Xref: utzoo comp.protocols.tcp-ip:2484 comp.protocols.misc:222 comp.protocols.iso:37 comp.protocols.ibm:79 comp.unix.questions:5517 comp.dcom.lans:1020 comp.os.vms:4598
Path: utzoo!utgpu!water!watmath!clyde!rutgers!mailrus!nrl-cmf!cmcl2!brl-adm!umd5!trantor.umd.edu!chris
From: chris@trantor.umd.edu (Chris Torek)
Newsgroups: comp.protocols.tcp-ip,comp.protocols.misc,comp.protocols.iso,comp.protocols.ibm,comp.unix.questions,comp.dcom.lans,comp.os.vms
Subject: Re: Pass an open socket to another process????
Keywords: sockets
Message-ID: <2281@umd5.umd.edu>
Date: 12 Feb 88 04:29:51 GMT
References: <291@tifsil.UUCP> <633@eden.quintus.UUCP> <22952@ucbvax.BERKELEY.EDU>
Sender: ris@umd5.umd.edu
Reply-To: chris@trantor.umd.edu (Chris Torek)
Organization: University of Maryland, College Park
Lines: 22

In article <22952@ucbvax.BERKELEY.EDU> sklower@sequoia.Berkeley.EDU.UUCP
								    ----?
(Keith Sklower) writes:

>4.2 and 4.3 BSD provide a means of passing an open file descriptor
>of any sort (including sockets) between two co-operating processes
>by means of the sendmsg system call.

Beware, however, of some rather serious bugs in the implementation
in 4.2BSD.  For instance, using MSG_PEEK with recvmsg() on a message
with rights can cause multiple acceptance of the passed file
descriptor, resulting in eventual file system corruption (without
the closef firewall) or a panic (with the firewall).

All of this is fixed in 4.3BSD (with the possible exception of the
fd garbage collection code---try not to send pipe descriptors to
yourself over those pipe descriptors, please).  Which SunOS releases
may have which bugs I cannot say.
-- 
In-Real-Life: Chris Torek, Univ of MD Computer Science, +1 301 454 7163
(hiding out on trantor.umd.edu until mimsy is reassembled in its new home)
Domain: chris@mimsy.umd.edu		Path: not easily reachable