1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/core/gen_stats.c
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 * Jamal Hadi Salim
7 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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
22
23 static inline int
24 gnet_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
30 nla_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 */
58 int
59 gnet_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 }
93 EXPORT_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 */
109 int
110 gnet_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 }
115 EXPORT_SYMBOL(gnet_stats_start_copy);
116
117 static void
118 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
119 struct gnet_stats_basic_cpu __percpu *cpu)
120 {
121 int i;
122
123 for_each_possible_cpu(i) {
124 struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
125 unsigned int start;
126 u64 bytes, packets;
127
128 do {
129 start = u64_stats_fetch_begin_irq(&bcpu->syncp);
130 bytes = bcpu->bstats.bytes;
131 packets = bcpu->bstats.packets;
132 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
133
134 bstats->bytes += bytes;
135 bstats->packets += packets;
136 }
137 }
138
139 void
140 __gnet_stats_copy_basic(const seqcount_t *running,
141 struct gnet_stats_basic_packed *bstats,
142 struct gnet_stats_basic_cpu __percpu *cpu,
143 struct gnet_stats_basic_packed *b)
144 {
145 unsigned int seq;
146
147 if (cpu) {
148 __gnet_stats_copy_basic_cpu(bstats, cpu);
149 return;
150 }
151 do {
152 if (running)
153 seq = read_seqcount_begin(running);
154 bstats->bytes = b->bytes;
155 bstats->packets = b->packets;
156 } while (running && read_seqcount_retry(running, seq));
157 }
158 EXPORT_SYMBOL(__gnet_stats_copy_basic);
159
160 static int
161 ___gnet_stats_copy_basic(const seqcount_t *running,
162 struct gnet_dump *d,
163 struct gnet_stats_basic_cpu __percpu *cpu,
164 struct gnet_stats_basic_packed *b,
165 int type)
166 {
167 struct gnet_stats_basic_packed bstats = {0};
168
169 __gnet_stats_copy_basic(running, &bstats, cpu, b);
170
171 if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
172 d->tc_stats.bytes = bstats.bytes;
173 d->tc_stats.packets = bstats.packets;
174 }
175
176 if (d->tail) {
177 struct gnet_stats_basic sb;
178 int res;
179
180 memset(&sb, 0, sizeof(sb));
181 sb.bytes = bstats.bytes;
182 sb.packets = bstats.packets;
183 res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
184 if (res < 0 || sb.packets == bstats.packets)
185 return res;
186 /* emit 64bit stats only if needed */
187 return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
188 sizeof(bstats.packets), TCA_STATS_PAD);
189 }
190 return 0;
191 }
192
193 /**
194 * gnet_stats_copy_basic - copy basic statistics into statistic TLV
195 * @running: seqcount_t pointer
196 * @d: dumping handle
197 * @cpu: copy statistic per cpu
198 * @b: basic statistics
199 *
200 * Appends the basic statistics to the top level TLV created by
201 * gnet_stats_start_copy().
202 *
203 * Returns 0 on success or -1 with the statistic lock released
204 * if the room in the socket buffer was not sufficient.
205 */
206 int
207 gnet_stats_copy_basic(const seqcount_t *running,
208 struct gnet_dump *d,
209 struct gnet_stats_basic_cpu __percpu *cpu,
210 struct gnet_stats_basic_packed *b)
211 {
212 return ___gnet_stats_copy_basic(running, d, cpu, b,
213 TCA_STATS_BASIC);
214 }
215 EXPORT_SYMBOL(gnet_stats_copy_basic);
216
217 /**
218 * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
219 * @running: seqcount_t pointer
220 * @d: dumping handle
221 * @cpu: copy statistic per cpu
222 * @b: basic statistics
223 *
224 * Appends the basic statistics to the top level TLV created by
225 * gnet_stats_start_copy().
226 *
227 * Returns 0 on success or -1 with the statistic lock released
228 * if the room in the socket buffer was not sufficient.
229 */
230 int
231 gnet_stats_copy_basic_hw(const seqcount_t *running,
232 struct gnet_dump *d,
233 struct gnet_stats_basic_cpu __percpu *cpu,
234 struct gnet_stats_basic_packed *b)
235 {
236 return ___gnet_stats_copy_basic(running, d, cpu, b,
237 TCA_STATS_BASIC_HW);
238 }
239 EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
240
241 /**
242 * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
243 * @d: dumping handle
244 * @rate_est: rate estimator
245 *
246 * Appends the rate estimator statistics to the top level TLV created by
247 * gnet_stats_start_copy().
248 *
249 * Returns 0 on success or -1 with the statistic lock released
250 * if the room in the socket buffer was not sufficient.
251 */
252 int
253 gnet_stats_copy_rate_est(struct gnet_dump *d,
254 struct net_rate_estimator __rcu **rate_est)
255 {
256 struct gnet_stats_rate_est64 sample;
257 struct gnet_stats_rate_est est;
258 int res;
259
260 if (!gen_estimator_read(rate_est, &sample))
261 return 0;
262 est.bps = min_t(u64, UINT_MAX, sample.bps);
263 /* we have some time before reaching 2^32 packets per second */
264 est.pps = sample.pps;
265
266 if (d->compat_tc_stats) {
267 d->tc_stats.bps = est.bps;
268 d->tc_stats.pps = est.pps;
269 }
270
271 if (d->tail) {
272 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
273 TCA_STATS_PAD);
274 if (res < 0 || est.bps == sample.bps)
275 return res;
276 /* emit 64bit stats only if needed */
277 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
278 sizeof(sample), TCA_STATS_PAD);
279 }
280
281 return 0;
282 }
283 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
284
285 static void
286 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
287 const struct gnet_stats_queue __percpu *q)
288 {
289 int i;
290
291 for_each_possible_cpu(i) {
292 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
293
294 qstats->qlen = 0;
295 qstats->backlog += qcpu->backlog;
296 qstats->drops += qcpu->drops;
297 qstats->requeues += qcpu->requeues;
298 qstats->overlimits += qcpu->overlimits;
299 }
300 }
301
302 void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
303 const struct gnet_stats_queue __percpu *cpu,
304 const struct gnet_stats_queue *q,
305 __u32 qlen)
306 {
307 if (cpu) {
308 __gnet_stats_copy_queue_cpu(qstats, cpu);
309 } else {
310 qstats->qlen = q->qlen;
311 qstats->backlog = q->backlog;
312 qstats->drops = q->drops;
313 qstats->requeues = q->requeues;
314 qstats->overlimits = q->overlimits;
315 }
316
317 qstats->qlen = qlen;
318 }
319 EXPORT_SYMBOL(__gnet_stats_copy_queue);
320
321 /**
322 * gnet_stats_copy_queue - copy queue statistics into statistics TLV
323 * @d: dumping handle
324 * @cpu_q: per cpu queue statistics
325 * @q: queue statistics
326 * @qlen: queue length statistics
327 *
328 * Appends the queue statistics to the top level TLV created by
329 * gnet_stats_start_copy(). Using per cpu queue statistics if
330 * they are available.
331 *
332 * Returns 0 on success or -1 with the statistic lock released
333 * if the room in the socket buffer was not sufficient.
334 */
335 int
336 gnet_stats_copy_queue(struct gnet_dump *d,
337 struct gnet_stats_queue __percpu *cpu_q,
338 struct gnet_stats_queue *q, __u32 qlen)
339 {
340 struct gnet_stats_queue qstats = {0};
341
342 __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
343
344 if (d->compat_tc_stats) {
345 d->tc_stats.drops = qstats.drops;
346 d->tc_stats.qlen = qstats.qlen;
347 d->tc_stats.backlog = qstats.backlog;
348 d->tc_stats.overlimits = qstats.overlimits;
349 }
350
351 if (d->tail)
352 return gnet_stats_copy(d, TCA_STATS_QUEUE,
353 &qstats, sizeof(qstats),
354 TCA_STATS_PAD);
355
356 return 0;
357 }
358 EXPORT_SYMBOL(gnet_stats_copy_queue);
359
360 /**
361 * gnet_stats_copy_app - copy application specific statistics into statistics TLV
362 * @d: dumping handle
363 * @st: application specific statistics data
364 * @len: length of data
365 *
366 * Appends the application specific statistics to the top level TLV created by
367 * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
368 * handle is in backward compatibility mode.
369 *
370 * Returns 0 on success or -1 with the statistic lock released
371 * if the room in the socket buffer was not sufficient.
372 */
373 int
374 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
375 {
376 if (d->compat_xstats) {
377 d->xstats = kmemdup(st, len, GFP_ATOMIC);
378 if (!d->xstats)
379 goto err_out;
380 d->xstats_len = len;
381 }
382
383 if (d->tail)
384 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
385 TCA_STATS_PAD);
386
387 return 0;
388
389 err_out:
390 if (d->lock)
391 spin_unlock_bh(d->lock);
392 d->xstats_len = 0;
393 return -1;
394 }
395 EXPORT_SYMBOL(gnet_stats_copy_app);
396
397 /**
398 * gnet_stats_finish_copy - finish dumping procedure
399 * @d: dumping handle
400 *
401 * Corrects the length of the top level TLV to include all TLVs added
402 * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
403 * if gnet_stats_start_copy_compat() was used and releases the statistics
404 * lock.
405 *
406 * Returns 0 on success or -1 with the statistic lock released
407 * if the room in the socket buffer was not sufficient.
408 */
409 int
410 gnet_stats_finish_copy(struct gnet_dump *d)
411 {
412 if (d->tail)
413 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
414
415 if (d->compat_tc_stats)
416 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
417 sizeof(d->tc_stats), d->padattr) < 0)
418 return -1;
419
420 if (d->compat_xstats && d->xstats) {
421 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
422 d->xstats_len, d->padattr) < 0)
423 return -1;
424 }
425
426 if (d->lock)
427 spin_unlock_bh(d->lock);
428 kfree(d->xstats);
429 d->xstats = NULL;
430 d->xstats_len = 0;
431 return 0;
432 }
433 EXPORT_SYMBOL(gnet_stats_finish_copy);
434
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