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path: root/drivers/usb/net/rndis_host.c
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Diffstat (limited to 'drivers/usb/net/rndis_host.c')
-rw-r--r--drivers/usb/net/rndis_host.c81
1 files changed, 62 insertions, 19 deletions
diff --git a/drivers/usb/net/rndis_host.c b/drivers/usb/net/rndis_host.c
index a322a16d9cf8..be888d2d813c 100644
--- a/drivers/usb/net/rndis_host.c
+++ b/drivers/usb/net/rndis_host.c
@@ -49,6 +49,8 @@
* - In some cases, MS-Windows will emit undocumented requests; this
* matters more to peripheral implementations than host ones.
*
+ * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
+ *
* For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
* favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
* currently rare) "Ethernet Emulation Model" (EEM).
@@ -61,6 +63,9 @@
* - control-in: GET_ENCAPSULATED
*
* We'll try to ignore the RESPONSE_AVAILABLE notifications.
+ *
+ * REVISIT some RNDIS implementations seem to have curious issues still
+ * to be resolved.
*/
struct rndis_msg_hdr {
__le32 msg_type; /* RNDIS_MSG_* */
@@ -71,8 +76,14 @@ struct rndis_msg_hdr {
// ... and more
} __attribute__ ((packed));
-/* RNDIS defines this (absurdly huge) control timeout */
-#define RNDIS_CONTROL_TIMEOUT_MS (10 * 1000)
+/* MS-Windows uses this strange size, but RNDIS spec says 1024 minimum */
+#define CONTROL_BUFFER_SIZE 1025
+
+/* RNDIS defines an (absurdly huge) 10 second control timeout,
+ * but ActiveSync seems to use a more usual 5 second timeout
+ * (which matches the USB 2.0 spec).
+ */
+#define RNDIS_CONTROL_TIMEOUT_MS (5 * 1000)
#define ccpu2 __constant_cpu_to_le32
@@ -270,6 +281,7 @@ static void rndis_status(struct usbnet *dev, struct urb *urb)
static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
{
struct cdc_state *info = (void *) &dev->data;
+ int master_ifnum;
int retval;
unsigned count;
__le32 rsp;
@@ -279,7 +291,7 @@ static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
* disconnect(): either serialize, or dispatch responses on xid
*/
- /* Issue the request; don't bother byteswapping our xid */
+ /* Issue the request; xid is unique, don't bother byteswapping it */
if (likely(buf->msg_type != RNDIS_MSG_HALT
&& buf->msg_type != RNDIS_MSG_RESET)) {
xid = dev->xid++;
@@ -287,11 +299,12 @@ static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
xid = dev->xid++;
buf->request_id = (__force __le32) xid;
}
+ master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
retval = usb_control_msg(dev->udev,
usb_sndctrlpipe(dev->udev, 0),
USB_CDC_SEND_ENCAPSULATED_COMMAND,
USB_TYPE_CLASS | USB_RECIP_INTERFACE,
- 0, info->u->bMasterInterface0,
+ 0, master_ifnum,
buf, le32_to_cpu(buf->msg_len),
RNDIS_CONTROL_TIMEOUT_MS);
if (unlikely(retval < 0 || xid == 0))
@@ -306,13 +319,13 @@ static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
*/
rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
for (count = 0; count < 10; count++) {
- memset(buf, 0, 1024);
+ memset(buf, 0, CONTROL_BUFFER_SIZE);
retval = usb_control_msg(dev->udev,
usb_rcvctrlpipe(dev->udev, 0),
USB_CDC_GET_ENCAPSULATED_RESPONSE,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
- 0, info->u->bMasterInterface0,
- buf, 1024,
+ 0, master_ifnum,
+ buf, CONTROL_BUFFER_SIZE,
RNDIS_CONTROL_TIMEOUT_MS);
if (likely(retval >= 8)) {
msg_len = le32_to_cpu(buf->msg_len);
@@ -350,7 +363,7 @@ static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
usb_sndctrlpipe(dev->udev, 0),
USB_CDC_SEND_ENCAPSULATED_COMMAND,
USB_TYPE_CLASS | USB_RECIP_INTERFACE,
- 0, info->u->bMasterInterface0,
+ 0, master_ifnum,
msg, sizeof *msg,
RNDIS_CONTROL_TIMEOUT_MS);
if (unlikely(retval < 0))
@@ -393,38 +406,64 @@ static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
u32 tmp;
/* we can't rely on i/o from stack working, or stack allocation */
- u.buf = kmalloc(1024, GFP_KERNEL);
+ u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
if (!u.buf)
return -ENOMEM;
retval = usbnet_generic_cdc_bind(dev, intf);
if (retval < 0)
goto fail;
- net->hard_header_len += sizeof (struct rndis_data_hdr);
-
- /* initialize; max transfer is 16KB at full speed */
u.init->msg_type = RNDIS_MSG_INIT;
u.init->msg_len = ccpu2(sizeof *u.init);
u.init->major_version = ccpu2(1);
u.init->minor_version = ccpu2(0);
- u.init->max_transfer_size = ccpu2(net->mtu + net->hard_header_len);
+ /* max transfer (in spec) is 0x4000 at full speed, but for
+ * TX we'll stick to one Ethernet packet plus RNDIS framing.
+ * For RX we handle drivers that zero-pad to end-of-packet.
+ * Don't let userspace change these settings.
+ */
+ net->hard_header_len += sizeof (struct rndis_data_hdr);
+ dev->hard_mtu = net->mtu + net->hard_header_len;
+
+ dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
+ dev->rx_urb_size &= ~(dev->maxpacket - 1);
+ u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
+
+ net->change_mtu = NULL;
retval = rndis_command(dev, u.header);
if (unlikely(retval < 0)) {
/* it might not even be an RNDIS device!! */
dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
+ goto fail_and_release;
+ }
+ tmp = le32_to_cpu(u.init_c->max_transfer_size);
+ if (tmp < dev->hard_mtu) {
+ dev_err(&intf->dev,
+ "dev can't take %u byte packets (max %u)\n",
+ dev->hard_mtu, tmp);
goto fail_and_release;
}
- dev->hard_mtu = le32_to_cpu(u.init_c->max_transfer_size);
+
/* REVISIT: peripheral "alignment" request is ignored ... */
- dev_dbg(&intf->dev, "hard mtu %u, align %d\n", dev->hard_mtu,
+ dev_dbg(&intf->dev,
+ "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
+ dev->hard_mtu, tmp, dev->rx_urb_size,
1 << le32_to_cpu(u.init_c->packet_alignment));
- /* get designated host ethernet address */
- memset(u.get, 0, sizeof *u.get);
+ /* Get designated host ethernet address.
+ *
+ * Adding a payload exactly the same size as the expected response
+ * payload is an evident requirement MSFT added for ActiveSync.
+ * This undocumented (and nonsensical) issue was found by sniffing
+ * protocol requests from the ActiveSync 4.1 Windows driver.
+ */
+ memset(u.get, 0, sizeof *u.get + 48);
u.get->msg_type = RNDIS_MSG_QUERY;
- u.get->msg_len = ccpu2(sizeof *u.get);
+ u.get->msg_len = ccpu2(sizeof *u.get + 48);
u.get->oid = OID_802_3_PERMANENT_ADDRESS;
+ u.get->len = ccpu2(48);
+ u.get->offset = ccpu2(20);
retval = rndis_command(dev, u.header);
if (unlikely(retval < 0)) {
@@ -432,7 +471,7 @@ static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
goto fail_and_release;
}
tmp = le32_to_cpu(u.get_c->offset);
- if (unlikely((tmp + 8) > (1024 - ETH_ALEN)
+ if (unlikely((tmp + 8) > (CONTROL_BUFFER_SIZE - ETH_ALEN)
|| u.get_c->len != ccpu2(ETH_ALEN))) {
dev_err(&intf->dev, "rndis ethaddr off %d len %d ?\n",
tmp, le32_to_cpu(u.get_c->len));
@@ -598,6 +637,10 @@ static const struct usb_device_id products [] = {
/* RNDIS is MSFT's un-official variant of CDC ACM */
USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
.driver_info = (unsigned long) &rndis_info,
+}, {
+ /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
+ USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
+ .driver_info = (unsigned long) &rndis_info,
},
{ }, // END
};
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.