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]; /* 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 40 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675) 41 * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header 42 */ 43 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) 44 45 /* 46 * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate 47 * between IPV6_ADDR_PREFERENCES socket option values 48 * IPV6_PREFER_SRC_TMP = 0x1 49 * IPV6_PREFER_SRC_PUBLIC = 0x2 50 * IPV6_PREFER_SRC_COA = 0x4 51 * and above RT6_LOOKUP_F_SRCPREF_xxx flags. 52 */ 53 static inline int rt6_srcprefs2flags(unsigned int srcprefs) 54 { 55 /* No need to bitmask because srcprefs have only 3 bits. */ 56 return srcprefs << 3; 57 } 58 59 static inline unsigned int rt6_flags2srcprefs(int flags) 60 { 61 return (flags >> 3) & 7; 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 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 97 const struct sk_buff *skb, int flags); 98 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 99 int ifindex, struct flowi6 *fl6, 100 const struct sk_buff *skb, int flags); 101 102 void ip6_route_init_special_entries(void); 103 int ip6_route_init(void); 104 void ip6_route_cleanup(void); 105 106 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg); 107 108 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 109 struct netlink_ext_ack *extack); 110 int ip6_ins_rt(struct net *net, struct fib6_info *f6i); 111 int ip6_del_rt(struct net *net, struct fib6_info *f6i); 112 113 void rt6_flush_exceptions(struct fib6_info *f6i); 114 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args, 115 unsigned long now); 116 117 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i, 118 const struct in6_addr *daddr, 119 unsigned int prefs, 120 struct in6_addr *saddr) 121 { 122 int err = 0; 123 124 if (f6i && f6i->fib6_prefsrc.plen) { 125 *saddr = f6i->fib6_prefsrc.addr; 126 } else { 127 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL; 128 129 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr); 130 } 131 132 return err; 133 } 134 135 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 136 const struct in6_addr *saddr, int oif, 137 const struct sk_buff *skb, int flags); 138 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 139 const struct sk_buff *skb, struct flow_keys *hkeys); 140 141 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); 142 143 void fib6_force_start_gc(struct net *net); 144 145 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev, 146 const struct in6_addr *addr, bool anycast, 147 gfp_t gfp_flags); 148 149 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 150 int flags); 151 152 /* 153 * support functions for ND 154 * 155 */ 156 struct fib6_info *rt6_get_dflt_router(struct net *net, 157 const struct in6_addr *addr, 158 struct net_device *dev); 159 struct fib6_info *rt6_add_dflt_router(struct net *net, 160 const struct in6_addr *gwaddr, 161 struct net_device *dev, unsigned int pref); 162 163 void rt6_purge_dflt_routers(struct net *net); 164 165 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 166 const struct in6_addr *gwaddr); 167 168 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 169 u32 mark, kuid_t uid); 170 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 171 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 172 kuid_t uid); 173 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 174 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 175 176 struct netlink_callback; 177 178 struct rt6_rtnl_dump_arg { 179 struct sk_buff *skb; 180 struct netlink_callback *cb; 181 struct net *net; 182 struct fib_dump_filter filter; 183 }; 184 185 int rt6_dump_route(struct fib6_info *f6i, void *p_arg); 186 void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 187 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 188 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 189 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 190 void rt6_disable_ip(struct net_device *dev, unsigned long event); 191 void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 192 void rt6_multipath_rebalance(struct fib6_info *f6i); 193 194 void rt6_uncached_list_add(struct rt6_info *rt); 195 void rt6_uncached_list_del(struct rt6_info *rt); 196 197 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) 198 { 199 const struct dst_entry *dst = skb_dst(skb); 200 const struct rt6_info *rt6 = NULL; 201 202 if (dst) 203 rt6 = container_of(dst, struct rt6_info, dst); 204 205 return rt6; 206 } 207 208 /* 209 * Store a destination cache entry in a socket 210 */ 211 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst, 212 const struct in6_addr *daddr, 213 const struct in6_addr *saddr) 214 { 215 struct ipv6_pinfo *np = inet6_sk(sk); 216 217 np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst); 218 sk_setup_caps(sk, dst); 219 np->daddr_cache = daddr; 220 #ifdef CONFIG_IPV6_SUBTREES 221 np->saddr_cache = saddr; 222 #endif 223 } 224 225 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 226 const struct flowi6 *fl6); 227 228 static inline bool ipv6_unicast_destination(const struct sk_buff *skb) 229 { 230 struct rt6_info *rt = (struct rt6_info *) skb_dst(skb); 231 232 return rt->rt6i_flags & RTF_LOCAL; 233 } 234 235 static inline bool ipv6_anycast_destination(const struct dst_entry *dst, 236 const struct in6_addr *daddr) 237 { 238 struct rt6_info *rt = (struct rt6_info *)dst; 239 240 return rt->rt6i_flags & RTF_ANYCAST || 241 (rt->rt6i_dst.plen < 127 && 242 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)); 243 } 244 245 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 246 int (*output)(struct net *, struct sock *, struct sk_buff *)); 247 248 static inline int ip6_skb_dst_mtu(struct sk_buff *skb) 249 { 250 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 251 inet6_sk(skb->sk) : NULL; 252 253 return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ? 254 skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); 255 } 256 257 static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 258 { 259 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE && 260 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT; 261 } 262 263 static inline bool ip6_sk_ignore_df(const struct sock *sk) 264 { 265 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO || 266 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT; 267 } 268 269 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt, 270 struct in6_addr *daddr) 271 { 272 if (rt->rt6i_flags & RTF_GATEWAY) 273 return &rt->rt6i_gateway; 274 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 275 return &rt->rt6i_dst.addr; 276 else 277 return daddr; 278 } 279 280 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 281 { 282 struct fib6_nh *nha, *nhb; 283 284 if (a->nh || b->nh) 285 return nexthop_cmp(a->nh, b->nh); 286 287 nha = a->fib6_nh; 288 nhb = b->fib6_nh; 289 return nha->fib_nh_dev == nhb->fib_nh_dev && 290 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 291 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 292 } 293 294 static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) 295 { 296 struct inet6_dev *idev; 297 unsigned int mtu; 298 299 if (dst_metric_locked(dst, RTAX_MTU)) { 300 mtu = dst_metric_raw(dst, RTAX_MTU); 301 if (mtu) 302 return mtu; 303 } 304 305 mtu = IPV6_MIN_MTU; 306 rcu_read_lock(); 307 idev = __in6_dev_get(dst->dev); 308 if (idev) 309 mtu = idev->cnf.mtu6; 310 rcu_read_unlock(); 311 312 return mtu; 313 } 314 315 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 316 const struct in6_addr *daddr, 317 const struct in6_addr *saddr); 318 319 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 320 struct net_device *dev, struct sk_buff *skb, 321 const void *daddr); 322 #endif 323