Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Monitoring code for network dropped packet alerts |
| 3 | * |
| 4 | * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com> |
| 5 | */ |
| 6 | |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 8 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 9 | #include <linux/netdevice.h> |
| 10 | #include <linux/etherdevice.h> |
| 11 | #include <linux/string.h> |
| 12 | #include <linux/if_arp.h> |
| 13 | #include <linux/inetdevice.h> |
| 14 | #include <linux/inet.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <linux/netpoll.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/delay.h> |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/workqueue.h> |
| 21 | #include <linux/netlink.h> |
| 22 | #include <linux/net_dropmon.h> |
| 23 | #include <linux/percpu.h> |
| 24 | #include <linux/timer.h> |
| 25 | #include <linux/bitops.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 26 | #include <linux/slab.h> |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 27 | #include <linux/module.h> |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 28 | #include <net/genetlink.h> |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 29 | #include <net/netevent.h> |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 30 | |
Steven Rostedt | ad8d75f | 2009-04-14 19:39:12 -0400 | [diff] [blame] | 31 | #include <trace/events/skb.h> |
David S. Miller | 9cbc1cb | 2009-06-15 03:02:23 -0700 | [diff] [blame] | 32 | #include <trace/events/napi.h> |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 33 | |
| 34 | #include <asm/unaligned.h> |
| 35 | |
| 36 | #define TRACE_ON 1 |
| 37 | #define TRACE_OFF 0 |
| 38 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 39 | /* |
| 40 | * Globals, our netlink socket pointer |
| 41 | * and the work handle that will send up |
| 42 | * netlink alerts |
| 43 | */ |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 44 | static int trace_state = TRACE_OFF; |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 45 | static DEFINE_MUTEX(trace_state_mutex); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 46 | |
| 47 | struct per_cpu_dm_data { |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 48 | spinlock_t lock; |
| 49 | struct sk_buff *skb; |
| 50 | struct work_struct dm_alert_work; |
| 51 | struct timer_list send_timer; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 52 | }; |
| 53 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 54 | struct dm_hw_stat_delta { |
| 55 | struct net_device *dev; |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 56 | unsigned long last_rx; |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 57 | struct list_head list; |
| 58 | struct rcu_head rcu; |
| 59 | unsigned long last_drop_val; |
| 60 | }; |
| 61 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 62 | static struct genl_family net_drop_monitor_family = { |
| 63 | .id = GENL_ID_GENERATE, |
| 64 | .hdrsize = 0, |
| 65 | .name = "NET_DM", |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 66 | .version = 2, |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 67 | .maxattr = NET_DM_CMD_MAX, |
| 68 | }; |
| 69 | |
| 70 | static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data); |
| 71 | |
| 72 | static int dm_hit_limit = 64; |
| 73 | static int dm_delay = 1; |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 74 | static unsigned long dm_hw_check_delta = 2*HZ; |
| 75 | static LIST_HEAD(hw_stats_list); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 76 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 77 | static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data) |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 78 | { |
| 79 | size_t al; |
| 80 | struct net_dm_alert_msg *msg; |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 81 | struct nlattr *nla; |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 82 | struct sk_buff *skb; |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 83 | unsigned long flags; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 84 | |
| 85 | al = sizeof(struct net_dm_alert_msg); |
| 86 | al += dm_hit_limit * sizeof(struct net_dm_drop_point); |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 87 | al += sizeof(struct nlattr); |
| 88 | |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 89 | skb = genlmsg_new(al, GFP_KERNEL); |
| 90 | |
| 91 | if (skb) { |
| 92 | genlmsg_put(skb, 0, 0, &net_drop_monitor_family, |
| 93 | 0, NET_DM_CMD_ALERT); |
| 94 | nla = nla_reserve(skb, NLA_UNSPEC, |
| 95 | sizeof(struct net_dm_alert_msg)); |
| 96 | msg = nla_data(nla); |
| 97 | memset(msg, 0, al); |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 98 | } else { |
| 99 | mod_timer(&data->send_timer, jiffies + HZ / 10); |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 100 | } |
| 101 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 102 | spin_lock_irqsave(&data->lock, flags); |
| 103 | swap(data->skb, skb); |
| 104 | spin_unlock_irqrestore(&data->lock, flags); |
| 105 | |
| 106 | return skb; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 107 | } |
| 108 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 109 | static void send_dm_alert(struct work_struct *work) |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 110 | { |
| 111 | struct sk_buff *skb; |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 112 | struct per_cpu_dm_data *data; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 113 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 114 | data = container_of(work, struct per_cpu_dm_data, dm_alert_work); |
Neil Horman | 4fdcfa1 | 2012-05-01 08:18:02 +0000 | [diff] [blame] | 115 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 116 | skb = reset_per_cpu_data(data); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 117 | |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 118 | if (skb) |
| 119 | genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 120 | } |
| 121 | |
| 122 | /* |
| 123 | * This is the timer function to delay the sending of an alert |
| 124 | * in the event that more drops will arrive during the |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 125 | * hysteresis period. |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 126 | */ |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 127 | static void sched_send_work(unsigned long _data) |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 128 | { |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 129 | struct per_cpu_dm_data *data = (struct per_cpu_dm_data *)_data; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 130 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 131 | schedule_work(&data->dm_alert_work); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 132 | } |
| 133 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 134 | static void trace_drop_common(struct sk_buff *skb, void *location) |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 135 | { |
| 136 | struct net_dm_alert_msg *msg; |
| 137 | struct nlmsghdr *nlh; |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 138 | struct nlattr *nla; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 139 | int i; |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 140 | struct sk_buff *dskb; |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 141 | struct per_cpu_dm_data *data; |
| 142 | unsigned long flags; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 143 | |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 144 | local_irq_save(flags); |
| 145 | data = &__get_cpu_var(dm_cpu_data); |
| 146 | spin_lock(&data->lock); |
| 147 | dskb = data->skb; |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 148 | |
| 149 | if (!dskb) |
| 150 | goto out; |
| 151 | |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 152 | nlh = (struct nlmsghdr *)dskb->data; |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 153 | nla = genlmsg_data(nlmsg_data(nlh)); |
| 154 | msg = nla_data(nla); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 155 | for (i = 0; i < msg->entries; i++) { |
| 156 | if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) { |
| 157 | msg->points[i].count++; |
| 158 | goto out; |
| 159 | } |
| 160 | } |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 161 | if (msg->entries == dm_hit_limit) |
| 162 | goto out; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 163 | /* |
| 164 | * We need to create a new entry |
| 165 | */ |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 166 | __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point)); |
Neil Horman | 683703a | 2009-04-27 03:17:31 -0700 | [diff] [blame] | 167 | nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point)); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 168 | memcpy(msg->points[msg->entries].pc, &location, sizeof(void *)); |
| 169 | msg->points[msg->entries].count = 1; |
| 170 | msg->entries++; |
| 171 | |
| 172 | if (!timer_pending(&data->send_timer)) { |
| 173 | data->send_timer.expires = jiffies + dm_delay * HZ; |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 174 | add_timer(&data->send_timer); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 175 | } |
| 176 | |
| 177 | out: |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 178 | spin_unlock_irqrestore(&data->lock, flags); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 179 | } |
| 180 | |
Steven Rostedt | 38516ab | 2010-04-20 17:04:50 -0400 | [diff] [blame] | 181 | static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location) |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 182 | { |
| 183 | trace_drop_common(skb, location); |
| 184 | } |
| 185 | |
Steven Rostedt | 38516ab | 2010-04-20 17:04:50 -0400 | [diff] [blame] | 186 | static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi) |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 187 | { |
| 188 | struct dm_hw_stat_delta *new_stat; |
| 189 | |
| 190 | /* |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 191 | * Don't check napi structures with no associated device |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 192 | */ |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 193 | if (!napi->dev) |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 194 | return; |
| 195 | |
| 196 | rcu_read_lock(); |
| 197 | list_for_each_entry_rcu(new_stat, &hw_stats_list, list) { |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 198 | /* |
| 199 | * only add a note to our monitor buffer if: |
| 200 | * 1) this is the dev we received on |
| 201 | * 2) its after the last_rx delta |
| 202 | * 3) our rx_dropped count has gone up |
| 203 | */ |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 204 | if ((new_stat->dev == napi->dev) && |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 205 | (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) && |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 206 | (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) { |
| 207 | trace_drop_common(NULL, NULL); |
| 208 | new_stat->last_drop_val = napi->dev->stats.rx_dropped; |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 209 | new_stat->last_rx = jiffies; |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 210 | break; |
| 211 | } |
| 212 | } |
| 213 | rcu_read_unlock(); |
| 214 | } |
| 215 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 216 | static int set_all_monitor_traces(int state) |
| 217 | { |
| 218 | int rc = 0; |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 219 | struct dm_hw_stat_delta *new_stat = NULL; |
| 220 | struct dm_hw_stat_delta *temp; |
| 221 | |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 222 | mutex_lock(&trace_state_mutex); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 223 | |
Neil Horman | 4b70637 | 2010-07-20 04:52:09 +0000 | [diff] [blame] | 224 | if (state == trace_state) { |
| 225 | rc = -EAGAIN; |
| 226 | goto out_unlock; |
| 227 | } |
| 228 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 229 | switch (state) { |
| 230 | case TRACE_ON: |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 231 | if (!try_module_get(THIS_MODULE)) { |
| 232 | rc = -ENODEV; |
| 233 | break; |
| 234 | } |
| 235 | |
Steven Rostedt | 38516ab | 2010-04-20 17:04:50 -0400 | [diff] [blame] | 236 | rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL); |
| 237 | rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 238 | break; |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 239 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 240 | case TRACE_OFF: |
Steven Rostedt | 38516ab | 2010-04-20 17:04:50 -0400 | [diff] [blame] | 241 | rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); |
| 242 | rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 243 | |
| 244 | tracepoint_synchronize_unregister(); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 245 | |
| 246 | /* |
| 247 | * Clean the device list |
| 248 | */ |
| 249 | list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { |
| 250 | if (new_stat->dev == NULL) { |
| 251 | list_del_rcu(&new_stat->list); |
Lai Jiangshan | fa81c0e | 2011-03-18 11:39:43 +0800 | [diff] [blame] | 252 | kfree_rcu(new_stat, rcu); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 253 | } |
| 254 | } |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 255 | |
| 256 | module_put(THIS_MODULE); |
| 257 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 258 | break; |
| 259 | default: |
| 260 | rc = 1; |
| 261 | break; |
| 262 | } |
| 263 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 264 | if (!rc) |
| 265 | trace_state = state; |
Neil Horman | 4b70637 | 2010-07-20 04:52:09 +0000 | [diff] [blame] | 266 | else |
| 267 | rc = -EINPROGRESS; |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 268 | |
Neil Horman | 4b70637 | 2010-07-20 04:52:09 +0000 | [diff] [blame] | 269 | out_unlock: |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 270 | mutex_unlock(&trace_state_mutex); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 271 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 272 | return rc; |
| 273 | } |
| 274 | |
| 275 | |
| 276 | static int net_dm_cmd_config(struct sk_buff *skb, |
| 277 | struct genl_info *info) |
| 278 | { |
| 279 | return -ENOTSUPP; |
| 280 | } |
| 281 | |
| 282 | static int net_dm_cmd_trace(struct sk_buff *skb, |
| 283 | struct genl_info *info) |
| 284 | { |
| 285 | switch (info->genlhdr->cmd) { |
| 286 | case NET_DM_CMD_START: |
| 287 | return set_all_monitor_traces(TRACE_ON); |
| 288 | break; |
| 289 | case NET_DM_CMD_STOP: |
| 290 | return set_all_monitor_traces(TRACE_OFF); |
| 291 | break; |
| 292 | } |
| 293 | |
| 294 | return -ENOTSUPP; |
| 295 | } |
| 296 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 297 | static int dropmon_net_event(struct notifier_block *ev_block, |
Jiri Pirko | 351638e | 2013-05-28 01:30:21 +0000 | [diff] [blame] | 298 | unsigned long event, void *ptr) |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 299 | { |
Jiri Pirko | 351638e | 2013-05-28 01:30:21 +0000 | [diff] [blame] | 300 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 301 | struct dm_hw_stat_delta *new_stat = NULL; |
| 302 | struct dm_hw_stat_delta *tmp; |
| 303 | |
| 304 | switch (event) { |
| 305 | case NETDEV_REGISTER: |
| 306 | new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL); |
| 307 | |
| 308 | if (!new_stat) |
| 309 | goto out; |
| 310 | |
| 311 | new_stat->dev = dev; |
Neil Horman | 5848cc0 | 2009-09-02 14:37:45 -0700 | [diff] [blame] | 312 | new_stat->last_rx = jiffies; |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 313 | mutex_lock(&trace_state_mutex); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 314 | list_add_rcu(&new_stat->list, &hw_stats_list); |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 315 | mutex_unlock(&trace_state_mutex); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 316 | break; |
| 317 | case NETDEV_UNREGISTER: |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 318 | mutex_lock(&trace_state_mutex); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 319 | list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { |
| 320 | if (new_stat->dev == dev) { |
| 321 | new_stat->dev = NULL; |
| 322 | if (trace_state == TRACE_OFF) { |
| 323 | list_del_rcu(&new_stat->list); |
Lai Jiangshan | fa81c0e | 2011-03-18 11:39:43 +0800 | [diff] [blame] | 324 | kfree_rcu(new_stat, rcu); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 325 | break; |
| 326 | } |
| 327 | } |
| 328 | } |
Neil Horman | cde2e9a | 2012-04-27 10:11:48 +0000 | [diff] [blame] | 329 | mutex_unlock(&trace_state_mutex); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 330 | break; |
| 331 | } |
| 332 | out: |
| 333 | return NOTIFY_DONE; |
| 334 | } |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 335 | |
Johannes Berg | 4534de8 | 2013-11-14 17:14:46 +0100 | [diff] [blame] | 336 | static const struct genl_ops dropmon_ops[] = { |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 337 | { |
| 338 | .cmd = NET_DM_CMD_CONFIG, |
| 339 | .doit = net_dm_cmd_config, |
| 340 | }, |
| 341 | { |
| 342 | .cmd = NET_DM_CMD_START, |
| 343 | .doit = net_dm_cmd_trace, |
| 344 | }, |
| 345 | { |
| 346 | .cmd = NET_DM_CMD_STOP, |
| 347 | .doit = net_dm_cmd_trace, |
| 348 | }, |
| 349 | }; |
| 350 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 351 | static struct notifier_block dropmon_net_notifier = { |
| 352 | .notifier_call = dropmon_net_event |
| 353 | }; |
| 354 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 355 | static int __init init_net_drop_monitor(void) |
| 356 | { |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 357 | struct per_cpu_dm_data *data; |
Changli Gao | a256be7 | 2010-07-26 20:59:42 -0700 | [diff] [blame] | 358 | int cpu, rc; |
| 359 | |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 360 | pr_info("Initializing network drop monitor service\n"); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 361 | |
| 362 | if (sizeof(void *) > 8) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 363 | pr_err("Unable to store program counters on this arch, Drop monitor failed\n"); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 364 | return -ENOSPC; |
| 365 | } |
| 366 | |
Changli Gao | a256be7 | 2010-07-26 20:59:42 -0700 | [diff] [blame] | 367 | rc = genl_register_family_with_ops(&net_drop_monitor_family, |
| 368 | dropmon_ops, |
| 369 | ARRAY_SIZE(dropmon_ops)); |
| 370 | if (rc) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 371 | pr_err("Could not create drop monitor netlink family\n"); |
Changli Gao | a256be7 | 2010-07-26 20:59:42 -0700 | [diff] [blame] | 372 | return rc; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 373 | } |
| 374 | |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 375 | rc = register_netdevice_notifier(&dropmon_net_notifier); |
| 376 | if (rc < 0) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 377 | pr_crit("Failed to register netdevice notifier\n"); |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 378 | goto out_unreg; |
| 379 | } |
| 380 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 381 | rc = 0; |
| 382 | |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 383 | for_each_possible_cpu(cpu) { |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 384 | data = &per_cpu(dm_cpu_data, cpu); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 385 | INIT_WORK(&data->dm_alert_work, send_dm_alert); |
| 386 | init_timer(&data->send_timer); |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 387 | data->send_timer.data = (unsigned long)data; |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 388 | data->send_timer.function = sched_send_work; |
Eric Dumazet | bec4596 | 2012-06-04 00:18:19 +0000 | [diff] [blame] | 389 | spin_lock_init(&data->lock); |
Neil Horman | 4fdcfa1 | 2012-05-01 08:18:02 +0000 | [diff] [blame] | 390 | reset_per_cpu_data(data); |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 391 | } |
Neil Horman | 4ea7e38 | 2009-05-21 07:36:08 +0000 | [diff] [blame] | 392 | |
Neil Horman | 3885ca7 | 2012-04-27 10:11:49 +0000 | [diff] [blame] | 393 | |
Neil Horman | 9a8afc8 | 2009-03-11 09:51:26 +0000 | [diff] [blame] | 394 | goto out; |
| 395 | |
| 396 | out_unreg: |
| 397 | genl_unregister_family(&net_drop_monitor_family); |
| 398 | out: |
| 399 | return rc; |
| 400 | } |
| 401 | |
Neil Horman | cad456d | 2012-05-17 10:04:00 +0000 | [diff] [blame] | 402 | static void exit_net_drop_monitor(void) |
| 403 | { |
| 404 | struct per_cpu_dm_data *data; |
| 405 | int cpu; |
| 406 | |
| 407 | BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier)); |
| 408 | |
| 409 | /* |
| 410 | * Because of the module_get/put we do in the trace state change path |
| 411 | * we are guarnateed not to have any current users when we get here |
| 412 | * all we need to do is make sure that we don't have any running timers |
| 413 | * or pending schedule calls |
| 414 | */ |
| 415 | |
| 416 | for_each_possible_cpu(cpu) { |
| 417 | data = &per_cpu(dm_cpu_data, cpu); |
| 418 | del_timer_sync(&data->send_timer); |
| 419 | cancel_work_sync(&data->dm_alert_work); |
| 420 | /* |
| 421 | * At this point, we should have exclusive access |
| 422 | * to this struct and can free the skb inside it |
| 423 | */ |
| 424 | kfree_skb(data->skb); |
| 425 | } |
| 426 | |
| 427 | BUG_ON(genl_unregister_family(&net_drop_monitor_family)); |
| 428 | } |
| 429 | |
| 430 | module_init(init_net_drop_monitor); |
| 431 | module_exit(exit_net_drop_monitor); |
| 432 | |
| 433 | MODULE_LICENSE("GPL v2"); |
| 434 | MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>"); |
Neil Horman | 3fdcbd4 | 2012-05-29 09:30:42 +0000 | [diff] [blame] | 435 | MODULE_ALIAS_GENL_FAMILY("NET_DM"); |