ieee802154: add proper length checks to header creations

Have mac802154 header_ops.create fail with -EMSGSIZE if the length
passed will be too large to fit a frame. Since 6lowpan will ensure that
no packet payload will be too large, pass a length of 0 there. 802.15.4
dgram sockets will also return -EMSGSIZE on payloads larger than the
device MTU instead of -EINVAL.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 2 deletions

diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c
index d4edd20dab5f..606039442a59 100644
--- a/net/ieee802154/6lowpan_rtnl.c
+++ b/net/ieee802154/6lowpan_rtnl.c
@@ -141,7 +141,7 @@ static int lowpan_header_create(struct sk_buff *skb,
         }
 
         return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
-                        type, (void *)&da, (void *)&sa, skb->len);
+                        type, (void *)&da, (void *)&sa, 0);
 }
 
 static int lowpan_give_skb_to_devices(struct sk_buff *skb,
diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c
index 55f2dc45a7dc..4c47154041b0 100644
--- a/net/ieee802154/dgram.c
+++ b/net/ieee802154/dgram.c
@@ -233,7 +233,7 @@ static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
 
         if (size > mtu) {
                 pr_debug("size = %Zu, mtu = %u\n", size, mtu);
-                err = -EINVAL;
+                err = -EMSGSIZE;
                 goto out_dev;
         }