net/xfrm/xfrm_input.c

   1 /*
   2  * xfrm_input.c
   3  *
   4  * Changes:
   5  *      YOSHIFUJI Hideaki @USAGI
   6  *              Split up af-specific portion
   7  *
   8  */
   9
  10 #include <linux/slab.h>
  11 #include <net/ip.h>
  12 #include <net/xfrm.h>
  13
  14 static kmem_cache_t *secpath_cachep;
  15
  16 void __secpath_destroy(struct sec_path *sp)
  17 {
  18         int i;
  19         for (i = 0; i < sp->len; i++)
  20                 xfrm_state_put(sp->x[i].xvec);
  21         kmem_cache_free(secpath_cachep, sp);
  22 }
  23
  24 struct sec_path *secpath_dup(struct sec_path *src)
  25 {
  26         struct sec_path *sp;
  27
  28         sp = kmem_cache_alloc(secpath_cachep, SLAB_ATOMIC);
  29         if (!sp)
  30                 return NULL;
  31
  32         sp->len = 0;
  33         if (src) {
  34                 int i;
  35
  36                 memcpy(sp, src, sizeof(*sp));
  37                 for (i = 0; i < sp->len; i++)
  38                         xfrm_state_hold(sp->x[i].xvec);
  39         }
  40         atomic_set(&sp->refcnt, 1);
  41         return sp;
  42 }
  43
  44 /* Fetch spi and seq from ipsec header */
  45
  46 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq)
  47 {
  48         int offset, offset_seq;
  49
  50         switch (nexthdr) {
  51         case IPPROTO_AH:
  52                 offset = offsetof(struct ip_auth_hdr, spi);
  53                 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
  54                 break;
  55         case IPPROTO_ESP:
  56                 offset = offsetof(struct ip_esp_hdr, spi);
  57                 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
  58                 break;
  59         case IPPROTO_COMP:
  60                 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
  61                         return -EINVAL;
  62                 *spi = ntohl(ntohs(*(u16*)(skb->h.raw + 2)));
  63                 *seq = 0;
  64                 return 0;
  65         default:
  66                 return 1;
  67         }
  68
  69         if (!pskb_may_pull(skb, 16))
  70                 return -EINVAL;
  71
  72         *spi = *(u32*)(skb->h.raw + offset);
  73         *seq = *(u32*)(skb->h.raw + offset_seq);
  74         return 0;
  75 }
  76
  77 void __init xfrm_input_init(void)
  78 {
  79         secpath_cachep = kmem_cache_create("secpath_cache",
  80                                            sizeof(struct sec_path),
  81                                            0, SLAB_HWCACHE_ALIGN,
  82                                            NULL, NULL);
  83         if (!secpath_cachep)
  84                 panic("XFRM: failed to allocate secpath_cache\n");
  85 }