resolved: when there's already somebody listening on the LLMNR ports, simple disable...

[elogind.git] / src / resolve / resolved-dns-scope.c

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 606176172338827c7476eba830a8c215c5486d44..0f654a6102bf2efff85de7670d068e43bd34f9ed 100644 (file)
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -85,7 +85,7 @@ DnsScope* dns_scope_free(DnsScope *s) {
         return NULL;
 }
 
-DnsServer *dns_scope_get_server(DnsScope *s) {
+DnsServer *dns_scope_get_dns_server(DnsScope *s) {
         assert(s);
 
         if (s->protocol != DNS_PROTOCOL_DNS)
@@ -133,7 +133,7 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) {
                 if (DNS_PACKET_QDCOUNT(p) > 1)
                         return -ENOTSUP;
 
-                srv = dns_scope_get_server(s);
+                srv = dns_scope_get_dns_server(s);
                 if (!srv)
                         return -ESRCH;
 
@@ -197,7 +197,7 @@ int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *add
         if (family == AF_UNSPEC) {
                 DnsServer *srv;
 
-                srv = dns_scope_get_server(s);
+                srv = dns_scope_get_dns_server(s);
                 if (!srv)
                         return -ESRCH;
 
@@ -353,6 +353,12 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
                 if (fd < 0)
                         return fd;
 
+                /* Always first try to drop membership before we add
+                 * one. This is necessary on some devices, such as
+                 * veth. */
+                if (b)
+                        setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn));
+
                 if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0)
                         return -errno;
 
@@ -366,6 +372,9 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
                 if (fd < 0)
                         return fd;
 
+                if (b)
+                        setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
+
                 if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
                         return -errno;
         } else
@@ -403,7 +412,9 @@ static int dns_scope_make_reply_packet(
 
         assert(s);
 
-        if (q->n_keys <= 0 && answer->n_rrs <= 0 && soa->n_rrs <= 0)
+        if ((!q || q->n_keys <= 0)
+            && (!answer || answer->n_rrs <= 0)
+            && (!soa || soa->n_rrs <= 0))
                 return -EINVAL;
 
         r = dns_packet_new(&p, s->protocol, 0);