// SPDX-License-Identifier: GPL-2.0
/*
 * RNDIS MSG parser
 *
 * Authors:     Benedikt Spranger, Pengutronix
 *              Robert Schwebel, Pengutronix
 *
 *              This software was originally developed in conformance with
 *              Microsoft's Remote NDIS Specification License Agreement.
 *
 * 03/12/2004 Kai-Uwe Bloem <linux-development@auerswald.de>
 *              Fixed message length bug in init_response
 *
 * 03/25/2004 Kai-Uwe Bloem <linux-development@auerswald.de>
 *              Fixed rndis_rm_hdr length bug.
 *
 * Copyright (C) 2004 by David Brownell
 *              updates to merge with Linux 2.6, better match RNDIS spec
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/idr.h>
#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/netdevice.h>

#include <asm/io.h>
#include <asm/byteorder.h>
#include <linux/unaligned.h>

#include "u_rndis.h"

#undef  VERBOSE_DEBUG

#include "rndis.h"


/* The driver for your USB chip needs to support ep0 OUT to work with
 * RNDIS, plus all three CDC Ethernet endpoints (interrupt not optional).
 *
 * Windows hosts need an INF file like Documentation/usb/linux.inf
 * and will be happier if you provide the host_addr module parameter.
 */

#if 0
static int rndis_debug = 0;
module_param (rndis_debug, int, 0);
MODULE_PARM_DESC (rndis_debug, "enable debugging");
#else
#define rndis_debug             0
#endif

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

#define NAME_TEMPLATE "driver/rndis-%03d"

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

static DEFINE_IDA(rndis_ida);

/* Driver Version */
static const __le32 rndis_driver_version = cpu_to_le32(1);

/* Function Prototypes */
static rndis_resp_t *rndis_add_response(struct rndis_params *params,
                                        u32 length);

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static const struct proc_ops rndis_proc_ops;

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

/* supported OIDs */
static const u32 oid_supported_list[] = {
        /* the general stuff */
        RNDIS_OID_GEN_SUPPORTED_LIST,
        RNDIS_OID_GEN_HARDWARE_STATUS,
        RNDIS_OID_GEN_MEDIA_SUPPORTED,
        RNDIS_OID_GEN_MEDIA_IN_USE,
        RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE,
        RNDIS_OID_GEN_LINK_SPEED,
        RNDIS_OID_GEN_TRANSMIT_BLOCK_SIZE,
        RNDIS_OID_GEN_RECEIVE_BLOCK_SIZE,
        RNDIS_OID_GEN_VENDOR_ID,
        RNDIS_OID_GEN_VENDOR_DESCRIPTION,
        RNDIS_OID_GEN_VENDOR_DRIVER_VERSION,
        RNDIS_OID_GEN_CURRENT_PACKET_FILTER,
        RNDIS_OID_GEN_MAXIMUM_TOTAL_SIZE,
        RNDIS_OID_GEN_MEDIA_CONNECT_STATUS,
        RNDIS_OID_GEN_PHYSICAL_MEDIUM,

        /* the statistical stuff */
        RNDIS_OID_GEN_XMIT_OK,
        RNDIS_OID_GEN_RCV_OK,
        RNDIS_OID_GEN_XMIT_ERROR,
        RNDIS_OID_GEN_RCV_ERROR,
        RNDIS_OID_GEN_RCV_NO_BUFFER,
#ifdef  RNDIS_OPTIONAL_STATS
        RNDIS_OID_GEN_DIRECTED_BYTES_XMIT,
        RNDIS_OID_GEN_DIRECTED_FRAMES_XMIT,
        RNDIS_OID_GEN_MULTICAST_BYTES_XMIT,
        RNDIS_OID_GEN_MULTICAST_FRAMES_XMIT,
        RNDIS_OID_GEN_BROADCAST_BYTES_XMIT,
        RNDIS_OID_GEN_BROADCAST_FRAMES_XMIT,
        RNDIS_OID_GEN_DIRECTED_BYTES_RCV,
        RNDIS_OID_GEN_DIRECTED_FRAMES_RCV,
        RNDIS_OID_GEN_MULTICAST_BYTES_RCV,
        RNDIS_OID_GEN_MULTICAST_FRAMES_RCV,
        RNDIS_OID_GEN_BROADCAST_BYTES_RCV,
        RNDIS_OID_GEN_BROADCAST_FRAMES_RCV,
        RNDIS_OID_GEN_RCV_CRC_ERROR,
        RNDIS_OID_GEN_TRANSMIT_QUEUE_LENGTH,
#endif  /* RNDIS_OPTIONAL_STATS */

        /* mandatory 802.3 */
        /* the general stuff */
        RNDIS_OID_802_3_PERMANENT_ADDRESS,
        RNDIS_OID_802_3_CURRENT_ADDRESS,
        RNDIS_OID_802_3_MULTICAST_LIST,
        RNDIS_OID_802_3_MAC_OPTIONS,
        RNDIS_OID_802_3_MAXIMUM_LIST_SIZE,

        /* the statistical stuff */
        RNDIS_OID_802_3_RCV_ERROR_ALIGNMENT,
        RNDIS_OID_802_3_XMIT_ONE_COLLISION,
        RNDIS_OID_802_3_XMIT_MORE_COLLISIONS,
#ifdef  RNDIS_OPTIONAL_STATS
        RNDIS_OID_802_3_XMIT_DEFERRED,
        RNDIS_OID_802_3_XMIT_MAX_COLLISIONS,
        RNDIS_OID_802_3_RCV_OVERRUN,
        RNDIS_OID_802_3_XMIT_UNDERRUN,
        RNDIS_OID_802_3_XMIT_HEARTBEAT_FAILURE,
        RNDIS_OID_802_3_XMIT_TIMES_CRS_LOST,
        RNDIS_OID_802_3_XMIT_LATE_COLLISIONS,
#endif  /* RNDIS_OPTIONAL_STATS */

#ifdef  RNDIS_PM
        /* PM and wakeup are "mandatory" for USB, but the RNDIS specs
         * don't say what they mean ... and the NDIS specs are often
         * confusing and/or ambiguous in this context.  (That is, more
         * so than their specs for the other OIDs.)
         *
         * FIXME someone who knows what these should do, please
         * implement them!
         */

        /* power management */
        OID_PNP_CAPABILITIES,
        OID_PNP_QUERY_POWER,
        OID_PNP_SET_POWER,

#ifdef  RNDIS_WAKEUP
        /* wake up host */
        OID_PNP_ENABLE_WAKE_UP,
        OID_PNP_ADD_WAKE_UP_PATTERN,
        OID_PNP_REMOVE_WAKE_UP_PATTERN,
#endif  /* RNDIS_WAKEUP */
#endif  /* RNDIS_PM */
};


/* NDIS Functions */
static int gen_ndis_query_resp(struct rndis_params *params, u32 OID, u8 *buf,
                               unsigned buf_len, rndis_resp_t *r)
{
        int retval = -ENOTSUPP;
        u32 length = 4; /* usually */
        __le32 *outbuf;
        int i, count;
        rndis_query_cmplt_type *resp;
        struct net_device *net;
        struct rtnl_link_stats64 temp;
        const struct rtnl_link_stats64 *stats;

        if (!r) return -ENOMEM;
        resp = (rndis_query_cmplt_type *)r->buf;

        if (!resp) return -ENOMEM;

        if (buf_len && rndis_debug > 1) {
                pr_debug("query OID %08x value, len %d:\n", OID, buf_len);
                for (i = 0; i < buf_len; i += 16) {
                        pr_debug("%03d: %08x %08x %08x %08x\n", i,
                                get_unaligned_le32(&buf[i]),
                                get_unaligned_le32(&buf[i + 4]),
                                get_unaligned_le32(&buf[i + 8]),
                                get_unaligned_le32(&buf[i + 12]));
                }
        }

        /* response goes here, right after the header */
        outbuf = (__le32 *)&resp[1];
        resp->InformationBufferOffset = cpu_to_le32(16);

        net = params->dev;
        stats = dev_get_stats(net, &temp);

        switch (OID) {

        /* general oids (table 4-1) */

        /* mandatory */
        case RNDIS_OID_GEN_SUPPORTED_LIST:
                pr_debug("%s: RNDIS_OID_GEN_SUPPORTED_LIST\n", __func__);
                length = sizeof(oid_supported_list);
                count  = length / sizeof(u32);
                for (i = 0; i < count; i++)
                        outbuf[i] = cpu_to_le32(oid_supported_list[i]);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_HARDWARE_STATUS:
                pr_debug("%s: RNDIS_OID_GEN_HARDWARE_STATUS\n", __func__);
                /* Bogus question!
                 * Hardware must be ready to receive high level protocols.
                 * BTW:
                 * reddite ergo quae sunt Caesaris Caesari
                 * et quae sunt Dei Deo!
                 */
                *outbuf = cpu_to_le32(0);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_MEDIA_SUPPORTED:
                pr_debug("%s: RNDIS_OID_GEN_MEDIA_SUPPORTED\n", __func__);
                *outbuf = cpu_to_le32(params->medium);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_MEDIA_IN_USE:
                pr_debug("%s: RNDIS_OID_GEN_MEDIA_IN_USE\n", __func__);
                /* one medium, one transport... (maybe you do it better) */
                *outbuf = cpu_to_le32(params->medium);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE:
                pr_debug("%s: RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE\n", __func__);
                if (params->dev) {
                        *outbuf = cpu_to_le32(params->dev->mtu);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_LINK_SPEED:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_LINK_SPEED\n", __func__);
                if (params->media_state == RNDIS_MEDIA_STATE_DISCONNECTED)
                        *outbuf = cpu_to_le32(0);
                else
                        *outbuf = cpu_to_le32(params->speed);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_TRANSMIT_BLOCK_SIZE:
                pr_debug("%s: RNDIS_OID_GEN_TRANSMIT_BLOCK_SIZE\n", __func__);
                if (params->dev) {
                        *outbuf = cpu_to_le32(params->dev->mtu);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_RECEIVE_BLOCK_SIZE:
                pr_debug("%s: RNDIS_OID_GEN_RECEIVE_BLOCK_SIZE\n", __func__);
                if (params->dev) {
                        *outbuf = cpu_to_le32(params->dev->mtu);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_VENDOR_ID:
                pr_debug("%s: RNDIS_OID_GEN_VENDOR_ID\n", __func__);
                *outbuf = cpu_to_le32(params->vendorID);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_VENDOR_DESCRIPTION:
                pr_debug("%s: RNDIS_OID_GEN_VENDOR_DESCRIPTION\n", __func__);
                if (params->vendorDescr) {
                        length = strlen(params->vendorDescr);
                        memcpy(outbuf, params->vendorDescr, length);
                } else {
                        outbuf[0] = 0;
                }
                retval = 0;
                break;

        case RNDIS_OID_GEN_VENDOR_DRIVER_VERSION:
                pr_debug("%s: RNDIS_OID_GEN_VENDOR_DRIVER_VERSION\n", __func__);
                /* Created as LE */
                *outbuf = rndis_driver_version;
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_CURRENT_PACKET_FILTER:
                pr_debug("%s: RNDIS_OID_GEN_CURRENT_PACKET_FILTER\n", __func__);
                *outbuf = cpu_to_le32(*params->filter);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_MAXIMUM_TOTAL_SIZE:
                pr_debug("%s: RNDIS_OID_GEN_MAXIMUM_TOTAL_SIZE\n", __func__);
                *outbuf = cpu_to_le32(RNDIS_MAX_TOTAL_SIZE);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_GEN_MEDIA_CONNECT_STATUS:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_MEDIA_CONNECT_STATUS\n", __func__);
                *outbuf = cpu_to_le32(params->media_state);
                retval = 0;
                break;

        case RNDIS_OID_GEN_PHYSICAL_MEDIUM:
                pr_debug("%s: RNDIS_OID_GEN_PHYSICAL_MEDIUM\n", __func__);
                *outbuf = cpu_to_le32(0);
                retval = 0;
                break;

        /* The RNDIS specification is incomplete/wrong.   Some versions
         * of MS-Windows expect OIDs that aren't specified there.  Other
         * versions emit undefined RNDIS messages. DOCUMENT ALL THESE!
         */
        case RNDIS_OID_GEN_MAC_OPTIONS:         /* from WinME */
                pr_debug("%s: RNDIS_OID_GEN_MAC_OPTIONS\n", __func__);
                *outbuf = cpu_to_le32(
                          RNDIS_MAC_OPTION_RECEIVE_SERIALIZED
                        | RNDIS_MAC_OPTION_FULL_DUPLEX);
                retval = 0;
                break;

        /* statistics OIDs (table 4-2) */

        /* mandatory */
        case RNDIS_OID_GEN_XMIT_OK:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_XMIT_OK\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->tx_packets
                                - stats->tx_errors - stats->tx_dropped);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_RCV_OK:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_RCV_OK\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->rx_packets
                                - stats->rx_errors - stats->rx_dropped);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_XMIT_ERROR:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_XMIT_ERROR\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->tx_errors);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_RCV_ERROR:
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_OID_GEN_RCV_ERROR\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->rx_errors);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_GEN_RCV_NO_BUFFER:
                pr_debug("%s: RNDIS_OID_GEN_RCV_NO_BUFFER\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->rx_dropped);
                        retval = 0;
                }
                break;

        /* ieee802.3 OIDs (table 4-3) */

        /* mandatory */
        case RNDIS_OID_802_3_PERMANENT_ADDRESS:
                pr_debug("%s: RNDIS_OID_802_3_PERMANENT_ADDRESS\n", __func__);
                if (params->dev) {
                        length = ETH_ALEN;
                        memcpy(outbuf, params->host_mac, length);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_802_3_CURRENT_ADDRESS:
                pr_debug("%s: RNDIS_OID_802_3_CURRENT_ADDRESS\n", __func__);
                if (params->dev) {
                        length = ETH_ALEN;
                        memcpy(outbuf, params->host_mac, length);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_802_3_MULTICAST_LIST:
                pr_debug("%s: RNDIS_OID_802_3_MULTICAST_LIST\n", __func__);
                /* Multicast base address only */
                *outbuf = cpu_to_le32(0xE0000000);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_802_3_MAXIMUM_LIST_SIZE:
                pr_debug("%s: RNDIS_OID_802_3_MAXIMUM_LIST_SIZE\n", __func__);
                /* Multicast base address only */
                *outbuf = cpu_to_le32(1);
                retval = 0;
                break;

        case RNDIS_OID_802_3_MAC_OPTIONS:
                pr_debug("%s: RNDIS_OID_802_3_MAC_OPTIONS\n", __func__);
                *outbuf = cpu_to_le32(0);
                retval = 0;
                break;

        /* ieee802.3 statistics OIDs (table 4-4) */

        /* mandatory */
        case RNDIS_OID_802_3_RCV_ERROR_ALIGNMENT:
                pr_debug("%s: RNDIS_OID_802_3_RCV_ERROR_ALIGNMENT\n", __func__);
                if (stats) {
                        *outbuf = cpu_to_le32(stats->rx_frame_errors);
                        retval = 0;
                }
                break;

        /* mandatory */
        case RNDIS_OID_802_3_XMIT_ONE_COLLISION:
                pr_debug("%s: RNDIS_OID_802_3_XMIT_ONE_COLLISION\n", __func__);
                *outbuf = cpu_to_le32(0);
                retval = 0;
                break;

        /* mandatory */
        case RNDIS_OID_802_3_XMIT_MORE_COLLISIONS:
                pr_debug("%s: RNDIS_OID_802_3_XMIT_MORE_COLLISIONS\n", __func__);
                *outbuf = cpu_to_le32(0);
                retval = 0;
                break;

        default:
                pr_warn("%s: query unknown OID 0x%08X\n", __func__, OID);
        }
        if (retval < 0)
                length = 0;

        resp->InformationBufferLength = cpu_to_le32(length);
        r->length = length + sizeof(*resp);
        resp->MessageLength = cpu_to_le32(r->length);
        return retval;
}

static int gen_ndis_set_resp(struct rndis_params *params, u32 OID,
                             u8 *buf, u32 buf_len, rndis_resp_t *r)
{
        rndis_set_cmplt_type *resp;
        int i, retval = -ENOTSUPP;

        if (!r)
                return -ENOMEM;
        resp = (rndis_set_cmplt_type *)r->buf;
        if (!resp)
                return -ENOMEM;

        if (buf_len && rndis_debug > 1) {
                pr_debug("set OID %08x value, len %d:\n", OID, buf_len);
                for (i = 0; i < buf_len; i += 16) {
                        pr_debug("%03d: %08x %08x %08x %08x\n", i,
                                get_unaligned_le32(&buf[i]),
                                get_unaligned_le32(&buf[i + 4]),
                                get_unaligned_le32(&buf[i + 8]),
                                get_unaligned_le32(&buf[i + 12]));
                }
        }

        switch (OID) {
        case RNDIS_OID_GEN_CURRENT_PACKET_FILTER:

                /* these NDIS_PACKET_TYPE_* bitflags are shared with
                 * cdc_filter; it's not RNDIS-specific
                 * NDIS_PACKET_TYPE_x == USB_CDC_PACKET_TYPE_x for x in:
                 *      PROMISCUOUS, DIRECTED,
                 *      MULTICAST, ALL_MULTICAST, BROADCAST
                 */
                *params->filter = (u16)get_unaligned_le32(buf);
                pr_debug("%s: RNDIS_OID_GEN_CURRENT_PACKET_FILTER %08x\n",
                        __func__, *params->filter);

                /* this call has a significant side effect:  it's
                 * what makes the packet flow start and stop, like
                 * activating the CDC Ethernet altsetting.
                 */
                retval = 0;
                if (*params->filter) {
                        params->state = RNDIS_DATA_INITIALIZED;
                        netif_carrier_on(params->dev);
                        if (netif_running(params->dev))
                                netif_wake_queue(params->dev);
                } else {
                        params->state = RNDIS_INITIALIZED;
                        netif_carrier_off(params->dev);
                        netif_stop_queue(params->dev);
                }
                break;

        case RNDIS_OID_802_3_MULTICAST_LIST:
                /* I think we can ignore this */
                pr_debug("%s: RNDIS_OID_802_3_MULTICAST_LIST\n", __func__);
                retval = 0;
                break;

        default:
                pr_warn("%s: set unknown OID 0x%08X, size %d\n",
                        __func__, OID, buf_len);
        }

        return retval;
}

/*
 * Response Functions
 */

static int rndis_init_response(struct rndis_params *params,
                               rndis_init_msg_type *buf)
{
        rndis_init_cmplt_type *resp;
        rndis_resp_t *r;

        if (!params->dev)
                return -ENOTSUPP;

        r = rndis_add_response(params, sizeof(rndis_init_cmplt_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_init_cmplt_type *)r->buf;

        resp->MessageType = cpu_to_le32(RNDIS_MSG_INIT_C);
        resp->MessageLength = cpu_to_le32(52);
        resp->RequestID = buf->RequestID; /* Still LE in msg buffer */
        resp->Status = cpu_to_le32(RNDIS_STATUS_SUCCESS);
        resp->MajorVersion = cpu_to_le32(RNDIS_MAJOR_VERSION);
        resp->MinorVersion = cpu_to_le32(RNDIS_MINOR_VERSION);
        resp->DeviceFlags = cpu_to_le32(RNDIS_DF_CONNECTIONLESS);
        resp->Medium = cpu_to_le32(RNDIS_MEDIUM_802_3);
        resp->MaxPacketsPerTransfer = cpu_to_le32(1);
        resp->MaxTransferSize = cpu_to_le32(
                  params->dev->mtu
                + sizeof(struct ethhdr)
                + sizeof(struct rndis_packet_msg_type)
                + 22);
        resp->PacketAlignmentFactor = cpu_to_le32(0);
        resp->AFListOffset = cpu_to_le32(0);
        resp->AFListSize = cpu_to_le32(0);

        params->resp_avail(params->v);
        return 0;
}

static int rndis_query_response(struct rndis_params *params,
                                rndis_query_msg_type *buf)
{
        rndis_query_cmplt_type *resp;
        rndis_resp_t *r;

        /* pr_debug("%s: OID = %08X\n", __func__, cpu_to_le32(buf->OID)); */
        if (!params->dev)
                return -ENOTSUPP;

        /*
         * we need more memory:
         * gen_ndis_query_resp expects enough space for
         * rndis_query_cmplt_type followed by data.
         * oid_supported_list is the largest data reply
         */
        r = rndis_add_response(params,
                sizeof(oid_supported_list) + sizeof(rndis_query_cmplt_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_query_cmplt_type *)r->buf;

        resp->MessageType = cpu_to_le32(RNDIS_MSG_QUERY_C);
        resp->RequestID = buf->RequestID; /* Still LE in msg buffer */

        if (gen_ndis_query_resp(params, le32_to_cpu(buf->OID),
                        le32_to_cpu(buf->InformationBufferOffset)
                                        + 8 + (u8 *)buf,
                        le32_to_cpu(buf->InformationBufferLength),
                        r)) {
                /* OID not supported */
                resp->Status = cpu_to_le32(RNDIS_STATUS_NOT_SUPPORTED);
                resp->MessageLength = cpu_to_le32(sizeof *resp);
                resp->InformationBufferLength = cpu_to_le32(0);
                resp->InformationBufferOffset = cpu_to_le32(0);
        } else
                resp->Status = cpu_to_le32(RNDIS_STATUS_SUCCESS);

        params->resp_avail(params->v);
        return 0;
}

static int rndis_set_response(struct rndis_params *params,
                              rndis_set_msg_type *buf)
{
        u32 BufLength, BufOffset;
        rndis_set_cmplt_type *resp;
        rndis_resp_t *r;

        BufLength = le32_to_cpu(buf->InformationBufferLength);
        BufOffset = le32_to_cpu(buf->InformationBufferOffset);
        if ((BufLength > RNDIS_MAX_TOTAL_SIZE) ||
            (BufOffset > RNDIS_MAX_TOTAL_SIZE) ||
            (BufOffset + 8 >= RNDIS_MAX_TOTAL_SIZE))
                    return -EINVAL;

        r = rndis_add_response(params, sizeof(rndis_set_cmplt_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_set_cmplt_type *)r->buf;

#ifdef  VERBOSE_DEBUG
        pr_debug("%s: Length: %d\n", __func__, BufLength);
        pr_debug("%s: Offset: %d\n", __func__, BufOffset);
        pr_debug("%s: InfoBuffer: ", __func__);

        for (i = 0; i < BufLength; i++) {
                pr_debug("%02x ", *(((u8 *) buf) + i + 8 + BufOffset));
        }

        pr_debug("\n");
#endif

        resp->MessageType = cpu_to_le32(RNDIS_MSG_SET_C);
        resp->MessageLength = cpu_to_le32(16);
        resp->RequestID = buf->RequestID; /* Still LE in msg buffer */
        if (gen_ndis_set_resp(params, le32_to_cpu(buf->OID),
                        ((u8 *)buf) + 8 + BufOffset, BufLength, r))
                resp->Status = cpu_to_le32(RNDIS_STATUS_NOT_SUPPORTED);
        else
                resp->Status = cpu_to_le32(RNDIS_STATUS_SUCCESS);

        params->resp_avail(params->v);
        return 0;
}

static int rndis_reset_response(struct rndis_params *params,
                                rndis_reset_msg_type *buf)
{
        rndis_reset_cmplt_type *resp;
        rndis_resp_t *r;
        u8 *xbuf;
        u32 length;

        /* drain the response queue */
        while ((xbuf = rndis_get_next_response(params, &length)))
                rndis_free_response(params, xbuf);

        r = rndis_add_response(params, sizeof(rndis_reset_cmplt_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_reset_cmplt_type *)r->buf;

        resp->MessageType = cpu_to_le32(RNDIS_MSG_RESET_C);
        resp->MessageLength = cpu_to_le32(16);
        resp->Status = cpu_to_le32(RNDIS_STATUS_SUCCESS);
        /* resent information */
        resp->AddressingReset = cpu_to_le32(1);

        params->resp_avail(params->v);
        return 0;
}

static int rndis_keepalive_response(struct rndis_params *params,
                                    rndis_keepalive_msg_type *buf)
{
        rndis_keepalive_cmplt_type *resp;
        rndis_resp_t *r;

        /* host "should" check only in RNDIS_DATA_INITIALIZED state */

        r = rndis_add_response(params, sizeof(rndis_keepalive_cmplt_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_keepalive_cmplt_type *)r->buf;

        resp->MessageType = cpu_to_le32(RNDIS_MSG_KEEPALIVE_C);
        resp->MessageLength = cpu_to_le32(16);
        resp->RequestID = buf->RequestID; /* Still LE in msg buffer */
        resp->Status = cpu_to_le32(RNDIS_STATUS_SUCCESS);

        params->resp_avail(params->v);
        return 0;
}


/*
 * Device to Host Comunication
 */
static int rndis_indicate_status_msg(struct rndis_params *params, u32 status)
{
        rndis_indicate_status_msg_type *resp;
        rndis_resp_t *r;

        if (params->state == RNDIS_UNINITIALIZED)
                return -ENOTSUPP;

        r = rndis_add_response(params, sizeof(rndis_indicate_status_msg_type));
        if (!r)
                return -ENOMEM;
        resp = (rndis_indicate_status_msg_type *)r->buf;

        resp->MessageType = cpu_to_le32(RNDIS_MSG_INDICATE);
        resp->MessageLength = cpu_to_le32(20);
        resp->Status = cpu_to_le32(status);
        resp->StatusBufferLength = cpu_to_le32(0);
        resp->StatusBufferOffset = cpu_to_le32(0);

        params->resp_avail(params->v);
        return 0;
}

int rndis_signal_connect(struct rndis_params *params)
{
        params->media_state = RNDIS_MEDIA_STATE_CONNECTED;
        return rndis_indicate_status_msg(params, RNDIS_STATUS_MEDIA_CONNECT);
}
EXPORT_SYMBOL_GPL(rndis_signal_connect);

int rndis_signal_disconnect(struct rndis_params *params)
{
        params->media_state = RNDIS_MEDIA_STATE_DISCONNECTED;
        return rndis_indicate_status_msg(params, RNDIS_STATUS_MEDIA_DISCONNECT);
}
EXPORT_SYMBOL_GPL(rndis_signal_disconnect);

void rndis_uninit(struct rndis_params *params)
{
        u8 *buf;
        u32 length;

        if (!params)
                return;
        params->state = RNDIS_UNINITIALIZED;

        /* drain the response queue */
        while ((buf = rndis_get_next_response(params, &length)))
                rndis_free_response(params, buf);
}
EXPORT_SYMBOL_GPL(rndis_uninit);

void rndis_set_host_mac(struct rndis_params *params, const u8 *addr)
{
        params->host_mac = addr;
}
EXPORT_SYMBOL_GPL(rndis_set_host_mac);

/*
 * Message Parser
 */
int rndis_msg_parser(struct rndis_params *params, u8 *buf)
{
        u32 MsgType, MsgLength;
        __le32 *tmp;

        if (!buf)
                return -ENOMEM;

        tmp = (__le32 *)buf;
        MsgType   = get_unaligned_le32(tmp++);
        MsgLength = get_unaligned_le32(tmp++);

        if (!params)
                return -ENOTSUPP;

        /* NOTE: RNDIS is *EXTREMELY* chatty ... Windows constantly polls for
         * rx/tx statistics and link status, in addition to KEEPALIVE traffic
         * and normal HC level polling to see if there's any IN traffic.
         */

        /* For USB: responses may take up to 10 seconds */
        switch (MsgType) {
        case RNDIS_MSG_INIT:
                pr_debug("%s: RNDIS_MSG_INIT\n",
                        __func__);
                params->state = RNDIS_INITIALIZED;
                return rndis_init_response(params, (rndis_init_msg_type *)buf);

        case RNDIS_MSG_HALT:
                pr_debug("%s: RNDIS_MSG_HALT\n",
                        __func__);
                params->state = RNDIS_UNINITIALIZED;
                if (params->dev) {
                        netif_carrier_off(params->dev);
                        netif_stop_queue(params->dev);
                }
                return 0;

        case RNDIS_MSG_QUERY:
                return rndis_query_response(params,
                                        (rndis_query_msg_type *)buf);

        case RNDIS_MSG_SET:
                return rndis_set_response(params, (rndis_set_msg_type *)buf);

        case RNDIS_MSG_RESET:
                pr_debug("%s: RNDIS_MSG_RESET\n",
                        __func__);
                return rndis_reset_response(params,
                                        (rndis_reset_msg_type *)buf);

        case RNDIS_MSG_KEEPALIVE:
                /* For USB: host does this every 5 seconds */
                if (rndis_debug > 1)
                        pr_debug("%s: RNDIS_MSG_KEEPALIVE\n",
                                __func__);
                return rndis_keepalive_response(params,
                                                 (rndis_keepalive_msg_type *)
                                                 buf);

        default:
                /* At least Windows XP emits some undefined RNDIS messages.
                 * In one case those messages seemed to relate to the host
                 * suspending itself.
                 */
                pr_warn("%s: unknown RNDIS message 0x%08X len %d\n",
                        __func__, MsgType, MsgLength);
                /* Garbled message can be huge, so limit what we display */
                if (MsgLength > 16)
                        MsgLength = 16;
                print_hex_dump_bytes(__func__, DUMP_PREFIX_OFFSET,
                                     buf, MsgLength);
                break;
        }

        return -ENOTSUPP;
}
EXPORT_SYMBOL_GPL(rndis_msg_parser);

static inline int rndis_get_nr(void)
{
        return ida_alloc_max(&rndis_ida, 999, GFP_KERNEL);
}

static inline void rndis_put_nr(int nr)
{
        ida_free(&rndis_ida, nr);
}

struct rndis_params *rndis_register(void (*resp_avail)(void *v), void *v)
{
        struct rndis_params *params;
        int i;

        if (!resp_avail)
                return ERR_PTR(-EINVAL);

        i = rndis_get_nr();
        if (i < 0) {
                pr_debug("failed\n");

                return ERR_PTR(-ENODEV);
        }

        params = kzalloc_obj(*params);
        if (!params) {
                rndis_put_nr(i);

                return ERR_PTR(-ENOMEM);
        }

#ifdef  CONFIG_USB_GADGET_DEBUG_FILES
        {
                struct proc_dir_entry *proc_entry;
                char name[20];

                sprintf(name, NAME_TEMPLATE, i);
                proc_entry = proc_create_data(name, 0660, NULL,
                                              &rndis_proc_ops, params);
                if (!proc_entry) {
                        kfree(params);
                        rndis_put_nr(i);

                        return ERR_PTR(-EIO);
                }
        }
#endif

        params->confignr = i;
        params->used = 1;
        params->state = RNDIS_UNINITIALIZED;
        params->media_state = RNDIS_MEDIA_STATE_DISCONNECTED;
        params->resp_avail = resp_avail;
        params->v = v;
        INIT_LIST_HEAD(&params->resp_queue);
        spin_lock_init(&params->resp_lock);
        pr_debug("%s: configNr = %d\n", __func__, i);

        return params;
}
EXPORT_SYMBOL_GPL(rndis_register);

void rndis_deregister(struct rndis_params *params)
{
        int i;

        pr_debug("%s:\n", __func__);

        if (!params)
                return;

        i = params->confignr;

#ifdef CONFIG_USB_GADGET_DEBUG_FILES
        {
                char name[20];

                sprintf(name, NAME_TEMPLATE, i);
                remove_proc_entry(name, NULL);
        }
#endif

        kfree(params);
        rndis_put_nr(i);
}
EXPORT_SYMBOL_GPL(rndis_deregister);
int rndis_set_param_dev(struct rndis_params *params, struct net_device *dev,
                        u16 *cdc_filter)
{
        pr_debug("%s:\n", __func__);
        if (!dev)
                return -EINVAL;
        if (!params)
                return -1;

        params->dev = dev;
        params->filter = cdc_filter;

        return 0;
}
EXPORT_SYMBOL_GPL(rndis_set_param_dev);

int rndis_set_param_vendor(struct rndis_params *params, u32 vendorID,
                           const char *vendorDescr)
{
        pr_debug("%s:\n", __func__);
        if (!vendorDescr) return -1;
        if (!params)
                return -1;

        params->vendorID = vendorID;
        params->vendorDescr = vendorDescr;

        return 0;
}
EXPORT_SYMBOL_GPL(rndis_set_param_vendor);

int rndis_set_param_medium(struct rndis_params *params, u32 medium, u32 speed)
{
        pr_debug("%s: %u %u\n", __func__, medium, speed);
        if (!params)
                return -1;

        params->medium = medium;
        params->speed = speed;

        return 0;
}
EXPORT_SYMBOL_GPL(rndis_set_param_medium);

void rndis_add_hdr(struct sk_buff *skb)
{
        struct rndis_packet_msg_type *header;

        if (!skb)
                return;
        header = skb_push(skb, sizeof(*header));
        memset(header, 0, sizeof *header);
        header->MessageType = cpu_to_le32(RNDIS_MSG_PACKET);
        header->MessageLength = cpu_to_le32(skb->len);
        header->DataOffset = cpu_to_le32(36);
        header->DataLength = cpu_to_le32(skb->len - sizeof(*header));
}
EXPORT_SYMBOL_GPL(rndis_add_hdr);

void rndis_free_response(struct rndis_params *params, u8 *buf)
{
        rndis_resp_t *r, *n;

        spin_lock(&params->resp_lock);
        list_for_each_entry_safe(r, n, &params->resp_queue, list) {
                if (r->buf == buf) {
                        list_del(&r->list);
                        kfree(r);
                }
        }
        spin_unlock(&params->resp_lock);
}
EXPORT_SYMBOL_GPL(rndis_free_response);

u8 *rndis_get_next_response(struct rndis_params *params, u32 *length)
{
        rndis_resp_t *r, *n;

        if (!length) return NULL;

        spin_lock(&params->resp_lock);
        list_for_each_entry_safe(r, n, &params->resp_queue, list) {
                if (!r->send) {
                        r->send = 1;
                        *length = r->length;
                        spin_unlock(&params->resp_lock);
                        return r->buf;
                }
        }

        spin_unlock(&params->resp_lock);
        return NULL;
}
EXPORT_SYMBOL_GPL(rndis_get_next_response);

static rndis_resp_t *rndis_add_response(struct rndis_params *params, u32 length)
{
        rndis_resp_t *r;

        /* NOTE: this gets copied into ether.c USB_BUFSIZ bytes ... */
        r = kmalloc(sizeof(rndis_resp_t) + length, GFP_ATOMIC);
        if (!r) return NULL;

        r->buf = (u8 *)(r + 1);
        r->length = length;
        r->send = 0;

        spin_lock(&params->resp_lock);
        list_add_tail(&r->list, &params->resp_queue);
        spin_unlock(&params->resp_lock);
        return r;
}

int rndis_rm_hdr(struct gether *port,
                        struct sk_buff *skb,
                        struct sk_buff_head *list)
{
        /* tmp points to a struct rndis_packet_msg_type */
        __le32 *tmp = (void *)skb->data;

        /* MessageType, MessageLength */
        if (cpu_to_le32(RNDIS_MSG_PACKET)
                        != get_unaligned(tmp++)) {
                dev_kfree_skb_any(skb);
                return -EINVAL;
        }
        tmp++;

        /* DataOffset, DataLength */
        if (!skb_pull(skb, get_unaligned_le32(tmp++) + 8)) {
                dev_kfree_skb_any(skb);
                return -EOVERFLOW;
        }
        skb_trim(skb, get_unaligned_le32(tmp++));

        skb_queue_tail(list, skb);
        return 0;
}
EXPORT_SYMBOL_GPL(rndis_rm_hdr);

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static int rndis_proc_show(struct seq_file *m, void *v)
{
        rndis_params *param = m->private;

        seq_printf(m,
                         "Config Nr. %d\n"
                         "used      : %s\n"
                         "state     : %s\n"
                         "medium    : 0x%08X\n"
                         "speed     : %u\n"
                         "cable     : %s\n"
                         "vendor ID : 0x%08X\n"
                         "vendor    : %s\n",
                         param->confignr, (param->used) ? "y" : "n",
                         ({ char *s = "?";
                         switch (param->state) {
                         case RNDIS_UNINITIALIZED:
                                s = "RNDIS_UNINITIALIZED"; break;
                         case RNDIS_INITIALIZED:
                                s = "RNDIS_INITIALIZED"; break;
                         case RNDIS_DATA_INITIALIZED:
                                s = "RNDIS_DATA_INITIALIZED"; break;
                        } s; }),
                         param->medium,
                         (param->media_state) ? 0 : param->speed*100,
                         (param->media_state) ? "disconnected" : "connected",
                         param->vendorID, param->vendorDescr);
        return 0;
}

static ssize_t rndis_proc_write(struct file *file, const char __user *buffer,
                                size_t count, loff_t *ppos)
{
        rndis_params *p = pde_data(file_inode(file));
        u32 speed = 0;
        int i, fl_speed = 0;

        for (i = 0; i < count; i++) {
                char c;
                if (get_user(c, buffer))
                        return -EFAULT;
                switch (c) {
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                case '8':
                case '9':
                        fl_speed = 1;
                        speed = speed * 10 + c - '0';
                        break;
                case 'C':
                case 'c':
                        rndis_signal_connect(p);
                        break;
                case 'D':
                case 'd':
                        rndis_signal_disconnect(p);
                        break;
                default:
                        if (fl_speed) p->speed = speed;
                        else pr_debug("%c is not valid\n", c);
                        break;
                }

                buffer++;
        }

        return count;
}

static int rndis_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, rndis_proc_show, pde_data(inode));
}

static const struct proc_ops rndis_proc_ops = {
        .proc_open      = rndis_proc_open,
        .proc_read      = seq_read,
        .proc_lseek     = seq_lseek,
        .proc_release   = single_release,
        .proc_write     = rndis_proc_write,
};

#define NAME_TEMPLATE "driver/rndis-%03d"

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */