1 // SPDX-License-Identifier: GPL-2.0-only
3 * Monitoring code for network dropped packet alerts
5 * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
34 #include <trace/events/skb.h>
35 #include <trace/events/napi.h>
36 #include <trace/events/devlink.h>
38 #include <asm/unaligned.h>
44 * Globals, our netlink socket pointer
45 * and the work handle that will send up
48 static int trace_state = TRACE_OFF;
49 static bool monitor_hw;
54 #define EM(a, b) [a] = #b,
55 #define EMe(a, b) [a] = #b
57 /* drop_reasons is used to translate 'enum skb_drop_reason' to string,
58 * which is reported to user space.
60 static const char * const drop_reasons[] = {
66 * An overall lock guarding every operation coming from userspace.
68 static DEFINE_MUTEX(net_dm_mutex);
72 struct u64_stats_sync syncp;
75 #define NET_DM_MAX_HW_TRAP_NAME_LEN 40
77 struct net_dm_hw_entry {
78 char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
82 struct net_dm_hw_entries {
84 struct net_dm_hw_entry entries[];
87 struct per_cpu_dm_data {
88 spinlock_t lock; /* Protects 'skb', 'hw_entries' and
93 struct net_dm_hw_entries *hw_entries;
95 struct sk_buff_head drop_queue;
96 struct work_struct dm_alert_work;
97 struct timer_list send_timer;
98 struct net_dm_stats stats;
101 struct dm_hw_stat_delta {
102 unsigned long last_rx;
103 unsigned long last_drop_val;
107 static struct genl_family net_drop_monitor_family;
109 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
110 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
112 static int dm_hit_limit = 64;
113 static int dm_delay = 1;
114 static unsigned long dm_hw_check_delta = 2*HZ;
116 static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
117 static u32 net_dm_trunc_len;
118 static u32 net_dm_queue_len = 1000;
120 struct net_dm_alert_ops {
121 void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
123 enum skb_drop_reason reason);
124 void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
125 int work, int budget);
126 void (*work_item_func)(struct work_struct *work);
127 void (*hw_work_item_func)(struct work_struct *work);
128 void (*hw_trap_probe)(void *ignore, const struct devlink *devlink,
130 const struct devlink_trap_metadata *metadata);
133 struct net_dm_skb_cb {
135 struct devlink_trap_metadata *hw_metadata;
138 enum skb_drop_reason reason;
141 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
143 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
146 struct net_dm_alert_msg *msg;
152 al = sizeof(struct net_dm_alert_msg);
153 al += dm_hit_limit * sizeof(struct net_dm_drop_point);
154 al += sizeof(struct nlattr);
156 skb = genlmsg_new(al, GFP_KERNEL);
161 msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
162 0, NET_DM_CMD_ALERT);
168 nla = nla_reserve(skb, NLA_UNSPEC,
169 sizeof(struct net_dm_alert_msg));
180 mod_timer(&data->send_timer, jiffies + HZ / 10);
182 spin_lock_irqsave(&data->lock, flags);
183 swap(data->skb, skb);
184 spin_unlock_irqrestore(&data->lock, flags);
187 struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
188 struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
190 genlmsg_end(skb, genlmsg_data(gnlh));
196 static const struct genl_multicast_group dropmon_mcgrps[] = {
197 { .name = "events", },
200 static void send_dm_alert(struct work_struct *work)
203 struct per_cpu_dm_data *data;
205 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
207 skb = reset_per_cpu_data(data);
210 genlmsg_multicast(&net_drop_monitor_family, skb, 0,
215 * This is the timer function to delay the sending of an alert
216 * in the event that more drops will arrive during the
219 static void sched_send_work(struct timer_list *t)
221 struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
223 schedule_work(&data->dm_alert_work);
226 static void trace_drop_common(struct sk_buff *skb, void *location)
228 struct net_dm_alert_msg *msg;
229 struct net_dm_drop_point *point;
230 struct nlmsghdr *nlh;
233 struct sk_buff *dskb;
234 struct per_cpu_dm_data *data;
237 local_irq_save(flags);
238 data = this_cpu_ptr(&dm_cpu_data);
239 spin_lock(&data->lock);
245 nlh = (struct nlmsghdr *)dskb->data;
246 nla = genlmsg_data(nlmsg_data(nlh));
249 for (i = 0; i < msg->entries; i++) {
250 if (!memcmp(&location, &point->pc, sizeof(void *))) {
256 if (msg->entries == dm_hit_limit)
259 * We need to create a new entry
261 __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
262 nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
263 memcpy(point->pc, &location, sizeof(void *));
267 if (!timer_pending(&data->send_timer)) {
268 data->send_timer.expires = jiffies + dm_delay * HZ;
269 add_timer(&data->send_timer);
273 spin_unlock_irqrestore(&data->lock, flags);
276 static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb,
278 enum skb_drop_reason reason)
280 trace_drop_common(skb, location);
283 static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
284 int work, int budget)
286 struct net_device *dev = napi->dev;
287 struct dm_hw_stat_delta *stat;
289 * Don't check napi structures with no associated device
295 stat = rcu_dereference(dev->dm_private);
298 * only add a note to our monitor buffer if:
299 * 1) its after the last_rx delta
300 * 2) our rx_dropped count has gone up
302 if (time_after(jiffies, stat->last_rx + dm_hw_check_delta) &&
303 (dev->stats.rx_dropped != stat->last_drop_val)) {
304 trace_drop_common(NULL, NULL);
305 stat->last_drop_val = dev->stats.rx_dropped;
306 stat->last_rx = jiffies;
312 static struct net_dm_hw_entries *
313 net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
315 struct net_dm_hw_entries *hw_entries;
318 hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit),
321 /* If the memory allocation failed, we try to perform another
322 * allocation in 1/10 second. Otherwise, the probe function
323 * will constantly bail out.
325 mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
328 spin_lock_irqsave(&hw_data->lock, flags);
329 swap(hw_data->hw_entries, hw_entries);
330 spin_unlock_irqrestore(&hw_data->lock, flags);
335 static int net_dm_hw_entry_put(struct sk_buff *msg,
336 const struct net_dm_hw_entry *hw_entry)
340 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
344 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
345 goto nla_put_failure;
347 if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
348 goto nla_put_failure;
350 nla_nest_end(msg, attr);
355 nla_nest_cancel(msg, attr);
359 static int net_dm_hw_entries_put(struct sk_buff *msg,
360 const struct net_dm_hw_entries *hw_entries)
365 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
369 for (i = 0; i < hw_entries->num_entries; i++) {
372 rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
374 goto nla_put_failure;
377 nla_nest_end(msg, attr);
382 nla_nest_cancel(msg, attr);
387 net_dm_hw_summary_report_fill(struct sk_buff *msg,
388 const struct net_dm_hw_entries *hw_entries)
390 struct net_dm_alert_msg anc_hdr = { 0 };
394 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
399 /* We need to put the ancillary header in order not to break user
402 if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
403 goto nla_put_failure;
405 rc = net_dm_hw_entries_put(msg, hw_entries);
407 goto nla_put_failure;
409 genlmsg_end(msg, hdr);
414 genlmsg_cancel(msg, hdr);
418 static void net_dm_hw_summary_work(struct work_struct *work)
420 struct net_dm_hw_entries *hw_entries;
421 struct per_cpu_dm_data *hw_data;
425 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
427 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
431 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
435 rc = net_dm_hw_summary_report_fill(msg, hw_entries);
441 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
448 net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink,
450 const struct devlink_trap_metadata *metadata)
452 struct net_dm_hw_entries *hw_entries;
453 struct net_dm_hw_entry *hw_entry;
454 struct per_cpu_dm_data *hw_data;
458 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
461 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
462 spin_lock_irqsave(&hw_data->lock, flags);
463 hw_entries = hw_data->hw_entries;
468 for (i = 0; i < hw_entries->num_entries; i++) {
469 hw_entry = &hw_entries->entries[i];
470 if (!strncmp(hw_entry->trap_name, metadata->trap_name,
471 NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
476 if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit))
479 hw_entry = &hw_entries->entries[hw_entries->num_entries];
480 strlcpy(hw_entry->trap_name, metadata->trap_name,
481 NET_DM_MAX_HW_TRAP_NAME_LEN - 1);
483 hw_entries->num_entries++;
485 if (!timer_pending(&hw_data->send_timer)) {
486 hw_data->send_timer.expires = jiffies + dm_delay * HZ;
487 add_timer(&hw_data->send_timer);
491 spin_unlock_irqrestore(&hw_data->lock, flags);
494 static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
495 .kfree_skb_probe = trace_kfree_skb_hit,
496 .napi_poll_probe = trace_napi_poll_hit,
497 .work_item_func = send_dm_alert,
498 .hw_work_item_func = net_dm_hw_summary_work,
499 .hw_trap_probe = net_dm_hw_trap_summary_probe,
502 static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
505 enum skb_drop_reason reason)
507 ktime_t tstamp = ktime_get_real();
508 struct per_cpu_dm_data *data;
509 struct net_dm_skb_cb *cb;
510 struct sk_buff *nskb;
513 if (!skb_mac_header_was_set(skb))
516 nskb = skb_clone(skb, GFP_ATOMIC);
520 if (unlikely(reason >= SKB_DROP_REASON_MAX || reason <= 0))
521 reason = SKB_DROP_REASON_NOT_SPECIFIED;
522 cb = NET_DM_SKB_CB(nskb);
525 /* Override the timestamp because we care about the time when the
526 * packet was dropped.
528 nskb->tstamp = tstamp;
530 data = this_cpu_ptr(&dm_cpu_data);
532 spin_lock_irqsave(&data->drop_queue.lock, flags);
533 if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
534 __skb_queue_tail(&data->drop_queue, nskb);
537 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
539 schedule_work(&data->dm_alert_work);
544 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
545 u64_stats_update_begin(&data->stats.syncp);
546 data->stats.dropped++;
547 u64_stats_update_end(&data->stats.syncp);
551 static void net_dm_packet_trace_napi_poll_hit(void *ignore,
552 struct napi_struct *napi,
553 int work, int budget)
557 static size_t net_dm_in_port_size(void)
559 /* NET_DM_ATTR_IN_PORT nest */
560 return nla_total_size(0) +
561 /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */
562 nla_total_size(sizeof(u32)) +
563 /* NET_DM_ATTR_PORT_NETDEV_NAME */
564 nla_total_size(IFNAMSIZ + 1);
567 #define NET_DM_MAX_SYMBOL_LEN 40
569 static size_t net_dm_packet_report_size(size_t payload_len,
570 enum skb_drop_reason reason)
574 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
576 return NLMSG_ALIGN(size) +
577 /* NET_DM_ATTR_ORIGIN */
578 nla_total_size(sizeof(u16)) +
580 nla_total_size(sizeof(u64)) +
581 /* NET_DM_ATTR_SYMBOL */
582 nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
583 /* NET_DM_ATTR_IN_PORT */
584 net_dm_in_port_size() +
585 /* NET_DM_ATTR_TIMESTAMP */
586 nla_total_size(sizeof(u64)) +
587 /* NET_DM_ATTR_ORIG_LEN */
588 nla_total_size(sizeof(u32)) +
589 /* NET_DM_ATTR_PROTO */
590 nla_total_size(sizeof(u16)) +
591 /* NET_DM_ATTR_REASON */
592 nla_total_size(strlen(drop_reasons[reason]) + 1) +
593 /* NET_DM_ATTR_PAYLOAD */
594 nla_total_size(payload_len);
597 static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
602 attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
607 nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
608 goto nla_put_failure;
610 if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name))
611 goto nla_put_failure;
613 nla_nest_end(msg, attr);
618 nla_nest_cancel(msg, attr);
622 static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
625 struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb);
626 char buf[NET_DM_MAX_SYMBOL_LEN];
631 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
632 NET_DM_CMD_PACKET_ALERT);
636 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
637 goto nla_put_failure;
639 if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, (u64)(uintptr_t)cb->pc,
641 goto nla_put_failure;
643 if (nla_put_string(msg, NET_DM_ATTR_REASON,
644 drop_reasons[cb->reason]))
645 goto nla_put_failure;
647 snprintf(buf, sizeof(buf), "%pS", cb->pc);
648 if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
649 goto nla_put_failure;
651 rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL);
653 goto nla_put_failure;
655 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
656 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
657 goto nla_put_failure;
659 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
660 goto nla_put_failure;
665 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
666 goto nla_put_failure;
668 attr = skb_put(msg, nla_total_size(payload_len));
669 attr->nla_type = NET_DM_ATTR_PAYLOAD;
670 attr->nla_len = nla_attr_size(payload_len);
671 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
672 goto nla_put_failure;
675 genlmsg_end(msg, hdr);
680 genlmsg_cancel(msg, hdr);
684 #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
686 static void net_dm_packet_report(struct sk_buff *skb)
692 /* Make sure we start copying the packet from the MAC header */
693 if (skb->data > skb_mac_header(skb))
694 skb_push(skb, skb->data - skb_mac_header(skb));
696 skb_pull(skb, skb_mac_header(skb) - skb->data);
698 /* Ensure packet fits inside a single netlink attribute */
699 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
700 if (net_dm_trunc_len)
701 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
703 msg = nlmsg_new(net_dm_packet_report_size(payload_len,
704 NET_DM_SKB_CB(skb)->reason),
709 rc = net_dm_packet_report_fill(msg, skb, payload_len);
715 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
721 static void net_dm_packet_work(struct work_struct *work)
723 struct per_cpu_dm_data *data;
724 struct sk_buff_head list;
728 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
730 __skb_queue_head_init(&list);
732 spin_lock_irqsave(&data->drop_queue.lock, flags);
733 skb_queue_splice_tail_init(&data->drop_queue, &list);
734 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
736 while ((skb = __skb_dequeue(&list)))
737 net_dm_packet_report(skb);
741 net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata)
743 return hw_metadata->fa_cookie ?
744 nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0;
748 net_dm_hw_packet_report_size(size_t payload_len,
749 const struct devlink_trap_metadata *hw_metadata)
753 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
755 return NLMSG_ALIGN(size) +
756 /* NET_DM_ATTR_ORIGIN */
757 nla_total_size(sizeof(u16)) +
758 /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */
759 nla_total_size(strlen(hw_metadata->trap_group_name) + 1) +
760 /* NET_DM_ATTR_HW_TRAP_NAME */
761 nla_total_size(strlen(hw_metadata->trap_name) + 1) +
762 /* NET_DM_ATTR_IN_PORT */
763 net_dm_in_port_size() +
764 /* NET_DM_ATTR_FLOW_ACTION_COOKIE */
765 net_dm_flow_action_cookie_size(hw_metadata) +
766 /* NET_DM_ATTR_TIMESTAMP */
767 nla_total_size(sizeof(u64)) +
768 /* NET_DM_ATTR_ORIG_LEN */
769 nla_total_size(sizeof(u32)) +
770 /* NET_DM_ATTR_PROTO */
771 nla_total_size(sizeof(u16)) +
772 /* NET_DM_ATTR_PAYLOAD */
773 nla_total_size(payload_len);
776 static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
777 struct sk_buff *skb, size_t payload_len)
779 struct devlink_trap_metadata *hw_metadata;
783 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
785 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
786 NET_DM_CMD_PACKET_ALERT);
790 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW))
791 goto nla_put_failure;
793 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME,
794 hw_metadata->trap_group_name))
795 goto nla_put_failure;
797 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME,
798 hw_metadata->trap_name))
799 goto nla_put_failure;
801 if (hw_metadata->input_dev) {
802 struct net_device *dev = hw_metadata->input_dev;
805 rc = net_dm_packet_report_in_port_put(msg, dev->ifindex,
808 goto nla_put_failure;
811 if (hw_metadata->fa_cookie &&
812 nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE,
813 hw_metadata->fa_cookie->cookie_len,
814 hw_metadata->fa_cookie->cookie))
815 goto nla_put_failure;
817 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
818 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
819 goto nla_put_failure;
821 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
822 goto nla_put_failure;
827 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
828 goto nla_put_failure;
830 attr = skb_put(msg, nla_total_size(payload_len));
831 attr->nla_type = NET_DM_ATTR_PAYLOAD;
832 attr->nla_len = nla_attr_size(payload_len);
833 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
834 goto nla_put_failure;
837 genlmsg_end(msg, hdr);
842 genlmsg_cancel(msg, hdr);
846 static struct devlink_trap_metadata *
847 net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata)
849 const struct flow_action_cookie *fa_cookie;
850 struct devlink_trap_metadata *hw_metadata;
851 const char *trap_group_name;
852 const char *trap_name;
854 hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC);
858 trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC);
859 if (!trap_group_name)
860 goto free_hw_metadata;
861 hw_metadata->trap_group_name = trap_group_name;
863 trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC);
865 goto free_trap_group;
866 hw_metadata->trap_name = trap_name;
868 if (metadata->fa_cookie) {
869 size_t cookie_size = sizeof(*fa_cookie) +
870 metadata->fa_cookie->cookie_len;
872 fa_cookie = kmemdup(metadata->fa_cookie, cookie_size,
876 hw_metadata->fa_cookie = fa_cookie;
879 hw_metadata->input_dev = metadata->input_dev;
880 dev_hold_track(hw_metadata->input_dev, &hw_metadata->dev_tracker, GFP_ATOMIC);
887 kfree(trap_group_name);
894 net_dm_hw_metadata_free(struct devlink_trap_metadata *hw_metadata)
896 dev_put_track(hw_metadata->input_dev, &hw_metadata->dev_tracker);
897 kfree(hw_metadata->fa_cookie);
898 kfree(hw_metadata->trap_name);
899 kfree(hw_metadata->trap_group_name);
903 static void net_dm_hw_packet_report(struct sk_buff *skb)
905 struct devlink_trap_metadata *hw_metadata;
910 if (skb->data > skb_mac_header(skb))
911 skb_push(skb, skb->data - skb_mac_header(skb));
913 skb_pull(skb, skb_mac_header(skb) - skb->data);
915 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
916 if (net_dm_trunc_len)
917 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
919 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
920 msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata),
925 rc = net_dm_hw_packet_report_fill(msg, skb, payload_len);
931 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
934 net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata);
938 static void net_dm_hw_packet_work(struct work_struct *work)
940 struct per_cpu_dm_data *hw_data;
941 struct sk_buff_head list;
945 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
947 __skb_queue_head_init(&list);
949 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
950 skb_queue_splice_tail_init(&hw_data->drop_queue, &list);
951 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
953 while ((skb = __skb_dequeue(&list)))
954 net_dm_hw_packet_report(skb);
958 net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink,
960 const struct devlink_trap_metadata *metadata)
962 struct devlink_trap_metadata *n_hw_metadata;
963 ktime_t tstamp = ktime_get_real();
964 struct per_cpu_dm_data *hw_data;
965 struct sk_buff *nskb;
968 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
971 if (!skb_mac_header_was_set(skb))
974 nskb = skb_clone(skb, GFP_ATOMIC);
978 n_hw_metadata = net_dm_hw_metadata_copy(metadata);
982 NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata;
983 nskb->tstamp = tstamp;
985 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
987 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
988 if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len)
989 __skb_queue_tail(&hw_data->drop_queue, nskb);
992 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
994 schedule_work(&hw_data->dm_alert_work);
999 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
1000 u64_stats_update_begin(&hw_data->stats.syncp);
1001 hw_data->stats.dropped++;
1002 u64_stats_update_end(&hw_data->stats.syncp);
1003 net_dm_hw_metadata_free(n_hw_metadata);
1008 static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
1009 .kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit,
1010 .napi_poll_probe = net_dm_packet_trace_napi_poll_hit,
1011 .work_item_func = net_dm_packet_work,
1012 .hw_work_item_func = net_dm_hw_packet_work,
1013 .hw_trap_probe = net_dm_hw_trap_packet_probe,
1016 static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
1017 [NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops,
1018 [NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops,
1021 #if IS_ENABLED(CONFIG_NET_DEVLINK)
1022 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
1024 return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1027 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1029 unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1030 tracepoint_synchronize_unregister();
1033 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
1038 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1043 static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack)
1045 const struct net_dm_alert_ops *ops;
1049 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled");
1053 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1055 if (!try_module_get(THIS_MODULE)) {
1056 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1060 for_each_possible_cpu(cpu) {
1061 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1062 struct net_dm_hw_entries *hw_entries;
1064 INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func);
1065 timer_setup(&hw_data->send_timer, sched_send_work, 0);
1066 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
1070 rc = net_dm_hw_probe_register(ops);
1072 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint");
1073 goto err_module_put;
1081 for_each_possible_cpu(cpu) {
1082 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1083 struct sk_buff *skb;
1085 del_timer_sync(&hw_data->send_timer);
1086 cancel_work_sync(&hw_data->dm_alert_work);
1087 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1088 struct devlink_trap_metadata *hw_metadata;
1090 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1091 net_dm_hw_metadata_free(hw_metadata);
1095 module_put(THIS_MODULE);
1099 static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack)
1101 const struct net_dm_alert_ops *ops;
1105 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled");
1109 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1113 net_dm_hw_probe_unregister(ops);
1115 for_each_possible_cpu(cpu) {
1116 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1117 struct sk_buff *skb;
1119 del_timer_sync(&hw_data->send_timer);
1120 cancel_work_sync(&hw_data->dm_alert_work);
1121 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1122 struct devlink_trap_metadata *hw_metadata;
1124 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1125 net_dm_hw_metadata_free(hw_metadata);
1130 module_put(THIS_MODULE);
1133 static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
1135 const struct net_dm_alert_ops *ops;
1138 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1140 if (!try_module_get(THIS_MODULE)) {
1141 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1145 for_each_possible_cpu(cpu) {
1146 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1147 struct sk_buff *skb;
1149 INIT_WORK(&data->dm_alert_work, ops->work_item_func);
1150 timer_setup(&data->send_timer, sched_send_work, 0);
1151 /* Allocate a new per-CPU skb for the summary alert message and
1152 * free the old one which might contain stale data from
1155 skb = reset_per_cpu_data(data);
1159 rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1161 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
1162 goto err_module_put;
1165 rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
1167 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
1168 goto err_unregister_trace;
1173 err_unregister_trace:
1174 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1176 for_each_possible_cpu(cpu) {
1177 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1178 struct sk_buff *skb;
1180 del_timer_sync(&data->send_timer);
1181 cancel_work_sync(&data->dm_alert_work);
1182 while ((skb = __skb_dequeue(&data->drop_queue)))
1185 module_put(THIS_MODULE);
1189 static void net_dm_trace_off_set(void)
1191 const struct net_dm_alert_ops *ops;
1194 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1196 unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
1197 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1199 tracepoint_synchronize_unregister();
1201 /* Make sure we do not send notifications to user space after request
1202 * to stop tracing returns.
1204 for_each_possible_cpu(cpu) {
1205 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1206 struct sk_buff *skb;
1208 del_timer_sync(&data->send_timer);
1209 cancel_work_sync(&data->dm_alert_work);
1210 while ((skb = __skb_dequeue(&data->drop_queue)))
1214 module_put(THIS_MODULE);
1217 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
1221 if (state == trace_state) {
1222 NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
1228 rc = net_dm_trace_on_set(extack);
1231 net_dm_trace_off_set();
1239 trace_state = state;
1246 static bool net_dm_is_monitoring(void)
1248 return trace_state == TRACE_ON || monitor_hw;
1251 static int net_dm_alert_mode_get_from_info(struct genl_info *info,
1252 enum net_dm_alert_mode *p_alert_mode)
1256 val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
1259 case NET_DM_ALERT_MODE_SUMMARY:
1260 case NET_DM_ALERT_MODE_PACKET:
1261 *p_alert_mode = val;
1270 static int net_dm_alert_mode_set(struct genl_info *info)
1272 struct netlink_ext_ack *extack = info->extack;
1273 enum net_dm_alert_mode alert_mode;
1276 if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
1279 rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
1281 NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
1285 net_dm_alert_mode = alert_mode;
1290 static void net_dm_trunc_len_set(struct genl_info *info)
1292 if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
1295 net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
1298 static void net_dm_queue_len_set(struct genl_info *info)
1300 if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
1303 net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
1306 static int net_dm_cmd_config(struct sk_buff *skb,
1307 struct genl_info *info)
1309 struct netlink_ext_ack *extack = info->extack;
1312 if (net_dm_is_monitoring()) {
1313 NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
1317 rc = net_dm_alert_mode_set(info);
1321 net_dm_trunc_len_set(info);
1323 net_dm_queue_len_set(info);
1328 static int net_dm_monitor_start(bool set_sw, bool set_hw,
1329 struct netlink_ext_ack *extack)
1331 bool sw_set = false;
1335 rc = set_all_monitor_traces(TRACE_ON, extack);
1342 rc = net_dm_hw_monitor_start(extack);
1344 goto err_monitor_hw;
1351 set_all_monitor_traces(TRACE_OFF, extack);
1355 static void net_dm_monitor_stop(bool set_sw, bool set_hw,
1356 struct netlink_ext_ack *extack)
1359 net_dm_hw_monitor_stop(extack);
1361 set_all_monitor_traces(TRACE_OFF, extack);
1364 static int net_dm_cmd_trace(struct sk_buff *skb,
1365 struct genl_info *info)
1367 bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS];
1368 bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS];
1369 struct netlink_ext_ack *extack = info->extack;
1371 /* To maintain backward compatibility, we start / stop monitoring of
1372 * software drops if no flag is specified.
1374 if (!set_sw && !set_hw)
1377 switch (info->genlhdr->cmd) {
1378 case NET_DM_CMD_START:
1379 return net_dm_monitor_start(set_sw, set_hw, extack);
1380 case NET_DM_CMD_STOP:
1381 net_dm_monitor_stop(set_sw, set_hw, extack);
1388 static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
1392 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1393 &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
1397 if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
1398 goto nla_put_failure;
1400 if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
1401 goto nla_put_failure;
1403 if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
1404 goto nla_put_failure;
1406 genlmsg_end(msg, hdr);
1411 genlmsg_cancel(msg, hdr);
1415 static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
1417 struct sk_buff *msg;
1420 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1424 rc = net_dm_config_fill(msg, info);
1428 return genlmsg_reply(msg, info);
1435 static void net_dm_stats_read(struct net_dm_stats *stats)
1439 memset(stats, 0, sizeof(*stats));
1440 for_each_possible_cpu(cpu) {
1441 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1442 struct net_dm_stats *cpu_stats = &data->stats;
1447 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1448 dropped = cpu_stats->dropped;
1449 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1451 stats->dropped += dropped;
1455 static int net_dm_stats_put(struct sk_buff *msg)
1457 struct net_dm_stats stats;
1458 struct nlattr *attr;
1460 net_dm_stats_read(&stats);
1462 attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
1466 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1467 stats.dropped, NET_DM_ATTR_PAD))
1468 goto nla_put_failure;
1470 nla_nest_end(msg, attr);
1475 nla_nest_cancel(msg, attr);
1479 static void net_dm_hw_stats_read(struct net_dm_stats *stats)
1483 memset(stats, 0, sizeof(*stats));
1484 for_each_possible_cpu(cpu) {
1485 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1486 struct net_dm_stats *cpu_stats = &hw_data->stats;
1491 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
1492 dropped = cpu_stats->dropped;
1493 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
1495 stats->dropped += dropped;
1499 static int net_dm_hw_stats_put(struct sk_buff *msg)
1501 struct net_dm_stats stats;
1502 struct nlattr *attr;
1504 net_dm_hw_stats_read(&stats);
1506 attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS);
1510 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1511 stats.dropped, NET_DM_ATTR_PAD))
1512 goto nla_put_failure;
1514 nla_nest_end(msg, attr);
1519 nla_nest_cancel(msg, attr);
1523 static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
1528 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1529 &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
1533 rc = net_dm_stats_put(msg);
1535 goto nla_put_failure;
1537 rc = net_dm_hw_stats_put(msg);
1539 goto nla_put_failure;
1541 genlmsg_end(msg, hdr);
1546 genlmsg_cancel(msg, hdr);
1550 static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
1552 struct sk_buff *msg;
1555 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1559 rc = net_dm_stats_fill(msg, info);
1563 return genlmsg_reply(msg, info);
1570 static int dropmon_net_event(struct notifier_block *ev_block,
1571 unsigned long event, void *ptr)
1573 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1574 struct dm_hw_stat_delta *stat;
1577 case NETDEV_REGISTER:
1578 if (WARN_ON_ONCE(rtnl_dereference(dev->dm_private)))
1580 stat = kzalloc(sizeof(*stat), GFP_KERNEL);
1584 stat->last_rx = jiffies;
1585 rcu_assign_pointer(dev->dm_private, stat);
1588 case NETDEV_UNREGISTER:
1589 stat = rtnl_dereference(dev->dm_private);
1591 rcu_assign_pointer(dev->dm_private, NULL);
1592 kfree_rcu(stat, rcu);
1599 static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
1600 [NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
1601 [NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
1602 [NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
1603 [NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
1604 [NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG },
1605 [NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG },
1608 static const struct genl_small_ops dropmon_ops[] = {
1610 .cmd = NET_DM_CMD_CONFIG,
1611 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1612 .doit = net_dm_cmd_config,
1613 .flags = GENL_ADMIN_PERM,
1616 .cmd = NET_DM_CMD_START,
1617 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1618 .doit = net_dm_cmd_trace,
1621 .cmd = NET_DM_CMD_STOP,
1622 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1623 .doit = net_dm_cmd_trace,
1626 .cmd = NET_DM_CMD_CONFIG_GET,
1627 .doit = net_dm_cmd_config_get,
1630 .cmd = NET_DM_CMD_STATS_GET,
1631 .doit = net_dm_cmd_stats_get,
1635 static int net_dm_nl_pre_doit(const struct genl_ops *ops,
1636 struct sk_buff *skb, struct genl_info *info)
1638 mutex_lock(&net_dm_mutex);
1643 static void net_dm_nl_post_doit(const struct genl_ops *ops,
1644 struct sk_buff *skb, struct genl_info *info)
1646 mutex_unlock(&net_dm_mutex);
1649 static struct genl_family net_drop_monitor_family __ro_after_init = {
1653 .maxattr = NET_DM_ATTR_MAX,
1654 .policy = net_dm_nl_policy,
1655 .pre_doit = net_dm_nl_pre_doit,
1656 .post_doit = net_dm_nl_post_doit,
1657 .module = THIS_MODULE,
1658 .small_ops = dropmon_ops,
1659 .n_small_ops = ARRAY_SIZE(dropmon_ops),
1660 .mcgrps = dropmon_mcgrps,
1661 .n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
1664 static struct notifier_block dropmon_net_notifier = {
1665 .notifier_call = dropmon_net_event
1668 static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data)
1670 spin_lock_init(&data->lock);
1671 skb_queue_head_init(&data->drop_queue);
1672 u64_stats_init(&data->stats.syncp);
1675 static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data)
1677 WARN_ON(!skb_queue_empty(&data->drop_queue));
1680 static void net_dm_cpu_data_init(int cpu)
1682 struct per_cpu_dm_data *data;
1684 data = &per_cpu(dm_cpu_data, cpu);
1685 __net_dm_cpu_data_init(data);
1688 static void net_dm_cpu_data_fini(int cpu)
1690 struct per_cpu_dm_data *data;
1692 data = &per_cpu(dm_cpu_data, cpu);
1693 /* At this point, we should have exclusive access
1694 * to this struct and can free the skb inside it.
1696 consume_skb(data->skb);
1697 __net_dm_cpu_data_fini(data);
1700 static void net_dm_hw_cpu_data_init(int cpu)
1702 struct per_cpu_dm_data *hw_data;
1704 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1705 __net_dm_cpu_data_init(hw_data);
1708 static void net_dm_hw_cpu_data_fini(int cpu)
1710 struct per_cpu_dm_data *hw_data;
1712 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1713 kfree(hw_data->hw_entries);
1714 __net_dm_cpu_data_fini(hw_data);
1717 static int __init init_net_drop_monitor(void)
1721 pr_info("Initializing network drop monitor service\n");
1723 if (sizeof(void *) > 8) {
1724 pr_err("Unable to store program counters on this arch, Drop monitor failed\n");
1728 rc = genl_register_family(&net_drop_monitor_family);
1730 pr_err("Could not create drop monitor netlink family\n");
1733 WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
1735 rc = register_netdevice_notifier(&dropmon_net_notifier);
1737 pr_crit("Failed to register netdevice notifier\n");
1743 for_each_possible_cpu(cpu) {
1744 net_dm_cpu_data_init(cpu);
1745 net_dm_hw_cpu_data_init(cpu);
1751 genl_unregister_family(&net_drop_monitor_family);
1756 static void exit_net_drop_monitor(void)
1760 BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
1763 * Because of the module_get/put we do in the trace state change path
1764 * we are guaranteed not to have any current users when we get here
1767 for_each_possible_cpu(cpu) {
1768 net_dm_hw_cpu_data_fini(cpu);
1769 net_dm_cpu_data_fini(cpu);
1772 BUG_ON(genl_unregister_family(&net_drop_monitor_family));
1775 module_init(init_net_drop_monitor);
1776 module_exit(exit_net_drop_monitor);
1778 MODULE_LICENSE("GPL v2");
1779 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
1780 MODULE_ALIAS_GENL_FAMILY("NET_DM");
1781 MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");