diff options
Diffstat (limited to 'protocols/jabber/stream.c')
| -rw-r--r-- | protocols/jabber/stream.c | 593 |
1 files changed, 593 insertions, 0 deletions
diff --git a/protocols/jabber/stream.c b/protocols/jabber/stream.c new file mode 100644 index 00000000..c88a72fd --- /dev/null +++ b/protocols/jabber/stream.c @@ -0,0 +1,593 @@ +/***************************************************************************\ +* * +* BitlBee - An IRC to IM gateway * +* Jabber module - stream handling * +* * +* Copyright 2007 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. * +* * +\***************************************************************************/ + +#include "jabber.h" +#include "sha1.h" +#include <poll.h> + +/* Some structs for the SOCKS5 handshake */ + +struct bs_handshake_data { + + struct jabber_transfer *tf; + + /* <query> element and <streamhost> elements */ + struct xt_node *qnode, *shnode; + + enum + { + BS_PHASE_CONNECT, + BS_PHASE_CONNECTED, + BS_PHASE_REQUEST, + BS_PHASE_REPLY, + BS_PHASE_REPLY_HAVE_LEN + } phase; + + /* SHA1( SID + Initiator JID + Target JID) */ + char *pseudoadr; + + void (*parentfree) ( file_transfer_t *ft ); + + gint connect_timeout; +}; + +struct socks5_hdr +{ + unsigned char ver; + union + { + unsigned char cmd; + unsigned char rep; + } cmdrep; + unsigned char rsv; + unsigned char atyp; +}; + +struct socks5_message +{ + struct socks5_hdr hdr; + unsigned char addrlen; + unsigned char address[64]; +}; + +/* connect() timeout in seconds. */ +#define JABBER_BS_CONTIMEOUT 15 + +/* shouldn't matter if it's mostly too much, kernel's smart about that + * and will only reserve some address space */ +#define JABBER_BS_BUFSIZE 65536 + +gboolean jabber_bs_handshake( gpointer data, gint fd, b_input_condition cond ); + +gboolean jabber_bs_handshake_abort( struct bs_handshake_data *bhd, char *format, ... ); + +void jabber_bs_answer_request( struct bs_handshake_data *bhd ); + +gboolean jabber_bs_read( gpointer data, gint fd, b_input_condition cond ); + +void jabber_bs_out_of_data( file_transfer_t *ft ); + +void jabber_bs_canceled( file_transfer_t *ft , char *reason ); + + +void jabber_bs_free_transfer( file_transfer_t *ft) { + struct jabber_transfer *tf = ft->data; + struct bs_handshake_data *bhd = tf->streamhandle; + void (*parentfree) ( file_transfer_t *ft ); + + parentfree = bhd->parentfree; + + if ( tf->watch_in ) + b_event_remove( tf->watch_in ); + + if( tf->watch_out ) + b_event_remove( tf->watch_out ); + + g_free( bhd->pseudoadr ); + xt_free_node( bhd->qnode ); + g_free( bhd ); + + parentfree( ft ); +} + +/* + * Parses an incoming bytestream request and calls jabber_bs_handshake on success. + */ +int jabber_bs_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_handshake_data *bhd; + + 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; + } + + /* 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] ); + + bhd = g_new0( struct bs_handshake_data, 1 ); + bhd->tf = tf; + bhd->qnode = xt_dup( qnode ); + bhd->shnode = bhd->qnode->children; + bhd->phase = BS_PHASE_CONNECT; + bhd->pseudoadr = g_strdup( hash_hex ); + tf->streamhandle = bhd; + bhd->parentfree = tf->ft->free; + tf->ft->free = jabber_bs_free_transfer; + + jabber_bs_handshake( bhd, 0, 0 ); + + return XT_HANDLED; +} + +/* + * 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_handshake_data *bhd = data; + + bhd->connect_timeout = 0; + + jabber_bs_handshake_abort( bhd, "no connection after %d seconds", JABBER_BS_CONTIMEOUT ); + + return FALSE; +} + +/* + * 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_handshake( gpointer data, gint fd, b_input_condition cond ) +{ + +/* very useful */ +#define ASSERTSOCKOP(op, msg) \ + if( (op) == -1 ) \ + return jabber_bs_handshake_abort( bhd , msg ": %s", strerror( errno ) ); + + struct bs_handshake_data *bhd = data; + struct pollfd pfd = { .fd = fd, .events = POLLHUP|POLLERR }; + short revents; + + if ( bhd->connect_timeout ) + { + b_event_remove( bhd->connect_timeout ); + bhd->connect_timeout = 0; + } + + + /* we need the real io condition */ + if ( poll( &pfd, 1, 0 ) == -1 ) + { + imcb_log( bhd->tf->ic, "poll() failed, weird!" ); + revents = 0; + }; + + revents = pfd.revents; + + if( revents & POLLERR ) + { + int sockerror; + socklen_t errlen = sizeof( sockerror ); + + if ( getsockopt( fd, SOL_SOCKET, SO_ERROR, &sockerror, &errlen ) ) + return jabber_bs_handshake_abort( bhd, "getsockopt() failed, unknown socket error during SOCKS5 handshake (weird!)" ); + + if ( bhd->phase == BS_PHASE_CONNECTED ) + return jabber_bs_handshake_abort( bhd, "connect() failed: %s", strerror( sockerror ) ); + + return jabber_bs_handshake_abort( bhd, "Socket error during SOCKS5 handshake(weird!): %s", strerror( sockerror ) ); + } + + if( revents & POLLHUP ) + return jabber_bs_handshake_abort( bhd, "Remote end closed connection" ); + + + switch( bhd->phase ) + { + case BS_PHASE_CONNECT: + { + struct xt_node *c; + char *host, *port; + struct addrinfo hints, *rp; + + if( ( c = bhd->shnode = xt_find_node( bhd->shnode, "streamhost" ) ) && + ( port = xt_find_attr( c, "port" ) ) && + ( host = xt_find_attr( c, "host" ) ) && + xt_find_attr( c, "jid" ) ) + { + memset( &hints, 0, sizeof( struct addrinfo ) ); + hints.ai_socktype = SOCK_STREAM; + + if ( getaddrinfo( host, port, &hints, &rp ) != 0 ) + return jabber_bs_handshake_abort( bhd, "getaddrinfo() failed: %s", strerror( errno ) ); + + ASSERTSOCKOP( bhd->tf->fd = fd = socket( rp->ai_family, rp->ai_socktype, 0 ), "Opening socket" ); + + sock_make_nonblocking( fd ); + + imcb_log( bhd->tf->ic, "Transferring file %s: Connecting to streamhost %s:%s", bhd->tf->ft->file_name, host, port ); + + if( ( connect( fd, rp->ai_addr, rp->ai_addrlen ) == -1 ) && + ( errno != EINPROGRESS ) ) + return jabber_bs_handshake_abort( bhd , "connect() failed: %s", strerror( errno ) ); + + freeaddrinfo( rp ); + + bhd->phase = BS_PHASE_CONNECTED; + + bhd->tf->watch_out = b_input_add( fd, GAIM_INPUT_WRITE, jabber_bs_handshake, bhd ); + + /* since it takes forever(3mins?) till connect() fails on itself we schedule a timeout */ + bhd->connect_timeout = b_timeout_add( JABBER_BS_CONTIMEOUT * 1000, jabber_bs_connect_timeout, bhd ); + + bhd->tf->watch_in = 0; + return FALSE; + } else + return jabber_bs_handshake_abort( bhd, c ? "incomplete streamhost entry: host=%s port=%s jid=%s" : NULL, + host, port, xt_find_attr( c, "jid" ) ); + } + 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" ); + + bhd->phase = BS_PHASE_REQUEST; + + bhd->tf->watch_in = b_input_add( fd, GAIM_INPUT_READ, jabber_bs_handshake, bhd ); + + bhd->tf->watch_out = 0; + return FALSE; + } + case BS_PHASE_REQUEST: + { + struct socks5_message socks5_connect = + { + .hdr = + { + .ver = 5, + .cmdrep.cmd = 0x01, + .rsv = 0, + .atyp = 0x03 + }, + .addrlen = strlen( bhd->pseudoadr ) + }; + 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_handshake_abort( bhd, "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, bhd->pseudoadr, socks5_connect.addrlen ); + + /* after the address comes the port, which is always 0 */ + memset( socks5_connect.address + socks5_connect.addrlen, 0, sizeof( in_port_t ) ); + + ASSERTSOCKOP( send( fd, &socks5_connect, sizeof( struct socks5_hdr ) + 1 + socks5_connect.addrlen + sizeof( in_port_t ), 0 ) , "Sending SOCKS5 Connect" ); + + bhd->phase = BS_PHASE_REPLY; + + return TRUE; + } + case BS_PHASE_REPLY: + case BS_PHASE_REPLY_HAVE_LEN: + { + /* we have to wait till we have the address length, then we know how much data is left + * (not that we'd actually care about that data, but we need to eat it all up anyway) + */ + struct socks5_message socks5_reply; + int ret; + int expectedbytes = + sizeof( struct socks5_hdr ) + 1 + + ( bhd->phase == BS_PHASE_REPLY_HAVE_LEN ? socks5_reply.addrlen + sizeof( in_port_t ) : 0 ); + + /* notice the peek, we're doing this till enough is there */ + ASSERTSOCKOP( ret = recv( fd, &socks5_reply, expectedbytes, MSG_PEEK ) , "Peeking for SOCKS5 CONNECT reply" ); + + if ( ret == 0 ) + return jabber_bs_handshake_abort( bhd , "peer has shutdown connection" ); + + /* come again */ + if ( ret < expectedbytes ) + return TRUE; + + if ( bhd->phase == BS_PHASE_REPLY ) + { + if( !( socks5_reply.hdr.ver == 5 ) || + !( socks5_reply.hdr.cmdrep.rep == 0 ) || + !( socks5_reply.hdr.atyp == 3 ) || + !( socks5_reply.addrlen <= 62 ) ) /* should also be 40, but who cares as long as all fits in the buffer... */ + return jabber_bs_handshake_abort( bhd, "SOCKS5 CONNECT failed (reply: ver=%d, rep=%d, atyp=%d, addrlen=%d", + socks5_reply.hdr.ver, + socks5_reply.hdr.cmdrep.rep, + socks5_reply.hdr.atyp, + socks5_reply.addrlen); + + /* and again for the rest */ + bhd->phase = BS_PHASE_REPLY_HAVE_LEN; + + /* since it's very likely that the rest is there as well, + * let's not wait for the event loop to call us again */ + return jabber_bs_handshake( bhd , fd, 0 ); + } + + /* got it all, remove it from the queue */ + ASSERTSOCKOP( ret = recv( fd, &socks5_reply, expectedbytes, 0 ) , "Dequeueing MSG_PEEK'ed data after SOCKS5 CONNECT" ); + + /* this shouldn't happen */ + if ( ret < expectedbytes ) + return jabber_bs_handshake_abort( bhd, "internal error, couldn't dequeue MSG_PEEK'ed data after SOCKS5 CONNECT" ); + + /* we're actually done now... */ + + jabber_bs_answer_request( bhd ); + + bhd->tf->watch_in = 0; + return FALSE; + } + default: + /* BUG */ + imcb_log( bhd->tf->ic, "BUG in file transfer code: undefined handshake phase" ); + + bhd->tf->watch_in = 0; + return FALSE; + } +#undef ASSERTSOCKOP +#undef JABBER_BS_ERR_CONDS +} + +/* + * 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 is an example here). That way, a (potentially) + * slow proxy is only used if neccessary. + */ +gboolean jabber_bs_handshake_abort( struct bs_handshake_data *bhd, char *format, ... ) +{ + struct jabber_transfer *tf = bhd->tf; + struct xt_node *reply, *iqnode; + + if( bhd->shnode ) + { + if( 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 ); + + imcb_log( tf->ic, "Transferring file %s: connection to streamhost %s:%s failed (%s)", + tf->ft->file_name, + xt_find_attr( bhd->shnode, "host" ), + xt_find_attr( bhd->shnode, "port" ), + error ); + } + + /* Alright, this streamhost failed, let's try the next... */ + bhd->phase = BS_PHASE_CONNECT; + bhd->shnode = bhd->shnode->next; + + /* the if is not neccessary but saves us one recursion */ + if( bhd->shnode ) + return jabber_bs_handshake( bhd, 0, 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" ); + + bhd->tf->watch_in = 0; + 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_answer_request( struct bs_handshake_data *bhd ) +{ + struct jabber_transfer *tf = bhd->tf; + struct xt_node *reply; + + imcb_log( tf->ic, "Transferring file %s: established SOCKS5 connection to %s:%s", + tf->ft->file_name, + xt_find_attr( bhd->shnode, "host" ), + xt_find_attr( bhd->shnode, "port" ) ); + + tf->ft->data = tf; + tf->ft->started = time( NULL ); + tf->watch_in = b_input_add( tf->fd, GAIM_INPUT_READ, jabber_bs_read, tf ); + tf->ft->out_of_data = jabber_bs_out_of_data; + + reply = xt_new_node( "streamhost-used", NULL, NULL ); + xt_add_attr( reply, "jid", xt_find_attr( bhd->shnode, "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 ); +} + +/* Reads till it is unscheduled or the receiver signifies an overflow. */ +gboolean jabber_bs_read( gpointer data, gint fd, b_input_condition cond ) +{ + int ret; + struct jabber_transfer *tf = data; + char *buffer = g_malloc( JABBER_BS_BUFSIZE ); + + if (tf->receiver_overflow) + { + if( tf->watch_in ) + { + /* should never happen, BUG */ + imcb_file_canceled( tf->ft, "Bug in jabber file transfer code: read while overflow is true. Please report" ); + return FALSE; + } + } + + ret = recv( fd, buffer, JABBER_BS_BUFSIZE, 0 ); + + if( ret == -1 ) + { + /* shouldn't actually happen */ + if( errno == EAGAIN ) + return TRUE; + + imcb_file_canceled( tf->ft, "Error reading tcp socket" ); /* , strerror( errnum ) */ + + return FALSE; + } + + /* that should be all */ + if( ret == 0 ) + return FALSE; + + tf->bytesread += ret; + + buffer = g_realloc( buffer, ret ); + + if ( ( tf->receiver_overflow = imcb_file_write( tf->ft, buffer, ret ) ) ) + { + /* wait for imcb to run out of data */ + tf->watch_in = 0; + return FALSE; + } + + + return TRUE; +} + +/* imcb callback that is invoked when it runs out of data. + * We reschedule jabber_bs_read here if neccessary. */ +void jabber_bs_out_of_data( file_transfer_t *ft ) +{ + struct jabber_transfer *tf = ft->data; + + tf->receiver_overflow = FALSE; + + if ( !tf->watch_in ) + tf->watch_in = b_input_add( tf->fd, GAIM_INPUT_READ, jabber_bs_read, tf ); +} + +/* 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 ); +} |