From e28564c5fa42a009523c3e088a14c863bab5c691 Mon Sep 17 00:00:00 2001
From: Justin Pettit <jpettit@nicira.com>
Date: Fri, 11 Apr 2008 17:40:05 -0700
Subject: [PATCH] Add support for OFPP_TABLE virtual port.

---
 datapath/datapath.c | 15 ++++++++++++++-
 datapath/forward.c  | 19 +++++++++++++++----
 datapath/forward.h  |  4 ++++
 include/openflow.h  |  6 +++++-
 4 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index b80c7b20..0929b704 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -6,6 +6,7 @@
 
 /* Functions for managing the dp interface/device. */
 
+#include <linux/init.h>
 #include <linux/module.h>
 #include <linux/if_arp.h>
 #include <linux/if_bridge.h>
@@ -465,7 +466,19 @@ int dp_output_port(struct datapath *dp, struct sk_buff *skb, int out_port)
 	else if (out_port == OFPP_CONTROLLER)
 		return dp_output_control(dp, skb, fwd_save_skb(skb), 0,
 						  OFPR_ACTION);
-	else if (out_port >= OFPP_MAX)
+	else if (out_port == OFPP_TABLE) {
+		struct sw_flow_key key;
+		struct sw_flow *flow;
+
+		flow_extract(skb, skb->dev->br_port->port_no, &key);
+		flow = chain_lookup(dp->chain, &key);
+		if (likely(flow != NULL)) {
+			flow_used(flow, skb);
+			execute_actions(dp, skb, &key, flow->actions, flow->n_actions);
+			return 0;
+		}
+		return -ESRCH;
+	} else if (out_port >= OFPP_MAX)
 		goto bad_port;
 
 	p = dp->ports[out_port];
diff --git a/datapath/forward.c b/datapath/forward.c
index a154393c..65a98aeb 100644
--- a/datapath/forward.c
+++ b/datapath/forward.c
@@ -21,9 +21,6 @@
 
 /* FIXME: do we need to use GFP_ATOMIC everywhere here? */
 
-static void execute_actions(struct datapath *, struct sk_buff *,
-				const struct sw_flow_key *,
-				const struct ofp_action *, int n_actions);
 static int make_writable(struct sk_buff **);
 
 static struct sk_buff *retrieve_skb(uint32_t id);
@@ -59,7 +56,7 @@ static int do_output(struct datapath *dp, struct sk_buff *skb, size_t max_len,
 					 max_len, OFPR_ACTION));
 }
 
-static void execute_actions(struct datapath *dp, struct sk_buff *skb,
+void execute_actions(struct datapath *dp, struct sk_buff *skb,
 				const struct sw_flow_key *key,
 				const struct ofp_action *actions, int n_actions)
 {
@@ -338,6 +335,7 @@ static int
 add_flow(struct sw_chain *chain, const struct ofp_flow_mod *ofm)
 {
 	int error = -ENOMEM;
+	int i;
 	int n_acts;
 	struct sw_flow *flow;
 
@@ -349,6 +347,19 @@ add_flow(struct sw_chain *chain, const struct ofp_flow_mod *ofm)
 		goto error;
 	}
 
+	/* To prevent loops, make sure there's no action to send to the
+	 * OFP_TABLE virtual port.
+	 */
+	for (i=0; i<n_acts; i++) {
+		const struct ofp_action *a = &ofm->actions[i];
+
+		if (a->type == htons(OFPAT_OUTPUT) 
+					&& a->arg.output.port == htons(OFPP_TABLE)) {
+			/* xxx Send fancy new error message? */
+			goto error;
+		}
+	}
+
 	/* Allocate memory. */
 	flow = flow_alloc(n_acts, GFP_ATOMIC);
 	if (flow == NULL)
diff --git a/datapath/forward.h b/datapath/forward.h
index 8e92330f..f061d2da 100644
--- a/datapath/forward.h
+++ b/datapath/forward.h
@@ -2,6 +2,7 @@
 #define FORWARD_H 1
 
 #include <linux/types.h>
+#include "datapath.h"
 #include "flow.h"
 
 struct sk_buff;
@@ -27,6 +28,9 @@ uint32_t fwd_save_skb(struct sk_buff *skb);
 
 void fwd_exit(void);
 
+void execute_actions(struct datapath *, struct sk_buff *,
+			const struct sw_flow_key *, 
+			const struct ofp_action *, int n_actions);
 struct sk_buff *execute_setter(struct sk_buff *, uint16_t,
 			const struct sw_flow_key *, const struct ofp_action *);
 
diff --git a/include/openflow.h b/include/openflow.h
index 96a60c25..9c469066 100644
--- a/include/openflow.h
+++ b/include/openflow.h
@@ -61,7 +61,11 @@ enum ofp_port {
     OFPP_MAX = 0x100,
 
     /* Fake output "ports". */
-    OFPP_NORMAL     = 0xfffa,  /* Process with normal L2/L3 switching */
+    OFPP_TABLE      = 0xfff9,  /* Perform actions in flow table.  
+                                * NB: This can only be the destination
+                                * port for packet-out messages. 
+                                */
+    OFPP_NORMAL     = 0xfffa,  /* Process with normal L2/L3 switching. */
     OFPP_FLOOD      = 0xfffb,  /* All physical ports except input port and 
                                   those disabled by STP. */
     OFPP_ALL        = 0xfffc,  /* All physical ports except input port. */
-- 
2.30.2