}
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;
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");
}
}
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;
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;
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);
}
if (IS_COMPRESSED(l))
return offset + 2;
+ if (l + 1 > len) return -1;
len -= l + 1;
offset += l + 1;
buffer += l + 1;
dns_consume_header(uint8_t **data, int *len)
{
struct dns_header *h = (struct dns_header *) *data;
- uint16_t *swap = (uint16_t *) h;
- int endianess = 6;
if (*len < sizeof(struct dns_header))
return NULL;
- while (endianess--) {
- *swap = be16_to_cpu(*swap);
- swap++;
- }
+ h->id = be16_to_cpu(h->id);
+ h->flags = be16_to_cpu(h->flags);
+ h->questions = be16_to_cpu(h->questions);
+ h->answers = be16_to_cpu(h->answers);
+ h->authority = be16_to_cpu(h->authority);
+ h->additional = be16_to_cpu(h->additional);
*len -= sizeof(struct dns_header);
*data += sizeof(struct dns_header);
dns_consume_question(uint8_t **data, int *len)
{
struct dns_question *q = (struct dns_question *) *data;
- uint16_t *swap = (uint16_t *) q;
- int endianess = 2;
if (*len < sizeof(struct dns_question))
return NULL;
- while (endianess--) {
- *swap = be16_to_cpu(*swap);
- swap++;
- }
+ q->type = be16_to_cpu(q->type);
+ q->class = be16_to_cpu(q->class);
*len -= sizeof(struct dns_question);
*data += sizeof(struct dns_question);
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;
uint8_t *rdata;
- if (!name) {
+ if (!name || *rlen < 0) {
fprintf(stderr, "dropping: bad question\n");
return -1;
}
*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);
- dns_reply_a(iface, announce_ttl);
+ 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 {
+ if (name[0] == '_') {
+ service_reply(iface, to, NULL, name, announce_ttl);
+ } else {
+ /* First dot separates instance name from the rest */
+ char *dot = strchr(name, '.');
+
+ if (dot) {
+ *dot = '\0';
+ service_reply(iface, to, name, dot + 1, announce_ttl);
+ *dot = '.';
+ }
+ }
+ }
break;
case TYPE_AAAA:
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;
return;
}
- if (h->questions && !iface->multicast && port != 5353)
+ if (h->questions && !iface->multicast && port != MCAST_PORT)
/* silently drop unicast questions that dont originate from port 5353 */
return;
char *name = dns_consume_name(buffer, len, &b, &rlen);
struct dns_question *q;
- if (!name) {
+ if (!name || rlen < 0) {
fprintf(stderr, "dropping: bad name\n");
return;
}
}
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;
}
projects / project / mdnsd.git / blobdiff