11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * INET An implementation of the TCP/IP protocol suite for the LINUX 31da177e4SLinus Torvalds * operating system. INET is implemented using the BSD Socket 41da177e4SLinus Torvalds * interface as the means of communication with the user level. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Definitions for the IP router. 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * Version: @(#)route.h 1.0.4 05/27/93 91da177e4SLinus Torvalds * 1002c30a84SJesper Juhl * Authors: Ross Biro 111da177e4SLinus Torvalds * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 121da177e4SLinus Torvalds * Fixes: 131da177e4SLinus Torvalds * Alan Cox : Reformatted. Added ip_rt_local() 141da177e4SLinus Torvalds * Alan Cox : Support for TCP parameters. 151da177e4SLinus Torvalds * Alexey Kuznetsov: Major changes for new routing code. 161da177e4SLinus Torvalds * Mike McLagan : Routing by source 171da177e4SLinus Torvalds * Robert Olsson : Added rt_cache statistics 181da177e4SLinus Torvalds * 191da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or 201da177e4SLinus Torvalds * modify it under the terms of the GNU General Public License 211da177e4SLinus Torvalds * as published by the Free Software Foundation; either version 221da177e4SLinus Torvalds * 2 of the License, or (at your option) any later version. 231da177e4SLinus Torvalds */ 241da177e4SLinus Torvalds #ifndef _ROUTE_H 251da177e4SLinus Torvalds #define _ROUTE_H 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds #include <net/dst.h> 281da177e4SLinus Torvalds #include <net/inetpeer.h> 291da177e4SLinus Torvalds #include <net/flow.h> 3079876874SKOVACS Krisztian #include <net/inet_sock.h> 311da177e4SLinus Torvalds #include <linux/in_route.h> 321da177e4SLinus Torvalds #include <linux/rtnetlink.h> 33c6cffba4SDavid S. Miller #include <linux/rcupdate.h> 341da177e4SLinus Torvalds #include <linux/route.h> 351da177e4SLinus Torvalds #include <linux/ip.h> 361da177e4SLinus Torvalds #include <linux/cache.h> 37beb8d13bSVenkat Yekkirala #include <linux/security.h> 381da177e4SLinus Torvalds 391da177e4SLinus Torvalds #define RTO_ONLINK 0x01 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds #define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE)) 42aa661581SFrancesco Fusco #define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE)) 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds struct fib_nh; 4562fa8a84SDavid S. Miller struct fib_info; 46fd2c3ef7SEric Dumazet struct rtable { 471da177e4SLinus Torvalds struct dst_entry dst; 481da177e4SLinus Torvalds 4929e75252SEric Dumazet int rt_genid; 5095c96174SEric Dumazet unsigned int rt_flags; 511da177e4SLinus Torvalds __u16 rt_type; 52155e8336SJulian Anastasov __u8 rt_is_input; 53155e8336SJulian Anastasov __u8 rt_uses_gateway; 541da177e4SLinus Torvalds 551da177e4SLinus Torvalds int rt_iif; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds /* Info on neighbour */ 58f2c3fe24SAl Viro __be32 rt_gateway; 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds /* Miscellaneous cached information */ 615943634fSDavid S. Miller u32 rt_pmtu; 62caacf05eSDavid S. Miller 63caacf05eSDavid S. Miller struct list_head rt_uncached; 641da177e4SLinus Torvalds }; 651da177e4SLinus Torvalds 66b8400f37SSteffen Klassert static inline bool rt_is_input_route(const struct rtable *rt) 67c7537967SDavid S. Miller { 689917e1e8SDavid S. Miller return rt->rt_is_input != 0; 69c7537967SDavid S. Miller } 70c7537967SDavid S. Miller 71b8400f37SSteffen Klassert static inline bool rt_is_output_route(const struct rtable *rt) 72c7537967SDavid S. Miller { 739917e1e8SDavid S. Miller return rt->rt_is_input == 0; 74c7537967SDavid S. Miller } 75c7537967SDavid S. Miller 76f8126f1dSDavid S. Miller static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr) 77f8126f1dSDavid S. Miller { 78f8126f1dSDavid S. Miller if (rt->rt_gateway) 79f8126f1dSDavid S. Miller return rt->rt_gateway; 80f8126f1dSDavid S. Miller return daddr; 81f8126f1dSDavid S. Miller } 82f8126f1dSDavid S. Miller 83fd2c3ef7SEric Dumazet struct ip_rt_acct { 841da177e4SLinus Torvalds __u32 o_bytes; 851da177e4SLinus Torvalds __u32 o_packets; 861da177e4SLinus Torvalds __u32 i_bytes; 871da177e4SLinus Torvalds __u32 i_packets; 881da177e4SLinus Torvalds }; 891da177e4SLinus Torvalds 90fd2c3ef7SEric Dumazet struct rt_cache_stat { 911da177e4SLinus Torvalds unsigned int in_hit; 921da177e4SLinus Torvalds unsigned int in_slow_tot; 931da177e4SLinus Torvalds unsigned int in_slow_mc; 941da177e4SLinus Torvalds unsigned int in_no_route; 951da177e4SLinus Torvalds unsigned int in_brd; 961da177e4SLinus Torvalds unsigned int in_martian_dst; 971da177e4SLinus Torvalds unsigned int in_martian_src; 981da177e4SLinus Torvalds unsigned int out_hit; 991da177e4SLinus Torvalds unsigned int out_slow_tot; 1001da177e4SLinus Torvalds unsigned int out_slow_mc; 1011da177e4SLinus Torvalds unsigned int gc_total; 1021da177e4SLinus Torvalds unsigned int gc_ignored; 1031da177e4SLinus Torvalds unsigned int gc_goal_miss; 1041da177e4SLinus Torvalds unsigned int gc_dst_overflow; 1051da177e4SLinus Torvalds unsigned int in_hlist_search; 1061da177e4SLinus Torvalds unsigned int out_hlist_search; 1071da177e4SLinus Torvalds }; 1081da177e4SLinus Torvalds 1097d720c3eSTejun Heo extern struct ip_rt_acct __percpu *ip_rt_acct; 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds struct in_device; 1122702c4bbSJoe Perches 1132702c4bbSJoe Perches int ip_rt_init(void); 1142702c4bbSJoe Perches void rt_cache_flush(struct net *net); 1152702c4bbSJoe Perches void rt_flush_dev(struct net_device *dev); 1162702c4bbSJoe Perches struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 1172702c4bbSJoe Perches struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 118b23dd4feSDavid S. Miller struct sock *sk); 1192702c4bbSJoe Perches struct dst_entry *ipv4_blackhole_route(struct net *net, 1202702c4bbSJoe Perches struct dst_entry *dst_orig); 121407eadd9SEric Dumazet 1229d6ec938SDavid S. Miller static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 1235bfa787fSDavid S. Miller { 1245bfa787fSDavid S. Miller return ip_route_output_flow(net, flp, NULL); 1255bfa787fSDavid S. Miller } 1265bfa787fSDavid S. Miller 12778fbfd8aSDavid S. Miller static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 12878fbfd8aSDavid S. Miller __be32 saddr, u8 tos, int oif) 12978fbfd8aSDavid S. Miller { 1309d6ec938SDavid S. Miller struct flowi4 fl4 = { 1319d6ec938SDavid S. Miller .flowi4_oif = oif, 132c5d21c4bSRoland Dreier .flowi4_tos = tos, 1339d6ec938SDavid S. Miller .daddr = daddr, 1349d6ec938SDavid S. Miller .saddr = saddr, 13578fbfd8aSDavid S. Miller }; 1369d6ec938SDavid S. Miller return ip_route_output_key(net, &fl4); 13778fbfd8aSDavid S. Miller } 13878fbfd8aSDavid S. Miller 13931e4543dSDavid S. Miller static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, 14031e4543dSDavid S. Miller struct sock *sk, 14178fbfd8aSDavid S. Miller __be32 daddr, __be32 saddr, 14278fbfd8aSDavid S. Miller __be16 dport, __be16 sport, 14378fbfd8aSDavid S. Miller __u8 proto, __u8 tos, int oif) 14478fbfd8aSDavid S. Miller { 14531e4543dSDavid S. Miller flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, 14694b92b88SDavid S. Miller RT_SCOPE_UNIVERSE, proto, 14794b92b88SDavid S. Miller sk ? inet_sk_flowi_flags(sk) : 0, 14894b92b88SDavid S. Miller daddr, saddr, dport, sport); 14978fbfd8aSDavid S. Miller if (sk) 15031e4543dSDavid S. Miller security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 15131e4543dSDavid S. Miller return ip_route_output_flow(net, fl4, sk); 15278fbfd8aSDavid S. Miller } 15378fbfd8aSDavid S. Miller 154cbb1e85fSDavid S. Miller static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, 15578fbfd8aSDavid S. Miller __be32 daddr, __be32 saddr, 15678fbfd8aSDavid S. Miller __be32 gre_key, __u8 tos, int oif) 15778fbfd8aSDavid S. Miller { 158cbb1e85fSDavid S. Miller memset(fl4, 0, sizeof(*fl4)); 159cbb1e85fSDavid S. Miller fl4->flowi4_oif = oif; 160cbb1e85fSDavid S. Miller fl4->daddr = daddr; 161cbb1e85fSDavid S. Miller fl4->saddr = saddr; 162cbb1e85fSDavid S. Miller fl4->flowi4_tos = tos; 163cbb1e85fSDavid S. Miller fl4->flowi4_proto = IPPROTO_GRE; 164cbb1e85fSDavid S. Miller fl4->fl4_gre_key = gre_key; 165cbb1e85fSDavid S. Miller return ip_route_output_key(net, fl4); 16678fbfd8aSDavid S. Miller } 16778fbfd8aSDavid S. Miller 1682702c4bbSJoe Perches int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 16938a424e4SDavid Miller u8 tos, struct net_device *devin); 170407eadd9SEric Dumazet 171c6cffba4SDavid S. Miller static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 172c6cffba4SDavid S. Miller u8 tos, struct net_device *devin) 173c6cffba4SDavid S. Miller { 174c6cffba4SDavid S. Miller int err; 175c6cffba4SDavid S. Miller 176c6cffba4SDavid S. Miller rcu_read_lock(); 177c6cffba4SDavid S. Miller err = ip_route_input_noref(skb, dst, src, tos, devin); 178c6cffba4SDavid S. Miller if (!err) 179c6cffba4SDavid S. Miller skb_dst_force(skb); 180c6cffba4SDavid S. Miller rcu_read_unlock(); 181c6cffba4SDavid S. Miller 182c6cffba4SDavid S. Miller return err; 183c6cffba4SDavid S. Miller } 184c6cffba4SDavid S. Miller 1852702c4bbSJoe Perches void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif, 1862702c4bbSJoe Perches u32 mark, u8 protocol, int flow_flags); 1872702c4bbSJoe Perches void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); 1882702c4bbSJoe Perches void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 1892702c4bbSJoe Perches u8 protocol, int flow_flags); 1902702c4bbSJoe Perches void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); 1912702c4bbSJoe Perches void ip_rt_send_redirect(struct sk_buff *skb); 1921da177e4SLinus Torvalds 1932702c4bbSJoe Perches unsigned int inet_addr_type(struct net *net, __be32 addr); 1942702c4bbSJoe Perches unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 1952702c4bbSJoe Perches __be32 addr); 1962702c4bbSJoe Perches void ip_rt_multicast_event(struct in_device *); 1972702c4bbSJoe Perches int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 1982702c4bbSJoe Perches void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 1992702c4bbSJoe Perches int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 2001da177e4SLinus Torvalds 2010ff60a45SJamal Hadi Salim struct in_ifaddr; 2022702c4bbSJoe Perches void fib_add_ifaddr(struct in_ifaddr *); 2032702c4bbSJoe Perches void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 2040ff60a45SJamal Hadi Salim 2051da177e4SLinus Torvalds static inline void ip_rt_put(struct rtable *rt) 2061da177e4SLinus Torvalds { 2076da025faSEric Dumazet /* dst_release() accepts a NULL parameter. 2086da025faSEric Dumazet * We rely on dst being first structure in struct rtable 2096da025faSEric Dumazet */ 2106da025faSEric Dumazet BUILD_BUG_ON(offsetof(struct rtable, dst) != 0); 211d8d1f30bSChangli Gao dst_release(&rt->dst); 2121da177e4SLinus Torvalds } 2131da177e4SLinus Torvalds 2141da177e4SLinus Torvalds #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 2151da177e4SLinus Torvalds 2164839c52bSPhilippe De Muyter extern const __u8 ip_tos2prio[16]; 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds static inline char rt_tos2priority(u8 tos) 2191da177e4SLinus Torvalds { 2201da177e4SLinus Torvalds return ip_tos2prio[IPTOS_TOS(tos)>>1]; 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds 2232d7192d6SDavid S. Miller /* ip_route_connect() and ip_route_newports() work in tandem whilst 2242d7192d6SDavid S. Miller * binding a socket for a new outgoing connection. 2252d7192d6SDavid S. Miller * 2262d7192d6SDavid S. Miller * In order to use IPSEC properly, we must, in the end, have a 2272d7192d6SDavid S. Miller * route that was looked up using all available keys including source 2282d7192d6SDavid S. Miller * and destination ports. 2292d7192d6SDavid S. Miller * 2302d7192d6SDavid S. Miller * However, if a source port needs to be allocated (the user specified 2312d7192d6SDavid S. Miller * a wildcard source port) we need to obtain addressing information 2322d7192d6SDavid S. Miller * in order to perform that allocation. 2332d7192d6SDavid S. Miller * 2342d7192d6SDavid S. Miller * So ip_route_connect() looks up a route using wildcarded source and 2352d7192d6SDavid S. Miller * destination ports in the key, simply so that we can get a pair of 2362d7192d6SDavid S. Miller * addresses to use for port allocation. 2372d7192d6SDavid S. Miller * 2382d7192d6SDavid S. Miller * Later, once the ports are allocated, ip_route_newports() will make 2392d7192d6SDavid S. Miller * another route lookup if needed to make sure we catch any IPSEC 2402d7192d6SDavid S. Miller * rules keyed on the port information. 2412d7192d6SDavid S. Miller * 2422d7192d6SDavid S. Miller * The callers allocate the flow key on their stack, and must pass in 2432d7192d6SDavid S. Miller * the same flowi4 object to both the ip_route_connect() and the 2442d7192d6SDavid S. Miller * ip_route_newports() calls. 2452d7192d6SDavid S. Miller */ 2462d7192d6SDavid S. Miller 2472d7192d6SDavid S. Miller static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 2482d7192d6SDavid S. Miller u32 tos, int oif, u8 protocol, 249b23dd4feSDavid S. Miller __be16 sport, __be16 dport, 250b23dd4feSDavid S. Miller struct sock *sk, bool can_sleep) 2511da177e4SLinus Torvalds { 2522d7192d6SDavid S. Miller __u8 flow_flags = 0; 25379876874SKOVACS Krisztian 25479876874SKOVACS Krisztian if (inet_sk(sk)->transparent) 25594b92b88SDavid S. Miller flow_flags |= FLOWI_FLAG_ANYSRC; 2565df65e55SDavid S. Miller if (can_sleep) 25794b92b88SDavid S. Miller flow_flags |= FLOWI_FLAG_CAN_SLEEP; 25894b92b88SDavid S. Miller 2592d7192d6SDavid S. Miller flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 26094b92b88SDavid S. Miller protocol, flow_flags, dst, src, dport, sport); 2612d7192d6SDavid S. Miller } 2622d7192d6SDavid S. Miller 2632d7192d6SDavid S. Miller static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 2642d7192d6SDavid S. Miller __be32 dst, __be32 src, u32 tos, 2652d7192d6SDavid S. Miller int oif, u8 protocol, 2662d7192d6SDavid S. Miller __be16 sport, __be16 dport, 2672d7192d6SDavid S. Miller struct sock *sk, bool can_sleep) 2682d7192d6SDavid S. Miller { 2692d7192d6SDavid S. Miller struct net *net = sock_net(sk); 2702d7192d6SDavid S. Miller struct rtable *rt; 2712d7192d6SDavid S. Miller 2722d7192d6SDavid S. Miller ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 2732d7192d6SDavid S. Miller sport, dport, sk, can_sleep); 27479876874SKOVACS Krisztian 2751da177e4SLinus Torvalds if (!dst || !src) { 2762d7192d6SDavid S. Miller rt = __ip_route_output_key(net, fl4); 277b23dd4feSDavid S. Miller if (IS_ERR(rt)) 278b23dd4feSDavid S. Miller return rt; 279b23dd4feSDavid S. Miller ip_rt_put(rt); 280e6b45241SJulian Anastasov flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 2811da177e4SLinus Torvalds } 2822d7192d6SDavid S. Miller security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 2832d7192d6SDavid S. Miller return ip_route_output_flow(net, fl4, sk); 2841da177e4SLinus Torvalds } 2851da177e4SLinus Torvalds 2862d7192d6SDavid S. Miller static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 2872d7192d6SDavid S. Miller __be16 orig_sport, __be16 orig_dport, 2882d7192d6SDavid S. Miller __be16 sport, __be16 dport, 2892d7192d6SDavid S. Miller struct sock *sk) 2901da177e4SLinus Torvalds { 291dca8b089SDavid S. Miller if (sport != orig_sport || dport != orig_dport) { 2922d7192d6SDavid S. Miller fl4->fl4_dport = dport; 2932d7192d6SDavid S. Miller fl4->fl4_sport = sport; 294b23dd4feSDavid S. Miller ip_rt_put(rt); 295e6b45241SJulian Anastasov flowi4_update_output(fl4, sk->sk_bound_dev_if, 296e6b45241SJulian Anastasov RT_CONN_FLAGS(sk), fl4->daddr, 297e6b45241SJulian Anastasov fl4->saddr); 2982d7192d6SDavid S. Miller security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 2992d7192d6SDavid S. Miller return ip_route_output_flow(sock_net(sk), fl4, sk); 3001da177e4SLinus Torvalds } 301b23dd4feSDavid S. Miller return rt; 3021da177e4SLinus Torvalds } 3031da177e4SLinus Torvalds 3041668e010SKOVACS Krisztian static inline int inet_iif(const struct sk_buff *skb) 3051668e010SKOVACS Krisztian { 30613378cadSDavid S. Miller int iif = skb_rtable(skb)->rt_iif; 30713378cadSDavid S. Miller 30813378cadSDavid S. Miller if (iif) 30913378cadSDavid S. Miller return iif; 31013378cadSDavid S. Miller return skb->skb_iif; 3111668e010SKOVACS Krisztian } 3121668e010SKOVACS Krisztian 313323e126fSDavid S. Miller extern int sysctl_ip_default_ttl; 314323e126fSDavid S. Miller 315323e126fSDavid S. Miller static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 316323e126fSDavid S. Miller { 317323e126fSDavid S. Miller int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 318323e126fSDavid S. Miller 319323e126fSDavid S. Miller if (hoplimit == 0) 320323e126fSDavid S. Miller hoplimit = sysctl_ip_default_ttl; 321323e126fSDavid S. Miller return hoplimit; 322323e126fSDavid S. Miller } 323323e126fSDavid S. Miller 3240ea9d5e3SHannes Frederic Sowa static inline int ip_skb_dst_mtu(struct sk_buff *skb) 3250ea9d5e3SHannes Frederic Sowa { 3260ea9d5e3SHannes Frederic Sowa struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; 3270ea9d5e3SHannes Frederic Sowa 3280ea9d5e3SHannes Frederic Sowa return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? 3290ea9d5e3SHannes Frederic Sowa skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); 3300ea9d5e3SHannes Frederic Sowa } 3310ea9d5e3SHannes Frederic Sowa 3321da177e4SLinus Torvalds #endif /* _ROUTE_H */ 333