include/net/ip6_route.h

   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
  31 #define RT6_LOOKUP_F_IFACE              0x00000001
  32 #define RT6_LOOKUP_F_REACHABLE          0x00000002
  33 #define RT6_LOOKUP_F_HAS_SADDR          0x00000004
  34 #define RT6_LOOKUP_F_SRCPREF_TMP        0x00000008
  35 #define RT6_LOOKUP_F_SRCPREF_PUBLIC     0x00000010
  36 #define RT6_LOOKUP_F_SRCPREF_COA        0x00000020
  37 #define RT6_LOOKUP_F_IGNORE_LINKSTATE   0x00000040
  38
  39 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
  40  * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
  41  */
  42 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
  43
  44 /*
  45  * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
  46  * between IPV6_ADDR_PREFERENCES socket option values
  47  *      IPV6_PREFER_SRC_TMP    = 0x1
  48  *      IPV6_PREFER_SRC_PUBLIC = 0x2
  49  *      IPV6_PREFER_SRC_COA    = 0x4
  50  * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
  51  */
  52 static inline int rt6_srcprefs2flags(unsigned int srcprefs)
  53 {
  54         /* No need to bitmask because srcprefs have only 3 bits. */
  55         return srcprefs << 3;
  56 }
  57
  58 static inline unsigned int rt6_flags2srcprefs(int flags)
  59 {
  60         return (flags >> 3) & 7;
  61 }
  62
  63 static inline bool rt6_need_strict(const struct in6_addr *daddr)
  64 {
  65         return ipv6_addr_type(daddr) &
  66                 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
  67 }
  68
  69 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
  70 {
  71         return (f6i->fib6_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
  72                RTF_GATEWAY;
  73 }
  74
  75 void ip6_route_input(struct sk_buff *skb);
  76 struct dst_entry *ip6_route_input_lookup(struct net *net,
  77                                          struct net_device *dev,
  78                                          struct flowi6 *fl6,
  79                                          const struct sk_buff *skb, int flags);
  80
  81 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
  82                                          struct flowi6 *fl6, int flags);
  83
  84 static inline struct dst_entry *ip6_route_output(struct net *net,
  85                                                  const struct sock *sk,
  86                                                  struct flowi6 *fl6)
  87 {
  88         return ip6_route_output_flags(net, sk, fl6, 0);
  89 }
  90
  91 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
  92                                    const struct sk_buff *skb, int flags);
  93 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
  94                                int ifindex, struct flowi6 *fl6,
  95                                const struct sk_buff *skb, int flags);
  96
  97 void ip6_route_init_special_entries(void);
  98 int ip6_route_init(void);
  99 void ip6_route_cleanup(void);
 100
 101 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
 102
 103 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
 104                   struct netlink_ext_ack *extack);
 105 int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
 106 int ip6_del_rt(struct net *net, struct fib6_info *f6i);
 107
 108 void rt6_flush_exceptions(struct fib6_info *f6i);
 109 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
 110                         unsigned long now);
 111
 112 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,
 113                                       const struct in6_addr *daddr,
 114                                       unsigned int prefs,
 115                                       struct in6_addr *saddr)
 116 {
 117         int err = 0;
 118
 119         if (f6i && f6i->fib6_prefsrc.plen) {
 120                 *saddr = f6i->fib6_prefsrc.addr;
 121         } else {
 122                 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL;
 123
 124                 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr);
 125         }
 126
 127         return err;
 128 }
 129
 130 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 131                             const struct in6_addr *saddr, int oif,
 132                             const struct sk_buff *skb, int flags);
 133 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
 134                        const struct sk_buff *skb, struct flow_keys *hkeys);
 135
 136 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
 137
 138 void fib6_force_start_gc(struct net *net);
 139
 140 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
 141                                      const struct in6_addr *addr, bool anycast,
 142                                      gfp_t gfp_flags);
 143
 144 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 145                                int flags);
 146
 147 /*
 148  *      support functions for ND
 149  *
 150  */
 151 struct fib6_info *rt6_get_dflt_router(struct net *net,
 152                                      const struct in6_addr *addr,
 153                                      struct net_device *dev);
 154 struct fib6_info *rt6_add_dflt_router(struct net *net,
 155                                      const struct in6_addr *gwaddr,
 156                                      struct net_device *dev, unsigned int pref);
 157
 158 void rt6_purge_dflt_routers(struct net *net);
 159
 160 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 161                   const struct in6_addr *gwaddr);
 162
 163 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
 164                      u32 mark, kuid_t uid);
 165 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
 166 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
 167                   kuid_t uid);
 168 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
 169 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 170
 171 struct netlink_callback;
 172
 173 struct rt6_rtnl_dump_arg {
 174         struct sk_buff *skb;
 175         struct netlink_callback *cb;
 176         struct net *net;
 177         struct fib_dump_filter filter;
 178 };
 179
 180 int rt6_dump_route(struct fib6_info *f6i, void *p_arg);
 181 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
 182 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
 183 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
 184 void rt6_sync_up(struct net_device *dev, unsigned int nh_flags);
 185 void rt6_disable_ip(struct net_device *dev, unsigned long event);
 186 void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
 187 void rt6_multipath_rebalance(struct fib6_info *f6i);
 188
 189 void rt6_uncached_list_add(struct rt6_info *rt);
 190 void rt6_uncached_list_del(struct rt6_info *rt);
 191
 192 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
 193 {
 194         const struct dst_entry *dst = skb_dst(skb);
 195         const struct rt6_info *rt6 = NULL;
 196
 197         if (dst)
 198                 rt6 = container_of(dst, struct rt6_info, dst);
 199
 200         return rt6;
 201 }
 202
 203 /*
 204  *      Store a destination cache entry in a socket
 205  */
 206 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
 207                                  const struct in6_addr *daddr,
 208                                  const struct in6_addr *saddr)
 209 {
 210         struct ipv6_pinfo *np = inet6_sk(sk);
 211
 212         np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
 213         sk_setup_caps(sk, dst);
 214         np->daddr_cache = daddr;
 215 #ifdef CONFIG_IPV6_SUBTREES
 216         np->saddr_cache = saddr;
 217 #endif
 218 }
 219
 220 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
 221                            const struct flowi6 *fl6);
 222
 223 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
 224 {
 225         struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
 226
 227         return rt->rt6i_flags & RTF_LOCAL;
 228 }
 229
 230 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
 231                                             const struct in6_addr *daddr)
 232 {
 233         struct rt6_info *rt = (struct rt6_info *)dst;
 234
 235         return rt->rt6i_flags & RTF_ANYCAST ||
 236                 (rt->rt6i_dst.plen < 127 &&
 237                  ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
 238 }
 239
 240 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 241                  int (*output)(struct net *, struct sock *, struct sk_buff *));
 242
 243 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
 244 {
 245         struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 246                                 inet6_sk(skb->sk) : NULL;
 247
 248         return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
 249                skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
 250 }
 251
 252 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
 253 {
 254         return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
 255                inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
 256 }
 257
 258 static inline bool ip6_sk_ignore_df(const struct sock *sk)
 259 {
 260         return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
 261                inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
 262 }
 263
 264 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
 265                                            struct in6_addr *daddr)
 266 {
 267         if (rt->rt6i_flags & RTF_GATEWAY)
 268                 return &rt->rt6i_gateway;
 269         else if (unlikely(rt->rt6i_flags & RTF_CACHE))
 270                 return &rt->rt6i_dst.addr;
 271         else
 272                 return daddr;
 273 }
 274
 275 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
 276 {
 277         return a->fib6_nh.nh_dev == b->fib6_nh.nh_dev &&
 278                ipv6_addr_equal(&a->fib6_nh.nh_gw, &b->fib6_nh.nh_gw) &&
 279                !lwtunnel_cmp_encap(a->fib6_nh.nh_lwtstate, b->fib6_nh.nh_lwtstate);
 280 }
 281
 282 static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
 283 {
 284         struct inet6_dev *idev;
 285         unsigned int mtu;
 286
 287         if (dst_metric_locked(dst, RTAX_MTU)) {
 288                 mtu = dst_metric_raw(dst, RTAX_MTU);
 289                 if (mtu)
 290                         return mtu;
 291         }
 292
 293         mtu = IPV6_MIN_MTU;
 294         rcu_read_lock();
 295         idev = __in6_dev_get(dst->dev);
 296         if (idev)
 297                 mtu = idev->cnf.mtu6;
 298         rcu_read_unlock();
 299
 300         return mtu;
 301 }
 302
 303 u32 ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
 304                       struct in6_addr *saddr);
 305
 306 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 307                                    struct net_device *dev, struct sk_buff *skb,
 308                                    const void *daddr);
 309 #endif