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