#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/bitfield.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 <net/flow_offload.h>
#include <net/dropreason.h>
#include <net/devlink.h>
#include <trace/events/skb.h>
#include <trace/events/napi.h>
#include <trace/events/devlink.h>
#include <linux/unaligned.h>
#define TRACE_ON 1
#define TRACE_OFF 0
static int trace_state = TRACE_OFF;
static bool monitor_hw;
static DEFINE_MUTEX(net_dm_mutex);
struct net_dm_stats {
u64_stats_t dropped;
struct u64_stats_sync syncp;
};
#define NET_DM_MAX_HW_TRAP_NAME_LEN 40
struct net_dm_hw_entry {
char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
u32 count;
};
struct net_dm_hw_entries {
u32 num_entries;
struct net_dm_hw_entry entries[];
};
struct per_cpu_dm_data {
raw_spinlock_t lock;
union {
struct sk_buff *skb;
struct net_dm_hw_entries *hw_entries;
};
struct sk_buff_head drop_queue;
struct work_struct dm_alert_work;
struct timer_list send_timer;
struct net_dm_stats stats;
};
struct dm_hw_stat_delta {
unsigned long last_rx;
unsigned long last_drop_val;
struct rcu_head rcu;
};
static struct genl_family net_drop_monitor_family;
static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
static int dm_hit_limit = 64;
static int dm_delay = 1;
static unsigned long dm_hw_check_delta = 2*HZ;
static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
static u32 net_dm_trunc_len;
static u32 net_dm_queue_len = 1000;
struct net_dm_alert_ops {
void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
void *location,
enum skb_drop_reason reason,
struct sock *rx_sk);
void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
int work, int budget);
void (*work_item_func)(struct work_struct *work);
void (*hw_work_item_func)(struct work_struct *work);
void (*hw_trap_probe)(void *ignore, const struct devlink *devlink,
struct sk_buff *skb,
const struct devlink_trap_metadata *metadata);
};
struct net_dm_skb_cb {
union {
struct devlink_trap_metadata *hw_metadata;
void *pc;
};
enum skb_drop_reason reason;
};
#define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
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:
raw_spin_lock_irqsave(&data->lock, flags);
swap(data->skb, skb);
raw_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", .flags = GENL_MCAST_CAP_SYS_ADMIN, },
};
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);
}
static void sched_send_work(struct timer_list *t)
{
struct per_cpu_dm_data *data = timer_container_of(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 net_dm_drop_point *point;
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);
raw_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);
point = msg->points;
for (i = 0; i < msg->entries; i++) {
if (!memcmp(&location, &point->pc, sizeof(void *))) {
point->count++;
goto out;
}
point++;
}
if (msg->entries == dm_hit_limit)
goto out;
__nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
memcpy(point->pc, &location, sizeof(void *));
point->count = 1;
msg->entries++;
if (!timer_pending(&data->send_timer)) {
data->send_timer.expires = jiffies + dm_delay * HZ;
add_timer(&data->send_timer);
}
out:
raw_spin_unlock_irqrestore(&data->lock, flags);
}
static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb,
void *location,
enum skb_drop_reason reason,
struct sock *rx_sk)
{
trace_drop_common(skb, location);
}
static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
int work, int budget)
{
struct net_device *dev = napi->dev;
struct dm_hw_stat_delta *stat;
if (!dev)
return;
rcu_read_lock();
stat = rcu_dereference(dev->dm_private);
if (stat) {
if (time_after(jiffies, stat->last_rx + dm_hw_check_delta) &&
(dev->stats.rx_dropped != stat->last_drop_val)) {
trace_drop_common(NULL, NULL);
stat->last_drop_val = dev->stats.rx_dropped;
stat->last_rx = jiffies;
}
}
rcu_read_unlock();
}
static struct net_dm_hw_entries *
net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
{
struct net_dm_hw_entries *hw_entries;
unsigned long flags;
hw_entries = kzalloc_flex(*hw_entries, entries, dm_hit_limit);
if (!hw_entries) {
mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
}
raw_spin_lock_irqsave(&hw_data->lock, flags);
swap(hw_data->hw_entries, hw_entries);
raw_spin_unlock_irqrestore(&hw_data->lock, flags);
return hw_entries;
}
static int net_dm_hw_entry_put(struct sk_buff *msg,
const struct net_dm_hw_entry *hw_entry)
{
struct nlattr *attr;
attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
if (!attr)
return -EMSGSIZE;
if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
goto nla_put_failure;
if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
goto nla_put_failure;
nla_nest_end(msg, attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, attr);
return -EMSGSIZE;
}
static int net_dm_hw_entries_put(struct sk_buff *msg,
const struct net_dm_hw_entries *hw_entries)
{
struct nlattr *attr;
int i;
attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
if (!attr)
return -EMSGSIZE;
for (i = 0; i < hw_entries->num_entries; i++) {
int rc;
rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
if (rc)
goto nla_put_failure;
}
nla_nest_end(msg, attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, attr);
return -EMSGSIZE;
}
static int
net_dm_hw_summary_report_fill(struct sk_buff *msg,
const struct net_dm_hw_entries *hw_entries)
{
struct net_dm_alert_msg anc_hdr = { 0 };
void *hdr;
int rc;
hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
NET_DM_CMD_ALERT);
if (!hdr)
return -EMSGSIZE;
if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
goto nla_put_failure;
rc = net_dm_hw_entries_put(msg, hw_entries);
if (rc)
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static void net_dm_hw_summary_work(struct work_struct *work)
{
struct net_dm_hw_entries *hw_entries;
struct per_cpu_dm_data *hw_data;
struct sk_buff *msg;
int rc;
hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
if (!hw_entries)
return;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
goto out;
rc = net_dm_hw_summary_report_fill(msg, hw_entries);
if (rc) {
nlmsg_free(msg);
goto out;
}
genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
out:
kfree(hw_entries);
}
static void
net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink,
struct sk_buff *skb,
const struct devlink_trap_metadata *metadata)
{
struct net_dm_hw_entries *hw_entries;
struct net_dm_hw_entry *hw_entry;
struct per_cpu_dm_data *hw_data;
unsigned long flags;
int i;
if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
return;
hw_data = this_cpu_ptr(&dm_hw_cpu_data);
raw_spin_lock_irqsave(&hw_data->lock, flags);
hw_entries = hw_data->hw_entries;
if (!hw_entries)
goto out;
for (i = 0; i < hw_entries->num_entries; i++) {
hw_entry = &hw_entries->entries[i];
if (!strncmp(hw_entry->trap_name, metadata->trap_name,
NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
hw_entry->count++;
goto out;
}
}
if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit))
goto out;
hw_entry = &hw_entries->entries[hw_entries->num_entries];
strscpy(hw_entry->trap_name, metadata->trap_name,
NET_DM_MAX_HW_TRAP_NAME_LEN - 1);
hw_entry->count = 1;
hw_entries->num_entries++;
if (!timer_pending(&hw_data->send_timer)) {
hw_data->send_timer.expires = jiffies + dm_delay * HZ;
add_timer(&hw_data->send_timer);
}
out:
raw_spin_unlock_irqrestore(&hw_data->lock, flags);
}
static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
.kfree_skb_probe = trace_kfree_skb_hit,
.napi_poll_probe = trace_napi_poll_hit,
.work_item_func = send_dm_alert,
.hw_work_item_func = net_dm_hw_summary_work,
.hw_trap_probe = net_dm_hw_trap_summary_probe,
};
static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
struct sk_buff *skb,
void *location,
enum skb_drop_reason reason,
struct sock *rx_sk)
{
ktime_t tstamp = ktime_get_real();
struct per_cpu_dm_data *data;
struct net_dm_skb_cb *cb;
struct sk_buff *nskb;
unsigned long flags;
if (!skb_mac_header_was_set(skb))
return;
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb)
return;
cb = NET_DM_SKB_CB(nskb);
cb->reason = reason;
cb->pc = location;
nskb->tstamp = tstamp;
data = this_cpu_ptr(&dm_cpu_data);
spin_lock_irqsave(&data->drop_queue.lock, flags);
if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
__skb_queue_tail(&data->drop_queue, nskb);
else
goto unlock_free;
spin_unlock_irqrestore(&data->drop_queue.lock, flags);
schedule_work(&data->dm_alert_work);
return;
unlock_free:
spin_unlock_irqrestore(&data->drop_queue.lock, flags);
u64_stats_update_begin(&data->stats.syncp);
u64_stats_inc(&data->stats.dropped);
u64_stats_update_end(&data->stats.syncp);
consume_skb(nskb);
}
static void net_dm_packet_trace_napi_poll_hit(void *ignore,
struct napi_struct *napi,
int work, int budget)
{
}
static size_t net_dm_in_port_size(void)
{
return nla_total_size(0) +
nla_total_size(sizeof(u32)) +
nla_total_size(IFNAMSIZ + 1);
}
#define NET_DM_MAX_SYMBOL_LEN 40
#define NET_DM_MAX_REASON_LEN 50
static size_t net_dm_packet_report_size(size_t payload_len)
{
size_t size;
size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
return NLMSG_ALIGN(size) +
nla_total_size(sizeof(u16)) +
nla_total_size(sizeof(u64)) +
nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
net_dm_in_port_size() +
nla_total_size(sizeof(u64)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u16)) +
nla_total_size(NET_DM_MAX_REASON_LEN + 1) +
nla_total_size(payload_len);
}
static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
const char *name)
{
struct nlattr *attr;
attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
if (!attr)
return -EMSGSIZE;
if (ifindex &&
nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
goto nla_put_failure;
if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name))
goto nla_put_failure;
nla_nest_end(msg, attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, attr);
return -EMSGSIZE;
}
static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
size_t payload_len)
{
struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb);
const struct drop_reason_list *list = NULL;
unsigned int subsys, subsys_reason;
char buf[NET_DM_MAX_SYMBOL_LEN];
struct nlattr *attr;
void *hdr;
int rc;
hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
NET_DM_CMD_PACKET_ALERT);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
goto nla_put_failure;
if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, (u64)(uintptr_t)cb->pc,
NET_DM_ATTR_PAD))
goto nla_put_failure;
rcu_read_lock();
subsys = u32_get_bits(cb->reason, SKB_DROP_REASON_SUBSYS_MASK);
if (subsys < SKB_DROP_REASON_SUBSYS_NUM)
list = rcu_dereference(drop_reasons_by_subsys[subsys]);
subsys_reason = cb->reason & ~SKB_DROP_REASON_SUBSYS_MASK;
if (!list ||
subsys_reason >= list->n_reasons ||
!list->reasons[subsys_reason] ||
strlen(list->reasons[subsys_reason]) > NET_DM_MAX_REASON_LEN) {
list = rcu_dereference(drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_CORE]);
subsys_reason = SKB_DROP_REASON_NOT_SPECIFIED;
}
if (nla_put_string(msg, NET_DM_ATTR_REASON,
list->reasons[subsys_reason])) {
rcu_read_unlock();
goto nla_put_failure;
}
rcu_read_unlock();
snprintf(buf, sizeof(buf), "%pS", cb->pc);
if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
goto nla_put_failure;
rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL);
if (rc)
goto nla_put_failure;
if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
goto nla_put_failure;
if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
goto nla_put_failure;
if (!payload_len)
goto out;
if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
goto nla_put_failure;
attr = skb_put(msg, nla_total_size(payload_len));
attr->nla_type = NET_DM_ATTR_PAYLOAD;
attr->nla_len = nla_attr_size(payload_len);
if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
goto nla_put_failure;
out:
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
#define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
static void net_dm_packet_report(struct sk_buff *skb)
{
struct sk_buff *msg;
size_t payload_len;
int rc;
if (skb->data > skb_mac_header(skb))
skb_push(skb, skb->data - skb_mac_header(skb));
else
skb_pull(skb, skb_mac_header(skb) - skb->data);
payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
if (net_dm_trunc_len)
payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
if (!msg)
goto out;
rc = net_dm_packet_report_fill(msg, skb, payload_len);
if (rc) {
nlmsg_free(msg);
goto out;
}
genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
out:
consume_skb(skb);
}
static void net_dm_packet_work(struct work_struct *work)
{
struct per_cpu_dm_data *data;
struct sk_buff_head list;
struct sk_buff *skb;
unsigned long flags;
data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
__skb_queue_head_init(&list);
spin_lock_irqsave(&data->drop_queue.lock, flags);
skb_queue_splice_tail_init(&data->drop_queue, &list);
spin_unlock_irqrestore(&data->drop_queue.lock, flags);
while ((skb = __skb_dequeue(&list)))
net_dm_packet_report(skb);
}
static size_t
net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata)
{
return hw_metadata->fa_cookie ?
nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0;
}
static size_t
net_dm_hw_packet_report_size(size_t payload_len,
const struct devlink_trap_metadata *hw_metadata)
{
size_t size;
size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
return NLMSG_ALIGN(size) +
nla_total_size(sizeof(u16)) +
nla_total_size(strlen(hw_metadata->trap_group_name) + 1) +
nla_total_size(strlen(hw_metadata->trap_name) + 1) +
net_dm_in_port_size() +
net_dm_flow_action_cookie_size(hw_metadata) +
nla_total_size(sizeof(u64)) +
nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(u16)) +
nla_total_size(payload_len);
}
static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
struct sk_buff *skb, size_t payload_len)
{
struct devlink_trap_metadata *hw_metadata;
struct nlattr *attr;
void *hdr;
hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
NET_DM_CMD_PACKET_ALERT);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW))
goto nla_put_failure;
if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME,
hw_metadata->trap_group_name))
goto nla_put_failure;
if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME,
hw_metadata->trap_name))
goto nla_put_failure;
if (hw_metadata->input_dev) {
struct net_device *dev = hw_metadata->input_dev;
int rc;
rc = net_dm_packet_report_in_port_put(msg, dev->ifindex,
dev->name);
if (rc)
goto nla_put_failure;
}
if (hw_metadata->fa_cookie &&
nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE,
hw_metadata->fa_cookie->cookie_len,
hw_metadata->fa_cookie->cookie))
goto nla_put_failure;
if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP,
ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD))
goto nla_put_failure;
if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
goto nla_put_failure;
if (!payload_len)
goto out;
if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
goto nla_put_failure;
attr = skb_put(msg, nla_total_size(payload_len));
attr->nla_type = NET_DM_ATTR_PAYLOAD;
attr->nla_len = nla_attr_size(payload_len);
if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
goto nla_put_failure;
out:
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static struct devlink_trap_metadata *
net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata)
{
const struct flow_action_cookie *fa_cookie;
struct devlink_trap_metadata *hw_metadata;
const char *trap_group_name;
const char *trap_name;
hw_metadata = kzalloc_obj(*hw_metadata, GFP_ATOMIC);
if (!hw_metadata)
return NULL;
trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC);
if (!trap_group_name)
goto free_hw_metadata;
hw_metadata->trap_group_name = trap_group_name;
trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC);
if (!trap_name)
goto free_trap_group;
hw_metadata->trap_name = trap_name;
if (metadata->fa_cookie) {
size_t cookie_size = sizeof(*fa_cookie) +
metadata->fa_cookie->cookie_len;
fa_cookie = kmemdup(metadata->fa_cookie, cookie_size,
GFP_ATOMIC);
if (!fa_cookie)
goto free_trap_name;
hw_metadata->fa_cookie = fa_cookie;
}
hw_metadata->input_dev = metadata->input_dev;
netdev_hold(hw_metadata->input_dev, &hw_metadata->dev_tracker,
GFP_ATOMIC);
return hw_metadata;
free_trap_name:
kfree(trap_name);
free_trap_group:
kfree(trap_group_name);
free_hw_metadata:
kfree(hw_metadata);
return NULL;
}
static void
net_dm_hw_metadata_free(struct devlink_trap_metadata *hw_metadata)
{
netdev_put(hw_metadata->input_dev, &hw_metadata->dev_tracker);
kfree(hw_metadata->fa_cookie);
kfree(hw_metadata->trap_name);
kfree(hw_metadata->trap_group_name);
kfree(hw_metadata);
}
static void net_dm_hw_packet_report(struct sk_buff *skb)
{
struct devlink_trap_metadata *hw_metadata;
struct sk_buff *msg;
size_t payload_len;
int rc;
if (skb->data > skb_mac_header(skb))
skb_push(skb, skb->data - skb_mac_header(skb));
else
skb_pull(skb, skb_mac_header(skb) - skb->data);
payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
if (net_dm_trunc_len)
payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata),
GFP_KERNEL);
if (!msg)
goto out;
rc = net_dm_hw_packet_report_fill(msg, skb, payload_len);
if (rc) {
nlmsg_free(msg);
goto out;
}
genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
out:
net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata);
consume_skb(skb);
}
static void net_dm_hw_packet_work(struct work_struct *work)
{
struct per_cpu_dm_data *hw_data;
struct sk_buff_head list;
struct sk_buff *skb;
unsigned long flags;
hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
__skb_queue_head_init(&list);
spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
skb_queue_splice_tail_init(&hw_data->drop_queue, &list);
spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
while ((skb = __skb_dequeue(&list)))
net_dm_hw_packet_report(skb);
}
static void
net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink,
struct sk_buff *skb,
const struct devlink_trap_metadata *metadata)
{
struct devlink_trap_metadata *n_hw_metadata;
ktime_t tstamp = ktime_get_real();
struct per_cpu_dm_data *hw_data;
struct sk_buff *nskb;
unsigned long flags;
if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
return;
if (!skb_mac_header_was_set(skb))
return;
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb)
return;
n_hw_metadata = net_dm_hw_metadata_copy(metadata);
if (!n_hw_metadata)
goto free;
NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata;
nskb->tstamp = tstamp;
hw_data = this_cpu_ptr(&dm_hw_cpu_data);
spin_lock_irqsave(&hw_data->drop_queue.lock, flags);
if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len)
__skb_queue_tail(&hw_data->drop_queue, nskb);
else
goto unlock_free;
spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
schedule_work(&hw_data->dm_alert_work);
return;
unlock_free:
spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags);
u64_stats_update_begin(&hw_data->stats.syncp);
u64_stats_inc(&hw_data->stats.dropped);
u64_stats_update_end(&hw_data->stats.syncp);
net_dm_hw_metadata_free(n_hw_metadata);
free:
consume_skb(nskb);
}
static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
.kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit,
.napi_poll_probe = net_dm_packet_trace_napi_poll_hit,
.work_item_func = net_dm_packet_work,
.hw_work_item_func = net_dm_hw_packet_work,
.hw_trap_probe = net_dm_hw_trap_packet_probe,
};
static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
[NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops,
[NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops,
};
#if IS_ENABLED(CONFIG_NET_DEVLINK)
static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
{
return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
}
static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
{
unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL);
tracepoint_synchronize_unregister();
}
#else
static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops)
{
return -EOPNOTSUPP;
}
static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops)
{
}
#endif
static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack)
{
const struct net_dm_alert_ops *ops;
int cpu, rc;
if (monitor_hw) {
NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled");
return -EAGAIN;
}
ops = net_dm_alert_ops_arr[net_dm_alert_mode];
if (!try_module_get(THIS_MODULE)) {
NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
return -ENODEV;
}
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
struct net_dm_hw_entries *hw_entries;
INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func);
timer_setup(&hw_data->send_timer, sched_send_work, 0);
hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
kfree(hw_entries);
}
rc = net_dm_hw_probe_register(ops);
if (rc) {
NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint");
goto err_module_put;
}
monitor_hw = true;
return 0;
err_module_put:
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
struct sk_buff *skb;
timer_delete_sync(&hw_data->send_timer);
cancel_work_sync(&hw_data->dm_alert_work);
while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
struct devlink_trap_metadata *hw_metadata;
hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
net_dm_hw_metadata_free(hw_metadata);
consume_skb(skb);
}
}
module_put(THIS_MODULE);
return rc;
}
static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack)
{
const struct net_dm_alert_ops *ops;
int cpu;
if (!monitor_hw) {
NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled");
return;
}
ops = net_dm_alert_ops_arr[net_dm_alert_mode];
monitor_hw = false;
net_dm_hw_probe_unregister(ops);
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
struct sk_buff *skb;
timer_delete_sync(&hw_data->send_timer);
cancel_work_sync(&hw_data->dm_alert_work);
while ((skb = __skb_dequeue(&hw_data->drop_queue))) {
struct devlink_trap_metadata *hw_metadata;
hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata;
net_dm_hw_metadata_free(hw_metadata);
consume_skb(skb);
}
}
module_put(THIS_MODULE);
}
static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
{
const struct net_dm_alert_ops *ops;
int cpu, rc;
ops = net_dm_alert_ops_arr[net_dm_alert_mode];
if (!try_module_get(THIS_MODULE)) {
NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
return -ENODEV;
}
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
struct sk_buff *skb;
INIT_WORK(&data->dm_alert_work, ops->work_item_func);
timer_setup(&data->send_timer, sched_send_work, 0);
skb = reset_per_cpu_data(data);
consume_skb(skb);
}
rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
if (rc) {
NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
goto err_module_put;
}
rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
if (rc) {
NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
goto err_unregister_trace;
}
return 0;
err_unregister_trace:
unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
err_module_put:
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
struct sk_buff *skb;
timer_delete_sync(&data->send_timer);
cancel_work_sync(&data->dm_alert_work);
while ((skb = __skb_dequeue(&data->drop_queue)))
consume_skb(skb);
}
module_put(THIS_MODULE);
return rc;
}
static void net_dm_trace_off_set(void)
{
const struct net_dm_alert_ops *ops;
int cpu;
ops = net_dm_alert_ops_arr[net_dm_alert_mode];
unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
tracepoint_synchronize_unregister();
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
struct sk_buff *skb;
timer_delete_sync(&data->send_timer);
cancel_work_sync(&data->dm_alert_work);
while ((skb = __skb_dequeue(&data->drop_queue)))
consume_skb(skb);
}
module_put(THIS_MODULE);
}
static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
{
int rc = 0;
if (state == trace_state) {
NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
return -EAGAIN;
}
switch (state) {
case TRACE_ON:
rc = net_dm_trace_on_set(extack);
break;
case TRACE_OFF:
net_dm_trace_off_set();
break;
default:
rc = 1;
break;
}
if (!rc)
trace_state = state;
else
rc = -EINPROGRESS;
return rc;
}
static bool net_dm_is_monitoring(void)
{
return trace_state == TRACE_ON || monitor_hw;
}
static int net_dm_alert_mode_get_from_info(struct genl_info *info,
enum net_dm_alert_mode *p_alert_mode)
{
u8 val;
val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
switch (val) {
case NET_DM_ALERT_MODE_SUMMARY:
case NET_DM_ALERT_MODE_PACKET:
*p_alert_mode = val;
break;
default:
return -EINVAL;
}
return 0;
}
static int net_dm_alert_mode_set(struct genl_info *info)
{
struct netlink_ext_ack *extack = info->extack;
enum net_dm_alert_mode alert_mode;
int rc;
if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
return 0;
rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
if (rc) {
NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
return -EINVAL;
}
net_dm_alert_mode = alert_mode;
return 0;
}
static void net_dm_trunc_len_set(struct genl_info *info)
{
if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
return;
net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
}
static void net_dm_queue_len_set(struct genl_info *info)
{
if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
return;
net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
}
static int net_dm_cmd_config(struct sk_buff *skb,
struct genl_info *info)
{
struct netlink_ext_ack *extack = info->extack;
int rc;
if (net_dm_is_monitoring()) {
NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
return -EBUSY;
}
rc = net_dm_alert_mode_set(info);
if (rc)
return rc;
net_dm_trunc_len_set(info);
net_dm_queue_len_set(info);
return 0;
}
static int net_dm_monitor_start(bool set_sw, bool set_hw,
struct netlink_ext_ack *extack)
{
bool sw_set = false;
int rc;
if (set_sw) {
rc = set_all_monitor_traces(TRACE_ON, extack);
if (rc)
return rc;
sw_set = true;
}
if (set_hw) {
rc = net_dm_hw_monitor_start(extack);
if (rc)
goto err_monitor_hw;
}
return 0;
err_monitor_hw:
if (sw_set)
set_all_monitor_traces(TRACE_OFF, extack);
return rc;
}
static void net_dm_monitor_stop(bool set_sw, bool set_hw,
struct netlink_ext_ack *extack)
{
if (set_hw)
net_dm_hw_monitor_stop(extack);
if (set_sw)
set_all_monitor_traces(TRACE_OFF, extack);
}
static int net_dm_cmd_trace(struct sk_buff *skb,
struct genl_info *info)
{
bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS];
bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS];
struct netlink_ext_ack *extack = info->extack;
if (!set_sw && !set_hw)
set_sw = true;
switch (info->genlhdr->cmd) {
case NET_DM_CMD_START:
return net_dm_monitor_start(set_sw, set_hw, extack);
case NET_DM_CMD_STOP:
net_dm_monitor_stop(set_sw, set_hw, extack);
return 0;
}
return -EOPNOTSUPP;
}
static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
{
void *hdr;
hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
&net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
goto nla_put_failure;
if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
goto nla_put_failure;
if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
int rc;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
rc = net_dm_config_fill(msg, info);
if (rc)
goto free_msg;
return genlmsg_reply(msg, info);
free_msg:
nlmsg_free(msg);
return rc;
}
static void net_dm_stats_read(struct net_dm_stats *stats)
{
int cpu;
memset(stats, 0, sizeof(*stats));
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
struct net_dm_stats *cpu_stats = &data->stats;
unsigned int start;
u64 dropped;
do {
start = u64_stats_fetch_begin(&cpu_stats->syncp);
dropped = u64_stats_read(&cpu_stats->dropped);
} while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
u64_stats_add(&stats->dropped, dropped);
}
}
static int net_dm_stats_put(struct sk_buff *msg)
{
struct net_dm_stats stats;
struct nlattr *attr;
net_dm_stats_read(&stats);
attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
if (!attr)
return -EMSGSIZE;
if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
u64_stats_read(&stats.dropped), NET_DM_ATTR_PAD))
goto nla_put_failure;
nla_nest_end(msg, attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, attr);
return -EMSGSIZE;
}
static void net_dm_hw_stats_read(struct net_dm_stats *stats)
{
int cpu;
memset(stats, 0, sizeof(*stats));
for_each_possible_cpu(cpu) {
struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu);
struct net_dm_stats *cpu_stats = &hw_data->stats;
unsigned int start;
u64 dropped;
do {
start = u64_stats_fetch_begin(&cpu_stats->syncp);
dropped = u64_stats_read(&cpu_stats->dropped);
} while (u64_stats_fetch_retry(&cpu_stats->syncp, start));
u64_stats_add(&stats->dropped, dropped);
}
}
static int net_dm_hw_stats_put(struct sk_buff *msg)
{
struct net_dm_stats stats;
struct nlattr *attr;
net_dm_hw_stats_read(&stats);
attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS);
if (!attr)
return -EMSGSIZE;
if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
u64_stats_read(&stats.dropped), NET_DM_ATTR_PAD))
goto nla_put_failure;
nla_nest_end(msg, attr);
return 0;
nla_put_failure:
nla_nest_cancel(msg, attr);
return -EMSGSIZE;
}
static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
{
void *hdr;
int rc;
hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
&net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
if (!hdr)
return -EMSGSIZE;
rc = net_dm_stats_put(msg);
if (rc)
goto nla_put_failure;
rc = net_dm_hw_stats_put(msg);
if (rc)
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
int rc;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
rc = net_dm_stats_fill(msg, info);
if (rc)
goto free_msg;
return genlmsg_reply(msg, info);
free_msg:
nlmsg_free(msg);
return rc;
}
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 *stat;
switch (event) {
case NETDEV_REGISTER:
if (WARN_ON_ONCE(rtnl_dereference(dev->dm_private)))
break;
stat = kzalloc_obj(*stat);
if (!stat)
break;
stat->last_rx = jiffies;
rcu_assign_pointer(dev->dm_private, stat);
break;
case NETDEV_UNREGISTER:
stat = rtnl_dereference(dev->dm_private);
if (stat) {
rcu_assign_pointer(dev->dm_private, NULL);
kfree_rcu(stat, rcu);
}
break;
}
return NOTIFY_DONE;
}
static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
[NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
[NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
[NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
[NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
[NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG },
[NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG },
};
static const struct genl_small_ops dropmon_ops[] = {
{
.cmd = NET_DM_CMD_CONFIG,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = net_dm_cmd_config,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NET_DM_CMD_START,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = net_dm_cmd_trace,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NET_DM_CMD_STOP,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = net_dm_cmd_trace,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NET_DM_CMD_CONFIG_GET,
.doit = net_dm_cmd_config_get,
},
{
.cmd = NET_DM_CMD_STATS_GET,
.doit = net_dm_cmd_stats_get,
},
};
static int net_dm_nl_pre_doit(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
mutex_lock(&net_dm_mutex);
return 0;
}
static void net_dm_nl_post_doit(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info)
{
mutex_unlock(&net_dm_mutex);
}
static struct genl_family net_drop_monitor_family __ro_after_init = {
.hdrsize = 0,
.name = "NET_DM",
.version = 2,
.maxattr = NET_DM_ATTR_MAX,
.policy = net_dm_nl_policy,
.pre_doit = net_dm_nl_pre_doit,
.post_doit = net_dm_nl_post_doit,
.module = THIS_MODULE,
.small_ops = dropmon_ops,
.n_small_ops = ARRAY_SIZE(dropmon_ops),
.resv_start_op = NET_DM_CMD_STATS_GET + 1,
.mcgrps = dropmon_mcgrps,
.n_mcgrps = ARRAY_SIZE(dropmon_mcgrps),
};
static struct notifier_block dropmon_net_notifier = {
.notifier_call = dropmon_net_event
};
static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data)
{
raw_spin_lock_init(&data->lock);
skb_queue_head_init(&data->drop_queue);
u64_stats_init(&data->stats.syncp);
}
static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data)
{
WARN_ON(!skb_queue_empty(&data->drop_queue));
}
static void net_dm_cpu_data_init(int cpu)
{
struct per_cpu_dm_data *data;
data = &per_cpu(dm_cpu_data, cpu);
__net_dm_cpu_data_init(data);
}
static void net_dm_cpu_data_fini(int cpu)
{
struct per_cpu_dm_data *data;
data = &per_cpu(dm_cpu_data, cpu);
consume_skb(data->skb);
__net_dm_cpu_data_fini(data);
}
static void net_dm_hw_cpu_data_init(int cpu)
{
struct per_cpu_dm_data *hw_data;
hw_data = &per_cpu(dm_hw_cpu_data, cpu);
__net_dm_cpu_data_init(hw_data);
}
static void net_dm_hw_cpu_data_fini(int cpu)
{
struct per_cpu_dm_data *hw_data;
hw_data = &per_cpu(dm_hw_cpu_data, cpu);
kfree(hw_data->hw_entries);
__net_dm_cpu_data_fini(hw_data);
}
static int __init init_net_drop_monitor(void)
{
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;
}
for_each_possible_cpu(cpu) {
net_dm_cpu_data_init(cpu);
net_dm_hw_cpu_data_init(cpu);
}
rc = register_netdevice_notifier(&dropmon_net_notifier);
if (rc < 0) {
pr_crit("Failed to register netdevice notifier\n");
return rc;
}
rc = genl_register_family(&net_drop_monitor_family);
if (rc) {
pr_err("Could not create drop monitor netlink family\n");
goto out_unreg;
}
WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT);
rc = 0;
goto out;
out_unreg:
WARN_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
out:
return rc;
}
static void exit_net_drop_monitor(void)
{
int cpu;
BUG_ON(genl_unregister_family(&net_drop_monitor_family));
BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier));
for_each_possible_cpu(cpu) {
net_dm_hw_cpu_data_fini(cpu);
net_dm_cpu_data_fini(cpu);
}
}
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");
MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");
