In this commit, we make ip_route_input_slow() return skb drop reasons, and following new skb drop reasons are added:
SKB_DROP_REASON_IP_INVALID_DEST The only caller of ip_route_input_slow() is ip_route_input_rcu(), and we adjust it by making it return -EINVAL on error. Signed-off-by: Menglong Dong <[email protected]> --- v4: - use indentation after the out label --- include/net/dropreason-core.h | 6 ++++ net/ipv4/route.c | 56 ++++++++++++++++++++++------------- 2 files changed, 41 insertions(+), 21 deletions(-) diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h index a2a1fb90e0e5..74624d369d48 100644 --- a/include/net/dropreason-core.h +++ b/include/net/dropreason-core.h @@ -79,6 +79,7 @@ FN(IP_LOCAL_SOURCE) \ FN(IP_INVALID_SOURCE) \ FN(IP_LOCALNET) \ + FN(IP_INVALID_DEST) \ FN(PKT_TOO_BIG) \ FN(DUP_FRAG) \ FN(FRAG_REASM_TIMEOUT) \ @@ -386,6 +387,11 @@ enum skb_drop_reason { SKB_DROP_REASON_IP_INVALID_SOURCE, /** @SKB_DROP_REASON_IP_LOCALNET: source or dest ip is local net */ SKB_DROP_REASON_IP_LOCALNET, + /** + * @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_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 61e316f93291..7976f687d039 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2204,9 +2204,10 @@ static struct net_device *ip_rt_get_dev(struct net *net, * called with rcu_read_lock() */ -static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, - dscp_t dscp, struct net_device *dev, - struct fib_result *res) +static enum skb_drop_reason +ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, + dscp_t dscp, struct net_device *dev, + struct fib_result *res) { enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; struct in_device *in_dev = __in_dev_get_rcu(dev); @@ -2236,8 +2237,10 @@ 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; @@ -2247,21 +2250,29 @@ 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; + } } /* @@ -2316,19 +2327,26 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, err = -EHOSTUNREACH; goto no_route; } - if (res->type != RTN_UNICAST) + if (res->type != RTN_UNICAST) { + reason = SKB_DROP_REASON_IP_INVALID_DEST; goto martian_destination; + } make_route: err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, flkeys); -out: return err; + if (!err) + reason = SKB_NOT_DROPPED_YET; + +out: + return reason; brd_input: - if (skb->protocol != htons(ETH_P_IP)) - goto e_inval; + if (skb->protocol != htons(ETH_P_IP)) { + reason = SKB_DROP_REASON_INVALID_PROTO; + goto out; + } if (!ipv4_is_zeronet(saddr)) { - err = -EINVAL; reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, dev, in_dev, &itag); if (reason) @@ -2349,7 +2367,7 @@ out: return err; rth = rcu_dereference(nhc->nhc_rth_input); if (rt_cache_valid(rth)) { skb_dst_set_noref(skb, &rth->dst); - err = 0; + reason = SKB_NOT_DROPPED_YET; goto out; } } @@ -2386,7 +2404,7 @@ out: return err; rt_add_uncached_list(rth); } skb_dst_set(skb, &rth->dst); - err = 0; + reason = SKB_NOT_DROPPED_YET; goto out; no_route: @@ -2407,12 +2425,8 @@ out: return err; &daddr, &saddr, dev->name); #endif -e_inval: - err = -EINVAL; - goto out; - e_nobufs: - err = -ENOBUFS; + reason = SKB_DROP_REASON_NOMEM; goto out; martian_source: @@ -2469,7 +2483,7 @@ static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, return reason ? -EINVAL : 0; } - return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); + return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res) ? -EINVAL : 0; } int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, -- 2.39.5
