/*

 * xfrm6_state.c: based on xfrm4_state.c

 *

 * Authors:

 *	Mitsuru KANDA @USAGI

 * 	Kazunori MIYAZAWA @USAGI

 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>

 * 		IPv6 support

 * 	YOSHIFUJI Hideaki @USAGI

 * 		Split up af-specific portion

 *

 */

#include <net/xfrm.h>

#include <linux/pfkeyv2.h>

#include <linux/ipsec.h>

#include <linux/netfilter_ipv6.h>

#include <net/dsfield.h>

#include <net/ipv6.h>

#include <net/addrconf.h>

static void

__xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,

		     struct xfrm_tmpl *tmpl,

		     xfrm_address_t *daddr, xfrm_address_t *saddr)

{

	/* Initialize temporary selector matching only

	 * to current session. */

	ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);

	ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);

	x->sel.dport = xfrm_flowi_dport(fl);

	x->sel.dport_mask = htons(0xffff);

	x->sel.sport = xfrm_flowi_sport(fl);

	x->sel.sport_mask = htons(0xffff);

	x->sel.family = AF_INET6;

	x->sel.prefixlen_d = 128;

	x->sel.prefixlen_s = 128;

	x->sel.proto = fl->proto;

	x->sel.ifindex = fl->oif;

	x->id = tmpl->id;

	if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))

		memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));

	memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));

	if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))

		memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));

	x->props.mode = tmpl->mode;

	x->props.reqid = tmpl->reqid;

	x->props.family = AF_INET6;

}

/* distribution counting sort function for xfrm_state and xfrm_tmpl */

static int

__xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)

{

	int i;

	int class[XFRM_MAX_DEPTH];

	int count[maxclass];

	memset(count, 0, sizeof(count));

	for (i = 0; i < n; i++) {

		int c;

		class[i] = c = cmp(src[i]);

		count[c]++;

	}

	for (i = 2; i < maxclass; i++)

		count[i] += count[i - 1];

	for (i = 0; i < n; i++) {

		dst[count[class[i] - 1]++] = src[i];

		src[i] = 0;

	}

	return 0;

}

/*

 * Rule for xfrm_state:

 *

 * rule 1: select IPsec transport except AH

 * rule 2: select MIPv6 RO or inbound trigger

 * rule 3: select IPsec transport AH

 * rule 4: select IPsec tunnel

 * rule 5: others

 */

static int __xfrm6_state_sort_cmp(void *p)

{

	struct xfrm_state *v = p;

	switch (v->props.mode) {

	case XFRM_MODE_TRANSPORT:

		if (v->id.proto != IPPROTO_AH)

			return 1;

		else

			return 3;

#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)

	case XFRM_MODE_ROUTEOPTIMIZATION:

	case XFRM_MODE_IN_TRIGGER:

		return 2;

#endif

	case XFRM_MODE_TUNNEL:

	case XFRM_MODE_BEET:

		return 4;

	}

	return 5;

}

static int

__xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)

{

	return __xfrm6_sort((void **)dst, (void **)src, n,

			    __xfrm6_state_sort_cmp, 6);

}

/*

 * Rule for xfrm_tmpl:

 *

 * rule 1: select IPsec transport

 * rule 2: select MIPv6 RO or inbound trigger

 * rule 3: select IPsec tunnel

 * rule 4: others

 */

static int __xfrm6_tmpl_sort_cmp(void *p)

{

	struct xfrm_tmpl *v = p;

	switch (v->mode) {

	case XFRM_MODE_TRANSPORT:

		return 1;

#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)

	case XFRM_MODE_ROUTEOPTIMIZATION:

	case XFRM_MODE_IN_TRIGGER:

		return 2;

#endif

	case XFRM_MODE_TUNNEL:

	case XFRM_MODE_BEET:

		return 3;

	}

	return 4;

}

static int

__xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)

{

	return __xfrm6_sort((void **)dst, (void **)src, n,

			    __xfrm6_tmpl_sort_cmp, 5);

}

int xfrm6_extract_header(struct sk_buff *skb)

{

	struct ipv6hdr *iph = ipv6_hdr(skb);

	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);

	XFRM_MODE_SKB_CB(skb)->id = 0;

	XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);

	XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);

	XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;

	XFRM_MODE_SKB_CB(skb)->optlen = 0;

	memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,

	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));

	return 0;

}

static struct xfrm_state_afinfo xfrm6_state_afinfo = {

	.family			= AF_INET6,

	.proto			= IPPROTO_IPV6,

	.eth_proto		= htons(ETH_P_IPV6),

	.owner			= THIS_MODULE,

	.init_tempsel		= __xfrm6_init_tempsel,

	.tmpl_sort		= __xfrm6_tmpl_sort,

	.state_sort		= __xfrm6_state_sort,

	.output			= xfrm6_output,

	.extract_input		= xfrm6_extract_input,

	.extract_output		= xfrm6_extract_output,

	.transport_finish	= xfrm6_transport_finish,

};

int __init xfrm6_state_init(void)

{

	return xfrm_state_register_afinfo(&xfrm6_state_afinfo);

}

void xfrm6_state_fini(void)

{

	xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);

}