net/ipv6/xfrm6_input.c

   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 <[email protected]>
   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
  19 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
  20 {
  21         return xfrm6_extract_header(skb);
  22 }
  23
  24 int 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 }
  32 EXPORT_SYMBOL(xfrm6_rcv_spi);
  33
  34 int xfrm6_transport_finish(struct sk_buff *skb, int async)
  35 {
  36         struct xfrm_offload *xo = xfrm_offload(skb);
  37
  38         skb_network_header(skb)[IP6CB(skb)->nhoff] =
  39                 XFRM_MODE_SKB_CB(skb)->protocol;
  40
  41 #ifndef CONFIG_NETFILTER
  42         if (!async)
  43                 return 1;
  44 #endif
  45
  46         ipv6_hdr(skb)->payload_len = htons(skb->len);
  47         __skb_push(skb, skb->data - skb_network_header(skb));
  48
  49         if (xo && (xo->flags & XFRM_GRO)) {
  50                 skb_mac_header_rebuild(skb);
  51                 return -1;
  52         }
  53
  54         NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
  55                 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
  56                 ip6_rcv_finish);
  57         return -1;
  58 }
  59
  60 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
  61 {
  62         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  63                              0, t);
  64 }
  65 EXPORT_SYMBOL(xfrm6_rcv_tnl);
  66
  67 int xfrm6_rcv(struct sk_buff *skb)
  68 {
  69         return xfrm6_rcv_tnl(skb, NULL);
  70 }
  71 EXPORT_SYMBOL(xfrm6_rcv);
  72 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  73                      xfrm_address_t *saddr, u8 proto)
  74 {
  75         struct net *net = dev_net(skb->dev);
  76         struct xfrm_state *x = NULL;
  77         int i = 0;
  78
  79         if (secpath_set(skb)) {
  80                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
  81                 goto drop;
  82         }
  83
  84         if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
  85                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
  86                 goto drop;
  87         }
  88
  89         for (i = 0; i < 3; i++) {
  90                 xfrm_address_t *dst, *src;
  91
  92                 switch (i) {
  93                 case 0:
  94                         dst = daddr;
  95                         src = saddr;
  96                         break;
  97                 case 1:
  98                         /* lookup state with wild-card source address */
  99                         dst = daddr;
 100                         src = (xfrm_address_t *)&in6addr_any;
 101                         break;
 102                 default:
 103                         /* lookup state with wild-card addresses */
 104                         dst = (xfrm_address_t *)&in6addr_any;
 105                         src = (xfrm_address_t *)&in6addr_any;
 106                         break;
 107                 }
 108
 109                 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
 110                 if (!x)
 111                         continue;
 112
 113                 spin_lock(&x->lock);
 114
 115                 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
 116                     likely(x->km.state == XFRM_STATE_VALID) &&
 117                     !xfrm_state_check_expire(x)) {
 118                         spin_unlock(&x->lock);
 119                         if (x->type->input(x, skb) > 0) {
 120                                 /* found a valid state */
 121                                 break;
 122                         }
 123                 } else
 124                         spin_unlock(&x->lock);
 125
 126                 xfrm_state_put(x);
 127                 x = NULL;
 128         }
 129
 130         if (!x) {
 131                 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
 132                 xfrm_audit_state_notfound_simple(skb, AF_INET6);
 133                 goto drop;
 134         }
 135
 136         skb->sp->xvec[skb->sp->len++] = x;
 137
 138         spin_lock(&x->lock);
 139
 140         x->curlft.bytes += skb->len;
 141         x->curlft.packets++;
 142
 143         spin_unlock(&x->lock);
 144
 145         return 1;
 146
 147 drop:
 148         return -1;
 149 }
 150 EXPORT_SYMBOL(xfrm6_input_addr);