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 <net/ipv6.h>
  18 #include <net/addrconf.h>
  19
  20 static struct xfrm_state_afinfo xfrm6_state_afinfo;
  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 = ~0;
  33         x->sel.sport = xfrm_flowi_sport(fl);
  34         x->sel.sport_mask = ~0;
  35         x->sel.prefixlen_d = 128;
  36         x->sel.prefixlen_s = 128;
  37         x->sel.proto = fl->proto;
  38         x->sel.ifindex = fl->oif;
  39         x->id = tmpl->id;
  40         if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
  41                 memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
  42         memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
  43         if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
  44                 memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
  45         if (tmpl->mode == XFRM_MODE_TUNNEL && ipv6_addr_any((struct in6_addr*)&x->props.saddr)) {
  46                 struct rt6_info *rt;
  47                 struct flowi fl_tunnel = {
  48                         .nl_u = {
  49                                 .ip6_u = {
  50                                         .daddr = *(struct in6_addr *)daddr,
  51                                 }
  52                         }
  53                 };
  54                 if (!xfrm_dst_lookup((struct xfrm_dst **)&rt,
  55                                      &fl_tunnel, AF_INET6)) {
  56                         ipv6_get_saddr(&rt->u.dst, (struct in6_addr *)daddr,
  57                                        (struct in6_addr *)&x->props.saddr);
  58                         dst_release(&rt->u.dst);
  59                 }
  60         }
  61         x->props.mode = tmpl->mode;
  62         x->props.reqid = tmpl->reqid;
  63         x->props.family = AF_INET6;
  64 }
  65
  66 static struct xfrm_state *
  67 __xfrm6_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr,
  68                             u8 proto)
  69 {
  70         struct xfrm_state *x = NULL;
  71         unsigned h;
  72
  73         h = __xfrm6_src_hash(saddr);
  74         list_for_each_entry(x, xfrm6_state_afinfo.state_bysrc+h, bysrc) {
  75                 if (x->props.family == AF_INET6 &&
  76                     ipv6_addr_equal((struct in6_addr *)daddr, (struct in6_addr *)x->id.daddr.a6) &&
  77                     ipv6_addr_equal((struct in6_addr *)saddr, (struct in6_addr *)x->props.saddr.a6) &&
  78                     proto == x->id.proto) {
  79                         xfrm_state_hold(x);
  80                         return x;
  81                 }
  82         }
  83         return NULL;
  84 }
  85
  86 static struct xfrm_state *
  87 __xfrm6_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto)
  88 {
  89         unsigned h = __xfrm6_spi_hash(daddr, spi, proto);
  90         struct xfrm_state *x;
  91
  92         list_for_each_entry(x, xfrm6_state_afinfo.state_byspi+h, byspi) {
  93                 if (x->props.family == AF_INET6 &&
  94                     spi == x->id.spi &&
  95                     ipv6_addr_equal((struct in6_addr *)daddr, (struct in6_addr *)x->id.daddr.a6) &&
  96                     proto == x->id.proto) {
  97                         xfrm_state_hold(x);
  98                         return x;
  99                 }
 100         }
 101         return NULL;
 102 }
 103
 104 static int
 105 __xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
 106 {
 107         int i;
 108         int j = 0;
 109
 110         /* Rule 1: select IPsec transport except AH */
 111         for (i = 0; i < n; i++) {
 112                 if (src[i]->props.mode == XFRM_MODE_TRANSPORT &&
 113                     src[i]->id.proto != IPPROTO_AH) {
 114                         dst[j++] = src[i];
 115                         src[i] = NULL;
 116                 }
 117         }
 118         if (j == n)
 119                 goto end;
 120
 121         /* Rule 2: select MIPv6 RO or inbound trigger */
 122 #ifdef CONFIG_IPV6_MIP6
 123         for (i = 0; i < n; i++) {
 124                 if (src[i] &&
 125                     (src[i]->props.mode == XFRM_MODE_ROUTEOPTIMIZATION ||
 126                      src[i]->props.mode == XFRM_MODE_IN_TRIGGER)) {
 127                         dst[j++] = src[i];
 128                         src[i] = NULL;
 129                 }
 130         }
 131         if (j == n)
 132                 goto end;
 133 #endif
 134
 135         /* Rule 3: select IPsec transport AH */
 136         for (i = 0; i < n; i++) {
 137                 if (src[i] &&
 138                     src[i]->props.mode == XFRM_MODE_TRANSPORT &&
 139                     src[i]->id.proto == IPPROTO_AH) {
 140                         dst[j++] = src[i];
 141                         src[i] = NULL;
 142                 }
 143         }
 144         if (j == n)
 145                 goto end;
 146
 147         /* Rule 4: select IPsec tunnel */
 148         for (i = 0; i < n; i++) {
 149                 if (src[i] &&
 150                     src[i]->props.mode == XFRM_MODE_TUNNEL) {
 151                         dst[j++] = src[i];
 152                         src[i] = NULL;
 153                 }
 154         }
 155         if (likely(j == n))
 156                 goto end;
 157
 158         /* Final rule */
 159         for (i = 0; i < n; i++) {
 160                 if (src[i]) {
 161                         dst[j++] = src[i];
 162                         src[i] = NULL;
 163                 }
 164         }
 165
 166  end:
 167         return 0;
 168 }
 169
 170 static int
 171 __xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
 172 {
 173         int i;
 174         int j = 0;
 175
 176         /* Rule 1: select IPsec transport */
 177         for (i = 0; i < n; i++) {
 178                 if (src[i]->mode == XFRM_MODE_TRANSPORT) {
 179                         dst[j++] = src[i];
 180                         src[i] = NULL;
 181                 }
 182         }
 183         if (j == n)
 184                 goto end;
 185
 186         /* Rule 2: select MIPv6 RO or inbound trigger */
 187 #ifdef CONFIG_IPV6_MIP6
 188         for (i = 0; i < n; i++) {
 189                 if (src[i] &&
 190                     (src[i]->mode == XFRM_MODE_ROUTEOPTIMIZATION ||
 191                      src[i]->mode == XFRM_MODE_IN_TRIGGER)) {
 192                         dst[j++] = src[i];
 193                         src[i] = NULL;
 194                 }
 195         }
 196         if (j == n)
 197                 goto end;
 198 #endif
 199
 200         /* Rule 3: select IPsec tunnel */
 201         for (i = 0; i < n; i++) {
 202                 if (src[i] &&
 203                     src[i]->mode == XFRM_MODE_TUNNEL) {
 204                         dst[j++] = src[i];
 205                         src[i] = NULL;
 206                 }
 207         }
 208         if (likely(j == n))
 209                 goto end;
 210
 211         /* Final rule */
 212         for (i = 0; i < n; i++) {
 213                 if (src[i]) {
 214                         dst[j++] = src[i];
 215                         src[i] = NULL;
 216                 }
 217         }
 218
 219  end:
 220         return 0;
 221 }
 222
 223 static struct xfrm_state_afinfo xfrm6_state_afinfo = {
 224         .family                 = AF_INET6,
 225         .init_tempsel           = __xfrm6_init_tempsel,
 226         .state_lookup           = __xfrm6_state_lookup,
 227         .state_lookup_byaddr    = __xfrm6_state_lookup_byaddr,
 228         .tmpl_sort              = __xfrm6_tmpl_sort,
 229         .state_sort             = __xfrm6_state_sort,
 230 };
 231
 232 void __init xfrm6_state_init(void)
 233 {
 234         xfrm_state_register_afinfo(&xfrm6_state_afinfo);
 235 }
 236
 237 void xfrm6_state_fini(void)
 238 {
 239         xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
 240 }
 241