Add a regression test for listen()'s backlog argument, both at time of

creation and at time of update using an additional call to listen().
This test also exercises SO_LISTENQLIMIT, a forthcoming socket option
that allows the retrieval (but not setting) of the queue limit.

Discussed with:	andre

2 files changed, 389 insertions, 0 deletions

diff --git a/tools/regression/sockets/listen_backlog/Makefile b/tools/regression/sockets/listen_backlog/Makefile
new file mode 100644
index 0000000..c220b17
--- /dev/null
+++ b/tools/regression/sockets/listen_backlog/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PROG=	listen_backlog
+WARNS=	3
+NO_MAN=
+
+.include <bsd.prog.mk>
diff --git a/tools/regression/sockets/listen_backlog/listen_backlog.c b/tools/regression/sockets/listen_backlog/listen_backlog.c
new file mode 100644
index 0000000..be170ab
--- /dev/null
+++ b/tools/regression/sockets/listen_backlog/listen_backlog.c
@@ -0,0 +1,382 @@
+/*-
+ * Copyright (c) 2005 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/sysctl.h>
+
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/*
+ * This regression test is intended to validate that the backlog parameter
+ * set by listen() is properly set, can be retrieved using SO_LISTENQLIMIT,
+ * and that it can be updated by later calls to listen().  We also check that
+ * SO_LISTENQLIMIT cannot be set.
+ *
+ * Future things to test:
+ *
+ * - That if we change the value of kern.ipc.somaxconn, the limits really
+ *   do change.
+ *
+ * - That limits are, approximately, enforced and implemented.
+ *
+ * - All this on multiple socket types -- i.e., PF_LOCAL.
+ *
+ * - That we also test SO_LISTENQLEN and SO_LISTENINCQLEN.
+ */
+
+/*
+ * We retrieve kern.ipc.somaxconn before running the tests in order to use a
+ * run-time set value of SOMAXCONN, rather than compile-time set.  We assume
+ * that no other process will be simultaneously frobbing it, and these tests
+ * may fail if that assumption is not held.
+ */
+static int	somaxconn;
+
+/*
+ * Retrieve the current socket listen queue limit using SO_LISTENQLIMIT.
+ */
+static int
+socket_get_backlog(int sock, int *backlogp, const char *testclass,
+    const char *test, const char *testfunc)
+{
+	socklen_t len;
+	int i;
+
+	len = sizeof(i);
+	if (getsockopt(sock, SOL_SOCKET, SO_LISTENQLIMIT, &i, &len) < 0) {
+		warn("%s: %s: %s: socket_get_backlog: getsockopt("
+		    "SOL_SOCKET, SO_LISTENQLIMIT)", testclass, test,
+		    testfunc);
+		return (-1);
+	}
+
+	if (len != sizeof(i)) {
+		warnx("%s: %s: %s: socket_get_backlog: getsockopt("
+		    "SOL_SOCKET, SO_LISTENQLIMIT): returned size %d",
+		    testclass, test, testfunc, len);
+		return (-1);
+	}
+
+	*backlogp = i;
+
+	return (0);
+}
+
+/*
+ * Create a socket, check the queue limit on creation, perform a listen(),
+ * and make sure that the limit was set as expected by listen().
+ */
+static int
+socket_listen(int domain, int type, int protocol, int backlog,
+    int create_backlog_assertion, int listen_backlog_assertion, int *sockp,
+    const char *domainstring, const char *typestring, const char *testclass,
+    const char *test)
+{
+	int backlog_retrieved, sock;
+
+	sock = socket(domain, type, protocol);
+	if (sock < 0) {
+		warn("%s: %s: socket_listen: socket(%s, %s)", testclass,
+		    test, domainstring, typestring);
+		close(sock);
+		return (-1);
+	}
+
+	if (socket_get_backlog(sock, &backlog_retrieved, testclass, test,
+	    "socket_listen") < 0) {
+		close(sock);
+		return (-1);
+	}
+
+	if (backlog_retrieved != create_backlog_assertion) {
+		warnx("%s: %s: socket_listen: create backlog is %d not %d",
+		    testclass, test, backlog_retrieved,
+		    create_backlog_assertion);
+		close(sock);
+		return (-1);
+	}
+
+	if (listen(sock, backlog) < 0) {
+		warn("%s: %s: socket_listen: listen(, %d)", testclass, test,
+		    backlog);
+		close(sock);
+		return (-1);
+	}
+
+	if (socket_get_backlog(sock, &backlog_retrieved, testclass, test,
+	    "socket_listen") < 0) {
+		close(sock);
+		return (-1);
+	}
+
+	if (backlog_retrieved != listen_backlog_assertion) {
+		warnx("%s: %s: socket_listen: listen backlog is %d not %d",
+		    testclass, test, backlog_retrieved,
+		    listen_backlog_assertion);
+		close(sock);
+		return (-1);
+	}
+
+	*sockp = sock;
+	return (0);
+}
+
+/*
+ * This test creates sockets and tests default states before and after
+ * listen().  Specifically, we expect a queue limit of 0 before listen, and
+ * then various settings for after listen().  If the passed backlog was
+ * either < 0 or > somaxconn, it should be set to somaxconn; otherwise, the
+ * passed queue depth.
+ */
+static void
+test_defaults(void)
+{
+	int sock;
+
+	/*
+	 * First pass.  Confirm the default is 0.  Listen with a backlog of
+	 * 0 and confirm it gets set that way.
+	 */
+	if (socket_listen(PF_INET, SOCK_STREAM, 0, 0, 0, 0, &sock, "PF_INET",
+	    "SOCK_STREAM", "test_defaults", "default_0_listen_0") < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Second pass.  Listen with a backlog of -1 and make sure it is set
+	 * to somaxconn.
+	 */
+	if (socket_listen(PF_INET, SOCK_STREAM, 0, -1, 0, somaxconn, &sock,
+	    "PF_INET", "SOCK_STREAM", "test_defaults", "default_0_listen_-1")
+	    < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Third pass.  Listen with a backlog of 1 and make sure it is set to
+	 * 1.
+	 */
+	if (socket_listen(PF_INET, SOCK_STREAM, 0, 1, 0, 1, &sock, "PF_INET",
+	    "SOCK_STREAM", "test_defaults", "default_0_listen_1") < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Fourth pass.  Listen with a backlog of somaxconn and make sure it
+	 * is set to somaxconn.
+	 */
+	if (socket_listen(PF_INET, SOCK_STREAM, 0, somaxconn, 0, somaxconn,
+	    &sock, "PF_INET", "SOCK_STREAM", "test_defaults",
+	    "default_0_listen_somaxconn") < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Fifth pass.  Listen with a backlog of somaxconn+1 and make sure it
+	 * is set to somaxconn.
+	 */
+	if (socket_listen(PF_INET, SOCK_STREAM, 0, somaxconn+1, 0, somaxconn,
+	    &sock, "PF_INET", "SOCK_STREAM", "test_defaults",
+	    "default_0_listen_somaxconn+1") < 0)
+		exit(-1);
+	close(sock);
+}
+
+/*
+ * Create a socket, set the initial listen() state, then update the queue
+ * depth using listen().  Check that the backlog is as expected after both
+ * the first and second listen().
+ */
+static int
+socket_listen_update(int domain, int type, int protocol, int backlog,
+    int update_backlog, int listen_backlog_assertion,
+    int update_backlog_assertion, int *sockp, const char *domainstring,
+    const char *typestring, const char *testclass, const char *test)
+{
+	int backlog_retrieved, sock;
+
+	sock = socket(PF_INET, SOCK_STREAM, 0);
+	if (sock < 0) {
+		warn("%s: %s: socket_listen_update: socket(%s, %s)",
+		    testclass, test, domainstring, typestring);
+		return (-1);
+	}
+
+	if (listen(sock, backlog) < 0) {
+		warn("%s: %s: socket_listen_update: initial listen(, %d)",
+		    testclass, test, backlog);
+		close(sock);
+		return (-1);
+	}
+
+	if (socket_get_backlog(sock, &backlog_retrieved, testclass, test,
+	    "socket_listen_update") < 0) {
+		close(sock);
+		return (-1);
+	}
+
+	if (backlog_retrieved != listen_backlog_assertion) {
+		warnx("%s: %s: socket_listen_update: initial backlog is %d "
+		    "not %d", testclass, test, backlog_retrieved,
+		    listen_backlog_assertion);
+		close(sock);
+		return (-1);
+	}
+
+	if (listen(sock, update_backlog) < 0) {
+		warn("%s: %s: socket_listen_update: update listen(, %d)",
+		    testclass, test, update_backlog);
+		close(sock);
+		return (-1);
+	}
+
+	if (socket_get_backlog(sock, &backlog_retrieved, testclass, test,
+	    "socket_listen_update") < 0) {
+		close(sock);
+		return (-1);
+	}
+
+	if (backlog_retrieved != update_backlog_assertion) {
+		warnx("%s: %s: socket_listen_update: updated backlog is %d "
+		    "not %d", testclass, test, backlog_retrieved,
+		    update_backlog_assertion);
+		close(sock);
+		return (-1);
+	}
+
+	*sockp = sock;
+	return (0);
+}
+
+/*
+ * This test tests using listen() to update the queue depth after a socket
+ * has already been marked as listening.  We test several cases: setting the
+ * socket < 0, 0, 1, somaxconn, and somaxconn + 1.
+ */
+static void
+test_listen_update(void)
+{
+	int sock;
+
+	/*
+	 * Set to 5, update to -1, which should give somaxconn.
+	 */
+	if (socket_listen_update(PF_INET, SOCK_STREAM, 0, 5, -1, 5, somaxconn,
+	    &sock, "PF_INET", "SOCK_STREAM", "test_listen_update",
+	    "update_5,-1") < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Set to 5, update to 0, which should give 0.
+	 */
+	if (socket_listen_update(PF_INET, SOCK_STREAM, 0, 5, 0, 5, 0, &sock,
+	    "PF_INET", "SOCK_STREAM", "test_listen_update", "update_5,0")
+	    < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Set to 5, update to 1, which should give 1.
+	 */
+	if (socket_listen_update(PF_INET, SOCK_STREAM, 0, 5, 1, 5, 1, &sock,
+	    "PF_INET", "SOCK_STREAM", "test_listen_update", "update_5,1")
+	    < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Set to 5, update to somaxconn, which should give somaxconn.
+	 */
+	if (socket_listen_update(PF_INET, SOCK_STREAM, 0, 5, somaxconn, 5,
+	    somaxconn, &sock, "PF_INET", "SOCK_STREAM", "test_listen_update",
+	    "update_5,somaxconn") < 0)
+		exit(-1);
+	close(sock);
+
+	/*
+	 * Set to 5, update to somaxconn+1, which should give somaxconn.
+	 */
+	if (socket_listen_update(PF_INET, SOCK_STREAM, 0, 5, somaxconn+1, 5,
+	    somaxconn, &sock, "PF_INET", "SOCK_STREAM", "test_listen_update",
+	    "update_5,somaxconn+1") < 0)
+		exit(-1);
+	close(sock);
+}
+
+/*
+ * SO_LISTENQLIMIT is a read-only socket option, so make sure we get an error
+ * if we try to write it.
+ */
+static void
+test_set_qlimit(void)
+{
+	int i, ret, sock;
+
+	sock = socket(PF_INET, SOCK_STREAM, 0);
+	if (sock < 0)
+		err(-1, "test_set_qlimit: socket(PF_INET, SOCK_STREAM)");
+
+	i = 0;
+	ret = setsockopt(sock, SOL_SOCKET, SO_LISTENQLIMIT, &i, sizeof(i));
+	if (ret < 0 && errno != ENOPROTOOPT) {
+		warn("test_set_qlimit: setsockopt(SOL_SOCKET, "
+		    "SO_LISTENQLIMIT, 0): unexpected error");
+		close(sock);
+	}
+
+	if (ret == 0) {
+		warnx("test_set_qlimit: setsockopt(SOL_SOCKET, "
+		    "SO_LISTENQLIMIT, 0) succeeded");
+		close(sock);
+		exit(-1);
+	}
+	close(sock);
+}
+
+int
+main(int argc, char *argv[])
+{
+	size_t len;
+
+	len = sizeof(somaxconn);
+	if (sysctlbyname("kern.ipc.somaxconn", &somaxconn, &len, NULL, 0)
+	    < 0)
+		err(-1, "sysctlbyname(kern.ipc.somaxconn)");
+
+	test_defaults();
+	test_listen_update();
+	test_set_qlimit();
+
+	return (0);
+}