linux/net/ipv6/xfrm6_input.c
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   1/*
   2 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
   3 *
   4 * Authors:
   5 *      Mitsuru KANDA @USAGI
   6 *      Kazunori MIYAZAWA @USAGI
   7 *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8 *      YOSHIFUJI Hideaki @USAGI
   9 *              IPv6 support
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/string.h>
  14#include <linux/netfilter.h>
  15#include <linux/netfilter_ipv6.h>
  16#include <net/ipv6.h>
  17#include <net/xfrm.h>
  18
  19int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
  20{
  21        return xfrm6_extract_header(skb);
  22}
  23
  24int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
  25{
  26        XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
  27        XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
  28        return xfrm_input(skb, nexthdr, spi, 0);
  29}
  30EXPORT_SYMBOL(xfrm6_rcv_spi);
  31
  32int xfrm6_transport_finish(struct sk_buff *skb, int async)
  33{
  34        skb_network_header(skb)[IP6CB(skb)->nhoff] =
  35                XFRM_MODE_SKB_CB(skb)->protocol;
  36
  37#ifndef CONFIG_NETFILTER
  38        if (!async)
  39                return 1;
  40#endif
  41
  42        ipv6_hdr(skb)->payload_len = htons(skb->len);
  43        __skb_push(skb, skb->data - skb_network_header(skb));
  44
  45        NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
  46                ip6_rcv_finish);
  47        return -1;
  48}
  49
  50int xfrm6_rcv(struct sk_buff *skb)
  51{
  52        return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  53                             0);
  54}
  55
  56EXPORT_SYMBOL(xfrm6_rcv);
  57
  58int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  59                     xfrm_address_t *saddr, u8 proto)
  60{
  61        struct net *net = dev_net(skb->dev);
  62        struct xfrm_state *x = NULL;
  63        int i = 0;
  64
  65        /* Allocate new secpath or COW existing one. */
  66        if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
  67                struct sec_path *sp;
  68
  69                sp = secpath_dup(skb->sp);
  70                if (!sp) {
  71                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  72                        goto drop;
  73                }
  74                if (skb->sp)
  75                        secpath_put(skb->sp);
  76                skb->sp = sp;
  77        }
  78
  79        if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
  80                XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  81                goto drop;
  82        }
  83
  84        for (i = 0; i < 3; i++) {
  85                xfrm_address_t *dst, *src;
  86
  87                switch (i) {
  88                case 0:
  89                        dst = daddr;
  90                        src = saddr;
  91                        break;
  92                case 1:
  93                        /* lookup state with wild-card source address */
  94                        dst = daddr;
  95                        src = (xfrm_address_t *)&in6addr_any;
  96                        break;
  97                default:
  98                        /* lookup state with wild-card addresses */
  99                        dst = (xfrm_address_t *)&in6addr_any;
 100                        src = (xfrm_address_t *)&in6addr_any;
 101                        break;
 102                }
 103
 104                x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 105                if (!x)
 106                        continue;
 107
 108                spin_lock(&x->lock);
 109
 110                if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 111                    likely(x->km.state == XFRM_STATE_VALID) &&
 112                    !xfrm_state_check_expire(x)) {
 113                        spin_unlock(&x->lock);
 114                        if (x->type->input(x, skb) > 0) {
 115                                /* found a valid state */
 116                                break;
 117                        }
 118                } else
 119                        spin_unlock(&x->lock);
 120
 121                xfrm_state_put(x);
 122                x = NULL;
 123        }
 124
 125        if (!x) {
 126                XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 127                xfrm_audit_state_notfound_simple(skb, AF_INET6);
 128                goto drop;
 129        }
 130
 131        skb->sp->xvec[skb->sp->len++] = x;
 132
 133        spin_lock(&x->lock);
 134
 135        x->curlft.bytes += skb->len;
 136        x->curlft.packets++;
 137
 138        spin_unlock(&x->lock);
 139
 140        return 1;
 141
 142drop:
 143        return -1;
 144}
 145
 146EXPORT_SYMBOL(xfrm6_input_addr);
 147
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