/* SPDX-License-Identifier: GPL-2.0 */#ifndef _NET_IP6_ROUTE_H#define _NET_IP6_ROUTE_H #include <net/addrconf.h>#include <net/flow.h>#include <net/ip6_fib.h>#include <net/sock.h>#include <net/lwtunnel.h>#include <linux/ip.h>#include <linux/ipv6.h>#include <linux/route.h>#include <net/nexthop.h> struct route_info {	__u8			type;	__u8			length;	__u8			prefix_len;#if defined(__BIG_ENDIAN_BITFIELD)	__u8			reserved_h:3,				route_pref:2,				reserved_l:3;#elif defined(__LITTLE_ENDIAN_BITFIELD)	__u8			reserved_l:3,				route_pref:2,				reserved_h:3;#endif	__be32			lifetime;	__u8			prefix[];	/* 0,8 or 16 */}; #define RT6_LOOKUP_F_IFACE		0x00000001#define RT6_LOOKUP_F_REACHABLE		0x00000002#define RT6_LOOKUP_F_HAS_SADDR		0x00000004#define RT6_LOOKUP_F_SRCPREF_TMP	0x00000008#define RT6_LOOKUP_F_SRCPREF_PUBLIC	0x00000010#define RT6_LOOKUP_F_SRCPREF_COA	0x00000020#define RT6_LOOKUP_F_IGNORE_LINKSTATE	0x00000040#define RT6_LOOKUP_F_DST_NOREF		0x00000080 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675) * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header */#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) /* * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate * between IPV6_ADDR_PREFERENCES socket option values *	IPV6_PREFER_SRC_TMP    = 0x1 *	IPV6_PREFER_SRC_PUBLIC = 0x2 *	IPV6_PREFER_SRC_COA    = 0x4 * and above RT6_LOOKUP_F_SRCPREF_xxx flags. */static inline int rt6_srcprefs2flags(unsigned int srcprefs){	return (srcprefs & IPV6_PREFER_SRC_MASK) << 3;} static inline unsigned int rt6_flags2srcprefs(int flags){	return (flags >> 3) & IPV6_PREFER_SRC_MASK;} static inline bool rt6_need_strict(const struct in6_addr *daddr){	return ipv6_addr_type(daddr) &		(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);} /* fib entries using a nexthop object can not be coalesced into * a multipath route */static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i){	/* the RTF_ADDRCONF flag filters out RA's */	return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh &&		f6i->fib6_nh->fib_nh_gw_family;} #if IS_ENABLED(CONFIG_IPV6)void ip6_route_input(struct sk_buff *skb);#elsestatic inline void ip6_route_input(struct sk_buff *skb){}#endif struct dst_entry *ip6_route_input_lookup(struct net *net,					 struct net_device *dev,					 struct flowi6 *fl6,					 const struct sk_buff *skb, int flags); struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,					 struct flowi6 *fl6, int flags); static inline struct dst_entry *ip6_route_output(struct net *net,						 const struct sock *sk,						 struct flowi6 *fl6){	return ip6_route_output_flags(net, sk, fl6, 0);} /* Only conditionally release dst if flags indicates * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list. */static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags){	if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||	    !list_empty(&rt->dst.rt_uncached))		ip6_rt_put(rt);} struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,				   const struct sk_buff *skb, int flags);struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,			       int ifindex, struct flowi6 *fl6,			       const struct sk_buff *skb, int flags); void ip6_route_init_special_entries(void);int ip6_route_init(void);void ip6_route_cleanup(void); int ipv6_route_ioctl(struct net *net, unsigned int cmd,		struct in6_rtmsg *rtmsg); int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,		  struct netlink_ext_ack *extack);int ip6_ins_rt(struct net *net, struct fib6_info *f6i);int ip6_del_rt_reason(struct net *net, struct fib6_info *f6i,		      enum rt_del_reason del_reason);#if IS_ENABLED(CONFIG_IPV6)int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);#elsestatic inline int ip6_del_rt(struct net *net, struct fib6_info *f6i,			     bool skip_notify){	return -EAFNOSUPPORT;}#endif void rt6_flush_exceptions(struct fib6_info *f6i);void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,			unsigned long now); static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,				      const struct in6_addr *daddr,				      unsigned int prefs, int l3mdev_index,				      struct in6_addr *saddr){	struct net_device *l3mdev;	struct net_device *dev;	bool same_vrf;	int err = 0; 	rcu_read_lock(); 	l3mdev = dev_get_by_index_rcu(net, l3mdev_index);	if (!f6i || !f6i->fib6_prefsrc.plen || l3mdev)		dev = f6i ? fib6_info_nh_dev(f6i) : NULL;	same_vrf = !l3mdev || l3mdev_master_dev_rcu(dev) == l3mdev;	if (f6i && f6i->fib6_prefsrc.plen && same_vrf)		*saddr = f6i->fib6_prefsrc.addr;	else		err = ipv6_dev_get_saddr(net, same_vrf ? dev : l3mdev, daddr, prefs, saddr); 	rcu_read_unlock(); 	return err;} struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,			    const struct in6_addr *saddr, int oif,			    const struct sk_buff *skb, int flags);u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,		       const struct sk_buff *skb, struct flow_keys *hkeys); struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6); void fib6_force_start_gc(struct net *net); struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,				     const struct in6_addr *addr, bool anycast,				     gfp_t gfp_flags, struct netlink_ext_ack *extack); struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,			       int flags); /* *	support functions for ND * */struct fib6_info *rt6_get_dflt_router(struct net *net,				     const struct in6_addr *addr,				     struct net_device *dev);struct fib6_info *rt6_add_dflt_router(struct net *net,				     const struct in6_addr *gwaddr,				     struct net_device *dev, unsigned int pref,				     u32 defrtr_usr_metric,				     int lifetime); void rt6_purge_dflt_routers(struct net *net); int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,		  const struct in6_addr *gwaddr); void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,		     u32 mark, kuid_t uid);void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,		  kuid_t uid);void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk); struct netlink_callback; struct rt6_rtnl_dump_arg {	struct sk_buff *skb;	struct netlink_callback *cb;	struct net *net;	struct fib_dump_filter filter;}; int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);void rt6_mtu_change(struct net_device *dev, unsigned int mtu);void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);void rt6_disable_ip(struct net_device *dev, unsigned long event);void rt6_sync_down_dev(struct net_device *dev, unsigned long event);void rt6_multipath_rebalance(struct fib6_info *f6i); void rt6_uncached_list_add(struct rt6_info *rt);void rt6_uncached_list_del(struct rt6_info *rt); static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb){	const struct dst_entry *dst = skb_dst(skb); 	if (dst)		return dst_rt6_info(dst); 	return NULL;} /* *	Store a destination cache entry in a socket */static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,				 bool daddr_set,				 bool saddr_set){	struct ipv6_pinfo *np = inet6_sk(sk); 	np->dst_cookie = rt6_get_cookie(dst_rt6_info(dst));	sk_setup_caps(sk, dst);	np->daddr_cache = daddr_set;#ifdef CONFIG_IPV6_SUBTREES	np->saddr_cache = saddr_set;#endif} void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,			   const struct flowi6 *fl6); static inline bool ipv6_unicast_destination(const struct sk_buff *skb){	const struct rt6_info *rt = dst_rt6_info(skb_dst(skb)); 	return rt->rt6i_flags & RTF_LOCAL;} static inline bool __ipv6_anycast_destination(const struct rt6key *rt6i_dst,					      u32 rt6i_flags,					      const struct in6_addr *daddr){	return rt6i_flags & RTF_ANYCAST ||	       (rt6i_dst->plen < 127 &&	       !(rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&	       ipv6_addr_equal(&rt6i_dst->addr, daddr));} static inline bool ipv6_anycast_destination(const struct dst_entry *dst,					    const struct in6_addr *daddr){	const struct rt6_info *rt = dst_rt6_info(dst); 	return __ipv6_anycast_destination(&rt->rt6i_dst, rt->rt6i_flags, daddr);} #if IS_ENABLED(CONFIG_IPV6)int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,		 int (*output)(struct net *, struct sock *, struct sk_buff *));#elsestatic inline int ip6_fragment(struct net *net, struct sock *sk,			       struct sk_buff *skb,			       int (*output)(struct net *, struct sock *,					     struct sk_buff *)){	kfree_skb(skb);	return -EAFNOSUPPORT;}#endif /* Variant of dst_mtu() for IPv6 users */static inline u32 dst6_mtu(const struct dst_entry *dst){	return INDIRECT_CALL_1(dst->ops->mtu, ip6_mtu, dst);} static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb){	const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?				inet6_sk(skb->sk) : NULL;	const struct dst_entry *dst = skb_dst(skb);	unsigned int mtu; 	if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) {		mtu = READ_ONCE(dst_dev(dst)->mtu);		mtu -= lwtunnel_headroom(dst->lwtstate, mtu);	} else {		mtu = dst_mtu(dst);	}	return mtu;} static inline bool ip6_sk_accept_pmtu(const struct sock *sk){	u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 	return pmtudisc != IPV6_PMTUDISC_INTERFACE &&	       pmtudisc != IPV6_PMTUDISC_OMIT;} static inline bool ip6_sk_ignore_df(const struct sock *sk){	u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc); 	return pmtudisc < IPV6_PMTUDISC_DO ||	       pmtudisc == IPV6_PMTUDISC_OMIT;} static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,						 const struct in6_addr *daddr){	if (rt->rt6i_flags & RTF_GATEWAY)		return &rt->rt6i_gateway;	else if (unlikely(rt->rt6i_flags & RTF_CACHE))		return &rt->rt6i_dst.addr;	else		return daddr;} static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b){	struct fib6_nh *nha, *nhb; 	if (a->nh || b->nh)		return nexthop_cmp(a->nh, b->nh); 	nha = a->fib6_nh;	nhb = b->fib6_nh;	return nha->fib_nh_dev == nhb->fib_nh_dev &&	       ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&	       !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);} static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst,						     bool forwarding){	struct inet6_dev *idev;	unsigned int mtu; 	if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) {		mtu = dst_metric_raw(dst, RTAX_MTU);		if (mtu)			goto out;	} 	mtu = IPV6_MIN_MTU;	rcu_read_lock();	idev = __in6_dev_get(dst_dev_rcu(dst));	if (idev)		mtu = READ_ONCE(idev->cnf.mtu6);	rcu_read_unlock(); out:	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); 	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);} /* Configured/administrative MTU of a route, for advertising the TCP MSS. * * Unlike ip6_dst_mtu_maybe_forward(), this ignores any ICMPv6-learned path * MTU (which is kept on the RTF_CACHE exception route) and returns the MTU of * the underlying route (fib6_pmtu) or the egress device.  The advertised MSS * bounds what the peer may send to us and must reflect our receive * capability, not a path MTU learned on the reverse (send) direction.  See * RFC 2923 section 2.3 and the comment above tcp_advertise_mss(). */static inline unsigned int ip6_dst_mtu_configured(const struct dst_entry *dst){	const struct rt6_info *rt = dst_rt6_info(dst);	const struct fib6_info *from;	struct inet6_dev *idev;	unsigned int mtu = 0; 	rcu_read_lock();	/* IPv6 keeps the learned PMTU and the configured MTU in the same	 * RTAX_MTU slot: the learned value sits on this (possibly RTF_CACHE)	 * dst, the configured one on the underlying route.  Reach the latter	 * via ->from (fib6_pmtu), populated by ip6_route_info_create().	 */	from = rcu_dereference(rt->from);	if (from)		mtu = from->fib6_pmtu;	if (!mtu) {		mtu = IPV6_MIN_MTU;		idev = __in6_dev_get(dst_dev_rcu(dst));		if (idev)			mtu = max_t(unsigned int, mtu, READ_ONCE(idev->cnf.mtu6));	}	rcu_read_unlock(); 	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);} u32 ip6_mtu_from_fib6(const struct fib6_result *res,		      const struct in6_addr *daddr,		      const struct in6_addr *saddr); struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,				   struct net_device *dev, struct sk_buff *skb,				   const void *daddr);#endif