X-Git-Url: https://git.archive.openwrt.org/?a=blobdiff_plain;f=dns.c;h=bccaa29525fdafde1de30060050b769ecc04b6a5;hb=26ce7dca8085d34e6c3910680da51695f3508eec;hp=7ca705ea416653099bde9a3329c81119d5bb9bae;hpb=55a5d75b5c051c5828b0b6390726b8353f909b3c;p=project%2Fmdnsd.git

diff --git a/dns.c b/dns.c
index 7ca705e..bccaa29 100644
--- a/dns.c
+++ b/dns.c
@@ -68,7 +68,8 @@ dns_type_string(uint16_t type)
 }
 
 void
-dns_send_question(struct interface *iface, const char *question, int type, int multicast)
+dns_send_question(struct interface *iface, struct sockaddr *to,
+		  const char *question, int type, int multicast)
 {
 	static struct dns_header h;
 	static struct dns_question q;
@@ -98,8 +99,8 @@ 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, to, iov, ARRAY_SIZE(iov)) < 0)
+		perror("failed to send question");
 }
 
 
@@ -138,7 +139,7 @@ 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 +178,12 @@ 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 +206,7 @@ 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);
 }
@@ -312,8 +313,9 @@ dns_consume_name(const uint8_t *base, int blen, uint8_t **data, int *len)
 	return name_buffer;
 }
 
-static int
-parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int *rlen, int cache)
+static int parse_answer(struct interface *iface, struct sockaddr *from,
+			uint8_t *buffer, int len, uint8_t **b, int *rlen,
+			int cache)
 {
 	char *name = dns_consume_name(buffer, len, b, rlen);
 	struct dns_answer *a;
@@ -343,30 +345,49 @@ parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int
 	*b += a->rdlength;
 
 	if (cache)
-		cache_answer(iface, buffer, len, name, a, rdata, a->class & CLASS_FLUSH);
+		cache_answer(iface, from, buffer, len, name, a, rdata, a->class & CLASS_FLUSH);
 
 	return 0;
 }
 
 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 = NULL;
 	char *host;
 
-	if ((q->class & CLASS_UNICAST) && iface->multicast)
-		iface = iface->peer;
+	/* TODO: Multicast if more than one quarter of TTL has passed */
+	if (q->class & CLASS_UNICAST) {
+		to = from;
+		if (iface->multicast)
+			iface = iface->peer;
+	}
 
 	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);
+		if (!strcmp(name, mdns_hostname_local)) {
+			dns_reply_a(iface, to, announce_ttl);
+			service_reply(iface, to, NULL, NULL, announce_ttl);
+		}
 		break;
 
 	case TYPE_PTR:
-		service_announce_services(iface, name, announce_ttl);
-		service_reply(iface, name, announce_ttl);
+		if (!strcmp(name, C_DNS_SD)) {
+			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(umdns_host_label) &&
+			    !strncmp(name, umdns_host_label, len))
+				service_reply(iface, to, NULL, dot + 1, announce_ttl);
+		}
 		break;
 
 	case TYPE_AAAA:
@@ -374,14 +395,14 @@ parse_question(struct interface *iface, char *name, struct dns_question *q)
 		host = strstr(name, ".local");
 		if (host)
 			*host = '\0';
-		if (!strcmp(mdns_hostname, name))
-			dns_reply_a(iface, announce_ttl);
+		if (!strcmp(umdns_host_label, name))
+			dns_reply_a(iface, to, announce_ttl);
 		break;
 	};
 }
 
 void
-dns_handle_packet(struct interface *iface, struct sockaddr *s, uint16_t port, uint8_t *buffer, int len)
+dns_handle_packet(struct interface *iface, struct sockaddr *from, uint16_t port, uint8_t *buffer, int len)
 {
 	struct dns_header *h;
 	uint8_t *b = buffer;
@@ -393,8 +414,8 @@ dns_handle_packet(struct interface *iface, struct sockaddr *s, uint16_t port, ui
 		return;
 	}
 
-	if (h->questions && !iface->multicast && port != 5353)
-		// silently drop unicast questions that dont originate from port 5353  
+	if (h->questions && !iface->multicast && port != MCAST_PORT)
+		/* silently drop unicast questions that dont originate from port 5353 */
 		return;
 
 	while (h->questions-- > 0) {
@@ -413,22 +434,22 @@ 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, from, name, q);
 	}
 
 	if (!(h->flags & FLAG_RESPONSE))
 		return;
 
 	while (h->answers-- > 0)
-		if (parse_answer(iface, buffer, len, &b, &rlen, 1))
+		if (parse_answer(iface, from, buffer, len, &b, &rlen, 1))
 			return;
 
 	while (h->authority-- > 0)
-		if (parse_answer(iface, buffer, len, &b, &rlen, 1))
+		if (parse_answer(iface, from, buffer, len, &b, &rlen, 1))
 			return;
 
 	while (h->additional-- > 0)
-		if (parse_answer(iface, buffer, len, &b, &rlen, 1))
+		if (parse_answer(iface, from, buffer, len, &b, &rlen, 1))
 			return;
 
 }