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(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 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 116static 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 case IPPROTO_AH: 186 case IPPROTO_ESP: 187 case IPPROTO_COMP: 188 default: 189 fl->fl_ipsec_spi = 0; 190 fl->proto = nexthdr; 191 return; 192 } 193 } 194} 195 196static inline int xfrm6_garbage_collect(struct dst_ops *ops) 197{ 198 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 199 200 xfrm6_policy_afinfo.garbage_collect(net); 201 return (atomic_read(&ops->entries) > ops->gc_thresh * 2); 202} 203 204static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 205{ 206 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 207 struct dst_entry *path = xdst->route; 208 209 path->ops->update_pmtu(path, mtu); 210} 211 212static void xfrm6_dst_destroy(struct dst_entry *dst) 213{ 214 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 215 216 if (likely(xdst->u.rt6.rt6i_idev)) 217 in6_dev_put(xdst->u.rt6.rt6i_idev); 218 xfrm_dst_destroy(xdst); 219} 220 221static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 222 int unregister) 223{ 224 struct xfrm_dst *xdst; 225 226 if (!unregister) 227 return; 228 229 xdst = (struct xfrm_dst *)dst; 230 if (xdst->u.rt6.rt6i_idev->dev == dev) { 231 struct inet6_dev *loopback_idev = 232 in6_dev_get(dev_net(dev)->loopback_dev); 233 BUG_ON(!loopback_idev); 234 235 do { 236 in6_dev_put(xdst->u.rt6.rt6i_idev); 237 xdst->u.rt6.rt6i_idev = loopback_idev; 238 in6_dev_hold(loopback_idev); 239 xdst = (struct xfrm_dst *)xdst->u.dst.child; 240 } while (xdst->u.dst.xfrm); 241 242 __in6_dev_put(loopback_idev); 243 } 244 245 xfrm_dst_ifdown(dst, dev); 246} 247 248static struct dst_ops xfrm6_dst_ops = { 249 .family = AF_INET6, 250 .protocol = cpu_to_be16(ETH_P_IPV6), 251 .gc = xfrm6_garbage_collect, 252 .update_pmtu = xfrm6_update_pmtu, 253 .destroy = xfrm6_dst_destroy, 254 .ifdown = xfrm6_dst_ifdown, 255 .local_out = __ip6_local_out, 256 .gc_thresh = 1024, 257 .entries = ATOMIC_INIT(0), 258}; 259 260static 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 271static int __init xfrm6_policy_init(void) 272{ 273 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 274} 275 276static void xfrm6_policy_fini(void) 277{ 278 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 279} 280 281#ifdef CONFIG_SYSCTL 282static 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 293static struct ctl_table_header *sysctl_hdr; 294#endif 295 296int __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; 314 315 ret = xfrm6_policy_init(); 316 if (ret) 317 goto out; 318 319 ret = xfrm6_state_init(); 320 if (ret) 321 goto out_policy; 322 323#ifdef CONFIG_SYSCTL 324 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, 325 xfrm6_policy_table); 326#endif 327out: 328 return ret; 329out_policy: 330 xfrm6_policy_fini(); 331 goto out; 332} 333 334void xfrm6_fini(void) 335{ 336#ifdef CONFIG_SYSCTL 337 if (sysctl_hdr) 338 unregister_net_sysctl_table(sysctl_hdr); 339#endif 340 //xfrm6_input_fini(); 341 xfrm6_policy_fini(); 342 xfrm6_state_fini(); 343} 344