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/bitfield.h>
25 #include <linux/percpu.h>
26 #include <linux/timer.h>
27 #include <linux/bitops.h>
28 #include <linux/slab.h>
29 #include <linux/module.h>
30 #include <net/genetlink.h>
31 #include <net/netevent.h>
32 #include <net/flow_offload.h>
33 #include <net/dropreason.h>
34 #include <net/devlink.h>
36 #include <trace/events/skb.h>
37 #include <trace/events/napi.h>
38 #include <trace/events/devlink.h>
40 #include <asm/unaligned.h>
46 * Globals, our netlink socket pointer
47 * and the work handle that will send up
50 static int trace_state = TRACE_OFF;
51 static bool monitor_hw;
55 * An overall lock guarding every operation coming from userspace.
57 static DEFINE_MUTEX(net_dm_mutex);
61 struct u64_stats_sync syncp;
64 #define NET_DM_MAX_HW_TRAP_NAME_LEN 40
66 struct net_dm_hw_entry {
67 char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
71 struct net_dm_hw_entries {
73 struct net_dm_hw_entry entries[];
76 struct per_cpu_dm_data {
77 raw_spinlock_t lock; /* Protects 'skb', 'hw_entries' and
82 struct net_dm_hw_entries *hw_entries;
84 struct sk_buff_head drop_queue;
85 struct work_struct dm_alert_work;
86 struct timer_list send_timer;
87 struct net_dm_stats stats;
90 struct dm_hw_stat_delta {
91 unsigned long last_rx;
92 unsigned long last_drop_val;
96 static struct genl_family net_drop_monitor_family;
98 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
99 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
101 static int dm_hit_limit = 64;
102 static int dm_delay = 1;
103 static unsigned long dm_hw_check_delta = 2*HZ;
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;
109 struct net_dm_alert_ops {
110 void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
112 enum skb_drop_reason reason,
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,
120 const struct devlink_trap_metadata *metadata);
123 struct net_dm_skb_cb {
125 struct devlink_trap_metadata *hw_metadata;
128 enum skb_drop_reason reason;
131 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
133 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
136 struct net_dm_alert_msg *msg;
142 al = sizeof(struct net_dm_alert_msg);
143 al += dm_hit_limit * sizeof(struct net_dm_drop_point);
144 al += sizeof(struct nlattr);
146 skb = genlmsg_new(al, GFP_KERNEL);
151 msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
152 0, NET_DM_CMD_ALERT);
158 nla = nla_reserve(skb, NLA_UNSPEC,
159 sizeof(struct net_dm_alert_msg));
170 mod_timer(&data->send_timer, jiffies + HZ / 10);
172 raw_spin_lock_irqsave(&data->lock, flags);
173 swap(data->skb, skb);
174 raw_spin_unlock_irqrestore(&data->lock, flags);
177 struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
178 struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
180 genlmsg_end(skb, genlmsg_data(gnlh));
186 static const struct genl_multicast_group dropmon_mcgrps[] = {
187 { .name = "events", .flags = GENL_MCAST_CAP_SYS_ADMIN, },
190 static void send_dm_alert(struct work_struct *work)
193 struct per_cpu_dm_data *data;
195 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
197 skb = reset_per_cpu_data(data);
200 genlmsg_multicast(&net_drop_monitor_family, skb, 0,
205 * This is the timer function to delay the sending of an alert
206 * in the event that more drops will arrive during the
209 static void sched_send_work(struct timer_list *t)
211 struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
213 schedule_work(&data->dm_alert_work);
216 static void trace_drop_common(struct sk_buff *skb, void *location)
218 struct net_dm_alert_msg *msg;
219 struct net_dm_drop_point *point;
220 struct nlmsghdr *nlh;
223 struct sk_buff *dskb;
224 struct per_cpu_dm_data *data;
227 local_irq_save(flags);
228 data = this_cpu_ptr(&dm_cpu_data);
229 raw_spin_lock(&data->lock);
235 nlh = (struct nlmsghdr *)dskb->data;
236 nla = genlmsg_data(nlmsg_data(nlh));
239 for (i = 0; i < msg->entries; i++) {
240 if (!memcmp(&location, &point->pc, sizeof(void *))) {
246 if (msg->entries == dm_hit_limit)
249 * We need to create a new entry
251 __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
252 nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
253 memcpy(point->pc, &location, sizeof(void *));
257 if (!timer_pending(&data->send_timer)) {
258 data->send_timer.expires = jiffies + dm_delay * HZ;
259 add_timer(&data->send_timer);
263 raw_spin_unlock_irqrestore(&data->lock, flags);
266 static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb,
268 enum skb_drop_reason reason,
271 trace_drop_common(skb, location);
274 static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
275 int work, int budget)
277 struct net_device *dev = napi->dev;
278 struct dm_hw_stat_delta *stat;
280 * Don't check napi structures with no associated device
286 stat = rcu_dereference(dev->dm_private);
289 * only add a note to our monitor buffer if:
290 * 1) its after the last_rx delta
291 * 2) our rx_dropped count has gone up
293 if (time_after(jiffies, stat->last_rx + dm_hw_check_delta) &&
294 (dev->stats.rx_dropped != stat->last_drop_val)) {
295 trace_drop_common(NULL, NULL);
296 stat->last_drop_val = dev->stats.rx_dropped;
297 stat->last_rx = jiffies;
303 static struct net_dm_hw_entries *
304 net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
306 struct net_dm_hw_entries *hw_entries;
309 hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit),
312 /* If the memory allocation failed, we try to perform another
313 * allocation in 1/10 second. Otherwise, the probe function
314 * will constantly bail out.
316 mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
319 raw_spin_lock_irqsave(&hw_data->lock, flags);
320 swap(hw_data->hw_entries, hw_entries);
321 raw_spin_unlock_irqrestore(&hw_data->lock, flags);
326 static int net_dm_hw_entry_put(struct sk_buff *msg,
327 const struct net_dm_hw_entry *hw_entry)
331 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
335 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
336 goto nla_put_failure;
338 if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
339 goto nla_put_failure;
341 nla_nest_end(msg, attr);
346 nla_nest_cancel(msg, attr);
350 static int net_dm_hw_entries_put(struct sk_buff *msg,
351 const struct net_dm_hw_entries *hw_entries)
356 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
360 for (i = 0; i < hw_entries->num_entries; i++) {
363 rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
365 goto nla_put_failure;
368 nla_nest_end(msg, attr);
373 nla_nest_cancel(msg, attr);
378 net_dm_hw_summary_report_fill(struct sk_buff *msg,
379 const struct net_dm_hw_entries *hw_entries)
381 struct net_dm_alert_msg anc_hdr = { 0 };
385 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
390 /* We need to put the ancillary header in order not to break user
393 if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
394 goto nla_put_failure;
396 rc = net_dm_hw_entries_put(msg, hw_entries);
398 goto nla_put_failure;
400 genlmsg_end(msg, hdr);
405 genlmsg_cancel(msg, hdr);
409 static void net_dm_hw_summary_work(struct work_struct *work)
411 struct net_dm_hw_entries *hw_entries;
412 struct per_cpu_dm_data *hw_data;
416 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
418 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
422 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
426 rc = net_dm_hw_summary_report_fill(msg, hw_entries);
432 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
439 net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink,
441 const struct devlink_trap_metadata *metadata)
443 struct net_dm_hw_entries *hw_entries;
444 struct net_dm_hw_entry *hw_entry;
445 struct per_cpu_dm_data *hw_data;
449 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
452 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
453 raw_spin_lock_irqsave(&hw_data->lock, flags);
454 hw_entries = hw_data->hw_entries;
459 for (i = 0; i < hw_entries->num_entries; i++) {
460 hw_entry = &hw_entries->entries[i];
461 if (!strncmp(hw_entry->trap_name, metadata->trap_name,
462 NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
467 if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit))
470 hw_entry = &hw_entries->entries[hw_entries->num_entries];
471 strscpy(hw_entry->trap_name, metadata->trap_name,
472 NET_DM_MAX_HW_TRAP_NAME_LEN - 1);
474 hw_entries->num_entries++;
476 if (!timer_pending(&hw_data->send_timer)) {
477 hw_data->send_timer.expires = jiffies + dm_delay * HZ;
478 add_timer(&hw_data->send_timer);
482 raw_spin_unlock_irqrestore(&hw_data->lock, flags);
485 static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
486 .kfree_skb_probe = trace_kfree_skb_hit,
487 .napi_poll_probe = trace_napi_poll_hit,
488 .work_item_func = send_dm_alert,
489 .hw_work_item_func = net_dm_hw_summary_work,
490 .hw_trap_probe = net_dm_hw_trap_summary_probe,
493 static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
496 enum skb_drop_reason reason,
499 ktime_t tstamp = ktime_get_real();
500 struct per_cpu_dm_data *data;
501 struct net_dm_skb_cb *cb;
502 struct sk_buff *nskb;
505 if (!skb_mac_header_was_set(skb))
508 nskb = skb_clone(skb, GFP_ATOMIC);
512 cb = NET_DM_SKB_CB(nskb);
515 /* Override the timestamp because we care about the time when the
516 * packet was dropped.
518 nskb->tstamp = tstamp;
520 data = this_cpu_ptr(&dm_cpu_data);
522 spin_lock_irqsave(&data->drop_queue.lock, flags);
523 if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
524 __skb_queue_tail(&data->drop_queue, nskb);
527 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
529 schedule_work(&data->dm_alert_work);
534 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
535 u64_stats_update_begin(&data->stats.syncp);
536 u64_stats_inc(&data->stats.dropped);
537 u64_stats_update_end(&data->stats.syncp);
541 static void net_dm_packet_trace_napi_poll_hit(void *ignore,
542 struct napi_struct *napi,
543 int work, int budget)
547 static size_t net_dm_in_port_size(void)
549 /* NET_DM_ATTR_IN_PORT nest */
550 return nla_total_size(0) +
551 /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */
552 nla_total_size(sizeof(u32)) +
553 /* NET_DM_ATTR_PORT_NETDEV_NAME */
554 nla_total_size(IFNAMSIZ + 1);
557 #define NET_DM_MAX_SYMBOL_LEN 40
558 #define NET_DM_MAX_REASON_LEN 50
560 static size_t net_dm_packet_report_size(size_t payload_len)
564 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
566 return NLMSG_ALIGN(size) +
567 /* NET_DM_ATTR_ORIGIN */
568 nla_total_size(sizeof(u16)) +
570 nla_total_size(sizeof(u64)) +
571 /* NET_DM_ATTR_SYMBOL */
572 nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
573 /* NET_DM_ATTR_IN_PORT */
574 net_dm_in_port_size() +
575 /* NET_DM_ATTR_TIMESTAMP */
576 nla_total_size(sizeof(u64)) +
577 /* NET_DM_ATTR_ORIG_LEN */
578 nla_total_size(sizeof(u32)) +
579 /* NET_DM_ATTR_PROTO */
580 nla_total_size(sizeof(u16)) +
581 /* NET_DM_ATTR_REASON */
582 nla_total_size(NET_DM_MAX_REASON_LEN + 1) +
583 /* NET_DM_ATTR_PAYLOAD */
584 nla_total_size(payload_len);
587 static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
592 attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
597 nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
598 goto nla_put_failure;
600 if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name))
601 goto nla_put_failure;
603 nla_nest_end(msg, attr);
608 nla_nest_cancel(msg, attr);
612 static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
615 struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb);
616 const struct drop_reason_list *list = NULL;
617 unsigned int subsys, subsys_reason;
618 char buf[NET_DM_MAX_SYMBOL_LEN];
623 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
624 NET_DM_CMD_PACKET_ALERT);
628 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
629 goto nla_put_failure;
631 if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, (u64)(uintptr_t)cb->pc,
633 goto nla_put_failure;
636 subsys = u32_get_bits(cb->reason, SKB_DROP_REASON_SUBSYS_MASK);
637 if (subsys < SKB_DROP_REASON_SUBSYS_NUM)
638 list = rcu_dereference(drop_reasons_by_subsys[subsys]);
639 subsys_reason = cb->reason & ~SKB_DROP_REASON_SUBSYS_MASK;
641 subsys_reason >= list->n_reasons ||
642 !list->reasons[subsys_reason] ||
643 strlen(list->reasons[subsys_reason]) > NET_DM_MAX_REASON_LEN) {
644 list = rcu_dereference(drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_CORE]);
645 subsys_reason = SKB_DROP_REASON_NOT_SPECIFIED;
647 if (nla_put_string(msg, NET_DM_ATTR_REASON,
648 list->reasons[subsys_reason])) {
650 goto nla_put_failure;
654 snprintf(buf, sizeof(buf), "%pS", cb->pc);
655 if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
656 goto nla_put_failure;
658 rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL);
660 goto nla_put_failure;
662 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
663 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
664 goto nla_put_failure;
666 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
667 goto nla_put_failure;
672 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
673 goto nla_put_failure;
675 attr = skb_put(msg, nla_total_size(payload_len));
676 attr->nla_type = NET_DM_ATTR_PAYLOAD;
677 attr->nla_len = nla_attr_size(payload_len);
678 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
679 goto nla_put_failure;
682 genlmsg_end(msg, hdr);
687 genlmsg_cancel(msg, hdr);
691 #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
693 static void net_dm_packet_report(struct sk_buff *skb)
699 /* Make sure we start copying the packet from the MAC header */
700 if (skb->data > skb_mac_header(skb))
701 skb_push(skb, skb->data - skb_mac_header(skb));
703 skb_pull(skb, skb_mac_header(skb) - skb->data);
705 /* Ensure packet fits inside a single netlink attribute */
706 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
707 if (net_dm_trunc_len)
708 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
710 msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
714 rc = net_dm_packet_report_fill(msg, skb, payload_len);
720 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
726 static void net_dm_packet_work(struct work_struct *work)
728 struct per_cpu_dm_data *data;
729 struct sk_buff_head list;
733 data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
735 __skb_queue_head_init(&list);
737 spin_lock_irqsave(&data->drop_queue.lock, flags);
738 skb_queue_splice_tail_init(&data->drop_queue, &list);
739 spin_unlock_irqrestore(&data->drop_queue.lock, flags);
741 while ((skb = __skb_dequeue(&list)))
742 net_dm_packet_report(skb);
746 net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata)
748 return hw_metadata->fa_cookie ?
749 nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0;
753 net_dm_hw_packet_report_size(size_t payload_len,
754 const struct devlink_trap_metadata *hw_metadata)
758 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
760 return NLMSG_ALIGN(size) +
761 /* NET_DM_ATTR_ORIGIN */
762 nla_total_size(sizeof(u16)) +
763 /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */
764 nla_total_size(strlen(hw_metadata->trap_group_name) + 1) +
765 /* NET_DM_ATTR_HW_TRAP_NAME */
766 nla_total_size(strlen(hw_metadata->trap_name) + 1) +
767 /* NET_DM_ATTR_IN_PORT */
768 net_dm_in_port_size() +
769 /* NET_DM_ATTR_FLOW_ACTION_COOKIE */
770 net_dm_flow_action_cookie_size(hw_metadata) +
771 /* NET_DM_ATTR_TIMESTAMP */
772 nla_total_size(sizeof(u64)) +
773 /* NET_DM_ATTR_ORIG_LEN */
774 nla_total_size(sizeof(u32)) +
775 /* NET_DM_ATTR_PROTO */
776 nla_total_size(sizeof(u16)) +
777 /* NET_DM_ATTR_PAYLOAD */
778 nla_total_size(payload_len);
781 static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
782 struct sk_buff *skb, size_t payload_len)
784 struct devlink_trap_metadata *hw_metadata;
788 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
790 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
791 NET_DM_CMD_PACKET_ALERT);
795 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW))
796 goto nla_put_failure;
798 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME,
799 hw_metadata->trap_group_name))
800 goto nla_put_failure;
802 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME,
803 hw_metadata->trap_name))
804 goto nla_put_failure;
806 if (hw_metadata->input_dev) {
807 struct net_device *dev = hw_metadata->input_dev;
810 rc = net_dm_packet_report_in_port_put(msg, dev->ifindex,
813 goto nla_put_failure;
816 if (hw_metadata->fa_cookie &&
817 nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE,
818 hw_metadata->fa_cookie->cookie_len,
819 hw_metadata->fa_cookie->cookie))
820 goto nla_put_failure;
822 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
823 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
824 goto nla_put_failure;
826 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
827 goto nla_put_failure;
832 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
833 goto nla_put_failure;
835 attr = skb_put(msg, nla_total_size(payload_len));
836 attr->nla_type = NET_DM_ATTR_PAYLOAD;
837 attr->nla_len = nla_attr_size(payload_len);
838 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
839 goto nla_put_failure;
842 genlmsg_end(msg, hdr);
847 genlmsg_cancel(msg, hdr);
851 static struct devlink_trap_metadata *
852 net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata)
854 const struct flow_action_cookie *fa_cookie;
855 struct devlink_trap_metadata *hw_metadata;
856 const char *trap_group_name;
857 const char *trap_name;
859 hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC);
863 trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC);
864 if (!trap_group_name)
865 goto free_hw_metadata;
866 hw_metadata->trap_group_name = trap_group_name;
868 trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC);
870 goto free_trap_group;
871 hw_metadata->trap_name = trap_name;
873 if (metadata->fa_cookie) {
874 size_t cookie_size = sizeof(*fa_cookie) +
875 metadata->fa_cookie->cookie_len;
877 fa_cookie = kmemdup(metadata->fa_cookie, cookie_size,
881 hw_metadata->fa_cookie = fa_cookie;
884 hw_metadata->input_dev = metadata->input_dev;
885 netdev_hold(hw_metadata->input_dev, &hw_metadata->dev_tracker,
893 kfree(trap_group_name);
900 net_dm_hw_metadata_free(struct devlink_trap_metadata *hw_metadata)
902 netdev_put(hw_metadata->input_dev, &hw_metadata->dev_tracker);
903 kfree(hw_metadata->fa_cookie);
904 kfree(hw_metadata->trap_name);
905 kfree(hw_metadata->trap_group_name);
909 static void net_dm_hw_packet_report(struct sk_buff *skb)
911 struct devlink_trap_metadata *hw_metadata;
916 if (skb->data > skb_mac_header(skb))
917 skb_push(skb, skb->data - skb_mac_header(skb));
919 skb_pull(skb, skb_mac_header(skb) - skb->data);
921 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
922 if (net_dm_trunc_len)
923 payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
925 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
926 msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata),
931 rc = net_dm_hw_packet_report_fill(msg, skb, payload_len);
937 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
940 net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata);
944 static void net_dm_hw_packet_work(struct work_struct *work)
946 struct per_cpu_dm_data *hw_data;
947 struct sk_buff_head list;
951 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
953 __skb_queue_head_init(&list);
955 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
956 skb_queue_splice_tail_init(&hw_data->drop_queue, &list);
957 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
959 while ((skb = __skb_dequeue(&list)))
960 net_dm_hw_packet_report(skb);
964 net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink,
966 const struct devlink_trap_metadata *metadata)
968 struct devlink_trap_metadata *n_hw_metadata;
969 ktime_t tstamp = ktime_get_real();
970 struct per_cpu_dm_data *hw_data;
971 struct sk_buff *nskb;
974 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
977 if (!skb_mac_header_was_set(skb))
980 nskb = skb_clone(skb, GFP_ATOMIC);
984 n_hw_metadata = net_dm_hw_metadata_copy(metadata);
988 NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata;
989 nskb->tstamp = tstamp;
991 hw_data = this_cpu_ptr(&dm_hw_cpu_data);
993 spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
994 if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len)
995 __skb_queue_tail(&hw_data->drop_queue, nskb);
998 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
1000 schedule_work(&hw_data->dm_alert_work);
1005 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
1006 u64_stats_update_begin(&hw_data->stats.syncp);
1007 u64_stats_inc(&hw_data->stats.dropped);
1008 u64_stats_update_end(&hw_data->stats.syncp);
1009 net_dm_hw_metadata_free(n_hw_metadata);
1014 static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
1015 .kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit,
1016 .napi_poll_probe = net_dm_packet_trace_napi_poll_hit,
1017 .work_item_func = net_dm_packet_work,
1018 .hw_work_item_func = net_dm_hw_packet_work,
1019 .hw_trap_probe = net_dm_hw_trap_packet_probe,
1022 static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
1023 [NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops,
1024 [NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops,
1027 #if IS_ENABLED(CONFIG_NET_DEVLINK)
1028 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
1030 return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1033 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1035 unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
1036 tracepoint_synchronize_unregister();
1039 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
1044 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
1049 static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack)
1051 const struct net_dm_alert_ops *ops;
1055 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled");
1059 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1061 if (!try_module_get(THIS_MODULE)) {
1062 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1066 for_each_possible_cpu(cpu) {
1067 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1068 struct net_dm_hw_entries *hw_entries;
1070 INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func);
1071 timer_setup(&hw_data->send_timer, sched_send_work, 0);
1072 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
1076 rc = net_dm_hw_probe_register(ops);
1078 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint");
1079 goto err_module_put;
1087 for_each_possible_cpu(cpu) {
1088 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1089 struct sk_buff *skb;
1091 del_timer_sync(&hw_data->send_timer);
1092 cancel_work_sync(&hw_data->dm_alert_work);
1093 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1094 struct devlink_trap_metadata *hw_metadata;
1096 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1097 net_dm_hw_metadata_free(hw_metadata);
1101 module_put(THIS_MODULE);
1105 static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack)
1107 const struct net_dm_alert_ops *ops;
1111 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled");
1115 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1119 net_dm_hw_probe_unregister(ops);
1121 for_each_possible_cpu(cpu) {
1122 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1123 struct sk_buff *skb;
1125 del_timer_sync(&hw_data->send_timer);
1126 cancel_work_sync(&hw_data->dm_alert_work);
1127 while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
1128 struct devlink_trap_metadata *hw_metadata;
1130 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
1131 net_dm_hw_metadata_free(hw_metadata);
1136 module_put(THIS_MODULE);
1139 static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
1141 const struct net_dm_alert_ops *ops;
1144 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1146 if (!try_module_get(THIS_MODULE)) {
1147 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
1151 for_each_possible_cpu(cpu) {
1152 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1153 struct sk_buff *skb;
1155 INIT_WORK(&data->dm_alert_work, ops->work_item_func);
1156 timer_setup(&data->send_timer, sched_send_work, 0);
1157 /* Allocate a new per-CPU skb for the summary alert message and
1158 * free the old one which might contain stale data from
1161 skb = reset_per_cpu_data(data);
1165 rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1167 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
1168 goto err_module_put;
1171 rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
1173 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
1174 goto err_unregister_trace;
1179 err_unregister_trace:
1180 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1182 for_each_possible_cpu(cpu) {
1183 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1184 struct sk_buff *skb;
1186 del_timer_sync(&data->send_timer);
1187 cancel_work_sync(&data->dm_alert_work);
1188 while ((skb = __skb_dequeue(&data->drop_queue)))
1191 module_put(THIS_MODULE);
1195 static void net_dm_trace_off_set(void)
1197 const struct net_dm_alert_ops *ops;
1200 ops = net_dm_alert_ops_arr[net_dm_alert_mode];
1202 unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
1203 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
1205 tracepoint_synchronize_unregister();
1207 /* Make sure we do not send notifications to user space after request
1208 * to stop tracing returns.
1210 for_each_possible_cpu(cpu) {
1211 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1212 struct sk_buff *skb;
1214 del_timer_sync(&data->send_timer);
1215 cancel_work_sync(&data->dm_alert_work);
1216 while ((skb = __skb_dequeue(&data->drop_queue)))
1220 module_put(THIS_MODULE);
1223 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
1227 if (state == trace_state) {
1228 NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
1234 rc = net_dm_trace_on_set(extack);
1237 net_dm_trace_off_set();
1245 trace_state = state;
1252 static bool net_dm_is_monitoring(void)
1254 return trace_state == TRACE_ON || monitor_hw;
1257 static int net_dm_alert_mode_get_from_info(struct genl_info *info,
1258 enum net_dm_alert_mode *p_alert_mode)
1262 val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
1265 case NET_DM_ALERT_MODE_SUMMARY:
1266 case NET_DM_ALERT_MODE_PACKET:
1267 *p_alert_mode = val;
1276 static int net_dm_alert_mode_set(struct genl_info *info)
1278 struct netlink_ext_ack *extack = info->extack;
1279 enum net_dm_alert_mode alert_mode;
1282 if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
1285 rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
1287 NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
1291 net_dm_alert_mode = alert_mode;
1296 static void net_dm_trunc_len_set(struct genl_info *info)
1298 if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
1301 net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
1304 static void net_dm_queue_len_set(struct genl_info *info)
1306 if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
1309 net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
1312 static int net_dm_cmd_config(struct sk_buff *skb,
1313 struct genl_info *info)
1315 struct netlink_ext_ack *extack = info->extack;
1318 if (net_dm_is_monitoring()) {
1319 NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
1323 rc = net_dm_alert_mode_set(info);
1327 net_dm_trunc_len_set(info);
1329 net_dm_queue_len_set(info);
1334 static int net_dm_monitor_start(bool set_sw, bool set_hw,
1335 struct netlink_ext_ack *extack)
1337 bool sw_set = false;
1341 rc = set_all_monitor_traces(TRACE_ON, extack);
1348 rc = net_dm_hw_monitor_start(extack);
1350 goto err_monitor_hw;
1357 set_all_monitor_traces(TRACE_OFF, extack);
1361 static void net_dm_monitor_stop(bool set_sw, bool set_hw,
1362 struct netlink_ext_ack *extack)
1365 net_dm_hw_monitor_stop(extack);
1367 set_all_monitor_traces(TRACE_OFF, extack);
1370 static int net_dm_cmd_trace(struct sk_buff *skb,
1371 struct genl_info *info)
1373 bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS];
1374 bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS];
1375 struct netlink_ext_ack *extack = info->extack;
1377 /* To maintain backward compatibility, we start / stop monitoring of
1378 * software drops if no flag is specified.
1380 if (!set_sw && !set_hw)
1383 switch (info->genlhdr->cmd) {
1384 case NET_DM_CMD_START:
1385 return net_dm_monitor_start(set_sw, set_hw, extack);
1386 case NET_DM_CMD_STOP:
1387 net_dm_monitor_stop(set_sw, set_hw, extack);
1394 static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
1398 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1399 &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
1403 if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
1404 goto nla_put_failure;
1406 if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
1407 goto nla_put_failure;
1409 if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
1410 goto nla_put_failure;
1412 genlmsg_end(msg, hdr);
1417 genlmsg_cancel(msg, hdr);
1421 static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
1423 struct sk_buff *msg;
1426 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1430 rc = net_dm_config_fill(msg, info);
1434 return genlmsg_reply(msg, info);
1441 static void net_dm_stats_read(struct net_dm_stats *stats)
1445 memset(stats, 0, sizeof(*stats));
1446 for_each_possible_cpu(cpu) {
1447 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
1448 struct net_dm_stats *cpu_stats = &data->stats;
1453 start = u64_stats_fetch_begin(&cpu_stats->syncp);
1454 dropped = u64_stats_read(&cpu_stats->dropped);
1455 } while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
1457 u64_stats_add(&stats->dropped, dropped);
1461 static int net_dm_stats_put(struct sk_buff *msg)
1463 struct net_dm_stats stats;
1464 struct nlattr *attr;
1466 net_dm_stats_read(&stats);
1468 attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
1472 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1473 u64_stats_read(&stats.dropped), NET_DM_ATTR_PAD))
1474 goto nla_put_failure;
1476 nla_nest_end(msg, attr);
1481 nla_nest_cancel(msg, attr);
1485 static void net_dm_hw_stats_read(struct net_dm_stats *stats)
1489 memset(stats, 0, sizeof(*stats));
1490 for_each_possible_cpu(cpu) {
1491 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1492 struct net_dm_stats *cpu_stats = &hw_data->stats;
1497 start = u64_stats_fetch_begin(&cpu_stats->syncp);
1498 dropped = u64_stats_read(&cpu_stats->dropped);
1499 } while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
1501 u64_stats_add(&stats->dropped, dropped);
1505 static int net_dm_hw_stats_put(struct sk_buff *msg)
1507 struct net_dm_stats stats;
1508 struct nlattr *attr;
1510 net_dm_hw_stats_read(&stats);
1512 attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS);
1516 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
1517 u64_stats_read(&stats.dropped), NET_DM_ATTR_PAD))
1518 goto nla_put_failure;
1520 nla_nest_end(msg, attr);
1525 nla_nest_cancel(msg, attr);
1529 static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
1534 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
1535 &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
1539 rc = net_dm_stats_put(msg);
1541 goto nla_put_failure;
1543 rc = net_dm_hw_stats_put(msg);
1545 goto nla_put_failure;
1547 genlmsg_end(msg, hdr);
1552 genlmsg_cancel(msg, hdr);
1556 static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
1558 struct sk_buff *msg;
1561 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1565 rc = net_dm_stats_fill(msg, info);
1569 return genlmsg_reply(msg, info);
1576 static int dropmon_net_event(struct notifier_block *ev_block,
1577 unsigned long event, void *ptr)
1579 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1580 struct dm_hw_stat_delta *stat;
1583 case NETDEV_REGISTER:
1584 if (WARN_ON_ONCE(rtnl_dereference(dev->dm_private)))
1586 stat = kzalloc(sizeof(*stat), GFP_KERNEL);
1590 stat->last_rx = jiffies;
1591 rcu_assign_pointer(dev->dm_private, stat);
1594 case NETDEV_UNREGISTER:
1595 stat = rtnl_dereference(dev->dm_private);
1597 rcu_assign_pointer(dev->dm_private, NULL);
1598 kfree_rcu(stat, rcu);
1605 static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
1606 [NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
1607 [NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
1608 [NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
1609 [NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
1610 [NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG },
1611 [NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG },
1614 static const struct genl_small_ops dropmon_ops[] = {
1616 .cmd = NET_DM_CMD_CONFIG,
1617 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1618 .doit = net_dm_cmd_config,
1619 .flags = GENL_ADMIN_PERM,
1622 .cmd = NET_DM_CMD_START,
1623 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1624 .doit = net_dm_cmd_trace,
1625 .flags = GENL_ADMIN_PERM,
1628 .cmd = NET_DM_CMD_STOP,
1629 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1630 .doit = net_dm_cmd_trace,
1631 .flags = GENL_ADMIN_PERM,
1634 .cmd = NET_DM_CMD_CONFIG_GET,
1635 .doit = net_dm_cmd_config_get,
1638 .cmd = NET_DM_CMD_STATS_GET,
1639 .doit = net_dm_cmd_stats_get,
1643 static int net_dm_nl_pre_doit(const struct genl_split_ops *ops,
1644 struct sk_buff *skb, struct genl_info *info)
1646 mutex_lock(&net_dm_mutex);
1651 static void net_dm_nl_post_doit(const struct genl_split_ops *ops,
1652 struct sk_buff *skb, struct genl_info *info)
1654 mutex_unlock(&net_dm_mutex);
1657 static struct genl_family net_drop_monitor_family __ro_after_init = {
1661 .maxattr = NET_DM_ATTR_MAX,
1662 .policy = net_dm_nl_policy,
1663 .pre_doit = net_dm_nl_pre_doit,
1664 .post_doit = net_dm_nl_post_doit,
1665 .module = THIS_MODULE,
1666 .small_ops = dropmon_ops,
1667 .n_small_ops = ARRAY_SIZE(dropmon_ops),
1668 .resv_start_op = NET_DM_CMD_STATS_GET + 1,
1669 .mcgrps = dropmon_mcgrps,
1670 .n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
1673 static struct notifier_block dropmon_net_notifier = {
1674 .notifier_call = dropmon_net_event
1677 static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data)
1679 raw_spin_lock_init(&data->lock);
1680 skb_queue_head_init(&data->drop_queue);
1681 u64_stats_init(&data->stats.syncp);
1684 static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data)
1686 WARN_ON(!skb_queue_empty(&data->drop_queue));
1689 static void net_dm_cpu_data_init(int cpu)
1691 struct per_cpu_dm_data *data;
1693 data = &per_cpu(dm_cpu_data, cpu);
1694 __net_dm_cpu_data_init(data);
1697 static void net_dm_cpu_data_fini(int cpu)
1699 struct per_cpu_dm_data *data;
1701 data = &per_cpu(dm_cpu_data, cpu);
1702 /* At this point, we should have exclusive access
1703 * to this struct and can free the skb inside it.
1705 consume_skb(data->skb);
1706 __net_dm_cpu_data_fini(data);
1709 static void net_dm_hw_cpu_data_init(int cpu)
1711 struct per_cpu_dm_data *hw_data;
1713 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1714 __net_dm_cpu_data_init(hw_data);
1717 static void net_dm_hw_cpu_data_fini(int cpu)
1719 struct per_cpu_dm_data *hw_data;
1721 hw_data = &per_cpu(dm_hw_cpu_data, cpu);
1722 kfree(hw_data->hw_entries);
1723 __net_dm_cpu_data_fini(hw_data);
1726 static int __init init_net_drop_monitor(void)
1730 pr_info("Initializing network drop monitor service\n");
1732 if (sizeof(void *) > 8) {
1733 pr_err("Unable to store program counters on this arch, Drop monitor failed\n");
1737 rc = genl_register_family(&net_drop_monitor_family);
1739 pr_err("Could not create drop monitor netlink family\n");
1742 WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
1744 rc = register_netdevice_notifier(&dropmon_net_notifier);
1746 pr_crit("Failed to register netdevice notifier\n");
1752 for_each_possible_cpu(cpu) {
1753 net_dm_cpu_data_init(cpu);
1754 net_dm_hw_cpu_data_init(cpu);
1760 genl_unregister_family(&net_drop_monitor_family);
1765 static void exit_net_drop_monitor(void)
1769 BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
1772 * Because of the module_get/put we do in the trace state change path
1773 * we are guaranteed not to have any current users when we get here
1776 for_each_possible_cpu(cpu) {
1777 net_dm_hw_cpu_data_fini(cpu);
1778 net_dm_cpu_data_fini(cpu);
1781 BUG_ON(genl_unregister_family(&net_drop_monitor_family));
1784 module_init(init_net_drop_monitor);
1785 module_exit(exit_net_drop_monitor);
1787 MODULE_LICENSE("GPL v2");
1788 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
1789 MODULE_ALIAS_GENL_FAMILY("NET_DM");
1790 MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");