libpcap-ruby doesn't work with ppp devices

[Hadmut Danisch]

Binary package hint: libpcap-ruby1.8

Hi,

the libpcap-ruby1.8 does not seem to work with ppp devices.

I ran the example program /usr/share/doc/libpcap-ruby1.8/examples/httpdump.rb on a computer that is connected with Ethernet to a LAN, and it worked.

I tried the same example on a computer that is not connected through ethernet, but with a UMTS mobile phone via USB, /dev/ttyACM0 and a ppp daemon. The daemon opens the IP interface ppp0, which is a point-to-point-Interface:

# ifconfig ppp0
ppp0 Link encap:Point-to-Point Protocol
          inet addr:10.161.204.249 P-t-P:10.6.6.6 Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
          RX packets:4410 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3662 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:5304327 (5.0 MB) TX bytes:346052 (337.9 KB)

In order to use that interface I modified the example program and added "-i ppp0":

   httpdump = Pcaplet.new('-s 1500 -i ppp0')

When i run it, it waits. But when I issue the first HTTP request the program aborts with the
error message

# ruby /tmp/httpdump.rb
1 packets received by filter
0 packets dropped by kernel
/usr/lib/ruby/1.8/pcaplet.rb:90:in `loop': Unknown data-link type (113) (Pcap::PcapError)
        from /usr/lib/ruby/1.8/pcaplet.rb:90:in `each_packet'
        from /tmp/httpdump.rb:9

libpcap0.8 defines type 113 as

#define LINKTYPE_LINUX_SLL 113 /* Linux cooked socket capture */

so this is a regular type and should be supported.

regards
Hadmut

[Antono Vasiljev (antono)]

same bug
Unknown data-link type (113) (Pcap::PcapError)
whery trying to use -s ppp0