ipv4: Kill rt->rt_{src, dst} usage in IP GRE tunnels.

First, make callers pass on-stack flowi4 to ip_route_output_gre()
so they can get at the fully resolved flow key.

Next, use that in ipgre_tunnel_xmit() to avoid the need to use
rt->rt_{dst,src}.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/route.h b/include/net/route.h
index 8c02c87..9f8070b 100644 (file)
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -152,19 +152,18 @@ static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi
        return ip_route_output_flow(net, fl4, sk);
 }
 
-static inline struct rtable *ip_route_output_gre(struct net *net,
+static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
                                                 __be32 daddr, __be32 saddr,
                                                 __be32 gre_key, __u8 tos, int oif)
 {
-       struct flowi4 fl4 = {
-               .flowi4_oif = oif,
-               .daddr = daddr,
-               .saddr = saddr,
-               .flowi4_tos = tos,
-               .flowi4_proto = IPPROTO_GRE,
-               .fl4_gre_key = gre_key,
-       };
-       return ip_route_output_key(net, &fl4);
+       memset(fl4, 0, sizeof(*fl4));
+       fl4->flowi4_oif = oif;
+       fl4->daddr = daddr;
+       fl4->saddr = saddr;
+       fl4->flowi4_tos = tos;
+       fl4->flowi4_proto = IPPROTO_GRE;
+       fl4->fl4_gre_key = gre_key;
+       return ip_route_output_key(net, fl4);
 }
 
 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 24efd35..10e9b5a 100644 (file)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -699,6 +699,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
        struct pcpu_tstats *tstats;
        const struct iphdr  *old_iph = ip_hdr(skb);
        const struct iphdr  *tiph;
+       struct flowi4 fl4;
        u8     tos;
        __be16 df;
        struct rtable *rt;                      /* Route to the other host */
@@ -769,7 +770,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
                        tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
        }
 
-       rt = ip_route_output_gre(dev_net(dev), dst, tiph->saddr,
+       rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
                                 tunnel->parms.o_key, RT_TOS(tos),
                                 tunnel->parms.link);
        if (IS_ERR(rt)) {
@@ -873,8 +874,8 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
        iph->frag_off           =       df;
        iph->protocol           =       IPPROTO_GRE;
        iph->tos                =       ipgre_ecn_encapsulate(tos, old_iph, skb);
-       iph->daddr              =       rt->rt_dst;
-       iph->saddr              =       rt->rt_src;
+       iph->daddr              =       fl4.daddr;
+       iph->saddr              =       fl4.saddr;
 
        if ((iph->ttl = tiph->ttl) == 0) {
                if (skb->protocol == htons(ETH_P_IP))
@@ -938,12 +939,14 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev)
        /* Guess output device to choose reasonable mtu and needed_headroom */
 
        if (iph->daddr) {
-               struct rtable *rt = ip_route_output_gre(dev_net(dev),
-                                                       iph->daddr, iph->saddr,
-                                                       tunnel->parms.o_key,
-                                                       RT_TOS(iph->tos),
-                                                       tunnel->parms.link);
-
+               struct flowi4 fl4;
+               struct rtable *rt;
+
+               rt = ip_route_output_gre(dev_net(dev), &fl4,
+                                        iph->daddr, iph->saddr,
+                                        tunnel->parms.o_key,
+                                        RT_TOS(iph->tos),
+                                        tunnel->parms.link);
                if (!IS_ERR(rt)) {
                        tdev = rt->dst.dev;
                        ip_rt_put(rt);
@@ -1196,13 +1199,15 @@ static int ipgre_open(struct net_device *dev)
        struct ip_tunnel *t = netdev_priv(dev);
 
        if (ipv4_is_multicast(t->parms.iph.daddr)) {
-               struct rtable *rt = ip_route_output_gre(dev_net(dev),
-                                                       t->parms.iph.daddr,
-                                                       t->parms.iph.saddr,
-                                                       t->parms.o_key,
-                                                       RT_TOS(t->parms.iph.tos),
-                                                       t->parms.link);
-
+               struct flowi4 fl4;
+               struct rtable *rt;
+
+               rt = ip_route_output_gre(dev_net(dev), &fl4,
+                                        t->parms.iph.daddr,
+                                        t->parms.iph.saddr,
+                                        t->parms.o_key,
+                                        RT_TOS(t->parms.iph.tos),
+                                        t->parms.link);
                if (IS_ERR(rt))
                        return -EADDRNOTAVAIL;
                dev = rt->dst.dev;