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dig: return a non-zero exit code for failed TCP EOF retries

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dig retries a TCP query when a server closes the connection prematurely.
However, dig's exit code remains unaffected even if the second attempt
to get a response also fails with the same error for the same lookup,
which should not be the case.  Ensure the exit code is updated
appropriately when a retry triggered by a TCP EOF condition fails.
This commit is contained in:
Michał Kępień
2019-01-18 11:15:19 +01:00
committed by Evan Hunt
parent 91d1218097
commit 0f168a4b37
4 changed files with 263 additions and 9 deletions
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33
bin/dig/dighost.c
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@@ -2991,6 +2991,27 @@ connect_timeout(isc_task_t *task, isc_event_t *event) {
UNLOCK_LOOKUP;
}
/*%
* Called when a peer closes a TCP socket prematurely.
*/
static void
requeue_or_update_exitcode(dig_lookup_t *lookup) {
if (lookup->eoferr == 0U) {
/*
* Peer closed the connection prematurely for the first time
* for this lookup. Try again, keeping track of this failure.
*/
dig_lookup_t *requeued_lookup = requeue_lookup(lookup, true);
requeued_lookup->eoferr++;
} else {
/*
* Peer closed the connection prematurely and it happened
* previously for this lookup. Indicate an error.
*/
exitcode = 9;
}
}
/*%
* Event handler for the TCP recv which gets the length header of TCP
* packets. Start the next recv of length bytes.
@@ -3002,7 +3023,7 @@ tcp_length_done(isc_task_t *task, isc_event_t *event) {
isc_region_t r;
isc_result_t result;
dig_query_t *query = NULL;
dig_lookup_t *l, *n;
dig_lookup_t *l;
uint16_t length;
REQUIRE(event->ev_type == ISC_SOCKEVENT_RECVDONE);
@@ -3041,9 +3062,8 @@ tcp_length_done(isc_task_t *task, isc_event_t *event) {
sockcount--;
debug("sockcount=%d", sockcount);
INSIST(sockcount >= 0);
if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
n = requeue_lookup(l, true);
n->eoferr++;
if (sevent->result == ISC_R_EOF) {
requeue_or_update_exitcode(l);
}
isc_event_free(&event);
clear_query(query);
@@ -3544,9 +3564,8 @@ recv_done(isc_task_t *task, isc_event_t *event) {
debug("sockcount=%d", sockcount);
INSIST(sockcount >= 0);
}
if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
n = requeue_lookup(l, true);
n->eoferr++;
if (sevent->result == ISC_R_EOF) {
requeue_or_update_exitcode(l);
}
isc_event_free(&event);
clear_query(query);