Revert "rose: zero length frame filtering in af_rose.c"

This reverts commit 244f46ae6e9e18f6fc0be7d1f49febde4762c34b.

Alan Cox did the research, and just like the other radio protocols
zero-length frames have meaning because at the top level ROSE is
X.25 PLP.

So this zero-length filtering is invalid.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 0f36e8d..877a7f6 100644 (file)
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1072,10 +1072,6 @@ static int rose_sendmsg(struct kiocb *iocb, struct socket *sock,
        unsigned char *asmptr;
        int n, size, qbit = 0;
 
-       /* ROSE empty 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;
 
@@ -1273,12 +1269,6 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
        skb_reset_transport_header(skb);
        copied     = skb->len;
 
-       /* ROSE empty frame has no meaning : ignore it */
-       if (copied == 0) {
-               skb_free_datagram(sk, skb);
-               return copied;
-       }
-
        if (copied > size) {
                copied = size;
                msg->msg_flags |= MSG_TRUNC;