1 files changed, 38 insertions, 12 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index da99cf153b33..e88f610fdb7b 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -90,23 +90,39 @@ struct raw_sock {
 	can_err_mask_t err_mask;
 };
 
+/*
+ * Return pointer to store the extra msg flags for raw_recvmsg().
+ * We use the space of one unsigned int beyond the 'struct sockaddr_can'
+ * in skb->cb.
+ */
+static inline unsigned int *raw_flags(struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
+					 sizeof(unsigned int)));
+
+	/* return pointer after struct sockaddr_can */
+	return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
+}
+
 static inline struct raw_sock *raw_sk(const struct sock *sk)
 {
 	return (struct raw_sock *)sk;
 }
 
-static void raw_rcv(struct sk_buff *skb, void *data)
+static void raw_rcv(struct sk_buff *oskb, void *data)
 {
 	struct sock *sk = (struct sock *)data;
 	struct raw_sock *ro = raw_sk(sk);
 	struct sockaddr_can *addr;
+	struct sk_buff *skb;
+	unsigned int *pflags;
 
 	/* check the received tx sock reference */
-	if (!ro->recv_own_msgs && skb->sk == sk)
+	if (!ro->recv_own_msgs && oskb->sk == sk)
 		return;
 
 	/* clone the given skb to be able to enqueue it into the rcv queue */
-	skb = skb_clone(skb, GFP_ATOMIC);
+	skb = skb_clone(oskb, GFP_ATOMIC);
 	if (!skb)
 		return;
 
@@ -123,6 +139,14 @@ static void raw_rcv(struct sk_buff *skb, void *data)
 	addr->can_family  = AF_CAN;
 	addr->can_ifindex = skb->dev->ifindex;
 
+	/* add CAN specific message flags for raw_recvmsg() */
+	pflags = raw_flags(skb);
+	*pflags = 0;
+	if (oskb->sk)
+		*pflags |= MSG_DONTROUTE;
+	if (oskb->sk == sk)
+		*pflags |= MSG_CONFIRM;
+
 	if (sock_queue_rcv_skb(sk, skb) < 0)
 		kfree_skb(skb);
 }
@@ -436,14 +460,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 
 		if (count > 1) {
 			/* filter does not fit into dfilter => alloc space */
-			filter = kmalloc(optlen, GFP_KERNEL);
-			if (!filter)
-				return -ENOMEM;
-
-			if (copy_from_user(filter, optval, optlen)) {
-				kfree(filter);
-				return -EFAULT;
-			}
+			filter = memdup_user(optval, optlen);
+			if (IS_ERR(filter))
+				return PTR_ERR(filter);
 		} else if (count == 1) {
 			if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 				return -EFAULT;
@@ -652,9 +671,13 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 	if (err < 0)
 		goto free_skb;
-	err = sock_tx_timestamp(msg, sk, skb_tx(skb));
+	err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
 	if (err < 0)
 		goto free_skb;
+
+	/* to be able to check the received tx sock reference in raw_rcv() */
+	skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
+
 	skb->dev = dev;
 	skb->sk  = sk;
 
@@ -708,6 +731,9 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
 		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
+	/* assign the flags that have been recorded in raw_rcv() */
+	msg->msg_flags |= *(raw_flags(skb));
+
 	skb_free_datagram(sk, skb);
 
 	return size;