mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 18:41:23 +00:00
2230a7ef51
The error code 'ENOTSUPP' is reserved for use with NFS. Use 'EOPNOTSUPP' instead. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
467 lines
10 KiB
C
467 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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(struct timer_list *t)
|
|
{
|
|
struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
|
|
|
|
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 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);
|
|
}
|
|
|
|
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,
|
|
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();
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
static int net_dm_cmd_config(struct sk_buff *skb,
|
|
struct genl_info *info)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
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 -EOPNOTSUPP;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static const struct genl_ops dropmon_ops[] = {
|
|
{
|
|
.cmd = NET_DM_CMD_CONFIG,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = net_dm_cmd_config,
|
|
},
|
|
{
|
|
.cmd = NET_DM_CMD_START,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = net_dm_cmd_trace,
|
|
},
|
|
{
|
|
.cmd = NET_DM_CMD_STOP,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.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);
|
|
timer_setup(&data->send_timer, sched_send_work, 0);
|
|
spin_lock_init(&data->lock);
|
|
reset_per_cpu_data(data);
|
|
}
|
|
|
|
|
|
goto out;
|
|
|
|
out_unreg:
|
|
genl_unregister_family(&net_drop_monitor_family);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
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");
|