Merge pull request #20997 from benpicco/backport/2024.10/gnrc_netif_n…

…etdev_new_api-leak

gnrc_netif: fix packet leak with gnrc_netif_pktq & netdev_new_api [backport 2024.10]

drivers/at86rf215/at86rf215_netdev.c

@@ -176,9 +176,11 @@ static int _send(netdev_t *netdev, const iolist_t *iolist)
         at86rf215_tx_exec(dev);
     }
 
-    /* return the number of bytes that were actually loaded into the frame
-     * buffer/send out */
-    return (int)len;
+    /* store successfully sent number of bytes */
+    dev->tx_frame_len = len;
+
+    /* netdev_new just returns 0 on success */
+    return 0;
 }
 
 static int _confirm_send(netdev_t *netdev, void *info)

sys/net/gnrc/netif/gnrc_netif.c

@@ -1810,7 +1810,7 @@ static void _tx_done(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt,
         }
         return;
     }
-    else {
+    else if (gnrc_netif_netdev_legacy_api(netif)) {
         /* remove previously held packet */
         gnrc_pktbuf_release(pkt);
         return;
@@ -1882,7 +1882,9 @@ static void _send(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt, bool push_back)
     }
     /* hold in case device was busy to not having to rewrite *all* the link
      * layer implementations in case `gnrc_netif_pktq` is included */
-    gnrc_pktbuf_hold(pkt, 1);
+    if (gnrc_netif_netdev_legacy_api(netif)) {
+        gnrc_pktbuf_hold(pkt, 1);
+    }
 #endif /* IS_USED(MODULE_GNRC_NETIF_PKTQ) */
 
     /* Record send in neighbor statistics if destination is unicast */

sys/net/gnrc/netif/gnrc_netif_raw.c

@@ -104,13 +104,24 @@ static gnrc_pktsnip_t *_recv(gnrc_netif_t *netif)
     return pkt;
 }
 
+static gnrc_pktsnip_t *_skip_pkt_head(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt)
+{
+    if (gnrc_netif_netdev_legacy_api(netif)) {
+        /* we don't need the netif snip: remove it */
+        return gnrc_pktbuf_remove_snip(pkt, pkt);
+    }
+    else {
+        /* _tx_done() will free the entire list */
+        return pkt->next;
+    }
+}
+
 static int _send(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt)
 {
     int res = -ENOBUFS;
 
     if (pkt->type == GNRC_NETTYPE_NETIF) {
-        /* we don't need the netif snip: remove it */
-        pkt = gnrc_pktbuf_remove_snip(pkt, pkt);
+        pkt = _skip_pkt_head(netif, pkt);
     }
 
     netdev_t *dev = netif->dev;