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Commit f8f62675 authored by Jesse Gross's avatar Jesse Gross
Browse files

ipv6: Move ipv6_find_hdr() out of Netfilter code. 



Open vSwitch will soon also use ipv6_find_hdr() so this moves it
out of Netfilter-specific code into a more common location.

Signed-off-by: default avatarJesse Gross <jesse@nicira.com>
parent c0618533

include/linux/netfilter_ipv6/ip6_tables.h

+0 −9
Original line number Diff line number Diff line
@@ -47,15 +47,6 @@ ip6t_ext_hdr(u8 nexthdr) 
	       (nexthdr == IPPROTO_DSTOPTS);

}



enum {

	IP6T_FH_F_FRAG	= (1 << 0),

	IP6T_FH_F_AUTH	= (1 << 1),

};



/* find specified header and get offset to it */

extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,

			 int target, unsigned short *fragoff, int *fragflg);



#ifdef CONFIG_COMPAT

#include <net/compat.h>

include/net/ipv6.h

+9 −0
Original line number Diff line number Diff line
@@ -630,6 +630,15 @@ extern int ipv6_skip_exthdr(const struct sk_buff *, int start, 


extern bool			ipv6_ext_hdr(u8 nexthdr);



enum {

	IP6_FH_F_FRAG	= (1 << 0),

	IP6_FH_F_AUTH	= (1 << 1),

};



/* find specified header and get offset to it */

extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,

			 int target, unsigned short *fragoff, int *fragflg);



extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);



extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,

net/ipv6/exthdrs_core.c

+103 −0
Original line number Diff line number Diff line
@@ -111,3 +111,106 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, 
	return start;

}

EXPORT_SYMBOL(ipv6_skip_exthdr);



/*

 * find the offset to specified header or the protocol number of last header

 * if target < 0. "last header" is transport protocol header, ESP, or

 * "No next header".

 *

 * Note that *offset is used as input/output parameter. an if it is not zero,

 * then it must be a valid offset to an inner IPv6 header. This can be used

 * to explore inner IPv6 header, eg. ICMPv6 error messages.

 *

 * If target header is found, its offset is set in *offset and return protocol

 * number. Otherwise, return -1.

 *

 * If the first fragment doesn't contain the final protocol header or

 * NEXTHDR_NONE it is considered invalid.

 *

 * Note that non-1st fragment is special case that "the protocol number

 * of last header" is "next header" field in Fragment header. In this case,

 * *offset is meaningless and fragment offset is stored in *fragoff if fragoff

 * isn't NULL.

 *

 * if flags is not NULL and it's a fragment, then the frag flag IP6_FH_F_FRAG

 * will be set. If it's an AH header, the IP6_FH_F_AUTH flag is set and

 * target < 0, then this function will stop at the AH header.

 */

int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,

		  int target, unsigned short *fragoff, int *flags)

{

	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);

	u8 nexthdr = ipv6_hdr(skb)->nexthdr;

	unsigned int len;



	if (fragoff)

		*fragoff = 0;



	if (*offset) {

		struct ipv6hdr _ip6, *ip6;



		ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);

		if (!ip6 || (ip6->version != 6)) {

			printk(KERN_ERR "IPv6 header not found\n");

			return -EBADMSG;

		}

		start = *offset + sizeof(struct ipv6hdr);

		nexthdr = ip6->nexthdr;

	}

	len = skb->len - start;



	while (nexthdr != target) {

		struct ipv6_opt_hdr _hdr, *hp;

		unsigned int hdrlen;



		if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {

			if (target < 0)

				break;

			return -ENOENT;

		}



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

		if (hp == NULL)

			return -EBADMSG;

		if (nexthdr == NEXTHDR_FRAGMENT) {

			unsigned short _frag_off;

			__be16 *fp;



			if (flags)	/* Indicate that this is a fragment */

				*flags |= IP6_FH_F_FRAG;

			fp = skb_header_pointer(skb,

						start+offsetof(struct frag_hdr,

							       frag_off),

						sizeof(_frag_off),

						&_frag_off);

			if (fp == NULL)

				return -EBADMSG;



			_frag_off = ntohs(*fp) & ~0x7;

			if (_frag_off) {

				if (target < 0 &&

				    ((!ipv6_ext_hdr(hp->nexthdr)) ||

				     hp->nexthdr == NEXTHDR_NONE)) {

					if (fragoff)

						*fragoff = _frag_off;

					return hp->nexthdr;

				}

				return -ENOENT;

			}

			hdrlen = 8;

		} else if (nexthdr == NEXTHDR_AUTH) {

			if (flags && (*flags & IP6_FH_F_AUTH) && (target < 0))

				break;

			hdrlen = (hp->hdrlen + 2) << 2;

		} else

			hdrlen = ipv6_optlen(hp);



		nexthdr = hp->nexthdr;

		len -= hdrlen;

		start += hdrlen;

	}



	*offset = start;

	return nexthdr;

}

EXPORT_SYMBOL(ipv6_find_hdr);

net/ipv6/netfilter/ip6_tables.c

+0 −103
Original line number Diff line number Diff line
@@ -2273,112 +2273,9 @@ static void __exit ip6_tables_fini(void) 
	unregister_pernet_subsys(&ip6_tables_net_ops);

}



/*

 * find the offset to specified header or the protocol number of last header

 * if target < 0. "last header" is transport protocol header, ESP, or

 * "No next header".

 *

 * Note that *offset is used as input/output parameter. an if it is not zero,

 * then it must be a valid offset to an inner IPv6 header. This can be used

 * to explore inner IPv6 header, eg. ICMPv6 error messages.

 *

 * If target header is found, its offset is set in *offset and return protocol

 * number. Otherwise, return -1.

 *

 * If the first fragment doesn't contain the final protocol header or

 * NEXTHDR_NONE it is considered invalid.

 *

 * Note that non-1st fragment is special case that "the protocol number

 * of last header" is "next header" field in Fragment header. In this case,

 * *offset is meaningless and fragment offset is stored in *fragoff if fragoff

 * isn't NULL.

 *

 * if flags is not NULL and it's a fragment, then the frag flag IP6T_FH_F_FRAG

 * will be set. If it's an AH header, the IP6T_FH_F_AUTH flag is set and

 * target < 0, then this function will stop at the AH header.

 */

int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,

		  int target, unsigned short *fragoff, int *flags)

{

	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);

	u8 nexthdr = ipv6_hdr(skb)->nexthdr;

	unsigned int len;



	if (fragoff)

		*fragoff = 0;



	if (*offset) {

		struct ipv6hdr _ip6, *ip6;



		ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);

		if (!ip6 || (ip6->version != 6)) {

			printk(KERN_ERR "IPv6 header not found\n");

			return -EBADMSG;

		}

		start = *offset + sizeof(struct ipv6hdr);

		nexthdr = ip6->nexthdr;

	}

	len = skb->len - start;



	while (nexthdr != target) {

		struct ipv6_opt_hdr _hdr, *hp;

		unsigned int hdrlen;



		if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {

			if (target < 0)

				break;

			return -ENOENT;

		}



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

		if (hp == NULL)

			return -EBADMSG;

		if (nexthdr == NEXTHDR_FRAGMENT) {

			unsigned short _frag_off;

			__be16 *fp;



			if (flags)	/* Indicate that this is a fragment */

				*flags |= IP6T_FH_F_FRAG;

			fp = skb_header_pointer(skb,

						start+offsetof(struct frag_hdr,

							       frag_off),

						sizeof(_frag_off),

						&_frag_off);

			if (fp == NULL)

				return -EBADMSG;



			_frag_off = ntohs(*fp) & ~0x7;

			if (_frag_off) {

				if (target < 0 &&

				    ((!ipv6_ext_hdr(hp->nexthdr)) ||

				     hp->nexthdr == NEXTHDR_NONE)) {

					if (fragoff)

						*fragoff = _frag_off;

					return hp->nexthdr;

				}

				return -ENOENT;

			}

			hdrlen = 8;

		} else if (nexthdr == NEXTHDR_AUTH) {

			if (flags && (*flags & IP6T_FH_F_AUTH) && (target < 0))

				break;

			hdrlen = (hp->hdrlen + 2) << 2;

		} else

			hdrlen = ipv6_optlen(hp);



		nexthdr = hp->nexthdr;

		len -= hdrlen;

		start += hdrlen;

	}



	*offset = start;

	return nexthdr;

}



EXPORT_SYMBOL(ip6t_register_table);

EXPORT_SYMBOL(ip6t_unregister_table);

EXPORT_SYMBOL(ip6t_do_table);

EXPORT_SYMBOL(ipv6_find_hdr);



module_init(ip6_tables_init);

module_exit(ip6_tables_fini);

net/netfilter/xt_HMARK.c

+4 −4
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ hmark_pkt_set_htuple_ipv6(const struct sk_buff *skb, struct hmark_tuple *t, 
			  const struct xt_hmark_info *info)

{

	struct ipv6hdr *ip6, _ip6;

	int flag = IP6T_FH_F_AUTH;

	int flag = IP6_FH_F_AUTH;

	unsigned int nhoff = 0;

	u16 fragoff = 0;

	int nexthdr;
@@ -177,7 +177,7 @@ hmark_pkt_set_htuple_ipv6(const struct sk_buff *skb, struct hmark_tuple *t, 
	if (nexthdr < 0)

		return 0;

	/* No need to check for icmp errors on fragments */

	if ((flag & IP6T_FH_F_FRAG) || (nexthdr != IPPROTO_ICMPV6))

	if ((flag & IP6_FH_F_FRAG) || (nexthdr != IPPROTO_ICMPV6))

		goto noicmp;

	/* Use inner header in case of ICMP errors */

	if (get_inner6_hdr(skb, &nhoff)) {
@@ -185,7 +185,7 @@ hmark_pkt_set_htuple_ipv6(const struct sk_buff *skb, struct hmark_tuple *t, 
		if (ip6 == NULL)

			return -1;

		/* If AH present, use SPI like in ESP. */

		flag = IP6T_FH_F_AUTH;

		flag = IP6_FH_F_AUTH;

		nexthdr = ipv6_find_hdr(skb, &nhoff, -1, &fragoff, &flag);

		if (nexthdr < 0)

			return -1;
@@ -201,7 +201,7 @@ noicmp: 
	if (t->proto == IPPROTO_ICMPV6)

		return 0;



	if (flag & IP6T_FH_F_FRAG)

	if (flag & IP6_FH_F_FRAG)

		return 0;



	hmark_set_tuple_ports(skb, nhoff, t, info);