LXR linux/net/ipv6/xfrm6

   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                  struct ip6_tnl *t)
  26{
  27        XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
  28        XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
  29        XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
  30        return xfrm_input(skb, nexthdr, spi, 0);
  31}
  32EXPORT_SYMBOL(xfrm6_rcv_spi);
  33
  34int xfrm6_transport_finish(struct sk_buff *skb, int async)
  35{
  36        skb_network_header(skb)[IP6CB(skb)->nhoff] =
  37                XFRM_MODE_SKB_CB(skb)->protocol;
  38
  39#ifndef CONFIG_NETFILTER
  40        if (!async)
  41                return 1;
  42#endif
  43
  44        ipv6_hdr(skb)->payload_len = htons(skb->len);
  45        __skb_push(skb, skb->data - skb_network_header(skb));
  46
  47        NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
  48                dev_net(skb->dev), NULL, skb, skb->dev, NULL,
  49                ip6_rcv_finish);
  50        return -1;
  51}
  52
  53int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
  54{
  55        return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  56                             0, t);
  57}
  58EXPORT_SYMBOL(xfrm6_rcv_tnl);
  59
  60int xfrm6_rcv(struct sk_buff *skb)
  61{
  62        return xfrm6_rcv_tnl(skb, NULL);
  63}
  64EXPORT_SYMBOL(xfrm6_rcv);
  65int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  66                     xfrm_address_t *saddr, u8 proto)
  67{
  68        struct net *net = dev_net(skb->dev);
  69        struct xfrm_state *x = NULL;
  70        int i = 0;
  71
  72        /* Allocate new secpath or COW existing one. */
  73        if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
  74                struct sec_path *sp;
  75
  76                sp = secpath_dup(skb->sp);
  77                if (!sp) {
  78                        XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  79                        goto drop;
  80                }
  81                if (skb->sp)
  82                        secpath_put(skb->sp);
  83                skb->sp = sp;
  84        }
  85
  86        if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
  87                XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  88                goto drop;
  89        }
  90
  91        for (i = 0; i < 3; i++) {
  92                xfrm_address_t *dst, *src;
  93
  94                switch (i) {
  95                case 0:
  96                        dst = daddr;
  97                        src = saddr;
  98                        break;
  99                case 1:
 100                        /* lookup state with wild-card source address */
 101                        dst = daddr;
 102                        src = (xfrm_address_t *)&in6addr_any;
 103                        break;
 104                default:
 105                        /* lookup state with wild-card addresses */
 106                        dst = (xfrm_address_t *)&in6addr_any;
 107                        src = (xfrm_address_t *)&in6addr_any;
 108                        break;
 109                }
 110
 111                x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 112                if (!x)
 113                        continue;
 114
 115                spin_lock(&x->lock);
 116
 117                if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 118                    likely(x->km.state == XFRM_STATE_VALID) &&
 119                    !xfrm_state_check_expire(x)) {
 120                        spin_unlock(&x->lock);
 121                        if (x->type->input(x, skb) > 0) {
 122                                /* found a valid state */
 123                                break;
 124                        }
 125                } else
 126                        spin_unlock(&x->lock);
 127
 128                xfrm_state_put(x);
 129                x = NULL;
 130        }
 131
 132        if (!x) {
 133                XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 134                xfrm_audit_state_notfound_simple(skb, AF_INET6);
 135                goto drop;
 136        }
 137
 138        skb->sp->xvec[skb->sp->len++] = x;
 139
 140        spin_lock(&x->lock);
 141
 142        x->curlft.bytes += skb->len;
 143        x->curlft.packets++;
 144
 145        spin_unlock(&x->lock);
 146
 147        return 1;
 148
 149drop:
 150        return -1;
 151}
 152EXPORT_SYMBOL(xfrm6_input_addr);
 153