LXR linux/include/net/ip6

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _NET_IP6_ROUTE_H
   3#define _NET_IP6_ROUTE_H
   4
   5struct 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 */
  54static 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
  60static inline unsigned int rt6_flags2srcprefs(int flags)
  61{
  62        return (flags >> 3) & 7;
  63}
  64
  65static 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 */
  74static 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
  81void ip6_route_input(struct sk_buff *skb);
  82struct 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
  87struct dst_entry *ip6_route_output_flags_noref(struct net *net,
  88                                               const struct sock *sk,
  89                                               struct flowi6 *fl6, int flags);
  90
  91struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
  92                                         struct flowi6 *fl6, int flags);
  93
  94static 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 */
 104static 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
 111struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
 112                                   const struct sk_buff *skb, int flags);
 113struct 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
 117void ip6_route_init_special_entries(void);
 118int ip6_route_init(void);
 119void ip6_route_cleanup(void);
 120
 121int ipv6_route_ioctl(struct net *net, unsigned int cmd,
 122                struct in6_rtmsg *rtmsg);
 123
 124int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
 125                  struct netlink_ext_ack *extack);
 126int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
 127int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
 128
 129void rt6_flush_exceptions(struct fib6_info *f6i);
 130void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
 131                        unsigned long now);
 132
 133static 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
 151struct 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);
 154u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
 155                       const struct sk_buff *skb, struct flow_keys *hkeys);
 156
 157struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
 158
 159void fib6_force_start_gc(struct net *net);
 160
 161struct 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
 165struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 166                               int flags);
 167
 168/*
 169 *      support functions for ND
 170 *
 171 */
 172struct fib6_info *rt6_get_dflt_router(struct net *net,
 173                                     const struct in6_addr *addr,
 174                                     struct net_device *dev);
 175struct 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
 180void rt6_purge_dflt_routers(struct net *net);
 181
 182int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 183                  const struct in6_addr *gwaddr);
 184
 185void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
 186                     u32 mark, kuid_t uid);
 187void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
 188void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
 189                  kuid_t uid);
 190void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
 191void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 192
 193struct netlink_callback;
 194
 195struct 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
 202int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
 203void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
 204void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
 205void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
 206void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
 207void rt6_disable_ip(struct net_device *dev, unsigned long event);
 208void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
 209void rt6_multipath_rebalance(struct fib6_info *f6i);
 210
 211void rt6_uncached_list_add(struct rt6_info *rt);
 212void rt6_uncached_list_del(struct rt6_info *rt);
 213
 214static 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 */
 228static 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
 242void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
 243                           const struct flowi6 *fl6);
 244
 245static 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
 252static 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
 263int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 264                 int (*output)(struct net *, struct sock *, struct sk_buff *));
 265
 266static inline unsigned int ip6_skb_dst_mtu(struct sk_buff *skb)
 267{
 268        unsigned int mtu;
 269
 270        struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 271                                inet6_sk(skb->sk) : NULL;
 272
 273        if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) {
 274                mtu = READ_ONCE(skb_dst(skb)->dev->mtu);
 275                mtu -= lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
 276        } else
 277                mtu = dst_mtu(skb_dst(skb));
 278
 279        return mtu;
 280}
 281
 282static 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
 288static 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
 294static 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
 305static 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
 319static 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
 338out:
 339        return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
 340}
 341
 342u32 ip6_mtu_from_fib6(const struct fib6_result *res,
 343                      const struct in6_addr *daddr,
 344                      const struct in6_addr *saddr);
 345
 346struct 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