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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/core/dst_cache.c - dst entry cache
4 *
5 * Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/percpu.h>
10#include <net/dst_cache.h>
11#include <net/route.h>
12#if IS_ENABLED(CONFIG_IPV6)
13#include <net/ip6_fib.h>
14#endif
15#include <uapi/linux/in.h>
16
17struct dst_cache_pcpu {
18 unsigned long refresh_ts;
19 struct dst_entry *dst;
20 u32 cookie;
21 union {
22 struct in_addr in_saddr;
23 struct in6_addr in6_saddr;
24 };
25};
26
27static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
28 struct dst_entry *dst, u32 cookie)
29{
30 dst_release(dst_cache->dst);
31 if (dst)
32 dst_hold(dst);
33
34 dst_cache->cookie = cookie;
35 dst_cache->dst = dst;
36}
37
38static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
39 struct dst_cache_pcpu *idst)
40{
41 struct dst_entry *dst;
42
43 dst = idst->dst;
44 if (!dst)
45 goto fail;
46
47 /* the cache already hold a dst reference; it can't go away */
48 dst_hold(dst);
49
50 if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) ||
51 (dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
52 dst_cache_per_cpu_dst_set(idst, NULL, 0);
53 dst_release(dst);
54 goto fail;
55 }
56 return dst;
57
58fail:
59 idst->refresh_ts = jiffies;
60 return NULL;
61}
62
63struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
64{
65 if (!dst_cache->cache)
66 return NULL;
67
68 return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
69}
70EXPORT_SYMBOL_GPL(dst_cache_get);
71
72struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
73{
74 struct dst_cache_pcpu *idst;
75 struct dst_entry *dst;
76
77 if (!dst_cache->cache)
78 return NULL;
79
80 idst = this_cpu_ptr(dst_cache->cache);
81 dst = dst_cache_per_cpu_get(dst_cache, idst);
82 if (!dst)
83 return NULL;
84
85 *saddr = idst->in_saddr.s_addr;
86 return dst_rtable(dst);
87}
88EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
89
90void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
91 __be32 saddr)
92{
93 struct dst_cache_pcpu *idst;
94
95 if (!dst_cache->cache)
96 return;
97
98 idst = this_cpu_ptr(dst_cache->cache);
99 dst_cache_per_cpu_dst_set(idst, dst, 0);
100 idst->in_saddr.s_addr = saddr;
101}
102EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
103
104#if IS_ENABLED(CONFIG_IPV6)
105void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
106 const struct in6_addr *saddr)
107{
108 struct dst_cache_pcpu *idst;
109
110 if (!dst_cache->cache)
111 return;
112
113 idst = this_cpu_ptr(dst_cache->cache);
114 dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
115 rt6_get_cookie(dst_rt6_info(dst)));
116 idst->in6_saddr = *saddr;
117}
118EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
119
120struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
121 struct in6_addr *saddr)
122{
123 struct dst_cache_pcpu *idst;
124 struct dst_entry *dst;
125
126 if (!dst_cache->cache)
127 return NULL;
128
129 idst = this_cpu_ptr(dst_cache->cache);
130 dst = dst_cache_per_cpu_get(dst_cache, idst);
131 if (!dst)
132 return NULL;
133
134 *saddr = idst->in6_saddr;
135 return dst;
136}
137EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
138#endif
139
140int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
141{
142 dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
143 gfp | __GFP_ZERO);
144 if (!dst_cache->cache)
145 return -ENOMEM;
146
147 dst_cache_reset(dst_cache);
148 return 0;
149}
150EXPORT_SYMBOL_GPL(dst_cache_init);
151
152void dst_cache_destroy(struct dst_cache *dst_cache)
153{
154 int i;
155
156 if (!dst_cache->cache)
157 return;
158
159 for_each_possible_cpu(i)
160 dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
161
162 free_percpu(dst_cache->cache);
163}
164EXPORT_SYMBOL_GPL(dst_cache_destroy);
165
166void dst_cache_reset_now(struct dst_cache *dst_cache)
167{
168 int i;
169
170 if (!dst_cache->cache)
171 return;
172
173 dst_cache->reset_ts = jiffies;
174 for_each_possible_cpu(i) {
175 struct dst_cache_pcpu *idst = per_cpu_ptr(dst_cache->cache, i);
176 struct dst_entry *dst = idst->dst;
177
178 idst->cookie = 0;
179 idst->dst = NULL;
180 dst_release(dst);
181 }
182}
183EXPORT_SYMBOL_GPL(dst_cache_reset_now);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/core/dst_cache.c - dst entry cache
4 *
5 * Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/percpu.h>
10#include <net/dst_cache.h>
11#include <net/route.h>
12#if IS_ENABLED(CONFIG_IPV6)
13#include <net/ip6_fib.h>
14#endif
15#include <uapi/linux/in.h>
16
17struct dst_cache_pcpu {
18 unsigned long refresh_ts;
19 struct dst_entry *dst;
20 u32 cookie;
21 union {
22 struct in_addr in_saddr;
23 struct in6_addr in6_saddr;
24 };
25};
26
27static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
28 struct dst_entry *dst, u32 cookie)
29{
30 dst_release(dst_cache->dst);
31 if (dst)
32 dst_hold(dst);
33
34 dst_cache->cookie = cookie;
35 dst_cache->dst = dst;
36}
37
38static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
39 struct dst_cache_pcpu *idst)
40{
41 struct dst_entry *dst;
42
43 dst = idst->dst;
44 if (!dst)
45 goto fail;
46
47 /* the cache already hold a dst reference; it can't go away */
48 dst_hold(dst);
49
50 if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) ||
51 (dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
52 dst_cache_per_cpu_dst_set(idst, NULL, 0);
53 dst_release(dst);
54 goto fail;
55 }
56 return dst;
57
58fail:
59 idst->refresh_ts = jiffies;
60 return NULL;
61}
62
63struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
64{
65 if (!dst_cache->cache)
66 return NULL;
67
68 return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
69}
70EXPORT_SYMBOL_GPL(dst_cache_get);
71
72struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
73{
74 struct dst_cache_pcpu *idst;
75 struct dst_entry *dst;
76
77 if (!dst_cache->cache)
78 return NULL;
79
80 idst = this_cpu_ptr(dst_cache->cache);
81 dst = dst_cache_per_cpu_get(dst_cache, idst);
82 if (!dst)
83 return NULL;
84
85 *saddr = idst->in_saddr.s_addr;
86 return container_of(dst, struct rtable, dst);
87}
88EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
89
90void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
91 __be32 saddr)
92{
93 struct dst_cache_pcpu *idst;
94
95 if (!dst_cache->cache)
96 return;
97
98 idst = this_cpu_ptr(dst_cache->cache);
99 dst_cache_per_cpu_dst_set(idst, dst, 0);
100 idst->in_saddr.s_addr = saddr;
101}
102EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
103
104#if IS_ENABLED(CONFIG_IPV6)
105void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
106 const struct in6_addr *saddr)
107{
108 struct dst_cache_pcpu *idst;
109
110 if (!dst_cache->cache)
111 return;
112
113 idst = this_cpu_ptr(dst_cache->cache);
114 dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
115 rt6_get_cookie((struct rt6_info *)dst));
116 idst->in6_saddr = *saddr;
117}
118EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
119
120struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
121 struct in6_addr *saddr)
122{
123 struct dst_cache_pcpu *idst;
124 struct dst_entry *dst;
125
126 if (!dst_cache->cache)
127 return NULL;
128
129 idst = this_cpu_ptr(dst_cache->cache);
130 dst = dst_cache_per_cpu_get(dst_cache, idst);
131 if (!dst)
132 return NULL;
133
134 *saddr = idst->in6_saddr;
135 return dst;
136}
137EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
138#endif
139
140int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
141{
142 dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
143 gfp | __GFP_ZERO);
144 if (!dst_cache->cache)
145 return -ENOMEM;
146
147 dst_cache_reset(dst_cache);
148 return 0;
149}
150EXPORT_SYMBOL_GPL(dst_cache_init);
151
152void dst_cache_destroy(struct dst_cache *dst_cache)
153{
154 int i;
155
156 if (!dst_cache->cache)
157 return;
158
159 for_each_possible_cpu(i)
160 dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
161
162 free_percpu(dst_cache->cache);
163}
164EXPORT_SYMBOL_GPL(dst_cache_destroy);
165
166void dst_cache_reset_now(struct dst_cache *dst_cache)
167{
168 int i;
169
170 if (!dst_cache->cache)
171 return;
172
173 dst_cache->reset_ts = jiffies;
174 for_each_possible_cpu(i) {
175 struct dst_cache_pcpu *idst = per_cpu_ptr(dst_cache->cache, i);
176 struct dst_entry *dst = idst->dst;
177
178 idst->cookie = 0;
179 idst->dst = NULL;
180 dst_release(dst);
181 }
182}
183EXPORT_SYMBOL_GPL(dst_cache_reset_now);