Fix wrong query accounting in the connect function in dighost.c

The start_udp() function didn't properly attach to the query and thus
a callback with ISC_R_CANCELED would end with wrong accounting on the
query object.

Usually, this doesn't happen because underlying libuv API
uv_udp_connect() is synchronous, but isc_nm_udpconnect() could return
ISC_R_CANCELED in case it's called while the netmgr is shutting down.

diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 09926547b557eeb9136a990694ce714bdc49f6a7..a941bcf87d6048d71c9b235dc6ee646266daa73d 100644 (file)
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -227,8 +227,9 @@ void (*dighost_shutdown)(void);
 
 /* forward declarations */
 
+#define cancel_lookup(l) _cancel_lookup(l, __FILE__, __LINE__)
 static void
-cancel_lookup(dig_lookup_t *lookup);
+_cancel_lookup(dig_lookup_t *lookup, const char *file, unsigned int line);
 
 static void
 recv_done(isc_nmhandle_t *handle, isc_result_t eresult, isc_region_t *region,
@@ -1694,6 +1695,9 @@ _query_detach(dig_query_t **queryp, const char *file, unsigned int line) {
              isc_refcount_current(&query->references) - 1);
 
        if (isc_refcount_decrement(&query->references) == 1) {
+               INSIST(query->readhandle == NULL);
+               INSIST(query->sendhandle == NULL);
+
                if (ISC_LINK_LINKED(query, link)) {
                        ISC_LIST_UNLINK(lookup->q, query, link);
                }
@@ -2669,11 +2673,12 @@ send_done(isc_nmhandle_t *handle, isc_result_t eresult, void *arg) {
 /*%
  * Cancel a lookup, sending canceling reads on all existing sockets.
  */
+
 static void
-cancel_lookup(dig_lookup_t *lookup) {
+_cancel_lookup(dig_lookup_t *lookup, const char *file, unsigned int line) {
        dig_query_t *query, *next;
 
-       debug("cancel_lookup()");
+       debug("%s:%u:%s()", file, line, __func__);
        query = ISC_LIST_HEAD(lookup->q);
        while (query != NULL) {
                REQUIRE(DIG_VALID_QUERY(query));
@@ -2939,6 +2944,7 @@ static void
 start_udp(dig_query_t *query) {
        isc_result_t result;
        dig_query_t *next = NULL;
+       dig_query_t *connectquery = NULL;
 
        REQUIRE(DIG_VALID_QUERY(query));
 
@@ -2990,8 +2996,10 @@ start_udp(dig_query_t *query) {
                }
        }
 
+       query_attach(query, &connectquery);
        isc_nm_udpconnect(netmgr, (isc_nmiface_t *)&localaddr,
-                         (isc_nmiface_t *)&query->sockaddr, udp_ready, query,
+                         (isc_nmiface_t *)&query->sockaddr, udp_ready,
+                         connectquery,
                          (timeout ? timeout : UDP_TIMEOUT) * 1000, 0);
 }
 
@@ -4186,15 +4194,13 @@ cancel_all(void) {
                return;
        }
        atomic_store(&cancel_now, true);
-       if (current_lookup != NULL) {
+       while (current_lookup != NULL) {
                for (q = ISC_LIST_HEAD(current_lookup->q); q != NULL; q = nq) {
                        nq = ISC_LIST_NEXT(q, link);
                        debug("canceling pending query %p, belonging to %p", q,
                              current_lookup);
                        if (q->readhandle != NULL) {
-                               isc_refcount_decrement0(&recvcount);
-                               debug("recvcount=%" PRIuFAST32,
-                                     isc_refcount_current(&recvcount));
+                               isc_nm_cancelread(q->readhandle);
                        }
                        query_detach(&q);
                }