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ARM: dma-api: fix max_pfn off-by-one error in __dma_supported()
[linux/fpc-iii.git] / net / core / drop_monitor.c
blobea46fc6aa883b97576d416d6684505bae7dc9843
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Monitoring code for network dropped packet alerts
4 *
5 * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10 #include <linux/netdevice.h>
11 #include <linux/etherdevice.h>
12 #include <linux/string.h>
13 #include <linux/if_arp.h>
14 #include <linux/inetdevice.h>
15 #include <linux/inet.h>
16 #include <linux/interrupt.h>
17 #include <linux/netpoll.h>
18 #include <linux/sched.h>
19 #include <linux/delay.h>
20 #include <linux/types.h>
21 #include <linux/workqueue.h>
22 #include <linux/netlink.h>
23 #include <linux/net_dropmon.h>
24 #include <linux/percpu.h>
25 #include <linux/timer.h>
26 #include <linux/bitops.h>
27 #include <linux/slab.h>
28 #include <linux/module.h>
29 #include <net/drop_monitor.h>
30 #include <net/genetlink.h>
31 #include <net/netevent.h>
32
33 #include <trace/events/skb.h>
34 #include <trace/events/napi.h>
35
36 #include <asm/unaligned.h>
37
38 #define TRACE_ON 1
39 #define TRACE_OFF 0
40
41 /*
42 * Globals, our netlink socket pointer
43 * and the work handle that will send up
44 * netlink alerts
45 */
46 static int trace_state = TRACE_OFF;
47 static bool monitor_hw;
48
49 /* net_dm_mutex
50 *
51 * An overall lock guarding every operation coming from userspace.
52 * It also guards the global 'hw_stats_list' list.
53 */
54 static DEFINE_MUTEX(net_dm_mutex);
55
56 struct net_dm_stats {
57 u64 dropped;
58 struct u64_stats_sync syncp;
59 };
60
61 #define NET_DM_MAX_HW_TRAP_NAME_LEN 40
62
63 struct net_dm_hw_entry {
64 char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
65 u32 count;
66 };
67
68 struct net_dm_hw_entries {
69 u32 num_entries;
70 struct net_dm_hw_entry entries[0];
71 };
72
73 struct per_cpu_dm_data {
74 spinlock_t lock; /* Protects 'skb', 'hw_entries' and
75 * 'send_timer'
76 */
77 union {
78 struct sk_buff *skb;
79 struct net_dm_hw_entries *hw_entries;
80 };
81 struct sk_buff_head drop_queue;
82 struct work_struct dm_alert_work;
83 struct timer_list send_timer;
84 struct net_dm_stats stats;
85 };
86
87 struct dm_hw_stat_delta {
88 struct net_device *dev;
89 unsigned long last_rx;
90 struct list_head list;
91 struct rcu_head rcu;
92 unsigned long last_drop_val;
93 };
94
95 static struct genl_family net_drop_monitor_family;
96
97 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
98 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
99
100 static int dm_hit_limit = 64;
101 static int dm_delay = 1;
102 static unsigned long dm_hw_check_delta = 2*HZ;
103 static LIST_HEAD(hw_stats_list);
104
105 static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
106 static u32 net_dm_trunc_len;
107 static u32 net_dm_queue_len = 1000;
108
109 struct net_dm_alert_ops {
110 void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
111 void *location);
112 void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
113 int work, int budget);
114 void (*work_item_func)(struct work_struct *work);
115 void (*hw_work_item_func)(struct work_struct *work);
116 void (*hw_probe)(struct sk_buff *skb,
117 const struct net_dm_hw_metadata *hw_metadata);
118 };
119
120 struct net_dm_skb_cb {
121 union {
122 struct net_dm_hw_metadata *hw_metadata;
123 void *pc;
124 };
125 };
126
127 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
128
129 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
130 {
131 size_t al;
132 struct net_dm_alert_msg *msg;
133 struct nlattr *nla;
134 struct sk_buff *skb;
135 unsigned long flags;
136 void *msg_header;
137
138 al = sizeof(struct net_dm_alert_msg);
139 al += dm_hit_limit * sizeof(struct net_dm_drop_point);
140 al += sizeof(struct nlattr);
141
142 skb = genlmsg_new(al, GFP_KERNEL);
143
144 if (!skb)
145 goto err;
146
147 msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
148 0, NET_DM_CMD_ALERT);
149 if (!msg_header) {
150 nlmsg_free(skb);
151 skb = NULL;
152 goto err;
153 }
154 nla = nla_reserve(skb, NLA_UNSPEC,
155 sizeof(struct net_dm_alert_msg));
156 if (!nla) {
157 nlmsg_free(skb);
158 skb = NULL;
159 goto err;
160 }
161 msg = nla_data(nla);
162 memset(msg, 0, al);
163 goto out;
164
165 err:
166 mod_timer(&data->send_timer, jiffies + HZ / 10);
167 out:
168 spin_lock_irqsave(&data->lock, flags);
169 swap(data->skb, skb);
170 spin_unlock_irqrestore(&data->lock, flags);
171
172 if (skb) {
173 struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
174 struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
175
176 genlmsg_end(skb, genlmsg_data(gnlh));
177 }
178
179 return skb;
180 }
181
182 static const struct genl_multicast_group dropmon_mcgrps[] = {
183 { .name = "events", },
184 };
185
186 static void send_dm_alert(struct work_struct *work)
187 {
188 struct sk_buff *skb;
189 struct per_cpu_dm_data *data;
190
191 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
192
193 skb = reset_per_cpu_data(data);
194
195 if (skb)
196 genlmsg_multicast(&net_drop_monitor_family, skb, 0,
197 0, GFP_KERNEL);
198 }
199
200 /*
201 * This is the timer function to delay the sending of an alert
202 * in the event that more drops will arrive during the
203 * hysteresis period.
204 */
205 static void sched_send_work(struct timer_list *t)
206 {
207 struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
208
209 schedule_work(&data->dm_alert_work);
210 }
211
212 static void trace_drop_common(struct sk_buff *skb, void *location)
213 {
214 struct net_dm_alert_msg *msg;
215 struct nlmsghdr *nlh;
216 struct nlattr *nla;
217 int i;
218 struct sk_buff *dskb;
219 struct per_cpu_dm_data *data;
220 unsigned long flags;
221
222 local_irq_save(flags);
223 data = this_cpu_ptr(&dm_cpu_data);
224 spin_lock(&data->lock);
225 dskb = data->skb;
226
227 if (!dskb)
228 goto out;
229
230 nlh = (struct nlmsghdr *)dskb->data;
231 nla = genlmsg_data(nlmsg_data(nlh));
232 msg = nla_data(nla);
233 for (i = 0; i < msg->entries; i++) {
234 if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
235 msg->points[i].count++;
236 goto out;
237 }
238 }
239 if (msg->entries == dm_hit_limit)
240 goto out;
241 /*
242 * We need to create a new entry
243 */
244 __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
245 nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
246 memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
247 msg->points[msg->entries].count = 1;
248 msg->entries++;
249
250 if (!timer_pending(&data->send_timer)) {
251 data->send_timer.expires = jiffies + dm_delay * HZ;
252 add_timer(&data->send_timer);
253 }
254
255 out:
256 spin_unlock_irqrestore(&data->lock, flags);
257 }
258
259 static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
260 {
261 trace_drop_common(skb, location);
262 }
263
264 static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
265 int work, int budget)
266 {
267 struct dm_hw_stat_delta *new_stat;
268
269 /*
270 * Don't check napi structures with no associated device
271 */
272 if (!napi->dev)
273 return;
274
275 rcu_read_lock();
276 list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
277 /*
278 * only add a note to our monitor buffer if:
279 * 1) this is the dev we received on
280 * 2) its after the last_rx delta
281 * 3) our rx_dropped count has gone up
282 */
283 if ((new_stat->dev == napi->dev) &&
284 (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) &&
285 (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
286 trace_drop_common(NULL, NULL);
287 new_stat->last_drop_val = napi->dev->stats.rx_dropped;
288 new_stat->last_rx = jiffies;
289 break;
290 }
291 }
292 rcu_read_unlock();
293 }
294
295 static struct net_dm_hw_entries *
296 net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
297 {
298 struct net_dm_hw_entries *hw_entries;
299 unsigned long flags;
300
301 hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit),
302 GFP_KERNEL);
303 if (!hw_entries) {
304 /* If the memory allocation failed, we try to perform another
305 * allocation in 1/10 second. Otherwise, the probe function
306 * will constantly bail out.
307 */
308 mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
309 }
310
311 spin_lock_irqsave(&hw_data->lock, flags);
312 swap(hw_data->hw_entries, hw_entries);
313 spin_unlock_irqrestore(&hw_data->lock, flags);
314
315 return hw_entries;
316 }
317
318 static int net_dm_hw_entry_put(struct sk_buff *msg,
319 const struct net_dm_hw_entry *hw_entry)
320 {
321 struct nlattr *attr;
322
323 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
324 if (!attr)
325 return -EMSGSIZE;
326
327 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
328 goto nla_put_failure;
329
330 if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
331 goto nla_put_failure;
332
333 nla_nest_end(msg, attr);
334
335 return 0;
336
337 nla_put_failure:
338 nla_nest_cancel(msg, attr);
339 return -EMSGSIZE;
340 }
341
342 static int net_dm_hw_entries_put(struct sk_buff *msg,
343 const struct net_dm_hw_entries *hw_entries)
344 {
345 struct nlattr *attr;
346 int i;
347
348 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
349 if (!attr)
350 return -EMSGSIZE;
351
352 for (i = 0; i < hw_entries->num_entries; i++) {
353 int rc;
354
355 rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
356 if (rc)
357 goto nla_put_failure;
358 }
359
360 nla_nest_end(msg, attr);
361
362 return 0;
363
364 nla_put_failure:
365 nla_nest_cancel(msg, attr);
366 return -EMSGSIZE;
367 }
368
369 static int
370 net_dm_hw_summary_report_fill(struct sk_buff *msg,
371 const struct net_dm_hw_entries *hw_entries)
372 {
373 struct net_dm_alert_msg anc_hdr = { 0 };
374 void *hdr;
375 int rc;
376
377 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
378 NET_DM_CMD_ALERT);
379 if (!hdr)
380 return -EMSGSIZE;
381
382 /* We need to put the ancillary header in order not to break user
383 * space.
384 */
385 if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
386 goto nla_put_failure;
387
388 rc = net_dm_hw_entries_put(msg, hw_entries);
389 if (rc)
390 goto nla_put_failure;
391
392 genlmsg_end(msg, hdr);
393
394 return 0;
395
396 nla_put_failure:
397 genlmsg_cancel(msg, hdr);
398 return -EMSGSIZE;
399 }
400
401 static void net_dm_hw_summary_work(struct work_struct *work)
402 {
403 struct net_dm_hw_entries *hw_entries;
404 struct per_cpu_dm_data *hw_data;
405 struct sk_buff *msg;
406 int rc;
407
408 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
409
410 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
411 if (!hw_entries)
412 return;
413
414 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
415 if (!msg)
416 goto out;
417
418 rc = net_dm_hw_summary_report_fill(msg, hw_entries);
419 if (rc) {
420 nlmsg_free(msg);
421 goto out;
422 }
423
424 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
425
426 out:
427 kfree(hw_entries);
428 }
429
430 static void
431 net_dm_hw_summary_probe(struct sk_buff *skb,
432 const struct net_dm_hw_metadata *hw_metadata)
433 {
434 struct net_dm_hw_entries *hw_entries;
435 struct net_dm_hw_entry *hw_entry;
436 struct per_cpu_dm_data *hw_data;
437 unsigned long flags;
438 int i;
439
440 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
441 spin_lock_irqsave(&hw_data->lock, flags);
442 hw_entries = hw_data->hw_entries;
443
444 if (!hw_entries)
445 goto out;
446
447 for (i = 0; i < hw_entries->num_entries; i++) {
448 hw_entry = &hw_entries->entries[i];
449 if (!strncmp(hw_entry->trap_name, hw_metadata->trap_name,
450 NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
451 hw_entry->count++;
452 goto out;
453 }
454 }
455 if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit))
456 goto out;
457
458 hw_entry = &hw_entries->entries[hw_entries->num_entries];
459 strlcpy(hw_entry->trap_name, hw_metadata->trap_name,
460 NET_DM_MAX_HW_TRAP_NAME_LEN - 1);
461 hw_entry->count = 1;
462 hw_entries->num_entries++;
463
464 if (!timer_pending(&hw_data->send_timer)) {
465 hw_data->send_timer.expires = jiffies + dm_delay * HZ;
466 add_timer(&hw_data->send_timer);
467 }
468
469 out:
470 spin_unlock_irqrestore(&hw_data->lock, flags);
471 }
472
473 static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
474 .kfree_skb_probe = trace_kfree_skb_hit,
475 .napi_poll_probe = trace_napi_poll_hit,
476 .work_item_func = send_dm_alert,
477 .hw_work_item_func = net_dm_hw_summary_work,
478 .hw_probe = net_dm_hw_summary_probe,
479 };
480
481 static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
482 struct sk_buff *skb,
483 void *location)
484 {
485 ktime_t tstamp = ktime_get_real();
486 struct per_cpu_dm_data *data;
487 struct sk_buff *nskb;
488 unsigned long flags;
489
490 if (!skb_mac_header_was_set(skb))
491 return;
492
493 nskb = skb_clone(skb, GFP_ATOMIC);
494 if (!nskb)
495 return;
496
497 NET_DM_SKB_CB(nskb)->pc = location;
498 /* Override the timestamp because we care about the time when the
499 * packet was dropped.
500 */
501 nskb->tstamp = tstamp;
502
503 data = this_cpu_ptr(&dm_cpu_data);
504
505 spin_lock_irqsave(&data->drop_queue.lock, flags);
506 if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
507 __skb_queue_tail(&data->drop_queue, nskb);
508 else
509 goto unlock_free;
510 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
511
512 schedule_work(&data->dm_alert_work);
513
514 return;
515
516 unlock_free:
517 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
518 u64_stats_update_begin(&data->stats.syncp);
519 data->stats.dropped++;
520 u64_stats_update_end(&data->stats.syncp);
521 consume_skb(nskb);
522 }
523
524 static void net_dm_packet_trace_napi_poll_hit(void *ignore,
525 struct napi_struct *napi,
526 int work, int budget)
527 {
528 }
529
530 static size_t net_dm_in_port_size(void)
531 {
532 /* NET_DM_ATTR_IN_PORT nest */
533 return nla_total_size(0) +
534 /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */
535 nla_total_size(sizeof(u32)) +
536 /* NET_DM_ATTR_PORT_NETDEV_NAME */
537 nla_total_size(IFNAMSIZ + 1);
538 }
539
540 #define NET_DM_MAX_SYMBOL_LEN 40
541
542 static size_t net_dm_packet_report_size(size_t payload_len)
543 {
544 size_t size;
545
546 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
547
548 return NLMSG_ALIGN(size) +
549 /* NET_DM_ATTR_ORIGIN */
550 nla_total_size(sizeof(u16)) +
551 /* NET_DM_ATTR_PC */
552 nla_total_size(sizeof(u64)) +
553 /* NET_DM_ATTR_SYMBOL */
554 nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
555 /* NET_DM_ATTR_IN_PORT */
556 net_dm_in_port_size() +
557 /* NET_DM_ATTR_TIMESTAMP */
558 nla_total_size(sizeof(u64)) +
559 /* NET_DM_ATTR_ORIG_LEN */
560 nla_total_size(sizeof(u32)) +
561 /* NET_DM_ATTR_PROTO */
562 nla_total_size(sizeof(u16)) +
563 /* NET_DM_ATTR_PAYLOAD */
564 nla_total_size(payload_len);
565 }
566
567 static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
568 const char *name)
569 {
570 struct nlattr *attr;
571
572 attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
573 if (!attr)
574 return -EMSGSIZE;
575
576 if (ifindex &&
577 nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
578 goto nla_put_failure;
579
580 if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name))
581 goto nla_put_failure;
582
583 nla_nest_end(msg, attr);
584
585 return 0;
586
587 nla_put_failure:
588 nla_nest_cancel(msg, attr);
589 return -EMSGSIZE;
590 }
591
592 static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
593 size_t payload_len)
594 {
595 u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
596 char buf[NET_DM_MAX_SYMBOL_LEN];
597 struct nlattr *attr;
598 void *hdr;
599 int rc;
600
601 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
602 NET_DM_CMD_PACKET_ALERT);
603 if (!hdr)
604 return -EMSGSIZE;
605
606 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
607 goto nla_put_failure;
608
609 if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
610 goto nla_put_failure;
611
612 snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc);
613 if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
614 goto nla_put_failure;
615
616 rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL);
617 if (rc)
618 goto nla_put_failure;
619
620 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
621 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
622 goto nla_put_failure;
623
624 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
625 goto nla_put_failure;
626
627 if (!payload_len)
628 goto out;
629
630 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
631 goto nla_put_failure;
632
633 attr = skb_put(msg, nla_total_size(payload_len));
634 attr->nla_type = NET_DM_ATTR_PAYLOAD;
635 attr->nla_len = nla_attr_size(payload_len);
636 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
637 goto nla_put_failure;
638
639 out:
640 genlmsg_end(msg, hdr);
641
642 return 0;
643
644 nla_put_failure:
645 genlmsg_cancel(msg, hdr);
646 return -EMSGSIZE;
647 }
648
649 #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
650
651 static void net_dm_packet_report(struct sk_buff *skb)
652 {
653 struct sk_buff *msg;
654 size_t payload_len;
655 int rc;
656
657 /* Make sure we start copying the packet from the MAC header */
658 if (skb->data > skb_mac_header(skb))
659 skb_push(skb, skb->data - skb_mac_header(skb));
660 else
661 skb_pull(skb, skb_mac_header(skb) - skb->data);
662
663 /* Ensure packet fits inside a single netlink attribute */
664 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
665 if (net_dm_trunc_len)
666 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
667
668 msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
669 if (!msg)
670 goto out;
671
672 rc = net_dm_packet_report_fill(msg, skb, payload_len);
673 if (rc) {
674 nlmsg_free(msg);
675 goto out;
676 }
677
678 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
679
680 out:
681 consume_skb(skb);
682 }
683
684 static void net_dm_packet_work(struct work_struct *work)
685 {
686 struct per_cpu_dm_data *data;
687 struct sk_buff_head list;
688 struct sk_buff *skb;
689 unsigned long flags;
690
691 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
692
693 __skb_queue_head_init(&list);
694
695 spin_lock_irqsave(&data->drop_queue.lock, flags);
696 skb_queue_splice_tail_init(&data->drop_queue, &list);
697 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
698
699 while ((skb = __skb_dequeue(&list)))
700 net_dm_packet_report(skb);
701 }
702
703 static size_t
704 net_dm_hw_packet_report_size(size_t payload_len,
705 const struct net_dm_hw_metadata *hw_metadata)
706 {
707 size_t size;
708
709 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
710
711 return NLMSG_ALIGN(size) +
712 /* NET_DM_ATTR_ORIGIN */
713 nla_total_size(sizeof(u16)) +
714 /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */
715 nla_total_size(strlen(hw_metadata->trap_group_name) + 1) +
716 /* NET_DM_ATTR_HW_TRAP_NAME */
717 nla_total_size(strlen(hw_metadata->trap_name) + 1) +
718 /* NET_DM_ATTR_IN_PORT */
719 net_dm_in_port_size() +
720 /* NET_DM_ATTR_TIMESTAMP */
721 nla_total_size(sizeof(u64)) +
722 /* NET_DM_ATTR_ORIG_LEN */
723 nla_total_size(sizeof(u32)) +
724 /* NET_DM_ATTR_PROTO */
725 nla_total_size(sizeof(u16)) +
726 /* NET_DM_ATTR_PAYLOAD */
727 nla_total_size(payload_len);
728 }
729
730 static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
731 struct sk_buff *skb, size_t payload_len)
732 {
733 struct net_dm_hw_metadata *hw_metadata;
734 struct nlattr *attr;
735 void *hdr;
736
737 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
738
739 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
740 NET_DM_CMD_PACKET_ALERT);
741 if (!hdr)
742 return -EMSGSIZE;
743
744 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW))
745 goto nla_put_failure;
746
747 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME,
748 hw_metadata->trap_group_name))
749 goto nla_put_failure;
750
751 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME,
752 hw_metadata->trap_name))
753 goto nla_put_failure;
754
755 if (hw_metadata->input_dev) {
756 struct net_device *dev = hw_metadata->input_dev;
757 int rc;
758
759 rc = net_dm_packet_report_in_port_put(msg, dev->ifindex,
760 dev->name);
761 if (rc)
762 goto nla_put_failure;
763 }
764
765 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
766 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
767 goto nla_put_failure;
768
769 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
770 goto nla_put_failure;
771
772 if (!payload_len)
773 goto out;
774
775 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
776 goto nla_put_failure;
777
778 attr = skb_put(msg, nla_total_size(payload_len));
779 attr->nla_type = NET_DM_ATTR_PAYLOAD;
780 attr->nla_len = nla_attr_size(payload_len);
781 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
782 goto nla_put_failure;
783
784 out:
785 genlmsg_end(msg, hdr);
786
787 return 0;
788
789 nla_put_failure:
790 genlmsg_cancel(msg, hdr);
791 return -EMSGSIZE;
792 }
793
794 static struct net_dm_hw_metadata *
795 net_dm_hw_metadata_clone(const struct net_dm_hw_metadata *hw_metadata)
796 {
797 struct net_dm_hw_metadata *n_hw_metadata;
798 const char *trap_group_name;
799 const char *trap_name;
800
801 n_hw_metadata = kmalloc(sizeof(*hw_metadata), GFP_ATOMIC);
802 if (!n_hw_metadata)
803 return NULL;
804
805 trap_group_name = kstrdup(hw_metadata->trap_group_name, GFP_ATOMIC);
806 if (!trap_group_name)
807 goto free_hw_metadata;
808 n_hw_metadata->trap_group_name = trap_group_name;
809
810 trap_name = kstrdup(hw_metadata->trap_name, GFP_ATOMIC);
811 if (!trap_name)
812 goto free_trap_group;
813 n_hw_metadata->trap_name = trap_name;
814
815 n_hw_metadata->input_dev = hw_metadata->input_dev;
816 if (n_hw_metadata->input_dev)
817 dev_hold(n_hw_metadata->input_dev);
818
819 return n_hw_metadata;
820
821 free_trap_group:
822 kfree(trap_group_name);
823 free_hw_metadata:
824 kfree(n_hw_metadata);
825 return NULL;
826 }
827
828 static void
829 net_dm_hw_metadata_free(const struct net_dm_hw_metadata *hw_metadata)
830 {
831 if (hw_metadata->input_dev)
832 dev_put(hw_metadata->input_dev);
833 kfree(hw_metadata->trap_name);
834 kfree(hw_metadata->trap_group_name);
835 kfree(hw_metadata);
836 }
837
838 static void net_dm_hw_packet_report(struct sk_buff *skb)
839 {
840 struct net_dm_hw_metadata *hw_metadata;
841 struct sk_buff *msg;
842 size_t payload_len;
843 int rc;
844
845 if (skb->data > skb_mac_header(skb))
846 skb_push(skb, skb->data - skb_mac_header(skb));
847 else
848 skb_pull(skb, skb_mac_header(skb) - skb->data);
849
850 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
851 if (net_dm_trunc_len)
852 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
853
854 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
855 msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata),
856 GFP_KERNEL);
857 if (!msg)
858 goto out;
859
860 rc = net_dm_hw_packet_report_fill(msg, skb, payload_len);
861 if (rc) {
862 nlmsg_free(msg);
863 goto out;
864 }
865
866 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
867
868 out:
869 net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata);
870 consume_skb(skb);
871 }
872
873 static void net_dm_hw_packet_work(struct work_struct *work)
874 {
875 struct per_cpu_dm_data *hw_data;
876 struct sk_buff_head list;
877 struct sk_buff *skb;
878 unsigned long flags;
879
880 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
881
882 __skb_queue_head_init(&list);
883
884 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
885 skb_queue_splice_tail_init(&hw_data->drop_queue, &list);
886 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
887
888 while ((skb = __skb_dequeue(&list)))
889 net_dm_hw_packet_report(skb);
890 }
891
892 static void
893 net_dm_hw_packet_probe(struct sk_buff *skb,
894 const struct net_dm_hw_metadata *hw_metadata)
895 {
896 struct net_dm_hw_metadata *n_hw_metadata;
897 ktime_t tstamp = ktime_get_real();
898 struct per_cpu_dm_data *hw_data;
899 struct sk_buff *nskb;
900 unsigned long flags;
901
902 if (!skb_mac_header_was_set(skb))
903 return;
904
905 nskb = skb_clone(skb, GFP_ATOMIC);
906 if (!nskb)
907 return;
908
909 n_hw_metadata = net_dm_hw_metadata_clone(hw_metadata);
910 if (!n_hw_metadata)
911 goto free;
912
913 NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata;
914 nskb->tstamp = tstamp;
915
916 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
917
918 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
919 if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len)
920 __skb_queue_tail(&hw_data->drop_queue, nskb);
921 else
922 goto unlock_free;
923 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
924
925 schedule_work(&hw_data->dm_alert_work);
926
927 return;
928
929 unlock_free:
930 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
931 u64_stats_update_begin(&hw_data->stats.syncp);
932 hw_data->stats.dropped++;
933 u64_stats_update_end(&hw_data->stats.syncp);
934 net_dm_hw_metadata_free(n_hw_metadata);
935 free:
936 consume_skb(nskb);
937 }
938
939 static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
940 .kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit,
941 .napi_poll_probe = net_dm_packet_trace_napi_poll_hit,
942 .work_item_func = net_dm_packet_work,
943 .hw_work_item_func = net_dm_hw_packet_work,
944 .hw_probe = net_dm_hw_packet_probe,
945 };
946
947 static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
948 [NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops,
949 [NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops,
950 };
951
952 void net_dm_hw_report(struct sk_buff *skb,
953 const struct net_dm_hw_metadata *hw_metadata)
954 {
955 rcu_read_lock();
956
957 if (!monitor_hw)
958 goto out;
959
960 net_dm_alert_ops_arr[net_dm_alert_mode]->hw_probe(skb, hw_metadata);
961
962 out:
963 rcu_read_unlock();
964 }
965 EXPORT_SYMBOL_GPL(net_dm_hw_report);
966
967 static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack)
968 {
969 const struct net_dm_alert_ops *ops;
970 int cpu;
971
972 if (monitor_hw) {
973 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled");
974 return -EAGAIN;
975 }
976
977 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
978
979 if (!try_module_get(THIS_MODULE)) {
980 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
981 return -ENODEV;
982 }
983
984 for_each_possible_cpu(cpu) {
985 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
986 struct net_dm_hw_entries *hw_entries;
987
988 INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func);
989 timer_setup(&hw_data->send_timer, sched_send_work, 0);
990 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
991 kfree(hw_entries);
992 }
993
994 monitor_hw = true;
995
996 return 0;
997 }
998
999 static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack)
1000 {
1001 int cpu;
1002
1003 if (!monitor_hw)
1004 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled");
1005
1006 monitor_hw = false;
1007
1008 /* After this call returns we are guaranteed that no CPU is processing
1009 * any hardware drops.
1010 */
1011 synchronize_rcu();
1012
1013 for_each_possible_cpu(cpu) {
1014 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1015 struct sk_buff *skb;
1016
1017 del_timer_sync(&hw_data->send_timer);
1018 cancel_work_sync(&hw_data->dm_alert_work);
1019 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1020 struct net_dm_hw_metadata *hw_metadata;
1021
1022 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1023 net_dm_hw_metadata_free(hw_metadata);
1024 consume_skb(skb);
1025 }
1026 }
1027
1028 module_put(THIS_MODULE);
1029 }
1030
1031 static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
1032 {
1033 const struct net_dm_alert_ops *ops;
1034 int cpu, rc;
1035
1036 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1037
1038 if (!try_module_get(THIS_MODULE)) {
1039 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1040 return -ENODEV;
1041 }
1042
1043 for_each_possible_cpu(cpu) {
1044 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1045 struct sk_buff *skb;
1046
1047 INIT_WORK(&data->dm_alert_work, ops->work_item_func);
1048 timer_setup(&data->send_timer, sched_send_work, 0);
1049 /* Allocate a new per-CPU skb for the summary alert message and
1050 * free the old one which might contain stale data from
1051 * previous tracing.
1052 */
1053 skb = reset_per_cpu_data(data);
1054 consume_skb(skb);
1055 }
1056
1057 rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1058 if (rc) {
1059 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
1060 goto err_module_put;
1061 }
1062
1063 rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
1064 if (rc) {
1065 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
1066 goto err_unregister_trace;
1067 }
1068
1069 return 0;
1070
1071 err_unregister_trace:
1072 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1073 err_module_put:
1074 module_put(THIS_MODULE);
1075 return rc;
1076 }
1077
1078 static void net_dm_trace_off_set(void)
1079 {
1080 struct dm_hw_stat_delta *new_stat, *temp;
1081 const struct net_dm_alert_ops *ops;
1082 int cpu;
1083
1084 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1085
1086 unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
1087 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1088
1089 tracepoint_synchronize_unregister();
1090
1091 /* Make sure we do not send notifications to user space after request
1092 * to stop tracing returns.
1093 */
1094 for_each_possible_cpu(cpu) {
1095 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1096 struct sk_buff *skb;
1097
1098 del_timer_sync(&data->send_timer);
1099 cancel_work_sync(&data->dm_alert_work);
1100 while ((skb = __skb_dequeue(&data->drop_queue)))
1101 consume_skb(skb);
1102 }
1103
1104 list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
1105 if (new_stat->dev == NULL) {
1106 list_del_rcu(&new_stat->list);
1107 kfree_rcu(new_stat, rcu);
1108 }
1109 }
1110
1111 module_put(THIS_MODULE);
1112 }
1113
1114 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
1115 {
1116 int rc = 0;
1117
1118 if (state == trace_state) {
1119 NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
1120 return -EAGAIN;
1121 }
1122
1123 switch (state) {
1124 case TRACE_ON:
1125 rc = net_dm_trace_on_set(extack);
1126 break;
1127 case TRACE_OFF:
1128 net_dm_trace_off_set();
1129 break;
1130 default:
1131 rc = 1;
1132 break;
1133 }
1134
1135 if (!rc)
1136 trace_state = state;
1137 else
1138 rc = -EINPROGRESS;
1139
1140 return rc;
1141 }
1142
1143 static bool net_dm_is_monitoring(void)
1144 {
1145 return trace_state == TRACE_ON || monitor_hw;
1146 }
1147
1148 static int net_dm_alert_mode_get_from_info(struct genl_info *info,
1149 enum net_dm_alert_mode *p_alert_mode)
1150 {
1151 u8 val;
1152
1153 val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
1154
1155 switch (val) {
1156 case NET_DM_ALERT_MODE_SUMMARY: /* fall-through */
1157 case NET_DM_ALERT_MODE_PACKET:
1158 *p_alert_mode = val;
1159 break;
1160 default:
1161 return -EINVAL;
1162 }
1163
1164 return 0;
1165 }
1166
1167 static int net_dm_alert_mode_set(struct genl_info *info)
1168 {
1169 struct netlink_ext_ack *extack = info->extack;
1170 enum net_dm_alert_mode alert_mode;
1171 int rc;
1172
1173 if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
1174 return 0;
1175
1176 rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
1177 if (rc) {
1178 NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
1179 return -EINVAL;
1180 }
1181
1182 net_dm_alert_mode = alert_mode;
1183
1184 return 0;
1185 }
1186
1187 static void net_dm_trunc_len_set(struct genl_info *info)
1188 {
1189 if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
1190 return;
1191
1192 net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
1193 }
1194
1195 static void net_dm_queue_len_set(struct genl_info *info)
1196 {
1197 if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
1198 return;
1199
1200 net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
1201 }
1202
1203 static int net_dm_cmd_config(struct sk_buff *skb,
1204 struct genl_info *info)
1205 {
1206 struct netlink_ext_ack *extack = info->extack;
1207 int rc;
1208
1209 if (net_dm_is_monitoring()) {
1210 NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
1211 return -EBUSY;
1212 }
1213
1214 rc = net_dm_alert_mode_set(info);
1215 if (rc)
1216 return rc;
1217
1218 net_dm_trunc_len_set(info);
1219
1220 net_dm_queue_len_set(info);
1221
1222 return 0;
1223 }
1224
1225 static int net_dm_monitor_start(bool set_sw, bool set_hw,
1226 struct netlink_ext_ack *extack)
1227 {
1228 bool sw_set = false;
1229 int rc;
1230
1231 if (set_sw) {
1232 rc = set_all_monitor_traces(TRACE_ON, extack);
1233 if (rc)
1234 return rc;
1235 sw_set = true;
1236 }
1237
1238 if (set_hw) {
1239 rc = net_dm_hw_monitor_start(extack);
1240 if (rc)
1241 goto err_monitor_hw;
1242 }
1243
1244 return 0;
1245
1246 err_monitor_hw:
1247 if (sw_set)
1248 set_all_monitor_traces(TRACE_OFF, extack);
1249 return rc;
1250 }
1251
1252 static void net_dm_monitor_stop(bool set_sw, bool set_hw,
1253 struct netlink_ext_ack *extack)
1254 {
1255 if (set_hw)
1256 net_dm_hw_monitor_stop(extack);
1257 if (set_sw)
1258 set_all_monitor_traces(TRACE_OFF, extack);
1259 }
1260
1261 static int net_dm_cmd_trace(struct sk_buff *skb,
1262 struct genl_info *info)
1263 {
1264 bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS];
1265 bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS];
1266 struct netlink_ext_ack *extack = info->extack;
1267
1268 /* To maintain backward compatibility, we start / stop monitoring of
1269 * software drops if no flag is specified.
1270 */
1271 if (!set_sw && !set_hw)
1272 set_sw = true;
1273
1274 switch (info->genlhdr->cmd) {
1275 case NET_DM_CMD_START:
1276 return net_dm_monitor_start(set_sw, set_hw, extack);
1277 case NET_DM_CMD_STOP:
1278 net_dm_monitor_stop(set_sw, set_hw, extack);
1279 return 0;
1280 }
1281
1282 return -EOPNOTSUPP;
1283 }
1284
1285 static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
1286 {
1287 void *hdr;
1288
1289 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1290 &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
1291 if (!hdr)
1292 return -EMSGSIZE;
1293
1294 if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
1295 goto nla_put_failure;
1296
1297 if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
1298 goto nla_put_failure;
1299
1300 if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
1301 goto nla_put_failure;
1302
1303 genlmsg_end(msg, hdr);
1304
1305 return 0;
1306
1307 nla_put_failure:
1308 genlmsg_cancel(msg, hdr);
1309 return -EMSGSIZE;
1310 }
1311
1312 static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
1313 {
1314 struct sk_buff *msg;
1315 int rc;
1316
1317 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1318 if (!msg)
1319 return -ENOMEM;
1320
1321 rc = net_dm_config_fill(msg, info);
1322 if (rc)
1323 goto free_msg;
1324
1325 return genlmsg_reply(msg, info);
1326
1327 free_msg:
1328 nlmsg_free(msg);
1329 return rc;
1330 }
1331
1332 static void net_dm_stats_read(struct net_dm_stats *stats)
1333 {
1334 int cpu;
1335
1336 memset(stats, 0, sizeof(*stats));
1337 for_each_possible_cpu(cpu) {
1338 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1339 struct net_dm_stats *cpu_stats = &data->stats;
1340 unsigned int start;
1341 u64 dropped;
1342
1343 do {
1344 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1345 dropped = cpu_stats->dropped;
1346 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1347
1348 stats->dropped += dropped;
1349 }
1350 }
1351
1352 static int net_dm_stats_put(struct sk_buff *msg)
1353 {
1354 struct net_dm_stats stats;
1355 struct nlattr *attr;
1356
1357 net_dm_stats_read(&stats);
1358
1359 attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
1360 if (!attr)
1361 return -EMSGSIZE;
1362
1363 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1364 stats.dropped, NET_DM_ATTR_PAD))
1365 goto nla_put_failure;
1366
1367 nla_nest_end(msg, attr);
1368
1369 return 0;
1370
1371 nla_put_failure:
1372 nla_nest_cancel(msg, attr);
1373 return -EMSGSIZE;
1374 }
1375
1376 static void net_dm_hw_stats_read(struct net_dm_stats *stats)
1377 {
1378 int cpu;
1379
1380 memset(stats, 0, sizeof(*stats));
1381 for_each_possible_cpu(cpu) {
1382 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1383 struct net_dm_stats *cpu_stats = &hw_data->stats;
1384 unsigned int start;
1385 u64 dropped;
1386
1387 do {
1388 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1389 dropped = cpu_stats->dropped;
1390 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1391
1392 stats->dropped += dropped;
1393 }
1394 }
1395
1396 static int net_dm_hw_stats_put(struct sk_buff *msg)
1397 {
1398 struct net_dm_stats stats;
1399 struct nlattr *attr;
1400
1401 net_dm_hw_stats_read(&stats);
1402
1403 attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS);
1404 if (!attr)
1405 return -EMSGSIZE;
1406
1407 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1408 stats.dropped, NET_DM_ATTR_PAD))
1409 goto nla_put_failure;
1410
1411 nla_nest_end(msg, attr);
1412
1413 return 0;
1414
1415 nla_put_failure:
1416 nla_nest_cancel(msg, attr);
1417 return -EMSGSIZE;
1418 }
1419
1420 static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
1421 {
1422 void *hdr;
1423 int rc;
1424
1425 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1426 &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
1427 if (!hdr)
1428 return -EMSGSIZE;
1429
1430 rc = net_dm_stats_put(msg);
1431 if (rc)
1432 goto nla_put_failure;
1433
1434 rc = net_dm_hw_stats_put(msg);
1435 if (rc)
1436 goto nla_put_failure;
1437
1438 genlmsg_end(msg, hdr);
1439
1440 return 0;
1441
1442 nla_put_failure:
1443 genlmsg_cancel(msg, hdr);
1444 return -EMSGSIZE;
1445 }
1446
1447 static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
1448 {
1449 struct sk_buff *msg;
1450 int rc;
1451
1452 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1453 if (!msg)
1454 return -ENOMEM;
1455
1456 rc = net_dm_stats_fill(msg, info);
1457 if (rc)
1458 goto free_msg;
1459
1460 return genlmsg_reply(msg, info);
1461
1462 free_msg:
1463 nlmsg_free(msg);
1464 return rc;
1465 }
1466
1467 static int dropmon_net_event(struct notifier_block *ev_block,
1468 unsigned long event, void *ptr)
1469 {
1470 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1471 struct dm_hw_stat_delta *new_stat = NULL;
1472 struct dm_hw_stat_delta *tmp;
1473
1474 switch (event) {
1475 case NETDEV_REGISTER:
1476 new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);
1477
1478 if (!new_stat)
1479 goto out;
1480
1481 new_stat->dev = dev;
1482 new_stat->last_rx = jiffies;
1483 mutex_lock(&net_dm_mutex);
1484 list_add_rcu(&new_stat->list, &hw_stats_list);
1485 mutex_unlock(&net_dm_mutex);
1486 break;
1487 case NETDEV_UNREGISTER:
1488 mutex_lock(&net_dm_mutex);
1489 list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
1490 if (new_stat->dev == dev) {
1491 new_stat->dev = NULL;
1492 if (trace_state == TRACE_OFF) {
1493 list_del_rcu(&new_stat->list);
1494 kfree_rcu(new_stat, rcu);
1495 break;
1496 }
1497 }
1498 }
1499 mutex_unlock(&net_dm_mutex);
1500 break;
1501 }
1502 out:
1503 return NOTIFY_DONE;
1504 }
1505
1506 static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
1507 [NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
1508 [NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
1509 [NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
1510 [NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
1511 [NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG },
1512 [NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG },
1513 };
1514
1515 static const struct genl_ops dropmon_ops[] = {
1516 {
1517 .cmd = NET_DM_CMD_CONFIG,
1518 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1519 .doit = net_dm_cmd_config,
1520 .flags = GENL_ADMIN_PERM,
1521 },
1522 {
1523 .cmd = NET_DM_CMD_START,
1524 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1525 .doit = net_dm_cmd_trace,
1526 },
1527 {
1528 .cmd = NET_DM_CMD_STOP,
1529 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1530 .doit = net_dm_cmd_trace,
1531 },
1532 {
1533 .cmd = NET_DM_CMD_CONFIG_GET,
1534 .doit = net_dm_cmd_config_get,
1535 },
1536 {
1537 .cmd = NET_DM_CMD_STATS_GET,
1538 .doit = net_dm_cmd_stats_get,
1539 },
1540 };
1541
1542 static int net_dm_nl_pre_doit(const struct genl_ops *ops,
1543 struct sk_buff *skb, struct genl_info *info)
1544 {
1545 mutex_lock(&net_dm_mutex);
1546
1547 return 0;
1548 }
1549
1550 static void net_dm_nl_post_doit(const struct genl_ops *ops,
1551 struct sk_buff *skb, struct genl_info *info)
1552 {
1553 mutex_unlock(&net_dm_mutex);
1554 }
1555
1556 static struct genl_family net_drop_monitor_family __ro_after_init = {
1557 .hdrsize = 0,
1558 .name = "NET_DM",
1559 .version = 2,
1560 .maxattr = NET_DM_ATTR_MAX,
1561 .policy = net_dm_nl_policy,
1562 .pre_doit = net_dm_nl_pre_doit,
1563 .post_doit = net_dm_nl_post_doit,
1564 .module = THIS_MODULE,
1565 .ops = dropmon_ops,
1566 .n_ops = ARRAY_SIZE(dropmon_ops),
1567 .mcgrps = dropmon_mcgrps,
1568 .n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
1569 };
1570
1571 static struct notifier_block dropmon_net_notifier = {
1572 .notifier_call = dropmon_net_event
1573 };
1574
1575 static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data)
1576 {
1577 spin_lock_init(&data->lock);
1578 skb_queue_head_init(&data->drop_queue);
1579 u64_stats_init(&data->stats.syncp);
1580 }
1581
1582 static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data)
1583 {
1584 WARN_ON(!skb_queue_empty(&data->drop_queue));
1585 }
1586
1587 static void net_dm_cpu_data_init(int cpu)
1588 {
1589 struct per_cpu_dm_data *data;
1590
1591 data = &per_cpu(dm_cpu_data, cpu);
1592 __net_dm_cpu_data_init(data);
1593 }
1594
1595 static void net_dm_cpu_data_fini(int cpu)
1596 {
1597 struct per_cpu_dm_data *data;
1598
1599 data = &per_cpu(dm_cpu_data, cpu);
1600 /* At this point, we should have exclusive access
1601 * to this struct and can free the skb inside it.
1602 */
1603 consume_skb(data->skb);
1604 __net_dm_cpu_data_fini(data);
1605 }
1606
1607 static void net_dm_hw_cpu_data_init(int cpu)
1608 {
1609 struct per_cpu_dm_data *hw_data;
1610
1611 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1612 __net_dm_cpu_data_init(hw_data);
1613 }
1614
1615 static void net_dm_hw_cpu_data_fini(int cpu)
1616 {
1617 struct per_cpu_dm_data *hw_data;
1618
1619 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1620 kfree(hw_data->hw_entries);
1621 __net_dm_cpu_data_fini(hw_data);
1622 }
1623
1624 static int __init init_net_drop_monitor(void)
1625 {
1626 int cpu, rc;
1627
1628 pr_info("Initializing network drop monitor service\n");
1629
1630 if (sizeof(void *) > 8) {
1631 pr_err("Unable to store program counters on this arch, Drop monitor failed\n");
1632 return -ENOSPC;
1633 }
1634
1635 rc = genl_register_family(&net_drop_monitor_family);
1636 if (rc) {
1637 pr_err("Could not create drop monitor netlink family\n");
1638 return rc;
1639 }
1640 WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
1641
1642 rc = register_netdevice_notifier(&dropmon_net_notifier);
1643 if (rc < 0) {
1644 pr_crit("Failed to register netdevice notifier\n");
1645 goto out_unreg;
1646 }
1647
1648 rc = 0;
1649
1650 for_each_possible_cpu(cpu) {
1651 net_dm_cpu_data_init(cpu);
1652 net_dm_hw_cpu_data_init(cpu);
1653 }
1654
1655 goto out;
1656
1657 out_unreg:
1658 genl_unregister_family(&net_drop_monitor_family);
1659 out:
1660 return rc;
1661 }
1662
1663 static void exit_net_drop_monitor(void)
1664 {
1665 int cpu;
1666
1667 BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
1668
1669 /*
1670 * Because of the module_get/put we do in the trace state change path
1671 * we are guarnateed not to have any current users when we get here
1672 */
1673
1674 for_each_possible_cpu(cpu) {
1675 net_dm_hw_cpu_data_fini(cpu);
1676 net_dm_cpu_data_fini(cpu);
1677 }
1678
1679 BUG_ON(genl_unregister_family(&net_drop_monitor_family));
1680 }
1681
1682 module_init(init_net_drop_monitor);
1683 module_exit(exit_net_drop_monitor);
1684
1685 MODULE_LICENSE("GPL v2");
1686 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
1687 MODULE_ALIAS_GENL_FAMILY("NET_DM");
Linux with added FPC-III support