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 <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
  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 {
  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 }
  30 EXPORT_SYMBOL(xfrm6_rcv_spi);
  31
  32 int 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 #ifdef CONFIG_NETFILTER
  38         ipv6_hdr(skb)->payload_len = htons(skb->len);
  39         __skb_push(skb, skb->data - skb_network_header(skb));
  40
  41         NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
  42                 ip6_rcv_finish);
  43         return -1;
  44 #else
  45         if (async)
  46                 return ip6_rcv_finish(skb);
  47
  48         return 1;
  49 #endif
  50 }
  51
  52 int xfrm6_rcv(struct sk_buff *skb)
  53 {
  54         return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
  55                              0);
  56 }
  57
  58 EXPORT_SYMBOL(xfrm6_rcv);
  59
  60 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
  61                      xfrm_address_t *saddr, u8 proto)
  62 {
  63         struct xfrm_state *x = NULL;
  64         int wildcard = 0;
  65         xfrm_address_t *xany;
  66         struct xfrm_state *xfrm_vec_one = NULL;
  67         int nh = 0;
  68         int i = 0;
  69
  70         xany = (xfrm_address_t *)&in6addr_any;
  71
  72         for (i = 0; i < 3; i++) {
  73                 xfrm_address_t *dst, *src;
  74                 switch (i) {
  75                 case 0:
  76                         dst = daddr;
  77                         src = saddr;
  78                         break;
  79                 case 1:
  80                         /* lookup state with wild-card source address */
  81                         wildcard = 1;
  82                         dst = daddr;
  83                         src = xany;
  84                         break;
  85                 case 2:
  86                 default:
  87                         /* lookup state with wild-card addresses */
  88                         wildcard = 1; /* XXX */
  89                         dst = xany;
  90                         src = xany;
  91                         break;
  92                 }
  93
  94                 x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
  95                 if (!x)
  96                         continue;
  97
  98                 spin_lock(&x->lock);
  99
 100                 if (wildcard) {
 101                         if ((x->props.flags & XFRM_STATE_WILDRECV) == 0) {
 102                                 spin_unlock(&x->lock);
 103                                 xfrm_state_put(x);
 104                                 x = NULL;
 105                                 continue;
 106                         }
 107                 }
 108
 109                 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
 110                         spin_unlock(&x->lock);
 111                         xfrm_state_put(x);
 112                         x = NULL;
 113                         continue;
 114                 }
 115                 if (xfrm_state_check_expire(x)) {
 116                         spin_unlock(&x->lock);
 117                         xfrm_state_put(x);
 118                         x = NULL;
 119                         continue;
 120                 }
 121
 122                 nh = x->type->input(x, skb);
 123                 if (nh <= 0) {
 124                         spin_unlock(&x->lock);
 125                         xfrm_state_put(x);
 126                         x = NULL;
 127                         continue;
 128                 }
 129
 130                 x->curlft.bytes += skb->len;
 131                 x->curlft.packets++;
 132
 133                 spin_unlock(&x->lock);
 134
 135                 xfrm_vec_one = x;
 136                 break;
 137         }
 138
 139         if (!xfrm_vec_one)
 140                 goto drop;
 141
 142         /* Allocate new secpath or COW existing one. */
 143         if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
 144                 struct sec_path *sp;
 145                 sp = secpath_dup(skb->sp);
 146                 if (!sp)
 147                         goto drop;
 148                 if (skb->sp)
 149                         secpath_put(skb->sp);
 150                 skb->sp = sp;
 151         }
 152
 153         if (1 + skb->sp->len > XFRM_MAX_DEPTH)
 154                 goto drop;
 155
 156         skb->sp->xvec[skb->sp->len] = xfrm_vec_one;
 157         skb->sp->len ++;
 158
 159         return 1;
 160 drop:
 161         if (xfrm_vec_one)
 162                 xfrm_state_put(xfrm_vec_one);
 163         return -1;
 164 }
 165
 166 EXPORT_SYMBOL(xfrm6_input_addr);