batman-adv: return netdev status in the TX path

Return the proper netdev TX status along the TX path so that the tp_meter
can understand when the queue is full and should stop sending packets.

Signed-off-by: Antonio Quartulli <antonio.quartulli@open-mesh.com>
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index 9f41a0a..0934730 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -433,11 +433,12 @@
  * @orig_node: final destination of the created fragments
  * @neigh_node: next-hop of the created fragments
  *
- * Return: true on success, false otherwise.
+ * Return: the netdev tx status or -1 in case of error.
+ * When -1 is returned the skb is not consumed.
  */
-bool batadv_frag_send_packet(struct sk_buff *skb,
-			     struct batadv_orig_node *orig_node,
-			     struct batadv_neigh_node *neigh_node)
+int batadv_frag_send_packet(struct sk_buff *skb,
+			    struct batadv_orig_node *orig_node,
+			    struct batadv_neigh_node *neigh_node)
 {
 	struct batadv_priv *bat_priv;
 	struct batadv_hard_iface *primary_if = NULL;
@@ -446,7 +447,7 @@
 	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;
 	unsigned int header_size = sizeof(frag_header);
 	unsigned int max_fragment_size, max_packet_size;
-	bool ret = false;
+	int ret = -1;
 
 	/* To avoid merge and refragmentation at next-hops we never send
 	 * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE
@@ -457,12 +458,12 @@
 
 	/* Don't even try to fragment, if we need more than 16 fragments */
 	if (skb->len > max_packet_size)
-		goto out_err;
+		goto out;
 
 	bat_priv = orig_node->bat_priv;
 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (!primary_if)
-		goto out_err;
+		goto out;
 
 	/* Create one header to be copied to all fragments */
 	frag_header.packet_type = BATADV_UNICAST_FRAG;
@@ -488,23 +489,33 @@
 	while (skb->len > max_fragment_size) {
 		skb_fragment = batadv_frag_create(skb, &frag_header, mtu);
 		if (!skb_fragment)
-			goto out_err;
+			goto out;
 
 		batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX);
 		batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,
 				   skb_fragment->len + ETH_HLEN);
-		batadv_send_unicast_skb(skb_fragment, neigh_node);
+		ret = batadv_send_unicast_skb(skb_fragment, neigh_node);
+		if (ret != NET_XMIT_SUCCESS) {
+			/* return -1 so that the caller can free the original
+			 * skb
+			 */
+			ret = -1;
+			goto out;
+		}
+
 		frag_header.no++;
 
 		/* The initial check in this function should cover this case */
-		if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1)
-			goto out_err;
+		if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) {
+			ret = -1;
+			goto out;
+		}
 	}
 
 	/* Make room for the fragment header. */
 	if (batadv_skb_head_push(skb, header_size) < 0 ||
 	    pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0)
-		goto out_err;
+		goto out;
 
 	memcpy(skb->data, &frag_header, header_size);
 
@@ -512,11 +523,9 @@
 	batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX);
 	batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES,
 			   skb->len + ETH_HLEN);
-	batadv_send_unicast_skb(skb, neigh_node);
+	ret = batadv_send_unicast_skb(skb, neigh_node);
 
-	ret = true;
-
-out_err:
+out:
 	if (primary_if)
 		batadv_hardif_put(primary_if);