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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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/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
/* * Globals, our netlink socket pointer * and the work handle that will send up * netlink alerts */static int trace_state = TRACE_OFF;static bool monitor_hw;
/* net_dm_mutex * * An overall lock guarding every operation coming from userspace. */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; /* Protects 'skb', 'hw_entries' and * 'send_timer' */ 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, const 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);}
/* * 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 = 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; /* * 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(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, const 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; /* * Don't check napi structures with no associated device */ if (!dev) return;
rcu_read_lock(); stat = rcu_dereference(dev->dm_private); if (stat) { /* * only add a note to our monitor buffer if: * 1) its after the last_rx delta * 2) our rx_dropped count has gone up */ 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) { /* If the memory allocation failed, we try to perform another * allocation in 1/10 second. Otherwise, the probe function * will constantly bail out. */ 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 intnet_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;
/* We need to put the ancillary header in order not to break user * space. */ 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 voidnet_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, const 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; /* Override the timestamp because we care about the time when the * packet was dropped. */ 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: u64_stats_update_begin(&data->stats.syncp); u64_stats_inc(&data->stats.dropped); u64_stats_update_end(&data->stats.syncp); spin_unlock_irqrestore(&data->drop_queue.lock, flags); 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){ /* NET_DM_ATTR_IN_PORT nest */ return nla_total_size(0) + /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */ nla_total_size(sizeof(u32)) + /* NET_DM_ATTR_PORT_NETDEV_NAME */ 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) + /* NET_DM_ATTR_ORIGIN */ nla_total_size(sizeof(u16)) + /* NET_DM_ATTR_PC */ nla_total_size_64bit(sizeof(u64)) + /* NET_DM_ATTR_SYMBOL */ nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) + /* NET_DM_ATTR_IN_PORT */ net_dm_in_port_size() + /* NET_DM_ATTR_TIMESTAMP */ nla_total_size_64bit(sizeof(u64)) + /* NET_DM_ATTR_ORIG_LEN */ nla_total_size(sizeof(u32)) + /* NET_DM_ATTR_PROTO */ nla_total_size(sizeof(u16)) + /* NET_DM_ATTR_REASON */ nla_total_size(NET_DM_MAX_REASON_LEN + 1) + /* NET_DM_ATTR_PAYLOAD */ 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 = __nla_reserve(msg, NET_DM_ATTR_PAYLOAD, 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;
/* Make sure we start copying the packet from the MAC header */ 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);
/* Ensure packet fits inside a single netlink attribute */ 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_tnet_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_tnet_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) + /* NET_DM_ATTR_ORIGIN */ nla_total_size(sizeof(u16)) + /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */ nla_total_size(strlen(hw_metadata->trap_group_name) + 1) + /* NET_DM_ATTR_HW_TRAP_NAME */ nla_total_size(strlen(hw_metadata->trap_name) + 1) + /* NET_DM_ATTR_IN_PORT */ net_dm_in_port_size() + /* NET_DM_ATTR_FLOW_ACTION_COOKIE */ net_dm_flow_action_cookie_size(hw_metadata) + /* NET_DM_ATTR_TIMESTAMP */ nla_total_size_64bit(sizeof(u64)) + /* NET_DM_ATTR_ORIG_LEN */ nla_total_size(sizeof(u32)) + /* NET_DM_ATTR_PROTO */ nla_total_size(sizeof(u16)) + /* NET_DM_ATTR_PAYLOAD */ 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 = __nla_reserve(msg, NET_DM_ATTR_PAYLOAD, 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 voidnet_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 voidnet_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: u64_stats_update_begin(&hw_data->stats.syncp); u64_stats_inc(&hw_data->stats.dropped); u64_stats_update_end(&hw_data->stats.syncp); spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); 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();}#elsestatic 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); /* Allocate a new per-CPU skb for the summary alert message and * free the old one which might contain stale data from * previous tracing. */ 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();
/* Make sure we do not send notifications to user space after request * to stop tracing returns. */ 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;
/* To maintain backward compatibility, we start / stop monitoring of * software drops if no flag is specified. */ 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); /* At this point, we should have exclusive access * to this struct and can free the skb inside it. */ 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;
/* * Because of the module_get/put we do in the trace state change path * we are guaranteed not to have any current users when we get here */ 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");