[PATCH v8 10/12] selftests/landlock: Add 10 new test suites dedicated to network

Konstantin Meskhidze (A) konstantin.meskhidze at huawei.com
Wed Jan 11 01:52:23 UTC 2023



1/10/2023 8:40 PM, Mickaël Salaün пишет:
> 
> On 10/01/2023 06:03, Konstantin Meskhidze (A) wrote:
>> 
>> 
>> 1/9/2023 3:46 PM, Mickaël Salaün пишет:
>>>
>>> On 21/10/2022 17:26, Konstantin Meskhidze wrote:
>>>> These test suites try to check edge cases for TCP sockets
>>>> bind() and connect() actions.
>>>>
>>>> socket:
>>>> * bind_no_restrictions: Tests with non-landlocked ipv4 and ipv6 sockets.
>>>> * bind_with_restrictions: Tests with mixed landlock rules for ipv4 and
>>>> ipv6 sockets.
>>>> * connect_no_restrictions: Tests with non-landlocked ipv4 and ipv6 sockets.
>>>> * connect_with_restrictions: Tests with mixed landlock rules for ipv4 and
>>>> ipv6 sockets.
>>>> * connect_afunspec_no_restrictions: Tests with no landlock restrictions
>>>> allowing to disconnect already connected socket with AF_UNSPEC socket
>>>> family.
>>>> * connect_afunspec_with_restrictions: Tests with landlocked process
>>>> refusing to disconnect already connected socket.
>>>> * ruleset_overlap: Tests with overlapping rules for one port.
>>>> * ruleset_expanding: Tests with expanding rulesets in which rules are
>>>> gradually added one by one, restricting sockets' connections.
>>>> * inval: Tests with invalid user space supplied data:
>>>>       - out of range ruleset attribute;
>>>>       - unhandled allowed access;
>>>>       - zero port value;
>>>>       - zero access value;
>>>>       - legitimate access values;
>>>>
>>>> layout1:
>>>> * with_net: Tests with network bind() socket action within
>>>> filesystem directory access test.
>>>>
>>>> Test coverage for security/landlock is 94.3% of 920 lines according
>>>> to gcc/gcov-11.
>>>>
>>>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
>>>> ---
>>>>
>>>> Changes since v7:
>>>> * Squashes all selftest commits.
>>>> * Adds fs test with network bind() socket action.
>>>> * Minor fixes.
>>>>
>>>> ---
>>>>    security/landlock/ruleset.h                 |   2 -
>>>>    tools/testing/selftests/landlock/config     |   4 +
>>>>    tools/testing/selftests/landlock/fs_test.c  |  65 ++
>>>>    tools/testing/selftests/landlock/net_test.c | 823 ++++++++++++++++++++
>>>>    4 files changed, 892 insertions(+), 2 deletions(-)
>>>>    create mode 100644 tools/testing/selftests/landlock/net_test.c
>>>>
>>>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
>>>> index f272d2cd518c..ee1a02a404ce 100644
>>>> --- a/security/landlock/ruleset.h
>>>> +++ b/security/landlock/ruleset.h
>>>> @@ -264,7 +264,6 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset,
>>>>
>>>>    	/* Should already be checked in sys_landlock_create_ruleset(). */
>>>>    	WARN_ON_ONCE(fs_access_mask != fs_mask);
>>>> -	// TODO: Add tests to check "|=" and not "="
>>>>    	ruleset->access_masks[layer_level] |=
>>>>    		(fs_mask << LANDLOCK_SHIFT_ACCESS_FS);
>>>>    }
>>>> @@ -278,7 +277,6 @@ landlock_add_net_access_mask(struct landlock_ruleset *const ruleset,
>>>>
>>>>    	/* Should already be checked in sys_landlock_create_ruleset(). */
>>>>    	WARN_ON_ONCE(net_access_mask != net_mask);
>>>> -	// TODO: Add tests to check "|=" and not "="
>>>>    	ruleset->access_masks[layer_level] |=
>>>>    		(net_mask << LANDLOCK_SHIFT_ACCESS_NET);
>>>>    }
>>>> diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config
>>>> index 0f0a65287bac..71f7e9a8a64c 100644
>>>> --- a/tools/testing/selftests/landlock/config
>>>> +++ b/tools/testing/selftests/landlock/config
>>>> @@ -1,3 +1,7 @@
>>>> +CONFIG_INET=y
>>>> +CONFIG_IPV6=y
>>>> +CONFIG_NET=y
>>>> +CONFIG_NET_NS=y
>>>>    CONFIG_OVERLAY_FS=y
>>>>    CONFIG_SECURITY_LANDLOCK=y
>>>>    CONFIG_SECURITY_PATH=y
>>>> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
>>>> index 20c1ac8485f1..5c52da1a5a69 100644
>>>> --- a/tools/testing/selftests/landlock/fs_test.c
>>>> +++ b/tools/testing/selftests/landlock/fs_test.c
>>>> @@ -8,14 +8,17 @@
>>>>     */
>>>>
>>>>    #define _GNU_SOURCE
>>>> +#include <arpa/inet.h>
>>>>    #include <fcntl.h>
>>>>    #include <linux/landlock.h>
>>>> +#include <netinet/in.h>
>>>>    #include <sched.h>
>>>>    #include <string.h>
>>>>    #include <sys/capability.h>
>>>>    #include <sys/mount.h>
>>>>    #include <sys/prctl.h>
>>>>    #include <sys/sendfile.h>
>>>> +#include <sys/socket.h>
>>>>    #include <sys/stat.h>
>>>>    #include <sys/sysmacros.h>
>>>>    #include <unistd.h>
>>>> @@ -4366,4 +4369,66 @@ TEST_F_FORK(layout2_overlay, same_content_different_file)
>>>>    	}
>>>>    }
>>>>
>>>> +#define IP_ADDRESS "127.0.0.1"
>>>> +
>>>> +TEST_F_FORK(layout1, with_net)
>>>> +{
>>>> +	int sockfd;
>>>> +	int sock_port = 15000;
>>>> +	struct sockaddr_in addr4;
>>>> +
>>>> +	addr4.sin_family = AF_INET;
>>>> +	addr4.sin_port = htons(sock_port);
>>>> +	addr4.sin_addr.s_addr = inet_addr(IP_ADDRESS);
>>>> +	memset(&addr4.sin_zero, '\0', 8);
>>>> +
>>>> +	const struct rule rules[] = {
>>>> +		{
>>>> +			.path = dir_s1d2,
>>>> +			.access = ACCESS_RO,
>>>> +		},
>>>> +		{},
>>>> +	};
>>>> +
>>>> +	struct landlock_ruleset_attr ruleset_attr_net = {
>>>> +		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
>>>> +				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
>>>> +	};
>>>> +	struct landlock_net_service_attr net_service = {
>>>> +		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
>>>> +
>>>> +		.port = sock_port,
>>>> +	};
>>>> +
>>>> +	/* Creates ruleset for network access. */
>>>> +	const int ruleset_fd_net = landlock_create_ruleset(
>>>> +		&ruleset_attr_net, sizeof(ruleset_attr_net), 0);
>>>> +	ASSERT_LE(0, ruleset_fd_net);
>>>> +
>>>> +	/* Adds a network rule. */
>>>> +	ASSERT_EQ(0,
>>>> +		  landlock_add_rule(ruleset_fd_net, LANDLOCK_RULE_NET_SERVICE,
>>>> +				    &net_service, 0));
>>>> +
>>>> +	enforce_ruleset(_metadata, ruleset_fd_net);
>>>> +	ASSERT_EQ(0, close(ruleset_fd_net));
>>>> +
>>>> +	const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
>>>> +	ASSERT_LE(0, ruleset_fd);
>>>> +	enforce_ruleset(_metadata, ruleset_fd);
>>>> +	ASSERT_EQ(0, close(ruleset_fd));
>>>> +
>>>> +	/* Tests on a directory with the network rule loaded. */
>>>> +	ASSERT_EQ(0, test_open(dir_s1d2, O_RDONLY));
>>>> +	ASSERT_EQ(0, test_open(file1_s1d2, O_RDONLY));
>>>> +
>>>> +	sockfd = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
>>>> +	ASSERT_LE(0, sockfd);
>>>> +	/* Binds a socket to port 15000. */
>>>> +	ASSERT_EQ(0, bind(sockfd, &addr4, sizeof(addr4)));
>>>> +
>>>> +	/* Closes bounded socket. */
>>>> +	ASSERT_EQ(0, close(sockfd));
>>>> +}
>>>> +
>>>>    TEST_HARNESS_MAIN
>>>> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
>>>> new file mode 100644
>>>> index 000000000000..d1548bd7ab60
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/landlock/net_test.c
>>>> @@ -0,0 +1,823 @@
>>>> +// SPDX-License-Identifier: GPL-2.0-only
>>>> +/*
>>>> + * Landlock tests - Network
>>>> + *
>>>> + * Copyright (C) 2022 Huawei Tech. Co., Ltd.
>>>> + */
>>>> +
>>>> +#define _GNU_SOURCE
>>>> +#include <arpa/inet.h>
>>>> +#include <errno.h>
>>>> +#include <fcntl.h>
>>>> +#include <linux/landlock.h>
>>>> +#include <netinet/in.h>
>>>> +#include <sched.h>
>>>> +#include <string.h>
>>>> +#include <sys/prctl.h>
>>>> +#include <sys/socket.h>
>>>> +#include <sys/types.h>
>>>> +
>>>> +#include "common.h"
>>>> +
>>>> +#define MAX_SOCKET_NUM 10
>>>> +
>>>> +#define SOCK_PORT_START 3470
>>>> +#define SOCK_PORT_ADD 10
>>>> +
>>>> +#define IP_ADDRESS "127.0.0.1"
>>>> +
>>>> +/* Number pending connections queue to be hold. */
>>>> +#define BACKLOG 10
>>>> +
>>>> +const struct sockaddr addr_unspec = { .sa_family = AF_UNSPEC };
>>>> +
>>>> +/* Invalid attribute, out of landlock network access range. */
>>>> +#define LANDLOCK_INVAL_ATTR 7
>>>> +
>>>> +FIXTURE(socket)
>>>> +{
>>>> +	uint port[MAX_SOCKET_NUM];
>>>> +	struct sockaddr_in addr4[MAX_SOCKET_NUM];
>>>> +	struct sockaddr_in6 addr6[MAX_SOCKET_NUM];
>>>> +};
>>>> +
>>>> +/* struct _fixture_variant_socket */
>>>> +FIXTURE_VARIANT(socket)
>>>> +{
>>>> +	const bool is_ipv4;
>>>> +};
>>>> +
>>>> +/* clang-format off */
>>>> +FIXTURE_VARIANT_ADD(socket, ipv4) {
>>>> +	/* clang-format on */
>>>> +	.is_ipv4 = true,
>>>> +};
>>>> +
>>>> +/* clang-format off */
>>>> +FIXTURE_VARIANT_ADD(socket, ipv6) {
>>>> +	/* clang-format on */
>>>> +	.is_ipv4 = false,
>>>> +};
>>>> +
>>>> +static int
>>>> +create_socket_variant(const struct _fixture_variant_socket *const variant,
>>>> +		      const int type)
>>>> +{
>>>> +	if (variant->is_ipv4)
>>>> +		return socket(AF_INET, type | SOCK_CLOEXEC, 0);
>>>> +	else
>>>> +		return socket(AF_INET6, type | SOCK_CLOEXEC, 0);
>>>> +}
>>>> +
>>>> +static int bind_variant(const struct _fixture_variant_socket *const variant,
>>>> +			const int sockfd,
>>>> +			const struct _test_data_socket *const self,
>>>> +			const size_t index)
>>>> +{
>>>> +	if (variant->is_ipv4)
>>>> +		return bind(sockfd, &self->addr4[index],
>>>> +			    sizeof(self->addr4[index]));
>>>> +	else
>>>> +		return bind(sockfd, &self->addr6[index],
>>>> +			    sizeof(self->addr6[index]));
>>>> +}
>>>> +
>>>> +static int connect_variant(const struct _fixture_variant_socket *const variant,
>>>> +			   const int sockfd,
>>>> +			   const struct _test_data_socket *const self,
>>>> +			   const size_t index)
>>>> +{
>>>> +	if (variant->is_ipv4)
>>>> +		return connect(sockfd, &self->addr4[index],
>>>> +			       sizeof(self->addr4[index]));
>>>> +	else
>>>> +		return connect(sockfd, &self->addr6[index],
>>>> +			       sizeof(self->addr6[index]));
>>>> +}
>>>> +
>>>> +FIXTURE_SETUP(socket)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	/* Creates IPv4 socket addresses. */
>>>> +	for (i = 0; i < MAX_SOCKET_NUM; i++) {
>>>> +		self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD * i;
>>>> +		self->addr4[i].sin_family = AF_INET;
>>>> +		self->addr4[i].sin_port = htons(self->port[i]);
>>>> +		self->addr4[i].sin_addr.s_addr = inet_addr(IP_ADDRESS);
>>>> +		memset(&(self->addr4[i].sin_zero), '\0', 8);
>>>> +	}
>>>> +
>>>> +	/* Creates IPv6 socket addresses. */
>>>> +	for (i = 0; i < MAX_SOCKET_NUM; i++) {
>>>> +		self->port[i] = SOCK_PORT_START + SOCK_PORT_ADD * i;
>>>> +		self->addr6[i].sin6_family = AF_INET6;
>>>> +		self->addr6[i].sin6_port = htons(self->port[i]);
>>>> +		inet_pton(AF_INET6, IP_ADDRESS, &(self->addr6[i].sin6_addr));
>>>> +	}
>>>> +
>>>> +	set_cap(_metadata, CAP_SYS_ADMIN);
>>>> +	ASSERT_EQ(0, unshare(CLONE_NEWNET));
>>>> +	ASSERT_EQ(0, system("ip link set dev lo up"));
>>>> +	clear_cap(_metadata, CAP_SYS_ADMIN);
>>>> +}
>>>> +
>>>> +FIXTURE_TEARDOWN(socket)
>>>> +{
>>>> +}
>>>> +
>>>> +TEST_F_FORK(socket, bind_no_restrictions)
>>>> +{
>>>> +	int sockfd;
>>>> +
>>>> +	sockfd = create_socket_variant(variant, SOCK_STREAM);
>>>> +	ASSERT_LE(0, sockfd);
>>>> +
>>>> +	/* Binds a socket to port[0]. */
>>>> +	ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
>>>> +
>>>> +	ASSERT_EQ(0, close(sockfd));
>>>> +}
>>>> +
>>>> +TEST_F_FORK(socket, bind_with_restrictions)
>>>> +{
>>>> +	int sockfd;
>>>> +
>>>> +	struct landlock_ruleset_attr ruleset_attr = {
>>>> +		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
>>>> +				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
>>>> +	};
>>>> +	struct landlock_net_service_attr net_service_1 = {
>>>> +		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
>>>> +				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
>>>> +		.port = self->port[0],
>>>> +	};
>>>> +	struct landlock_net_service_attr net_service_2 = {
>>>> +		.allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
>>>> +		.port = self->port[1],
>>>> +	};
>>>> +	struct landlock_net_service_attr net_service_3 = {
>>>> +		.allowed_access = 0,
>>>> +		.port = self->port[2],
>>>> +	};
>>>> +
>>>> +	const int ruleset_fd =
>>>> +		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
>>>> +	ASSERT_LE(0, ruleset_fd);
>>>> +
>>>> +	/* Allows connect and bind operations to the port[0] socket. */
>>>> +	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
>>>> +				       &net_service_1, 0));
>>>> +	/* Allows connect and deny bind operations to the port[1] socket. */
>>>> +	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
>>>> +				       &net_service_2, 0));
>>>> +	/*
>>>> +	 * Empty allowed_access (i.e. deny rules) are ignored in network actions
>>>> +	 * for port[2] socket.
>>>> +	 */
>>>> +	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_SERVICE,
>>>> +					&net_service_3, 0));
>>>> +	ASSERT_EQ(ENOMSG, errno);
>>>> +
>>>> +	/* Enforces the ruleset. */
>>>> +	enforce_ruleset(_metadata, ruleset_fd);
>>>> +
>>>> +	sockfd = create_socket_variant(variant, SOCK_STREAM);
>>>> +	ASSERT_LE(0, sockfd);
>>>> +	/* Binds a socket to port[0]. */
>>>> +	ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
>>>> +
>>>> +	/* Closes bounded socket. */
>>>> +	ASSERT_EQ(0, close(sockfd));
>>>> +
>>>> +	sockfd = create_socket_variant(variant, SOCK_STREAM);
>>>> +	ASSERT_LE(0, sockfd);
>>>> +	/* Binds a socket to port[1]. */
>>>> +	ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 1));
>>>> +	ASSERT_EQ(EACCES, errno);
>>>> +
>>>> +	sockfd = create_socket_variant(variant, SOCK_STREAM);
>>>> +	ASSERT_LE(0, sockfd);
>>>> +	/* Binds a socket to port[2]. */
>>>> +	ASSERT_EQ(-1, bind_variant(variant, sockfd, self, 2));
>>>> +	ASSERT_EQ(EACCES, errno);
>>>
>>> This is inconsistent with the bind_no_restrictions test. If you
>>> deduplicate the tests with and without restrictions (i.e. only one
>>> "bind" test, and another "connect"…), you can extend
>>> FIXTURE_VARIANT(socket) with a new const bool enforce_landlock, and
>>> check that in all tests to either do Landlock syscalls or not. You can
>>> still initialize most variable whatever Landlock should be enforced or
>>> not (e.g. ruleset_attr, net_service_1…) to make it easiear to read.
>>>
>> 
>>     I think it's not a deduplication. Tests enforeced with landlock are
>> more various regarding port and net_service attributes used. The number
>> of landlock atributes vary from test ot test. I'dont see how to unify it
>> with FIXTURE_VARIANT and enforce_landlock const will it make harder
>> merging tests.
>> Please your opinion and suggestions?
> 
> What about that?


> 
> TEST_F_FORK(socket, bind)
> {
> 	int sockfd;
> 
> 	struct landlock_ruleset_attr ruleset_attr = {
> 		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
> 				      LANDLOCK_ACCESS_NET_CONNECT_TCP,
> 	};
> 	struct landlock_net_service_attr net_service_1 = {
> 		.allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP |
> 				  LANDLOCK_ACCESS_NET_CONNECT_TCP,
> 		.port = self->port[0],
> 	};
> 	struct landlock_net_service_attr net_service_2 = {
> 		.allowed_access = LANDLOCK_ACCESS_NET_CONNECT_TCP,
> 		.port = self->port[1],
> 	};
> 	struct landlock_net_service_attr net_service_3 = {
> 		.allowed_access = 0,
> 		.port = self->port[2],
> 	};
> 	int ruleset_fd, ret;
> 
> 	if (variant->is_sandboxed) {
> 		ruleset_fd = landlock_create_ruleset(&ruleset_attr,
> 						     sizeof(ruleset_attr), 0);
> 		ASSERT_LE(0, ruleset_fd);
> 
> 		/* Allows connect and bind operations to the port[0] socket. */
> 		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
> 					       LANDLOCK_RULE_NET_SERVICE,
> 					       &net_service_1, 0));
> 
> 		/* Allows connect and deny bind operations to the port[1] socket. */
> 		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
> 					       LANDLOCK_RULE_NET_SERVICE,
> 					       &net_service_2, 0));
> 
> 		/*
> 		 * Empty allowed_access (i.e. deny rules) are ignored in network actions
> 		 * for port[2] socket.
> 		 */
> 		ASSERT_EQ(-1, landlock_add_rule(ruleset_fd,
> 						LANDLOCK_RULE_NET_SERVICE,
> 						&net_service_3, 0));
> 		ASSERT_EQ(ENOMSG, errno);
> 
> 		enforce_ruleset(_metadata, ruleset_fd);
> 		ASSERT_EQ(0, close(ruleset_fd));
> 	}
> 
> 	sockfd = create_socket_variant(variant, SOCK_STREAM);
> 	ASSERT_LE(0, sockfd);
> 	/* Binds a socket to port[0]. */
> 	ASSERT_EQ(0, bind_variant(variant, sockfd, self, 0));
> 
> 	/* Closes bounded socket. */
> 	ASSERT_EQ(0, close(sockfd));
> 
> 	sockfd = create_socket_variant(variant, SOCK_STREAM);
> 	ASSERT_LE(0, sockfd);
> 	/* Binds a socket to port[1]. */
> 	ret = bind_variant(variant, sockfd, self, 1);
> 	if (variant->is_sandboxed) {
> 		ASSERT_EQ(-1, ret);
> 		ASSERT_EQ(EACCES, errno);
> 	} else {
> 		ASSERT_EQ(0, ret);
> 	}
> 
> 	sockfd = create_socket_variant(variant, SOCK_STREAM);
> 	ASSERT_LE(0, sockfd);
> 	/* Binds a socket to port[2]. */
> 	ret = bind_variant(variant, sockfd, self, 2);
> 	if (variant->is_sandboxed) {
> 		ASSERT_EQ(-1, ret);
> 		ASSERT_EQ(EACCES, errno);
> 	} else {
> 		ASSERT_EQ(0, ret);
> 	}
> }

   oh...This way.
   Sorry. There was a misunderstadting from me.
   Got your point now. Thanks for the tip.
> .



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