drop_monitor: extend by passing cookie from driver

If driver passed along the cookie, push it through Netlink.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/drop_monitor.h

@@ -6,17 +6,20 @@
 #include <linux/ktime.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
+#include <net/flow_offload.h>
 
 /**
  * struct net_dm_hw_metadata - Hardware-supplied packet metadata.
  * @trap_group_name: Hardware trap group name.
  * @trap_name: Hardware trap name.
  * @input_dev: Input netdevice.
+ * @fa_cookie: Flow action user cookie.
  */
 struct net_dm_hw_metadata {
 	const char *trap_group_name;
 	const char *trap_name;
 	struct net_device *input_dev;
+	const struct flow_action_cookie *fa_cookie;
 };
 
 #if IS_ENABLED(CONFIG_NET_DROP_MONITOR)

include/uapi/linux/net_dropmon.h

@@ -92,6 +92,7 @@ enum net_dm_attr {
 	NET_DM_ATTR_HW_TRAP_COUNT,		/* u32 */
 	NET_DM_ATTR_SW_DROPS,			/* flag */
 	NET_DM_ATTR_HW_DROPS,			/* flag */
+	NET_DM_ATTR_FLOW_ACTION_COOKIE,		/* binary */
 
 	__NET_DM_ATTR_MAX,
 	NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1

net/core/drop_monitor.c

@@ -29,6 +29,7 @@
 #include <net/drop_monitor.h>
 #include <net/genetlink.h>
 #include <net/netevent.h>
+#include <net/flow_offload.h>
 
 #include <trace/events/skb.h>
 #include <trace/events/napi.h>
@@ -700,6 +701,13 @@ static void net_dm_packet_work(struct work_struct *work)
 		net_dm_packet_report(skb);
 }
 
+static size_t
+net_dm_flow_action_cookie_size(const struct net_dm_hw_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 net_dm_hw_metadata *hw_metadata)
@@ -717,6 +725,8 @@ net_dm_hw_packet_report_size(size_t payload_len,
 	       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 */
@@ -762,6 +772,12 @@ static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
 			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;
@@ -794,11 +810,12 @@ static int net_dm_hw_packet_report_fill(struct sk_buff *msg,
 static struct net_dm_hw_metadata *
 net_dm_hw_metadata_clone(const struct net_dm_hw_metadata *hw_metadata)
 {
+	const struct flow_action_cookie *fa_cookie;
 	struct net_dm_hw_metadata *n_hw_metadata;
 	const char *trap_group_name;
 	const char *trap_name;
 
-	n_hw_metadata = kmalloc(sizeof(*hw_metadata), GFP_ATOMIC);
+	n_hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC);
 	if (!n_hw_metadata)
 		return NULL;
 
@@ -812,12 +829,25 @@ net_dm_hw_metadata_clone(const struct net_dm_hw_metadata *hw_metadata)
 		goto free_trap_group;
 	n_hw_metadata->trap_name = trap_name;
 
+	if (hw_metadata->fa_cookie) {
+		size_t cookie_size = sizeof(*fa_cookie) +
+				     hw_metadata->fa_cookie->cookie_len;
+
+		fa_cookie = kmemdup(hw_metadata->fa_cookie, cookie_size,
+				    GFP_ATOMIC);
+		if (!fa_cookie)
+			goto free_trap_name;
+		n_hw_metadata->fa_cookie = fa_cookie;
+	}
+
 	n_hw_metadata->input_dev = hw_metadata->input_dev;
 	if (n_hw_metadata->input_dev)
 		dev_hold(n_hw_metadata->input_dev);
 
 	return n_hw_metadata;
 
+free_trap_name:
+	kfree(trap_name);
 free_trap_group:
 	kfree(trap_group_name);
 free_hw_metadata:
@@ -830,6 +860,7 @@ net_dm_hw_metadata_free(const struct net_dm_hw_metadata *hw_metadata)
 {
 	if (hw_metadata->input_dev)
 		dev_put(hw_metadata->input_dev);
+	kfree(hw_metadata->fa_cookie);
 	kfree(hw_metadata->trap_name);
 	kfree(hw_metadata->trap_group_name);
 	kfree(hw_metadata);