ip6_route.h 10 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _NET_IP6_ROUTE_H
  3. #define _NET_IP6_ROUTE_H
  4. #include <net/addrconf.h>
  5. #include <net/flow.h>
  6. #include <net/ip6_fib.h>
  7. #include <net/sock.h>
  8. #include <net/lwtunnel.h>
  9. #include <linux/ip.h>
  10. #include <linux/ipv6.h>
  11. #include <linux/route.h>
  12. #include <net/nexthop.h>
  13. struct route_info {
  14. __u8 type;
  15. __u8 length;
  16. __u8 prefix_len;
  17. #if defined(__BIG_ENDIAN_BITFIELD)
  18. __u8 reserved_h:3,
  19. route_pref:2,
  20. reserved_l:3;
  21. #elif defined(__LITTLE_ENDIAN_BITFIELD)
  22. __u8 reserved_l:3,
  23. route_pref:2,
  24. reserved_h:3;
  25. #endif
  26. __be32 lifetime;
  27. __u8 prefix[]; /* 0,8 or 16 */
  28. };
  29. #define RT6_LOOKUP_F_IFACE 0x00000001
  30. #define RT6_LOOKUP_F_REACHABLE 0x00000002
  31. #define RT6_LOOKUP_F_HAS_SADDR 0x00000004
  32. #define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008
  33. #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010
  34. #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020
  35. #define RT6_LOOKUP_F_IGNORE_LINKSTATE 0x00000040
  36. #define RT6_LOOKUP_F_DST_NOREF 0x00000080
  37. /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
  38. * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
  39. */
  40. #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
  41. /*
  42. * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
  43. * between IPV6_ADDR_PREFERENCES socket option values
  44. * IPV6_PREFER_SRC_TMP = 0x1
  45. * IPV6_PREFER_SRC_PUBLIC = 0x2
  46. * IPV6_PREFER_SRC_COA = 0x4
  47. * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
  48. */
  49. static inline int rt6_srcprefs2flags(unsigned int srcprefs)
  50. {
  51. /* No need to bitmask because srcprefs have only 3 bits. */
  52. return srcprefs << 3;
  53. }
  54. static inline unsigned int rt6_flags2srcprefs(int flags)
  55. {
  56. return (flags >> 3) & 7;
  57. }
  58. static inline bool rt6_need_strict(const struct in6_addr *daddr)
  59. {
  60. return ipv6_addr_type(daddr) &
  61. (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
  62. }
  63. /* fib entries using a nexthop object can not be coalesced into
  64. * a multipath route
  65. */
  66. static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
  67. {
  68. /* the RTF_ADDRCONF flag filters out RA's */
  69. return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh &&
  70. f6i->fib6_nh->fib_nh_gw_family;
  71. }
  72. void ip6_route_input(struct sk_buff *skb);
  73. struct dst_entry *ip6_route_input_lookup(struct net *net,
  74. struct net_device *dev,
  75. struct flowi6 *fl6,
  76. const struct sk_buff *skb, int flags);
  77. struct dst_entry *ip6_route_output_flags_noref(struct net *net,
  78. const struct sock *sk,
  79. struct flowi6 *fl6, int flags);
  80. struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
  81. struct flowi6 *fl6, int flags);
  82. static inline struct dst_entry *ip6_route_output(struct net *net,
  83. const struct sock *sk,
  84. struct flowi6 *fl6)
  85. {
  86. return ip6_route_output_flags(net, sk, fl6, 0);
  87. }
  88. /* Only conditionally release dst if flags indicates
  89. * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list.
  90. */
  91. static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags)
  92. {
  93. if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||
  94. !list_empty(&rt->rt6i_uncached))
  95. ip6_rt_put(rt);
  96. }
  97. struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
  98. const struct sk_buff *skb, int flags);
  99. struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
  100. int ifindex, struct flowi6 *fl6,
  101. const struct sk_buff *skb, int flags);
  102. void ip6_route_init_special_entries(void);
  103. int ip6_route_init(void);
  104. void ip6_route_cleanup(void);
  105. int ipv6_route_ioctl(struct net *net, unsigned int cmd,
  106. struct in6_rtmsg *rtmsg);
  107. int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
  108. struct netlink_ext_ack *extack);
  109. int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
  110. int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
  111. void rt6_flush_exceptions(struct fib6_info *f6i);
  112. void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
  113. unsigned long now);
  114. static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,
  115. const struct in6_addr *daddr,
  116. unsigned int prefs,
  117. struct in6_addr *saddr)
  118. {
  119. int err = 0;
  120. if (f6i && f6i->fib6_prefsrc.plen) {
  121. *saddr = f6i->fib6_prefsrc.addr;
  122. } else {
  123. struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL;
  124. err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr);
  125. }
  126. return err;
  127. }
  128. struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
  129. const struct in6_addr *saddr, int oif,
  130. const struct sk_buff *skb, int flags);
  131. u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
  132. const struct sk_buff *skb, struct flow_keys *hkeys);
  133. struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
  134. void fib6_force_start_gc(struct net *net);
  135. struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
  136. const struct in6_addr *addr, bool anycast,
  137. gfp_t gfp_flags);
  138. struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
  139. int flags);
  140. /*
  141. * support functions for ND
  142. *
  143. */
  144. struct fib6_info *rt6_get_dflt_router(struct net *net,
  145. const struct in6_addr *addr,
  146. struct net_device *dev);
  147. struct fib6_info *rt6_add_dflt_router(struct net *net,
  148. const struct in6_addr *gwaddr,
  149. struct net_device *dev, unsigned int pref,
  150. u32 defrtr_usr_metric);
  151. void rt6_purge_dflt_routers(struct net *net);
  152. int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
  153. const struct in6_addr *gwaddr);
  154. void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
  155. u32 mark, kuid_t uid);
  156. void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
  157. void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
  158. kuid_t uid);
  159. void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
  160. void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
  161. struct netlink_callback;
  162. struct rt6_rtnl_dump_arg {
  163. struct sk_buff *skb;
  164. struct netlink_callback *cb;
  165. struct net *net;
  166. struct fib_dump_filter filter;
  167. };
  168. int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
  169. void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
  170. void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
  171. void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
  172. void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
  173. void rt6_disable_ip(struct net_device *dev, unsigned long event);
  174. void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
  175. void rt6_multipath_rebalance(struct fib6_info *f6i);
  176. void rt6_uncached_list_add(struct rt6_info *rt);
  177. void rt6_uncached_list_del(struct rt6_info *rt);
  178. static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
  179. {
  180. const struct dst_entry *dst = skb_dst(skb);
  181. const struct rt6_info *rt6 = NULL;
  182. if (dst)
  183. rt6 = container_of(dst, struct rt6_info, dst);
  184. return rt6;
  185. }
  186. /*
  187. * Store a destination cache entry in a socket
  188. */
  189. static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
  190. const struct in6_addr *daddr,
  191. const struct in6_addr *saddr)
  192. {
  193. struct ipv6_pinfo *np = inet6_sk(sk);
  194. np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
  195. sk_setup_caps(sk, dst);
  196. np->daddr_cache = daddr;
  197. #ifdef CONFIG_IPV6_SUBTREES
  198. np->saddr_cache = saddr;
  199. #endif
  200. }
  201. void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
  202. const struct flowi6 *fl6);
  203. static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
  204. {
  205. struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
  206. return rt->rt6i_flags & RTF_LOCAL;
  207. }
  208. static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
  209. const struct in6_addr *daddr)
  210. {
  211. struct rt6_info *rt = (struct rt6_info *)dst;
  212. return rt->rt6i_flags & RTF_ANYCAST ||
  213. (rt->rt6i_dst.plen < 127 &&
  214. !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&
  215. ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
  216. }
  217. int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
  218. int (*output)(struct net *, struct sock *, struct sk_buff *));
  219. static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb)
  220. {
  221. const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
  222. inet6_sk(skb->sk) : NULL;
  223. const struct dst_entry *dst = skb_dst(skb);
  224. unsigned int mtu;
  225. if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) {
  226. mtu = READ_ONCE(dst->dev->mtu);
  227. mtu -= lwtunnel_headroom(dst->lwtstate, mtu);
  228. } else {
  229. mtu = dst_mtu(dst);
  230. }
  231. return mtu;
  232. }
  233. static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
  234. {
  235. return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
  236. inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
  237. }
  238. static inline bool ip6_sk_ignore_df(const struct sock *sk)
  239. {
  240. return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
  241. inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
  242. }
  243. static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,
  244. const struct in6_addr *daddr)
  245. {
  246. if (rt->rt6i_flags & RTF_GATEWAY)
  247. return &rt->rt6i_gateway;
  248. else if (unlikely(rt->rt6i_flags & RTF_CACHE))
  249. return &rt->rt6i_dst.addr;
  250. else
  251. return daddr;
  252. }
  253. static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
  254. {
  255. struct fib6_nh *nha, *nhb;
  256. if (a->nh || b->nh)
  257. return nexthop_cmp(a->nh, b->nh);
  258. nha = a->fib6_nh;
  259. nhb = b->fib6_nh;
  260. return nha->fib_nh_dev == nhb->fib_nh_dev &&
  261. ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&
  262. !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);
  263. }
  264. static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst,
  265. bool forwarding)
  266. {
  267. struct inet6_dev *idev;
  268. unsigned int mtu;
  269. if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) {
  270. mtu = dst_metric_raw(dst, RTAX_MTU);
  271. if (mtu)
  272. goto out;
  273. }
  274. mtu = IPV6_MIN_MTU;
  275. rcu_read_lock();
  276. idev = __in6_dev_get(dst->dev);
  277. if (idev)
  278. mtu = idev->cnf.mtu6;
  279. rcu_read_unlock();
  280. out:
  281. return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
  282. }
  283. u32 ip6_mtu_from_fib6(const struct fib6_result *res,
  284. const struct in6_addr *daddr,
  285. const struct in6_addr *saddr);
  286. struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
  287. struct net_device *dev, struct sk_buff *skb,
  288. const void *daddr);
  289. #endif