Hi Dmitry,
I just found the patch set has been merged. Sorry for the noise of tested-by replies. Please feel free to ignore the question for unsigned-md5_ipv6. The test passed with 6.7.0-rc5.
Thanks Hangbin
On Fri, Dec 15, 2023 at 02:36:14AM +0000, Dmitry Safonov wrote:
Hi,
An essential part of any big kernel submissions is selftests. At the beginning of TCP-AO project, I made patches to fcnal-test.sh and nettest.c to have the benefits of easy refactoring, early noticing breakages, putting a moat around the code, documenting and designing uAPI.
While tests based on fcnal-test.sh/nettest.c provided initial testing* and were very easy to add, the pile of TCP-AO quickly grew out of one-binary + shell-script testing.
The design of the TCP-AO testing is a bit different than one-big selftest binary as I did previously in net/ipsec.c. I found it beneficial to avoid implementing a tests runner/scheduler and delegate it to the user or Makefile. The approach is very influenced by CRIU/ZDTM testing[1]: it provides a static library with helper functions and selftest binaries that create specific scenarios. I also tried to utilize kselftest.h.
test_init() function does all needed preparations. To not leave any traces after a selftest exists, it creates a network namespace and if the test wants to establish a TCP connection, a child netns. The parent and child netns have veth pair with proper ip addresses and routes set up. Both peers, the client and server are different pthreads. The treading model was chosen over forking mostly by easiness of cleanup on a failure: no need to search for children, handle SIGCHLD, make sure not to wait for a dead peer to perform anything, etc. Any thread that does exit() naturally kills the tests, sweet! The selftests are compiled currently in two variants: ipv4 and ipv6. Ipv4-mapped-ipv6 addresses might be a third variant to add, but it's not there in this version. As pretty much all tests are shared between two address families, most of the code can be shared, too. To differ in code what kind of test is running, Makefile supplies -DIPV6_TEST to compiler and ifdeffery in tests can do things that have to be different between address families. This is similar to TARGETS_C_BOTHBITS in x86 selftests and also to tests code sharing in CRIU/ZDTM.
The total number of tests is 832. From them rst_ipv{4,6} has currently one flaky subtest, that may fail:
not ok 9 client connection was not reset: 0
I'll investigate what happens there. Also, unsigned-md5_ipv{4,6} are flaky because of netns counter checks: it doesn't expect that there may be retransmitted TCP segments from a previous sub-selftest. That will be fixed. Besides, key-management_ipv{4,6} has 3 sub-tests passing with XFAIL:
ok 15 # XFAIL listen() after current/rnext keys set: the socket has current/rnext keys: 100:200 ok 16 # XFAIL listen socket, delete current key from before listen(): failed to delete the key 100:100 -16 ok 17 # XFAIL listen socket, delete rnext key from before listen(): failed to delete the key 200:200 -16
...
# Totals: pass:117 fail:0 xfail:3 xpass:0 skip:0 error:0
Those need some more kernel work to pass instead of xfail.
The overview of selftests (see the diffstat at the bottom): ├── lib │ ├── aolib.h │ │ The header for all selftests to include. │ ├── kconfig.c │ │ Kernel kconfig detector to SKIP tests that depend on something. │ ├── netlink.c │ │ Netlink helper to add/modify/delete VETH/IPs/routes/VRFs │ │ I considered just using libmnl, but this is around 400 lines │ │ and avoids selftests dependency on out-of-tree sources/packets. │ ├── proc.c │ │ SNMP/netstat procfs parser and the counters comparator. │ ├── repair.c │ │ Heavily influenced by libsoccr and reduced to minimum TCP │ │ socket checkpoint/repair. Shouldn't be used out of selftests, │ │ though. │ ├── setup.c │ │ All the needed netns/veth/ips/etc preparations for test init. │ ├── sock.c │ │ Socket helpers: {s,g}etsockopt()s/connect()/listen()/etc. │ └── utils.c │ Random stuff (a pun intended). ├── bench-lookups.c │ The only benchmark in selftests currently: checks how well TCP-AO │ setsockopt()s perform, depending on the amount of keys on a socket. ├── connect.c │ Trivial sample, can be used as a boilerplate to write a new test. ├── connect-deny.c │ More-or-less what could be expected for TCP-AO in fcnal-test.sh ├── icmps-accept.c -> icmps-discard.c ├── icmps-discard.c │ Verifies RFC5925 (7.8) by checking that TCP-AO connection can be │ broken if ICMPs are accepted and survives when ::accept_icmps = 0 ├── key-management.c │ Key manipulations, rotations between randomized hashing algorithms │ and counter checks for those scenarios. ├── restore.c │ TCP_AO_REPAIR: verifies that a socket can be re-created without │ TCP-AO connection being interrupted. ├── rst.c │ As RST segments are signed on a separate code-path in kernel, │ verifies passive/active TCP send_reset(). ├── self-connect.c │ Verifies that TCP self-connect and also simultaneous open work. ├── seq-ext.c │ Utilizes TCP_AO_REPAIR to check that on SEQ roll-over SNE │ increment is performed and segments with different SNEs fail to │ pass verification. ├── setsockopt-closed.c │ Checks that {s,g}etsockopt()s are extendable syscalls and common │ error-paths for them. └── unsigned-md5.c Checks listen() socket for (non-)matching peers with: AO/MD5/none keys. As well as their interaction with VRFs and AO_REQUIRED flag.
There are certainly more test scenarios that can be added, but even so, I'm pretty happy that this much of TCP-AO functionality and uAPIs got covered. These selftests were iteratively developed by me during TCP-AO kernel upstreaming and the resulting kernel patches would have been worse without having these tests. They provided the user-side perspective but also allowed safer refactoring with less possibility of introducing a regression. Now it's time to use them to dig a moat around the TCP-AO code!
There are also people from other network companies that work on TCP-AO (+testing), so sharing these selftests will allow them to contribute and may benefit from their efforts.
The following changes since commit c7402612e2e61b76177f22e6e7f705adcbecc6fe:
Merge tag 'net-6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (2023-12-14 13:11:49 -0800)
are available in the Git repository at:
git@github.com:0x7f454c46/linux.git tcp-ao-selftests-v1
for you to fetch changes up to 85dc9bc676985d81f9043fd9c3a506f30851597b:
selftests/net: Add TCP-AO key-management test (2023-12-15 00:44:49 +0000)
- Planning to submit basic TCP-AO tests to fcnal-test.sh/nettest.c separately.
Signed-off-by: Dmitry Safonov dima@arista.com
Dmitry Safonov (12): selftests/net: Add TCP-AO library selftests/net: Verify that TCP-AO complies with ignoring ICMPs selftests/net: Add TCP-AO ICMPs accept test selftests/net: Add a test for TCP-AO keys matching selftests/net: Add test for TCP-AO add setsockopt() command selftests/net: Add TCP-AO + TCP-MD5 + no sign listen socket tests selftests/net: Add test/benchmark for removing MKTs selftests/net: Add TCP_REPAIR TCP-AO tests selftests/net: Add SEQ number extension test selftests/net: Add TCP-AO RST test selftests/net: Add TCP-AO selfconnect/simultaneous connect test selftests/net: Add TCP-AO key-management test
tools/testing/selftests/Makefile | 1 + tools/testing/selftests/net/tcp_ao/.gitignore | 2 + tools/testing/selftests/net/tcp_ao/Makefile | 59 + tools/testing/selftests/net/tcp_ao/bench-lookups.c | 358 ++++++ tools/testing/selftests/net/tcp_ao/connect-deny.c | 264 +++++ tools/testing/selftests/net/tcp_ao/connect.c | 90 ++ tools/testing/selftests/net/tcp_ao/icmps-accept.c | 1 + tools/testing/selftests/net/tcp_ao/icmps-discard.c | 449 ++++++++ .../testing/selftests/net/tcp_ao/key-management.c | 1180 ++++++++++++++++++++ tools/testing/selftests/net/tcp_ao/lib/aolib.h | 605 ++++++++++ tools/testing/selftests/net/tcp_ao/lib/kconfig.c | 148 +++ tools/testing/selftests/net/tcp_ao/lib/netlink.c | 415 +++++++ tools/testing/selftests/net/tcp_ao/lib/proc.c | 273 +++++ tools/testing/selftests/net/tcp_ao/lib/repair.c | 254 +++++ tools/testing/selftests/net/tcp_ao/lib/setup.c | 342 ++++++ tools/testing/selftests/net/tcp_ao/lib/sock.c | 592 ++++++++++ tools/testing/selftests/net/tcp_ao/lib/utils.c | 30 + tools/testing/selftests/net/tcp_ao/restore.c | 236 ++++ tools/testing/selftests/net/tcp_ao/rst.c | 415 +++++++ tools/testing/selftests/net/tcp_ao/self-connect.c | 197 ++++ tools/testing/selftests/net/tcp_ao/seq-ext.c | 245 ++++ .../selftests/net/tcp_ao/setsockopt-closed.c | 835 ++++++++++++++ tools/testing/selftests/net/tcp_ao/unsigned-md5.c | 742 ++++++++++++ 23 files changed, 7733 insertions(+)
base-commit: c7402612e2e61b76177f22e6e7f705adcbecc6fe change-id: 20231213-tcp-ao-selftests-d0f323006667
Best regards,
Dmitry Safonov dima@arista.com