Propagate DPDK mbuf RX timestamp to FreeBSD mbuf rcv_tstmp #1045

ff_veth_input() in ff_dpdk_if.c never copies mbuf->timestamp from the DPDK mbuf to the FreeBSD mbuf's m_pkthdr.rcv_tstmp . The FreeBSD side already has the full
SO_TIMESTAMP → recvmsg() → SCM_TIMESTAMP path wired up — the timestamp just gets dropped at the DPDK→FreeBSD boundary.

The fix is ~10 lines across ff_veth.c , ff_veth.h , ff_dpdk_if.c :

void ff_mbuf_set_timestamp(void *hdr, uint64_t timestamp) {
    struct mbuf *m = (struct mbuf *)hdr;
    m->m_pkthdr.rcv_tstmp = timestamp;
    m->m_flags |= M_TSTMP | M_TSTMP_HPREC;
Enable RTE_ETH_RX_OFFLOAD_TIMESTAMP on the port when the NIC supports it.
Call the helper in ff_veth_input() when RTE_MBUF_F_RX_IEEE1588_TMST is set:
if (pkt->ol_flags & RTE_MBUF_F_RX_IEEE1588_TMST)
     ff_mbuf_set_timestamp(hdr, pkt->timestamp);
When HW timestamps aren't available the flag is never set, so nothing changes — fully backward compatible.
Happy to raise a PR if you're interested.