1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/uaccess.h>
14#include <linux/bitops.h>
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/jiffies.h>
19#include <linux/string.h>
20#include <linux/mm.h>
21#include <linux/socket.h>
22#include <linux/sockios.h>
23#include <linux/in.h>
24#include <linux/errno.h>
25#include <linux/interrupt.h>
26#include <linux/netdevice.h>
27#include <linux/skbuff.h>
28#include <linux/rtnetlink.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/seqlock.h>
32#include <net/sock.h>
33#include <net/gen_stats.h>
34
35
36
37
38
39
40
41
42struct net_rate_estimator {
43 struct gnet_stats_basic_packed *bstats;
44 spinlock_t *stats_lock;
45 seqcount_t *running;
46 struct gnet_stats_basic_cpu __percpu *cpu_bstats;
47 u8 ewma_log;
48 u8 intvl_log;
49
50 seqcount_t seq;
51 u64 last_packets;
52 u64 last_bytes;
53
54 u64 avpps;
55 u64 avbps;
56
57 unsigned long next_jiffies;
58 struct timer_list timer;
59 struct rcu_head rcu;
60};
61
62static void est_fetch_counters(struct net_rate_estimator *e,
63 struct gnet_stats_basic_packed *b)
64{
65 memset(b, 0, sizeof(*b));
66 if (e->stats_lock)
67 spin_lock(e->stats_lock);
68
69 __gnet_stats_copy_basic(e->running, b, e->cpu_bstats, e->bstats);
70
71 if (e->stats_lock)
72 spin_unlock(e->stats_lock);
73
74}
75
76static void est_timer(struct timer_list *t)
77{
78 struct net_rate_estimator *est = from_timer(est, t, timer);
79 struct gnet_stats_basic_packed b;
80 u64 rate, brate;
81
82 est_fetch_counters(est, &b);
83 brate = (b.bytes - est->last_bytes) << (10 - est->intvl_log);
84 brate = (brate >> est->ewma_log) - (est->avbps >> est->ewma_log);
85
86 rate = (b.packets - est->last_packets) << (10 - est->intvl_log);
87 rate = (rate >> est->ewma_log) - (est->avpps >> est->ewma_log);
88
89 write_seqcount_begin(&est->seq);
90 est->avbps += brate;
91 est->avpps += rate;
92 write_seqcount_end(&est->seq);
93
94 est->last_bytes = b.bytes;
95 est->last_packets = b.packets;
96
97 est->next_jiffies += ((HZ/4) << est->intvl_log);
98
99 if (unlikely(time_after_eq(jiffies, est->next_jiffies))) {
100
101 est->next_jiffies = jiffies + 1;
102 }
103 mod_timer(&est->timer, est->next_jiffies);
104}
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
125 struct gnet_stats_basic_cpu __percpu *cpu_bstats,
126 struct net_rate_estimator __rcu **rate_est,
127 spinlock_t *lock,
128 seqcount_t *running,
129 struct nlattr *opt)
130{
131 struct gnet_estimator *parm = nla_data(opt);
132 struct net_rate_estimator *old, *est;
133 struct gnet_stats_basic_packed b;
134 int intvl_log;
135
136 if (nla_len(opt) < sizeof(*parm))
137 return -EINVAL;
138
139
140
141
142
143 if (parm->interval < -2 || parm->interval > 3)
144 return -EINVAL;
145
146 if (parm->ewma_log == 0 || parm->ewma_log >= 31)
147 return -EINVAL;
148
149 est = kzalloc(sizeof(*est), GFP_KERNEL);
150 if (!est)
151 return -ENOBUFS;
152
153 seqcount_init(&est->seq);
154 intvl_log = parm->interval + 2;
155 est->bstats = bstats;
156 est->stats_lock = lock;
157 est->running = running;
158 est->ewma_log = parm->ewma_log;
159 est->intvl_log = intvl_log;
160 est->cpu_bstats = cpu_bstats;
161
162 if (lock)
163 local_bh_disable();
164 est_fetch_counters(est, &b);
165 if (lock)
166 local_bh_enable();
167 est->last_bytes = b.bytes;
168 est->last_packets = b.packets;
169
170 if (lock)
171 spin_lock_bh(lock);
172 old = rcu_dereference_protected(*rate_est, 1);
173 if (old) {
174 del_timer_sync(&old->timer);
175 est->avbps = old->avbps;
176 est->avpps = old->avpps;
177 }
178
179 est->next_jiffies = jiffies + ((HZ/4) << intvl_log);
180 timer_setup(&est->timer, est_timer, 0);
181 mod_timer(&est->timer, est->next_jiffies);
182
183 rcu_assign_pointer(*rate_est, est);
184 if (lock)
185 spin_unlock_bh(lock);
186 if (old)
187 kfree_rcu(old, rcu);
188 return 0;
189}
190EXPORT_SYMBOL(gen_new_estimator);
191
192
193
194
195
196
197
198
199void gen_kill_estimator(struct net_rate_estimator __rcu **rate_est)
200{
201 struct net_rate_estimator *est;
202
203 est = xchg((__force struct net_rate_estimator **)rate_est, NULL);
204 if (est) {
205 del_timer_sync(&est->timer);
206 kfree_rcu(est, rcu);
207 }
208}
209EXPORT_SYMBOL(gen_kill_estimator);
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
226 struct gnet_stats_basic_cpu __percpu *cpu_bstats,
227 struct net_rate_estimator __rcu **rate_est,
228 spinlock_t *lock,
229 seqcount_t *running, struct nlattr *opt)
230{
231 return gen_new_estimator(bstats, cpu_bstats, rate_est,
232 lock, running, opt);
233}
234EXPORT_SYMBOL(gen_replace_estimator);
235
236
237
238
239
240
241
242bool gen_estimator_active(struct net_rate_estimator __rcu **rate_est)
243{
244 return !!rcu_access_pointer(*rate_est);
245}
246EXPORT_SYMBOL(gen_estimator_active);
247
248bool gen_estimator_read(struct net_rate_estimator __rcu **rate_est,
249 struct gnet_stats_rate_est64 *sample)
250{
251 struct net_rate_estimator *est;
252 unsigned seq;
253
254 rcu_read_lock();
255 est = rcu_dereference(*rate_est);
256 if (!est) {
257 rcu_read_unlock();
258 return false;
259 }
260
261 do {
262 seq = read_seqcount_begin(&est->seq);
263 sample->bps = est->avbps >> 8;
264 sample->pps = est->avpps >> 8;
265 } while (read_seqcount_retry(&est->seq, seq));
266
267 rcu_read_unlock();
268 return true;
269}
270EXPORT_SYMBOL(gen_estimator_read);
271