path: root/drivers/hv/hv_kvp.c

/*
 * An implementation of key value pair (KVP) functionality for Linux.
 *
 *
 * Copyright (C) 2010, Novell, Inc.
 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/net.h>
#include <linux/nls.h>
#include <linux/connector.h>
#include <linux/workqueue.h>
#include <linux/hyperv.h>
#include <asm/hyperv-tlfs.h>

#include "hyperv_vmbus.h"
#include "hv_utils_transport.h"

/*
 * Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
 */
#define WS2008_SRV_MAJOR	1
#define WS2008_SRV_MINOR	0
#define WS2008_SRV_VERSION     (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)

#define WIN7_SRV_MAJOR   3
#define WIN7_SRV_MINOR   0
#define WIN7_SRV_VERSION     (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)

#define WIN8_SRV_MAJOR   4
#define WIN8_SRV_MINOR   0
#define WIN8_SRV_VERSION     (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)

#define KVP_VER_COUNT 3
static const int kvp_versions[] = {
	WIN8_SRV_VERSION,
	WIN7_SRV_VERSION,
	WS2008_SRV_VERSION
};

#define FW_VER_COUNT 2
static const int fw_versions[] = {
	UTIL_FW_VERSION,
	UTIL_WS2K8_FW_VERSION
};

/*
 * Global state maintained for transaction that is being processed. For a class
 * of integration services, including the "KVP service", the specified protocol
 * is a "request/response" protocol which means that there can only be single
 * outstanding transaction from the host at any given point in time. We use
 * this to simplify memory management in this driver - we cache and process
 * only one message at a time.
 *
 * While the request/response protocol is guaranteed by the host, we further
 * ensure this by serializing packet processing in this driver - we do not
 * read additional packets from the VMBUS until the current packet is fully
 * handled.
 */

static struct {
	int state;   /* hvutil_device_state */
	int recv_len; /* number of bytes received. */
	struct hv_kvp_msg  *kvp_msg; /* current message */
	struct vmbus_channel *recv_channel; /* chn we got the request */
	u64 recv_req_id; /* request ID. */
} kvp_transaction;

/*
 * This state maintains the version number registered by the daemon.
 */
static int dm_reg_value;

static void kvp_send_key(struct work_struct *dummy);


static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
static void kvp_timeout_func(struct work_struct *dummy);
static void kvp_host_handshake_func(struct work_struct *dummy);
static void kvp_register(int);

static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);

static const char kvp_devname[] = "vmbus/hv_kvp";
static u8 *recv_buffer;
static struct hvutil_transport *hvt;
/*
 * Register the kernel component with the user-level daemon.
 * As part of this registration, pass the LIC version number.
 * This number has no meaning, it satisfies the registration protocol.
 */
#define HV_DRV_VERSION           "3.1"

static void kvp_poll_wrapper(void *channel)
{
	/* Transaction is finished, reset the state here to avoid races. */
	kvp_transaction.state = HVUTIL_READY;
	tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
}

static void kvp_register_done(void)
{
	/*
	 * If we're still negotiating with the host cancel the timeout
	 * work to not poll the channel twice.
	 */
	pr_debug("KVP: userspace daemon registered\n");
	cancel_delayed_work_sync(&kvp_host_handshake_work);
	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}

static void
kvp_register(int reg_value)
{

	struct hv_kvp_msg *kvp_msg;
	char *version;

	kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);

	if (kvp_msg) {
		version = kvp_msg->body.kvp_register.version;
		kvp_msg->kvp_hdr.operation = reg_value;
		strcpy(version, HV_DRV_VERSION);

		hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
				      kvp_register_done);
		kfree(kvp_msg);
	}
}

static void kvp_timeout_func(struct work_struct *dummy)
{
	/*
	 * If the timer fires, the user-mode component has not responded;
	 * process the pending transaction.
	 */
	kvp_respond_to_host(NULL, HV_E_FAIL);

	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}

static void kvp_host_handshake_func(struct work_struct *dummy)
{
	tasklet_schedule(&kvp_transaction.recv_channel->callback_event);
}

static int kvp_handle_handshake(struct hv_kvp_msg *msg)
{
	switch (msg->kvp_hdr.operation) {
	case KVP_OP_REGISTER:
		dm_reg_value = KVP_OP_REGISTER;
		pr_info("KVP: IP injection functionality not available\n");
		pr_info("KVP: Upgrade the KVP daemon\n");
		break;
	case KVP_OP_REGISTER1:
		dm_reg_value = KVP_OP_REGISTER1;
		break;
	default:
		pr_info("KVP: incompatible daemon\n");
		pr_info("KVP: KVP version: %d, Daemon version: %d\n",
			KVP_OP_REGISTER1, msg->kvp_hdr.operation);
		return -EINVAL;
	}

	/*
	 * We have a compatible daemon; complete the handshake.
	 */
	pr_debug("KVP: userspace daemon ver. %d connected\n",
		 msg->kvp_hdr.operation);
	kvp_register(dm_reg_value);

	return 0;
}


/*
 * Callback when data is received from user mode.
 */

static int kvp_on_msg(void *msg, int len)
{
	struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
	struct hv_kvp_msg_enumerate *data;
	int	error = 0;

	if (len < sizeof(*message))
		return -EINVAL;

	/*
	 * If we are negotiating the version information
	 * with the daemon; handle that first.
	 */

	if (kvp_transaction.state < HVUTIL_READY) {
		return kvp_handle_handshake(message);
	}

	/* We didn't send anything to userspace so the reply is spurious */
	if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
		return -EINVAL;

	kvp_transaction.state = HVUTIL_USERSPACE_RECV;

	/*
	 * Based on the version of the daemon, we propagate errors from the
	 * daemon differently.
	 */

	data = &message->body.kvp_enum_data;

	switch (dm_reg_value) {
	case KVP_OP_REGISTER:
		/*
		 * Null string is used to pass back error condition.
		 */
		if (data->data.key[0] == 0)
			error = HV_S_CONT;
		break;

	case KVP_OP_REGISTER1:
		/*
		 * We use the message header information from
		 * the user level daemon to transmit errors.
		 */
		error = message->error;
		break;
	}

	/*
	 * Complete the transaction by forwarding the key value
	 * to the host. But first, cancel the timeout.
	 */
	if (cancel_delayed_work_sync(&kvp_timeout_work)) {
		kvp_respond_to_host(message, error);
		hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
	}

	return 0;
}


static int process_ob_ipinfo(void *in_msg, void *out_msg, int