[deliverable/linux.git] / drivers / staging / 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 "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. */
	struct vmbus_channel *recv_channel; /* chn we got the request */
	u64 recv_req_id; /* request ID. */
} kvp_transaction;

static int kvp_send_key(int index);

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 struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
static const char kvp_name[] = "kvp_kernel_module";
static int timeout_fired;
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);
	timeout_fired = 1;
}

/*
 * 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 int
kvp_send_key(int index)
{
	struct cn_msg *msg;

	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 0;
	}
	return 1;
}

/*
 * 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;

	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);

	kvp_transaction.active = false;
}

/*
 * 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;


	if (kvp_transaction.active)
		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) {
			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;

			/*
			 * 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.
			 */
			kvp_send_key(kvp_data->index);
			schedule_delayed_work(&kvp_work, 100);

			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);
}
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>
	29
3f335ea2	30	#include "hyperv.h"
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. */
	47	struct vmbus_channel recv_channel; / chn we got the request */
	48	u64 recv_req_id; /* request ID. */
	49	} kvp_transaction;
	50
	51	static int kvp_send_key(int index);
	52
	53	static void kvp_respond_to_host(char key, char value, int error);
	54	static void kvp_work_func(struct work_struct *dummy);
	55	static void kvp_register(void);
	56
	57	static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
	58
	59	static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
	60	static const char kvp_name[] = "kvp_kernel_module";
	61	static int timeout_fired;
	62	static u8 *recv_buffer;
	63	/*
	64	* Register the kernel component with the user-level daemon.
	65	* As part of this registration, pass the LIC version number.
	66	*/
	67
	68	static void
	69	kvp_register(void)
	70	{
	71
	72	struct cn_msg *msg;
	73
	74	msg = kzalloc(sizeof(*msg) + strlen(HV_DRV_VERSION) + 1 , GFP_ATOMIC);
	75
	76	if (msg) {
	77	msg->id.idx = CN_KVP_IDX;
	78	msg->id.val = CN_KVP_VAL;
	79	msg->seq = KVP_REGISTER;
	80	strcpy(msg->data, HV_DRV_VERSION);
	81	msg->len = strlen(HV_DRV_VERSION) + 1;
	82	cn_netlink_send(msg, 0, GFP_ATOMIC);
	83	kfree(msg);
	84	}
	85	}
	86	static void
	87	kvp_work_func(struct work_struct *dummy)
	88	{
	89	/*
	90	* If the timer fires, the user-mode component has not responded;
	91	* process the pending transaction.
	92	*/
	93	kvp_respond_to_host("Unknown key", "Guest timed out", timeout_fired);
	94	timeout_fired = 1;
95	}
96
97	/*
98	* Callback when data is received from user mode.
99	*/
100
101	static void
102	kvp_cn_callback(struct cn_msg msg, struct netlink_skb_parms nsp)
103	{
104	struct hv_ku_msg *message;
105
106	message = (struct hv_ku_msg *)msg->data;
107	if (msg->seq == KVP_REGISTER) {
af7a5b6e	108	pr_info("KVP: user-mode registering done.\n");
245ba56a KS	109	kvp_register();
	110	}
	111
	112	if (msg->seq == KVP_USER_SET) {
	113	/*
	114	* Complete the transaction by forwarding the key value
	115	* to the host. But first, cancel the timeout.
	116	*/
	117	if (cancel_delayed_work_sync(&kvp_work))
	118	kvp_respond_to_host(message->kvp_key,
	119	message->kvp_value,
	120	!strlen(message->kvp_key));
	121	}
	122	}
	123
	124	static int
	125	kvp_send_key(int index)
	126	{
	127	struct cn_msg *msg;
	128
	129	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
	130
	131	if (msg) {
	132	msg->id.idx = CN_KVP_IDX;
	133	msg->id.val = CN_KVP_VAL;
	134	msg->seq = KVP_KERNEL_GET;
	135	((struct hv_ku_msg *)msg->data)->kvp_index = index;
	136	msg->len = sizeof(struct hv_ku_msg);
	137	cn_netlink_send(msg, 0, GFP_ATOMIC);
	138	kfree(msg);
	139	return 0;
	140	}
	141	return 1;
	142	}
	143
	144	/*
	145	* Send a response back to the host.
	146	*/
	147
	148	static void
	149	kvp_respond_to_host(char key, char value, int error)
	150	{
	151	struct hv_kvp_msg *kvp_msg;
	152	struct hv_kvp_msg_enumerate *kvp_data;
	153	char *key_name;
	154	struct icmsg_hdr *icmsghdrp;
	155	int keylen, valuelen;
	156	u32 buf_len;
	157	struct vmbus_channel *channel;
	158	u64 req_id;
	159
	160	/*
	161	* If a transaction is not active; log and return.
	162	*/
	163
	164	if (!kvp_transaction.active) {
	165	/*
	166	* This is a spurious call!
	167	*/
af7a5b6e	168	pr_warn("KVP: Transaction not active\n");
245ba56a KS	169	return;
	170	}
	171	/*
	172	* Copy the global state for completing the transaction. Note that
	173	* only one transaction can be active at a time.
	174	*/
	175
	176	buf_len = kvp_transaction.recv_len;
	177	channel = kvp_transaction.recv_channel;
	178	req_id = kvp_transaction.recv_req_id;
	179
	180	icmsghdrp = (struct icmsg_hdr *)
	181	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	182	kvp_msg = (struct hv_kvp_msg *)
	183	&recv_buffer[sizeof(struct vmbuspipe_hdr) +
	184	sizeof(struct icmsg_hdr)];
	185	kvp_data = &kvp_msg->kvp_data;
	186	key_name = key;
	187
	188	/*
	189	* If the error parameter is set, terminate the host's enumeration.
	190	*/
	191	if (error) {
	192	/*
	193	* We don't support this index or the we have timedout;
	194	* terminate the host-side iteration by returning an error.
	195	*/
	196	icmsghdrp->status = HV_E_FAIL;
	197	goto response_done;
	198	}
	199
	200	/*
	201	* The windows host expects the key/value pair to be encoded
	202	* in utf16.
	203	*/
	204	keylen = utf8s_to_utf16s(key_name, strlen(key_name),
	205	(wchar_t *)kvp_data->data.key);
	206	kvp_data->data.key_size = 2(keylen + 1); / utf16 encoding */
	207	valuelen = utf8s_to_utf16s(value, strlen(value),
	208	(wchar_t *)kvp_data->data.value);
	209	kvp_data->data.value_size = 2(valuelen + 1); / utf16 encoding */
	210
	211	kvp_data->data.value_type = REG_SZ; /* all our values are strings */
	212	icmsghdrp->status = HV_S_OK;
	213
	214	response_done:
	215	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	216
	217	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
415f2287	218	VM_PKT_DATA_INBAND, 0);
245ba56a KS	219
	220	kvp_transaction.active = false;
	221	}
	222
	223	/*
	224	* This callback is invoked when we get a KVP message from the host.
	225	* The host ensures that only one KVP transaction can be active at a time.
	226	* KVP implementation in Linux needs to forward the key to a user-mde
	227	* component to retrive the corresponding value. Consequently, we cannot
	228	* respond to the host in the conext of this callback. Since the host
	229	* guarantees that at most only one transaction can be active at a time,
	230	* we stash away the transaction state in a set of global variables.
	231	*/
	232
	233	void hv_kvp_onchannelcallback(void *context)
	234	{
	235	struct vmbus_channel *channel = context;
	236	u32 recvlen;
	237	u64 requestid;
	238
	239	struct hv_kvp_msg *kvp_msg;
	240	struct hv_kvp_msg_enumerate *kvp_data;
	241
	242	struct icmsg_hdr *icmsghdrp;
	243	struct icmsg_negotiate *negop = NULL;
	244
	245
	246	if (kvp_transaction.active)
	247	return;
	248
	249
	250	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE, &recvlen, &requestid);
	251
	252	if (recvlen > 0) {
245ba56a KS	253	icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
	254	sizeof(struct vmbuspipe_hdr)];
	255
	256	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
	257	prep_negotiate_resp(icmsghdrp, negop, recv_buffer);
	258	} else {
	259	kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
	260	sizeof(struct vmbuspipe_hdr) +
	261	sizeof(struct icmsg_hdr)];
	262
	263	kvp_data = &kvp_msg->kvp_data;
	264
	265	/*
	266	* We only support the "get" operation on
	267	* "KVP_POOL_AUTO" pool.
	268	*/
	269
	270	if ((kvp_msg->kvp_hdr.pool != KVP_POOL_AUTO) \|\|
	271	(kvp_msg->kvp_hdr.operation !=
	272	KVP_OP_ENUMERATE)) {
	273	icmsghdrp->status = HV_E_FAIL;
	274	goto callback_done;
	275	}
	276
	277	/*
	278	* Stash away this global state for completing the
	279	* transaction; note transactions are serialized.
	280	*/
	281	kvp_transaction.recv_len = recvlen;
	282	kvp_transaction.recv_channel = channel;
	283	kvp_transaction.recv_req_id = requestid;
	284	kvp_transaction.active = true;
	285
	286	/*
	287	* Get the information from the
	288	* user-mode component.
	289	* component. This transaction will be
	290	* completed when we get the value from
	291	* the user-mode component.
	292	* Set a timeout to deal with
	293	* user-mode not responding.
	294	*/
	295	kvp_send_key(kvp_data->index);
	296	schedule_delayed_work(&kvp_work, 100);
	297
	298	return;
	299
	300	}
	301
	302	callback_done:
	303
	304	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	305	\| ICMSGHDRFLAG_RESPONSE;
	306
	307	vmbus_sendpacket(channel, recv_buffer,
	308	recvlen, requestid,
415f2287	309	VM_PKT_DATA_INBAND, 0);
245ba56a KS	310	}
	311
	312	}
	313
	314	int
a29b643c	315	hv_kvp_init(struct hv_util_service *srv)
245ba56a KS	316	{
	317	int err;
	318
	319	err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
	320	if (err)
	321	return err;
a29b643c	322	recv_buffer = srv->recv_buffer;
245ba56a KS	323
	324	return 0;
	325	}
	326
	327	void hv_kvp_deinit(void)
	328	{
	329	cn_del_callback(&kvp_id);
	330	cancel_delayed_work_sync(&kvp_work);
245ba56a	331	}