+----------------------------------------------------------------------------+ | | | This man page documents libpcap version 1.10.4. | | | | Your system may have a different version installed, possibly with some | | local modifications. To achieve the best results, please make sure this | | version of this man page suits your needs. If necessary, try to look for | | a different version on this web site or in the man pages available in your | | installation. | | | +----------------------------------------------------------------------------+ PCAP_DATALINK(3PCAP) PCAP_DATALINK(3PCAP) NAME pcap_datalink - get the link-layer header type SYNOPSIS #include int pcap_datalink(pcap_t *p); DESCRIPTION pcap_datalink() returns the link-layer header type for the live capture or ``savefile'' specified by p. It must not be called on a pcap descriptor created by pcap_create(3PCAP) that has not yet been activated by pcap_activate(3PCAP). https://www.tcpdump.org/linktypes.html lists the values pcap_datalink() can return and describes the packet formats that correspond to those values. Do NOT assume that the packets for a given capture or ``savefile`` will have any given link-layer header type, such as DLT_EN10MB for Ethernet. For example, the "any" device on Linux will have a link-layer header type of DLT_LINUX_SLL or DLT_LINUX_SLL2 even if all devices on the sys- tem at the time the "any" device is opened have some other data link type, such as DLT_EN10MB for Ethernet. RETURN VALUE pcap_datalink() returns the link-layer header type on success and PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been created but not activated. SEE ALSO pcap(3PCAP), pcap-linktype(7) 7 April 2014 PCAP_DATALINK(3PCAP)