Function if_addgroup

freebsd/net/if.c:1495–1559

* Add a group to an interface */

 * Add a group to an interface
 */
int
if_addgroup(struct ifnet *ifp, const char *groupname)
{
	struct ifg_list		*ifgl;
	struct ifg_group	*ifg = NULL;
	struct ifg_member	*ifgm;
	int 			 new = 0;

	if (groupname[0] && groupname[strlen(groupname) - 1] >= '0' &&
	    groupname[strlen(groupname) - 1] <= '9')
		return (EINVAL);

	IFNET_WLOCK();
	CK_STAILQ_FOREACH(ifgl, &ifp->if_groups, ifgl_next)
		if (!strcmp(ifgl->ifgl_group->ifg_group, groupname)) {
			IFNET_WUNLOCK();
			return (EEXIST);
		}

	if ((ifgl = malloc(sizeof(*ifgl), M_TEMP, M_NOWAIT)) == NULL) {
	    	IFNET_WUNLOCK();
		return (ENOMEM);
	}

	if ((ifgm = malloc(sizeof(*ifgm), M_TEMP, M_NOWAIT)) == NULL) {
		free(ifgl, M_TEMP);
		IFNET_WUNLOCK();
		return (ENOMEM);
	}

	CK_STAILQ_FOREACH(ifg, &V_ifg_head, ifg_next)
		if (!strcmp(ifg->ifg_group, groupname))
			break;

	if (ifg == NULL) {
		if ((ifg = malloc(sizeof(*ifg), M_TEMP, M_NOWAIT)) == NULL) {
			free(ifgl, M_TEMP);
			free(ifgm, M_TEMP);
			IFNET_WUNLOCK();
			return (ENOMEM);
		}
		strlcpy(ifg->ifg_group, groupname, sizeof(ifg->ifg_group));
		ifg->ifg_refcnt = 0;
		CK_STAILQ_INIT(&ifg->ifg_members);
		CK_STAILQ_INSERT_TAIL(&V_ifg_head, ifg, ifg_next);
		new = 1;
	}

	ifg->ifg_refcnt++;
	ifgl->ifgl_group = ifg;
	ifgm->ifgm_ifp = ifp;

	IF_ADDR_WLOCK(ifp);
	CK_STAILQ_INSERT_TAIL(&ifg->ifg_members, ifgm, ifgm_next);
	CK_STAILQ_INSERT_TAIL(&ifp->if_groups, ifgl, ifgl_next);
	IF_ADDR_WUNLOCK(ifp);

	IFNET_WUNLOCK();