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root/net/ipv6/xfrm6_tunnel.c

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DEFINITIONS

This source file includes following definitions.
  1. xfrm6_tunnel_spi_hash_byaddr
  2. xfrm6_tunnel_spi_hash_byspi
  3. xfrm6_tunnel_spi_init
  4. xfrm6_tunnel_spi_fini
  5. __xfrm6_tunnel_spi_lookup
  6. xfrm6_tunnel_spi_lookup
  7. __xfrm6_tunnel_spi_check
  8. __xfrm6_tunnel_alloc_spi
  9. xfrm6_tunnel_alloc_spi
  10. xfrm6_tunnel_free_spi
  11. xfrm6_tunnel_output
  12. xfrm6_tunnel_input
  13. xfrm6_tunnel_rcv
  14. xfrm6_tunnel_err
  15. xfrm6_tunnel_init_state
  16. xfrm6_tunnel_destroy
  17. xfrm6_tunnel_init
  18. xfrm6_tunnel_fini

/*
 * Copyright (C)2003,2004 USAGI/WIDE Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Authors      Mitsuru KANDA  <mk@linux-ipv6.org>
 *              YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
 *
 * Based on net/ipv4/xfrm4_tunnel.c
 *
 */
#include <linux/module.h>
#include <linux/xfrm.h>
#include <linux/list.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipv6.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>

/*
 * xfrm_tunnel_spi things are for allocating unique id ("spi")
 * per xfrm_address_t.
 */
struct xfrm6_tunnel_spi {
        struct hlist_node list_byaddr;
        struct hlist_node list_byspi;
        xfrm_address_t addr;
        u32 spi;
        atomic_t refcnt;
};

static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock);

static u32 xfrm6_tunnel_spi;

#define XFRM6_TUNNEL_SPI_MIN    1
#define XFRM6_TUNNEL_SPI_MAX    0xffffffff

static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;

#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256

static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];

static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
{
        unsigned h;

        h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]);
        h ^= h >> 16;
        h ^= h >> 8;
        h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;

        return h;
}

static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi)
{
        return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
}


static int xfrm6_tunnel_spi_init(void)
{
        int i;

        xfrm6_tunnel_spi = 0;
        xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
                                                  sizeof(struct xfrm6_tunnel_spi),
                                                  0, SLAB_HWCACHE_ALIGN,
                                                  NULL);
        if (!xfrm6_tunnel_spi_kmem)
                return -ENOMEM;

        for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
                INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]);
        for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
                INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]);
        return 0;
}

static void xfrm6_tunnel_spi_fini(void)
{
        int i;

        for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) {
                if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i]))
                        return;
        }
        for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) {
                if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i]))
                        return;
        }
        kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
        xfrm6_tunnel_spi_kmem = NULL;
}

static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
        struct xfrm6_tunnel_spi *x6spi;
        struct hlist_node *pos;

        hlist_for_each_entry(x6spi, pos,
                             &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
                             list_byaddr) {
                if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0)
                        return x6spi;
        }

        return NULL;
}

__be32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
        struct xfrm6_tunnel_spi *x6spi;
        u32 spi;

        read_lock_bh(&xfrm6_tunnel_spi_lock);
        x6spi = __xfrm6_tunnel_spi_lookup(saddr);
        spi = x6spi ? x6spi->spi : 0;
        read_unlock_bh(&xfrm6_tunnel_spi_lock);
        return htonl(spi);
}

EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);

static int __xfrm6_tunnel_spi_check(u32 spi)
{
        struct xfrm6_tunnel_spi *x6spi;
        int index = xfrm6_tunnel_spi_hash_byspi(spi);
        struct hlist_node *pos;

        hlist_for_each_entry(x6spi, pos,
                             &xfrm6_tunnel_spi_byspi[index],
                             list_byspi) {
                if (x6spi->spi == spi)
                        return -1;
        }
        return index;
}

static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
        u32 spi;
        struct xfrm6_tunnel_spi *x6spi;
        int index;

        if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN ||
            xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX)
                xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN;
        else
                xfrm6_tunnel_spi++;

        for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
                index = __xfrm6_tunnel_spi_check(spi);
                if (index >= 0)
                        goto alloc_spi;
        }
        for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
                index = __xfrm6_tunnel_spi_check(spi);
                if (index >= 0)
                        goto alloc_spi;
        }
        spi = 0;
        goto out;
alloc_spi:
        xfrm6_tunnel_spi = spi;
        x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
        if (!x6spi)
                goto out;

        memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
        x6spi->spi = spi;
        atomic_set(&x6spi->refcnt, 1);

        hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);

        index = xfrm6_tunnel_spi_hash_byaddr(saddr);
        hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
out:
        return spi;
}

__be32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
        struct xfrm6_tunnel_spi *x6spi;
        u32 spi;

        write_lock_bh(&xfrm6_tunnel_spi_lock);
        x6spi = __xfrm6_tunnel_spi_lookup(saddr);
        if (x6spi) {
                atomic_inc(&x6spi->refcnt);
                spi = x6spi->spi;
        } else
                spi = __xfrm6_tunnel_alloc_spi(saddr);
        write_unlock_bh(&xfrm6_tunnel_spi_lock);

        return htonl(spi);
}

EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);

void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
{
        struct xfrm6_tunnel_spi *x6spi;
        struct hlist_node *pos, *n;

        write_lock_bh(&xfrm6_tunnel_spi_lock);

        hlist_for_each_entry_safe(x6spi, pos, n,
                                  &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
                                  list_byaddr)
        {
                if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
                        if (atomic_dec_and_test(&x6spi->refcnt)) {
                                hlist_del(&x6spi->list_byaddr);
                                hlist_del(&x6spi->list_byspi);
                                kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi);
                                break;
                        }
                }
        }
        write_unlock_bh(&xfrm6_tunnel_spi_lock);
}

EXPORT_SYMBOL(xfrm6_tunnel_free_spi);

static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
        skb_push(skb, -skb_network_offset(skb));
        return 0;
}

static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
        return skb_network_header(skb)[IP6CB(skb)->nhoff];
}

static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
        struct ipv6hdr *iph = ipv6_hdr(skb);
        __be32 spi;

        spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
        return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0;
}

static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                            int type, int code, int offset, __be32 info)
{
        /* xfrm6_tunnel native err handling */
        switch (type) {
        case ICMPV6_DEST_UNREACH:
                switch (code) {
                case ICMPV6_NOROUTE:
                case ICMPV6_ADM_PROHIBITED:
                case ICMPV6_NOT_NEIGHBOUR:
                case ICMPV6_ADDR_UNREACH:
                case ICMPV6_PORT_UNREACH:
                default:
                        break;
                }
                break;
        case ICMPV6_PKT_TOOBIG:
                break;
        case ICMPV6_TIME_EXCEED:
                switch (code) {
                case ICMPV6_EXC_HOPLIMIT:
                        break;
                case ICMPV6_EXC_FRAGTIME:
                default:
                        break;
                }
                break;
        case ICMPV6_PARAMPROB:
                switch (code) {
                case ICMPV6_HDR_FIELD: break;
                case ICMPV6_UNK_NEXTHDR: break;
                case ICMPV6_UNK_OPTION: break;
                }
                break;
        default:
                break;
        }

        return 0;
}

static int xfrm6_tunnel_init_state(struct xfrm_state *x)
{
        if (x->props.mode != XFRM_MODE_TUNNEL)
                return -EINVAL;

        if (x->encap)
                return -EINVAL;

        x->props.header_len = sizeof(struct ipv6hdr);

        return 0;
}

static void xfrm6_tunnel_destroy(struct xfrm_state *x)
{
        xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
}

static const struct xfrm_type xfrm6_tunnel_type = {
        .description    = "IP6IP6",
        .owner          = THIS_MODULE,
        .proto          = IPPROTO_IPV6,
        .init_state     = xfrm6_tunnel_init_state,
        .destructor     = xfrm6_tunnel_destroy,
        .input          = xfrm6_tunnel_input,
        .output         = xfrm6_tunnel_output,
};

static struct xfrm6_tunnel xfrm6_tunnel_handler = {
        .handler        = xfrm6_tunnel_rcv,
        .err_handler    = xfrm6_tunnel_err,
        .priority       = 2,
};

static struct xfrm6_tunnel xfrm46_tunnel_handler = {
        .handler        = xfrm6_tunnel_rcv,
        .err_handler    = xfrm6_tunnel_err,
        .priority       = 2,
};

static int __init xfrm6_tunnel_init(void)
{
        if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0)
                return -EAGAIN;

        if (xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6)) {
                xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
                return -EAGAIN;
        }
        if (xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET)) {
                xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
                xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
                return -EAGAIN;
        }
        if (xfrm6_tunnel_spi_init() < 0) {
                xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
                xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
                xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
                return -EAGAIN;
        }
        return 0;
}

static void __exit xfrm6_tunnel_fini(void)
{
        xfrm6_tunnel_spi_fini();
        xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
        xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
        xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
}

module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);

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