Bug 17204 - EndPointManager.GetEPListener() binds to all IP addresses when given a host-name instead of looking one up
Summary: EndPointManager.GetEPListener() binds to all IP addresses when given a host-n...
Status: RESOLVED FIXED
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: 3.2.x
Hardware: All All
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2014-01-13 12:43 UTC by paul firth
Modified: 2014-02-12 12:08 UTC (History)
2 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED FIXED

Description paul firth 2014-01-13 12:43:41 UTC
Hi Guys,

The problem lies inside EndPointManager.GetEPListener(). The line:

https://github.com/mono/mono/blob/a31c107f59298053e4ff17fd09b2fa617b75c1ba/mcs/class/System/System.Net/EndPointManager.cs

if (IPAddress.TryParse(host, out addr) == false)
      addr = IPAddress.Any;

means that any non-ip address host will automatically bind to all IP addresses on the machine, instead of looking up the correct ip.

A fix would be something along the lines of this:

if (IPAddress.TryParse(host, out addr) == false)
{
	// look up the damn host ip address rather than use all of them!
	IPHostEntry iphost = Dns.GetHostByName(host);
	addr = iphost.AddressList[0];
}

but with better error checking.

This bug is in the latest code on github, and makes it impossible to have an HttpListener bound to a specific host when there are multiple different HTTP servers on the machine, using the same port, but different IP addresses.

Cheers, Paul.
Comment 1 Miguel de Icaza [MSFT] 2014-02-12 12:08:06 UTC
Fixed in master.