ipv4: Cache input routes in fib_info nexthops.
Caching input routes is slightly simpler than output routes, since we
don't need to be concerned with nexthop exceptions. (locally
destined, and routed packets, never trigger PMTU events or redirects
that will be processed by us).
However, we have to elide caching for the DIRECTSRC and non-zero itag
cases.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8a02600..97cca8a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1231,6 +1231,9 @@
{
struct rtable *orig, *prev, **p = &nh->nh_rth_output;
+ if (rt_is_input_route(rt))
+ p = &nh->nh_rth_input;
+
orig = *p;
prev = cmpxchg(p, orig, rt);
@@ -1241,6 +1244,11 @@
}
}
+static bool rt_cache_valid(struct rtable *rt)
+{
+ return (rt && rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK);
+}
+
static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
const struct fib_result *res,
struct fib_nh_exception *fnhe,
@@ -1257,8 +1265,7 @@
#ifdef CONFIG_IP_ROUTE_CLASSID
rt->dst.tclassid = nh->nh_tclassid;
#endif
- if (!(rt->dst.flags & DST_HOST) &&
- rt_is_output_route(rt))
+ if (!(rt->dst.flags & DST_HOST))
rt_cache_route(nh, rt);
}
@@ -1384,11 +1391,11 @@
__be32 daddr, __be32 saddr, u32 tos,
struct rtable **result)
{
- struct fib_nh_exception *fnhe;
struct rtable *rth;
int err;
struct in_device *out_dev;
unsigned int flags = 0;
+ bool do_cache;
u32 itag;
/* get a working reference to the output device */
@@ -1431,13 +1438,21 @@
}
}
- fnhe = NULL;
- if (res->fi)
- fnhe = find_exception(&FIB_RES_NH(*res), daddr);
+ do_cache = false;
+ if (res->fi) {
+ if (!(flags & RTCF_DIRECTSRC) && !itag) {
+ rth = FIB_RES_NH(*res).nh_rth_input;
+ if (rt_cache_valid(rth)) {
+ dst_use(&rth->dst, jiffies);
+ goto out;
+ }
+ do_cache = true;
+ }
+ }
rth = rt_dst_alloc(out_dev->dev,
IN_DEV_CONF_GET(in_dev, NOPOLICY),
- IN_DEV_CONF_GET(out_dev, NOXFRM), false);
+ IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
if (!rth) {
err = -ENOBUFS;
goto cleanup;
@@ -1456,8 +1471,8 @@
rth->dst.input = ip_forward;
rth->dst.output = ip_output;
- rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
-
+ rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
+out:
*result = rth;
err = 0;
cleanup:
@@ -1509,6 +1524,7 @@
struct rtable *rth;
int err = -EINVAL;
struct net *net = dev_net(dev);
+ bool do_cache;
/* IP on this device is disabled. */
@@ -1522,6 +1538,7 @@
if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
goto martian_source;
+ res.fi = NULL;
if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
goto brd_input;
@@ -1597,8 +1614,20 @@
RT_CACHE_STAT_INC(in_brd);
local_input:
+ do_cache = false;
+ if (res.fi) {
+ if (!(flags & RTCF_DIRECTSRC) && !itag) {
+ rth = FIB_RES_NH(res).nh_rth_input;
+ if (rt_cache_valid(rth)) {
+ dst_use(&rth->dst, jiffies);
+ goto set_and_out;
+ }
+ do_cache = true;
+ }
+ }
+
rth = rt_dst_alloc(net->loopback_dev,
- IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
+ IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
if (!rth)
goto e_nobufs;
@@ -1622,6 +1651,9 @@
rth->dst.error= -err;
rth->rt_flags &= ~RTCF_LOCAL;
}
+ if (do_cache)
+ rt_cache_route(&FIB_RES_NH(res), rth);
+set_and_out:
skb_dst_set(skb, &rth->dst);
err = 0;
goto out;
@@ -1756,8 +1788,7 @@
fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
if (!fnhe) {
rth = FIB_RES_NH(*res).nh_rth_output;
- if (rth &&
- rth->dst.obsolete == DST_OBSOLETE_FORCE_CHK) {
+ if (rt_cache_valid(rth)) {
dst_use(&rth->dst, jiffies);
return rth;
}