1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/core/dst_cache.c - dst entry cache
*
* Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
*/
#include <linux/kernel.h>
#include <linux/percpu.h>
#include <net/dst_cache.h>
#include <net/route.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_fib.h>
#endif
#include <uapi/linux/in.h>
struct dst_cache_pcpu {
unsigned long refresh_ts;
struct dst_entry *dst;
u32 cookie;
union {
struct in_addr in_saddr;
struct in6_addr in6_saddr;
};
};
static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
struct dst_entry *dst, u32 cookie)
{
DEBUG_NET_WARN_ON_ONCE(!in_softirq());
dst_release(dst_cache->dst);
if (dst)
dst_hold(dst);
dst_cache->cookie = cookie;
dst_cache->dst = dst;
}
static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
struct dst_cache_pcpu *idst)
{
struct dst_entry *dst;
DEBUG_NET_WARN_ON_ONCE(!in_softirq());
dst = idst->dst;
if (!dst)
goto fail;
/* the cache already hold a dst reference; it can't go away */
dst_hold(dst);
if (unlikely(!time_after(idst->refresh_ts,
READ_ONCE(dst_cache->reset_ts)) ||
(dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
dst_cache_per_cpu_dst_set(idst, NULL, 0);
dst_release(dst);
goto fail;
}
return dst;
fail:
idst->refresh_ts = jiffies;
return NULL;
}
struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
{
if (!dst_cache->cache)
return NULL;
return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
}
EXPORT_SYMBOL_GPL(dst_cache_get);
struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
{
struct dst_cache_pcpu *idst;
struct dst_entry *dst;
if (!dst_cache->cache)
return NULL;
idst = this_cpu_ptr(dst_cache->cache);
dst = dst_cache_per_cpu_get(dst_cache, idst);
if (!dst)
return NULL;
*saddr = idst->in_saddr.s_addr;
return dst_rtable(dst);
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
__be32 saddr)
{
struct dst_cache_pcpu *idst;
if (!dst_cache->cache)
return;
idst = this_cpu_ptr(dst_cache->cache);
dst_cache_per_cpu_dst_set(idst, dst, 0);
idst->in_saddr.s_addr = saddr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
#if IS_ENABLED(CONFIG_IPV6)
void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
const struct in6_addr *saddr)
{
struct dst_cache_pcpu *idst;
if (!dst_cache->cache)
return;
idst = this_cpu_ptr(dst_cache->cache);
dst_cache_per_cpu_dst_set(idst, dst,
rt6_get_cookie(dst_rt6_info(dst)));
idst->in6_saddr = *saddr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
struct in6_addr *saddr)
{
struct dst_cache_pcpu *idst;
struct dst_entry *dst;
if (!dst_cache->cache)
return NULL;
idst = this_cpu_ptr(dst_cache->cache);
dst = dst_cache_per_cpu_get(dst_cache, idst);
if (!dst)
return NULL;
*saddr = idst->in6_saddr;
return dst;
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
#endif
int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
{
dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
gfp | __GFP_ZERO);
if (!dst_cache->cache)
return -ENOMEM;
dst_cache_reset(dst_cache);
return 0;
}
EXPORT_SYMBOL_GPL(dst_cache_init);
void dst_cache_destroy(struct dst_cache *dst_cache)
{
int i;
if (!dst_cache->cache)
return;
for_each_possible_cpu(i)
dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
free_percpu(dst_cache->cache);
}
EXPORT_SYMBOL_GPL(dst_cache_destroy);
void dst_cache_reset_now(struct dst_cache *dst_cache)
{
int i;
if (!dst_cache->cache)
return;
dst_cache_reset(dst_cache);
for_each_possible_cpu(i) {
struct dst_cache_pcpu *idst = per_cpu_ptr(dst_cache->cache, i);
struct dst_entry *dst = idst->dst;
idst->cookie = 0;
idst->dst = NULL;
dst_release(dst);
}
}
EXPORT_SYMBOL_GPL(dst_cache_reset_now);
|
