[deliverable/linux.git] / 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>


/*
 * Global state maintained for transaction that is being processed.
 * Note that only one transaction can be active at any point in time.
 *
 * This state is set when we receive a request from the host; we
 * cleanup this state when the transaction is completed - when we respond
 * to the host with the key value.
 */

static struct {
	bool active; /* transaction status - active or not */
	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. */
	void *kvp_context; /* for the channel callback */
} kvp_transaction;

static void kvp_send_key(struct work_struct *dummy);

#define TIMEOUT_FIRED 1

static void kvp_respond_to_host(char *key, char *value, int error);
static void kvp_work_func(struct work_struct *dummy);
static void kvp_register(void);

static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);

static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
static const char kvp_name[] = "kvp_kernel_module";
static u8 *recv_buffer;
/*
 * Register the kernel component with the user-level daemon.
 * As part of this registration, pass the LIC version number.
 */

static void
kvp_register(void)
{

	struct cn_msg *msg;
	struct hv_kvp_msg *kvp_msg;
	char *version;

	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);

	if (msg) {
		kvp_msg = (struct hv_kvp_msg *)msg->data;
		version = kvp_msg->body.kvp_register.version;
		msg->id.idx =  CN_KVP_IDX;
		msg->id.val = CN_KVP_VAL;

		kvp_msg->kvp_hdr.operation = KVP_OP_REGISTER;
		strcpy(version, HV_DRV_VERSION);
		msg->len = sizeof(struct hv_kvp_msg);
		cn_netlink_send(msg, 0, GFP_ATOMIC);
		kfree(msg);
	}
}
static void
kvp_work_func(struct work_struct *dummy)
{
	/*
	 * If the timer fires, the user-mode component has not responded;
	 * process the pending transaction.
	 */
	kvp_respond_to_host("Unknown key", "Guest timed out", TIMEOUT_FIRED);
}

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

static void
kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
	struct hv_kvp_msg *message;
	struct hv_kvp_msg_enumerate *data;

	message = (struct hv_kvp_msg *)msg->data;
	switch (message->kvp_hdr.operation) {
	case KVP_OP_REGISTER:
		pr_info("KVP: user-mode registering done.\n");
		kvp_register();
		kvp_transaction.active = false;
		hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
		break;

	default:
		data = &message->body.kvp_enum_data;
		/*
		 * Complete the transaction by forwarding the key value
		 * to the host. But first, cancel the timeout.
		 */
		if (cancel_delayed_work_sync(&kvp_work))
			kvp_respond_to_host(data->data.key,
					 data->data.value,
					!strlen(data->data.key));
	}
}

static void
kvp_send_key(struct work_struct *dummy)
{
	struct cn_msg *msg;
	struct hv_kvp_msg *message;
	struct hv_kvp_msg *in_msg;
	__u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
	__u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
	__u32 val32;
	__u64 val64;

	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
	if (!msg)
		return;

	msg->id.idx =  CN_KVP_IDX;
	msg->id.val = CN_KVP_VAL;

	message = (struct hv_kvp_msg *)msg->data;
	message->kvp_hdr.operation = operation;
	message->kvp_hdr.pool = pool;
	in_msg = kvp_transaction.kvp_msg;

	/*
	 * The key/value strings sent from the host are encoded in
	 * in utf16; convert it to utf8 strings.
	 * The host assures us that the utf16 strings will not exceed
	 * the max lengths specified. We will however, reserve room
	 * for the string terminating character - in the utf16s_utf8s()
	 * function we limit the size of the buffer where the converted
	 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
	 * that the strings can be properly terminated!
	 */

	switch (message->kvp_hdr.operation) {
	case KVP_OP_SET:
		switch (in_msg->body.kvp_set.data.value_type) {
		case REG_SZ:
			/*
			 * The value is a string - utf16 encoding.
			 */
			message->body.kvp_set.data.value_size =
				utf16s_to_utf8s(
				(wchar_t *)in_msg->body.kvp_set.data.value,
				in_msg->body.kvp_set.data.value_size,
				UTF16_LITTLE_ENDIAN,
				message->body.kvp_set.data.value,
				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
				break;

		case REG_U32:
			/*
			 * The value is a 32 bit scalar.
			 * We save this as a utf8 string.
			 */
			val32 = in_msg->body.kvp_set.data.value_u32;
			message->body.kvp_set.data.value_size =
				sprintf(message->body.kvp_set.data.value,
					"%d", val32) + 1;
			break;

		case REG_U64:
			/*
			 * The value is a 64 bit scalar.
			 * We save this as a utf8 string.
			 */
			val64 = in_msg->body.kvp_set.data.value_u64;
			message->body.kvp_set.data.value_size =
				sprintf(message->body.kvp_set.data.value,
					"%llu", val64) + 1;
			break;

		}
	case KVP_OP_GET:
		message->body.kvp_set.data.key_size =
			utf16s_to_utf8s(
			(wchar_t *)in_msg->body.kvp_set.data.key,
			in_msg->body.kvp_set.data.key_size,
			UTF16_LITTLE_ENDIAN,
			message->body.kvp_set.data.key,
			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
			break;

	case KVP_OP_DELETE:
		message->body.kvp_delete.key_size =
			utf16s_to_utf8s(
			(wchar_t *)in_msg->body.kvp_delete.key,
			in_msg->body.kvp_delete.key_size,
			UTF16_LITTLE_ENDIAN,
			message->body.kvp_delete.key,
			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
			break;

	case KVP_OP_ENUMERATE:
		message->body.kvp_enum_data.index =
			in_msg->body.kvp_enum_data.index;
			break;
	}

	msg->len = sizeof(struct hv_kvp_msg);
	cn_netlink_send(msg, 0, GFP_ATOMIC);
	kfree(msg);

	return;
}

/*
 * Send a response back to the host.
 */

static void
kvp_respond_to_host(char *key, char *value, int error)
{
	struct hv_kvp_msg  *kvp_msg;
	struct hv_kvp_exchg_msg_value  *kvp_data;
	char	*key_name;
	struct icmsg_hdr *icmsghdrp;
	int	keylen = 0;
	int	valuelen = 0;
	u32	buf_len;
	struct vmbus_channel *channel;
	u64	req_id;

	/*
	 * If a transaction is not active; log and return.
	 */

	if (!kvp_transaction.active) {
		/*
		 * This is a spurious call!
		 */
		pr_warn("KVP: Transaction not active\n");
		return;
	}
	/*
	 * Copy the global state for completing the transaction. Note that
	 * only one transaction can be active at a time.
	 */

	buf_len = kvp_transaction.recv_len;
	channel = kvp_transaction.recv_channel;
	req_id = kvp_transaction.recv_req_id;

	kvp_transaction.active = false;

	icmsghdrp = (struct icmsg_hdr *)
			&recv_buffer[sizeof(struct vmbuspipe_hdr)];

	if (channel->onchannel_callback == NULL)
		/*
		 * We have raced with util driver being unloaded;
		 * silently return.
		 */
		return;


	/*
	 * If the error parameter is set, terminate the host's enumeration.
	 */
	if (error) {
		/*
		 * Something failed or the we have timedout;
		 * terminate the host-side iteration by returning an error.
		 */
		icmsghdrp->status = HV_E_FAIL;
		goto response_done;
	}

	icmsghdrp->status = HV_S_OK;

	kvp_msg = (struct hv_kvp_msg *)
			&recv_buffer[sizeof(struct vmbuspipe_hdr) +
			sizeof(struct icmsg_hdr)];

	switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
	case KVP_OP_GET:
		kvp_data = &kvp_msg->body.kvp_get.data;
		goto copy_value;

	case KVP_OP_SET:
	case KVP_OP_DELETE:
		goto response_done;

	default:
		break;
	}

	kvp_data = &kvp_msg->body.kvp_enum_data.data;
	key_name = key;

	/*
	 * The windows host expects the key/value pair to be encoded
	 * in utf16. Ensure that the key/value size reported to the host
	 * will be less than or equal to the MAX size (including the
	 * terminating character).
	 */
	keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
				(wchar_t *) kvp_data->key,
				(HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
	kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */

copy_value:
	valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
				(wchar_t *) kvp_data->value,
				(HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
	kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */

	/*
	 * If the utf8s to utf16s conversion failed; notify host
	 * of the error.
	 */
	if ((keylen < 0) || (valuelen < 0))
		icmsghdrp->status = HV_E_FAIL;

	kvp_data->value_type = REG_SZ; /* all our values are strings */

response_done:
	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;

	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
				VM_PKT_DATA_INBAND, 0);

}

/*
 * This callback is invoked when we get a KVP message from the host.
 * The host ensures that only one KVP transaction can be active at a time.
 * KVP implementation in Linux needs to forward the key to a user-mde
 * component to retrive the corresponding value. Consequently, we cannot
 * respond to the host in the conext of this callback. Since the host
 * guarantees that at most only one transaction can be active at a time,
 * we stash away the transaction state in a set of global variables.
 */

void hv_kvp_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;

	struct hv_kvp_msg *kvp_msg;

	struct icmsg_hdr *icmsghdrp;
	struct icmsg_negotiate *negop = NULL;

	if (kvp_transaction.active) {
		/*
		 * We will defer processing this callback once
		 * the current transaction is complete.
		 */
		kvp_transaction.kvp_context = context;
		return;
	}

	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
		icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
			sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer);
		} else {
			kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
				sizeof(struct vmbuspipe_hdr) +
				sizeof(struct icmsg_hdr)];

			/*
			 * Stash away this global state for completing the
			 * transaction; note transactions are serialized.
			 */

			kvp_transaction.recv_len = recvlen;
			kvp_transaction.recv_channel = channel;
			kvp_transaction.recv_req_id = requestid;
			kvp_transaction.active = true;
			kvp_transaction.kvp_msg = kvp_msg;

			/*
			 * Get the information from the
			 * user-mode component.
			 * component. This transaction will be
			 * completed when we get the value from
			 * the user-mode component.
			 * Set a timeout to deal with
			 * user-mode not responding.
			 */
			schedule_work(&kvp_sendkey_work);
			schedule_delayed_work(&kvp_work, 5*HZ);

			return;

		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, recv_buffer,
				       recvlen, requestid,
				       VM_PKT_DATA_INBAND, 0);
	}

}

int
hv_kvp_init(struct hv_util_service *srv)
{
	int err;

	err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
	if (err)
		return err;
	recv_buffer = srv->recv_buffer;

	/*
	 * When this driver loads, the user level daemon that
	 * processes the host requests may not yet be running.
	 * Defer processing channel callbacks until the daemon
	 * has registered.
	 */
	kvp_transaction.active = true;

	return 0;
}

void hv_kvp_deinit(void)
{
	cn_del_callback(&kvp_id);
	cancel_delayed_work_sync(&kvp_work);
	cancel_work_sync(&kvp_sendkey_work);
}
Commit	Line	Data
245ba56a KS	1	/*
	2	* An implementation of key value pair (KVP) functionality for Linux.
	3	*
	4	*
	5	* Copyright (C) 2010, Novell, Inc.
	6	* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License version 2 as published
	10	* by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	15	* NON INFRINGEMENT. See the GNU General Public License for more
	16	* details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	21	*
	22	*/
af7a5b6e	23	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
245ba56a KS	24
	25	#include <linux/net.h>
	26	#include <linux/nls.h>
	27	#include <linux/connector.h>
	28	#include <linux/workqueue.h>
46a97191	29	#include <linux/hyperv.h>
245ba56a	30
245ba56a KS	31
	32
	33	/*
	34	* Global state maintained for transaction that is being processed.
	35	* Note that only one transaction can be active at any point in time.
	36	*
	37	* This state is set when we receive a request from the host; we
	38	* cleanup this state when the transaction is completed - when we respond
	39	* to the host with the key value.
	40	*/
	41
	42	static struct {
	43	bool active; /* transaction status - active or not */
	44	int recv_len; /* number of bytes received. */
fa3d5b85	45	struct hv_kvp_msg kvp_msg; / current message */
245ba56a KS	46	struct vmbus_channel recv_channel; / chn we got the request */
245ba56a KS	47	u64 recv_req_id; /* request ID. */
fa3d5b85	48	void kvp_context; / for the channel callback */
245ba56a KS	49	} kvp_transaction;
245ba56a KS	50
e2bb6537	51	static void kvp_send_key(struct work_struct *dummy);
245ba56a	52
76e5f813 S	53	#define TIMEOUT_FIRED 1
76e5f813 S	54
245ba56a KS	55	static void kvp_respond_to_host(char key, char value, int error);
	56	static void kvp_work_func(struct work_struct *dummy);
	57	static void kvp_register(void);
	58
	59	static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
e2bb6537	60	static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
245ba56a KS	61
	62	static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
	63	static const char kvp_name[] = "kvp_kernel_module";
245ba56a KS	64	static u8 *recv_buffer;
	65	/*
	66	* Register the kernel component with the user-level daemon.
	67	* As part of this registration, pass the LIC version number.
	68	*/
	69
	70	static void
	71	kvp_register(void)
	72	{
	73
	74	struct cn_msg *msg;
26403354 S	75	struct hv_kvp_msg *kvp_msg;
26403354 S	76	char *version;
245ba56a	77
26403354	78	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
245ba56a KS	79
245ba56a KS	80	if (msg) {
26403354	81	kvp_msg = (struct hv_kvp_msg *)msg->data;
e485ceac	82	version = kvp_msg->body.kvp_register.version;
245ba56a KS	83	msg->id.idx = CN_KVP_IDX;
245ba56a KS	84	msg->id.val = CN_KVP_VAL;
26403354 S	85
	86	kvp_msg->kvp_hdr.operation = KVP_OP_REGISTER;
	87	strcpy(version, HV_DRV_VERSION);
	88	msg->len = sizeof(struct hv_kvp_msg);
245ba56a KS	89	cn_netlink_send(msg, 0, GFP_ATOMIC);
	90	kfree(msg);
	91	}
	92	}
	93	static void
	94	kvp_work_func(struct work_struct *dummy)
	95	{
	96	/*
	97	* If the timer fires, the user-mode component has not responded;
	98	* process the pending transaction.
	99	*/
76e5f813	100	kvp_respond_to_host("Unknown key", "Guest timed out", TIMEOUT_FIRED);
245ba56a KS	101	}
	102
	103	/*
	104	* Callback when data is received from user mode.
	105	*/
	106
	107	static void
	108	kvp_cn_callback(struct cn_msg msg, struct netlink_skb_parms nsp)
	109	{
26403354 S	110	struct hv_kvp_msg *message;
26403354 S	111	struct hv_kvp_msg_enumerate *data;
245ba56a	112
26403354	113	message = (struct hv_kvp_msg *)msg->data;
fa3d5b85 S	114	switch (message->kvp_hdr.operation) {
fa3d5b85 S	115	case KVP_OP_REGISTER:
af7a5b6e	116	pr_info("KVP: user-mode registering done.\n");
245ba56a	117	kvp_register();
fa3d5b85 S	118	kvp_transaction.active = false;
	119	hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
	120	break;
245ba56a	121
fa3d5b85	122	default:
26403354	123	data = &message->body.kvp_enum_data;
245ba56a KS	124	/*
	125	* Complete the transaction by forwarding the key value
	126	* to the host. But first, cancel the timeout.
	127	*/
	128	if (cancel_delayed_work_sync(&kvp_work))
e485ceac S	129	kvp_respond_to_host(data->data.key,
e485ceac S	130	data->data.value,
26403354	131	!strlen(data->data.key));
245ba56a KS	132	}
	133	}
	134
e2bb6537 S	135	static void
e2bb6537 S	136	kvp_send_key(struct work_struct *dummy)
245ba56a KS	137	{
245ba56a KS	138	struct cn_msg *msg;
26403354	139	struct hv_kvp_msg *message;
fa3d5b85 S	140	struct hv_kvp_msg *in_msg;
	141	__u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
	142	__u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
	143	__u32 val32;
	144	__u64 val64;
245ba56a KS	145
245ba56a KS	146	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
fa3d5b85 S	147	if (!msg)
fa3d5b85 S	148	return;
245ba56a	149
fa3d5b85 S	150	msg->id.idx = CN_KVP_IDX;
fa3d5b85 S	151	msg->id.val = CN_KVP_VAL;
26403354	152
fa3d5b85 S	153	message = (struct hv_kvp_msg *)msg->data;
	154	message->kvp_hdr.operation = operation;
	155	message->kvp_hdr.pool = pool;
	156	in_msg = kvp_transaction.kvp_msg;
	157
	158	/*
	159	* The key/value strings sent from the host are encoded in
	160	* in utf16; convert it to utf8 strings.
	161	* The host assures us that the utf16 strings will not exceed
	162	* the max lengths specified. We will however, reserve room
	163	* for the string terminating character - in the utf16s_utf8s()
	164	* function we limit the size of the buffer where the converted
	165	* string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
	166	* that the strings can be properly terminated!
	167	*/
	168
	169	switch (message->kvp_hdr.operation) {
	170	case KVP_OP_SET:
	171	switch (in_msg->body.kvp_set.data.value_type) {
	172	case REG_SZ:
	173	/*
	174	* The value is a string - utf16 encoding.
	175	*/
	176	message->body.kvp_set.data.value_size =
	177	utf16s_to_utf8s(
	178	(wchar_t *)in_msg->body.kvp_set.data.value,
	179	in_msg->body.kvp_set.data.value_size,
	180	UTF16_LITTLE_ENDIAN,
	181	message->body.kvp_set.data.value,
	182	HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
	183	break;
	184
	185	case REG_U32:
	186	/*
	187	* The value is a 32 bit scalar.
	188	* We save this as a utf8 string.
	189	*/
	190	val32 = in_msg->body.kvp_set.data.value_u32;
	191	message->body.kvp_set.data.value_size =
	192	sprintf(message->body.kvp_set.data.value,
	193	"%d", val32) + 1;
	194	break;
	195
	196	case REG_U64:
	197	/*
	198	* The value is a 64 bit scalar.
	199	* We save this as a utf8 string.
	200	*/
	201	val64 = in_msg->body.kvp_set.data.value_u64;
	202	message->body.kvp_set.data.value_size =
	203	sprintf(message->body.kvp_set.data.value,
	204	"%llu", val64) + 1;
	205	break;
	206
	207	}
	208	case KVP_OP_GET:
	209	message->body.kvp_set.data.key_size =
	210	utf16s_to_utf8s(
	211	(wchar_t *)in_msg->body.kvp_set.data.key,
	212	in_msg->body.kvp_set.data.key_size,
	213	UTF16_LITTLE_ENDIAN,
	214	message->body.kvp_set.data.key,
	215	HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
	216	break;
217
218	case KVP_OP_DELETE:
219	message->body.kvp_delete.key_size =
220	utf16s_to_utf8s(
221	(wchar_t *)in_msg->body.kvp_delete.key,
222	in_msg->body.kvp_delete.key_size,
223	UTF16_LITTLE_ENDIAN,
224	message->body.kvp_delete.key,
225	HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
226	break;
227
228	case KVP_OP_ENUMERATE:
229	message->body.kvp_enum_data.index =
230	in_msg->body.kvp_enum_data.index;
231	break;
245ba56a	232	}
fa3d5b85 S	233
	234	msg->len = sizeof(struct hv_kvp_msg);
	235	cn_netlink_send(msg, 0, GFP_ATOMIC);
	236	kfree(msg);
	237
e2bb6537	238	return;
245ba56a KS	239	}
	240
	241	/*
	242	* Send a response back to the host.
	243	*/
	244
	245	static void
	246	kvp_respond_to_host(char key, char value, int error)
	247	{
	248	struct hv_kvp_msg *kvp_msg;
fa3d5b85	249	struct hv_kvp_exchg_msg_value *kvp_data;
245ba56a KS	250	char *key_name;
245ba56a KS	251	struct icmsg_hdr *icmsghdrp;
fa3d5b85 S	252	int keylen = 0;
fa3d5b85 S	253	int valuelen = 0;
245ba56a KS	254	u32 buf_len;
	255	struct vmbus_channel *channel;
	256	u64 req_id;
	257
	258	/*
	259	* If a transaction is not active; log and return.
	260	*/
	261
	262	if (!kvp_transaction.active) {
	263	/*
	264	* This is a spurious call!
	265	*/
af7a5b6e	266	pr_warn("KVP: Transaction not active\n");
245ba56a KS	267	return;
	268	}
	269	/*
	270	* Copy the global state for completing the transaction. Note that
	271	* only one transaction can be active at a time.
	272	*/
	273
	274	buf_len = kvp_transaction.recv_len;
	275	channel = kvp_transaction.recv_channel;
	276	req_id = kvp_transaction.recv_req_id;
	277
76e5f813 S	278	kvp_transaction.active = false;
76e5f813 S	279
fa3d5b85 S	280	icmsghdrp = (struct icmsg_hdr *)
	281	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	282
4e65f6e8 S	283	if (channel->onchannel_callback == NULL)
	284	/*
	285	* We have raced with util driver being unloaded;
	286	* silently return.
	287	*/
	288	return;
	289
245ba56a KS	290
	291	/*
	292	* If the error parameter is set, terminate the host's enumeration.
	293	*/
	294	if (error) {
	295	/*
fa3d5b85	296	* Something failed or the we have timedout;
245ba56a KS	297	* terminate the host-side iteration by returning an error.
	298	*/
	299	icmsghdrp->status = HV_E_FAIL;
	300	goto response_done;
	301	}
	302
fa3d5b85 S	303	icmsghdrp->status = HV_S_OK;
	304
	305	kvp_msg = (struct hv_kvp_msg *)
	306	&recv_buffer[sizeof(struct vmbuspipe_hdr) +
	307	sizeof(struct icmsg_hdr)];
	308
	309	switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
	310	case KVP_OP_GET:
	311	kvp_data = &kvp_msg->body.kvp_get.data;
	312	goto copy_value;
	313
	314	case KVP_OP_SET:
	315	case KVP_OP_DELETE:
	316	goto response_done;
	317
	318	default:
	319	break;
	320	}
	321
	322	kvp_data = &kvp_msg->body.kvp_enum_data.data;
	323	key_name = key;
	324
245ba56a KS	325	/*
245ba56a KS	326	* The windows host expects the key/value pair to be encoded
fa3d5b85 S	327	* in utf16. Ensure that the key/value size reported to the host
	328	* will be less than or equal to the MAX size (including the
	329	* terminating character).
245ba56a	330	*/
0720a06a	331	keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
fa3d5b85 S	332	(wchar_t *) kvp_data->key,
	333	(HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
	334	kvp_data->key_size = 2(keylen + 1); / utf16 encoding */
	335
	336	copy_value:
0720a06a	337	valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
fa3d5b85 S	338	(wchar_t *) kvp_data->value,
	339	(HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
	340	kvp_data->value_size = 2(valuelen + 1); / utf16 encoding */
245ba56a	341
fa3d5b85 S	342	/*
	343	* If the utf8s to utf16s conversion failed; notify host
	344	* of the error.
	345	*/
	346	if ((keylen < 0) \|\| (valuelen < 0))
	347	icmsghdrp->status = HV_E_FAIL;
	348
	349	kvp_data->value_type = REG_SZ; /* all our values are strings */
245ba56a KS	350
	351	response_done:
	352	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	353
	354	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
415f2287	355	VM_PKT_DATA_INBAND, 0);
245ba56a	356
245ba56a KS	357	}
	358
	359	/*
	360	* This callback is invoked when we get a KVP message from the host.
	361	* The host ensures that only one KVP transaction can be active at a time.
	362	* KVP implementation in Linux needs to forward the key to a user-mde
	363	* component to retrive the corresponding value. Consequently, we cannot
	364	* respond to the host in the conext of this callback. Since the host
	365	* guarantees that at most only one transaction can be active at a time,
	366	* we stash away the transaction state in a set of global variables.
	367	*/
	368
	369	void hv_kvp_onchannelcallback(void *context)
	370	{
	371	struct vmbus_channel *channel = context;
	372	u32 recvlen;
	373	u64 requestid;
	374
	375	struct hv_kvp_msg *kvp_msg;
245ba56a KS	376
	377	struct icmsg_hdr *icmsghdrp;
	378	struct icmsg_negotiate *negop = NULL;
	379
fa3d5b85 S	380	if (kvp_transaction.active) {
	381	/*
	382	* We will defer processing this callback once
	383	* the current transaction is complete.
	384	*/
	385	kvp_transaction.kvp_context = context;
	386	return;
	387	}
245ba56a	388
245ba56a KS	389	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE, &recvlen, &requestid);
	390
	391	if (recvlen > 0) {
245ba56a KS	392	icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
	393	sizeof(struct vmbuspipe_hdr)];
	394
	395	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
da0e9631	396	vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer);
245ba56a KS	397	} else {
	398	kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
	399	sizeof(struct vmbuspipe_hdr) +
	400	sizeof(struct icmsg_hdr)];
	401
245ba56a KS	402	/*
	403	* Stash away this global state for completing the
	404	* transaction; note transactions are serialized.
	405	*/
fa3d5b85	406
245ba56a KS	407	kvp_transaction.recv_len = recvlen;
	408	kvp_transaction.recv_channel = channel;
	409	kvp_transaction.recv_req_id = requestid;
	410	kvp_transaction.active = true;
fa3d5b85	411	kvp_transaction.kvp_msg = kvp_msg;
245ba56a KS	412
	413	/*
	414	* Get the information from the
	415	* user-mode component.
	416	* component. This transaction will be
	417	* completed when we get the value from
	418	* the user-mode component.
	419	* Set a timeout to deal with
	420	* user-mode not responding.
	421	*/
e2bb6537 S	422	schedule_work(&kvp_sendkey_work);
e2bb6537 S	423	schedule_delayed_work(&kvp_work, 5*HZ);
245ba56a KS	424
	425	return;
	426
	427	}
	428
245ba56a KS	429	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	430	\| ICMSGHDRFLAG_RESPONSE;
	431
	432	vmbus_sendpacket(channel, recv_buffer,
	433	recvlen, requestid,
415f2287	434	VM_PKT_DATA_INBAND, 0);
245ba56a KS	435	}
	436
	437	}
	438
	439	int
a29b643c	440	hv_kvp_init(struct hv_util_service *srv)
245ba56a KS	441	{
	442	int err;
	443
	444	err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
	445	if (err)
	446	return err;
a29b643c	447	recv_buffer = srv->recv_buffer;
245ba56a	448
fa3d5b85 S	449	/*
	450	* When this driver loads, the user level daemon that
	451	* processes the host requests may not yet be running.
	452	* Defer processing channel callbacks until the daemon
	453	* has registered.
	454	*/
	455	kvp_transaction.active = true;
	456
245ba56a KS	457	return 0;
	458	}
	459
	460	void hv_kvp_deinit(void)
	461	{
	462	cn_del_callback(&kvp_id);
	463	cancel_delayed_work_sync(&kvp_work);
e2bb6537	464	cancel_work_sync(&kvp_sendkey_work);
245ba56a	465	}