net: Abstract default MTU metric calculation behind an accessor.

[pandora-kernel.git] / net / ipv4 / route.c

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8099733..ae52096 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -140,6 +140,7 @@ static unsigned long expires_ljiffies;
 
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int     ipv4_default_advmss(const struct dst_entry *dst);
+static unsigned int     ipv4_default_mtu(const struct dst_entry *dst);
 static void             ipv4_dst_destroy(struct dst_entry *dst);
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 static void             ipv4_link_failure(struct sk_buff *skb);
@@ -157,6 +158,7 @@ static struct dst_ops ipv4_dst_ops = {
        .gc =                   rt_garbage_collect,
        .check =                ipv4_dst_check,
        .default_advmss =       ipv4_default_advmss,
+       .default_mtu =          ipv4_default_mtu,
        .destroy =              ipv4_dst_destroy,
        .ifdown =               ipv4_dst_ifdown,
        .negative_advice =      ipv4_negative_advice,
@@ -1812,6 +1814,23 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
        return advmss;
 }
 
+static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
+{
+       unsigned int mtu = dst->dev->mtu;
+
+       if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
+               const struct rtable *rt = (const struct rtable *) dst;
+
+               if (rt->rt_gateway != rt->rt_dst && mtu > 576)
+                       mtu = 576;
+       }
+
+       if (mtu > IP_MAX_MTU)
+               mtu = IP_MAX_MTU;
+
+       return mtu;
+}
+
 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
 {
        struct dst_entry *dst = &rt->dst;
@@ -1822,18 +1841,10 @@ static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
                    FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
                        rt->rt_gateway = FIB_RES_GW(*res);
                dst_import_metrics(dst, fi->fib_metrics);
-               if (fi->fib_mtu == 0) {
-                       dst_metric_set(dst, RTAX_MTU, dst->dev->mtu);
-                       if (dst_metric_locked(dst, RTAX_MTU) &&
-                           rt->rt_gateway != rt->rt_dst &&
-                           dst->dev->mtu > 576)
-                               dst_metric_set(dst, RTAX_MTU, 576);
-               }
 #ifdef CONFIG_NET_CLS_ROUTE
                dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
 #endif
-       } else
-               dst_metric_set(dst, RTAX_MTU, dst->dev->mtu);
+       }
 
        if (dst_mtu(dst) > IP_MAX_MTU)
                dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);