Add simple regression tests that creates UNIX domain sockets using

socket() and socketpair() of SOCK_STREAM and SOCK_DGRAM types.  It
also confirms that SOCK_RAW fails.

tools/regression/sockets/unix_socket/Makefile

@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PROG=	unix_socket
+NO_MAN=
+WARNS=	3
+
+.include <bsd.prog.mk>

tools/regression/sockets/unix_socket/unix_socket.c

@@ -0,0 +1,84 @@
+/*-
+ * Copyright (c) 2006 Robert N. M. Watson
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Simple UNIX domain socket regression test: create and tear down various
+ * supported and unsupported socket types.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <err.h>
+#include <errno.h>
+#include <unistd.h>
+
+int
+main(int argc, char *argv[])
+{
+	int sock, socks[2];
+
+	sock = socket(PF_LOCAL, SOCK_STREAM, 0);
+	if (sock < 0)
+		err(-1, "socket(PF_LOCAL, SOCK_STREAM, 0)");
+	close(sock);
+
+	sock = socket(PF_LOCAL, SOCK_DGRAM, 0);
+	if (sock < 0)
+		err(-1, "socket(PF_LOCAL, SOCK_DGRAM, 0)");
+	close(sock);
+
+	sock = socket(PF_LOCAL, SOCK_RAW, 0);
+	if (sock >= 0) {
+		close(sock);
+		errx(-1, "socket(PF_LOCAL, SOCK_RAW, 0) returned %d", sock);
+	}
+	if (errno != EPROTONOSUPPORT)
+		err(-1, "socket(PF_LOCAL, SOCK_RAW, 0)");
+
+	if (socketpair(PF_LOCAL, SOCK_STREAM, 0, socks) < 0)
+		err(-1, "socketpair(PF_LOCAL, SOCK_STREAM, 0, socks)");
+	if (socks[0] < 0)
+		errx(-1, "socketpair(PF_LOCAL, SOCK_STREAM, 0, socks) [0] < 0");
+	if (socks[1] < 0)
+		errx(-1, "socketpair(PF_LOCAL, SOCK_STREAM, 0, socks) [1] < 1");
+	close(socks[0]);
+	close(socks[1]);
+
+	if (socketpair(PF_LOCAL, SOCK_DGRAM, 0, socks) < 0)
+		err(-1, "socketpair(PF_LOCAL, SOCK_DGRAM, 0, socks)");
+	if (socks[0] < 0)
+		errx(-1, "socketpair(PF_LOCAL, SOCK_DGRAM, 0, socks) [0] < 0");
+	if (socks[1] < 0)
+		errx(-1, "socketpair(PF_LOCAL, SOCK_DGRAM, 0, socks) [1] < 1");
+	close(socks[0]);
+	close(socks[1]);
+
+	return (0);
+}