From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [net-next 5/5] net_sched: better precise estimation on packet length for untrusted packets Date: Tue, 26 Mar 2013 14:19:59 +0800 Message-ID: <1364278799-37285-6-git-send-email-jasowang@redhat.com> References: <1364278799-37285-1-git-send-email-jasowang@redhat.com> Cc: mst@redhat.com, Jason Wang , Eric Dumazet To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1364278799-37285-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 Signed-off-by: Jason Wang --- net/core/dev.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index de930b7..f5ad23b 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; } } -- 1.7.1