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 #include "hyperv_vmbus.h"
  32 #include "hv_utils_transport.h"
  33
  34 /*
  35  * Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
  36  */
  37 #define WS2008_SRV_MAJOR        1
  38 #define WS2008_SRV_MINOR        0
  39 #define WS2008_SRV_VERSION     (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)
  40
  41 #define WIN7_SRV_MAJOR   3
  42 #define WIN7_SRV_MINOR   0
  43 #define WIN7_SRV_VERSION     (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)
  44
  45 #define WIN8_SRV_MAJOR   4
  46 #define WIN8_SRV_MINOR   0
  47 #define WIN8_SRV_VERSION     (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
  48
  49 /*
  50  * Global state maintained for transaction that is being processed. For a class
  51  * of integration services, including the "KVP service", the specified protocol
  52  * is a "request/response" protocol which means that there can only be single
  53  * outstanding transaction from the host at any given point in time. We use
  54  * this to simplify memory management in this driver - we cache and process
  55  * only one message at a time.
  56  *
  57  * While the request/response protocol is guaranteed by the host, we further
  58  * ensure this by serializing packet processing in this driver - we do not
  59  * read additional packets from the VMBUs until the current packet is fully
  60  * handled.
  61  */
  62
  63 static struct {
  64         int state;   /* hvutil_device_state */
  65         int recv_len; /* number of bytes received. */
  66         struct hv_kvp_msg  *kvp_msg; /* current message */
  67         struct vmbus_channel *recv_channel; /* chn we got the request */
  68         u64 recv_req_id; /* request ID. */
  69 } kvp_transaction;
  70
  71 /*
  72  * This state maintains the version number registered by the daemon.
  73  */
  74 static int dm_reg_value;
  75
  76 static void kvp_send_key(struct work_struct *dummy);
  77
  78
  79 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
  80 static void kvp_timeout_func(struct work_struct *dummy);
  81 static void kvp_host_handshake_func(struct work_struct *dummy);
  82 static void kvp_register(int);
  83
  84 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
  85 static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
  86 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
  87
  88 static const char kvp_devname[] = "vmbus/hv_kvp";
  89 static u8 *recv_buffer;
  90 static struct hvutil_transport *hvt;
  91 /*
  92  * Register the kernel component with the user-level daemon.
  93  * As part of this registration, pass the LIC version number.
  94  * This number has no meaning, it satisfies the registration protocol.
  95  */
  96 #define HV_DRV_VERSION           "3.1"
  97
  98 static void kvp_poll_wrapper(void *channel)
  99 {
 100         /* Transaction is finished, reset the state here to avoid races. */
 101         kvp_transaction.state = HVUTIL_READY;
 102         hv_kvp_onchannelcallback(channel);
 103 }
 104
 105 static void kvp_register_done(void)
 106 {
 107         /*
 108          * If we're still negotiating with the host cancel the timeout
 109          * work to not poll the channel twice.
 110          */
 111         pr_debug("KVP: userspace daemon registered\n");
 112         cancel_delayed_work_sync(&kvp_host_handshake_work);
 113         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 114 }
 115
 116 static void
 117 kvp_register(int reg_value)
 118 {
 119
 120         struct hv_kvp_msg *kvp_msg;
 121         char *version;
 122
 123         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
 124
 125         if (kvp_msg) {
 126                 version = kvp_msg->body.kvp_register.version;
 127                 kvp_msg->kvp_hdr.operation = reg_value;
 128                 strcpy(version, HV_DRV_VERSION);
 129
 130                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
 131                                       kvp_register_done);
 132                 kfree(kvp_msg);
 133         }
 134 }
 135
 136 static void kvp_timeout_func(struct work_struct *dummy)
 137 {
 138         /*
 139          * If the timer fires, the user-mode component has not responded;
 140          * process the pending transaction.
 141          */
 142         kvp_respond_to_host(NULL, HV_E_FAIL);
 143
 144         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 145 }
 146
 147 static void kvp_host_handshake_func(struct work_struct *dummy)
 148 {
 149         hv_poll_channel(kvp_transaction.recv_channel, hv_kvp_onchannelcallback);
 150 }
 151
 152 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 153 {
 154         switch (msg->kvp_hdr.operation) {
 155         case KVP_OP_REGISTER:
 156                 dm_reg_value = KVP_OP_REGISTER;
 157                 pr_info("KVP: IP injection functionality not available\n");
 158                 pr_info("KVP: Upgrade the KVP daemon\n");
 159                 break;
 160         case KVP_OP_REGISTER1:
 161                 dm_reg_value = KVP_OP_REGISTER1;
 162                 break;
 163         default:
 164                 pr_info("KVP: incompatible daemon\n");
 165                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 166                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 167                 return -EINVAL;
 168         }
 169
 170         /*
 171          * We have a compatible daemon; complete the handshake.
 172          */
 173         pr_debug("KVP: userspace daemon ver. %d connected\n",
 174                  msg->kvp_hdr.operation);
 175         kvp_register(dm_reg_value);
 176
 177         return 0;
 178 }
 179
 180
 181 /*
 182  * Callback when data is received from user mode.
 183  */
 184
 185 static int kvp_on_msg(void *msg, int len)
 186 {
 187         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
 188         struct hv_kvp_msg_enumerate *data;
 189         int     error = 0;
 190
 191         if (len < sizeof(*message))
 192                 return -EINVAL;
 193
 194         /*
 195          * If we are negotiating the version information
 196          * with the daemon; handle that first.
 197          */
 198
 199         if (kvp_transaction.state < HVUTIL_READY) {
 200                 return kvp_handle_handshake(message);
 201         }
 202
 203         /* We didn't send anything to userspace so the reply is spurious */
 204         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
 205                 return -EINVAL;
 206
 207         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
 208
 209         /*
 210          * Based on the version of the daemon, we propagate errors from the
 211          * daemon differently.
 212          */
 213
 214         data = &message->body.kvp_enum_data;
 215
 216         switch (dm_reg_value) {
 217         case KVP_OP_REGISTER:
 218                 /*
 219                  * Null string is used to pass back error condition.
 220                  */
 221                 if (data->data.key[0] == 0)
 222                         error = HV_S_CONT;
 223                 break;
 224
 225         case KVP_OP_REGISTER1:
 226                 /*
 227                  * We use the message header information from
 228                  * the user level daemon to transmit errors.
 229                  */
 230                 error = message->error;
 231                 break;
 232         }
 233
 234         /*
 235          * Complete the transaction by forwarding the key value
 236          * to the host. But first, cancel the timeout.
 237          */
 238         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 239                 kvp_respond_to_host(message, error);
 240                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 241         }
 242
 243         return 0;
 244 }
 245
 246
 247 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 248 {
 249         struct hv_kvp_msg *in = in_msg;
 250         struct hv_kvp_ip_msg *out = out_msg;
 251         int len;
 252
 253         switch (op) {
 254         case KVP_OP_GET_IP_INFO:
 255                 /*
 256                  * Transform all parameters into utf16 encoding.
 257                  */
 258                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 259                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 260                                 UTF16_HOST_ENDIAN,
 261                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 262                                 MAX_IP_ADDR_SIZE);
 263                 if (len < 0)
 264                         return len;
 265
 266                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 267                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 268                                 UTF16_HOST_ENDIAN,
 269                                 (wchar_t *)out->kvp_ip_val.sub_net,
 270                                 MAX_IP_ADDR_SIZE);
 271                 if (len < 0)
 272                         return len;
 273
 274                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 275                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 276                                 UTF16_HOST_ENDIAN,
 277                                 (wchar_t *)out->kvp_ip_val.gate_way,
 278                                 MAX_GATEWAY_SIZE);
 279                 if (len < 0)
 280                         return len;
 281
 282                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 283                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 284                                 UTF16_HOST_ENDIAN,
 285                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 286                                 MAX_IP_ADDR_SIZE);
 287                 if (len < 0)
 288                         return len;
 289
 290                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 291                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 292                                 UTF16_HOST_ENDIAN,
 293                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 294                                 MAX_IP_ADDR_SIZE);
 295                 if (len < 0)
 296                         return len;
 297
 298                 out->kvp_ip_val.dhcp_enabled =
 299                         in->body.kvp_ip_val.dhcp_enabled;
 300                 out->kvp_ip_val.addr_family =
 301                         in->body.kvp_ip_val.addr_family;
 302         }
 303
 304         return 0;
 305 }
 306
 307 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 308 {
 309         struct hv_kvp_ip_msg *in = in_msg;
 310         struct hv_kvp_msg *out = out_msg;
 311
 312         switch (op) {
 313         case KVP_OP_SET_IP_INFO:
 314                 /*
 315                  * Transform all parameters into utf8 encoding.
 316                  */
 317                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 318                                 MAX_IP_ADDR_SIZE,
 319                                 UTF16_LITTLE_ENDIAN,
 320                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 321                                 MAX_IP_ADDR_SIZE);
 322
 323                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 324                                 MAX_IP_ADDR_SIZE,
 325                                 UTF16_LITTLE_ENDIAN,
 326                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 327                                 MAX_IP_ADDR_SIZE);
 328
 329                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 330                                 MAX_GATEWAY_SIZE,
 331                                 UTF16_LITTLE_ENDIAN,
 332                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 333                                 MAX_GATEWAY_SIZE);
 334
 335                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 336                                 MAX_IP_ADDR_SIZE,
 337                                 UTF16_LITTLE_ENDIAN,
 338                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 339                                 MAX_IP_ADDR_SIZE);
 340
 341                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 342
 343         default:
 344                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 345                                 MAX_ADAPTER_ID_SIZE,
 346                                 UTF16_LITTLE_ENDIAN,
 347                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 348                                 MAX_ADAPTER_ID_SIZE);
 349
 350                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 351         }
 352 }
 353
 354
 355
 356
 357 static void
 358 kvp_send_key(struct work_struct *dummy)
 359 {
 360         struct hv_kvp_msg *message;
 361         struct hv_kvp_msg *in_msg;
 362         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 363         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 364         __u32 val32;
 365         __u64 val64;
 366         int rc;
 367
 368         /* The transaction state is wrong. */
 369         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 370                 return;
 371
 372         message = kzalloc(sizeof(*message), GFP_KERNEL);
 373         if (!message)
 374                 return;
 375
 376         message->kvp_hdr.operation = operation;
 377         message->kvp_hdr.pool = pool;
 378         in_msg = kvp_transaction.kvp_msg;
 379
 380         /*
 381          * The key/value strings sent from the host are encoded in
 382          * in utf16; convert it to utf8 strings.
 383          * The host assures us that the utf16 strings will not exceed
 384          * the max lengths specified. We will however, reserve room
 385          * for the string terminating character - in the utf16s_utf8s()
 386          * function we limit the size of the buffer where the converted
 387          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 388          * that the strings can be properly terminated!
 389          */
 390
 391         switch (message->kvp_hdr.operation) {
 392         case KVP_OP_SET_IP_INFO:
 393                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 394                 break;
 395         case KVP_OP_GET_IP_INFO:
 396                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 397                 break;
 398         case KVP_OP_SET:
 399                 switch (in_msg->body.kvp_set.data.value_type) {
 400                 case REG_SZ:
 401                         /*
 402                          * The value is a string - utf16 encoding.
 403                          */
 404                         message->body.kvp_set.data.value_size =
 405                                 utf16s_to_utf8s(
 406                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 407                                 in_msg->body.kvp_set.data.value_size,
 408                                 UTF16_LITTLE_ENDIAN,
 409                                 message->body.kvp_set.data.value,
 410                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 411                                 break;
 412
 413                 case REG_U32:
 414                         /*
 415                          * The value is a 32 bit scalar.
 416                          * We save this as a utf8 string.
 417                          */
 418                         val32 = in_msg->body.kvp_set.data.value_u32;
 419                         message->body.kvp_set.data.value_size =
 420                                 sprintf(message->body.kvp_set.data.value,
 421                                         "%d", val32) + 1;
 422                         break;
 423
 424                 case REG_U64:
 425                         /*
 426                          * The value is a 64 bit scalar.
 427                          * We save this as a utf8 string.
 428                          */
 429                         val64 = in_msg->body.kvp_set.data.value_u64;
 430                         message->body.kvp_set.data.value_size =
 431                                 sprintf(message->body.kvp_set.data.value,
 432                                         "%llu", val64) + 1;
 433                         break;
 434
 435                 }
 436         case KVP_OP_GET:
 437                 message->body.kvp_set.data.key_size =
 438                         utf16s_to_utf8s(
 439                         (wchar_t *)in_msg->body.kvp_set.data.key,
 440                         in_msg->body.kvp_set.data.key_size,
 441                         UTF16_LITTLE_ENDIAN,
 442                         message->body.kvp_set.data.key,
 443                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 444                         break;
 445
 446         case KVP_OP_DELETE:
 447                 message->body.kvp_delete.key_size =
 448                         utf16s_to_utf8s(
 449                         (wchar_t *)in_msg->body.kvp_delete.key,
 450                         in_msg->body.kvp_delete.key_size,
 451                         UTF16_LITTLE_ENDIAN,
 452                         message->body.kvp_delete.key,
 453                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 454                         break;
 455
 456         case KVP_OP_ENUMERATE:
 457                 message->body.kvp_enum_data.index =
 458                         in_msg->body.kvp_enum_data.index;
 459                         break;
 460         }
 461
 462         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 463         rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
 464         if (rc) {
 465                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 466                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 467                         kvp_respond_to_host(message, HV_E_FAIL);
 468                         kvp_transaction.state = HVUTIL_READY;
 469                 }
 470         }
 471
 472         kfree(message);
 473
 474         return;
 475 }
 476
 477 /*
 478  * Send a response back to the host.
 479  */
 480
 481 static void
 482 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 483 {
 484         struct hv_kvp_msg  *kvp_msg;
 485         struct hv_kvp_exchg_msg_value  *kvp_data;
 486         char    *key_name;
 487         char    *value;
 488         struct icmsg_hdr *icmsghdrp;
 489         int     keylen = 0;
 490         int     valuelen = 0;
 491         u32     buf_len;
 492         struct vmbus_channel *channel;
 493         u64     req_id;
 494         int ret;
 495
 496         /*
 497          * Copy the global state for completing the transaction. Note that
 498          * only one transaction can be active at a time.
 499          */
 500
 501         buf_len = kvp_transaction.recv_len;
 502         channel = kvp_transaction.recv_channel;
 503         req_id = kvp_transaction.recv_req_id;
 504
 505         icmsghdrp = (struct icmsg_hdr *)
 506                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 507
 508         if (channel->onchannel_callback == NULL)
 509                 /*
 510                  * We have raced with util driver being unloaded;
 511                  * silently return.
 512                  */
 513                 return;
 514
 515         icmsghdrp->status = error;
 516
 517         /*
 518          * If the error parameter is set, terminate the host's enumeration
 519          * on this pool.
 520          */
 521         if (error) {
 522                 /*
 523                  * Something failed or we have timedout;
 524                  * terminate the current host-side iteration.
 525                  */
 526                 goto response_done;
 527         }
 528
 529         kvp_msg = (struct hv_kvp_msg *)
 530                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 531                         sizeof(struct icmsg_hdr)];
 532
 533         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 534         case KVP_OP_GET_IP_INFO:
 535                 ret = process_ob_ipinfo(msg_to_host,
 536                                  (struct hv_kvp_ip_msg *)kvp_msg,
 537                                  KVP_OP_GET_IP_INFO);
 538                 if (ret < 0)
 539                         icmsghdrp->status = HV_E_FAIL;
 540
 541                 goto response_done;
 542         case KVP_OP_SET_IP_INFO:
 543                 goto response_done;
 544         case KVP_OP_GET:
 545                 kvp_data = &kvp_msg->body.kvp_get.data;
 546                 goto copy_value;
 547
 548         case KVP_OP_SET:
 549         case KVP_OP_DELETE:
 550                 goto response_done;
 551
 552         default:
 553                 break;
 554         }
 555
 556         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 557         key_name = msg_to_host->body.kvp_enum_data.data.key;
 558
 559         /*
 560          * The windows host expects the key/value pair to be encoded
 561          * in utf16. Ensure that the key/value size reported to the host
 562          * will be less than or equal to the MAX size (including the
 563          * terminating character).
 564          */
 565         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 566                                 (wchar_t *) kvp_data->key,
 567                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 568         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 569
 570 copy_value:
 571         value = msg_to_host->body.kvp_enum_data.data.value;
 572         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 573                                 (wchar_t *) kvp_data->value,
 574                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 575         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 576
 577         /*
 578          * If the utf8s to utf16s conversion failed; notify host
 579          * of the error.
 580          */
 581         if ((keylen < 0) || (valuelen < 0))
 582                 icmsghdrp->status = HV_E_FAIL;
 583
 584         kvp_data->value_type = REG_SZ; /* all our values are strings */
 585
 586 response_done:
 587         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 588
 589         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 590                                 VM_PKT_DATA_INBAND, 0);
 591 }
 592
 593 /*
 594  * This callback is invoked when we get a KVP message from the host.
 595  * The host ensures that only one KVP transaction can be active at a time.
 596  * KVP implementation in Linux needs to forward the key to a user-mde
 597  * component to retrive the corresponding value. Consequently, we cannot
 598  * respond to the host in the conext of this callback. Since the host
 599  * guarantees that at most only one transaction can be active at a time,
 600  * we stash away the transaction state in a set of global variables.
 601  */
 602
 603 void hv_kvp_onchannelcallback(void *context)
 604 {
 605         struct vmbus_channel *channel = context;
 606         u32 recvlen;
 607         u64 requestid;
 608
 609         struct hv_kvp_msg *kvp_msg;
 610
 611         struct icmsg_hdr *icmsghdrp;
 612         struct icmsg_negotiate *negop = NULL;
 613         int util_fw_version;
 614         int kvp_srv_version;
 615         static enum {NEGO_NOT_STARTED,
 616                      NEGO_IN_PROGRESS,
 617                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
 618
 619         if (host_negotiatied == NEGO_NOT_STARTED &&
 620             kvp_transaction.state < HVUTIL_READY) {
 621                 /*
 622                  * If userspace daemon is not connected and host is asking
 623                  * us to negotiate we need to delay to not lose messages.
 624                  * This is important for Failover IP setting.
 625                  */
 626                 host_negotiatied = NEGO_IN_PROGRESS;
 627                 schedule_delayed_work(&kvp_host_handshake_work,
 628                                       HV_UTIL_NEGO_TIMEOUT * HZ);
 629                 return;
 630         }
 631         if (kvp_transaction.state > HVUTIL_READY)
 632                 return;
 633
 634         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 635                          &requestid);
 636
 637         if (recvlen > 0) {
 638                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 639                         sizeof(struct vmbuspipe_hdr)];
 640
 641                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 642                         /*
 643                          * Based on the host, select appropriate
 644                          * framework and service versions we will
 645                          * negotiate.
 646                          */
 647                         switch (vmbus_proto_version) {
 648                         case (VERSION_WS2008):
 649                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 650                                 kvp_srv_version = WS2008_SRV_VERSION;
 651                                 break;
 652                         case (VERSION_WIN7):
 653                                 util_fw_version = UTIL_FW_VERSION;
 654                                 kvp_srv_version = WIN7_SRV_VERSION;
 655                                 break;
 656                         default:
 657                                 util_fw_version = UTIL_FW_VERSION;
 658                                 kvp_srv_version = WIN8_SRV_VERSION;
 659                         }
 660                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 661                                  recv_buffer, util_fw_version,
 662                                  kvp_srv_version);
 663
 664                 } else {
 665                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 666                                 sizeof(struct vmbuspipe_hdr) +
 667                                 sizeof(struct icmsg_hdr)];
 668
 669                         /*
 670                          * Stash away this global state for completing the
 671                          * transaction; note transactions are serialized.
 672                          */
 673
 674                         kvp_transaction.recv_len = recvlen;
 675                         kvp_transaction.recv_req_id = requestid;
 676                         kvp_transaction.kvp_msg = kvp_msg;
 677
 678                         if (kvp_transaction.state < HVUTIL_READY) {
 679                                 /* Userspace is not registered yet */
 680                                 kvp_respond_to_host(NULL, HV_E_FAIL);
 681                                 return;
 682                         }
 683                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 684
 685                         /*
 686                          * Get the information from the
 687                          * user-mode component.
 688                          * component. This transaction will be
 689                          * completed when we get the value from
 690                          * the user-mode component.
 691                          * Set a timeout to deal with
 692                          * user-mode not responding.
 693                          */
 694                         schedule_work(&kvp_sendkey_work);
 695                         schedule_delayed_work(&kvp_timeout_work,
 696                                               HV_UTIL_TIMEOUT * HZ);
 697
 698                         return;
 699
 700                 }
 701
 702                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 703                         | ICMSGHDRFLAG_RESPONSE;
 704
 705                 vmbus_sendpacket(channel, recv_buffer,
 706                                        recvlen, requestid,
 707                                        VM_PKT_DATA_INBAND, 0);
 708
 709                 host_negotiatied = NEGO_FINISHED;
 710         }
 711
 712 }
 713
 714 static void kvp_on_reset(void)
 715 {
 716         if (cancel_delayed_work_sync(&kvp_timeout_work))
 717                 kvp_respond_to_host(NULL, HV_E_FAIL);
 718         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 719 }
 720
 721 int
 722 hv_kvp_init(struct hv_util_service *srv)
 723 {
 724         recv_buffer = srv->recv_buffer;
 725         kvp_transaction.recv_channel = srv->channel;
 726
 727         /*
 728          * When this driver loads, the user level daemon that
 729          * processes the host requests may not yet be running.
 730          * Defer processing channel callbacks until the daemon
 731          * has registered.
 732          */
 733         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 734
 735         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 736                                     kvp_on_msg, kvp_on_reset);
 737         if (!hvt)
 738                 return -EFAULT;
 739
 740         return 0;
 741 }
 742
 743 void hv_kvp_deinit(void)
 744 {
 745         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 746         cancel_delayed_work_sync(&kvp_host_handshake_work);
 747         cancel_delayed_work_sync(&kvp_timeout_work);
 748         cancel_work_sync(&kvp_sendkey_work);
 749         hvutil_transport_destroy(hvt);
 750 }