/* 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, * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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); 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_tos = inet_dscp_to_dsfield(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); } static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, __be32 daddr, __be32 saddr, __be32 gre_key, __u8 tos, int oif) { memset(fl4, 0, sizeof(*fl4)); fl4->flowi4_oif = oif; fl4->daddr = daddr; fl4->saddr = saddr; fl4->flowi4_tos = tos; fl4->flowi4_proto = IPPROTO_GRE; fl4->fl4_gre_key = gre_key; return ip_route_output_key(net, fl4); } enum skb_drop_reason ip_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_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, dscp_t dscp, struct net_device *dev); enum skb_drop_reason ip_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_reason ip_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); 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; 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->sk_uid); } 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); struct net *net = dev_net(dst->dev); if (hoplimit == 0) hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl); 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 */