<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> </head> <body text="#000000" bgcolor="#ffffff"> Hello, I followed the steps from here <a class="moz-txt-link-freetext" href="http://0pointer.de/blog/projects/inetd.html">http://0pointer.de/blog/projects/inetd.html</a> to set-up ssh server to start when an it detect an incoming connection from remote host vis 22 port. I make the sshd.socket unit : <pre>[Unit] Description=SSH Socket for Per-Connection Servers [Socket] ListenStream=22 Accept=yes [Install] WantedBy=sockets.target and the <a class="moz-txt-link-abbreviated" href="mailto:sshd@.service">sshd@.service</a> unit : [Unit] Description=SSH Per-Connection Server [Service] ExecStart=-/usr/sbin/sshd -i -d StandardInput=socket enabled the sshd.socker unit : systemctl enable sshd.socket and output the same like in the <a class="moz-txt-link-freetext" href="http://0pointer.de/blog/projects/inetd.html">http://0pointer.de/blog/projects/inetd.html</a> example: ln -s '/etc/systemd/system/sshd.socket' '/etc/systemd/system/sockets.target.wants/sshd.socket # systemctl start sshd.socket # systemctl status sshd.socket sshd.socket - SSH Socket for Per-Connection Servers Loaded: loaded (/etc/systemd/system/sshd.socket; enabled) Active: active (listening) since Mon, 26 Sep 2011 20:24:31 +0200; 14s ago Accepted: 0; Connected: 0 CGroup: name=systemd:/system/sshd.socket My problem is the following : - when I'm trying to connect from the remote host by the ssh -vvv root@<ip_target_machine> I got the following output from ssh : OpenSSH_5.5p1, OpenSSL 1.0.0a-fips 1 Jun 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to 128.224.124.159 [128.224.124.159] port 22. debug1: Connection established. debug3: Not a RSA1 key file /home/mbadiu/.ssh/id_rsa. debug2: key_type_from_name: unknown key type '-----BEGIN' debug3: key_read: missing keytype debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug3: key_read: missing whitespace debug2: key_type_from_name: unknown key type '-----END' debug3: key_read: missing keytype debug1: identity file /home/mbadiu/.ssh/id_rsa type 1 debug1: identity file /home/mbadiu/.ssh/id_rsa-cert type -1 debug1: identity file /home/mbadiu/.ssh/id_dsa type -1 debug1: identity file /home/mbadiu/.ssh/id_dsa-cert type -1 and here the ssh command is hanging up. And on target with systemd.log_level=debug and systemd.log_target=kmsg enabled I have the following output : [ 106.994169] <31>systemd[1]: Incoming traffic on sshd.socket [ 107.060984] <31>systemd[1]: Trying to enqueue job <a class="moz-txt-link-abbreviated" href="mailto:sshd@128.224.124.159:22-128.224.124.181:51810.service/start/replace">sshd@128.224.124.159:22-128.224.124.181:51810.service/start/replace</a> [ 107.188360] <31>systemd[1]: Installed new job <a class="moz-txt-link-abbreviated" href="mailto:sshd@128.224.124.159:22-128.224.124.181:51810.service/start">sshd@128.224.124.159:22-128.224.124.181:51810.service/start</a> as 157 [ 107.310350] <31>systemd[1]: Enqueued job <a class="moz-txt-link-abbreviated" href="mailto:sshd@128.224.124.159:22-128.224.124.181:51810.service/start">sshd@128.224.124.159:22-128.224.124.181:51810.service/start</a> as 157 [ 107.427256] <31>systemd[1]: About to execute: /usr/sbin/sshd -d -i [ 107.503677] <31>systemd[1]: Forked /usr/sbin/sshd as 373 [ 107.568625] <31>systemd[1]: <a class="moz-txt-link-abbreviated" href="mailto:sshd@128.224.124.159:22-128.224.124.181:51810.service">sshd@128.224.124.159:22-128.224.124.181:51810.service</a> changed dead -> running [ 107.683831] <31>systemd[1]: Job <a class="moz-txt-link-abbreviated" href="mailto:sshd@128.224.124.159:22-128.224.124.181:51810.service/start">sshd@128.224.124.159:22-128.224.124.181:51810.service/start</a> finished, result=done [ 107.911948] <39>sshd[373]: debug1: sshd version OpenSSH_5.6p1 [ 108.000619] <39>sshd[373]: debug1: read PEM private key done: type RSA [ 108.079175] <39>sshd[373]: debug1: private host key: #0 type 1 RSA [ 108.153394] <39>sshd[373]: debug1: read PEM private key done: type DSA [ 108.231531] <39>sshd[373]: debug1: private host key: #1 type 2 DSA [ 108.305615] <87>sshd[373]: debug1: inetd sockets after dupping: 3, 4 [ 108.381723] <86>sshd[373]: Connection from UNKNOWN port 65535 [ 108.450502] <30>sshd[373]: SSH-2.0-OpenSSH_5.6 The output of the lsof -i :22 command shown me that connection is established by socket but it can't log in : COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME systemd 1 root 19u IPv4 5395 0t0 TCP *:ssh (LISTEN) systemd 1 root 22u IPv4 6940 0t0 TCP 128.224.124.159:ssh->128.224.124.181:51810 (ESTABLISHED) sshd 373 root 3w IPv4 6940 0t0 TCP 128.224.124.159:ssh->128.224.124.181:51810 (ESTABLISHED) When I manually give /usr/sbin/sshd -d on target I have the following output : debug1: sshd version OpenSSH_5.6p1 debug1: read PEM private key done: type RSA debug1: private host key: #0 type 1 RSA debug1: read PEM private key done: type DSA debug1: private host key: #1 type 2 DSA debug1: rexec_argv[0]='/usr/sbin/sshd' debug1: rexec_argv[1]='-d' Set /proc/self/oom_adj from 0 to -17 debug1: Bind to port 22 on 0.0.0.0. Bind to port 22 on 0.0.0.0 failed: Address already in use. which I think that the sshd.socket service is listening also on the 22 port like /usr/sbin/sshd daemon, and the 22 port is occupied. I am using systemd-35. Thanks in advance, Mircea </pre> </body> </html>