1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _NET_IP6_ROUTE_H 3 #define _NET_IP6_ROUTE_H 4 5 struct route_info { 6 __u8 type; 7 __u8 length; 8 __u8 prefix_len; 9 #if defined(__BIG_ENDIAN_BITFIELD) 10 __u8 reserved_h:3, 11 route_pref:2, 12 reserved_l:3; 13 #elif defined(__LITTLE_ENDIAN_BITFIELD) 14 __u8 reserved_l:3, 15 route_pref:2, 16 reserved_h:3; 17 #endif 18 __be32 lifetime; 19 __u8 prefix[]; /* 0,8 or 16 */ 20 }; 21 22 #include <net/addrconf.h> 23 #include <net/flow.h> 24 #include <net/ip6_fib.h> 25 #include <net/sock.h> 26 #include <net/lwtunnel.h> 27 #include <linux/ip.h> 28 #include <linux/ipv6.h> 29 #include <linux/route.h> 30 #include <net/nexthop.h> 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_noref(struct net *net, 88 const struct sock *sk, 89 struct flowi6 *fl6, int flags); 90 91 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, 92 struct flowi6 *fl6, int flags); 93 94 static inline struct dst_entry *ip6_route_output(struct net *net, 95 const struct sock *sk, 96 struct flowi6 *fl6) 97 { 98 return ip6_route_output_flags(net, sk, fl6, 0); 99 } 100 101 /* Only conditionally release dst if flags indicates 102 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list. 103 */ 104 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags) 105 { 106 if (!(flags & RT6_LOOKUP_F_DST_NOREF) || 107 !list_empty(&rt->rt6i_uncached)) 108 ip6_rt_put(rt); 109 } 110 111 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 112 const struct sk_buff *skb, int flags); 113 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 114 int ifindex, struct flowi6 *fl6, 115 const struct sk_buff *skb, int flags); 116 117 void ip6_route_init_special_entries(void); 118 int ip6_route_init(void); 119 void ip6_route_cleanup(void); 120 121 int ipv6_route_ioctl(struct net *net, unsigned int cmd, 122 struct in6_rtmsg *rtmsg); 123 124 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 125 struct netlink_ext_ack *extack); 126 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 127 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify); 128 129 void rt6_flush_exceptions(struct fib6_info *f6i); 130 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 131 unsigned long now); 132 133 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 134 const struct in6_addr *daddr, 135 unsigned int prefs, 136 struct in6_addr *saddr) 137 { 138 int err = 0; 139 140 if (f6i && f6i->fib6_prefsrc.plen) { 141 *saddr = f6i->fib6_prefsrc.addr; 142 } else { 143 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 144 145 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); 146 } 147 148 return err; 149 } 150 151 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 152 const struct in6_addr *saddr, int oif, 153 const struct sk_buff *skb, int flags); 154 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 155 const struct sk_buff *skb, struct flow_keys *hkeys); 156 157 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 158 159 void fib6_force_start_gc(struct net *net); 160 161 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 162 const struct in6_addr *addr, bool anycast, 163 gfp_t gfp_flags); 164 165 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 166 int flags); 167 168 /* 169 * support functions for ND 170 * 171 */ 172 struct fib6_info *rt6_get_dflt_router(struct net *net, 173 const struct in6_addr *addr, 174 struct net_device *dev); 175 struct fib6_info *rt6_add_dflt_router(struct net *net, 176 const struct in6_addr *gwaddr, 177 struct net_device *dev, unsigned int pref, 178 u32 defrtr_usr_metric); 179 180 void rt6_purge_dflt_routers(struct net *net); 181 182 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 183 const struct in6_addr *gwaddr); 184 185 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 186 u32 mark, kuid_t uid); 187 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 188 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 189 kuid_t uid); 190 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 191 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 192 193 struct netlink_callback; 194 195 struct rt6_rtnl_dump_arg { 196 struct sk_buff *skb; 197 struct netlink_callback *cb; 198 struct net *net; 199 struct fib_dump_filter filter; 200 }; 201 202 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 203 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 204 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 205 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 206 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 207 void rt6_disable_ip(struct net_device *dev, unsigned long event); 208 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 209 void rt6_multipath_rebalance(struct fib6_info *f6i); 210 211 void rt6_uncached_list_add(struct rt6_info *rt); 212 void rt6_uncached_list_del(struct rt6_info *rt); 213 214 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 215 { 216 const struct dst_entry *dst = skb_dst(skb); 217 const struct rt6_info *rt6 = NULL; 218 219 if (dst) 220 rt6 = container_of(dst, struct rt6_info, dst); 221 222 return rt6; 223 } 224 225 /* 226 * Store a destination cache entry in a socket 227 */ 228 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 229 const struct in6_addr *daddr, 230 const struct in6_addr *saddr) 231 { 232 struct ipv6_pinfo *np = inet6_sk(sk); 233 234 np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst); 235 sk_setup_caps(sk, dst); 236 np->daddr_cache = daddr; 237 #ifdef CONFIG_IPV6_SUBTREES 238 np->saddr_cache = saddr; 239 #endif 240 } 241 242 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 243 const struct flowi6 *fl6); 244 245 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 246 { 247 struct rt6_info *rt = (struct rt6_info *) skb_dst(skb); 248 249 return rt->rt6i_flags & RTF_LOCAL; 250 } 251 252 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 253 const struct in6_addr *daddr) 254 { 255 struct rt6_info *rt = (struct rt6_info *)dst; 256 257 return rt->rt6i_flags & RTF_ANYCAST || 258 (rt->rt6i_dst.plen < 127 && 259 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) && 260 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)); 261 } 262 263 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 264 int (*output)(struct net *, struct sock *, struct sk_buff *)); 265 266 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb) 267 { 268 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 269 inet6_sk(skb->sk) : NULL; 270 const struct dst_entry *dst = skb_dst(skb); 271 unsigned int mtu; 272 273 if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) { 274 mtu = READ_ONCE(dst->dev->mtu); 275 mtu -= lwtunnel_headroom(dst->lwtstate, mtu); 276 } else { 277 mtu = dst_mtu(dst); 278 } 279 return mtu; 280 } 281 282 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 283 { 284 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE && 285 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT; 286 } 287 288 static inline bool ip6_sk_ignore_df(const struct sock *sk) 289 { 290 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO || 291 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT; 292 } 293 294 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 295 const struct in6_addr *daddr) 296 { 297 if (rt->rt6i_flags & RTF_GATEWAY) 298 return &rt->rt6i_gateway; 299 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 300 return &rt->rt6i_dst.addr; 301 else 302 return daddr; 303 } 304 305 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 306 { 307 struct fib6_nh *nha, *nhb; 308 309 if (a->nh || b->nh) 310 return nexthop_cmp(a->nh, b->nh); 311 312 nha = a->fib6_nh; 313 nhb = b->fib6_nh; 314 return nha->fib_nh_dev == nhb->fib_nh_dev && 315 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 316 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 317 } 318 319 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst, 320 bool forwarding) 321 { 322 struct inet6_dev *idev; 323 unsigned int mtu; 324 325 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) { 326 mtu = dst_metric_raw(dst, RTAX_MTU); 327 if (mtu) 328 goto out; 329 } 330 331 mtu = IPV6_MIN_MTU; 332 rcu_read_lock(); 333 idev = __in6_dev_get(dst->dev); 334 if (idev) 335 mtu = idev->cnf.mtu6; 336 rcu_read_unlock(); 337 338 out: 339 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 340 } 341 342 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 343 const struct in6_addr *daddr, 344 const struct in6_addr *saddr); 345 346 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 347 struct net_device *dev, struct sk_buff *skb, 348 const void *daddr); 349 #endif 350