seconds. */ #define JABBER_BS_CONTIMEOUT 15 /* listen timeout */ #define JABBER_BS_LISTEN_TIMEOUT 90 /* very useful */ #define ASSERTSOCKOP(op, msg) \ if( (op) == -1 ) \ return jabber_bs_abort( bt , msg ": %s", strerror( errno ) ); gboolean jabber_bs_abort( struct bs_transfer *bt, char *format, ... ); void jabber_bs_canceled( file_transfer_t *ft , char *reason ); void jabber_bs_free_transfer( file_transfer_t *ft ); gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond ); gboolean jabber_bs_poll( struct bs_transfer *bt, int fd, short *revents ); gboolean jabber_bs_peek( struct bs_transfer *bt, void *buffer, int buflen ); void jabber_bs_recv_answer_request( struct bs_transfer *bt ); gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond ); gboolean jabber_bs_recv_write_request( file_transfer_t *ft ); gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond ); gboolean jabber_bs_recv_handshake_abort( struct bs_transfer *bt, char *error ); int jabber_bs_recv_request( struct im_connection *ic, struct xt_node *node, struct xt_node *qnode ); gboolean jabber_bs_send_handshake_abort( struct bs_transfer *bt, char *error ); gboolean jabber_bs_send_request( struct jabber_transfer *tf, GSList *streamhosts ); gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond ); static xt_status jabber_bs_send_handle_activate( struct im_connection *ic, struct xt_node *node, struct xt_node *orig ); void jabber_bs_send_activate( struct bs_transfer *bt ); /* * Frees a bs_transfer struct and calls the SI free function */ void jabber_bs_free_transfer( file_transfer_t *ft) { struct jabber_transfer *tf = ft->data; struct bs_transfer *bt = tf->streamhandle; jabber_streamhost_t *sh; if ( bt->connect_timeout ) { b_event_remove( bt->connect_timeout ); bt->connect_timeout = 0; } if ( tf->watch_in ) b_event_remove( tf->watch_in ); if( tf->watch_out ) b_event_remove( tf->watch_out ); g_free( bt->pseudoadr ); while( bt->streamhosts ) { sh = bt->streamhosts->data; bt->streamhosts = g_slist_remove( bt->streamhosts, sh ); g_free( sh->jid ); g_free( sh->host ); g_free( sh ); } g_free( bt ); jabber_si_free_transfer( ft ); } /* * Checks if buflen data is available on the socket and * writes it to buffer if that's the case. */ gboolean jabber_bs_peek( struct bs_transfer *bt, void *buffer, int buflen ) { int ret; int fd = bt->tf->fd; if( buflen > sizeof( bt->peek_buf ) ) return jabber_bs_abort( bt, "BUG: %d > sizeof(peek_buf)", buflen ); ASSERTSOCKOP( ret = recv( fd, bt->peek_buf + bt->peek_buf_len, buflen - bt->peek_buf_len, 0 ), "recv() on SOCKS5 connection" ); if( ret == 0 ) return jabber_bs_abort( bt, "Remote end closed connection" ); bt->peek_buf_len += ret; memcpy( buffer, bt->peek_buf, bt->peek_buf_len ); if( bt->peek_buf_len == buflen ) { /* If we have everything the caller wanted, reset the peek buffer. */ bt->peek_buf_len = 0; return buflen; } else return bt->peek_buf_len; } /* * This function is scheduled in bs_handshake via b_timeout_add after a (non-blocking) connect(). */ gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond ) { struct bs_transfer *bt = data; bt->connect_timeout = 0; jabber_bs_abort( bt, "no connection after %d seconds", bt->tf->ft->sending ? JABBER_BS_LISTEN_TIMEOUT : JABBER_BS_CONTIMEOUT ); return FALSE; } /* * Polls the socket, checks for errors and removes a connect timer * if there is one. */ gboolean jabber_bs_poll( struct bs_transfer *bt, int fd, short *revents ) { struct pollfd pfd = { .fd = fd, .events = POLLHUP|POLLERR }; if ( bt->connect_timeout ) { b_event_remove( bt->connect_timeout ); bt->connect_timeout = 0; } ASSERTSOCKOP( poll( &pfd, 1, 0 ), "poll()" ) if( pfd.revents & POLLERR ) { int sockerror; socklen_t errlen = sizeof( sockerror ); if ( getsockopt( fd, SOL_SOCKET, SO_ERROR, &sockerror, &errlen ) ) return jabber_bs_abort( bt, "getsockopt() failed, unknown socket error during SOCKS5 handshake (weird!)" ); if ( bt->phase == BS_PHASE_CONNECTED ) return jabber_bs_abort( bt, "connect failed: %s", strerror( sockerror ) ); return jabber_bs_abort( bt, "Socket error during SOCKS5 handshake(weird!): %s", strerror( sockerror ) ); } if( pfd.revents & POLLHUP ) return jabber_bs_abort( bt, "Remote end closed connection" ); *revents = pfd.revents; return TRUE; } /* * Used for receive and send path. */ gboolean jabber_bs_abort( struct bs_transfer *bt, char *format, ... ) { va_list params; va_start( params, format ); char error[128]; if( vsnprintf( error, 128, format, params ) < 0 ) sprintf( error, "internal error parsing error string (BUG)" ); va_end( params ); if( bt->tf->ft->sending ) return jabber_bs_send_handshake_abort( bt, error ); else return jabber_bs_recv_handshake_abort( bt, error ); } /* Bad luck */ void jabber_bs_canceled( file_transfer_t *ft , char *reason ) { struct jabber_transfer *tf = ft->data; imcb_log( tf->ic, "File transfer aborted: %s", reason ); } /* * Parses an incoming bytestream request and calls jabber_bs_handshake on success. */ int jabber_bs_recv_request( struct im_connection *ic, struct xt_node *node, struct xt_node *qnode) { char *sid, *ini_jid, *tgt_jid, *mode, *iq_id; struct jabber_data *jd = ic->proto_data; struct jabber_transfer *tf = NULL; GSList *tflist; struct bs_transfer *bt; GSList *shlist=NULL; struct xt_node *shnode; sha1_state_t sha; char hash_hex[41]; unsigned char hash[20]; int i; if( !(iq_id = xt_find_attr( node, "id" ) ) || !(ini_jid = xt_find_attr( node, "from" ) ) || !(tgt_jid = xt_find_attr( node, "to" ) ) || !(sid = xt_find_attr( qnode, "sid" ) ) ) { imcb_log( ic, "WARNING: Received incomplete SI bytestream request"); return XT_HANDLED; } if( ( mode = xt_find_attr( qnode, "mode" ) ) && ( strcmp( mode, "tcp" ) != 0 ) ) { imcb_log( ic, "WARNING: Received SI Request for unsupported bytestream mode %s", xt_find_attr( qnode, "mode" ) ); return XT_HANDLED; } shnode = qnode->children; while( ( shnode = xt_find_node( shnode, "streamhost" ) ) ) { char *jid, *host, *port_s; int port; if( ( jid = xt_find_attr( shnode, "jid" ) ) && ( host = xt_find_attr( shnode, "host" ) ) && ( port_s = xt_find_attr( shnode, "port" ) ) && ( sscanf( port_s, "%d", &port ) == 1 ) ) { jabber_streamhost_t *sh = g_new0( jabber_streamhost_t, 1 ); sh->jid = g_strdup(jid); sh->host = g_strdup(host); sprintf( sh->port, "%u", port ); shlist = g_slist_append( shlist, sh ); } shnode = shnode->next; } if( !shlist ) { imcb_log( ic, "WARNING: Received incomplete SI bytestream request, no parseable streamhost entries"); return XT_HANDLED; } /* Let's see if we can find out what this bytestream should be for... */ for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) ) { struct jabber_transfer *tft = tflist->data; if( ( strcmp( tft->sid, sid ) == 0 ) && ( strcmp( tft->ini_jid, ini_jid ) == 0 ) && ( strcmp( tft->tgt_jid, tgt_jid ) == 0 ) ) { tf = tft; break; } } if (!tf) { imcb_log( ic, "WARNING: Received bytestream request from %s that doesn't match an SI request", ini_jid ); return XT_HANDLED; } /* iq_id and canceled can be reused since SI is done */ g_free( tf->iq_id ); tf->iq_id = g_strdup( iq_id ); tf->ft->canceled = jabber_bs_canceled; /* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */ sha1_init( &sha ); sha1_append( &sha, (unsigned char*) sid, strlen( sid ) ); sha1_append( &sha, (unsigned char*) ini_jid, strlen( ini_jid ) ); sha1_append( &sha, (unsigned char*) tgt_jid, strlen( tgt_jid ) ); sha1_finish( &sha, hash ); for( i = 0; i < 20; i ++ ) sprintf( hash_hex + i * 2, "%02x", hash[i] ); bt = g_new0( struct bs_transfer, 1 ); bt->tf = tf; bt->streamhosts = shlist; bt->sh = shlist->data; bt->phase = BS_PHASE_CONNECT; bt->pseudoadr = g_strdup( hash_hex ); tf->streamhandle = bt; tf->ft->free = jabber_bs_free_transfer; jabber_bs_recv_handshake( bt, -1, 0 ); return XT_HANDLED; } /* * This is what a protocol handshake can look like in cooperative multitasking :) * Might be confusing at first because it's called from different places and is recursing. * (places being the event thread, bs_request, bs_handshake_abort, and itself) * * All in all, it turned out quite nice :) */ gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond ) { struct bs_transfer *bt = data; short revents; int gret; if ( ( fd != -1 ) && !jabber_bs_poll( bt, fd, &revents ) ) return FALSE; switch( bt->phase ) { case BS_PHASE_CONNECT: { struct addrinfo hints, *rp; memset( &hints, 0, sizeof( struct addrinfo ) ); hints.ai_socktype = SOCK_STREAM; if ( ( gret = getaddrinfo( bt->sh->host, bt->sh->port, &hints, &rp ) ) != 0 ) return jabber_bs_abort( bt, "getaddrinfo() failed: %s", gai_strerror( gret ) ); ASSERTSOCKOP( bt->tf->fd = fd = socket( rp->ai_family, rp->ai_socktype, 0 ), "Opening socket" ); sock_make_nonblocking( fd ); imcb_log( bt->tf->ic, "File %s: Connecting to streamhost %s:%s", bt->tf->ft->file_name, bt->sh->host, bt->sh->port ); if( ( connect( fd, rp->ai_addr, rp->ai_addrlen ) == -1 ) && ( errno != EINPROGRESS ) ) return jabber_bs_abort( bt , "connect() failed: %s", strerror( errno ) ); freeaddrinfo( rp ); bt->phase = BS_PHASE_CONNECTED; bt->tf->watch_out = b_input_add( fd, B_EV_IO_WRITE, jabber_bs_recv_handshake, bt ); /* since it takes forever(3mins?) till connect() fails on itself we schedule a timeout */ bt->connect_timeout = b_timeout_add( JABBER_BS_CONTIMEOUT * 1000, jabber_bs_connect_timeout, bt ); bt->tf->watch_in = 0; return FALSE; } case BS_PHASE_CONNECTED: { struct { unsigned char ver; unsigned char nmethods; unsigned char method; } socks5_hello = { .ver = 5, .nmethods = 1, .method = 0x00 /* no auth */ /* one could also implement username/password. If you know * a jabber client or proxy that actually does it, tell me. */ }; ASSERTSOCKOP( send( fd, &socks5_hello, sizeof( socks5_hello ) , 0 ), "Sending auth request" ); bt->phase = BS_PHASE_REQUEST; bt->tf->watch_in = b_input_add( fd, B_EV_IO_READ, jabber_bs_recv_handshake, bt ); bt->tf->watch_out = 0; return FALSE; } case BS_PHASE_REQUEST: { struct socks5_message socks5_connect = { .ver = 5, .cmdrep.cmd = 0x01, .rsv = 0, .atyp = 0x03, .addrlen = strlen( bt->pseudoadr ), .port = 0 }; int ret; char buf[2]; /* If someone's trying to be funny and sends only one byte at a time we'll fail :) */ ASSERTSOCKOP( ret = recv( fd, buf, 2, 0 ) , "Receiving auth reply" ); if( !( ret == 2 ) || !( buf[0] == 5 ) || !( buf[1] == 0 ) ) return jabber_bs_abort( bt, "Auth not accepted by streamhost (reply: len=%d, ver=%d, status=%d)", ret, buf[0], buf[1] ); /* copy hash into connect message */ memcpy( socks5_connect.address, bt->pseudoadr, socks5_connect.addrlen ); ASSERTSOCKOP( send( fd, &socks5_connect, sizeof( struct socks5_message ), 0 ) , "Sending SOCKS5 Connect" ); bt->phase = BS_PHASE_REPLY; return TRUE; } case BS_PHASE_REPLY: { struct socks5_message socks5_reply; int ret; if ( !( ret = jabber_bs_peek( bt, &socks5_reply, sizeof( struct socks5_message ) ) ) ) return FALSE; if ( ret < 5 ) /* header up to address length */ return TRUE; else if( ret < sizeof( struct socks5_message ) ) { /* Either a buggy proxy or just one that doesnt regard the SHOULD in XEP-0065 * saying the reply SHOULD contain the address */ ASSERTSOCKOP( ret = recv( fd, &socks5_reply, ret, 0 ), "Dequeuing after MSG_PEEK" ); } if( !( socks5_reply.ver == 5 ) || !( socks5_reply.cmdrep.rep == 0 ) ) { char errstr[128] = ""; if( ( socks5_reply.ver == 5 ) && ( socks5_reply.cmdrep.rep < ( sizeof( socks5_reply_code ) / sizeof( socks5_reply_code[0] ) ) ) ) { sprintf( errstr, "with \"%s\" ", socks5_reply_code[ socks5_reply.cmdrep.rep ] ); } return jabber_bs_abort( bt, "SOCKS5 CONNECT failed %s(reply: ver=%d, rep=%d, atyp=%d, addrlen=%d)", errstr, socks5_reply.ver, socks5_reply.cmdrep.rep, socks5_reply.atyp, socks5_reply.addrlen); } /* usually a proxy sends back the 40 bytes address but I encountered at least one (of jabber.cz) * that sends atyp=0 addrlen=0 and only 6 bytes (one less than one would expect). * Therefore I removed the wait for more bytes. Since we don't care about what else the proxy * is sending, it shouldnt matter */ if( bt->tf->ft->sending ) jabber_bs_send_activate( bt ); else jabber_bs_recv_answer_request( bt ); return FALSE; } default: /* BUG */ imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" ); bt->tf->watch_in = 0; return FALSE; } } /* * If the handshake failed we can try the next streamhost, if there is one. * An intelligent sender would probably specify himself as the first streamhost and * a proxy as the second (Kopete and PSI are examples here). That way, a (potentially) * slow proxy is only used if neccessary. This of course also means, that the timeout * per streamhost should be kept short. If one or two firewalled adresses are specified, * they have to timeout first before a proxy is tried. */ gboolean jabber_bs_recv_handshake_abort( struct bs_transfer *bt, char *error ) { struct jabber_transfer *tf = bt->tf; struct xt_node *reply, *iqnode; GSList *shlist; imcb_log( tf->ic, "Transferring file %s: connection to streamhost %s:%s failed (%s)", tf->ft->file_name, bt->sh->host, bt->sh->port, error ); /* Alright, this streamhost failed, let's try the next... */ bt->phase = BS_PHASE_CONNECT; shlist = g_slist_find( bt->streamhosts, bt->sh ); if( shlist && shlist->next ) { bt->sh = shlist->next->data; return jabber_bs_recv_handshake( bt, -1, 0 ); } /* out of stream hosts */ iqnode = jabber_make_packet( "iq", "result", tf->ini_jid, NULL ); reply = jabber_make_error_packet( iqnode, "item-not-found", "cancel" , "404" ); xt_free_node( iqnode ); xt_add_attr( reply, "id", tf->iq_id ); if( !jabber_write_packet( tf->ic, reply ) ) imcb_log( tf->ic, "WARNING: Error transmitting bytestream response" ); xt_free_node( reply ); imcb_file_canceled( tf->ft, "couldn't connect to any streamhosts" ); bt->tf->watch_in = 0; /* MUST always return FALSE! */ return FALSE; } /* * After the SOCKS5 handshake succeeds we need to inform the initiator which streamhost we chose. * If he is the streamhost himself, he might already know that. However, if it's a proxy, * the initiator will have to make a connection himself. */ void jabber_bs_recv_answer_request( struct bs_transfer *bt ) { struct jabber_transfer *tf = bt->tf; struct xt_node *reply; imcb_log( tf->ic, "File %s: established SOCKS5 connection to %s:%s", tf->ft->file_name, bt->sh->host, bt->sh->port ); tf->ft->data = tf; tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_recv_read, bt ); tf->ft->write_request = jabber_bs_recv_write_request; reply = xt_new_node( "streamhost-used", NULL, NULL ); xt_add_attr( reply, "jid", bt->sh->jid ); reply = xt_new_node( "query", NULL, reply ); xt_add_attr( reply, "xmlns", XMLNS_BYTESTREAMS ); reply = jabber_make_packet( "iq", "result", tf->ini_jid, reply ); xt_add_attr( reply, "id", tf->iq_id ); if( !jabber_write_packet( tf->ic, reply ) ) imcb_file_canceled( tf->ft, "Error transmitting bytestream response" ); xt_free_node( reply ); } /* * This function is called from write_request directly. If no data is available, it will install itself * as a watcher for input on fd and once that happens, deliver the data and unschedule itself again. */ gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond ) { int ret; struct bs_transfer *bt = data; struct jabber_transfer *tf = bt->tf; if( fd != -1 ) /* called via event thread */ { tf->watch_in = 0; ASSERTSOCKOP( ret = recv( fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) , "Receiving" ); } else { /* called directly. There might not be any data available. */ if( ( ( ret = recv( tf->fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) ) == -1 ) && ( errno != EAGAIN ) ) return jabber_bs_abort( bt, "Receiving: %s", strerror( errno ) ); if( ( ret == -1 ) && ( errno == EAGAIN ) ) { tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_recv_read, bt ); return FALSE; } } /* shouldn't happen since we know the file size */ if( ret == 0 ) return jabber_bs_abort( bt, "Remote end closed connection" ); tf->bytesread += ret; if( tf->bytesread >= tf->ft->file_size ) imcb_file_finished( tf->ft ); tf->ft->write( tf->ft, tf->ft->buffer, ret ); return FALSE; } /* * imc callback that is invoked when it is ready to receive some data. */ gboolean jabber_bs_recv_write_request( file_transfer_t *ft ) { struct jabber_transfer *tf = ft->data; if( tf->watch_in ) { imcb_file_canceled( ft, "BUG in jabber file transfer: write_request called when already watching for input" ); return FALSE; } jabber_bs_recv_read( tf->streamhandle, -1 , 0 ); return TRUE; } /* * Issues a write_request to imc. * */ gboolean jabber_bs_send_can_write( gpointer data, gint fd, b_input_condition cond ) { struct bs_transfer *bt = data; bt->tf->watch_out = 0; bt->tf->ft->write_request( bt->tf->ft ); return FALSE; } /* * This should only be called if we can write, so just do it. * Add a write watch so we can write more during the next cycle (if possible). */ gboolean jabber_bs_send_write( file_transfer_t *ft, char *buffer, unsigned int len ) { struct jabber_transfer *tf = ft->data; struct bs_transfer *bt = tf->streamhandle; int ret; if( tf->watch_out ) return jabber_bs_abort( bt, "BUG: write() called while watching " ); /* TODO: catch broken pipe */ ASSERTSOCKOP( ret = send( tf->fd, buffer, len, 0 ), "Sending" ); tf->byteswritten += ret; /* TODO: this should really not be fatal */ if( ret < len ) return jabber_bs_abort( bt, "send() sent %d instead of %d (send buffer too big!)", ret, len ); if( tf->byteswritten >= ft->file_size ) imcb_file_finished( ft ); else bt->tf->watch_out = b_input_add( tf->fd, B_EV_IO_WRITE, jabber_bs_send_can_write, bt ); return TRUE; } /* * Handles the reply by the receiver containing the used streamhost. */ static xt_status jabber_bs_send_handle_reply(struct im_connection *ic, struct xt_node *node, struct xt_node *orig ) { struct jabber_transfer *tf = NULL; struct jabber_data *jd = ic->proto_data; struct bs_transfer *bt; GSList *tflist; struct xt_node *c; char *sid, *jid; if( !( c = xt_find_node( node->children, "query" ) ) || !( c = xt_find_node( c->children, "streamhost-used" ) ) || !( jid = xt_find_attr( c, "jid" ) ) ) { imcb_log( ic, "WARNING: Received incomplete bytestream reply" ); return XT_HANDLED; } if( !( c = xt_find_node( orig->children, "query" ) ) || !( sid = xt_find_attr( c, "sid" ) ) ) { imcb_log( ic, "WARNING: Error parsing request corresponding to the incoming bytestream reply" ); return XT_HANDLED; } /* Let's see if we can find out what this bytestream should be for... */ for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) ) { struct jabber_transfer *tft = tflist->data; if( ( strcmp( tft->sid, sid ) == 0 ) ) { tf = tft; break; } } if( !tf ) { imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply to unknown request" ); return XT_HANDLED; } bt = tf->streamhandle; tf->accepted = TRUE; if( strcmp( jid, tf->ini_jid ) == 0 ) { /* we're streamhost and target */ if( bt->phase == BS_PHASE_REPLY ) { /* handshake went through, let's start transferring */ tf->ft->write_request( tf->ft ); } } else { /* using a proxy, abort listen */ if( tf->watch_in ) { b_event_remove( tf->watch_in ); tf->watch_in = 0; } if( tf->fd != -1 ) { closesocket( tf->fd ); tf->fd = -1; } if ( bt->connect_timeout ) { b_event_remove( bt->connect_timeout ); bt->connect_timeout = 0; } GSList *shlist; for( shlist = jd->streamhosts ; shlist ; shlist = g_slist_next( shlist ) ) { jabber_streamhost_t *sh = shlist->data; if( strcmp( sh->jid, jid ) == 0 ) { bt->sh = sh; jabber_bs_recv_handshake( bt, -1, 0 ); return XT_HANDLED; } } imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply with unknown streamhost %s", jid ); } return XT_HANDLED; } /* * Tell the proxy to activate the stream. Looks like this: * * * * tgt_jid * * */ void jabber_bs_send_activate( struct bs_transfer *bt ) { struct xt_node *node; node = xt_new_node( "activate", bt->tf->tgt_jid, NULL ); node = xt_new_node( "query", NULL, node ); xt_add_attr( node, "xmlns", XMLNS_BYTESTREAMS ); xt_add_attr( node, "sid", bt->tf->sid ); node = jabber_make_packet( "iq", "set", bt->sh->jid, node ); jabber_cache_add( bt->tf->ic, node, jabber_bs_send_handle_activate ); jabber_write_packet( bt->tf->ic, node ); } /* * The proxy has activated the bytestream. * We can finally start pushing some data out. */ static xt_status jabber_bs_send_handle_activate( struct im_connection *ic, struct xt_node *node, struct xt_node *orig ) { char *sid; GSList *tflist; struct jabber_transfer *tf = NULL; struct xt_node *query; struct jabber_data *jd = ic->proto_data; query = xt_find_node( orig->children, "query" ); sid = xt_find_attr( query, "sid" ); for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) ) { struct jabber_transfer *tft = tflist->data; if( ( strcmp( tft->sid, sid ) == 0 ) ) { tf = tft; break; } } if( !tf ) { imcb_log( ic, "WARNING: Received SOCKS5 bytestream activation for unknown stream" ); return XT_HANDLED; } imcb_log( tf->ic, "File %s: SOCKS5 handshake and activation successful! Transfer about to start...", tf->ft->file_name ); /* handshake went through, let's start transferring */ tf->ft->write_request( tf->ft ); return XT_HANDLED; } jabber_streamhost_t *jabber_si_parse_proxy( struct im_connection *ic, char *proxy ) { char *host, *port, *jid; jabber_streamhost_t *sh; if( ( ( host = strchr( proxy, ',' ) ) == 0 ) || ( ( port = strchr( host+1, ',' ) ) == 0 ) ) { imcb_log( ic, "Error parsing proxy setting: \"%s\" (ignored)", proxy ); return NULL; } jid = proxy; *host++ = '\0'; *port++ = '\0'; sh = g_new0( jabber_streamhost_t, 1 ); sh->jid = g_strdup( jid ); sh->host = g_strdup( host ); strcpy( sh->port, port ); return sh; } void jabber_si_set_proxies( struct bs_transfer *bt ) { struct jabber_transfer *tf = bt->tf; struct jabber_data *jd = tf->ic->proto_data; char *proxysetting = g_strdup ( set_getstr( &tf->ic->acc->set, "proxy" ) ); char *proxy, *next, *errmsg = NULL; char port[6]; char host[HOST_NAME_MAX+1]; jabber_streamhost_t *sh, *sh2; GSList *streamhosts = jd->streamhosts; proxy = proxysetting; while ( proxy && ( *proxy!='\0' ) ) { if( ( next = strchr( proxy, ';' ) ) ) *next++ = '\0'; if( strcmp( proxy, "" ) == 0 ) { if( ( tf->fd = ft_listen( &tf->saddr, host, port, FALSE, &errmsg ) ) != -1 ) { sh = g_new0( jabber_streamhost_t, 1 ); sh->jid = g_strdup( tf->ini_jid ); sh->host = g_strdup( host ); strcpy( sh->port, port ); bt->streamhosts = g_slist_append( bt->streamhosts, sh ); bt->tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_send_handshake, bt ); bt->connect_timeout = b_timeout_add( JABBER_BS_LISTEN_TIMEOUT * 1000, jabber_bs_connect_timeout, bt ); } else { imcb_log( tf->ic, "Transferring file %s: couldn't listen locally(non fatal, check your ft_listen setting in bitlbee.conf): %s", tf->ft->file_name, errmsg ); } } else if( strcmp( proxy, "" ) == 0 ) { while ( streamhosts ) { sh = g_new0( jabber_streamhost_t, 1 ); sh2 = streamhosts->data; sh->jid = g_strdup( sh2->jid ); sh->host = g_strdup( sh2->host ); strcpy( sh->port, sh2->port ); bt->streamhosts = g_slist_append( bt->streamhosts, sh ); streamhosts = g_slist_next( streamhosts ); } } else if( ( sh = jabber_si_parse_proxy( tf->ic, proxy ) ) ) bt->streamhosts = g_slist_append( bt->streamhosts, sh ); proxy = next; } } /* * Starts a bytestream. */ gboolean jabber_bs_send_start( struct jabber_transfer *tf ) { struct bs_transfer *bt; sha1_state_t sha; char hash_hex[41]; unsigned char hash[20]; int i,ret; /* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */ sha1_init( &sha ); sha1_append( &sha, (unsigned char*) tf->sid, strlen( tf->sid ) ); sha1_append( &sha, (unsigned char*) tf->ini_jid, strlen( tf->ini_jid ) ); sha1_append( &sha, (unsigned char*) tf->tgt_jid, strlen( tf->tgt_jid ) ); sha1_finish( &sha, hash ); for( i = 0; i < 20; i ++ ) sprintf( hash_hex + i * 2, "%02x", hash[i] ); bt = g_new0( struct bs_transfer, 1 ); bt->tf = tf; bt->phase = BS_PHASE_CONNECT; bt->pseudoadr = g_strdup( hash_hex ); tf->streamhandle = bt; tf->ft->free = jabber_bs_free_transfer; tf->ft->canceled = jabber_bs_canceled; jabber_si_set_proxies( bt ); ret = jabber_bs_send_request( tf, bt->streamhosts); return ret; } gboolean jabber_bs_send_request( struct jabber_transfer *tf, GSList *streamhosts ) { struct xt_node *shnode, *query, *iq; query = xt_new_node( "query", NULL, NULL ); xt_add_attr( query, "xmlns", XMLNS_BYTESTREAMS ); xt_add_attr( query, "sid", tf->sid ); xt_add_attr( query, "mode", "tcp" ); while( streamhosts ) { jabber_streamhost_t *sh = streamhosts->data; shnode = xt_new_node( "streamhost", NULL, NULL ); xt_add_attr( shnode, "jid", sh->jid ); xt_add_attr( shnode, "host", sh->host ); xt_add_attr( shnode, "port", sh->port ); xt_add_child( query, shnode ); streamhosts = g_slist_next( streamhosts ); } iq = jabber_make_packet( "iq", "set", tf->tgt_jid, query ); xt_add_attr( iq, "from", tf->ini_jid ); jabber_cache_add( tf->ic, iq, jabber_bs_send_handle_reply ); if( !jabber_write_packet( tf->ic, iq ) ) imcb_file_canceled( tf->ft, "Error transmitting bytestream request" ); return TRUE; } gboolean jabber_bs_send_handshake_abort(struct bs_transfer *bt, char *error ) { struct jabber_transfer *tf = bt->tf; struct jabber_data *jd = tf->ic->proto_data; /* TODO: did the receiver get here somehow??? */ imcb_log( tf->ic, "Transferring file %s: SOCKS5 handshake failed: %s", tf->ft->file_name, error ); if( jd->streamhosts==NULL ) /* we're done here unless we have a proxy to try */ imcb_file_canceled( tf->ft, error ); /* MUST always return FALSE! */ return FALSE; } /* * SOCKS5BYTESTREAM protocol for the sender */ gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond ) { struct bs_transfer *bt = data; struct jabber_transfer *tf = bt->tf; short revents; if ( !jabber_bs_poll( bt, fd, &revents ) ) return FALSE; switch( bt->phase ) { case BS_PHASE_CONNECT: { struct sockaddr_storage clt_addr; socklen_t ssize = sizeof( clt_addr ); /* Connect */ ASSERTSOCKOP( tf->fd = accept( fd, (struct sockaddr *) &clt_addr, &ssize ), "Accepting connection" ); closesocket( fd ); fd = tf->fd; sock_make_nonblocking( fd ); bt->phase = BS_PHASE_CONNECTED; bt->tf->watch_in = b_input_add( fd, B_EV_IO_READ, jabber_bs_send_handshake, bt ); return FALSE; } case BS_PHASE_CONNECTED: { int ret, have_noauth=FALSE; struct { unsigned char ver; unsigned char method; } socks5_auth_reply = { .ver = 5, .method = 0 }; struct { unsigned char ver; unsigned char nmethods; unsigned char method; } socks5_hello; if( !( ret = jabber_bs_peek( bt, &socks5_hello, sizeof( socks5_hello ) ) ) ) return FALSE; if( ret < sizeof( socks5_hello ) ) return TRUE; if( !( socks5_hello.ver == 5 ) || !( socks5_hello.nmethods >= 1 ) || !( socks5_hello.nmethods < 32 ) ) return jabber_bs_abort( bt, "Invalid auth request ver=%d nmethods=%d method=%d", socks5_hello.ver, socks5_hello.nmethods, socks5_hello.method ); have_noauth = socks5_hello.method == 0; if( socks5_hello.nmethods > 1 ) { char mbuf[32]; int i; ASSERTSOCKOP( ret = recv( fd, mbuf, socks5_hello.nmethods - 1, 0 ) , "Receiving auth methods" ); if( ret < ( socks5_hello.nmethods - 1 ) ) return jabber_bs_abort( bt, "Partial auth request"); for( i = 0 ; !have_noauth && ( i < socks5_hello.nmethods - 1 ) ; i ++ ) if( mbuf[i] == 0 ) have_noauth = TRUE; } if( !have_noauth ) return jabber_bs_abort( bt, "Auth request didn't include no authentication" ); ASSERTSOCKOP( send( fd, &socks5_auth_reply, sizeof( socks5_auth_reply ) , 0 ), "Sending auth reply" ); bt->phase = BS_PHASE_REQUEST; return TRUE; } case BS_PHASE_REQUEST: { struct socks5_message socks5_connect; int msgsize = sizeof( struct socks5_message ); int ret; if( !( ret = jabber_bs_peek( bt, &socks5_connect, msgsize ) ) ) return FALSE; if( ret < msgsize ) return TRUE; if( !( socks5_connect.ver == 5) || !( socks5_connect.cmdrep.cmd == 1 ) || !( socks5_connect.atyp == 3 ) || !(socks5_connect.addrlen == 40 ) ) return jabber_bs_abort( bt, "Invalid SOCKS5 Connect message (addrlen=%d, ver=%d, cmd=%d, atyp=%d)", socks5_connect.addrlen, socks5_connect.ver, socks5_connect.cmdrep.cmd, socks5_connect.atyp ); if( !( memcmp( socks5_connect.address, bt->pseudoadr, 40 ) == 0 ) ) return jabber_bs_abort( bt, "SOCKS5 Connect message contained wrong digest"); socks5_connect.cmdrep.rep = 0; ASSERTSOCKOP( send( fd, &socks5_connect, msgsize, 0 ), "Sending connect reply" ); bt->phase = BS_PHASE_REPLY; imcb_log( tf->ic, "File %s: SOCKS5 handshake successful! Transfer about to start...", tf->ft->file_name ); if( tf->accepted ) { /* streamhost-used message came already in(possible?), let's start sending */ tf->ft->write_request( tf->ft ); } tf->watch_in = 0; return FALSE; } default: /* BUG */ imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" ); bt->tf->watch_in = 0; return FALSE; } } #undef ASSERTSOCKOP