mir/bind
2
0
Fork 0
mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-30 22:15:20 +00:00
Code Issues Releases Wiki Activity

If a response was received on port 53 and failed to parse, the server

Browse Source 
would respond to the response, potentially causing packet storms.
This bug was introduced on the mainline by the dispatch-bypass changes and
does not affect any released version.
This commit is contained in:
Andreas Gustafsson
2001-05-09 23:13:03 +00:00
parent 8e4da48fa7
commit 8ea814ce5f
1 changed files with 26 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
bin/named/client.c
View File

@@ -15,7 +15,7 @@
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: client.c,v 1.164 2001/04/19 18:29:53 bwelling Exp $ */
/* $Id: client.c,v 1.165 2001/05/09 23:13:03 gson Exp $ */
#include <config.h>
@@ -1203,6 +1203,8 @@ client_request(isc_task_t *task, isc_event_t *event) {
isc_boolean_t ra; /* Recursion available. */
isc_netaddr_t netaddr;
int match;
dns_messageid_t id;
unsigned int flags;
REQUIRE(event != NULL);
client = event->ev_arg;
@@ -1299,18 +1301,22 @@ client_request(isc_task_t *task, isc_event_t *event) {
#endif
}
result = dns_message_parse(client->message, buffer, 0);
result = dns_message_peekheader(buffer, &id, &flags);
if (result != ISC_R_SUCCESS) {
ns_client_error(client, result);
/*
* There isn't enough header to determine whether
* this was a request or a response. Drop it.
*/
ns_client_next(client, result);
goto cleanup;
}
/*
* We expect a query, not a response. If this is a UDP response,
* forward it to the dispatcher. If it's a TCP response,
* discarded it here.
* The client object handles requests, not responses.
* If this is a UDP response, forward it to the dispatcher.
* If it's a TCP response, discard it here.
*/
if ((client->message->flags & DNS_MESSAGEFLAG_QR) != 0) {
if ((flags & DNS_MESSAGEFLAG_QR) != 0) {
if (TCP_CLIENT(client)) {
CTRACE("unexpected response");
ns_client_next(client, DNS_R_FORMERR);
@@ -1322,6 +1328,19 @@ client_request(isc_task_t *task, isc_event_t *event) {
}
}
/*
* It's a request. Parse it.
*/
result = dns_message_parse(client->message, buffer, 0);
if (result != ISC_R_SUCCESS) {
/*
* Parsing the request failed. Send a response
* (typically FORMERR or SERVFAIL).
*/
ns_client_error(client, result);
goto cleanup;
}
/*
* Deal with EDNS.
*/