diff options
Diffstat (limited to 'contrib/libpcap/pcap_datalink.3pcap.in')
| -rw-r--r-- | contrib/libpcap/pcap_datalink.3pcap.in | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/contrib/libpcap/pcap_datalink.3pcap.in b/contrib/libpcap/pcap_datalink.3pcap.in index 3d4ace1d794c..b07fc28f0982 100644 --- a/contrib/libpcap/pcap_datalink.3pcap.in +++ b/contrib/libpcap/pcap_datalink.3pcap.in @@ -1,5 +1,3 @@ -.\" @(#) $Header: /tcpdump/master/libpcap/pcap_datalink.3pcap.in,v 1.1 2008-10-21 07:33:02 guy Exp $ -.\" .\" Copyright (c) 1994, 1996, 1997 .\" The Regents of the University of California. All rights reserved. .\" @@ -19,7 +17,7 @@ .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. .\" -.TH PCAP_DATALINK 3PCAP "22 August 2010" +.TH PCAP_DATALINK 3PCAP "13 October 2013" .SH NAME pcap_datalink \- get the link-layer header type .SH SYNOPSIS @@ -37,5 +35,34 @@ int pcap_datalink(pcap_t *p); 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@) |