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 /* Sheit... I remember I did this right. Apparently, 102 * it was magically lost, so this code needs audit */ 103 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 104 RTF_LOCAL); 105 xdst->u.rt6.rt6i_metric = rt->rt6i_metric; 106 xdst->u.rt6.rt6i_node = rt->rt6i_node; 107 if (rt->rt6i_node) 108 xdst->route_cookie = rt->rt6i_node->fn_sernum; 109 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 110 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 111 xdst->u.rt6.rt6i_src = rt->rt6i_src; 112 113 return 0; 114 } 115 116 static inline void 117 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 118 { 119 int onlyproto = 0; 120 u16 offset = skb_network_header_len(skb); 121 struct ipv6hdr *hdr = ipv6_hdr(skb); 122 struct ipv6_opt_hdr *exthdr; 123 const unsigned char *nh = skb_network_header(skb); 124 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 125 126 memset(fl, 0, sizeof(struct flowi)); 127 fl->mark = skb->mark; 128 129 ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr); 130 ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); 131 132 while (nh + offset + 1 < skb->data || 133 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 134 nh = skb_network_header(skb); 135 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 136 137 switch (nexthdr) { 138 case NEXTHDR_FRAGMENT: 139 onlyproto = 1; 140 case NEXTHDR_ROUTING: 141 case NEXTHDR_HOP: 142 case NEXTHDR_DEST: 143 offset += ipv6_optlen(exthdr); 144 nexthdr = exthdr->nexthdr; 145 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 146 break; 147 148 case IPPROTO_UDP: 149 case IPPROTO_UDPLITE: 150 case IPPROTO_TCP: 151 case IPPROTO_SCTP: 152 case IPPROTO_DCCP: 153 if (!onlyproto && (nh + offset + 4 < skb->data || 154 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 155 __be16 *ports = (__be16 *)exthdr; 156 157 fl->fl_ip_sport = ports[!!reverse]; 158 fl->fl_ip_dport = ports[!reverse]; 159 } 160 fl->proto = nexthdr; 161 return; 162 163 case IPPROTO_ICMPV6: 164 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 165 u8 *icmp = (u8 *)exthdr; 166 167 fl->fl_icmp_type = icmp[0]; 168 fl->fl_icmp_code = icmp[1]; 169 } 170 fl->proto = nexthdr; 171 return; 172 173 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 174 case IPPROTO_MH: 175 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 176 struct ip6_mh *mh; 177 mh = (struct ip6_mh *)exthdr; 178 179 fl->fl_mh_type = mh->ip6mh_type; 180 } 181 fl->proto = nexthdr; 182 return; 183 #endif 184 185 /* XXX Why are there these headers? */ 186 case IPPROTO_AH: 187 case IPPROTO_ESP: 188 case IPPROTO_COMP: 189 default: 190 fl->fl_ipsec_spi = 0; 191 fl->proto = nexthdr; 192 return; 193 } 194 } 195 } 196 197 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 198 { 199 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 200 201 xfrm6_policy_afinfo.garbage_collect(net); 202 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 203 } 204 205 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 206 { 207 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 208 struct dst_entry *path = xdst->route; 209 210 path->ops->update_pmtu(path, mtu); 211 } 212 213 static void xfrm6_dst_destroy(struct dst_entry *dst) 214 { 215 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 216 217 if (likely(xdst->u.rt6.rt6i_idev)) 218 in6_dev_put(xdst->u.rt6.rt6i_idev); 219 xfrm_dst_destroy(xdst); 220 } 221 222 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 223 int unregister) 224 { 225 struct xfrm_dst *xdst; 226 227 if (!unregister) 228 return; 229 230 xdst = (struct xfrm_dst *)dst; 231 if (xdst->u.rt6.rt6i_idev->dev == dev) { 232 struct inet6_dev *loopback_idev = 233 in6_dev_get(dev_net(dev)->loopback_dev); 234 BUG_ON(!loopback_idev); 235 236 do { 237 in6_dev_put(xdst->u.rt6.rt6i_idev); 238 xdst->u.rt6.rt6i_idev = loopback_idev; 239 in6_dev_hold(loopback_idev); 240 xdst = (struct xfrm_dst *)xdst->u.dst.child; 241 } while (xdst->u.dst.xfrm); 242 243 __in6_dev_put(loopback_idev); 244 } 245 246 xfrm_dst_ifdown(dst, dev); 247 } 248 249 static struct dst_ops xfrm6_dst_ops = { 250 .family = AF_INET6, 251 .protocol = cpu_to_be16(ETH_P_IPV6), 252 .gc = xfrm6_garbage_collect, 253 .update_pmtu = xfrm6_update_pmtu, 254 .destroy = xfrm6_dst_destroy, 255 .ifdown = xfrm6_dst_ifdown, 256 .local_out = __ip6_local_out, 257 .gc_thresh = 1024, 258 }; 259 260 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 261 .family = AF_INET6, 262 .dst_ops = &xfrm6_dst_ops, 263 .dst_lookup = xfrm6_dst_lookup, 264 .get_saddr = xfrm6_get_saddr, 265 .decode_session = _decode_session6, 266 .get_tos = xfrm6_get_tos, 267 .init_path = xfrm6_init_path, 268 .fill_dst = xfrm6_fill_dst, 269 }; 270 271 static int __init xfrm6_policy_init(void) 272 { 273 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 274 } 275 276 static void xfrm6_policy_fini(void) 277 { 278 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 279 } 280 281 #ifdef CONFIG_SYSCTL 282 static struct ctl_table xfrm6_policy_table[] = { 283 { 284 .procname = "xfrm6_gc_thresh", 285 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 286 .maxlen = sizeof(int), 287 .mode = 0644, 288 .proc_handler = proc_dointvec, 289 }, 290 { } 291 }; 292 293 static struct ctl_table_header *sysctl_hdr; 294 #endif 295 296 int __init xfrm6_init(void) 297 { 298 int ret; 299 unsigned int gc_thresh; 300 301 /* 302 * We need a good default value for the xfrm6 gc threshold. 303 * In ipv4 we set it to the route hash table size * 8, which 304 * is half the size of the maximaum route cache for ipv4. It 305 * would be good to do the same thing for v6, except the table is 306 * constructed differently here. Here each table for a net namespace 307 * can have FIB_TABLE_HASHSZ entries, so lets go with the same 308 * computation that we used for ipv4 here. Also, lets keep the initial 309 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults 310 * to that as a minimum as well 311 */ 312 gc_thresh = FIB6_TABLE_HASHSZ * 8; 313 xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; 314 dst_entries_init(&xfrm6_dst_ops); 315 316 ret = xfrm6_policy_init(); 317 if (ret) { 318 dst_entries_destroy(&xfrm6_dst_ops); 319 goto out; 320 } 321 ret = xfrm6_state_init(); 322 if (ret) 323 goto out_policy; 324 325 #ifdef CONFIG_SYSCTL 326 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, 327 xfrm6_policy_table); 328 #endif 329 out: 330 return ret; 331 out_policy: 332 xfrm6_policy_fini(); 333 goto out; 334 } 335 336 void xfrm6_fini(void) 337 { 338 #ifdef CONFIG_SYSCTL 339 if (sysctl_hdr) 340 unregister_net_sysctl_table(sysctl_hdr); 341 #endif 342 //xfrm6_input_fini(); 343 xfrm6_policy_fini(); 344 xfrm6_state_fini(); 345 dst_entries_destroy(&xfrm6_dst_ops); 346 } 347