diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_dropmon.h
index 0fecdedeb6ca28c248c84f9db5b81360c9ace7b9..cfaaf75371b8316234f005b456e737c795d62637 100644
--- a/include/uapi/linux/net_dropmon.h
+++ b/include/uapi/linux/net_dropmon.h
@@ -53,6 +53,7 @@ enum {
NET_DM_CMD_CONFIG,
NET_DM_CMD_START,
NET_DM_CMD_STOP,
+ NET_DM_CMD_PACKET_ALERT,
_NET_DM_CMD_MAX,
};
@@ -63,12 +64,38 @@ enum {
*/
#define NET_DM_GRP_ALERT 1
+enum net_dm_attr {
+ NET_DM_ATTR_UNSPEC,
+
+ NET_DM_ATTR_ALERT_MODE, /* u8 */
+ NET_DM_ATTR_PC, /* u64 */
+ NET_DM_ATTR_SYMBOL, /* string */
+ NET_DM_ATTR_IN_PORT, /* nested */
+ NET_DM_ATTR_TIMESTAMP, /* struct timespec */
+ NET_DM_ATTR_PROTO, /* u16 */
+ NET_DM_ATTR_PAYLOAD, /* binary */
+ NET_DM_ATTR_PAD,
+
+ __NET_DM_ATTR_MAX,
+ NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1
+};
+
/**
* enum net_dm_alert_mode - Alert mode.
* @NET_DM_ALERT_MODE_SUMMARY: A summary of recent drops is sent to user space.
+ * @NET_DM_ALERT_MODE_PACKET: Each dropped packet is sent to user space along
+ * with metadata.
*/
enum net_dm_alert_mode {
NET_DM_ALERT_MODE_SUMMARY,
+ NET_DM_ALERT_MODE_PACKET,
+};
+
+enum {
+ NET_DM_ATTR_PORT_NETDEV_IFINDEX, /* u32 */
+
+ __NET_DM_ATTR_PORT_MAX,
+ NET_DM_ATTR_PORT_MAX = __NET_DM_ATTR_PORT_MAX - 1
};
#endif
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 9cd2f662cb9ee8f413596593d3b2df770dbf5d28..ba765832413b425aac9f00537aa9c4403540091a 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -54,6 +54,7 @@ static DEFINE_MUTEX(net_dm_mutex);
struct per_cpu_dm_data {
spinlock_t lock; /* Protects 'skb' and 'send_timer' */
struct sk_buff *skb;
+ struct sk_buff_head drop_queue;
struct work_struct dm_alert_work;
struct timer_list send_timer;
};
@@ -85,6 +86,14 @@ struct net_dm_alert_ops {
void (*work_item_func)(struct work_struct *work);
};
+struct net_dm_skb_cb {
+ void *pc;
+};
+
+#define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
+
+#define NET_DM_QUEUE_LEN 1000
+
static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
{
size_t al;
@@ -257,8 +266,214 @@ static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
.work_item_func = send_dm_alert,
};
+static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
+ struct sk_buff *skb,
+ void *location)
+{
+ ktime_t tstamp = ktime_get_real();
+ struct per_cpu_dm_data *data;
+ struct sk_buff *nskb;
+ unsigned long flags;
+
+ nskb = skb_clone(skb, GFP_ATOMIC);
+ if (!nskb)
+ return;
+
+ NET_DM_SKB_CB(nskb)->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);
+ 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));
+}
+
+#define NET_DM_MAX_SYMBOL_LEN 40
+
+static size_t net_dm_packet_report_size(size_t payload_len)
+{
+ size_t size;
+
+ size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
+
+ return NLMSG_ALIGN(size) +
+ /* NET_DM_ATTR_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(struct timespec)) +
+ /* NET_DM_ATTR_PROTO */
+ nla_total_size(sizeof(u16)) +
+ /* NET_DM_ATTR_PAYLOAD */
+ nla_total_size(payload_len);
+}
+
+static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex)
+{
+ 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;
+
+ 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)
+{
+ u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
+ char buf[NET_DM_MAX_SYMBOL_LEN];
+ struct nlattr *attr;
+ struct timespec ts;
+ 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_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
+ goto nla_put_failure;
+
+ snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->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);
+ if (rc)
+ goto nla_put_failure;
+
+ if (ktime_to_timespec_cond(skb->tstamp, &ts) &&
+ nla_put(msg, NET_DM_ATTR_TIMESTAMP, sizeof(ts), &ts))
+ 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);
+
+ msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
+ if (!msg)
+ goto out;
+
+ rc = net_dm_packet_report_fill(msg, skb, payload_len);
+ if (rc) {
+ nlmsg_free(msg);
+ goto out;
+ }
+
+ genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
+
+out:
+ consume_skb(skb);
+}
+
+static void net_dm_packet_work(struct work_struct *work)
+{
+ struct per_cpu_dm_data *data;
+ struct sk_buff_head list;
+ struct sk_buff *skb;
+ unsigned long flags;
+
+ data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
+
+ __skb_queue_head_init(&list);
+
+ spin_lock_irqsave(&data->drop_queue.lock, flags);
+ skb_queue_splice_tail_init(&data->drop_queue, &list);
+ spin_unlock_irqrestore(&data->drop_queue.lock, flags);
+
+ while ((skb = __skb_dequeue(&list)))
+ net_dm_packet_report(skb);
+}
+
+static 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,
+};
+
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,
};
static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
@@ -326,9 +541,12 @@ static void net_dm_trace_off_set(void)
*/
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);
}
list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
@@ -370,12 +588,61 @@ static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
return rc;
}
+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: /* fall-through */
+ 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 int net_dm_cmd_config(struct sk_buff *skb,
struct genl_info *info)
{
- NL_SET_ERR_MSG_MOD(info->extack, "Command not supported");
+ struct netlink_ext_ack *extack = info->extack;
+ int rc;
- return -EOPNOTSUPP;
+ if (trace_state == TRACE_ON) {
+ NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor while tracing is on");
+ return -EBUSY;
+ }
+
+ rc = net_dm_alert_mode_set(info);
+ if (rc)
+ return rc;
+
+ return 0;
}
static int net_dm_cmd_trace(struct sk_buff *skb,
@@ -430,6 +697,11 @@ static int dropmon_net_event(struct notifier_block *ev_block,
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 },
+};
+
static const struct genl_ops dropmon_ops[] = {
{
.cmd = NET_DM_CMD_CONFIG,
@@ -467,6 +739,8 @@ 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,
@@ -510,6 +784,7 @@ static int __init init_net_drop_monitor(void)
for_each_possible_cpu(cpu) {
data = &per_cpu(dm_cpu_data, cpu);
spin_lock_init(&data->lock);
+ skb_queue_head_init(&data->drop_queue);
}
goto out;
@@ -539,6 +814,7 @@ static void exit_net_drop_monitor(void)
* to this struct and can free the skb inside it
*/
kfree_skb(data->skb);
+ WARN_ON(!skb_queue_empty(&data->drop_queue));
}
BUG_ON(genl_unregister_family(&net_drop_monitor_family));