/*
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/nls.h>

#include "hyperv_net.h"


#define RNDIS_EXT_LEN PAGE_SIZE
struct rndis_request {
	struct list_head list_ent;
	struct completion  wait_event;

	struct rndis_message response_msg;
	/*
	 * The buffer for extended info after the RNDIS response message. It's
	 * referenced based on the data offset in the RNDIS message. Its size
	 * is enough for current needs, and should be sufficient for the near
	 * future.
	 */
	u8 response_ext[RNDIS_EXT_LEN];

	/* Simplify allocation by having a netvsc packet inline */
	struct hv_netvsc_packet	pkt;
	/* Set 2 pages for rndis requests crossing page boundary */
	struct hv_page_buffer buf[2];

	struct rndis_message request_msg;
	/*
	 * The buffer for the extended info after the RNDIS request message.
	 * It is referenced and sized in a similar way as response_ext.
	 */
	u8 request_ext[RNDIS_EXT_LEN];
};

static struct rndis_device *get_rndis_device(void)
{
	struct rndis_device *device;

	device = kzalloc(sizeof(struct rndis_device), GFP_KERNEL);
	if (!device)
		return NULL;

	spin_lock_init(&device->request_lock);

	INIT_LIST_HEAD(&device->req_list);

	device->state = RNDIS_DEV_UNINITIALIZED;

	return device;
}

static struct rndis_request *get_rndis_request(struct rndis_device *dev,
					     u32 msg_type,
					     u32 msg_len)
{
	struct rndis_request *request;
	struct rndis_message *rndis_msg;
	struct rndis_set_request *set;
	unsigned long flags;

	request = kzalloc(sizeof(struct rndis_request), GFP_KERNEL);
	if (!request)
		return NULL;

	init_completion(&request->wait_event);

	rndis_msg = &request->request_msg;
	rndis_msg->ndis_msg_type = msg_type;
	rndis_msg->msg_len = msg_len;

	request->pkt.q_idx = 0;

	/*
	 * Set the request id. This field is always after the rndis header for
	 * request/response packet types so we just used the SetRequest as a
	 * template
	 */
	set = &rndis_msg->msg.set_req;
	set->req_id = atomic_inc_return(&dev->new_req_id);

	/* Add to the request list */
	spin_lock_irqsave(&dev->request_lock, flags);
	list_add_tail(&request->list_ent, &dev->req_list);
	spin_unlock_irqrestore(&dev->request_lock, flags);

	return request;
}

static void put_rndis_request(struct rndis_device *dev,
			    struct rndis_request *req)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->request_lock, flags);
	list_del(&req->list_ent);
	spin_unlock_irqrestore(&dev->request_lock, flags);

	kfree(req);
}

static void dump_rndis_message(struct hv_device *hv_dev,
			struct rndis_message *rndis_msg)
{
	struct net_device *netdev;
	struct netvsc_device *net_device;

	net_device = hv_get_drvdata(hv_dev);
	netdev = net_device->ndev;

	switch (rndis_msg->ndis_msg_type) {
	case RNDIS_MSG_PACKET:
		netdev_dbg(netdev, "RNDIS_MSG_PACKET (len %u, "
			   "data offset %u data len %u, # oob %u, "
			   "oob offset %u, oob len %u, pkt offset %u, "
			   "pkt len %u\n",
			   rndis_msg->msg_len,
			   rndis_msg->msg.pkt.data_offset,
			   rndis_msg->msg.pkt.data_len,
			   rndis_msg->msg.pkt.num_oob_data_elements,
			   rndis_msg->msg.pkt.oob_data_offset,
			   rndis_msg->msg.pkt.oob_data_len,
			   rndis_msg->msg.pkt.per_pkt_info_offset,
			   rndis_msg->msg.pkt.per_pkt_info_len);
		break;

	case RNDIS_MSG_INIT_C:
		netdev_dbg(netdev, "RNDIS_MSG_INIT_C "
			"(len %u, id 0x%x, status 0x%x, major %d, minor %d, "
			"device flags %d, max xfer size 0x%x, max pkts %u, "
			"pkt aligned %u)\n",
			rndis_msg->msg_len,
			rndis_msg->msg.init_complete.req_id,
			rndis_msg->msg.init_complete.status,
			rndis_msg->msg.init_complete.major_ver,
			rndis_msg->msg.init_complete.minor_ver,
			rndis_msg->msg.init_complete.dev_flags,
			rndis_msg->msg.init_complete.max_xfer_size,
			rndis_msg->msg.init_complete.
			   max_pkt_per_msg,
			rndis_msg->msg.init_complete.
			   pkt_alignment_factor);
		break;

	case RNDIS_MSG_QUERY_C:
		netdev_dbg(netdev, "RNDIS_MSG_QUERY_C "
			"(len %u, id 0x%x, status 0x%x, buf len %u, "
			"buf offset %u)\n",
			rndis_msg->msg_len,
			rndis_msg->msg.query_complete.req_id,
			rndis_msg->msg.query_complete.status,
			rndis_msg->msg.query_complete.
			   info_buflen,
			rndis_msg->msg.query_complete.
			   info_buf_offset);
		break;

	case RNDIS_MSG_SET_C:
		netdev_dbg(netdev,
			"RNDIS_MSG_SET_C (len %u, id 0x%x, status 0x%x)\n",
			rndis_msg->msg_len,
			rndis_msg->msg.set_complete.req_id,
			rndis_msg->msg.set_complete.status);
		break;

	case RNDIS_MSG_INDICATE:
		netdev_dbg(netdev, "RNDIS_MSG_INDICATE "
			"(len %u, status 0x%x, buf len %u, buf offset %u)\n",
			rndis_msg->msg_len,
			rndis_msg->msg.indicate_status.status,
			rndis_msg->msg.indicate_status.status_buflen,
			rndis_msg->msg.indicate_status.status_buf_offset);
		break;

	default:
		netdev_dbg(netdev, "0x%x (len %u)\n",
			rndis_msg->ndis_msg_type,
			rndis_msg->msg_len);
		break;
	}
}

static int rndis_filter_send_request(struct rndis_device *dev,
				  struct rndis_request *req)
{
	int ret;
	struct hv_netvsc_packet *packet;

	/* Setup the packet to send it */
	packet = &req->pkt;

	packet->is_data_pkt = false;
	packet->total_data_buflen = req->request_msg.msg_len;
	packet->page_buf_cnt = 1;

	packet->page_buf[0].pfn = virt_to_phys(&req->request_msg) >>
					PAGE_SHIFT;
	packet->page_buf[0].len = req->request_msg.msg_len;
	packet->page_buf[0].offset =
		(unsigned long)&req->request_msg & (PAGE_SIZE - 1);

	/* Add one page_buf when request_msg crossing page boundary */
	if (packet->page_buf[0].offset + packet->page_buf[0].len > PAGE_SIZE) {
		packet->page_buf_cnt++;
		packet->page_buf[0].len = PAGE_SIZE -
			packet->page_buf[0].offset;
		packet->page_buf[1].pfn = virt_to_phys((void *)&req->request_msg
			+ packet->page_buf[0].len) >> PAGE_SHIFT;
		packet->page_buf[1].offset = 0;
		packet->page_buf[1].len = req->request_msg.msg_len -
			packet->page_buf[0].len;
	}

	packet->send_completion = NULL;
	packet->xmit_more = false;

	ret = netvsc_send(dev->net_dev->dev, packet);
	return ret;
}

static void rndis_set_link_state(struct rndis_device *rdev,
				 struct rndis_request *request)
{
	u32 link_status;
	struct rndis_query_complete *query_complete;

	query_complete = &request->response_msg.msg.query_complete;

	if (query_complete->status == RNDIS_STATUS_SUCCESS &&
	    query_complete->info_buflen == sizeof(u32)) {
		memcpy(&link_status, (void *)((unsigned long)query_complete +
		       query_complete->info_buf_offset), sizeof(u32));
		rdev->link_state = link_status != 0;
	}
}

static void rndis_filter_receive_response(struct rndis_device *dev,
				       struct rndis_message *resp)
{
	struct rndis_request *request = NULL;
	bool found = false;
	unsigned long flags;
	struct net_device *ndev;

	ndev = dev->net_dev->ndev;

	spin_lock_irqsave(&dev->request_lock, flags);
	list_for_each_entry(request, &dev->req_list, list_ent) {
		/*
		 * All request/response message contains RequestId as the 1st
		 * field
		 */
		if (request->request_msg.msg.init_req.req_id
		    == resp->msg.init_complete.req_id) {
			found = true;
			break;
		}
	}
	spin_unlock_irqrestore(&dev->request_lock, flags);

	if (found) {
		if (resp->msg_len <=
		    sizeof(struct rndis_message) + RNDIS_EXT_LEN) {
			memcpy(&request->response_msg, resp,
			       resp->msg_len);
			if (request->request_msg.ndis_msg_type ==
			    RNDIS_MSG_QUERY && request->request_msg.msg.
			    query_req.oid == RNDIS_OID_GEN_MEDIA_CONNECT_STATUS)
				rndis_set_link_state(dev, request);
		} else {
			netdev_err(ndev,
				"rndis response buffer overflow "
				"detected (size %u max %zu)\n",
				resp->msg_len,
				sizeof(struct rndis_message));

			if (resp->ndis_msg_type ==
			    RNDIS_MSG_RESET_C) {
				/* does not have a request id field */
				request->response_msg.msg.reset_complete.
					status = RNDIS_STATUS_BUFFER_OVERFLOW;
			} else {
				request->response_msg.msg.
				init_complete.status =
					RNDIS_STATUS_BUFFER_OVERFLOW;
			}
		}

		complete(&request->wait_event);
	} else {
		netdev_err(ndev,
			"no rndis request found for this response "
			"(id 0x%x res type 0x%x)\n",
			resp->msg.init_complete.req_id,
			resp->ndis_msg_type);
	}
}

/*
 * Get the Per-Packet-Info with the specified type
 * return NULL if not found.
 */
static inline void *rndis_get_ppi(struct rndis_packet *rpkt, u32 type)
{
	struct rndis_per_packet_info *ppi;
	int len;

	if (rpkt->per_pkt_info_offset == 0)
		return NULL;

	ppi = (struct rndis_per_packet_info *)((ulong)rpkt +
		rpkt->per_pkt_info_offset);
	len = rpkt->per_pkt_info_len;

	while (len > 0) {
		if (ppi->type == type)
			return (void *)((ulong)ppi + ppi->ppi_offset);
		len -= ppi->size;
		ppi = (struct rndis_per_packet_info *)((ulong)ppi + ppi->size);
	}

	return NULL;
}

static void rndis_filter_receive_data(struct rndis_device *dev,
				   struct rndis_message *msg,
				   struct hv_netvsc_packet *pkt)
{
	struct rndis_packet *rndis_pkt;
	u32 data_offset;
	struct ndis_pkt_8021q_info *vlan;
	struct ndis_tcp_ip_checksum_info *csum_info;

	rndis_pkt = &msg->msg.pkt;

	/* Remove the rndis header and pass it back up the stack */
	data_offset = RNDIS_HEADER_SIZE + rndis_pkt->data_offset;

	pkt->total_data_buflen -= data_offset;

	/*
	 * Make sure we got a valid RNDIS message, now total_data_buflen
	 * should be the data packet size plus the trailer padding size
	 */
	if (pkt->total_data_buflen < rndis_pkt->data_len) {
		netdev_err(dev->net_dev->ndev, "rndis message buffer "
			   "overflow detected (got %u, min %u)"
			   "...dropping this message!\n",
			   pkt->total_data_buflen, rndis_pkt->data_len);
		return;
	}

	/*
	 * Remove the rndis trailer padding from rndis packet message
	 * rndis_pkt->data_len tell us the real data length, we only copy
	 * the data packet to the stack, without the rndis trailer padding
	 */
	pkt->total_data_buflen = rndis_pkt->data_len;
	pkt->data = (void *)((unsigned long)pkt->data + data_offset);

	vlan = rndis_get_ppi(rndis_pkt, IEEE_8021Q_INFO);
	if (vlan) {
		pkt->vlan_tci = VLAN_TAG_PRESENT | vlan->vlanid |
			(vlan->pri << VLAN_PRIO_SHIFT);
	} else {
		pkt->vlan_tci = 0;
	}

	csum_info = rndis_get_ppi(rndis_pkt, TCPIP_CHKSUM_PKTINFO);
	netvsc_recv_callback(dev->net_dev->dev, pkt, csum_info);
}

int rndis_filter_receive(struct hv_device *dev,
				struct hv_netvsc_packet	*pkt)
{
	struct netvsc_device *net_dev = hv_get_drvdata(dev);
	struct rndis_device *rndis_dev;
	struct rndis_message *rndis_msg;
	struct net_device *ndev;
	int ret = 0;

	if (!net_dev) {
		ret = -EINVAL;
		goto exit;
	}

	ndev = net_dev->ndev;

	/* Make sure the rndis device state is initialized */
	if (!net_dev->extension) {
		netdev_err(ndev, "got rndis message but no rndis device - "
			  "dropping this message!\n");
		ret = -ENODEV;
		goto exit;
	}

	rndis_dev = (struct rndis_device *)net_dev->extension;
	if (rndis_dev->state == RNDIS_DEV_UNINITIALIZED) {
		netdev_err(ndev, "got rndis message but rndis device "
			   "uninitialized...dropping this message!\n");
		ret = -ENODEV;
		goto exit;
	}

	rndis_msg = pkt->data;

	dump_rndis_message(dev, rndis_msg);

	switch (rndis_msg->ndis_msg_type) {
	case RNDIS_MSG_PACKET:
		/* data msg */
		rndis_filter_receive_data(rndis_dev, rndis_msg, pkt);
		break;

	case RNDIS_MSG_INIT_C:
	case RNDIS_MSG_QUERY_C:
	case RNDIS_MSG_SET_C:
		/* completion msgs */
		rndis_filter_receive_response(rndis_dev, rndis_msg);
		break;

	case RNDIS_MSG_INDICATE:
		/* notification msgs */
		netvsc_linkstatus_callback(dev, rndis_msg);
		break;
	default:
		netdev_err(ndev,
			"unhandled rndis message (type %u len %u)\n",
			   rndis_msg->ndis_msg_type,
			   rndis_msg->msg_len);
		break;
	}

exit:
	if (ret != 0)
		pkt->status = NVSP_STAT_FAIL;

	return ret;
}

static int rndis_filter_query_device(struct rndis_device *dev, u32 oid,
				  void *result, u32 *result_size)
{
	struct rndis_request *request;
	u32 inresult_size = *result_size;
	struct rndis_query_request *query;
	struct rndis_query_complete *query_complete;
	int ret = 0;
	unsigned long t;

	if (!result)
		return -EINVAL;

	*result_size = 0;
	request = get_rndis_request(dev, RNDIS_MSG_QUERY,
			RNDIS_MESSAGE_SIZE(struct rndis_query_request));
	if (!request) {
		ret = -ENOMEM;
		goto cleanup;
	}

	/* Setup the rndis query */
	query = &request->request_msg.msg.query_req;
	query->oid = oid;
	query->info_buf_offset = sizeof(struct rndis_query_request);
	query->info_buflen = 0;
	query->dev_vc_handle = 0;

	if (oid == OID_GEN_RECEIVE_SCALE_CAPABILITIES) {
		struct ndis_recv_scale_cap *cap;

		request->request_msg.msg_len +=
			sizeof(struct ndis_recv_scale_cap);
		query->info_buflen = sizeof(struct ndis_recv_scale_cap);
		cap = (struct ndis_recv_scale_cap *)((unsigned long)query +
						     query->info_buf_offset);
		cap->hdr.type = NDIS_OBJECT_TYPE_RSS_CAPABILITIES;
		cap->hdr.rev = NDIS_RECEIVE_SCALE_CAPABILITIES_REVISION_2;
		cap->hdr.size = sizeof(struct ndis_recv_scale_cap);
	}

	ret = rndis_filter_send_request(dev, request);
	if (ret != 0)
		goto cleanup;

	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
	if (t == 0) {
		ret = -ETIMEDOUT;
		goto cleanup;
	}

	/* Copy the response back */
	query_complete = &request->response_msg.msg.query_complete;

	if (query_complete->info_buflen > inresult_size) {
		ret = -1;
		goto cleanup;
	}

	memcpy(result,
	       (void *)((unsigned long)query_complete +
			 query_complete->info_buf_offset),
	       query_complete->info_buflen);

	*result_size = query_complete->info_buflen;

cleanup:
	if (request)
		put_rndis_request(dev, request);

	return ret;
}

static int rndis_filter_query_device_mac(struct rndis_device *dev)
{
	u32 size = ETH_ALEN;

	return rndis_filter_query_device(dev,
				      RNDIS_OID_802_3_PERMANENT_ADDRESS,
				      dev->hw_mac_adr, &size);
}

#define NWADR_STR "NetworkAddress"
#define NWADR_STRLEN 14

int rndis_filter_set_device_mac(struct hv_device *hdev, char *mac)
{
	struct netvsc_device *nvdev = hv_get_drvdata(hdev);
	struct rndis_device *rdev = nvdev->extension;
	struct net_device *ndev = nvdev->ndev;
	struct rndis_request *request;
	struct rndis_set_request *set;
	struct rndis_config_parameter_info *cpi;
	wchar_t *cfg_nwadr, *cfg_mac;
	struct rndis_set_complete *set_complete;
	char macstr[2*ETH_ALEN+1];
	u32 extlen = sizeof(struct rndis_config_parameter_info) +
		2*NWADR_STRLEN + 4*ETH_ALEN;
	int ret;
	unsigned long t;

	request = get_rndis_request(rdev, RNDIS_MSG_SET,
		RNDIS_MESSAGE_SIZE(struct rndis_set_request) + extlen);
	if (!request)
		return -ENOMEM;

	set = &request->request_msg.msg.set_req;
	set->oid = RNDIS_OID_GEN_RNDIS_CONFIG_PARAMETER;
	set->info_buflen = extlen;
	set->info_buf_offset = sizeof(struct rndis_set_request);
	set->dev_vc_handle = 0;

	cpi = (struct rndis_config_parameter_info *)((ulong)set +
		set->info_buf_offset);
	cpi->parameter_name_offset =
		sizeof(struct rndis_config_parameter_info);
	/* Multiply by 2 because host needs 2 bytes (utf16) for each char */
	cpi->parameter_name_length = 2*NWADR_STRLEN;
	cpi->parameter_type = RNDIS_CONFIG_PARAM_TYPE_STRING;
	cpi->parameter_value_offset =
		cpi->parameter_name_offset + cpi->parameter_name_length;
	/* Multiply by 4 because each MAC byte displayed as 2 utf16 chars */
	cpi->parameter_value_length = 4*ETH_ALEN;

	cfg_nwadr = (wchar_t *)((ulong)cpi + cpi->parameter_name_offset);
	cfg_mac = (wchar_t *)((ulong)cpi + cpi->parameter_value_offset);
	ret = utf8s_to_utf16s(NWADR_STR, NWADR_STRLEN, UTF16_HOST_ENDIAN,
			      cfg_nwadr, NWADR_STRLEN);
	if (ret < 0)
		goto cleanup;
	snprintf(macstr, 2*ETH_ALEN+1, "%pm", mac);
	ret = utf8s_to_utf16s(macstr, 2*ETH_ALEN, UTF16_HOST_ENDIAN,
			      cfg_mac, 2*ETH_ALEN);
	if (ret < 0)
		goto cleanup;

	ret = rndis_filter_send_request(rdev, request);
	if (ret != 0)
		goto cleanup;

	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
	if (t == 0) {
		netdev_err(ndev, "timeout before we got a set response...\n");
		/*
		 * can't put_rndis_request, since we may still receive a
		 * send-completion.
		 */
		return -EBUSY;
	} else {
		set_complete = &request->response_msg.msg.set_complete;
		if (set_complete->status != RNDIS_STATUS_SUCCESS) {
			netdev_err(ndev, "Fail to set MAC on host side:0x%x\n",
				   set_complete->status);
			ret = -EINVAL;
		}
	}

cleanup:
	put_rndis_request(rdev, request);
	return ret;
}

static int
rndis_filter_set_offload_params(struct hv_device *hdev,
				struct ndis_offload_params *req_offloads)
{
	struct netvsc_device *nvdev = hv_get_drvdata(hdev);
	struct rndis_device *rdev = nvdev->extension;
	struct net_device *ndev = nvdev->ndev;
	struct rndis_request *request;
	struct rndis_set_request *set;
	struct ndis_offload_params *offload_params;
	struct rndis_set_complete *set_complete;
	u32 extlen = sizeof(struct ndis_offload_params);
	int ret;
	unsigned long t;
	u32 vsp_version = nvdev->nvsp_version;

	if (vsp_version <= NVSP_PROTOCOL_VERSION_4) {
		extlen = VERSION_4_OFFLOAD_SIZE;
		/* On NVSP_PROTOCOL_VERSION_4 and below, we do not support
		 * UDP checksum offload.
		 */
		req_offloads->udp_ip_v4_csum = 0;
		req_offloads->udp_ip_v6_csum = 0;
	}

	request = get_rndis_request(rdev, RNDIS_MSG_SET,
		RNDIS_MESSAGE_SIZE(struct rndis_set_request) + extlen);
	if (!request)
		return -ENOMEM;

	set = &request->request_msg.msg.set_req;
	set->oid = OID_TCP_OFFLOAD_PARAMETERS;
	set->info_buflen = extlen;
	set->info_buf_offset = sizeof(struct rndis_set_request);
	set->dev_vc_handle = 0;

	offload_params = (struct ndis_offload_params *)((ulong)set +
				set->info_buf_offset);
	*offload_params = *req_offloads;
	offload_params->header.type = NDIS_OBJECT_TYPE_DEFAULT;
	offload_params->header.revision = NDIS_OFFLOAD_PARAMETERS_REVISION_3;
	offload_params->header.size = extlen;

	ret = rndis_filter_send_request(rdev, request);
	if (ret != 0)
		goto cleanup;

	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
	if (t == 0) {
		netdev_err(ndev, "timeout before we got aOFFLOAD set response...\n");
		/* can't put_rndis_request, since we may still receive a
		 * send-completion.
		 */
		return -EBUSY;
	} else {
		set_complete = &request->response_msg.msg.set_complete;
		if (set_complete->status != RNDIS_STATUS_SUCCESS) {
			netdev_err(ndev, "Fail to set offload on host side:0x%x\n",
				   set_complete->status);
			ret = -EINVAL;
		}
	}

cleanup:
	put_rndis_request(rdev, request);
	return ret;
}

u8 netvsc_hash_key[HASH_KEYLEN] = {
	0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
	0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
	0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
	0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
	0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa
};

static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue)
{
	struct net_device *ndev = rdev->net_dev->ndev;
	struct rndis_request *request;
	struct rndis_set_request *set;
	struct rndis_set_complete *set_complete;
	u32 extlen = sizeof(struct ndis_recv_scale_param) +
		     4*ITAB_NUM + HASH_KEYLEN;
	struct ndis_recv_scale_param *rssp;
	u32 *itab;
	u8 *keyp;
	int i, ret;
	unsigned long t;

	request = get_rndis_request(
			rdev, RNDIS_MSG_SET,
			RNDIS_MESSAGE_SIZE(struct rndis_set_request) + extlen);
	if (!request)
		return -ENOMEM;

	set = &request->request_msg.msg.set_req;
	set->oid = OID_GEN_RECEIVE_SCALE_PARAMETERS;
	set->info_buflen = extlen;
	set->info_buf_offset = sizeof(struct rndis_set_request);
	set->dev_vc_handle = 0;

	rssp = (struct ndis_recv_scale_param *)(set + 1);
	rssp->hdr.type = NDIS_OBJECT_TYPE_RSS_PARAMETERS;
	rssp->hdr.rev = NDIS_RECEIVE_SCALE_PARAMETERS_REVISION_2;
	rssp->hdr.size = sizeof(struct ndis_recv_scale_param);
	rssp->flag = 0;
	rssp->hashinfo = NDIS_HASH_FUNC_TOEPLITZ | NDIS_HASH_IPV4 |
			 NDIS_HASH_TCP_IPV4 | NDIS_HASH_IPV6 |
			 NDIS_HASH_TCP_IPV6;
	rssp->indirect_tabsize = 4*ITAB_NUM;
	rssp->indirect_taboffset = sizeof(struct ndis_recv_scale_param);
	rssp->hashkey_size = HASH_KEYLEN;
	rssp->kashkey_offset = rssp->indirect_taboffset +
			       rssp->indirect_tabsize;

	/* Set indirection table entries */
	itab = (u32 *)(rssp + 1);
	for (i = 0; i < ITAB_NUM; i++)
		itab[i] = i % num_queue;

	/* Set hask key values */
	keyp = (u8 *)((unsigned long)rssp + rssp->kashkey_offset);
	for (i = 0; i < HASH_KEYLEN; i++)
		keyp[i] = netvsc_hash_key[i];


	ret = rndis_filter_send_request(rdev, request);
	if (ret != 0)
		goto cleanup;

	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
	if (t == 0) {
		netdev_err(ndev, "timeout before we got a set response...\n");
		/* can't put_rndis_request, since we may still receive a
		 * send-completion.
		 */
		return -ETIMEDOUT;
	} else {
		set_complete = &request->response_msg.msg.set_complete;
		if (set_complete->status != RNDIS_STATUS_SUCCESS) {
			netdev_err(ndev, "Fail to set RSS parameters:0x%x\n",
				   set_complete->status);
			ret = -EINVAL;
		}
	}

cleanup:
	put_rndis_request(rdev, request);
	return ret;
}


static int rndis_filter_query_device_link_status(struct rndis_device *dev)
{
	u32 size = sizeof(u32);
	u32 link_status;
	int ret;

	ret = rndis_filter_query_device(dev,
				      RNDIS_OID_GEN_MEDIA_CONNECT_STATUS,
				      &link_status, &size);

	return ret;
}

int rndis_filter_set_packet_filter(struct rndis_device *dev, u32 new_filter)
{
	struct rndis_request *request;
	struct rndis_set_request *set;
	struct rndis_set_complete *set_complete;
	u32 status;
	int ret;
	unsigned long t;
	struct net_device *ndev;

	ndev = dev->net_dev->ndev;

	request = get_rndis_request(dev, RNDIS_MSG_SET,
			RNDIS_MESSAGE_SIZE(struct rndis_set_request) +
			sizeof(u32));
	if (!request) {
		ret = -ENOMEM;
		goto cleanup;
	}

	/* Setup the rndis set */
	set = &request->request_msg.msg.set_req;
	set->oid = RNDIS_OID_GEN_CURRENT_PACKET_FILTER;
	set->info_buflen = sizeof(u32);
	set->info_buf_offset = sizeof(struct rndis_set_request);

	memcpy((void *)(unsigned long)set + sizeof(struct rndis_set_request),
	       &new_filter, sizeof(u32));

	ret = rndis_filter_send_request(dev, request);
	if (ret != 0)
		goto cleanup;

	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);

	if (t == 0) {
		netdev_err(ndev,
			"timeout before we got a set response...\n");
		ret = -ETIMEDOUT;
		/*
		 * We can't deallocate the request since we may still receive a
		 * send completion for it.
		 */
		goto exit;
	} else {
		set_complete = &request->response_msg.msg.set_complete;
		status = set_complete->status;
	}

cleanup:
	if (request)
		put_rndis_request(dev, request);
exit:
	return ret;
}


static int rndis_filter_init_device(struct rndis_device *dev)
{
	struct rndis_request *request;
	struct rndis_initialize_request *init;
	struct rndis_initialize_complete *init_complete;
	u32 status;
	int ret;
	unsigned long t;
	struct netvsc_device *nvdev = dev->net_dev;

	request = get_rndis_request(dev, RNDIS_MSG_INIT,
			RNDIS_MESSAGE_SIZE(struct rndis_initialize_request));
	if (!request) {
		ret = -ENOMEM;
		goto cleanup;
	}

	/* Setup the rndis set */
	init = &request->request_msg.msg.init_req;
	init->major_ver = RNDIS_MAJOR_VERSION;
	init->minor_ver = RNDIS_MINOR_VERSION;
	init->max_xfer_size = 0x4000;

	dev->state = RNDIS_DEV_INITIALIZING;

	ret = rndis_filter_send_request(dev, request);
	if (ret != 0) {
		dev->state = RNDIS_DEV_UNINITIALIZED;
		goto cleanup;
	}


	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);

	if (t == 0) {
		ret = -ETIMEDOUT;
		goto cleanup;
	}

	init_complete = &request->response_msg.msg.init_complete;
	status = init_complete->status;
	if (status == RNDIS_STATUS_SUCCESS) {
		dev->state = RNDIS_DEV_INITIALIZED;
		nvdev->max_pkt = init_complete->max_pkt_per_msg;
		nvdev->pkt_align = 1 << init_complete->pkt_alignment_factor;
		ret = 0;
	} else {
		dev->state = RNDIS_DEV_UNINITIALIZED;
		ret = -EINVAL;
	}

cleanup:
	if (request)
		put_rndis_request(dev, request);

	return ret;
}

static void rndis_filter_halt_device(struct rndis_device *dev)
{
	struct rndis_request *request;
	struct rndis_halt_request *halt;
	struct netvsc_device *nvdev = dev->net_dev;
	struct hv_device *hdev = nvdev->dev;
	ulong flags;

	/* Attempt to do a rndis device halt */
	request = get_rndis_request(dev, RNDIS_MSG_HALT,
				RNDIS_MESSAGE_SIZE(struct rndis_halt_request));
	if (!request)
		goto cleanup;

	/* Setup the rndis set */
	halt = &request->request_msg.msg.halt_req;
	halt->req_id = atomic_inc_return(&dev->new_req_id);

	/* Ignore return since this msg is optional. */
	rndis_filter_send_request(dev, request);

	dev->state = RNDIS_DEV_UNINITIALIZED;

cleanup:
	spin_lock_irqsave(&hdev->channel->inbound_lock, flags);
	nvdev->destroy = true;
	spin_unlock_irqrestore(&hdev->channel->inbound_lock, flags);

	/* Wait for all send completions */
	wait_event(nvdev->wait_drain,
		atomic_read(&nvdev->num_outstanding_sends) == 0);

	if (request)
		put_rndis_request(dev, request);
	return;
}

static int rndis_filter_open_device(struct rndis_device *dev)
{
	int ret;

	if (dev->state != RNDIS_DEV_INITIALIZED)
		return 0;

	ret = rndis_filter_set_packet_filter(dev,
					 NDIS_PACKET_TYPE_BROADCAST |
					 NDIS_PACKET_TYPE_ALL_MULTICAST |
					 NDIS_PACKET_TYPE_DIRECTED);
	if (ret == 0)
		dev->state = RNDIS_DEV_DATAINITIALIZED;

	return ret;
}

static int rndis_filter_close_device(struct rndis_device *dev)
{
	int ret;

	if (dev->state != RNDIS_DEV_DATAINITIALIZED)
		return 0;

	ret = rndis_filter_set_packet_filter(dev, 0);
	if (ret == -ENODEV)
		ret = 0;

	if (ret == 0)
		dev->state = RNDIS_DEV_INITIALIZED;

	return ret;
}

static void netvsc_sc_open(struct vmbus_channel *new_sc)
{
	struct netvsc_device *nvscdev;
	u16 chn_index = new_sc->offermsg.offer.sub_channel_index;
	int ret;

	nvscdev = hv_get_drvdata(new_sc->primary_channel->device_obj);

	if (chn_index >= nvscdev->num_chn)
		return;

	set_per_channel_state(new_sc, nvscdev->sub_cb_buf + (chn_index - 1) *
			      NETVSC_PACKET_SIZE);

	ret = vmbus_open(new_sc, nvscdev->ring_size * PAGE_SIZE,
			 nvscdev->ring_size * PAGE_SIZE, NULL, 0,
			 netvsc_channel_cb, new_sc);

	if (ret == 0)
		nvscdev->chn_table[chn_index] = new_sc;
}

int rndis_filter_device_add(struct hv_device *dev,
				  void *additional_info)
{
	int ret;
	struct netvsc_device *net_device;
	struct rndis_device *rndis_device;
	struct netvsc_device_info *device_info = additional_info;
	struct ndis_offload_params offloads;
	struct nvsp_message *init_packet;
	unsigned long t;
	struct ndis_recv_scale_cap rsscap;
	u32 rsscap_size = sizeof(struct ndis_recv_scale_cap);
	u32 mtu, size;

	rndis_device = get_rndis_device();
	if (!rndis_device)
		return -ENODEV;

	/*
	 * Let the inner driver handle this first to create the netvsc channel
	 * NOTE! Once the channel is created, we may get a receive callback
	 * (RndisFilterOnReceive()) before this call is completed
	 */
	ret = netvsc_device_add(dev, additional_info);
	if (ret != 0) {
		kfree(rndis_device);
		return ret;
	}


	/* Initialize the rndis device */
	net_device = hv_get_drvdata(dev);
	net_device->max_chn = 1;
	net_device->num_chn = 1;

	net_device->extension = rndis_device;
	rndis_device->net_dev = net_device;

	/* Send the rndis initialization message */
	ret = rndis_filter_init_device(rndis_device);
	if (ret != 0) {
		rndis_filter_device_remove(dev);
		return ret;
	}

	/* Get the MTU from the host */
	size = sizeof(u32);
	ret = rndis_filter_query_device(rndis_device,
					RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE,
					&mtu, &size);
	if (ret == 0 && size == sizeof(u32))
		net_device->ndev->mtu = mtu;

	/* Get the mac address */
	ret = rndis_filter_query_device_mac(rndis_device);
	if (ret != 0) {
		rndis_filter_device_remove(dev);
		return ret;
	}

	memcpy(device_info->mac_adr, rndis_device->hw_mac_adr, ETH_ALEN);

	/* Turn on the offloads; the host supports all of the relevant
	 * offloads.
	 */
	memset(&offloads, 0, sizeof(struct ndis_offload_params));
	/* A value of zero means "no change"; now turn on what we
	 * want.
	 */
	offloads.ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
	offloads.tcp_ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
	offloads.udp_ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
	offloads.tcp_ip_v6_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
	offloads.udp_ip_v6_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
	offloads.lso_v2_ipv4 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;


	ret = rndis_filter_set_offload_params(dev, &offloads);
	if (ret)
		goto err_dev_remv;

	rndis_filter_query_device_link_status(rndis_device);

	device_info->link_state = rndis_device->link_state;

	dev_info(&dev->device, "Device MAC %pM link state %s\n",
		 rndis_device->hw_mac_adr,
		 device_info->link_state ? "down" : "up");

	if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5)
		return 0;

	/* vRSS setup */
	memset(&rsscap, 0, rsscap_size);
	ret = rndis_filter_query_device(rndis_device,
					OID_GEN_RECEIVE_SCALE_CAPABILITIES,
					&rsscap, &rsscap_size);
	if (ret || rsscap.num_recv_que < 2)
		goto out;

	net_device->max_chn = rsscap.num_recv_que;
	net_device->num_chn = (num_online_cpus() < rsscap.num_recv_que) ?
			       num_online_cpus() : rsscap.num_recv_que;
	if (net_device->num_chn == 1)
		goto out;

	net_device->sub_cb_buf = vzalloc((net_device->num_chn - 1) *
					 NETVSC_PACKET_SIZE);
	if (!net_device->sub_cb_buf) {
		net_device->num_chn = 1;
		dev_info(&dev->device, "No memory for subchannels.\n");
		goto out;
	}

	vmbus_set_sc_create_callback(dev->channel, netvsc_sc_open);

	init_packet = &net_device->channel_init_pkt;
	memset(init_packet, 0, sizeof(struct nvsp_message));
	init_packet->hdr.msg_type = NVSP_MSG5_TYPE_SUBCHANNEL;
	init_packet->msg.v5_msg.subchn_req.op = NVSP_SUBCHANNEL_ALLOCATE;
	init_packet->msg.v5_msg.subchn_req.num_subchannels =
						net_device->num_chn - 1;
	ret = vmbus_sendpacket(dev->channel, init_packet,
			       sizeof(struct nvsp_message),
			       (unsigned long)init_packet,
			       VM_PKT_DATA_INBAND,
			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
	if (ret)
		goto out;
	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
	if (t == 0) {
		ret = -ETIMEDOUT;
		goto out;
	}
	if (init_packet->msg.v5_msg.subchn_comp.status !=
	    NVSP_STAT_SUCCESS) {
		ret = -ENODEV;
		goto out;
	}
	net_device->num_chn = 1 +
		init_packet->msg.v5_msg.subchn_comp.num_subchannels;

	vmbus_are_subchannels_present(dev->channel);

	ret = rndis_filter_set_rss_param(rndis_device, net_device->num_chn);

out:
	if (ret) {
		net_device->max_chn = 1;
		net_device->num_chn = 1;
	}
	return 0; /* return 0 because primary channel can be used alone */

err_dev_remv:
	rndis_filter_device_remove(dev);
	return ret;
}

void rndis_filter_device_remove(struct hv_device *dev)
{
	struct netvsc_device *net_dev = hv_get_drvdata(dev);
	struct rndis_device *rndis_dev = net_dev->extension;

	/* Halt and release the rndis device */
	rndis_filter_halt_device(rndis_dev);

	kfree(rndis_dev);
	net_dev->extension = NULL;

	netvsc_device_remove(dev);
}


int rndis_filter_open(struct hv_device *dev)
{
	struct netvsc_device *net_device = hv_get_drvdata(dev);

	if (!net_device)
		return -EINVAL;

	return rndis_filter_open_device(net_device->extension);
}

int rndis_filter_close(struct hv_device *dev)
{
	struct netvsc_device *nvdev = hv_get_drvdata(dev);

	if (!nvdev)
		return -EINVAL;

	return rndis_filter_close_device(nvdev->extension);
}