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 179void rt6_purge_dflt_routers(struct net *net); 180 181int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 182 const struct in6_addr *gwaddr); 183 184void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, 185 u32 mark, kuid_t uid); 186void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu); 187void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 188 kuid_t uid); 189void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif); 190void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); 191 192struct netlink_callback; 193 194struct 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 201int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip); 202void rt6_mtu_change(struct net_device *dev, unsigned int mtu); 203void rt6_remove_prefsrc(struct inet6_ifaddr *ifp); 204void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); 205void rt6_sync_up(struct net_device *dev, unsigned char nh_flags); 206void rt6_disable_ip(struct net_device *dev, unsigned long event); 207void rt6_sync_down_dev(struct net_device *dev, unsigned long event); 208void rt6_multipath_rebalance(struct fib6_info *f6i); 209 210void rt6_uncached_list_add(struct rt6_info *rt); 211void rt6_uncached_list_del(struct rt6_info *rt); 212 213static 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 */ 227static 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 241void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 242 const struct flowi6 *fl6); 243 244static 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 251static 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 262int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 263 int (*output)(struct net *, struct sock *, struct sk_buff *)); 264 265static inline unsigned int ip6_skb_dst_mtu(struct sk_buff *skb) 266{ 267 unsigned int mtu; 268 269 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 270 inet6_sk(skb->sk) : NULL; 271 272 if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) { 273 mtu = READ_ONCE(skb_dst(skb)->dev->mtu); 274 mtu -= lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 275 } else 276 mtu = dst_mtu(skb_dst(skb)); 277 278 return mtu; 279} 280 281static inline bool ip6_sk_accept_pmtu(const struct sock *sk) 282{ 283 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE && 284 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT; 285} 286 287static inline bool ip6_sk_ignore_df(const struct sock *sk) 288{ 289 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO || 290 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT; 291} 292 293static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt, 294 const struct in6_addr *daddr) 295{ 296 if (rt->rt6i_flags & RTF_GATEWAY) 297 return &rt->rt6i_gateway; 298 else if (unlikely(rt->rt6i_flags & RTF_CACHE)) 299 return &rt->rt6i_dst.addr; 300 else 301 return daddr; 302} 303 304static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b) 305{ 306 struct fib6_nh *nha, *nhb; 307 308 if (a->nh || b->nh) 309 return nexthop_cmp(a->nh, b->nh); 310 311 nha = a->fib6_nh; 312 nhb = b->fib6_nh; 313 return nha->fib_nh_dev == nhb->fib_nh_dev && 314 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) && 315 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws); 316} 317 318static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) 319{ 320 struct inet6_dev *idev; 321 unsigned int mtu; 322 323 if (dst_metric_locked(dst, RTAX_MTU)) { 324 mtu = dst_metric_raw(dst, RTAX_MTU); 325 if (mtu) 326 goto out; 327 } 328 329 mtu = IPV6_MIN_MTU; 330 rcu_read_lock(); 331 idev = __in6_dev_get(dst->dev); 332 if (idev) 333 mtu = idev->cnf.mtu6; 334 rcu_read_unlock(); 335 336out: 337 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 338} 339 340u32 ip6_mtu_from_fib6(const struct fib6_result *res, 341 const struct in6_addr *daddr, 342 const struct in6_addr *saddr); 343 344struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 345 struct net_device *dev, struct sk_buff *skb, 346 const void *daddr); 347#endif 348