avahi: fix wrong use of netlink flags for dump operations

The avahi-daemon uses a wrong flag combination to operate with
rtnetlink. This patch fixes the problems.

No need to set NLM_F_ACK since the dump operation already includes
the trailing NLMSG_DONE message that informs about the end of the
dump operation.

Please, consider porting the avahi-daemon to libmnl:

http://www.netfilter.org/projects/libmnl/index.html

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Index: avahi-0.6.27/avahi-autoipd/iface-linux.c
===================================================================
--- avahi-0.6.27.orig/avahi-autoipd/iface-linux.c	2011-01-16 22:06:20.000000000 +0100
+++ avahi-0.6.27/avahi-autoipd/iface-linux.c	2011-01-16 22:07:34.000000000 +0100
@@ -262,7 +262,7 @@ int iface_get_initial_state(State *state
     n->nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
     n->nlmsg_type = RTM_GETLINK;
     n->nlmsg_seq = seq;
-    n->nlmsg_flags = NLM_F_MATCH|NLM_F_REQUEST|NLM_F_ACK;
+    n->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
     n->nlmsg_pid = 0;
 
     ifi = NLMSG_DATA(n);
Index: avahi-0.6.27/avahi-core/iface-linux.c
===================================================================
--- avahi-0.6.27.orig/avahi-core/iface-linux.c	2011-01-16 22:06:51.000000000 +0100
+++ avahi-0.6.27/avahi-core/iface-linux.c	2011-01-16 22:07:08.000000000 +0100
@@ -53,7 +53,7 @@ static int netlink_list_items(AvahiNetli
     n = (struct nlmsghdr*) req;
     n->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
     n->nlmsg_type = type;
-    n->nlmsg_flags = NLM_F_ROOT|NLM_F_REQUEST;
+    n->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
     n->nlmsg_pid = 0;
 
     gen = NLMSG_DATA(n);