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[];       /* 0,8 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
 179 void rt6_purge_dflt_routers(struct net *net);
 180
 181 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 182                   const struct in6_addr *gwaddr);
 183
 184 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
 185                      u32 mark, kuid_t uid);
 186 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
 187 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
 188                   kuid_t uid);
 189 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
 190 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 191
 192 struct netlink_callback;
 193
 194 struct rt6_rtnl_dump_arg {
 195         struct sk_buff *skb;
 196         struct netlink_callback *cb;
 197         struct net *net;
 198         struct fib_dump_filter filter;
 199 };
 200
 201 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
 202 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
 203 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
 204 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
 205 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
 206 void rt6_disable_ip(struct net_device *dev, unsigned long event);
 207 void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
 208 void rt6_multipath_rebalance(struct fib6_info *f6i);
 209
 210 void rt6_uncached_list_add(struct rt6_info *rt);
 211 void rt6_uncached_list_del(struct rt6_info *rt);
 212
 213 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
 214 {
 215         const struct dst_entry *dst = skb_dst(skb);
 216         const struct rt6_info *rt6 = NULL;
 217
 218         if (dst)
 219                 rt6 = container_of(dst, struct rt6_info, dst);
 220
 221         return rt6;
 222 }
 223
 224 /*
 225  *      Store a destination cache entry in a socket
 226  */
 227 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
 228                                  const struct in6_addr *daddr,
 229                                  const struct in6_addr *saddr)
 230 {
 231         struct ipv6_pinfo *np = inet6_sk(sk);
 232
 233         np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
 234         sk_setup_caps(sk, dst);
 235         np->daddr_cache = daddr;
 236 #ifdef CONFIG_IPV6_SUBTREES
 237         np->saddr_cache = saddr;
 238 #endif
 239 }
 240
 241 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
 242                            const struct flowi6 *fl6);
 243
 244 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
 245 {
 246         struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
 247
 248         return rt->rt6i_flags & RTF_LOCAL;
 249 }
 250
 251 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
 252                                             const struct in6_addr *daddr)
 253 {
 254         struct rt6_info *rt = (struct rt6_info *)dst;
 255
 256         return rt->rt6i_flags & RTF_ANYCAST ||
 257                 (rt->rt6i_dst.plen < 127 &&
 258                  !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&
 259                  ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
 260 }
 261
 262 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 263                  int (*output)(struct net *, struct sock *, struct sk_buff *));
 264
 265 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
 266 {
 267         struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 268                                 inet6_sk(skb->sk) : NULL;
 269
 270         return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
 271                skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
 272 }
 273
 274 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
 275 {
 276         return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
 277                inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
 278 }
 279
 280 static inline bool ip6_sk_ignore_df(const struct sock *sk)
 281 {
 282         return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
 283                inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
 284 }
 285
 286 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,
 287                                                  const struct in6_addr *daddr)
 288 {
 289         if (rt->rt6i_flags & RTF_GATEWAY)
 290                 return &rt->rt6i_gateway;
 291         else if (unlikely(rt->rt6i_flags & RTF_CACHE))
 292                 return &rt->rt6i_dst.addr;
 293         else
 294                 return daddr;
 295 }
 296
 297 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
 298 {
 299         struct fib6_nh *nha, *nhb;
 300
 301         if (a->nh || b->nh)
 302                 return nexthop_cmp(a->nh, b->nh);
 303
 304         nha = a->fib6_nh;
 305         nhb = b->fib6_nh;
 306         return nha->fib_nh_dev == nhb->fib_nh_dev &&
 307                ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&
 308                !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);
 309 }
 310
 311 static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
 312 {
 313         struct inet6_dev *idev;
 314         unsigned int mtu;
 315
 316         if (dst_metric_locked(dst, RTAX_MTU)) {
 317                 mtu = dst_metric_raw(dst, RTAX_MTU);
 318                 if (mtu)
 319                         return mtu;
 320         }
 321
 322         mtu = IPV6_MIN_MTU;
 323         rcu_read_lock();
 324         idev = __in6_dev_get(dst->dev);
 325         if (idev)
 326                 mtu = idev->cnf.mtu6;
 327         rcu_read_unlock();
 328
 329         return mtu;
 330 }
 331
 332 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
 333                       const struct in6_addr *daddr,
 334                       const struct in6_addr *saddr);
 335
 336 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 337                                    struct net_device *dev, struct sk_buff *skb,
 338                                    const void *daddr);
 339 #endif