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 void ip6_route_input(struct sk_buff *skb);
  70 struct dst_entry *ip6_route_input_lookup(struct net *net,
  71                                          struct net_device *dev,
  72                                          struct flowi6 *fl6, int flags);
  73
  74 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
  75                                          struct flowi6 *fl6, int flags);
  76
  77 static inline struct dst_entry *ip6_route_output(struct net *net,
  78                                                  const struct sock *sk,
  79                                                  struct flowi6 *fl6)
  80 {
  81         return ip6_route_output_flags(net, sk, fl6, 0);
  82 }
  83
  84 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
  85                                    int flags);
  86 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
  87                                int ifindex, struct flowi6 *fl6, int flags);
  88
  89 void ip6_route_init_special_entries(void);
  90 int ip6_route_init(void);
  91 void ip6_route_cleanup(void);
  92
  93 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
  94
  95 int ip6_route_add(struct fib6_config *cfg, struct netlink_ext_ack *extack);
  96 int ip6_ins_rt(struct rt6_info *);
  97 int ip6_del_rt(struct rt6_info *);
  98
  99 static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
 100                                       const struct in6_addr *daddr,
 101                                       unsigned int prefs,
 102                                       struct in6_addr *saddr)
 103 {
 104         struct inet6_dev *idev =
 105                         rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
 106         int err = 0;
 107
 108         if (rt && rt->rt6i_prefsrc.plen)
 109                 *saddr = rt->rt6i_prefsrc.addr;
 110         else
 111                 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
 112                                          daddr, prefs, saddr);
 113
 114         return err;
 115 }
 116
 117 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 118                             const struct in6_addr *saddr, int oif, int flags);
 119 u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb);
 120
 121 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
 122
 123 void fib6_force_start_gc(struct net *net);
 124
 125 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 126                                     const struct in6_addr *addr, bool anycast);
 127
 128 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 129                                int flags);
 130
 131 /*
 132  *      support functions for ND
 133  *
 134  */
 135 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr,
 136                                      struct net_device *dev);
 137 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
 138                                      struct net_device *dev, unsigned int pref);
 139
 140 void rt6_purge_dflt_routers(struct net *net);
 141
 142 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 143                   const struct in6_addr *gwaddr);
 144
 145 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
 146                      u32 mark, kuid_t uid);
 147 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
 148 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
 149                   kuid_t uid);
 150 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
 151                             u32 mark);
 152 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 153
 154 struct netlink_callback;
 155
 156 struct rt6_rtnl_dump_arg {
 157         struct sk_buff *skb;
 158         struct netlink_callback *cb;
 159         struct net *net;
 160 };
 161
 162 int rt6_dump_route(struct rt6_info *rt, void *p_arg);
 163 void rt6_ifdown(struct net *net, struct net_device *dev);
 164 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
 165 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
 166 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
 167
 168 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
 169 {
 170         const struct dst_entry *dst = skb_dst(skb);
 171         const struct rt6_info *rt6 = NULL;
 172
 173         if (dst)
 174                 rt6 = container_of(dst, struct rt6_info, dst);
 175
 176         return rt6;
 177 }
 178
 179 /*
 180  *      Store a destination cache entry in a socket
 181  */
 182 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
 183                                  const struct in6_addr *daddr,
 184                                  const struct in6_addr *saddr)
 185 {
 186         struct ipv6_pinfo *np = inet6_sk(sk);
 187
 188         np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
 189         sk_setup_caps(sk, dst);
 190         np->daddr_cache = daddr;
 191 #ifdef CONFIG_IPV6_SUBTREES
 192         np->saddr_cache = saddr;
 193 #endif
 194 }
 195
 196 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
 197 {
 198         struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
 199
 200         return rt->rt6i_flags & RTF_LOCAL;
 201 }
 202
 203 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
 204                                             const struct in6_addr *daddr)
 205 {
 206         struct rt6_info *rt = (struct rt6_info *)dst;
 207
 208         return rt->rt6i_flags & RTF_ANYCAST ||
 209                 (rt->rt6i_dst.plen < 127 &&
 210                  ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
 211 }
 212
 213 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 214                  int (*output)(struct net *, struct sock *, struct sk_buff *));
 215
 216 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
 217 {
 218         struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 219                                 inet6_sk(skb->sk) : NULL;
 220
 221         return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
 222                skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
 223 }
 224
 225 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
 226 {
 227         return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
 228                inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
 229 }
 230
 231 static inline bool ip6_sk_ignore_df(const struct sock *sk)
 232 {
 233         return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
 234                inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
 235 }
 236
 237 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
 238                                            struct in6_addr *daddr)
 239 {
 240         if (rt->rt6i_flags & RTF_GATEWAY)
 241                 return &rt->rt6i_gateway;
 242         else if (unlikely(rt->rt6i_flags & RTF_CACHE))
 243                 return &rt->rt6i_dst.addr;
 244         else
 245                 return daddr;
 246 }
 247
 248 static inline bool rt6_duplicate_nexthop(struct rt6_info *a, struct rt6_info *b)
 249 {
 250         return a->dst.dev == b->dst.dev &&
 251                a->rt6i_idev == b->rt6i_idev &&
 252                ipv6_addr_equal(&a->rt6i_gateway, &b->rt6i_gateway) &&
 253                !lwtunnel_cmp_encap(a->dst.lwtstate, b->dst.lwtstate);
 254 }
 255 #endif