openflow: Implement OF1.4+ OFPMP_QUEUE_DESC multipart message.

[cascardo/ovs.git] / lib / ofpbuf.c

diff --git a/lib/ofpbuf.c b/lib/ofpbuf.c
index 7510edb..c190f8b 100644 (file)
--- a/lib/ofpbuf.c
+++ b/lib/ofpbuf.c
@@ -33,12 +33,12 @@ ofpbuf_init__(struct ofpbuf *b, size_t allocated, enum ofpbuf_source source)
 }
 
 static void
-ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated,
+ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated, size_t size,
              enum ofpbuf_source source)
 {
     b->base = base;
     b->data = base;
-    b->size = 0;
+    b->size = size;
 
     ofpbuf_init__(b, allocated, source);
 }
@@ -47,10 +47,20 @@ ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated,
  * memory starting at 'base'.  'base' should be the first byte of a region
  * obtained from malloc().  It will be freed (with free()) if 'b' is resized or
  * freed. */
-void
+static void
 ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
 {
-    ofpbuf_use__(b, base, allocated, OFPBUF_MALLOC);
+    ofpbuf_use__(b, base, allocated, 0, OFPBUF_MALLOC);
+}
+
+/* Converts ds into ofpbuf 'b'. 'b' contains the 'ds->allocated' bytes of
+ * memory starting at 'ds->string'.  'ds' should not be modified any more.
+ * The memory allocated for 'ds' will be freed (with free()) if 'b' is
+ * resized or freed. */
+void
+ofpbuf_use_ds(struct ofpbuf *b, const struct ds *ds)
+{
+    ofpbuf_use__(b, ds->string, ds->allocated + 1, ds->length, OFPBUF_MALLOC);
 }
 
 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
@@ -70,7 +80,7 @@ ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
 void
 ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
 {
-    ofpbuf_use__(b, base, allocated, OFPBUF_STACK);
+    ofpbuf_use__(b, base, allocated, 0, OFPBUF_STACK);
 }
 
 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
@@ -90,7 +100,7 @@ ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
 void
 ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
 {
-    ofpbuf_use__(b, base, allocated, OFPBUF_STUB);
+    ofpbuf_use__(b, base, allocated, 0, OFPBUF_STUB);
 }
 
 /* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
@@ -103,8 +113,7 @@ ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
 void
 ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size)
 {
-    ofpbuf_use__(b, CONST_CAST(void *, data), size, OFPBUF_STACK);
-    b->size = size;
+    ofpbuf_use__(b, CONST_CAST(void *, data), size, size, OFPBUF_STACK);
 }
 
 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
@@ -258,9 +267,14 @@ ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
     new_data = (char *) new_base + new_headroom;
     if (b->data != new_data) {
         if (b->header) {
-            uintptr_t data_delta = (char *) new_data - (char *) b->data;
+            uintptr_t data_delta = (char *) b->header - (char *) b->data;
 
-            b->header = (char *) b->header + data_delta;
+            b->header = (char *) new_data + data_delta;
+        }
+        if (b->msg) {
+            uintptr_t data_delta = (char *) b->msg - (char *) b->data;
+
+            b->msg = (char *) new_data + data_delta;
         }
         b->data = new_data;
     }
@@ -292,7 +306,13 @@ ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
  * tailroom to 0, if any.
  *
  * Buffers not obtained from malloc() are not resized, since that wouldn't save
- * any memory. */
+ * any memory.
+ *
+ * Caller needs to updates 'b->header' and 'b->msg' so that they point to the
+ * same locations in the data.  (If they pointed into the tailroom or headroom
+ * then they become invalid.)
+ *
+ */
 void
 ofpbuf_trim(struct ofpbuf *b)
 {
@@ -315,7 +335,11 @@ ofpbuf_padto(struct ofpbuf *b, size_t length)
 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
  * For example, a 'delta' of 1 would cause each byte of data to move one byte
  * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
- * byte to move one byte backward (from 'p' to 'p-1'). */
+ * byte to move one byte backward (from 'p' to 'p-1').
+ *
+ * If used, user must make sure the 'header' and 'msg' pointers are updated
+ * after shifting.
+ */
 void
 ofpbuf_shift(struct ofpbuf *b, int delta)
 {
@@ -454,6 +478,8 @@ ofpbuf_steal_data(struct ofpbuf *b)
     }
     b->base = NULL;
     b->data = NULL;
+    b->header = NULL;
+    b->msg = NULL;
     return p;
 }
 
@@ -477,10 +503,9 @@ ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
 void
 ofpbuf_list_delete(struct ovs_list *list)
 {
-    struct ofpbuf *b, *next;
+    struct ofpbuf *b;
 
-    LIST_FOR_EACH_SAFE (b, next, list_node, list) {
-        list_remove(&b->list_node);
+    LIST_FOR_EACH_POP (b, list_node, list) {
         ofpbuf_delete(b);
     }
 }