bpf_filter
slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
slen = bpf_filter(bpf->bf_insn, (u_char *)m, m_lengthm(m, NULL), 0);
len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
len = bpf_filter(hip->prog->bpf_prog, (u_char *)m, totlen, 0);