linux/tools/testing/selftests/net, branch v6.17

selftests: fib_nexthops: Add test cases for FDB status change

2025-09-24T00:01:05Z

Add the following test cases for both IPv4 and IPv6: * Can change from FDB nexthop to non-FDB nexthop and vice versa. * Can change FDB nexthop address while in a group. * Cannot change from FDB nexthop to non-FDB nexthop and vice versa while in a group. Output without "nexthop: Forbid FDB status change while nexthop is in a group": # ./fib_nexthops.sh -t "ipv6_fdb_grp_fcnal ipv4_fdb_grp_fcnal" IPv6 fdb groups functional -------------------------- [...] TEST: Replace FDB nexthop to non-FDB nexthop [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop [ OK ] TEST: Replace FDB nexthop address while in a group [ OK ] TEST: Replace FDB nexthop to non-FDB nexthop while in a group [FAIL] TEST: Replace non-FDB nexthop to FDB nexthop while in a group [FAIL] [...] IPv4 fdb groups functional -------------------------- [...] TEST: Replace FDB nexthop to non-FDB nexthop [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop [ OK ] TEST: Replace FDB nexthop address while in a group [ OK ] TEST: Replace FDB nexthop to non-FDB nexthop while in a group [FAIL] TEST: Replace non-FDB nexthop to FDB nexthop while in a group [FAIL] [...] Tests passed: 36 Tests failed: 4 Tests skipped: 0 Output with "nexthop: Forbid FDB status change while nexthop is in a group": # ./fib_nexthops.sh -t "ipv6_fdb_grp_fcnal ipv4_fdb_grp_fcnal" IPv6 fdb groups functional -------------------------- [...] TEST: Replace FDB nexthop to non-FDB nexthop [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop [ OK ] TEST: Replace FDB nexthop address while in a group [ OK ] TEST: Replace FDB nexthop to non-FDB nexthop while in a group [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop while in a group [ OK ] [...] IPv4 fdb groups functional -------------------------- [...] TEST: Replace FDB nexthop to non-FDB nexthop [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop [ OK ] TEST: Replace FDB nexthop address while in a group [ OK ] TEST: Replace FDB nexthop to non-FDB nexthop while in a group [ OK ] TEST: Replace non-FDB nexthop to FDB nexthop while in a group [ OK ] [...] Tests passed: 40 Tests failed: 0 Tests skipped: 0 Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20250921150824.149157-4-idosch@nvidia.com Signed-off-by: Jakub Kicinski

selftests: fib_nexthops: Fix creation of non-FDB nexthops

2025-09-24T00:01:05Z

The test creates non-FDB nexthops without a nexthop device which leads to the expected failure, but for the wrong reason: # ./fib_nexthops.sh -t "ipv6_fdb_grp_fcnal ipv4_fdb_grp_fcnal" -v IPv6 fdb groups functional -------------------------- [...] COMMAND: ip -netns me-nRsN3E nexthop add id 63 via 2001:db8:91::4 Error: Device attribute required for non-blackhole and non-fdb nexthops. COMMAND: ip -netns me-nRsN3E nexthop add id 64 via 2001:db8:91::5 Error: Device attribute required for non-blackhole and non-fdb nexthops. COMMAND: ip -netns me-nRsN3E nexthop add id 103 group 63/64 fdb Error: Invalid nexthop id. TEST: Fdb Nexthop group with non-fdb nexthops [ OK ] [...] IPv4 fdb groups functional -------------------------- [...] COMMAND: ip -netns me-nRsN3E nexthop add id 14 via 172.16.1.2 Error: Device attribute required for non-blackhole and non-fdb nexthops. COMMAND: ip -netns me-nRsN3E nexthop add id 15 via 172.16.1.3 Error: Device attribute required for non-blackhole and non-fdb nexthops. COMMAND: ip -netns me-nRsN3E nexthop add id 103 group 14/15 fdb Error: Invalid nexthop id. TEST: Fdb Nexthop group with non-fdb nexthops [ OK ] COMMAND: ip -netns me-nRsN3E nexthop add id 16 via 172.16.1.2 fdb COMMAND: ip -netns me-nRsN3E nexthop add id 17 via 172.16.1.3 fdb COMMAND: ip -netns me-nRsN3E nexthop add id 104 group 14/15 Error: Invalid nexthop id. TEST: Non-Fdb Nexthop group with fdb nexthops [ OK ] [...] COMMAND: ip -netns me-0dlhyd ro add 172.16.0.0/22 nhid 15 Error: Nexthop id does not exist. TEST: Route add with fdb nexthop [ OK ] In addition, as can be seen in the above output, a couple of IPv4 test cases used the non-FDB nexthops (14 and 15) when they intended to use the FDB nexthops (16 and 17). These test cases only passed because failure was expected, but they failed for the wrong reason. Fix the test to create the non-FDB nexthops with a nexthop device and adjust the IPv4 test cases to use the FDB nexthops instead of the non-FDB nexthops. Output after the fix: # ./fib_nexthops.sh -t "ipv6_fdb_grp_fcnal ipv4_fdb_grp_fcnal" -v IPv6 fdb groups functional -------------------------- [...] COMMAND: ip -netns me-lNzfHP nexthop add id 63 via 2001:db8:91::4 dev veth1 COMMAND: ip -netns me-lNzfHP nexthop add id 64 via 2001:db8:91::5 dev veth1 COMMAND: ip -netns me-lNzfHP nexthop add id 103 group 63/64 fdb Error: FDB nexthop group can only have fdb nexthops. TEST: Fdb Nexthop group with non-fdb nexthops [ OK ] [...] IPv4 fdb groups functional -------------------------- [...] COMMAND: ip -netns me-lNzfHP nexthop add id 14 via 172.16.1.2 dev veth1 COMMAND: ip -netns me-lNzfHP nexthop add id 15 via 172.16.1.3 dev veth1 COMMAND: ip -netns me-lNzfHP nexthop add id 103 group 14/15 fdb Error: FDB nexthop group can only have fdb nexthops. TEST: Fdb Nexthop group with non-fdb nexthops [ OK ] COMMAND: ip -netns me-lNzfHP nexthop add id 16 via 172.16.1.2 fdb COMMAND: ip -netns me-lNzfHP nexthop add id 17 via 172.16.1.3 fdb COMMAND: ip -netns me-lNzfHP nexthop add id 104 group 16/17 Error: Non FDB nexthop group cannot have fdb nexthops. TEST: Non-Fdb Nexthop group with fdb nexthops [ OK ] [...] COMMAND: ip -netns me-lNzfHP ro add 172.16.0.0/22 nhid 16 Error: Route cannot point to a fdb nexthop. TEST: Route add with fdb nexthop [ OK ] [...] Tests passed: 30 Tests failed: 0 Tests skipped: 0 Fixes: 0534c5489c11 ("selftests: net: add fdb nexthop tests") Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20250921150824.149157-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski

selftests: tls: test skb copy under mem pressure and OOB

2025-09-18T10:43:54Z

Add a test which triggers mem pressure via OOB writes. Reviewed-by: Sabrina Dubroca Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20250917002814.1743558-2-kuba@kernel.org Signed-off-by: Paolo Abeni

selftest: packetdrill: Add tcp_fastopen_server_reset-after-disconnect.pkt.

2025-09-17T23:01:52Z

The test reproduces the scenario explained in the previous patch. Without the patch, the test triggers the warning and cannot see the last retransmitted packet. # ./ksft_runner.sh tcp_fastopen_server_reset-after-disconnect.pkt TAP version 13 1..2 [ 29.229250] ------------[ cut here ]------------ [ 29.231414] WARNING: CPU: 26 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer+0x32/0x9f0 ... tcp_fastopen_server_reset-after-disconnect.pkt:26: error handling packet: Timed out waiting for packet not ok 1 ipv4 tcp_fastopen_server_reset-after-disconnect.pkt:26: error handling packet: Timed out waiting for packet not ok 2 ipv6 # Totals: pass:0 fail:2 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250915175800.118793-3-kuniyu@google.com Signed-off-by: Jakub Kicinski

selftests: mptcp: sockopt: fix error messages

2025-09-16T01:12:05Z

This patch fixes several issues in the error reporting of the MPTCP sockopt selftest: 1. Fix diff not printed: The error messages for counter mismatches had the actual difference ('diff') as argument, but it was missing in the format string. Displaying it makes the debugging easier. 2. Fix variable usage: The error check for 'mptcpi_bytes_acked' incorrectly used 'ret2' (sent bytes) for both the expected value and the difference calculation. It now correctly uses 'ret' (received bytes), which is the expected value for bytes_acked. 3. Fix off-by-one in diff: The calculation for the 'mptcpi_rcv_delta' diff was 's.mptcpi_rcv_delta - ret', which is off-by-one. It has been corrected to 's.mptcpi_rcv_delta - (ret + 1)' to match the expected value in the condition above it. Fixes: 5dcff89e1455 ("selftests: mptcp: explicitly tests aggregate counters") Signed-off-by: Geliang Tang Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-pm-uspace-deny_join_id0-v1-5-40171884ade8@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: userspace pm: validate deny-join-id0 flag

2025-09-16T01:12:05Z

The previous commit adds the MPTCP_PM_EV_FLAG_DENY_JOIN_ID0 flag. Make sure it is correctly announced by the other peer when it has been received. pm_nl_ctl will now display 'deny_join_id0:1' when monitoring the events, and when this flag was set by the other peer. The 'Fixes' tag here below is the same as the one from the previous commit: this patch here is not fixing anything wrong in the selftests, but it validates the previous fix for an issue introduced by this commit ID. Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment") Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-pm-uspace-deny_join_id0-v1-3-40171884ade8@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: connect: print pcap prefix

2025-09-16T01:10:37Z

To be able to find which capture files have been produced after several runs. This prefix was not printed anywhere before. While at it, always use the same prefix by taking info from ns1, instead of "$connector_ns", which is sometimes ns1, sometimes ns2 in the subtests. Reviewed-by: Mat Martineau Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-fix-sft-connect-v1-5-d40e77cbbf02@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: print trailing bytes with od

2025-09-16T01:10:37Z

This is better than printing random bytes in the terminal. Note that Jakub suggested 'hexdump', but Mat found out this tool is not often installed by default. 'od' can do a similar job, and it is in the POSIX specs and available in coreutils, so it should be on more systems. While at it, display a few more bytes, just to fill in the two lines. And no need to display the 3rd only line showing the next number of bytes: 0000040. Suggested-by: Jakub Kicinski Suggested-by: Mat Martineau Reviewed-by: Mat Martineau Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-fix-sft-connect-v1-4-d40e77cbbf02@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: avoid spurious errors on TCP disconnect

2025-09-16T01:10:37Z

The disconnect test-case, with 'plain' TCP sockets generates spurious errors, e.g. 07 ns1 TCP -> ns1 (dead:beef:1::1:10006) MPTCP read: Connection reset by peer read: Connection reset by peer (duration 155ms) [FAIL] client exit code 3, server 3 netns ns1-FloSdv (listener) socket stat for 10006: TcpActiveOpens 2 0.0 TcpPassiveOpens 2 0.0 TcpEstabResets 2 0.0 TcpInSegs 274 0.0 TcpOutSegs 276 0.0 TcpOutRsts 3 0.0 TcpExtPruneCalled 2 0.0 TcpExtRcvPruned 1 0.0 TcpExtTCPPureAcks 104 0.0 TcpExtTCPRcvCollapsed 2 0.0 TcpExtTCPBacklogCoalesce 42 0.0 TcpExtTCPRcvCoalesce 43 0.0 TcpExtTCPChallengeACK 1 0.0 TcpExtTCPFromZeroWindowAdv 42 0.0 TcpExtTCPToZeroWindowAdv 41 0.0 TcpExtTCPWantZeroWindowAdv 13 0.0 TcpExtTCPOrigDataSent 164 0.0 TcpExtTCPDelivered 165 0.0 TcpExtTCPRcvQDrop 1 0.0 In the failing scenarios (TCP -> MPTCP), the involved sockets are actually plain TCP ones, as fallbacks for passive sockets at 2WHS time cause the MPTCP listeners to actually create 'plain' TCP sockets. Similar to commit 218cc166321f ("selftests: mptcp: avoid spurious errors on disconnect"), the root cause is in the user-space bits: the test program tries to disconnect as soon as all the pending data has been spooled, generating an RST. If such option reaches the peer before the connection has reached the closed status, the TCP socket will report an error to the user-space, as per protocol specification, causing the above failure. Note that it looks like this issue got more visible since the "tcp: receiver changes" series from commit 06baf9bfa6ca ("Merge branch 'tcp-receiver-changes'"). Address the issue by explicitly waiting for the TCP sockets (-t) to reach a closed status before performing the disconnect. More precisely, the test program now waits for plain TCP sockets or TCP subflows in addition to the MPTCP sockets that were already monitored. While at it, use 'ss' with '-n' to avoid resolving service names, which is not needed here. Fixes: 218cc166321f ("selftests: mptcp: avoid spurious errors on disconnect") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni Reviewed-by: Mat Martineau Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-fix-sft-connect-v1-3-d40e77cbbf02@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: connect: catch IO errors on listen side

2025-09-16T01:10:36Z

IO errors were correctly printed to stderr, and propagated up to the main loop for the server side, but the returned value was ignored. As a consequence, the program for the listener side was no longer exiting with an error code in case of IO issues. Because of that, some issues might not have been seen. But very likely, most issues either had an effect on the client side, or the file transfer was not the expected one, e.g. the connection got reset before the end. Still, it is better to fix this. The main consequence of this issue is the error that was reported by the selftests: the received and sent files were different, and the MIB counters were not printed. Also, when such errors happened during the 'disconnect' tests, the program tried to continue until the timeout. Now when an IO error is detected, the program exits directly with an error. Fixes: 05be5e273c84 ("selftests: mptcp: add disconnect tests") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Reviewed-by: Geliang Tang Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250912-net-mptcp-fix-sft-connect-v1-2-d40e77cbbf02@kernel.org Signed-off-by: Jakub Kicinski