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-rw-r--r--include/net/route.h4
-rw-r--r--net/ipv4/ip_input.c35
-rw-r--r--net/ipv4/route.c42
3 files changed, 77 insertions, 4 deletions
diff --git a/include/net/route.h b/include/net/route.h
index 6c516840380d..a9c60fc68e36 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -185,6 +185,10 @@ int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin,
struct fib_result *res);
+int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src,
+ u8 tos, struct net_device *devin,
+ const struct sk_buff *hint);
+
static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin)
{
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 24a95126e698..aa438c6758a7 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -302,16 +302,31 @@ drop:
return true;
}
+static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph,
+ const struct sk_buff *hint)
+{
+ return hint && !skb_dst(skb) && ip_hdr(hint)->daddr == iph->daddr &&
+ ip_hdr(hint)->tos == iph->tos;
+}
+
INDIRECT_CALLABLE_DECLARE(int udp_v4_early_demux(struct sk_buff *));
INDIRECT_CALLABLE_DECLARE(int tcp_v4_early_demux(struct sk_buff *));
static int ip_rcv_finish_core(struct net *net, struct sock *sk,
- struct sk_buff *skb, struct net_device *dev)
+ struct sk_buff *skb, struct net_device *dev,
+ const struct sk_buff *hint)
{
const struct iphdr *iph = ip_hdr(skb);
int (*edemux)(struct sk_buff *skb);
struct rtable *rt;
int err;
+ if (ip_can_use_hint(skb, iph, hint)) {
+ err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos,
+ dev, hint);
+ if (unlikely(err))
+ goto drop_error;
+ }
+
if (net->ipv4.sysctl_ip_early_demux &&
!skb_dst(skb) &&
!skb->sk &&
@@ -408,7 +423,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
if (!skb)
return NET_RX_SUCCESS;
- ret = ip_rcv_finish_core(net, sk, skb, dev);
+ ret = ip_rcv_finish_core(net, sk, skb, dev, NULL);
if (ret != NET_RX_DROP)
ret = dst_input(skb);
return ret;
@@ -535,11 +550,20 @@ static void ip_sublist_rcv_finish(struct list_head *head)
}
}
+static struct sk_buff *ip_extract_route_hint(const struct net *net,
+ struct sk_buff *skb, int rt_type)
+{
+ if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST)
+ return NULL;
+
+ return skb;
+}
+
static void ip_list_rcv_finish(struct net *net, struct sock *sk,
struct list_head *head)
{
+ struct sk_buff *skb, *next, *hint = NULL;
struct dst_entry *curr_dst = NULL;
- struct sk_buff *skb, *next;
struct list_head sublist;
INIT_LIST_HEAD(&sublist);
@@ -554,11 +578,14 @@ static void ip_list_rcv_finish(struct net *net, struct sock *sk,
skb = l3mdev_ip_rcv(skb);
if (!skb)
continue;
- if (ip_rcv_finish_core(net, sk, skb, dev) == NET_RX_DROP)
+ if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP)
continue;
dst = skb_dst(skb);
if (curr_dst != dst) {
+ hint = ip_extract_route_hint(net, skb,
+ ((struct rtable *)dst)->rt_type);
+
/* dispatch old sublist */
if (!list_empty(&sublist))
ip_sublist_rcv_finish(&sublist);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index dcc4fa10138d..f88c93c38f11 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2019,10 +2019,52 @@ static int ip_mkroute_input(struct sk_buff *skb,
return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
}
+/* Implements all the saddr-related checks as ip_route_input_slow(),
+ * assuming daddr is valid and the destination is not a local broadcast one.
+ * Uses the provided hint instead of performing a route lookup.
+ */
+int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev,
+ const struct sk_buff *hint)
+{
+ struct in_device *in_dev = __in_dev_get_rcu(dev);
+ struct rtable *rt = (struct rtable *)hint;
+ struct net *net = dev_net(dev);
+ int err = -EINVAL;
+ u32 tag = 0;
+
+ if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+ goto martian_source;
+
+ if (ipv4_is_zeronet(saddr))
+ goto martian_source;
+
+ if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+ goto martian_source;
+
+ if (rt->rt_type != RTN_LOCAL)
+ goto skip_validate_source;
+
+ tos &= IPTOS_RT_MASK;
+ err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag);
+ if (err < 0)
+ goto martian_source;
+
+skip_validate_source:
+ skb_dst_copy(skb, hint);
+ return 0;
+
+martian_source:
+ ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
+ return err;
+}
+
/*
* NOTE. We drop all the packets that has local source
* addresses, because every properly looped back packet
* must have correct destination already attached by output routine.
+ * Changes in the enforced policies must be applied also to
+ * ip_route_use_hint().
*
* Such approach solves two big problems:
* 1. Not simplex devices are handled properly.