| 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * Definitions for the IP router. |
| 7 | * |
| 8 | * Version: @(#)route.h 1.0.4 05/27/93 |
| 9 | * |
| 10 | * Authors: Ross Biro |
| 11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 12 | * Fixes: |
| 13 | * Alan Cox : Reformatted. Added ip_rt_local() |
| 14 | * Alan Cox : Support for TCP parameters. |
| 15 | * Alexey Kuznetsov: Major changes for new routing code. |
| 16 | * Mike McLagan : Routing by source |
| 17 | * Robert Olsson : Added rt_cache statistics |
| 18 | * |
| 19 | * This program is free software; you can redistribute it and/or |
| 20 | * modify it under the terms of the GNU General Public License |
| 21 | * as published by the Free Software Foundation; either version |
| 22 | * 2 of the License, or (at your option) any later version. |
| 23 | */ |
| 24 | #ifndef _ROUTE_H |
| 25 | #define _ROUTE_H |
| 26 | |
| 27 | #include <net/dst.h> |
| 28 | #include <net/inetpeer.h> |
| 29 | #include <net/flow.h> |
| 30 | #include <net/inet_sock.h> |
| 31 | #include <net/ip_fib.h> |
| 32 | #include <net/l3mdev.h> |
| 33 | #include <linux/in_route.h> |
| 34 | #include <linux/rtnetlink.h> |
| 35 | #include <linux/rcupdate.h> |
| 36 | #include <linux/route.h> |
| 37 | #include <linux/ip.h> |
| 38 | #include <linux/cache.h> |
| 39 | #include <linux/security.h> |
| 40 | |
| 41 | /* IPv4 datagram length is stored into 16bit field (tot_len) */ |
| 42 | #define IP_MAX_MTU 0xFFFFU |
| 43 | |
| 44 | #define RTO_ONLINK 0x01 |
| 45 | |
| 46 | #define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE)) |
| 47 | #define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE)) |
| 48 | |
| 49 | struct fib_nh; |
| 50 | struct fib_info; |
| 51 | struct uncached_list; |
| 52 | struct rtable { |
| 53 | struct dst_entry dst; |
| 54 | |
| 55 | int rt_genid; |
| 56 | unsigned int rt_flags; |
| 57 | __u16 rt_type; |
| 58 | __u8 rt_is_input; |
| 59 | __u8 rt_uses_gateway; |
| 60 | |
| 61 | int rt_iif; |
| 62 | |
| 63 | /* Info on neighbour */ |
| 64 | __be32 rt_gateway; |
| 65 | |
| 66 | /* Miscellaneous cached information */ |
| 67 | u32 rt_pmtu; |
| 68 | |
| 69 | u32 rt_table_id; |
| 70 | |
| 71 | struct list_head rt_uncached; |
| 72 | struct uncached_list *rt_uncached_list; |
| 73 | }; |
| 74 | |
| 75 | static inline bool rt_is_input_route(const struct rtable *rt) |
| 76 | { |
| 77 | return rt->rt_is_input != 0; |
| 78 | } |
| 79 | |
| 80 | static inline bool rt_is_output_route(const struct rtable *rt) |
| 81 | { |
| 82 | return rt->rt_is_input == 0; |
| 83 | } |
| 84 | |
| 85 | static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr) |
| 86 | { |
| 87 | if (rt->rt_gateway) |
| 88 | return rt->rt_gateway; |
| 89 | return daddr; |
| 90 | } |
| 91 | |
| 92 | struct ip_rt_acct { |
| 93 | __u32 o_bytes; |
| 94 | __u32 o_packets; |
| 95 | __u32 i_bytes; |
| 96 | __u32 i_packets; |
| 97 | }; |
| 98 | |
| 99 | struct rt_cache_stat { |
| 100 | unsigned int in_slow_tot; |
| 101 | unsigned int in_slow_mc; |
| 102 | unsigned int in_no_route; |
| 103 | unsigned int in_brd; |
| 104 | unsigned int in_martian_dst; |
| 105 | unsigned int in_martian_src; |
| 106 | unsigned int out_slow_tot; |
| 107 | unsigned int out_slow_mc; |
| 108 | }; |
| 109 | |
| 110 | extern struct ip_rt_acct __percpu *ip_rt_acct; |
| 111 | |
| 112 | struct in_device; |
| 113 | |
| 114 | int ip_rt_init(void); |
| 115 | void rt_cache_flush(struct net *net); |
| 116 | void rt_flush_dev(struct net_device *dev); |
| 117 | struct rtable *__ip_route_output_key_hash(struct net *, struct flowi4 *flp, |
| 118 | int mp_hash); |
| 119 | |
| 120 | static inline struct rtable *__ip_route_output_key(struct net *net, |
| 121 | struct flowi4 *flp) |
| 122 | { |
| 123 | return __ip_route_output_key_hash(net, flp, -1); |
| 124 | } |
| 125 | |
| 126 | struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, |
| 127 | const struct sock *sk); |
| 128 | struct dst_entry *ipv4_blackhole_route(struct net *net, |
| 129 | struct dst_entry *dst_orig); |
| 130 | |
| 131 | static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) |
| 132 | { |
| 133 | return ip_route_output_flow(net, flp, NULL); |
| 134 | } |
| 135 | |
| 136 | static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, |
| 137 | __be32 saddr, u8 tos, int oif) |
| 138 | { |
| 139 | struct flowi4 fl4 = { |
| 140 | .flowi4_oif = oif, |
| 141 | .flowi4_tos = tos, |
| 142 | .daddr = daddr, |
| 143 | .saddr = saddr, |
| 144 | }; |
| 145 | return ip_route_output_key(net, &fl4); |
| 146 | } |
| 147 | |
| 148 | static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, |
| 149 | struct sock *sk, |
| 150 | __be32 daddr, __be32 saddr, |
| 151 | __be16 dport, __be16 sport, |
| 152 | __u8 proto, __u8 tos, int oif) |
| 153 | { |
| 154 | flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, |
| 155 | RT_SCOPE_UNIVERSE, proto, |
| 156 | sk ? inet_sk_flowi_flags(sk) : 0, |
| 157 | daddr, saddr, dport, sport); |
| 158 | if (sk) |
| 159 | security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); |
| 160 | return ip_route_output_flow(net, fl4, sk); |
| 161 | } |
| 162 | |
| 163 | static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, |
| 164 | __be32 daddr, __be32 saddr, |
| 165 | __be32 gre_key, __u8 tos, int oif) |
| 166 | { |
| 167 | memset(fl4, 0, sizeof(*fl4)); |
| 168 | fl4->flowi4_oif = oif; |
| 169 | fl4->daddr = daddr; |
| 170 | fl4->saddr = saddr; |
| 171 | fl4->flowi4_tos = tos; |
| 172 | fl4->flowi4_proto = IPPROTO_GRE; |
| 173 | fl4->fl4_gre_key = gre_key; |
| 174 | return ip_route_output_key(net, fl4); |
| 175 | } |
| 176 | |
| 177 | int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, |
| 178 | u8 tos, struct net_device *devin); |
| 179 | |
| 180 | static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, |
| 181 | u8 tos, struct net_device *devin) |
| 182 | { |
| 183 | int err; |
| 184 | |
| 185 | rcu_read_lock(); |
| 186 | err = ip_route_input_noref(skb, dst, src, tos, devin); |
| 187 | if (!err) |
| 188 | skb_dst_force(skb); |
| 189 | rcu_read_unlock(); |
| 190 | |
| 191 | return err; |
| 192 | } |
| 193 | |
| 194 | void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif, |
| 195 | u32 mark, u8 protocol, int flow_flags); |
| 196 | void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); |
| 197 | void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, |
| 198 | u8 protocol, int flow_flags); |
| 199 | void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); |
| 200 | void ip_rt_send_redirect(struct sk_buff *skb); |
| 201 | |
| 202 | unsigned int inet_addr_type(struct net *net, __be32 addr); |
| 203 | unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id); |
| 204 | unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, |
| 205 | __be32 addr); |
| 206 | unsigned int inet_addr_type_dev_table(struct net *net, |
| 207 | const struct net_device *dev, |
| 208 | __be32 addr); |
| 209 | void ip_rt_multicast_event(struct in_device *); |
| 210 | int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); |
| 211 | void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); |
| 212 | struct rtable *rt_dst_alloc(struct net_device *dev, |
| 213 | unsigned int flags, u16 type, |
| 214 | bool nopolicy, bool noxfrm, bool will_cache); |
| 215 | |
| 216 | struct in_ifaddr; |
| 217 | void fib_add_ifaddr(struct in_ifaddr *); |
| 218 | void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); |
| 219 | |
| 220 | static inline void ip_rt_put(struct rtable *rt) |
| 221 | { |
| 222 | /* dst_release() accepts a NULL parameter. |
| 223 | * We rely on dst being first structure in struct rtable |
| 224 | */ |
| 225 | BUILD_BUG_ON(offsetof(struct rtable, dst) != 0); |
| 226 | dst_release(&rt->dst); |
| 227 | } |
| 228 | |
| 229 | #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) |
| 230 | |
| 231 | extern const __u8 ip_tos2prio[16]; |
| 232 | |
| 233 | static inline char rt_tos2priority(u8 tos) |
| 234 | { |
| 235 | return ip_tos2prio[IPTOS_TOS(tos)>>1]; |
| 236 | } |
| 237 | |
| 238 | /* ip_route_connect() and ip_route_newports() work in tandem whilst |
| 239 | * binding a socket for a new outgoing connection. |
| 240 | * |
| 241 | * In order to use IPSEC properly, we must, in the end, have a |
| 242 | * route that was looked up using all available keys including source |
| 243 | * and destination ports. |
| 244 | * |
| 245 | * However, if a source port needs to be allocated (the user specified |
| 246 | * a wildcard source port) we need to obtain addressing information |
| 247 | * in order to perform that allocation. |
| 248 | * |
| 249 | * So ip_route_connect() looks up a route using wildcarded source and |
| 250 | * destination ports in the key, simply so that we can get a pair of |
| 251 | * addresses to use for port allocation. |
| 252 | * |
| 253 | * Later, once the ports are allocated, ip_route_newports() will make |
| 254 | * another route lookup if needed to make sure we catch any IPSEC |
| 255 | * rules keyed on the port information. |
| 256 | * |
| 257 | * The callers allocate the flow key on their stack, and must pass in |
| 258 | * the same flowi4 object to both the ip_route_connect() and the |
| 259 | * ip_route_newports() calls. |
| 260 | */ |
| 261 | |
| 262 | static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, |
| 263 | u32 tos, int oif, u8 protocol, |
| 264 | __be16 sport, __be16 dport, |
| 265 | struct sock *sk) |
| 266 | { |
| 267 | __u8 flow_flags = 0; |
| 268 | |
| 269 | if (inet_sk(sk)->transparent) |
| 270 | flow_flags |= FLOWI_FLAG_ANYSRC; |
| 271 | |
| 272 | flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, |
| 273 | protocol, flow_flags, dst, src, dport, sport); |
| 274 | } |
| 275 | |
| 276 | static inline struct rtable *ip_route_connect(struct flowi4 *fl4, |
| 277 | __be32 dst, __be32 src, u32 tos, |
| 278 | int oif, u8 protocol, |
| 279 | __be16 sport, __be16 dport, |
| 280 | struct sock *sk) |
| 281 | { |
| 282 | struct net *net = sock_net(sk); |
| 283 | struct rtable *rt; |
| 284 | |
| 285 | ip_route_connect_init(fl4, dst, src, tos, oif, protocol, |
| 286 | sport, dport, sk); |
| 287 | |
| 288 | if (!src && oif) { |
| 289 | int rc; |
| 290 | |
| 291 | rc = l3mdev_get_saddr(net, oif, fl4); |
| 292 | if (rc < 0) |
| 293 | return ERR_PTR(rc); |
| 294 | |
| 295 | src = fl4->saddr; |
| 296 | } |
| 297 | if (!dst || !src) { |
| 298 | rt = __ip_route_output_key(net, fl4); |
| 299 | if (IS_ERR(rt)) |
| 300 | return rt; |
| 301 | ip_rt_put(rt); |
| 302 | flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); |
| 303 | } |
| 304 | security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); |
| 305 | return ip_route_output_flow(net, fl4, sk); |
| 306 | } |
| 307 | |
| 308 | static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, |
| 309 | __be16 orig_sport, __be16 orig_dport, |
| 310 | __be16 sport, __be16 dport, |
| 311 | struct sock *sk) |
| 312 | { |
| 313 | if (sport != orig_sport || dport != orig_dport) { |
| 314 | fl4->fl4_dport = dport; |
| 315 | fl4->fl4_sport = sport; |
| 316 | ip_rt_put(rt); |
| 317 | flowi4_update_output(fl4, sk->sk_bound_dev_if, |
| 318 | RT_CONN_FLAGS(sk), fl4->daddr, |
| 319 | fl4->saddr); |
| 320 | security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); |
| 321 | return ip_route_output_flow(sock_net(sk), fl4, sk); |
| 322 | } |
| 323 | return rt; |
| 324 | } |
| 325 | |
| 326 | static inline int inet_iif(const struct sk_buff *skb) |
| 327 | { |
| 328 | struct rtable *rt = skb_rtable(skb); |
| 329 | |
| 330 | if (rt && rt->rt_iif) |
| 331 | return rt->rt_iif; |
| 332 | |
| 333 | return skb->skb_iif; |
| 334 | } |
| 335 | |
| 336 | static inline int ip4_dst_hoplimit(const struct dst_entry *dst) |
| 337 | { |
| 338 | int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); |
| 339 | struct net *net = dev_net(dst->dev); |
| 340 | |
| 341 | if (hoplimit == 0) |
| 342 | hoplimit = net->ipv4.sysctl_ip_default_ttl; |
| 343 | return hoplimit; |
| 344 | } |
| 345 | |
| 346 | #endif /* _ROUTE_H */ |