net: Support all valid IP_MTU_DISCOVER values for UDP and TCP#12852
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copybara-service[bot] merged 1 commit intogoogle:masterfrom Apr 3, 2026
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net: Support all valid IP_MTU_DISCOVER values for UDP and TCP#12852copybara-service[bot] merged 1 commit intogoogle:masterfrom
copybara-service[bot] merged 1 commit intogoogle:masterfrom
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The UDP endpoint only accepted PMTUDiscoveryDont and the TCP endpoint rejected PMTUDiscoveryProbe, causing QUIC libraries (quic-go) to fail when setting IP_PMTUDISC_DO or IP_PMTUDISC_PROBE on UDP sockets. Accept all valid PMTUD strategies (DONT/WANT/DO/PROBE) for both UDP and TCP, since gVisor does not implement ICMP-based PMTU feedback, `PROBE` and `DO` are functionally equivalent — both set DF but neither updates a cached route PMTU. Test: UdpSocketTest.SetPMTUD, TcpSocketTest.SetPMTUD Signed-off-by: Tan Yifeng <yiftan@tencent.com>
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ProblemThe UDP/datagram endpoint only accepted This breaks QUIC libraries like quic-go, which call |
nybidari
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Apr 3, 2026
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The UDP endpoint only accepted PMTUDiscoveryDont and the TCP endpoint rejected PMTUDiscoveryProbe, causing QUIC libraries (quic-go) to fail when setting IP_PMTUDISC_DO or IP_PMTUDISC_PROBE on UDP sockets. Accept all valid PMTUD strategies (DONT/WANT/DO/PROBE) for both UDP and TCP, since gVisor does not implement ICMP-based PMTU feedback, `PROBE` and `DO` are functionally equivalent — both set DF but neither updates a cached route PMTU. Test: UdpSocketTest.SetPMTUD, TcpSocketTest.SetPMTUD FUTURE_COPYBARA_INTEGRATE_REVIEW=#12852 from tanyifeng:net-ip-mtu-discover 03548dc PiperOrigin-RevId: 894078264
copybara-service bot
pushed a commit
that referenced
this pull request
Apr 3, 2026
The UDP endpoint only accepted PMTUDiscoveryDont and the TCP endpoint rejected PMTUDiscoveryProbe, causing QUIC libraries (quic-go) to fail when setting IP_PMTUDISC_DO or IP_PMTUDISC_PROBE on UDP sockets. Accept all valid PMTUD strategies (DONT/WANT/DO/PROBE) for both UDP and TCP, since gVisor does not implement ICMP-based PMTU feedback, `PROBE` and `DO` are functionally equivalent — both set DF but neither updates a cached route PMTU. Test: UdpSocketTest.SetPMTUD, TcpSocketTest.SetPMTUD FUTURE_COPYBARA_INTEGRATE_REVIEW=#12852 from tanyifeng:net-ip-mtu-discover 03548dc PiperOrigin-RevId: 894078264
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The UDP endpoint only accepted PMTUDiscoveryDont and the TCP endpoint rejected PMTUDiscoveryProbe, causing QUIC libraries (quic-go) to fail when setting IP_PMTUDISC_DO or IP_PMTUDISC_PROBE on UDP sockets.
Accept all valid PMTUD strategies (DONT/WANT/DO/PROBE) for both UDP and TCP, since gVisor does not implement ICMP-based PMTU feedback,
PROBEandDOare functionally equivalent — both set DF but neither updates a cached route PMTU.Test: UdpSocketTest.SetPMTUD, TcpSocketTest.SetPMTUD