dpif: Allow execute to modify the packet.

[sliver-openvswitch.git] / lib / dpif.h

diff --git a/lib/dpif.h b/lib/dpif.h
index 499ee79..d447a86 100644 (file)
--- a/lib/dpif.h
+++ b/lib/dpif.h
@@ -35,10 +35,10 @@
  * The terms written in quotes below are defined in later sections.
  *
  * When a datapath "port" receives a packet, it extracts the headers (the
- * "flow").  If the datapath's "flow table" contains a "flow entry" whose flow
- * is the same as the packet's, then it executes the "actions" in the flow
- * entry and increments the flow's statistics.  If there is no matching flow
- * entry, the datapath instead appends the packet to an "upcall" queue.
+ * "flow").  If the datapath's "flow table" contains a "flow entry" matching
+ * the packet, then it executes the "actions" in the flow entry and increments
+ * the flow's statistics.  If there is no matching flow entry, the datapath
+ * instead appends the packet to an "upcall" queue.
  *
  *
  * Ports
@@ -368,6 +368,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include "ofpbuf.h"
 #include "openflow/openflow.h"
 #include "netdev.h"
 #include "util.h"
@@ -380,7 +381,6 @@ struct dpif;
 struct ds;
 struct flow;
 struct nlattr;
-struct ofpbuf;
 struct sset;
 struct dpif_class;
 
@@ -521,8 +521,7 @@ int dpif_flow_dump_done(struct dpif_flow_dump *);
 int dpif_execute(struct dpif *,
                  const struct nlattr *key, size_t key_len,
                  const struct nlattr *actions, size_t actions_len,
-                 const struct ofpbuf *,
-                 bool needs_help);
+                 struct ofpbuf *, bool needs_help);
 \f
 /* Operation batching interface.
  *
@@ -565,7 +564,7 @@ struct dpif_execute {
     size_t key_len;                 /* Length of 'key' in bytes. */
     const struct nlattr *actions;   /* Actions to execute on packet. */
     size_t actions_len;             /* Length of 'actions' in bytes. */
-    const struct ofpbuf *packet;    /* Packet to execute. */
+    struct ofpbuf *packet;          /* Packet to execute. */
 
     /* Some dpif providers do not implement every action.  The Linux kernel
      * datapath, in particular, does not implement ARP field modification.
@@ -601,15 +600,17 @@ const char *dpif_upcall_type_to_string(enum dpif_upcall_type);
 
 /* A packet passed up from the datapath to userspace.
  *
- * If 'key', 'actions', or 'userdata' is nonnull, then it points into data
- * owned by 'packet', so their memory cannot be freed separately.  (This is
- * hardly a great way to do things but it works out OK for the dpif providers
- * and clients that exist so far.)
+ * The 'packet', 'key' and 'userdata' may point into data in a buffer
+ * provided by the caller, so the buffer should be released only after the
+ * upcall processing has been finished.
+ *
+ * While being processed, the 'packet' may be reallocated, so the packet must
+ * be separately released with ofpbuf_uninit().
  */
 struct dpif_upcall {
     /* All types. */
     enum dpif_upcall_type type;
-    struct ofpbuf *packet;      /* Packet data. */
+    struct ofpbuf packet;       /* Packet data. */
     struct nlattr *key;         /* Flow key. */
     size_t key_len;             /* Length of 'key' in bytes. */