Merge branch 'master' of git://gitorious.org/linux-can/linux-can-next

Marc Kleine-Budde says:

====================
here is our second pull request for net-next. In this series Federico
Vaga adds a pci driver for c_can/d_can hardware using the existing
generic c_can driver. The remaining 6 patches are by Oliver Hartkopp.
He adds CANFD support to the CAN stack while keeping binary
compatibility for existing applications. CANFD is an extension to the
existing CAN standard, it allows longer CAN frames and/or higher data
rates. There's no real hardware available yet, but this series adds
CANFD support to the vcan driver.
====================

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

1 files changed, 46 insertions, 4 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index 46cca3a91d19..3e9c89356a93 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -82,6 +82,7 @@ struct raw_sock {
 	struct notifier_block notifier;
 	int loopback;
 	int recv_own_msgs;
+	int fd_frames;
 	int count;                 /* number of active filters */
 	struct can_filter dfilter; /* default/single filter */
 	struct can_filter *filter; /* pointer to filter(s) */
@@ -119,6 +120,14 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
 	if (!ro->recv_own_msgs && oskb->sk == sk)
 		return;
 
+	/* do not pass frames with DLC > 8 to a legacy socket */
+	if (!ro->fd_frames) {
+		struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
+
+		if (unlikely(cfd->len > CAN_MAX_DLEN))
+			return;
+	}
+
 	/* clone the given skb to be able to enqueue it into the rcv queue */
 	skb = skb_clone(oskb, GFP_ATOMIC);
 	if (!skb)
@@ -291,6 +300,7 @@ static int raw_init(struct sock *sk)
 	/* set default loopback behaviour */
 	ro->loopback         = 1;
 	ro->recv_own_msgs    = 0;
+	ro->fd_frames        = 0;
 
 	/* set notifier */
 	ro->notifier.notifier_call = raw_notifier;
@@ -569,6 +579,15 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 
 		break;
 
+	case CAN_RAW_FD_FRAMES:
+		if (optlen != sizeof(ro->fd_frames))
+			return -EINVAL;
+
+		if (copy_from_user(&ro->fd_frames, optval, optlen))
+			return -EFAULT;
+
+		break;
+
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -627,6 +646,12 @@ static int raw_getsockopt(struct socket *sock, int level, int optname,
 		val = &ro->recv_own_msgs;
 		break;
 
+	case CAN_RAW_FD_FRAMES:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		val = &ro->fd_frames;
+		break;
+
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -662,8 +687,13 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 	} else
 		ifindex = ro->ifindex;
 
-	if (size != sizeof(struct can_frame))
-		return -EINVAL;
+	if (ro->fd_frames) {
+		if (unlikely(size != CANFD_MTU && size != CAN_MTU))
+			return -EINVAL;
+	} else {
+		if (unlikely(size != CAN_MTU))
+			return -EINVAL;
+	}
 
 	dev = dev_get_by_index(&init_net, ifindex);
 	if (!dev)
@@ -705,7 +735,9 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 		       struct msghdr *msg, size_t size, int flags)
 {
 	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
 	struct sk_buff *skb;
+	int rxmtu;
 	int err = 0;
 	int noblock;
 
@@ -716,10 +748,20 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 	if (!skb)
 		return err;
 
-	if (size < skb->len)
+	/*
+	 * when serving a legacy socket the DLC <= 8 is already checked inside
+	 * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
+	 * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
+	 */
+	if (!ro->fd_frames)
+		rxmtu = CAN_MTU;
+	else
+		rxmtu = skb->len;
+
+	if (size < rxmtu)
 		msg->msg_flags |= MSG_TRUNC;
 	else
-		size = skb->len;
+		size = rxmtu;
 
 	err = memcpy_toiovec(msg->msg_iov, skb->data, size);
 	if (err < 0) {