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Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c83
1 files changed, 30 insertions, 53 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ac6559cb54f9..04e0df82b88c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1107,6 +1107,7 @@ restart:
* on the route gc list.
*/
+ rt->dst.flags |= DST_NOCACHE;
if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
int err = arp_bind_neighbour(&rt->dst);
if (err) {
@@ -1268,18 +1269,11 @@ skip_hashing:
void rt_bind_peer(struct rtable *rt, int create)
{
- static DEFINE_SPINLOCK(rt_peer_lock);
struct inet_peer *peer;
peer = inet_getpeer(rt->rt_dst, create);
- spin_lock_bh(&rt_peer_lock);
- if (rt->peer == NULL) {
- rt->peer = peer;
- peer = NULL;
- }
- spin_unlock_bh(&rt_peer_lock);
- if (peer)
+ if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
inet_putpeer(peer);
}
@@ -2365,9 +2359,8 @@ static int __mkroute_output(struct rtable **result,
struct rtable *rth;
struct in_device *in_dev;
u32 tos = RT_FL_TOS(oldflp);
- int err = 0;
- if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
+ if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
return -EINVAL;
if (fl->fl4_dst == htonl(0xFFFFFFFF))
@@ -2380,11 +2373,12 @@ static int __mkroute_output(struct rtable **result,
if (dev_out->flags & IFF_LOOPBACK)
flags |= RTCF_LOCAL;
- /* get work reference to inet device */
- in_dev = in_dev_get(dev_out);
- if (!in_dev)
+ rcu_read_lock();
+ in_dev = __in_dev_get_rcu(dev_out);
+ if (!in_dev) {
+ rcu_read_unlock();
return -EINVAL;
-
+ }
if (res->type == RTN_BROADCAST) {
flags |= RTCF_BROADCAST | RTCF_LOCAL;
if (res->fi) {
@@ -2392,13 +2386,13 @@ static int __mkroute_output(struct rtable **result,
res->fi = NULL;
}
} else if (res->type == RTN_MULTICAST) {
- flags |= RTCF_MULTICAST|RTCF_LOCAL;
+ flags |= RTCF_MULTICAST | RTCF_LOCAL;
if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
oldflp->proto))
flags &= ~RTCF_LOCAL;
/* If multicast route do not exist use
- default one, but do not gateway in this case.
- Yes, it is hack.
+ * default one, but do not gateway in this case.
+ * Yes, it is hack.
*/
if (res->fi && res->prefixlen < 4) {
fib_info_put(res->fi);
@@ -2409,9 +2403,12 @@ static int __mkroute_output(struct rtable **result,
rth = dst_alloc(&ipv4_dst_ops);
if (!rth) {
- err = -ENOBUFS;
- goto cleanup;
+ rcu_read_unlock();
+ return -ENOBUFS;
}
+ in_dev_hold(in_dev);
+ rcu_read_unlock();
+ rth->idev = in_dev;
atomic_set(&rth->dst.__refcnt, 1);
rth->dst.flags= DST_HOST;
@@ -2432,7 +2429,6 @@ static int __mkroute_output(struct rtable **result,
cache entry */
rth->dst.dev = dev_out;
dev_hold(dev_out);
- rth->idev = in_dev_get(dev_out);
rth->rt_gateway = fl->fl4_dst;
rth->rt_spec_dst= fl->fl4_src;
@@ -2467,13 +2463,8 @@ static int __mkroute_output(struct rtable **result,
rt_set_nexthop(rth, res, 0);
rth->rt_flags = flags;
-
*result = rth;
- cleanup:
- /* release work reference to inet device */
- in_dev_put(in_dev);
-
- return err;
+ return 0;
}
static int ip_mkroute_output(struct rtable **rp,
@@ -2497,6 +2488,7 @@ static int ip_mkroute_output(struct rtable **rp,
/*
* Major route resolver routine.
+ * called with rcu_read_lock();
*/
static int ip_route_output_slow(struct net *net, struct rtable **rp,
@@ -2515,7 +2507,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
.iif = net->loopback_dev->ifindex,
.oif = oldflp->oif };
struct fib_result res;
- unsigned flags = 0;
+ unsigned int flags = 0;
struct net_device *dev_out = NULL;
int free_res = 0;
int err;
@@ -2545,7 +2537,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
(ipv4_is_multicast(oldflp->fl4_dst) ||
oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
- dev_out = ip_dev_find(net, oldflp->fl4_src);
+ dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
if (dev_out == NULL)
goto out;
@@ -2570,26 +2562,21 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
- dev_out = ip_dev_find(net, oldflp->fl4_src);
- if (dev_out == NULL)
+ if (!__ip_dev_find(net, oldflp->fl4_src, false))
goto out;
- dev_put(dev_out);
- dev_out = NULL;
}
}
if (oldflp->oif) {
- dev_out = dev_get_by_index(net, oldflp->oif);
+ dev_out = dev_get_by_index_rcu(net, oldflp->oif);
err = -ENODEV;
if (dev_out == NULL)
goto out;
/* RACE: Check return value of inet_select_addr instead. */
- if (__in_dev_get_rtnl(dev_out) == NULL) {
- dev_put(dev_out);
+ if (rcu_dereference(dev_out->ip_ptr) == NULL)
goto out; /* Wrong error code */
- }
if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
@@ -2612,10 +2599,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
fl.fl4_dst = fl.fl4_src;
if (!fl.fl4_dst)
fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
- if (dev_out)
- dev_put(dev_out);
dev_out = net->loopback_dev;
- dev_hold(dev_out);
fl.oif = net->loopback_dev->ifindex;
res.type = RTN_LOCAL;
flags |= RTCF_LOCAL;
@@ -2649,8 +2633,6 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
res.type = RTN_UNICAST;
goto make_route;
}
- if (dev_out)
- dev_put(dev_out);
err = -ENETUNREACH;
goto out;
}
@@ -2659,10 +2641,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
if (res.type == RTN_LOCAL) {
if (!fl.fl4_src)
fl.fl4_src = fl.fl4_dst;
- if (dev_out)
- dev_put(dev_out);
dev_out = net->loopback_dev;
- dev_hold(dev_out);
fl.oif = dev_out->ifindex;
if (res.fi)
fib_info_put(res.fi);
@@ -2682,28 +2661,23 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
if (!fl.fl4_src)
fl.fl4_src = FIB_RES_PREFSRC(res);
- if (dev_out)
- dev_put(dev_out);
dev_out = FIB_RES_DEV(res);
- dev_hold(dev_out);
fl.oif = dev_out->ifindex;
make_route:
err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
-
if (free_res)
fib_res_put(&res);
- if (dev_out)
- dev_put(dev_out);
out: return err;
}
int __ip_route_output_key(struct net *net, struct rtable **rp,
const struct flowi *flp)
{
- unsigned hash;
+ unsigned int hash;
+ int res;
struct rtable *rth;
if (!rt_caching(net))
@@ -2734,7 +2708,10 @@ int __ip_route_output_key(struct net *net, struct rtable **rp,
rcu_read_unlock_bh();
slow_output:
- return ip_route_output_slow(net, rp, flp);
+ rcu_read_lock();
+ res = ip_route_output_slow(net, rp, flp);
+ rcu_read_unlock();
+ return res;
}
EXPORT_SYMBOL_GPL(__ip_route_output_key);
@@ -2798,7 +2775,7 @@ static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi
dst_release(&(*rp)->dst);
*rp = rt;
- return (rt ? 0 : -ENOMEM);
+ return rt ? 0 : -ENOMEM;
}
int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.