On 3/26/19 3:15 PM, Stephen Hemminger wrote:
If mbuf refcnt was > 1 then rte_vlan_insert() would incorrectly
modify the original copy. Original code was expecting clone to make
a copy (it doesn't). Better to let the caller deal with making
a copy or setting up mbuf chain to allow for header to be added.
Also fix docbook comment about parameters (function takes
pointer to mbuf).
Fixes: c974021a5949 ("ether: add soft vlan encap/decap")
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
lib/librte_net/rte_ether.h | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
index c2c5e249ffe9..bab2b198fa79 100644
--- a/lib/librte_net/rte_ether.h
+++ b/lib/librte_net/rte_ether.h
@@ -374,7 +374,7 @@ static inline int rte_vlan_strip(struct rte_mbuf *m)
* Software version of VLAN unstripping
*
* @param m
- * The packet mbuf.
+ * Pointer to the packet mbuf.
* @return
* - 0: On success
* -EPERM: mbuf is is shared overwriting would be unsafe
@@ -385,16 +385,9 @@ static inline int rte_vlan_insert(struct rte_mbuf **m)
struct ether_hdr *oh, *nh;
struct vlan_hdr *vh;
- /* Can't insert header if mbuf is shared */
- if (rte_mbuf_refcnt_read(*m) > 1) {
- struct rte_mbuf *copy;
-
- copy = rte_pktmbuf_clone(*m, (*m)->pool);
- if (unlikely(copy == NULL))
- return -ENOMEM;
- rte_pktmbuf_free(*m);
- *m = copy;
- }
+ /* Can't directly insert header if mbuf is shared */
+ if (rte_mbuf_refcnt_read(*m) > 1)
This check probably isn't sufficient. You need something more like:
if (rte_mbuf_refcnt_read(mbuf) > 1 ||
(RTE_MBUF_INDIRECT(mbuf) &&
rte_mbuf_refcnt_read(rte_mbuf_from_indirect(mbuf)) > 1)) {
If this is a cloned packet, the refcnt will be 1. So you need to examine
the parent mbuf to see if other clones exist.
+ return -EPERM;
oh = rte_pktmbuf_mtod(*m, struct ether_hdr *);
nh = (struct ether_hdr *)
