Date: Wed, 15 Mar 2006 12:09:51 +0100 (CET) From: Sven Berkvens-Matthijsse <sven@ilse.net> To: FreeBSD-gnats-submit@FreeBSD.org Subject: threads/94467: send(), sendto() and sendmsg() are not correct in libc_r Message-ID: <200603151109.k2FB9pCN037532@serv7.ilse.net> Resent-Message-ID: <200603151110.k2FBAM65065616@freefall.freebsd.org>
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>Number: 94467 >Category: threads >Synopsis: send(), sendto() and sendmsg() are not correct in libc_r >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-threads >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Mar 15 11:10:21 GMT 2006 >Closed-Date: >Last-Modified: >Originator: Sven Berkvens-Matthijsse >Release: FreeBSD 4.10-STABLE i386 >Organization: ilse media BV >Environment: System: FreeBSD serv7.ilse.net 4.10-STABLE FreeBSD 4.10-STABLE #23: Wed Aug 4 15:18:52 CEST 2004 root@tango.ilse.net:/usr/obj/usr/src/sys/BAROQUE i386 >Description: send(), sendto() and sendmsg() can return prematurely in the libc_r implementation. If the socket has space available, but not enough to accommodate the whole data block at once, the kernel's sendto() will return with a premature byte count, because all the sockets are always put into nonblocking mode. However, unlike write(), which does implement this correctly, the implementation of sendto() and co do not check for this condition if the thread's notion of the socket was non-blocking. Instead, it just returns the permature bytecount instead of starting another sendto()/sendmsg() to complete the action (and possibly putting the thread to sleep until poll() says it's okay to try again), like a non-blocking version should. >How-To-Repeat: sendto() using a socket and try to write 1 MB of data, for example. >Fix: Working on this one... will post a patch when available. >Release-Note: >Audit-Trail: >Unformatted:
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