Updated: 2021/Apr/14

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

     bpf - Berkeley Packet Filter kernel interface

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

     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_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.

     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

NetBSD 9.99                      June 25, 2018                     NetBSD 9.99