Copyright (c) 1994, 1996, 1997
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that: (1) source code distributions
retain the above copyright notice and this paragraph in its entirety, (2)
distributions including binary code include the above copyright notice and
this paragraph in its entirety in the documentation or other materials
provided with the distribution, and (3) all advertising materials mentioning
features or use of this software display the following acknowledgement:
``This product includes software developed by the University of California,
Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
the University nor the names of its contributors may be used to endorse
or promote products derived from this software without specific prior
written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that: (1) source code distributions
retain the above copyright notice and this paragraph in its entirety, (2)
distributions including binary code include the above copyright notice and
this paragraph in its entirety in the documentation or other materials
provided with the distribution, and (3) all advertising materials mentioning
features or use of this software display the following acknowledgement:
``This product includes software developed by the University of California,
Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
the University nor the names of its contributors may be used to endorse
or promote products derived from this software without specific prior
written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
PCAP_DATALINK 3PCAP "7 April 2014"
NAME
pcap_datalink - get the link-layer header type
SYNOPSIS
#include <pcap/pcap.h>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 system 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 (@MAN_MISC_INFO@)