On Mon, Oct 23, 2023 at 10:09:54AM +0300, Konstantin Meskhidze (A) wrote: > > > 10/20/2023 6:40 PM, Mickaël Salaün пишет: > > On Fri, Oct 20, 2023 at 02:41:42PM +0300, Konstantin Meskhidze (A) wrote: > > > > > > > > > 10/18/2023 3:32 PM, Mickaël Salaün пишет: > > > > You can update the subject with: > > > > "selftests/landlock: Add network tests" > > > > > > Ok. > > > > > On Mon, Oct 16, 2023 at 09:50:28AM +0800, Konstantin Meskhidze > > > wrote: > > > > > These test suites try to check edge cases for TCP sockets > > > > > bind() and connect() actions. > > > > > You can replace with that: > > > > Add 77 test suites to check edge cases related to bind() and connect() > > > > actions. They are defined with 6 fixtures and their variants: > > > > > > > > protocol: > > > > > * bind: Tests with non-landlocked/landlocked ipv4, ipv6 and unix sockets. > > > > > As you already did, you can write one paragraph per fixture, but > > > > starting by explaining the fixture and its related variants, and then > > > > listing the tests and explaining their specificities. For instance: > > > > > The "protocol" fixture is extended with 12 variants defined as a > > > matrix > > > > of: sandboxed/not-sandboxed, IPv4/IPv6/unix network domain, and > > > > stream/datagram socket. 4 related tests suites are defined: > > > > * bind: Test bind combinations with increasingly more > > > > restricting domains. > > > > * connect: Test connect combinations with increasingly more > > > > restricting domains. > > > > ... > > > > > > Ok. Will be updated. > > > > > s/ipv/IPv/g > > > > > > Got it. Thanks. > > > > > > * connect: Tests with non-landlocked/landlocked ipv4, ipv6 and > > > unix > > > > > sockets. > > > > > * bind_unspec: Tests with non-landlocked/landlocked restrictions > > > > > for bind action with AF_UNSPEC socket family. > > > > > * connect_unspec: Tests with non-landlocked/landlocked restrictions > > > > > for connect action with AF_UNSPEC socket family. > > > > > > > ipv4: > > > > > * from_unix_to_inet: Tests to make sure unix sockets' actions are not > > > > > restricted by Landlock rules applied to TCP ones. > > > > > > > tcp_layers: > > > > > * ruleset_overlap. > > > > > * ruleset_expand. > > > > > > > mini: > > > > > * network_access_rights: Tests with legitimate access values. > > > > > * unknown_access_rights: Tests with invalid attributes, out of access range. > > > > > * inval: > > > > > - unhandled allowed access. > > > > > - zero access value. > > > > > * tcp_port_overflow: Tests with wrong port values more than U16_MAX. > > > > > > > ipv4_tcp: > > > > > * port_endianness: Tests with big/little endian port formats. > > > > > > > port_specific: > > > > > * bind_connect: Tests with specific port values. > > > > > > > layout1: > > > > > * with_net: Tests with network bind() socket action within > > > > > filesystem directory access test. > > > > > > > Test coverage for security/landlock is 94.5% of 932 lines > > > according > > > > > to gcc/gcov-11. > > > > > > > Signed-off-by: Konstantin Meskhidze > > > <konstantin.meskhidze@xxxxxxxxxx> > > > > > Link: https://lore.kernel.org/r/20230920092641.832134-11-konstantin.meskhidze@xxxxxxxxxx > > > > > Co-developed-by:: Mickaël Salaün <mic@xxxxxxxxxxx> > > > > > Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> > > > > > --- > > > > > > > Changes since v12: > > > > > * Renames port_zero to port_specific fixture. > > > > > * Refactors port_specific test: > > > > > - Adds set_port() and get_binded_port() helpers. > > > > > - Adds checks for port 0, allowed by Landlock in this version. > > > > > - Adds checks for port 1023. > > > > > * Refactors commit message. > > > > > > > > +static void set_port(struct service_fixture *const srv, > > > in_port_t port) > > > > > +{ > > > > > + switch (srv->protocol.domain) { > > > > > + case AF_UNSPEC: > > > > > + case AF_INET: > > > > > + srv->ipv4_addr.sin_port = port; > > > > > We should call htons() here, and make port a uint16_t. > > > > > > Done. > > > > > > + return; > > > > > + > > > > > + case AF_INET6: > > > > > + srv->ipv6_addr.sin6_port = port; > > > > > + return; > > > > > + > > > > > + default: > > > > > + return; > > > > > + } > > > > > +} > > > > > + > > > > > +static in_port_t get_binded_port(int socket_fd, > > > > > The returned type should be uint16_t (i.e. host endianess). > > > > > > Done. > > > > > > + const struct protocol_variant *const prot) > > > > > +{ > > > > > + struct sockaddr_in ipv4_addr; > > > > > + struct sockaddr_in6 ipv6_addr; > > > > > + socklen_t ipv4_addr_len, ipv6_addr_len; > > > > > + > > > > > + /* Gets binded port. */ > > > > > + switch (prot->domain) { > > > > > + case AF_UNSPEC: > > > > > + case AF_INET: > > > > > + ipv4_addr_len = sizeof(ipv4_addr); > > > > > + getsockname(socket_fd, &ipv4_addr, &ipv4_addr_len); > > > > > + return ntohs(ipv4_addr.sin_port); > > > > > + > > > > > + case AF_INET6: > > > > > + ipv6_addr_len = sizeof(ipv6_addr); > > > > > + getsockname(socket_fd, &ipv6_addr, &ipv6_addr_len); > > > > > + return ntohs(ipv6_addr.sin6_port); > > > > > + > > > > > + default: > > > > > + return 0; > > > > > + } > > > > > +} > > > > > These are good helpers! > > > > > > > +FIXTURE_TEARDOWN(ipv4) > > > > > +{ > > > > > +} > > > > > + > > > > > +// Kernel FIXME: tcp_sandbox_with_tcp and tcp_sandbox_with_udp > > > > > No FIXME should remain. > > > > > > Ok. Deleted. > > > > > > +TEST_F(ipv4, from_unix_to_inet) > > > > > > +TEST_F(mini, network_access_rights) > > > > > +{ > > > > > + const struct landlock_ruleset_attr ruleset_attr = { > > > > > + .handled_access_net = ACCESS_ALL, > > > > > + }; > > > > > + struct landlock_net_port_attr net_service = { > > > > > Please rename to "net_port" everywhere. > > > > > > Done. > > > > > > +TEST_F(port_specific, bind_connect) > > > > > +{ > > > > > + int socket_fd, ret; > > > > > + > > > > > + /* Adds the first rule layer with bind and connect actions. */ > > > > > + if (variant->sandbox == TCP_SANDBOX) { > > > > > + const struct landlock_ruleset_attr ruleset_attr = { > > > > > + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP | > > > > > + LANDLOCK_ACCESS_NET_CONNECT_TCP > > > > > + }; > > > > > + const struct landlock_net_port_attr tcp_bind_connect_zero = { > > > > > + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP | > > > > > + LANDLOCK_ACCESS_NET_CONNECT_TCP, > > > > > + .port = htons(0), > > > > > We don't need any htons() calls anymore. It doesn't change the 0 > > > value > > > > in this case but this is not correct. > > > > > > Yep. We call htons(port) in landlock_append_net_rule(). > > > Thanks. > > > > > > + }; > > > > > + > > > > > Useless new line. > > > > > > Ok. Thanks. > > > > > > + int ruleset_fd; > > > > > + > > > > > + ruleset_fd = landlock_create_ruleset(&ruleset_attr, > > > > > + sizeof(ruleset_attr), 0); > > > > > + ASSERT_LE(0, ruleset_fd); > > > > > + > > > > > + /* Checks zero port value on bind and connect actions. */ > > > > > + EXPECT_EQ(0, > > > > > + landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT, > > > > > + &tcp_bind_connect_zero, 0)); > > > > > + > > > > > + enforce_ruleset(_metadata, ruleset_fd); > > > > > + EXPECT_EQ(0, close(ruleset_fd)); > > > > > + } > > > > > + > > > > > + socket_fd = socket_variant(&self->srv0); > > > > > + ASSERT_LE(0, socket_fd); > > > > > + > > > > > + /* Sets address port to 0 for both protocol families. */ > > > > > + set_port(&self->srv0, htons(0)); > > > > > ditto > > > > > > + > > > > > + /* Binds on port 0. */ > > > > > + ret = bind_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > + } else { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > If the results are the same, no need to add an if block. > > > > > > Right. Updated. > > > > > > + } > > > > > + > > > > > + /* Connects on port 0. */ > > > > > + ret = connect_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + EXPECT_EQ(-ECONNREFUSED, ret); > > > > > + } else { > > > > > + EXPECT_EQ(-ECONNREFUSED, ret); > > > > > + } > > > > > ditto > > > > Updated. > > > > > + > > > > > + /* Binds on port 0. */ > > > > > Please close sockets once they are used, and recreate one for > > > another > > > > bind/connect to avoid wrong checks. > > > > > > Ok. But I can reuse socket_fd after closeing a socket. Correct? > > > > It would be clearer to have one variable for the client socket > > (connect_fd) and another variable for the server socket (bind_fd). > > But once the socket is closed, you can reuse the same variable by > > storing a new socket in it. You then only need two variables for sockets > > in this test. > > Ok. Thanks. > > > > > > > > + ret = bind_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > + } else { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > + } > > > > > Why this second bind() block? Furthermore, it is using the same > > > > socket_fd. > > > > Is this block useful? > > For a self-connected socket after connection try we need to rebind it > again. I checked this logic in a small standalone test (with gdb on). So for > 2 sockets (differnt fds) there is no need to do that. > > > > > > > > I will refactor the code this way - sockets will be recreated for each > > > bind/connect, and I prefer to use self-connected sockets (use one socket > > > descriptor) in these tests to make code simpler; testing logic remains the > > > same way as if we have 2 sockets. > > > > > > What do you think??? > > > > I find it confusing to use self-connected sockets, it's not clear at all > > what is going on, and AFAIK it doesn't reflect real use cases. Please > > don't do that. > > > > Using the same variable for both bind and connect socket will lead to > > issues difficult to debug, and leaked FDs. For instance with the bind + > > get_binded_port + connect test you should use one variable per socket. > > To make it easier to read, please follow this rule everywhere (the only > > case when this is done seems to be with the port_specific.bind_connect > > test). > > OK. I will use 2 fds for bind and connect sockets. > > > > > > > > > > > + > > > > > + /* Sets binded port for both protocol families. */ > > > > > + set_port(&self->srv0, > > > > > + htons(get_binded_port(socket_fd, &variant->prot))); > > > > > Ditto, these two endianess translations are useless. > > > > > > Updated. Thanks. > > > > > You can also add this to make sure the returned port is not 0: > > > > port = get_binded_port(socket_fd, &variant->prot); > > > > EXPECT_NE(0, port); > > > > set_port(&self->srv0, port); > > > > > > Ok. Thanks for the tip. > > > > > > + > > > > > + /* Connects on the binded port. */ > > > > > + ret = connect_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + /* Denied by Landlock. */ > > > > > + EXPECT_EQ(-EACCES, ret); > > > > > + } else { > > > > > + EXPECT_EQ(0, ret); > > > > > + } > > > > > + > > > > > + EXPECT_EQ(0, close(socket_fd)); > > > > > + > > > > > > > > + /* Adds the second rule layer with just bind action. */ > > > > > There is not only bind actions here. > > > > > > Right. > > > > > This second part of the tests should be in a dedicated > > > > TEST_F(port_specific, bind_1023). > > > > > > Got it. > > > > > > + if (variant->sandbox == TCP_SANDBOX) { > > > > > + const struct landlock_ruleset_attr ruleset_attr = { > > > > > + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP | > > > > > + LANDLOCK_ACCESS_NET_CONNECT_TCP > > > > > + }; > > > > > + > > > > > + const struct landlock_net_port_attr tcp_bind_zero = { > > > > > + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP, > > > > > + .port = htons(0), > > > > > + }; > > > > > + > > > > > Useless new lines. > > > > > > Got it. > > > > > > + /* A rule with port value less than 1024. */ > > > > > + const struct landlock_net_port_attr tcp_bind_lower_range = { > > > > > + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP, > > > > > + .port = htons(1023), > > > > > + }; > > > > > + > > > > > Useless new line. > > > > > > Got it. > > > > > > + int ruleset_fd; > > > > > + > > > > > + ruleset_fd = landlock_create_ruleset(&ruleset_attr, > > > > > + sizeof(ruleset_attr), 0); > > > > > + ASSERT_LE(0, ruleset_fd); > > > > > + > > > > > + ASSERT_EQ(0, > > > > > + landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT, > > > > > + &tcp_bind_lower_range, 0)); > > > > > + ASSERT_EQ(0, > > > > > + landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT, > > > > > + &tcp_bind_zero, 0)); > > > > > + > > > > > + enforce_ruleset(_metadata, ruleset_fd); > > > > > + EXPECT_EQ(0, close(ruleset_fd)); > > > > > + } > > > > > + > > > > > + socket_fd = socket_variant(&self->srv0); > > > > > We must have one socket FD dedicated to bind an another > > > dedicated to > > > > connect, e.g. bind_fd and connect_fd, an close them after each use, > > > > otherwise tests might be inconsistent. > > > > > > Why can't we use self-connected sockets here? Why tests might be > > > inconsistent? Tests will be working the same way as if we have 2 sockets, > > > plus the code is simpler. > > > > AFAIK it doesn't reflect real use cases of sockets, and I find it really > > confusing. Where did you see this kind of usage? > > > > Test might be inconsistent for instance if you change the port from 1023 > > to 1024 and you adjust the (denied by system) EXPECT_EQ(-EACCES, ret), > > you'll get a new error in the following block, which doesn't make sense > > at first, but then you realize it is because the socket is already > > binded. To avoid this kind of issues, and avoid leaking FDs, please use > > a socket per usage and close them before testing something else. > > Ok. Got it. > > > > > > > > + ASSERT_LE(0, socket_fd); > > > > > + > > > > > + /* Sets address port to 1023 for both protocol families. */ > > > > > + set_port(&self->srv0, htons(1023)); > > > > > + > > > > > + /* Binds on port 1023. */ > > > > > + ret = bind_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > No need to add this check if the result is the same for > > > sandboxed and > > > > not sandboxed tests. > > > > > > Ok. Thanks. > > > > > Instead, use set_cap(_metadata, CAP_NET_BIND_SERVICE) and > > > clear_cap() > > > > around this bind_variant() to make this test useful. > > > > > You will also need to patch common.h like this: > > > > @@ -112,10 +112,13 @@ static void _init_caps(struct __test_metadata *const _metadata, bool drop_all) > > > > cap_t cap_p; > > > > /* Only these three capabilities are useful for the tests. */ > > > > const cap_value_t caps[] = { > > > > + /* clang-format off */ > > > > CAP_DAC_OVERRIDE, > > > > CAP_MKNOD, > > > > CAP_SYS_ADMIN, > > > > CAP_SYS_CHROOT, > > > > + CAP_NET_BIND_SERVICE, > > > > + /* clang-format on */ > > > > }; > > > > > > OK. Thanks. > > > > > > + /* Denied by the system. */ > > > > > + EXPECT_EQ(-EACCES, ret); > > > > > + } else { > > > > > + /* Denied by the system. */ > > > > > + EXPECT_EQ(-EACCES, ret); > > > > > + } > > > > > + > > > > > I don't see why the following part is useful. Why did you add > > > it? > > > Binding to ports < 1024 are forbidden by the system, not by Landlock. > > > I added a rule with port 1023 to make sure it works as expected. > > > > Landlock, as any LSM, can only add more restrictions. That's why it > > would make more sense to test with CAP_NET_BIND_SERVICE, to make sure > > Landlock rules work the same with this kind of privileged ports, but you > > can test both cases (all within the same TEST_F though, and without > > other tests). > > Do you mean during the test to set CAP_NET_BIND_SERVICE, check it with > landlock (it will success), then switch CAP_NET_BIND_SERVICE cap off and > bind it again ( will be refused by the system)? > Am I correct? Yes, you can use something like this: set_cap(_metadata, CAP_NET_BIND_SERVICE); ret = bind_variant(socket_fd, &self->srv0); clear_cap(_metadata, CAP_NET_BIND_SERVICE); > > > > > > > > > Why tcp_bind_zero? > > > Beacause it's a bind action with port zero rule. > > > > Yes but I don't see why it's relevant to test that here, because it was > > tested just before. > > > OK. I just leave binding to 1023 port here. > I'm thinking to add binding to 1024 port then to show that this port is > allowed by the system but denied by landlock ( we have just rule with 1023 > port). > What do you think? Yes, you can do that. I guess you could use test_bind_and_connect() for this test. You can group these checks (ports 1023 and 1024) in the same dedicated TEST_F. > > > > > > > > The other parts are good though! > > > > > > + /* Sets address port to 0 for both protocol families. */ > > > > > + set_port(&self->srv0, htons(0)); > > > > > + > > > > > + /* Binds on port 0. */ > > > > > + ret = bind_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > + } else { > > > > > + /* Binds to a random port within ip_local_port_range. */ > > > > > + EXPECT_EQ(0, ret); > > > > > + } > > > > > + > > > > > + /* Sets binded port for both protocol families. */ > > > > > + set_port(&self->srv0, > > > > > + htons(get_binded_port(socket_fd, &variant->prot))); > > > > > + > > > > > + /* Connects on the binded port. */ > > > > > + ret = connect_variant(socket_fd, &self->srv0); > > > > > + if (is_restricted(&variant->prot, variant->sandbox)) { > > > > > + /* Denied by Landlock. */ > > > > > + EXPECT_EQ(-EACCES, ret); > > > > > + } else { > > > > > + EXPECT_EQ(0, ret); > > > > > + } > > > > > + > > > > > + EXPECT_EQ(0, close(socket_fd)); > > > > > +} > > > > > + > > > > > +TEST_HARNESS_MAIN > > > > > -- > > > > > 2.25.1 > > > > > > . > > .
