1 /* 2 * Linux INET6 implementation 3 * 4 * Authors: 5 * Pedro Roque <[email protected]> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #ifndef _IP6_FIB_H 14 #define _IP6_FIB_H 15 16 #include <linux/ipv6_route.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/spinlock.h> 19 #include <net/dst.h> 20 #include <net/flow.h> 21 #include <net/netlink.h> 22 #include <net/inetpeer.h> 23 24 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 25 #define FIB6_TABLE_HASHSZ 256 26 #else 27 #define FIB6_TABLE_HASHSZ 1 28 #endif 29 30 struct rt6_info; 31 32 struct fib6_config { 33 u32 fc_table; 34 u32 fc_metric; 35 int fc_dst_len; 36 int fc_src_len; 37 int fc_ifindex; 38 u32 fc_flags; 39 u32 fc_protocol; 40 u16 fc_type; /* only 8 bits are used */ 41 u16 fc_delete_all_nh : 1, 42 __unused : 15; 43 44 struct in6_addr fc_dst; 45 struct in6_addr fc_src; 46 struct in6_addr fc_prefsrc; 47 struct in6_addr fc_gateway; 48 49 unsigned long fc_expires; 50 struct nlattr *fc_mx; 51 int fc_mx_len; 52 int fc_mp_len; 53 struct nlattr *fc_mp; 54 55 struct nl_info fc_nlinfo; 56 struct nlattr *fc_encap; 57 u16 fc_encap_type; 58 }; 59 60 struct fib6_node { 61 struct fib6_node *parent; 62 struct fib6_node *left; 63 struct fib6_node *right; 64 #ifdef CONFIG_IPV6_SUBTREES 65 struct fib6_node *subtree; 66 #endif 67 struct rt6_info *leaf; 68 69 __u16 fn_bit; /* bit key */ 70 __u16 fn_flags; 71 int fn_sernum; 72 struct rt6_info *rr_ptr; 73 struct rcu_head rcu; 74 }; 75 76 #ifndef CONFIG_IPV6_SUBTREES 77 #define FIB6_SUBTREE(fn) NULL 78 #else 79 #define FIB6_SUBTREE(fn) ((fn)->subtree) 80 #endif 81 82 struct mx6_config { 83 const u32 *mx; 84 DECLARE_BITMAP(mx_valid, RTAX_MAX); 85 }; 86 87 /* 88 * routing information 89 * 90 */ 91 92 struct rt6key { 93 struct in6_addr addr; 94 int plen; 95 }; 96 97 struct fib6_table; 98 99 struct rt6_info { 100 struct dst_entry dst; 101 102 /* 103 * Tail elements of dst_entry (__refcnt etc.) 104 * and these elements (rarely used in hot path) are in 105 * the same cache line. 106 */ 107 struct fib6_table *rt6i_table; 108 struct fib6_node __rcu *rt6i_node; 109 110 struct in6_addr rt6i_gateway; 111 112 /* Multipath routes: 113 * siblings is a list of rt6_info that have the the same metric/weight, 114 * destination, but not the same gateway. nsiblings is just a cache 115 * to speed up lookup. 116 */ 117 struct list_head rt6i_siblings; 118 unsigned int rt6i_nsiblings; 119 120 atomic_t rt6i_ref; 121 122 /* These are in a separate cache line. */ 123 struct rt6key rt6i_dst ____cacheline_aligned_in_smp; 124 u32 rt6i_flags; 125 struct rt6key rt6i_src; 126 struct rt6key rt6i_prefsrc; 127 128 struct list_head rt6i_uncached; 129 struct uncached_list *rt6i_uncached_list; 130 131 struct inet6_dev *rt6i_idev; 132 struct rt6_info * __percpu *rt6i_pcpu; 133 134 u32 rt6i_metric; 135 u32 rt6i_pmtu; 136 /* more non-fragment space at head required */ 137 unsigned short rt6i_nfheader_len; 138 u8 rt6i_protocol; 139 }; 140 141 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 142 { 143 return ((struct rt6_info *)dst)->rt6i_idev; 144 } 145 146 static inline void rt6_clean_expires(struct rt6_info *rt) 147 { 148 rt->rt6i_flags &= ~RTF_EXPIRES; 149 rt->dst.expires = 0; 150 } 151 152 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires) 153 { 154 rt->dst.expires = expires; 155 rt->rt6i_flags |= RTF_EXPIRES; 156 } 157 158 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 159 { 160 struct rt6_info *rt; 161 162 for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); 163 rt = (struct rt6_info *)rt->dst.from); 164 if (rt && rt != rt0) 165 rt0->dst.expires = rt->dst.expires; 166 167 dst_set_expires(&rt0->dst, timeout); 168 rt0->rt6i_flags |= RTF_EXPIRES; 169 } 170 171 /* Function to safely get fn->sernum for passed in rt 172 * and store result in passed in cookie. 173 * Return true if we can get cookie safely 174 * Return false if not 175 */ 176 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt, 177 u32 *cookie) 178 { 179 struct fib6_node *fn; 180 bool status = false; 181 182 rcu_read_lock(); 183 fn = rcu_dereference(rt->rt6i_node); 184 185 if (fn) { 186 *cookie = fn->fn_sernum; 187 status = true; 188 } 189 190 rcu_read_unlock(); 191 return status; 192 } 193 194 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 195 { 196 u32 cookie = 0; 197 198 if (rt->rt6i_flags & RTF_PCPU || 199 (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from)) 200 rt = (struct rt6_info *)(rt->dst.from); 201 202 rt6_get_cookie_safe(rt, &cookie); 203 204 return cookie; 205 } 206 207 static inline void ip6_rt_put(struct rt6_info *rt) 208 { 209 /* dst_release() accepts a NULL parameter. 210 * We rely on dst being first structure in struct rt6_info 211 */ 212 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 213 dst_release(&rt->dst); 214 } 215 216 enum fib6_walk_state { 217 #ifdef CONFIG_IPV6_SUBTREES 218 FWS_S, 219 #endif 220 FWS_L, 221 FWS_R, 222 FWS_C, 223 FWS_U 224 }; 225 226 struct fib6_walker { 227 struct list_head lh; 228 struct fib6_node *root, *node; 229 struct rt6_info *leaf; 230 enum fib6_walk_state state; 231 bool prune; 232 unsigned int skip; 233 unsigned int count; 234 int (*func)(struct fib6_walker *); 235 void *args; 236 }; 237 238 struct rt6_statistics { 239 __u32 fib_nodes; 240 __u32 fib_route_nodes; 241 __u32 fib_rt_alloc; /* permanent routes */ 242 __u32 fib_rt_entries; /* rt entries in table */ 243 __u32 fib_rt_cache; /* cache routes */ 244 __u32 fib_discarded_routes; 245 }; 246 247 #define RTN_TL_ROOT 0x0001 248 #define RTN_ROOT 0x0002 /* tree root node */ 249 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 250 251 /* 252 * priority levels (or metrics) 253 * 254 */ 255 256 257 struct fib6_table { 258 struct hlist_node tb6_hlist; 259 u32 tb6_id; 260 rwlock_t tb6_lock; 261 struct fib6_node tb6_root; 262 struct inet_peer_base tb6_peers; 263 unsigned int flags; 264 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 265 }; 266 267 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 268 #define RT6_TABLE_MAIN RT_TABLE_MAIN 269 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 270 #define RT6_TABLE_INFO RT6_TABLE_MAIN 271 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 272 273 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 274 #define FIB6_TABLE_MIN 1 275 #define FIB6_TABLE_MAX RT_TABLE_MAX 276 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 277 #else 278 #define FIB6_TABLE_MIN RT_TABLE_MAIN 279 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 280 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 281 #endif 282 283 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 284 struct fib6_table *, 285 struct flowi6 *, int); 286 287 /* 288 * exported functions 289 */ 290 291 struct fib6_table *fib6_get_table(struct net *net, u32 id); 292 struct fib6_table *fib6_new_table(struct net *net, u32 id); 293 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 294 int flags, pol_lookup_t lookup); 295 296 struct fib6_node *fib6_lookup(struct fib6_node *root, 297 const struct in6_addr *daddr, 298 const struct in6_addr *saddr); 299 300 struct fib6_node *fib6_locate(struct fib6_node *root, 301 const struct in6_addr *daddr, int dst_len, 302 const struct in6_addr *saddr, int src_len); 303 304 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 305 void *arg); 306 307 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 308 struct nl_info *info, struct mx6_config *mxc, 309 struct netlink_ext_ack *extack); 310 int fib6_del(struct rt6_info *rt, struct nl_info *info); 311 312 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info, 313 unsigned int flags); 314 315 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 316 317 void fib6_gc_cleanup(void); 318 319 int fib6_init(void); 320 321 int ipv6_route_open(struct inode *inode, struct file *file); 322 323 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 324 int fib6_rules_init(void); 325 void fib6_rules_cleanup(void); 326 #else 327 static inline int fib6_rules_init(void) 328 { 329 return 0; 330 } 331 static inline void fib6_rules_cleanup(void) 332 { 333 return ; 334 } 335 #endif 336 #endif 337