[net-next-2.6.git] / net / core / drop_monitor.c

/*
 * Monitoring code for network dropped packet alerts
 *
 * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
 */

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/string.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/inet.h>
#include <linux/interrupt.h>
#include <linux/netpoll.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <linux/netlink.h>
#include <linux/net_dropmon.h>
#include <linux/percpu.h>
#include <linux/timer.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <net/genetlink.h>
#include <net/netevent.h>

#include <trace/events/skb.h>
#include <trace/events/napi.h>

#include <asm/unaligned.h>

#define TRACE_ON 1
#define TRACE_OFF 0

static void send_dm_alert(struct work_struct *unused);


/*
 * Globals, our netlink socket pointer
 * and the work handle that will send up
 * netlink alerts
 */
static int trace_state = TRACE_OFF;
static DEFINE_SPINLOCK(trace_state_lock);

struct per_cpu_dm_data {
	struct work_struct dm_alert_work;
	struct sk_buff *skb;
	atomic_t dm_hit_count;
	struct timer_list send_timer;
};

struct dm_hw_stat_delta {
	struct net_device *dev;
	unsigned long last_rx;
	struct list_head list;
	struct rcu_head rcu;
	unsigned long last_drop_val;
};

static struct genl_family net_drop_monitor_family = {
	.id             = GENL_ID_GENERATE,
	.hdrsize        = 0,
	.name           = "NET_DM",
	.version        = 2,
	.maxattr        = NET_DM_CMD_MAX,
};

static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);

static int dm_hit_limit = 64;
static int dm_delay = 1;
static unsigned long dm_hw_check_delta = 2*HZ;
static LIST_HEAD(hw_stats_list);

static void reset_per_cpu_data(struct per_cpu_dm_data *data)
{
	size_t al;
	struct net_dm_alert_msg *msg;
	struct nlattr *nla;

	al = sizeof(struct net_dm_alert_msg);
	al += dm_hit_limit * sizeof(struct net_dm_drop_point);
	al += sizeof(struct nlattr);

	data->skb = genlmsg_new(al, GFP_KERNEL);
	genlmsg_put(data->skb, 0, 0, &net_drop_monitor_family,
			0, NET_DM_CMD_ALERT);
	nla = nla_reserve(data->skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));
	msg = nla_data(nla);
	memset(msg, 0, al);
	atomic_set(&data->dm_hit_count, dm_hit_limit);
}

static void send_dm_alert(struct work_struct *unused)
{
	struct sk_buff *skb;
	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);

	/*
	 * Grab the skb we're about to send
	 */
	skb = data->skb;

	/*
	 * Replace it with a new one
	 */
	reset_per_cpu_data(data);

	/*
	 * Ship it!
	 */
	genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL);

}

/*
 * This is the timer function to delay the sending of an alert
 * in the event that more drops will arrive during the
 * hysteresis period.  Note that it operates under the timer interrupt
 * so we don't need to disable preemption here
 */
static void sched_send_work(unsigned long unused)
{
	struct per_cpu_dm_data *data =  &__get_cpu_var(dm_cpu_data);

	schedule_work(&data->dm_alert_work);
}

static void trace_drop_common(struct sk_buff *skb, void *location)
{
	struct net_dm_alert_msg *msg;
	struct nlmsghdr *nlh;
	struct nlattr *nla;
	int i;
	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);


	if (!atomic_add_unless(&data->dm_hit_count, -1, 0)) {
		/*
		 * we're already at zero, discard this hit
		 */
		goto out;
	}

	nlh = (struct nlmsghdr *)data->skb->data;
	nla = genlmsg_data(nlmsg_data(nlh));
	msg = nla_data(nla);
	for (i = 0; i < msg->entries; i++) {
		if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
			msg->points[i].count++;
			goto out;
		}
	}

	/*
	 * We need to create a new entry
	 */
	__nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
	nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
	memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
	msg->points[msg->entries].count = 1;
	msg->entries++;

	if (!timer_pending(&data->send_timer)) {
		data->send_timer.expires = jiffies + dm_delay * HZ;
		add_timer_on(&data->send_timer, smp_processor_id());
	}

out:
	return;
}

static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
{
	trace_drop_common(skb, location);
}

static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi)
{
	struct dm_hw_stat_delta *new_stat;

	/*
	 * Don't check napi structures with no associated device
	 */
	if (!napi->dev)
		return;

	rcu_read_lock();
	list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
		/*
		 * only add a note to our monitor buffer if:
		 * 1) this is the dev we received on
		 * 2) its after the last_rx delta
		 * 3) our rx_dropped count has gone up
		 */
		if ((new_stat->dev == napi->dev)  &&
		    (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) &&
		    (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
			trace_drop_common(NULL, NULL);
			new_stat->last_drop_val = napi->dev->stats.rx_dropped;
			new_stat->last_rx = jiffies;
			break;
		}
	}
	rcu_read_unlock();
}


static void free_dm_hw_stat(struct rcu_head *head)
{
	struct dm_hw_stat_delta *n;
	n = container_of(head, struct dm_hw_stat_delta, rcu);
	kfree(n);
}

static int set_all_monitor_traces(int state)
{
	int rc = 0;
	struct dm_hw_stat_delta *new_stat = NULL;
	struct dm_hw_stat_delta *temp;

	spin_lock(&trace_state_lock);

	if (state == trace_state) {
		rc = -EAGAIN;
		goto out_unlock;
	}

	switch (state) {
	case TRACE_ON:
		rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL);
		rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL);
		break;
	case TRACE_OFF:
		rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL);
		rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL);

		tracepoint_synchronize_unregister();

		/*
		 * Clean the device list
		 */
		list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
			if (new_stat->dev == NULL) {
				list_del_rcu(&new_stat->list);
				call_rcu(&new_stat->rcu, free_dm_hw_stat);
			}
		}
		break;
	default:
		rc = 1;
		break;
	}

	if (!rc)
		trace_state = state;
	else
		rc = -EINPROGRESS;

out_unlock:
	spin_unlock(&trace_state_lock);

	return rc;
}


static int net_dm_cmd_config(struct sk_buff *skb,
			struct genl_info *info)
{
	return -ENOTSUPP;
}

static int net_dm_cmd_trace(struct sk_buff *skb,
			struct genl_info *info)
{
	switch (info->genlhdr->cmd) {
	case NET_DM_CMD_START:
		return set_all_monitor_traces(TRACE_ON);
		break;
	case NET_DM_CMD_STOP:
		return set_all_monitor_traces(TRACE_OFF);
		break;
	}

	return -ENOTSUPP;
}

static int dropmon_net_event(struct notifier_block *ev_block,
			unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;
	struct dm_hw_stat_delta *new_stat = NULL;
	struct dm_hw_stat_delta *tmp;

	switch (event) {
	case NETDEV_REGISTER:
		new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);

		if (!new_stat)
			goto out;

		new_stat->dev = dev;
		new_stat->last_rx = jiffies;
		spin_lock(&trace_state_lock);
		list_add_rcu(&new_stat->list, &hw_stats_list);
		spin_unlock(&trace_state_lock);
		break;
	case NETDEV_UNREGISTER:
		spin_lock(&trace_state_lock);
		list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
			if (new_stat->dev == dev) {
				new_stat->dev = NULL;
				if (trace_state == TRACE_OFF) {
					list_del_rcu(&new_stat->list);
					call_rcu(&new_stat->rcu, free_dm_hw_stat);
					break;
				}
			}
		}
		spin_unlock(&trace_state_lock);
		break;
	}
out:
	return NOTIFY_DONE;
}

static struct genl_ops dropmon_ops[] = {
	{
		.cmd = NET_DM_CMD_CONFIG,
		.doit = net_dm_cmd_config,
	},
	{
		.cmd = NET_DM_CMD_START,
		.doit = net_dm_cmd_trace,
	},
	{
		.cmd = NET_DM_CMD_STOP,
		.doit = net_dm_cmd_trace,
	},
};

static struct notifier_block dropmon_net_notifier = {
	.notifier_call = dropmon_net_event
};

static int __init init_net_drop_monitor(void)
{
	struct per_cpu_dm_data *data;
	int cpu, rc;

	printk(KERN_INFO "Initalizing network drop monitor service\n");

	if (sizeof(void *) > 8) {
		printk(KERN_ERR "Unable to store program counters on this arch, Drop monitor failed\n");
		return -ENOSPC;
	}

	rc = genl_register_family_with_ops(&net_drop_monitor_family,
					   dropmon_ops,
					   ARRAY_SIZE(dropmon_ops));
	if (rc) {
		printk(KERN_ERR "Could not create drop monitor netlink family\n");
		return rc;
	}

	rc = register_netdevice_notifier(&dropmon_net_notifier);
	if (rc < 0) {
		printk(KERN_CRIT "Failed to register netdevice notifier\n");
		goto out_unreg;
	}

	rc = 0;

	for_each_present_cpu(cpu) {
		data = &per_cpu(dm_cpu_data, cpu);
		reset_per_cpu_data(data);
		INIT_WORK(&data->dm_alert_work, send_dm_alert);
		init_timer(&data->send_timer);
		data->send_timer.data = cpu;
		data->send_timer.function = sched_send_work;
	}

	goto out;

out_unreg:
	genl_unregister_family(&net_drop_monitor_family);
out:
	return rc;
}

late_initcall(init_net_drop_monitor);
Commit	Line	Data
9a8afc8d NH	1	/*
	2	* Monitoring code for network dropped packet alerts
	3	*
	4	* Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
	5	*/
	6
	7	#include <linux/netdevice.h>
	8	#include <linux/etherdevice.h>
	9	#include <linux/string.h>
	10	#include <linux/if_arp.h>
	11	#include <linux/inetdevice.h>
	12	#include <linux/inet.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/netpoll.h>
	15	#include <linux/sched.h>
	16	#include <linux/delay.h>
	17	#include <linux/types.h>
	18	#include <linux/workqueue.h>
	19	#include <linux/netlink.h>
	20	#include <linux/net_dropmon.h>
	21	#include <linux/percpu.h>
	22	#include <linux/timer.h>
	23	#include <linux/bitops.h>
5a0e3ad6	24	#include <linux/slab.h>
9a8afc8d	25	#include <net/genetlink.h>
4ea7e386	26	#include <net/netevent.h>
9a8afc8d	27
ad8d75ff	28	#include <trace/events/skb.h>
9cbc1cb8	29	#include <trace/events/napi.h>
9a8afc8d NH	30
	31	#include <asm/unaligned.h>
	32
	33	#define TRACE_ON 1
	34	#define TRACE_OFF 0
	35
	36	static void send_dm_alert(struct work_struct *unused);
	37
	38
	39	/*
	40	* Globals, our netlink socket pointer
	41	* and the work handle that will send up
	42	* netlink alerts
	43	*/
4ea7e386	44	static int trace_state = TRACE_OFF;
d3bcfefa	45	static DEFINE_SPINLOCK(trace_state_lock);
9a8afc8d NH	46
	47	struct per_cpu_dm_data {
	48	struct work_struct dm_alert_work;
	49	struct sk_buff *skb;
	50	atomic_t dm_hit_count;
	51	struct timer_list send_timer;
	52	};
	53
4ea7e386 NH	54	struct dm_hw_stat_delta {
4ea7e386 NH	55	struct net_device *dev;
5848cc09	56	unsigned long last_rx;
4ea7e386 NH	57	struct list_head list;
	58	struct rcu_head rcu;
	59	unsigned long last_drop_val;
	60	};
	61
9a8afc8d NH	62	static struct genl_family net_drop_monitor_family = {
	63	.id = GENL_ID_GENERATE,
	64	.hdrsize = 0,
	65	.name = "NET_DM",
683703a2	66	.version = 2,
9a8afc8d NH	67	.maxattr = NET_DM_CMD_MAX,
	68	};
	69
	70	static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
	71
	72	static int dm_hit_limit = 64;
	73	static int dm_delay = 1;
4ea7e386 NH	74	static unsigned long dm_hw_check_delta = 2*HZ;
4ea7e386 NH	75	static LIST_HEAD(hw_stats_list);
9a8afc8d NH	76
	77	static void reset_per_cpu_data(struct per_cpu_dm_data *data)
	78	{
	79	size_t al;
	80	struct net_dm_alert_msg *msg;
683703a2	81	struct nlattr *nla;
9a8afc8d NH	82
	83	al = sizeof(struct net_dm_alert_msg);
	84	al += dm_hit_limit * sizeof(struct net_dm_drop_point);
683703a2 NH	85	al += sizeof(struct nlattr);
683703a2 NH	86
9a8afc8d NH	87	data->skb = genlmsg_new(al, GFP_KERNEL);
	88	genlmsg_put(data->skb, 0, 0, &net_drop_monitor_family,
	89	0, NET_DM_CMD_ALERT);
683703a2 NH	90	nla = nla_reserve(data->skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));
683703a2 NH	91	msg = nla_data(nla);
9a8afc8d NH	92	memset(msg, 0, al);
	93	atomic_set(&data->dm_hit_count, dm_hit_limit);
	94	}
	95
	96	static void send_dm_alert(struct work_struct *unused)
	97	{
	98	struct sk_buff *skb;
	99	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	100
	101	/*
	102	* Grab the skb we're about to send
	103	*/
	104	skb = data->skb;
	105
	106	/*
	107	* Replace it with a new one
	108	*/
	109	reset_per_cpu_data(data);
	110
	111	/*
	112	* Ship it!
	113	*/
	114	genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL);
	115
	116	}
	117
	118	/*
	119	* This is the timer function to delay the sending of an alert
	120	* in the event that more drops will arrive during the
	121	* hysteresis period. Note that it operates under the timer interrupt
	122	* so we don't need to disable preemption here
	123	*/
	124	static void sched_send_work(unsigned long unused)
	125	{
	126	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	127
	128	schedule_work(&data->dm_alert_work);
	129	}
	130
4ea7e386	131	static void trace_drop_common(struct sk_buff skb, void location)
9a8afc8d NH	132	{
	133	struct net_dm_alert_msg *msg;
	134	struct nlmsghdr *nlh;
683703a2	135	struct nlattr *nla;
9a8afc8d NH	136	int i;
	137	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	138
	139
	140	if (!atomic_add_unless(&data->dm_hit_count, -1, 0)) {
	141	/*
	142	* we're already at zero, discard this hit
	143	*/
	144	goto out;
	145	}
	146
	147	nlh = (struct nlmsghdr *)data->skb->data;
683703a2 NH	148	nla = genlmsg_data(nlmsg_data(nlh));
683703a2 NH	149	msg = nla_data(nla);
9a8afc8d NH	150	for (i = 0; i < msg->entries; i++) {
	151	if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
	152	msg->points[i].count++;
	153	goto out;
	154	}
	155	}
	156
	157	/*
	158	* We need to create a new entry
	159	*/
	160	__nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
683703a2	161	nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
9a8afc8d NH	162	memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
	163	msg->points[msg->entries].count = 1;
	164	msg->entries++;
	165
	166	if (!timer_pending(&data->send_timer)) {
	167	data->send_timer.expires = jiffies + dm_delay * HZ;
	168	add_timer_on(&data->send_timer, smp_processor_id());
	169	}
	170
	171	out:
	172	return;
	173	}
	174
38516ab5	175	static void trace_kfree_skb_hit(void ignore, struct sk_buff skb, void *location)
4ea7e386 NH	176	{
	177	trace_drop_common(skb, location);
	178	}
	179
38516ab5	180	static void trace_napi_poll_hit(void ignore, struct napi_struct napi)
4ea7e386 NH	181	{
	182	struct dm_hw_stat_delta *new_stat;
	183
	184	/*
5848cc09	185	* Don't check napi structures with no associated device
4ea7e386	186	*/
5848cc09	187	if (!napi->dev)
4ea7e386 NH	188	return;
	189
	190	rcu_read_lock();
	191	list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
5848cc09 NH	192	/*
	193	* only add a note to our monitor buffer if:
	194	* 1) this is the dev we received on
	195	* 2) its after the last_rx delta
	196	* 3) our rx_dropped count has gone up
	197	*/
4ea7e386	198	if ((new_stat->dev == napi->dev) &&
5848cc09	199	(time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) &&
4ea7e386 NH	200	(napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
	201	trace_drop_common(NULL, NULL);
	202	new_stat->last_drop_val = napi->dev->stats.rx_dropped;
5848cc09	203	new_stat->last_rx = jiffies;
4ea7e386 NH	204	break;
	205	}
	206	}
	207	rcu_read_unlock();
	208	}
	209
	210
	211	static void free_dm_hw_stat(struct rcu_head *head)
	212	{
	213	struct dm_hw_stat_delta *n;
	214	n = container_of(head, struct dm_hw_stat_delta, rcu);
	215	kfree(n);
	216	}
	217
9a8afc8d NH	218	static int set_all_monitor_traces(int state)
	219	{
	220	int rc = 0;
4ea7e386 NH	221	struct dm_hw_stat_delta *new_stat = NULL;
	222	struct dm_hw_stat_delta *temp;
	223
	224	spin_lock(&trace_state_lock);
9a8afc8d	225
4b706372 NH	226	if (state == trace_state) {
	227	rc = -EAGAIN;
	228	goto out_unlock;
	229	}
	230
9a8afc8d NH	231	switch (state) {
9a8afc8d NH	232	case TRACE_ON:
38516ab5 SR	233	rc \|= register_trace_kfree_skb(trace_kfree_skb_hit, NULL);
38516ab5 SR	234	rc \|= register_trace_napi_poll(trace_napi_poll_hit, NULL);
9a8afc8d NH	235	break;
9a8afc8d NH	236	case TRACE_OFF:
38516ab5 SR	237	rc \|= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL);
38516ab5 SR	238	rc \|= unregister_trace_napi_poll(trace_napi_poll_hit, NULL);
9a8afc8d NH	239
9a8afc8d NH	240	tracepoint_synchronize_unregister();
4ea7e386 NH	241
	242	/*
	243	* Clean the device list
	244	*/
	245	list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
	246	if (new_stat->dev == NULL) {
	247	list_del_rcu(&new_stat->list);
	248	call_rcu(&new_stat->rcu, free_dm_hw_stat);
	249	}
	250	}
9a8afc8d NH	251	break;
	252	default:
	253	rc = 1;
	254	break;
	255	}
	256
4ea7e386 NH	257	if (!rc)
4ea7e386 NH	258	trace_state = state;
4b706372 NH	259	else
4b706372 NH	260	rc = -EINPROGRESS;
4ea7e386	261
4b706372	262	out_unlock:
4ea7e386 NH	263	spin_unlock(&trace_state_lock);
4ea7e386 NH	264
9a8afc8d NH	265	return rc;
	266	}
	267
	268
	269	static int net_dm_cmd_config(struct sk_buff *skb,
	270	struct genl_info *info)
	271	{
	272	return -ENOTSUPP;
	273	}
	274
	275	static int net_dm_cmd_trace(struct sk_buff *skb,
	276	struct genl_info *info)
	277	{
	278	switch (info->genlhdr->cmd) {
	279	case NET_DM_CMD_START:
	280	return set_all_monitor_traces(TRACE_ON);
	281	break;
	282	case NET_DM_CMD_STOP:
	283	return set_all_monitor_traces(TRACE_OFF);
	284	break;
	285	}
	286
	287	return -ENOTSUPP;
	288	}
	289
4ea7e386 NH	290	static int dropmon_net_event(struct notifier_block *ev_block,
	291	unsigned long event, void *ptr)
	292	{
	293	struct net_device *dev = ptr;
	294	struct dm_hw_stat_delta *new_stat = NULL;
	295	struct dm_hw_stat_delta *tmp;
	296
	297	switch (event) {
	298	case NETDEV_REGISTER:
	299	new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);
	300
	301	if (!new_stat)
	302	goto out;
	303
	304	new_stat->dev = dev;
5848cc09	305	new_stat->last_rx = jiffies;
4ea7e386 NH	306	spin_lock(&trace_state_lock);
	307	list_add_rcu(&new_stat->list, &hw_stats_list);
	308	spin_unlock(&trace_state_lock);
	309	break;
	310	case NETDEV_UNREGISTER:
	311	spin_lock(&trace_state_lock);
	312	list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
	313	if (new_stat->dev == dev) {
	314	new_stat->dev = NULL;
	315	if (trace_state == TRACE_OFF) {
	316	list_del_rcu(&new_stat->list);
	317	call_rcu(&new_stat->rcu, free_dm_hw_stat);
	318	break;
	319	}
	320	}
	321	}
	322	spin_unlock(&trace_state_lock);
	323	break;
	324	}
	325	out:
	326	return NOTIFY_DONE;
	327	}
9a8afc8d NH	328
	329	static struct genl_ops dropmon_ops[] = {
	330	{
	331	.cmd = NET_DM_CMD_CONFIG,
	332	.doit = net_dm_cmd_config,
	333	},
	334	{
	335	.cmd = NET_DM_CMD_START,
	336	.doit = net_dm_cmd_trace,
	337	},
	338	{
	339	.cmd = NET_DM_CMD_STOP,
	340	.doit = net_dm_cmd_trace,
	341	},
	342	};
	343
4ea7e386 NH	344	static struct notifier_block dropmon_net_notifier = {
	345	.notifier_call = dropmon_net_event
	346	};
	347
9a8afc8d NH	348	static int __init init_net_drop_monitor(void)
9a8afc8d NH	349	{
9a8afc8d	350	struct per_cpu_dm_data *data;
a256be70 CG	351	int cpu, rc;
a256be70 CG	352
9a8afc8d NH	353	printk(KERN_INFO "Initalizing network drop monitor service\n");
	354
	355	if (sizeof(void *) > 8) {
	356	printk(KERN_ERR "Unable to store program counters on this arch, Drop monitor failed\n");
	357	return -ENOSPC;
	358	}
	359
a256be70 CG	360	rc = genl_register_family_with_ops(&net_drop_monitor_family,
	361	dropmon_ops,
	362	ARRAY_SIZE(dropmon_ops));
	363	if (rc) {
9a8afc8d	364	printk(KERN_ERR "Could not create drop monitor netlink family\n");
a256be70	365	return rc;
9a8afc8d NH	366	}
9a8afc8d NH	367
4ea7e386 NH	368	rc = register_netdevice_notifier(&dropmon_net_notifier);
	369	if (rc < 0) {
	370	printk(KERN_CRIT "Failed to register netdevice notifier\n");
	371	goto out_unreg;
	372	}
	373
9a8afc8d NH	374	rc = 0;
	375
	376	for_each_present_cpu(cpu) {
	377	data = &per_cpu(dm_cpu_data, cpu);
	378	reset_per_cpu_data(data);
	379	INIT_WORK(&data->dm_alert_work, send_dm_alert);
	380	init_timer(&data->send_timer);
	381	data->send_timer.data = cpu;
	382	data->send_timer.function = sched_send_work;
	383	}
4ea7e386	384
9a8afc8d NH	385	goto out;
	386
	387	out_unreg:
	388	genl_unregister_family(&net_drop_monitor_family);
	389	out:
	390	return rc;
	391	}
	392
	393	late_initcall(init_net_drop_monitor);