Merge branch '2746-fix-the-typo-in-setsockopt_off' into 'main'

Fix copy&paste error in setsockopt_off

Closes #2746

See merge request isc-projects/bind9!5138

CHANGES

@@ -1,3 +1,6 @@
+5652.	[bug]		Copy and paste error caused the socket option to
+			be enabled instead of disabled. [GL #2746]
+
 5651.	[func]		Refactor zone dumping to be processed asynchronously
 			via the uv_work_t thread pool API. [GL #2732]
 

doc/notes/notes-current.rst

@@ -72,3 +72,7 @@ Bug Fixes
 - Fixed an assertion failure that could occur if stale data was used
   to answer a query, and then a prefetch was triggered after the query
   was restarted (for example, to follow a CNAME). :gl:`#2733`
+
+- Fix an error that would enable don't fragment socket option instead
+  of disabling it leading to errors when sending the oversized UDP
+  packets. [GL #2746]

lib/isc/netmgr/netmgr.c

@@ -2985,7 +2985,7 @@ isc__nm_closesocket(uv_os_sock_t sock) {
 	setsockopt(socket, level, name, &(int){ 1 }, sizeof(int))
 
 #define setsockopt_off(socket, level, name) \
-	setsockopt(socket, level, name, &(int){ 1 }, sizeof(int))
+	setsockopt(socket, level, name, &(int){ 0 }, sizeof(int))
 
 isc_result_t
 isc__nm_socket_freebind(uv_os_sock_t fd, sa_family_t sa_family) {