From david-b@pacbell.net Sat Aug 13 14:34:43 2005
From: David Brownell <david-b@pacbell.net>
Subject: USB: usbnet (8/9) module for RNDIS devices
Date: Sat, 13 Aug 2005 14:18:13 -0700
Cc: Greg KH <greg@kroah.com>
Message-Id: <200508131418.13732.david-b@pacbell.net>
This driver is EXPERIMENTAL, new, and only lightly tested.
But it ought to be useful. :)
This adds host-side RNDIS support to the "usbnet" driver, so Linux can talk
to various devices (often based on WinCE) that otherwise only Windows could
talk to.
Tested with little-endian Linux talking to a Linux-USB Ethernet/RNDIS based
peripheral. This also includes updates from Eddie C. Dost <ecd@brainaid.de>
for big-endian SPARC Linux talking to a Nokia 9500 Communicator.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/usb/net/Kconfig | 14 +
drivers/usb/net/Makefile | 1
drivers/usb/net/rndis.c | 614 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/net/usbnet.c | 9
4 files changed, 630 insertions(+), 8 deletions(-)
--- gregkh-2.6.orig/drivers/usb/net/Makefile 2005-08-15 17:51:25.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/Makefile 2005-08-15 17:51:26.000000000 -0700
@@ -10,6 +10,7 @@
obj-$(CONFIG_USB_NET_CDCETHER) += cdc_ether.o
obj-$(CONFIG_USB_NET_GL620A) += gl620a.o
obj-$(CONFIG_USB_NET_NET1080) += net1080.o
+obj-$(CONFIG_USB_NET_RNDIS) += rndis.o
obj-$(CONFIG_USB_NET_SIMPLE) += simple.o
obj-$(CONFIG_USB_NET_ZAURUS) += zaurus.o
obj-$(CONFIG_USB_USBNET) += usbnet.o
--- gregkh-2.6.orig/drivers/usb/net/Kconfig 2005-08-15 17:51:25.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/Kconfig 2005-08-15 17:51:26.000000000 -0700
@@ -213,6 +213,20 @@
on this design: one NetChip 1080 chips and supporting logic,
supporting LEDs that indicate traffic
+config USB_NET_RNDIS
+ tristate "RNDIS devices (EXPERIMENTAL)"
+ depends on USB_USBNET && EXPERIMENTAL
+ select USB_NET_CDCETHER
+ default n
+ help
+ Choose this option to support "Remote NDIS" usb networking links,
+ as encouraged by Microsoft (instead of CDC Ethernet!) for use in
+ various devices that may only support this protocol.
+
+ Avoid using this protocol unless you have no better options.
+ The protocol specification is incomplete, and is controlled by
+ (and for) Microsoft; it isn't an "Open" ecosystem or market.
+
config USB_NET_SIMPLE
tristate "Simple USB Network Links"
depends on USB_USBNET
--- gregkh-2.6.orig/drivers/usb/net/usbnet.c 2005-08-15 17:51:25.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/usbnet.c 2005-08-15 17:51:26.000000000 -0700
@@ -103,6 +103,7 @@
* disconnect; other cleanups. (db) Flush net1080 fifos
* after several sequential framing errors. (Johannes Erdfelt)
* 22-aug-2003 AX8817X support (Dave Hollis).
+ *
* 14-jun-2004 Trivial patch for AX8817X based Buffalo LUA-U2-KTX in Japan
* (Neil Bortnak)
* 03-nov-2004 Trivial patch for KC2190 (KC-190) chip. (Jonathan McDowell)
@@ -1357,14 +1358,6 @@
.driver_info = (unsigned long) &prolific_info,
},
#endif
-
-#ifdef CONFIG_USB_RNDIS
-{
- /* 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,
-},
-#endif
{ }, // END
};
MODULE_DEVICE_TABLE (usb, products);
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gregkh-2.6/drivers/usb/net/rndis.c 2005-08-15 17:51:26.000000000 -0700
@@ -0,0 +1,614 @@
+/*
+ * 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>
+#ifdef CONFIG_USB_DEBUG
+# define DEBUG
+#endif
+#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.
+ */
+
+/*
+ * 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;
+
+ // REVISIT: seems like some devices discard responses when
+ // we time out and cancel our "get response" requests...
+
+ /* 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, unsigned 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 = {
+ .owner = THIS_MODULE,
+ .name = "rndis",
+ .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");