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From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Stephen Hemminger <stephen@networkplumber.org>,
	Stephen Hemminger <sthemmin@microsoft.com>
Subject: [dpdk-dev] [PATCH] net: fix rte_vlan_insert with shared mbuf
Date: Tue, 26 Mar 2019 12:15:15 -0700	[thread overview]
Message-ID: <20190326191516.20675-1-stephen@networkplumber.org> (raw)
Message-ID: <20190326191515.VICI4PBYt3TUPlFBsgcAzX5JKBsg2ltLrABRa4eVj5Y@z> (raw)

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 <sthemmin@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)
+		return -EPERM;
 
 	oh = rte_pktmbuf_mtod(*m, struct ether_hdr *);
 	nh = (struct ether_hdr *)
-- 
2.17.1


             reply	other threads:[~2019-03-26 19:15 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-26 19:15 Stephen Hemminger [this message]
2019-03-26 19:15 ` Stephen Hemminger
2019-03-26 22:38 ` Chas Williams
2019-03-26 22:38   ` Chas Williams
2019-03-27 15:18   ` Stephen Hemminger
2019-03-27 15:18     ` Stephen Hemminger
2019-03-27 15:31     ` Chas Williams
2019-03-27 15:31       ` Chas Williams
2019-03-28 14:04       ` Ferruh Yigit
2019-03-28 14:04         ` Ferruh Yigit
2019-03-28 20:53         ` [dpdk-dev] [RFC v2] " Stephen Hemminger
2019-03-28 20:53           ` Stephen Hemminger
2019-03-30 12:41           ` Chas Williams
2019-03-30 12:41             ` Chas Williams
2019-04-04 23:54             ` Stephen Hemminger
2019-04-04 23:54               ` Stephen Hemminger
2019-04-06 23:11               ` Chas Williams
2019-04-06 23:11                 ` Chas Williams
2019-04-12 16:35           ` Ferruh Yigit
2019-04-12 16:35             ` Ferruh Yigit
2019-07-04 18:40             ` Ferruh Yigit

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