net/ipv6/xfrm6_state.c

   1 /*
   2  * xfrm6_state.c: based on xfrm4_state.c
   3  *
   4  * Authors:
   5  *      Mitsuru KANDA @USAGI
   6  *      Kazunori MIYAZAWA @USAGI
   7  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
   8  *              IPv6 support
   9  *      YOSHIFUJI Hideaki @USAGI
  10  *              Split up af-specific portion
  11  *
  12  */
  13
  14 #include <net/xfrm.h>
  15 #include <linux/pfkeyv2.h>
  16 #include <linux/ipsec.h>
  17 #include <linux/netfilter_ipv6.h>
  18 #include <net/dsfield.h>
  19 #include <net/ipv6.h>
  20 #include <net/addrconf.h>
  21
  22 static struct xfrm_state_afinfo xfrm6_state_afinfo;
  23
  24 static void
  25 __xfrm6_init_tempsel(struct xfrm_state *x, struct flowi *fl,
  26                      struct xfrm_tmpl *tmpl,
  27                      xfrm_address_t *daddr, xfrm_address_t *saddr)
  28 {
  29         /* Initialize temporary selector matching only
  30          * to current session. */
  31         ipv6_addr_copy((struct in6_addr *)&x->sel.daddr, &fl->fl6_dst);
  32         ipv6_addr_copy((struct in6_addr *)&x->sel.saddr, &fl->fl6_src);
  33         x->sel.dport = xfrm_flowi_dport(fl);
  34         x->sel.dport_mask = htons(0xffff);
  35         x->sel.sport = xfrm_flowi_sport(fl);
  36         x->sel.sport_mask = htons(0xffff);
  37         x->sel.family = AF_INET6;
  38         x->sel.prefixlen_d = 128;
  39         x->sel.prefixlen_s = 128;
  40         x->sel.proto = fl->proto;
  41         x->sel.ifindex = fl->oif;
  42         x->id = tmpl->id;
  43         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
  44                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  45         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  46         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
  47                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  48         x->props.mode = tmpl->mode;
  49         x->props.reqid = tmpl->reqid;
  50         x->props.family = AF_INET6;
  51 }
  52
  53 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
  54 static int
  55 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
  56 {
  57         int i;
  58         int class[XFRM_MAX_DEPTH];
  59         int count[maxclass];
  60
  61         memset(count, 0, sizeof(count));
  62
  63         for (i = 0; i < n; i++) {
  64                 int c;
  65                 class[i] = c = cmp(src[i]);
  66                 count[c]++;
  67         }
  68
  69         for (i = 2; i < maxclass; i++)
  70                 count[i] += count[i - 1];
  71
  72         for (i = 0; i < n; i++) {
  73                 dst[count[class[i] - 1]++] = src[i];
  74                 src[i] = 0;
  75         }
  76
  77         return 0;
  78 }
  79
  80 /*
  81  * Rule for xfrm_state:
  82  *
  83  * rule 1: select IPsec transport except AH
  84  * rule 2: select MIPv6 RO or inbound trigger
  85  * rule 3: select IPsec transport AH
  86  * rule 4: select IPsec tunnel
  87  * rule 5: others
  88  */
  89 static int __xfrm6_state_sort_cmp(void *p)
  90 {
  91         struct xfrm_state *v = p;
  92
  93         switch (v->props.mode) {
  94         case XFRM_MODE_TRANSPORT:
  95                 if (v->id.proto != IPPROTO_AH)
  96                         return 1;
  97                 else
  98                         return 3;
  99 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 100         case XFRM_MODE_ROUTEOPTIMIZATION:
 101         case XFRM_MODE_IN_TRIGGER:
 102                 return 2;
 103 #endif
 104         case XFRM_MODE_TUNNEL:
 105         case XFRM_MODE_BEET:
 106                 return 4;
 107         }
 108         return 5;
 109 }
 110
 111 static int
 112 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
 113 {
 114         return __xfrm6_sort((void **)dst, (void **)src, n,
 115                             __xfrm6_state_sort_cmp, 6);
 116 }
 117
 118 /*
 119  * Rule for xfrm_tmpl:
 120  *
 121  * rule 1: select IPsec transport
 122  * rule 2: select MIPv6 RO or inbound trigger
 123  * rule 3: select IPsec tunnel
 124  * rule 4: others
 125  */
 126 static int __xfrm6_tmpl_sort_cmp(void *p)
 127 {
 128         struct xfrm_tmpl *v = p;
 129         switch (v->mode) {
 130         case XFRM_MODE_TRANSPORT:
 131                 return 1;
 132 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 133         case XFRM_MODE_ROUTEOPTIMIZATION:
 134         case XFRM_MODE_IN_TRIGGER:
 135                 return 2;
 136 #endif
 137         case XFRM_MODE_TUNNEL:
 138         case XFRM_MODE_BEET:
 139                 return 3;
 140         }
 141         return 4;
 142 }
 143
 144 static int
 145 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 146 {
 147         return __xfrm6_sort((void **)dst, (void **)src, n,
 148                             __xfrm6_tmpl_sort_cmp, 5);
 149 }
 150
 151 int xfrm6_extract_header(struct sk_buff *skb)
 152 {
 153         struct ipv6hdr *iph = ipv6_hdr(skb);
 154
 155         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
 156         XFRM_MODE_SKB_CB(skb)->id = 0;
 157         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
 158         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
 159         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
 160         XFRM_MODE_SKB_CB(skb)->optlen = 0;
 161         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
 162                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
 163
 164         return 0;
 165 }
 166
 167 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 168         .family                 = AF_INET6,
 169         .proto                  = IPPROTO_IPV6,
 170         .eth_proto              = htons(ETH_P_IPV6),
 171         .owner                  = THIS_MODULE,
 172         .init_tempsel           = __xfrm6_init_tempsel,
 173         .tmpl_sort              = __xfrm6_tmpl_sort,
 174         .state_sort             = __xfrm6_state_sort,
 175         .output                 = xfrm6_output,
 176         .extract_input          = xfrm6_extract_input,
 177         .extract_output         = xfrm6_extract_output,
 178         .transport_finish       = xfrm6_transport_finish,
 179 };
 180
 181 int __init xfrm6_state_init(void)
 182 {
 183         return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 184 }
 185
 186 void xfrm6_state_fini(void)
 187 {
 188         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 189 }
 190