[OE-core] [PATCH 1/1] iputils: backport patch to fix arping hang problem

[Chen Qi]

arping hangs if SIGALARM is blocked. Backport a patch to fix this problem.

Unblock SIGALRM so that the previously called alarm() can prevent recvfrom()
from blocking forever in case the inherited procmask is blocking SIGALRM and
no packet is received.

Signed-off-by: Chen Qi <Qi.Chen at windriver.com>
---
 ...ing-fix-arping-hang-if-SIGALRM-is-blocked.patch | 44 ++++++++++++++++++++++
 meta/recipes-extended/iputils/iputils_s20151218.bb |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 meta/recipes-extended/iputils/files/arping-fix-arping-hang-if-SIGALRM-is-blocked.patch

diff --git a/meta/recipes-extended/iputils/files/arping-fix-arping-hang-if-SIGALRM-is-blocked.patch b/meta/recipes-extended/iputils/files/arping-fix-arping-hang-if-SIGALRM-is-blocked.patch
new file mode 100644
index 0000000..7b56276
--- /dev/null
+++ b/meta/recipes-extended/iputils/files/arping-fix-arping-hang-if-SIGALRM-is-blocked.patch
@@ -0,0 +1,44 @@
+arping: fix arping hang if SIGALRM is blocked
+
+Unblock SIGALRM so that the previously called alarm() can prevent
+recvfrom() from blocking forever in case the inherited procmask is
+blocking SIGALRM and no packet is received.
+
+Upstream-Status: Backport
+
+Reported-by: Rui Prior <rprior at dcc.fc.up.pt>
+RH-Bugzilla: #1085971
+Signed-off-by: Jan Synacek <jsynacek at redhat.com>
+Signed-off-by: Zhenbo Gao <zhenbo.gao at windriver.com>
+
+diff --git a/arping.c.orig b/arping.c
+index 35408c1..2098159 100644
+--- a/arping.c.orig
++++ b/arping.c
+@@ -1215,16 +1215,22 @@ main(int argc, char **argv)
+ 		socklen_t alen = sizeof(from);
+ 		int cc;
+ 
++		sigemptyset(&sset);
++		sigaddset(&sset, SIGALRM);
++		sigaddset(&sset, SIGINT);
++		/* Unblock SIGALRM so that the previously called alarm()
++		 * can prevent recvfrom from blocking forever in case the
++		 * inherited procmask is blocking SIGALRM and no packet
++		 * is received. */
++		sigprocmask(SIG_UNBLOCK, &sset, &osset);
++
+ 		if ((cc = recvfrom(s, packet, sizeof(packet), 0,
+ 				   (struct sockaddr *)&from, &alen)) < 0) {
+ 			perror("arping: recvfrom");
+ 			continue;
+ 		}
+ 
+-		sigemptyset(&sset);
+-		sigaddset(&sset, SIGALRM);
+-		sigaddset(&sset, SIGINT);
+-		sigprocmask(SIG_BLOCK, &sset, &osset);
++		sigprocmask(SIG_BLOCK, &sset, NULL);
+ 		recv_pack(packet, cc, (struct sockaddr_ll *)&from);
+ 		sigprocmask(SIG_SETMASK, &osset, NULL);
+ 	}
diff --git a/meta/recipes-extended/iputils/iputils_s20151218.bb b/meta/recipes-extended/iputils/iputils_s20151218.bb
index 0d4dd1b..46de6fc 100644
--- a/meta/recipes-extended/iputils/iputils_s20151218.bb
+++ b/meta/recipes-extended/iputils/iputils_s20151218.bb
@@ -20,6 +20,7 @@ SRC_URI = "http://www.skbuff.net/iputils/${BPN}-${PV}.tar.bz2 \
            file://nsgmls-path-fix.patch \
            file://0001-Fix-header-inclusion-for-musl.patch \
            file://0001-Intialize-struct-elements-by-name.patch \
+           file://arping-fix-arping-hang-if-SIGALRM-is-blocked.patch \
           "
 
 SRC_URI[md5sum] = "8aaa7395f27dff9f57ae016d4bc753ce"
-- 
1.9.1