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 /* No need to bitmask because srcprefs have only 3 bits. */ 57 return srcprefs << 3; 58 } 59 60 static inline unsigned int rt6_flags2srcprefs(int flags) 61 { 62 return (flags >> 3) & 7; 63 } 64 65 static inline bool rt6_need_strict(const struct in6_addr *daddr) 66 { 67 return ipv6_addr_type(daddr) & 68 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); 69 } 70 71 /* fib entries using a nexthop object can not be coalesced into 72 * a multipath route 73 */ 74 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i) 75 { 76 /* the RTF_ADDRCONF flag filters out RA's */ 77 return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh && 78 f6i->fib6_nh->fib_nh_gw_family; 79 } 80 81 void ip6_route_input(struct sk_buff *skb); 82 struct dst_entry *ip6_route_input_lookup(struct net *net, 83 struct net_device *dev, 84 struct flowi6 *fl6, 85 const struct sk_buff *skb, int flags); 86 87 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, 88 struct flowi6 *fl6, int flags); 89 90 static inline struct dst_entry *ip6_route_output(struct net *net, 91 const struct sock *sk, 92 struct flowi6 *fl6) 93 { 94 return ip6_route_output_flags(net, sk, fl6, 0); 95 } 96 97 /* Only conditionally release dst if flags indicates 98 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list. 99 */ 100 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags) 101 { 102 if (!(flags & RT6_LOOKUP_F_DST_NOREF) || 103 !list_empty(&rt->dst.rt_uncached)) 104 ip6_rt_put(rt); 105 } 106 107 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 108 const struct sk_buff *skb, int flags); 109 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 110 int ifindex, struct flowi6 *fl6, 111 const struct sk_buff *skb, int flags); 112 113 void ip6_route_init_special_entries(void); 114 int ip6_route_init(void); 115 void ip6_route_cleanup(void); 116 117 int ipv6_route_ioctl(struct net *net, unsigned int cmd, 118 struct in6_rtmsg *rtmsg); 119 120 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 121 struct netlink_ext_ack *extack); 122 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 123 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify); 124 125 void rt6_flush_exceptions(struct fib6_info *f6i); 126 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 127 unsigned long now); 128 129 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 130 const struct in6_addr *daddr, 131 unsigned int prefs, int l3mdev_index, 132 struct in6_addr *saddr) 133 { 134 struct net_device *l3mdev; 135 struct net_device *dev; 136 bool same_vrf; 137 int err = 0; 138 139 rcu_read_lock(); 140 141 l3mdev = dev_get_by_index_rcu(net, l3mdev_index); 142 if (!f6i || !f6i->fib6_prefsrc.plen || l3mdev) 143 dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 144 same_vrf = !l3mdev || l3mdev_master_dev_rcu(dev) == l3mdev; 145 if (f6i && f6i->fib6_prefsrc.plen && same_vrf) 146 *saddr = f6i->fib6_prefsrc.addr; 147 else 148 err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr); 149 150 rcu_read_unlock(); 151 152 return err; 153 } 154 155 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 156 const struct in6_addr *saddr, int oif, 157 const struct sk_buff *skb, int flags); 158 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 159 const struct sk_buff *skb, struct flow_keys *hkeys); 160 161 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 162 163 void fib6_force_start_gc(struct net *net); 164 165 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 166 const struct in6_addr *addr, bool anycast, 167 gfp_t gfp_flags, struct netlink_ext_ack *extack); 168 169 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 170 int flags); 171 172 /* 173 * support functions for ND 174 * 175 */ 176 struct fib6_info *rt6_get_dflt_router(struct net *net, 177 const struct in6_addr *addr, 178 struct net_device *dev); 179 struct fib6_info *rt6_add_dflt_router(struct net *net, 180 const struct in6_addr *gwaddr, 181 struct net_device *dev, unsigned int pref, 182 u32 defrtr_usr_metric); 183 184 void rt6_purge_dflt_routers(struct net *net); 185 186 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 187 const struct in6_addr *gwaddr); 188 189 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 190 u32 mark, kuid_t uid); 191 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 192 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 193 kuid_t uid); 194 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 195 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 196 197 struct netlink_callback; 198 199 struct rt6_rtnl_dump_arg { 200 struct sk_buff *skb; 201 struct netlink_callback *cb; 202 struct net *net; 203 struct fib_dump_filter filter; 204 }; 205 206 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 207 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 208 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 209 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 210 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 211 void rt6_disable_ip(struct net_device *dev, unsigned long event); 212 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 213 void rt6_multipath_rebalance(struct fib6_info *f6i); 214 215 void rt6_uncached_list_add(struct rt6_info *rt); 216 void rt6_uncached_list_del(struct rt6_info *rt); 217 218 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 219 { 220 const struct dst_entry *dst = skb_dst(skb); 221 const struct rt6_info *rt6 = NULL; 222 223 if (dst) 224 rt6 = container_of(dst, struct rt6_info, dst); 225 226 return rt6; 227 } 228 229 /* 230 * Store a destination cache entry in a socket 231 */ 232 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 233 const struct in6_addr *daddr, 234 const struct in6_addr *saddr) 235 { 236 struct ipv6_pinfo *np = inet6_sk(sk); 237 238 np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst); 239 sk_setup_caps(sk, dst); 240 np->daddr_cache = daddr; 241 #ifdef CONFIG_IPV6_SUBTREES 242 np->saddr_cache = saddr; 243 #endif 244 } 245 246 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 247 const struct flowi6 *fl6); 248 249 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 250 { 251 struct rt6_info *rt = (struct rt6_info *) skb_dst(skb); 252 253 return rt->rt6i_flags & RTF_LOCAL; 254 } 255 256 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 257 const struct in6_addr *daddr) 258 { 259 struct rt6_info *rt = (struct rt6_info *)dst; 260 261 return rt->rt6i_flags & RTF_ANYCAST || 262 (rt->rt6i_dst.plen < 127 && 263 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) && 264 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)); 265 } 266 267 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 268 int (*output)(struct net *, struct sock *, struct sk_buff *)); 269 270 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb) 271 { 272 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 273 inet6_sk(skb->sk) : NULL; 274 const struct dst_entry *dst = skb_dst(skb); 275 unsigned int mtu; 276 277 if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) { 278 mtu = READ_ONCE(dst->dev->mtu); 279 mtu -= lwtunnel_headroom(dst->lwtstate, mtu); 280 } else { 281 mtu = dst_mtu(dst); 282 } 283 return mtu; 284 } 285 286 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 287 { 288 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE && 289 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT; 290 } 291 292 static inline bool ip6_sk_ignore_df(const struct sock *sk) 293 { 294 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO || 295 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT; 296 } 297 298 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 299 const struct in6_addr *daddr) 300 { 301 if (rt->rt6i_flags & RTF_GATEWAY) 302 return &rt->rt6i_gateway; 303 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 304 return &rt->rt6i_dst.addr; 305 else 306 return daddr; 307 } 308 309 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 310 { 311 struct fib6_nh *nha, *nhb; 312 313 if (a->nh || b->nh) 314 return nexthop_cmp(a->nh, b->nh); 315 316 nha = a->fib6_nh; 317 nhb = b->fib6_nh; 318 return nha->fib_nh_dev == nhb->fib_nh_dev && 319 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 320 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 321 } 322 323 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst, 324 bool forwarding) 325 { 326 struct inet6_dev *idev; 327 unsigned int mtu; 328 329 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) { 330 mtu = dst_metric_raw(dst, RTAX_MTU); 331 if (mtu) 332 goto out; 333 } 334 335 mtu = IPV6_MIN_MTU; 336 rcu_read_lock(); 337 idev = __in6_dev_get(dst->dev); 338 if (idev) 339 mtu = idev->cnf.mtu6; 340 rcu_read_unlock(); 341 342 out: 343 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 344 } 345 346 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 347 const struct in6_addr *daddr, 348 const struct in6_addr *saddr); 349 350 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 351 struct net_device *dev, struct sk_buff *skb, 352 const void *daddr); 353 #endif 354