Commit 5e187189 authored by Menglong Dong's avatar Menglong Dong Committed by David S. Miller
Browse files

net: ip: add skb drop reasons for ip egress path 



Replace kfree_skb() which is used in the packet egress path of IP layer
with kfree_skb_reason(). Functions that are involved include:

__ip_queue_xmit()
ip_finish_output()
ip_mc_finish_output()
ip6_output()
ip6_finish_output()
ip6_finish_output2()

Following new drop reasons are introduced:

SKB_DROP_REASON_IP_OUTNOROUTES
SKB_DROP_REASON_BPF_CGROUP_EGRESS
SKB_DROP_REASON_IPV6DISABLED
SKB_DROP_REASON_NEIGH_CREATEFAIL

Reviewed-by: default avatarMengen Sun <mengensun@tencent.com>
Reviewed-by: default avatarHao Peng <flyingpeng@tencent.com>
Signed-off-by: default avatarMenglong Dong <imagedong@tencent.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0cc70c6e

include/linux/skbuff.h

+9 −0
Original line number Diff line number Diff line
@@ -380,6 +380,15 @@ enum skb_drop_reason { 
					 * the ofo queue, corresponding to

					 * LINUX_MIB_TCPOFOMERGE

					 */

	SKB_DROP_REASON_IP_OUTNOROUTES,	/* route lookup failed */

	SKB_DROP_REASON_BPF_CGROUP_EGRESS,	/* dropped by

						 * BPF_PROG_TYPE_CGROUP_SKB

						 * eBPF program

						 */

	SKB_DROP_REASON_IPV6DISABLED,	/* IPv6 is disabled on the device */

	SKB_DROP_REASON_NEIGH_CREATEFAIL,	/* failed to create neigh

						 * entry

						 */

	SKB_DROP_REASON_MAX,

};

include/trace/events/skb.h

+5 −0
Original line number Diff line number Diff line
@@ -37,6 +37,11 @@ 
	EM(SKB_DROP_REASON_TCP_OLD_DATA, TCP_OLD_DATA)		\

	EM(SKB_DROP_REASON_TCP_OVERWINDOW, TCP_OVERWINDOW)	\

	EM(SKB_DROP_REASON_TCP_OFOMERGE, TCP_OFOMERGE)		\

	EM(SKB_DROP_REASON_IP_OUTNOROUTES, IP_OUTNOROUTES)	\

	EM(SKB_DROP_REASON_BPF_CGROUP_EGRESS,			\

	   BPF_CGROUP_EGRESS)					\

	EM(SKB_DROP_REASON_IPV6DISABLED, IPV6DISABLED)		\

	EM(SKB_DROP_REASON_NEIGH_CREATEFAIL, NEIGH_CREATEFAIL)	\

	EMe(SKB_DROP_REASON_MAX, MAX)



#undef EM

net/ipv4/ip_output.c

+4 −4
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s 


	net_dbg_ratelimited("%s: No header cache and no neighbour!\n",

			    __func__);

	kfree_skb(skb);

	kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);

	return -EINVAL;

}
@@ -317,7 +317,7 @@ static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *sk 
	case NET_XMIT_CN:

		return __ip_finish_output(net, sk, skb) ? : ret;

	default:

		kfree_skb(skb);

		kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);

		return ret;

	}

}
@@ -337,7 +337,7 @@ static int ip_mc_finish_output(struct net *net, struct sock *sk, 
	case NET_XMIT_SUCCESS:

		break;

	default:

		kfree_skb(skb);

		kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);

		return ret;

	}
@@ -536,7 +536,7 @@ int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 
no_route:

	rcu_read_unlock();

	IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);

	kfree_skb(skb);

	kfree_skb_reason(skb, SKB_DROP_REASON_IP_OUTNOROUTES);

	return -EHOSTUNREACH;

}

EXPORT_SYMBOL(__ip_queue_xmit);

net/ipv6/ip6_output.c

+3 −3
Original line number Diff line number Diff line
@@ -130,7 +130,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * 
	rcu_read_unlock_bh();



	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES);

	kfree_skb(skb);

	kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);

	return -EINVAL;

}
@@ -202,7 +202,7 @@ static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *s 
	case NET_XMIT_CN:

		return __ip6_finish_output(net, sk, skb) ? : ret;

	default:

		kfree_skb(skb);

		kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);

		return ret;

	}

}
@@ -217,7 +217,7 @@ int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 


	if (unlikely(idev->cnf.disable_ipv6)) {

		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);

		kfree_skb(skb);

		kfree_skb_reason(skb, SKB_DROP_REASON_IPV6DISABLED);

		return 0;

	}