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root/net/xfrm/xfrm_input.c

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DEFINITIONS

This source file includes following definitions.
  1. __secpath_destroy
  2. secpath_dup
  3. xfrm_parse_spi
  4. xfrm_prepare_input
  5. xfrm_input
  6. xfrm_input_resume
  7. xfrm_input_init

/*
 * xfrm_input.c
 *
 * Changes:
 *      YOSHIFUJI Hideaki @USAGI
 *              Split up af-specific portion
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>

static struct kmem_cache *secpath_cachep __read_mostly;

void __secpath_destroy(struct sec_path *sp)
{
        int i;
        for (i = 0; i < sp->len; i++)
                xfrm_state_put(sp->xvec[i]);
        kmem_cache_free(secpath_cachep, sp);
}
EXPORT_SYMBOL(__secpath_destroy);

struct sec_path *secpath_dup(struct sec_path *src)
{
        struct sec_path *sp;

        sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
        if (!sp)
                return NULL;

        sp->len = 0;
        if (src) {
                int i;

                memcpy(sp, src, sizeof(*sp));
                for (i = 0; i < sp->len; i++)
                        xfrm_state_hold(sp->xvec[i]);
        }
        atomic_set(&sp->refcnt, 1);
        return sp;
}
EXPORT_SYMBOL(secpath_dup);

/* Fetch spi and seq from ipsec header */

int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
{
        int offset, offset_seq;
        int hlen;

        switch (nexthdr) {
        case IPPROTO_AH:
                hlen = sizeof(struct ip_auth_hdr);
                offset = offsetof(struct ip_auth_hdr, spi);
                offset_seq = offsetof(struct ip_auth_hdr, seq_no);
                break;
        case IPPROTO_ESP:
                hlen = sizeof(struct ip_esp_hdr);
                offset = offsetof(struct ip_esp_hdr, spi);
                offset_seq = offsetof(struct ip_esp_hdr, seq_no);
                break;
        case IPPROTO_COMP:
                if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
                        return -EINVAL;
                *spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
                *seq = 0;
                return 0;
        default:
                return 1;
        }

        if (!pskb_may_pull(skb, hlen))
                return -EINVAL;

        *spi = *(__be32*)(skb_transport_header(skb) + offset);
        *seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
        return 0;
}

int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
{
        struct xfrm_mode *inner_mode = x->inner_mode;
        int err;

        err = x->outer_mode->afinfo->extract_input(x, skb);
        if (err)
                return err;

        if (x->sel.family == AF_UNSPEC) {
                inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
                if (inner_mode == NULL)
                        return -EAFNOSUPPORT;
        }

        skb->protocol = inner_mode->afinfo->eth_proto;
        return inner_mode->input2(x, skb);
}
EXPORT_SYMBOL(xfrm_prepare_input);

int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
{
        int err;
        __be32 seq;
        struct xfrm_state *x;
        xfrm_address_t *daddr;
        struct xfrm_mode *inner_mode;
        unsigned int family;
        int decaps = 0;
        int async = 0;

        /* A negative encap_type indicates async resumption. */
        if (encap_type < 0) {
                async = 1;
                x = xfrm_input_state(skb);
                seq = XFRM_SKB_CB(skb)->seq.input;
                goto resume;
        }

        /* 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;
        }

        daddr = (xfrm_address_t *)(skb_network_header(skb) +
                                   XFRM_SPI_SKB_CB(skb)->daddroff);
        family = XFRM_SPI_SKB_CB(skb)->family;

        seq = 0;
        if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
                XFRM_INC_STATS(LINUX_MIB_XFRMINHDRERROR);
                goto drop;
        }

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

                x = xfrm_state_lookup(daddr, spi, nexthdr, family);
                if (x == NULL) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINNOSTATES);
                        xfrm_audit_state_notfound(skb, family, spi, seq);
                        goto drop;
                }

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

                spin_lock(&x->lock);
                if (unlikely(x->km.state != XFRM_STATE_VALID)) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEINVALID);
                        goto drop_unlock;
                }

                if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMISMATCH);
                        goto drop_unlock;
                }

                if (x->props.replay_window && xfrm_replay_check(x, skb, seq)) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATESEQERROR);
                        goto drop_unlock;
                }

                if (xfrm_state_check_expire(x)) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEEXPIRED);
                        goto drop_unlock;
                }

                spin_unlock(&x->lock);

                XFRM_SKB_CB(skb)->seq.input = seq;

                nexthdr = x->type->input(x, skb);

                if (nexthdr == -EINPROGRESS)
                        return 0;

resume:
                spin_lock(&x->lock);
                if (nexthdr <= 0) {
                        if (nexthdr == -EBADMSG) {
                                xfrm_audit_state_icvfail(x, skb,
                                                         x->type->proto);
                                x->stats.integrity_failed++;
                        }
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEPROTOERROR);
                        goto drop_unlock;
                }

                /* only the first xfrm gets the encap type */
                encap_type = 0;

                if (x->props.replay_window)
                        xfrm_replay_advance(x, seq);

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

                spin_unlock(&x->lock);

                XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;

                inner_mode = x->inner_mode;

                if (x->sel.family == AF_UNSPEC) {
                        inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
                        if (inner_mode == NULL)
                                goto drop;
                }

                if (inner_mode->input(x, skb)) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMODEERROR);
                        goto drop;
                }

                if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
                        decaps = 1;
                        break;
                }

                /*
                 * We need the inner address.  However, we only get here for
                 * transport mode so the outer address is identical.
                 */
                daddr = &x->id.daddr;
                family = x->outer_mode->afinfo->family;

                err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
                if (err < 0) {
                        XFRM_INC_STATS(LINUX_MIB_XFRMINHDRERROR);
                        goto drop;
                }
        } while (!err);

        nf_reset(skb);

        if (decaps) {
                dst_release(skb->dst);
                skb->dst = NULL;
                netif_rx(skb);
                return 0;
        } else {
                return x->inner_mode->afinfo->transport_finish(skb, async);
        }

drop_unlock:
        spin_unlock(&x->lock);
drop:
        kfree_skb(skb);
        return 0;
}
EXPORT_SYMBOL(xfrm_input);

int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
{
        return xfrm_input(skb, nexthdr, 0, -1);
}
EXPORT_SYMBOL(xfrm_input_resume);

void __init xfrm_input_init(void)
{
        secpath_cachep = kmem_cache_create("secpath_cache",
                                           sizeof(struct sec_path),
                                           0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
                                           NULL);
}

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