2051272 - With Happy Eyeballs enabled, Alt-Svc mappings are not validated through AltSvcTransaction.

Status: RESOLVED FIXED

(Core :: Networking: HTTP, defect, P2)

Description

[Kershaw Chang [:kershaw]]

Bug 1953464 made nsHttpConnectionInfo::BuildHashKey drop the routed host/port from the hash key when HE is enabled, so the alternate now shares the origin’s ConnectionEntry. As a side effect, the alternate’s connection info hashes identically to the origin’s, which breaks validation in two ways:

1. Validation is bypassed (h2 and h3): AltSvcMapping::ProcessHeader uses ci->HashKey().Equals(aTransConnInfo->HashKey()) as a skip check. With the new hash key behavior, that comparison now matches for every normal Alt-Svc header, so the mapping is treated as valid without actually being validated. Claim can also abort an in-flight validation attempt. This part is protocol-agnostic.
2. Validation can never complete (h2 only): if validation is forced, SpeculativeConnect reuses the origin’s entry, and ProcessTCPConn returns the H2 connection to the pool without binding it to the AltSvcTransaction. As a result, MaybeValidate fails its precondition: conn=0 ... Failed due to precondition. (ProcessUDPConn for h3 already activates the transaction, so for h3, MaybeValidate works once the bypass issue is fixed.)

Comment 1

[Kershaw Chang [:kershaw]]

Attachment: Bug 2051272 - Validate h3 Alt-Svc mappings under Happy Eyeballs, r=#necko

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/607de6ace543
https://hg.mozilla.org/integration/autoland/rev/5a275a85fd12
Validate h3 Alt-Svc mappings under Happy Eyeballs, r=mxinden

Comment 3

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/5a275a85fd12

Comment 4

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/5a275a85fd12

Comment 5

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/5a275a85fd12

Comment 6

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/5a275a85fd12

Comment 7

[Kershaw Chang [:kershaw]]

Attachment: Bug 2051272 - Validate h3 Alt-Svc mappings under Happy Eyeballs,

Original Revision: https://phabricator.services.mozilla.com/D313385

Comment 8

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined/Reason for urgency: We won't create a HTTP/3 connection when a Alt-svc header is received.
  We mainly need this patch on beta because we probably want to do an experiment for HEv3 on beta.
• Code covered by automated testing?: yes
• Fix verified in Nightly?: yes
• Needs manual QE testing?: no
• Steps to reproduce for manual QE testing:
• Risk associated with taking this patch: low
• Explanation of risk level: The patch is verified on nightly and the pref is false by default.
• String changes made/needed?: N/A
• Is Android affected?: yes

Comment 9

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/898510e43949
https://hg.mozilla.org/releases/mozilla-beta/rev/cac567fa2280