socket tests: add socket_accept

Start with most basic functionality on a TCP socket.

tests/sys/kern/Makefile

@@ -28,6 +28,7 @@ ATF_TESTS_C+=	reaper
 ATF_TESTS_C+=	sched_affinity
 ATF_TESTS_C+=	sigaltstack
 ATF_TESTS_C+=	sigwait
+ATF_TESTS_C+=	socket_accept
 ATF_TESTS_C+=	socket_accf
 ATF_TESTS_C+=	socket_msg_trunc
 ATF_TESTS_C+=	socket_msg_waitall

tests/sys/kern/socket_accept.c

@@ -0,0 +1,130 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Gleb Smirnoff <glebius@FreeBSD.org>
+ *
+ * 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.
+ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <atf-c.h>
+
+static int
+tcp4_listensock(struct sockaddr_in *sin)
+{
+	int l;
+
+	ATF_REQUIRE((l = socket(PF_INET, SOCK_STREAM, 0)) > 0);
+	ATF_REQUIRE(setsockopt(l, SOL_SOCKET, SO_REUSEADDR, &(socklen_t){1},
+	    sizeof(int)) == 0);
+	*sin = (struct sockaddr_in){
+		.sin_len = sizeof(sin),
+		.sin_family = AF_INET,
+		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
+	};
+	ATF_REQUIRE(bind(l, (struct sockaddr *)sin, sizeof(*sin)) == 0);
+	ATF_REQUIRE(getsockname(l, (struct sockaddr *)sin,
+	    &(socklen_t){ sizeof(*sin) }) == 0);
+	ATF_REQUIRE(listen(l, -1) == 0);
+
+	return (l);
+}
+
+static int
+tcp4_clientsock(struct sockaddr_in *sin)
+{
+	int s;
+
+	ATF_REQUIRE((s = socket(PF_INET, SOCK_STREAM, 0)) > 0);
+	ATF_REQUIRE(connect(s, (struct sockaddr *)sin, sizeof(*sin)) == 0);
+
+	return (s);
+}
+
+ATF_TC_WITHOUT_HEAD(tcp4_zerolen);
+ATF_TC_BODY(tcp4_zerolen, tc)
+{
+	static char canary[sizeof(struct sockaddr_in)] =
+	    { [0 ... sizeof(struct sockaddr_in) - 1] = 0xa };
+	struct sockaddr_in sin, ret;
+	socklen_t salen;
+	int l;
+
+	l = tcp4_listensock(&sin);
+	(void )tcp4_clientsock(&sin);
+
+	memcpy(&ret, &canary, sizeof(ret));
+	salen = 0;
+	ATF_REQUIRE(accept(l, (struct sockaddr *)&ret, &salen) > 0);
+	ATF_REQUIRE(memcmp(&ret, &canary, sizeof(ret)) == 0);
+#if 0
+	/* Linux behavior. Matches my reading of accept(2) and POSIX. */
+	ATF_REQUIRE(salen == sizeof(struct sockaddr_in));
+#endif
+	/* Note: Linux will block for connection here, we fail immediately. */
+	ATF_REQUIRE(accept(l, (struct sockaddr *)&ret, NULL) == -1);
+	ATF_REQUIRE(errno == EFAULT);
+}
+
+ATF_TC_WITHOUT_HEAD(tcp4);
+ATF_TC_BODY(tcp4, tc)
+{
+	struct sockaddr_in sin, ret;
+	socklen_t salen;
+	int l, s;
+
+	l = tcp4_listensock(&sin);
+	s = tcp4_clientsock(&sin);
+
+	salen = sizeof(struct sockaddr_in) + 2;
+	ATF_REQUIRE(accept(l, (struct sockaddr *)&ret, &salen) > 0);
+	ATF_REQUIRE(salen == sizeof(struct sockaddr_in));
+	ATF_REQUIRE(getsockname(s, (struct sockaddr *)&sin,
+	    &(socklen_t){ sizeof(sin) }) == 0);
+	ATF_REQUIRE(memcmp(&ret, &sin, sizeof(sin)) == 0);
+}
+
+ATF_TC_WITHOUT_HEAD(tcp4_noaddr);
+ATF_TC_BODY(tcp4_noaddr, tc)
+{
+	struct sockaddr_in sin;
+	int l;
+
+	l = tcp4_listensock(&sin);
+	(void )tcp4_clientsock(&sin);
+
+	ATF_REQUIRE(accept(l, NULL, NULL) > 0);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, tcp4);
+	ATF_TP_ADD_TC(tp, tcp4_noaddr);
+	ATF_TP_ADD_TC(tp, tcp4_zerolen);
+
+	return (atf_no_error());
+}