socket: avoid SIGPIPE using SO_NOSIGPIPE or MSG_NOSIGNAL

src/socket.c

diff --git a/src/socket.c b/src/socket.c
index c35de33..fe7d06c 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -55,6 +55,7 @@
 	struct sockaddr_un name;
 	int sock;
 	size_t size;
+	int yes = 1;
 
 	// remove if still present
 	unlink(filename);
@@ -66,6 +67,14 @@
 		return -1;
 	}
 
+#ifdef SO_NOSIGPIPE
+	if (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sock);
+		return -1;
+	}
+#endif
+
 	/* Bind a name to the socket. */
 	name.sun_family = AF_LOCAL;
 	strncpy(name.sun_path, filename, sizeof(name.sun_path));
@@ -102,6 +111,7 @@
 	int sfd = -1;
 	size_t size;
 	struct stat fst;
+	int yes = 1;
 
 	// check if socket file exists...
 	if (stat(filename, &fst) != 0) {
@@ -123,6 +133,15 @@
 			fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
 		return -1;
 	}
+
+#ifdef SO_NOSIGPIPE
+	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+#endif
+
 	// and connect to 'filename'
 	name.sun_family = AF_LOCAL;
 	strncpy(name.sun_path, filename, sizeof(name.sun_path));
@@ -170,6 +189,14 @@
 		return -1;
 	}
 
+#ifdef SO_NOSIGPIPE
+	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+#endif
+
 	memset((void *) &saddr, 0, sizeof(saddr));
 	saddr.sin_family = AF_INET;
 	saddr.sin_addr.s_addr = htonl(INADDR_ANY);
@@ -236,6 +263,14 @@
 		return -1;
 	}
 
+#ifdef SO_NOSIGPIPE
+	if (setsockopt(sfd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+#endif
+
 	memset((void *) &saddr, 0, sizeof(saddr));
 	saddr.sin_family = AF_INET;
 	saddr.sin_addr.s_addr = *(uint32_t *) hp->h_addr;
@@ -388,5 +423,9 @@
 
 int socket_send(int fd, void *data, size_t length)
 {
-	return send(fd, data, length, 0);
+	int flags = 0;
+#ifdef MSG_NOSIGNAL
+	flags |= MSG_NOSIGNAL;
+#endif
+	return send(fd, data, length, flags);
 }