From aceabacdb8de37c84dd18a12f40a09c1daa04b62 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Tue, 27 Dec 2016 07:02:33 +1100
Subject: [PATCH] 4538.   [bug]           Call dns_client_startresolve from
 client->task.                         [RT #43896]

---
 CHANGES                      |  3 ++
 lib/dns/client.c             | 91 +++++++++++++++++++++++++-----------
 lib/dns/include/dns/events.h |  1 +
 3 files changed, 69 insertions(+), 26 deletions(-)

diff --git a/CHANGES b/CHANGES
index f824b03532..8656e1c55f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4538.	[bug]		Call dns_client_startresolve from client->task.
+			[RT #43896]
+
 4537.	[bug]		Handle timouts better in dig/host/nslookup. [RT #43576]
 
 4536.	[bug]		ISC_SOCKEVENTATTR_USEMINMTU was not being cleared
diff --git a/lib/dns/client.c b/lib/dns/client.c
index 0ec1953eb1..d91862c43c 100644
--- a/lib/dns/client.c
+++ b/lib/dns/client.c
@@ -2772,6 +2772,48 @@ dns_client_update(dns_client_t *client, dns_rdataclass_t rdclass,
 	return (result);
 }
 
+static void
+runintask(isc_task_t *task, isc_event_t *event) {
+	updatectx_t *uctx;
+	isc_result_t result;
+	unsigned int resoptions;
+
+	REQUIRE(event != NULL);
+
+	UNUSED(task);
+
+	uctx = event->ev_arg;
+
+	if (uctx->zonename != NULL && uctx->currentserver != NULL) {
+		result = send_update(uctx);
+		if (result != ISC_R_SUCCESS)
+			goto fail;
+	} else if (uctx->currentserver != NULL) {
+		result = request_soa(uctx);
+		if (result != ISC_R_SUCCESS)
+			goto fail;
+	} else {
+		resoptions = 0;
+		if (uctx->want_tcp)
+			resoptions |= DNS_CLIENTRESOPT_TCP;
+		dns_name_clone(uctx->firstname, &uctx->soaqname);
+		result = dns_client_startresolve(uctx->client, &uctx->soaqname,
+						 uctx->rdclass,
+						 dns_rdatatype_soa, resoptions,
+						 uctx->client->task,
+						 resolvesoa_done, uctx,
+						 &uctx->restrans);
+		if (result != ISC_R_SUCCESS)
+			goto fail;
+	}
+
+	isc_event_free(&event);
+
+fail:
+	if (result != ISC_R_SUCCESS)
+		update_sendevent(uctx, result);
+}
+
 isc_result_t
 dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
 		       dns_name_t *zonename, dns_namelist_t *prerequisites,
@@ -2789,7 +2831,7 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
 	isc_sockaddr_t *server, *sa = NULL;
 	dns_tsectype_t tsectype = dns_tsectype_none;
 	isc_boolean_t want_tcp;
-	unsigned int resoptions;
+	isc_event_t *runinevent;
 
 	UNUSED(options);
 
@@ -2810,20 +2852,36 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
 	UNLOCK(&client->lock);
 	if (result != ISC_R_SUCCESS)
 		return (result);
+
 	want_tcp = ISC_TF((options & DNS_CLIENTUPDOPT_TCP) != 0);
 
-	/* Create a context and prepare some resources */
+	/*
+	 * Create a context and prepare some resources.
+	 */
+
 	uctx = isc_mem_get(client->mctx, sizeof(*uctx));
 	if (uctx == NULL) {
 		dns_view_detach(&view);
 		return (ISC_R_NOMEMORY);
 	}
-	result = isc_mutex_init(&uctx->lock);
-	if (result != ISC_R_SUCCESS) {
+
+	runinevent = isc_event_allocate(client->mctx, client->task,
+					DNS_EVENT_RUNIN, runintask,
+					uctx, sizeof(*runinevent));
+	if (runinevent == NULL) { 
 		dns_view_detach(&view);
 		isc_mem_put(client->mctx, uctx, sizeof(*uctx));
 		return (ISC_R_NOMEMORY);
 	}
+
+	result = isc_mutex_init(&uctx->lock);
+	if (result != ISC_R_SUCCESS) {
+		dns_view_detach(&view);
+		isc_event_free(&runinevent);
+		isc_mem_put(client->mctx, uctx, sizeof(*uctx));
+		return (ISC_R_NOMEMORY);
+	}
+
 	tclone = NULL;
 	isc_task_attach(task, &tclone);
 	uctx->client = client;
@@ -2925,33 +2983,14 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
 	ISC_LIST_APPEND(client->updatectxs, uctx, link);
 	UNLOCK(&client->lock);
 
-	if (uctx->zonename != NULL && uctx->currentserver != NULL) {
-		result = send_update(uctx);
-		if (result != ISC_R_SUCCESS)
-			goto fail;
-	} else if (uctx->currentserver != NULL) {
-		result = request_soa(uctx);
-		if (result != ISC_R_SUCCESS)
-			goto fail;
-	} else {
-		resoptions = 0;
-		if (want_tcp)
-			resoptions |= DNS_CLIENTRESOPT_TCP;
-		dns_name_clone(uctx->firstname, &uctx->soaqname);
-		result = dns_client_startresolve(uctx->client, &uctx->soaqname,
-						 uctx->rdclass,
-						 dns_rdatatype_soa, resoptions,
-						 client->task, resolvesoa_done,
-						 uctx, &uctx->restrans);
-		if (result != ISC_R_SUCCESS)
-			goto fail;
-	}
-
 	*transp = (dns_clientupdatetrans_t *)uctx;
+	isc_task_send(client->task, &runinevent);
 
 	return (ISC_R_SUCCESS);
 
  fail:
+	if (runinevent != NULL)
+		isc_event_free(&runinevent);
 	if (ISC_LINK_LINKED(uctx, link)) {
 		LOCK(&client->lock);
 		ISC_LIST_UNLINK(client->updatectxs, uctx, link);
diff --git a/lib/dns/include/dns/events.h b/lib/dns/include/dns/events.h
index 2023f01e98..41cee1028f 100644
--- a/lib/dns/include/dns/events.h
+++ b/lib/dns/include/dns/events.h
@@ -75,6 +75,7 @@
 #define DNS_EVENT_CATZADDZONE			(ISC_EVENTCLASS_DNS + 54)
 #define DNS_EVENT_CATZMODZONE			(ISC_EVENTCLASS_DNS + 55)
 #define DNS_EVENT_CATZDELZONE			(ISC_EVENTCLASS_DNS + 56)
+#define DNS_EVENT_RUNIN				(ISC_EVENTCLASS_DNS + 57)
 
 #define DNS_EVENT_FIRSTEVENT			(ISC_EVENTCLASS_DNS + 0)
 #define DNS_EVENT_LASTEVENT			(ISC_EVENTCLASS_DNS + 65535)