On 11 Jun 2018, at 18:21, Tiago Lam wrote:
From: Mark Kavanagh <[email protected]>
dp_packets are created using xmalloc(); in the case of OvS-DPDK, it's
possible the the resultant mbuf portion of the dp_packet contains
random data. For some mbuf fields, specifically those related to
multi-segment mbufs and/or offload features, random values may cause
unexpected behaviour, should the dp_packet's contents be later copied
to a DPDK mbuf. It is critical therefore, that these fields should be
initialized to 0.
This patch ensures that the following mbuf fields are initialized to
appropriate values on creation of a new dp_packet:
- ol_flags=0
- nb_segs=1
- tx_offload=0
- packet_type=0
- next=NULL
Adapted from an idea by Michael Qiu <[email protected]>:
https://patchwork.ozlabs.org/patch/777570/
Co-authored-by: Tiago Lam <[email protected]>
Signed-off-by: Mark Kavanagh <[email protected]>
Signed-off-by: Tiago Lam <[email protected]>
---
lib/dp-packet.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/lib/dp-packet.h b/lib/dp-packet.h
index 596cfe6..82e45ad 100644
--- a/lib/dp-packet.h
+++ b/lib/dp-packet.h
@@ -626,13 +626,15 @@ dp_packet_mbuf_rss_flag_reset(struct dp_packet
*p OVS_UNUSED)
/* This initialization is needed for packets that do not come
* from DPDK interfaces, when vswitchd is built with --with-dpdk.
- * The DPDK rte library will still otherwise manage the mbuf.
- * We only need to initialize the mbuf ol_flags. */
+ * The DPDK rte library will still otherwise manage the mbuf. */
static inline void
dp_packet_mbuf_init(struct dp_packet *p OVS_UNUSED)
{
#ifdef DPDK_NETDEV
- p->mbuf.ol_flags = 0;
+ struct rte_mbuf *mbuf = &(p->mbuf);
+ mbuf->ol_flags = mbuf->tx_offload = mbuf->packet_type = 0;
+ mbuf->nb_segs = 1;
+ mbuf->next = NULL;
Are we sure this is all we need? Asking as rte_pktmbuf_reset() cleans of
some more field, so want to make sure we hit all the corner cases.
Unfortunately, we can not use it here due to the sanity check.
#endif
}
--
2.7.4
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