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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2017 Nicira, Inc.
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/if.h>
9#include <linux/skbuff.h>
10#include <linux/ip.h>
11#include <linux/kernel.h>
12#include <linux/openvswitch.h>
13#include <linux/netlink.h>
14#include <linux/rculist.h>
15
16#include <net/netlink.h>
17#include <net/genetlink.h>
18
19#include "datapath.h"
20#include "meter.h"
21
22#define METER_HASH_BUCKETS 1024
23
24static const struct nla_policy meter_policy[OVS_METER_ATTR_MAX + 1] = {
25 [OVS_METER_ATTR_ID] = { .type = NLA_U32, },
26 [OVS_METER_ATTR_KBPS] = { .type = NLA_FLAG },
27 [OVS_METER_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) },
28 [OVS_METER_ATTR_BANDS] = { .type = NLA_NESTED },
29 [OVS_METER_ATTR_USED] = { .type = NLA_U64 },
30 [OVS_METER_ATTR_CLEAR] = { .type = NLA_FLAG },
31 [OVS_METER_ATTR_MAX_METERS] = { .type = NLA_U32 },
32 [OVS_METER_ATTR_MAX_BANDS] = { .type = NLA_U32 },
33};
34
35static const struct nla_policy band_policy[OVS_BAND_ATTR_MAX + 1] = {
36 [OVS_BAND_ATTR_TYPE] = { .type = NLA_U32, },
37 [OVS_BAND_ATTR_RATE] = { .type = NLA_U32, },
38 [OVS_BAND_ATTR_BURST] = { .type = NLA_U32, },
39 [OVS_BAND_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) },
40};
41
42static void ovs_meter_free(struct dp_meter *meter)
43{
44 if (!meter)
45 return;
46
47 kfree_rcu(meter, rcu);
48}
49
50static struct hlist_head *meter_hash_bucket(const struct datapath *dp,
51 u32 meter_id)
52{
53 return &dp->meters[meter_id & (METER_HASH_BUCKETS - 1)];
54}
55
56/* Call with ovs_mutex or RCU read lock. */
57static struct dp_meter *lookup_meter(const struct datapath *dp,
58 u32 meter_id)
59{
60 struct dp_meter *meter;
61 struct hlist_head *head;
62
63 head = meter_hash_bucket(dp, meter_id);
64 hlist_for_each_entry_rcu(meter, head, dp_hash_node) {
65 if (meter->id == meter_id)
66 return meter;
67 }
68 return NULL;
69}
70
71static void attach_meter(struct datapath *dp, struct dp_meter *meter)
72{
73 struct hlist_head *head = meter_hash_bucket(dp, meter->id);
74
75 hlist_add_head_rcu(&meter->dp_hash_node, head);
76}
77
78static void detach_meter(struct dp_meter *meter)
79{
80 ASSERT_OVSL();
81 if (meter)
82 hlist_del_rcu(&meter->dp_hash_node);
83}
84
85static struct sk_buff *
86ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
87 struct ovs_header **ovs_reply_header)
88{
89 struct sk_buff *skb;
90 struct ovs_header *ovs_header = info->userhdr;
91
92 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
93 if (!skb)
94 return ERR_PTR(-ENOMEM);
95
96 *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
97 info->snd_seq,
98 &dp_meter_genl_family, 0, cmd);
99 if (!*ovs_reply_header) {
100 nlmsg_free(skb);
101 return ERR_PTR(-EMSGSIZE);
102 }
103 (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
104
105 return skb;
106}
107
108static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
109 struct dp_meter *meter)
110{
111 struct nlattr *nla;
112 struct dp_meter_band *band;
113 u16 i;
114
115 if (nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id))
116 goto error;
117
118 if (!meter)
119 return 0;
120
121 if (nla_put(reply, OVS_METER_ATTR_STATS,
122 sizeof(struct ovs_flow_stats), &meter->stats) ||
123 nla_put_u64_64bit(reply, OVS_METER_ATTR_USED, meter->used,
124 OVS_METER_ATTR_PAD))
125 goto error;
126
127 nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
128 if (!nla)
129 goto error;
130
131 band = meter->bands;
132
133 for (i = 0; i < meter->n_bands; ++i, ++band) {
134 struct nlattr *band_nla;
135
136 band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
137 if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS,
138 sizeof(struct ovs_flow_stats),
139 &band->stats))
140 goto error;
141 nla_nest_end(reply, band_nla);
142 }
143 nla_nest_end(reply, nla);
144
145 return 0;
146error:
147 return -EMSGSIZE;
148}
149
150static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
151{
152 struct sk_buff *reply;
153 struct ovs_header *ovs_reply_header;
154 struct nlattr *nla, *band_nla;
155 int err;
156
157 reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_FEATURES,
158 &ovs_reply_header);
159 if (IS_ERR(reply))
160 return PTR_ERR(reply);
161
162 if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS, U32_MAX) ||
163 nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
164 goto nla_put_failure;
165
166 nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
167 if (!nla)
168 goto nla_put_failure;
169
170 band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
171 if (!band_nla)
172 goto nla_put_failure;
173 /* Currently only DROP band type is supported. */
174 if (nla_put_u32(reply, OVS_BAND_ATTR_TYPE, OVS_METER_BAND_TYPE_DROP))
175 goto nla_put_failure;
176 nla_nest_end(reply, band_nla);
177 nla_nest_end(reply, nla);
178
179 genlmsg_end(reply, ovs_reply_header);
180 return genlmsg_reply(reply, info);
181
182nla_put_failure:
183 nlmsg_free(reply);
184 err = -EMSGSIZE;
185 return err;
186}
187
188static struct dp_meter *dp_meter_create(struct nlattr **a)
189{
190 struct nlattr *nla;
191 int rem;
192 u16 n_bands = 0;
193 struct dp_meter *meter;
194 struct dp_meter_band *band;
195 int err;
196
197 /* Validate attributes, count the bands. */
198 if (!a[OVS_METER_ATTR_BANDS])
199 return ERR_PTR(-EINVAL);
200
201 nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem)
202 if (++n_bands > DP_MAX_BANDS)
203 return ERR_PTR(-EINVAL);
204
205 /* Allocate and set up the meter before locking anything. */
206 meter = kzalloc(struct_size(meter, bands, n_bands), GFP_KERNEL);
207 if (!meter)
208 return ERR_PTR(-ENOMEM);
209
210 meter->id = nla_get_u32(a[OVS_METER_ATTR_ID]);
211 meter->used = div_u64(ktime_get_ns(), 1000 * 1000);
212 meter->kbps = a[OVS_METER_ATTR_KBPS] ? 1 : 0;
213 meter->keep_stats = !a[OVS_METER_ATTR_CLEAR];
214 spin_lock_init(&meter->lock);
215 if (meter->keep_stats && a[OVS_METER_ATTR_STATS]) {
216 meter->stats = *(struct ovs_flow_stats *)
217 nla_data(a[OVS_METER_ATTR_STATS]);
218 }
219 meter->n_bands = n_bands;
220
221 /* Set up meter bands. */
222 band = meter->bands;
223 nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem) {
224 struct nlattr *attr[OVS_BAND_ATTR_MAX + 1];
225 u32 band_max_delta_t;
226
227 err = nla_parse_deprecated((struct nlattr **)&attr,
228 OVS_BAND_ATTR_MAX, nla_data(nla),
229 nla_len(nla), band_policy, NULL);
230 if (err)
231 goto exit_free_meter;
232
233 if (!attr[OVS_BAND_ATTR_TYPE] ||
234 !attr[OVS_BAND_ATTR_RATE] ||
235 !attr[OVS_BAND_ATTR_BURST]) {
236 err = -EINVAL;
237 goto exit_free_meter;
238 }
239
240 band->type = nla_get_u32(attr[OVS_BAND_ATTR_TYPE]);
241 band->rate = nla_get_u32(attr[OVS_BAND_ATTR_RATE]);
242 if (band->rate == 0) {
243 err = -EINVAL;
244 goto exit_free_meter;
245 }
246
247 band->burst_size = nla_get_u32(attr[OVS_BAND_ATTR_BURST]);
248 /* Figure out max delta_t that is enough to fill any bucket.
249 * Keep max_delta_t size to the bucket units:
250 * pkts => 1/1000 packets, kilobits => bits.
251 *
252 * Start with a full bucket.
253 */
254 band->bucket = (band->burst_size + band->rate) * 1000;
255 band_max_delta_t = band->bucket / band->rate;
256 if (band_max_delta_t > meter->max_delta_t)
257 meter->max_delta_t = band_max_delta_t;
258 band++;
259 }
260
261 return meter;
262
263exit_free_meter:
264 kfree(meter);
265 return ERR_PTR(err);
266}
267
268static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
269{
270 struct nlattr **a = info->attrs;
271 struct dp_meter *meter, *old_meter;
272 struct sk_buff *reply;
273 struct ovs_header *ovs_reply_header;
274 struct ovs_header *ovs_header = info->userhdr;
275 struct datapath *dp;
276 int err;
277 u32 meter_id;
278 bool failed;
279
280 if (!a[OVS_METER_ATTR_ID]) {
281 return -ENODEV;
282 }
283
284 meter = dp_meter_create(a);
285 if (IS_ERR_OR_NULL(meter))
286 return PTR_ERR(meter);
287
288 reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_SET,
289 &ovs_reply_header);
290 if (IS_ERR(reply)) {
291 err = PTR_ERR(reply);
292 goto exit_free_meter;
293 }
294
295 ovs_lock();
296 dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
297 if (!dp) {
298 err = -ENODEV;
299 goto exit_unlock;
300 }
301
302 meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
303
304 /* Cannot fail after this. */
305 old_meter = lookup_meter(dp, meter_id);
306 detach_meter(old_meter);
307 attach_meter(dp, meter);
308 ovs_unlock();
309
310 /* Build response with the meter_id and stats from
311 * the old meter, if any.
312 */
313 failed = nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id);
314 WARN_ON(failed);
315 if (old_meter) {
316 spin_lock_bh(&old_meter->lock);
317 if (old_meter->keep_stats) {
318 err = ovs_meter_cmd_reply_stats(reply, meter_id,
319 old_meter);
320 WARN_ON(err);
321 }
322 spin_unlock_bh(&old_meter->lock);
323 ovs_meter_free(old_meter);
324 }
325
326 genlmsg_end(reply, ovs_reply_header);
327 return genlmsg_reply(reply, info);
328
329exit_unlock:
330 ovs_unlock();
331 nlmsg_free(reply);
332exit_free_meter:
333 kfree(meter);
334 return err;
335}
336
337static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info)
338{
339 struct nlattr **a = info->attrs;
340 u32 meter_id;
341 struct ovs_header *ovs_header = info->userhdr;
342 struct ovs_header *ovs_reply_header;
343 struct datapath *dp;
344 int err;
345 struct sk_buff *reply;
346 struct dp_meter *meter;
347
348 if (!a[OVS_METER_ATTR_ID])
349 return -EINVAL;
350
351 meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
352
353 reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_GET,
354 &ovs_reply_header);
355 if (IS_ERR(reply))
356 return PTR_ERR(reply);
357
358 ovs_lock();
359
360 dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
361 if (!dp) {
362 err = -ENODEV;
363 goto exit_unlock;
364 }
365
366 /* Locate meter, copy stats. */
367 meter = lookup_meter(dp, meter_id);
368 if (!meter) {
369 err = -ENOENT;
370 goto exit_unlock;
371 }
372
373 spin_lock_bh(&meter->lock);
374 err = ovs_meter_cmd_reply_stats(reply, meter_id, meter);
375 spin_unlock_bh(&meter->lock);
376 if (err)
377 goto exit_unlock;
378
379 ovs_unlock();
380
381 genlmsg_end(reply, ovs_reply_header);
382 return genlmsg_reply(reply, info);
383
384exit_unlock:
385 ovs_unlock();
386 nlmsg_free(reply);
387 return err;
388}
389
390static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info)
391{
392 struct nlattr **a = info->attrs;
393 u32 meter_id;
394 struct ovs_header *ovs_header = info->userhdr;
395 struct ovs_header *ovs_reply_header;
396 struct datapath *dp;
397 int err;
398 struct sk_buff *reply;
399 struct dp_meter *old_meter;
400
401 if (!a[OVS_METER_ATTR_ID])
402 return -EINVAL;
403 meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
404
405 reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_DEL,
406 &ovs_reply_header);
407 if (IS_ERR(reply))
408 return PTR_ERR(reply);
409
410 ovs_lock();
411
412 dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
413 if (!dp) {
414 err = -ENODEV;
415 goto exit_unlock;
416 }
417
418 old_meter = lookup_meter(dp, meter_id);
419 if (old_meter) {
420 spin_lock_bh(&old_meter->lock);
421 err = ovs_meter_cmd_reply_stats(reply, meter_id, old_meter);
422 WARN_ON(err);
423 spin_unlock_bh(&old_meter->lock);
424 detach_meter(old_meter);
425 }
426 ovs_unlock();
427 ovs_meter_free(old_meter);
428 genlmsg_end(reply, ovs_reply_header);
429 return genlmsg_reply(reply, info);
430
431exit_unlock:
432 ovs_unlock();
433 nlmsg_free(reply);
434 return err;
435}
436
437/* Meter action execution.
438 *
439 * Return true 'meter_id' drop band is triggered. The 'skb' should be
440 * dropped by the caller'.
441 */
442bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
443 struct sw_flow_key *key, u32 meter_id)
444{
445 struct dp_meter *meter;
446 struct dp_meter_band *band;
447 long long int now_ms = div_u64(ktime_get_ns(), 1000 * 1000);
448 long long int long_delta_ms;
449 u32 delta_ms;
450 u32 cost;
451 int i, band_exceeded_max = -1;
452 u32 band_exceeded_rate = 0;
453
454 meter = lookup_meter(dp, meter_id);
455 /* Do not drop the packet when there is no meter. */
456 if (!meter)
457 return false;
458
459 /* Lock the meter while using it. */
460 spin_lock(&meter->lock);
461
462 long_delta_ms = (now_ms - meter->used); /* ms */
463
464 /* Make sure delta_ms will not be too large, so that bucket will not
465 * wrap around below.
466 */
467 delta_ms = (long_delta_ms > (long long int)meter->max_delta_t)
468 ? meter->max_delta_t : (u32)long_delta_ms;
469
470 /* Update meter statistics.
471 */
472 meter->used = now_ms;
473 meter->stats.n_packets += 1;
474 meter->stats.n_bytes += skb->len;
475
476 /* Bucket rate is either in kilobits per second, or in packets per
477 * second. We maintain the bucket in the units of either bits or
478 * 1/1000th of a packet, correspondingly.
479 * Then, when rate is multiplied with milliseconds, we get the
480 * bucket units:
481 * msec * kbps = bits, and
482 * msec * packets/sec = 1/1000 packets.
483 *
484 * 'cost' is the number of bucket units in this packet.
485 */
486 cost = (meter->kbps) ? skb->len * 8 : 1000;
487
488 /* Update all bands and find the one hit with the highest rate. */
489 for (i = 0; i < meter->n_bands; ++i) {
490 long long int max_bucket_size;
491
492 band = &meter->bands[i];
493 max_bucket_size = (band->burst_size + band->rate) * 1000LL;
494
495 band->bucket += delta_ms * band->rate;
496 if (band->bucket > max_bucket_size)
497 band->bucket = max_bucket_size;
498
499 if (band->bucket >= cost) {
500 band->bucket -= cost;
501 } else if (band->rate > band_exceeded_rate) {
502 band_exceeded_rate = band->rate;
503 band_exceeded_max = i;
504 }
505 }
506
507 if (band_exceeded_max >= 0) {
508 /* Update band statistics. */
509 band = &meter->bands[band_exceeded_max];
510 band->stats.n_packets += 1;
511 band->stats.n_bytes += skb->len;
512
513 /* Drop band triggered, let the caller drop the 'skb'. */
514 if (band->type == OVS_METER_BAND_TYPE_DROP) {
515 spin_unlock(&meter->lock);
516 return true;
517 }
518 }
519
520 spin_unlock(&meter->lock);
521 return false;
522}
523
524static struct genl_ops dp_meter_genl_ops[] = {
525 { .cmd = OVS_METER_CMD_FEATURES,
526 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
527 .flags = 0, /* OK for unprivileged users. */
528 .doit = ovs_meter_cmd_features
529 },
530 { .cmd = OVS_METER_CMD_SET,
531 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
532 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
533 * privilege.
534 */
535 .doit = ovs_meter_cmd_set,
536 },
537 { .cmd = OVS_METER_CMD_GET,
538 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
539 .flags = 0, /* OK for unprivileged users. */
540 .doit = ovs_meter_cmd_get,
541 },
542 { .cmd = OVS_METER_CMD_DEL,
543 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
544 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
545 * privilege.
546 */
547 .doit = ovs_meter_cmd_del
548 },
549};
550
551static const struct genl_multicast_group ovs_meter_multicast_group = {
552 .name = OVS_METER_MCGROUP,
553};
554
555struct genl_family dp_meter_genl_family __ro_after_init = {
556 .hdrsize = sizeof(struct ovs_header),
557 .name = OVS_METER_FAMILY,
558 .version = OVS_METER_VERSION,
559 .maxattr = OVS_METER_ATTR_MAX,
560 .policy = meter_policy,
561 .netnsok = true,
562 .parallel_ops = true,
563 .ops = dp_meter_genl_ops,
564 .n_ops = ARRAY_SIZE(dp_meter_genl_ops),
565 .mcgrps = &ovs_meter_multicast_group,
566 .n_mcgrps = 1,
567 .module = THIS_MODULE,
568};
569
570int ovs_meters_init(struct datapath *dp)
571{
572 int i;
573
574 dp->meters = kmalloc_array(METER_HASH_BUCKETS,
575 sizeof(struct hlist_head), GFP_KERNEL);
576
577 if (!dp->meters)
578 return -ENOMEM;
579
580 for (i = 0; i < METER_HASH_BUCKETS; i++)
581 INIT_HLIST_HEAD(&dp->meters[i]);
582
583 return 0;
584}
585
586void ovs_meters_exit(struct datapath *dp)
587{
588 int i;
589
590 for (i = 0; i < METER_HASH_BUCKETS; i++) {
591 struct hlist_head *head = &dp->meters[i];
592 struct dp_meter *meter;
593 struct hlist_node *n;
594
595 hlist_for_each_entry_safe(meter, n, head, dp_hash_node)
596 kfree(meter);
597 }
598
599 kfree(dp->meters);
600}