[OE-core] [PATCH] dhcp: fix genetle shutdown not work while bind9 compile with --enable-threads

[Hongxu Jia]

Previously, OE enabled threads in bind9:
...
commit 598e5da5a2af2bd93ad890687dd32009e348fc85
Author: Kai Kang <kai.kang at windriver.com>
Date:   Fri May 19 16:52:46 2017 +0800

    bind: build with threads and update configure options
...

And enabled gentle shutdown in dhcp:
...
commit 2c789bac353e17637549a7b31706761ba848728e
Author: Chen Qi <Qi.Chen at windriver.com>
Date:   Tue Mar 15 14:39:40 2016 +0800

    dhcp: enable gentle shutdown
...

Both of them caused systemd's reboot hung. The reason is
bind9 blocked SIGHUP, SIGINT and SIGTERM while compiled with
--enable-threads, and dhcp use SIGINT and SIGTERM for
gentle shutdown.

While systemd's reboot, it sends SIGTERM to dhclient by default,
and dhclient block the singnal that caused reboot hung.

Signed-off-by: Hongxu Jia <hongxu.jia at windriver.com>
---
 ...-shutdown-not-work-while-bind9-compile-wi.patch | 74 ++++++++++++++++++++++
 meta/recipes-connectivity/dhcp/dhcp_4.3.5.bb       |  1 +
 2 files changed, 75 insertions(+)
 create mode 100644 meta/recipes-connectivity/dhcp/dhcp/fix-genetle-shutdown-not-work-while-bind9-compile-wi.patch

diff --git a/meta/recipes-connectivity/dhcp/dhcp/fix-genetle-shutdown-not-work-while-bind9-compile-wi.patch b/meta/recipes-connectivity/dhcp/dhcp/fix-genetle-shutdown-not-work-while-bind9-compile-wi.patch
new file mode 100644
index 0000000..6340420
--- /dev/null
+++ b/meta/recipes-connectivity/dhcp/dhcp/fix-genetle-shutdown-not-work-while-bind9-compile-wi.patch
@@ -0,0 +1,74 @@
+From 91c50f7feb36ef13dba5fa0cefb918ae044da94f Mon Sep 17 00:00:00 2001
+From: Hongxu Jia <hongxu.jia at windriver.com>
+Date: Mon, 10 Jul 2017 05:20:55 -0400
+Subject: [PATCH] fix genetle shutdown not work while bind9 compile with --enable-threads
+
+While bind9 compile with --enable-threads, it blocked SIGHUP, SIGINT,
+SIGTERM which caused genetle shutdown not work.
+
+Unblock SIGTERM and SIGINT for genetle shutdown.
+
+The upstream (https://source.isc.org/git/dhcp.git) could work without
+the fix, because it disable gentle shutdown by default:
+...
+commit e9326fd0f4561db5496f18523da15612213bd1b4
+Author: Shawn Routhier <sar at isc.org>
+Date:   Wed Jul 2 08:49:19 2014 -0700
+
+    [master] Add define to disable gentle shutodwn by default
+...
+And built bind9 without --enable-threads does not require the fix neither.
+
+Upstream-Status: Inappropriate [OE specific]
+
+Signed-off-by: Hongxu Jia <hongxu.jia at windriver.com>
+---
+ omapip/isclib.c | 25 +++++++++++++++++++++++++
+ 1 file changed, 25 insertions(+)
+
+diff --git a/omapip/isclib.c b/omapip/isclib.c
+index 13f0d3e..4fe3328 100644
+--- a/omapip/isclib.c
++++ b/omapip/isclib.c
+@@ -29,6 +29,25 @@
+ 
+ #include <sys/time.h>
+ #include <signal.h>
++#include <pthread.h>
++
++#if defined(ENABLE_GENTLE_SHUTDOWN)
++void unblock_signal(void)
++{
++	sigset_t sset;
++
++	if (sigemptyset(&sset) != 0 ||
++	    sigaddset(&sset, SIGTERM) != 0 ||
++	    sigaddset(&sset, SIGINT) != 0) {
++		log_error("sigsetops: %d\n", errno);
++		return;
++	}
++	if (sigprocmask(SIG_UNBLOCK, &sset, NULL) != 0) {
++		log_error("sigprocmask: %d\n", errno);
++		return;
++	}
++}
++#endif
+ 
+ dhcp_context_t dhcp_gbl_ctx;
+ int shutdown_signal = 0;
+@@ -188,6 +207,12 @@ dhcp_context_create(int flags,
+ 		result = isc_app_ctxstart(dhcp_gbl_ctx.actx);
+ 		if (result != ISC_R_SUCCESS)
+ 			return (result);
++
++
++#if defined(ENABLE_GENTLE_SHUTDOWN)
++		unblock_signal();
++#endif
++
+ 		dhcp_gbl_ctx.actx_started = ISC_TRUE;
+ 
+ 		/* Not all OSs support suppressing SIGPIPE through socket
+-- 
+2.8.1
+
diff --git a/meta/recipes-connectivity/dhcp/dhcp_4.3.5.bb b/meta/recipes-connectivity/dhcp/dhcp_4.3.5.bb
index 0a73ecc..b20147a 100644
--- a/meta/recipes-connectivity/dhcp/dhcp_4.3.5.bb
+++ b/meta/recipes-connectivity/dhcp/dhcp_4.3.5.bb
@@ -10,6 +10,7 @@ SRC_URI += "file://dhcp-3.0.3-dhclient-dbus.patch;striplevel=0 \
             file://tweak-to-support-external-bind.patch \
             file://remove-dhclient-script-bash-dependency.patch \
             file://build-shared-libs.patch \
+            file://fix-genetle-shutdown-not-work-while-bind9-compile-wi.patch \
            "
 
 SRC_URI[md5sum] = "2b5e5b2fa31c2e27e487039d86f83d3f"
-- 
2.8.1