Bug 45443

Summary:	Linux credentials-passing is no longer tested
Product:	Telepathy	Reporter:	Simon McVittie <smcv>
Component:	gabble	Assignee:	Telepathy bugs list <telepathy-bugs>
Status:	RESOLVED MOVED	QA Contact:	Telepathy bugs list <telepathy-bugs>
Severity:	normal
Priority:	medium
Version:	git master
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Simon McVittie 2012-01-31 05:56:20 UTC

Recent Linux has this commit:

commit 16e5726269611b71c930054ffe9b858c1cea88eb
Author: Eric Dumazet <eric.dumazet@gmail.com>
Date:   2011-09-19 05:52:27 +0000

    af_unix: dont send SCM_CREDENTIALS by default
    
    Since commit 7361c36c5224 (af_unix: Allow credentials to work across
    user and pid namespaces) af_unix performance dropped a lot.
...
    This patch includes SCM_CREDENTIALS information in a af_unix message/skb
    only if requested by the sender, [man 7 unix for details how to include
    ancillary data using sendmsg() system call]
    
    Note: This might break buggy applications that expected SCM_CREDENTIAL
    from an unaware write() system call, and receiver not using SO_PASSCRED
    socket option.
    
    If SOCK_PASSCRED is set on source or destination socket, we still
    include credentials for mere write() syscalls.

so we need to do at least one of these:

* teach the Python (Twisted) code to send ancillary data
  (probably somewhat difficult)

* have Gabble enable SO_PASSCRED before telling the Tubes client
  about the socket, instead of enabling it just in time for the relevant
  read, and keep it enabled until the creds have been passed

Comment 1 Simon McVittie 2012-01-31 06:00:27 UTC

Of course, using GLib for the credentials-passing would also be good (but we'll have to check that it doesn't have the same bug).

I also spotted a related problem when receiving creds: we blindly assume that the CMSG_FIRSTHDR is of type (SOL_SOCKET, SCM_CREDENTIALS), rather than iterating through all cmsg headers.

Comment 2 Guillaume Desmottes 2012-02-21 08:02:34 UTC

I disabled the test for now with this commit: 8d7efad30c8633d6df4a0635eb7f78f2fa326e9a

Comment 3 GitLab Migration User 2019-12-03 19:55:21 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/telepathy/telepathy-gabble/issues/205.

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