Commit 4d3c5db4 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-ipv4-some-drop-reason-cleanup-and-improvements' 

Antoine Tenart says:

====================
net: ipv4: some drop reason cleanup and improvements

A few patches that were laying around cleaning up and improving drop
reasons in net/ipv4.
====================

Link: https://patch.msgid.link/20250915091958.15382-1-atenart@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents b73b8146 9e1e2f4e

include/net/udp.h

+1 −1
Original line number Diff line number Diff line
@@ -404,7 +404,7 @@ static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags, 
	return __skb_recv_udp(sk, flags, &off, err);

}



int udp_v4_early_demux(struct sk_buff *skb);

enum skb_drop_reason udp_v4_early_demux(struct sk_buff *skb);

bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);

int udp_err(struct sk_buff *, u32);

int udp_abort(struct sock *sk, int err);

net/ipv4/ip_input.c

+14 −15
Original line number Diff line number Diff line
@@ -263,10 +263,11 @@ int ip_local_deliver(struct sk_buff *skb) 
}

EXPORT_SYMBOL(ip_local_deliver);



static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)

static inline enum skb_drop_reason

ip_rcv_options(struct sk_buff *skb, struct net_device *dev)

{

	struct ip_options *opt;

	const struct iphdr *iph;

	struct ip_options *opt;



	/* It looks as overkill, because not all

	   IP options require packet mangling.
@@ -277,7 +278,7 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev) 
	*/

	if (skb_cow(skb, skb_headroom(skb))) {

		__IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INDISCARDS);

		goto drop;

		return SKB_DROP_REASON_NOMEM;

	}



	iph = ip_hdr(skb);
@@ -286,7 +287,7 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev) 


	if (ip_options_compile(dev_net(dev), opt, skb)) {

		__IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INHDRERRORS);

		goto drop;

		return SKB_DROP_REASON_IP_INHDR;

	}



	if (unlikely(opt->srr)) {
@@ -298,17 +299,15 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev) 
					net_info_ratelimited("source route option %pI4 -> %pI4\n",

							     &iph->saddr,

							     &iph->daddr);

				goto drop;

				return SKB_DROP_REASON_NOT_SPECIFIED;

			}

		}



		if (ip_options_rcv_srr(skb, dev))

			goto drop;

			return SKB_DROP_REASON_NOT_SPECIFIED;

	}



	return false;

drop:

	return true;

	return SKB_NOT_DROPPED_YET;

}



static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph,
@@ -319,7 +318,7 @@ static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph, 
}



int tcp_v4_early_demux(struct sk_buff *skb);

int udp_v4_early_demux(struct sk_buff *skb);

enum skb_drop_reason udp_v4_early_demux(struct sk_buff *skb);

static int ip_rcv_finish_core(struct net *net,

			      struct sk_buff *skb, struct net_device *dev,

			      const struct sk_buff *hint)
@@ -335,7 +334,6 @@ static int ip_rcv_finish_core(struct net *net, 
			goto drop_error;

	}



	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;

	if (READ_ONCE(net->ipv4.sysctl_ip_early_demux) &&

	    !skb_dst(skb) &&

	    !skb->sk &&
@@ -354,7 +352,6 @@ static int ip_rcv_finish_core(struct net *net, 
				drop_reason = udp_v4_early_demux(skb);

				if (unlikely(drop_reason))

					goto drop_error;

				drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;



				/* must reload iph, skb->head might have changed */

				iph = ip_hdr(skb);
@@ -372,7 +369,6 @@ static int ip_rcv_finish_core(struct net *net, 
						   ip4h_dscp(iph), dev);

		if (unlikely(drop_reason))

			goto drop_error;

		drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;

	} else {

		struct in_device *in_dev = __in_dev_get_rcu(dev);
@@ -391,8 +387,11 @@ static int ip_rcv_finish_core(struct net *net, 
	}

#endif



	if (iph->ihl > 5 && ip_rcv_options(skb, dev))

	if (iph->ihl > 5) {

		drop_reason = ip_rcv_options(skb, dev);

		if (drop_reason)

			goto drop;

	}



	rt = skb_rtable(skb);

	if (rt->rt_type == RTN_MULTICAST) {

net/ipv4/udp.c

+6 −6
Original line number Diff line number Diff line
@@ -2811,7 +2811,7 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net, 
	return NULL;

}



int udp_v4_early_demux(struct sk_buff *skb)

enum skb_drop_reason udp_v4_early_demux(struct sk_buff *skb)

{

	struct net *net = dev_net(skb->dev);

	struct in_device *in_dev = NULL;
@@ -2825,7 +2825,7 @@ int udp_v4_early_demux(struct sk_buff *skb) 


	/* validate the packet */

	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))

		return 0;

		return SKB_NOT_DROPPED_YET;



	iph = ip_hdr(skb);

	uh = udp_hdr(skb);
@@ -2834,12 +2834,12 @@ int udp_v4_early_demux(struct sk_buff *skb) 
		in_dev = __in_dev_get_rcu(skb->dev);



		if (!in_dev)

			return 0;

			return SKB_NOT_DROPPED_YET;



		ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,

				       iph->protocol);

		if (!ours)

			return 0;

			return SKB_NOT_DROPPED_YET;



		sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,

						   uh->source, iph->saddr,
@@ -2850,7 +2850,7 @@ int udp_v4_early_demux(struct sk_buff *skb) 
	}



	if (!sk)

		return 0;

		return SKB_NOT_DROPPED_YET;



	skb->sk = sk;

	DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
@@ -2877,7 +2877,7 @@ int udp_v4_early_demux(struct sk_buff *skb) 
						     ip4h_dscp(iph),

						     skb->dev, in_dev, &itag);

	}

	return 0;

	return SKB_NOT_DROPPED_YET;

}



int udp_rcv(struct sk_buff *skb)