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Commit dcda138d authored by Sjur Braendeland's avatar Sjur Braendeland Committed by David S. Miller
Browse files

caif: Bugfix - use MSG_TRUNC in receive 



Fixed handling when skb don't fit in user buffer,
instead of returning -EMSGSIZE, the buffer is truncated (just
as unix seqpakcet does).

Signed-off-by: default avatarSjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a9a8f107

net/caif/caif_socket.c

+18 −29
Original line number Diff line number Diff line
@@ -292,53 +292,42 @@ static void caif_check_flow_release(struct sock *sk) 
			caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);

	}

}



/*

 * Copied from sock.c:sock_queue_rcv_skb(), and added check that user buffer

 * has sufficient size.

 * Copied from unix_dgram_recvmsg, but removed credit checks,

 * changed locking, address handling and added MSG_TRUNC.

 */



static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,

				struct msghdr *m, size_t buf_len, int flags)

				struct msghdr *m, size_t len, int flags)



{

	struct sock *sk = sock->sk;

	struct sk_buff *skb;

	int ret = 0;

	int len;

	int ret;

	int copylen;



	if (unlikely(!buf_len))

		return -EINVAL;

	ret = -EOPNOTSUPP;

	if (m->msg_flags&MSG_OOB)

		goto read_error;



	skb = skb_recv_datagram(sk, flags, 0 , &ret);

	if (!skb)

		goto read_error;



	len = skb->len;



	if (skb && skb->len > buf_len && !(flags & MSG_PEEK)) {

		len = buf_len;

		/*

		 * Push skb back on receive queue if buffer too small.

		 * This has a built-in race where multi-threaded receive

		 * may get packet in wrong order, but multiple read does

		 * not really guarantee ordered delivery anyway.

		 * Let's optimize for speed without taking locks.

		 */



		skb_queue_head(&sk->sk_receive_queue, skb);

		ret = -EMSGSIZE;

		goto read_error;

	copylen = skb->len;

	if (len < copylen) {

		m->msg_flags |= MSG_TRUNC;

		copylen = len;

	}



	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len);

	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);

	if (ret)

		goto read_error;

		goto out_free;



	ret = (flags & MSG_TRUNC) ? skb->len : copylen;

out_free:

	skb_free_datagram(sk, skb);



	caif_check_flow_release(sk);



	return len;

	return ret;



read_error:

	return ret;