sFlow: Genericize/simplify kernel sFlow implementation

Following patch adds sampling action which takes probability and set
of actions as arguments. When probability is hit, actions are executed for
given packet.
USERSPACE action's userdata (u64) is used to store struct
user_action_cookie as cookie. CONTROLLER action is fixed accordingly.

Now we can remove sFlow code from kernel and implement sFlow generically
as SAMPLE action. sFlow is defined as SAMPLE Action with probability (sFlow
sampling rate) and USERSPACE action as argument. USERSPACE action's data
is used as cookie. sFlow uses this cookie to store output-port, number of
output ports and vlan-id. sample-pool is calculated by using vport
stats.

Signed-off-by: Pravin Shelar <pshelar@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

1 files changed, 23 insertions, 13 deletions

diff --git a/include/openvswitch/datapath-protocol.h b/include/openvswitch/datapath-protocol.h
index c48426f5..3db960a9 100644
--- a/include/openvswitch/datapath-protocol.h
+++ b/include/openvswitch/datapath-protocol.h
@@ -94,10 +94,6 @@ struct ovs_header {
  * @OVS_DP_ATTR_IPV4_FRAGS: One of %OVS_DP_FRAG_*.  Always present in
  * notifications.  May be included in %OVS_DP_NEW or %OVS_DP_SET requests to
  * change the fragment handling policy.
- * @OVS_DP_ATTR_SAMPLING: 32-bit fraction of packets to sample with
- * @OVS_PACKET_CMD_SAMPLE.  A value of 0 samples no packets, a value of
- * %UINT32_MAX samples all packets, and intermediate values sample intermediate
- * fractions of packets.
  *
  * These attributes follow the &struct ovs_header within the Generic Netlink
  * payload for %OVS_DP_* commands.
@@ -108,7 +104,6 @@ enum ovs_datapath_attr {
 	OVS_DP_ATTR_UPCALL_PID, /* Netlink PID to receive upcalls */
 	OVS_DP_ATTR_STATS,      /* struct ovs_dp_stats */
 	OVS_DP_ATTR_IPV4_FRAGS,	/* 32-bit enum ovs_frag_handling */
-	OVS_DP_ATTR_SAMPLING,   /* 32-bit fraction of packets to sample. */
 	__OVS_DP_ATTR_MAX
 };
 
@@ -157,7 +152,6 @@ enum ovs_packet_cmd {
         /* Kernel-to-user notifications. */
         OVS_PACKET_CMD_MISS,    /* Flow table miss. */
         OVS_PACKET_CMD_ACTION,  /* OVS_ACTION_ATTR_USERSPACE action. */
-        OVS_PACKET_CMD_SAMPLE,  /* Sampled packet. */
 
         /* User commands. */
         OVS_PACKET_CMD_EXECUTE  /* Apply actions to a packet. */
@@ -174,6 +168,8 @@ enum ovs_packet_cmd {
  * extracted from the packet as nested %OVS_KEY_ATTR_* attributes.  This allows
  * userspace to adapt its flow setup strategy by comparing its notion of the
  * flow key against the kernel's.
+ * @OVS_PACKET_ATTR_ACTIONS: Contains actions for the packet.  Used
+ * for %OVS_PACKET_CMD_EXECUTE.  It has nested %OVS_ACTION_ATTR_* attributes.
  * @OVS_PACKET_ATTR_UPCALL_PID: Optionally present for OVS_PACKET_CMD_EXECUTE.
  * The Netlink socket in userspace that OVS_PACKET_CMD_USERSPACE and
  * OVS_PACKET_CMD_SAMPLE upcalls will be directed to for actions triggered by
@@ -181,11 +177,6 @@ enum ovs_packet_cmd {
  * @OVS_PACKET_ATTR_USERDATA: Present for an %OVS_PACKET_CMD_ACTION
  * notification if the %OVS_ACTION_ATTR_USERSPACE, action's argument was
  * nonzero.
- * @OVS_PACKET_ATTR_SAMPLE_POOL: Present for %OVS_PACKET_CMD_SAMPLE.  Contains
- * the number of packets processed so far that were candidates for sampling.
- * @OVS_PACKET_ATTR_ACTIONS: Present for %OVS_PACKET_CMD_SAMPLE.  Contains a
- * copy of the actions applied to the packet, as nested %OVS_ACTION_ATTR_*
- * attributes.
  *
  * These attributes follow the &struct ovs_header within the Generic Netlink
  * payload for %OVS_PACKET_* commands.
@@ -194,10 +185,9 @@ enum ovs_packet_attr {
 	OVS_PACKET_ATTR_UNSPEC,
 	OVS_PACKET_ATTR_PACKET,      /* Packet data. */
 	OVS_PACKET_ATTR_KEY,         /* Nested OVS_KEY_ATTR_* attributes. */
+	OVS_PACKET_ATTR_ACTIONS,     /* Nested OVS_ACTION_ATTR_* attributes. */
 	OVS_PACKET_ATTR_UPCALL_PID,  /* Netlink PID to receive upcalls. */
 	OVS_PACKET_ATTR_USERDATA,    /* u64 OVS_ACTION_ATTR_USERSPACE arg. */
-	OVS_PACKET_ATTR_SAMPLE_POOL, /* # sampling candidate packets so far. */
-	OVS_PACKET_ATTR_ACTIONS,     /* Nested OVS_ACTION_ATTR_* attributes. */
 	__OVS_PACKET_ATTR_MAX
 };
 
@@ -425,6 +415,24 @@ enum ovs_flow_attr {
 
 #define OVS_FLOW_ATTR_MAX (__OVS_FLOW_ATTR_MAX - 1)
 
+/**
+ * enum ovs_sample_attr - Attributes for OVS_ACTION_ATTR_SAMPLE
+ * @OVS_SAMPLE_ATTR_PROBABILITY: 32-bit fraction of packets to sample with
+ * @OVS_ACTION_ATTR_SAMPLE.  A value of 0 samples no packets, a value of
+ * %UINT32_MAX samples all packets and intermediate values sample intermediate
+ * fractions of packets.
+ * @OVS_SAMPLE_ATTR_ACTIONS: Set of actions to execute in sampling event.
+ * Actions are passed as nested attributes.
+ */
+enum ovs_sample_attr {
+	OVS_SAMPLE_ATTR_UNSPEC,
+	OVS_SAMPLE_ATTR_PROBABILITY, /* u32 number */
+	OVS_SAMPLE_ATTR_ACTIONS,     /* Nested OVS_ACTION_ATTR_* attributes. */
+	__OVS_SAMPLE_ATTR_MAX,
+};
+
+#define OVS_SAMPLE_ATTR_MAX (__OVS_SAMPLE_ATTR_MAX - 1)
+
 /* Action types. */
 enum ovs_action_type {
 	OVS_ACTION_ATTR_UNSPEC,
@@ -442,6 +450,8 @@ enum ovs_action_type {
 	OVS_ACTION_ATTR_SET_TUNNEL,   /* Set the encapsulating tunnel ID. */
 	OVS_ACTION_ATTR_SET_PRIORITY, /* Set skb->priority. */
 	OVS_ACTION_ATTR_POP_PRIORITY, /* Restore original skb->priority. */
+	OVS_ACTION_ATTR_SAMPLE,       /* Execute list of actions at given
+					 probability. */
 	__OVS_ACTION_ATTR_MAX
 };