diff mbox series

[RFC,v3,15/19] selftests/landlock: Test SCTP peeloff restriction

Message ID 20240904104824.1844082-16-ivanov.mikhail1@huawei-partners.com (mailing list archive)
State Handled Elsewhere
Headers show
Series Support socket access-control | expand

Commit Message

Mikhail Ivanov Sept. 4, 2024, 10:48 a.m. UTC
It is possible to branch off an SCTP UDP association into a separate
user space UDP socket. Add test validating that such scenario is not
restricted by Landlock.

Move setup_loopback() helper from net_test to common.h to use it to
enable connection in this test.

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
---
 tools/testing/selftests/landlock/common.h     |  12 +++
 tools/testing/selftests/landlock/net_test.c   |  11 --
 .../testing/selftests/landlock/socket_test.c  | 102 +++++++++++++++++-
 3 files changed, 113 insertions(+), 12 deletions(-)

Comments

Günther Noack Sept. 27, 2024, 2:35 p.m. UTC | #1
On Wed, Sep 04, 2024 at 06:48:20PM +0800, Mikhail Ivanov wrote:
> It is possible to branch off an SCTP UDP association into a separate
> user space UDP socket. Add test validating that such scenario is not
> restricted by Landlock.
> 
> Move setup_loopback() helper from net_test to common.h to use it to
> enable connection in this test.
> 
> Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
> ---
>  tools/testing/selftests/landlock/common.h     |  12 +++
>  tools/testing/selftests/landlock/net_test.c   |  11 --
>  .../testing/selftests/landlock/socket_test.c  | 102 +++++++++++++++++-
>  3 files changed, 113 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
> index 28df49fa22d5..07d959a8ac7b 100644
> --- a/tools/testing/selftests/landlock/common.h
> +++ b/tools/testing/selftests/landlock/common.h
> @@ -16,6 +16,7 @@
>  #include <sys/types.h>
>  #include <sys/wait.h>
>  #include <unistd.h>
> +#include <sched.h>
>  
>  #include "../kselftest_harness.h"
>  
> @@ -227,3 +228,14 @@ enforce_ruleset(struct __test_metadata *const _metadata, const int ruleset_fd)
>  		TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
>  	}
>  }
> +
> +static void setup_loopback(struct __test_metadata *const _metadata)
> +{
> +	set_cap(_metadata, CAP_SYS_ADMIN);
> +	ASSERT_EQ(0, unshare(CLONE_NEWNET));
> +	clear_cap(_metadata, CAP_SYS_ADMIN);
> +
> +	set_ambient_cap(_metadata, CAP_NET_ADMIN);
> +	ASSERT_EQ(0, system("ip link set dev lo up"));
> +	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
> +}
> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
> index f21cfbbc3638..0b8386657c72 100644
> --- a/tools/testing/selftests/landlock/net_test.c
> +++ b/tools/testing/selftests/landlock/net_test.c
> @@ -103,17 +103,6 @@ static int set_service(struct service_fixture *const srv,
>  	return 1;
>  }
>  
> -static void setup_loopback(struct __test_metadata *const _metadata)
> -{
> -	set_cap(_metadata, CAP_SYS_ADMIN);
> -	ASSERT_EQ(0, unshare(CLONE_NEWNET));
> -	clear_cap(_metadata, CAP_SYS_ADMIN);
> -
> -	set_ambient_cap(_metadata, CAP_NET_ADMIN);
> -	ASSERT_EQ(0, system("ip link set dev lo up"));
> -	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
> -}
> -
>  static bool is_restricted(const struct protocol_variant *const prot,
>  			  const enum sandbox_type sandbox)
>  {
> diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
> index 67db0e1c1121..2ab27196fa3d 100644
> --- a/tools/testing/selftests/landlock/socket_test.c
> +++ b/tools/testing/selftests/landlock/socket_test.c
> @@ -11,8 +11,11 @@
>  #include <linux/pfkeyv2.h>
>  #include <linux/kcm.h>
>  #include <linux/can.h>
> -#include <linux/in.h>
> +#include <sys/socket.h>
> +#include <stdint.h>
> +#include <linux/sctp.h>
>  #include <sys/prctl.h>
> +#include <arpa/inet.h>
>  
>  #include "common.h"
>  
> @@ -839,4 +842,101 @@ TEST_F(socket_creation, socketpair)
>  	}
>  }
>  
> +static const char loopback_ipv4[] = "127.0.0.1";
> +static const int backlog = 10;
> +static const int loopback_port = 1024;
> +
> +TEST_F(socket_creation, sctp_peeloff)
> +{
> +	int status, ret;
> +	pid_t child;
> +	struct sockaddr_in addr;
> +	int server_fd;
> +
> +	server_fd =
> +		socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC, IPPROTO_SCTP);
> +	ASSERT_LE(0, server_fd);
> +
> +	addr.sin_family = AF_INET;
> +	addr.sin_port = htons(loopback_port);
> +	addr.sin_addr.s_addr = inet_addr(loopback_ipv4);
> +
> +	ASSERT_EQ(0, bind(server_fd, &addr, sizeof(addr)));
> +	ASSERT_EQ(0, listen(server_fd, backlog));
> +
> +	child = fork();
> +	ASSERT_LE(0, child);
> +	if (child == 0) {
> +		int client_fd;
> +		sctp_peeloff_flags_arg_t peeloff;
> +		socklen_t peeloff_size = sizeof(peeloff);
> +		const struct landlock_ruleset_attr ruleset_attr = {
> +			.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
> +		};
> +		struct landlock_socket_attr sctp_socket_create = {
> +			.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
> +			.family = AF_INET,
> +			.type = SOCK_SEQPACKET,
> +		};
> +
> +		/* Closes listening socket for the child. */
> +		ASSERT_EQ(0, close(server_fd));
> +
> +		client_fd = socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC,
> +				   IPPROTO_SCTP);
> +		ASSERT_LE(0, client_fd);
> +
> +		/*
> +		 * Establishes connection between sockets and
> +		 * gets SCTP association id.
> +		 */
> +		ret = setsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_CONNECTX,
> +				 &addr, sizeof(addr));
> +		ASSERT_LE(0, ret);
> +
> +		if (self->sandboxed) {
> +			/* Denies creation of SCTP sockets. */
> +			int ruleset_fd = landlock_create_ruleset(
> +				&ruleset_attr, sizeof(ruleset_attr), 0);
> +			ASSERT_LE(0, ruleset_fd);
> +
> +			if (self->allowed) {
> +				ASSERT_EQ(0, landlock_add_rule(
> +						     ruleset_fd,
> +						     LANDLOCK_RULE_SOCKET,
> +						     &sctp_socket_create, 0));
> +			}
> +			enforce_ruleset(_metadata, ruleset_fd);
> +			ASSERT_EQ(0, close(ruleset_fd));
> +		}
> +		/*
> +		 * Branches off current SCTP association into a separate socket
> +		 * and returns it to user space.
> +		 */
> +		peeloff.p_arg.associd = ret;
> +		ret = getsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_PEELOFF,
> +				 &peeloff, &peeloff_size);
> +
> +		/*
> +		 * Creation of SCTP socket by branching off existing SCTP association
> +		 * should not be restricted by Landlock.
> +		 */
> +		EXPECT_LE(0, ret);
> +
> +		/* Closes peeloff socket if such was created. */
> +		if (!ret) {
> +			ASSERT_EQ(0, close(peeloff.p_arg.sd));
> +		}

Nit: Should this check for (ret >= 0) instead?

I imagine that getsockopt returns -1 on error, normally,
and that would make it past the EXPECT_LE (even if it logs a failure).


> +		ASSERT_EQ(0, close(client_fd));
> +		_exit(_metadata->exit_code);
> +		return;
> +	}
> +
> +	ASSERT_EQ(child, waitpid(child, &status, 0));
> +	ASSERT_EQ(1, WIFEXITED(status));
> +	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
> +
> +	ASSERT_EQ(0, close(server_fd));
> +}
> +
>  TEST_HARNESS_MAIN
> -- 
> 2.34.1
> 

Reviewed-by: Günther Noack <gnoack@google.com>
Mikhail Ivanov Oct. 3, 2024, 12:15 p.m. UTC | #2
On 9/27/2024 5:35 PM, Günther Noack wrote:
> On Wed, Sep 04, 2024 at 06:48:20PM +0800, Mikhail Ivanov wrote:
>> It is possible to branch off an SCTP UDP association into a separate
>> user space UDP socket. Add test validating that such scenario is not
>> restricted by Landlock.
>>
>> Move setup_loopback() helper from net_test to common.h to use it to
>> enable connection in this test.
>>
>> Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
>> ---
>>   tools/testing/selftests/landlock/common.h     |  12 +++
>>   tools/testing/selftests/landlock/net_test.c   |  11 --
>>   .../testing/selftests/landlock/socket_test.c  | 102 +++++++++++++++++-
>>   3 files changed, 113 insertions(+), 12 deletions(-)
>>
>> diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
>> index 28df49fa22d5..07d959a8ac7b 100644
>> --- a/tools/testing/selftests/landlock/common.h
>> +++ b/tools/testing/selftests/landlock/common.h
>> @@ -16,6 +16,7 @@
>>   #include <sys/types.h>
>>   #include <sys/wait.h>
>>   #include <unistd.h>
>> +#include <sched.h>
>>   
>>   #include "../kselftest_harness.h"
>>   
>> @@ -227,3 +228,14 @@ enforce_ruleset(struct __test_metadata *const _metadata, const int ruleset_fd)
>>   		TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
>>   	}
>>   }
>> +
>> +static void setup_loopback(struct __test_metadata *const _metadata)
>> +{
>> +	set_cap(_metadata, CAP_SYS_ADMIN);
>> +	ASSERT_EQ(0, unshare(CLONE_NEWNET));
>> +	clear_cap(_metadata, CAP_SYS_ADMIN);
>> +
>> +	set_ambient_cap(_metadata, CAP_NET_ADMIN);
>> +	ASSERT_EQ(0, system("ip link set dev lo up"));
>> +	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
>> +}
>> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
>> index f21cfbbc3638..0b8386657c72 100644
>> --- a/tools/testing/selftests/landlock/net_test.c
>> +++ b/tools/testing/selftests/landlock/net_test.c
>> @@ -103,17 +103,6 @@ static int set_service(struct service_fixture *const srv,
>>   	return 1;
>>   }
>>   
>> -static void setup_loopback(struct __test_metadata *const _metadata)
>> -{
>> -	set_cap(_metadata, CAP_SYS_ADMIN);
>> -	ASSERT_EQ(0, unshare(CLONE_NEWNET));
>> -	clear_cap(_metadata, CAP_SYS_ADMIN);
>> -
>> -	set_ambient_cap(_metadata, CAP_NET_ADMIN);
>> -	ASSERT_EQ(0, system("ip link set dev lo up"));
>> -	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
>> -}
>> -
>>   static bool is_restricted(const struct protocol_variant *const prot,
>>   			  const enum sandbox_type sandbox)
>>   {
>> diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
>> index 67db0e1c1121..2ab27196fa3d 100644
>> --- a/tools/testing/selftests/landlock/socket_test.c
>> +++ b/tools/testing/selftests/landlock/socket_test.c
>> @@ -11,8 +11,11 @@
>>   #include <linux/pfkeyv2.h>
>>   #include <linux/kcm.h>
>>   #include <linux/can.h>
>> -#include <linux/in.h>
>> +#include <sys/socket.h>
>> +#include <stdint.h>
>> +#include <linux/sctp.h>
>>   #include <sys/prctl.h>
>> +#include <arpa/inet.h>
>>   
>>   #include "common.h"
>>   
>> @@ -839,4 +842,101 @@ TEST_F(socket_creation, socketpair)
>>   	}
>>   }
>>   
>> +static const char loopback_ipv4[] = "127.0.0.1";
>> +static const int backlog = 10;
>> +static const int loopback_port = 1024;
>> +
>> +TEST_F(socket_creation, sctp_peeloff)
>> +{
>> +	int status, ret;
>> +	pid_t child;
>> +	struct sockaddr_in addr;
>> +	int server_fd;
>> +
>> +	server_fd =
>> +		socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC, IPPROTO_SCTP);
>> +	ASSERT_LE(0, server_fd);
>> +
>> +	addr.sin_family = AF_INET;
>> +	addr.sin_port = htons(loopback_port);
>> +	addr.sin_addr.s_addr = inet_addr(loopback_ipv4);
>> +
>> +	ASSERT_EQ(0, bind(server_fd, &addr, sizeof(addr)));
>> +	ASSERT_EQ(0, listen(server_fd, backlog));
>> +
>> +	child = fork();
>> +	ASSERT_LE(0, child);
>> +	if (child == 0) {
>> +		int client_fd;
>> +		sctp_peeloff_flags_arg_t peeloff;
>> +		socklen_t peeloff_size = sizeof(peeloff);
>> +		const struct landlock_ruleset_attr ruleset_attr = {
>> +			.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
>> +		};
>> +		struct landlock_socket_attr sctp_socket_create = {
>> +			.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
>> +			.family = AF_INET,
>> +			.type = SOCK_SEQPACKET,
>> +		};
>> +
>> +		/* Closes listening socket for the child. */
>> +		ASSERT_EQ(0, close(server_fd));
>> +
>> +		client_fd = socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC,
>> +				   IPPROTO_SCTP);
>> +		ASSERT_LE(0, client_fd);
>> +
>> +		/*
>> +		 * Establishes connection between sockets and
>> +		 * gets SCTP association id.
>> +		 */
>> +		ret = setsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_CONNECTX,
>> +				 &addr, sizeof(addr));
>> +		ASSERT_LE(0, ret);
>> +
>> +		if (self->sandboxed) {
>> +			/* Denies creation of SCTP sockets. */
>> +			int ruleset_fd = landlock_create_ruleset(
>> +				&ruleset_attr, sizeof(ruleset_attr), 0);
>> +			ASSERT_LE(0, ruleset_fd);
>> +
>> +			if (self->allowed) {
>> +				ASSERT_EQ(0, landlock_add_rule(
>> +						     ruleset_fd,
>> +						     LANDLOCK_RULE_SOCKET,
>> +						     &sctp_socket_create, 0));
>> +			}
>> +			enforce_ruleset(_metadata, ruleset_fd);
>> +			ASSERT_EQ(0, close(ruleset_fd));
>> +		}
>> +		/*
>> +		 * Branches off current SCTP association into a separate socket
>> +		 * and returns it to user space.
>> +		 */
>> +		peeloff.p_arg.associd = ret;
>> +		ret = getsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_PEELOFF,
>> +				 &peeloff, &peeloff_size);
>> +
>> +		/*
>> +		 * Creation of SCTP socket by branching off existing SCTP association
>> +		 * should not be restricted by Landlock.
>> +		 */
>> +		EXPECT_LE(0, ret);
>> +
>> +		/* Closes peeloff socket if such was created. */
>> +		if (!ret) {
>> +			ASSERT_EQ(0, close(peeloff.p_arg.sd));
>> +		}
> 
> Nit: Should this check for (ret >= 0) instead?

Ofc, thank you

> 
> I imagine that getsockopt returns -1 on error, normally,
> and that would make it past the EXPECT_LE (even if it logs a failure).
> 
> 
>> +		ASSERT_EQ(0, close(client_fd));
>> +		_exit(_metadata->exit_code);
>> +		return;
>> +	}
>> +
>> +	ASSERT_EQ(child, waitpid(child, &status, 0));
>> +	ASSERT_EQ(1, WIFEXITED(status));
>> +	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
>> +
>> +	ASSERT_EQ(0, close(server_fd));
>> +}
>> +
>>   TEST_HARNESS_MAIN
>> -- 
>> 2.34.1
>>
> 
> Reviewed-by: Günther Noack <gnoack@google.com>
diff mbox series

Patch

diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
index 28df49fa22d5..07d959a8ac7b 100644
--- a/tools/testing/selftests/landlock/common.h
+++ b/tools/testing/selftests/landlock/common.h
@@ -16,6 +16,7 @@ 
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#include <sched.h>
 
 #include "../kselftest_harness.h"
 
@@ -227,3 +228,14 @@  enforce_ruleset(struct __test_metadata *const _metadata, const int ruleset_fd)
 		TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
 	}
 }
+
+static void setup_loopback(struct __test_metadata *const _metadata)
+{
+	set_cap(_metadata, CAP_SYS_ADMIN);
+	ASSERT_EQ(0, unshare(CLONE_NEWNET));
+	clear_cap(_metadata, CAP_SYS_ADMIN);
+
+	set_ambient_cap(_metadata, CAP_NET_ADMIN);
+	ASSERT_EQ(0, system("ip link set dev lo up"));
+	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
+}
diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index f21cfbbc3638..0b8386657c72 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -103,17 +103,6 @@  static int set_service(struct service_fixture *const srv,
 	return 1;
 }
 
-static void setup_loopback(struct __test_metadata *const _metadata)
-{
-	set_cap(_metadata, CAP_SYS_ADMIN);
-	ASSERT_EQ(0, unshare(CLONE_NEWNET));
-	clear_cap(_metadata, CAP_SYS_ADMIN);
-
-	set_ambient_cap(_metadata, CAP_NET_ADMIN);
-	ASSERT_EQ(0, system("ip link set dev lo up"));
-	clear_ambient_cap(_metadata, CAP_NET_ADMIN);
-}
-
 static bool is_restricted(const struct protocol_variant *const prot,
 			  const enum sandbox_type sandbox)
 {
diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
index 67db0e1c1121..2ab27196fa3d 100644
--- a/tools/testing/selftests/landlock/socket_test.c
+++ b/tools/testing/selftests/landlock/socket_test.c
@@ -11,8 +11,11 @@ 
 #include <linux/pfkeyv2.h>
 #include <linux/kcm.h>
 #include <linux/can.h>
-#include <linux/in.h>
+#include <sys/socket.h>
+#include <stdint.h>
+#include <linux/sctp.h>
 #include <sys/prctl.h>
+#include <arpa/inet.h>
 
 #include "common.h"
 
@@ -839,4 +842,101 @@  TEST_F(socket_creation, socketpair)
 	}
 }
 
+static const char loopback_ipv4[] = "127.0.0.1";
+static const int backlog = 10;
+static const int loopback_port = 1024;
+
+TEST_F(socket_creation, sctp_peeloff)
+{
+	int status, ret;
+	pid_t child;
+	struct sockaddr_in addr;
+	int server_fd;
+
+	server_fd =
+		socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC, IPPROTO_SCTP);
+	ASSERT_LE(0, server_fd);
+
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(loopback_port);
+	addr.sin_addr.s_addr = inet_addr(loopback_ipv4);
+
+	ASSERT_EQ(0, bind(server_fd, &addr, sizeof(addr)));
+	ASSERT_EQ(0, listen(server_fd, backlog));
+
+	child = fork();
+	ASSERT_LE(0, child);
+	if (child == 0) {
+		int client_fd;
+		sctp_peeloff_flags_arg_t peeloff;
+		socklen_t peeloff_size = sizeof(peeloff);
+		const struct landlock_ruleset_attr ruleset_attr = {
+			.handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
+		};
+		struct landlock_socket_attr sctp_socket_create = {
+			.allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
+			.family = AF_INET,
+			.type = SOCK_SEQPACKET,
+		};
+
+		/* Closes listening socket for the child. */
+		ASSERT_EQ(0, close(server_fd));
+
+		client_fd = socket(AF_INET, SOCK_SEQPACKET | SOCK_CLOEXEC,
+				   IPPROTO_SCTP);
+		ASSERT_LE(0, client_fd);
+
+		/*
+		 * Establishes connection between sockets and
+		 * gets SCTP association id.
+		 */
+		ret = setsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_CONNECTX,
+				 &addr, sizeof(addr));
+		ASSERT_LE(0, ret);
+
+		if (self->sandboxed) {
+			/* Denies creation of SCTP sockets. */
+			int ruleset_fd = landlock_create_ruleset(
+				&ruleset_attr, sizeof(ruleset_attr), 0);
+			ASSERT_LE(0, ruleset_fd);
+
+			if (self->allowed) {
+				ASSERT_EQ(0, landlock_add_rule(
+						     ruleset_fd,
+						     LANDLOCK_RULE_SOCKET,
+						     &sctp_socket_create, 0));
+			}
+			enforce_ruleset(_metadata, ruleset_fd);
+			ASSERT_EQ(0, close(ruleset_fd));
+		}
+		/*
+		 * Branches off current SCTP association into a separate socket
+		 * and returns it to user space.
+		 */
+		peeloff.p_arg.associd = ret;
+		ret = getsockopt(client_fd, IPPROTO_SCTP, SCTP_SOCKOPT_PEELOFF,
+				 &peeloff, &peeloff_size);
+
+		/*
+		 * Creation of SCTP socket by branching off existing SCTP association
+		 * should not be restricted by Landlock.
+		 */
+		EXPECT_LE(0, ret);
+
+		/* Closes peeloff socket if such was created. */
+		if (!ret) {
+			ASSERT_EQ(0, close(peeloff.p_arg.sd));
+		}
+		ASSERT_EQ(0, close(client_fd));
+		_exit(_metadata->exit_code);
+		return;
+	}
+
+	ASSERT_EQ(child, waitpid(child, &status, 0));
+	ASSERT_EQ(1, WIFEXITED(status));
+	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
+
+	ASSERT_EQ(0, close(server_fd));
+}
+
 TEST_HARNESS_MAIN