Fix parsing of multiple records.

src/parse.c

@@ -57,7 +57,7 @@ rdns_request_reply_cmp (struct rdns_request *req, uint8_t *in, int len)
 
  /* In p we would store current position in reply and in c - position in request */
  p = in;
- c = req->packet + sizeof (struct dns_header);
+ c = req->packet + req->pos;
 
  for (;;) {
  /* Get current label */
@@ -83,8 +83,8 @@ rdns_request_reply_cmp (struct rdns_request *req, uint8_t *in, int len)
  p += len1;
  }
  if (len2 & DNS_COMPRESSION_BITS) {
- len2 = UNCOMPRESS_DNS_OFFSET(p);
- l2 = rdns_decompress_label (req->packet, &len2, len);
+ len2 = UNCOMPRESS_DNS_OFFSET(c);
+ l2 = rdns_decompress_label (c, &len2, len);
  if (l2 == NULL) {
  rdns_info ("invalid DNS pointer, cannot decompress");
  return NULL;
@@ -115,6 +115,7 @@ rdns_request_reply_cmp (struct rdns_request *req, uint8_t *in, int len)
  /* p now points to the end of QR section */
  /* Compare class and type */
  if (memcmp (p, c, sizeof (uint16_t) * 2) == 0) {
+ req->pos = c - req->packet + sizeof (uint16_t) * 2;
  return p + sizeof (uint16_t) * 2;
  }
  return NULL;

src/resolver.c

@@ -149,8 +149,9 @@ rdns_parse_reply (uint8_t *in, int r, struct rdns_request *req,
  struct dns_header *header = (struct dns_header *)in;
  struct rdns_reply *rep;
  struct rdns_reply_entry *elt;
- uint8_t *pos;
+ uint8_t *pos, *npos;
  struct rdns_resolver *resolver = req->resolver;
+ uint16_t qdcount;
 
  int i, t;
 
@@ -160,14 +161,27 @@ rdns_parse_reply (uint8_t *in, int r, struct rdns_request *req,
  return false;
  }
 
+ qdcount = ntohs (header->qdcount);
+
+ if (qdcount != req->qcount) {
+ rdns_info ("request has %d queries, reply has %d queries", (int)req->qcount, (int)header->qdcount);
+ return false;
+ }
+
  /* 
  * Now we have request and query data is now at the end of header, so compare
  * request QR section and reply QR section
  */
- if ((pos = rdns_request_reply_cmp (req, in + sizeof (struct dns_header),
- r - sizeof (struct dns_header))) == NULL) {
- rdns_info ("DNS request with id %d is for different query, ignoring", (int)req->id);
- return false;
+ req->pos = sizeof (struct dns_header);
+ pos = in + sizeof (struct dns_header);
+ t = r - sizeof (struct dns_header);
+ for (i = 0; i < (int)qdcount; i ++) {
+ if ((npos = rdns_request_reply_cmp (req, pos,t)) == NULL) {
+ rdns_info ("DNS request with id %d is for different query, ignoring", (int)req->id);
+ return false;
+ }
+ t -= npos - pos;
+ pos = npos;
  }
  /*
  * Now pos is in answer section, so we should extract data and form reply

test/dns_regress.c

@@ -85,18 +85,18 @@ static void
 rdns_test_a (struct rdns_resolver *resolver)
 {
  const char *names[] = {
- "google.com",
- "github.com",
+ //"google.com",
+ //"github.com",
  "freebsd.org",
- "kernel.org",
- "www.ник.рф",
+ //"kernel.org",
+ //"www.ник.рф",
  NULL
  };
  const char **cur;
 
  for (cur = names; *cur != NULL; cur ++) {
- rdns_make_request_full (resolver, rdns_regress_callback, *cur, 1.0, 2, 1,
- *cur, RDNS_REQUEST_AAAA);
+ rdns_make_request_full (resolver, rdns_regress_callback, *cur, 1.0, 2, 2,
+ *cur, RDNS_REQUEST_AAAA, *cur, RDNS_REQUEST_A);
  remain_tests ++;
  }
 }
@@ -137,8 +137,8 @@ main (int argc, char **argv)
  rdns_bind_libevent (resolver_event, base);
  rdns_resolver_set_log_level (resolver_event, RDNS_LOG_DEBUG);
  /* Google and opendns */
- assert (rdns_resolver_add_server (resolver_event, "208.67.222.222", 53, 0, 8));
- assert (rdns_resolver_add_server (resolver_event, "8.8.8.8", 53, 0, 1));
+ assert (rdns_resolver_add_server (resolver_event, "127.0.0.1", 53, 0, 8));
+ //assert (rdns_resolver_add_server (resolver_event, "8.8.8.8", 53, 0, 1));
 
  assert (rdns_resolver_init (resolver_ev));
  assert (rdns_resolver_init (resolver_event));