net: mdns: set the correct type of dst addr
Check for the address family of the packet when setting the multicast
destination address used in the response. Current code checks either the
query type or the stack configuration, which can result in setting the
wrong type of address for the frame.
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
diff --git a/subsys/net/lib/dns/mdns_responder.c b/subsys/net/lib/dns/mdns_responder.c
index c1c6f48..bf590d3 100644
--- a/subsys/net/lib/dns/mdns_responder.c
+++ b/subsys/net/lib/dns/mdns_responder.c
@@ -73,6 +73,28 @@
addr->sin_addr.s_addr = htonl(0xE00000FB);
}
+static int setup_dst_addr(struct net_context *ctx,
+ struct net_pkt *pkt,
+ struct sockaddr *dst,
+ socklen_t *dst_len)
+{
+ if (IS_ENABLED(CONFIG_NET_IPV4) &&
+ net_pkt_family(pkt) == AF_INET) {
+ create_ipv4_addr(net_sin(dst));
+ *dst_len = sizeof(struct sockaddr_in);
+ net_context_set_ipv4_ttl(ctx, 255);
+ } else if (IS_ENABLED(CONFIG_NET_IPV6) &&
+ net_pkt_family(pkt) == AF_INET6) {
+ create_ipv6_addr(net_sin6(dst));
+ *dst_len = sizeof(struct sockaddr_in6);
+ net_context_set_ipv6_hop_limit(ctx, 255);
+ } else {
+ return -EPFNOSUPPORT;
+ }
+
+ return 0;
+}
+
static struct net_context *get_ctx(sa_family_t family)
{
struct net_context *ctx;
@@ -217,48 +239,34 @@
socklen_t dst_len;
int ret;
- if (qtype == DNS_RR_TYPE_A) {
-#if defined(CONFIG_NET_IPV4)
+ ret = setup_dst_addr(ctx, pkt, &dst, &dst_len);
+ if (ret < 0) {
+ NET_DBG("unable to set up the response address");
+ return ret;
+ }
+
+ if (IS_ENABLED(CONFIG_NET_IPV4) && qtype == DNS_RR_TYPE_A) {
const struct in_addr *addr;
addr = net_if_ipv4_select_src_addr(net_pkt_iface(pkt),
&ip_hdr->ipv4->src);
- create_ipv4_addr(net_sin(&dst));
- dst_len = sizeof(struct sockaddr_in);
-
ret = create_answer(ctx, query, qtype,
sizeof(struct in_addr), (uint8_t *)addr);
if (ret != 0) {
return ret;
}
-
- net_context_set_ipv4_ttl(ctx, 255);
-#else /* CONFIG_NET_IPV4 */
- return -EPFNOSUPPORT;
-#endif /* CONFIG_NET_IPV4 */
-
- } else if (qtype == DNS_RR_TYPE_AAAA) {
-#if defined(CONFIG_NET_IPV6)
+ } else if (IS_ENABLED(CONFIG_NET_IPV6) && qtype == DNS_RR_TYPE_AAAA) {
const struct in6_addr *addr;
addr = net_if_ipv6_select_src_addr(net_pkt_iface(pkt),
&ip_hdr->ipv6->src);
- create_ipv6_addr(net_sin6(&dst));
- dst_len = sizeof(struct sockaddr_in6);
-
ret = create_answer(ctx, query, qtype,
sizeof(struct in6_addr), (uint8_t *)addr);
if (ret != 0) {
return -ENOMEM;
}
-
- net_context_set_ipv6_hop_limit(ctx, 255);
-#else /* CONFIG_NET_IPV6 */
- return -EPFNOSUPPORT;
-#endif /* CONFIG_NET_IPV6 */
-
} else {
/* TODO: support also service PTRs */
return -EINVAL;
@@ -294,6 +302,7 @@
const struct dns_sd_rec *record;
struct dns_sd_rec filter;
struct sockaddr dst;
+ socklen_t dst_len;
const struct in6_addr *addr6 = NULL;
const struct in_addr *addr4 = NULL;
char service_buf[DNS_SD_SERVICE_MAX_SIZE + 1];
@@ -303,20 +312,22 @@
/* This actually is used but the compiler doesn't see that */
ARG_UNUSED(record);
+ ret = setup_dst_addr(ctx, pkt, &dst, &dst_len);
+ if (ret < 0) {
+ NET_DBG("unable to set up the response address");
+ return;
+ }
+
if (IS_ENABLED(CONFIG_NET_IPV4)) {
/* Look up the local IPv4 address */
addr4 = net_if_ipv4_select_src_addr(net_pkt_iface(pkt),
&ip_hdr->ipv4->src);
- create_ipv4_addr(net_sin(&dst));
- net_context_set_ipv4_ttl(ctx, 255);
}
if (IS_ENABLED(CONFIG_NET_IPV6)) {
/* Look up the local IPv6 address */
addr6 = net_if_ipv6_select_src_addr(net_pkt_iface(pkt),
&ip_hdr->ipv6->src);
- create_ipv6_addr(net_sin6(&dst));
- net_context_set_ipv6_hop_limit(ctx, 255);
}
ret = dns_sd_extract_service_proto_domain(dns_msg->msg,
@@ -349,7 +360,7 @@
/* Send the response */
ret = net_context_sendto(ctx, result->data,
- result->len, &dst, sizeof(dst), NULL,
+ result->len, &dst, dst_len, NULL,
K_NO_WAIT, NULL);
if (ret < 0) {
NET_DBG("Cannot send mDNS reply (%d)", ret);
