Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6.git] / net / core / drop_monitor.c
index b75b6ce..9d66fa9 100644 (file)
 #include <linux/timer.h>
 #include <linux/bitops.h>
 #include <net/genetlink.h>
+#include <net/netevent.h>
 
 #include <trace/events/skb.h>
+#include <trace/events/napi.h>
 
 #include <asm/unaligned.h>
 
@@ -38,7 +40,8 @@ static void send_dm_alert(struct work_struct *unused);
  * and the work handle that will send up
  * netlink alerts
  */
-struct sock *dm_sock;
+static int trace_state = TRACE_OFF;
+static spinlock_t trace_state_lock = SPIN_LOCK_UNLOCKED;
 
 struct per_cpu_dm_data {
        struct work_struct dm_alert_work;
@@ -47,11 +50,18 @@ struct per_cpu_dm_data {
        struct timer_list send_timer;
 };
 
+struct dm_hw_stat_delta {
+       struct net_device *dev;
+       struct list_head list;
+       struct rcu_head rcu;
+       unsigned long last_drop_val;
+};
+
 static struct genl_family net_drop_monitor_family = {
        .id             = GENL_ID_GENERATE,
        .hdrsize        = 0,
        .name           = "NET_DM",
-       .version        = 1,
+       .version        = 2,
        .maxattr        = NET_DM_CMD_MAX,
 };
 
@@ -59,19 +69,24 @@ static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
 
 static int dm_hit_limit = 64;
 static int dm_delay = 1;
-
+static unsigned long dm_hw_check_delta = 2*HZ;
+static LIST_HEAD(hw_stats_list);
 
 static void reset_per_cpu_data(struct per_cpu_dm_data *data)
 {
        size_t al;
        struct net_dm_alert_msg *msg;
+       struct nlattr *nla;
 
        al = sizeof(struct net_dm_alert_msg);
        al += dm_hit_limit * sizeof(struct net_dm_drop_point);
+       al += sizeof(struct nlattr);
+
        data->skb = genlmsg_new(al, GFP_KERNEL);
        genlmsg_put(data->skb, 0, 0, &net_drop_monitor_family,
                        0, NET_DM_CMD_ALERT);
-       msg = __nla_reserve_nohdr(data->skb, sizeof(struct net_dm_alert_msg));
+       nla = nla_reserve(data->skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));
+       msg = nla_data(nla);
        memset(msg, 0, al);
        atomic_set(&data->dm_hit_count, dm_hit_limit);
 }
@@ -111,10 +126,11 @@ static void sched_send_work(unsigned long unused)
        schedule_work(&data->dm_alert_work);
 }
 
-static void trace_kfree_skb_hit(struct sk_buff *skb, void *location)
+static void trace_drop_common(struct sk_buff *skb, void *location)
 {
        struct net_dm_alert_msg *msg;
        struct nlmsghdr *nlh;
+       struct nlattr *nla;
        int i;
        struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
 
@@ -127,7 +143,8 @@ static void trace_kfree_skb_hit(struct sk_buff *skb, void *location)
        }
 
        nlh = (struct nlmsghdr *)data->skb->data;
-       msg = genlmsg_data(nlmsg_data(nlh));
+       nla = genlmsg_data(nlmsg_data(nlh));
+       msg = nla_data(nla);
        for (i = 0; i < msg->entries; i++) {
                if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
                        msg->points[i].count++;
@@ -139,6 +156,7 @@ static void trace_kfree_skb_hit(struct sk_buff *skb, void *location)
         * We need to create a new entry
         */
        __nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
+       nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
        memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
        msg->points[msg->entries].count = 1;
        msg->entries++;
@@ -152,24 +170,80 @@ out:
        return;
 }
 
+static void trace_kfree_skb_hit(struct sk_buff *skb, void *location)
+{
+       trace_drop_common(skb, location);
+}
+
+static void trace_napi_poll_hit(struct napi_struct *napi)
+{
+       struct dm_hw_stat_delta *new_stat;
+
+       /*
+        * Ratelimit our check time to dm_hw_check_delta jiffies
+        */
+       if (!time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
+               return;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
+               if ((new_stat->dev == napi->dev)  &&
+                   (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
+                       trace_drop_common(NULL, NULL);
+                       new_stat->last_drop_val = napi->dev->stats.rx_dropped;
+                       break;
+               }
+       }
+       rcu_read_unlock();
+}
+
+
+static void free_dm_hw_stat(struct rcu_head *head)
+{
+       struct dm_hw_stat_delta *n;
+       n = container_of(head, struct dm_hw_stat_delta, rcu);
+       kfree(n);
+}
+
 static int set_all_monitor_traces(int state)
 {
        int rc = 0;
+       struct dm_hw_stat_delta *new_stat = NULL;
+       struct dm_hw_stat_delta *temp;
+
+       spin_lock(&trace_state_lock);
 
        switch (state) {
        case TRACE_ON:
                rc |= register_trace_kfree_skb(trace_kfree_skb_hit);
+               rc |= register_trace_napi_poll(trace_napi_poll_hit);
                break;
        case TRACE_OFF:
                rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit);
+               rc |= unregister_trace_napi_poll(trace_napi_poll_hit);
 
                tracepoint_synchronize_unregister();
+
+               /*
+                * Clean the device list
+                */
+               list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
+                       if (new_stat->dev == NULL) {
+                               list_del_rcu(&new_stat->list);
+                               call_rcu(&new_stat->rcu, free_dm_hw_stat);
+                       }
+               }
                break;
        default:
                rc = 1;
                break;
        }
 
+       if (!rc)
+               trace_state = state;
+
+       spin_unlock(&trace_state_lock);
+
        if (rc)
                return -EINPROGRESS;
        return rc;
@@ -197,6 +271,44 @@ static int net_dm_cmd_trace(struct sk_buff *skb,
        return -ENOTSUPP;
 }
 
+static int dropmon_net_event(struct notifier_block *ev_block,
+                       unsigned long event, void *ptr)
+{
+       struct net_device *dev = ptr;
+       struct dm_hw_stat_delta *new_stat = NULL;
+       struct dm_hw_stat_delta *tmp;
+
+       switch (event) {
+       case NETDEV_REGISTER:
+               new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);
+
+               if (!new_stat)
+                       goto out;
+
+               new_stat->dev = dev;
+               INIT_RCU_HEAD(&new_stat->rcu);
+               spin_lock(&trace_state_lock);
+               list_add_rcu(&new_stat->list, &hw_stats_list);
+               spin_unlock(&trace_state_lock);
+               break;
+       case NETDEV_UNREGISTER:
+               spin_lock(&trace_state_lock);
+               list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
+                       if (new_stat->dev == dev) {
+                               new_stat->dev = NULL;
+                               if (trace_state == TRACE_OFF) {
+                                       list_del_rcu(&new_stat->list);
+                                       call_rcu(&new_stat->rcu, free_dm_hw_stat);
+                                       break;
+                               }
+                       }
+               }
+               spin_unlock(&trace_state_lock);
+               break;
+       }
+out:
+       return NOTIFY_DONE;
+}
 
 static struct genl_ops dropmon_ops[] = {
        {
@@ -213,6 +325,10 @@ static struct genl_ops dropmon_ops[] = {
        },
 };
 
+static struct notifier_block dropmon_net_notifier = {
+       .notifier_call = dropmon_net_event
+};
+
 static int __init init_net_drop_monitor(void)
 {
        int cpu;
@@ -236,12 +352,18 @@ static int __init init_net_drop_monitor(void)
                ret = genl_register_ops(&net_drop_monitor_family,
                                        &dropmon_ops[i]);
                if (ret) {
-                       printk(KERN_CRIT "failed to register operation %d\n",
+                       printk(KERN_CRIT "Failed to register operation %d\n",
                                dropmon_ops[i].cmd);
                        goto out_unreg;
                }
        }
 
+       rc = register_netdevice_notifier(&dropmon_net_notifier);
+       if (rc < 0) {
+               printk(KERN_CRIT "Failed to register netdevice notifier\n");
+               goto out_unreg;
+       }
+
        rc = 0;
 
        for_each_present_cpu(cpu) {
@@ -252,6 +374,7 @@ static int __init init_net_drop_monitor(void)
                data->send_timer.data = cpu;
                data->send_timer.function = sched_send_work;
        }
+
        goto out;
 
 out_unreg: