[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>

#include "hv_kvp.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. */
	int index; /* current index */
	struct vmbus_channel *recv_channel; /* chn we got the request */
	u64 recv_req_id; /* request ID. */
} 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;

	msg = kzalloc(sizeof(*msg) + strlen(HV_DRV_VERSION) + 1 , GFP_ATOMIC);

	if (msg) {
		msg->id.idx =  CN_KVP_IDX;
		msg->id.val = CN_KVP_VAL;
		msg->seq = KVP_REGISTER;
		strcpy(msg->data, HV_DRV_VERSION);
		msg->len = strlen(HV_DRV_VERSION) + 1;
		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_ku_msg *message;

	message = (struct hv_ku_msg *)msg->data;
	if (msg->seq == KVP_REGISTER) {
		pr_info("KVP: user-mode registering done.\n");
		kvp_register();
	}

	if (msg->seq == KVP_USER_SET) {
		/*
		 * 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(message->kvp_key,
						message->kvp_value,
						!strlen(message->kvp_key));
	}
}

static void
kvp_send_key(struct work_struct *dummy)
{
	struct cn_msg *msg;
	int index = kvp_transaction.index;

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

	if (msg) {
		msg->id.idx =  CN_KVP_IDX;
		msg->id.val = CN_KVP_VAL;
		msg->seq = KVP_KERNEL_GET;
		((struct hv_ku_msg *)msg->data)->kvp_index = index;
		msg->len = sizeof(struct hv_ku_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_msg_enumerate  *kvp_data;
	char	*key_name;
	struct icmsg_hdr *icmsghdrp;
	int	keylen, valuelen;
	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;

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

	icmsghdrp = (struct icmsg_hdr *)
			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	kvp_msg = (struct hv_kvp_msg *)
			&recv_buffer[sizeof(struct vmbuspipe_hdr) +
			sizeof(struct icmsg_hdr)];
	kvp_data = &kvp_msg->kvp_data;
	key_name = key;

	/*
	 * If the error parameter is set, terminate the host's enumeration.
	 */
	if (error) {
		/*
		 * We don't support this index or the we have timedout;
		 * terminate the host-side iteration by returning an error.
		 */
		icmsghdrp->status = HV_E_FAIL;
		goto response_done;
	}

	/*
	 * The windows host expects the key/value pair to be encoded
	 * in utf16.
	 */
	keylen = utf8s_to_utf16s(key_name, strlen(key_name),
				(wchar_t *)kvp_data->data.key);
	kvp_data->data.key_size = 2*(keylen + 1); /* utf16 encoding */
	valuelen = utf8s_to_utf16s(value, strlen(value),
				(wchar_t *)kvp_data->data.value);
	kvp_data->data.value_size = 2*(valuelen + 1); /* utf16 encoding */

	kvp_data->data.value_type = REG_SZ; /* all our values are strings */
	icmsghdrp->status = HV_S_OK;

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 hv_kvp_msg_enumerate *kvp_data;

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


	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)];

			kvp_data = &kvp_msg->kvp_data;

			/*
			 * We only support the "get" operation on
			 * "KVP_POOL_AUTO" pool.
			 */

			if ((kvp_msg->kvp_hdr.pool != KVP_POOL_AUTO) ||
				(kvp_msg->kvp_hdr.operation !=
				KVP_OP_ENUMERATE)) {
				icmsghdrp->status = HV_E_FAIL;
				goto callback_done;
			}

			/*
			 * 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.index = kvp_data->index;

			/*
			 * 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;

		}

callback_done:

		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;

	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	#include "hv_kvp.h"
	32
	33
	34
	35	/*
	36	* Global state maintained for transaction that is being processed.
	37	* Note that only one transaction can be active at any point in time.
	38	*
	39	* This state is set when we receive a request from the host; we
	40	* cleanup this state when the transaction is completed - when we respond
	41	* to the host with the key value.
	42	*/
	43
	44	static struct {
	45	bool active; /* transaction status - active or not */
	46	int recv_len; /* number of bytes received. */
e2bb6537	47	int index; /* current index */
245ba56a KS	48	struct vmbus_channel recv_channel; / chn we got the request */
	49	u64 recv_req_id; /* request ID. */
	50	} kvp_transaction;
	51
e2bb6537	52	static void kvp_send_key(struct work_struct *dummy);
245ba56a	53
76e5f813 S	54	#define TIMEOUT_FIRED 1
76e5f813 S	55
245ba56a KS	56	static void kvp_respond_to_host(char key, char value, int error);
	57	static void kvp_work_func(struct work_struct *dummy);
	58	static void kvp_register(void);
	59
	60	static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
e2bb6537	61	static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
245ba56a KS	62
	63	static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
	64	static const char kvp_name[] = "kvp_kernel_module";
245ba56a KS	65	static u8 *recv_buffer;
	66	/*
	67	* Register the kernel component with the user-level daemon.
	68	* As part of this registration, pass the LIC version number.
	69	*/
	70
	71	static void
	72	kvp_register(void)
	73	{
	74
	75	struct cn_msg *msg;
	76
	77	msg = kzalloc(sizeof(*msg) + strlen(HV_DRV_VERSION) + 1 , GFP_ATOMIC);
	78
	79	if (msg) {
	80	msg->id.idx = CN_KVP_IDX;
	81	msg->id.val = CN_KVP_VAL;
	82	msg->seq = KVP_REGISTER;
	83	strcpy(msg->data, HV_DRV_VERSION);
	84	msg->len = strlen(HV_DRV_VERSION) + 1;
	85	cn_netlink_send(msg, 0, GFP_ATOMIC);
	86	kfree(msg);
	87	}
	88	}
	89	static void
	90	kvp_work_func(struct work_struct *dummy)
	91	{
	92	/*
	93	* If the timer fires, the user-mode component has not responded;
	94	* process the pending transaction.
	95	*/
76e5f813	96	kvp_respond_to_host("Unknown key", "Guest timed out", TIMEOUT_FIRED);
245ba56a KS	97	}
	98
	99	/*
	100	* Callback when data is received from user mode.
	101	*/
	102
	103	static void
	104	kvp_cn_callback(struct cn_msg msg, struct netlink_skb_parms nsp)
	105	{
	106	struct hv_ku_msg *message;
	107
	108	message = (struct hv_ku_msg *)msg->data;
	109	if (msg->seq == KVP_REGISTER) {
af7a5b6e	110	pr_info("KVP: user-mode registering done.\n");
245ba56a KS	111	kvp_register();
	112	}
	113
	114	if (msg->seq == KVP_USER_SET) {
	115	/*
	116	* Complete the transaction by forwarding the key value
	117	* to the host. But first, cancel the timeout.
	118	*/
	119	if (cancel_delayed_work_sync(&kvp_work))
	120	kvp_respond_to_host(message->kvp_key,
	121	message->kvp_value,
	122	!strlen(message->kvp_key));
	123	}
	124	}
	125
e2bb6537 S	126	static void
e2bb6537 S	127	kvp_send_key(struct work_struct *dummy)
245ba56a KS	128	{
245ba56a KS	129	struct cn_msg *msg;
e2bb6537	130	int index = kvp_transaction.index;
245ba56a KS	131
	132	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
	133
	134	if (msg) {
	135	msg->id.idx = CN_KVP_IDX;
	136	msg->id.val = CN_KVP_VAL;
	137	msg->seq = KVP_KERNEL_GET;
	138	((struct hv_ku_msg *)msg->data)->kvp_index = index;
	139	msg->len = sizeof(struct hv_ku_msg);
	140	cn_netlink_send(msg, 0, GFP_ATOMIC);
	141	kfree(msg);
245ba56a	142	}
e2bb6537	143	return;
245ba56a KS	144	}
	145
	146	/*
	147	* Send a response back to the host.
	148	*/
	149
	150	static void
	151	kvp_respond_to_host(char key, char value, int error)
	152	{
	153	struct hv_kvp_msg *kvp_msg;
	154	struct hv_kvp_msg_enumerate *kvp_data;
	155	char *key_name;
	156	struct icmsg_hdr *icmsghdrp;
	157	int keylen, valuelen;
	158	u32 buf_len;
	159	struct vmbus_channel *channel;
	160	u64 req_id;
	161
	162	/*
	163	* If a transaction is not active; log and return.
	164	*/
	165
	166	if (!kvp_transaction.active) {
	167	/*
	168	* This is a spurious call!
	169	*/
af7a5b6e	170	pr_warn("KVP: Transaction not active\n");
245ba56a KS	171	return;
	172	}
	173	/*
	174	* Copy the global state for completing the transaction. Note that
	175	* only one transaction can be active at a time.
	176	*/
	177
	178	buf_len = kvp_transaction.recv_len;
	179	channel = kvp_transaction.recv_channel;
	180	req_id = kvp_transaction.recv_req_id;
	181
76e5f813 S	182	kvp_transaction.active = false;
76e5f813 S	183
4e65f6e8 S	184	if (channel->onchannel_callback == NULL)
	185	/*
	186	* We have raced with util driver being unloaded;
	187	* silently return.
	188	*/
	189	return;
	190
245ba56a KS	191	icmsghdrp = (struct icmsg_hdr *)
	192	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	193	kvp_msg = (struct hv_kvp_msg *)
	194	&recv_buffer[sizeof(struct vmbuspipe_hdr) +
	195	sizeof(struct icmsg_hdr)];
	196	kvp_data = &kvp_msg->kvp_data;
	197	key_name = key;
	198
	199	/*
	200	* If the error parameter is set, terminate the host's enumeration.
	201	*/
	202	if (error) {
	203	/*
	204	* We don't support this index or the we have timedout;
	205	* terminate the host-side iteration by returning an error.
	206	*/
	207	icmsghdrp->status = HV_E_FAIL;
	208	goto response_done;
	209	}
	210
	211	/*
	212	* The windows host expects the key/value pair to be encoded
	213	* in utf16.
	214	*/
	215	keylen = utf8s_to_utf16s(key_name, strlen(key_name),
	216	(wchar_t *)kvp_data->data.key);
	217	kvp_data->data.key_size = 2(keylen + 1); / utf16 encoding */
	218	valuelen = utf8s_to_utf16s(value, strlen(value),
	219	(wchar_t *)kvp_data->data.value);
	220	kvp_data->data.value_size = 2(valuelen + 1); / utf16 encoding */
	221
	222	kvp_data->data.value_type = REG_SZ; /* all our values are strings */
	223	icmsghdrp->status = HV_S_OK;
	224
	225	response_done:
	226	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	227
	228	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
415f2287	229	VM_PKT_DATA_INBAND, 0);
245ba56a	230
245ba56a KS	231	}
	232
	233	/*
	234	* This callback is invoked when we get a KVP message from the host.
	235	* The host ensures that only one KVP transaction can be active at a time.
	236	* KVP implementation in Linux needs to forward the key to a user-mde
	237	* component to retrive the corresponding value. Consequently, we cannot
	238	* respond to the host in the conext of this callback. Since the host
	239	* guarantees that at most only one transaction can be active at a time,
	240	* we stash away the transaction state in a set of global variables.
	241	*/
	242
	243	void hv_kvp_onchannelcallback(void *context)
	244	{
	245	struct vmbus_channel *channel = context;
	246	u32 recvlen;
	247	u64 requestid;
	248
	249	struct hv_kvp_msg *kvp_msg;
	250	struct hv_kvp_msg_enumerate *kvp_data;
	251
	252	struct icmsg_hdr *icmsghdrp;
	253	struct icmsg_negotiate *negop = NULL;
	254
	255
245ba56a KS	256	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE, &recvlen, &requestid);
	257
	258	if (recvlen > 0) {
245ba56a KS	259	icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
	260	sizeof(struct vmbuspipe_hdr)];
	261
	262	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
da0e9631	263	vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer);
245ba56a KS	264	} else {
	265	kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
	266	sizeof(struct vmbuspipe_hdr) +
	267	sizeof(struct icmsg_hdr)];
	268
	269	kvp_data = &kvp_msg->kvp_data;
	270
	271	/*
	272	* We only support the "get" operation on
	273	* "KVP_POOL_AUTO" pool.
	274	*/
	275
	276	if ((kvp_msg->kvp_hdr.pool != KVP_POOL_AUTO) \|\|
	277	(kvp_msg->kvp_hdr.operation !=
	278	KVP_OP_ENUMERATE)) {
	279	icmsghdrp->status = HV_E_FAIL;
	280	goto callback_done;
	281	}
	282
	283	/*
	284	* Stash away this global state for completing the
	285	* transaction; note transactions are serialized.
	286	*/
	287	kvp_transaction.recv_len = recvlen;
	288	kvp_transaction.recv_channel = channel;
	289	kvp_transaction.recv_req_id = requestid;
	290	kvp_transaction.active = true;
e2bb6537	291	kvp_transaction.index = kvp_data->index;
245ba56a KS	292
	293	/*
	294	* Get the information from the
	295	* user-mode component.
	296	* component. This transaction will be
	297	* completed when we get the value from
	298	* the user-mode component.
	299	* Set a timeout to deal with
	300	* user-mode not responding.
	301	*/
e2bb6537 S	302	schedule_work(&kvp_sendkey_work);
e2bb6537 S	303	schedule_delayed_work(&kvp_work, 5*HZ);
245ba56a KS	304
	305	return;
	306
	307	}
	308
	309	callback_done:
	310
	311	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	312	\| ICMSGHDRFLAG_RESPONSE;
	313
	314	vmbus_sendpacket(channel, recv_buffer,
	315	recvlen, requestid,
415f2287	316	VM_PKT_DATA_INBAND, 0);
245ba56a KS	317	}
	318
	319	}
	320
	321	int
a29b643c	322	hv_kvp_init(struct hv_util_service *srv)
245ba56a KS	323	{
	324	int err;
	325
	326	err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
	327	if (err)
	328	return err;
a29b643c	329	recv_buffer = srv->recv_buffer;
245ba56a KS	330
	331	return 0;
	332	}
	333
	334	void hv_kvp_deinit(void)
	335	{
	336	cn_del_callback(&kvp_id);
	337	cancel_delayed_work_sync(&kvp_work);
e2bb6537	338	cancel_work_sync(&kvp_sendkey_work);
245ba56a	339	}