From: Thomas Markwalder <tmark@isc.org>
Date: Wed, 5 Nov 2014 12:31:17 +0000 (-0500)
Subject: [master] Set signal action to ingore for SIGPIPE
X-Git-Tag: v4_3_2.pre-beta~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6067cd48daa03514267859ca4b52fa0dc57dfc74;p=thirdparty%2Fdhcp.git

[master] Set signal action to ingore for SIGPIPE

    Merges in rt32222.
---

diff --git a/RELNOTES b/RELNOTES
index a01b7d928..aad275320 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -129,6 +129,12 @@ by Eric Young (eay@cryptsoft.com).
   BOOTP request handling.
   [ISC-Bugs #36233]
 
+- Added logic to ignore the signal, SIGPIPE, which ensures write failures
+  will be delivered as errors rather than as SIGPIPE signals on all OSs.
+  Thanks to Marius Tomaschewski from SUSE who reported the issue and provided
+  the patch upon which the fix is based.
+  [ISC-Bugs #32222]
+
 			Changes since 4.3.1b1
 
 - Modify the linux and openwrt dhclient scripts to process information
diff --git a/omapip/isclib.c b/omapip/isclib.c
index 3e5e1c2b3..13f0d3ebc 100644
--- a/omapip/isclib.c
+++ b/omapip/isclib.c
@@ -120,6 +120,20 @@ isclib_cleanup(void)
 	return;
 }
 
+/* Installs a handler for a signal using sigaction */
+static void
+handle_signal(int sig, void (*handler)(int)) {
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = handler;
+	sigfillset(&sa.sa_mask);
+	if (sigaction(sig, &sa, NULL) != 0) {
+		log_debug("handle_signal() failed for signal %d error: %s",
+                          sig, strerror(errno));
+	}
+}
+
 isc_result_t
 dhcp_context_create(int flags,
 		    struct in_addr  *local4,
@@ -176,6 +190,11 @@ dhcp_context_create(int flags,
 			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,