Re: [PATCH v3 09/10] vmxnet3: add check for jumbo segment

[Yong Wang <yongwang-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>]

On 3/5/15, 4:10 PM, "Stephen Hemminger" <stephen@networkplumber.org> wrote:

>From: Stephen Hemminger <shemming@brocade.com>
>
>It is possible that some rogue application might pass a segment
>larger than 16K to the vmxnet3 transmit routine. In which case
>just drop it and increment counter.
>
>Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

One minor comment below. Otherwise looks good to me.


Acked-by: Yong Wang <yongwang@vmware.com>

>---
> lib/librte_pmd_vmxnet3/vmxnet3_ring.h |  1 +
> lib/librte_pmd_vmxnet3/vmxnet3_rxtx.c | 18 ++++++++++++++++++
> 2 files changed, 19 insertions(+)
>
>diff --git a/lib/librte_pmd_vmxnet3/vmxnet3_ring.h
>b/lib/librte_pmd_vmxnet3/vmxnet3_ring.h
>index 55ceadf..5cdcb23 100644
>--- a/lib/librte_pmd_vmxnet3/vmxnet3_ring.h
>+++ b/lib/librte_pmd_vmxnet3/vmxnet3_ring.h
>@@ -126,6 +126,7 @@ struct vmxnet3_txq_stats {
> 				     * different reasons
> 				     */
> 	uint64_t	drop_too_many_segs;
>+	uint64_t	drop_too_big;
> 	uint64_t	drop_tso;
> 	uint64_t	tx_ring_full;
> };
>diff --git a/lib/librte_pmd_vmxnet3/vmxnet3_rxtx.c
>b/lib/librte_pmd_vmxnet3/vmxnet3_rxtx.c
>index 3bd13ef..f6c3452 100644
>--- a/lib/librte_pmd_vmxnet3/vmxnet3_rxtx.c
>+++ b/lib/librte_pmd_vmxnet3/vmxnet3_rxtx.c
>@@ -327,6 +327,17 @@ vmxnet3_tq_tx_complete(vmxnet3_tx_queue_t *txq)
> 	PMD_TX_LOG(DEBUG, "Processed %d tx comps & command descs.", completed);
> }
> 
>+static inline int
>+vmxnet3_seg_too_big(const struct rte_mbuf *m)
>+{
>+	do {
>+		if (m->data_len > VMXNET3_MAX_TX_BUF_SIZE)
>+			return 1;
>+	} while  ((m = m->next) != NULL);

nit: extra space after "while”.

>+
>+	return 0;
>+}
>+
> uint16_t
> vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> 		  uint16_t nb_pkts)
>@@ -353,6 +364,13 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf
>**tx_pkts,
> 		/* Is this packet execessively fragmented, then drop */
> 		if (unlikely(txm->nb_segs > VMXNET3_MAX_TXD_PER_PKT)) {
> 			++txq->stats.drop_too_many_segs;
>+			goto drop;
>+		}
>+
>+		/* Check for case of monster segment */
>+		if (unlikely(vmxnet3_seg_too_big(txm))) {
>+			++txq->stats.drop_too_big;
>+		drop:
> 			++txq->stats.drop_total;
> 			rte_pktmbuf_free(txm);
> 			++nb_tx;
>-- 
>2.1.4
>