Re: pcap_findalldevs() failing on FreeBSD 7.2

[Wesley Shields <wxs () FreeBSD org>]

On Wed, Oct 28, 2009 at 10:57:33AM -0400, Wesley Shields wrote:
> On Tue, Oct 27, 2009 at 12:00:04PM -0700, Aaron Turner wrote:
> > On Tue, Oct 27, 2009 at 11:55 AM, Jung-uk Kim <jkim () freebsd org> wrote:
> > > On Friday 25 September 2009 01:18 am, Aaron Turner wrote:
> > > > I've got a user of tcpreplay having issues where his interfaces are
> > > > not being returned via pcap_findalldevs() under FreeBSD 7.2 using
> > > > libpcap 0.9.7. ?I don't have much more information unfortunately,
> > > > but I do know he has an "nVIDIA nForce 10/100/1000 Ethernet" NIC as
> > > > well as the obvious loopback.
> > > >
> > > > I've confirmed he is running as root and the interface is up:
> > > >
> > > > nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0
> > > > mtu 1500
> > > > options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
> > > > ether 00:1e:8c:b1:de:91
> > > > ? ? ? ? inet 192.168.1.111 netmask 0xffffff00 broadcast
> > > > 192.168.1.255 media: Ethernet autoselect (100baseTX
> > > > <full-duplex,flag0,flag1>) status: active
> > > >
> > > > Actually, none of his interfaces are being returned (nfe0, nfe1 and
> > > > lo0). ?I looked in the change log and don't see any mention of any
> > > > improvements/fixes in pcap_finalldevs() since 0.9.7 so I figured
> > > > I'd mention it.
> > >
> > > It's working fine for me:
> > >
> > > %uname -mrs
> > > FreeBSD 9.0-CURRENT amd64
> > > %tcpdump -D
> > > 1.re0
> > > 2.lo0
> > > %tcpdump -c 10 -w /dev/null
> > > tcpdump: listening on re0, link-type EN10MB (Ethernet), capture size
> > > 96 bytes
> > > 10 packets captured
> > > 18 packets received by filter
> > > 0 packets dropped by kernel
> > >
> > > Note "tcpdump -D" is using pcap_findalldevs() as well:
> > >
> > > tcpdump.c:
> > > --------------------------------------------------
> > > #ifdef HAVE_PCAP_FINDALLDEVS
> > > ? ?case 'D':
> > > ? ? ? ?if (pcap_findalldevs(&devpointer, ebuf) < 0)
> > > ? ? ? ? ? ?error("%s", ebuf);
> > > ? ? ? ?else {
> > > ? ? ? ? ? ?for (i = 0; devpointer != 0; i++) {
> > > ? ? ? ? ? ? ? ?printf("%d.%s", i+1, devpointer->name);
> > > ? ? ? ? ? ? ? ?if (devpointer->description != NULL)
> > > ? ? ? ? ? ? ? ? ? ?printf(" (%s)", devpointer->description);
> > > ? ? ? ? ? ? ? ?printf("\n");
> > > ? ? ? ? ? ? ? ?devpointer = devpointer->next;
> > > ? ? ? ? ? ?}
> > > ? ? ? ?}
> > > ? ? ? ?return 0;
> > > --------------------------------------------------
> > >
> > > Jung-uk Kim
> >
> > I notice you're using FreeBSD 9.0... what version of libpcap?  I
> > wonder if this is a libpcap bug or something in FreeBSD?
>
> I have two machines with identical hardware. They both have an nfe and
> bge interface. I don't use the nfe one at all.
>
> wxs@syn wxs % uname -sr
> FreeBSD 7.1-RELEASE-p5
> wxs@syn wxs % ifconfig -l
> bge0 fwe0 fwip0 nfe0 lo0 pflog0
> wxs@syn wxs % ifconfig nfe0
> nfe0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         options=10b<RXCSUM,TXCSUM,VLAN_MTU,TSO4>
>         ether 00:e0:81:5b:6b:4f
>         media: Ethernet autoselect (none)
>         status: no carrier
> wxs@syn wxs % sudo tcpdump -D
> 1.bge0
> 2.lo0
> wxs@syn wxs % sudo ifconfig nfe0 192.168.3.100/24
> wxs@syn wxs % sudo tcpdump -D                    
> 1.bge0
> 2.nfe0
> 3.lo0
> wxs@syn wxs % tcpdump -V
> tcpdump version 3.9.8
> libpcap version 0.9.8
>
> I get the same results on a 9-CURRENT machine.
>
> That is with tcpdump version 4.0.0 and libpcap version 1.0.0.

Sorry if another one comes through but my first attempt at this message
never made it through.

nfe0 doesn't need to have an IP address, just be up. Maybe that is what
is going on?

-- WXS
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