Hi, First @Anakien, i checked a target computer, and there are even no logins happening here, so the communication is not reaching. I have no internal firewalls or so, and the server where Guacamole runs, can reach this computer with ssh command from shell. In addition, ssh from Guacamole does not work towards none of the computers here. (But this was a good idea, anyway, it could be reveal problems, so thx :) )
@Nick Couchman : Yes, the UUID appears in this way in the logs. Was strange for me too but not enough... :D Stopping traffic - i have no firewalls on the computers, and SSH itself works. So this can be an issue with guacd, i think. The double free is strange, but i have no signs of something crashing or segfaulting (also suspicious, because such an error cold be related...). Guacd and Guacamole webserver are running on the same computer. All other connection types are working, except SSH. How do i put the client in debug mode? Tomcat log in normal mode during an SSH connection - during this i can see the gray "Connected to Guacamole. Waiting for response" : [2025-07-05 19:33:35] [info] 19:33:35.887 [http-nio-8080-exec-11] DEBUG o.a.g.event.EventLoggingListener - User "user" (authenticated by "default") successfully re-authenticated their existing session from [192.168.1.103, 127.0.0.1] [2025-07-05 19:33:36] [info] 19:33:36.024 [http-nio-8080-exec-19] DEBUG o.a.g.net.InetGuacamoleSocket - Connecting to guacd at localhost:4822. [2025-07-05 19:33:36] [info] 19:33:36.043 [http-nio-8080-exec-19] INFO o.a.g.tunnel.TunnelRequestService - User "user" connected to connection "T480 SSH". [2025-07-05 19:33:36] [info] 19:33:36.043 [http-nio-8080-exec-19] DEBUG o.a.g.event.EventLoggingListener - Ignoring unknown/unimplemented event type: class org.apache.guacamole.net.event.TunnelConnectEvent [2025-07-05 19:33:36] [info] 19:33:36.043 [http-nio-8080-exec-19] INFO o.a.g.t.h.RestrictedGuacamoleHTTPTunnelServlet - Using HTTP tunnel (not WebSocket). Performance may be sub-optimal. [2025-07-05 19:33:36] [info] 19:33:36.043 [http-nio-8080-exec-19] DEBUG o.a.g.s.GuacamoleHTTPTunnelServlet - Registered tunnel "a9296166-2ac3-4267-aeee-98e246c7a2c1". [2025-07-05 19:33:36] [info] 19:33:36.092 [http-nio-8080-exec-17] DEBUG o.a.g.rest.RESTExceptionMapper - Client request rejected: No readable active connection for tunnel. [2025-07-05 19:33:36] [info] 19:33:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Checking for expired or invalid sessions... [2025-07-05 19:33:36] [info] 19:33:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Session check completed in 0 ms. [2025-07-05 19:34:36] [info] 19:34:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Checking for expired or invalid sessions... [2025-07-05 19:34:36] [info] 19:34:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Session check completed in 0 ms. [2025-07-05 19:35:36] [info] 19:35:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Checking for expired or invalid sessions... [2025-07-05 19:35:36] [info] 19:35:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Session check completed in 0 ms. [2025-07-05 19:36:36] [info] 19:36:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Checking for expired or invalid sessions... [2025-07-05 19:36:36] [info] 19:36:36.918 [pool-4-thread-1] DEBUG o.a.g.rest.auth.HashTokenSessionMap - Session check completed in 0 ms. (This continues to the infinity) During this, two guacd processes are there # ps aux|grep guac root 2665853 0.0 0.2 764912 16144 ? Sl 15:20 0:00 /usr/local/sbin/guacd -f -b 127.0.0.1 -L debug -l 4822 -p /tmp/guacd.pid root 2925052 0.0 0.2 777144 17320 ? Sl 19:33 0:00 /usr/local/sbin/guacd -f -b 127.0.0.1 -L debug -l 4822 -p /tmp/guacd.pid root 2927526 0.0 0.0 6528 2340 pts/4 S+ 19:36 0:00 grep guac The no readable active connection is a WTF. During this on the 192.168.1.103 there are no connection requests in the SSH log. I plan to check this on my test VM where i tested the Guacamole install for 1.5.5 but i have omitted the test for 1.6, so i can reproduce the issue with upgrading. As soon as i have time :( Thanks for your help :) Cs. On Sat, Jul 5, 2025 at 6:14 PM Nick Couchman <vn...@apache.org> wrote: > > On Sat, Jul 5, 2025 at 9:27 AM Horváth Csaba <horvathcsabalas...@gmail.com> > wrote: >> >> Hi, >> >> The previous log was written by guacd with parameter -L debug, i only >> copied from syslog. >> >> Now i tried again. In the below log i first connected to a VNC server >> (so you can see the server is basically working) and then tried SSH, >> but this time i got the message "Connected to Guacamole" and right >> after the red ribbon with "Error occurred within the Guacamole >> server..." >> >> # /usr/local/sbin/guacd -f -b 127.0.0.1 -L debug -l 4822 -p /tmp/guacd.pid >> guacd[2658943]: INFO: Guacamole proxy daemon (guacd) version 1.6.0 started >> guacd[2658943]: DEBUG: Successfully bound AF_INET socket to host >> 127.0.0.1, port 4822 >> guacd[2658943]: INFO: Listening on host 127.0.0.1, port 4822 >> ... >> guacd[2658943]: INFO: Creating new client for protocol "ssh" >> guacd[2658943]: INFO: Connection ID is >> "$0eb617c4-ec41-46a0-9be9-7d0705aea227" >> guacd[2659316]: DEBUG: Processing instruction: size >> guacd[2659316]: DEBUG: Processing instruction: audio >> guacd[2659316]: DEBUG: Processing instruction: video >> guacd[2659316]: DEBUG: Processing instruction: image >> guacd[2659316]: DEBUG: Processing instruction: timezone >> guacd[2659316]: DEBUG: Processing instruction: name >> guacd[2659316]: INFO: User "@04f87cbf-6f45-4785-897f-5df0cdfd8fbc" >> joined connection "�!A�" (1 users now present) >> guacd[2659316]: DEBUG: Client is using protocol version "VERSION_1_5_0" >> guacd[2658943]: INFO: Creating new client for protocol "ssh" >> guacd[2658943]: INFO: Connection ID is >> "$ad924c87-097e-4f1b-b0ab-8e3788c0a7ab" >> guacd[2659508]: DEBUG: Processing instruction: size >> guacd[2659508]: DEBUG: Processing instruction: audio >> guacd[2659508]: DEBUG: Processing instruction: video >> guacd[2659508]: DEBUG: Processing instruction: image >> guacd[2659508]: DEBUG: Processing instruction: timezone >> guacd[2659508]: DEBUG: Processing instruction: name >> guacd[2659508]: INFO: User "@ca7f6e87-53c6-4b6b-be2c-9e28255a04d9" >> joined connection "�@�" (1 users now present) >> guacd[2659508]: DEBUG: Client is using protocol version "VERSION_1_5_0" >> guacd[2659316]: ERROR: User is not responding. >> guacd[2659316]: INFO: User "@04f87cbf-6f45-4785-897f-5df0cdfd8fbc" >> disconnected (0 users remain) >> guacd[2659316]: INFO: Last user of connection "�!A�" disconnected >> guacd[2659316]: DEBUG: Requesting termination of client... >> double free or corruption (out) >> >> guacd[2658943]: INFO: Connection >> "$0eb617c4-ec41-46a0-9be9-7d0705aea227" removed. >> guacd[2658943]: DEBUG: Unable to request termination of client >> process: No such process >> guacd[2658943]: DEBUG: All child processes for connection >> "$0eb617c4-ec41-46a0-9be9-7d0705aea227" have been terminated. >> guacd[2659508]: ERROR: User is not responding. >> guacd[2659508]: INFO: User "@ca7f6e87-53c6-4b6b-be2c-9e28255a04d9" >> disconnected (0 users remain) >> guacd[2659508]: INFO: Last user of connection "�@�" disconnected >> guacd[2659508]: DEBUG: Requesting termination of client... >> double free or corruption (out) >> guacd[2658943]: INFO: Connection >> "$ad924c87-097e-4f1b-b0ab-8e3788c0a7ab" removed. >> guacd[2658943]: DEBUG: Unable to request termination of client >> process: No such process >> guacd[2658943]: DEBUG: All child processes for connection >> "$ad924c87-097e-4f1b-b0ab-8e3788c0a7ab" have been terminated. >> > > There are a few things that jump out to me here: > * First, the connection name or UUID appears to be mangled, as if something > is getting messed up with that. I'm not sure if this is an artifact of > copy/paste in e-mail, or if it really shows up that way in the log? > * Second, something is stopping traffic between Guacamole Client and guacd. > It's not entirely clear what, but the "User is not responding" message > indicates that guacd has stopped receiving its regular pings from the > client-side. This is likely related to the next issue (the double-free or > corruption) in some way or another, though it isn't exactly clear why. > * Finally, the double free or corruption message is interesting as it > indicates that we've a bug somewhere in the code that is trying to free > something that has already been freed. Whether this is causing the issues > you're seeing or is just a byproduct or unrelated bug is unclear. > > The next things I'd suggest are: > * Look for indications that you're getting a segfault in the guacd process > somewhere - any message in dmesg or other log facilities that indicate that > the guacd process is crashing? If so, get a stack trace of that crash and see > if you can post the contents of the stack back here. > * Look at network traffic between Guacamole Client and guacd, and between > guacd and the SSH server, and see if something is shutting down the > connection for some reason. The fact that guacd is saying the client stopped > responding indicates the potential that something network-related may be > amiss. > * Look at the Guacamole Client logs (Tomcat) and see if there's anything in > those logs that indicates a reason why the conversation between the browser > and guacd is getting shut down. You may also need to put Guacamole Client > into debug mode to see better messages related to that. > > -Nick --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@guacamole.apache.org For additional commands, e-mail: user-h...@guacamole.apache.org
