DPDK patches and discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Andrew Rybchenko <arybchenko@solarflare.com>
Cc: Olivier Matz <olivier.matz@6wind.com>, <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] ether: check the first segment length on SW VLAN insertion
Date: Thu, 28 May 2020 22:43:48 -0700
Message-ID: <20200528224348.261307f7@hermes.lan> (raw)
In-Reply-To: <1590589902-31034-1-git-send-email-arybchenko@solarflare.com>

On Wed, 27 May 2020 15:31:41 +0100
Andrew Rybchenko <arybchenko@solarflare.com> wrote:

> SW VLAN insertion relies on Ethernet addresses location in contigous
> memory (do not split across mbuf segments). There is no any formal
> requirements on data location and mbuf structure which guarantee it.
> So, check it explicitly to avoid corrupted packets if the condition
> is violated. Typically software VLAN insertion is done on Tx prepare
> stage and application will get indication that the packet is invalid
> and cannot be transmitted.
> 
> Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
> ---
>  lib/librte_net/rte_ether.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
> index 0ae4e75b6c..d7c076bba8 100644
> --- a/lib/librte_net/rte_ether.h
> +++ b/lib/librte_net/rte_ether.h
> @@ -357,6 +357,10 @@ static inline int rte_vlan_insert(struct rte_mbuf **m)
>  	if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1)
>  		return -EINVAL;
>  
> +	/* Can't insert header if the first segment is too short */
> +	if (rte_pktmbuf_data_len(*m) < 2 * RTE_ETHER_ADDR_LEN)
> +		return -EINVAL;

Looks good, but you could also make it handle the fragment case with:

diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
index 0ae4e75b6c58..4d0e310a4fac 100644
--- a/lib/librte_net/rte_ether.h
+++ b/lib/librte_net/rte_ether.h
@@ -350,14 +350,18 @@ static inline int rte_vlan_strip(struct rte_mbuf *m)
  */
 static inline int rte_vlan_insert(struct rte_mbuf **m)
 {
-	struct rte_ether_hdr *oh, *nh;
+	struct rte_ether_hdr *nh, tmp;
+	const struct rte_ether_hdr *oh;
 	struct rte_vlan_hdr *vh;
 
 	/* Can't insert header if mbuf is shared */
 	if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1)
 		return -EINVAL;
 
-	oh = rte_pktmbuf_mtod(*m, struct rte_ether_hdr *);
+	oh = rte_pktmbuf_read(*m, 0, sizeof(*oh), &tmp);
+	if (unlikely(oh == NULL))
+		return -EINVAL;
+
 	nh = (struct rte_ether_hdr *)
 		rte_pktmbuf_prepend(*m, sizeof(struct rte_vlan_hdr));
 	if (nh == NULL)

  reply	other threads:[~2020-05-29  5:44 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-27 14:31 Andrew Rybchenko
2020-05-29  5:43 ` Stephen Hemminger [this message]
2020-06-25 12:27   ` Andrew Rybchenko
2020-09-14 13:09     ` Ferruh Yigit

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200528224348.261307f7@hermes.lan \
    --to=stephen@networkplumber.org \
    --cc=arybchenko@solarflare.com \
    --cc=dev@dpdk.org \
    --cc=olivier.matz@6wind.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ https://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git