From: Artem Boldariev <artem@boldariev.com>
Date: Tue, 10 May 2022 16:46:12 +0000 (+0300)
Subject: Fix an abort in DoH (client-side) when writing on closing sock
X-Git-Tag: v9.19.2~22^2~1
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=9abb00bb5f66c1d365fb0e69bc96fa2e49bd37cf;p=thirdparty%2Fbind9.git

Fix an abort in DoH (client-side) when writing on closing sock

The commit fixes a corner case in client-side DoH code, when a write
attempt is done on a closing socket (session).

The change ensures that the write call-back will be called with a
proper error code (see failed_send_cb() call in client_httpsend()).
---

diff --git a/lib/isc/netmgr/http.c b/lib/isc/netmgr/http.c
index a787e2d3102..4cde316236c 100644
--- a/lib/isc/netmgr/http.c
+++ b/lib/isc/netmgr/http.c
@@ -1509,7 +1509,12 @@ client_send(isc_nmhandle_t *handle, const isc_region_t *region) {
 	REQUIRE(region != NULL);
 	REQUIRE(region->base != NULL);
 	REQUIRE(region->length <= MAX_DNS_MESSAGE_SIZE);
-	REQUIRE(cstream != NULL);
+
+	if (session->closed) {
+		return (ISC_R_CANCELED);
+	}
+
+	INSIST(cstream != NULL);
 
 	if (cstream->post) {
 		/* POST */