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 struct kmem_cache *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, GFP_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, __be32 *spi, __be32 *seq)
  50 {
  51         int offset, offset_seq;
  52         int hlen;
  53
  54         switch (nexthdr) {
  55         case IPPROTO_AH:
  56                 hlen = sizeof(struct ip_auth_hdr);
  57                 offset = offsetof(struct ip_auth_hdr, spi);
  58                 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
  59                 break;
  60         case IPPROTO_ESP:
  61                 hlen = sizeof(struct ip_esp_hdr);
  62                 offset = offsetof(struct ip_esp_hdr, spi);
  63                 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
  64                 break;
  65         case IPPROTO_COMP:
  66                 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
  67                         return -EINVAL;
  68                 *spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
  69                 *seq = 0;
  70                 return 0;
  71         default:
  72                 return 1;
  73         }
  74
  75         if (!pskb_may_pull(skb, hlen))
  76                 return -EINVAL;
  77
  78         *spi = *(__be32*)(skb_transport_header(skb) + offset);
  79         *seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
  80         return 0;
  81 }
  82 EXPORT_SYMBOL(xfrm_parse_spi);
  83
  84 void __init xfrm_input_init(void)
  85 {
  86         secpath_cachep = kmem_cache_create("secpath_cache",
  87                                            sizeof(struct sec_path),
  88                                            0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
  89                                            NULL);
  90 }