netrom: zero length frame filtering in NetRom

A zero length frame filter was recently introduced in ROSE protocole.
Previous commit makes the same at AX25 protocole level.
This patch has the same purpose for NetRom  protocole.
The reason is that empty frames have no meaning in NetRom protocole.

Signed-off-by: Bernard Pidoux <f6bvp@amsat.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Bernard Pidoux 2009-03-21 13:34:20 -07:00 committed by David S. Miller
parent f99bcff7a2
commit a3ac80a130

View file

@ -1037,6 +1037,10 @@ static int nr_sendmsg(struct kiocb *iocb, struct socket *sock,
unsigned char *asmptr;
int size;
/* Netrom empty data frame has no meaning : don't send */
if (len == 0)
return 0;
if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
return -EINVAL;
@ -1167,6 +1171,11 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,
skb_reset_transport_header(skb);
copied = skb->len;
/* NetRom empty data frame has no meaning : ignore it */
if (copied == 0) {
goto out;
}
if (copied > size) {
copied = size;
msg->msg_flags |= MSG_TRUNC;
@ -1182,7 +1191,7 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,
msg->msg_namelen = sizeof(*sax);
skb_free_datagram(sk, skb);
out: skb_free_datagram(sk, skb);
release_sock(sk);
return copied;