Add sys/kern/unixsockets directory to contain all unix(4) sockets tests.

Add 'undgram_selfconn' test to check unix(4) socket connecting to itself.

Discussed and ok visa@ bluhm@

3 files changed, 106 insertions, 2 deletions

diff --git a/regress/sys/kern/Makefile b/regress/sys/kern/Makefile
index 00daa065c97..23aeacf8eff 100644
--- a/regress/sys/kern/Makefile
+++ b/regress/sys/kern/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.95 2021/11/29 13:05:04 mvs Exp $
+#	$OpenBSD: Makefile,v 1.96 2021/12/09 17:25:54 mvs Exp $
 
 SUBDIR+= __syscall
 SUBDIR+= accept access
@@ -24,7 +24,7 @@ SUBDIR+= setuid
 SUBDIR+= signal sosplice stackjmp stackpivot syscall syscall_segment
 SUBDIR+= sysvmsg sysvsem sysvshm
 SUBDIR+= unalign unconacc undgram_conclose unfdpass unfdpassfail ungc
-SUBDIR+= unsendrecvthr unixsock unveil unveil-unmount
+SUBDIR+= unixsockets unsendrecvthr unixsock unveil unveil-unmount
 SUBDIR+= wait
 
 install:
diff --git a/regress/sys/kern/unixsockets/Makefile b/regress/sys/kern/unixsockets/Makefile
new file mode 100644
index 00000000000..f3f1a81c38f
--- /dev/null
+++ b/regress/sys/kern/unixsockets/Makefile
@@ -0,0 +1,23 @@
+# $OpenBSD: Makefile,v 1.1 2021/12/09 17:25:54 mvs Exp $
+
+# Copyright (c) 2021 Makkoveev Vitaliy <mvs@openbsd.org>
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+WARNINGS = yes
+
+PROGS = undgram_selfconn
+
+CLEANFILES += *.socket
+
+.include <bsd.regress.mk>
diff --git a/regress/sys/kern/unixsockets/undgram_selfconn.c b/regress/sys/kern/unixsockets/undgram_selfconn.c
new file mode 100644
index 00000000000..332188057be
--- /dev/null
+++ b/regress/sys/kern/unixsockets/undgram_selfconn.c
@@ -0,0 +1,81 @@
+/* $OpenBSD: undgram_selfconn.c,v 1.1 2021/12/09 17:25:54 mvs Exp $ */
+
+/*
+ * Copyright (c) 2021 Vitaliy Makkoveev <mvs@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * unix(4) datagram socket could be connected to itself. There are two
+ * cases: temporary connection for sendto(2) syscall and normal connection
+ * provided by connect(2) syscall.
+ * Be sure socket doesn't deadlock itself and doesn't crash kernel while
+ * disconnecting and connecting again.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+#include <unistd.h>
+
+int
+main(void)
+{
+	static struct sockaddr_un sun;
+	int s, buf;
+	ssize_t ret;
+
+	umask(0077);
+
+	memset(&sun, 0, sizeof(sun));
+	sun.sun_len = sizeof(sun);
+	sun.sun_family = AF_UNIX;
+	snprintf(sun.sun_path, sizeof(sun.sun_path) - 1,
+	    "undgram_selfconn%d.socket", getpid());
+
+	unlink(sun.sun_path);
+
+	if ((s = socket(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK, 0)) < 0)
+		err(1, "socket");
+	if (bind(s, (struct sockaddr *)&sun, sizeof(sun)) < 0)
+		err(1, "bind");
+
+	if (sendto(s, &s, sizeof(s), 0,
+	    (struct sockaddr *)&sun, sizeof(sun)) < 0)
+		err(1, "sendto");
+
+	/*
+	 * Check received data to be sure the temporary connection
+	 * was successful.
+	 */
+	if ((ret = recvfrom(s, &buf, sizeof(buf), 0, NULL, NULL)) < 0)
+		err(1, "recvfrom");
+	if (ret != sizeof(s))
+		errx(1, "recvfrom: wrong size");
+	if (buf != s)
+		errx(1, "recvfrom: wrong data");
+
+	if (connect(s, (struct sockaddr *)&sun, sizeof(sun)) < 0)
+		err(1, "connect");
+	/* Disconnect and connect it again */
+	if (connect(s, (struct sockaddr *)&sun, sizeof(sun)) < 0)
+		err(1, "connect");
+	close(s);
+
+	return 0;
+}