Date: Sat, 9 Oct 2004 15:07:14 -0400 From: Brian Fundakowski Feldman <green@FreeBSD.org> To: Andrea Campi <andrea+freebsd_cvs@webcom.it> Cc: src-committers@FreeBSD.org Subject: Re: cvs commit: src/lib/libc/gen syslog.c Message-ID: <20041009190714.GB1093@green.homeunix.org> In-Reply-To: <20041009153916.GA2003@webcom.it> References: <200410082115.i98LFLMU034965@repoman.freebsd.org> <20041009153916.GA2003@webcom.it>
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On Sat, Oct 09, 2004 at 05:39:17PM +0200, Andrea Campi wrote: > On Fri, Oct 08, 2004 at 09:15:21PM +0000, Gleb Smirnoff wrote: > > glebius 2004-10-08 21:15:21 UTC > > > > FreeBSD src repository > > > > Modified files: > > lib/libc/gen syslog.c > > Log: > > When send()ing to syslogd return ENOBUFS keep trying until success. > > > > This fixes a case, when DoSed syslogd completely loses messages. > > Unless I'm missing something, this would make the calling application > loop for an unbounded time (potentially forever), thus making the DoS > even more effective. Personally, I've never thought of syslog as a > reliable service, and I'm quite sure I prefer to lose messages but > keep my apps running than the opposite. If an application needs a > failsafe logging mechanism, chances are it will use something else > anyway. > > What about: > > retry = 1000; > do { > usleep(1); > if (send(LogFile, tbuf, cnt, 0) >= 0) > break; > } while (errno == ENOBUFS && retry-- > 0); I think that this is something very application-dependant, and it's probably best to implement as a timeout that it specifies. But why would a DoSed syslogd lose messages on its end if we're getting ENOBUFS locally? The protocol doesn't provide a way to acknowledge reception, does it? -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
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