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 xfrm_address_t *saddr, 31 xfrm_address_t *daddr) 32 { 33 struct flowi fl = {}; 34 struct dst_entry *dst; 35 int err; 36 37 memcpy(&fl.fl6_dst, daddr, sizeof(fl.fl6_dst)); 38 if (saddr) 39 memcpy(&fl.fl6_src, saddr, sizeof(fl.fl6_src)); 40 41 dst = ip6_route_output(net, NULL, &fl); 42 43 err = dst->error; 44 if (dst->error) { 45 dst_release(dst); 46 dst = ERR_PTR(err); 47 } 48 49 return dst; 50 } 51 52 static int xfrm6_get_saddr(struct net *net, 53 xfrm_address_t *saddr, xfrm_address_t *daddr) 54 { 55 struct dst_entry *dst; 56 struct net_device *dev; 57 58 dst = xfrm6_dst_lookup(net, 0, NULL, daddr); 59 if (IS_ERR(dst)) 60 return -EHOSTUNREACH; 61 62 dev = ip6_dst_idev(dst)->dev; 63 ipv6_dev_get_saddr(dev_net(dev), dev, 64 (struct in6_addr *)&daddr->a6, 0, 65 (struct in6_addr *)&saddr->a6); 66 dst_release(dst); 67 return 0; 68 } 69 70 static int xfrm6_get_tos(struct flowi *fl) 71 { 72 return 0; 73 } 74 75 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 76 int nfheader_len) 77 { 78 if (dst->ops->family == AF_INET6) { 79 struct rt6_info *rt = (struct rt6_info*)dst; 80 if (rt->rt6i_node) 81 path->path_cookie = rt->rt6i_node->fn_sernum; 82 } 83 84 path->u.rt6.rt6i_nfheader_len = nfheader_len; 85 86 return 0; 87 } 88 89 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 90 struct flowi *fl) 91 { 92 struct rt6_info *rt = (struct rt6_info*)xdst->route; 93 94 xdst->u.dst.dev = dev; 95 dev_hold(dev); 96 97 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 98 if (!xdst->u.rt6.rt6i_idev) 99 return -ENODEV; 100 101 xdst->u.rt6.rt6i_peer = rt->rt6i_peer; 102 if (rt->rt6i_peer) 103 atomic_inc(&rt->rt6i_peer->refcnt); 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 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 int onlyproto = 0; 124 u16 offset = skb_network_header_len(skb); 125 struct ipv6hdr *hdr = ipv6_hdr(skb); 126 struct ipv6_opt_hdr *exthdr; 127 const unsigned char *nh = skb_network_header(skb); 128 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 129 130 memset(fl, 0, sizeof(struct flowi)); 131 fl->mark = skb->mark; 132 133 ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr); 134 ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); 135 136 while (nh + offset + 1 < skb->data || 137 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 138 nh = skb_network_header(skb); 139 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 140 141 switch (nexthdr) { 142 case NEXTHDR_FRAGMENT: 143 onlyproto = 1; 144 case NEXTHDR_ROUTING: 145 case NEXTHDR_HOP: 146 case NEXTHDR_DEST: 147 offset += ipv6_optlen(exthdr); 148 nexthdr = exthdr->nexthdr; 149 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 150 break; 151 152 case IPPROTO_UDP: 153 case IPPROTO_UDPLITE: 154 case IPPROTO_TCP: 155 case IPPROTO_SCTP: 156 case IPPROTO_DCCP: 157 if (!onlyproto && (nh + offset + 4 < skb->data || 158 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 159 __be16 *ports = (__be16 *)exthdr; 160 161 fl->fl_ip_sport = ports[!!reverse]; 162 fl->fl_ip_dport = ports[!reverse]; 163 } 164 fl->proto = nexthdr; 165 return; 166 167 case IPPROTO_ICMPV6: 168 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 169 u8 *icmp = (u8 *)exthdr; 170 171 fl->fl_icmp_type = icmp[0]; 172 fl->fl_icmp_code = icmp[1]; 173 } 174 fl->proto = nexthdr; 175 return; 176 177 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 178 case IPPROTO_MH: 179 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 180 struct ip6_mh *mh; 181 mh = (struct ip6_mh *)exthdr; 182 183 fl->fl_mh_type = mh->ip6mh_type; 184 } 185 fl->proto = nexthdr; 186 return; 187 #endif 188 189 /* XXX Why are there these headers? */ 190 case IPPROTO_AH: 191 case IPPROTO_ESP: 192 case IPPROTO_COMP: 193 default: 194 fl->fl_ipsec_spi = 0; 195 fl->proto = nexthdr; 196 return; 197 } 198 } 199 } 200 201 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 202 { 203 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 204 205 xfrm6_policy_afinfo.garbage_collect(net); 206 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 207 } 208 209 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 210 { 211 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 212 struct dst_entry *path = xdst->route; 213 214 path->ops->update_pmtu(path, mtu); 215 } 216 217 static void xfrm6_dst_destroy(struct dst_entry *dst) 218 { 219 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 220 221 if (likely(xdst->u.rt6.rt6i_idev)) 222 in6_dev_put(xdst->u.rt6.rt6i_idev); 223 if (likely(xdst->u.rt6.rt6i_peer)) 224 inet_putpeer(xdst->u.rt6.rt6i_peer); 225 xfrm_dst_destroy(xdst); 226 } 227 228 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 229 int unregister) 230 { 231 struct xfrm_dst *xdst; 232 233 if (!unregister) 234 return; 235 236 xdst = (struct xfrm_dst *)dst; 237 if (xdst->u.rt6.rt6i_idev->dev == dev) { 238 struct inet6_dev *loopback_idev = 239 in6_dev_get(dev_net(dev)->loopback_dev); 240 BUG_ON(!loopback_idev); 241 242 do { 243 in6_dev_put(xdst->u.rt6.rt6i_idev); 244 xdst->u.rt6.rt6i_idev = loopback_idev; 245 in6_dev_hold(loopback_idev); 246 xdst = (struct xfrm_dst *)xdst->u.dst.child; 247 } while (xdst->u.dst.xfrm); 248 249 __in6_dev_put(loopback_idev); 250 } 251 252 xfrm_dst_ifdown(dst, dev); 253 } 254 255 static struct dst_ops xfrm6_dst_ops = { 256 .family = AF_INET6, 257 .protocol = cpu_to_be16(ETH_P_IPV6), 258 .gc = xfrm6_garbage_collect, 259 .update_pmtu = xfrm6_update_pmtu, 260 .destroy = xfrm6_dst_destroy, 261 .ifdown = xfrm6_dst_ifdown, 262 .local_out = __ip6_local_out, 263 .gc_thresh = 1024, 264 }; 265 266 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 267 .family = AF_INET6, 268 .dst_ops = &xfrm6_dst_ops, 269 .dst_lookup = xfrm6_dst_lookup, 270 .get_saddr = xfrm6_get_saddr, 271 .decode_session = _decode_session6, 272 .get_tos = xfrm6_get_tos, 273 .init_path = xfrm6_init_path, 274 .fill_dst = xfrm6_fill_dst, 275 }; 276 277 static int __init xfrm6_policy_init(void) 278 { 279 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 280 } 281 282 static void xfrm6_policy_fini(void) 283 { 284 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 285 } 286 287 #ifdef CONFIG_SYSCTL 288 static struct ctl_table xfrm6_policy_table[] = { 289 { 290 .procname = "xfrm6_gc_thresh", 291 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 292 .maxlen = sizeof(int), 293 .mode = 0644, 294 .proc_handler = proc_dointvec, 295 }, 296 { } 297 }; 298 299 static struct ctl_table_header *sysctl_hdr; 300 #endif 301 302 int __init xfrm6_init(void) 303 { 304 int ret; 305 unsigned int gc_thresh; 306 307 /* 308 * We need a good default value for the xfrm6 gc threshold. 309 * In ipv4 we set it to the route hash table size * 8, which 310 * is half the size of the maximaum route cache for ipv4. It 311 * would be good to do the same thing for v6, except the table is 312 * constructed differently here. Here each table for a net namespace 313 * can have FIB_TABLE_HASHSZ entries, so lets go with the same 314 * computation that we used for ipv4 here. Also, lets keep the initial 315 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults 316 * to that as a minimum as well 317 */ 318 gc_thresh = FIB6_TABLE_HASHSZ * 8; 319 xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; 320 dst_entries_init(&xfrm6_dst_ops); 321 322 ret = xfrm6_policy_init(); 323 if (ret) { 324 dst_entries_destroy(&xfrm6_dst_ops); 325 goto out; 326 } 327 ret = xfrm6_state_init(); 328 if (ret) 329 goto out_policy; 330 331 #ifdef CONFIG_SYSCTL 332 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, 333 xfrm6_policy_table); 334 #endif 335 out: 336 return ret; 337 out_policy: 338 xfrm6_policy_fini(); 339 goto out; 340 } 341 342 void xfrm6_fini(void) 343 { 344 #ifdef CONFIG_SYSCTL 345 if (sysctl_hdr) 346 unregister_net_sysctl_table(sysctl_hdr); 347 #endif 348 //xfrm6_input_fini(); 349 xfrm6_policy_fini(); 350 xfrm6_state_fini(); 351 dst_entries_destroy(&xfrm6_dst_ops); 352 } 353