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