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 IS_ENABLED(CONFIG_IPV6_MIP6) 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 void xfrm6_init_dst(struct net *net, struct xfrm_dst *xdst) 77 { 78 struct rt6_info *rt = (struct rt6_info *)xdst; 79 80 rt6_init_peer(rt, net->ipv6.peers); 81 } 82 83 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 84 int nfheader_len) 85 { 86 if (dst->ops->family == AF_INET6) { 87 struct rt6_info *rt = (struct rt6_info*)dst; 88 if (rt->rt6i_node) 89 path->path_cookie = rt->rt6i_node->fn_sernum; 90 } 91 92 path->u.rt6.rt6i_nfheader_len = nfheader_len; 93 94 return 0; 95 } 96 97 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 98 const struct flowi *fl) 99 { 100 struct rt6_info *rt = (struct rt6_info*)xdst->route; 101 102 xdst->u.dst.dev = dev; 103 dev_hold(dev); 104 105 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 106 if (!xdst->u.rt6.rt6i_idev) 107 return -ENODEV; 108 109 rt6_transfer_peer(&xdst->u.rt6, rt); 110 111 /* Sheit... I remember I did this right. Apparently, 112 * it was magically lost, so this code needs audit */ 113 xdst->u.rt6.n = neigh_clone(rt->n); 114 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 115 RTF_LOCAL); 116 xdst->u.rt6.rt6i_metric = rt->rt6i_metric; 117 xdst->u.rt6.rt6i_node = rt->rt6i_node; 118 if (rt->rt6i_node) 119 xdst->route_cookie = rt->rt6i_node->fn_sernum; 120 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 121 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 122 xdst->u.rt6.rt6i_src = rt->rt6i_src; 123 124 return 0; 125 } 126 127 static inline void 128 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 129 { 130 struct flowi6 *fl6 = &fl->u.ip6; 131 int onlyproto = 0; 132 u16 offset = skb_network_header_len(skb); 133 const struct ipv6hdr *hdr = ipv6_hdr(skb); 134 struct ipv6_opt_hdr *exthdr; 135 const unsigned char *nh = skb_network_header(skb); 136 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 137 138 memset(fl6, 0, sizeof(struct flowi6)); 139 fl6->flowi6_mark = skb->mark; 140 141 fl6->daddr = reverse ? hdr->saddr : hdr->daddr; 142 fl6->saddr = reverse ? hdr->daddr : hdr->saddr; 143 144 while (nh + offset + 1 < skb->data || 145 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 146 nh = skb_network_header(skb); 147 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 148 149 switch (nexthdr) { 150 case NEXTHDR_FRAGMENT: 151 onlyproto = 1; 152 case NEXTHDR_ROUTING: 153 case NEXTHDR_HOP: 154 case NEXTHDR_DEST: 155 offset += ipv6_optlen(exthdr); 156 nexthdr = exthdr->nexthdr; 157 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 158 break; 159 160 case IPPROTO_UDP: 161 case IPPROTO_UDPLITE: 162 case IPPROTO_TCP: 163 case IPPROTO_SCTP: 164 case IPPROTO_DCCP: 165 if (!onlyproto && (nh + offset + 4 < skb->data || 166 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 167 __be16 *ports = (__be16 *)exthdr; 168 169 fl6->fl6_sport = ports[!!reverse]; 170 fl6->fl6_dport = ports[!reverse]; 171 } 172 fl6->flowi6_proto = nexthdr; 173 return; 174 175 case IPPROTO_ICMPV6: 176 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 177 u8 *icmp = (u8 *)exthdr; 178 179 fl6->fl6_icmp_type = icmp[0]; 180 fl6->fl6_icmp_code = icmp[1]; 181 } 182 fl6->flowi6_proto = nexthdr; 183 return; 184 185 #if IS_ENABLED(CONFIG_IPV6_MIP6) 186 case IPPROTO_MH: 187 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 188 struct ip6_mh *mh; 189 mh = (struct ip6_mh *)exthdr; 190 191 fl6->fl6_mh_type = mh->ip6mh_type; 192 } 193 fl6->flowi6_proto = nexthdr; 194 return; 195 #endif 196 197 /* XXX Why are there these headers? */ 198 case IPPROTO_AH: 199 case IPPROTO_ESP: 200 case IPPROTO_COMP: 201 default: 202 fl6->fl6_ipsec_spi = 0; 203 fl6->flowi6_proto = nexthdr; 204 return; 205 } 206 } 207 } 208 209 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 210 { 211 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 212 213 xfrm6_policy_afinfo.garbage_collect(net); 214 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 215 } 216 217 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 218 struct sk_buff *skb, u32 mtu) 219 { 220 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 221 struct dst_entry *path = xdst->route; 222 223 path->ops->update_pmtu(path, sk, skb, mtu); 224 } 225 226 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 227 struct sk_buff *skb) 228 { 229 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 230 struct dst_entry *path = xdst->route; 231 232 path->ops->redirect(path, sk, skb); 233 } 234 235 static void xfrm6_dst_destroy(struct dst_entry *dst) 236 { 237 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 238 239 if (likely(xdst->u.rt6.rt6i_idev)) 240 in6_dev_put(xdst->u.rt6.rt6i_idev); 241 dst_destroy_metrics_generic(dst); 242 if (rt6_has_peer(&xdst->u.rt6)) { 243 struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6); 244 inet_putpeer(peer); 245 } 246 xfrm_dst_destroy(xdst); 247 } 248 249 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 250 int unregister) 251 { 252 struct xfrm_dst *xdst; 253 254 if (!unregister) 255 return; 256 257 xdst = (struct xfrm_dst *)dst; 258 if (xdst->u.rt6.rt6i_idev->dev == dev) { 259 struct inet6_dev *loopback_idev = 260 in6_dev_get(dev_net(dev)->loopback_dev); 261 BUG_ON(!loopback_idev); 262 263 do { 264 in6_dev_put(xdst->u.rt6.rt6i_idev); 265 xdst->u.rt6.rt6i_idev = loopback_idev; 266 in6_dev_hold(loopback_idev); 267 xdst = (struct xfrm_dst *)xdst->u.dst.child; 268 } while (xdst->u.dst.xfrm); 269 270 __in6_dev_put(loopback_idev); 271 } 272 273 xfrm_dst_ifdown(dst, dev); 274 } 275 276 static struct dst_ops xfrm6_dst_ops = { 277 .family = AF_INET6, 278 .protocol = cpu_to_be16(ETH_P_IPV6), 279 .gc = xfrm6_garbage_collect, 280 .update_pmtu = xfrm6_update_pmtu, 281 .redirect = xfrm6_redirect, 282 .cow_metrics = dst_cow_metrics_generic, 283 .destroy = xfrm6_dst_destroy, 284 .ifdown = xfrm6_dst_ifdown, 285 .local_out = __ip6_local_out, 286 .gc_thresh = 1024, 287 }; 288 289 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 290 .family = AF_INET6, 291 .dst_ops = &xfrm6_dst_ops, 292 .dst_lookup = xfrm6_dst_lookup, 293 .get_saddr = xfrm6_get_saddr, 294 .decode_session = _decode_session6, 295 .get_tos = xfrm6_get_tos, 296 .init_dst = xfrm6_init_dst, 297 .init_path = xfrm6_init_path, 298 .fill_dst = xfrm6_fill_dst, 299 .blackhole_route = ip6_blackhole_route, 300 }; 301 302 static int __init xfrm6_policy_init(void) 303 { 304 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 305 } 306 307 static void xfrm6_policy_fini(void) 308 { 309 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 310 } 311 312 #ifdef CONFIG_SYSCTL 313 static struct ctl_table xfrm6_policy_table[] = { 314 { 315 .procname = "xfrm6_gc_thresh", 316 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 317 .maxlen = sizeof(int), 318 .mode = 0644, 319 .proc_handler = proc_dointvec, 320 }, 321 { } 322 }; 323 324 static struct ctl_table_header *sysctl_hdr; 325 #endif 326 327 int __init xfrm6_init(void) 328 { 329 int ret; 330 331 dst_entries_init(&xfrm6_dst_ops); 332 333 ret = xfrm6_policy_init(); 334 if (ret) { 335 dst_entries_destroy(&xfrm6_dst_ops); 336 goto out; 337 } 338 ret = xfrm6_state_init(); 339 if (ret) 340 goto out_policy; 341 342 #ifdef CONFIG_SYSCTL 343 sysctl_hdr = register_net_sysctl(&init_net, "net/ipv6", 344 xfrm6_policy_table); 345 #endif 346 out: 347 return ret; 348 out_policy: 349 xfrm6_policy_fini(); 350 goto out; 351 } 352 353 void xfrm6_fini(void) 354 { 355 #ifdef CONFIG_SYSCTL 356 if (sysctl_hdr) 357 unregister_net_sysctl_table(sysctl_hdr); 358 #endif 359 xfrm6_policy_fini(); 360 xfrm6_state_fini(); 361 dst_entries_destroy(&xfrm6_dst_ops); 362 } 363