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Merge tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
[linux/fpc-iii.git] / net / core / drop_monitor.c
blob571f191c06d947440858e91f4ad3a52ec9630538
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/genetlink.h>
30 #include <net/netevent.h>
31 #include <net/flow_offload.h>
32 #include <net/devlink.h>
33
34 #include <trace/events/skb.h>
35 #include <trace/events/napi.h>
36 #include <trace/events/devlink.h>
37
38 #include <asm/unaligned.h>
39
40 #define TRACE_ON 1
41 #define TRACE_OFF 0
42
43 /*
44 * Globals, our netlink socket pointer
45 * and the work handle that will send up
46 * netlink alerts
47 */
48 static int trace_state = TRACE_OFF;
49 static bool monitor_hw;
50
51 /* net_dm_mutex
52 *
53 * An overall lock guarding every operation coming from userspace.
54 * It also guards the global 'hw_stats_list' list.
55 */
56 static DEFINE_MUTEX(net_dm_mutex);
57
58 struct net_dm_stats {
59 u64 dropped;
60 struct u64_stats_sync syncp;
61 };
62
63 #define NET_DM_MAX_HW_TRAP_NAME_LEN 40
64
65 struct net_dm_hw_entry {
66 char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
67 u32 count;
68 };
69
70 struct net_dm_hw_entries {
71 u32 num_entries;
72 struct net_dm_hw_entry entries[];
73 };
74
75 struct per_cpu_dm_data {
76 spinlock_t lock; /* Protects 'skb', 'hw_entries' and
77 * 'send_timer'
78 */
79 union {
80 struct sk_buff *skb;
81 struct net_dm_hw_entries *hw_entries;
82 };
83 struct sk_buff_head drop_queue;
84 struct work_struct dm_alert_work;
85 struct timer_list send_timer;
86 struct net_dm_stats stats;
87 };
88
89 struct dm_hw_stat_delta {
90 struct net_device *dev;
91 unsigned long last_rx;
92 struct list_head list;
93 struct rcu_head rcu;
94 unsigned long last_drop_val;
95 };
96
97 static struct genl_family net_drop_monitor_family;
98
99 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
100 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
101
102 static int dm_hit_limit = 64;
103 static int dm_delay = 1;
104 static unsigned long dm_hw_check_delta = 2*HZ;
105 static LIST_HEAD(hw_stats_list);
106
107 static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
108 static u32 net_dm_trunc_len;
109 static u32 net_dm_queue_len = 1000;
110
111 struct net_dm_alert_ops {
112 void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
113 void *location);
114 void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
115 int work, int budget);
116 void (*work_item_func)(struct work_struct *work);
117 void (*hw_work_item_func)(struct work_struct *work);
118 void (*hw_trap_probe)(void *ignore, const struct devlink *devlink,
119 struct sk_buff *skb,
120 const struct devlink_trap_metadata *metadata);
121 };
122
123 struct net_dm_skb_cb {
124 union {
125 struct devlink_trap_metadata *hw_metadata;
126 void *pc;
127 };
128 };
129
130 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
131
132 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
133 {
134 size_t al;
135 struct net_dm_alert_msg *msg;
136 struct nlattr *nla;
137 struct sk_buff *skb;
138 unsigned long flags;
139 void *msg_header;
140
141 al = sizeof(struct net_dm_alert_msg);
142 al += dm_hit_limit * sizeof(struct net_dm_drop_point);
143 al += sizeof(struct nlattr);
144
145 skb = genlmsg_new(al, GFP_KERNEL);
146
147 if (!skb)
148 goto err;
149
150 msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
151 0, NET_DM_CMD_ALERT);
152 if (!msg_header) {
153 nlmsg_free(skb);
154 skb = NULL;
155 goto err;
156 }
157 nla = nla_reserve(skb, NLA_UNSPEC,
158 sizeof(struct net_dm_alert_msg));
159 if (!nla) {
160 nlmsg_free(skb);
161 skb = NULL;
162 goto err;
163 }
164 msg = nla_data(nla);
165 memset(msg, 0, al);
166 goto out;
167
168 err:
169 mod_timer(&data->send_timer, jiffies + HZ / 10);
170 out:
171 spin_lock_irqsave(&data->lock, flags);
172 swap(data->skb, skb);
173 spin_unlock_irqrestore(&data->lock, flags);
174
175 if (skb) {
176 struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
177 struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
178
179 genlmsg_end(skb, genlmsg_data(gnlh));
180 }
181
182 return skb;
183 }
184
185 static const struct genl_multicast_group dropmon_mcgrps[] = {
186 { .name = "events", },
187 };
188
189 static void send_dm_alert(struct work_struct *work)
190 {
191 struct sk_buff *skb;
192 struct per_cpu_dm_data *data;
193
194 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
195
196 skb = reset_per_cpu_data(data);
197
198 if (skb)
199 genlmsg_multicast(&net_drop_monitor_family, skb, 0,
200 0, GFP_KERNEL);
201 }
202
203 /*
204 * This is the timer function to delay the sending of an alert
205 * in the event that more drops will arrive during the
206 * hysteresis period.
207 */
208 static void sched_send_work(struct timer_list *t)
209 {
210 struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
211
212 schedule_work(&data->dm_alert_work);
213 }
214
215 static void trace_drop_common(struct sk_buff *skb, void *location)
216 {
217 struct net_dm_alert_msg *msg;
218 struct net_dm_drop_point *point;
219 struct nlmsghdr *nlh;
220 struct nlattr *nla;
221 int i;
222 struct sk_buff *dskb;
223 struct per_cpu_dm_data *data;
224 unsigned long flags;
225
226 local_irq_save(flags);
227 data = this_cpu_ptr(&dm_cpu_data);
228 spin_lock(&data->lock);
229 dskb = data->skb;
230
231 if (!dskb)
232 goto out;
233
234 nlh = (struct nlmsghdr *)dskb->data;
235 nla = genlmsg_data(nlmsg_data(nlh));
236 msg = nla_data(nla);
237 point = msg->points;
238 for (i = 0; i < msg->entries; i++) {
239 if (!memcmp(&location, &point->pc, sizeof(void *))) {
240 point->count++;
241 goto out;
242 }
243 point++;
244 }
245 if (msg->entries == dm_hit_limit)
246 goto out;
247 /*
248 * We need to create a new entry
249 */
250 __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
251 nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
252 memcpy(point->pc, &location, sizeof(void *));
253 point->count = 1;
254 msg->entries++;
255
256 if (!timer_pending(&data->send_timer)) {
257 data->send_timer.expires = jiffies + dm_delay * HZ;
258 add_timer(&data->send_timer);
259 }
260
261 out:
262 spin_unlock_irqrestore(&data->lock, flags);
263 }
264
265 static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
266 {
267 trace_drop_common(skb, location);
268 }
269
270 static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
271 int work, int budget)
272 {
273 struct dm_hw_stat_delta *new_stat;
274
275 /*
276 * Don't check napi structures with no associated device
277 */
278 if (!napi->dev)
279 return;
280
281 rcu_read_lock();
282 list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
283 /*
284 * only add a note to our monitor buffer if:
285 * 1) this is the dev we received on
286 * 2) its after the last_rx delta
287 * 3) our rx_dropped count has gone up
288 */
289 if ((new_stat->dev == napi->dev) &&
290 (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) &&
291 (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
292 trace_drop_common(NULL, NULL);
293 new_stat->last_drop_val = napi->dev->stats.rx_dropped;
294 new_stat->last_rx = jiffies;
295 break;
296 }
297 }
298 rcu_read_unlock();
299 }
300
301 static struct net_dm_hw_entries *
302 net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
303 {
304 struct net_dm_hw_entries *hw_entries;
305 unsigned long flags;
306
307 hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit),
308 GFP_KERNEL);
309 if (!hw_entries) {
310 /* If the memory allocation failed, we try to perform another
311 * allocation in 1/10 second. Otherwise, the probe function
312 * will constantly bail out.
313 */
314 mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
315 }
316
317 spin_lock_irqsave(&hw_data->lock, flags);
318 swap(hw_data->hw_entries, hw_entries);
319 spin_unlock_irqrestore(&hw_data->lock, flags);
320
321 return hw_entries;
322 }
323
324 static int net_dm_hw_entry_put(struct sk_buff *msg,
325 const struct net_dm_hw_entry *hw_entry)
326 {
327 struct nlattr *attr;
328
329 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
330 if (!attr)
331 return -EMSGSIZE;
332
333 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
334 goto nla_put_failure;
335
336 if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
337 goto nla_put_failure;
338
339 nla_nest_end(msg, attr);
340
341 return 0;
342
343 nla_put_failure:
344 nla_nest_cancel(msg, attr);
345 return -EMSGSIZE;
346 }
347
348 static int net_dm_hw_entries_put(struct sk_buff *msg,
349 const struct net_dm_hw_entries *hw_entries)
350 {
351 struct nlattr *attr;
352 int i;
353
354 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
355 if (!attr)
356 return -EMSGSIZE;
357
358 for (i = 0; i < hw_entries->num_entries; i++) {
359 int rc;
360
361 rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
362 if (rc)
363 goto nla_put_failure;
364 }
365
366 nla_nest_end(msg, attr);
367
368 return 0;
369
370 nla_put_failure:
371 nla_nest_cancel(msg, attr);
372 return -EMSGSIZE;
373 }
374
375 static int
376 net_dm_hw_summary_report_fill(struct sk_buff *msg,
377 const struct net_dm_hw_entries *hw_entries)
378 {
379 struct net_dm_alert_msg anc_hdr = { 0 };
380 void *hdr;
381 int rc;
382
383 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
384 NET_DM_CMD_ALERT);
385 if (!hdr)
386 return -EMSGSIZE;
387
388 /* We need to put the ancillary header in order not to break user
389 * space.
390 */
391 if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
392 goto nla_put_failure;
393
394 rc = net_dm_hw_entries_put(msg, hw_entries);
395 if (rc)
396 goto nla_put_failure;
397
398 genlmsg_end(msg, hdr);
399
400 return 0;
401
402 nla_put_failure:
403 genlmsg_cancel(msg, hdr);
404 return -EMSGSIZE;
405 }
406
407 static void net_dm_hw_summary_work(struct work_struct *work)
408 {
409 struct net_dm_hw_entries *hw_entries;
410 struct per_cpu_dm_data *hw_data;
411 struct sk_buff *msg;
412 int rc;
413
414 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
415
416 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
417 if (!hw_entries)
418 return;
419
420 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
421 if (!msg)
422 goto out;
423
424 rc = net_dm_hw_summary_report_fill(msg, hw_entries);
425 if (rc) {
426 nlmsg_free(msg);
427 goto out;
428 }
429
430 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
431
432 out:
433 kfree(hw_entries);
434 }
435
436 static void
437 net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink,
438 struct sk_buff *skb,
439 const struct devlink_trap_metadata *metadata)
440 {
441 struct net_dm_hw_entries *hw_entries;
442 struct net_dm_hw_entry *hw_entry;
443 struct per_cpu_dm_data *hw_data;
444 unsigned long flags;
445 int i;
446
447 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
448 return;
449
450 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
451 spin_lock_irqsave(&hw_data->lock, flags);
452 hw_entries = hw_data->hw_entries;
453
454 if (!hw_entries)
455 goto out;
456
457 for (i = 0; i < hw_entries->num_entries; i++) {
458 hw_entry = &hw_entries->entries[i];
459 if (!strncmp(hw_entry->trap_name, metadata->trap_name,
460 NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
461 hw_entry->count++;
462 goto out;
463 }
464 }
465 if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit))
466 goto out;
467
468 hw_entry = &hw_entries->entries[hw_entries->num_entries];
469 strlcpy(hw_entry->trap_name, metadata->trap_name,
470 NET_DM_MAX_HW_TRAP_NAME_LEN - 1);
471 hw_entry->count = 1;
472 hw_entries->num_entries++;
473
474 if (!timer_pending(&hw_data->send_timer)) {
475 hw_data->send_timer.expires = jiffies + dm_delay * HZ;
476 add_timer(&hw_data->send_timer);
477 }
478
479 out:
480 spin_unlock_irqrestore(&hw_data->lock, flags);
481 }
482
483 static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
484 .kfree_skb_probe = trace_kfree_skb_hit,
485 .napi_poll_probe = trace_napi_poll_hit,
486 .work_item_func = send_dm_alert,
487 .hw_work_item_func = net_dm_hw_summary_work,
488 .hw_trap_probe = net_dm_hw_trap_summary_probe,
489 };
490
491 static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
492 struct sk_buff *skb,
493 void *location)
494 {
495 ktime_t tstamp = ktime_get_real();
496 struct per_cpu_dm_data *data;
497 struct sk_buff *nskb;
498 unsigned long flags;
499
500 if (!skb_mac_header_was_set(skb))
501 return;
502
503 nskb = skb_clone(skb, GFP_ATOMIC);
504 if (!nskb)
505 return;
506
507 NET_DM_SKB_CB(nskb)->pc = location;
508 /* Override the timestamp because we care about the time when the
509 * packet was dropped.
510 */
511 nskb->tstamp = tstamp;
512
513 data = this_cpu_ptr(&dm_cpu_data);
514
515 spin_lock_irqsave(&data->drop_queue.lock, flags);
516 if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
517 __skb_queue_tail(&data->drop_queue, nskb);
518 else
519 goto unlock_free;
520 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
521
522 schedule_work(&data->dm_alert_work);
523
524 return;
525
526 unlock_free:
527 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
528 u64_stats_update_begin(&data->stats.syncp);
529 data->stats.dropped++;
530 u64_stats_update_end(&data->stats.syncp);
531 consume_skb(nskb);
532 }
533
534 static void net_dm_packet_trace_napi_poll_hit(void *ignore,
535 struct napi_struct *napi,
536 int work, int budget)
537 {
538 }
539
540 static size_t net_dm_in_port_size(void)
541 {
542 /* NET_DM_ATTR_IN_PORT nest */
543 return nla_total_size(0) +
544 /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */
545 nla_total_size(sizeof(u32)) +
546 /* NET_DM_ATTR_PORT_NETDEV_NAME */
547 nla_total_size(IFNAMSIZ + 1);
548 }
549
550 #define NET_DM_MAX_SYMBOL_LEN 40
551
552 static size_t net_dm_packet_report_size(size_t payload_len)
553 {
554 size_t size;
555
556 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
557
558 return NLMSG_ALIGN(size) +
559 /* NET_DM_ATTR_ORIGIN */
560 nla_total_size(sizeof(u16)) +
561 /* NET_DM_ATTR_PC */
562 nla_total_size(sizeof(u64)) +
563 /* NET_DM_ATTR_SYMBOL */
564 nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
565 /* NET_DM_ATTR_IN_PORT */
566 net_dm_in_port_size() +
567 /* NET_DM_ATTR_TIMESTAMP */
568 nla_total_size(sizeof(u64)) +
569 /* NET_DM_ATTR_ORIG_LEN */
570 nla_total_size(sizeof(u32)) +
571 /* NET_DM_ATTR_PROTO */
572 nla_total_size(sizeof(u16)) +
573 /* NET_DM_ATTR_PAYLOAD */
574 nla_total_size(payload_len);
575 }
576
577 static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
578 const char *name)
579 {
580 struct nlattr *attr;
581
582 attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
583 if (!attr)
584 return -EMSGSIZE;
585
586 if (ifindex &&
587 nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
588 goto nla_put_failure;
589
590 if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name))
591 goto nla_put_failure;
592
593 nla_nest_end(msg, attr);
594
595 return 0;
596
597 nla_put_failure:
598 nla_nest_cancel(msg, attr);
599 return -EMSGSIZE;
600 }
601
602 static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
603 size_t payload_len)
604 {
605 u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
606 char buf[NET_DM_MAX_SYMBOL_LEN];
607 struct nlattr *attr;
608 void *hdr;
609 int rc;
610
611 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
612 NET_DM_CMD_PACKET_ALERT);
613 if (!hdr)
614 return -EMSGSIZE;
615
616 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
617 goto nla_put_failure;
618
619 if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
620 goto nla_put_failure;
621
622 snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc);
623 if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
624 goto nla_put_failure;
625
626 rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL);
627 if (rc)
628 goto nla_put_failure;
629
630 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
631 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
632 goto nla_put_failure;
633
634 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
635 goto nla_put_failure;
636
637 if (!payload_len)
638 goto out;
639
640 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
641 goto nla_put_failure;
642
643 attr = skb_put(msg, nla_total_size(payload_len));
644 attr->nla_type = NET_DM_ATTR_PAYLOAD;
645 attr->nla_len = nla_attr_size(payload_len);
646 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
647 goto nla_put_failure;
648
649 out:
650 genlmsg_end(msg, hdr);
651
652 return 0;
653
654 nla_put_failure:
655 genlmsg_cancel(msg, hdr);
656 return -EMSGSIZE;
657 }
658
659 #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
660
661 static void net_dm_packet_report(struct sk_buff *skb)
662 {
663 struct sk_buff *msg;
664 size_t payload_len;
665 int rc;
666
667 /* Make sure we start copying the packet from the MAC header */
668 if (skb->data > skb_mac_header(skb))
669 skb_push(skb, skb->data - skb_mac_header(skb));
670 else
671 skb_pull(skb, skb_mac_header(skb) - skb->data);
672
673 /* Ensure packet fits inside a single netlink attribute */
674 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
675 if (net_dm_trunc_len)
676 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
677
678 msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
679 if (!msg)
680 goto out;
681
682 rc = net_dm_packet_report_fill(msg, skb, payload_len);
683 if (rc) {
684 nlmsg_free(msg);
685 goto out;
686 }
687
688 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
689
690 out:
691 consume_skb(skb);
692 }
693
694 static void net_dm_packet_work(struct work_struct *work)
695 {
696 struct per_cpu_dm_data *data;
697 struct sk_buff_head list;
698 struct sk_buff *skb;
699 unsigned long flags;
700
701 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
702
703 __skb_queue_head_init(&list);
704
705 spin_lock_irqsave(&data->drop_queue.lock, flags);
706 skb_queue_splice_tail_init(&data->drop_queue, &list);
707 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
708
709 while ((skb = __skb_dequeue(&list)))
710 net_dm_packet_report(skb);
711 }
712
713 static size_t
714 net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata)
715 {
716 return hw_metadata->fa_cookie ?
717 nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0;
718 }
719
720 static size_t
721 net_dm_hw_packet_report_size(size_t payload_len,
722 const struct devlink_trap_metadata *hw_metadata)
723 {
724 size_t size;
725
726 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
727
728 return NLMSG_ALIGN(size) +
729 /* NET_DM_ATTR_ORIGIN */
730 nla_total_size(sizeof(u16)) +
731 /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */
732 nla_total_size(strlen(hw_metadata->trap_group_name) + 1) +
733 /* NET_DM_ATTR_HW_TRAP_NAME */
734 nla_total_size(strlen(hw_metadata->trap_name) + 1) +
735 /* NET_DM_ATTR_IN_PORT */
736 net_dm_in_port_size() +
737 /* NET_DM_ATTR_FLOW_ACTION_COOKIE */
738 net_dm_flow_action_cookie_size(hw_metadata) +
739 /* NET_DM_ATTR_TIMESTAMP */
740 nla_total_size(sizeof(u64)) +
741 /* NET_DM_ATTR_ORIG_LEN */
742 nla_total_size(sizeof(u32)) +
743 /* NET_DM_ATTR_PROTO */
744 nla_total_size(sizeof(u16)) +
745 /* NET_DM_ATTR_PAYLOAD */
746 nla_total_size(payload_len);
747 }
748
749 static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
750 struct sk_buff *skb, size_t payload_len)
751 {
752 struct devlink_trap_metadata *hw_metadata;
753 struct nlattr *attr;
754 void *hdr;
755
756 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
757
758 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
759 NET_DM_CMD_PACKET_ALERT);
760 if (!hdr)
761 return -EMSGSIZE;
762
763 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW))
764 goto nla_put_failure;
765
766 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME,
767 hw_metadata->trap_group_name))
768 goto nla_put_failure;
769
770 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME,
771 hw_metadata->trap_name))
772 goto nla_put_failure;
773
774 if (hw_metadata->input_dev) {
775 struct net_device *dev = hw_metadata->input_dev;
776 int rc;
777
778 rc = net_dm_packet_report_in_port_put(msg, dev->ifindex,
779 dev->name);
780 if (rc)
781 goto nla_put_failure;
782 }
783
784 if (hw_metadata->fa_cookie &&
785 nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE,
786 hw_metadata->fa_cookie->cookie_len,
787 hw_metadata->fa_cookie->cookie))
788 goto nla_put_failure;
789
790 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
791 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
792 goto nla_put_failure;
793
794 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
795 goto nla_put_failure;
796
797 if (!payload_len)
798 goto out;
799
800 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
801 goto nla_put_failure;
802
803 attr = skb_put(msg, nla_total_size(payload_len));
804 attr->nla_type = NET_DM_ATTR_PAYLOAD;
805 attr->nla_len = nla_attr_size(payload_len);
806 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
807 goto nla_put_failure;
808
809 out:
810 genlmsg_end(msg, hdr);
811
812 return 0;
813
814 nla_put_failure:
815 genlmsg_cancel(msg, hdr);
816 return -EMSGSIZE;
817 }
818
819 static struct devlink_trap_metadata *
820 net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata)
821 {
822 const struct flow_action_cookie *fa_cookie;
823 struct devlink_trap_metadata *hw_metadata;
824 const char *trap_group_name;
825 const char *trap_name;
826
827 hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC);
828 if (!hw_metadata)
829 return NULL;
830
831 trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC);
832 if (!trap_group_name)
833 goto free_hw_metadata;
834 hw_metadata->trap_group_name = trap_group_name;
835
836 trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC);
837 if (!trap_name)
838 goto free_trap_group;
839 hw_metadata->trap_name = trap_name;
840
841 if (metadata->fa_cookie) {
842 size_t cookie_size = sizeof(*fa_cookie) +
843 metadata->fa_cookie->cookie_len;
844
845 fa_cookie = kmemdup(metadata->fa_cookie, cookie_size,
846 GFP_ATOMIC);
847 if (!fa_cookie)
848 goto free_trap_name;
849 hw_metadata->fa_cookie = fa_cookie;
850 }
851
852 hw_metadata->input_dev = metadata->input_dev;
853 if (hw_metadata->input_dev)
854 dev_hold(hw_metadata->input_dev);
855
856 return hw_metadata;
857
858 free_trap_name:
859 kfree(trap_name);
860 free_trap_group:
861 kfree(trap_group_name);
862 free_hw_metadata:
863 kfree(hw_metadata);
864 return NULL;
865 }
866
867 static void
868 net_dm_hw_metadata_free(const struct devlink_trap_metadata *hw_metadata)
869 {
870 if (hw_metadata->input_dev)
871 dev_put(hw_metadata->input_dev);
872 kfree(hw_metadata->fa_cookie);
873 kfree(hw_metadata->trap_name);
874 kfree(hw_metadata->trap_group_name);
875 kfree(hw_metadata);
876 }
877
878 static void net_dm_hw_packet_report(struct sk_buff *skb)
879 {
880 struct devlink_trap_metadata *hw_metadata;
881 struct sk_buff *msg;
882 size_t payload_len;
883 int rc;
884
885 if (skb->data > skb_mac_header(skb))
886 skb_push(skb, skb->data - skb_mac_header(skb));
887 else
888 skb_pull(skb, skb_mac_header(skb) - skb->data);
889
890 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
891 if (net_dm_trunc_len)
892 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
893
894 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
895 msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata),
896 GFP_KERNEL);
897 if (!msg)
898 goto out;
899
900 rc = net_dm_hw_packet_report_fill(msg, skb, payload_len);
901 if (rc) {
902 nlmsg_free(msg);
903 goto out;
904 }
905
906 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
907
908 out:
909 net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata);
910 consume_skb(skb);
911 }
912
913 static void net_dm_hw_packet_work(struct work_struct *work)
914 {
915 struct per_cpu_dm_data *hw_data;
916 struct sk_buff_head list;
917 struct sk_buff *skb;
918 unsigned long flags;
919
920 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
921
922 __skb_queue_head_init(&list);
923
924 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
925 skb_queue_splice_tail_init(&hw_data->drop_queue, &list);
926 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
927
928 while ((skb = __skb_dequeue(&list)))
929 net_dm_hw_packet_report(skb);
930 }
931
932 static void
933 net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink,
934 struct sk_buff *skb,
935 const struct devlink_trap_metadata *metadata)
936 {
937 struct devlink_trap_metadata *n_hw_metadata;
938 ktime_t tstamp = ktime_get_real();
939 struct per_cpu_dm_data *hw_data;
940 struct sk_buff *nskb;
941 unsigned long flags;
942
943 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
944 return;
945
946 if (!skb_mac_header_was_set(skb))
947 return;
948
949 nskb = skb_clone(skb, GFP_ATOMIC);
950 if (!nskb)
951 return;
952
953 n_hw_metadata = net_dm_hw_metadata_copy(metadata);
954 if (!n_hw_metadata)
955 goto free;
956
957 NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata;
958 nskb->tstamp = tstamp;
959
960 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
961
962 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
963 if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len)
964 __skb_queue_tail(&hw_data->drop_queue, nskb);
965 else
966 goto unlock_free;
967 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
968
969 schedule_work(&hw_data->dm_alert_work);
970
971 return;
972
973 unlock_free:
974 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
975 u64_stats_update_begin(&hw_data->stats.syncp);
976 hw_data->stats.dropped++;
977 u64_stats_update_end(&hw_data->stats.syncp);
978 net_dm_hw_metadata_free(n_hw_metadata);
979 free:
980 consume_skb(nskb);
981 }
982
983 static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
984 .kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit,
985 .napi_poll_probe = net_dm_packet_trace_napi_poll_hit,
986 .work_item_func = net_dm_packet_work,
987 .hw_work_item_func = net_dm_hw_packet_work,
988 .hw_trap_probe = net_dm_hw_trap_packet_probe,
989 };
990
991 static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
992 [NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops,
993 [NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops,
994 };
995
996 #if IS_ENABLED(CONFIG_NET_DEVLINK)
997 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
998 {
999 return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1000 }
1001
1002 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1003 {
1004 unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1005 tracepoint_synchronize_unregister();
1006 }
1007 #else
1008 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
1009 {
1010 return -EOPNOTSUPP;
1011 }
1012
1013 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1014 {
1015 }
1016 #endif
1017
1018 static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack)
1019 {
1020 const struct net_dm_alert_ops *ops;
1021 int cpu, rc;
1022
1023 if (monitor_hw) {
1024 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled");
1025 return -EAGAIN;
1026 }
1027
1028 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1029
1030 if (!try_module_get(THIS_MODULE)) {
1031 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1032 return -ENODEV;
1033 }
1034
1035 for_each_possible_cpu(cpu) {
1036 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1037 struct net_dm_hw_entries *hw_entries;
1038
1039 INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func);
1040 timer_setup(&hw_data->send_timer, sched_send_work, 0);
1041 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
1042 kfree(hw_entries);
1043 }
1044
1045 rc = net_dm_hw_probe_register(ops);
1046 if (rc) {
1047 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint");
1048 goto err_module_put;
1049 }
1050
1051 monitor_hw = true;
1052
1053 return 0;
1054
1055 err_module_put:
1056 module_put(THIS_MODULE);
1057 return rc;
1058 }
1059
1060 static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack)
1061 {
1062 const struct net_dm_alert_ops *ops;
1063 int cpu;
1064
1065 if (!monitor_hw) {
1066 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled");
1067 return;
1068 }
1069
1070 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1071
1072 monitor_hw = false;
1073
1074 net_dm_hw_probe_unregister(ops);
1075
1076 for_each_possible_cpu(cpu) {
1077 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1078 struct sk_buff *skb;
1079
1080 del_timer_sync(&hw_data->send_timer);
1081 cancel_work_sync(&hw_data->dm_alert_work);
1082 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1083 struct devlink_trap_metadata *hw_metadata;
1084
1085 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1086 net_dm_hw_metadata_free(hw_metadata);
1087 consume_skb(skb);
1088 }
1089 }
1090
1091 module_put(THIS_MODULE);
1092 }
1093
1094 static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
1095 {
1096 const struct net_dm_alert_ops *ops;
1097 int cpu, rc;
1098
1099 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1100
1101 if (!try_module_get(THIS_MODULE)) {
1102 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1103 return -ENODEV;
1104 }
1105
1106 for_each_possible_cpu(cpu) {
1107 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1108 struct sk_buff *skb;
1109
1110 INIT_WORK(&data->dm_alert_work, ops->work_item_func);
1111 timer_setup(&data->send_timer, sched_send_work, 0);
1112 /* Allocate a new per-CPU skb for the summary alert message and
1113 * free the old one which might contain stale data from
1114 * previous tracing.
1115 */
1116 skb = reset_per_cpu_data(data);
1117 consume_skb(skb);
1118 }
1119
1120 rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1121 if (rc) {
1122 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
1123 goto err_module_put;
1124 }
1125
1126 rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
1127 if (rc) {
1128 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
1129 goto err_unregister_trace;
1130 }
1131
1132 return 0;
1133
1134 err_unregister_trace:
1135 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1136 err_module_put:
1137 module_put(THIS_MODULE);
1138 return rc;
1139 }
1140
1141 static void net_dm_trace_off_set(void)
1142 {
1143 struct dm_hw_stat_delta *new_stat, *temp;
1144 const struct net_dm_alert_ops *ops;
1145 int cpu;
1146
1147 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1148
1149 unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
1150 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1151
1152 tracepoint_synchronize_unregister();
1153
1154 /* Make sure we do not send notifications to user space after request
1155 * to stop tracing returns.
1156 */
1157 for_each_possible_cpu(cpu) {
1158 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1159 struct sk_buff *skb;
1160
1161 del_timer_sync(&data->send_timer);
1162 cancel_work_sync(&data->dm_alert_work);
1163 while ((skb = __skb_dequeue(&data->drop_queue)))
1164 consume_skb(skb);
1165 }
1166
1167 list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
1168 if (new_stat->dev == NULL) {
1169 list_del_rcu(&new_stat->list);
1170 kfree_rcu(new_stat, rcu);
1171 }
1172 }
1173
1174 module_put(THIS_MODULE);
1175 }
1176
1177 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
1178 {
1179 int rc = 0;
1180
1181 if (state == trace_state) {
1182 NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
1183 return -EAGAIN;
1184 }
1185
1186 switch (state) {
1187 case TRACE_ON:
1188 rc = net_dm_trace_on_set(extack);
1189 break;
1190 case TRACE_OFF:
1191 net_dm_trace_off_set();
1192 break;
1193 default:
1194 rc = 1;
1195 break;
1196 }
1197
1198 if (!rc)
1199 trace_state = state;
1200 else
1201 rc = -EINPROGRESS;
1202
1203 return rc;
1204 }
1205
1206 static bool net_dm_is_monitoring(void)
1207 {
1208 return trace_state == TRACE_ON || monitor_hw;
1209 }
1210
1211 static int net_dm_alert_mode_get_from_info(struct genl_info *info,
1212 enum net_dm_alert_mode *p_alert_mode)
1213 {
1214 u8 val;
1215
1216 val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
1217
1218 switch (val) {
1219 case NET_DM_ALERT_MODE_SUMMARY:
1220 case NET_DM_ALERT_MODE_PACKET:
1221 *p_alert_mode = val;
1222 break;
1223 default:
1224 return -EINVAL;
1225 }
1226
1227 return 0;
1228 }
1229
1230 static int net_dm_alert_mode_set(struct genl_info *info)
1231 {
1232 struct netlink_ext_ack *extack = info->extack;
1233 enum net_dm_alert_mode alert_mode;
1234 int rc;
1235
1236 if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
1237 return 0;
1238
1239 rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
1240 if (rc) {
1241 NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
1242 return -EINVAL;
1243 }
1244
1245 net_dm_alert_mode = alert_mode;
1246
1247 return 0;
1248 }
1249
1250 static void net_dm_trunc_len_set(struct genl_info *info)
1251 {
1252 if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
1253 return;
1254
1255 net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
1256 }
1257
1258 static void net_dm_queue_len_set(struct genl_info *info)
1259 {
1260 if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
1261 return;
1262
1263 net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
1264 }
1265
1266 static int net_dm_cmd_config(struct sk_buff *skb,
1267 struct genl_info *info)
1268 {
1269 struct netlink_ext_ack *extack = info->extack;
1270 int rc;
1271
1272 if (net_dm_is_monitoring()) {
1273 NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
1274 return -EBUSY;
1275 }
1276
1277 rc = net_dm_alert_mode_set(info);
1278 if (rc)
1279 return rc;
1280
1281 net_dm_trunc_len_set(info);
1282
1283 net_dm_queue_len_set(info);
1284
1285 return 0;
1286 }
1287
1288 static int net_dm_monitor_start(bool set_sw, bool set_hw,
1289 struct netlink_ext_ack *extack)
1290 {
1291 bool sw_set = false;
1292 int rc;
1293
1294 if (set_sw) {
1295 rc = set_all_monitor_traces(TRACE_ON, extack);
1296 if (rc)
1297 return rc;
1298 sw_set = true;
1299 }
1300
1301 if (set_hw) {
1302 rc = net_dm_hw_monitor_start(extack);
1303 if (rc)
1304 goto err_monitor_hw;
1305 }
1306
1307 return 0;
1308
1309 err_monitor_hw:
1310 if (sw_set)
1311 set_all_monitor_traces(TRACE_OFF, extack);
1312 return rc;
1313 }
1314
1315 static void net_dm_monitor_stop(bool set_sw, bool set_hw,
1316 struct netlink_ext_ack *extack)
1317 {
1318 if (set_hw)
1319 net_dm_hw_monitor_stop(extack);
1320 if (set_sw)
1321 set_all_monitor_traces(TRACE_OFF, extack);
1322 }
1323
1324 static int net_dm_cmd_trace(struct sk_buff *skb,
1325 struct genl_info *info)
1326 {
1327 bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS];
1328 bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS];
1329 struct netlink_ext_ack *extack = info->extack;
1330
1331 /* To maintain backward compatibility, we start / stop monitoring of
1332 * software drops if no flag is specified.
1333 */
1334 if (!set_sw && !set_hw)
1335 set_sw = true;
1336
1337 switch (info->genlhdr->cmd) {
1338 case NET_DM_CMD_START:
1339 return net_dm_monitor_start(set_sw, set_hw, extack);
1340 case NET_DM_CMD_STOP:
1341 net_dm_monitor_stop(set_sw, set_hw, extack);
1342 return 0;
1343 }
1344
1345 return -EOPNOTSUPP;
1346 }
1347
1348 static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
1349 {
1350 void *hdr;
1351
1352 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1353 &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
1354 if (!hdr)
1355 return -EMSGSIZE;
1356
1357 if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
1358 goto nla_put_failure;
1359
1360 if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
1361 goto nla_put_failure;
1362
1363 if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
1364 goto nla_put_failure;
1365
1366 genlmsg_end(msg, hdr);
1367
1368 return 0;
1369
1370 nla_put_failure:
1371 genlmsg_cancel(msg, hdr);
1372 return -EMSGSIZE;
1373 }
1374
1375 static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
1376 {
1377 struct sk_buff *msg;
1378 int rc;
1379
1380 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1381 if (!msg)
1382 return -ENOMEM;
1383
1384 rc = net_dm_config_fill(msg, info);
1385 if (rc)
1386 goto free_msg;
1387
1388 return genlmsg_reply(msg, info);
1389
1390 free_msg:
1391 nlmsg_free(msg);
1392 return rc;
1393 }
1394
1395 static void net_dm_stats_read(struct net_dm_stats *stats)
1396 {
1397 int cpu;
1398
1399 memset(stats, 0, sizeof(*stats));
1400 for_each_possible_cpu(cpu) {
1401 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1402 struct net_dm_stats *cpu_stats = &data->stats;
1403 unsigned int start;
1404 u64 dropped;
1405
1406 do {
1407 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1408 dropped = cpu_stats->dropped;
1409 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1410
1411 stats->dropped += dropped;
1412 }
1413 }
1414
1415 static int net_dm_stats_put(struct sk_buff *msg)
1416 {
1417 struct net_dm_stats stats;
1418 struct nlattr *attr;
1419
1420 net_dm_stats_read(&stats);
1421
1422 attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
1423 if (!attr)
1424 return -EMSGSIZE;
1425
1426 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1427 stats.dropped, NET_DM_ATTR_PAD))
1428 goto nla_put_failure;
1429
1430 nla_nest_end(msg, attr);
1431
1432 return 0;
1433
1434 nla_put_failure:
1435 nla_nest_cancel(msg, attr);
1436 return -EMSGSIZE;
1437 }
1438
1439 static void net_dm_hw_stats_read(struct net_dm_stats *stats)
1440 {
1441 int cpu;
1442
1443 memset(stats, 0, sizeof(*stats));
1444 for_each_possible_cpu(cpu) {
1445 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1446 struct net_dm_stats *cpu_stats = &hw_data->stats;
1447 unsigned int start;
1448 u64 dropped;
1449
1450 do {
1451 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1452 dropped = cpu_stats->dropped;
1453 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1454
1455 stats->dropped += dropped;
1456 }
1457 }
1458
1459 static int net_dm_hw_stats_put(struct sk_buff *msg)
1460 {
1461 struct net_dm_stats stats;
1462 struct nlattr *attr;
1463
1464 net_dm_hw_stats_read(&stats);
1465
1466 attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS);
1467 if (!attr)
1468 return -EMSGSIZE;
1469
1470 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1471 stats.dropped, NET_DM_ATTR_PAD))
1472 goto nla_put_failure;
1473
1474 nla_nest_end(msg, attr);
1475
1476 return 0;
1477
1478 nla_put_failure:
1479 nla_nest_cancel(msg, attr);
1480 return -EMSGSIZE;
1481 }
1482
1483 static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
1484 {
1485 void *hdr;
1486 int rc;
1487
1488 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1489 &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
1490 if (!hdr)
1491 return -EMSGSIZE;
1492
1493 rc = net_dm_stats_put(msg);
1494 if (rc)
1495 goto nla_put_failure;
1496
1497 rc = net_dm_hw_stats_put(msg);
1498 if (rc)
1499 goto nla_put_failure;
1500
1501 genlmsg_end(msg, hdr);
1502
1503 return 0;
1504
1505 nla_put_failure:
1506 genlmsg_cancel(msg, hdr);
1507 return -EMSGSIZE;
1508 }
1509
1510 static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
1511 {
1512 struct sk_buff *msg;
1513 int rc;
1514
1515 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1516 if (!msg)
1517 return -ENOMEM;
1518
1519 rc = net_dm_stats_fill(msg, info);
1520 if (rc)
1521 goto free_msg;
1522
1523 return genlmsg_reply(msg, info);
1524
1525 free_msg:
1526 nlmsg_free(msg);
1527 return rc;
1528 }
1529
1530 static int dropmon_net_event(struct notifier_block *ev_block,
1531 unsigned long event, void *ptr)
1532 {
1533 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1534 struct dm_hw_stat_delta *new_stat = NULL;
1535 struct dm_hw_stat_delta *tmp;
1536
1537 switch (event) {
1538 case NETDEV_REGISTER:
1539 new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);
1540
1541 if (!new_stat)
1542 goto out;
1543
1544 new_stat->dev = dev;
1545 new_stat->last_rx = jiffies;
1546 mutex_lock(&net_dm_mutex);
1547 list_add_rcu(&new_stat->list, &hw_stats_list);
1548 mutex_unlock(&net_dm_mutex);
1549 break;
1550 case NETDEV_UNREGISTER:
1551 mutex_lock(&net_dm_mutex);
1552 list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
1553 if (new_stat->dev == dev) {
1554 new_stat->dev = NULL;
1555 if (trace_state == TRACE_OFF) {
1556 list_del_rcu(&new_stat->list);
1557 kfree_rcu(new_stat, rcu);
1558 break;
1559 }
1560 }
1561 }
1562 mutex_unlock(&net_dm_mutex);
1563 break;
1564 }
1565 out:
1566 return NOTIFY_DONE;
1567 }
1568
1569 static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
1570 [NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
1571 [NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
1572 [NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
1573 [NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
1574 [NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG },
1575 [NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG },
1576 };
1577
1578 static const struct genl_small_ops dropmon_ops[] = {
1579 {
1580 .cmd = NET_DM_CMD_CONFIG,
1581 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1582 .doit = net_dm_cmd_config,
1583 .flags = GENL_ADMIN_PERM,
1584 },
1585 {
1586 .cmd = NET_DM_CMD_START,
1587 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1588 .doit = net_dm_cmd_trace,
1589 },
1590 {
1591 .cmd = NET_DM_CMD_STOP,
1592 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1593 .doit = net_dm_cmd_trace,
1594 },
1595 {
1596 .cmd = NET_DM_CMD_CONFIG_GET,
1597 .doit = net_dm_cmd_config_get,
1598 },
1599 {
1600 .cmd = NET_DM_CMD_STATS_GET,
1601 .doit = net_dm_cmd_stats_get,
1602 },
1603 };
1604
1605 static int net_dm_nl_pre_doit(const struct genl_ops *ops,
1606 struct sk_buff *skb, struct genl_info *info)
1607 {
1608 mutex_lock(&net_dm_mutex);
1609
1610 return 0;
1611 }
1612
1613 static void net_dm_nl_post_doit(const struct genl_ops *ops,
1614 struct sk_buff *skb, struct genl_info *info)
1615 {
1616 mutex_unlock(&net_dm_mutex);
1617 }
1618
1619 static struct genl_family net_drop_monitor_family __ro_after_init = {
1620 .hdrsize = 0,
1621 .name = "NET_DM",
1622 .version = 2,
1623 .maxattr = NET_DM_ATTR_MAX,
1624 .policy = net_dm_nl_policy,
1625 .pre_doit = net_dm_nl_pre_doit,
1626 .post_doit = net_dm_nl_post_doit,
1627 .module = THIS_MODULE,
1628 .small_ops = dropmon_ops,
1629 .n_small_ops = ARRAY_SIZE(dropmon_ops),
1630 .mcgrps = dropmon_mcgrps,
1631 .n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
1632 };
1633
1634 static struct notifier_block dropmon_net_notifier = {
1635 .notifier_call = dropmon_net_event
1636 };
1637
1638 static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data)
1639 {
1640 spin_lock_init(&data->lock);
1641 skb_queue_head_init(&data->drop_queue);
1642 u64_stats_init(&data->stats.syncp);
1643 }
1644
1645 static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data)
1646 {
1647 WARN_ON(!skb_queue_empty(&data->drop_queue));
1648 }
1649
1650 static void net_dm_cpu_data_init(int cpu)
1651 {
1652 struct per_cpu_dm_data *data;
1653
1654 data = &per_cpu(dm_cpu_data, cpu);
1655 __net_dm_cpu_data_init(data);
1656 }
1657
1658 static void net_dm_cpu_data_fini(int cpu)
1659 {
1660 struct per_cpu_dm_data *data;
1661
1662 data = &per_cpu(dm_cpu_data, cpu);
1663 /* At this point, we should have exclusive access
1664 * to this struct and can free the skb inside it.
1665 */
1666 consume_skb(data->skb);
1667 __net_dm_cpu_data_fini(data);
1668 }
1669
1670 static void net_dm_hw_cpu_data_init(int cpu)
1671 {
1672 struct per_cpu_dm_data *hw_data;
1673
1674 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1675 __net_dm_cpu_data_init(hw_data);
1676 }
1677
1678 static void net_dm_hw_cpu_data_fini(int cpu)
1679 {
1680 struct per_cpu_dm_data *hw_data;
1681
1682 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1683 kfree(hw_data->hw_entries);
1684 __net_dm_cpu_data_fini(hw_data);
1685 }
1686
1687 static int __init init_net_drop_monitor(void)
1688 {
1689 int cpu, rc;
1690
1691 pr_info("Initializing network drop monitor service\n");
1692
1693 if (sizeof(void *) > 8) {
1694 pr_err("Unable to store program counters on this arch, Drop monitor failed\n");
1695 return -ENOSPC;
1696 }
1697
1698 rc = genl_register_family(&net_drop_monitor_family);
1699 if (rc) {
1700 pr_err("Could not create drop monitor netlink family\n");
1701 return rc;
1702 }
1703 WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
1704
1705 rc = register_netdevice_notifier(&dropmon_net_notifier);
1706 if (rc < 0) {
1707 pr_crit("Failed to register netdevice notifier\n");
1708 goto out_unreg;
1709 }
1710
1711 rc = 0;
1712
1713 for_each_possible_cpu(cpu) {
1714 net_dm_cpu_data_init(cpu);
1715 net_dm_hw_cpu_data_init(cpu);
1716 }
1717
1718 goto out;
1719
1720 out_unreg:
1721 genl_unregister_family(&net_drop_monitor_family);
1722 out:
1723 return rc;
1724 }
1725
1726 static void exit_net_drop_monitor(void)
1727 {
1728 int cpu;
1729
1730 BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
1731
1732 /*
1733 * Because of the module_get/put we do in the trace state change path
1734 * we are guarnateed not to have any current users when we get here
1735 */
1736
1737 for_each_possible_cpu(cpu) {
1738 net_dm_hw_cpu_data_fini(cpu);
1739 net_dm_cpu_data_fini(cpu);
1740 }
1741
1742 BUG_ON(genl_unregister_family(&net_drop_monitor_family));
1743 }
1744
1745 module_init(init_net_drop_monitor);
1746 module_exit(exit_net_drop_monitor);
1747
1748 MODULE_LICENSE("GPL v2");
1749 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
1750 MODULE_ALIAS_GENL_FAMILY("NET_DM");
1751 MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");
Linux with added FPC-III support