From: ben Date: Sun, 30 Sep 2007 19:42:31 +0000 (+0000) Subject: Merge the looking up of channel numbers for SSH-2 channel messages into X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/commitdiff_plain/e223b7c7fb42431f9d4f7111c5df209d6b8b1d25 Merge the looking up of channel numbers for SSH-2 channel messages into a single function which also handles checking that channels exist and are properly open. This should make PuTTY a little less tolerant of servers that send bogus messages. git-svn-id: svn://svn.tartarus.org/sgt/putty@7751 cda61777-01e9-0310-a592-d414129be87e --- diff --git a/ssh.c b/ssh.c index d1a2c80f..0c878c91 100644 --- a/ssh.c +++ b/ssh.c @@ -6276,6 +6276,30 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) } } +/* + * Find the channel associated with a message. If there's no channel, + * or it's not properly open, make a noise about it and return NULL. + */ +static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) +{ + unsigned localid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &localid, ssh_channelfind); + if (!c || + (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && + pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { + char *buf = dupprintf("Received %s for %s channel %u", + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + pktin->type), + c ? "half-open" : "nonexistent", localid); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); + return NULL; + } + return c; +} + static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin) { /* @@ -6284,13 +6308,12 @@ static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin) * sent with want_reply false or are sent before this handler gets * installed. */ - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; struct winadj *wa; - c = find234(ssh->channels, &i, ssh_channelfind); + c = ssh2_channel_msg(ssh, pktin); if (!c) - return; /* nonexistent channel */ + return; wa = c->v.v2.winadj_head; if (!wa) logevent("excess SSH_MSG_CHANNEL_FAILURE"); @@ -6310,10 +6333,11 @@ static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) { - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c && !c->closes) { + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (!c->closes) { c->v.v2.remwindow += ssh_pkt_getuint32(pktin); ssh2_try_send_and_unthrottle(c); } @@ -6323,11 +6347,10 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) { char *data; int length; - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); + c = ssh2_channel_msg(ssh, pktin); if (!c) - return; /* nonexistent channel */ + return; if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) return; /* extended but not stderr */ @@ -6414,12 +6437,11 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) { - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); + c = ssh2_channel_msg(ssh, pktin); if (!c) - return; /* nonexistent channel */ + return; if (c->type == CHAN_X11) { /* @@ -6438,16 +6460,12 @@ static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) { - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; struct Packet *pktout; - c = find234(ssh->channels, &i, ssh_channelfind); - if (!c || c->halfopen) { - bombout(("Received CHANNEL_CLOSE for %s channel %d\n", - c ? "half-open" : "nonexistent", i)); + c = ssh2_channel_msg(ssh, pktin); + if (!c) return; - } /* Do pre-close processing on the channel. */ switch (c->type) { case CHAN_MAINSESSION: @@ -6500,13 +6518,12 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) { - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; struct Packet *pktout; - c = find234(ssh->channels, &i, ssh_channelfind); + c = ssh2_channel_msg(ssh, pktin); if (!c) - return; /* nonexistent channel */ + return; if (c->type != CHAN_SOCKDATA_DORMANT) return; /* dunno why they're confirming this */ c->remoteid = ssh_pkt_getuint32(pktin); @@ -6538,14 +6555,13 @@ static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) "Unknown channel type", "Resource shortage", }; - unsigned i = ssh_pkt_getuint32(pktin); unsigned reason_code; char *reason_string; int reason_length; struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); + c = ssh2_channel_msg(ssh, pktin); if (!c) - return; /* nonexistent channel */ + return; if (c->type != CHAN_SOCKDATA_DORMANT) return; /* dunno why they're failing this */ @@ -6564,31 +6580,19 @@ static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) { - unsigned localid; char *type; int typelen, want_reply; int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ struct ssh_channel *c; struct Packet *pktout; - localid = ssh_pkt_getuint32(pktin); + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; ssh_pkt_getstring(pktin, &type, &typelen); want_reply = ssh2_pkt_getbool(pktin); /* - * First, check that the channel exists. Otherwise, - * we can instantly disconnect with a rude message. - */ - c = find234(ssh->channels, &localid, ssh_channelfind); - if (!c) { - char *buf = dupprintf("Received channel request for nonexistent" - " channel %d", localid); - ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); - sfree(buf); - return; - } - - /* * Having got the channel number, we now look at * the request type string to see if it's something * we recognise.