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/err.h> 15 #include <linux/kernel.h> 16 #include <linux/netdevice.h> 17 #include <net/addrconf.h> 18 #include <net/dst.h> 19 #include <net/xfrm.h> 20 #include <net/ip.h> 21 #include <net/ipv6.h> 22 #include <net/ip6_route.h> 23 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 24 #include <net/mip6.h> 25 #endif 26 27 static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 28 29 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, 30 const xfrm_address_t *saddr, 31 const xfrm_address_t *daddr) 32 { 33 struct flowi6 fl6; 34 struct dst_entry *dst; 35 int err; 36 37 memset(&fl6, 0, sizeof(fl6)); 38 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 39 if (saddr) 40 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 41 42 dst = ip6_route_output(net, NULL, &fl6); 43 44 err = dst->error; 45 if (dst->error) { 46 dst_release(dst); 47 dst = ERR_PTR(err); 48 } 49 50 return dst; 51 } 52 53 static int xfrm6_get_saddr(struct net *net, 54 xfrm_address_t *saddr, xfrm_address_t *daddr) 55 { 56 struct dst_entry *dst; 57 struct net_device *dev; 58 59 dst = xfrm6_dst_lookup(net, 0, NULL, daddr); 60 if (IS_ERR(dst)) 61 return -EHOSTUNREACH; 62 63 dev = ip6_dst_idev(dst)->dev; 64 ipv6_dev_get_saddr(dev_net(dev), dev, 65 (struct in6_addr *)&daddr->a6, 0, 66 (struct in6_addr *)&saddr->a6); 67 dst_release(dst); 68 return 0; 69 } 70 71 static int xfrm6_get_tos(const struct flowi *fl) 72 { 73 return 0; 74 } 75 76 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 77 int nfheader_len) 78 { 79 if (dst->ops->family == AF_INET6) { 80 struct rt6_info *rt = (struct rt6_info*)dst; 81 if (rt->rt6i_node) 82 path->path_cookie = rt->rt6i_node->fn_sernum; 83 } 84 85 path->u.rt6.rt6i_nfheader_len = nfheader_len; 86 87 return 0; 88 } 89 90 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 91 const struct flowi *fl) 92 { 93 struct rt6_info *rt = (struct rt6_info*)xdst->route; 94 95 xdst->u.dst.dev = dev; 96 dev_hold(dev); 97 98 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 99 if (!xdst->u.rt6.rt6i_idev) 100 return -ENODEV; 101 102 rt6_transfer_peer(&xdst->u.rt6, rt); 103 104 /* Sheit... I remember I did this right. Apparently, 105 * it was magically lost, so this code needs audit */ 106 xdst->u.rt6.n = neigh_clone(rt->n); 107 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 108 RTF_LOCAL); 109 xdst->u.rt6.rt6i_metric = rt->rt6i_metric; 110 xdst->u.rt6.rt6i_node = rt->rt6i_node; 111 if (rt->rt6i_node) 112 xdst->route_cookie = rt->rt6i_node->fn_sernum; 113 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 114 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 115 xdst->u.rt6.rt6i_src = rt->rt6i_src; 116 117 return 0; 118 } 119 120 static inline void 121 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 122 { 123 struct flowi6 *fl6 = &fl->u.ip6; 124 int onlyproto = 0; 125 u16 offset = skb_network_header_len(skb); 126 const struct ipv6hdr *hdr = ipv6_hdr(skb); 127 struct ipv6_opt_hdr *exthdr; 128 const unsigned char *nh = skb_network_header(skb); 129 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 130 131 memset(fl6, 0, sizeof(struct flowi6)); 132 fl6->flowi6_mark = skb->mark; 133 134 fl6->daddr = reverse ? hdr->saddr : hdr->daddr; 135 fl6->saddr = reverse ? hdr->daddr : hdr->saddr; 136 137 while (nh + offset + 1 < skb->data || 138 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 139 nh = skb_network_header(skb); 140 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 141 142 switch (nexthdr) { 143 case NEXTHDR_FRAGMENT: 144 onlyproto = 1; 145 case NEXTHDR_ROUTING: 146 case NEXTHDR_HOP: 147 case NEXTHDR_DEST: 148 offset += ipv6_optlen(exthdr); 149 nexthdr = exthdr->nexthdr; 150 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 151 break; 152 153 case IPPROTO_UDP: 154 case IPPROTO_UDPLITE: 155 case IPPROTO_TCP: 156 case IPPROTO_SCTP: 157 case IPPROTO_DCCP: 158 if (!onlyproto && (nh + offset + 4 < skb->data || 159 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 160 __be16 *ports = (__be16 *)exthdr; 161 162 fl6->fl6_sport = ports[!!reverse]; 163 fl6->fl6_dport = ports[!reverse]; 164 } 165 fl6->flowi6_proto = nexthdr; 166 return; 167 168 case IPPROTO_ICMPV6: 169 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 170 u8 *icmp = (u8 *)exthdr; 171 172 fl6->fl6_icmp_type = icmp[0]; 173 fl6->fl6_icmp_code = icmp[1]; 174 } 175 fl6->flowi6_proto = nexthdr; 176 return; 177 178 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 179 case IPPROTO_MH: 180 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 181 struct ip6_mh *mh; 182 mh = (struct ip6_mh *)exthdr; 183 184 fl6->fl6_mh_type = mh->ip6mh_type; 185 } 186 fl6->flowi6_proto = nexthdr; 187 return; 188 #endif 189 190 /* XXX Why are there these headers? */ 191 case IPPROTO_AH: 192 case IPPROTO_ESP: 193 case IPPROTO_COMP: 194 default: 195 fl6->fl6_ipsec_spi = 0; 196 fl6->flowi6_proto = nexthdr; 197 return; 198 } 199 } 200 } 201 202 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 203 { 204 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 205 206 xfrm6_policy_afinfo.garbage_collect(net); 207 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 208 } 209 210 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 211 struct sk_buff *skb, u32 mtu) 212 { 213 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 214 struct dst_entry *path = xdst->route; 215 216 path->ops->update_pmtu(path, sk, skb, mtu); 217 } 218 219 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 220 struct sk_buff *skb) 221 { 222 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 223 struct dst_entry *path = xdst->route; 224 225 path->ops->redirect(path, sk, skb); 226 } 227 228 static void xfrm6_dst_destroy(struct dst_entry *dst) 229 { 230 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 231 232 if (likely(xdst->u.rt6.rt6i_idev)) 233 in6_dev_put(xdst->u.rt6.rt6i_idev); 234 dst_destroy_metrics_generic(dst); 235 if (rt6_has_peer(&xdst->u.rt6)) { 236 struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6); 237 inet_putpeer(peer); 238 } 239 xfrm_dst_destroy(xdst); 240 } 241 242 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 243 int unregister) 244 { 245 struct xfrm_dst *xdst; 246 247 if (!unregister) 248 return; 249 250 xdst = (struct xfrm_dst *)dst; 251 if (xdst->u.rt6.rt6i_idev->dev == dev) { 252 struct inet6_dev *loopback_idev = 253 in6_dev_get(dev_net(dev)->loopback_dev); 254 BUG_ON(!loopback_idev); 255 256 do { 257 in6_dev_put(xdst->u.rt6.rt6i_idev); 258 xdst->u.rt6.rt6i_idev = loopback_idev; 259 in6_dev_hold(loopback_idev); 260 xdst = (struct xfrm_dst *)xdst->u.dst.child; 261 } while (xdst->u.dst.xfrm); 262 263 __in6_dev_put(loopback_idev); 264 } 265 266 xfrm_dst_ifdown(dst, dev); 267 } 268 269 static struct dst_ops xfrm6_dst_ops = { 270 .family = AF_INET6, 271 .protocol = cpu_to_be16(ETH_P_IPV6), 272 .gc = xfrm6_garbage_collect, 273 .update_pmtu = xfrm6_update_pmtu, 274 .redirect = xfrm6_redirect, 275 .cow_metrics = dst_cow_metrics_generic, 276 .destroy = xfrm6_dst_destroy, 277 .ifdown = xfrm6_dst_ifdown, 278 .local_out = __ip6_local_out, 279 .gc_thresh = 1024, 280 }; 281 282 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 283 .family = AF_INET6, 284 .dst_ops = &xfrm6_dst_ops, 285 .dst_lookup = xfrm6_dst_lookup, 286 .get_saddr = xfrm6_get_saddr, 287 .decode_session = _decode_session6, 288 .get_tos = xfrm6_get_tos, 289 .init_path = xfrm6_init_path, 290 .fill_dst = xfrm6_fill_dst, 291 .blackhole_route = ip6_blackhole_route, 292 }; 293 294 static int __init xfrm6_policy_init(void) 295 { 296 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 297 } 298 299 static void xfrm6_policy_fini(void) 300 { 301 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 302 } 303 304 #ifdef CONFIG_SYSCTL 305 static struct ctl_table xfrm6_policy_table[] = { 306 { 307 .procname = "xfrm6_gc_thresh", 308 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 309 .maxlen = sizeof(int), 310 .mode = 0644, 311 .proc_handler = proc_dointvec, 312 }, 313 { } 314 }; 315 316 static struct ctl_table_header *sysctl_hdr; 317 #endif 318 319 int __init xfrm6_init(void) 320 { 321 int ret; 322 unsigned int gc_thresh; 323 324 /* 325 * We need a good default value for the xfrm6 gc threshold. 326 * In ipv4 we set it to the route hash table size * 8, which 327 * is half the size of the maximaum route cache for ipv4. It 328 * would be good to do the same thing for v6, except the table is 329 * constructed differently here. Here each table for a net namespace 330 * can have FIB_TABLE_HASHSZ entries, so lets go with the same 331 * computation that we used for ipv4 here. Also, lets keep the initial 332 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults 333 * to that as a minimum as well 334 */ 335 gc_thresh = FIB6_TABLE_HASHSZ * 8; 336 xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; 337 dst_entries_init(&xfrm6_dst_ops); 338 339 ret = xfrm6_policy_init(); 340 if (ret) { 341 dst_entries_destroy(&xfrm6_dst_ops); 342 goto out; 343 } 344 ret = xfrm6_state_init(); 345 if (ret) 346 goto out_policy; 347 348 #ifdef CONFIG_SYSCTL 349 sysctl_hdr = register_net_sysctl(&init_net, "net/ipv6", 350 xfrm6_policy_table); 351 #endif 352 out: 353 return ret; 354 out_policy: 355 xfrm6_policy_fini(); 356 goto out; 357 } 358 359 void xfrm6_fini(void) 360 { 361 #ifdef CONFIG_SYSCTL 362 if (sysctl_hdr) 363 unregister_net_sysctl_table(sysctl_hdr); 364 #endif 365 //xfrm6_input_fini(); 366 xfrm6_policy_fini(); 367 xfrm6_state_fini(); 368 dst_entries_destroy(&xfrm6_dst_ops); 369 } 370