+----------------------------------------------------------------------------+ | | | This man page documents libpcap version 1.11.0-PRE-GIT. | | | | 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_SET_PROTOCOL_LINUX(3PCAP) PCAP_SET_PROTOCOL_LINUX(3PCAP) NAME pcap_set_protocol_linux - set capture protocol for a not-yet-activated capture handle SYNOPSIS #include int pcap_set_protocol_linux(pcap_t *p, int protocol); DESCRIPTION On network interface devices on Linux, pcap_set_protocol_linux() sets the protocol to be used in the socket(2) call to create a capture socket when the handle is activated. The argument is a link-layer pro- tocol value, such as the values in the header file, specified in host byte order. If protocol is non-zero, packets of that protocol will be captured when the handle is activated, otherwise, all packets will be captured. This function is only provided on Linux, and, if it is used on any device other than a network interface, it will have no effect. It should not be used in portable code; instead, a filter should be specified with pcap_setfilter(3PCAP). If a given network interface provides a standard link-layer header, with a standard packet type, but provides some packet types with a dif- ferent socket-layer protocol type from the one in the link-layer header, that packet type cannot be filtered with a filter specified with pcap_setfilter() but can be filtered by specifying the socket- layer protocol type using pcap_set_protocol_linux(). RETURN VALUE pcap_set_protocol_linux() returns 0 on success or PCAP_ERROR_ACTIVATED if called on a capture handle that has been activated. BACKWARD COMPATIBILITY This function became available in libpcap release 1.9.0. SEE ALSO pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP) 22 August 2018 PCAP_SET_PROTOCOL_LINUX(3PCAP)