Date: Fri, 16 Jan 2015 18:40:50 +0000 From: "Quattlebaum, Ryan" <Ryan.Quattlebaum@netapp.com> To: Adrian Chadd <adrian@freebsd.org> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: RE: Accessing socket APIs soon after accept Message-ID: <1421433650372.44369@netapp.com> In-Reply-To: <CAJ-VmomJ0GnHTK9NuKnJ3iLht6XbabKZV-2KKnu3i%2BuABrN8iQ@mail.gmail.com> References: <1421339375968.94209@netapp.com> <CAJ-VmonYaAUior3aGBioVUvMPM1OMHJnHt7-rQgzMGQ4co4ATQ@mail.gmail.com> <1421428048190.48193@netapp.com>, <CAJ-VmomJ0GnHTK9NuKnJ3iLht6XbabKZV-2KKnu3i%2BuABrN8iQ@mail.gmail.com>
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I haven't checked head of line. I'll go take a look. We are in the process = of moving to 9.x, so I'll check that as well.=0A= =0A= Thanks for the help!=0A= Ryan=0A= ________________________________________=0A= From: adrian.chadd@gmail.com <adrian.chadd@gmail.com> on behalf of Adrian C= hadd <adrian@freebsd.org>=0A= Sent: Friday, January 16, 2015 1:39 PM=0A= To: Quattlebaum, Ryan=0A= Cc: freebsd-net@freebsd.org=0A= Subject: Re: Accessing socket APIs soon after accept=0A= =0A= Oh, I've no idea about -8. If that's what the code does then yeah,=0A= that seems wrong. Is it like that in -10 or -11 ?=0A= =0A= =0A= =0A= -adrian=0A= =0A= =0A= On 16 January 2015 at 09:07, Quattlebaum, Ryan=0A= <Ryan.Quattlebaum@netapp.com> wrote:=0A= > Hi, Adrian. Thanks for taking a look at this.=0A= >=0A= > We're using FreeBSD 8.2 and httpd-2.4.10 with arp-1.5.1 and apr-util-1.5.= 4.=0A= >=0A= > The problem we're seeing is pretty intermittent, so I hope this test case= can shine a little bit of light on th= e problem. We tried debugging this on our own by adding calls to getsocknam= e() right after the accept call (in srclib/apr/network_io/unix/sockets.c: a= pr_socket_accept()) and logging the output. That's where we saw invalid dat= a.=0A= >=0A= > I took a look at the source code for the TCP syncache module and the acce= pt syscall. It looks like the new child socket is available for the applica= tion to accept after the call to sonewconn returns, but the address informa= tion isn't set until further down in the function. Wouldn't this open a win= dow where an application could accept on a socket that the syncache code is= n't done configuring?=0A= >=0A= > - Ryan Quattlebaum=0A= > ________________________________________=0A= > From: adrian.chadd@gmail.com <adrian.chadd@gmail.com> on behalf of Adrian= Chadd <adrian@freebsd.org>=0A= > Sent: Thursday, January 15, 2015 1:20 PM=0A= > To: Quattlebaum, Ryan=0A= > Cc: freebsd-net@freebsd.org=0A= > Subject: Re: Accessing socket APIs soon after accept=0A= >=0A= > On 15 January 2015 at 08:29, Quattlebaum, Ryan=0A= > <Ryan.Quattlebaum@netapp.com> wrote:=0A= >> Is there anything preventing applications from calling functions e.g. ge= tsockname() right after accept()? Or is there a recommended pattern that ap= plications should use to ensure they get correct data? We recently upgraded= to a new version of Apache and are seeing uninitialized data coming back f= rom a few of these calls.=0A= >=0A= > I'm under the impression that once you get the FD from accept(), it=0A= > should be fully formed and ready.=0A= >=0A= > Which version of FreeBSD/apache is it? can you come up with a test=0A= > case that shows that it's happening?=0A= >=0A= >=0A= >=0A= > -adrian=0A= >=0A= >> Thanks,=0A= >>=0A= >> Ryan Quattlebaum=0A= >> Software Developer, NetApp, Inc.=0A= >> _______________________________________________=0A= >> freebsd-net@freebsd.org mailing list=0A= >> http://lists.freebsd.org/mailman/listinfo/freebsd-net=0A= >> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"= =0A=
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