Bug 1648

Summary: Fix IPV6_V6ONLY for -L with -g
Product: Portable OpenSSH Reporter: Jan Kratochvil <jan.kratochvil>
Component: sshAssignee: Assigned to nobody <unassigned-bugs>
Status: CLOSED FIXED    
Severity: minor CC: djm
Priority: P2    
Version: -current   
Hardware: All   
OS: Linux   
Bug Depends on:    
Bug Blocks: 1626    
Attachments:
Description Flags
Fix following the current openssh style.
none
unify setsockopt(...,IPV6_V6ONLY,...) calls none

Description Jan Kratochvil 2009-09-13 23:58:45 AEST 
Created attachment 1695 [details]
Fix following the current openssh style.

$ /usr/bin/ssh -g -L 5000:localhost:22 localhost cat
bind: Address already in use
[... running]
# netstat -apn|grep 5000
tcp  0  0  0.0.0.0:5000  0.0.0.0:*  LISTEN  23526/ssh
$ telnet localhost6 5000
Trying ::1...
telnet: connect to address ::1: Connection refused

patched:

$ ./ssh -g -L 5000:localhost:22 localhost cat
[... running]
# netstat -apn|grep 5000
tcp  0  0  0.0.0.0:5000  0.0.0.0:*  LISTEN  23139/ssh
tcp  0  0  :::5000       :::*       LISTEN  23139/ssh
$ telnet localhost6 5000
Trying ::1...
Connected to localhost6.
Escape character is '^]'.
SSH-2.0-OpenSSH_5.2


Using Fedora 11 kernel with its (+AFAIK upstream) defaults:
# cat /proc/version 
Linux version 2.6.30.5-43.fc11.x86_64
(mockbuild@xenbuilder4.fedora.phx.redhat.com) (gcc version 4.4.1
20090725 (Red Hat 4.4.1-2) (GCC) ) #1 SMP Thu Aug 27 21:39:52 EDT 2009
# cat /proc/sys/net/ipv6/bindv6only
0

In the current case one cannot access IPv6 because the IPv4 socket was
created first.  If IPv6 would be created first it would work.

The copy-pasted code could be probably moved to some unified function. 
This is out of scope of this patch.

Similiar problem+resolution was in Bug 164, Bug 1309 and Bug 1392.
Comment 1 Damien Miller 2009-11-10 14:13:52 AEDT 
Created attachment 1720 [details]
unify setsockopt(...,IPV6_V6ONLY,...) calls

Good idea about unifying the calls to setsockopt. Here is a diff that does that (includes your change too).
Comment 2 Damien Miller 2009-11-18 17:49:05 AEDT 
patch applied. this will be in openssh-5.4, thanks for the report+patch.
Comment 3 Darren Tucker 2010-03-26 10:51:11 AEDT 
With the release of 5.4p1, this bug is now considered closed.