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Differential D43797

tcp: prevent div by zero in cc_htcp
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Authored by rscheff on Feb 8 2024, 7:47 PM.
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grahamperrin
imp
melifaro

Details

Reviewers
tuexen
glebius
cc
Group Reviewers
transport
Commits
rG6e298c3612da: tcp: prevent div by zero in cc_htcp
rG419848219b40: tcp: prevent div by zero in cc_htcp
rG38983d40c18e: tcp: prevent div by zero in cc_htcp
Summary

Make sure the divident is at least mss. While this
prevents subsequent division by zero, cwnd should
never be smaller than smss.

Bug: 276674

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Repository
rG FreeBSD src repository
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Event Timeline

rscheff created this revision.Feb 8 2024, 7:47 PM
Herald added a reviewer: transport. · View Herald TranscriptFeb 8 2024, 7:47 PM
Herald added subscribers: melifaro, imp. · View Herald Transcript
rscheff requested review of this revision.Feb 8 2024, 7:47 PM
Harbormaster completed remote builds in B55870: Diff 134023.Feb 8 2024, 7:47 PM
tuexen added a comment.Feb 8 2024, 8:13 PM

This patch is not fixing the root cause, but mitigating the consequences. I think I have an idea what the root cause is. Let me do some testing tomorrow....

grahamperrin added a subscriber: grahamperrin.Feb 11 2024, 8:01 PM
rscheff added a comment.Feb 22 2024, 3:20 PM

max(div, 1) prior of outer division.

rscheff updated this revision to Diff 134847.Feb 22 2024, 4:42 PM
  • do max(1, div) instead max(maxseg, cwnd)/div
Harbormaster completed remote builds in B56170: Diff 134847.Feb 22 2024, 4:42 PM
tuexen accepted this revision.Feb 22 2024, 5:08 PM
This revision is now accepted and ready to land.Feb 22 2024, 5:08 PM
Closed by commit rG38983d40c18e: tcp: prevent div by zero in cc_htcp (authored by rscheff). · Explain WhyFeb 24 2024, 4:16 PM
This revision was automatically updated to reflect the committed changes.
rscheff added a commit: rG38983d40c18e: tcp: prevent div by zero in cc_htcp.
rscheff added a commit: rG419848219b40: tcp: prevent div by zero in cc_htcp.Feb 27 2024, 11:03 AM
rscheff added a commit: rG6e298c3612da: tcp: prevent div by zero in cc_htcp.Feb 28 2024, 12:27 AM

Revision Contents
Changeset List

PathSize
sys/
netinet/
cc/
6 lines

Diff 134929

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sys/netinet/cc/cc_htcp.c

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