Release 4.14 net/core/drop_monitor.c
/*
* Monitoring code for network dropped packet alerts
*
* Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <linux/module.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
/*
* Globals, our netlink socket pointer
* and the work handle that will send up
* netlink alerts
*/
static int trace_state = TRACE_OFF;
static DEFINE_MUTEX(trace_state_mutex);
struct per_cpu_dm_data {
spinlock_t lock;
struct sk_buff *skb;
struct work_struct dm_alert_work;
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;
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 struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
{
size_t al;
struct net_dm_alert_msg *msg;
struct nlattr *nla;
struct sk_buff *skb;
unsigned long flags;
void *msg_header;
al = sizeof(struct net_dm_alert_msg);
al += dm_hit_limit * sizeof(struct net_dm_drop_point);
al += sizeof(struct nlattr);
skb = genlmsg_new(al, GFP_KERNEL);
if (!skb)
goto err;
msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
0, NET_DM_CMD_ALERT);
if (!msg_header) {
nlmsg_free(skb);
skb = NULL;
goto err;
}
nla = nla_reserve(skb, NLA_UNSPEC,
sizeof(struct net_dm_alert_msg));
if (!nla) {
nlmsg_free(skb);
skb = NULL;
goto err;
}
msg = nla_data(nla);
memset(msg, 0, al);
goto out;
err:
mod_timer(&data->send_timer, jiffies + HZ / 10);
out:
spin_lock_irqsave(&data->lock, flags);
swap(data->skb, skb);
spin_unlock_irqrestore(&data->lock, flags);
if (skb) {
struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
genlmsg_end(skb, genlmsg_data(gnlh));
}
return skb;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 139 | 52.06% | 4 | 57.14% |
| Reiter Wolfgang | 100 | 37.45% | 2 | 28.57% |
| Eric Dumazet | 28 | 10.49% | 1 | 14.29% |
| Total | 267 | 100.00% | 7 | 100.00% |
static const struct genl_multicast_group dropmon_mcgrps[] = {
{ .name = "events", },
};
static void send_dm_alert(struct work_struct *work)
{
struct sk_buff *skb;
struct per_cpu_dm_data *data;
data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
skb = reset_per_cpu_data(data);
if (skb)
genlmsg_multicast(&net_drop_monitor_family, skb, 0,
0, GFP_KERNEL);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 45 | 77.59% | 3 | 50.00% |
| Eric Dumazet | 9 | 15.52% | 1 | 16.67% |
| Johannes Berg | 4 | 6.90% | 2 | 33.33% |
| Total | 58 | 100.00% | 6 | 100.00% |
/*
* This is the timer function to delay the sending of an alert
* in the event that more drops will arrive during the
* hysteresis period.
*/
static void sched_send_work(unsigned long _data)
{
struct per_cpu_dm_data *data = (struct per_cpu_dm_data *)_data;
schedule_work(&data->dm_alert_work);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 22 | 73.33% | 1 | 50.00% |
| Eric Dumazet | 8 | 26.67% | 1 | 50.00% |
| Total | 30 | 100.00% | 2 | 100.00% |
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 sk_buff *dskb;
struct per_cpu_dm_data *data;
unsigned long flags;
local_irq_save(flags);
data = this_cpu_ptr(&dm_cpu_data);
spin_lock(&data->lock);
dskb = data->skb;
if (!dskb)
goto out;
nlh = (struct nlmsghdr *)dskb->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;
}
}
if (msg->entries == dm_hit_limit)
goto out;
/*
* We need to create a new entry
*/
__nla_reserve_nohdr(dskb, 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(&data->send_timer);
}
out:
spin_unlock_irqrestore(&data->lock, flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 247 | 85.76% | 4 | 66.67% |
| Eric Dumazet | 39 | 13.54% | 1 | 16.67% |
| Christoph Lameter | 2 | 0.69% | 1 | 16.67% |
| Total | 288 | 100.00% | 6 | 100.00% |
static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
{
trace_drop_common(skb, location);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 22 | 84.62% | 1 | 50.00% |
| Steven Rostedt | 4 | 15.38% | 1 | 50.00% |
| Total | 26 | 100.00% | 2 | 100.00% |
static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
int work, int budget)
{
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();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 106 | 89.08% | 2 | 40.00% |
| Jesper Dangaard Brouer | 6 | 5.04% | 1 | 20.00% |
| Steven Rostedt | 4 | 3.36% | 1 | 20.00% |
| Xiao Guangrong | 3 | 2.52% | 1 | 20.00% |
| Total | 119 | 100.00% | 5 | 100.00% |
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;
mutex_lock(&trace_state_mutex);
if (state == trace_state) {
rc = -EAGAIN;
goto out_unlock;
}
switch (state) {
case TRACE_ON:
if (!try_module_get(THIS_MODULE)) {
rc = -ENODEV;
break;
}
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);
kfree_rcu(new_stat, rcu);
}
}
module_put(THIS_MODULE);
break;
default:
rc = 1;
break;
}
if (!rc)
trace_state = state;
else
rc = -EINPROGRESS;
out_unlock:
mutex_unlock(&trace_state_mutex);
return rc;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 182 | 94.79% | 5 | 71.43% |
| Steven Rostedt | 8 | 4.17% | 1 | 14.29% |
| Lai Jiangshan | 2 | 1.04% | 1 | 14.29% |
| Total | 192 | 100.00% | 7 | 100.00% |
static int net_dm_cmd_config(struct sk_buff *skb,
struct genl_info *info)
{
return -ENOTSUPP;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 20 | 100.00% | 1 | 100.00% |
| Total | 20 | 100.00% | 1 | 100.00% |
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);
case NET_DM_CMD_STOP:
return set_all_monitor_traces(TRACE_OFF);
}
return -ENOTSUPP;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 48 | 100.00% | 1 | 100.00% |
| Total | 48 | 100.00% | 1 | 100.00% |
static int dropmon_net_event(struct notifier_block *ev_block,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_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;
mutex_lock(&trace_state_mutex);
list_add_rcu(&new_stat->list, &hw_stats_list);
mutex_unlock(&trace_state_mutex);
break;
case NETDEV_UNREGISTER:
mutex_lock(&trace_state_mutex);
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);
kfree_rcu(new_stat, rcu);
break;
}
}
}
mutex_unlock(&trace_state_mutex);
break;
}
out:
return NOTIFY_DONE;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 175 | 97.22% | 3 | 60.00% |
| Jiri Pirko | 3 | 1.67% | 1 | 20.00% |
| Lai Jiangshan | 2 | 1.11% | 1 | 20.00% |
| Total | 180 | 100.00% | 5 | 100.00% |
static const 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 genl_family net_drop_monitor_family __ro_after_init = {
.hdrsize = 0,
.name = "NET_DM",
.version = 2,
.module = THIS_MODULE,
.ops = dropmon_ops,
.n_ops = ARRAY_SIZE(dropmon_ops),
.mcgrps = dropmon_mcgrps,
.n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
};
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;
pr_info("Initializing network drop monitor service\n");
if (sizeof(void *) > 8) {
pr_err("Unable to store program counters on this arch, Drop monitor failed\n");
return -ENOSPC;
}
rc = genl_register_family(&net_drop_monitor_family);
if (rc) {
pr_err("Could not create drop monitor netlink family\n");
return rc;
}
WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
rc = register_netdevice_notifier(&dropmon_net_notifier);
if (rc < 0) {
pr_crit("Failed to register netdevice notifier\n");
goto out_unreg;
}
rc = 0;
for_each_possible_cpu(cpu) {
data = &per_cpu(dm_cpu_data, cpu);
INIT_WORK(&data->dm_alert_work, send_dm_alert);
setup_timer(&data->send_timer, sched_send_work,
(unsigned long)data);
spin_lock_init(&data->lock);
reset_per_cpu_data(data);
}
goto out;
out_unreg:
genl_unregister_family(&net_drop_monitor_family);
out:
return rc;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 131 | 74.86% | 6 | 46.15% |
| Eric Dumazet | 13 | 7.43% | 1 | 7.69% |
| Johannes Berg | 12 | 6.86% | 3 | 23.08% |
| Changli Gao | 10 | 5.71% | 1 | 7.69% |
| Geliang Tang | 5 | 2.86% | 1 | 7.69% |
| Joe Perches | 4 | 2.29% | 1 | 7.69% |
| Total | 175 | 100.00% | 13 | 100.00% |
static void exit_net_drop_monitor(void)
{
struct per_cpu_dm_data *data;
int cpu;
BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
/*
* Because of the module_get/put we do in the trace state change path
* we are guarnateed not to have any current users when we get here
* all we need to do is make sure that we don't have any running timers
* or pending schedule calls
*/
for_each_possible_cpu(cpu) {
data = &per_cpu(dm_cpu_data, cpu);
del_timer_sync(&data->send_timer);
cancel_work_sync(&data->dm_alert_work);
/*
* At this point, we should have exclusive access
* to this struct and can free the skb inside it
*/
kfree_skb(data->skb);
}
BUG_ON(genl_unregister_family(&net_drop_monitor_family));
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 75 | 100.00% | 1 | 100.00% |
| Total | 75 | 100.00% | 1 | 100.00% |
module_init(init_net_drop_monitor);
module_exit(exit_net_drop_monitor);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
MODULE_ALIAS_GENL_FAMILY("NET_DM");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Neil Horman | 1462 | 80.33% | 11 | 32.35% |
| Eric Dumazet | 103 | 5.66% | 1 | 2.94% |
| Reiter Wolfgang | 100 | 5.49% | 2 | 5.88% |
| Johannes Berg | 86 | 4.73% | 6 | 17.65% |
| Steven Rostedt | 17 | 0.93% | 2 | 5.88% |
| Joe Perches | 11 | 0.60% | 1 | 2.94% |
| Changli Gao | 10 | 0.55% | 1 | 2.94% |
| Jesper Dangaard Brouer | 6 | 0.33% | 1 | 2.94% |
| Geliang Tang | 5 | 0.27% | 1 | 2.94% |
| Lai Jiangshan | 4 | 0.22% | 1 | 2.94% |
| Jiri Pirko | 3 | 0.16% | 1 | 2.94% |
| Thomas Gleixner | 3 | 0.16% | 1 | 2.94% |
| Tejun Heo | 3 | 0.16% | 1 | 2.94% |
| Xiao Guangrong | 3 | 0.16% | 1 | 2.94% |
| Christoph Lameter | 2 | 0.11% | 1 | 2.94% |
| Stephen Hemminger | 1 | 0.05% | 1 | 2.94% |
| David S. Miller | 1 | 0.05% | 1 | 2.94% |
| Total | 1820 | 100.00% | 34 | 100.00% |
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