1700857 - Firefox fails to connect to any website with SOCKS proxy if network is set to 'Use system proxy settings' on macOS

Status: VERIFIED FIXED

(Core :: Networking, defect, P2)

Description

[Haonan Yu]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:88.0) Gecko/20100101 Firefox/88.0

Steps to reproduce:

1. Open https://www.websocket.org/echo.html
2. Click 'Connect' button

Actual results:

It says
ERROR: undefined
DISCONNECTED

Expected results:

CONNECTED

Comment 1

[Haonan Yu]

macOS version: 11.3 Beta (20E5217a)
Firefox version: 88.0b2

I have set both SOCKS and HTTP proxy in system preferences.

Some tests:

1. Use system settings + set http/https proxy in system preferences = Work
2. Use system settings + set socks proxy in system preferences = Not Work
3. Manually set proxy with http/https proxy = Work
4. Manually set proxy with socks proxy = Work
5. Manually set proxy with http/https proxy = Work
6. Manually set proxy with both http/https proxy and socks proxy = Work

It seems not work only when Use system settings and set a SOCKS proxy in system.

Comment 2

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

The Bugbug bot thinks this bug should belong to the 'DevTools::Netmonitor' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 3

[Haonan Yu]

My SOCKS proxy only supports version 5. I notice Firefox sends a packet starting with 0x040101bb 00000001 ..... which indicates a SOCKS 4 handshake packet. However network.proxy.socks_version is set to 5 by default. Is this a bug or I missed something?

Comment 4

[Haonan Yu]

I compiled Firefox on my Mac and modified network/socket/nsSOCKSIOLayer.cpp line #373 to mVersion = 5; to force use SOCKSv5 and everything works fine now. So I think Firefox does not check SOCKS version and uses v4 by default when using system proxy...?

Comment 5

[Kershaw Chang [:kershaw]]

Could you check if the value of this pref network.proxy.socks_version is 5?
Thanks.

Comment 6

[Haonan Yu]

Yes, it is 5.

Comment 7

[Kershaw Chang [:kershaw]]

The problem is at this line. The system proxy setting only indicates to use SOCKS proxy without specifying the version, we chose version 4 for compatibility.
I'll add a new pref network.proxy.default_socks_version so that one could choose to use version 5.

Comment 8

[Kershaw Chang [:kershaw]]

Attachment: Bug 1700857 - Add a pref to allow a user to use SOCKS5, r=#necko

Comment 9

[Kershaw Chang [:kershaw]]

We could also go with the other approach in bug 1424820 comment #12, but I think introducing another pref would be easier.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c446ec523901
Add a pref to allow a user to use SOCKS5, r=necko-reviewers,valentin

Comment 12

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/c446ec523901

Comment 13

[Oana Botisan, Desktop QA]

I can't seem to be able to reproduce this issue. Can you please verify the fix using latest beta? You can find the build
here.

Comment 14

[Haonan Yu]

The new pref works as expected in 91.0b9 (64-bit).

1. Set a SOCKS5 proxy in System Preferences
2. Select Use system proxy settings in Firefox
3. Set network.proxy.default_pac_script_socks_version to 4 = Not work
4. Set network.proxy.default_pac_script_socks_version to 5 = Work

Comment 15

[Monica Chiorean]

Since I was not able to reproduce this issue on latest Beta_95.0b3(20211104185958) and based on comment 14. Closing as fixed.

Comment 16

[huangcy]

(In reply to Haonan Yu from comment #14)

The new pref works as expected in 91.0b9 (64-bit).

1. Set a SOCKS5 proxy in System Preferences
2. Select Use system proxy settings in Firefox
3. Set network.proxy.default_pac_script_socks_version to 4 = Not work
4. Set network.proxy.default_pac_script_socks_version to 5 = Work

network.proxy.default_pac_script_socks_version. It works for me. Thanks.