MPLS_STACK_BOTTOM
if (pkt_dev->labels[i] & MPLS_STACK_BOTTOM)
pkt_dev->labels[i] = MPLS_STACK_BOTTOM |
*mpls++ = pkt_dev->labels[i] & ~MPLS_STACK_BOTTOM;
*mpls |= MPLS_STACK_BOTTOM;
if (pkt_dev->labels[n] & MPLS_STACK_BOTTOM)