Don't cache hosts as services

[project/mdnsd.git] / dns.c

diff --git a/dns.c b/dns.c
index 550befc..7c49236 100644 (file)
--- a/dns.c
+++ b/dns.c
@@ -98,8 +98,8 @@ dns_send_question(struct interface *iface, const char *question, int type, int m
        iov[1].iov_len = len;
 
        DBG(1, "Q <- %s %s\n", dns_type_string(type), question);
-       if (interface_send_packet(iface, iov, ARRAY_SIZE(iov)) < 0)
-               perror("failed to send question :");
+       if (interface_send_packet(iface, NULL, iov, ARRAY_SIZE(iov)) < 0)
+               perror("failed to send question");
 }
 
 
@@ -138,7 +138,7 @@ dns_add_answer(int type, const uint8_t *rdata, uint16_t rdlength, int ttl)
 }
 
 void
-dns_send_answer(struct interface *iface, const char *answer)
+dns_send_answer(struct interface *iface, struct sockaddr *to, const char *answer)
 {
        uint8_t buffer[256];
        struct blob_attr *attr;
@@ -177,12 +177,12 @@ dns_send_answer(struct interface *iface, const char *answer)
                DBG(1, "A <- %s %s\n", dns_type_string(be16_to_cpu(a->type)), answer);
        }
 
-       if (interface_send_packet(iface, iov, n_iov) < 0)
-               fprintf(stderr, "failed to send question\n");
+       if (interface_send_packet(iface, to, iov, n_iov) < 0)
+               perror("failed to send answer");
 }
 
 void
-dns_reply_a(struct interface *iface, int ttl)
+dns_reply_a(struct interface *iface, struct sockaddr *to, int ttl)
 {
        struct ifaddrs *ifap, *ifa;
        struct sockaddr_in *sa;
@@ -205,7 +205,7 @@ dns_reply_a(struct interface *iface, int ttl)
                                dns_add_answer(TYPE_AAAA, (uint8_t *) &sa6->sin6_addr, 16, ttl);
                }
        }
-       dns_send_answer(iface, mdns_hostname_local);
+       dns_send_answer(iface, to, mdns_hostname_local);
 
        freeifaddrs(ifap);
 }
@@ -349,29 +349,44 @@ parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int
 }
 
 static void
-parse_question(struct interface *iface, char *name, struct dns_question *q)
+parse_question(struct interface *iface, struct sockaddr *from, char *name, struct dns_question *q)
 {
+       struct sockaddr *to;
        char *host;
 
-       if ((q->class & CLASS_UNICAST) && iface->multicast)
+       /* TODO: Multicast if more than one quarter of TTL has passed */
+       if ((q->class & CLASS_UNICAST) && iface->multicast) {
                iface = iface->peer;
+               to = from;
+       } else {
+               to = NULL;
+       }
 
        DBG(1, "Q -> %s %s\n", dns_type_string(q->type), name);
 
        switch (q->type) {
        case TYPE_ANY:
                if (!strcmp(name, mdns_hostname_local)) {
-                       service_reply(iface, NULL, announce_ttl);
-                       dns_reply_a(iface, announce_ttl);
+                       dns_reply_a(iface, to, announce_ttl);
+                       service_reply(iface, to, NULL, announce_ttl);
                }
                break;
 
        case TYPE_PTR:
-               if (!strcmp(name, sdudp))
-                       service_announce_services(iface, 0, announce_ttl);
-               else if (!strcmp(name, sdtcp))
-                       service_announce_services(iface, 1, announce_ttl);
-               service_reply(iface, name, announce_ttl);
+               if (!strcmp(name, sdudp)) {
+                       dns_reply_a(iface, to, announce_ttl);
+                       service_announce_services(iface, to, announce_ttl);
+               } else {
+                       /* First dot separates instance name from the rest */
+                       char *dot = strchr(name, '.');
+                       /* Length of queried instance */
+                       size_t len = dot ? dot - name : 0;
+
+                       /* Make sure it's query for the instance name we use */
+                       if (len && len == strlen(mdns_hostname) &&
+                           !strncmp(name, mdns_hostname, len))
+                               service_reply(iface, to, dot + 1, announce_ttl);
+               }
                break;
 
        case TYPE_AAAA:
@@ -380,7 +395,7 @@ parse_question(struct interface *iface, char *name, struct dns_question *q)
                if (host)
                        *host = '\0';
                if (!strcmp(mdns_hostname, name))
-                       dns_reply_a(iface, announce_ttl);
+                       dns_reply_a(iface, to, announce_ttl);
                break;
        };
 }
@@ -418,7 +433,7 @@ dns_handle_packet(struct interface *iface, struct sockaddr *s, uint16_t port, ui
                }
 
                if (!(h->flags & FLAG_RESPONSE))
-                       parse_question(iface, name, q);
+                       parse_question(iface, s, name, q);
        }
 
        if (!(h->flags & FLAG_RESPONSE))