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