Add a basic kqueue + UNIX domain socket pair regression test to do some

elementary exercising of kqueues on datagram and stream sockets.  Note
that the datagram write kqueue case is left untested due to potentially
confusing behavior for the developer (me) that might require attention.

2 files changed, 340 insertions, 0 deletions

diff --git a/tools/regression/sockets/kqueue/Makefile b/tools/regression/sockets/kqueue/Makefile
new file mode 100644
index 0000000..5a2d6b0
--- /dev/null
+++ b/tools/regression/sockets/kqueue/Makefile
@@ -0,0 +1,11 @@
+#
+# $FreeBSD$
+#
+
+PROG=	kqueue
+NOMAN=	yes
+
+kqueue: kqueue.c
+	gcc -Wall -o kqueue kqueue.c
+
+.include <bsd.prog.mk>
diff --git a/tools/regression/sockets/kqueue/kqueue.c b/tools/regression/sockets/kqueue/kqueue.c
new file mode 100644
index 0000000..e1f6a9c
--- /dev/null
+++ b/tools/regression/sockets/kqueue/kqueue.c
@@ -0,0 +1,329 @@
+/*-
+ * Copyright (c) 2004 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/event.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/*-
+ * This test uses UNIX domain socket pairs to perform some basic exercising
+ * of kqueue functionality on sockets.  In particular, testing that for read
+ * and write filters, we see the correct detection of whether reads and
+ * writes should actually be able to occur.
+ *
+ * TODO:
+ * - Test read/write filters for listen/accept sockets.
+ * - Handle the XXXRW below regarding datagram sockets.
+ * - Test that watermark/buffer size "data" fields returned by kqueue are
+ *   correct.
+ * - Check that kqueue does something sensible when the remote endpoing is
+ *   closed.
+ */
+
+static void
+fail(int error, const char *func, const char *socktype, const char *rest)
+{
+
+	fprintf(stderr, "FAIL\n");
+
+	if (socktype == NULL)
+		fprintf(stderr, "%s(): %s\n", func, strerror(error));
+	else if (rest == NULL)
+		fprintf(stderr, "%s(%s): %s\n", func, socktype,
+		    strerror(error));
+	else
+		fprintf(stderr, "%s(%s, %s): %s\n", func, socktype, rest,
+		    strerror(error));
+	exit(-1);
+}
+
+static void
+fail_assertion(const char *func, const char *socktype, const char *rest,
+    const char *assertion)
+{
+
+	fprintf(stderr, "FAIL\n");
+
+	if (socktype == NULL)
+		fprintf(stderr, "%s(): assertion %s failed\n", func,
+		    assertion);
+	else if (rest == NULL)
+		fprintf(stderr, "%s(%s): assertion %s failed\n", func,
+		    socktype, assertion);
+	else
+		fprintf(stderr, "%s(%s, %s): assertion %s failed\n", func,
+		    socktype, rest, assertion);
+	exit(-1);
+}
+
+/*
+ * Test read kevent on a socket pair: check to make sure endpoint 0 isn't
+ * readable when we start, then write to endpoint 1 and confirm that endpoint
+ * 0 is now readable.  Drain the write, then check that it's not readable
+ * again.  Use non-blocking kqueue operations and socket operations.
+ */
+static void
+test_evfilt_read(int kq, int fd[2], const char *socktype)
+{
+	struct timespec ts;
+	struct kevent ke;
+	ssize_t len;
+	char ch;
+	int i;
+
+	EV_SET(&ke, fd[0], EVFILT_READ, EV_ADD, 0, 0, NULL);
+	if (kevent(kq, &ke, 1, NULL, 0, NULL) == -1)
+		fail(errno, "kevent", socktype, "EVFILT_READ, EV_ADD");
+
+	/*
+	 * Confirm not readable to begin with, no I/O yet.
+	 */
+	ts.tv_sec = 0;
+	ts.tv_nsec = 0;
+	i = kevent(kq, NULL, 0, &ke, 1, &ts);
+	if (i == -1)
+		fail(errno, "kevent", socktype, "EVFILT_READ");
+	if (i != 0)
+		fail_assertion("kevent", socktype, "EVFILT_READ",
+		    "empty socket unreadable");
+
+	/*
+	 * Write a byte to one end.
+	 */
+	ch = 'a';
+	len = write(fd[1], &ch, sizeof(ch));
+	if (len == -1)
+		fail(errno, "write", socktype, NULL);
+	if (len != sizeof(ch))
+		fail_assertion("write", socktype, NULL, "write length");
+
+	/*
+	 * Other end should now be readable.
+	 */
+	ts.tv_sec = 0;
+	ts.tv_nsec = 0;
+	i = kevent(kq, NULL, 0, &ke, 1, &ts);
+	if (i == -1)
+		fail(errno, "kevent", socktype, "EVFILT_READ");
+	if (i != 1)
+		fail_assertion("kevent", socktype, "EVFILT_READ",
+		    "non-empty socket unreadable");
+
+	/*
+	 * Read a byte to clear the readable state.
+	 */
+	len = read(fd[0], &ch, sizeof(ch));
+	if (len == -1)
+		fail(errno, "read", socktype, NULL);
+	if (len != sizeof(ch))
+		fail_assertion("read", socktype, NULL, "read length");
+
+	/*
+	 * Now re-check for readability.
+	 */
+	ts.tv_sec = 0;
+	ts.tv_nsec = 0;
+	i = kevent(kq, NULL, 0, &ke, 1, &ts);
+	if (i == -1)
+		fail(errno, "kevent", socktype, "EVFILT_READ");
+	if (i != 0)
+		fail_assertion("kevent", socktype, "EVFILT_READ",
+		    "empty socket unreadable");
+
+	EV_SET(&ke, fd[0], EVFILT_READ, EV_DELETE, 0, 0, NULL);
+	if (kevent(kq, &ke, 1, NULL, 0, NULL) == -1)
+		fail(errno, "kevent", socktype, "EVFILT_READ, EV_DELETE");
+}
+
+static void
+test_evfilt_write(int kq, int fd[2], const char *socktype)
+{
+	struct timespec ts;
+	struct kevent ke;
+	ssize_t len;
+	char ch;
+	int i;
+
+	EV_SET(&ke, fd[0], EVFILT_WRITE, EV_ADD, 0, 0, NULL);
+	if (kevent(kq, &ke, 1, NULL, 0, NULL) == -1)
+		fail(errno, "kevent", socktype, "EVFILT_WRITE, EV_ADD");
+
+	/*
+	 * Confirm writable to begin with, no I/O yet.
+	 */
+	ts.tv_sec = 0;
+	ts.tv_nsec = 0;
+	i = kevent(kq, NULL, 0, &ke, 1, &ts);
+	if (i == -1)
+		fail(errno, "kevent", socktype, "EVFILT_WRITE");
+	if (i != 1)
+		fail_assertion("kevent", socktype, "EVFILT_WRITE",
+		    "empty socket unwritable");
+
+	/*
+	 * Write bytes into the socket until we can't write anymore.
+	 */
+	ch = 'a';
+	while ((len = write(fd[0], &ch, sizeof(ch))) == sizeof(ch)) {};
+	if (len == -1 && errno != EAGAIN && errno != ENOBUFS)
+		fail(errno, "write", socktype, NULL);
+	if (len != -1 && len != sizeof(ch))
+		fail_assertion("write", socktype, NULL, "write length");
+
+	/*
+	 * Check to make sure the socket is no longer writable.
+	 */
+	ts.tv_sec = 0;
+	ts.tv_nsec = 0;
+	i = kevent(kq, NULL, 0, &ke, 1, &ts);
+	if (i == -1)
+		fail(errno, "kevent", socktype, "EVFILT_WRITE");
+	if (i != 0)
+		fail_assertion("kevent", socktype, "EVFILT_WRITE",
+		    "full socket writable");
+
+	EV_SET(&ke, fd[0], EVFILT_WRITE, EV_DELETE, 0, 0, NULL);
+	if (kevent(kq, &ke, 1, NULL, 0, NULL) == -1)
+		fail(errno, "kevent", socktype, "EVFILT_WRITE, EV_DELETE");
+}
+
+/*
+ * Basic registration exercise for kqueue(2).  Create several types/brands of
+ * sockets, and confirm that we can register for various events on them.
+ */
+int
+main(int argc, char *argv[])
+{
+	int i, kq, sv[2];
+
+	kq = kqueue();
+	if (kq == -1)
+		fail(errno, "kqueue", NULL, NULL);
+
+	/*
+	 * Create a UNIX domain datagram socket, and attach/test/detach a
+	 * read filter on it.
+	 */
+	if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sv) == -1)
+		fail(errno, "socketpair", "PF_UNIX, SOCK_DGRAM", NULL);
+
+	i = O_NONBLOCK;
+	if (fcntl(sv[0], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_DGRAM", "O_NONBLOCK");
+	if (fcntl(sv[1], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_DGRAM", "O_NONBLOCK");
+
+	test_evfilt_read(kq, sv, "PF_UNIX, SOCK_DGRAM");
+
+	if (close(sv[0]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_DGRAM", "sv[0]");
+	if (close(sv[1]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_DGRAM", "sv[1]");
+
+#if 0
+	/*
+	 * XXXRW: We disable the write test in the case of datagram sockets,
+	 * as kqueue can't tell when the remote socket receive buffer is
+	 * full, whereas the UNIX domain socket implementation can tell and
+	 * returns ENOBUFS.
+	 */
+	/*
+	 * Create a UNIX domain datagram socket, and attach/test/detach a
+	 * write filter on it.
+	 */
+	if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sv) == -1)
+		fail(errno, "socketpair", "PF_UNIX, SOCK_DGRAM", NULL);
+
+	i = O_NONBLOCK;
+	if (fcntl(sv[0], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_DGRAM", "O_NONBLOCK");
+	if (fcntl(sv[1], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_DGRAM", "O_NONBLOCK");
+
+	test_evfilt_write(kq, sv, "PF_UNIX, SOCK_DGRAM");
+
+	if (close(sv[0]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_DGRAM", "sv[0]");
+	if (close(sv[1]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_DGRAM", "sv[1]");
+#endif
+
+	/*
+	 * Create a UNIX domain stream socket, and attach/test/detach a
+	 * read filter on it.
+	 */
+	if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1)
+		fail(errno, "socketpair", "PF_UNIX, SOCK_STREAM", NULL);
+
+	i = O_NONBLOCK;
+	if (fcntl(sv[0], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_STREAM", "O_NONBLOCK");
+	if (fcntl(sv[1], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_STREAM", "O_NONBLOCK");
+
+	test_evfilt_read(kq, sv, "PF_UNIX, SOCK_STREAM");
+
+	if (close(sv[0]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_STREAM", "sv[0]");
+	if (close(sv[1]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_STREAM", "sv[1]");
+
+	/*
+	 * Create a UNIX domain stream socket, and attach/test/detach a
+	 * write filter on it.
+	 */
+	if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1)
+		fail(errno, "socketpair", "PF_UNIX, SOCK_STREAM", NULL);
+
+	i = O_NONBLOCK;
+	if (fcntl(sv[0], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_STREAM", "O_NONBLOCK");
+	if (fcntl(sv[1], F_SETFL, &i) != 0)
+		fail(errno, "fcntl", "PF_UNIX, SOCK_STREAM", "O_NONBLOCK");
+
+	test_evfilt_write(kq, sv, "PF_UNIX, SOCK_STREAM");
+
+	if (close(sv[0]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_STREAM", "sv[0]");
+	if (close(sv[1]) == -1)
+		fail(errno, "close", "PF_UNIX/SOCK_STREAM", "sv[1]");
+
+	if (close(kq) == -1)
+		fail(errno, "close", "kq", NULL);
+
+	printf("PASS\n");
+	return (0);
+}