drivers/hv/hv_kvp.c

   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  */
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  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>
  30
  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. */
  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 */
  49 } kvp_transaction;
  50
  51 /*
  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.
  55  */
  56 static bool in_hand_shake = true;
  57
  58 /*
  59  * This state maintains the version number registered by the daemon.
  60  */
  61 static int dm_reg_value;
  62
  63 static void kvp_send_key(struct work_struct *dummy);
  64
  65
  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);
  69
  70 static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
  71 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
  72
  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;
  76 /*
  77  * Register the kernel component with the user-level daemon.
  78  * As part of this registration, pass the LIC version number.
  79  */
  80
  81 static void
  82 kvp_register(int reg_value)
  83 {
  84
  85         struct cn_msg *msg;
  86         struct hv_kvp_msg *kvp_msg;
  87         char *version;
  88
  89         msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
  90
  91         if (msg) {
  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;
  96
  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);
 101                 kfree(msg);
 102         }
 103 }
 104 static void
 105 kvp_work_func(struct work_struct *dummy)
 106 {
 107         /*
 108          * If the timer fires, the user-mode component has not responded;
 109          * process the pending transaction.
 110          */
 111         kvp_respond_to_host(NULL, HV_E_FAIL);
 112 }
 113
 114 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 115 {
 116         int ret = 1;
 117
 118         switch (msg->kvp_hdr.operation) {
 119         case KVP_OP_REGISTER:
 120                 dm_reg_value = KVP_OP_REGISTER;
 121                 pr_info("KVP: IP injection functionality not available\n");
 122                 pr_info("KVP: Upgrade the KVP daemon\n");
 123                 break;
 124         case KVP_OP_REGISTER1:
 125                 dm_reg_value = KVP_OP_REGISTER1;
 126                 break;
 127         default:
 128                 pr_info("KVP: incompatible daemon\n");
 129                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 130                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 131                 ret = 0;
 132         }
 133
 134         if (ret) {
 135                 /*
 136                  * We have a compatible daemon; complete the handshake.
 137                  */
 138                 pr_info("KVP: user-mode registering done.\n");
 139                 kvp_register(dm_reg_value);
 140                 kvp_transaction.active = false;
 141                 if (kvp_transaction.kvp_context)
 142                         hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
 143         }
 144         return ret;
 145 }
 146
 147
 148 /*
 149  * Callback when data is received from user mode.
 150  */
 151
 152 static void
 153 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 154 {
 155         struct hv_kvp_msg *message;
 156         struct hv_kvp_msg_enumerate *data;
 157         int     error = 0;
 158
 159         message = (struct hv_kvp_msg *)msg->data;
 160
 161         /*
 162          * If we are negotiating the version information
 163          * with the daemon; handle that first.
 164          */
 165
 166         if (in_hand_shake) {
 167                 if (kvp_handle_handshake(message))
 168                         in_hand_shake = false;
 169                 return;
 170         }
 171
 172         /*
 173          * Based on the version of the daemon, we propagate errors from the
 174          * daemon differently.
 175          */
 176
 177         data = &message->body.kvp_enum_data;
 178
 179         switch (dm_reg_value) {
 180         case KVP_OP_REGISTER:
 181                 /*
 182                  * Null string is used to pass back error condition.
 183                  */
 184                 if (data->data.key[0] == 0)
 185                         error = HV_S_CONT;
 186                 break;
 187
 188         case KVP_OP_REGISTER1:
 189                 /*
 190                  * We use the message header information from
 191                  * the user level daemon to transmit errors.
 192                  */
 193                 error = message->error;
 194                 break;
 195         }
 196
 197         /*
 198          * Complete the transaction by forwarding the key value
 199          * to the host. But first, cancel the timeout.
 200          */
 201         if (cancel_delayed_work_sync(&kvp_work))
 202                 kvp_respond_to_host(message, error);
 203 }
 204
 205
 206 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 207 {
 208         struct hv_kvp_msg *in = in_msg;
 209         struct hv_kvp_ip_msg *out = out_msg;
 210         int len;
 211
 212         switch (op) {
 213         case KVP_OP_GET_IP_INFO:
 214                 /*
 215                  * Transform all parameters into utf16 encoding.
 216                  */
 217                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 218                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 219                                 UTF16_HOST_ENDIAN,
 220                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 221                                 MAX_IP_ADDR_SIZE);
 222                 if (len < 0)
 223                         return len;
 224
 225                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 226                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 227                                 UTF16_HOST_ENDIAN,
 228                                 (wchar_t *)out->kvp_ip_val.sub_net,
 229                                 MAX_IP_ADDR_SIZE);
 230                 if (len < 0)
 231                         return len;
 232
 233                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 234                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 235                                 UTF16_HOST_ENDIAN,
 236                                 (wchar_t *)out->kvp_ip_val.gate_way,
 237                                 MAX_GATEWAY_SIZE);
 238                 if (len < 0)
 239                         return len;
 240
 241                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 242                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 243                                 UTF16_HOST_ENDIAN,
 244                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 245                                 MAX_IP_ADDR_SIZE);
 246                 if (len < 0)
 247                         return len;
 248
 249                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 250                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 251                                 UTF16_HOST_ENDIAN,
 252                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 253                                 MAX_IP_ADDR_SIZE);
 254                 if (len < 0)
 255                         return len;
 256
 257                 out->kvp_ip_val.dhcp_enabled =
 258                         in->body.kvp_ip_val.dhcp_enabled;
 259                 out->kvp_ip_val.addr_family =
 260                         in->body.kvp_ip_val.addr_family;
 261         }
 262
 263         return 0;
 264 }
 265
 266 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 267 {
 268         struct hv_kvp_ip_msg *in = in_msg;
 269         struct hv_kvp_msg *out = out_msg;
 270
 271         switch (op) {
 272         case KVP_OP_SET_IP_INFO:
 273                 /*
 274                  * Transform all parameters into utf8 encoding.
 275                  */
 276                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 277                                 MAX_IP_ADDR_SIZE,
 278                                 UTF16_LITTLE_ENDIAN,
 279                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 280                                 MAX_IP_ADDR_SIZE);
 281
 282                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 283                                 MAX_IP_ADDR_SIZE,
 284                                 UTF16_LITTLE_ENDIAN,
 285                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 286                                 MAX_IP_ADDR_SIZE);
 287
 288                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 289                                 MAX_GATEWAY_SIZE,
 290                                 UTF16_LITTLE_ENDIAN,
 291                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 292                                 MAX_GATEWAY_SIZE);
 293
 294                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 295                                 MAX_IP_ADDR_SIZE,
 296                                 UTF16_LITTLE_ENDIAN,
 297                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 298                                 MAX_IP_ADDR_SIZE);
 299
 300                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 301
 302         default:
 303                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 304                                 MAX_ADAPTER_ID_SIZE,
 305                                 UTF16_LITTLE_ENDIAN,
 306                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 307                                 MAX_ADAPTER_ID_SIZE);
 308
 309                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 310         }
 311 }
 312
 313
 314
 315
 316 static void
 317 kvp_send_key(struct work_struct *dummy)
 318 {
 319         struct cn_msg *msg;
 320         struct hv_kvp_msg *message;
 321         struct hv_kvp_msg *in_msg;
 322         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 323         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 324         __u32 val32;
 325         __u64 val64;
 326
 327         msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
 328         if (!msg)
 329                 return;
 330
 331         msg->id.idx =  CN_KVP_IDX;
 332         msg->id.val = CN_KVP_VAL;
 333
 334         message = (struct hv_kvp_msg *)msg->data;
 335         message->kvp_hdr.operation = operation;
 336         message->kvp_hdr.pool = pool;
 337         in_msg = kvp_transaction.kvp_msg;
 338
 339         /*
 340          * The key/value strings sent from the host are encoded in
 341          * in utf16; convert it to utf8 strings.
 342          * The host assures us that the utf16 strings will not exceed
 343          * the max lengths specified. We will however, reserve room
 344          * for the string terminating character - in the utf16s_utf8s()
 345          * function we limit the size of the buffer where the converted
 346          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 347          * that the strings can be properly terminated!
 348          */
 349
 350         switch (message->kvp_hdr.operation) {
 351         case KVP_OP_SET_IP_INFO:
 352                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 353                 break;
 354         case KVP_OP_GET_IP_INFO:
 355                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 356                 break;
 357         case KVP_OP_SET:
 358                 switch (in_msg->body.kvp_set.data.value_type) {
 359                 case REG_SZ:
 360                         /*
 361                          * The value is a string - utf16 encoding.
 362                          */
 363                         message->body.kvp_set.data.value_size =
 364                                 utf16s_to_utf8s(
 365                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 366                                 in_msg->body.kvp_set.data.value_size,
 367                                 UTF16_LITTLE_ENDIAN,
 368                                 message->body.kvp_set.data.value,
 369                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 370                                 break;
 371
 372                 case REG_U32:
 373                         /*
 374                          * The value is a 32 bit scalar.
 375                          * We save this as a utf8 string.
 376                          */
 377                         val32 = in_msg->body.kvp_set.data.value_u32;
 378                         message->body.kvp_set.data.value_size =
 379                                 sprintf(message->body.kvp_set.data.value,
 380                                         "%d", val32) + 1;
 381                         break;
 382
 383                 case REG_U64:
 384                         /*
 385                          * The value is a 64 bit scalar.
 386                          * We save this as a utf8 string.
 387                          */
 388                         val64 = in_msg->body.kvp_set.data.value_u64;
 389                         message->body.kvp_set.data.value_size =
 390                                 sprintf(message->body.kvp_set.data.value,
 391                                         "%llu", val64) + 1;
 392                         break;
 393
 394                 }
 395         case KVP_OP_GET:
 396                 message->body.kvp_set.data.key_size =
 397                         utf16s_to_utf8s(
 398                         (wchar_t *)in_msg->body.kvp_set.data.key,
 399                         in_msg->body.kvp_set.data.key_size,
 400                         UTF16_LITTLE_ENDIAN,
 401                         message->body.kvp_set.data.key,
 402                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 403                         break;
 404
 405         case KVP_OP_DELETE:
 406                 message->body.kvp_delete.key_size =
 407                         utf16s_to_utf8s(
 408                         (wchar_t *)in_msg->body.kvp_delete.key,
 409                         in_msg->body.kvp_delete.key_size,
 410                         UTF16_LITTLE_ENDIAN,
 411                         message->body.kvp_delete.key,
 412                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 413                         break;
 414
 415         case KVP_OP_ENUMERATE:
 416                 message->body.kvp_enum_data.index =
 417                         in_msg->body.kvp_enum_data.index;
 418                         break;
 419         }
 420
 421         msg->len = sizeof(struct hv_kvp_msg);
 422         cn_netlink_send(msg, 0, GFP_ATOMIC);
 423         kfree(msg);
 424
 425         return;
 426 }
 427
 428 /*
 429  * Send a response back to the host.
 430  */
 431
 432 static void
 433 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 434 {
 435         struct hv_kvp_msg  *kvp_msg;
 436         struct hv_kvp_exchg_msg_value  *kvp_data;
 437         char    *key_name;
 438         char    *value;
 439         struct icmsg_hdr *icmsghdrp;
 440         int     keylen = 0;
 441         int     valuelen = 0;
 442         u32     buf_len;
 443         struct vmbus_channel *channel;
 444         u64     req_id;
 445         int ret;
 446
 447         /*
 448          * If a transaction is not active; log and return.
 449          */
 450
 451         if (!kvp_transaction.active) {
 452                 /*
 453                  * This is a spurious call!
 454                  */
 455                 pr_warn("KVP: Transaction not active\n");
 456                 return;
 457         }
 458         /*
 459          * Copy the global state for completing the transaction. Note that
 460          * only one transaction can be active at a time.
 461          */
 462
 463         buf_len = kvp_transaction.recv_len;
 464         channel = kvp_transaction.recv_channel;
 465         req_id = kvp_transaction.recv_req_id;
 466
 467         kvp_transaction.active = false;
 468
 469         icmsghdrp = (struct icmsg_hdr *)
 470                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 471
 472         if (channel->onchannel_callback == NULL)
 473                 /*
 474                  * We have raced with util driver being unloaded;
 475                  * silently return.
 476                  */
 477                 return;
 478
 479         icmsghdrp->status = error;
 480
 481         /*
 482          * If the error parameter is set, terminate the host's enumeration
 483          * on this pool.
 484          */
 485         if (error) {
 486                 /*
 487                  * Something failed or we have timedout;
 488                  * terminate the current host-side iteration.
 489                  */
 490                 goto response_done;
 491         }
 492
 493         kvp_msg = (struct hv_kvp_msg *)
 494                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 495                         sizeof(struct icmsg_hdr)];
 496
 497         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 498         case KVP_OP_GET_IP_INFO:
 499                 ret = process_ob_ipinfo(msg_to_host,
 500                                  (struct hv_kvp_ip_msg *)kvp_msg,
 501                                  KVP_OP_GET_IP_INFO);
 502                 if (ret < 0)
 503                         icmsghdrp->status = HV_E_FAIL;
 504
 505                 goto response_done;
 506         case KVP_OP_SET_IP_INFO:
 507                 goto response_done;
 508         case KVP_OP_GET:
 509                 kvp_data = &kvp_msg->body.kvp_get.data;
 510                 goto copy_value;
 511
 512         case KVP_OP_SET:
 513         case KVP_OP_DELETE:
 514                 goto response_done;
 515
 516         default:
 517                 break;
 518         }
 519
 520         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 521         key_name = msg_to_host->body.kvp_enum_data.data.key;
 522
 523         /*
 524          * The windows host expects the key/value pair to be encoded
 525          * in utf16. Ensure that the key/value size reported to the host
 526          * will be less than or equal to the MAX size (including the
 527          * terminating character).
 528          */
 529         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 530                                 (wchar_t *) kvp_data->key,
 531                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 532         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 533
 534 copy_value:
 535         value = msg_to_host->body.kvp_enum_data.data.value;
 536         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 537                                 (wchar_t *) kvp_data->value,
 538                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 539         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 540
 541         /*
 542          * If the utf8s to utf16s conversion failed; notify host
 543          * of the error.
 544          */
 545         if ((keylen < 0) || (valuelen < 0))
 546                 icmsghdrp->status = HV_E_FAIL;
 547
 548         kvp_data->value_type = REG_SZ; /* all our values are strings */
 549
 550 response_done:
 551         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 552
 553         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 554                                 VM_PKT_DATA_INBAND, 0);
 555
 556 }
 557
 558 /*
 559  * This callback is invoked when we get a KVP message from the host.
 560  * The host ensures that only one KVP transaction can be active at a time.
 561  * KVP implementation in Linux needs to forward the key to a user-mde
 562  * component to retrive the corresponding value. Consequently, we cannot
 563  * respond to the host in the conext of this callback. Since the host
 564  * guarantees that at most only one transaction can be active at a time,
 565  * we stash away the transaction state in a set of global variables.
 566  */
 567
 568 void hv_kvp_onchannelcallback(void *context)
 569 {
 570         struct vmbus_channel *channel = context;
 571         u32 recvlen;
 572         u64 requestid;
 573
 574         struct hv_kvp_msg *kvp_msg;
 575
 576         struct icmsg_hdr *icmsghdrp;
 577         struct icmsg_negotiate *negop = NULL;
 578
 579         if (kvp_transaction.active) {
 580                 /*
 581                  * We will defer processing this callback once
 582                  * the current transaction is complete.
 583                  */
 584                 kvp_transaction.kvp_context = context;
 585                 return;
 586         }
 587
 588         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
 589                          &requestid);
 590
 591         if (recvlen > 0) {
 592                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 593                         sizeof(struct vmbuspipe_hdr)];
 594
 595                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 596                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 597                                  recv_buffer, MAX_SRV_VER, MAX_SRV_VER);
 598                 } else {
 599                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 600                                 sizeof(struct vmbuspipe_hdr) +
 601                                 sizeof(struct icmsg_hdr)];
 602
 603                         /*
 604                          * Stash away this global state for completing the
 605                          * transaction; note transactions are serialized.
 606                          */
 607
 608                         kvp_transaction.recv_len = recvlen;
 609                         kvp_transaction.recv_channel = channel;
 610                         kvp_transaction.recv_req_id = requestid;
 611                         kvp_transaction.active = true;
 612                         kvp_transaction.kvp_msg = kvp_msg;
 613
 614                         /*
 615                          * Get the information from the
 616                          * user-mode component.
 617                          * component. This transaction will be
 618                          * completed when we get the value from
 619                          * the user-mode component.
 620                          * Set a timeout to deal with
 621                          * user-mode not responding.
 622                          */
 623                         schedule_work(&kvp_sendkey_work);
 624                         schedule_delayed_work(&kvp_work, 5*HZ);
 625
 626                         return;
 627
 628                 }
 629
 630                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 631                         | ICMSGHDRFLAG_RESPONSE;
 632
 633                 vmbus_sendpacket(channel, recv_buffer,
 634                                        recvlen, requestid,
 635                                        VM_PKT_DATA_INBAND, 0);
 636         }
 637
 638 }
 639
 640 int
 641 hv_kvp_init(struct hv_util_service *srv)
 642 {
 643         int err;
 644
 645         err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
 646         if (err)
 647                 return err;
 648         recv_buffer = srv->recv_buffer;
 649
 650         /*
 651          * When this driver loads, the user level daemon that
 652          * processes the host requests may not yet be running.
 653          * Defer processing channel callbacks until the daemon
 654          * has registered.
 655          */
 656         kvp_transaction.active = true;
 657
 658         return 0;
 659 }
 660
 661 void hv_kvp_deinit(void)
 662 {
 663         cn_del_callback(&kvp_id);
 664         cancel_delayed_work_sync(&kvp_work);
 665         cancel_work_sync(&kvp_sendkey_work);
 666 }