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resolved: handle more mDNS protocol details

This commit is contained in:
Daniel Mack 2015-09-03 12:09:11 +02:00
parent a20b959217
commit 547493c5ad
1 changed files with 32 additions and 23 deletions
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55
src/resolve/resolved-dns-transaction.c
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@ -458,6 +458,13 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
}
if (DNS_PACKET_TC(p)) {
/* Truncated packets for mDNS are not allowed. Give up immediately. */
if (t->scope->protocol == DNS_PROTOCOL_MDNS) {
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
return;
}
/* Response was truncated, let's try again with good old TCP */
r = dns_transaction_open_tcp(t);
if (r == -ESRCH) {
@ -466,7 +473,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
return;
}
if (r < 0) {
/* On LLMNR, if we cannot connect to the host,
/* On LLMNR and mDNS, if we cannot connect to the host,
* we immediately give up */
if (t->scope->protocol == DNS_PROTOCOL_LLMNR) {
dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES);
@ -493,30 +500,32 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
return;
}
/* Only consider responses with equivalent query section to the request */
if (p->question->n_keys != 1 || dns_resource_key_equal(p->question->keys[0], t->key) <= 0) {
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
return;
if (t->scope->protocol == DNS_PROTOCOL_DNS) {
/* Only consider responses with equivalent query section to the request */
if (p->question->n_keys != 1 || dns_resource_key_equal(p->question->keys[0], t->key) <= 0) {
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
return;
}
/* Install the answer as answer to the transaction */
dns_answer_unref(t->answer);
t->answer = dns_answer_ref(p->answer);
t->answer_rcode = DNS_PACKET_RCODE(p);
t->answer_authenticated = t->scope->dnssec_mode == DNSSEC_TRUST && DNS_PACKET_AD(p);
/* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */
if (DNS_PACKET_SHALL_CACHE(p))
dns_cache_put(&t->scope->cache,
t->key,
DNS_PACKET_RCODE(p),
p->answer,
DNS_PACKET_ANCOUNT(p),
t->answer_authenticated,
0,
p->family,
&p->sender);
}
/* Install the answer as answer to the transaction */
dns_answer_unref(t->answer);
t->answer = dns_answer_ref(p->answer);
t->answer_rcode = DNS_PACKET_RCODE(p);
t->answer_authenticated = t->scope->dnssec_mode == DNSSEC_TRUST && DNS_PACKET_AD(p);
/* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */
if (DNS_PACKET_SHALL_CACHE(p))
dns_cache_put(&t->scope->cache,
t->key,
DNS_PACKET_RCODE(p),
p->answer,
DNS_PACKET_ANCOUNT(p),
t->answer_authenticated,
0,
p->family,
&p->sender);
if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS)
dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS);
else