Function ng_bpf_setprog

freebsd/netgraph/ng_bpf.c:554–593

* Set the BPF program associated with a hook */

 * Set the BPF program associated with a hook
 */
static int
ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
{
	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
	struct ng_bpf_hookprog *hp;
#ifdef BPF_JITTER
	bpf_jit_filter *jit_prog;
#endif
	int size;

	/* Check program for validity */
	if (hp0->bpf_prog_len > bpf_maxinsns ||
	    !bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
		return (EINVAL);

	/* Make a copy of the program */
	size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
	hp = malloc(size, M_NETGRAPH_BPF, M_NOWAIT);
	if (hp == NULL)
		return (ENOMEM);
	bcopy(hp0, hp, size);
#ifdef BPF_JITTER
	jit_prog = bpf_jitter(hp->bpf_prog, hp->bpf_prog_len);
#endif

	/* Free previous program, if any, and assign new one */
	if (hip->prog != NULL)
		free(hip->prog, M_NETGRAPH_BPF);
	hip->prog = hp;
#ifdef BPF_JITTER
	if (hip->jit_prog != NULL)
		bpf_destroy_jit_filter(hip->jit_prog);
	hip->jit_prog = jit_prog;
#endif

	/* Prepare direct references on target hooks. */
	hip->match = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifMatch);
	hip->nomatch = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifNotMatch);
	return (0);
}