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 rt6_info *rt)
  70 {
  71         return (rt->rt6i_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, int flags);
  79
  80 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
  81                                          struct flowi6 *fl6, int flags);
  82
  83 static inline struct dst_entry *ip6_route_output(struct net *net,
  84                                                  const struct sock *sk,
  85                                                  struct flowi6 *fl6)
  86 {
  87         return ip6_route_output_flags(net, sk, fl6, 0);
  88 }
  89
  90 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
  91                                    int flags);
  92 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
  93                                int ifindex, struct flowi6 *fl6, int flags);
  94
  95 void ip6_route_init_special_entries(void);
  96 int ip6_route_init(void);
  97 void ip6_route_cleanup(void);
  98
  99 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
 100
 101 int ip6_route_add(struct fib6_config *cfg, struct netlink_ext_ack *extack);
 102 int ip6_ins_rt(struct rt6_info *);
 103 int ip6_del_rt(struct rt6_info *);
 104
 105 void rt6_flush_exceptions(struct rt6_info *rt);
 106 int rt6_remove_exception_rt(struct rt6_info *rt);
 107 void rt6_age_exceptions(struct rt6_info *rt, struct fib6_gc_args *gc_args,
 108                         unsigned long now);
 109
 110 static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
 111                                       const struct in6_addr *daddr,
 112                                       unsigned int prefs,
 113                                       struct in6_addr *saddr)
 114 {
 115         struct inet6_dev *idev =
 116                         rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
 117         int err = 0;
 118
 119         if (rt && rt->rt6i_prefsrc.plen)
 120                 *saddr = rt->rt6i_prefsrc.addr;
 121         else
 122                 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
 123                                          daddr, prefs, saddr);
 124
 125         return err;
 126 }
 127
 128 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 129                             const struct in6_addr *saddr, int oif, int flags);
 130 u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb);
 131
 132 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
 133
 134 void fib6_force_start_gc(struct net *net);
 135
 136 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 137                                     const struct in6_addr *addr, bool anycast);
 138
 139 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 140                                int flags);
 141
 142 /*
 143  *      support functions for ND
 144  *
 145  */
 146 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr,
 147                                      struct net_device *dev);
 148 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
 149                                      struct net_device *dev, unsigned int pref);
 150
 151 void rt6_purge_dflt_routers(struct net *net);
 152
 153 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 154                   const struct in6_addr *gwaddr);
 155
 156 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
 157                      u32 mark, kuid_t uid);
 158 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
 159 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
 160                   kuid_t uid);
 161 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
 162                             u32 mark);
 163 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
 164
 165 struct netlink_callback;
 166
 167 struct rt6_rtnl_dump_arg {
 168         struct sk_buff *skb;
 169         struct netlink_callback *cb;
 170         struct net *net;
 171 };
 172
 173 int rt6_dump_route(struct rt6_info *rt, void *p_arg);
 174 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
 175 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
 176 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
 177 void rt6_sync_up(struct net_device *dev, unsigned int nh_flags);
 178 void rt6_disable_ip(struct net_device *dev, unsigned long event);
 179 void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
 180 void rt6_multipath_rebalance(struct rt6_info *rt);
 181
 182 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
 183 {
 184         const struct dst_entry *dst = skb_dst(skb);
 185         const struct rt6_info *rt6 = NULL;
 186
 187         if (dst)
 188                 rt6 = container_of(dst, struct rt6_info, dst);
 189
 190         return rt6;
 191 }
 192
 193 /*
 194  *      Store a destination cache entry in a socket
 195  */
 196 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
 197                                  const struct in6_addr *daddr,
 198                                  const struct in6_addr *saddr)
 199 {
 200         struct ipv6_pinfo *np = inet6_sk(sk);
 201
 202         np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
 203         sk_setup_caps(sk, dst);
 204         np->daddr_cache = daddr;
 205 #ifdef CONFIG_IPV6_SUBTREES
 206         np->saddr_cache = saddr;
 207 #endif
 208 }
 209
 210 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
 211 {
 212         struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
 213
 214         return rt->rt6i_flags & RTF_LOCAL;
 215 }
 216
 217 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
 218                                             const struct in6_addr *daddr)
 219 {
 220         struct rt6_info *rt = (struct rt6_info *)dst;
 221
 222         return rt->rt6i_flags & RTF_ANYCAST ||
 223                 (rt->rt6i_dst.plen < 127 &&
 224                  ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
 225 }
 226
 227 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 228                  int (*output)(struct net *, struct sock *, struct sk_buff *));
 229
 230 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
 231 {
 232         struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 233                                 inet6_sk(skb->sk) : NULL;
 234
 235         return (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) ?
 236                skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
 237 }
 238
 239 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
 240 {
 241         return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
 242                inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
 243 }
 244
 245 static inline bool ip6_sk_ignore_df(const struct sock *sk)
 246 {
 247         return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
 248                inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
 249 }
 250
 251 static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
 252                                            struct in6_addr *daddr)
 253 {
 254         if (rt->rt6i_flags & RTF_GATEWAY)
 255                 return &rt->rt6i_gateway;
 256         else if (unlikely(rt->rt6i_flags & RTF_CACHE))
 257                 return &rt->rt6i_dst.addr;
 258         else
 259                 return daddr;
 260 }
 261
 262 static inline bool rt6_duplicate_nexthop(struct rt6_info *a, struct rt6_info *b)
 263 {
 264         return a->dst.dev == b->dst.dev &&
 265                a->rt6i_idev == b->rt6i_idev &&
 266                ipv6_addr_equal(&a->rt6i_gateway, &b->rt6i_gateway) &&
 267                !lwtunnel_cmp_encap(a->dst.lwtstate, b->dst.lwtstate);
 268 }
 269 #endif