projects/linux·blob master · refs

484 lines · 13.4 KiB

1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/core/gen_stats.c
4 *
5 * Authors: Thomas Graf <[email protected]>
6 * Jamal Hadi Salim
7 * Alexey Kuznetsov, <[email protected]>
8 *
9 * See Documentation/networking/gen_stats.rst
10 */
11
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/interrupt.h>
16#include <linux/socket.h>
17#include <linux/rtnetlink.h>
18#include <linux/gen_stats.h>
19#include <net/netlink.h>
20#include <net/gen_stats.h>
21#include <net/sch_generic.h>
22
23static inline int
24gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
25{
26 if (nla_put_64bit(d->skb, type, size, buf, padattr))
27 goto nla_put_failure;
28 return 0;
29
30nla_put_failure:
31 if (d->lock)
32 spin_unlock_bh(d->lock);
33 kfree(d->xstats);
34 d->xstats = NULL;
35 d->xstats_len = 0;
36 return -1;
37}
38
39/**
40 * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
41 * @skb: socket buffer to put statistics TLVs into
42 * @type: TLV type for top level statistic TLV
43 * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
44 * @xstats_type: TLV type for backward compatibility xstats TLV
45 * @lock: statistics lock
46 * @d: dumping handle
47 * @padattr: padding attribute
48 *
49 * Initializes the dumping handle, grabs the statistic lock and appends
50 * an empty TLV header to the socket buffer for use a container for all
51 * other statistic TLVS.
52 *
53 * The dumping handle is marked to be in backward compatibility mode telling
54 * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
55 *
56 * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
57 */
58int
59gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
60 int xstats_type, spinlock_t *lock,
61 struct gnet_dump *d, int padattr)
62 __acquires(lock)
63{
64 memset(d, 0, sizeof(*d));
65
66 if (type)
67 d->tail = (struct nlattr *)skb_tail_pointer(skb);
68 d->skb = skb;
69 d->compat_tc_stats = tc_stats_type;
70 d->compat_xstats = xstats_type;
71 d->padattr = padattr;
72 if (lock) {
73 d->lock = lock;
74 spin_lock_bh(lock);
75 }
76 if (d->tail) {
77 int ret = gnet_stats_copy(d, type, NULL, 0, padattr);
78
79 /* The initial attribute added in gnet_stats_copy() may be
80 * preceded by a padding attribute, in which case d->tail will
81 * end up pointing at the padding instead of the real attribute.
82 * Fix this so gnet_stats_finish_copy() adjusts the length of
83 * the right attribute.
84 */
85 if (ret == 0 && d->tail->nla_type == padattr)
86 d->tail = (struct nlattr *)((char *)d->tail +
87 NLA_ALIGN(d->tail->nla_len));
88 return ret;
89 }
90
91 return 0;
92}
93EXPORT_SYMBOL(gnet_stats_start_copy_compat);
94
95/**
96 * gnet_stats_start_copy - start dumping procedure in compatibility mode
97 * @skb: socket buffer to put statistics TLVs into
98 * @type: TLV type for top level statistic TLV
99 * @lock: statistics lock
100 * @d: dumping handle
101 * @padattr: padding attribute
102 *
103 * Initializes the dumping handle, grabs the statistic lock and appends
104 * an empty TLV header to the socket buffer for use a container for all
105 * other statistic TLVS.
106 *
107 * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
108 */
109int
110gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
111 struct gnet_dump *d, int padattr)
112{
113 return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
114}
115EXPORT_SYMBOL(gnet_stats_start_copy);
116
117/* Must not be inlined, due to u64_stats seqcount_t lockdep key */
118void gnet_stats_basic_sync_init(struct gnet_stats_basic_sync *b)
119{
120 u64_stats_set(&b->bytes, 0);
121 u64_stats_set(&b->packets, 0);
122 u64_stats_init(&b->syncp);
123}
124EXPORT_SYMBOL(gnet_stats_basic_sync_init);
125
126static void gnet_stats_add_basic_cpu(struct gnet_stats_basic_sync *bstats,
127 const struct gnet_stats_basic_sync __percpu *cpu)
128{
129 u64 t_bytes = 0, t_packets = 0;
130 int i;
131
132 for_each_possible_cpu(i) {
133 const struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
134 unsigned int start;
135 u64 bytes, packets;
136
137 do {
138 start = u64_stats_fetch_begin(&bcpu->syncp);
139 bytes = u64_stats_read(&bcpu->bytes);
140 packets = u64_stats_read(&bcpu->packets);
141 } while (u64_stats_fetch_retry(&bcpu->syncp, start));
142
143 t_bytes += bytes;
144 t_packets += packets;
145 }
146 _bstats_update(bstats, t_bytes, t_packets);
147}
148
149void gnet_stats_add_basic(struct gnet_stats_basic_sync *bstats,
150 const struct gnet_stats_basic_sync __percpu *cpu,
151 const struct gnet_stats_basic_sync *b, bool running)
152{
153 unsigned int start;
154 u64 bytes = 0;
155 u64 packets = 0;
156
157 WARN_ON_ONCE((cpu || running) && in_hardirq());
158
159 if (cpu) {
160 gnet_stats_add_basic_cpu(bstats, cpu);
161 return;
162 }
163 do {
164 if (running)
165 start = u64_stats_fetch_begin(&b->syncp);
166 bytes = u64_stats_read(&b->bytes);
167 packets = u64_stats_read(&b->packets);
168 } while (running && u64_stats_fetch_retry(&b->syncp, start));
169
170 _bstats_update(bstats, bytes, packets);
171}
172EXPORT_SYMBOL(gnet_stats_add_basic);
173
174static void gnet_stats_read_basic(u64 *ret_bytes, u64 *ret_packets,
175 const struct gnet_stats_basic_sync __percpu *cpu,
176 const struct gnet_stats_basic_sync *b, bool running)
177{
178 unsigned int start;
179
180 if (cpu) {
181 u64 t_bytes = 0, t_packets = 0;
182 int i;
183
184 for_each_possible_cpu(i) {
185 const struct gnet_stats_basic_sync *bcpu = per_cpu_ptr(cpu, i);
186 u64 bytes, packets;
187
188 do {
189 start = u64_stats_fetch_begin(&bcpu->syncp);
190 bytes = u64_stats_read(&bcpu->bytes);
191 packets = u64_stats_read(&bcpu->packets);
192 } while (u64_stats_fetch_retry(&bcpu->syncp, start));
193
194 t_bytes += bytes;
195 t_packets += packets;
196 }
197 *ret_bytes = t_bytes;
198 *ret_packets = t_packets;
199 return;
200 }
201 do {
202 if (running)
203 start = u64_stats_fetch_begin(&b->syncp);
204 *ret_bytes = u64_stats_read(&b->bytes);
205 *ret_packets = u64_stats_read(&b->packets);
206 } while (running && u64_stats_fetch_retry(&b->syncp, start));
207}
208
209static int
210___gnet_stats_copy_basic(struct gnet_dump *d,
211 const struct gnet_stats_basic_sync __percpu *cpu,
212 const struct gnet_stats_basic_sync *b,
213 int type, bool running)
214{
215 u64 bstats_bytes, bstats_packets;
216
217 gnet_stats_read_basic(&bstats_bytes, &bstats_packets, cpu, b, running);
218
219 if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
220 d->tc_stats.bytes = bstats_bytes;
221 d->tc_stats.packets = bstats_packets;
222 }
223
224 if (d->tail) {
225 struct gnet_stats_basic sb;
226 int res;
227
228 memset(&sb, 0, sizeof(sb));
229 sb.bytes = bstats_bytes;
230 sb.packets = bstats_packets;
231 res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
232 if (res < 0 || sb.packets == bstats_packets)
233 return res;
234 /* emit 64bit stats only if needed */
235 return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats_packets,
236 sizeof(bstats_packets), TCA_STATS_PAD);
237 }
238 return 0;
239}
240
241/**
242 * gnet_stats_copy_basic - copy basic statistics into statistic TLV
243 * @d: dumping handle
244 * @cpu: copy statistic per cpu
245 * @b: basic statistics
246 * @running: true if @b represents a running qdisc, thus @b's
247 * internal values might change during basic reads.
248 * Only used if @cpu is NULL
249 *
250 * Context: task; must not be run from IRQ or BH contexts
251 *
252 * Appends the basic statistics to the top level TLV created by
253 * gnet_stats_start_copy().
254 *
255 * Returns 0 on success or -1 with the statistic lock released
256 * if the room in the socket buffer was not sufficient.
257 */
258int
259gnet_stats_copy_basic(struct gnet_dump *d,
260 const struct gnet_stats_basic_sync __percpu *cpu,
261 const struct gnet_stats_basic_sync *b,
262 bool running)
263{
264 return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC, running);
265}
266EXPORT_SYMBOL(gnet_stats_copy_basic);
267
268/**
269 * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
270 * @d: dumping handle
271 * @cpu: copy statistic per cpu
272 * @b: basic statistics
273 * @running: true if @b represents a running qdisc, thus @b's
274 * internal values might change during basic reads.
275 * Only used if @cpu is NULL
276 *
277 * Context: task; must not be run from IRQ or BH contexts
278 *
279 * Appends the basic statistics to the top level TLV created by
280 * gnet_stats_start_copy().
281 *
282 * Returns 0 on success or -1 with the statistic lock released
283 * if the room in the socket buffer was not sufficient.
284 */
285int
286gnet_stats_copy_basic_hw(struct gnet_dump *d,
287 const struct gnet_stats_basic_sync __percpu *cpu,
288 const struct gnet_stats_basic_sync *b,
289 bool running)
290{
291 return ___gnet_stats_copy_basic(d, cpu, b, TCA_STATS_BASIC_HW, running);
292}
293EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
294
295/**
296 * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
297 * @d: dumping handle
298 * @rate_est: rate estimator
299 *
300 * Appends the rate estimator statistics to the top level TLV created by
301 * gnet_stats_start_copy().
302 *
303 * Returns 0 on success or -1 with the statistic lock released
304 * if the room in the socket buffer was not sufficient.
305 */
306int
307gnet_stats_copy_rate_est(struct gnet_dump *d,
308 struct net_rate_estimator __rcu **rate_est)
309{
310 struct gnet_stats_rate_est64 sample;
311 struct gnet_stats_rate_est est;
312 int res;
313
314 if (!gen_estimator_read(rate_est, &sample))
315 return 0;
316 est.bps = min_t(u64, UINT_MAX, sample.bps);
317 /* we have some time before reaching 2^32 packets per second */
318 est.pps = sample.pps;
319
320 if (d->compat_tc_stats) {
321 d->tc_stats.bps = est.bps;
322 d->tc_stats.pps = est.pps;
323 }
324
325 if (d->tail) {
326 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
327 TCA_STATS_PAD);
328 if (res < 0 || est.bps == sample.bps)
329 return res;
330 /* emit 64bit stats only if needed */
331 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
332 sizeof(sample), TCA_STATS_PAD);
333 }
334
335 return 0;
336}
337EXPORT_SYMBOL(gnet_stats_copy_rate_est);
338
339static void gnet_stats_add_queue_cpu(struct gnet_stats_queue *qstats,
340 const struct gnet_stats_queue __percpu *q)
341{
342 int i;
343
344 for_each_possible_cpu(i) {
345 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
346
347 qstats->qlen += READ_ONCE(qcpu->qlen);
348 qstats->backlog += READ_ONCE(qcpu->backlog);
349 qstats->drops += READ_ONCE(qcpu->drops);
350 qstats->requeues += READ_ONCE(qcpu->requeues);
351 qstats->overlimits += READ_ONCE(qcpu->overlimits);
352 }
353}
354
355void gnet_stats_add_queue(struct gnet_stats_queue *qstats,
356 const struct gnet_stats_queue __percpu *cpu,
357 const struct gnet_stats_queue *q)
358{
359 if (cpu) {
360 gnet_stats_add_queue_cpu(qstats, cpu);
361 } else {
362 qstats->qlen += READ_ONCE(q->qlen);
363 qstats->backlog += READ_ONCE(q->backlog);
364 qstats->drops += READ_ONCE(q->drops);
365 qstats->requeues += READ_ONCE(q->requeues);
366 qstats->overlimits += READ_ONCE(q->overlimits);
367 }
368}
369EXPORT_SYMBOL(gnet_stats_add_queue);
370
371/**
372 * gnet_stats_copy_queue - copy queue statistics into statistics TLV
373 * @d: dumping handle
374 * @cpu_q: per cpu queue statistics
375 * @q: queue statistics
376 * @qlen: queue length statistics
377 *
378 * Appends the queue statistics to the top level TLV created by
379 * gnet_stats_start_copy(). Using per cpu queue statistics if
380 * they are available.
381 *
382 * Returns 0 on success or -1 with the statistic lock released
383 * if the room in the socket buffer was not sufficient.
384 */
385int
386gnet_stats_copy_queue(struct gnet_dump *d,
387 const struct gnet_stats_queue __percpu *cpu_q,
388 const struct gnet_stats_queue *q, __u32 qlen)
389{
390 struct gnet_stats_queue qstats = {0};
391
392 gnet_stats_add_queue(&qstats, cpu_q, q);
393 qstats.qlen = qlen;
394
395 if (d->compat_tc_stats) {
396 d->tc_stats.drops = qstats.drops;
397 d->tc_stats.qlen = qstats.qlen;
398 d->tc_stats.backlog = qstats.backlog;
399 d->tc_stats.overlimits = qstats.overlimits;
400 }
401
402 if (d->tail)
403 return gnet_stats_copy(d, TCA_STATS_QUEUE,
404 &qstats, sizeof(qstats),
405 TCA_STATS_PAD);
406
407 return 0;
408}
409EXPORT_SYMBOL(gnet_stats_copy_queue);
410
411/**
412 * gnet_stats_copy_app - copy application specific statistics into statistics TLV
413 * @d: dumping handle
414 * @st: application specific statistics data
415 * @len: length of data
416 *
417 * Appends the application specific statistics to the top level TLV created by
418 * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
419 * handle is in backward compatibility mode.
420 *
421 * Returns 0 on success or -1 with the statistic lock released
422 * if the room in the socket buffer was not sufficient.
423 */
424int
425gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
426{
427 if (d->compat_xstats) {
428 d->xstats = kmemdup(st, len, GFP_ATOMIC);
429 if (!d->xstats)
430 goto err_out;
431 d->xstats_len = len;
432 }
433
434 if (d->tail)
435 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
436 TCA_STATS_PAD);
437
438 return 0;
439
440err_out:
441 if (d->lock)
442 spin_unlock_bh(d->lock);
443 d->xstats_len = 0;
444 return -1;
445}
446EXPORT_SYMBOL(gnet_stats_copy_app);
447
448/**
449 * gnet_stats_finish_copy - finish dumping procedure
450 * @d: dumping handle
451 *
452 * Corrects the length of the top level TLV to include all TLVs added
453 * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
454 * if gnet_stats_start_copy_compat() was used and releases the statistics
455 * lock.
456 *
457 * Returns 0 on success or -1 with the statistic lock released
458 * if the room in the socket buffer was not sufficient.
459 */
460int
461gnet_stats_finish_copy(struct gnet_dump *d)
462{
463 if (d->tail)
464 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
465
466 if (d->compat_tc_stats)
467 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
468 sizeof(d->tc_stats), d->padattr) < 0)
469 return -1;
470
471 if (d->compat_xstats && d->xstats) {
472 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
473 d->xstats_len, d->padattr) < 0)
474 return -1;
475 }
476
477 if (d->lock)
478 spin_unlock_bh(d->lock);
479 kfree(d->xstats);
480 d->xstats = NULL;
481 d->xstats_len = 0;
482 return 0;
483}
484EXPORT_SYMBOL(gnet_stats_finish_copy);