tests/netinet: add test for IP_MULTICAST_IF

tests/sys/netinet/Makefile

@@ -24,6 +24,7 @@ ATF_TESTS_SH=	arp \
 		fibs_test \
 		forward \
 		lpm \
+		multicast \
 		output \
 		redirect
 
@@ -47,7 +48,7 @@ TEST_METADATA.forward+=	required_programs="python"	\
 TEST_METADATA.output+=	required_programs="python"
 TEST_METADATA.redirect+= required_programs="python"
 
-PROGS=	udp_dontroute tcp_user_cookie
+PROGS=	udp_dontroute tcp_user_cookie sendto-IP_MULTICAST_IF
 
 ${PACKAGE}FILES+=		redirect.py
 

tests/sys/netinet/multicast.sh

@@ -0,0 +1,61 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2025 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.
+
+. $(atf_get_srcdir)/../common/vnet.subr
+
+# See regression fixed in baad45c9c12028964acd0b58096f3aaa0fb22859
+atf_test_case "IP_MULTICAST_IF" "cleanup"
+IP_MULTICAST_IF_head()
+{
+	atf_set descr \
+	    'sendto() for IP_MULTICAST_IF socket does not do routing lookup'
+	atf_set require.user root
+
+}
+
+IP_MULTICAST_IF_body()
+{
+	local epair mjail
+
+	vnet_init
+	# The test doesn't use our half of epair
+	epair=$(vnet_mkepair)
+	vnet_mkjail mjail ${epair}a
+	jexec mjail ifconfig ${epair}a up
+	jexec mjail ifconfig ${epair}a 192.0.2.1/24
+	atf_check -s exit:0 -o empty \
+	    jexec mjail $(atf_get_srcdir)/sendto-IP_MULTICAST_IF 192.0.2.1
+}
+
+IP_MULTICAST_IF_cleanup()
+{
+	vnet_cleanup
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case "IP_MULTICAST_IF"
+}

tests/sys/netinet/sendto-IP_MULTICAST_IF.c

@@ -0,0 +1,63 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 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 <arpa/inet.h>
+#include <assert.h>
+#include <err.h>
+
+int
+main(int argc, char *argv[])
+{
+	struct sockaddr_in sin = {
+		.sin_family = AF_INET,
+		.sin_len = sizeof(struct sockaddr_in),
+	};
+	struct in_addr in;
+	int s, rv;
+
+	if (argc < 2)
+		errx(1, "Usage: %s IPv4-address", argv[0]);
+
+	if (inet_pton(AF_INET, argv[1], &in) != 1)
+		err(1, "inet_pton(%s) failed", argv[1]);
+
+	assert((s = socket(PF_INET, SOCK_DGRAM, 0)) > 0);
+	assert(bind(s, (struct sockaddr *)&sin, sizeof(sin)) == 0);
+	assert(setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &in, sizeof(in))
+	  == 0);
+	/* RFC 6676 */
+	assert(inet_pton(AF_INET, "233.252.0.1", &sin.sin_addr) == 1);
+	sin.sin_port = htons(6676);
+	rv = sendto(s, &sin, sizeof(sin), 0,
+	    (struct sockaddr *)&sin, sizeof(sin));
+	if (rv != sizeof(sin))
+		err(1, "sendto failed");
+
+	return (0);
+}