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