NAME

pfopen − Open a packet filter file

SYNOPSIS

int pfopen(
        char ∗ifname,
        int flags );

LIBRARY

Standard C Library (libc.so, libc.a)

PARAMETERS

ifname
Points to a null-terminated string containing the name of the interface for which the application is opening the packet filter. This name may be the name of an actual interface on the system (for example, ln0) or it may be a pseudo-interface name of the form pfn, used to specify the nth interface attached to the system.  For example, pf0 specifies the first such interface.  If ifname is NULL, the default interface (pf0) is used. 

flagsHas the same meaning as the corresponding argument to the open(2) system call. 

DESCRIPTION

The packet filter (see packetfilter(7)) provides raw access to Ethernets and similar network data link layers. The pfopen() function is used to open a packet filter file descriptor. The function hides various details about the way packet filter files are opened and named. 

The file descriptor returned by pfopen() is otherwise identical to one returned by open(2). 

ERRORS

The pfopen() function returns a negative integer if the file could not be opened. This may be because of resource limitations, or because the specified interface does not exist. 

SEE ALSO

Functions: open(2)

Files: bpf(7), packetfilter(7)