> -----Original Message-----
> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Stephen Hemminger
> Sent: Saturday, September 28, 2019 2:38 AM
>
> This is a commonly used operation that surprisingly the
> DPDK has not supported. The new rte_pktmbuf_copy does a
> deep copy of packet. This is a complete copy including
> meta-data.
>
> It handles the case where the source mbuf comes from a pool
> with larger data area than the destination pool. The routine
> also has options for skipping data, or truncating at a fixed
> length.
Great initiative, and the offset/length params makes it even better!
>
> Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
> ---
> lib/librte_mbuf/rte_mbuf.c | 70 ++++++++++++++++++++++++++++
> lib/librte_mbuf/rte_mbuf.h | 26 +++++++++++
> lib/librte_mbuf/rte_mbuf_version.map | 1 +
> 3 files changed, 97 insertions(+)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
> index 12d0258a120d..6888d6bd5dfc 100644
> --- a/lib/librte_mbuf/rte_mbuf.c
> +++ b/lib/librte_mbuf/rte_mbuf.c
> @@ -324,6 +324,76 @@ rte_pktmbuf_linearize(struct rte_mbuf *mbuf)
> return 0;
> }
>
> +/* Create a deep copy of mbuf */
> +struct rte_mbuf *
> +rte_pktmbuf_copy(const struct rte_mbuf *m, struct rte_mempool *mp,
> + uint32_t off, uint32_t len)
> +{
> + const struct rte_mbuf *seg = m;
> + struct rte_mbuf *mc, *m_last, **prev;
> +
> + if (unlikely(off >= m->pkt_len))
> + return NULL;
> +
> + mc = rte_pktmbuf_alloc(mp);
> + if (unlikely(mc == NULL))
> + return NULL;
> +
> + if (len > m->pkt_len - off)
> + len = m->pkt_len - off;
> +
> + /* clone meta data from original */
> + mc->port = m->port;
> + mc->vlan_tci = m->vlan_tci;
> + mc->vlan_tci_outer = m->vlan_tci_outer;
> + mc->tx_offload = m->tx_offload;
> + mc->hash = m->hash;
> + mc->packet_type = m->packet_type;
> + mc->timestamp = m->timestamp;
At the dynamic mbuf presentation at DPDK Userspace, it was mentioned that the
last 8 bytes of the mbuf could be used by applications. Consider if their
values should be copied too, and thus if they should be explicitly define in
the mbuf, e.g. dynfield[1,2] like in the dynamic mbuf patch. I don't have an
opinion on this, I'm just bringing it to your attention.
Med venlig hilsen / kind regards
- Morten Brørup
