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 dst_ops xfrm6_dst_ops; 28 static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 29 30 static struct dst_entry *xfrm6_dst_lookup(int tos, 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(&init_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(xfrm_address_t *saddr, xfrm_address_t *daddr) 53 { 54 struct dst_entry *dst; 55 struct net_device *dev; 56 57 dst = xfrm6_dst_lookup(0, NULL, daddr); 58 if (IS_ERR(dst)) 59 return -EHOSTUNREACH; 60 61 dev = ip6_dst_idev(dst)->dev; 62 ipv6_dev_get_saddr(dev_net(dev), dev, 63 (struct in6_addr *)&daddr->a6, 0, 64 (struct in6_addr *)&saddr->a6); 65 dst_release(dst); 66 return 0; 67 } 68 69 static struct dst_entry * 70 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy) 71 { 72 struct dst_entry *dst; 73 74 /* Still not clear if we should set fl->fl6_{src,dst}... */ 75 read_lock_bh(&policy->lock); 76 for (dst = policy->bundles; dst; dst = dst->next) { 77 struct xfrm_dst *xdst = (struct xfrm_dst*)dst; 78 struct in6_addr fl_dst_prefix, fl_src_prefix; 79 80 ipv6_addr_prefix(&fl_dst_prefix, 81 &fl->fl6_dst, 82 xdst->u.rt6.rt6i_dst.plen); 83 ipv6_addr_prefix(&fl_src_prefix, 84 &fl->fl6_src, 85 xdst->u.rt6.rt6i_src.plen); 86 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) && 87 ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) && 88 xfrm_bundle_ok(policy, xdst, fl, AF_INET6, 89 (xdst->u.rt6.rt6i_dst.plen != 128 || 90 xdst->u.rt6.rt6i_src.plen != 128))) { 91 dst_clone(dst); 92 break; 93 } 94 } 95 read_unlock_bh(&policy->lock); 96 return dst; 97 } 98 99 static int xfrm6_get_tos(struct flowi *fl) 100 { 101 return 0; 102 } 103 104 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 105 int nfheader_len) 106 { 107 if (dst->ops->family == AF_INET6) { 108 struct rt6_info *rt = (struct rt6_info*)dst; 109 if (rt->rt6i_node) 110 path->path_cookie = rt->rt6i_node->fn_sernum; 111 } 112 113 path->u.rt6.rt6i_nfheader_len = nfheader_len; 114 115 return 0; 116 } 117 118 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev) 119 { 120 struct rt6_info *rt = (struct rt6_info*)xdst->route; 121 122 xdst->u.dst.dev = dev; 123 dev_hold(dev); 124 125 xdst->u.rt6.rt6i_idev = in6_dev_get(rt->u.dst.dev); 126 if (!xdst->u.rt6.rt6i_idev) 127 return -ENODEV; 128 129 /* Sheit... I remember I did this right. Apparently, 130 * it was magically lost, so this code needs audit */ 131 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 132 RTF_LOCAL); 133 xdst->u.rt6.rt6i_metric = rt->rt6i_metric; 134 xdst->u.rt6.rt6i_node = rt->rt6i_node; 135 if (rt->rt6i_node) 136 xdst->route_cookie = rt->rt6i_node->fn_sernum; 137 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 138 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 139 xdst->u.rt6.rt6i_src = rt->rt6i_src; 140 141 return 0; 142 } 143 144 static inline void 145 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 146 { 147 u16 offset = skb_network_header_len(skb); 148 struct ipv6hdr *hdr = ipv6_hdr(skb); 149 struct ipv6_opt_hdr *exthdr; 150 const unsigned char *nh = skb_network_header(skb); 151 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 152 153 memset(fl, 0, sizeof(struct flowi)); 154 ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr); 155 ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); 156 157 while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 158 nh = skb_network_header(skb); 159 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 160 161 switch (nexthdr) { 162 case NEXTHDR_ROUTING: 163 case NEXTHDR_HOP: 164 case NEXTHDR_DEST: 165 offset += ipv6_optlen(exthdr); 166 nexthdr = exthdr->nexthdr; 167 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 168 break; 169 170 case IPPROTO_UDP: 171 case IPPROTO_UDPLITE: 172 case IPPROTO_TCP: 173 case IPPROTO_SCTP: 174 case IPPROTO_DCCP: 175 if (pskb_may_pull(skb, nh + offset + 4 - skb->data)) { 176 __be16 *ports = (__be16 *)exthdr; 177 178 fl->fl_ip_sport = ports[!!reverse]; 179 fl->fl_ip_dport = ports[!reverse]; 180 } 181 fl->proto = nexthdr; 182 return; 183 184 case IPPROTO_ICMPV6: 185 if (pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 186 u8 *icmp = (u8 *)exthdr; 187 188 fl->fl_icmp_type = icmp[0]; 189 fl->fl_icmp_code = icmp[1]; 190 } 191 fl->proto = nexthdr; 192 return; 193 194 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 195 case IPPROTO_MH: 196 if (pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 197 struct ip6_mh *mh; 198 mh = (struct ip6_mh *)exthdr; 199 200 fl->fl_mh_type = mh->ip6mh_type; 201 } 202 fl->proto = nexthdr; 203 return; 204 #endif 205 206 /* XXX Why are there these headers? */ 207 case IPPROTO_AH: 208 case IPPROTO_ESP: 209 case IPPROTO_COMP: 210 default: 211 fl->fl_ipsec_spi = 0; 212 fl->proto = nexthdr; 213 return; 214 } 215 } 216 } 217 218 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 219 { 220 xfrm6_policy_afinfo.garbage_collect(); 221 return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2); 222 } 223 224 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 225 { 226 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 227 struct dst_entry *path = xdst->route; 228 229 path->ops->update_pmtu(path, mtu); 230 } 231 232 static void xfrm6_dst_destroy(struct dst_entry *dst) 233 { 234 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 235 236 if (likely(xdst->u.rt6.rt6i_idev)) 237 in6_dev_put(xdst->u.rt6.rt6i_idev); 238 xfrm_dst_destroy(xdst); 239 } 240 241 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 242 int unregister) 243 { 244 struct xfrm_dst *xdst; 245 246 if (!unregister) 247 return; 248 249 xdst = (struct xfrm_dst *)dst; 250 if (xdst->u.rt6.rt6i_idev->dev == dev) { 251 struct inet6_dev *loopback_idev = 252 in6_dev_get(dev_net(dev)->loopback_dev); 253 BUG_ON(!loopback_idev); 254 255 do { 256 in6_dev_put(xdst->u.rt6.rt6i_idev); 257 xdst->u.rt6.rt6i_idev = loopback_idev; 258 in6_dev_hold(loopback_idev); 259 xdst = (struct xfrm_dst *)xdst->u.dst.child; 260 } while (xdst->u.dst.xfrm); 261 262 __in6_dev_put(loopback_idev); 263 } 264 265 xfrm_dst_ifdown(dst, dev); 266 } 267 268 static struct dst_ops xfrm6_dst_ops = { 269 .family = AF_INET6, 270 .protocol = __constant_htons(ETH_P_IPV6), 271 .gc = xfrm6_garbage_collect, 272 .update_pmtu = xfrm6_update_pmtu, 273 .destroy = xfrm6_dst_destroy, 274 .ifdown = xfrm6_dst_ifdown, 275 .local_out = __ip6_local_out, 276 .gc_thresh = 1024, 277 .entry_size = sizeof(struct xfrm_dst), 278 .entries = ATOMIC_INIT(0), 279 }; 280 281 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 282 .family = AF_INET6, 283 .dst_ops = &xfrm6_dst_ops, 284 .dst_lookup = xfrm6_dst_lookup, 285 .get_saddr = xfrm6_get_saddr, 286 .find_bundle = __xfrm6_find_bundle, 287 .decode_session = _decode_session6, 288 .get_tos = xfrm6_get_tos, 289 .init_path = xfrm6_init_path, 290 .fill_dst = xfrm6_fill_dst, 291 }; 292 293 static int __init xfrm6_policy_init(void) 294 { 295 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 296 } 297 298 static void xfrm6_policy_fini(void) 299 { 300 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 301 } 302 303 int __init xfrm6_init(void) 304 { 305 int ret; 306 307 ret = xfrm6_policy_init(); 308 if (ret) 309 goto out; 310 311 ret = xfrm6_state_init(); 312 if (ret) 313 goto out_policy; 314 out: 315 return ret; 316 out_policy: 317 xfrm6_policy_fini(); 318 goto out; 319 } 320 321 void xfrm6_fini(void) 322 { 323 //xfrm6_input_fini(); 324 xfrm6_policy_fini(); 325 xfrm6_state_fini(); 326 } 327