Commit 30c89bad authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv6: icmp6: add drop reason support to icmpv6_notify() 



Accurately reports what happened in icmpv6_notify() when handling
a packet.

This makes use of the new IPV6_BAD_EXTHDR drop reason.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1fb2d415

include/net/ipv6.h

+2 −1
Original line number Diff line number Diff line
@@ -436,7 +436,8 @@ static inline void fl6_sock_release(struct ip6_flowlabel *fl) 
		atomic_dec(&fl->users);

}



void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);

enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,

				   u8 code, __be32 info);



void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,

				struct icmp6hdr *thdr, int len);

net/ipv6/icmp.c

+17 −8
Original line number Diff line number Diff line
@@ -813,16 +813,19 @@ static void icmpv6_echo_reply(struct sk_buff *skb) 
	local_bh_enable();

}



void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)

enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,

				   u8 code, __be32 info)

{

	struct inet6_skb_parm *opt = IP6CB(skb);

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

	const struct inet6_protocol *ipprot;

	enum skb_drop_reason reason;

	int inner_offset;

	__be16 frag_off;

	u8 nexthdr;

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



	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))

	reason = pskb_may_pull_reason(skb, sizeof(struct ipv6hdr));

	if (reason != SKB_NOT_DROPPED_YET)

		goto out;



	seg6_icmp_srh(skb, opt);
@@ -832,14 +835,17 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) 
		/* now skip over extension headers */

		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),

						&nexthdr, &frag_off);

		if (inner_offset < 0)

		if (inner_offset < 0) {

			SKB_DR_SET(reason, IPV6_BAD_EXTHDR);

			goto out;

		}

	} else {

		inner_offset = sizeof(struct ipv6hdr);

	}



	/* Checkin header including 8 bytes of inner protocol header. */

	if (!pskb_may_pull(skb, inner_offset+8))

	reason = pskb_may_pull_reason(skb, inner_offset + 8);

	if (reason != SKB_NOT_DROPPED_YET)

		goto out;



	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
@@ -854,10 +860,11 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) 
		ipprot->err_handler(skb, opt, type, code, inner_offset, info);



	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);

	return;

	return SKB_CONSUMED;



out:

	__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);

	return reason;

}



/*
@@ -953,7 +960,8 @@ static int icmpv6_rcv(struct sk_buff *skb) 
	case ICMPV6_DEST_UNREACH:

	case ICMPV6_TIME_EXCEED:

	case ICMPV6_PARAMPROB:

		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);

		reason = icmpv6_notify(skb, type, hdr->icmp6_code,

				       hdr->icmp6_mtu);

		break;



	case NDISC_ROUTER_SOLICITATION:
@@ -995,7 +1003,8 @@ static int icmpv6_rcv(struct sk_buff *skb) 
		 * must pass to upper level

		 */



		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);

		reason = icmpv6_notify(skb, type, hdr->icmp6_code,

				       hdr->icmp6_mtu);

	}



	/* until the v6 path can be better sorted assume failure and