netbsd man page for bpf

BPF(9)							   BSD Kernel Developer's Manual						    BPF(9)

NAME
     bpf -- Berkeley Packet Filter kernel interface

SYNOPSIS
     #include <sys/mbuf.h>
     #include <net/bpf.h>

DESCRIPTION
     bpf is called via an operations vector described by the following struct:

     struct bpf_ops {
	     void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
	     void (*bpf_detach)(struct ifnet *);
	     void (*bpf_change_type)(struct ifnet *, u_int, u_int);

	     void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
	     void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
	     void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
	     void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
	     void (*bpf_mtap_et)(struct bpf_if *, uint16_t, struct mbuf *);
	     void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
	     void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
     };

     This vector is found from struct bpf_ops * bpf_ops.  It is either a ``stub'' implementation or a real implementation, depending on whether
     bpf is absent or present in the kernel, respectively.

CODE REFERENCES
     The bpf implementation is located in sys/net/bpf.c, the stub implementation is in sys/net/bpf_stub.c, and sys/net/bpf.h describes the inter-
     face.

BSD
								   June 8, 2010 							       BSD