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ipv4: remove sparse error in ip_neigh_gw4()
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2874c5fd 1/* SPDX-License-Identifier: GPL-2.0-or-later */
1da177e4
LT
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 *
02c30a84 11 * Authors: Ross Biro
1da177e4
LT
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
1da177e4
LT
19 */
20#ifndef _ROUTE_H
21#define _ROUTE_H
22
1da177e4
LT
23#include <net/dst.h>
24#include <net/inetpeer.h>
25#include <net/flow.h>
79876874 26#include <net/inet_sock.h>
79a13159 27#include <net/ip_fib.h>
5c9f7c1d
DA
28#include <net/arp.h>
29#include <net/ndisc.h>
1da177e4
LT
30#include <linux/in_route.h>
31#include <linux/rtnetlink.h>
c6cffba4 32#include <linux/rcupdate.h>
1da177e4
LT
33#include <linux/route.h>
34#include <linux/ip.h>
35#include <linux/cache.h>
beb8d13b 36#include <linux/security.h>
1da177e4 37
f87c10a8
HFS
38/* IPv4 datagram length is stored into 16bit field (tot_len) */
39#define IP_MAX_MTU 0xFFFFU
40
1da177e4
LT
41#define RTO_ONLINK 0x01
42
1da177e4 43#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
aa661581 44#define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
1da177e4
LT
45
46struct fib_nh;
62fa8a84 47struct fib_info;
5055c371 48struct uncached_list;
fd2c3ef7 49struct rtable {
d8d1f30b 50 struct dst_entry dst;
1da177e4 51
29e75252 52 int rt_genid;
95c96174 53 unsigned int rt_flags;
1da177e4 54 __u16 rt_type;
155e8336 55 __u8 rt_is_input;
77d5bc7e 56 __u8 rt_uses_gateway;
1da177e4 57
1da177e4
LT
58 int rt_iif;
59
77d5bc7e 60 u8 rt_gw_family;
1da177e4 61 /* Info on neighbour */
0f5f7d7b
DA
62 union {
63 __be32 rt_gw4;
64 struct in6_addr rt_gw6;
65 };
1da177e4 66
1da177e4 67 /* Miscellaneous cached information */
d52e5a7e
SD
68 u32 rt_mtu_locked:1,
69 rt_pmtu:31;
caacf05e
DM
70
71 struct list_head rt_uncached;
5055c371 72 struct uncached_list *rt_uncached_list;
1da177e4
LT
73};
74
b8400f37 75static inline bool rt_is_input_route(const struct rtable *rt)
c7537967 76{
9917e1e8 77 return rt->rt_is_input != 0;
c7537967
DM
78}
79
b8400f37 80static inline bool rt_is_output_route(const struct rtable *rt)
c7537967 81{
9917e1e8 82 return rt->rt_is_input == 0;
c7537967
DM
83}
84
f8126f1d
DM
85static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
86{
1550c171
DA
87 if (rt->rt_gw_family == AF_INET)
88 return rt->rt_gw4;
f8126f1d
DM
89 return daddr;
90}
91
fd2c3ef7 92struct ip_rt_acct {
1da177e4
LT
93 __u32 o_bytes;
94 __u32 o_packets;
95 __u32 i_bytes;
96 __u32 i_packets;
97};
98
fd2c3ef7 99struct rt_cache_stat {
1da177e4
LT
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;
1da177e4
LT
106 unsigned int out_slow_tot;
107 unsigned int out_slow_mc;
1da177e4
LT
108};
109
7d720c3e 110extern struct ip_rt_acct __percpu *ip_rt_acct;
1da177e4
LT
111
112struct in_device;
2702c4bb
JP
113
114int ip_rt_init(void);
115void rt_cache_flush(struct net *net);
116void rt_flush_dev(struct net_device *dev);
3abd1ade
DA
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);
79a13159
PN
122
123static inline struct rtable *__ip_route_output_key(struct net *net,
124 struct flowi4 *flp)
125{
3abd1ade 126 return ip_route_output_key_hash(net, flp, NULL);
79a13159
PN
127}
128
2702c4bb 129struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
6f9c9615 130 const struct sock *sk);
2702c4bb
JP
131struct dst_entry *ipv4_blackhole_route(struct net *net,
132 struct dst_entry *dst_orig);
407eadd9 133
9d6ec938 134static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
5bfa787f
DM
135{
136 return ip_route_output_flow(net, flp, NULL);
137}
138
78fbfd8a
DM
139static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
140 __be32 saddr, u8 tos, int oif)
141{
9d6ec938
DM
142 struct flowi4 fl4 = {
143 .flowi4_oif = oif,
c5d21c4b 144 .flowi4_tos = tos,
9d6ec938
DM
145 .daddr = daddr,
146 .saddr = saddr,
78fbfd8a 147 };
9d6ec938 148 return ip_route_output_key(net, &fl4);
78fbfd8a
DM
149}
150
31e4543d
DM
151static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
152 struct sock *sk,
78fbfd8a
DM
153 __be32 daddr, __be32 saddr,
154 __be16 dport, __be16 sport,
155 __u8 proto, __u8 tos, int oif)
156{
31e4543d 157 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos,
94b92b88
DM
158 RT_SCOPE_UNIVERSE, proto,
159 sk ? inet_sk_flowi_flags(sk) : 0,
e2d118a1 160 daddr, saddr, dport, sport, sock_net_uid(net, sk));
78fbfd8a 161 if (sk)
31e4543d
DM
162 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
163 return ip_route_output_flow(net, fl4, sk);
78fbfd8a
DM
164}
165
cbb1e85f 166static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
78fbfd8a
DM
167 __be32 daddr, __be32 saddr,
168 __be32 gre_key, __u8 tos, int oif)
169{
cbb1e85f
DM
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);
78fbfd8a 178}
bc044e8d
PA
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);
2702c4bb
JP
182int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
183 u8 tos, struct net_device *devin);
5510cdf7
DA
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);
c6cffba4
DM
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);
64327fc8 195 if (!err) {
222d7dbd 196 skb_dst_force(skb);
64327fc8
SB
197 if (!skb_dst(skb))
198 err = -EINVAL;
199 }
c6cffba4
DM
200 rcu_read_unlock();
201
202 return err;
203}
407eadd9 204
2702c4bb 205void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
d888f396 206 u8 protocol);
2702c4bb 207void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
1042caa7 208void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
2702c4bb
JP
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);
9b8ff518 213unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
2702c4bb
JP
214unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
215 __be32 addr);
30bbaa19
DA
216unsigned int inet_addr_type_dev_table(struct net *net,
217 const struct net_device *dev,
218 __be32 addr);
2702c4bb 219void ip_rt_multicast_event(struct in_device *);
ca25c300 220int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
2702c4bb 221void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
9ab179d8
DA
222struct rtable *rt_dst_alloc(struct net_device *dev,
223 unsigned int flags, u16 type,
224 bool nopolicy, bool noxfrm, bool will_cache);
5b18f128 225struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
1da177e4 226
0ff60a45 227struct in_ifaddr;
2702c4bb
JP
228void fib_add_ifaddr(struct in_ifaddr *);
229void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
af4d768a 230void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
0ff60a45 231
510c321b
XL
232void rt_add_uncached_list(struct rtable *rt);
233void rt_del_uncached_list(struct rtable *rt);
234
ee28906f
SB
235int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
236 u32 table_id, struct fib_info *fi,
e93fb3e9 237 int *fa_index, int fa_start, unsigned int flags);
ee28906f 238
6da025fa 239static inline void ip_rt_put(struct rtable *rt)
1da177e4 240{
6da025fa
ED
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);
1da177e4
LT
246}
247
248#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
249
4839c52b 250extern const __u8 ip_tos2prio[16];
1da177e4
LT
251
252static inline char rt_tos2priority(u8 tos)
253{
254 return ip_tos2prio[IPTOS_TOS(tos)>>1];
255}
256
2d7192d6
DM
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,
0e0d44ab 284 struct sock *sk)
1da177e4 285{
2d7192d6 286 __u8 flow_flags = 0;
79876874
KK
287
288 if (inet_sk(sk)->transparent)
94b92b88 289 flow_flags |= FLOWI_FLAG_ANYSRC;
94b92b88 290
2d7192d6 291 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
e2d118a1
LC
292 protocol, flow_flags, dst, src, dport, sport,
293 sk->sk_uid);
2d7192d6
DM
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,
0e0d44ab 300 struct sock *sk)
2d7192d6
DM
301{
302 struct net *net = sock_net(sk);
303 struct rtable *rt;
304
305 ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
0e0d44ab 306 sport, dport, sk);
79876874 307
1da177e4 308 if (!dst || !src) {
2d7192d6 309 rt = __ip_route_output_key(net, fl4);
b23dd4fe
DM
310 if (IS_ERR(rt))
311 return rt;
b23dd4fe 312 ip_rt_put(rt);
e6b45241 313 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
1da177e4 314 }
2d7192d6
DM
315 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
316 return ip_route_output_flow(net, fl4, sk);
1da177e4
LT
317}
318
2d7192d6
DM
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)
1da177e4 323{
dca8b089 324 if (sport != orig_sport || dport != orig_dport) {
2d7192d6
DM
325 fl4->fl4_dport = dport;
326 fl4->fl4_sport = sport;
b23dd4fe 327 ip_rt_put(rt);
e6b45241
JA
328 flowi4_update_output(fl4, sk->sk_bound_dev_if,
329 RT_CONN_FLAGS(sk), fl4->daddr,
330 fl4->saddr);
2d7192d6
DM
331 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
332 return ip_route_output_flow(sock_net(sk), fl4, sk);
1da177e4 333 }
b23dd4fe 334 return rt;
1da177e4
LT
335}
336
1668e010
KK
337static inline int inet_iif(const struct sk_buff *skb)
338{
0340d0b9
TH
339 struct rtable *rt = skb_rtable(skb);
340
341 if (rt && rt->rt_iif)
342 return rt->rt_iif;
13378cad 343
13378cad 344 return skb->skb_iif;
1668e010
KK
345}
346
323e126f
DM
347static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
348{
349 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
fa50d974 350 struct net *net = dev_net(dst->dev);
323e126f
DM
351
352 if (hoplimit == 0)
fa50d974 353 hoplimit = net->ipv4.sysctl_ip_default_ttl;
323e126f
DM
354 return hoplimit;
355}
356
5c9f7c1d
DA
357static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
358 __be32 daddr)
359{
360 struct neighbour *neigh;
361
e8057215 362 neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);
5c9f7c1d
DA
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
1da177e4 387#endif /* _ROUTE_H */