selftests/landlock: Test TCP accesses with protocol=IPPROTO_TCP

Extend protocol_variant structure with protocol field (Cf. socket(2)).

Extend protocol fixture with TCP test suits with protocol=IPPROTO_TCP
which can be used as an alias for IPPROTO_IP (=0) in socket(2).

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
Link: https://lore.kernel.org/r/20250205093651.1424339-3-ivanov.mikhail1@huawei-partners.com
Cc: <stable@vger.kernel.org> # 6.7.x
Signed-off-by: Mickaël Salaün <mic@digikod.net>

Author: sm1ling-knight

tools/testing/selftests/landlock/common.h

@@ -207,6 +207,7 @@ enforce_ruleset(struct __test_metadata *const _metadata, const int ruleset_fd)
 struct protocol_variant {
 	int domain;
 	int type;
+	int protocol;
 };
 
 struct service_fixture {

tools/testing/selftests/landlock/net_test.c

@@ -85,18 +85,18 @@ static void setup_loopback(struct __test_metadata *const _metadata)
 	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
 }
 
+static bool prot_is_tcp(const struct protocol_variant *const prot)
+{
+	return (prot->domain == AF_INET || prot->domain == AF_INET6) &&
+	       prot->type == SOCK_STREAM &&
+	       (prot->protocol == IPPROTO_TCP || prot->protocol == IPPROTO_IP);
+}
+
 static bool is_restricted(const struct protocol_variant *const prot,
 			  const enum sandbox_type sandbox)
 {
-	switch (prot->domain) {
-	case AF_INET:
-	case AF_INET6:
-		switch (prot->type) {
-		case SOCK_STREAM:
-			return sandbox == TCP_SANDBOX;
-		}
-		break;
-	}
+	if (sandbox == TCP_SANDBOX)
+		return prot_is_tcp(prot);
 	return false;
 }
 
@@ -105,7 +105,7 @@ static int socket_variant(const struct service_fixture *const srv)
 	int ret;
 
 	ret = socket(srv->protocol.domain, srv->protocol.type | SOCK_CLOEXEC,
-		     0);
+		     srv->protocol.protocol);
 	if (ret < 0)
 		return -errno;
 	return ret;
@@ -290,22 +290,48 @@ FIXTURE_TEARDOWN(protocol)
 }
 
 /* clang-format off */
-FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv4_tcp) {
+FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv4_tcp1) {
 	/* clang-format on */
 	.sandbox = NO_SANDBOX,
 	.prot = {
 		.domain = AF_INET,
 		.type = SOCK_STREAM,
+		/* IPPROTO_IP == 0 */
+		.protocol = IPPROTO_IP,
 	},
 };
 
 /* clang-format off */
-FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv6_tcp) {
+FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv4_tcp2) {
+	/* clang-format on */
+	.sandbox = NO_SANDBOX,
+	.prot = {
+		.domain = AF_INET,
+		.type = SOCK_STREAM,
+		.protocol = IPPROTO_TCP,
+	},
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv6_tcp1) {
 	/* clang-format on */
 	.sandbox = NO_SANDBOX,
 	.prot = {
 		.domain = AF_INET6,
 		.type = SOCK_STREAM,
+		/* IPPROTO_IP == 0 */
+		.protocol = IPPROTO_IP,
+	},
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_ipv6_tcp2) {
+	/* clang-format on */
+	.sandbox = NO_SANDBOX,
+	.prot = {
+		.domain = AF_INET6,
+		.type = SOCK_STREAM,
+		.protocol = IPPROTO_TCP,
 	},
 };
 
@@ -350,22 +376,48 @@ FIXTURE_VARIANT_ADD(protocol, no_sandbox_with_unix_datagram) {
 };
 
 /* clang-format off */
-FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv4_tcp) {
+FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv4_tcp1) {
+	/* clang-format on */
+	.sandbox = TCP_SANDBOX,
+	.prot = {
+		.domain = AF_INET,
+		.type = SOCK_STREAM,
+		/* IPPROTO_IP == 0 */
+		.protocol = IPPROTO_IP,
+	},
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv4_tcp2) {
 	/* clang-format on */
 	.sandbox = TCP_SANDBOX,
 	.prot = {
 		.domain = AF_INET,
 		.type = SOCK_STREAM,
+		.protocol = IPPROTO_TCP,
+	},
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv6_tcp1) {
+	/* clang-format on */
+	.sandbox = TCP_SANDBOX,
+	.prot = {
+		.domain = AF_INET6,
+		.type = SOCK_STREAM,
+		/* IPPROTO_IP == 0 */
+		.protocol = IPPROTO_IP,
 	},
 };
 
 /* clang-format off */
-FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv6_tcp) {
+FIXTURE_VARIANT_ADD(protocol, tcp_sandbox_with_ipv6_tcp2) {
 	/* clang-format on */
 	.sandbox = TCP_SANDBOX,
 	.prot = {
 		.domain = AF_INET6,
 		.type = SOCK_STREAM,
+		.protocol = IPPROTO_TCP,
 	},
 };