int rfc1035MessageUnpack(const char *buf, size_t sz, rfc1035_message ** answer)
{
int off = 0;
int i;
int nr = 0;
rfc1035_message *msg;
rfc1035_rr *recs;
rfc1035_query *querys;
msg = (rfc1035_message*) acl_mycalloc(1, sizeof(*msg));
if (rfc1035HeaderUnpack(buf + off, sz - off, &off, msg)) {
RFC1035_UNPACK_DEBUG;
rfc1035SetErrno(rfc1035_unpack_error);
acl_myfree(msg);
return -rfc1035_unpack_error;
}
rfc1035_errno = 0;
rfc1035_error_message = NULL;
i = (int) msg->qdcount;
if (i != 1) {
/* This can not be an answer to our queries.. */
RFC1035_UNPACK_DEBUG;
rfc1035SetErrno(rfc1035_unpack_error);
acl_myfree(msg);
return -rfc1035_unpack_error;
}
querys = msg->query = (rfc1035_query*) acl_mycalloc((int) msg->qdcount, sizeof(*querys));
for (i = 0; i < (int) msg->qdcount; i++) {
if (rfc1035QueryUnpack(buf, sz, &off, &querys[i])) {
RFC1035_UNPACK_DEBUG;
rfc1035SetErrno(rfc1035_unpack_error);
rfc1035MessageDestroy(msg);
return -rfc1035_unpack_error;
}
}
*answer = msg;
if (msg->rcode) {
RFC1035_UNPACK_DEBUG;
rfc1035SetErrno((int) msg->rcode);
return -((int) msg->rcode);
}
if (msg->ancount == 0)
return 0;
recs = msg->answer = (rfc1035_rr*) acl_mycalloc((int) msg->ancount, sizeof(*recs));
for (i = 0; i < (int) msg->ancount; i++) {
if (off >= (int) sz) { /* corrupt packet */
RFC1035_UNPACK_DEBUG;
break;
}
if (rfc1035RRUnpack(buf, sz, &off, &recs[i])) { /* corrupt RR */
RFC1035_UNPACK_DEBUG;
break;
}
nr++;
}
if (nr == 0) {
/*
* we expected to unpack some answers (ancount != 0), but
* didn't actually get any.
*/
rfc1035MessageDestroy(msg);
*answer = NULL;
rfc1035SetErrno(rfc1035_unpack_error);
return -rfc1035_unpack_error;
}
if (msg->nscount > 0) {
//rfc1035NSUnpack(buf, sz, &off);
}
if (msg->arcount > 0) {
//rfc1035ARUnpack(buf, sz, &off);
}
return nr;
}
static void
idnsGrokReply(const char *buf, size_t sz)
{
int n;
rfc1035_message *message = NULL;
idns_query *q;
n = rfc1035MessageUnpack(buf,
sz,
&message);
if (message == NULL) {
debug(78, 2) ("idnsGrokReply: Malformed DNS response\n");
return;
}
debug(78, 3) ("idnsGrokReply: ID %#hx, %d answers\n", message->id, n);
q = idnsFindQuery(message->id);
if (q == NULL) {
debug(78, 3) ("idnsGrokReply: Late response\n");
rfc1035MessageDestroy(message);
return;
}
if (rfc1035QueryCompare(&q->query, message->query) != 0) {
debug(78, 3) ("idnsGrokReply: Query mismatch (%s != %s)\n", q->query.name, message->query->name);
rfc1035MessageDestroy(message);
return;
}
dlinkDelete(&q->lru, &lru_list);
if (message->tc && q->tcp_socket == -1) {
debug(78, 2) ("idnsGrokReply: Response for %s truncated. Retrying using TCP\n", message->query->name);
rfc1035MessageDestroy(message);
idnsRetryTcp(q);
return;
}
idnsRcodeCount(n, q->attempt);
q->error = NULL;
if (n < 0) {
debug(78, 3) ("idnsGrokReply: error %s (%d)\n", rfc1035_error_message, rfc1035_errno);
q->error = rfc1035_error_message;
q->rcode = -n;
if (q->rcode == 2 && ++q->attempt < MAX_ATTEMPT) {
/*
* RCODE 2 is "Server failure - The name server was
* unable to process this query due to a problem with
* the name server."
*/
rfc1035MessageDestroy(message);
q->start_t = current_time;
q->id = idnsQueryID();
rfc1035SetQueryID(q->buf, q->id);
idnsSendQuery(q);
return;
}
if (q->rcode == 3 && q->do_searchpath && q->attempt < MAX_ATTEMPT) {
strcpy(q->name, q->orig);
if (q->domain < npc) {
strcat(q->name, ".");
strcat(q->name, searchpath[q->domain].domain);
debug(78, 3) ("idnsGrokReply: searchpath used for %s\n",
q->name);
q->domain++;
} else {
q->attempt++;
}
rfc1035MessageDestroy(message);
if (q->hash.key) {
hash_remove_link(idns_lookup_hash, &q->hash);
q->hash.key = NULL;
}
q->start_t = current_time;
q->id = idnsQueryID();
rfc1035SetQueryID(q->buf, q->id);
q->sz = rfc1035BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id,
&q->query);
idnsCacheQuery(q);
idnsSendQuery(q);
return;
}
}
idnsCallback(q, message->answer, n, q->error);
rfc1035MessageDestroy(message);
idnsTcpCleanup(q);
cbdataFree(q);
}