Add a bug-compatibility flag to disable the

winadj@putty.projects.tartarus.org request. Not currently enabled
automatically, but should be usable as a manual workaround.


git-svn-id: svn://svn.tartarus.org/sgt/putty@9592 cda61777-01e9-0310-a592-d414129be87e

config.c

@@ -2457,6 +2457,9 @@ void setup_config_box(struct controlbox *b, int midsession,
 	    ctrl_droplist(s, "Chokes on SSH-2 ignore messages", '2', 20,
 			  HELPCTX(ssh_bugs_ignore2),
 			  sshbug_handler, I(CONF_sshbug_ignore2));
+	    ctrl_droplist(s, "Chokes on PuTTY's SSH-2 'winadj' requests", 'j',
+                          20, HELPCTX(ssh_bugs_winadj),
+			  sshbug_handler, I(CONF_sshbug_winadj));
 	    ctrl_droplist(s, "Miscomputes SSH-2 HMAC keys", 'm', 20,
 			  HELPCTX(ssh_bugs_hmac2),
 			  sshbug_handler, I(CONF_sshbug_hmac2));

doc/config.but

@@ -3208,6 +3208,29 @@ send an over-sized packet.  If this bug is enabled when talking to a
 correct server, the session will work correctly, but download
 performance will be less than it could be.
 
+\S{config-ssh-bug-winadj} \q{Chokes on PuTTY's SSH-2 \cq{winadj} requests}
+
+\cfg{winhelp-topic}{ssh.bugs.winadj}
+
+PuTTY sometimes sends a special request to SSH servers in the middle
+of channel data, with the name \cw{winadj@putty.projects.tartarus.org}
+(see \k{sshnames-channel}). The purpose of this request is to measure
+the round-trip time to the server, which PuTTY uses to tune its flow
+control. The server does not actually have to \e{understand} the
+message; it is expected to send back a \cw{SSH_MSG_CHANNEL_FAILURE}
+message indicating that it didn't understand it. (All PuTTY needs for
+its timing calculations is \e{some} kind of response.)
+
+It has been known for some SSH servers to get confused by this message
+in one way or another \dash because it has a long name, or because
+they can't cope with unrecognised request names even to the extent of
+sending back the correct failure response, or because they handle it
+sensibly but fill up the server's log file with pointless spam, or
+whatever. PuTTY therefore supports this bug-compatibility flag: if it
+believes the server has this bug, it will never send its
+\cq{winadj@putty.projects.tartarus.org} request, and will make do
+without its timing data.
+
 \H{config-serial} The Serial panel
 
 The \i{Serial} panel allows you to configure options that only apply

putty.h

@@ -836,6 +836,7 @@ void cleanup_exit(int);
     X(INT, NONE, sshbug_rekey2) \
     X(INT, NONE, sshbug_maxpkt2) \
     X(INT, NONE, sshbug_ignore2) \
+    X(INT, NONE, sshbug_winadj) \
     /*                                                                \
      * ssh_simple means that we promise never to open any channel     \
      * other than the main one, which means it can safely use a very  \

settings.c

@@ -620,6 +620,7 @@ void save_open_settings(void *sesskey, Conf *conf)
     write_setting_i(sesskey, "BugPKSessID2", 2-conf_get_int(conf, CONF_sshbug_pksessid2));
     write_setting_i(sesskey, "BugRekey2", 2-conf_get_int(conf, CONF_sshbug_rekey2));
     write_setting_i(sesskey, "BugMaxPkt2", 2-conf_get_int(conf, CONF_sshbug_maxpkt2));
+    write_setting_i(sesskey, "BugWinadj", 2-conf_get_int(conf, CONF_sshbug_winadj));
     write_setting_i(sesskey, "StampUtmp", conf_get_int(conf, CONF_stamp_utmp));
     write_setting_i(sesskey, "LoginShell", conf_get_int(conf, CONF_login_shell));
     write_setting_i(sesskey, "ScrollbarOnLeft", conf_get_int(conf, CONF_scrollbar_on_left));
@@ -960,6 +961,7 @@ void load_open_settings(void *sesskey, Conf *conf)
     i = gppi_raw(sesskey, "BugPKSessID2", 0); conf_set_int(conf, CONF_sshbug_pksessid2, 2-i);
     i = gppi_raw(sesskey, "BugRekey2", 0); conf_set_int(conf, CONF_sshbug_rekey2, 2-i);
     i = gppi_raw(sesskey, "BugMaxPkt2", 0); conf_set_int(conf, CONF_sshbug_maxpkt2, 2-i);
+    i = gppi_raw(sesskey, "BugWinadj", 0); conf_set_int(conf, CONF_sshbug_winadj, 2-i);
     conf_set_int(conf, CONF_ssh_simple, FALSE);
     gppi(sesskey, "StampUtmp", 1, conf, CONF_stamp_utmp);
     gppi(sesskey, "LoginShell", 1, conf, CONF_login_shell);

ssh.c

@@ -196,6 +196,7 @@ static const char *const ssh2_disconnect_reasons[] = {
 #define BUG_SSH2_PK_SESSIONID                   128
 #define BUG_SSH2_MAXPKT				256
 #define BUG_CHOKES_ON_SSH2_IGNORE               512
+#define BUG_CHOKES_ON_WINADJ                   1024
 
 /*
  * Codes for terminal modes.
@@ -2580,6 +2581,15 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 	ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
 	logevent("We believe remote version has SSH-2 ignore bug");
     }
+
+    if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
+	/*
+	 * Servers that don't support our winadj request for one
+	 * reason or another. Currently, none detected automatically.
+	 */
+	ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
+	logevent("We believe remote version has winadj bug");
+    }
 }
 
 /*
@@ -6635,7 +6645,8 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin)
 	 * unexpected CHANNEL_FAILUREs.
 	 */
 	if (newwin == c->v.v2.locmaxwin &&
-	    ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
+	    ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] &&
+            !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
 	    pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
 	    ssh2_pkt_adduint32(pktout, c->remoteid);
 	    ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");

windows/winhelp.h

@@ -144,6 +144,7 @@
 #define WINHELP_CTX_ssh_bugs_pksessid2 "ssh.bugs.pksessid2:config-ssh-bug-pksessid2"
 #define WINHELP_CTX_ssh_bugs_rekey2 "ssh.bugs.rekey2:config-ssh-bug-rekey"
 #define WINHELP_CTX_ssh_bugs_maxpkt2 "ssh.bugs.maxpkt2:config-ssh-bug-maxpkt2"
+#define WINHELP_CTX_ssh_bugs_winadj "ssh.bugs.winadj:config-ssh-bug-winadj"
 #define WINHELP_CTX_serial_line "serial.line:config-serial-line"
 #define WINHELP_CTX_serial_speed "serial.speed:config-serial-speed"
 #define WINHELP_CTX_serial_databits "serial.databits:config-serial-databits"