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-rw-r--r--include/net/dst.h17
-rw-r--r--net/ipv4/ip_output.c10
-rw-r--r--net/ipv4/route.c14
-rw-r--r--net/ipv6/addrconf.c2
-rw-r--r--net/ipv6/ip6_fib.c2
-rw-r--r--net/ipv6/ip6_output.c13
-rw-r--r--net/ipv6/route.c35
7 files changed, 67 insertions, 26 deletions
diff --git a/include/net/dst.h b/include/net/dst.h
index 29e255796ce1..13d507d69ddb 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -37,7 +37,7 @@ struct dst_entry {
unsigned long _metrics;
unsigned long expires;
struct dst_entry *path;
- struct neighbour *_neighbour;
+ struct neighbour __rcu *_neighbour;
#ifdef CONFIG_XFRM
struct xfrm_state *xfrm;
#else
@@ -88,12 +88,17 @@ struct dst_entry {
static inline struct neighbour *dst_get_neighbour(struct dst_entry *dst)
{
- return dst->_neighbour;
+ return rcu_dereference(dst->_neighbour);
+}
+
+static inline struct neighbour *dst_get_neighbour_raw(struct dst_entry *dst)
+{
+ return rcu_dereference_raw(dst->_neighbour);
}
static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh)
{
- dst->_neighbour = neigh;
+ rcu_assign_pointer(dst->_neighbour, neigh);
}
extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
@@ -382,8 +387,12 @@ static inline void dst_rcu_free(struct rcu_head *head)
static inline void dst_confirm(struct dst_entry *dst)
{
if (dst) {
- struct neighbour *n = dst_get_neighbour(dst);
+ struct neighbour *n;
+
+ rcu_read_lock();
+ n = dst_get_neighbour(dst);
neigh_confirm(n);
+ rcu_read_unlock();
}
}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index ccaaa851ab42..77d3eded665a 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -204,9 +204,15 @@ static inline int ip_finish_output2(struct sk_buff *skb)
skb = skb2;
}
+ rcu_read_lock();
neigh = dst_get_neighbour(dst);
- if (neigh)
- return neigh_output(neigh, skb);
+ if (neigh) {
+ int res = neigh_output(neigh, skb);
+
+ rcu_read_unlock();
+ return res;
+ }
+ rcu_read_unlock();
if (net_ratelimit())
printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1730689f560e..6afc4eb50591 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1628,16 +1628,18 @@ static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
{
struct rtable *rt = (struct rtable *) dst;
__be32 orig_gw = rt->rt_gateway;
- struct neighbour *n;
+ struct neighbour *n, *old_n;
dst_confirm(&rt->dst);
- neigh_release(dst_get_neighbour(&rt->dst));
- dst_set_neighbour(&rt->dst, NULL);
-
rt->rt_gateway = peer->redirect_learned.a4;
- rt_bind_neighbour(rt);
- n = dst_get_neighbour(&rt->dst);
+
+ n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
+ if (IS_ERR(n))
+ return PTR_ERR(n);
+ old_n = xchg(&rt->dst._neighbour, n);
+ if (old_n)
+ neigh_release(old_n);
if (!n || !(n->nud_state & NUD_VALID)) {
if (n)
neigh_event_send(n, NULL);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a55500cc0b29..f012ebd87b43 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -656,7 +656,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
* layer address of our nexhop router
*/
- if (dst_get_neighbour(&rt->dst) == NULL)
+ if (dst_get_neighbour_raw(&rt->dst) == NULL)
ifa->flags &= ~IFA_F_OPTIMISTIC;
ifa->idev = idev;
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 54a4678955bf..320d91d20ad7 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1455,7 +1455,7 @@ static int fib6_age(struct rt6_info *rt, void *arg)
RT6_TRACE("aging clone %p\n", rt);
return -1;
} else if ((rt->rt6i_flags & RTF_GATEWAY) &&
- (!(dst_get_neighbour(&rt->dst)->flags & NTF_ROUTER))) {
+ (!(dst_get_neighbour_raw(&rt->dst)->flags & NTF_ROUTER))) {
RT6_TRACE("purging route %p via non-router but gateway\n",
rt);
return -1;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 32e5339db0c8..4c882cf4e8a1 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -135,10 +135,15 @@ static int ip6_finish_output2(struct sk_buff *skb)
skb->len);
}
+ rcu_read_lock();
neigh = dst_get_neighbour(dst);
- if (neigh)
- return neigh_output(neigh, skb);
+ if (neigh) {
+ int res = neigh_output(neigh, skb);
+ rcu_read_unlock();
+ return res;
+ }
+ rcu_read_unlock();
IP6_INC_STATS_BH(dev_net(dst->dev),
ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
kfree_skb(skb);
@@ -975,12 +980,14 @@ static int ip6_dst_lookup_tail(struct sock *sk,
* dst entry and replace it instead with the
* dst entry of the nexthop router
*/
+ rcu_read_lock();
n = dst_get_neighbour(*dst);
if (n && !(n->nud_state & NUD_VALID)) {
struct inet6_ifaddr *ifp;
struct flowi6 fl_gw6;
int redirect;
+ rcu_read_unlock();
ifp = ipv6_get_ifaddr(net, &fl6->saddr,
(*dst)->dev, 1);
@@ -1000,6 +1007,8 @@ static int ip6_dst_lookup_tail(struct sock *sk,
if ((err = (*dst)->error))
goto out_err_release;
}
+ } else {
+ rcu_read_unlock();
}
#endif
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index e8987da06667..9e69eb0ec6dd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -364,7 +364,7 @@ out:
#ifdef CONFIG_IPV6_ROUTER_PREF
static void rt6_probe(struct rt6_info *rt)
{
- struct neighbour *neigh = rt ? dst_get_neighbour(&rt->dst) : NULL;
+ struct neighbour *neigh;
/*
* Okay, this does not seem to be appropriate
* for now, however, we need to check if it
@@ -373,8 +373,10 @@ static void rt6_probe(struct rt6_info *rt)
* Router Reachability Probe MUST be rate-limited
* to no more than one per minute.
*/
+ rcu_read_lock();
+ neigh = rt ? dst_get_neighbour(&rt->dst) : NULL;
if (!neigh || (neigh->nud_state & NUD_VALID))
- return;
+ goto out;
read_lock_bh(&neigh->lock);
if (!(neigh->nud_state & NUD_VALID) &&
time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
@@ -387,8 +389,11 @@ static void rt6_probe(struct rt6_info *rt)
target = (struct in6_addr *)&neigh->primary_key;
addrconf_addr_solict_mult(target, &mcaddr);
ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
- } else
+ } else {
read_unlock_bh(&neigh->lock);
+ }
+out:
+ rcu_read_unlock();
}
#else
static inline void rt6_probe(struct rt6_info *rt)
@@ -412,8 +417,11 @@ static inline int rt6_check_dev(struct rt6_info *rt, int oif)
static inline int rt6_check_neigh(struct rt6_info *rt)
{
- struct neighbour *neigh = dst_get_neighbour(&rt->dst);
+ struct neighbour *neigh;
int m;
+
+ rcu_read_lock();
+ neigh = dst_get_neighbour(&rt->dst);
if (rt->rt6i_flags & RTF_NONEXTHOP ||
!(rt->rt6i_flags & RTF_GATEWAY))
m = 1;
@@ -430,6 +438,7 @@ static inline int rt6_check_neigh(struct rt6_info *rt)
read_unlock_bh(&neigh->lock);
} else
m = 0;
+ rcu_read_unlock();
return m;
}
@@ -769,7 +778,7 @@ static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort,
rt->rt6i_dst.plen = 128;
rt->rt6i_flags |= RTF_CACHE;
rt->dst.flags |= DST_HOST;
- dst_set_neighbour(&rt->dst, neigh_clone(dst_get_neighbour(&ort->dst)));
+ dst_set_neighbour(&rt->dst, neigh_clone(dst_get_neighbour_raw(&ort->dst)));
}
return rt;
}
@@ -803,7 +812,7 @@ restart:
dst_hold(&rt->dst);
read_unlock_bh(&table->tb6_lock);
- if (!dst_get_neighbour(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
+ if (!dst_get_neighbour_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
else if (!(rt->dst.flags & DST_HOST))
nrt = rt6_alloc_clone(rt, &fl6->daddr);
@@ -1587,7 +1596,7 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src,
dst_confirm(&rt->dst);
/* Duplicate redirect: silently ignore. */
- if (neigh == dst_get_neighbour(&rt->dst))
+ if (neigh == dst_get_neighbour_raw(&rt->dst))
goto out;
nrt = ip6_rt_copy(rt, dest);
@@ -1682,7 +1691,7 @@ again:
1. It is connected route. Action: COW
2. It is gatewayed route or NONEXTHOP route. Action: clone it.
*/
- if (!dst_get_neighbour(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
+ if (!dst_get_neighbour_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
nrt = rt6_alloc_cow(rt, daddr, saddr);
else
nrt = rt6_alloc_clone(rt, daddr);
@@ -2326,6 +2335,7 @@ static int rt6_fill_node(struct net *net,
struct nlmsghdr *nlh;
long expires;
u32 table;
+ struct neighbour *n;
if (prefix) { /* user wants prefix routes only */
if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
@@ -2414,8 +2424,11 @@ static int rt6_fill_node(struct net *net,
if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
goto nla_put_failure;
- if (dst_get_neighbour(&rt->dst))
- NLA_PUT(skb, RTA_GATEWAY, 16, &dst_get_neighbour(&rt->dst)->primary_key);
+ rcu_read_lock();
+ n = dst_get_neighbour(&rt->dst);
+ if (n)
+ NLA_PUT(skb, RTA_GATEWAY, 16, &n->primary_key);
+ rcu_read_unlock();
if (rt->dst.dev)
NLA_PUT_U32(skb, RTA_OIF, rt->rt6i_dev->ifindex);
@@ -2608,12 +2621,14 @@ static int rt6_info_route(struct rt6_info *rt, void *p_arg)
#else
seq_puts(m, "00000000000000000000000000000000 00 ");
#endif
+ rcu_read_lock();
n = dst_get_neighbour(&rt->dst);
if (n) {
seq_printf(m, "%pi6", n->primary_key);
} else {
seq_puts(m, "00000000000000000000000000000000");
}
+ rcu_read_unlock();
seq_printf(m, " %08x %08x %08x %08x %8s\n",
rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
rt->dst.__use, rt->rt6i_flags,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.