From: Rafał Miłecki <rafal@milecki.pl>
Date: Tue, 14 Feb 2017 11:18:06 +0000 (+0100)
Subject: Don't try sending unicast responses with multicast address
X-Git-Url: https://git.archive.openwrt.org/?p=project%2Fmdnsd.git;a=commitdiff_plain;h=55138ca9b501bd32c870bb468d6736a42d026cfb

Don't try sending unicast responses with multicast address

So far we were doing that when destination IP address wasn't specified.
Now we have all places in code cleaned up, stop accepting this and print
an error if needed.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---

diff --git a/interface.c b/interface.c
index 1cc9499..ada8acb 100644
--- a/interface.c
+++ b/interface.c
@@ -69,7 +69,7 @@ interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct i
 	pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
 	pkti->ipi_ifindex = iface->ifindex;
 
-	if (iface->multicast || !to) {
+	if (iface->multicast) {
 		a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
 		if (to)
 			fprintf(stderr, "Ignoring IPv4 address for multicast interface\n");
@@ -109,7 +109,7 @@ interface_send_packet6(struct interface *iface, struct sockaddr_in6 *to, struct
 	pkti = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 	pkti->ipi6_ifindex = iface->ifindex;
 
-	if (iface->multicast || !to) {
+	if (iface->multicast) {
 		inet_pton(AF_INET6, MCAST_ADDR6, &a.sin6_addr);
 		if (to)
 			fprintf(stderr, "Ignoring IPv6 address for multicast interface\n");
@@ -123,6 +123,11 @@ interface_send_packet6(struct interface *iface, struct sockaddr_in6 *to, struct
 int
 interface_send_packet(struct interface *iface, struct sockaddr *to, struct iovec *iov, int iov_len)
 {
+	if (!iface->multicast && !to) {
+		fprintf(stderr, "No IP address specified for unicast interface\n");
+		return -1;
+	}
+
 	if (debug > 1) {
 		fprintf(stderr, "TX ipv%d: %s\n", iface->v6 * 2 + 4, iface->name);
 		fprintf(stderr, "  multicast: %d\n", iface->multicast);