xfrm6_policy.c revision 0c7b3eefb4ab8df245e94feb0d83c1c3450a3d87
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 27static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 28 29static 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 52static 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 70static int xfrm6_get_tos(const struct flowi *fl) 71{ 72 return 0; 73} 74 75static 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 89static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 90 const 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 120static 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 201static 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 209static 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 217static 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 dst_destroy_metrics_generic(dst); 224 if (likely(xdst->u.rt6.rt6i_peer)) 225 inet_putpeer(xdst->u.rt6.rt6i_peer); 226 xfrm_dst_destroy(xdst); 227} 228 229static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 230 int unregister) 231{ 232 struct xfrm_dst *xdst; 233 234 if (!unregister) 235 return; 236 237 xdst = (struct xfrm_dst *)dst; 238 if (xdst->u.rt6.rt6i_idev->dev == dev) { 239 struct inet6_dev *loopback_idev = 240 in6_dev_get(dev_net(dev)->loopback_dev); 241 BUG_ON(!loopback_idev); 242 243 do { 244 in6_dev_put(xdst->u.rt6.rt6i_idev); 245 xdst->u.rt6.rt6i_idev = loopback_idev; 246 in6_dev_hold(loopback_idev); 247 xdst = (struct xfrm_dst *)xdst->u.dst.child; 248 } while (xdst->u.dst.xfrm); 249 250 __in6_dev_put(loopback_idev); 251 } 252 253 xfrm_dst_ifdown(dst, dev); 254} 255 256static struct dst_ops xfrm6_dst_ops = { 257 .family = AF_INET6, 258 .protocol = cpu_to_be16(ETH_P_IPV6), 259 .gc = xfrm6_garbage_collect, 260 .update_pmtu = xfrm6_update_pmtu, 261 .cow_metrics = dst_cow_metrics_generic, 262 .destroy = xfrm6_dst_destroy, 263 .ifdown = xfrm6_dst_ifdown, 264 .local_out = __ip6_local_out, 265 .gc_thresh = 1024, 266}; 267 268static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 269 .family = AF_INET6, 270 .dst_ops = &xfrm6_dst_ops, 271 .dst_lookup = xfrm6_dst_lookup, 272 .get_saddr = xfrm6_get_saddr, 273 .decode_session = _decode_session6, 274 .get_tos = xfrm6_get_tos, 275 .init_path = xfrm6_init_path, 276 .fill_dst = xfrm6_fill_dst, 277}; 278 279static int __init xfrm6_policy_init(void) 280{ 281 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 282} 283 284static void xfrm6_policy_fini(void) 285{ 286 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 287} 288 289#ifdef CONFIG_SYSCTL 290static struct ctl_table xfrm6_policy_table[] = { 291 { 292 .procname = "xfrm6_gc_thresh", 293 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 294 .maxlen = sizeof(int), 295 .mode = 0644, 296 .proc_handler = proc_dointvec, 297 }, 298 { } 299}; 300 301static struct ctl_table_header *sysctl_hdr; 302#endif 303 304int __init xfrm6_init(void) 305{ 306 int ret; 307 unsigned int gc_thresh; 308 309 /* 310 * We need a good default value for the xfrm6 gc threshold. 311 * In ipv4 we set it to the route hash table size * 8, which 312 * is half the size of the maximaum route cache for ipv4. It 313 * would be good to do the same thing for v6, except the table is 314 * constructed differently here. Here each table for a net namespace 315 * can have FIB_TABLE_HASHSZ entries, so lets go with the same 316 * computation that we used for ipv4 here. Also, lets keep the initial 317 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults 318 * to that as a minimum as well 319 */ 320 gc_thresh = FIB6_TABLE_HASHSZ * 8; 321 xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; 322 dst_entries_init(&xfrm6_dst_ops); 323 324 ret = xfrm6_policy_init(); 325 if (ret) { 326 dst_entries_destroy(&xfrm6_dst_ops); 327 goto out; 328 } 329 ret = xfrm6_state_init(); 330 if (ret) 331 goto out_policy; 332 333#ifdef CONFIG_SYSCTL 334 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, 335 xfrm6_policy_table); 336#endif 337out: 338 return ret; 339out_policy: 340 xfrm6_policy_fini(); 341 goto out; 342} 343 344void xfrm6_fini(void) 345{ 346#ifdef CONFIG_SYSCTL 347 if (sysctl_hdr) 348 unregister_net_sysctl_table(sysctl_hdr); 349#endif 350 //xfrm6_input_fini(); 351 xfrm6_policy_fini(); 352 xfrm6_state_fini(); 353 dst_entries_destroy(&xfrm6_dst_ops); 354} 355