In this commit, we make ip_route_use_hint() return drop reasons. The
drop reasons that we return are similar to what we do in
ip_route_input_slow(), and no drop reasons are added in this commit.
Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
v5:
- replace "return 0" with "return SKB_NOT_DROPPED_YET" in
ip_route_use_hint()
---
include/net/route.h | 7 ++++---
net/ipv4/ip_input.c | 9 ++++-----
net/ipv4/route.c | 28 +++++++++++++++++-----------
3 files changed, 25 insertions(+), 19 deletions(-)
diff --git a/include/net/route.h b/include/net/route.h
index f4ab5412c9c9..4debc335d276 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -206,9 +206,10 @@ ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
enum skb_drop_reason
ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
dscp_t dscp, struct net_device *dev);
-int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
- dscp_t dscp, struct net_device *dev,
- const struct sk_buff *hint);
+enum skb_drop_reason
+ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ dscp_t dscp, struct net_device *dev,
+ const struct sk_buff *hint);
static inline enum skb_drop_reason
ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, dscp_t dscp,
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 513eb0c6435a..f0a4dda246ab 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -322,15 +322,14 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
int err, drop_reason;
struct rtable *rt;
- drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
-
if (ip_can_use_hint(skb, iph, hint)) {
- err = ip_route_use_hint(skb, iph->daddr, iph->saddr,
- ip4h_dscp(iph), dev, hint);
- if (unlikely(err))
+ drop_reason = ip_route_use_hint(skb, iph->daddr, iph->saddr,
+ ip4h_dscp(iph), dev, hint);
+ if (unlikely(drop_reason))
goto drop_error;
}
+ drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (READ_ONCE(net->ipv4.sysctl_ip_early_demux) &&
!skb_dst(skb) &&
!skb->sk &&
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 5061a935ce62..d1c4367d3c20 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2141,28 +2141,34 @@ ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
* 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,
- dscp_t dscp, struct net_device *dev,
- const struct sk_buff *hint)
+enum skb_drop_reason
+ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ dscp_t dscp, struct net_device *dev,
+ const struct sk_buff *hint)
{
+ enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
struct in_device *in_dev = __in_dev_get_rcu(dev);
struct rtable *rt = skb_rtable(hint);
struct net *net = dev_net(dev);
- enum skb_drop_reason reason;
- int err = -EINVAL;
u32 tag = 0;
if (!in_dev)
- return -EINVAL;
+ return reason;
- if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+ if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
+ reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
goto martian_source;
+ }
- if (ipv4_is_zeronet(saddr))
+ if (ipv4_is_zeronet(saddr)) {
+ reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
goto martian_source;
+ }
- if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+ if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+ reason = SKB_DROP_REASON_IP_LOCALNET;
goto martian_source;
+ }
if (rt->rt_type != RTN_LOCAL)
goto skip_validate_source;
@@ -2174,11 +2180,11 @@ int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
skip_validate_source:
skb_dst_copy(skb, hint);
- return 0;
+ return SKB_NOT_DROPPED_YET;
martian_source:
ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
- return err;
+ return reason;
}
/* get device for dst_alloc with local routes */
--
2.39.5
