X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=dns.c;h=89cd4ce5a76fc4ebd736784cf6d6fcbe4180bf0d;hb=000402bc86dacf2ffe64cdd376145fa8c7294e34;hp=0d192acf8faa439ffb3dbbef8af6d4aa2140a941;hpb=9091a2b0fa7f91be6d0d4b03ec8d7ef8cbe1e559;p=oweals%2Fmdnsd.git

diff --git a/dns.c b/dns.c
index 0d192ac..89cd4ce 100644
--- a/dns.c
+++ b/dns.c
@@ -39,6 +39,7 @@
 #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 +67,7 @@ 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 unicast)
 {
 	static struct dns_header h;
 	static struct dns_question q;
@@ -76,7 +77,7 @@ 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 +87,18 @@ 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(((unicast) ? (CLASS_UNICAST) : (0))  | 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 :");
 }
 
 
@@ -300,6 +300,9 @@ 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 +313,7 @@ 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;
 }
@@ -320,6 +323,9 @@ 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) {
@@ -329,7 +335,7 @@ parse_question(struct interface *iface, char *name, struct dns_question *q)
 		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 +345,13 @@ 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);
+			service_reply_a(iface, announce_ttl);
 		break;
 	};
 }
 
 void
-dns_handle_packet(struct interface *iface, uint8_t *buffer, int len)
+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 +363,10 @@ dns_handle_packet(struct interface *iface, uint8_t *buffer, int len)
 		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;