Message ID | 1322548235.2970.57.camel@edumazet-laptop |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 29 Nov 2011 07:30:35 +0100 > [PATCH net-next] flow_dissector: use a 64bit load/store > > gcc compiler is smart enough to use a single load/store if we > memcpy(dptr, sptr, 8) on x86_64, regardless of > CONFIG_CC_OPTIMIZE_FOR_SIZE > > In IP header, daddr immediately follows saddr, this wont change in the > future. We only need to make sure our flow_keys (src,dst) fields wont > break the rule. > > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h index e4cb285..80461c1 100644 --- a/include/net/flow_keys.h +++ b/include/net/flow_keys.h @@ -2,6 +2,7 @@ #define _NET_FLOW_KEYS_H struct flow_keys { + /* (src,dst) must be grouped, in the same way than in IP header */ __be32 src; __be32 dst; union { diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index f0516d9..87bb35c 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -8,6 +8,16 @@ #include <linux/ppp_defs.h> #include <net/flow_keys.h> +/* copy saddr & daddr, possibly using 64bit load/store + * Equivalent to : flow->src = iph->saddr; + * flow->dst = iph->daddr; + */ +static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) +{ + BUILD_BUG_ON(offsetof(typeof(*flow), dst) != + offsetof(typeof(*flow), src) + sizeof(flow->src)); + memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); +} bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) { @@ -31,8 +41,7 @@ ip: ip_proto = 0; else ip_proto = iph->protocol; - flow->src = iph->saddr; - flow->dst = iph->daddr; + iph_to_flow_copy_addrs(flow, iph); nhoff += iph->ihl * 4; break; }