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 void
  23 __xfrm6_init_tempsel(struct xfrm_selector *sel, struct flowi *fl)
  24 {
  25         /* Initialize temporary selector matching only
  26          * to current session. */
  27         ipv6_addr_copy((struct in6_addr *)&sel->daddr, &fl->fl6_dst);
  28         ipv6_addr_copy((struct in6_addr *)&sel->saddr, &fl->fl6_src);
  29         sel->dport = xfrm_flowi_dport(fl);
  30         sel->dport_mask = htons(0xffff);
  31         sel->sport = xfrm_flowi_sport(fl);
  32         sel->sport_mask = htons(0xffff);
  33         sel->family = AF_INET6;
  34         sel->prefixlen_d = 128;
  35         sel->prefixlen_s = 128;
  36         sel->proto = fl->proto;
  37         sel->ifindex = fl->oif;
  38 }
  39
  40 static void
  41 xfrm6_init_temprop(struct xfrm_state *x, struct xfrm_tmpl *tmpl,
  42                    xfrm_address_t *daddr, xfrm_address_t *saddr)
  43 {
  44         x->id = tmpl->id;
  45         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
  46                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  47         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  48         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
  49                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  50         x->props.mode = tmpl->mode;
  51         x->props.reqid = tmpl->reqid;
  52         x->props.family = AF_INET6;
  53 }
  54
  55 /* distribution counting sort function for xfrm_state and xfrm_tmpl */
  56 static int
  57 __xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
  58 {
  59         int i;
  60         int class[XFRM_MAX_DEPTH];
  61         int count[maxclass];
  62
  63         memset(count, 0, sizeof(count));
  64
  65         for (i = 0; i < n; i++) {
  66                 int c;
  67                 class[i] = c = cmp(src[i]);
  68                 count[c]++;
  69         }
  70
  71         for (i = 2; i < maxclass; i++)
  72                 count[i] += count[i - 1];
  73
  74         for (i = 0; i < n; i++) {
  75                 dst[count[class[i] - 1]++] = src[i];
  76                 src[i] = NULL;
  77         }
  78
  79         return 0;
  80 }
  81
  82 /*
  83  * Rule for xfrm_state:
  84  *
  85  * rule 1: select IPsec transport except AH
  86  * rule 2: select MIPv6 RO or inbound trigger
  87  * rule 3: select IPsec transport AH
  88  * rule 4: select IPsec tunnel
  89  * rule 5: others
  90  */
  91 static int __xfrm6_state_sort_cmp(void *p)
  92 {
  93         struct xfrm_state *v = p;
  94
  95         switch (v->props.mode) {
  96         case XFRM_MODE_TRANSPORT:
  97                 if (v->id.proto != IPPROTO_AH)
  98                         return 1;
  99                 else
 100                         return 3;
 101 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 102         case XFRM_MODE_ROUTEOPTIMIZATION:
 103         case XFRM_MODE_IN_TRIGGER:
 104                 return 2;
 105 #endif
 106         case XFRM_MODE_TUNNEL:
 107         case XFRM_MODE_BEET:
 108                 return 4;
 109         }
 110         return 5;
 111 }
 112
 113 static int
 114 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
 115 {
 116         return __xfrm6_sort((void **)dst, (void **)src, n,
 117                             __xfrm6_state_sort_cmp, 6);
 118 }
 119
 120 /*
 121  * Rule for xfrm_tmpl:
 122  *
 123  * rule 1: select IPsec transport
 124  * rule 2: select MIPv6 RO or inbound trigger
 125  * rule 3: select IPsec tunnel
 126  * rule 4: others
 127  */
 128 static int __xfrm6_tmpl_sort_cmp(void *p)
 129 {
 130         struct xfrm_tmpl *v = p;
 131         switch (v->mode) {
 132         case XFRM_MODE_TRANSPORT:
 133                 return 1;
 134 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 135         case XFRM_MODE_ROUTEOPTIMIZATION:
 136         case XFRM_MODE_IN_TRIGGER:
 137                 return 2;
 138 #endif
 139         case XFRM_MODE_TUNNEL:
 140         case XFRM_MODE_BEET:
 141                 return 3;
 142         }
 143         return 4;
 144 }
 145
 146 static int
 147 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 148 {
 149         return __xfrm6_sort((void **)dst, (void **)src, n,
 150                             __xfrm6_tmpl_sort_cmp, 5);
 151 }
 152
 153 int xfrm6_extract_header(struct sk_buff *skb)
 154 {
 155         struct ipv6hdr *iph = ipv6_hdr(skb);
 156
 157         XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
 158         XFRM_MODE_SKB_CB(skb)->id = 0;
 159         XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
 160         XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
 161         XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
 162         XFRM_MODE_SKB_CB(skb)->optlen = 0;
 163         memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
 164                sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
 165
 166         return 0;
 167 }
 168
 169 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 170         .family                 = AF_INET6,
 171         .proto                  = IPPROTO_IPV6,
 172         .eth_proto              = htons(ETH_P_IPV6),
 173         .owner                  = THIS_MODULE,
 174         .init_tempsel           = __xfrm6_init_tempsel,
 175         .init_temprop           = xfrm6_init_temprop,
 176         .tmpl_sort              = __xfrm6_tmpl_sort,
 177         .state_sort             = __xfrm6_state_sort,
 178         .output                 = xfrm6_output,
 179         .extract_input          = xfrm6_extract_input,
 180         .extract_output         = xfrm6_extract_output,
 181         .transport_finish       = xfrm6_transport_finish,
 182 };
 183
 184 int __init xfrm6_state_init(void)
 185 {
 186         return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 187 }
 188
 189 void xfrm6_state_fini(void)
 190 {
 191         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 192 }
 193