In this commit, we make ip_route_input_slow() support skb drop reason by
adding the pointer of drop reason to its functions aeguments.
Following new skb drop reasons are added:
SKB_DROP_REASON_IP_LOCAL_SOURCE
SKB_DROP_REASON_IP_INVALID_SOURCE
SKB_DROP_REASON_IP_INVALID_DEST
SKB_DROP_REASON_IP_LOCALNET
Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
include/net/dropreason-core.h | 19 +++++++++++++++++++
net/ipv4/route.c | 32 ++++++++++++++++++++++++--------
2 files changed, 43 insertions(+), 8 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 4748680e8c88..3d1b09f70bbd 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -76,6 +76,10 @@
FN(INVALID_PROTO) \
FN(IP_INADDRERRORS) \
FN(IP_INNOROUTES) \
+ FN(IP_LOCAL_SOURCE) \
+ FN(IP_INVALID_SOURCE) \
+ FN(IP_INVALID_DEST) \
+ FN(IP_LOCALNET) \
FN(PKT_TOO_BIG) \
FN(DUP_FRAG) \
FN(FRAG_REASM_TIMEOUT) \
@@ -365,6 +369,21 @@ enum skb_drop_reason {
* IPSTATS_MIB_INADDRERRORS
*/
SKB_DROP_REASON_IP_INNOROUTES,
+ /** @SKB_DROP_REASON_IP_LOCAL_SOURCE: the source ip is local */
+ SKB_DROP_REASON_IP_LOCAL_SOURCE,
+ /**
+ * @SKB_DROP_REASON_IP_INVALID_SOURCE: the source ip is invalid:
+ * 1) source ip is multicast or limited broadcast
+ * 2) source ip is zero and not IGMP
+ */
+ SKB_DROP_REASON_IP_INVALID_SOURCE,
+ /**
+ * @SKB_DROP_REASON_IP_INVALID_DEST: the dest ip is invalid:
+ * 1) dest ip is 0
+ */
+ SKB_DROP_REASON_IP_INVALID_DEST,
+ /** @SKB_DROP_REASON_IP_LOCALNET: source or dest ip is local net */
+ SKB_DROP_REASON_IP_LOCALNET,
/**
* @SKB_DROP_REASON_PKT_TOO_BIG: packet size is too big (maybe exceed the
* MTU)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 385efe6d71a7..ab70917c62e5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2202,8 +2202,10 @@ static struct net_device *ip_rt_get_dev(struct net *net,
static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
u8 tos, struct net_device *dev,
- struct fib_result *res)
+ struct fib_result *res,
+ enum skb_drop_reason *reason)
{
+ enum skb_drop_reason __reason = SKB_DROP_REASON_NOT_SPECIFIED;
struct in_device *in_dev = __in_dev_get_rcu(dev);
struct flow_keys *flkeys = NULL, _flkeys;
struct net *net = dev_net(dev);
@@ -2231,8 +2233,10 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
fl4.flowi4_tun_key.tun_id = 0;
skb_dst_drop(skb);
- 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;
+ }
res->fi = NULL;
res->table = NULL;
@@ -2242,21 +2246,29 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
/* Accept zero addresses only to limited broadcast;
* I even do not know to fix it or not. Waiting for complains :-)
*/
- if (ipv4_is_zeronet(saddr))
+ if (ipv4_is_zeronet(saddr)) {
+ __reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
goto martian_source;
+ }
- if (ipv4_is_zeronet(daddr))
+ if (ipv4_is_zeronet(daddr)) {
+ __reason = SKB_DROP_REASON_IP_INVALID_DEST;
goto martian_destination;
+ }
/* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
* and call it once if daddr or/and saddr are loopback addresses
*/
if (ipv4_is_loopback(daddr)) {
- if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+ if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+ __reason = SKB_DROP_REASON_IP_LOCALNET;
goto martian_destination;
+ }
} else if (ipv4_is_loopback(saddr)) {
- if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
+ if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
+ __reason = SKB_DROP_REASON_IP_LOCALNET;
goto martian_source;
+ }
}
/*
@@ -2315,7 +2327,10 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
make_route:
err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
-out: return err;
+out:
+ if (reason && err)
+ *reason = __reason;
+ return err;
brd_input:
if (skb->protocol != htons(ETH_P_IP))
@@ -2406,6 +2421,7 @@ out: return err;
e_nobufs:
err = -ENOBUFS;
+ __reason = SKB_DROP_REASON_NOMEM;
goto out;
martian_source:
@@ -2462,7 +2478,7 @@ static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
return err;
}
- return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
+ return ip_route_input_slow(skb, daddr, saddr, tos, dev, res, reason);
}
int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
--
2.39.5
