shaba/systemd-stable
1
1
Fork 0
mirror of https://github.com/systemd/systemd-stable.git synced 2025-01-25 06:03:40 +03:00
Code

resolved: split out check whether reply matches our question

Browse Source 
It's complicated enough, it deserves its own call.

(Also contains some unrelated whitespace, comment and assertion changes)
This commit is contained in:
Lennart Poettering 2015-12-09 17:49:05 +01:00
parent 8b5b564947
commit 8af5b88322
3 changed files with 40 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
src/resolve/resolved-dns-packet.c
View File

@ -2021,6 +2021,30 @@ finish:
return r;
}
int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key) {
int r;
assert(p);
assert(key);
/* Checks if the specified packet is a reply for the specified
* key and the specified key is the only one in the question
* section. */
if (DNS_PACKET_QR(p) != 1)
return 0;
/* Let's unpack the packet, if that hasn't happened yet. */
r = dns_packet_extract(p);
if (r < 0)
return r;
if (p->question->n_keys != 1)
return 0;
return dns_resource_key_equal(p->question->keys[0], key);
}
static const char* const dns_rcode_table[_DNS_RCODE_MAX_DEFINED] = {
[DNS_RCODE_SUCCESS] = "SUCCESS",
[DNS_RCODE_FORMERR] = "FORMERR",

2
src/resolve/resolved-dns-packet.h
View File

@ -161,6 +161,8 @@ int dns_packet_validate(DnsPacket *p);
int dns_packet_validate_reply(DnsPacket *p);
int dns_packet_validate_query(DnsPacket *p);
int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key);
int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start);
int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start);
int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start);

21
src/resolve/resolved-dns-transaction.c
View File

@ -428,12 +428,13 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0);
switch (t->scope->protocol) {
case DNS_PROTOCOL_DNS:
assert(t->server);
if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) {
/* request failed, immediately try again with reduced features */
/* Request failed, immediately try again with reduced features */
log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p)));
dns_server_packet_failed(t->server, t->current_features);
@ -449,13 +450,14 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
dns_server_packet_received(t->server, t->current_features, ts - t->start_usec, p->size);
break;
case DNS_PROTOCOL_LLMNR:
case DNS_PROTOCOL_MDNS:
dns_scope_packet_received(t->scope, ts - t->start_usec);
break;
break;
default:
break;
assert_not_reached("Invalid DNS protocol.");
}
if (DNS_PACKET_TC(p)) {
@ -474,7 +476,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
return;
}
if (r < 0) {
/* On LLMNR and mDNS, if we cannot connect to the host,
/* On LLMNR, 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);
@ -494,7 +496,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
}
}
/* Parse and update the cache */
/* Parse message, if it isn't parsed yet. */
r = dns_packet_extract(p);
if (r < 0) {
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
@ -503,7 +505,12 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
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) {
r = dns_packet_is_reply_for(p, t->key);
if (r < 0) {
dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES);
return;
}
if (r == 0) {
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
return;
}
@ -549,7 +556,7 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use
DNS_PACKET_ID(p) == t->id)
dns_transaction_process_reply(t, p);
else
log_debug("Invalid DNS packet.");
log_debug("Invalid DNS packet, ignoring.");
return 0;
}