File libtirpc-0.1.9-0002-Always-make-IPv6-sockets-V6... of Package libtirpc

Overview Repositories Revisions Requests Users Attributes Meta

File libtirpc-0.1.9-0002-Always-make-IPv6-sockets-V6ONLY.patch of Package libtirpc

From ea9f048761d0b9a2ab6310bffa07351f0b04d8c5 Mon Sep 17 00:00:00 2001
From: Olaf Kirch <okir@suse.de>
Date: Tue, 2 Sep 2008 12:11:15 -0400
Subject: [PATCH] Always make IPv6 sockets V6ONLY

Assume you have a netconfig file looking like this:

udp        tpi_clts      v     inet     udp     -       -
udp6       tpi_clts      v     inet6    udp     -       -
...

a call to svc_tli_create(... &someaddr, "udp") will fail to create an
IPv6 server socket. The problem is that on Linux, passive IPv6 sockets
will also accept packets/connections from IPv4, and will simply map
the sender's address to an IPv6 mapped IPv4 address. So if you want to
bind both a UDPv4 and UDPv6 socket to the same port, this will fail with
EADDRINUSE.

The way to avoid this behavior is to change the socket to V6ONLY,
which tells the kernel to avoid the autmatic mapping.

The change proposed in the patch below does this. I *think* this is
a good place to do this, as it will also fix applications that do not
use svc_tli_create() - such as rpcbind, which creates the sockets on
its own using __rpc_nconf2fd.

I think this also improves portability, as BSD code assumes BSD
behavior, where this mapping does not occur either.

Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>
---
 src/rpc_generic.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/src/rpc_generic.c b/src/rpc_generic.c
index 583aff0..ff4ba16 100644
--- a/src/rpc_generic.c
+++ b/src/rpc_generic.c
@@ -525,11 +525,18 @@ int
 __rpc_nconf2fd(const struct netconfig *nconf)
 {
 	struct __rpc_sockinfo si;
+	int fd;
 
 	if (!__rpc_nconf2sockinfo(nconf, &si))
 		return 0;
 
-	return socket(si.si_af, si.si_socktype, si.si_proto);
+	if ((fd = socket(si.si_af, si.si_socktype, si.si_proto)) >= 0 &&
+	    si.si_af == AF_INET6) {
+		int val = 1;
+
+		setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &val, sizeof(val));
+	}
+	return fd;
 }
 
 int
-- 
1.5.6

Places

File libtirpc-0.1.9-0002-Always-make-IPv6-sockets-V6ONLY.patch of Package libtirpc

Places