can: bcm: add support for MSG_CMSG_COMPAT
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/net/can/bcm.c b/net/can/bcm.c
index a24232a..953d0c7 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -40,6 +40,7 @@
*
*/
+#include <linux/compat.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -61,6 +62,27 @@
#include <net/sock.h>
#include <net/net_namespace.h>
+/**
+ * struct bcm_msg_head_compat - head of messages to/from the broadcast manager
+ * @opcode: opcode, see enum below.
+ * @flags: special flags, see below.
+ * @count: number of frames to send before changing interval.
+ * @ival1: interval for the first @count frames (using s32).
+ * @ival2: interval for the following frames (using s32).
+ * @can_id: CAN ID of frames to be sent or received.
+ * @nframes: number of frames appended to the message head.
+ * @frames: array of CAN frames.
+ */
+struct bcm_msg_head_compat {
+ __u32 opcode;
+ __u32 flags;
+ __u32 count;
+ struct old_timeval32 ival1, ival2;
+ canid_t can_id;
+ __u32 nframes;
+ struct can_frame frames[];
+};
+
/*
* To send multiple CAN frame content within TX_SETUP or to filter
* CAN messages with multiplex index within RX_SETUP, the number of
@@ -1302,16 +1324,41 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
if (!bo->bound)
return -ENOTCONN;
- msg_head_size = sizeof(msg_head);
+ if (msg->msg_flags & MSG_CMSG_COMPAT) {
+ struct bcm_msg_head_compat msg_head_compat;
- /* check for valid message length from userspace */
- if (size < msg_head_size)
- return -EINVAL;
+ msg_head_size = sizeof(msg_head_compat);
- /* read message head information */
- ret = memcpy_from_msg((u8 *)&msg_head, msg, msg_head_size);
- if (ret < 0)
- return ret;
+ /* check for valid message length from userspace */
+ if (size < msg_head_size)
+ return -EINVAL;
+
+ /* read message head information */
+ ret = memcpy_from_msg(&msg_head_compat, msg, msg_head_size);
+ if (ret < 0)
+ return ret;
+
+ msg_head.opcode = msg_head_compat.opcode;
+ msg_head.flags = msg_head_compat.flags;
+ msg_head.count = msg_head_compat.count;
+ msg_head.ival1.tv_sec = msg_head_compat.ival1.tv_sec;
+ msg_head.ival1.tv_usec = msg_head_compat.ival1.tv_usec;
+ msg_head.ival2.tv_sec = msg_head_compat.ival2.tv_sec;
+ msg_head.ival2.tv_usec = msg_head_compat.ival2.tv_usec;
+ msg_head.can_id = msg_head_compat.can_id;
+ msg_head.nframes = msg_head_compat.nframes;
+ } else {
+ msg_head_size = sizeof(msg_head);
+
+ /* check for valid message length from userspace */
+ if (size < msg_head_size)
+ return -EINVAL;
+
+ /* read message head information */
+ ret = memcpy_from_msg((u8 *)&msg_head, msg, msg_head_size);
+ if (ret < 0)
+ return ret;
+ }
cfsiz = CFSIZ(msg_head.flags);
if ((size - msg_head_size) % cfsiz)
@@ -1657,6 +1704,7 @@ static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
struct sock *sk = sock->sk;
struct sk_buff *skb;
int error = 0;
+ int rem_len;
int err;
skb = skb_recv_datagram(sk, flags, &error);
@@ -1666,7 +1714,39 @@ static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
if (skb->len < size)
size = skb->len;
- err = memcpy_to_msg(msg, skb->data, size);
+ rem_len = size;
+
+ if (flags & MSG_CMSG_COMPAT) {
+ struct bcm_msg_head_compat msg_head_compat;
+ struct bcm_msg_head *msg_head;
+
+ if (skb->len < sizeof(*msg_head)) {
+ skb_free_datagram(sk, skb);
+ return -EINVAL;
+ }
+
+ msg_head = skb_pull_data(skb, sizeof(*msg_head));
+ msg_head_compat.opcode = msg_head->opcode;
+ msg_head_compat.flags = msg_head->flags;
+ msg_head_compat.count = msg_head->count;
+ msg_head_compat.ival1.tv_sec = msg_head->ival1.tv_sec;
+ msg_head_compat.ival1.tv_usec = msg_head->ival1.tv_usec;
+ msg_head_compat.ival2.tv_sec = msg_head->ival2.tv_sec;
+ msg_head_compat.ival2.tv_usec = msg_head->ival2.tv_usec;
+ msg_head_compat.can_id = msg_head->can_id;
+ msg_head_compat.nframes = msg_head->nframes;
+
+ err = memcpy_to_msg(msg, &msg_head_compat, sizeof(msg_head_compat));
+ if (err < 0) {
+ skb_free_datagram(sk, skb);
+ return err;
+ }
+
+ rem_len = size - sizeof(*msg_head);
+ size = rem_len + sizeof(msg_head_compat);
+ }
+
+ err = memcpy_to_msg(msg, skb->data, rem_len);
if (err < 0) {
skb_free_datagram(sk, skb);
return err;
