diff options
Diffstat (limited to 'tools/plink/ssh.c')
| -rw-r--r-- | tools/plink/ssh.c | 51 |
1 files changed, 46 insertions, 5 deletions
diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c index 4eb84f899..7e63b4e0b 100644 --- a/tools/plink/ssh.c +++ b/tools/plink/ssh.c @@ -75,6 +75,7 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_SSH2_MAXPKT 256 #define BUG_CHOKES_ON_SSH2_IGNORE 512 #define BUG_CHOKES_ON_WINADJ 1024 +#define BUG_SENDS_LATE_REQUEST_REPLY 2048 /* * Codes for terminal modes. @@ -2812,6 +2813,19 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ; logevent("We believe remote version has winadj bug"); } + + if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO && + (wc_match("OpenSSH_[2-5].*", imp) || + wc_match("OpenSSH_6.[0-6]*", imp)))) { + /* + * These versions have the SSH-2 channel request bug. 6.7 and + * above do not: + * https://bugzilla.mindrot.org/show_bug.cgi?id=1818 + */ + ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY; + logevent("We believe remote version has SSH-2 channel request bug"); + } } /* @@ -7119,10 +7133,11 @@ static void ssh2_queue_chanreq_handler(struct ssh_channel *c, * request-specific data added and be sent. Note that if a handler is * provided, it's essential that the request actually be sent. * - * The handler will usually be passed the response packet in pktin. - * If pktin is NULL, this means that no reply will ever be forthcoming - * (e.g. because the entire connection is being destroyed) and the - * handler should free any storage it's holding. + * The handler will usually be passed the response packet in pktin. If + * pktin is NULL, this means that no reply will ever be forthcoming + * (e.g. because the entire connection is being destroyed, or because + * the server initiated channel closure before we saw the response) + * and the handler should free any storage it's holding. */ static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type, cchandler_fn_t handler, void *ctx) @@ -7612,6 +7627,21 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) */ ssh2_channel_got_eof(c); + if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) { + /* + * It also means we stop expecting to see replies to any + * outstanding channel requests, so clean those up too. + * (ssh_chanreq_init will enforce by assertion that we don't + * subsequently put anything back on this list.) + */ + while (c->v.v2.chanreq_head) { + struct outstanding_channel_request *ocr = c->v.v2.chanreq_head; + ocr->handler(c, NULL, ocr->ctx); + c->v.v2.chanreq_head = ocr->next; + sfree(ocr); + } + } + /* * And we also send an outgoing EOF, if we haven't already, on the * assumption that CLOSE is a pretty forceful announcement that @@ -7787,6 +7817,16 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) ssh_pkt_getstring(pktin, &type, &typelen); want_reply = ssh2_pkt_getbool(pktin); + if (c->closes & CLOSES_SENT_CLOSE) { + /* + * We don't reply to channel requests after we've sent + * CHANNEL_CLOSE for the channel, because our reply might + * cross in the network with the other side's CHANNEL_CLOSE + * and arrive after they have wound the channel up completely. + */ + want_reply = FALSE; + } + /* * Having got the channel number, we now look at * the request type string to see if it's something @@ -8416,7 +8456,8 @@ static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin) static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin, void *ctx) { - do_ssh2_authconn(c->ssh, NULL, 0, pktin); + if (pktin) + do_ssh2_authconn(c->ssh, NULL, 0, pktin); } static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, |