1813355 - The cached alternative service entries expire overly soon

Status: UNCONFIRMED

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

Description

[fantasyfate]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/109.0

Steps to reproduce:

1. Enable "DNS over HTTPS"
2. Open "https://cdnjs.cloudflare.com/"
3. Close Firefox.
4. Observe results from "AlternateServices.txt" in the corresponding profile folder.

Actual results:

https:www.cloudflare.com:443:.:^partitionKey=%28https%2Ccloudflare.com%29:3 0 19385 https:www.cloudflare.com:443:www.cloudflare.com:443::n:1674919187:h3:n:1674919180:n:^partitionKey=%28https%2Ccloudflare.com%29:|n:y:
https:cdnjs.cloudflare.com:443:.:^partitionKey=%28https%2Ccloudflare.com%29:3 0 19385 https:cdnjs.cloudflare.com:443:cdnjs.cloudflare.com:443::n:1674919185:h3:n:1674919180:n:^partitionKey=%28https%2Ccloudflare.com%29:|n:y:

Expected results:

The meaning of alternative service entries could be interpreted by reading https://searchfox.org/mozilla-central/source/netwerk/protocol/http/AlternateServices.cpp#368-404

Therefore, the lifetimes of alternative service entries are unexpectedly less than 10 seconds, which seems not to conform with the definition of Alt-Svc HTTP header.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Networking: DNS' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Valentin Gosu [:valentin] (he/him)]

I couldn't reproduce your example with https://cdnjs.cloudflare.com/

Could you maybe capture some HTTP logs? https://firefox-source-docs.mozilla.org/networking/http/logging.html

Thanks

Comment 3

[fantasyfate]

Attachment: log.txt.7z

I attempted to open https://cdnjs.cloudflare.com/, close browser, and clear cache several times, and discovered that the lifetimes of cached alternative service is normal only for the first time.

Additionally, I have added one entry to "AlternateServices.txt", thereby always enabling "DNS over HTTP/3":
https:mozilla.cloudflare-dns.com:443:.::3 0 0 https:mozilla.cloudflare-dns.com:443:mozilla.cloudflare-dns.com:443::n:2147483647:h3:y:0:n::|n:y:

The following command I used captured some HTTP logs:

set MOZ_LOG=nsHttp:5
set MOZ_LOG_FILE=%TEMP%\log.txt
"c:\Program Files\Mozilla Firefox\firefox.exe" https://cdnjs.cloudflare.com/

The contents of "AlternateServices.txt" as follow:

https:cdnjs.cloudflare.com:443:.:^partitionKey=%28https%2Ccloudflare.com%29:3	0	19387	https:cdnjs.cloudflare.com:443:cdnjs.cloudflare.com:443::n:1675117177:h3:n:1675117172:n:^partitionKey=%28https%2Ccloudflare.com%29:|n:y:
https:www.cloudflare.com:443:.:^partitionKey=%28https%2Ccloudflare.com%29:3	0	19387	https:www.cloudflare.com:443:www.cloudflare.com:443::n:1675117178:h3:n:1675117172:n:^partitionKey=%28https%2Ccloudflare.com%29:|n:y:

The lifetime of "cdnjs.cloudflare.com" is 1675117177 - 1675117172 = 5 seconds.
The lifetime of "www.cloudflare.com" is 1675117178 - 1675117172 = 6 seconds.