From 15e5a030716468dce4032fa0f398d840fa2756f6 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Mon, 25 Mar 2013 20:19:59 +0000
Subject: [PATCH] net_sched: better precise estimation on packet length for
untrusted packets
gso_segs were reset to zero when kernel receive packets from untrusted
source. But we use this zero value to estimate precise packet len which is
wrong. So this patch tries to estimate the correct gso_segs value before using
it in qdisc_pkt_len_init().
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/core/dev.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index de930b751712..f5ad23bb24fc 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2588,6 +2588,7 @@ static void qdisc_pkt_len_init(struct sk_buff *skb)
*/
if (shinfo->gso_size) {
unsigned int hdr_len;
+ u16 gso_segs = shinfo->gso_segs;
/* mac layer + network layer */
hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
@@ -2597,7 +2598,12 @@ static void qdisc_pkt_len_init(struct sk_buff *skb)
hdr_len += tcp_hdrlen(skb);
else
hdr_len += sizeof(struct udphdr);
- qdisc_skb_cb(skb)->pkt_len += (shinfo->gso_segs - 1) * hdr_len;
+
+ if (shinfo->gso_type & SKB_GSO_DODGY)
+ gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
+ shinfo->gso_size);
+
+ qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
}
}
--
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