/* SPDX-License-Identifier: GPL-2.0-or-later *//* * INET		An implementation of the TCP/IP protocol suite for the LINUX *		operating system.  INET  is implemented using the  BSD Socket *		interface as the means of communication with the user level. * *		Definitions for the IP router. * * Version:	@(#)route.h	1.0.4	05/27/93 * * Authors:	Ross Biro *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * Fixes: *		Alan Cox	:	Reformatted. Added ip_rt_local() *		Alan Cox	:	Support for TCP parameters. *		Alexey Kuznetsov:	Major changes for new routing code. *		Mike McLagan    :	Routing by source *		Robert Olsson   :	Added rt_cache statistics */#ifndef _ROUTE_H#define _ROUTE_H #include <net/dst.h>#include <net/inetpeer.h>#include <net/flow.h>#include <net/inet_sock.h>#include <net/ip_fib.h>#include <net/arp.h>#include <net/ndisc.h>#include <net/inet_dscp.h>#include <net/sock.h>#include <linux/in_route.h>#include <linux/rtnetlink.h>#include <linux/rcupdate.h>#include <linux/route.h>#include <linux/ip.h>#include <linux/cache.h>#include <linux/security.h> static inline __u8 ip_sock_rt_scope(const struct sock *sk){	if (sock_flag(sk, SOCK_LOCALROUTE))		return RT_SCOPE_LINK; 	return RT_SCOPE_UNIVERSE;} static inline __u8 ip_sock_rt_tos(const struct sock *sk){	return READ_ONCE(inet_sk(sk)->tos) & INET_DSCP_MASK;} struct ip_tunnel_info;struct fib_nh;struct fib_info;struct uncached_list;struct rtable {	struct dst_entry	dst; 	int			rt_genid;	unsigned int		rt_flags;	__u16			rt_type;	__u8			rt_is_input;	__u8			rt_uses_gateway; 	int			rt_iif; 	u8			rt_gw_family;	/* Info on neighbour */	union {		__be32		rt_gw4;		struct in6_addr	rt_gw6;	}; 	/* Miscellaneous cached information */	u32			rt_mtu_locked:1,				rt_pmtu:31;}; #define dst_rtable(_ptr) container_of_const(_ptr, struct rtable, dst) /** * skb_rtable - Returns the skb &rtable * @skb: buffer */static inline struct rtable *skb_rtable(const struct sk_buff *skb){	return dst_rtable(skb_dst(skb));} static inline bool rt_is_input_route(const struct rtable *rt){	return rt->rt_is_input != 0;} static inline bool rt_is_output_route(const struct rtable *rt){	return rt->rt_is_input == 0;} static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr){	if (rt->rt_gw_family == AF_INET)		return rt->rt_gw4;	return daddr;} struct ip_rt_acct {	__u32 	o_bytes;	__u32 	o_packets;	__u32 	i_bytes;	__u32 	i_packets;}; struct rt_cache_stat {        unsigned int in_slow_tot;        unsigned int in_slow_mc;        unsigned int in_no_route;        unsigned int in_brd;        unsigned int in_martian_dst;        unsigned int in_martian_src;        unsigned int out_slow_tot;        unsigned int out_slow_mc;}; extern struct ip_rt_acct __percpu *ip_rt_acct; struct in_device; int ip_rt_init(void);void rt_cache_flush(struct net *net);void rt_flush_dev(struct net_device *dev); static inline void inet_sk_init_flowi4(const struct inet_sock *inet,				       struct flowi4 *fl4){	const struct ip_options_rcu *ip4_opt;	const struct sock *sk;	__be32 daddr; 	rcu_read_lock();	ip4_opt = rcu_dereference(inet->inet_opt); 	/* Source routing option overrides the socket destination address */	if (ip4_opt && ip4_opt->opt.srr)		daddr = ip4_opt->opt.faddr;	else		daddr = inet->inet_daddr;	rcu_read_unlock(); 	sk = &inet->sk;	flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark),			   ip_sock_rt_tos(sk), ip_sock_rt_scope(sk),			   sk->sk_protocol, inet_sk_flowi_flags(sk), daddr,			   inet->inet_saddr, inet->inet_dport,			   inet->inet_sport, sk_uid(sk));	security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));} struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,					const struct sk_buff *skb);struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,					    struct fib_result *res,					    const struct sk_buff *skb); static inline struct rtable *__ip_route_output_key(struct net *net,						   struct flowi4 *flp){	return ip_route_output_key_hash(net, flp, NULL);} struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,				    const struct sock *sk);struct dst_entry *ipv4_blackhole_route(struct net *net,				       struct dst_entry *dst_orig); static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp){	return ip_route_output_flow(net, flp, NULL);} /* Simplistic IPv4 route lookup function. * This is only suitable for some particular use cases: since the flowi4 * structure is only partially set, it may bypass some fib-rules. */static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,					     __be32 saddr, dscp_t dscp,					     int oif, __u8 scope){	struct flowi4 fl4 = {		.flowi4_oif = oif,		.flowi4_dscp = dscp,		.flowi4_scope = scope,		.daddr = daddr,		.saddr = saddr,	}; 	return ip_route_output_key(net, &fl4);} static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,						   const struct sock *sk,						   __be32 daddr, __be32 saddr,						   __be16 dport, __be16 sport,						   __u8 proto, __u8 tos, int oif){	flowi4_init_output(fl4, oif, sk ? READ_ONCE(sk->sk_mark) : 0, tos,			   sk ? ip_sock_rt_scope(sk) : RT_SCOPE_UNIVERSE,			   proto, sk ? inet_sk_flowi_flags(sk) : 0,			   daddr, saddr, dport, sport, sock_net_uid(net, sk));	if (sk)		security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));	return ip_route_output_flow(net, fl4, sk);} enum skb_drop_reasonip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,		      dscp_t dscp, struct net_device *dev,		      struct in_device *in_dev, u32 *itag);enum skb_drop_reasonip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,		     dscp_t dscp, struct net_device *dev);enum skb_drop_reasonip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,		  dscp_t dscp, struct net_device *dev,		  const struct sk_buff *hint); static inline enum skb_drop_reasonip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, dscp_t dscp,	       struct net_device *devin){	enum skb_drop_reason reason; 	rcu_read_lock();	reason = ip_route_input_noref(skb, dst, src, dscp, devin);	if (!reason) {		skb_dst_force(skb);		if (!skb_dst(skb))			reason = SKB_DROP_REASON_NOT_SPECIFIED;	}	rcu_read_unlock(); 	return reason;} void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,		      u8 protocol);void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);void ip_rt_send_redirect(struct sk_buff *skb); unsigned int inet_addr_type(struct net *net, __be32 addr);unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,				__be32 addr);unsigned int inet_addr_type_dev_table(struct net *net,				      const struct net_device *dev,				      __be32 addr);void ip_rt_multicast_event(struct in_device *);int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);struct rtable *rt_dst_alloc(struct net_device *dev,			    unsigned int flags, u16 type, bool noxfrm);struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt); struct in_ifaddr;void fib_add_ifaddr(struct in_ifaddr *);void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric); void rt_add_uncached_list(struct rtable *rt);void rt_del_uncached_list(struct rtable *rt); int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,		       u32 table_id, struct fib_info *fi,		       int *fa_index, int fa_start, unsigned int flags); void fnhe_update_pmtu(struct fib_nh_exception *fnhe, u32 new, u32 orig); static inline void ip_rt_put(struct rtable *rt){	/* dst_release() accepts a NULL parameter.	 * We rely on dst being first structure in struct rtable	 */	BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);	dst_release(&rt->dst);} extern const __u8 ip_tos2prio[16]; static inline char rt_tos2priority(u8 tos){	return ip_tos2prio[IPTOS_TOS(tos)>>1];} /* ip_route_connect() and ip_route_newports() work in tandem whilst * binding a socket for a new outgoing connection. * * In order to use IPSEC properly, we must, in the end, have a * route that was looked up using all available keys including source * and destination ports. * * However, if a source port needs to be allocated (the user specified * a wildcard source port) we need to obtain addressing information * in order to perform that allocation. * * So ip_route_connect() looks up a route using wildcarded source and * destination ports in the key, simply so that we can get a pair of * addresses to use for port allocation. * * Later, once the ports are allocated, ip_route_newports() will make * another route lookup if needed to make sure we catch any IPSEC * rules keyed on the port information. * * The callers allocate the flow key on their stack, and must pass in * the same flowi4 object to both the ip_route_connect() and the * ip_route_newports() calls. */ static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst,					 __be32 src, int oif, u8 protocol,					 __be16 sport, __be16 dport,					 const struct sock *sk){	__u8 flow_flags = 0; 	if (inet_test_bit(TRANSPARENT, sk))		flow_flags |= FLOWI_FLAG_ANYSRC; 	if (IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) && !sport)		flow_flags |= FLOWI_FLAG_ANY_SPORT; 	flowi4_init_output(fl4, oif, READ_ONCE(sk->sk_mark), ip_sock_rt_tos(sk),			   ip_sock_rt_scope(sk), protocol, flow_flags, dst,			   src, dport, sport, sk_uid(sk));} static inline struct rtable *ip_route_connect(struct flowi4 *fl4, __be32 dst,					      __be32 src, int oif, u8 protocol,					      __be16 sport, __be16 dport,					      const struct sock *sk){	struct net *net = sock_net(sk);	struct rtable *rt; 	ip_route_connect_init(fl4, dst, src, oif, protocol, sport, dport, sk); 	if (!dst || !src) {		rt = __ip_route_output_key(net, fl4);		if (IS_ERR(rt))			return rt;		ip_rt_put(rt);		flowi4_update_output(fl4, oif, fl4->daddr, fl4->saddr);	}	security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));	return ip_route_output_flow(net, fl4, sk);} static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,					       __be16 orig_sport, __be16 orig_dport,					       __be16 sport, __be16 dport,					       const struct sock *sk){	if (sport != orig_sport || dport != orig_dport) {		fl4->fl4_dport = dport;		fl4->fl4_sport = sport;		ip_rt_put(rt);		flowi4_update_output(fl4, sk->sk_bound_dev_if, fl4->daddr,				     fl4->saddr);		security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));		return ip_route_output_flow(sock_net(sk), fl4, sk);	}	return rt;} static inline int inet_iif(const struct sk_buff *skb){	struct rtable *rt = skb_rtable(skb); 	if (rt && rt->rt_iif)		return rt->rt_iif; 	return skb->skb_iif;} static inline int ip4_dst_hoplimit(const struct dst_entry *dst){	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 	if (hoplimit == 0) {		const struct net *net; 		rcu_read_lock();		net = dst_dev_net_rcu(dst);		hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl);		rcu_read_unlock();	}	return hoplimit;} static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,					     __be32 daddr){	struct neighbour *neigh; 	neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);	if (unlikely(!neigh))		neigh = __neigh_create(&arp_tbl, &daddr, dev, false); 	return neigh;} static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,						struct sk_buff *skb,						bool *is_v6gw){	struct net_device *dev = rt->dst.dev;	struct neighbour *neigh; 	if (likely(rt->rt_gw_family == AF_INET)) {		neigh = ip_neigh_gw4(dev, rt->rt_gw4);	} else if (rt->rt_gw_family == AF_INET6) {		neigh = ip_neigh_gw6(dev, &rt->rt_gw6);		*is_v6gw = true;	} else {		neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);	}	return neigh;} #endif	/* _ROUTE_H */