On 07/10/2015 01:37 AM, Stephen Hemminger wrote:
> From: Stephen Hemminger <shemming at brocade.com>
>
> Added rte_pktmbuf_copy() function since copying multi-part
> segments is common issue and can be problematic.
>
> Signed-off-by: Mike Davison <mdavison at brocade.com>
> Reviewed-by: Stephen Hemminger <shemming at brocade.com>
> ---
> lib/librte_mbuf/rte_mbuf.h | 59
> ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index 80419df..f0a543b 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -60,6 +60,7 @@
> #include <rte_atomic.h>
> #include <rte_prefetch.h>
> #include <rte_branch_prediction.h>
> +#include <rte_memcpy.h>
>
> #ifdef __cplusplus
> extern "C" {
> @@ -1272,6 +1273,64 @@ static inline int rte_pktmbuf_is_contiguous(const
> struct rte_mbuf *m)
> return !!(m->nb_segs == 1);
> }
>
> +/*
> + * Creates a copy of the given packet mbuf.
> + *
> + * Walks through all segments of the given packet mbuf, and for each of them:
> + * - Creates a new packet mbuf from the given pool.
> + * - Copy segment to newly created mbuf.
> + * Then updates pkt_len and nb_segs of the new packet mbuf to match values
> + * from the original packet mbuf.
> + *
> + * @param md
> + * The packet mbuf to be copied.
> + * @param mp
> + * The mempool from which the mbufs are allocated.
> + * @return
> + * - The pointer to the new mbuf on success.
> + * - NULL if allocation fails.
> + */
> +static inline struct rte_mbuf *rte_pktmbuf_copy(struct rte_mbuf *md,
> + struct rte_mempool *mp)
> +{
> + struct rte_mbuf *mc = NULL;
> + struct rte_mbuf **prev = &mc;
> +
> + do {
> + struct rte_mbuf *mi;
> +
> + mi = rte_pktmbuf_alloc(mp);
> + if (unlikely(mi == NULL)) {
> + rte_pktmbuf_free(mc);
> + return NULL;
> + }
> +
I think we should check that the destination mbuf is large enough
to store the segment data. Then we have 2 options on failure:
- split the original segment into several destination segments
- return an error
> + mi->data_off = md->data_off;
> + mi->data_len = md->data_len;
> + mi->port = md->port;
> + mi->vlan_tci = md->vlan_tci;
> + mi->tx_offload = md->tx_offload;
> + mi->hash = md->hash;
> +
> + mi->next = NULL;
> + mi->pkt_len = md->pkt_len;
> + mi->nb_segs = md->nb_segs;
> + mi->ol_flags = md->ol_flags;
> + mi->packet_type = md->packet_type;
> +
> + rte_memcpy(rte_pktmbuf_mtod(mi, char *),
> + rte_pktmbuf_mtod(md, char *),
> + md->data_len);
> +
> + *prev = mi;
> + prev = &mi->next;
> + } while ((md = md->next) != NULL);
> +
> + *prev = NULL;
> + __rte_mbuf_sanity_check(mc, 1);
> + return mc;
> +}
> +
> /**
> * Dump an mbuf structure to the console.
> *
>
