388 lines
11 KiB
C
388 lines
11 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for the IP router.
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*
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* Version: @(#)route.h 1.0.4 05/27/93
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*
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* Authors: Ross Biro
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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* Fixes:
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* Alan Cox : Reformatted. Added ip_rt_local()
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* Alan Cox : Support for TCP parameters.
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* Alexey Kuznetsov: Major changes for new routing code.
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* Mike McLagan : Routing by source
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* Robert Olsson : Added rt_cache statistics
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*/
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#ifndef _ROUTE_H
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#define _ROUTE_H
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#include <net/dst.h>
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#include <net/inetpeer.h>
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#include <net/flow.h>
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#include <net/inet_sock.h>
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#include <net/ip_fib.h>
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#include <net/arp.h>
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#include <net/ndisc.h>
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#include <linux/in_route.h>
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#include <linux/rtnetlink.h>
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#include <linux/rcupdate.h>
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#include <linux/route.h>
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#include <linux/ip.h>
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#include <linux/cache.h>
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#include <linux/security.h>
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/* IPv4 datagram length is stored into 16bit field (tot_len) */
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#define IP_MAX_MTU 0xFFFFU
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#define RTO_ONLINK 0x01
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#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
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#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
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struct fib_nh;
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struct fib_info;
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struct uncached_list;
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struct rtable {
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struct dst_entry dst;
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int rt_genid;
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unsigned int rt_flags;
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__u16 rt_type;
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__u8 rt_is_input;
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__u8 rt_uses_gateway;
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int rt_iif;
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u8 rt_gw_family;
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/* Info on neighbour */
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union {
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__be32 rt_gw4;
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struct in6_addr rt_gw6;
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};
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/* Miscellaneous cached information */
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u32 rt_mtu_locked:1,
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rt_pmtu:31;
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struct list_head rt_uncached;
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struct uncached_list *rt_uncached_list;
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};
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static inline bool rt_is_input_route(const struct rtable *rt)
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{
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return rt->rt_is_input != 0;
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}
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static inline bool rt_is_output_route(const struct rtable *rt)
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{
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return rt->rt_is_input == 0;
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}
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static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
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{
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if (rt->rt_gw_family == AF_INET)
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return rt->rt_gw4;
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return daddr;
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}
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struct ip_rt_acct {
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__u32 o_bytes;
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__u32 o_packets;
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__u32 i_bytes;
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__u32 i_packets;
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};
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struct rt_cache_stat {
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unsigned int in_slow_tot;
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unsigned int in_slow_mc;
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unsigned int in_no_route;
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unsigned int in_brd;
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unsigned int in_martian_dst;
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unsigned int in_martian_src;
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unsigned int out_slow_tot;
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unsigned int out_slow_mc;
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};
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extern struct ip_rt_acct __percpu *ip_rt_acct;
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struct in_device;
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int ip_rt_init(void);
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void rt_cache_flush(struct net *net);
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void rt_flush_dev(struct net_device *dev);
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struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
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const struct sk_buff *skb);
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struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
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struct fib_result *res,
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const struct sk_buff *skb);
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static inline struct rtable *__ip_route_output_key(struct net *net,
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struct flowi4 *flp)
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{
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return ip_route_output_key_hash(net, flp, NULL);
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}
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struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
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const struct sock *sk);
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struct dst_entry *ipv4_blackhole_route(struct net *net,
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struct dst_entry *dst_orig);
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static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
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{
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return ip_route_output_flow(net, flp, NULL);
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}
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static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
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__be32 saddr, u8 tos, int oif)
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{
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struct flowi4 fl4 = {
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.flowi4_oif = oif,
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.flowi4_tos = tos,
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.daddr = daddr,
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.saddr = saddr,
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};
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return ip_route_output_key(net, &fl4);
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}
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static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
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struct sock *sk,
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__be32 daddr, __be32 saddr,
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__be16 dport, __be16 sport,
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__u8 proto, __u8 tos, int oif)
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{
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flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos,
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RT_SCOPE_UNIVERSE, proto,
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sk ? inet_sk_flowi_flags(sk) : 0,
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daddr, saddr, dport, sport, sock_net_uid(net, sk));
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if (sk)
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security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
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return ip_route_output_flow(net, fl4, sk);
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}
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static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
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__be32 daddr, __be32 saddr,
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__be32 gre_key, __u8 tos, int oif)
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{
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memset(fl4, 0, sizeof(*fl4));
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fl4->flowi4_oif = oif;
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fl4->daddr = daddr;
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fl4->saddr = saddr;
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fl4->flowi4_tos = tos;
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fl4->flowi4_proto = IPPROTO_GRE;
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fl4->fl4_gre_key = gre_key;
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return ip_route_output_key(net, fl4);
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}
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int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
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u8 tos, struct net_device *dev,
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struct in_device *in_dev, u32 *itag);
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int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
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u8 tos, struct net_device *devin);
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int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
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u8 tos, struct net_device *devin,
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struct fib_result *res);
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static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
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u8 tos, struct net_device *devin)
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{
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int err;
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rcu_read_lock();
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err = ip_route_input_noref(skb, dst, src, tos, devin);
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if (!err) {
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skb_dst_force(skb);
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if (!skb_dst(skb))
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err = -EINVAL;
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}
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rcu_read_unlock();
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return err;
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}
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void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
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u8 protocol);
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void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
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void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
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void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
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void ip_rt_send_redirect(struct sk_buff *skb);
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unsigned int inet_addr_type(struct net *net, __be32 addr);
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unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
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unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
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__be32 addr);
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unsigned int inet_addr_type_dev_table(struct net *net,
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const struct net_device *dev,
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__be32 addr);
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void ip_rt_multicast_event(struct in_device *);
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int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
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void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
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struct rtable *rt_dst_alloc(struct net_device *dev,
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unsigned int flags, u16 type,
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bool nopolicy, bool noxfrm, bool will_cache);
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struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
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struct in_ifaddr;
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void fib_add_ifaddr(struct in_ifaddr *);
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void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
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void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
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void rt_add_uncached_list(struct rtable *rt);
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void rt_del_uncached_list(struct rtable *rt);
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int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
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u32 table_id, struct fib_info *fi,
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int *fa_index, int fa_start, unsigned int flags);
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static inline void ip_rt_put(struct rtable *rt)
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{
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/* dst_release() accepts a NULL parameter.
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* We rely on dst being first structure in struct rtable
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*/
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BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
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dst_release(&rt->dst);
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}
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#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
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extern const __u8 ip_tos2prio[16];
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static inline char rt_tos2priority(u8 tos)
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{
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return ip_tos2prio[IPTOS_TOS(tos)>>1];
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}
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/* ip_route_connect() and ip_route_newports() work in tandem whilst
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* binding a socket for a new outgoing connection.
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*
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* In order to use IPSEC properly, we must, in the end, have a
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* route that was looked up using all available keys including source
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* and destination ports.
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*
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* However, if a source port needs to be allocated (the user specified
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* a wildcard source port) we need to obtain addressing information
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* in order to perform that allocation.
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*
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* So ip_route_connect() looks up a route using wildcarded source and
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* destination ports in the key, simply so that we can get a pair of
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* addresses to use for port allocation.
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*
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* Later, once the ports are allocated, ip_route_newports() will make
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* another route lookup if needed to make sure we catch any IPSEC
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* rules keyed on the port information.
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*
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* The callers allocate the flow key on their stack, and must pass in
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* the same flowi4 object to both the ip_route_connect() and the
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* ip_route_newports() calls.
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*/
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static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
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u32 tos, int oif, u8 protocol,
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__be16 sport, __be16 dport,
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struct sock *sk)
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{
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__u8 flow_flags = 0;
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if (inet_sk(sk)->transparent)
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flow_flags |= FLOWI_FLAG_ANYSRC;
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flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
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protocol, flow_flags, dst, src, dport, sport,
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sk->sk_uid);
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}
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static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
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__be32 dst, __be32 src, u32 tos,
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int oif, u8 protocol,
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__be16 sport, __be16 dport,
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struct sock *sk)
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{
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struct net *net = sock_net(sk);
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struct rtable *rt;
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ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
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sport, dport, sk);
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if (!dst || !src) {
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rt = __ip_route_output_key(net, fl4);
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if (IS_ERR(rt))
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return rt;
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ip_rt_put(rt);
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flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
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}
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security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
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return ip_route_output_flow(net, fl4, sk);
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}
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static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
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__be16 orig_sport, __be16 orig_dport,
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__be16 sport, __be16 dport,
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struct sock *sk)
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{
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if (sport != orig_sport || dport != orig_dport) {
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fl4->fl4_dport = dport;
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fl4->fl4_sport = sport;
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ip_rt_put(rt);
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flowi4_update_output(fl4, sk->sk_bound_dev_if,
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RT_CONN_FLAGS(sk), fl4->daddr,
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fl4->saddr);
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security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
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return ip_route_output_flow(sock_net(sk), fl4, sk);
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}
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return rt;
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}
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static inline int inet_iif(const struct sk_buff *skb)
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{
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struct rtable *rt = skb_rtable(skb);
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if (rt && rt->rt_iif)
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return rt->rt_iif;
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return skb->skb_iif;
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}
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static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
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{
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int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
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struct net *net = dev_net(dst->dev);
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if (hoplimit == 0)
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hoplimit = net->ipv4.sysctl_ip_default_ttl;
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return hoplimit;
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}
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static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
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__be32 daddr)
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{
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struct neighbour *neigh;
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neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);
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if (unlikely(!neigh))
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neigh = __neigh_create(&arp_tbl, &daddr, dev, false);
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return neigh;
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}
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static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,
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struct sk_buff *skb,
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bool *is_v6gw)
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{
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struct net_device *dev = rt->dst.dev;
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struct neighbour *neigh;
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if (likely(rt->rt_gw_family == AF_INET)) {
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neigh = ip_neigh_gw4(dev, rt->rt_gw4);
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} else if (rt->rt_gw_family == AF_INET6) {
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neigh = ip_neigh_gw6(dev, &rt->rt_gw6);
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*is_v6gw = true;
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} else {
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neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);
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}
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return neigh;
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}
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#endif /* _ROUTE_H */
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