Re: [PATCH net-next v3 1/4] net: sched: em_ipt: match only on ip/ipv6 traffic
From: Eyal Birger <hidden>
Date: 2019-06-27 16:02:48
Hi Nik, On Thu, 27 Jun 2019 11:10:44 +0300 Nikolay Aleksandrov [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Restrict matching only to ip/ipv6 traffic and make sure we can use the headers, otherwise matches will be attempted on any protocol which can be unexpected by the xt matches. Currently policy supports only ipv4/6. Signed-off-by: Nikolay Aleksandrov <redacted> --- v3: no change v2: no change net/sched/em_ipt.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)diff --git a/net/sched/em_ipt.c b/net/sched/em_ipt.c index 243fd22f2248..64dbafe4e94c 100644 --- a/net/sched/em_ipt.c +++ b/net/sched/em_ipt.c@@ -185,6 +185,19 @@ static int em_ipt_match(struct sk_buff *skb,struct tcf_ematch *em, struct nf_hook_state state; int ret; + switch (tc_skb_protocol(skb)) { + case htons(ETH_P_IP): + if (!pskb_network_may_pull(skb, sizeof(struct iphdr))) + return 0; + break; + case htons(ETH_P_IPV6): + if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr))) + return 0; + break; + default: + return 0; + } +
I just realized that I didn't consider the egress direction in my review. Don't we need an skb_pull() in that direction to make the skb->data point to L3? I see this is done e.g. in em_ipset. Eyal.