Function vxlan_socket_mc_add_group

freebsd/net/if_vxlan.c:1242–1304

}

static int
vxlan_socket_mc_add_group(struct vxlan_socket *vso,
    const union vxlan_sockaddr *group, const union vxlan_sockaddr *local,
    int ifidx, int *idx)
{
	union vxlan_sockaddr source;
	struct vxlan_socket_mc_info *mc;
	int i, empty, error;

	/*
	 * Within a socket, the same multicast group may be used by multiple
	 * interfaces, each with a different network identifier. But a socket
	 * may only join a multicast group once, so keep track of the users
	 * here.
	 */

	VXLAN_SO_WLOCK(vso);
	for (empty = 0, i = 0; i < VXLAN_SO_MC_MAX_GROUPS; i++) {
		mc = &vso->vxlso_mc[i];

		if (mc->vxlsomc_gaddr.sa.sa_family == AF_UNSPEC) {
			empty++;
			continue;
		}

		if (vxlan_sockaddr_mc_info_match(mc, group, local, ifidx))
			goto out;
	}
	VXLAN_SO_WUNLOCK(vso);

	if (empty == 0)
		return (ENOSPC);

	error = vxlan_socket_mc_join_group(vso, group, local, &ifidx, &source);
	if (error)
		return (error);

	VXLAN_SO_WLOCK(vso);
	for (i = 0; i < VXLAN_SO_MC_MAX_GROUPS; i++) {
		mc = &vso->vxlso_mc[i];

		if (mc->vxlsomc_gaddr.sa.sa_family == AF_UNSPEC) {
			vxlan_sockaddr_copy(&mc->vxlsomc_gaddr, &group->sa);
			vxlan_sockaddr_copy(&mc->vxlsomc_saddr, &source.sa);
			mc->vxlsomc_ifidx = ifidx;
			goto out;
		}
	}
	VXLAN_SO_WUNLOCK(vso);

	error = vxlan_socket_mc_leave_group(vso, group, &source, ifidx);
	MPASS(error == 0);

	return (ENOSPC);

out:
	mc->vxlsomc_users++;
	VXLAN_SO_WUNLOCK(vso);