From c56fd7ebd442c7986826dad06c7aff402bafb144 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 30 Nov 2011 19:00:53 +0000
Subject: [PATCH] --- yaml --- r: 278320 b: refs/heads/master c:
 84f9307c5da84a7c8513e7607dc8427d2cbd63e3 h: refs/heads/master v: v3

---
 [refs]                     |  2 +-
 trunk/include/net/flow.h   |  5 ++++-
 trunk/net/ipv4/ip_output.c | 21 +++++++++++++++++----
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index f2078136a2d0..f70d7edba948 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 898f73585bbe4bdbb471636ecdede071f7473e51
+refs/heads/master: 84f9307c5da84a7c8513e7607dc8427d2cbd63e3
diff --git a/trunk/include/net/flow.h b/trunk/include/net/flow.h
index a09447749e2d..9192d690b562 100644
--- a/trunk/include/net/flow.h
+++ b/trunk/include/net/flow.h
@@ -59,8 +59,11 @@ struct flowi4 {
 #define flowi4_proto		__fl_common.flowic_proto
 #define flowi4_flags		__fl_common.flowic_flags
 #define flowi4_secid		__fl_common.flowic_secid
-	__be32			daddr;
+
+	/* (saddr,daddr) must be grouped, same order as in IP header */
 	__be32			saddr;
+	__be32			daddr;
+
 	union flowi_uli		uli;
 #define fl4_sport		uli.ports.sport
 #define fl4_dport		uli.ports.dport
diff --git a/trunk/net/ipv4/ip_output.c b/trunk/net/ipv4/ip_output.c
index 0bc95f3977d2..0d5e5672f3d1 100644
--- a/trunk/net/ipv4/ip_output.c
+++ b/trunk/net/ipv4/ip_output.c
@@ -319,6 +319,20 @@ int ip_output(struct sk_buff *skb)
 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
 }
 
+/*
+ * copy saddr and daddr, possibly using 64bit load/stores
+ * Equivalent to :
+ *   iph->saddr = fl4->saddr;
+ *   iph->daddr = fl4->daddr;
+ */
+static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4)
+{
+	BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) !=
+		     offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr));
+	memcpy(&iph->saddr, &fl4->saddr,
+	       sizeof(fl4->saddr) + sizeof(fl4->daddr));
+}
+
 int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl)
 {
 	struct sock *sk = skb->sk;
@@ -381,8 +395,8 @@ int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl)
 		iph->frag_off = 0;
 	iph->ttl      = ip_select_ttl(inet, &rt->dst);
 	iph->protocol = sk->sk_protocol;
-	iph->saddr    = fl4->saddr;
-	iph->daddr    = fl4->daddr;
+	ip_copy_addrs(iph, fl4);
+
 	/* Transport layer set skb->h.foo itself. */
 
 	if (inet_opt && inet_opt->opt.optlen) {
@@ -1337,8 +1351,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
 	ip_select_ident(iph, &rt->dst, sk);
 	iph->ttl = ttl;
 	iph->protocol = sk->sk_protocol;
-	iph->saddr = fl4->saddr;
-	iph->daddr = fl4->daddr;
+	ip_copy_addrs(iph, fl4);
 
 	if (opt) {
 		iph->ihl += opt->optlen>>2;