Up to this series, it was possible to add a "signal" MPTCP endpoint with an IPv6 address and a port, or to directly request to send an ADD_ADDR with a v6 address and a port, but the expected ADD_ADDR wasn't sent when TCP timestamps was used for the connection.
In fact, such signalling option cannot be sent when TCP timestamps is used due to a lack of option space: the limit is at 40 bytes, and, with padding, TCP timestamps is taking 12 bytes, while an ADD_ADDR IPv6 + port is taking 30 bytes. The selected solution here is to simply drop the TCP timestamps option when such ADD_ADDR of 30 bytes needs to be sent. - Patches 1-3: small cleanups to avoid computing ADD/RM_ADDR twice. - Patches 4-7: the new feature, controlled by a new sysctl knob. - Patch 8: extra checks in the MPTCP Join selftests. - Patches 9-11: small pcap-related improvements in the selftests. Signed-off-by: Matthieu Baerts (NGI0) <[email protected]> --- Matthieu Baerts (NGI0) (11): mptcp: options: suboptions sizes can be negative mptcp: pm: avoid computing rm_addr size twice mptcp: pm: avoid computing add_addr size twice mptcp: introduce add_addr_v6_port_drop_ts sysctl knob tcp: allow mptcp to drop TS for some packets mptcp: pm: drop TCP TS with ADD_ADDRv6 + port selftests: mptcp: validate ADD_ADDRv6 + TS + port selftests: mptcp: always check sent/dropped ADD_ADDRs selftests: mptcp: connect: test name in pcap file selftests: mptcp: simult_flow: test name in pcap file selftests: mptcp: pcap: drop most of the payload Documentation/networking/mptcp-sysctl.rst | 13 ++++ include/net/mptcp.h | 3 +- net/ipv4/tcp_output.c | 6 +- net/mptcp/ctrl.c | 18 ++++- net/mptcp/options.c | 64 ++++++---------- net/mptcp/pm.c | 49 +++++++++++-- net/mptcp/protocol.h | 30 +------- tools/testing/selftests/net/mptcp/mptcp_connect.sh | 8 +- tools/testing/selftests/net/mptcp/mptcp_join.sh | 85 ++++++++++------------ tools/testing/selftests/net/mptcp/simult_flows.sh | 11 ++- 10 files changed, 159 insertions(+), 128 deletions(-) --- base-commit: 8415598365503ced2e3d019491b0a2756c85c494 change-id: 20260601-net-next-mptcp-add-addr6-port-ts-40d8d74d8e20 Best regards, -- Matthieu Baerts (NGI0) <[email protected]>
