243986 - SOCKS5: DNS error (hostname not found) -> proxy hostname not found error

Status: RESOLVED FIXED

(Core :: Networking, defect)

Description

[benc]

STEPS:
Configure SOCKS5 w/ correct configuration.

Click on link w/ incorrect/non-existent hostname.

OBSERVED:
The error message displayed is the error for a proxy w/ a bad hostname, not the
actual connection.

EXPECTED:
The normal DNS error (under current SOCKS5 DNS behavior, see bug 134105). 

-or- correct SOCKS error handling (if that bug is ever fixed).

Comment 1

[Frank Wein [:mcsmurf]]

benc: Might it be that this bug here also applies to SOCKS4 (see Bug 276269)?

Comment 2

[Gary Chen [:xeonchen]]

I use OpenSSH tunneling to create a SOCKS5 server, and I can reproduce this bug.
However, the the server closes the connection ([1]) if we send an invalid host name to resolve on server side, looks like OpenSSH doesn't handle this correctly:

> debug1: channel 8: new [dynamic-tcpip]
> debug2: channel 8: pre_dynamic: have 0
> debug2: channel 8: pre_dynamic: have 3
> debug2: channel 8: decode socks5
> debug2: channel 8: socks5 auth done
> debug2: channel 8: pre_dynamic: need more
> debug2: channel 8: pre_dynamic: have 0
> debug2: channel 8: pre_dynamic: have 28
> debug2: channel 8: decode socks5
> debug2: channel 8: socks5 post auth
> debug2: channel 8: dynamic request: socks5 host nonexistent.mozilla.org port 443 command 1
> debug3: send packet: type 90
> debug3: receive packet: type 92
> channel 8: open failed: administratively prohibited: open failed
> debug2: channel 8: zombie
> debug2: channel 8: garbage collecting
> debug1: channel 8: free: direct-tcpip: listening port 1080 for nonexistent.mozilla.org port 443, connect from ::1 port 60847 to ::1 port 1080, nchannels 9

In Sec. 6 "Replies" of RFC 1928, it is supposed to response an error code instead of closing directly.

[1] https://dxr.mozilla.org/mozilla-central/rev/7083c0d30e75fc102c715887af9faec933e936f8/netwerk/socket/nsSOCKSIOLayer.cpp#1158

Comment 3

[Gary Chen [:xeonchen]]

Attachment: Bug 243986 - Handle SOCKS5 remote DNS resolution error;

Review commit: https://reviewboard.mozilla.org/r/100112/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/100112/

Comment 4

[Gary Chen [:xeonchen]]

I've just tested this with TorSocks

Comment 5

[Daniel Stenberg [:bagder]]

Comment on attachment 8820642 [details]
Bug 243986 - Handle SOCKS5 remote DNS resolution error;

https://reviewboard.mozilla.org/r/100112/#review104112

ship it!

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/10aef51fa9df
Handle SOCKS5 remote DNS resolution error; r=bagder

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/10aef51fa9df