bpf_validate
if (!bpf_validate(fr->fr_data, bpf.bf_len)) {
extern int bpf_validate(struct bpf_insn *, int);
extern int bpf_validate();
if (!bpf_validate(ptr, fp->fr_dsize/sizeof(struct bpf_insn))) {
if (bpf_validate(fcode, (int)prog.bf_len)) {
if (bpf_validate(fcode, (int)flen)) {
extern int bpf_validate(struct bpf_insn *, int);