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ppp: improve MSS clamping
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Authored by tuexen on Dec 7 2022, 5:11 PM.
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Details

Summary

ppp supports MSS clamping for TCP/IPv4. This patch

  • improves MSS clamping by correctly computing the MSS to be reported as specified in RFC 6691.
  • adds support for MSS clamping when using TCP/IPv6.

Diff Detail

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rG FreeBSD src repository
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Event Timeline

tuexen requested review of this revision.Dec 7 2022, 5:11 PM
usr.sbin/ppp/tcpmss.c
165

This should move into to switch statement below to be consistent with the v6 path

usr.sbin/ppp/tcpmss.c
165

The reason I added the check here is that from the next line on I assume that pip points to an IP header and in the line after that I look at the first component of it. Don't I need to make sure I have at least enough data to look at the ip_v field? I think only checking in the switch statement is too late, since I have already accessed a component. Or am I wrong?

This revision is now accepted and ready to land.Dec 7 2022, 10:16 PM
This revision was automatically updated to reflect the committed changes.