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authorJulian Anastasov <ja@ssi.bg>2012-10-08 11:41:18 +0000
committerDavid S. Miller <davem@davemloft.net>2012-10-08 17:42:36 -0400
commit155e8336c373d14d87a7f91e356d85ef4b93b8f9 (patch)
tree5d31e9d9c197129fcf26fd8ae9d54da770503a6c /net/ipv4/route.c
parentf8a17175c63fd3e8b573719f7538816f8c96abf4 (diff)
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ipv4: introduce rt_uses_gateway
Add new flag to remember when route is via gateway. We will use it to allow rt_gateway to contain address of directly connected host for the cases when DST_NOCACHE is used or when the NH exception caches per-destination route without DST_NOCACHE flag, i.e. when routes are not used for other destinations. By this way we force the neighbour resolving to work with the routed destination but we can use different address in the packet, feature needed for IPVS-DR where original packet for virtual IP is routed via route to real IP. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c48
1 files changed, 26 insertions, 22 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5b0180f11b20..3a116cb0991a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1126,7 +1126,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
mtu = dst->dev->mtu;
if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
- if (rt->rt_gateway && mtu > 576)
+ if (rt->rt_uses_gateway && mtu > 576)
mtu = 576;
}
@@ -1177,7 +1177,9 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
if (fnhe->fnhe_gw) {
rt->rt_flags |= RTCF_REDIRECTED;
rt->rt_gateway = fnhe->fnhe_gw;
- }
+ rt->rt_uses_gateway = 1;
+ } else if (!rt->rt_gateway)
+ rt->rt_gateway = daddr;
orig = rcu_dereference(fnhe->fnhe_rth);
rcu_assign_pointer(fnhe->fnhe_rth, rt);
@@ -1186,13 +1188,6 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
fnhe->fnhe_stamp = jiffies;
ret = true;
- } else {
- /* Routes we intend to cache in nexthop exception have
- * the DST_NOCACHE bit clear. However, if we are
- * unsuccessful at storing this route into the cache
- * we really need to set it.
- */
- rt->dst.flags |= DST_NOCACHE;
}
spin_unlock_bh(&fnhe_lock);
@@ -1215,15 +1210,8 @@ static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
if (prev == orig) {
if (orig)
rt_free(orig);
- } else {
- /* Routes we intend to cache in the FIB nexthop have
- * the DST_NOCACHE bit clear. However, if we are
- * unsuccessful at storing this route into the cache
- * we really need to set it.
- */
- rt->dst.flags |= DST_NOCACHE;
+ } else
ret = false;
- }
return ret;
}
@@ -1284,8 +1272,10 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
if (fi) {
struct fib_nh *nh = &FIB_RES_NH(*res);
- if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
+ if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
rt->rt_gateway = nh->nh_gw;
+ rt->rt_uses_gateway = 1;
+ }
dst_init_metrics(&rt->dst, fi->fib_metrics, true);
#ifdef CONFIG_IP_ROUTE_CLASSID
rt->dst.tclassid = nh->nh_tclassid;
@@ -1294,8 +1284,18 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
cached = rt_bind_exception(rt, fnhe, daddr);
else if (!(rt->dst.flags & DST_NOCACHE))
cached = rt_cache_route(nh, rt);
- }
- if (unlikely(!cached))
+ if (unlikely(!cached)) {
+ /* Routes we intend to cache in nexthop exception or
+ * FIB nexthop have the DST_NOCACHE bit clear.
+ * However, if we are unsuccessful at storing this
+ * route into the cache we really need to set it.
+ */
+ rt->dst.flags |= DST_NOCACHE;
+ if (!rt->rt_gateway)
+ rt->rt_gateway = daddr;
+ rt_add_uncached_list(rt);
+ }
+ } else
rt_add_uncached_list(rt);
#ifdef CONFIG_IP_ROUTE_CLASSID
@@ -1363,6 +1363,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->rt_iif = 0;
rth->rt_pmtu = 0;
rth->rt_gateway = 0;
+ rth->rt_uses_gateway = 0;
INIT_LIST_HEAD(&rth->rt_uncached);
if (our) {
rth->dst.input= ip_local_deliver;
@@ -1432,7 +1433,6 @@ static int __mkroute_input(struct sk_buff *skb,
return -EINVAL;
}
-
err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
in_dev->dev, in_dev, &itag);
if (err < 0) {
@@ -1488,6 +1488,7 @@ static int __mkroute_input(struct sk_buff *skb,
rth->rt_iif = 0;
rth->rt_pmtu = 0;
rth->rt_gateway = 0;
+ rth->rt_uses_gateway = 0;
INIT_LIST_HEAD(&rth->rt_uncached);
rth->dst.input = ip_forward;
@@ -1658,6 +1659,7 @@ local_input:
rth->rt_iif = 0;
rth->rt_pmtu = 0;
rth->rt_gateway = 0;
+ rth->rt_uses_gateway = 0;
INIT_LIST_HEAD(&rth->rt_uncached);
if (res.type == RTN_UNREACHABLE) {
rth->dst.input= ip_error;
@@ -1826,6 +1828,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
rth->rt_iif = orig_oif ? : 0;
rth->rt_pmtu = 0;
rth->rt_gateway = 0;
+ rth->rt_uses_gateway = 0;
INIT_LIST_HEAD(&rth->rt_uncached);
RT_CACHE_STAT_INC(out_slow_tot);
@@ -2104,6 +2107,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
rt->rt_flags = ort->rt_flags;
rt->rt_type = ort->rt_type;
rt->rt_gateway = ort->rt_gateway;
+ rt->rt_uses_gateway = ort->rt_uses_gateway;
INIT_LIST_HEAD(&rt->rt_uncached);
@@ -2182,7 +2186,7 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
goto nla_put_failure;
}
- if (rt->rt_gateway &&
+ if (rt->rt_uses_gateway &&
nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
goto nla_put_failure;