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![Eric Dumazet](/assets/img/avatar_default.png)
drop_monitor is using an unique list on which all netdevices in the host have an element, regardless of their netns. This scales poorly, not only at device unregister time (what I caught during my netns dismantle stress tests), but also at packet processing time whenever trace_napi_poll_hit() is called. If the intent was to avoid adding one pointer in 'struct net_device' then surely we prefer O(1) behavior. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1781 lines
41 KiB
C
1781 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Monitoring code for network dropped packet alerts
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*
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* Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/string.h>
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#include <linux/if_arp.h>
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#include <linux/inetdevice.h>
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#include <linux/inet.h>
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#include <linux/interrupt.h>
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#include <linux/netpoll.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <linux/types.h>
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#include <linux/workqueue.h>
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#include <linux/netlink.h>
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#include <linux/net_dropmon.h>
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#include <linux/percpu.h>
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#include <linux/timer.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <net/genetlink.h>
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#include <net/netevent.h>
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#include <net/flow_offload.h>
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#include <net/devlink.h>
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#include <trace/events/skb.h>
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#include <trace/events/napi.h>
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#include <trace/events/devlink.h>
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#include <asm/unaligned.h>
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#define TRACE_ON 1
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#define TRACE_OFF 0
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/*
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* Globals, our netlink socket pointer
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* and the work handle that will send up
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* netlink alerts
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*/
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static int trace_state = TRACE_OFF;
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static bool monitor_hw;
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#undef EM
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#undef EMe
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#define EM(a, b) [a] = #b,
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#define EMe(a, b) [a] = #b
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/* drop_reasons is used to translate 'enum skb_drop_reason' to string,
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* which is reported to user space.
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*/
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static const char * const drop_reasons[] = {
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TRACE_SKB_DROP_REASON
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};
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/* net_dm_mutex
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*
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* An overall lock guarding every operation coming from userspace.
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*/
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static DEFINE_MUTEX(net_dm_mutex);
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struct net_dm_stats {
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u64 dropped;
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struct u64_stats_sync syncp;
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};
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#define NET_DM_MAX_HW_TRAP_NAME_LEN 40
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struct net_dm_hw_entry {
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char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN];
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u32 count;
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};
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struct net_dm_hw_entries {
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u32 num_entries;
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struct net_dm_hw_entry entries[];
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};
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struct per_cpu_dm_data {
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spinlock_t lock; /* Protects 'skb', 'hw_entries' and
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* 'send_timer'
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*/
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union {
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struct sk_buff *skb;
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struct net_dm_hw_entries *hw_entries;
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};
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struct sk_buff_head drop_queue;
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struct work_struct dm_alert_work;
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struct timer_list send_timer;
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struct net_dm_stats stats;
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};
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struct dm_hw_stat_delta {
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unsigned long last_rx;
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unsigned long last_drop_val;
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struct rcu_head rcu;
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};
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static struct genl_family net_drop_monitor_family;
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static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
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static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data);
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static int dm_hit_limit = 64;
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static int dm_delay = 1;
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static unsigned long dm_hw_check_delta = 2*HZ;
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static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
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static u32 net_dm_trunc_len;
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static u32 net_dm_queue_len = 1000;
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struct net_dm_alert_ops {
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void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
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void *location,
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enum skb_drop_reason reason);
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void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
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int work, int budget);
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void (*work_item_func)(struct work_struct *work);
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void (*hw_work_item_func)(struct work_struct *work);
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void (*hw_trap_probe)(void *ignore, const struct devlink *devlink,
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struct sk_buff *skb,
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const struct devlink_trap_metadata *metadata);
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};
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struct net_dm_skb_cb {
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union {
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struct devlink_trap_metadata *hw_metadata;
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void *pc;
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};
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enum skb_drop_reason reason;
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};
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#define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
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static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
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{
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size_t al;
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struct net_dm_alert_msg *msg;
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struct nlattr *nla;
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struct sk_buff *skb;
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unsigned long flags;
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void *msg_header;
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al = sizeof(struct net_dm_alert_msg);
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al += dm_hit_limit * sizeof(struct net_dm_drop_point);
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al += sizeof(struct nlattr);
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skb = genlmsg_new(al, GFP_KERNEL);
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if (!skb)
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goto err;
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msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
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0, NET_DM_CMD_ALERT);
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if (!msg_header) {
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nlmsg_free(skb);
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skb = NULL;
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goto err;
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}
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nla = nla_reserve(skb, NLA_UNSPEC,
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sizeof(struct net_dm_alert_msg));
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if (!nla) {
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nlmsg_free(skb);
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skb = NULL;
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goto err;
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}
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msg = nla_data(nla);
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memset(msg, 0, al);
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goto out;
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err:
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mod_timer(&data->send_timer, jiffies + HZ / 10);
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out:
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spin_lock_irqsave(&data->lock, flags);
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swap(data->skb, skb);
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spin_unlock_irqrestore(&data->lock, flags);
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if (skb) {
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struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data;
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struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh);
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genlmsg_end(skb, genlmsg_data(gnlh));
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}
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return skb;
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}
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static const struct genl_multicast_group dropmon_mcgrps[] = {
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{ .name = "events", },
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};
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static void send_dm_alert(struct work_struct *work)
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{
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struct sk_buff *skb;
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struct per_cpu_dm_data *data;
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data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
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skb = reset_per_cpu_data(data);
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if (skb)
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genlmsg_multicast(&net_drop_monitor_family, skb, 0,
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0, GFP_KERNEL);
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}
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/*
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* This is the timer function to delay the sending of an alert
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* in the event that more drops will arrive during the
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* hysteresis period.
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*/
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static void sched_send_work(struct timer_list *t)
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{
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struct per_cpu_dm_data *data = from_timer(data, t, send_timer);
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schedule_work(&data->dm_alert_work);
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}
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static void trace_drop_common(struct sk_buff *skb, void *location)
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{
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struct net_dm_alert_msg *msg;
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struct net_dm_drop_point *point;
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struct nlmsghdr *nlh;
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struct nlattr *nla;
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int i;
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struct sk_buff *dskb;
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struct per_cpu_dm_data *data;
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unsigned long flags;
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local_irq_save(flags);
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data = this_cpu_ptr(&dm_cpu_data);
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spin_lock(&data->lock);
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dskb = data->skb;
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if (!dskb)
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goto out;
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nlh = (struct nlmsghdr *)dskb->data;
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nla = genlmsg_data(nlmsg_data(nlh));
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msg = nla_data(nla);
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point = msg->points;
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for (i = 0; i < msg->entries; i++) {
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if (!memcmp(&location, &point->pc, sizeof(void *))) {
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point->count++;
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goto out;
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}
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point++;
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}
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if (msg->entries == dm_hit_limit)
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goto out;
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/*
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* We need to create a new entry
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*/
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__nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point));
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nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
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memcpy(point->pc, &location, sizeof(void *));
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point->count = 1;
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msg->entries++;
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if (!timer_pending(&data->send_timer)) {
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data->send_timer.expires = jiffies + dm_delay * HZ;
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add_timer(&data->send_timer);
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}
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out:
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spin_unlock_irqrestore(&data->lock, flags);
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}
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static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb,
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void *location,
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enum skb_drop_reason reason)
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{
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trace_drop_common(skb, location);
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}
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static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
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int work, int budget)
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{
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struct net_device *dev = napi->dev;
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struct dm_hw_stat_delta *stat;
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/*
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* Don't check napi structures with no associated device
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*/
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if (!dev)
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return;
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rcu_read_lock();
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stat = rcu_dereference(dev->dm_private);
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if (stat) {
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/*
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* only add a note to our monitor buffer if:
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* 1) its after the last_rx delta
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* 2) our rx_dropped count has gone up
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*/
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if (time_after(jiffies, stat->last_rx + dm_hw_check_delta) &&
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(dev->stats.rx_dropped != stat->last_drop_val)) {
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trace_drop_common(NULL, NULL);
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stat->last_drop_val = dev->stats.rx_dropped;
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stat->last_rx = jiffies;
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}
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}
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rcu_read_unlock();
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}
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static struct net_dm_hw_entries *
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net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data)
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{
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struct net_dm_hw_entries *hw_entries;
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unsigned long flags;
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hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit),
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GFP_KERNEL);
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if (!hw_entries) {
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/* If the memory allocation failed, we try to perform another
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* allocation in 1/10 second. Otherwise, the probe function
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* will constantly bail out.
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*/
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mod_timer(&hw_data->send_timer, jiffies + HZ / 10);
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}
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spin_lock_irqsave(&hw_data->lock, flags);
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swap(hw_data->hw_entries, hw_entries);
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spin_unlock_irqrestore(&hw_data->lock, flags);
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return hw_entries;
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}
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static int net_dm_hw_entry_put(struct sk_buff *msg,
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const struct net_dm_hw_entry *hw_entry)
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{
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struct nlattr *attr;
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attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY);
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if (!attr)
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return -EMSGSIZE;
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if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name))
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goto nla_put_failure;
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if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count))
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goto nla_put_failure;
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nla_nest_end(msg, attr);
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return 0;
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nla_put_failure:
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nla_nest_cancel(msg, attr);
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return -EMSGSIZE;
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}
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static int net_dm_hw_entries_put(struct sk_buff *msg,
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const struct net_dm_hw_entries *hw_entries)
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{
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struct nlattr *attr;
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int i;
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attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES);
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if (!attr)
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return -EMSGSIZE;
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for (i = 0; i < hw_entries->num_entries; i++) {
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int rc;
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rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]);
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if (rc)
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goto nla_put_failure;
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}
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nla_nest_end(msg, attr);
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return 0;
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nla_put_failure:
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nla_nest_cancel(msg, attr);
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return -EMSGSIZE;
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}
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static int
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net_dm_hw_summary_report_fill(struct sk_buff *msg,
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const struct net_dm_hw_entries *hw_entries)
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{
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struct net_dm_alert_msg anc_hdr = { 0 };
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void *hdr;
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int rc;
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hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
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NET_DM_CMD_ALERT);
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if (!hdr)
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return -EMSGSIZE;
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/* We need to put the ancillary header in order not to break user
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* space.
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*/
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if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr))
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goto nla_put_failure;
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rc = net_dm_hw_entries_put(msg, hw_entries);
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if (rc)
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goto nla_put_failure;
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genlmsg_end(msg, hdr);
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return 0;
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nla_put_failure:
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genlmsg_cancel(msg, hdr);
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return -EMSGSIZE;
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}
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static void net_dm_hw_summary_work(struct work_struct *work)
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{
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struct net_dm_hw_entries *hw_entries;
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struct per_cpu_dm_data *hw_data;
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struct sk_buff *msg;
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int rc;
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hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
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hw_entries = net_dm_hw_reset_per_cpu_data(hw_data);
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if (!hw_entries)
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return;
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msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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if (!msg)
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goto out;
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rc = net_dm_hw_summary_report_fill(msg, hw_entries);
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if (rc) {
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nlmsg_free(msg);
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goto out;
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}
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genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
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|
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out:
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kfree(hw_entries);
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}
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|
|
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static void
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net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink,
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struct sk_buff *skb,
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const struct devlink_trap_metadata *metadata)
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|
{
|
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struct net_dm_hw_entries *hw_entries;
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struct net_dm_hw_entry *hw_entry;
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struct per_cpu_dm_data *hw_data;
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unsigned long flags;
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int i;
|
|
|
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if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL)
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|
return;
|
|
|
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hw_data = this_cpu_ptr(&dm_hw_cpu_data);
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|
spin_lock_irqsave(&hw_data->lock, flags);
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|
hw_entries = hw_data->hw_entries;
|
|
|
|
if (!hw_entries)
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|
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,
|
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NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) {
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|
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];
|
|
strlcpy(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:
|
|
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,
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|
.work_item_func = send_dm_alert,
|
|
.hw_work_item_func = net_dm_hw_summary_work,
|
|
.hw_trap_probe = net_dm_hw_trap_summary_probe,
|
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};
|
|
|
|
static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
|
|
struct sk_buff *skb,
|
|
void *location,
|
|
enum skb_drop_reason reason)
|
|
{
|
|
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;
|
|
|
|
if ((unsigned int)reason >= SKB_DROP_REASON_MAX)
|
|
reason = SKB_DROP_REASON_NOT_SPECIFIED;
|
|
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:
|
|
spin_unlock_irqrestore(&data->drop_queue.lock, flags);
|
|
u64_stats_update_begin(&data->stats.syncp);
|
|
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)
|
|
{
|
|
/* 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
|
|
|
|
static size_t net_dm_packet_report_size(size_t payload_len,
|
|
enum skb_drop_reason reason)
|
|
{
|
|
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(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(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(strlen(drop_reasons[reason]) + 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);
|
|
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;
|
|
|
|
if (nla_put_string(msg, NET_DM_ATTR_REASON,
|
|
drop_reasons[cb->reason]))
|
|
goto nla_put_failure;
|
|
|
|
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;
|
|
|
|
/* 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,
|
|
NET_DM_SKB_CB(skb)->reason),
|
|
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) +
|
|
/* 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(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 = 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(sizeof(*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;
|
|
dev_hold_track(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)
|
|
{
|
|
dev_put_track(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);
|
|
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;
|
|
|
|
del_timer_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;
|
|
|
|
del_timer_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;
|
|
|
|
del_timer_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;
|
|
|
|
del_timer_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_irq(&cpu_stats->syncp);
|
|
dropped = cpu_stats->dropped;
|
|
} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
|
|
|
|
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,
|
|
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_irq(&cpu_stats->syncp);
|
|
dropped = cpu_stats->dropped;
|
|
} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
|
|
|
|
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,
|
|
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(sizeof(*stat), GFP_KERNEL);
|
|
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,
|
|
},
|
|
{
|
|
.cmd = NET_DM_CMD_STOP,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = net_dm_cmd_trace,
|
|
},
|
|
{
|
|
.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_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_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),
|
|
.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)
|
|
{
|
|
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;
|
|
}
|
|
|
|
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) {
|
|
net_dm_cpu_data_init(cpu);
|
|
net_dm_hw_cpu_data_init(cpu);
|
|
}
|
|
|
|
goto out;
|
|
|
|
out_unreg:
|
|
genl_unregister_family(&net_drop_monitor_family);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static void exit_net_drop_monitor(void)
|
|
{
|
|
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 guaranteed not to have any current users when we get here
|
|
*/
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
net_dm_hw_cpu_data_fini(cpu);
|
|
net_dm_cpu_data_fini(cpu);
|
|
}
|
|
|
|
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");
|
|
MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");
|