1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _NET_IP6_ROUTE_H 3 #define _NET_IP6_ROUTE_H 4 5 #include <net/addrconf.h> 6 #include <net/flow.h> 7 #include <net/ip6_fib.h> 8 #include <net/sock.h> 9 #include <net/lwtunnel.h> 10 #include <linux/ip.h> 11 #include <linux/ipv6.h> 12 #include <linux/route.h> 13 #include <net/nexthop.h> 14 15 struct route_info { 16 __u8 type; 17 __u8 length; 18 __u8 prefix_len; 19 #if defined(__BIG_ENDIAN_BITFIELD) 20 __u8 reserved_h:3, 21 route_pref:2, 22 reserved_l:3; 23 #elif defined(__LITTLE_ENDIAN_BITFIELD) 24 __u8 reserved_l:3, 25 route_pref:2, 26 reserved_h:3; 27 #endif 28 __be32 lifetime; 29 __u8 prefix[]; /* 0,8 or 16 */ 30 }; 31 32 #define RT6_LOOKUP_F_IFACE 0x00000001 33 #define RT6_LOOKUP_F_REACHABLE 0x00000002 34 #define RT6_LOOKUP_F_HAS_SADDR 0x00000004 35 #define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008 36 #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010 37 #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020 38 #define RT6_LOOKUP_F_IGNORE_LINKSTATE 0x00000040 39 #define RT6_LOOKUP_F_DST_NOREF 0x00000080 40 41 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675) 42 * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header 43 */ 44 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) 45 46 /* 47 * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate 48 * between IPV6_ADDR_PREFERENCES socket option values 49 * IPV6_PREFER_SRC_TMP = 0x1 50 * IPV6_PREFER_SRC_PUBLIC = 0x2 51 * IPV6_PREFER_SRC_COA = 0x4 52 * and above RT6_LOOKUP_F_SRCPREF_xxx flags. 53 */ 54 static inline int rt6_srcprefs2flags(unsigned int srcprefs) 55 { 56 return (srcprefs & IPV6_PREFER_SRC_MASK) << 3; 57 } 58 59 static inline unsigned int rt6_flags2srcprefs(int flags) 60 { 61 return (flags >> 3) & IPV6_PREFER_SRC_MASK; 62 } 63 64 static inline bool rt6_need_strict(const struct in6_addr *daddr) 65 { 66 return ipv6_addr_type(daddr) & 67 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); 68 } 69 70 /* fib entries using a nexthop object can not be coalesced into 71 * a multipath route 72 */ 73 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i) 74 { 75 /* the RTF_ADDRCONF flag filters out RA's */ 76 return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh && 77 f6i->fib6_nh->fib_nh_gw_family; 78 } 79 80 #if IS_ENABLED(CONFIG_IPV6) 81 void ip6_route_input(struct sk_buff *skb); 82 #else 83 static inline void ip6_route_input(struct sk_buff *skb) 84 { 85 } 86 #endif 87 88 struct dst_entry *ip6_route_input_lookup(struct net *net, 89 struct net_device *dev, 90 struct flowi6 *fl6, 91 const struct sk_buff *skb, int flags); 92 93 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, 94 struct flowi6 *fl6, int flags); 95 96 static inline struct dst_entry *ip6_route_output(struct net *net, 97 const struct sock *sk, 98 struct flowi6 *fl6) 99 { 100 return ip6_route_output_flags(net, sk, fl6, 0); 101 } 102 103 /* Only conditionally release dst if flags indicates 104 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list. 105 */ 106 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags) 107 { 108 if (!(flags & RT6_LOOKUP_F_DST_NOREF) || 109 !list_empty(&rt->dst.rt_uncached)) 110 ip6_rt_put(rt); 111 } 112 113 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 114 const struct sk_buff *skb, int flags); 115 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 116 int ifindex, struct flowi6 *fl6, 117 const struct sk_buff *skb, int flags); 118 119 void ip6_route_init_special_entries(void); 120 int ip6_route_init(void); 121 void ip6_route_cleanup(void); 122 123 int ipv6_route_ioctl(struct net *net, unsigned int cmd, 124 struct in6_rtmsg *rtmsg); 125 126 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 127 struct netlink_ext_ack *extack); 128 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 129 int ip6_del_rt_reason(struct net *net, struct fib6_info *f6i, 130 enum rt_del_reason del_reason); 131 #if IS_ENABLED(CONFIG_IPV6) 132 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify); 133 #else 134 static inline int ip6_del_rt(struct net *net, struct fib6_info *f6i, 135 bool skip_notify) 136 { 137 return -EAFNOSUPPORT; 138 } 139 #endif 140 141 void rt6_flush_exceptions(struct fib6_info *f6i); 142 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 143 unsigned long now); 144 145 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 146 const struct in6_addr *daddr, 147 unsigned int prefs, int l3mdev_index, 148 struct in6_addr *saddr) 149 { 150 struct net_device *l3mdev; 151 struct net_device *dev; 152 bool same_vrf; 153 int err = 0; 154 155 rcu_read_lock(); 156 157 l3mdev = dev_get_by_index_rcu(net, l3mdev_index); 158 if (!f6i || !f6i->fib6_prefsrc.plen || l3mdev) 159 dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 160 same_vrf = !l3mdev || l3mdev_master_dev_rcu(dev) == l3mdev; 161 if (f6i && f6i->fib6_prefsrc.plen && same_vrf) 162 *saddr = f6i->fib6_prefsrc.addr; 163 else 164 err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr); 165 166 rcu_read_unlock(); 167 168 return err; 169 } 170 171 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 172 const struct in6_addr *saddr, int oif, 173 const struct sk_buff *skb, int flags); 174 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 175 const struct sk_buff *skb, struct flow_keys *hkeys); 176 177 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 178 179 void fib6_force_start_gc(struct net *net); 180 181 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 182 const struct in6_addr *addr, bool anycast, 183 gfp_t gfp_flags, struct netlink_ext_ack *extack); 184 185 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 186 int flags); 187 188 /* 189 * support functions for ND 190 * 191 */ 192 struct fib6_info *rt6_get_dflt_router(struct net *net, 193 const struct in6_addr *addr, 194 struct net_device *dev); 195 struct fib6_info *rt6_add_dflt_router(struct net *net, 196 const struct in6_addr *gwaddr, 197 struct net_device *dev, unsigned int pref, 198 u32 defrtr_usr_metric, 199 int lifetime); 200 201 void rt6_purge_dflt_routers(struct net *net); 202 203 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 204 const struct in6_addr *gwaddr); 205 206 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 207 u32 mark, kuid_t uid); 208 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 209 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 210 kuid_t uid); 211 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 212 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 213 214 struct netlink_callback; 215 216 struct rt6_rtnl_dump_arg { 217 struct sk_buff *skb; 218 struct netlink_callback *cb; 219 struct net *net; 220 struct fib_dump_filter filter; 221 }; 222 223 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 224 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 225 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 226 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 227 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 228 void rt6_disable_ip(struct net_device *dev, unsigned long event); 229 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 230 void rt6_multipath_rebalance(struct fib6_info *f6i); 231 232 void rt6_uncached_list_add(struct rt6_info *rt); 233 void rt6_uncached_list_del(struct rt6_info *rt); 234 235 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 236 { 237 const struct dst_entry *dst = skb_dst(skb); 238 239 if (dst) 240 return dst_rt6_info(dst); 241 242 return NULL; 243 } 244 245 /* 246 * Store a destination cache entry in a socket 247 */ 248 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 249 bool daddr_set, 250 bool saddr_set) 251 { 252 struct ipv6_pinfo *np = inet6_sk(sk); 253 254 np->dst_cookie = rt6_get_cookie(dst_rt6_info(dst)); 255 sk_setup_caps(sk, dst); 256 np->daddr_cache = daddr_set; 257 #ifdef CONFIG_IPV6_SUBTREES 258 np->saddr_cache = saddr_set; 259 #endif 260 } 261 262 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 263 const struct flowi6 *fl6); 264 265 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 266 { 267 const struct rt6_info *rt = dst_rt6_info(skb_dst(skb)); 268 269 return rt->rt6i_flags & RTF_LOCAL; 270 } 271 272 static inline bool __ipv6_anycast_destination(const struct rt6key *rt6i_dst, 273 u32 rt6i_flags, 274 const struct in6_addr *daddr) 275 { 276 return rt6i_flags & RTF_ANYCAST || 277 (rt6i_dst->plen < 127 && 278 !(rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) && 279 ipv6_addr_equal(&rt6i_dst->addr, daddr)); 280 } 281 282 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 283 const struct in6_addr *daddr) 284 { 285 const struct rt6_info *rt = dst_rt6_info(dst); 286 287 return __ipv6_anycast_destination(&rt->rt6i_dst, rt->rt6i_flags, daddr); 288 } 289 290 #if IS_ENABLED(CONFIG_IPV6) 291 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 292 int (*output)(struct net *, struct sock *, struct sk_buff *)); 293 #else 294 static inline int ip6_fragment(struct net *net, struct sock *sk, 295 struct sk_buff *skb, 296 int (*output)(struct net *, struct sock *, 297 struct sk_buff *)) 298 { 299 kfree_skb(skb); 300 return -EAFNOSUPPORT; 301 } 302 #endif 303 304 /* Variant of dst_mtu() for IPv6 users */ 305 static inline u32 dst6_mtu(const struct dst_entry *dst) 306 { 307 return INDIRECT_CALL_1(dst->ops->mtu, ip6_mtu, dst); 308 } 309 310 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb) 311 { 312 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 313 inet6_sk(skb->sk) : NULL; 314 const struct dst_entry *dst = skb_dst(skb); 315 unsigned int mtu; 316 317 if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) { 318 mtu = READ_ONCE(dst_dev(dst)->mtu); 319 mtu -= lwtunnel_headroom(dst->lwtstate, mtu); 320 } else { 321 mtu = dst_mtu(dst); 322 } 323 return mtu; 324 } 325 326 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 327 { 328 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 329 330 return pmtudisc != IPV6_PMTUDISC_INTERFACE && 331 pmtudisc != IPV6_PMTUDISC_OMIT; 332 } 333 334 static inline bool ip6_sk_ignore_df(const struct sock *sk) 335 { 336 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 337 338 return pmtudisc < IPV6_PMTUDISC_DO || 339 pmtudisc == IPV6_PMTUDISC_OMIT; 340 } 341 342 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 343 const struct in6_addr *daddr) 344 { 345 if (rt->rt6i_flags & RTF_GATEWAY) 346 return &rt->rt6i_gateway; 347 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 348 return &rt->rt6i_dst.addr; 349 else 350 return daddr; 351 } 352 353 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 354 { 355 struct fib6_nh *nha, *nhb; 356 357 if (a->nh || b->nh) 358 return nexthop_cmp(a->nh, b->nh); 359 360 nha = a->fib6_nh; 361 nhb = b->fib6_nh; 362 return nha->fib_nh_dev == nhb->fib_nh_dev && 363 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 364 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 365 } 366 367 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst, 368 bool forwarding) 369 { 370 struct inet6_dev *idev; 371 unsigned int mtu; 372 373 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) { 374 mtu = dst_metric_raw(dst, RTAX_MTU); 375 if (mtu) 376 goto out; 377 } 378 379 mtu = IPV6_MIN_MTU; 380 rcu_read_lock(); 381 idev = __in6_dev_get(dst_dev_rcu(dst)); 382 if (idev) 383 mtu = READ_ONCE(idev->cnf.mtu6); 384 rcu_read_unlock(); 385 386 out: 387 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 388 } 389 390 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 391 const struct in6_addr *daddr, 392 const struct in6_addr *saddr); 393 394 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 395 struct net_device *dev, struct sk_buff *skb, 396 const void *daddr); 397 #endif 398