Bug 127784

Summary: Provide option to listen on ipv6 socket if ipv6 available and fallback to ipv4 if not.
Product: [openSUSE] SUSE Linux 10.1 Reporter: Marian Jancar <mjancar>
Component: BasesystemAssignee: Michal Marek <mmarek>
Status: RESOLVED FIXED QA Contact: E-mail List <qa-bugs>
Severity: Enhancement    
Priority: P5 - None    
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: All   
Whiteboard:
Found By: Other Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---
Attachments: patch allowing 'flags = IPv4 IPv6'

Description Marian Jancar 2005-10-12 13:18:17 UTC 
There is IPv6 flag for xinet that makes it listen on ipv6 socket, but it fails
to start the service when only ipv4 is available. Please provide an option to
listen on ipv6 if avilable and fallback to ipv4 if not (just like ssh does by
default).
Comment 1 Michal Marek 2005-10-18 12:41:37 UTC 
Do you mean something like

flags = IPv6orIPv4

meaning

bind() to :::port;
if that fails
  bind() to 0.0.0.0:port;

OR

flags = IPv6 IPv4

meaning

bind() to :::port;
bind() to 0.0.0.0:port;

? (Will talk to you when you're back from vacation)
Comment 2 Marian Jancar 2005-10-18 13:44:29 UTC 
The second seems better. bind() to ::: is enough, ipv6 sockets can accept ipv4 connections (thats the point of this enhancement). Currently when both the IPv6 IPv4 flags are set, xinetd warns and listens on ipv4 only, it would be best to change this to try bind to ::: and if that fails bind to 0.0.0.0.
Comment 3 Michal Marek 2005-10-31 12:40:16 UTC 
Created attachment 56001 [details]
patch allowing 'flags = IPv4 IPv6'
Comment 4 Michal Marek 2005-10-31 12:51:30 UTC 
Does the above patch do what you want? Specify 

    flags = IPv6 IPv4 # order doesn't matter

and xinetd will first try to create an IPv6 socket and fallback to an
IPv4 socket. BTW you can achieve the same by creating two services:

    service foo {
        id     = foo-4
        flags  = IPv4
        ...
    }
    service foo {
        id     = foo-6
        flags  = IPv6
        v6only = yes
        ...
    }

So this patch might not be needed.
Comment 5 Marian Jancar 2005-11-01 08:23:07 UTC 
Right, this would work too. But the one socket solution is neat, it would be nice if it were accepted upstream, so we wouldn't have to use the two sockets or maintain the patch.
Comment 6 Michal Marek 2005-11-01 08:47:21 UTC 
OK, so I'm setting this to FIXEd and will talk to upstream.
Comment 7 Michal Marek 2005-11-03 08:52:33 UTC 
Seems like it will be accepted by upstream:


On Tue, Nov 01, 2005 at 11:50:00AM +0100, Michal Marek wrote:
> 
> Do you think this patch could make it info official xinetd?

My initial reaction was negative, but after more thought and
bouncing the idea off others, I think it's probably fine.

Rob