From 37725f3e22edb50e0ca2d1fff971321a5a4d5112 Mon Sep 17 00:00:00 2001
From: Hongxu Jia <hongxu.jia@windriver.com>
Date: Wed, 12 Jul 2017 03:05:13 -0400
Subject: [PATCH 11/11] Moved the call to isc_app_ctxstart() to not get signal
 block by all threads

Signed-off-by: Francis Dupont <fdupont@isc.org>

In https://source.isc.org/git/bind9.git, since the following
commit applied:
...
commit b99bfa184bc9375421b5df915eea7dfac6a68a99
Author: Evan Hunt <each@isc.org>
Date:   Wed Apr 10 13:49:57 2013 -0700

    [master] unify internal and export libraries

    3550.       [func]          Unified the internal and export versions of the
                        BIND libraries, allowing external clients to use
                        the same libraries as BIND. [RT #33131]
...
(git show b99bfa184bc9375421b5df915eea7dfac6a68a99 -- ./lib/isc/unix/app.c)

In this commit, if bind9 enable threads(ISC_PLATFORM_USETHREADS),
it blocks signal SIGHUP, SIGINT and SIGTERM in isc__app_ctxstart.
Which caused dhclient/dhcpd could not be stopped by SIGTERM.

It caused systemd's reboot hung which send SIGTERM by default.

Upstream-Status: Backport [https://source.isc.org/git/dhcp.git]
Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
---
 omapip/isclib.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/omapip/isclib.c b/omapip/isclib.c
index ce86490..6a04345 100644
--- a/omapip/isclib.c
+++ b/omapip/isclib.c
@@ -185,16 +185,6 @@ dhcp_context_create(int flags,
 		if (result != ISC_R_SUCCESS)
 			goto cleanup;
 
-		result = isc_app_ctxstart(dhcp_gbl_ctx.actx);
-		if (result != ISC_R_SUCCESS)
-			return (result);
-		dhcp_gbl_ctx.actx_started = ISC_TRUE;
-
-		/* Not all OSs support suppressing SIGPIPE through socket
-		 * options, so set the sigal action to be ignore.  This allows
-		 * broken connections to fail gracefully with EPIPE on writes */
-		handle_signal(SIGPIPE, SIG_IGN);
-
 		result = isc_taskmgr_createinctx(dhcp_gbl_ctx.mctx,
 						 dhcp_gbl_ctx.actx,
 						 1, 0,
@@ -217,6 +207,21 @@ dhcp_context_create(int flags,
 		result = isc_task_create(dhcp_gbl_ctx.taskmgr, 0, &dhcp_gbl_ctx.task);
 		if (result != ISC_R_SUCCESS)
 			goto cleanup;
+
+		result = isc_app_ctxstart(dhcp_gbl_ctx.actx);
+		if (result != ISC_R_SUCCESS)
+			return (result);
+		dhcp_gbl_ctx.actx_started = ISC_TRUE;
+
+		/* Not all OSs support suppressing SIGPIPE through socket
+		 * options, so set the sigal action to be ignore.  This allows
+		 * broken connections to fail gracefully with EPIPE on writes */
+		handle_signal(SIGPIPE, SIG_IGN);
+
+		/* Reset handlers installed by isc_app_ctxstart()
+		 * to default for control-c and kill */
+		handle_signal(SIGINT, SIG_DFL);
+		handle_signal(SIGTERM, SIG_DFL);
 	}
 
 #if defined (NSUPDATE)
-- 
1.8.3.1