dpif: Update dpif interface to match netdev.

This brings over some features that were added to the netdev interface,
most notably the separation between the name and the type.  In addition
to being cleaner, this also avoids problems where it is expected that
the local port has the same name as the datapath.

1 files changed, 97 insertions, 53 deletions

diff --git a/lib/dpif.c b/lib/dpif.c
index 793eaa118..5947179b0 100644
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -95,57 +95,86 @@ dp_wait(void)
     }
 }
 
-/* Clears 'all_dps' and enumerates the names of all known created datapaths, 
- * where possible, into it.  The caller must first initialize 'all_dps'.
- * Returns 0 if successful, otherwise a positive errno value.
+
+/* Clears 'types' and enumerates the types of all known datapath providers,
+ * into it.  The caller must first initialize the svec. */
+void
+dp_enumerate_types(struct svec *types)
+{
+    int i;
+
+    svec_clear(types);
+
+    for (i = 0; i < N_DPIF_CLASSES; i++) {
+        svec_add(types, dpif_classes[i]->type);
+    }
+}
+
+/* Clears 'names' and enumerates the names of all known created datapaths with
+ * the given 'type'.  The caller must first initialize the svec. Returns 0 if
+ * successful, otherwise a positive errno value.
  *
  * Some kinds of datapaths might not be practically enumerable.  This is not
  * considered an error. */
 int
-dp_enumerate(struct svec *all_dps)
+dp_enumerate_names(const char *type, struct svec *names)
 {
-    int error;
     int i;
 
-    svec_clear(all_dps);
-    error = 0;
+    svec_clear(names);
+
     for (i = 0; i < N_DPIF_CLASSES; i++) {
         const struct dpif_class *class = dpif_classes[i];
-        int retval = class->enumerate ? class->enumerate(all_dps) : 0;
-        if (retval) {
-            VLOG_WARN("failed to enumerate %s datapaths: %s",
-                      class->name, strerror(retval));
-            if (!error) {
-                error = retval;
+
+        if (!strcmp(type, class->type)) {
+            int error = class->enumerate ? class->enumerate(names) : 0;
+
+            if (error) {
+                VLOG_WARN("failed to enumerate %s datapaths: %s",
+                          class->type, strerror(error));
             }
+
+            return error;
         }
     }
-    return error;
+
+    return EAFNOSUPPORT;
+}
+
+/* Parses 'datapath name', which is of the form type@name into its
+ * component pieces.  'name' and 'type' must be freed by the caller. */
+void
+dp_parse_name(const char *datapath_name_, char **name, char **type)
+{
+    char *datapath_name = xstrdup(datapath_name_);
+    char *separator;
+
+    separator = strchr(datapath_name, '@');
+    if (separator) {
+        *separator = '\0';
+        *type = datapath_name;
+        *name = xstrdup(separator + 1);
+    } else {
+        *name = datapath_name;
+        *type = NULL;
+    }
 }
 
 static int
-do_open(const char *name_, bool create, struct dpif **dpifp)
+do_open(const char *name, const char *type, bool create, struct dpif **dpifp)
 {
-    char *name = xstrdup(name_);
-    char *prefix, *suffix, *colon;
     struct dpif *dpif = NULL;
     int error;
     int i;
 
-    colon = strchr(name, ':');
-    if (colon) {
-        *colon = '\0';
-        prefix = name;
-        suffix = colon + 1;
-    } else {
-        prefix = "";
-        suffix = name;
+    if (!type || *type == '\0') {
+        type = "system";
     }
 
     for (i = 0; i < N_DPIF_CLASSES; i++) {
         const struct dpif_class *class = dpif_classes[i];
-        if (!strcmp(prefix, class->prefix)) {
-            error = class->open(name_, suffix, create, &dpif);
+        if (!strcmp(type, class->type)) {
+            error = class->open(name, type, create, &dpif);
             goto exit;
         }
     }
@@ -156,38 +185,41 @@ exit:
     return error;
 }
 
-/* Tries to open an existing datapath named 'name'.  Will fail if no datapath
- * named 'name' exists.  Returns 0 if successful, otherwise a positive errno
- * value.  On success stores a pointer to the datapath in '*dpifp', otherwise a
- * null pointer. */
+/* Tries to open an existing datapath named 'name' and type 'type'.  Will fail
+ * if no datapath with 'name' and 'type' exists.  'type' may be either NULL or
+ * the empty string to specify the default system type.  Returns 0 if
+ * successful, otherwise a positive errno value.  On success stores a pointer
+ * to the datapath in '*dpifp', otherwise a null pointer. */
 int
-dpif_open(const char *name, struct dpif **dpifp)
+dpif_open(const char *name, const char *type, struct dpif **dpifp)
 {
-    return do_open(name, false, dpifp);
+    return do_open(name, type, false, dpifp);
 }
 
-/* Tries to create and open a new datapath with the given 'name'.  Will fail if
- * a datapath named 'name' already exists.  Returns 0 if successful, otherwise
- * a positive errno value.  On success stores a pointer to the datapath in
- * '*dpifp', otherwise a null pointer. */
+/* Tries to create and open a new datapath with the given 'name' and 'type'.
+ * 'type' may be either NULL or the empty string to specify the default system
+ * type.  Will fail if a datapath with 'name' and 'type' already exists.
+ * Returns 0 if successful, otherwise a positive errno value.  On success
+ * stores a pointer to the datapath in '*dpifp', otherwise a null pointer. */
 int
-dpif_create(const char *name, struct dpif **dpifp)
+dpif_create(const char *name, const char *type, struct dpif **dpifp)
 {
-    return do_open(name, true, dpifp);
+    return do_open(name, type, true, dpifp);
 }
 
-/* Tries to open a datapath with the given 'name', creating it if it does not
- * exist.  Returns 0 if successful, otherwise a positive errno value.  On
- * success stores a pointer to the datapath in '*dpifp', otherwise a null
- * pointer. */
+/* Tries to open a datapath with the given 'name' and 'type', creating it if it
+ * does not exist.  'type' may be either NULL or the empty string to specify
+ * the default system type.  Returns 0 if successful, otherwise a positive
+ * errno value. On success stores a pointer to the datapath in '*dpifp',
+ * otherwise a null pointer. */
 int
-dpif_create_and_open(const char *name, struct dpif **dpifp)
+dpif_create_and_open(const char *name, const char *type, struct dpif **dpifp)
 {
     int error;
 
-    error = dpif_create(name, dpifp);
+    error = dpif_create(name, type, dpifp);
     if (error == EEXIST || error == EBUSY) {
-        error = dpif_open(name, dpifp);
+        error = dpif_open(name, type, dpifp);
         if (error) {
             VLOG_WARN("datapath %s already exists but cannot be opened: %s",
                       name, strerror(error));
@@ -204,17 +236,28 @@ void
 dpif_close(struct dpif *dpif)
 {
     if (dpif) {
-        char *name = dpif->name;
+        char *base_name = dpif->base_name;
+        char *full_name = dpif->full_name;
         dpif->class->close(dpif);
-        free(name);
+        free(base_name);
+        free(full_name);
     }
 }
 
-/* Returns the name of datapath 'dpif' (for use in log messages). */
+/* Returns the name of datapath 'dpif' prefixed with the type
+ * (for use in log messages). */
 const char *
 dpif_name(const struct dpif *dpif)
 {
-    return dpif->name;
+    return dpif->full_name;
+}
+
+/* Returns the name of datapath 'dpif' without the type
+ * (for use in device names). */
+const char *
+dpif_base_name(const struct dpif *dpif)
+{
+    return dpif->base_name;
 }
 
 /* Enumerates all names that may be used to open 'dpif' into 'all_names'.  The
@@ -238,7 +281,7 @@ dpif_get_all_names(const struct dpif *dpif, struct svec *all_names)
         }
         return error;
     } else {
-        svec_add(all_names, dpif_name(dpif));
+        svec_add(all_names, dpif_base_name(dpif));
         return 0;
     }
 }
@@ -927,7 +970,8 @@ dpif_init(struct dpif *dpif, const struct dpif_class *class, const char *name,
           uint8_t netflow_engine_type, uint8_t netflow_engine_id)
 {
     dpif->class = class;
-    dpif->name = xstrdup(name);
+    dpif->base_name = xstrdup(name);
+    dpif->full_name = xasprintf("%s@%s", class->type, name);
     dpif->netflow_engine_type = netflow_engine_type;
     dpif->netflow_engine_id = netflow_engine_id;
 }