summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/function/f_rndis.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/usb/gadget/function/f_rndis.c')
-rw-r--r--drivers/usb/gadget/function/f_rndis.c1032
1 files changed, 1032 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
new file mode 100644
index 000000000..f20c55d42
--- /dev/null
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -0,0 +1,1032 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_rndis.c -- RNDIS link function driver
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
+ * Copyright (C) 2008 Nokia Corporation
+ * Copyright (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz (mina86@mina86.com)
+ */
+
+/* #define VERBOSE_DEBUG */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/etherdevice.h>
+
+#include <linux/atomic.h>
+
+#include "u_ether.h"
+#include "u_ether_configfs.h"
+#include "u_rndis.h"
+#include "rndis.h"
+#include "configfs.h"
+
+/*
+ * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
+ * been promoted instead of the standard CDC Ethernet. The published RNDIS
+ * spec is ambiguous, incomplete, and needlessly complex. Variants such as
+ * ActiveSync have even worse status in terms of specification.
+ *
+ * In short: it's a protocol controlled by (and for) Microsoft, not for an
+ * Open ecosystem or markets. Linux supports it *only* because Microsoft
+ * doesn't support the CDC Ethernet standard.
+ *
+ * The RNDIS data transfer model is complex, with multiple Ethernet packets
+ * per USB message, and out of band data. The control model is built around
+ * what's essentially an "RNDIS RPC" protocol. It's all wrapped in a CDC ACM
+ * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
+ * useless (they're ignored). RNDIS expects to be the only function in its
+ * configuration, so it's no real help if you need composite devices; and
+ * it expects to be the first configuration too.
+ *
+ * There is a single technical advantage of RNDIS over CDC Ethernet, if you
+ * discount the fluff that its RPC can be made to deliver: it doesn't need
+ * a NOP altsetting for the data interface. That lets it work on some of the
+ * "so smart it's stupid" hardware which takes over configuration changes
+ * from the software, and adds restrictions like "no altsettings".
+ *
+ * Unfortunately MSFT's RNDIS drivers are buggy. They hang or oops, and
+ * have all sorts of contrary-to-specification oddities that can prevent
+ * them from working sanely. Since bugfixes (or accurate specs, letting
+ * Linux work around those bugs) are unlikely to ever come from MSFT, you
+ * may want to avoid using RNDIS on purely operational grounds.
+ *
+ * Omissions from the RNDIS 1.0 specification include:
+ *
+ * - Power management ... references data that's scattered around lots
+ * of other documentation, which is incorrect/incomplete there too.
+ *
+ * - There are various undocumented protocol requirements, like the need
+ * to send garbage in some control-OUT messages.
+ *
+ * - MS-Windows drivers sometimes emit undocumented requests.
+ */
+
+struct f_rndis {
+ struct gether port;
+ u8 ctrl_id, data_id;
+ u8 ethaddr[ETH_ALEN];
+ u32 vendorID;
+ const char *manufacturer;
+ struct rndis_params *params;
+
+ struct usb_ep *notify;
+ struct usb_request *notify_req;
+ atomic_t notify_count;
+};
+
+static inline struct f_rndis *func_to_rndis(struct usb_function *f)
+{
+ return container_of(f, struct f_rndis, port.func);
+}
+
+/* peak (theoretical) bulk transfer rate in bits-per-second */
+static unsigned int bitrate(struct usb_gadget *g)
+{
+ if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
+ return 4250000000U;
+ if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
+ return 3750000000U;
+ else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
+ return 13 * 512 * 8 * 1000 * 8;
+ else
+ return 19 * 64 * 1 * 1000 * 8;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ */
+
+#define RNDIS_STATUS_INTERVAL_MS 32
+#define STATUS_BYTECOUNT 8 /* 8 bytes data */
+
+
+/* interface descriptor: */
+
+static struct usb_interface_descriptor rndis_control_intf = {
+ .bLength = sizeof rndis_control_intf,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ /* .bInterfaceNumber = DYNAMIC */
+ /* status endpoint is optional; this could be patched later */
+ .bNumEndpoints = 1,
+ .bInterfaceClass = USB_CLASS_COMM,
+ .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
+ .bInterfaceProtocol = USB_CDC_ACM_PROTO_VENDOR,
+ /* .iInterface = DYNAMIC */
+};
+
+static struct usb_cdc_header_desc header_desc = {
+ .bLength = sizeof header_desc,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_HEADER_TYPE,
+
+ .bcdCDC = cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
+ .bLength = sizeof call_mgmt_descriptor,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
+
+ .bmCapabilities = 0x00,
+ .bDataInterface = 0x01,
+};
+
+static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
+ .bLength = sizeof rndis_acm_descriptor,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_ACM_TYPE,
+
+ .bmCapabilities = 0x00,
+};
+
+static struct usb_cdc_union_desc rndis_union_desc = {
+ .bLength = sizeof(rndis_union_desc),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_UNION_TYPE,
+ /* .bMasterInterface0 = DYNAMIC */
+ /* .bSlaveInterface0 = DYNAMIC */
+};
+
+/* the data interface has two bulk endpoints */
+
+static struct usb_interface_descriptor rndis_data_intf = {
+ .bLength = sizeof rndis_data_intf,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ /* .bInterfaceNumber = DYNAMIC */
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_CDC_DATA,
+ .bInterfaceSubClass = 0,
+ .bInterfaceProtocol = 0,
+ /* .iInterface = DYNAMIC */
+};
+
+
+static struct usb_interface_assoc_descriptor
+rndis_iad_descriptor = {
+ .bLength = sizeof rndis_iad_descriptor,
+ .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
+
+ .bFirstInterface = 0, /* XXX, hardcoded */
+ .bInterfaceCount = 2, // control + data
+ .bFunctionClass = USB_CLASS_COMM,
+ .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
+ .bFunctionProtocol = USB_CDC_PROTO_NONE,
+ /* .iFunction = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
+ .bInterval = RNDIS_STATUS_INTERVAL_MS,
+};
+
+static struct usb_endpoint_descriptor fs_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor fs_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *eth_fs_function[] = {
+ (struct usb_descriptor_header *) &rndis_iad_descriptor,
+
+ /* control interface matches ACM, not Ethernet */
+ (struct usb_descriptor_header *) &rndis_control_intf,
+ (struct usb_descriptor_header *) &header_desc,
+ (struct usb_descriptor_header *) &call_mgmt_descriptor,
+ (struct usb_descriptor_header *) &rndis_acm_descriptor,
+ (struct usb_descriptor_header *) &rndis_union_desc,
+ (struct usb_descriptor_header *) &fs_notify_desc,
+
+ /* data interface has no altsetting */
+ (struct usb_descriptor_header *) &rndis_data_intf,
+ (struct usb_descriptor_header *) &fs_in_desc,
+ (struct usb_descriptor_header *) &fs_out_desc,
+ NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
+ .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
+};
+
+static struct usb_endpoint_descriptor hs_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *eth_hs_function[] = {
+ (struct usb_descriptor_header *) &rndis_iad_descriptor,
+
+ /* control interface matches ACM, not Ethernet */
+ (struct usb_descriptor_header *) &rndis_control_intf,
+ (struct usb_descriptor_header *) &header_desc,
+ (struct usb_descriptor_header *) &call_mgmt_descriptor,
+ (struct usb_descriptor_header *) &rndis_acm_descriptor,
+ (struct usb_descriptor_header *) &rndis_union_desc,
+ (struct usb_descriptor_header *) &hs_notify_desc,
+
+ /* data interface has no altsetting */
+ (struct usb_descriptor_header *) &rndis_data_intf,
+ (struct usb_descriptor_header *) &hs_in_desc,
+ (struct usb_descriptor_header *) &hs_out_desc,
+ NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(STATUS_BYTECOUNT),
+ .bInterval = USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
+};
+
+static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
+ .bLength = sizeof ss_intr_comp_desc,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+
+ /* the following 3 values can be tweaked if necessary */
+ /* .bMaxBurst = 0, */
+ /* .bmAttributes = 0, */
+ .wBytesPerInterval = cpu_to_le16(STATUS_BYTECOUNT),
+};
+
+static struct usb_endpoint_descriptor ss_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor ss_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
+ .bLength = sizeof ss_bulk_comp_desc,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+
+ /* the following 2 values can be tweaked if necessary */
+ /* .bMaxBurst = 0, */
+ /* .bmAttributes = 0, */
+};
+
+static struct usb_descriptor_header *eth_ss_function[] = {
+ (struct usb_descriptor_header *) &rndis_iad_descriptor,
+
+ /* control interface matches ACM, not Ethernet */
+ (struct usb_descriptor_header *) &rndis_control_intf,
+ (struct usb_descriptor_header *) &header_desc,
+ (struct usb_descriptor_header *) &call_mgmt_descriptor,
+ (struct usb_descriptor_header *) &rndis_acm_descriptor,
+ (struct usb_descriptor_header *) &rndis_union_desc,
+ (struct usb_descriptor_header *) &ss_notify_desc,
+ (struct usb_descriptor_header *) &ss_intr_comp_desc,
+
+ /* data interface has no altsetting */
+ (struct usb_descriptor_header *) &rndis_data_intf,
+ (struct usb_descriptor_header *) &ss_in_desc,
+ (struct usb_descriptor_header *) &ss_bulk_comp_desc,
+ (struct usb_descriptor_header *) &ss_out_desc,
+ (struct usb_descriptor_header *) &ss_bulk_comp_desc,
+ NULL,
+};
+
+/* string descriptors: */
+
+static struct usb_string rndis_string_defs[] = {
+ [0].s = "RNDIS Communications Control",
+ [1].s = "RNDIS Ethernet Data",
+ [2].s = "RNDIS",
+ { } /* end of list */
+};
+
+static struct usb_gadget_strings rndis_string_table = {
+ .language = 0x0409, /* en-us */
+ .strings = rndis_string_defs,
+};
+
+static struct usb_gadget_strings *rndis_strings[] = {
+ &rndis_string_table,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static struct sk_buff *rndis_add_header(struct gether *port,
+ struct sk_buff *skb)
+{
+ struct sk_buff *skb2;
+
+ if (!skb)
+ return NULL;
+
+ skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
+ rndis_add_hdr(skb2);
+
+ dev_kfree_skb(skb);
+ return skb2;
+}
+
+static void rndis_response_available(void *_rndis)
+{
+ struct f_rndis *rndis = _rndis;
+ struct usb_request *req = rndis->notify_req;
+ struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
+ __le32 *data = req->buf;
+ int status;
+
+ if (atomic_inc_return(&rndis->notify_count) != 1)
+ return;
+
+ /* Send RNDIS RESPONSE_AVAILABLE notification; a
+ * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
+ *
+ * This is the only notification defined by RNDIS.
+ */
+ data[0] = cpu_to_le32(1);
+ data[1] = cpu_to_le32(0);
+
+ status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
+ if (status) {
+ atomic_dec(&rndis->notify_count);
+ DBG(cdev, "notify/0 --> %d\n", status);
+ }
+}
+
+static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_rndis *rndis = req->context;
+ struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
+ int status = req->status;
+
+ /* after TX:
+ * - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
+ * - RNDIS_RESPONSE_AVAILABLE (status/irq)
+ */
+ switch (status) {
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ /* connection gone */
+ atomic_set(&rndis->notify_count, 0);
+ break;
+ default:
+ DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
+ ep->name, status,
+ req->actual, req->length);
+ /* FALLTHROUGH */
+ case 0:
+ if (ep != rndis->notify)
+ break;
+
+ /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
+ * notifications by resending until we're done
+ */
+ if (atomic_dec_and_test(&rndis->notify_count))
+ break;
+ status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
+ if (status) {
+ atomic_dec(&rndis->notify_count);
+ DBG(cdev, "notify/1 --> %d\n", status);
+ }
+ break;
+ }
+}
+
+static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_rndis *rndis = req->context;
+ int status;
+
+ /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
+// spin_lock(&dev->lock);
+ status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
+ if (status < 0)
+ pr_err("RNDIS command error %d, %d/%d\n",
+ status, req->actual, req->length);
+// spin_unlock(&dev->lock);
+}
+
+static int
+rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+ struct f_rndis *rndis = func_to_rndis(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+ struct usb_request *req = cdev->req;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ /* composite driver infrastructure handles everything except
+ * CDC class messages; interface activation uses set_alt().
+ */
+ switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+
+ /* RNDIS uses the CDC command encapsulation mechanism to implement
+ * an RPC scheme, with much getting/setting of attributes by OID.
+ */
+ case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+ | USB_CDC_SEND_ENCAPSULATED_COMMAND:
+ if (w_value || w_index != rndis->ctrl_id)
+ goto invalid;
+ /* read the request; process it later */
+ value = w_length;
+ req->complete = rndis_command_complete;
+ req->context = rndis;
+ /* later, rndis_response_available() sends a notification */
+ break;
+
+ case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+ | USB_CDC_GET_ENCAPSULATED_RESPONSE:
+ if (w_value || w_index != rndis->ctrl_id)
+ goto invalid;
+ else {
+ u8 *buf;
+ u32 n;
+
+ /* return the result */
+ buf = rndis_get_next_response(rndis->params, &n);
+ if (buf) {
+ memcpy(req->buf, buf, n);
+ req->complete = rndis_response_complete;
+ req->context = rndis;
+ rndis_free_response(rndis->params, buf);
+ value = n;
+ }
+ /* else stalls ... spec says to avoid that */
+ }
+ break;
+
+ default:
+invalid:
+ VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ }
+
+ /* respond with data transfer or status phase? */
+ if (value >= 0) {
+ DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ req->zero = (value < w_length);
+ req->length = value;
+ value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0)
+ ERROR(cdev, "rndis response on err %d\n", value);
+ }
+
+ /* device either stalls (value < 0) or reports success */
+ return value;
+}
+
+
+static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+ struct f_rndis *rndis = func_to_rndis(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ /* we know alt == 0 */
+
+ if (intf == rndis->ctrl_id) {
+ VDBG(cdev, "reset rndis control %d\n", intf);
+ usb_ep_disable(rndis->notify);
+
+ if (!rndis->notify->desc) {
+ VDBG(cdev, "init rndis ctrl %d\n", intf);
+ if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
+ goto fail;
+ }
+ usb_ep_enable(rndis->notify);
+
+ } else if (intf == rndis->data_id) {
+ struct net_device *net;
+
+ if (rndis->port.in_ep->enabled) {
+ DBG(cdev, "reset rndis\n");
+ gether_disconnect(&rndis->port);
+ }
+
+ if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
+ DBG(cdev, "init rndis\n");
+ if (config_ep_by_speed(cdev->gadget, f,
+ rndis->port.in_ep) ||
+ config_ep_by_speed(cdev->gadget, f,
+ rndis->port.out_ep)) {
+ rndis->port.in_ep->desc = NULL;
+ rndis->port.out_ep->desc = NULL;
+ goto fail;
+ }
+ }
+
+ /* Avoid ZLPs; they can be troublesome. */
+ rndis->port.is_zlp_ok = false;
+
+ /* RNDIS should be in the "RNDIS uninitialized" state,
+ * either never activated or after rndis_uninit().
+ *
+ * We don't want data to flow here until a nonzero packet
+ * filter is set, at which point it enters "RNDIS data
+ * initialized" state ... but we do want the endpoints
+ * to be activated. It's a strange little state.
+ *
+ * REVISIT the RNDIS gadget code has done this wrong for a
+ * very long time. We need another call to the link layer
+ * code -- gether_updown(...bool) maybe -- to do it right.
+ */
+ rndis->port.cdc_filter = 0;
+
+ DBG(cdev, "RNDIS RX/TX early activation ... \n");
+ net = gether_connect(&rndis->port);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ rndis_set_param_dev(rndis->params, net,
+ &rndis->port.cdc_filter);
+ } else
+ goto fail;
+
+ return 0;
+fail:
+ return -EINVAL;
+}
+
+static void rndis_disable(struct usb_function *f)
+{
+ struct f_rndis *rndis = func_to_rndis(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ if (!rndis->notify->enabled)
+ return;
+
+ DBG(cdev, "rndis deactivated\n");
+
+ rndis_uninit(rndis->params);
+ gether_disconnect(&rndis->port);
+
+ usb_ep_disable(rndis->notify);
+ rndis->notify->desc = NULL;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * This isn't quite the same mechanism as CDC Ethernet, since the
+ * notification scheme passes less data, but the same set of link
+ * states must be tested. A key difference is that altsettings are
+ * not used to tell whether the link should send packets or not.
+ */
+
+static void rndis_open(struct gether *geth)
+{
+ struct f_rndis *rndis = func_to_rndis(&geth->func);
+ struct usb_composite_dev *cdev = geth->func.config->cdev;
+
+ DBG(cdev, "%s\n", __func__);
+
+ rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
+ bitrate(cdev->gadget) / 100);
+ rndis_signal_connect(rndis->params);
+}
+
+static void rndis_close(struct gether *geth)
+{
+ struct f_rndis *rndis = func_to_rndis(&geth->func);
+
+ DBG(geth->func.config->cdev, "%s\n", __func__);
+
+ rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
+ rndis_signal_disconnect(rndis->params);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* Some controllers can't support RNDIS ... */
+static inline bool can_support_rndis(struct usb_configuration *c)
+{
+ /* everything else is *presumably* fine */
+ return true;
+}
+
+/* ethernet function driver setup/binding */
+
+static int
+rndis_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct f_rndis *rndis = func_to_rndis(f);
+ struct usb_string *us;
+ int status;
+ struct usb_ep *ep;
+
+ struct f_rndis_opts *rndis_opts;
+
+ if (!can_support_rndis(c))
+ return -EINVAL;
+
+ rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
+
+ if (cdev->use_os_string) {
+ f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
+ GFP_KERNEL);
+ if (!f->os_desc_table)
+ return -ENOMEM;
+ f->os_desc_n = 1;
+ f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
+ }
+
+ rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
+ rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
+ rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
+
+ /*
+ * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
+ * configurations are bound in sequence with list_for_each_entry,
+ * in each configuration its functions are bound in sequence
+ * with list_for_each_entry, so we assume no race condition
+ * with regard to rndis_opts->bound access
+ */
+ if (!rndis_opts->bound) {
+ gether_set_gadget(rndis_opts->net, cdev->gadget);
+ status = gether_register_netdev(rndis_opts->net);
+ if (status)
+ goto fail;
+ rndis_opts->bound = true;
+ }
+
+ us = usb_gstrings_attach(cdev, rndis_strings,
+ ARRAY_SIZE(rndis_string_defs));
+ if (IS_ERR(us)) {
+ status = PTR_ERR(us);
+ goto fail;
+ }
+ rndis_control_intf.iInterface = us[0].id;
+ rndis_data_intf.iInterface = us[1].id;
+ rndis_iad_descriptor.iFunction = us[2].id;
+
+ /* allocate instance-specific interface IDs */
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ rndis->ctrl_id = status;
+ rndis_iad_descriptor.bFirstInterface = status;
+
+ rndis_control_intf.bInterfaceNumber = status;
+ rndis_union_desc.bMasterInterface0 = status;
+
+ if (cdev->use_os_string)
+ f->os_desc_table[0].if_id =
+ rndis_iad_descriptor.bFirstInterface;
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ rndis->data_id = status;
+
+ rndis_data_intf.bInterfaceNumber = status;
+ rndis_union_desc.bSlaveInterface0 = status;
+
+ status = -ENODEV;
+
+ /* allocate instance-specific endpoints */
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
+ if (!ep)
+ goto fail;
+ rndis->port.in_ep = ep;
+
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
+ if (!ep)
+ goto fail;
+ rndis->port.out_ep = ep;
+
+ /* NOTE: a status/notification endpoint is, strictly speaking,
+ * optional. We don't treat it that way though! It's simpler,
+ * and some newer profiles don't treat it as optional.
+ */
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
+ if (!ep)
+ goto fail;
+ rndis->notify = ep;
+
+ status = -ENOMEM;
+
+ /* allocate notification request and buffer */
+ rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (!rndis->notify_req)
+ goto fail;
+ rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
+ if (!rndis->notify_req->buf)
+ goto fail;
+ rndis->notify_req->length = STATUS_BYTECOUNT;
+ rndis->notify_req->context = rndis;
+ rndis->notify_req->complete = rndis_response_complete;
+
+ /* support all relevant hardware speeds... we expect that when
+ * hardware is dual speed, all bulk-capable endpoints work at
+ * both speeds
+ */
+ hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
+ hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
+ hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
+
+ ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
+ ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
+ ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
+
+ status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
+ eth_ss_function, eth_ss_function);
+ if (status)
+ goto fail;
+
+ rndis->port.open = rndis_open;
+ rndis->port.close = rndis_close;
+
+ rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
+ rndis_set_host_mac(rndis->params, rndis->ethaddr);
+
+ if (rndis->manufacturer && rndis->vendorID &&
+ rndis_set_param_vendor(rndis->params, rndis->vendorID,
+ rndis->manufacturer)) {
+ status = -EINVAL;
+ goto fail_free_descs;
+ }
+
+ /* NOTE: all that is done without knowing or caring about
+ * the network link ... which is unavailable to this code
+ * until we're activated via set_alt().
+ */
+
+ DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
+ gadget_is_superspeed(c->cdev->gadget) ? "super" :
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ rndis->port.in_ep->name, rndis->port.out_ep->name,
+ rndis->notify->name);
+ return 0;
+
+fail_free_descs:
+ usb_free_all_descriptors(f);
+fail:
+ kfree(f->os_desc_table);
+ f->os_desc_n = 0;
+
+ if (rndis->notify_req) {
+ kfree(rndis->notify_req->buf);
+ usb_ep_free_request(rndis->notify, rndis->notify_req);
+ }
+
+ ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+ return status;
+}
+
+void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
+{
+ struct f_rndis_opts *opts;
+
+ opts = container_of(f, struct f_rndis_opts, func_inst);
+ if (opts->bound)
+ gether_cleanup(netdev_priv(opts->net));
+ else
+ free_netdev(opts->net);
+ opts->borrowed_net = opts->bound = true;
+ opts->net = net;
+}
+EXPORT_SYMBOL_GPL(rndis_borrow_net);
+
+static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_rndis_opts,
+ func_inst.group);
+}
+
+/* f_rndis_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(rndis);
+
+/* f_rndis_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
+
+/* f_rndis_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
+
+/* f_rndis_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
+
+/* f_rndis_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
+
+/* f_rndis_opts_class */
+USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
+
+/* f_rndis_opts_subclass */
+USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
+
+/* f_rndis_opts_protocol */
+USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
+
+static struct configfs_attribute *rndis_attrs[] = {
+ &rndis_opts_attr_dev_addr,
+ &rndis_opts_attr_host_addr,
+ &rndis_opts_attr_qmult,
+ &rndis_opts_attr_ifname,
+ &rndis_opts_attr_class,
+ &rndis_opts_attr_subclass,
+ &rndis_opts_attr_protocol,
+ NULL,
+};
+
+static const struct config_item_type rndis_func_type = {
+ .ct_item_ops = &rndis_item_ops,
+ .ct_attrs = rndis_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void rndis_free_inst(struct usb_function_instance *f)
+{
+ struct f_rndis_opts *opts;
+
+ opts = container_of(f, struct f_rndis_opts, func_inst);
+ if (!opts->borrowed_net) {
+ if (opts->bound)
+ gether_cleanup(netdev_priv(opts->net));
+ else
+ free_netdev(opts->net);
+ }
+
+ kfree(opts->rndis_interf_group); /* single VLA chunk */
+ kfree(opts);
+}
+
+static struct usb_function_instance *rndis_alloc_inst(void)
+{
+ struct f_rndis_opts *opts;
+ struct usb_os_desc *descs[1];
+ char *names[1];
+ struct config_group *rndis_interf_group;
+
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return ERR_PTR(-ENOMEM);
+ opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
+
+ mutex_init(&opts->lock);
+ opts->func_inst.free_func_inst = rndis_free_inst;
+ opts->net = gether_setup_default();
+ if (IS_ERR(opts->net)) {
+ struct net_device *net = opts->net;
+ kfree(opts);
+ return ERR_CAST(net);
+ }
+ INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
+
+ opts->class = rndis_iad_descriptor.bFunctionClass;
+ opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
+ opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
+
+ descs[0] = &opts->rndis_os_desc;
+ names[0] = "rndis";
+ config_group_init_type_name(&opts->func_inst.group, "",
+ &rndis_func_type);
+ rndis_interf_group =
+ usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
+ names, THIS_MODULE);
+ if (IS_ERR(rndis_interf_group)) {
+ rndis_free_inst(&opts->func_inst);
+ return ERR_CAST(rndis_interf_group);
+ }
+ opts->rndis_interf_group = rndis_interf_group;
+
+ return &opts->func_inst;
+}
+
+static void rndis_free(struct usb_function *f)
+{
+ struct f_rndis *rndis;
+ struct f_rndis_opts *opts;
+
+ rndis = func_to_rndis(f);
+ rndis_deregister(rndis->params);
+ opts = container_of(f->fi, struct f_rndis_opts, func_inst);
+ kfree(rndis);
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+}
+
+static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct f_rndis *rndis = func_to_rndis(f);
+
+ kfree(f->os_desc_table);
+ f->os_desc_n = 0;
+ usb_free_all_descriptors(f);
+
+ kfree(rndis->notify_req->buf);
+ usb_ep_free_request(rndis->notify, rndis->notify_req);
+}
+
+static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
+{
+ struct f_rndis *rndis;
+ struct f_rndis_opts *opts;
+ struct rndis_params *params;
+
+ /* allocate and initialize one new instance */
+ rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
+ if (!rndis)
+ return ERR_PTR(-ENOMEM);
+
+ opts = container_of(fi, struct f_rndis_opts, func_inst);
+ mutex_lock(&opts->lock);
+ opts->refcnt++;
+
+ gether_get_host_addr_u8(opts->net, rndis->ethaddr);
+ rndis->vendorID = opts->vendor_id;
+ rndis->manufacturer = opts->manufacturer;
+
+ rndis->port.ioport = netdev_priv(opts->net);
+ mutex_unlock(&opts->lock);
+ /* RNDIS activates when the host changes this filter */
+ rndis->port.cdc_filter = 0;
+
+ /* RNDIS has special (and complex) framing */
+ rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
+ rndis->port.wrap = rndis_add_header;
+ rndis->port.unwrap = rndis_rm_hdr;
+
+ rndis->port.func.name = "rndis";
+ /* descriptors are per-instance copies */
+ rndis->port.func.bind = rndis_bind;
+ rndis->port.func.unbind = rndis_unbind;
+ rndis->port.func.set_alt = rndis_set_alt;
+ rndis->port.func.setup = rndis_setup;
+ rndis->port.func.disable = rndis_disable;
+ rndis->port.func.free_func = rndis_free;
+
+ params = rndis_register(rndis_response_available, rndis);
+ if (IS_ERR(params)) {
+ kfree(rndis);
+ return ERR_CAST(params);
+ }
+ rndis->params = params;
+
+ return &rndis->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Brownell");