/*
* Host Side support for RNDIS Networking Links
* Copyright (C) 2005 by David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include "usbnet.h"
/*
* RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
* course ACM was intended for modems, not Ethernet links! USB's standard
* for Ethernet links is "CDC Ethernet", which is significantly simpler.
*
* NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
* include:
* - Power management in particular relies on information that's scattered
* through other documentation, and which is incomplete or incorrect even
* there.
* - There are various undocumented protocol requirements, such as the
* need to send unused garbage in control-OUT messages.
* - In some cases, MS-Windows will emit undocumented requests; this
* matters more to peripheral implementations than host ones.
*
* 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).
*/
/*
* CONTROL uses CDC "encapsulated commands" with funky notifications.
* - control-out: SEND_ENCAPSULATED
* - interrupt-in: RESPONSE_AVAILABLE
* - control-in: GET_ENCAPSULATED
*
* We'll try to ignore the RESPONSE_AVAILABLE notifications.
*/
struct rndis_msg_hdr {
__le32 msg_type; /* RNDIS_MSG_* */
__le32 msg_len;
// followed by data that varies between messages
__le32 request_id;
__le32 status;
// ... and more
} __attribute__ ((packed));
/* RNDIS defines this (absurdly huge) control timeout */
#define RNDIS_CONTROL_TIMEOUT_MS (10 * 1000)
#define ccpu2 __constant_cpu_to_le32
#define RNDIS_MSG_COMPLETION ccpu2(0x80000000)
/* codes for "msg_type" field of rndis messages;
* only the data channel uses packet messages (maybe batched);
* everything else goes on the control channel.
*/
#define RNDIS_MSG_PACKET ccpu2(0x00000001) /* 1-N packets */
#define RNDIS_MSG_INIT ccpu2(0x00000002)
#define RNDIS_MSG_INIT_C (RNDIS_MSG_INIT|RNDIS_MSG_COMPLETION)
#define RNDIS_MSG_HALT ccpu2(0x00000003)
#define RNDIS_MSG_QUERY ccpu2(0x00000004)
#define RNDIS_MSG_QUERY_C (RNDIS_MSG_QUERY|RNDIS_MSG_COMPLETION)
#define RNDIS_MSG_SET ccpu2(0x00000005)
#define RNDIS_MSG_SET_C (RNDIS_MSG_SET|RNDIS_MSG_COMPLETION)
#define RNDIS_MSG_RESET ccpu2(0x00000006)
#define RNDIS_MSG_RESET_C (RNDIS_MSG_RESET|RNDIS_MSG_COMPLETION)
#define RNDIS_MSG_INDICATE ccpu2(0x00000007)
#define RNDIS_MSG_KEEPALIVE ccpu2(0x00000008)
#define RNDIS_MSG_KEEPALIVE_C (RNDIS_MSG_KEEPALIVE|RNDIS_MSG_COMPLETION)
/* codes for "status" field of completion messages */
#define RNDIS_STATUS_SUCCESS ccpu2(0x00000000)
#define RNDIS_STATUS_FAILURE ccpu2(0xc0000001)
#define RNDIS_STATUS_INVALID_DATA ccpu2(0xc0010015)
#define RNDIS_STATUS_NOT_SUPPORTED ccpu2(0xc00000bb)
#define RNDIS_STATUS_MEDIA_CONNECT ccpu2(0x4001000b)
#define RNDIS_STATUS_MEDIA_DISCONNECT ccpu2(0x4001000c)
struct rndis_data_hdr {
__le32 msg_type; /* RNDIS_MSG_PACKET */
__le32 msg_len; // rndis_data_hdr + data_len + pad
__le32 data_offset; // 36 -- right after header
__le32 data_len; // ... real packet size
__le32 oob_data_offset; // zero
__le32 oob_data_len; // zero
__le32 num_oob; // zero
__le32 packet_data_offset; // zero
__le32 packet_data_len; // zero
__le32 vc_handle; // zero
__le32 reserved; // zero
} __attribute__ ((packed));
struct rndis_init { /* OUT */
// header and:
__le32 msg_type; /* RNDIS_MSG_INIT */
__le32 msg_len; // 24
__le32 request_id;
__le32 major_version; // of rndis (1.0)
__le32 minor_version;
__le32 max_transfer_size;
} __attribute__ ((packed));
struct rndis_init_c { /* IN */
// header and:
__le32 msg_type; /* RNDIS_MSG_INIT_C */
__le32 msg_len;
__le32 request_id;
__le32 status;
__le32 major_version; // of rndis (1.0)
__le32 minor_version;
__le32 device_flags;
__le32 medium; // zero == 802.3
__le32 max_packets_per_message;
__le32 max_transfer_size;
__le32 packet_alignment; // max 7; (1<<n) bytes
__le32 af_list_offset; // zero
__le32 af_list_size; // zero
} __attribute__ ((packed));
struct rndis_halt { /* OUT (no reply) */
// header and:
__le32 msg_type; /* RNDIS_MSG_HALT */
__le32 msg_len;
__le32 request_id;
} __attribute__ ((packed));
struct rndis_query { /* OUT */
// header and:
__le32 msg_type; /* RNDIS_MSG_QUERY */
__le32 msg_len;
__le32 request_id;
__le32 oid;
__le32 len;
__le32 offset;
/*?*/ __le32 handle; // zero
} __attribute__ ((packed));
struct rndis_query_c { /* IN */
// header and:
__le32 msg_type; /* RNDIS_MSG_QUERY_C */
__le32 msg_len;
__le32 request_id;
__le32 status;
__le32 len;
__le32 offset;
} __attribute__ ((packed));
struct rndis_set { /* OUT */
// header and:
__le32 msg_type; /* RNDIS_MSG_SET */
__le32 msg_len;
__le32 request_id;
__le32 oid;
__le32 len;
__le32 offset;
/*?*/ __le32 handle; // zero
} __attribute__ ((packed));
struct rndis_set_c { /* IN */
// header and:
__le32 msg_type; /* RNDIS_MSG_SET_C */
__le32 msg_len;
__le32 request_id;
__le32 status;
} __attribute__ ((packed));
struct rndis_reset { /* IN */
// header and:
__le32 msg_type; /* RNDIS_MSG_RESET */
__le32 msg_len;
__le32 reserved;
} __attribute__ ((packed));
struct rndis_reset_c { /* OUT */
// header and:
__le32 msg_type; /* RNDIS_MSG_RESET_C */
__le32 msg_len;
__le32 status;
__le32 addressing_lost;
} __attribute__ ((packed));
struct rndis_indicate { /* IN (unrequested) */
// header and:
__le32 msg_type; /* RNDIS_MSG_INDICATE */
__le32 msg_len;
__le32 status;
__le32 length;
__le32 offset;
/**/ __le32 diag_status;
__le32 error_offset;
/**/ __le32 message;
} __attribute__ ((packed));
struct rndis_keepalive { /* OUT (optionally IN) */
// header and:
__le32 msg_type; /* RNDIS_MSG_KEEPALIVE */
__le32 msg_len;
__le32 request_id;
} __attribute__ ((packed));
struct rndis_keepalive_c { /* IN (optionally OUT) */
// header and:
__le32 msg_type; /* RNDIS_MSG_KEEPALIVE_C */
__le32 msg_len;
__le32 request_id;
__le32 status;
} __attribute__ ((packed));
/* NOTE: about 30 OIDs are "mandatory" for peripherals to support ... and
* there are gobs more that may optionally be supported. We'll avoid as much
* of that mess as possible.
*/
#define OID_802_3_PERMANENT_ADDRESS ccpu2(0x01010101)
#define OID_GEN_CURRENT_PACKET_FILTER ccpu2(0x0001010e)
/*
* RNDIS notifications from device: command completion; "reverse"
* keepalives; etc
*/
static void rndis_status(struct usbnet *dev, struct urb *urb)
{
devdbg(dev, "rndis status urb, len %d stat %d",
urb->actual_length, urb->status);
// FIXME for keepalives, respond immediately (asynchronously)
// if not an RNDIS status, do like cdc_status(dev,urb) does
}
/*
* RPC done RNDIS-style. Caller guarantees:
* - message is properly byteswapped
* - there's no other request pending
* - buf can hold up to 1KB response (required by RNDIS spec)
* On return, the first few entries are already byteswapped.
*
* Call context is likely probe(), before interface name is known,
* which is why we won't try to use it in the diagnostics.
*/
static int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
{
struct cdc_state *info = (void *) &dev->data;
int retval;
unsigned count;
__le32 rsp;
u32 xid = 0, msg_len, request_id;
/* REVISIT when this gets called from contexts other than probe() or
* disconnect(): either serialize, or dispatch responses on xid
*/
/* Issue the request; don't bother byteswapping our xid */
if (likely(buf->msg_type != RNDIS_MSG_HALT
&& buf->msg_type != RNDIS_MSG_RESET)) {
xid = dev->xid++;
if (!xid)
xid = dev->xid++;
buf->request_id = (__force __le32) xid;
}
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,
buf, le32_to_cpu(buf->msg_len),
RNDIS_CONTROL_TIMEOUT_MS);
if (unlikely(retval < 0 || xid == 0))
return retval;
// FIXME Seems like some devices discard responses when
// we time out and cancel our "get response" requests...
// so, this is fragile. Probably need to poll for status.
/* ignore status endpoint, just poll the control channel;
* the request probably completed immediately
*/
rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
for (count = 0; count < 10; count++) {
memset(buf, 0, 1024);
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,
RNDIS_CONTROL_TIMEOUT_MS);
if (likely(retval >= 8)) {
msg_len = le32_to_cpu(buf->msg_len);
request_id = (__force u32) buf->request_id;
if (likely(buf->msg_type == rsp)) {
if (likely(request_id == xid)) {
if (unlikely(rsp == RNDIS_MSG_RESET_C))
return 0;
if (likely(RNDIS_STATUS_SUCCESS
== buf->status))
return 0;
dev_dbg(&info->control->dev,
"rndis reply status %08x\n",
le32_to_cpu(buf->status));
return -EL3RST;
}
dev_dbg(&info->control->dev,
"rndis reply id %d expected %d\n",
request_id, xid);
/* then likely retry */
} else switch (buf->msg_type) {
case RNDIS_MSG_INDICATE: { /* fault */
// struct rndis_indicate *msg = (void *)buf;
dev_info(&info->control->dev,
"rndis fault indication\n");
}
break;
case RNDIS_MSG_KEEPALIVE: { /* ping */
struct rndis_keepalive_c *msg = (void *)buf;
msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
msg->msg_len = ccpu2(sizeof *msg);
msg->status = RNDIS_STATUS_SUCCESS;
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,
msg, sizeof *msg,
RNDIS_CONTROL_TIMEOUT_MS);
if (unlikely(retval < 0))
dev_dbg(&info->control->dev,
"rndis keepalive err %d\n",
retval);
}
break;
default:
dev_dbg(&info->control->dev,
"unexpected rndis msg %08x len %d\n",
le32_to_cpu(buf->msg_type), msg_len);
}
} else {
/* device probably issued a protocol stall; ignore */
dev_dbg(&info->control->dev,
"rndis response error, code %d\n", retval);
}
msleep(2);
}
dev_dbg(&info->control->dev, "rndis response timeout\n");
return -ETIMEDOUT;
}
static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
{
int retval;
struct net_device *net = dev->net;
union {
void *buf;
struct rndis_msg_hdr *header;
struct rndis_init *init;
struct rndis_init_c *init_c;
struct rndis_query *get;
struct rndis_query_c *get_c;
struct rndis_set *set;
struct rndis_set_c *set_c;
} u;
u32 tmp;
/* we can't rely on i/o from stack working, or stack allocation */
u.buf = kmalloc(1024, GFP_KERNEL);
if (!u.buf)
return -ENOMEM;
retval = usbnet_generic_cdc_bind(dev, intf);
if (retval < 0)
goto done;
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);
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);
fail:
usb_driver_release_interface(driver_of(intf),
((struct cdc_state *)&(dev->data))->data);
goto done;
}
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,
1 << le32_to_cpu(u.init_c->packet_alignment));
/* get designated host ethernet address */
memset(u.get, 0, sizeof *u.get);
u.get->msg_type = RNDIS_MSG_QUERY;
u.get->msg_len = ccpu2(sizeof *u.get);
u.get->oid = OID_802_3_PERMANENT_ADDRESS;
retval = rndis_command(dev, u.header);
if (unlikely(retval < 0)) {
dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
goto fail;
}
tmp = le32_to_cpu(u.get_c->offset);
if (unlikely((tmp + 8) > (1024 - 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));
retval = -EDOM;
goto fail;
}
memcpy(net->dev_addr, tmp + (char *)&u.get_c->request_id, ETH_ALEN);
/* set a nonzero filter to enable data transfers */
memset(u.set, 0, sizeof *u.set);
u.set->msg_type = RNDIS_MSG_SET;
u.set->msg_len = ccpu2(4 + sizeof *u.set);
u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
u.set->len = ccpu2(4);
u.set->offset = ccpu2((sizeof *u.set) - 8);
*(__le32 *)(u.buf + sizeof *u.set) = ccpu2(DEFAULT_FILTER);
retval = rndis_command(dev, u.header);
if (unlikely(retval < 0)) {
dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
goto fail;
}
retval = 0;
done:
kfree(u.buf);
return retval;
}
static void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
{
struct rndis_halt *halt;
/* try to clear any rndis state/activity (no i/o from stack!) */
halt = kcalloc(1, sizeof *halt, SLAB_KERNEL);
if (halt) {
halt->msg_type = RNDIS_MSG_HALT;
halt->msg_len = ccpu2(sizeof *halt);
(void) rndis_command(dev, (void *)halt);
kfree(halt);
}
return usbnet_cdc_unbind(dev, intf);
}
/*
* DATA -- host must not write zlps
*/
static int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
/* peripheral may have batched packets to us... */
while (likely(skb->len)) {
struct rndis_data_hdr *hdr = (void *)skb->data;
struct sk_buff *skb2;
u32 msg_len, data_offset, data_len;
msg_len = le32_to_cpu(hdr->msg_len);
data_offset = le32_to_cpu(hdr->data_offset);
data_len = le32_to_cpu(hdr->data_len);
/* don't choke if we see oob, per-packet data, etc */
if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
|| skb->len < msg_len
|| (data_offset + data_len + 8) > msg_len)) {
dev->stats.rx_frame_errors++;
devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
le32_to_cpu(hdr->msg_type),
msg_len, data_offset, data_len, skb->len);
return 0;
}
skb_pull(skb, 8 + data_offset);
/* at most one packet left? */
if (likely((data_len - skb->len) <= sizeof *hdr)) {
skb_trim(skb, data_len);
break;
}
/* try to return all the packets in the batch */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!skb2))
break;
skb_pull(skb, msg_len - sizeof *hdr);
skb_trim(skb2, data_len);
usbnet_skb_return(dev, skb2);
}
/* caller will usbnet_skb_return the remaining packet */
return 1;
}
static struct sk_buff *
rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
{
struct rndis_data_hdr *hdr;
struct sk_buff *skb2;
unsigned len = skb->len;
if (likely(!skb_cloned(skb))) {
int room = skb_headroom(skb);
/* enough head room as-is? */
if (unlikely((sizeof *hdr) <= room))
goto fill;
/* enough room, but needs to be readjusted? */
room += skb_tailroom(skb);
if (likely((sizeof *hdr) <= room)) {
skb->data = memmove(skb->head + sizeof *hdr,
skb->data, len);
skb->tail = skb->data + len;
goto fill;
}
}
/* create a new skb, with the correct size (and tailpad) */
skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
dev_kfree_skb_any(skb);
if (unlikely(!skb2))
return skb2;
skb = skb2;
/* fill out the RNDIS header. we won't bother trying to batch
* packets; Linux minimizes wasted bandwidth through tx queues.
*/
fill:
hdr = (void *) __skb_push(skb, sizeof *hdr);
memset(hdr, 0, sizeof *hdr);
hdr->msg_type = RNDIS_MSG_PACKET;
hdr->msg_len = cpu_to_le32(skb->len);
hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
hdr->data_len = cpu_to_le32(len);
/* FIXME make the last packet always be short ... */
return skb;
}
static const struct driver_info rndis_info = {
.description = "RNDIS device",
.flags = FLAG_ETHER | FLAG_FRAMING_RN,
.bind = rndis_bind,
.unbind = rndis_unbind,
.status = rndis_status,
.rx_fixup = rndis_rx_fixup,
.tx_fixup = rndis_tx_fixup,
};
#undef ccpu2
/*-------------------------------------------------------------------------*/
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,
},
{ }, // END
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver rndis_driver = {
.name = "rndis_host",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
};
static int __init rndis_init(void)
{
return usb_register(&rndis_driver);
}
module_init(rndis_init);
static void __exit rndis_exit(void)
{
usb_deregister(&rndis_driver);
}
module_exit(rndis_exit);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("USB Host side RNDIS driver");
MODULE_LICENSE("GPL");
