2 * An implementation of key value pair (KVP) functionality for Linux.
5 * Copyright (C) 2010, Novell, Inc.
6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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.
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
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.
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/net.h>
26 #include <linux/nls.h>
27 #include <linux/connector.h>
28 #include <linux/workqueue.h>
29 #include <linux/hyperv.h>
34 * Global state maintained for transaction that is being processed.
35 * Note that only one transaction can be active at any point in time.
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.
43 bool active; /* transaction status - active or not */
44 int recv_len; /* number of bytes received. */
45 struct hv_kvp_msg *kvp_msg; /* current message */
46 struct vmbus_channel *recv_channel; /* chn we got the request */
47 u64 recv_req_id; /* request ID. */
48 void *kvp_context; /* for the channel callback */
52 * Before we can accept KVP messages from the host, we need
53 * to handshake with the user level daemon. This state tracks
54 * if we are in the handshake phase.
56 static bool in_hand_shake = true;
59 * This state maintains the version number registered by the daemon.
61 static int dm_reg_value;
63 static void kvp_send_key(struct work_struct *dummy);
66 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
67 static void kvp_work_func(struct work_struct *dummy);
68 static void kvp_register(int);
70 static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
71 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
73 static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
74 static const char kvp_name[] = "kvp_kernel_module";
75 static u8 *recv_buffer;
77 * Register the kernel component with the user-level daemon.
78 * As part of this registration, pass the LIC version number.
82 kvp_register(int reg_value)
86 struct hv_kvp_msg *kvp_msg;
89 msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
92 kvp_msg = (struct hv_kvp_msg *)msg->data;
93 version = kvp_msg->body.kvp_register.version;
94 msg->id.idx = CN_KVP_IDX;
95 msg->id.val = CN_KVP_VAL;
97 kvp_msg->kvp_hdr.operation = reg_value;
98 strcpy(version, HV_DRV_VERSION);
99 msg->len = sizeof(struct hv_kvp_msg);
100 cn_netlink_send(msg, 0, GFP_ATOMIC);
105 kvp_work_func(struct work_struct *dummy)
108 * If the timer fires, the user-mode component has not responded;
109 * process the pending transaction.
111 kvp_respond_to_host(NULL, HV_E_FAIL);
114 static void poll_channel(struct vmbus_channel *channel)
118 spin_lock_irqsave(&channel->inbound_lock, flags);
119 hv_kvp_onchannelcallback(channel);
120 spin_unlock_irqrestore(&channel->inbound_lock, flags);
123 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
127 switch (msg->kvp_hdr.operation) {
128 case KVP_OP_REGISTER:
129 dm_reg_value = KVP_OP_REGISTER;
130 pr_info("KVP: IP injection functionality not available\n");
131 pr_info("KVP: Upgrade the KVP daemon\n");
133 case KVP_OP_REGISTER1:
134 dm_reg_value = KVP_OP_REGISTER1;
137 pr_info("KVP: incompatible daemon\n");
138 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
139 KVP_OP_REGISTER1, msg->kvp_hdr.operation);
145 * We have a compatible daemon; complete the handshake.
147 pr_info("KVP: user-mode registering done.\n");
148 kvp_register(dm_reg_value);
149 kvp_transaction.active = false;
150 if (kvp_transaction.kvp_context)
151 poll_channel(kvp_transaction.kvp_context);
158 * Callback when data is received from user mode.
162 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
164 struct hv_kvp_msg *message;
165 struct hv_kvp_msg_enumerate *data;
168 message = (struct hv_kvp_msg *)msg->data;
171 * If we are negotiating the version information
172 * with the daemon; handle that first.
176 if (kvp_handle_handshake(message))
177 in_hand_shake = false;
182 * Based on the version of the daemon, we propagate errors from the
183 * daemon differently.
186 data = &message->body.kvp_enum_data;
188 switch (dm_reg_value) {
189 case KVP_OP_REGISTER:
191 * Null string is used to pass back error condition.
193 if (data->data.key[0] == 0)
197 case KVP_OP_REGISTER1:
199 * We use the message header information from
200 * the user level daemon to transmit errors.
202 error = message->error;
207 * Complete the transaction by forwarding the key value
208 * to the host. But first, cancel the timeout.
210 if (cancel_delayed_work_sync(&kvp_work))
211 kvp_respond_to_host(message, error);
215 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
217 struct hv_kvp_msg *in = in_msg;
218 struct hv_kvp_ip_msg *out = out_msg;
222 case KVP_OP_GET_IP_INFO:
224 * Transform all parameters into utf16 encoding.
226 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
227 strlen((char *)in->body.kvp_ip_val.ip_addr),
229 (wchar_t *)out->kvp_ip_val.ip_addr,
234 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
235 strlen((char *)in->body.kvp_ip_val.sub_net),
237 (wchar_t *)out->kvp_ip_val.sub_net,
242 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
243 strlen((char *)in->body.kvp_ip_val.gate_way),
245 (wchar_t *)out->kvp_ip_val.gate_way,
250 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
251 strlen((char *)in->body.kvp_ip_val.dns_addr),
253 (wchar_t *)out->kvp_ip_val.dns_addr,
258 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
259 strlen((char *)in->body.kvp_ip_val.adapter_id),
261 (wchar_t *)out->kvp_ip_val.adapter_id,
266 out->kvp_ip_val.dhcp_enabled =
267 in->body.kvp_ip_val.dhcp_enabled;
268 out->kvp_ip_val.addr_family =
269 in->body.kvp_ip_val.addr_family;
275 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
277 struct hv_kvp_ip_msg *in = in_msg;
278 struct hv_kvp_msg *out = out_msg;
281 case KVP_OP_SET_IP_INFO:
283 * Transform all parameters into utf8 encoding.
285 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
288 (__u8 *)out->body.kvp_ip_val.ip_addr,
291 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
294 (__u8 *)out->body.kvp_ip_val.sub_net,
297 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
300 (__u8 *)out->body.kvp_ip_val.gate_way,
303 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
306 (__u8 *)out->body.kvp_ip_val.dns_addr,
309 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
312 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
315 (__u8 *)out->body.kvp_ip_val.adapter_id,
316 MAX_ADAPTER_ID_SIZE);
318 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
326 kvp_send_key(struct work_struct *dummy)
329 struct hv_kvp_msg *message;
330 struct hv_kvp_msg *in_msg;
331 __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
332 __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
336 msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
340 msg->id.idx = CN_KVP_IDX;
341 msg->id.val = CN_KVP_VAL;
343 message = (struct hv_kvp_msg *)msg->data;
344 message->kvp_hdr.operation = operation;
345 message->kvp_hdr.pool = pool;
346 in_msg = kvp_transaction.kvp_msg;
349 * The key/value strings sent from the host are encoded in
350 * in utf16; convert it to utf8 strings.
351 * The host assures us that the utf16 strings will not exceed
352 * the max lengths specified. We will however, reserve room
353 * for the string terminating character - in the utf16s_utf8s()
354 * function we limit the size of the buffer where the converted
355 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
356 * that the strings can be properly terminated!
359 switch (message->kvp_hdr.operation) {
360 case KVP_OP_SET_IP_INFO:
361 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
363 case KVP_OP_GET_IP_INFO:
364 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
367 switch (in_msg->body.kvp_set.data.value_type) {
370 * The value is a string - utf16 encoding.
372 message->body.kvp_set.data.value_size =
374 (wchar_t *)in_msg->body.kvp_set.data.value,
375 in_msg->body.kvp_set.data.value_size,
377 message->body.kvp_set.data.value,
378 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
383 * The value is a 32 bit scalar.
384 * We save this as a utf8 string.
386 val32 = in_msg->body.kvp_set.data.value_u32;
387 message->body.kvp_set.data.value_size =
388 sprintf(message->body.kvp_set.data.value,
394 * The value is a 64 bit scalar.
395 * We save this as a utf8 string.
397 val64 = in_msg->body.kvp_set.data.value_u64;
398 message->body.kvp_set.data.value_size =
399 sprintf(message->body.kvp_set.data.value,
405 message->body.kvp_set.data.key_size =
407 (wchar_t *)in_msg->body.kvp_set.data.key,
408 in_msg->body.kvp_set.data.key_size,
410 message->body.kvp_set.data.key,
411 HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
415 message->body.kvp_delete.key_size =
417 (wchar_t *)in_msg->body.kvp_delete.key,
418 in_msg->body.kvp_delete.key_size,
420 message->body.kvp_delete.key,
421 HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
424 case KVP_OP_ENUMERATE:
425 message->body.kvp_enum_data.index =
426 in_msg->body.kvp_enum_data.index;
430 msg->len = sizeof(struct hv_kvp_msg);
431 cn_netlink_send(msg, 0, GFP_ATOMIC);
438 * Send a response back to the host.
442 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
444 struct hv_kvp_msg *kvp_msg;
445 struct hv_kvp_exchg_msg_value *kvp_data;
448 struct icmsg_hdr *icmsghdrp;
452 struct vmbus_channel *channel;
457 * If a transaction is not active; log and return.
460 if (!kvp_transaction.active) {
462 * This is a spurious call!
464 pr_warn("KVP: Transaction not active\n");
468 * Copy the global state for completing the transaction. Note that
469 * only one transaction can be active at a time.
472 buf_len = kvp_transaction.recv_len;
473 channel = kvp_transaction.recv_channel;
474 req_id = kvp_transaction.recv_req_id;
476 kvp_transaction.active = false;
478 icmsghdrp = (struct icmsg_hdr *)
479 &recv_buffer[sizeof(struct vmbuspipe_hdr)];
481 if (channel->onchannel_callback == NULL)
483 * We have raced with util driver being unloaded;
488 icmsghdrp->status = error;
491 * If the error parameter is set, terminate the host's enumeration
496 * Something failed or we have timedout;
497 * terminate the current host-side iteration.
502 kvp_msg = (struct hv_kvp_msg *)
503 &recv_buffer[sizeof(struct vmbuspipe_hdr) +
504 sizeof(struct icmsg_hdr)];
506 switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
507 case KVP_OP_GET_IP_INFO:
508 ret = process_ob_ipinfo(msg_to_host,
509 (struct hv_kvp_ip_msg *)kvp_msg,
512 icmsghdrp->status = HV_E_FAIL;
515 case KVP_OP_SET_IP_INFO:
518 kvp_data = &kvp_msg->body.kvp_get.data;
529 kvp_data = &kvp_msg->body.kvp_enum_data.data;
530 key_name = msg_to_host->body.kvp_enum_data.data.key;
533 * The windows host expects the key/value pair to be encoded
534 * in utf16. Ensure that the key/value size reported to the host
535 * will be less than or equal to the MAX size (including the
536 * terminating character).
538 keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
539 (wchar_t *) kvp_data->key,
540 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
541 kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
544 value = msg_to_host->body.kvp_enum_data.data.value;
545 valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
546 (wchar_t *) kvp_data->value,
547 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
548 kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
551 * If the utf8s to utf16s conversion failed; notify host
554 if ((keylen < 0) || (valuelen < 0))
555 icmsghdrp->status = HV_E_FAIL;
557 kvp_data->value_type = REG_SZ; /* all our values are strings */
560 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
562 vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
563 VM_PKT_DATA_INBAND, 0);
564 poll_channel(channel);
569 * This callback is invoked when we get a KVP message from the host.
570 * The host ensures that only one KVP transaction can be active at a time.
571 * KVP implementation in Linux needs to forward the key to a user-mde
572 * component to retrive the corresponding value. Consequently, we cannot
573 * respond to the host in the conext of this callback. Since the host
574 * guarantees that at most only one transaction can be active at a time,
575 * we stash away the transaction state in a set of global variables.
578 void hv_kvp_onchannelcallback(void *context)
580 struct vmbus_channel *channel = context;
584 struct hv_kvp_msg *kvp_msg;
586 struct icmsg_hdr *icmsghdrp;
587 struct icmsg_negotiate *negop = NULL;
589 if (kvp_transaction.active) {
591 * We will defer processing this callback once
592 * the current transaction is complete.
594 kvp_transaction.kvp_context = context;
598 vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
602 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
603 sizeof(struct vmbuspipe_hdr)];
605 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
606 vmbus_prep_negotiate_resp(icmsghdrp, negop,
607 recv_buffer, MAX_SRV_VER, MAX_SRV_VER);
609 kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
610 sizeof(struct vmbuspipe_hdr) +
611 sizeof(struct icmsg_hdr)];
614 * Stash away this global state for completing the
615 * transaction; note transactions are serialized.
618 kvp_transaction.recv_len = recvlen;
619 kvp_transaction.recv_channel = channel;
620 kvp_transaction.recv_req_id = requestid;
621 kvp_transaction.active = true;
622 kvp_transaction.kvp_msg = kvp_msg;
625 * Get the information from the
626 * user-mode component.
627 * component. This transaction will be
628 * completed when we get the value from
629 * the user-mode component.
630 * Set a timeout to deal with
631 * user-mode not responding.
633 schedule_work(&kvp_sendkey_work);
634 schedule_delayed_work(&kvp_work, 5*HZ);
640 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
641 | ICMSGHDRFLAG_RESPONSE;
643 vmbus_sendpacket(channel, recv_buffer,
645 VM_PKT_DATA_INBAND, 0);
651 hv_kvp_init(struct hv_util_service *srv)
655 err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
658 recv_buffer = srv->recv_buffer;
661 * When this driver loads, the user level daemon that
662 * processes the host requests may not yet be running.
663 * Defer processing channel callbacks until the daemon
666 kvp_transaction.active = true;
671 void hv_kvp_deinit(void)
673 cn_del_callback(&kvp_id);
674 cancel_delayed_work_sync(&kvp_work);
675 cancel_work_sync(&kvp_sendkey_work);