the-tcpdump-group/libpcap — pull request #346 by atzm (2014-03-31 07:50:49+00:00)
Title: pcap-linux: Obtain VLAN TPID from the kernel when available

The VLAN TPID was hardcoded in pcap-linux.c but recent Linux kernel
supports 802.1ad Q-in-Q.
Since Linux 3.14, kernel gives the TPID value to the userspace when
available.