search for: channel_still_open

...ld apply to newer versions (which I've not tried). Here's the gist: server_loop2() has a race condition with respect to reception of SIGCHLD and checking/setting child_terminated. This patch does two things: wait_until_can_do_something() adds a 1 second timeout to select() IF AND ONLY IF (!channel_still_open) AND, server_loop2() breaks out of its loop when there are no sessions left. Blocking SIGCHLD before select()ing would not fix the problem, nor would that be very portable. So, summary of changes: - session.h Added prototype for session_still_used() boolean function. - session.c Added...

channel_still_open() does not count "larval" channels as open. If the server sets up a protocol 2 connection with no remote command (as with "ssh -N ..."), the "server-session" channel remains larval, and the server exits as soon as it notices that there are no open channels besides thi...

...39;s possible the timing attack mitigation interacts badly with X11 forwarding. Could you try this patch? If you still have problems, then please post another -vvv debug trace. diff --git a/channels.c b/channels.c index 1b310e3..111c808 100644 --- a/channels.c +++ b/channels.c @@ -886,6 +886,23 @@ channel_still_open(struct ssh *ssh) return 0; } +/* Returns true if a channel with a TTY is open. */ +int +channel_tty_open(struct ssh *ssh) +{ + u_int i; + Channel *c; + + for (i = 0; i < ssh->chanctxt->channels_alloc; i++) { + c = ssh->chanctxt->channels[i]; + if (c == NULL || c->type != SS...

...a message when I exit my login shell: Closing connection to 130.207.167.32 However, when connecting with v2, it only ever logs: Connection closed by remote host. Tracing through the code, it appears that instead of breaking in serverloop.c:server_loop2() at: if (had_channel && !channel_still_open()) { debug("!channel_still_open."); break; } and returning to sshd.c:main() and logging the nice message, it continues to process_input(), gets a len==0 from the read(), and does: verbose("Connection closed by remote host."); fatal_cleanup(); Comparing th...

.../* Add any selections by the channel mechanism. */ channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); @@ -343,7 +349,7 @@ FD_SET(fileno(stderr), *writesetp); } else { /* channel_prepare_select could have closed the last channel */ - if (session_closed && !channel_still_open() && + if (session_status == SessionClose && !channel_still_open() && !packet_have_data_to_write()) { /* clear mask since we did not call select() */ memset(*readsetp, 0, *nallocp); @@ -367,7 +373,16 @@ * SSH_MSG_IGNORE packet when the timeout expires....

...* Add any selections by the channel mechanism. */ channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); @@ -343,11 +349,12 @@ FD_SET(fileno(stderr), *writesetp); } else { /* channel_prepare_select could have closed the last channel */ - if (session_closed && !channel_still_open()) { + if ((session_status == SessionClose) + && !channel_still_open()) { if (!packet_have_data_to_write()) return; } else { - FD_SET(connection_in, *readsetp); + FD_SET(connection_in, *readsetp); } } @@ -364,7 +371,17 @@ * SSH_MSG_IGNORE packet when the t...

...xfdp, rekeying); @@ -346,7 +350,15 @@ if (buffer_len(&stderr_buffer) > 0) FD_SET(fileno(stderr), *writesetp); } else { - FD_SET(connection_in, *readsetp); + /* channel_prepare_select could have closed the last channel */ + if ((session_status == SessionClose) + && !channel_still_open()) { + if (!packet_have_data_to_write()) { + return; + } + } else { + FD_SET(connection_in, *readsetp); + } } /* Select server connection if have data to write to the server. */ @@ -362,7 +374,16 @@ * SSH_MSG_IGNORE packet when the timeout expires. */ - if (select((*maxfd...

.../* Add any selections by the channel mechanism. */ channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); @@ -343,7 +349,7 @@ FD_SET(fileno(stderr), *writesetp); } else { /* channel_prepare_select could have closed the last channel */ - if (session_closed && !channel_still_open() && + if (session_status == SessionClose && !channel_still_open() && !packet_have_data_to_write()) { /* clear mask since we did not call select() */ memset(*readsetp, 0, *maxfdp); @@ -367,7 +373,17 @@ * SSH_MSG_IGNORE packet when the timeout expires. *...

http://bugzilla.mindrot.org/show_bug.cgi?id=160 ------- Additional Comments From Nicolas.Williams at ubsw.com 2002-03-13 09:10 ------- Created an attachment (id=40) Debug output, lsof output, etc... ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee.

...E debug1: channel 0: obuf empty debug1: channel 0: output drain -> closed debug1: channel 0: close_write debug1: channel 0: send close debug1: channel 0: is dead debug1: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug2: !channel_still_open. debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.0 seconds debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0 debug1: Exit status 0 --------------------------------- Prior to haning situation: (normal execution): debug2: callback start debug1: client_init id 0 arg 0 debug1: Se...

In the changelog, there is an entry: 20001129 - (djm) Back out all the serverloop.c hacks. sshd will now hang again if there are background children with open fds. Does this mean that this is regarded as expected (and correct) behavior, that should not change in the future, or does it mean that this behavior is a known problem that someone will eventually fix? --Adam -- Adam McKenna

...message a bit more helpful to the less experienced user. diff -u -r openssh-3.0p1-orig/serverloop.c openssh-3.0p1/serverloop.c --- openssh-3.0p1-orig/serverloop.c Fri Oct 12 02:35:06 2001 +++ openssh-3.0p1/serverloop.c Thu Nov 8 18:12:10 2001 @@ -557,7 +557,7 @@ if (!channel_still_open()) break; if (!waiting_termination) { - const char *s = "Waiting for forwarded connectio ns to terminate...\r\n"; + const char *s = "Waiting for forwarded connectio ns...

...en->closed debug1: channel 0: close_read debug1: channel 0: send close debug1: channel 0: full closed2 debug1: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug1: channel_free: channel 0: dettaching channel user debug2: !channel_still_open. debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 14.5 seconds debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0 debug1: Exit status -1 rsync error: unexplained error (code 255) at main.c(925) _exit_cleanup(code=255, file=main.c, line=925): about to call exit(255) I've tried...

...ad debug: channel 0: obuf empty debug: channel 0: output drain -> closed debug: channel 0: close_write debug: channel 0: send close debug: channel 0: full closed2 debug: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug: !channel_still_open. debug: Transferred: stdin 0, stdout 0, stderr 0 bytes in 2.3 seconds debug: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0 debug: Exit status -1 Couldn't read packet: Bad file descriptor

I have an openssh server running on solaris 7 and the client running on a clean RH linux 6.1 box. I am using the latest release (2.1.1p1 -- i had the known solaris utmp problem and the read_key problem when using 2.1.0p2 so i upgraded). scp from the linux machine to solaris machine gives a "lost connection" message [root at dog /root]# scp foo.bar solmachine:/tmp/ lost connection the

I've just built openssh 3.1 for my Redhat 5.1 system (running on a 486 DX-66) using the latest zlib and openssl libraries. Connecting to the machine with ssh seems to work fine (although it takes a while to initiate a connection). But when I transfer a file to the machine with scp, it seems to work fine and the scp completes, but an ssh sub-process remains behind on the client and an sshd

...ad debug: channel 0: obuf empty debug: channel 0: output drain -> closed debug: channel 0: close_write debug: channel 0: send close debug: channel 0: full closed2 debug: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug: !channel_still_open. debug: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.8 seconds debug: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0 debug: Exit status 127 debug: compress outgoing: raw data 656, compressed 615, factor 0.94 debug: compress incoming: raw data 103, compressed 96, factor 0.93 lost connect...

...ad debug: channel 0: obuf empty debug: channel 0: output drain -> closed debug: channel 0: close_write debug: channel 0: send close debug: channel 0: full closed2 debug: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug: !channel_still_open. Connection to saturn closed. debug: Transferred: stdin 0, stdout 0, stderr 30 bytes in 59.7 seconds debug: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.5 debug: Exit status 1 ------------------------------------------------------------------------ Does anybody know, where I've done a mi...

...taching channel user debug1: session_by_channel: session 0 channel 0 debug1: session_close_by_channel: channel 0 kill 6864 debug1: Received SIGCHLD. debug1: tvp!=NULL kid 1 mili 100 error: select: Bad file descriptor debug1: session_by_pid: pid 6864 debug1: session_free: session 0 pid 6864 debug1: !channel_still_open. Closing connection to 128.2.xx.xxx debug1: compress outgoing: raw data 400, compressed 312, factor 0.78 debug1: compress incoming: raw data 165, compressed 129, factor 0.78 $ Both the sender and receiver were compiled with the following configuration: --with-kerberos4 --with-afs=/usr...

...ad debug: channel 0: obuf empty debug: channel 0: output drain -> closed debug: channel 0: close_write debug: channel 0: send close debug: channel 0: full closed2 debug: channel_free: channel 0: status: The following connections are open: #0 client-session (t4 r0 i8/0 o128/0 fd -1/-1) debug: !channel_still_open. debug: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.2 seconds debug: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0 debug: Exit status 0