mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-20 11:11:24 +00:00
69 lines
2.4 KiB
Plaintext
69 lines
2.4 KiB
Plaintext
.\" 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.
|
|
.\"
|
|
.TH PCAP_DATALINK 3PCAP "13 October 2013"
|
|
.SH NAME
|
|
pcap_datalink \- get the link-layer header type
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.ft B
|
|
#include <pcap/pcap.h>
|
|
.ft
|
|
.LP
|
|
.ft B
|
|
int pcap_datalink(pcap_t *p);
|
|
.ft
|
|
.fi
|
|
.SH DESCRIPTION
|
|
.B pcap_datalink()
|
|
returns the link-layer header type for the live capture or ``savefile''
|
|
specified by
|
|
.IR p .
|
|
.PP
|
|
It must not be called on a pcap descriptor created by
|
|
.B pcap_create()
|
|
that has not yet been activated by
|
|
.BR pcap_activate() .
|
|
.PP
|
|
.I http://www.tcpdump.org/linktypes.html
|
|
lists the values
|
|
.B pcap_datalink()
|
|
can return and describes the packet formats that
|
|
correspond to those values.
|
|
.PP
|
|
Do
|
|
.B NOT
|
|
assume that the packets for a given capture or ``savefile`` will have
|
|
any given link-layer header type, such as
|
|
.B DLT_EN10MB
|
|
for Ethernet. For example, the "any" device on Linux will have a
|
|
link-layer header type of
|
|
.B DLT_LINUX_SLL
|
|
even if all devices on the system at the time the "any" device is opened
|
|
have some other data link type, such as
|
|
.B DLT_EN10MB
|
|
for Ethernet.
|
|
.SH RETURN VALUE
|
|
.B pcap_datalink()
|
|
returns the link-layer header type on success and
|
|
.B PCAP_ERROR_NOT_ACTIVATED
|
|
if called on a capture handle that has been created but not activated.
|
|
.SH SEE ALSO
|
|
pcap(3PCAP), pcap-linktype(@MAN_MISC_INFO@)
|