How to transfer file descriptors with UNIX domain sockets?

[Conor P. Cahill]

In article <10981 at hydra.gatech.EDU> gt0178a at prism.gatech.EDU (BURNS,JIM) writes:
>in article <1990Jul01.130157.3627 at virtech.uucp>, cpcahil at virtech.uucp (Conor P. Cahill) says:
>>>in article <1421 at tub.UUCP>, net at tub.UUCP (Oliver Laumann) says:
>	[code deleted]
>> The system knows because the person, or persons, that added that capability
>> to the sockets code ensured that the file descriptor that was passed became
>> a valid file descriptor in the process that received it.
>
>I'm sure that it *can* be done - my question is what was it in Oliver
>Laumann's code that informed the kernel that what was in the message was a
>file descriptor?

Essentially it is the portion of the that supports the passing of "access
rights".  The access rights to the file descriptor are passed using a
send/recvmsg().  For more info, you could look at section 6.10 "Passing
file descriptors" in UNIX Network Programming (by W. Richard Stevens).

-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
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