Re: net: rps: support 802.1Q
flat view
From: Ben Hutchings <hidden>
Date: 2011-08-19 11:54:17
On Fri, 2011-08-19 at 13:05 +0800, Changli Gao wrote:
For the 802.1Q packets, if the NIC doesn't support hw-accel-vlan-rx, RPS won't inspect the internal 4 tuples to generate skb->rxhash, so this kind of traffic can't get any benefit from RPS. This patch adds the support for 802.1Q to RPS.
[...]
quoted hunk ↗ jump to hunk
@@ -2565,6 +2566,13 @@ again: addr2 = (__force u32) ip6->daddr.s6_addr32[3]; nhoff += 40; break; + case __constant_htons(ETH_P_8021Q): + if (!pskb_may_pull(skb, sizeof(*vlan) + nhoff)) + goto done; + vlan = (const struct vlan_hdr *) (skb->data + nhoff); + proto = vlan->h_vlan_encapsulated_proto; + nhoff += sizeof(*vlan); + goto again; default: goto done; }
Should this really be reading an unlimited number of tags? What if an attacker starts sending packets full of VLAN tags? Since this runs before netfilter, there would be no way to prevent those packets burning our CPU time. And if there are legitimately multiple VLAN tags, they presumably won't all have the 802.1q Ethertype. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.