root/net/ipv6/xfrm6_input.c

DEFINITIONS

1. xfrm6_extract_input
2. xfrm6_rcv_spi
3. xfrm6_transport_finish
4. xfrm6_rcv
5. xfrm6_input_addr

/*
 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
 *
 * Authors:
 *      Mitsuru KANDA @USAGI
 *      Kazunori MIYAZAWA @USAGI
 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *      YOSHIFUJI Hideaki @USAGI
 *              IPv6 support
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
{
        return xfrm6_extract_header(skb);
}

int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
{
        XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
        XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
        return xfrm_input(skb, nexthdr, spi, 0);
}
EXPORT_SYMBOL(xfrm6_rcv_spi);

int xfrm6_transport_finish(struct sk_buff *skb, int async)
{
        skb_network_header(skb)[IP6CB(skb)->nhoff] =
                XFRM_MODE_SKB_CB(skb)->protocol;

#ifndef CONFIG_NETFILTER
        if (!async)
                return 1;
#endif

        ipv6_hdr(skb)->payload_len = htons(skb->len);
        __skb_push(skb, skb->data - skb_network_header(skb));

        NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
                ip6_rcv_finish);
        return -1;
}

int xfrm6_rcv(struct sk_buff *skb)
{
        return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
                             0);
}

EXPORT_SYMBOL(xfrm6_rcv);

int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
                     xfrm_address_t *saddr, u8 proto)
{
        struct xfrm_state *x = NULL;
        int i = 0;

        /* Allocate new secpath or COW existing one. */
        if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
                struct sec_path *sp;

                sp = secpath_dup(skb->sp);
                if (!sp) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINERROR);
                        goto drop;
                }
                if (skb->sp)
                        secpath_put(skb->sp);
                skb->sp = sp;
        }

        if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
                XFRM_INC_STATS(LINUX_MIB_XFRMINBUFFERERROR);
                goto drop;
        }

        for (i = 0; i < 3; i++) {
                xfrm_address_t *dst, *src;

                switch (i) {
                case 0:
                        dst = daddr;
                        src = saddr;
                        break;
                case 1:
                        /* lookup state with wild-card source address */
                        dst = daddr;
                        src = (xfrm_address_t *)&in6addr_any;
                        break;
                default:
                        /* lookup state with wild-card addresses */
                        dst = (xfrm_address_t *)&in6addr_any;
                        src = (xfrm_address_t *)&in6addr_any;
                        break;
                }

                x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
                if (!x)
                        continue;

                spin_lock(&x->lock);

                if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
                    likely(x->km.state == XFRM_STATE_VALID) &&
                    !xfrm_state_check_expire(x)) {
                        spin_unlock(&x->lock);
                        if (x->type->input(x, skb) > 0) {
                                /* found a valid state */
                                break;
                        }
                } else
                        spin_unlock(&x->lock);

                xfrm_state_put(x);
                x = NULL;
        }

        if (!x) {
                XFRM_INC_STATS(LINUX_MIB_XFRMINNOSTATES);
                xfrm_audit_state_notfound_simple(skb, AF_INET6);
                goto drop;
        }

        skb->sp->xvec[skb->sp->len++] = x;

        spin_lock(&x->lock);

        x->curlft.bytes += skb->len;
        x->curlft.packets++;

        spin_unlock(&x->lock);

        return 1;

drop:
        return -1;
}

EXPORT_SYMBOL(xfrm6_input_addr);