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, void __user *arg); 122 123 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 124 struct netlink_ext_ack *extack); 125 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 126 int ip6_del_rt(struct net *net, struct fib6_info *f6i); 127 128 void rt6_flush_exceptions(struct fib6_info *f6i); 129 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 130 unsigned long now); 131 132 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 133 const struct in6_addr *daddr, 134 unsigned int prefs, 135 struct in6_addr *saddr) 136 { 137 int err = 0; 138 139 if (f6i && f6i->fib6_prefsrc.plen) { 140 *saddr = f6i->fib6_prefsrc.addr; 141 } else { 142 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 143 144 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); 145 } 146 147 return err; 148 } 149 150 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 151 const struct in6_addr *saddr, int oif, 152 const struct sk_buff *skb, int flags); 153 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 154 const struct sk_buff *skb, struct flow_keys *hkeys); 155 156 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 157 158 void fib6_force_start_gc(struct net *net); 159 160 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 161 const struct in6_addr *addr, bool anycast, 162 gfp_t gfp_flags); 163 164 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 165 int flags); 166 167 /* 168 * support functions for ND 169 * 170 */ 171 struct fib6_info *rt6_get_dflt_router(struct net *net, 172 const struct in6_addr *addr, 173 struct net_device *dev); 174 struct fib6_info *rt6_add_dflt_router(struct net *net, 175 const struct in6_addr *gwaddr, 176 struct net_device *dev, unsigned int pref); 177 178 void rt6_purge_dflt_routers(struct net *net); 179 180 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 181 const struct in6_addr *gwaddr); 182 183 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 184 u32 mark, kuid_t uid); 185 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 186 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 187 kuid_t uid); 188 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 189 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 190 191 struct netlink_callback; 192 193 struct rt6_rtnl_dump_arg { 194 struct sk_buff *skb; 195 struct netlink_callback *cb; 196 struct net *net; 197 struct fib_dump_filter filter; 198 }; 199 200 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 201 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 202 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 203 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 204 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 205 void rt6_disable_ip(struct net_device *dev, unsigned long event); 206 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 207 void rt6_multipath_rebalance(struct fib6_info *f6i); 208 209 void rt6_uncached_list_add(struct rt6_info *rt); 210 void rt6_uncached_list_del(struct rt6_info *rt); 211 212 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 213 { 214 const struct dst_entry *dst = skb_dst(skb); 215 const struct rt6_info *rt6 = NULL; 216 217 if (dst) 218 rt6 = container_of(dst, struct rt6_info, dst); 219 220 return rt6; 221 } 222 223 /* 224 * Store a destination cache entry in a socket 225 */ 226 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 227 const struct in6_addr *daddr, 228 const struct in6_addr *saddr) 229 { 230 struct ipv6_pinfo *np = inet6_sk(sk); 231 232 np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst); 233 sk_setup_caps(sk, dst); 234 np->daddr_cache = daddr; 235 #ifdef CONFIG_IPV6_SUBTREES 236 np->saddr_cache = saddr; 237 #endif 238 } 239 240 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 241 const struct flowi6 *fl6); 242 243 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 244 { 245 struct rt6_info *rt = (struct rt6_info *) skb_dst(skb); 246 247 return rt->rt6i_flags & RTF_LOCAL; 248 } 249 250 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 251 const struct in6_addr *daddr) 252 { 253 struct rt6_info *rt = (struct rt6_info *)dst; 254 255 return rt->rt6i_flags & RTF_ANYCAST || 256 (rt->rt6i_dst.plen < 127 && 257 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) && 258 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)); 259 } 260 261 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 262 int (*output)(struct net *, struct sock *, struct sk_buff *)); 263 264 static inline int ip6_skb_dst_mtu(struct sk_buff *skb) 265 { 266 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 267 inet6_sk(skb->sk) : NULL; 268 269 return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ? 270 skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); 271 } 272 273 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 274 { 275 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE && 276 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT; 277 } 278 279 static inline bool ip6_sk_ignore_df(const struct sock *sk) 280 { 281 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO || 282 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT; 283 } 284 285 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 286 const struct in6_addr *daddr) 287 { 288 if (rt->rt6i_flags & RTF_GATEWAY) 289 return &rt->rt6i_gateway; 290 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 291 return &rt->rt6i_dst.addr; 292 else 293 return daddr; 294 } 295 296 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 297 { 298 struct fib6_nh *nha, *nhb; 299 300 if (a->nh || b->nh) 301 return nexthop_cmp(a->nh, b->nh); 302 303 nha = a->fib6_nh; 304 nhb = b->fib6_nh; 305 return nha->fib_nh_dev == nhb->fib_nh_dev && 306 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 307 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 308 } 309 310 static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) 311 { 312 struct inet6_dev *idev; 313 unsigned int mtu; 314 315 if (dst_metric_locked(dst, RTAX_MTU)) { 316 mtu = dst_metric_raw(dst, RTAX_MTU); 317 if (mtu) 318 return mtu; 319 } 320 321 mtu = IPV6_MIN_MTU; 322 rcu_read_lock(); 323 idev = __in6_dev_get(dst->dev); 324 if (idev) 325 mtu = idev->cnf.mtu6; 326 rcu_read_unlock(); 327 328 return mtu; 329 } 330 331 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 332 const struct in6_addr *daddr, 333 const struct in6_addr *saddr); 334 335 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 336 struct net_device *dev, struct sk_buff *skb, 337 const void *daddr); 338 #endif 339