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Commit e2a3123f authored by Yasuyuki Kozakai's avatar Yasuyuki Kozakai Committed by David S. Miller
Browse files

[NETFILTER]: nf_conntrack: Introduces nf_ct_get_tuplepr and uses it 



nf_ct_get_tuple() requires the offset to transport header and that bothers
callers such as icmp[v6] l4proto modules. This introduces new function
to simplify them.

Signed-off-by: default avatarYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ffc30690

include/net/netfilter/nf_conntrack.h

+4 −0
Original line number Diff line number Diff line
@@ -186,6 +186,10 @@ extern void nf_conntrack_hash_insert(struct nf_conn *ct); 


extern void nf_conntrack_flush(void);



extern int nf_ct_get_tuplepr(const struct sk_buff *skb,

			     unsigned int nhoff,

			     u_int16_t l3num,

			     struct nf_conntrack_tuple *tuple);

extern int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,

				const struct nf_conntrack_tuple *orig);

net/ipv4/netfilter/nf_conntrack_proto_icmp.c

+7 −25
Original line number Diff line number Diff line
@@ -136,40 +136,22 @@ icmp_error_message(struct sk_buff *skb, 
		 unsigned int hooknum)

{

	struct nf_conntrack_tuple innertuple, origtuple;

	struct {

		struct icmphdr icmp;

		struct iphdr ip;

	} _in, *inside;

	struct nf_conntrack_l4proto *innerproto;

	struct nf_conntrack_tuple_hash *h;

	int dataoff;



	NF_CT_ASSERT(skb->nfct == NULL);



	/* Not enough header? */

	inside = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_in), &_in);

	if (inside == NULL)

		return -NF_ACCEPT;



	/* Ignore ICMP's containing fragments (shouldn't happen) */

	if (inside->ip.frag_off & htons(IP_OFFSET)) {

		pr_debug("icmp_error_message: fragment of proto %u\n",

			 inside->ip.protocol);

	/* Are they talking about one of our connections? */

	if (!nf_ct_get_tuplepr(skb,

			       skb_network_offset(skb) + ip_hdrlen(skb)

						       + sizeof(struct icmphdr),

			       PF_INET, &origtuple)) {

		pr_debug("icmp_error_message: failed to get tuple\n");

		return -NF_ACCEPT;

	}



	/* rcu_read_lock()ed by nf_hook_slow */

	innerproto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);



	dataoff = ip_hdrlen(skb) + sizeof(inside->icmp);

	/* Are they talking about one of our connections? */

	if (!nf_ct_get_tuple(skb, dataoff, dataoff + inside->ip.ihl*4, PF_INET,

			     inside->ip.protocol, &origtuple,

			     &nf_conntrack_l3proto_ipv4, innerproto)) {

		pr_debug("icmp_error_message: ! get_tuple p=%u",

			 inside->ip.protocol);

		return -NF_ACCEPT;

	}

	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);



	/* Ordinarily, we'd expect the inverted tupleproto, but it's

	   been preserved inside the ICMP. */

net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c

+8 −34
Original line number Diff line number Diff line
@@ -136,49 +136,23 @@ icmpv6_error_message(struct sk_buff *skb, 
{

	struct nf_conntrack_tuple intuple, origtuple;

	struct nf_conntrack_tuple_hash *h;

	struct icmp6hdr _hdr, *hp;

	unsigned int inip6off;

	struct nf_conntrack_l4proto *inproto;

	u_int8_t inprotonum;

	unsigned int inprotoff;



	NF_CT_ASSERT(skb->nfct == NULL);



	hp = skb_header_pointer(skb, icmp6off, sizeof(_hdr), &_hdr);

	if (hp == NULL) {

		pr_debug("icmpv6_error: Can't get ICMPv6 hdr.\n");

		return -NF_ACCEPT;

	}



	inip6off = icmp6off + sizeof(_hdr);

	if (skb_copy_bits(skb, inip6off+offsetof(struct ipv6hdr, nexthdr),

			  &inprotonum, sizeof(inprotonum)) != 0) {

		pr_debug("icmpv6_error: Can't get nexthdr in inner IPv6 "

			 "header.\n");

		return -NF_ACCEPT;

	}

	inprotoff = nf_ct_ipv6_skip_exthdr(skb,

					   inip6off + sizeof(struct ipv6hdr),

					   &inprotonum,

					   skb->len - inip6off

						    - sizeof(struct ipv6hdr));



	if ((inprotoff > skb->len) || (inprotonum == NEXTHDR_FRAGMENT)) {

		pr_debug("icmpv6_error: Can't get protocol header in ICMPv6 "

			 "payload.\n");

		return -NF_ACCEPT;

	}



	/* rcu_read_lock()ed by nf_hook_slow */

	inproto = __nf_ct_l4proto_find(PF_INET6, inprotonum);



	/* Are they talking about one of our connections? */

	if (!nf_ct_get_tuple(skb, inip6off, inprotoff, PF_INET6, inprotonum,

			     &origtuple, &nf_conntrack_l3proto_ipv6, inproto)) {

	if (!nf_ct_get_tuplepr(skb,

			       skb_network_offset(skb)

				+ sizeof(struct ipv6hdr)

				+ sizeof(struct icmp6hdr),

			       PF_INET6, &origtuple)) {

		pr_debug("icmpv6_error: Can't get tuple\n");

		return -NF_ACCEPT;

	}



	/* rcu_read_lock()ed by nf_hook_slow */

	inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);



	/* Ordinarily, we'd expect the inverted tupleproto, but it's

	   been preserved inside the ICMP. */

	if (!nf_ct_invert_tuple(&intuple, &origtuple,

net/netfilter/nf_conntrack_core.c

+30 −0
Original line number Diff line number Diff line
@@ -113,6 +113,36 @@ nf_ct_get_tuple(const struct sk_buff *skb, 
}

EXPORT_SYMBOL_GPL(nf_ct_get_tuple);



int nf_ct_get_tuplepr(const struct sk_buff *skb,

		      unsigned int nhoff,

		      u_int16_t l3num,

		      struct nf_conntrack_tuple *tuple)

{

	struct nf_conntrack_l3proto *l3proto;

	struct nf_conntrack_l4proto *l4proto;

	unsigned int protoff;

	u_int8_t protonum;

	int ret;



	rcu_read_lock();



	l3proto = __nf_ct_l3proto_find(l3num);

	ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);

	if (ret != NF_ACCEPT) {

		rcu_read_unlock();

		return 0;

	}



	l4proto = __nf_ct_l4proto_find(l3num, protonum);



	ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,

			      l3proto, l4proto);



	rcu_read_unlock();

	return ret;

}

EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);



int

nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,

		   const struct nf_conntrack_tuple *orig,