From 02c7b6922899621aa8e8babe27fca7b6b2e497b0 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 18 Sep 2015 11:30:44 +0200 Subject: [PATCH] mac802154: tx: add warning if MTU exceeds Sending over AF_PACKET RAW sockets we can sending frames which exceeds MTU size. To handling it correct we need to change things in AF_PACKET which knows on RAW sockets an additional FCS is set by hardware or mac802154 transmit functionality. Signed-off-by: Alexander Aring Signed-off-by: Marcel Holtmann --- net/mac802154/tx.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c index 66d7ecb7c56b..5ee596e00a6d 100644 --- a/net/mac802154/tx.c +++ b/net/mac802154/tx.c @@ -71,6 +71,17 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb) struct net_device *dev = skb->dev; int ret; + /* This check is for AF_PACKET RAW socket only, which doesn't + * know about the FCS which is set here or by hardware. otherwise + * it should not occur in any case! + * + * TODO: This should be handled in AF_PACKET and return -EMSGSIZE. + */ + if (skb->len > IEEE802154_MTU - IEEE802154_FCS_LEN) { + netdev_warn(dev, "Frame len above MTU limit. Dropped.\n"); + goto err_tx; + } + if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) { u16 crc = crc_ccitt(0, skb->data, skb->len); -- 2.39.5