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 <linux/module.h>
  12 #include <net/ip.h>
  13 #include <net/xfrm.h>
  14
  15 static kmem_cache_t *secpath_cachep __read_mostly;
  16
  17 void __secpath_destroy(struct sec_path *sp)
  18 {
  19         int i;
  20         for (i = 0; i < sp->len; i++)
  21                 xfrm_state_put(sp->xvec[i]);
  22         kmem_cache_free(secpath_cachep, sp);
  23 }
  24 EXPORT_SYMBOL(__secpath_destroy);
  25
  26 struct sec_path *secpath_dup(struct sec_path *src)
  27 {
  28         struct sec_path *sp;
  29
  30         sp = kmem_cache_alloc(secpath_cachep, SLAB_ATOMIC);
  31         if (!sp)
  32                 return NULL;
  33
  34         sp->len = 0;
  35         if (src) {
  36                 int i;
  37
  38                 memcpy(sp, src, sizeof(*sp));
  39                 for (i = 0; i < sp->len; i++)
  40                         xfrm_state_hold(sp->xvec[i]);
  41         }
  42         atomic_set(&sp->refcnt, 1);
  43         return sp;
  44 }
  45 EXPORT_SYMBOL(secpath_dup);
  46
  47 /* Fetch spi and seq from ipsec header */
  48
  49 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq)
  50 {
  51         int offset, offset_seq;
  52
  53         switch (nexthdr) {
  54         case IPPROTO_AH:
  55                 offset = offsetof(struct ip_auth_hdr, spi);
  56                 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
  57                 break;
  58         case IPPROTO_ESP:
  59                 offset = offsetof(struct ip_esp_hdr, spi);
  60                 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
  61                 break;
  62         case IPPROTO_COMP:
  63                 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
  64                         return -EINVAL;
  65                 *spi = htonl(ntohs(*(u16*)(skb->h.raw + 2)));
  66                 *seq = 0;
  67                 return 0;
  68         default:
  69                 return 1;
  70         }
  71
  72         if (!pskb_may_pull(skb, 16))
  73                 return -EINVAL;
  74
  75         *spi = *(u32*)(skb->h.raw + offset);
  76         *seq = *(u32*)(skb->h.raw + offset_seq);
  77         return 0;
  78 }
  79 EXPORT_SYMBOL(xfrm_parse_spi);
  80
  81 void __init xfrm_input_init(void)
  82 {
  83         secpath_cachep = kmem_cache_create("secpath_cache",
  84                                            sizeof(struct sec_path),
  85                                            0, SLAB_HWCACHE_ALIGN,
  86                                            NULL, NULL);
  87         if (!secpath_cachep)
  88                 panic("XFRM: failed to allocate secpath_cache\n");
  89 }