1 /* 2 * xfrm6_policy.c: based on xfrm4_policy.c 3 * 4 * Authors: 5 * Mitsuru KANDA @USAGI 6 * Kazunori MIYAZAWA @USAGI 7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 8 * IPv6 support 9 * YOSHIFUJI Hideaki 10 * Split up af-specific portion 11 * 12 */ 13 14 #include <linux/compiler.h> 15 #include <linux/config.h> 16 #include <linux/netdevice.h> 17 #include <net/addrconf.h> 18 #include <net/xfrm.h> 19 #include <net/ip.h> 20 #include <net/ipv6.h> 21 #include <net/ip6_route.h> 22 23 static struct dst_ops xfrm6_dst_ops; 24 static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 25 26 static struct xfrm_type_map xfrm6_type_map = { .lock = RW_LOCK_UNLOCKED }; 27 28 static int xfrm6_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) 29 { 30 int err = 0; 31 *dst = (struct xfrm_dst*)ip6_route_output(NULL, fl); 32 if (!*dst) 33 err = -ENETUNREACH; 34 return err; 35 } 36 37 static struct dst_entry * 38 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy) 39 { 40 struct dst_entry *dst; 41 42 /* Still not clear if we should set fl->fl6_{src,dst}... */ 43 read_lock_bh(&policy->lock); 44 for (dst = policy->bundles; dst; dst = dst->next) { 45 struct xfrm_dst *xdst = (struct xfrm_dst*)dst; 46 struct in6_addr fl_dst_prefix, fl_src_prefix; 47 48 ipv6_addr_prefix(&fl_dst_prefix, 49 &fl->fl6_dst, 50 xdst->u.rt6.rt6i_dst.plen); 51 ipv6_addr_prefix(&fl_src_prefix, 52 &fl->fl6_src, 53 xdst->u.rt6.rt6i_src.plen); 54 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) && 55 ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) && 56 xfrm_bundle_ok(xdst, fl, AF_INET6)) { 57 dst_clone(dst); 58 break; 59 } 60 } 61 read_unlock_bh(&policy->lock); 62 return dst; 63 } 64 65 /* Allocate chain of dst_entry's, attach known xfrm's, calculate 66 * all the metrics... Shortly, bundle a bundle. 67 */ 68 69 static int 70 __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, 71 struct flowi *fl, struct dst_entry **dst_p) 72 { 73 struct dst_entry *dst, *dst_prev; 74 struct rt6_info *rt0 = (struct rt6_info*)(*dst_p); 75 struct rt6_info *rt = rt0; 76 struct in6_addr *remote = &fl->fl6_dst; 77 struct in6_addr *local = &fl->fl6_src; 78 struct flowi fl_tunnel = { 79 .nl_u = { 80 .ip6_u = { 81 .saddr = *local, 82 .daddr = *remote 83 } 84 } 85 }; 86 int i; 87 int err = 0; 88 int header_len = 0; 89 int trailer_len = 0; 90 91 dst = dst_prev = NULL; 92 dst_hold(&rt->u.dst); 93 94 for (i = 0; i < nx; i++) { 95 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops); 96 struct xfrm_dst *xdst; 97 int tunnel = 0; 98 99 if (unlikely(dst1 == NULL)) { 100 err = -ENOBUFS; 101 dst_release(&rt->u.dst); 102 goto error; 103 } 104 105 if (!dst) 106 dst = dst1; 107 else { 108 dst_prev->child = dst1; 109 dst1->flags |= DST_NOHASH; 110 dst_clone(dst1); 111 } 112 113 xdst = (struct xfrm_dst *)dst1; 114 xdst->route = &rt->u.dst; 115 if (rt->rt6i_node) 116 xdst->route_cookie = rt->rt6i_node->fn_sernum; 117 118 dst1->next = dst_prev; 119 dst_prev = dst1; 120 if (xfrm[i]->props.mode) { 121 remote = (struct in6_addr*)&xfrm[i]->id.daddr; 122 local = (struct in6_addr*)&xfrm[i]->props.saddr; 123 tunnel = 1; 124 } 125 header_len += xfrm[i]->props.header_len; 126 trailer_len += xfrm[i]->props.trailer_len; 127 128 if (tunnel) { 129 ipv6_addr_copy(&fl_tunnel.fl6_dst, remote); 130 ipv6_addr_copy(&fl_tunnel.fl6_src, local); 131 err = xfrm_dst_lookup((struct xfrm_dst **) &rt, 132 &fl_tunnel, AF_INET6); 133 if (err) 134 goto error; 135 } else 136 dst_hold(&rt->u.dst); 137 } 138 139 dst_prev->child = &rt->u.dst; 140 dst->path = &rt->u.dst; 141 if (rt->rt6i_node) 142 ((struct xfrm_dst *)dst)->path_cookie = rt->rt6i_node->fn_sernum; 143 144 *dst_p = dst; 145 dst = dst_prev; 146 147 dst_prev = *dst_p; 148 i = 0; 149 for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { 150 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; 151 152 dst_prev->xfrm = xfrm[i++]; 153 dst_prev->dev = rt->u.dst.dev; 154 if (rt->u.dst.dev) 155 dev_hold(rt->u.dst.dev); 156 dst_prev->obsolete = -1; 157 dst_prev->flags |= DST_HOST; 158 dst_prev->lastuse = jiffies; 159 dst_prev->header_len = header_len; 160 dst_prev->trailer_len = trailer_len; 161 memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); 162 163 /* Copy neighbour for reachability confirmation */ 164 dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); 165 dst_prev->input = rt->u.dst.input; 166 dst_prev->output = xfrm6_output; 167 /* Sheit... I remember I did this right. Apparently, 168 * it was magically lost, so this code needs audit */ 169 x->u.rt6.rt6i_flags = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); 170 x->u.rt6.rt6i_metric = rt0->rt6i_metric; 171 x->u.rt6.rt6i_node = rt0->rt6i_node; 172 x->u.rt6.rt6i_gateway = rt0->rt6i_gateway; 173 memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway)); 174 x->u.rt6.rt6i_dst = rt0->rt6i_dst; 175 x->u.rt6.rt6i_src = rt0->rt6i_src; 176 x->u.rt6.rt6i_idev = rt0->rt6i_idev; 177 in6_dev_hold(rt0->rt6i_idev); 178 header_len -= x->u.dst.xfrm->props.header_len; 179 trailer_len -= x->u.dst.xfrm->props.trailer_len; 180 } 181 182 xfrm_init_pmtu(dst); 183 return 0; 184 185 error: 186 if (dst) 187 dst_free(dst); 188 return err; 189 } 190 191 static inline void 192 _decode_session6(struct sk_buff *skb, struct flowi *fl) 193 { 194 u16 offset = sizeof(struct ipv6hdr); 195 struct ipv6hdr *hdr = skb->nh.ipv6h; 196 struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); 197 u8 nexthdr = skb->nh.ipv6h->nexthdr; 198 199 memset(fl, 0, sizeof(struct flowi)); 200 ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr); 201 ipv6_addr_copy(&fl->fl6_src, &hdr->saddr); 202 203 while (pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data)) { 204 switch (nexthdr) { 205 case NEXTHDR_ROUTING: 206 case NEXTHDR_HOP: 207 case NEXTHDR_DEST: 208 offset += ipv6_optlen(exthdr); 209 nexthdr = exthdr->nexthdr; 210 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); 211 break; 212 213 case IPPROTO_UDP: 214 case IPPROTO_TCP: 215 case IPPROTO_SCTP: 216 case IPPROTO_DCCP: 217 if (pskb_may_pull(skb, skb->nh.raw + offset + 4 - skb->data)) { 218 u16 *ports = (u16 *)exthdr; 219 220 fl->fl_ip_sport = ports[0]; 221 fl->fl_ip_dport = ports[1]; 222 } 223 fl->proto = nexthdr; 224 return; 225 226 case IPPROTO_ICMPV6: 227 if (pskb_may_pull(skb, skb->nh.raw + offset + 2 - skb->data)) { 228 u8 *icmp = (u8 *)exthdr; 229 230 fl->fl_icmp_type = icmp[0]; 231 fl->fl_icmp_code = icmp[1]; 232 } 233 fl->proto = nexthdr; 234 return; 235 236 /* XXX Why are there these headers? */ 237 case IPPROTO_AH: 238 case IPPROTO_ESP: 239 case IPPROTO_COMP: 240 default: 241 fl->fl_ipsec_spi = 0; 242 fl->proto = nexthdr; 243 return; 244 }; 245 } 246 } 247 248 static inline int xfrm6_garbage_collect(void) 249 { 250 read_lock(&xfrm6_policy_afinfo.lock); 251 xfrm6_policy_afinfo.garbage_collect(); 252 read_unlock(&xfrm6_policy_afinfo.lock); 253 return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2); 254 } 255 256 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 257 { 258 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 259 struct dst_entry *path = xdst->route; 260 261 path->ops->update_pmtu(path, mtu); 262 } 263 264 static void xfrm6_dst_destroy(struct dst_entry *dst) 265 { 266 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 267 268 if (likely(xdst->u.rt6.rt6i_idev)) 269 in6_dev_put(xdst->u.rt6.rt6i_idev); 270 xfrm_dst_destroy(xdst); 271 } 272 273 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 274 int unregister) 275 { 276 struct xfrm_dst *xdst; 277 278 if (!unregister) 279 return; 280 281 xdst = (struct xfrm_dst *)dst; 282 if (xdst->u.rt6.rt6i_idev->dev == dev) { 283 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev); 284 BUG_ON(!loopback_idev); 285 286 do { 287 in6_dev_put(xdst->u.rt6.rt6i_idev); 288 xdst->u.rt6.rt6i_idev = loopback_idev; 289 in6_dev_hold(loopback_idev); 290 xdst = (struct xfrm_dst *)xdst->u.dst.child; 291 } while (xdst->u.dst.xfrm); 292 293 __in6_dev_put(loopback_idev); 294 } 295 296 xfrm_dst_ifdown(dst, dev); 297 } 298 299 static struct dst_ops xfrm6_dst_ops = { 300 .family = AF_INET6, 301 .protocol = __constant_htons(ETH_P_IPV6), 302 .gc = xfrm6_garbage_collect, 303 .update_pmtu = xfrm6_update_pmtu, 304 .destroy = xfrm6_dst_destroy, 305 .ifdown = xfrm6_dst_ifdown, 306 .gc_thresh = 1024, 307 .entry_size = sizeof(struct xfrm_dst), 308 }; 309 310 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 311 .family = AF_INET6, 312 .lock = RW_LOCK_UNLOCKED, 313 .type_map = &xfrm6_type_map, 314 .dst_ops = &xfrm6_dst_ops, 315 .dst_lookup = xfrm6_dst_lookup, 316 .find_bundle = __xfrm6_find_bundle, 317 .bundle_create = __xfrm6_bundle_create, 318 .decode_session = _decode_session6, 319 }; 320 321 static void __init xfrm6_policy_init(void) 322 { 323 xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 324 } 325 326 static void xfrm6_policy_fini(void) 327 { 328 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 329 } 330 331 void __init xfrm6_init(void) 332 { 333 xfrm6_policy_init(); 334 xfrm6_state_init(); 335 } 336 337 void xfrm6_fini(void) 338 { 339 //xfrm6_input_fini(); 340 xfrm6_policy_fini(); 341 xfrm6_state_fini(); 342 } 343