Resolved memory leak

Cherry-picked 81cde92 from development.

modules/pico_ethernet.c

@@ -295,7 +295,7 @@ static int pico_ethernet_ipv6_dst(struct pico_frame *f, struct pico_eth *const d
 
 /* Ethernet send, first attempt: try our own address.
  * Returns 0 if the packet is not for us.
- * Returns 1 if the packet is cloned to our own receive queue, so the caller can discard the original frame.
+ * Returns 1 if the packet is cloned to our own receive queue and the original frame is dicarded.
  * */
 static int32_t pico_ethsend_local(struct pico_frame *f, struct pico_eth_hdr *hdr)
 {
@@ -308,7 +308,9 @@ static int32_t pico_ethsend_local(struct pico_frame *f, struct pico_eth_hdr *hdr
         dbg("sending out packet destined for our own mac\n");
         if (pico_ethernet_receive(clone) < 0) {
             dbg("pico_ethernet_receive() failed\n");
+            return 0;
         }
+        pico_frame_discard(f);
         return 1;
     }
 
@@ -317,13 +319,12 @@ static int32_t pico_ethsend_local(struct pico_frame *f, struct pico_eth_hdr *hdr
 
 /* Ethernet send, second attempt: try bcast.
  * Returns 0 if the packet is not bcast, so it will be handled somewhere else.
- * Returns 1 if the packet is handled by the pico_device_broadcast() function, so it can be discarded.
+ * Returns 1 if the packet is handled by the pico_device_broadcast() function and is discarded.
  * */
 static int32_t pico_ethsend_bcast(struct pico_frame *f)
 {
     if (IS_LIMITED_BCAST(f)) {
-        (void)pico_device_broadcast(f); /* We can discard broadcast even if it's not sent. */
-        return 1;
+        return (pico_device_broadcast(f) > 0); // Return 1 on success, ret > 0
     }
 
     return 0;

stack/pico_device.c

@@ -450,6 +450,7 @@ int32_t pico_device_broadcast(struct pico_frame *f)
 {
     struct pico_tree_node *index;
     int32_t ret = -1;
+    int sent = 0;
 
     pico_tree_foreach(index, &Device_tree)
     {
@@ -462,14 +463,29 @@ int32_t pico_device_broadcast(struct pico_frame *f)
                 break;
 
             copy->dev = dev;
-            copy->dev->send(copy->dev, copy->start, (int)copy->len);
+            ret = copy->dev->send(copy->dev, copy->start, (int)copy->len);
+            /* FIXME: If a device driver returns zero (which means the device
+             * driver is currently busy) there is no means to retry the
+             * broadcast operation later. */
             pico_frame_discard(copy);
         }
         else
         {
             ret = f->dev->send(f->dev, f->start, (int)f->len);
+            /* FIXME: If a device driver returns zero (which means the device
+             * driver is currently busy) there is no means to retry the
+             * broadcast operation later. */
+        }
+
+        /* FIXME: If at least one device driver was able to sent the frame on
+         * the wire, the broadcast operation will be considered successful. */
+        if (ret > 0) {
+            sent = 1;
         }
     }
+
+    ret = sent ? f->len : -1;
+    pico_frame_discard(f);
     return ret;
 }