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 #include <net/l3mdev.h> 24 #if IS_ENABLED(CONFIG_IPV6_MIP6) 25 #include <net/mip6.h> 26 #endif 27 28 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif, 29 const xfrm_address_t *saddr, 30 const xfrm_address_t *daddr, 31 u32 mark) 32 { 33 struct flowi6 fl6; 34 struct dst_entry *dst; 35 int err; 36 37 memset(&fl6, 0, sizeof(fl6)); 38 fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif); 39 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; 40 fl6.flowi6_mark = mark; 41 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 42 if (saddr) 43 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 44 45 dst = ip6_route_output(net, NULL, &fl6); 46 47 err = dst->error; 48 if (dst->error) { 49 dst_release(dst); 50 dst = ERR_PTR(err); 51 } 52 53 return dst; 54 } 55 56 static int xfrm6_get_saddr(struct net *net, int oif, 57 xfrm_address_t *saddr, xfrm_address_t *daddr, 58 u32 mark) 59 { 60 struct dst_entry *dst; 61 struct net_device *dev; 62 63 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark); 64 if (IS_ERR(dst)) 65 return -EHOSTUNREACH; 66 67 dev = ip6_dst_idev(dst)->dev; 68 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6); 69 dst_release(dst); 70 return 0; 71 } 72 73 static int xfrm6_get_tos(const struct flowi *fl) 74 { 75 return 0; 76 } 77 78 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 79 int nfheader_len) 80 { 81 if (dst->ops->family == AF_INET6) { 82 struct rt6_info *rt = (struct rt6_info *)dst; 83 path->path_cookie = rt6_get_cookie(rt); 84 } 85 86 path->u.rt6.rt6i_nfheader_len = nfheader_len; 87 88 return 0; 89 } 90 91 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 92 const struct flowi *fl) 93 { 94 struct rt6_info *rt = (struct rt6_info *)xdst->route; 95 96 xdst->u.dst.dev = dev; 97 dev_hold(dev); 98 99 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 100 if (!xdst->u.rt6.rt6i_idev) { 101 dev_put(dev); 102 return -ENODEV; 103 } 104 105 /* Sheit... I remember I did this right. Apparently, 106 * it was magically lost, so this code needs audit */ 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 xdst->route_cookie = rt6_get_cookie(rt); 112 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 113 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 114 xdst->u.rt6.rt6i_src = rt->rt6i_src; 115 116 return 0; 117 } 118 119 static inline void 120 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 121 { 122 struct flowi6 *fl6 = &fl->u.ip6; 123 int onlyproto = 0; 124 const struct ipv6hdr *hdr = ipv6_hdr(skb); 125 u16 offset = sizeof(*hdr); 126 struct ipv6_opt_hdr *exthdr; 127 const unsigned char *nh = skb_network_header(skb); 128 u16 nhoff = IP6CB(skb)->nhoff; 129 int oif = 0; 130 u8 nexthdr; 131 132 if (!nhoff) 133 nhoff = offsetof(struct ipv6hdr, nexthdr); 134 135 nexthdr = nh[nhoff]; 136 137 if (skb_dst(skb)) 138 oif = skb_dst(skb)->dev->ifindex; 139 140 memset(fl6, 0, sizeof(struct flowi6)); 141 fl6->flowi6_mark = skb->mark; 142 fl6->flowi6_oif = reverse ? skb->skb_iif : oif; 143 144 fl6->daddr = reverse ? hdr->saddr : hdr->daddr; 145 fl6->saddr = reverse ? hdr->daddr : hdr->saddr; 146 147 while (nh + offset + 1 < skb->data || 148 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 149 nh = skb_network_header(skb); 150 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 151 152 switch (nexthdr) { 153 case NEXTHDR_FRAGMENT: 154 onlyproto = 1; 155 case NEXTHDR_ROUTING: 156 case NEXTHDR_HOP: 157 case NEXTHDR_DEST: 158 offset += ipv6_optlen(exthdr); 159 nexthdr = exthdr->nexthdr; 160 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 161 break; 162 163 case IPPROTO_UDP: 164 case IPPROTO_UDPLITE: 165 case IPPROTO_TCP: 166 case IPPROTO_SCTP: 167 case IPPROTO_DCCP: 168 if (!onlyproto && (nh + offset + 4 < skb->data || 169 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 170 __be16 *ports; 171 172 nh = skb_network_header(skb); 173 ports = (__be16 *)(nh + offset); 174 fl6->fl6_sport = ports[!!reverse]; 175 fl6->fl6_dport = ports[!reverse]; 176 } 177 fl6->flowi6_proto = nexthdr; 178 return; 179 180 case IPPROTO_ICMPV6: 181 if (!onlyproto && (nh + offset + 2 < skb->data || 182 pskb_may_pull(skb, nh + offset + 2 - skb->data))) { 183 u8 *icmp; 184 185 nh = skb_network_header(skb); 186 icmp = (u8 *)(nh + offset); 187 fl6->fl6_icmp_type = icmp[0]; 188 fl6->fl6_icmp_code = icmp[1]; 189 } 190 fl6->flowi6_proto = nexthdr; 191 return; 192 193 #if IS_ENABLED(CONFIG_IPV6_MIP6) 194 case IPPROTO_MH: 195 offset += ipv6_optlen(exthdr); 196 if (!onlyproto && (nh + offset + 3 < skb->data || 197 pskb_may_pull(skb, nh + offset + 3 - skb->data))) { 198 struct ip6_mh *mh; 199 200 nh = skb_network_header(skb); 201 mh = (struct ip6_mh *)(nh + offset); 202 fl6->fl6_mh_type = mh->ip6mh_type; 203 } 204 fl6->flowi6_proto = nexthdr; 205 return; 206 #endif 207 208 /* XXX Why are there these headers? */ 209 case IPPROTO_AH: 210 case IPPROTO_ESP: 211 case IPPROTO_COMP: 212 default: 213 fl6->fl6_ipsec_spi = 0; 214 fl6->flowi6_proto = nexthdr; 215 return; 216 } 217 } 218 } 219 220 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 221 struct sk_buff *skb, u32 mtu) 222 { 223 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 224 struct dst_entry *path = xdst->route; 225 226 path->ops->update_pmtu(path, sk, skb, mtu); 227 } 228 229 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 230 struct sk_buff *skb) 231 { 232 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 233 struct dst_entry *path = xdst->route; 234 235 path->ops->redirect(path, sk, skb); 236 } 237 238 static void xfrm6_dst_destroy(struct dst_entry *dst) 239 { 240 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 241 242 if (likely(xdst->u.rt6.rt6i_idev)) 243 in6_dev_put(xdst->u.rt6.rt6i_idev); 244 dst_destroy_metrics_generic(dst); 245 xfrm_dst_destroy(xdst); 246 } 247 248 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 249 int unregister) 250 { 251 struct xfrm_dst *xdst; 252 253 if (!unregister) 254 return; 255 256 xdst = (struct xfrm_dst *)dst; 257 if (xdst->u.rt6.rt6i_idev->dev == dev) { 258 struct inet6_dev *loopback_idev = 259 in6_dev_get(dev_net(dev)->loopback_dev); 260 BUG_ON(!loopback_idev); 261 262 do { 263 in6_dev_put(xdst->u.rt6.rt6i_idev); 264 xdst->u.rt6.rt6i_idev = loopback_idev; 265 in6_dev_hold(loopback_idev); 266 xdst = (struct xfrm_dst *)xdst->u.dst.child; 267 } while (xdst->u.dst.xfrm); 268 269 __in6_dev_put(loopback_idev); 270 } 271 272 xfrm_dst_ifdown(dst, dev); 273 } 274 275 static struct dst_ops xfrm6_dst_ops_template = { 276 .family = AF_INET6, 277 .update_pmtu = xfrm6_update_pmtu, 278 .redirect = xfrm6_redirect, 279 .cow_metrics = dst_cow_metrics_generic, 280 .destroy = xfrm6_dst_destroy, 281 .ifdown = xfrm6_dst_ifdown, 282 .local_out = __ip6_local_out, 283 .gc_thresh = 32768, 284 }; 285 286 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 287 .dst_ops = &xfrm6_dst_ops_template, 288 .dst_lookup = xfrm6_dst_lookup, 289 .get_saddr = xfrm6_get_saddr, 290 .decode_session = _decode_session6, 291 .get_tos = xfrm6_get_tos, 292 .init_path = xfrm6_init_path, 293 .fill_dst = xfrm6_fill_dst, 294 .blackhole_route = ip6_blackhole_route, 295 }; 296 297 static int __init xfrm6_policy_init(void) 298 { 299 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); 300 } 301 302 static void xfrm6_policy_fini(void) 303 { 304 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 305 } 306 307 #ifdef CONFIG_SYSCTL 308 static struct ctl_table xfrm6_policy_table[] = { 309 { 310 .procname = "xfrm6_gc_thresh", 311 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 312 .maxlen = sizeof(int), 313 .mode = 0644, 314 .proc_handler = proc_dointvec, 315 }, 316 { } 317 }; 318 319 static int __net_init xfrm6_net_sysctl_init(struct net *net) 320 { 321 struct ctl_table *table; 322 struct ctl_table_header *hdr; 323 324 table = xfrm6_policy_table; 325 if (!net_eq(net, &init_net)) { 326 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 327 if (!table) 328 goto err_alloc; 329 330 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 331 } 332 333 hdr = register_net_sysctl(net, "net/ipv6", table); 334 if (!hdr) 335 goto err_reg; 336 337 net->ipv6.sysctl.xfrm6_hdr = hdr; 338 return 0; 339 340 err_reg: 341 if (!net_eq(net, &init_net)) 342 kfree(table); 343 err_alloc: 344 return -ENOMEM; 345 } 346 347 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 348 { 349 struct ctl_table *table; 350 351 if (!net->ipv6.sysctl.xfrm6_hdr) 352 return; 353 354 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 355 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 356 if (!net_eq(net, &init_net)) 357 kfree(table); 358 } 359 #else /* CONFIG_SYSCTL */ 360 static inline int xfrm6_net_sysctl_init(struct net *net) 361 { 362 return 0; 363 } 364 365 static inline void xfrm6_net_sysctl_exit(struct net *net) 366 { 367 } 368 #endif 369 370 static int __net_init xfrm6_net_init(struct net *net) 371 { 372 int ret; 373 374 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 375 sizeof(xfrm6_dst_ops_template)); 376 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 377 if (ret) 378 return ret; 379 380 ret = xfrm6_net_sysctl_init(net); 381 if (ret) 382 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 383 384 return ret; 385 } 386 387 static void __net_exit xfrm6_net_exit(struct net *net) 388 { 389 xfrm6_net_sysctl_exit(net); 390 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 391 } 392 393 static struct pernet_operations xfrm6_net_ops = { 394 .init = xfrm6_net_init, 395 .exit = xfrm6_net_exit, 396 }; 397 398 int __init xfrm6_init(void) 399 { 400 int ret; 401 402 ret = xfrm6_policy_init(); 403 if (ret) 404 goto out; 405 ret = xfrm6_state_init(); 406 if (ret) 407 goto out_policy; 408 409 ret = xfrm6_protocol_init(); 410 if (ret) 411 goto out_state; 412 413 register_pernet_subsys(&xfrm6_net_ops); 414 out: 415 return ret; 416 out_state: 417 xfrm6_state_fini(); 418 out_policy: 419 xfrm6_policy_fini(); 420 goto out; 421 } 422 423 void xfrm6_fini(void) 424 { 425 unregister_pernet_subsys(&xfrm6_net_ops); 426 xfrm6_protocol_fini(); 427 xfrm6_policy_fini(); 428 xfrm6_state_fini(); 429 } 430