Function append_nhops

freebsd/net/route/nhgrp_ctl.c:511–554

* Appends one or more nexthops denoted by @wm to the nexthop group @gr_orig. * * Returns referenced nexthop group or NULL. In the latter case, @perror is * filled with an error code. * Note that function does NOT care if the next nexthops already exists * in the @gr_orig. As a result, they will be added, resulting in the * same nexthop being present multiple times in the new group. */

 * same nexthop being present multiple times in the new group.
 */
static struct nhgrp_priv *
append_nhops(struct nh_control *ctl, const struct nhgrp_object *gr_orig,
    struct weightened_nhop *wn, int num_nhops, int *perror)
{
	char storage[64];
	struct weightened_nhop *pnhops;
	struct nhgrp_priv *nhg_priv;
	const struct nhgrp_priv *src_priv;
	size_t sz;
	int curr_nhops;

	src_priv = NHGRP_PRIV_CONST(gr_orig);
	curr_nhops = src_priv->nhg_nh_count;

	*perror = 0;

	sz = (src_priv->nhg_nh_count + num_nhops) * (sizeof(struct weightened_nhop));
	/* optimize for <= 4 paths, each path=16 bytes */
	if (sz <= sizeof(storage))
		pnhops = (struct weightened_nhop *)&storage[0];
	else {
		pnhops = malloc(sz, M_TEMP, M_NOWAIT);
		if (pnhops == NULL) {
			*perror = ENOMEM;
			return (NULL);
		}
	}

	/* Copy nhops from original group first */
	memcpy(pnhops, src_priv->nhg_nh_weights,
	  curr_nhops * sizeof(struct weightened_nhop));
	memcpy(&pnhops[curr_nhops], wn, num_nhops * sizeof(struct weightened_nhop));
	curr_nhops += num_nhops;

	nhg_priv = get_nhgrp(ctl, pnhops, curr_nhops, perror);

	if (pnhops != (struct weightened_nhop *)&storage[0])
		free(pnhops, M_TEMP);

	if (nhg_priv == NULL)
		return (NULL);

	return (nhg_priv);
}


/*