From d566e3ce9bc083dae60ea7bdd3cf2da270e682da Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Fri, 14 Dec 2007 04:00:53 +0000
Subject: [PATCH] 2279.   [bug]           Use setsockopt(SO_NOSIGPIPE), when
 available,                         to protect applications from receiving
 spurious                         SIGPIPE signals when using the resolver.

---
 CHANGES                    |  4 ++++
 lib/bind/resolv/res_send.c | 16 +++++++++++++++-
 lib/isc/unix/socket.c      | 16 +++++++++++++++-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 5d43b45015..982884a8ac 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+2279.   [bug]           Use setsockopt(SO_NOSIGPIPE), when available,
+			to protect applications from receiving spurious
+			SIGPIPE signals when using the resolver.
+
 2278.	[bug]		win32: handle the case where Windows returns no
 			searchlist or DNS suffix. [RT #17354]
 
diff --git a/lib/bind/resolv/res_send.c b/lib/bind/resolv/res_send.c
index 39dc998da7..ec83d2712c 100644
--- a/lib/bind/resolv/res_send.c
+++ b/lib/bind/resolv/res_send.c
@@ -70,7 +70,7 @@
 
 #if defined(LIBC_SCCS) && !defined(lint)
 static const char sccsid[] = "@(#)res_send.c	8.1 (Berkeley) 6/4/93";
-static const char rcsid[] = "$Id: res_send.c,v 1.9.18.8 2006/10/16 23:00:58 marka Exp $";
+static const char rcsid[] = "$Id: res_send.c,v 1.9.18.9 2007/12/14 04:00:53 marka Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 /*! \file
@@ -601,6 +601,9 @@ send_vc(res_state statp,
 	u_short len;
 	u_char *cp;
 	void *tmp;
+#ifdef SO_NOSIGPIPE
+	int on = 1;
+#endif
 
 	nsap = get_nsaddr(statp, ns);
 	nsaplen = get_salen(nsap);
@@ -646,6 +649,17 @@ send_vc(res_state statp,
 				return (-1);
 			}
 		}
+#ifdef SO_NOSIGPIPE
+		/*
+		 * Disable generation of SIGPIPE when writing to a closed
+		 * socket.  Write should return -1 and set errno to EPIPE
+		 * instead. 
+		 *
+		 * Push on even if setsockopt(SO_NOSIGPIPE) fails.
+		 */
+		(void)setsockopt(statp->_vcsock, SOL_SOCKET, SO_NOSIGPIPE, &on,
+			         sizeof(on));
+#endif
 		errno = 0;
 		if (connect(statp->_vcsock, nsap, nsaplen) < 0) {
 			*terrno = errno;
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index e0b902167e..0e15ab8674 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.c,v 1.237.18.29 2007/08/28 07:20:06 tbox Exp $ */
+/* $Id: socket.c,v 1.237.18.30 2007/12/14 04:00:53 marka Exp $ */
 
 /*! \file */
 
@@ -1557,6 +1557,20 @@ isc_socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
 	}
 #endif
 
+#ifdef SO_NOSIGPIPE
+	if (setsockopt(sock->fd, SOL_SOCKET, SO_NOSIGPIPE,
+		       (void *)&on, sizeof(on)) < 0) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "setsockopt(%d, SO_NOSIGPIPE) %s: %s",
+				 sock->fd,
+				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
+						ISC_MSG_FAILED, "failed"),
+				 strbuf);
+		/* Press on... */
+	}
+#endif
+
 #if defined(USE_CMSG) || defined(SO_RCVBUF)
 	if (type == isc_sockettype_udp) {