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Commit 58e35d14 authored by Patrick McHardy's avatar Patrick McHardy Committed by Pablo Neira Ayuso
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netfilter: ipv6: propagate routing errors from ip6_route_me_harder() 



Propagate routing errors from ip_route_me_harder() when dropping a packet
using NF_DROP_ERR(). This makes userspace get the proper error instead of
EPERM for everything.

# ip -6 r a unreachable default table 100
# ip -6 ru add fwmark 0x1 lookup 100
# ip6tables -t mangle -A OUTPUT -d 2001:4860:4860::8888 -j MARK --set-mark 0x1

Old behaviour:

PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted

New behaviour:

PING 2001:4860:4860::8888(2001:4860:4860::8888) 56 data bytes
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent c9e1673a

net/ipv6/netfilter.c

+3 −3
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ int ip6_route_me_harder(struct sk_buff *skb) 
		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);

		LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");

		dst_release(dst);

		return -EINVAL;

		return dst->error;

	}



	/* Drop old route. */
@@ -43,7 +43,7 @@ int ip6_route_me_harder(struct sk_buff *skb) 
		skb_dst_set(skb, NULL);

		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);

		if (IS_ERR(dst))

			return -1;

			return PTR_ERR(dst);

		skb_dst_set(skb, dst);

	}

#endif
@@ -53,7 +53,7 @@ int ip6_route_me_harder(struct sk_buff *skb) 
	if (skb_headroom(skb) < hh_len &&

	    pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),

			     0, GFP_ATOMIC))

		return -1;

		return -ENOMEM;



	return 0;

}

net/ipv6/netfilter/ip6table_mangle.c

+6 −3
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out) 
	struct in6_addr saddr, daddr;

	u_int8_t hop_limit;

	u_int32_t flowlabel, mark;



	int err;

#if 0

	/* root is playing with raw sockets. */

	if (skb->len < sizeof(struct iphdr) ||
@@ -65,8 +65,11 @@ ip6t_mangle_out(struct sk_buff *skb, const struct net_device *out) 
	     !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) ||

	     skb->mark != mark ||

	     ipv6_hdr(skb)->hop_limit != hop_limit ||

	     flowlabel != *((u_int32_t *)ipv6_hdr(skb))))

		return ip6_route_me_harder(skb) == 0 ? ret : NF_DROP;

	     flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) {

		err = ip6_route_me_harder(skb);

		if (err < 0)

			ret = NF_DROP_ERR(err);

	}



	return ret;

}

net/ipv6/netfilter/ip6table_nat.c

+4 −2
Original line number Diff line number Diff line
@@ -215,6 +215,7 @@ nf_nat_ipv6_local_fn(unsigned int hooknum, 
	const struct nf_conn *ct;

	enum ip_conntrack_info ctinfo;

	unsigned int ret;

	int err;



	/* root is playing with raw sockets. */

	if (skb->len < sizeof(struct ipv6hdr))
@@ -227,8 +228,9 @@ nf_nat_ipv6_local_fn(unsigned int hooknum, 


		if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3,

				      &ct->tuplehash[!dir].tuple.src.u3)) {

			if (ip6_route_me_harder(skb))

				ret = NF_DROP;

			err = ip6_route_me_harder(skb);

			if (err < 0)

				ret = NF_DROP_ERR(err);

		}

#ifdef CONFIG_XFRM

		else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&