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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the IP router.
8 *
9 * Version: @(#)route.h 1.0.4 05/27/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Fixes:
14 * Alan Cox : Reformatted. Added ip_rt_local()
15 * Alan Cox : Support for TCP parameters.
16 * Alexey Kuznetsov: Major changes for new routing code.
17 * Mike McLagan : Routing by source
18 * Robert Olsson : Added rt_cache statistics
19 */
20#ifndef _ROUTE_H
21#define _ROUTE_H
22
23#include <net/dst.h>
24#include <net/inetpeer.h>
25#include <net/flow.h>
26#include <net/inet_sock.h>
27#include <net/ip_fib.h>
28#include <net/arp.h>
29#include <net/ndisc.h>
30#include <linux/in_route.h>
31#include <linux/rtnetlink.h>
32#include <linux/rcupdate.h>
33#include <linux/route.h>
34#include <linux/ip.h>
35#include <linux/cache.h>
36#include <linux/security.h>
37
38#define RTO_ONLINK 0x01
39
40#define RT_CONN_FLAGS(sk) (RT_TOS(READ_ONCE(inet_sk(sk)->tos)) | sock_flag(sk, SOCK_LOCALROUTE))
41#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
42
43static inline __u8 ip_sock_rt_scope(const struct sock *sk)
44{
45 if (sock_flag(sk, SOCK_LOCALROUTE))
46 return RT_SCOPE_LINK;
47
48 return RT_SCOPE_UNIVERSE;
49}
50
51static inline __u8 ip_sock_rt_tos(const struct sock *sk)
52{
53 return RT_TOS(READ_ONCE(inet_sk(sk)->tos));
54}
55
56struct ip_tunnel_info;
57struct fib_nh;
58struct fib_info;
59struct uncached_list;
60struct rtable {
61 struct dst_entry dst;
62
63 int rt_genid;
64 unsigned int rt_flags;
65 __u16 rt_type;
66 __u8 rt_is_input;
67 __u8 rt_uses_gateway;
68
69 int rt_iif;
70
71 u8 rt_gw_family;
72 /* Info on neighbour */
73 union {
74 __be32 rt_gw4;
75 struct in6_addr rt_gw6;
76 };
77
78 /* Miscellaneous cached information */
79 u32 rt_mtu_locked:1,
80 rt_pmtu:31;
81};
82
83static inline bool rt_is_input_route(const struct rtable *rt)
84{
85 return rt->rt_is_input != 0;
86}
87
88static inline bool rt_is_output_route(const struct rtable *rt)
89{
90 return rt->rt_is_input == 0;
91}
92
93static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
94{
95 if (rt->rt_gw_family == AF_INET)
96 return rt->rt_gw4;
97 return daddr;
98}
99
100struct ip_rt_acct {
101 __u32 o_bytes;
102 __u32 o_packets;
103 __u32 i_bytes;
104 __u32 i_packets;
105};
106
107struct rt_cache_stat {
108 unsigned int in_slow_tot;
109 unsigned int in_slow_mc;
110 unsigned int in_no_route;
111 unsigned int in_brd;
112 unsigned int in_martian_dst;
113 unsigned int in_martian_src;
114 unsigned int out_slow_tot;
115 unsigned int out_slow_mc;
116};
117
118extern struct ip_rt_acct __percpu *ip_rt_acct;
119
120struct in_device;
121
122int ip_rt_init(void);
123void rt_cache_flush(struct net *net);
124void rt_flush_dev(struct net_device *dev);
125struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
126 const struct sk_buff *skb);
127struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
128 struct fib_result *res,
129 const struct sk_buff *skb);
130
131static inline struct rtable *__ip_route_output_key(struct net *net,
132 struct flowi4 *flp)
133{
134 return ip_route_output_key_hash(net, flp, NULL);
135}
136
137struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
138 const struct sock *sk);
139struct dst_entry *ipv4_blackhole_route(struct net *net,
140 struct dst_entry *dst_orig);
141
142static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
143{
144 return ip_route_output_flow(net, flp, NULL);
145}
146
147static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
148 __be32 saddr, u8 tos, int oif)
149{
150 struct flowi4 fl4 = {
151 .flowi4_oif = oif,
152 .flowi4_tos = tos,
153 .daddr = daddr,
154 .saddr = saddr,
155 };
156 return ip_route_output_key(net, &fl4);
157}
158
159static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
160 const struct sock *sk,
161 __be32 daddr, __be32 saddr,
162 __be16 dport, __be16 sport,
163 __u8 proto, __u8 tos, int oif)
164{
165 flowi4_init_output(fl4, oif, sk ? READ_ONCE(sk->sk_mark) : 0, tos,
166 RT_SCOPE_UNIVERSE, proto,
167 sk ? inet_sk_flowi_flags(sk) : 0,
168 daddr, saddr, dport, sport, sock_net_uid(net, sk));
169 if (sk)
170 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
171 return ip_route_output_flow(net, fl4, sk);
172}
173
174static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
175 __be32 daddr, __be32 saddr,
176 __be32 gre_key, __u8 tos, int oif)
177{
178 memset(fl4, 0, sizeof(*fl4));
179 fl4->flowi4_oif = oif;
180 fl4->daddr = daddr;
181 fl4->saddr = saddr;
182 fl4->flowi4_tos = tos;
183 fl4->flowi4_proto = IPPROTO_GRE;
184 fl4->fl4_gre_key = gre_key;
185 return ip_route_output_key(net, fl4);
186}
187int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
188 u8 tos, struct net_device *dev,
189 struct in_device *in_dev, u32 *itag);
190int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
191 u8 tos, struct net_device *devin);
192int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src,
193 u8 tos, struct net_device *devin,
194 const struct sk_buff *hint);
195
196static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
197 u8 tos, struct net_device *devin)
198{
199 int err;
200
201 rcu_read_lock();
202 err = ip_route_input_noref(skb, dst, src, tos, devin);
203 if (!err) {
204 skb_dst_force(skb);
205 if (!skb_dst(skb))
206 err = -EINVAL;
207 }
208 rcu_read_unlock();
209
210 return err;
211}
212
213void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
214 u8 protocol);
215void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
216void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
217void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
218void ip_rt_send_redirect(struct sk_buff *skb);
219
220unsigned int inet_addr_type(struct net *net, __be32 addr);
221unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
222unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
223 __be32 addr);
224unsigned int inet_addr_type_dev_table(struct net *net,
225 const struct net_device *dev,
226 __be32 addr);
227void ip_rt_multicast_event(struct in_device *);
228int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
229void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
230struct rtable *rt_dst_alloc(struct net_device *dev,
231 unsigned int flags, u16 type, bool noxfrm);
232struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
233
234struct in_ifaddr;
235void fib_add_ifaddr(struct in_ifaddr *);
236void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
237void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
238
239void rt_add_uncached_list(struct rtable *rt);
240void rt_del_uncached_list(struct rtable *rt);
241
242int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
243 u32 table_id, struct fib_info *fi,
244 int *fa_index, int fa_start, unsigned int flags);
245
246static inline void ip_rt_put(struct rtable *rt)
247{
248 /* dst_release() accepts a NULL parameter.
249 * We rely on dst being first structure in struct rtable
250 */
251 BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
252 dst_release(&rt->dst);
253}
254
255#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
256
257extern const __u8 ip_tos2prio[16];
258
259static inline char rt_tos2priority(u8 tos)
260{
261 return ip_tos2prio[IPTOS_TOS(tos)>>1];
262}
263
264/* ip_route_connect() and ip_route_newports() work in tandem whilst
265 * binding a socket for a new outgoing connection.
266 *
267 * In order to use IPSEC properly, we must, in the end, have a
268 * route that was looked up using all available keys including source
269 * and destination ports.
270 *
271 * However, if a source port needs to be allocated (the user specified
272 * a wildcard source port) we need to obtain addressing information
273 * in order to perform that allocation.
274 *
275 * So ip_route_connect() looks up a route using wildcarded source and
276 * destination ports in the key, simply so that we can get a pair of
277 * addresses to use for port allocation.
278 *
279 * Later, once the ports are allocated, ip_route_newports() will make
280 * another route lookup if needed to make sure we catch any IPSEC
281 * rules keyed on the port information.
282 *
283 * The callers allocate the flow key on their stack, and must pass in
284 * the same flowi4 object to both the ip_route_connect() and the
285 * ip_route_newports() calls.
286 */
287
288static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst,
289 __be32 src, int oif, u8 protocol,
290 __be16 sport, __be16 dport,
291 const struct sock *sk)
292{
293 __u8 flow_flags = 0;
294
295 if (inet_test_bit(TRANSPARENT, sk))
296 flow_flags |= FLOWI_FLAG_ANYSRC;
297
298 flowi4_init_output(fl4, oif, READ_ONCE(sk->sk_mark), ip_sock_rt_tos(sk),
299 ip_sock_rt_scope(sk), protocol, flow_flags, dst,
300 src, dport, sport, sk->sk_uid);
301}
302
303static inline struct rtable *ip_route_connect(struct flowi4 *fl4, __be32 dst,
304 __be32 src, int oif, u8 protocol,
305 __be16 sport, __be16 dport,
306 const struct sock *sk)
307{
308 struct net *net = sock_net(sk);
309 struct rtable *rt;
310
311 ip_route_connect_init(fl4, dst, src, oif, protocol, sport, dport, sk);
312
313 if (!dst || !src) {
314 rt = __ip_route_output_key(net, fl4);
315 if (IS_ERR(rt))
316 return rt;
317 ip_rt_put(rt);
318 flowi4_update_output(fl4, oif, fl4->daddr, fl4->saddr);
319 }
320 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
321 return ip_route_output_flow(net, fl4, sk);
322}
323
324static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
325 __be16 orig_sport, __be16 orig_dport,
326 __be16 sport, __be16 dport,
327 const struct sock *sk)
328{
329 if (sport != orig_sport || dport != orig_dport) {
330 fl4->fl4_dport = dport;
331 fl4->fl4_sport = sport;
332 ip_rt_put(rt);
333 flowi4_update_output(fl4, sk->sk_bound_dev_if, fl4->daddr,
334 fl4->saddr);
335 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
336 return ip_route_output_flow(sock_net(sk), fl4, sk);
337 }
338 return rt;
339}
340
341static inline int inet_iif(const struct sk_buff *skb)
342{
343 struct rtable *rt = skb_rtable(skb);
344
345 if (rt && rt->rt_iif)
346 return rt->rt_iif;
347
348 return skb->skb_iif;
349}
350
351static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
352{
353 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
354 struct net *net = dev_net(dst->dev);
355
356 if (hoplimit == 0)
357 hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl);
358 return hoplimit;
359}
360
361static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
362 __be32 daddr)
363{
364 struct neighbour *neigh;
365
366 neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);
367 if (unlikely(!neigh))
368 neigh = __neigh_create(&arp_tbl, &daddr, dev, false);
369
370 return neigh;
371}
372
373static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,
374 struct sk_buff *skb,
375 bool *is_v6gw)
376{
377 struct net_device *dev = rt->dst.dev;
378 struct neighbour *neigh;
379
380 if (likely(rt->rt_gw_family == AF_INET)) {
381 neigh = ip_neigh_gw4(dev, rt->rt_gw4);
382 } else if (rt->rt_gw_family == AF_INET6) {
383 neigh = ip_neigh_gw6(dev, &rt->rt_gw6);
384 *is_v6gw = true;
385 } else {
386 neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);
387 }
388 return neigh;
389}
390
391#endif /* _ROUTE_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the IP router.
8 *
9 * Version: @(#)route.h 1.0.4 05/27/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Fixes:
14 * Alan Cox : Reformatted. Added ip_rt_local()
15 * Alan Cox : Support for TCP parameters.
16 * Alexey Kuznetsov: Major changes for new routing code.
17 * Mike McLagan : Routing by source
18 * Robert Olsson : Added rt_cache statistics
19 */
20#ifndef _ROUTE_H
21#define _ROUTE_H
22
23#include <net/dst.h>
24#include <net/inetpeer.h>
25#include <net/flow.h>
26#include <net/inet_sock.h>
27#include <net/ip_fib.h>
28#include <net/arp.h>
29#include <net/ndisc.h>
30#include <linux/in_route.h>
31#include <linux/rtnetlink.h>
32#include <linux/rcupdate.h>
33#include <linux/route.h>
34#include <linux/ip.h>
35#include <linux/cache.h>
36#include <linux/security.h>
37
38/* IPv4 datagram length is stored into 16bit field (tot_len) */
39#define IP_MAX_MTU 0xFFFFU
40
41#define RTO_ONLINK 0x01
42
43#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
44#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
45
46struct fib_nh;
47struct fib_info;
48struct uncached_list;
49struct rtable {
50 struct dst_entry dst;
51
52 int rt_genid;
53 unsigned int rt_flags;
54 __u16 rt_type;
55 __u8 rt_is_input;
56 __u8 rt_uses_gateway;
57
58 int rt_iif;
59
60 u8 rt_gw_family;
61 /* Info on neighbour */
62 union {
63 __be32 rt_gw4;
64 struct in6_addr rt_gw6;
65 };
66
67 /* Miscellaneous cached information */
68 u32 rt_mtu_locked:1,
69 rt_pmtu:31;
70
71 struct list_head rt_uncached;
72 struct uncached_list *rt_uncached_list;
73};
74
75static inline bool rt_is_input_route(const struct rtable *rt)
76{
77 return rt->rt_is_input != 0;
78}
79
80static inline bool rt_is_output_route(const struct rtable *rt)
81{
82 return rt->rt_is_input == 0;
83}
84
85static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
86{
87 if (rt->rt_gw_family == AF_INET)
88 return rt->rt_gw4;
89 return daddr;
90}
91
92struct ip_rt_acct {
93 __u32 o_bytes;
94 __u32 o_packets;
95 __u32 i_bytes;
96 __u32 i_packets;
97};
98
99struct 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
110extern struct ip_rt_acct __percpu *ip_rt_acct;
111
112struct in_device;
113
114int ip_rt_init(void);
115void rt_cache_flush(struct net *net);
116void rt_flush_dev(struct net_device *dev);
117struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
118 const struct sk_buff *skb);
119struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
120 struct fib_result *res,
121 const struct sk_buff *skb);
122
123static inline struct rtable *__ip_route_output_key(struct net *net,
124 struct flowi4 *flp)
125{
126 return ip_route_output_key_hash(net, flp, NULL);
127}
128
129struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
130 const struct sock *sk);
131struct dst_entry *ipv4_blackhole_route(struct net *net,
132 struct dst_entry *dst_orig);
133
134static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
135{
136 return ip_route_output_flow(net, flp, NULL);
137}
138
139static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
140 __be32 saddr, u8 tos, int oif)
141{
142 struct flowi4 fl4 = {
143 .flowi4_oif = oif,
144 .flowi4_tos = tos,
145 .daddr = daddr,
146 .saddr = saddr,
147 };
148 return ip_route_output_key(net, &fl4);
149}
150
151static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
152 struct sock *sk,
153 __be32 daddr, __be32 saddr,
154 __be16 dport, __be16 sport,
155 __u8 proto, __u8 tos, int oif)
156{
157 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos,
158 RT_SCOPE_UNIVERSE, proto,
159 sk ? inet_sk_flowi_flags(sk) : 0,
160 daddr, saddr, dport, sport, sock_net_uid(net, sk));
161 if (sk)
162 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
163 return ip_route_output_flow(net, fl4, sk);
164}
165
166static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
167 __be32 daddr, __be32 saddr,
168 __be32 gre_key, __u8 tos, int oif)
169{
170 memset(fl4, 0, sizeof(*fl4));
171 fl4->flowi4_oif = oif;
172 fl4->daddr = daddr;
173 fl4->saddr = saddr;
174 fl4->flowi4_tos = tos;
175 fl4->flowi4_proto = IPPROTO_GRE;
176 fl4->fl4_gre_key = gre_key;
177 return ip_route_output_key(net, fl4);
178}
179int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
180 u8 tos, struct net_device *dev,
181 struct in_device *in_dev, u32 *itag);
182int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
183 u8 tos, struct net_device *devin);
184int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
185 u8 tos, struct net_device *devin,
186 struct fib_result *res);
187
188static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
189 u8 tos, struct net_device *devin)
190{
191 int err;
192
193 rcu_read_lock();
194 err = ip_route_input_noref(skb, dst, src, tos, devin);
195 if (!err) {
196 skb_dst_force(skb);
197 if (!skb_dst(skb))
198 err = -EINVAL;
199 }
200 rcu_read_unlock();
201
202 return err;
203}
204
205void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
206 u8 protocol);
207void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
208void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
209void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
210void ip_rt_send_redirect(struct sk_buff *skb);
211
212unsigned int inet_addr_type(struct net *net, __be32 addr);
213unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
214unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
215 __be32 addr);
216unsigned int inet_addr_type_dev_table(struct net *net,
217 const struct net_device *dev,
218 __be32 addr);
219void ip_rt_multicast_event(struct in_device *);
220int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
221void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
222struct rtable *rt_dst_alloc(struct net_device *dev,
223 unsigned int flags, u16 type,
224 bool nopolicy, bool noxfrm, bool will_cache);
225struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
226
227struct in_ifaddr;
228void fib_add_ifaddr(struct in_ifaddr *);
229void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
230void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
231
232void rt_add_uncached_list(struct rtable *rt);
233void rt_del_uncached_list(struct rtable *rt);
234
235int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
236 u32 table_id, struct fib_info *fi,
237 int *fa_index, int fa_start, unsigned int flags);
238
239static inline void ip_rt_put(struct rtable *rt)
240{
241 /* dst_release() accepts a NULL parameter.
242 * We rely on dst being first structure in struct rtable
243 */
244 BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
245 dst_release(&rt->dst);
246}
247
248#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
249
250extern const __u8 ip_tos2prio[16];
251
252static inline char rt_tos2priority(u8 tos)
253{
254 return ip_tos2prio[IPTOS_TOS(tos)>>1];
255}
256
257/* ip_route_connect() and ip_route_newports() work in tandem whilst
258 * binding a socket for a new outgoing connection.
259 *
260 * In order to use IPSEC properly, we must, in the end, have a
261 * route that was looked up using all available keys including source
262 * and destination ports.
263 *
264 * However, if a source port needs to be allocated (the user specified
265 * a wildcard source port) we need to obtain addressing information
266 * in order to perform that allocation.
267 *
268 * So ip_route_connect() looks up a route using wildcarded source and
269 * destination ports in the key, simply so that we can get a pair of
270 * addresses to use for port allocation.
271 *
272 * Later, once the ports are allocated, ip_route_newports() will make
273 * another route lookup if needed to make sure we catch any IPSEC
274 * rules keyed on the port information.
275 *
276 * The callers allocate the flow key on their stack, and must pass in
277 * the same flowi4 object to both the ip_route_connect() and the
278 * ip_route_newports() calls.
279 */
280
281static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
282 u32 tos, int oif, u8 protocol,
283 __be16 sport, __be16 dport,
284 struct sock *sk)
285{
286 __u8 flow_flags = 0;
287
288 if (inet_sk(sk)->transparent)
289 flow_flags |= FLOWI_FLAG_ANYSRC;
290
291 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
292 protocol, flow_flags, dst, src, dport, sport,
293 sk->sk_uid);
294}
295
296static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
297 __be32 dst, __be32 src, u32 tos,
298 int oif, u8 protocol,
299 __be16 sport, __be16 dport,
300 struct sock *sk)
301{
302 struct net *net = sock_net(sk);
303 struct rtable *rt;
304
305 ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
306 sport, dport, sk);
307
308 if (!dst || !src) {
309 rt = __ip_route_output_key(net, fl4);
310 if (IS_ERR(rt))
311 return rt;
312 ip_rt_put(rt);
313 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
314 }
315 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
316 return ip_route_output_flow(net, fl4, sk);
317}
318
319static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
320 __be16 orig_sport, __be16 orig_dport,
321 __be16 sport, __be16 dport,
322 struct sock *sk)
323{
324 if (sport != orig_sport || dport != orig_dport) {
325 fl4->fl4_dport = dport;
326 fl4->fl4_sport = sport;
327 ip_rt_put(rt);
328 flowi4_update_output(fl4, sk->sk_bound_dev_if,
329 RT_CONN_FLAGS(sk), fl4->daddr,
330 fl4->saddr);
331 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
332 return ip_route_output_flow(sock_net(sk), fl4, sk);
333 }
334 return rt;
335}
336
337static inline int inet_iif(const struct sk_buff *skb)
338{
339 struct rtable *rt = skb_rtable(skb);
340
341 if (rt && rt->rt_iif)
342 return rt->rt_iif;
343
344 return skb->skb_iif;
345}
346
347static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
348{
349 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
350 struct net *net = dev_net(dst->dev);
351
352 if (hoplimit == 0)
353 hoplimit = net->ipv4.sysctl_ip_default_ttl;
354 return hoplimit;
355}
356
357static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
358 __be32 daddr)
359{
360 struct neighbour *neigh;
361
362 neigh = __ipv4_neigh_lookup_noref(dev, daddr);
363 if (unlikely(!neigh))
364 neigh = __neigh_create(&arp_tbl, &daddr, dev, false);
365
366 return neigh;
367}
368
369static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,
370 struct sk_buff *skb,
371 bool *is_v6gw)
372{
373 struct net_device *dev = rt->dst.dev;
374 struct neighbour *neigh;
375
376 if (likely(rt->rt_gw_family == AF_INET)) {
377 neigh = ip_neigh_gw4(dev, rt->rt_gw4);
378 } else if (rt->rt_gw_family == AF_INET6) {
379 neigh = ip_neigh_gw6(dev, &rt->rt_gw6);
380 *is_v6gw = true;
381 } else {
382 neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);
383 }
384 return neigh;
385}
386
387#endif /* _ROUTE_H */