[Bug 1259939] [NEW] ssh -g has no effect if master socket already open

[Ken Sharp]

Public bug reported:

>From the man page:
 -g      Allows remote hosts to connect to local forwarded ports.

When working with a control socket, this works fine if -g is included
with the initial connect attempt, for example:

$ cat ~/.ssh/config
Host *
ControlMaster		auto
ControlPath		~/.ssh/%r@%h:%p

$ ssh -gTfNL 12345:localhost:12345 host
$ netstat -tln

tcp        0      0 0.0.0.0:12345             0.0.0.0:*
LISTEN      -

$ lsof -n

ssh       182446        user    3u     IPv4           76397177       0t0      TCP 192.168.0.9:51181->192.168.0.15:ssh (ESTABLISHED)
ssh       182446        user    4u     IPv4           76397181       0t0      TCP *:3128 (LISTEN)
ssh       182446        user    5u     IPv6           76397182       0t0      TCP *:3128 (LISTEN)

and similarly:

$ ssh -g host
user at host:~$ exit
$ ssh -gTfNL 12345:localhost:12345 host
$ netstat -tln

tcp        0      0 0.0.0.0:12345             0.0.0.0:*
LISTEN      -

However, if it isn't then -g is ignored on subsequent attempts to
forward ports:

$ ssh host
user at host:~$ exit
$ ssh -g -L 12345:localhost:12345 host
$ netstat -tln

tcp        0      0 127.0.0.1:12345             0.0.0.0:*
LISTEN      -

$ lsof -n

ssh       182399        user    3u     IPv4           76390396       0t0      TCP 192.168.0.9:51178->192.168.0.15:ssh (ESTABLISHED)
ssh       182399        user    4u     unix 0x0000000000000000       0t0 76390976 /home/user/.ssh/user at host
ssh       182399        user    6u     IPv6           76392394       0t0      TCP [::1]:3128 (LISTEN)
ssh       182399        user    7u     IPv4           76392395       0t0      TCP 127.0.0.1:3128 (LISTEN)

This doesn't really make sense: ssh should still be capable of binding
to the correct address as requested.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ssh (not installed)
ProcVersionSignature: Ubuntu 3.8.0-33.48~precise1-generic 3.8.13.11
Uname: Linux 3.8.0-33-generic i686
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: i386
Date: Tue Dec 10 12:59:33 2013
InstallationMedia: Ubuntu-Server 12.04.1 LTS "Precise Pangolin" - Release i386 (20120817.3)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: openssh
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: openssh (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: apport-bug i386 precise

** Summary changed:

- ssh -g has no effect is master socket already open
+ ssh -g has no effect if master socket already open

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is subscribed to openssh in Ubuntu.
https://bugs.launchpad.net/bugs/1259939

Title:
  ssh -g has no effect if master socket already open

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1259939/+subscriptions