On Sat, Aug 12, 2023 at 05:37:00PM +0300, Konstantin Meskhidze (A) wrote: > > > 7/12/2023 10:02 AM, Mickaël Salaün пишет: > > > > On 06/07/2023 16:55, Mickaël Salaün wrote: > > > From: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx> > > > > > > This patch is a revamp of the v11 tests [1] with new tests (see the > > > "Changes since v11" description). I (Mickaël) only added the following > > > todo list and the "Changes since v11" sections in this commit message. > > > I think this patch is good but it would appreciate reviews. > > > You can find the diff of my changes here but it is not really readable: > > > https://git.kernel.org/mic/c/78edf722fba5 (landlock-net-v11 branch) > > > [1] https://lore.kernel.org/all/20230515161339.631577-11-konstantin.meskhidze@xxxxxxxxxx/ > > > TODO: > > > - Rename all "net_service" to "net_port". > > > - Fix the two kernel bugs found with the new tests. > > > - Update this commit message with a small description of all tests. > > > > [...] > > We should also add a test to make sure errno is the same with and > > without sandboxing when using port 0 for connect and consistent with > > bind (using an available port). The test fixture and variants should be > > quite similar to the "ipv4" ones, but we can also add AF_INET6 variants, > > which will result in 8 "ip" variants: > > > > TEST_F(ip, port_zero) > > { > > if (variant->sandbox == TCP_SANDBOX) { > > /* Denies any connect and bind. */ > > } > > /* Checks errno for port 0. */ > > } > As I understand the would be the next test cases: > > 1. ip4, sandboxed, bind port 0 -> should return EACCES (denied by > landlock). Without any allowed port, yes. This test case is useful. By tuning /proc/sys/net/ipv4/ip_local_port_range (see inet_csk_find_open_port call) we should be able to pick a specific allowed port and test it. We can also test for the EADDRINUSE error to make sure error ordering is correct (compared with -EACCES). However, I think the current LSM API don't enable to infer this random port because the LSM hook is called before a port is picked. If this is correct, the best way to control port binding would be to always deny binding on port zero/random (when restricting port binding, whatever exception rules are in place). This explanation should be part of a comment for this specific exception. Cc Paul > 2. ip4, non-sandboxed, bind port 0 -> should return 0 (should be bounded to > random port). I think so but we need to make sure the random port cannot be < 1024, I guess with /proc/sys/net/ipv4/ip_local_port_range but I don't know for IPv6. > 3. ip6, sandboxed, bind port 0 -> should return EACCES (denied by > landlock). > 4. ip6, non-sandboxed, bind port 0 -> should return 0 (should be bounded to > random port). > 5. ip4, sandboxed, bind some available port, connect port 0 -> should > return -EACCES (denied by landlock). Yes, but don't need to bind to anything (same for the next ones). > 6. ip4, non-sandboxed, bind some available port, connect port 0 -> should > return ECONNREFUSED. Yes, but without any binding. > 7. ip6, sandboxed, bind some available port, connect port 0 -> should > return -EACCES (denied by landlock) > 8. ip6, non-sandboxed, some bind available port, connect port 0 -> should > return ECONNREFUSED. > > Correct? Thinking more about this case, being able to add a rule with port zero *for a connect action* looks legitimate. A rule with both connect and bind actions on port zero should then be denied. We should fix add_rule_net_service() and test that (with a first layer allowing port zero, and a second without rule, for connect). > > > > > [...] > > > > > +FIXTURE(inet) > > > +{ > > > + struct service_fixture srv0, srv1; > > > +}; > > > > The "inet" variants are useless and should be removed. The "inet" > > fixture can then be renamed to "ipv4_tcp". > > > So inet should be changed to ipv4_tcp and ipv6_tcp with next variants: > > - ipv4_tcp.no_sandbox_with_ipv4.port_endianness > - ipv4_tcp.sandbox_with_ipv4.port_endianness > - ipv6_tcp.no_sandbox_with_ipv6.port_endianness > - ipv6_tcp.sandbox_with_ipv6.port_endianness > ???? > > in this case we need double copy of TEST_F(inet, port_endianness) : > TEST_F(ipv4_tcp, port_endianness) > TEST_F(ipv6_tcp, port_endianness) There is no need for any variant for the port_endianness test. You can rename "inet" to "ipv4_tcp" (and not "inet_tcp" like I said before).
