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 void ip6_route_input(struct sk_buff *skb); 81 struct dst_entry *ip6_route_input_lookup(struct net *net, 82 struct net_device *dev, 83 struct flowi6 *fl6, 84 const struct sk_buff *skb, int flags); 85 86 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, 87 struct flowi6 *fl6, int flags); 88 89 static inline struct dst_entry *ip6_route_output(struct net *net, 90 const struct sock *sk, 91 struct flowi6 *fl6) 92 { 93 return ip6_route_output_flags(net, sk, fl6, 0); 94 } 95 96 /* Only conditionally release dst if flags indicates 97 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list. 98 */ 99 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags) 100 { 101 if (!(flags & RT6_LOOKUP_F_DST_NOREF) || 102 !list_empty(&rt->dst.rt_uncached)) 103 ip6_rt_put(rt); 104 } 105 106 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 107 const struct sk_buff *skb, int flags); 108 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 109 int ifindex, struct flowi6 *fl6, 110 const struct sk_buff *skb, int flags); 111 112 void ip6_route_init_special_entries(void); 113 int ip6_route_init(void); 114 void ip6_route_cleanup(void); 115 116 int ipv6_route_ioctl(struct net *net, unsigned int cmd, 117 struct in6_rtmsg *rtmsg); 118 119 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 120 struct netlink_ext_ack *extack); 121 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 122 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify); 123 124 void rt6_flush_exceptions(struct fib6_info *f6i); 125 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 126 unsigned long now); 127 128 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 129 const struct in6_addr *daddr, 130 unsigned int prefs, 131 struct in6_addr *saddr) 132 { 133 int err = 0; 134 135 if (f6i && f6i->fib6_prefsrc.plen) { 136 *saddr = f6i->fib6_prefsrc.addr; 137 } else { 138 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 139 140 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); 141 } 142 143 return err; 144 } 145 146 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 147 const struct in6_addr *saddr, int oif, 148 const struct sk_buff *skb, int flags); 149 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 150 const struct sk_buff *skb, struct flow_keys *hkeys); 151 152 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 153 154 void fib6_force_start_gc(struct net *net); 155 156 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 157 const struct in6_addr *addr, bool anycast, 158 gfp_t gfp_flags, struct netlink_ext_ack *extack); 159 160 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 161 int flags); 162 163 /* 164 * support functions for ND 165 * 166 */ 167 struct fib6_info *rt6_get_dflt_router(struct net *net, 168 const struct in6_addr *addr, 169 struct net_device *dev); 170 struct fib6_info *rt6_add_dflt_router(struct net *net, 171 const struct in6_addr *gwaddr, 172 struct net_device *dev, unsigned int pref, 173 u32 defrtr_usr_metric, 174 int lifetime); 175 176 void rt6_purge_dflt_routers(struct net *net); 177 178 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 179 const struct in6_addr *gwaddr); 180 181 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 182 u32 mark, kuid_t uid); 183 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 184 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 185 kuid_t uid); 186 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 187 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 188 189 struct netlink_callback; 190 191 struct rt6_rtnl_dump_arg { 192 struct sk_buff *skb; 193 struct netlink_callback *cb; 194 struct net *net; 195 struct fib_dump_filter filter; 196 }; 197 198 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 199 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 200 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 201 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 202 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 203 void rt6_disable_ip(struct net_device *dev, unsigned long event); 204 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 205 void rt6_multipath_rebalance(struct fib6_info *f6i); 206 207 void rt6_uncached_list_add(struct rt6_info *rt); 208 void rt6_uncached_list_del(struct rt6_info *rt); 209 210 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 211 { 212 const struct dst_entry *dst = skb_dst(skb); 213 214 if (dst) 215 return dst_rt6_info(dst); 216 217 return NULL; 218 } 219 220 /* 221 * Store a destination cache entry in a socket 222 */ 223 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 224 const struct in6_addr *daddr, 225 const struct in6_addr *saddr) 226 { 227 struct ipv6_pinfo *np = inet6_sk(sk); 228 229 np->dst_cookie = rt6_get_cookie(dst_rt6_info(dst)); 230 sk_setup_caps(sk, dst); 231 np->daddr_cache = daddr; 232 #ifdef CONFIG_IPV6_SUBTREES 233 np->saddr_cache = saddr; 234 #endif 235 } 236 237 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 238 const struct flowi6 *fl6); 239 240 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 241 { 242 const struct rt6_info *rt = dst_rt6_info(skb_dst(skb)); 243 244 return rt->rt6i_flags & RTF_LOCAL; 245 } 246 247 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 248 const struct in6_addr *daddr) 249 { 250 const struct rt6_info *rt = dst_rt6_info(dst); 251 252 return rt->rt6i_flags & RTF_ANYCAST || 253 (rt->rt6i_dst.plen < 127 && 254 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) && 255 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)); 256 } 257 258 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 259 int (*output)(struct net *, struct sock *, struct sk_buff *)); 260 261 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb) 262 { 263 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 264 inet6_sk(skb->sk) : NULL; 265 const struct dst_entry *dst = skb_dst(skb); 266 unsigned int mtu; 267 268 if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) { 269 mtu = READ_ONCE(dst->dev->mtu); 270 mtu -= lwtunnel_headroom(dst->lwtstate, mtu); 271 } else { 272 mtu = dst_mtu(dst); 273 } 274 return mtu; 275 } 276 277 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 278 { 279 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 280 281 return pmtudisc != IPV6_PMTUDISC_INTERFACE && 282 pmtudisc != IPV6_PMTUDISC_OMIT; 283 } 284 285 static inline bool ip6_sk_ignore_df(const struct sock *sk) 286 { 287 u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 288 289 return pmtudisc < IPV6_PMTUDISC_DO || 290 pmtudisc == IPV6_PMTUDISC_OMIT; 291 } 292 293 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 294 const struct in6_addr *daddr) 295 { 296 if (rt->rt6i_flags & RTF_GATEWAY) 297 return &rt->rt6i_gateway; 298 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 299 return &rt->rt6i_dst.addr; 300 else 301 return daddr; 302 } 303 304 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 305 { 306 struct fib6_nh *nha, *nhb; 307 308 if (a->nh || b->nh) 309 return nexthop_cmp(a->nh, b->nh); 310 311 nha = a->fib6_nh; 312 nhb = b->fib6_nh; 313 return nha->fib_nh_dev == nhb->fib_nh_dev && 314 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 315 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 316 } 317 318 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst, 319 bool forwarding) 320 { 321 struct inet6_dev *idev; 322 unsigned int mtu; 323 324 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) { 325 mtu = dst_metric_raw(dst, RTAX_MTU); 326 if (mtu) 327 goto out; 328 } 329 330 mtu = IPV6_MIN_MTU; 331 rcu_read_lock(); 332 idev = __in6_dev_get(dst->dev); 333 if (idev) 334 mtu = READ_ONCE(idev->cnf.mtu6); 335 rcu_read_unlock(); 336 337 out: 338 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 339 } 340 341 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 342 const struct in6_addr *daddr, 343 const struct in6_addr *saddr); 344 345 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 346 struct net_device *dev, struct sk_buff *skb, 347 const void *daddr); 348 #endif 349