X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fmdnsd.git;a=blobdiff_plain;f=dns.c;h=de0c21ade1b79f87244572732ac4ddba580d77f6;hp=961c2d0a2fded8459f23adde7432ca05b14c4202;hb=c0c78c92d57c53276bb7f08468bcc716ba272497;hpb=891447c1a9db8a55f769241c94f4400e16f43dd9

diff --git a/dns.c b/dns.c
index 961c2d0..de0c21a 100644
--- a/dns.c
+++ b/dns.c
@@ -15,6 +15,7 @@
 #include <sys/stat.h>
 
 #include <fcntl.h>
+#include <ifaddrs.h>
 #include <time.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -39,6 +40,7 @@
 #include "interface.h"
 
 static char name_buffer[MAX_NAME_LEN + 1];
+static char dns_buffer[MAX_NAME_LEN];
 static struct blob_buf ans_buf;
 
 const char*
@@ -66,7 +68,7 @@ dns_type_string(uint16_t type)
 }
 
 void
-dns_send_question(struct interface *iface, const char *question, int type)
+dns_send_question(struct interface *iface, const char *question, int type, int multicast)
 {
 	static struct dns_header h;
 	static struct dns_question q;
@@ -76,7 +78,7 @@ dns_send_question(struct interface *iface, const char *question, int type)
 			.iov_len = sizeof(h),
 		},
 		{
-			.iov_base = name_buffer,
+			.iov_base = dns_buffer,
 		},
 		{
 			.iov_base = &q,
@@ -86,19 +88,18 @@ dns_send_question(struct interface *iface, const char *question, int type)
 	int len;
 
 	h.questions = cpu_to_be16(1);
-	q.class = cpu_to_be16(1);
+	q.class = cpu_to_be16((multicast ? 0 : CLASS_UNICAST) | 1);
 	q.type = cpu_to_be16(type);
 
-	len = dn_comp(question, (void *) name_buffer, sizeof(name_buffer), NULL, NULL);
+	len = dn_comp(question, (void *) dns_buffer, sizeof(dns_buffer), NULL, NULL);
 	if (len < 1)
 		return;
 
 	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)
-		fprintf(stderr, "failed to send question\n");
-	else
-		DBG(1, "Q <- %s %s\n", dns_type_string(type), question);
+		perror("failed to send question :");
 }
 
 
@@ -180,6 +181,35 @@ dns_send_answer(struct interface *iface, const char *answer)
 		fprintf(stderr, "failed to send question\n");
 }
 
+void
+dns_reply_a(struct interface *iface, int ttl)
+{
+	struct ifaddrs *ifap, *ifa;
+	struct sockaddr_in *sa;
+	struct sockaddr_in6 *sa6;
+
+	getifaddrs(&ifap);
+
+	dns_init_answer();
+	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+		if (strcmp(ifa->ifa_name, iface->name))
+			continue;
+		if (ifa->ifa_addr->sa_family == AF_INET) {
+			sa = (struct sockaddr_in *) ifa->ifa_addr;
+			dns_add_answer(TYPE_A, (uint8_t *) &sa->sin_addr, 4, ttl);
+		}
+		if (ifa->ifa_addr->sa_family == AF_INET6) {
+			uint8_t ll_prefix[] = {0xfe, 0x80 };
+			sa6 = (struct sockaddr_in6 *) ifa->ifa_addr;
+			if (!memcmp(&sa6->sin6_addr, &ll_prefix, 2))
+				dns_add_answer(TYPE_AAAA, (uint8_t *) &sa6->sin6_addr, 16, ttl);
+		}
+	}
+	dns_send_answer(iface, mdns_hostname_local);
+
+	freeifaddrs(ifap);
+}
+
 static int
 scan_name(const uint8_t *buffer, int len)
 {
@@ -300,6 +330,9 @@ parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int
 		return -1;
 	}
 
+	if ((a->class & ~CLASS_FLUSH) != CLASS_IN)
+		return -1;
+
 	rdata = *b;
 	if (a->rdlength > *rlen) {
 		fprintf(stderr, "dropping: bad question\n");
@@ -310,7 +343,7 @@ 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);
+		cache_answer(iface, buffer, len, name, a, rdata, a->class & CLASS_FLUSH);
 
 	return 0;
 }
@@ -320,16 +353,21 @@ parse_question(struct interface *iface, char *name, struct dns_question *q)
 {
 	char *host;
 
+	if ((q->class & CLASS_UNICAST) && 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))
+		if (!strcmp(name, mdns_hostname_local)) {
 			service_reply(iface, NULL, announce_ttl);
+			dns_reply_a(iface, announce_ttl);
+		}
 		break;
 
 	case TYPE_PTR:
-		service_announce_services(iface, name);
+		service_announce_services(iface, name, announce_ttl);
 		service_reply(iface, name, announce_ttl);
 		break;
 
@@ -339,13 +377,13 @@ parse_question(struct interface *iface, char *name, struct dns_question *q)
 		if (host)
 			*host = '\0';
 		if (!strcmp(mdns_hostname, name))
-			service_reply_a(iface, q->type, announce_ttl);
+			dns_reply_a(iface, announce_ttl);
 		break;
 	};
 }
 
 void
-dns_handle_packet(struct interface *iface, uint8_t *buffer, int len, int unicast)
+dns_handle_packet(struct interface *iface, struct sockaddr *s, uint16_t port, uint8_t *buffer, int len)
 {
 	struct dns_header *h;
 	uint8_t *b = buffer;
@@ -357,6 +395,10 @@ dns_handle_packet(struct interface *iface, uint8_t *buffer, int len, int unicast
 		return;
 	}
 
+	if (h->questions && !iface->multicast && port != 5353)
+		/* silently drop unicast questions that dont originate from port 5353 */
+		return;
+
 	while (h->questions-- > 0) {
 		char *name = dns_consume_name(buffer, len, &b, &rlen);
 		struct dns_question *q;