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 /*
 105  * Register the kernel component with the user-level daemon.
 106  * As part of this registration, pass the LIC version number.
 107  * This number has no meaning, it satisfies the registration protocol.
 108  */
 109 #define HV_DRV_VERSION           "3.1"
 110
 111 static void kvp_poll_wrapper(void *channel)
 112 {
 113         /* Transaction is finished, reset the state here to avoid races. */
 114         kvp_transaction.state = HVUTIL_READY;
 115         tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
 116 }
 117
 118 static void kvp_register_done(void)
 119 {
 120         /*
 121          * If we're still negotiating with the host cancel the timeout
 122          * work to not poll the channel twice.
 123          */
 124         pr_debug("KVP: userspace daemon registered\n");
 125         cancel_delayed_work_sync(&kvp_host_handshake_work);
 126         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 127 }
 128
 129 static void
 130 kvp_register(int reg_value)
 131 {
 132
 133         struct hv_kvp_msg *kvp_msg;
 134         char *version;
 135
 136         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
 137
 138         if (kvp_msg) {
 139                 version = kvp_msg->body.kvp_register.version;
 140                 kvp_msg->kvp_hdr.operation = reg_value;
 141                 strcpy(version, HV_DRV_VERSION);
 142
 143                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
 144                                       kvp_register_done);
 145                 kfree(kvp_msg);
 146         }
 147 }
 148
 149 static void kvp_timeout_func(struct work_struct *dummy)
 150 {
 151         /*
 152          * If the timer fires, the user-mode component has not responded;
 153          * process the pending transaction.
 154          */
 155         kvp_respond_to_host(NULL, HV_E_FAIL);
 156
 157         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 158 }
 159
 160 static void kvp_host_handshake_func(struct work_struct *dummy)
 161 {
 162         tasklet_schedule(&kvp_transaction.recv_channel->callback_event);
 163 }
 164
 165 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 166 {
 167         switch (msg->kvp_hdr.operation) {
 168         case KVP_OP_REGISTER:
 169                 dm_reg_value = KVP_OP_REGISTER;
 170                 pr_info("KVP: IP injection functionality not available\n");
 171                 pr_info("KVP: Upgrade the KVP daemon\n");
 172                 break;
 173         case KVP_OP_REGISTER1:
 174                 dm_reg_value = KVP_OP_REGISTER1;
 175                 break;
 176         default:
 177                 pr_info("KVP: incompatible daemon\n");
 178                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 179                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 180                 return -EINVAL;
 181         }
 182
 183         /*
 184          * We have a compatible daemon; complete the handshake.
 185          */
 186         pr_debug("KVP: userspace daemon ver. %d connected\n",
 187                  msg->kvp_hdr.operation);
 188         kvp_register(dm_reg_value);
 189
 190         return 0;
 191 }
 192
 193
 194 /*
 195  * Callback when data is received from user mode.
 196  */
 197
 198 static int kvp_on_msg(void *msg, int len)
 199 {
 200         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
 201         struct hv_kvp_msg_enumerate *data;
 202         int     error = 0;
 203
 204         if (len < sizeof(*message))
 205                 return -EINVAL;
 206
 207         /*
 208          * If we are negotiating the version information
 209          * with the daemon; handle that first.
 210          */
 211
 212         if (kvp_transaction.state < HVUTIL_READY) {
 213                 return kvp_handle_handshake(message);
 214         }
 215
 216         /* We didn't send anything to userspace so the reply is spurious */
 217         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
 218                 return -EINVAL;
 219
 220         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
 221
 222         /*
 223          * Based on the version of the daemon, we propagate errors from the
 224          * daemon differently.
 225          */
 226
 227         data = &message->body.kvp_enum_data;
 228
 229         switch (dm_reg_value) {
 230         case KVP_OP_REGISTER:
 231                 /*
 232                  * Null string is used to pass back error condition.
 233                  */
 234                 if (data->data.key[0] == 0)
 235                         error = HV_S_CONT;
 236                 break;
 237
 238         case KVP_OP_REGISTER1:
 239                 /*
 240                  * We use the message header information from
 241                  * the user level daemon to transmit errors.
 242                  */
 243                 error = message->error;
 244                 break;
 245         }
 246
 247         /*
 248          * Complete the transaction by forwarding the key value
 249          * to the host. But first, cancel the timeout.
 250          */
 251         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 252                 kvp_respond_to_host(message, error);
 253                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 254         }
 255
 256         return 0;
 257 }
 258
 259
 260 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 261 {
 262         struct hv_kvp_msg *in = in_msg;
 263         struct hv_kvp_ip_msg *out = out_msg;
 264         int len;
 265
 266         switch (op) {
 267         case KVP_OP_GET_IP_INFO:
 268                 /*
 269                  * Transform all parameters into utf16 encoding.
 270                  */
 271                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 272                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 273                                 UTF16_HOST_ENDIAN,
 274                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 275                                 MAX_IP_ADDR_SIZE);
 276                 if (len < 0)
 277                         return len;
 278
 279                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 280                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 281                                 UTF16_HOST_ENDIAN,
 282                                 (wchar_t *)out->kvp_ip_val.sub_net,
 283                                 MAX_IP_ADDR_SIZE);
 284                 if (len < 0)
 285                         return len;
 286
 287                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 288                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 289                                 UTF16_HOST_ENDIAN,
 290                                 (wchar_t *)out->kvp_ip_val.gate_way,
 291                                 MAX_GATEWAY_SIZE);
 292                 if (len < 0)
 293                         return len;
 294
 295                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 296                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 297                                 UTF16_HOST_ENDIAN,
 298                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 299                                 MAX_IP_ADDR_SIZE);
 300                 if (len < 0)
 301                         return len;
 302
 303                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 304                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 305                                 UTF16_HOST_ENDIAN,
 306                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 307                                 MAX_ADAPTER_ID_SIZE);
 308                 if (len < 0)
 309                         return len;
 310
 311                 out->kvp_ip_val.dhcp_enabled =
 312                         in->body.kvp_ip_val.dhcp_enabled;
 313                 out->kvp_ip_val.addr_family =
 314                         in->body.kvp_ip_val.addr_family;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 321 {
 322         struct hv_kvp_ip_msg *in = in_msg;
 323         struct hv_kvp_msg *out = out_msg;
 324
 325         switch (op) {
 326         case KVP_OP_SET_IP_INFO:
 327                 /*
 328                  * Transform all parameters into utf8 encoding.
 329                  */
 330                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 331                                 MAX_IP_ADDR_SIZE,
 332                                 UTF16_LITTLE_ENDIAN,
 333                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 334                                 MAX_IP_ADDR_SIZE);
 335
 336                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 337                                 MAX_IP_ADDR_SIZE,
 338                                 UTF16_LITTLE_ENDIAN,
 339                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 340                                 MAX_IP_ADDR_SIZE);
 341
 342                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 343                                 MAX_GATEWAY_SIZE,
 344                                 UTF16_LITTLE_ENDIAN,
 345                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 346                                 MAX_GATEWAY_SIZE);
 347
 348                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 349                                 MAX_IP_ADDR_SIZE,
 350                                 UTF16_LITTLE_ENDIAN,
 351                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 352                                 MAX_IP_ADDR_SIZE);
 353
 354                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 355
 356                 /* fallthrough */
 357
 358         case KVP_OP_GET_IP_INFO:
 359                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 360                                 MAX_ADAPTER_ID_SIZE,
 361                                 UTF16_LITTLE_ENDIAN,
 362                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 363                                 MAX_ADAPTER_ID_SIZE);
 364
 365                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 366         }
 367 }
 368
 369
 370
 371
 372 static void
 373 kvp_send_key(struct work_struct *dummy)
 374 {
 375         struct hv_kvp_msg *message;
 376         struct hv_kvp_msg *in_msg;
 377         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 378         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 379         __u32 val32;
 380         __u64 val64;
 381         int rc;
 382
 383         /* The transaction state is wrong. */
 384         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 385                 return;
 386
 387         message = kzalloc(sizeof(*message), GFP_KERNEL);
 388         if (!message)
 389                 return;
 390
 391         message->kvp_hdr.operation = operation;
 392         message->kvp_hdr.pool = pool;
 393         in_msg = kvp_transaction.kvp_msg;
 394
 395         /*
 396          * The key/value strings sent from the host are encoded in
 397          * in utf16; convert it to utf8 strings.
 398          * The host assures us that the utf16 strings will not exceed
 399          * the max lengths specified. We will however, reserve room
 400          * for the string terminating character - in the utf16s_utf8s()
 401          * function we limit the size of the buffer where the converted
 402          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
 403          * that the strings can be properly terminated!
 404          */
 405
 406         switch (message->kvp_hdr.operation) {
 407         case KVP_OP_SET_IP_INFO:
 408                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 409                 break;
 410         case KVP_OP_GET_IP_INFO:
 411                 /*
 412                  * We only need to pass on the info of operation, adapter_id
 413                  * and addr_family to the userland kvp daemon.
 414                  */
 415                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 416                 break;
 417         case KVP_OP_SET:
 418                 switch (in_msg->body.kvp_set.data.value_type) {
 419                 case REG_SZ:
 420                         /*
 421                          * The value is a string - utf16 encoding.
 422                          */
 423                         message->body.kvp_set.data.value_size =
 424                                 utf16s_to_utf8s(
 425                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 426                                 in_msg->body.kvp_set.data.value_size,
 427                                 UTF16_LITTLE_ENDIAN,
 428                                 message->body.kvp_set.data.value,
 429                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 430                         break;
 431
 432                 case REG_U32:
 433                         /*
 434                          * The value is a 32 bit scalar.
 435                          * We save this as a utf8 string.
 436                          */
 437                         val32 = in_msg->body.kvp_set.data.value_u32;
 438                         message->body.kvp_set.data.value_size =
 439                                 sprintf(message->body.kvp_set.data.value,
 440                                         "%u", val32) + 1;
 441                         break;
 442
 443                 case REG_U64:
 444                         /*
 445                          * The value is a 64 bit scalar.
 446                          * We save this as a utf8 string.
 447                          */
 448                         val64 = in_msg->body.kvp_set.data.value_u64;
 449                         message->body.kvp_set.data.value_size =
 450                                 sprintf(message->body.kvp_set.data.value,
 451                                         "%llu", val64) + 1;
 452                         break;
 453
 454                 }
 455
 456                 /*
 457                  * The key is always a string - utf16 encoding.
 458                  */
 459                 message->body.kvp_set.data.key_size =
 460                         utf16s_to_utf8s(
 461                         (wchar_t *)in_msg->body.kvp_set.data.key,
 462                         in_msg->body.kvp_set.data.key_size,
 463                         UTF16_LITTLE_ENDIAN,
 464                         message->body.kvp_set.data.key,
 465                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 466
 467                 break;
 468
 469         case KVP_OP_GET:
 470                 message->body.kvp_get.data.key_size =
 471                         utf16s_to_utf8s(
 472                         (wchar_t *)in_msg->body.kvp_get.data.key,
 473                         in_msg->body.kvp_get.data.key_size,
 474                         UTF16_LITTLE_ENDIAN,
 475                         message->body.kvp_get.data.key,
 476                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 477                 break;
 478
 479         case KVP_OP_DELETE:
 480                 message->body.kvp_delete.key_size =
 481                         utf16s_to_utf8s(
 482                         (wchar_t *)in_msg->body.kvp_delete.key,
 483                         in_msg->body.kvp_delete.key_size,
 484                         UTF16_LITTLE_ENDIAN,
 485                         message->body.kvp_delete.key,
 486                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 487                 break;
 488
 489         case KVP_OP_ENUMERATE:
 490                 message->body.kvp_enum_data.index =
 491                         in_msg->body.kvp_enum_data.index;
 492                 break;
 493         }
 494
 495         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 496         rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
 497         if (rc) {
 498                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 499                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 500                         kvp_respond_to_host(message, HV_E_FAIL);
 501                         kvp_transaction.state = HVUTIL_READY;
 502                 }
 503         }
 504
 505         kfree(message);
 506 }
 507
 508 /*
 509  * Send a response back to the host.
 510  */
 511
 512 static void
 513 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 514 {
 515         struct hv_kvp_msg  *kvp_msg;
 516         struct hv_kvp_exchg_msg_value  *kvp_data;
 517         char    *key_name;
 518         char    *value;
 519         struct icmsg_hdr *icmsghdrp;
 520         int     keylen = 0;
 521         int     valuelen = 0;
 522         u32     buf_len;
 523         struct vmbus_channel *channel;
 524         u64     req_id;
 525         int ret;
 526
 527         /*
 528          * Copy the global state for completing the transaction. Note that
 529          * only one transaction can be active at a time.
 530          */
 531
 532         buf_len = kvp_transaction.recv_len;
 533         channel = kvp_transaction.recv_channel;
 534         req_id = kvp_transaction.recv_req_id;
 535
 536         icmsghdrp = (struct icmsg_hdr *)
 537                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 538
 539         if (channel->onchannel_callback == NULL)
 540                 /*
 541                  * We have raced with util driver being unloaded;
 542                  * silently return.
 543                  */
 544                 return;
 545
 546         icmsghdrp->status = error;
 547
 548         /*
 549          * If the error parameter is set, terminate the host's enumeration
 550          * on this pool.
 551          */
 552         if (error) {
 553                 /*
 554                  * Something failed or we have timed out;
 555                  * terminate the current host-side iteration.
 556                  */
 557                 goto response_done;
 558         }
 559
 560         kvp_msg = (struct hv_kvp_msg *)
 561                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 562                         sizeof(struct icmsg_hdr)];
 563
 564         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 565         case KVP_OP_GET_IP_INFO:
 566                 ret = process_ob_ipinfo(msg_to_host,
 567                                  (struct hv_kvp_ip_msg *)kvp_msg,
 568                                  KVP_OP_GET_IP_INFO);
 569                 if (ret < 0)
 570                         icmsghdrp->status = HV_E_FAIL;
 571
 572                 goto response_done;
 573         case KVP_OP_SET_IP_INFO:
 574                 goto response_done;
 575         case KVP_OP_GET:
 576                 kvp_data = &kvp_msg->body.kvp_get.data;
 577                 goto copy_value;
 578
 579         case KVP_OP_SET:
 580         case KVP_OP_DELETE:
 581                 goto response_done;
 582
 583         default:
 584                 break;
 585         }
 586
 587         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 588         key_name = msg_to_host->body.kvp_enum_data.data.key;
 589
 590         /*
 591          * The windows host expects the key/value pair to be encoded
 592          * in utf16. Ensure that the key/value size reported to the host
 593          * will be less than or equal to the MAX size (including the
 594          * terminating character).
 595          */
 596         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 597                                 (wchar_t *) kvp_data->key,
 598                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 599         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 600
 601 copy_value:
 602         value = msg_to_host->body.kvp_enum_data.data.value;
 603         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 604                                 (wchar_t *) kvp_data->value,
 605                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 606         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 607
 608         /*
 609          * If the utf8s to utf16s conversion failed; notify host
 610          * of the error.
 611          */
 612         if ((keylen < 0) || (valuelen < 0))
 613                 icmsghdrp->status = HV_E_FAIL;
 614
 615         kvp_data->value_type = REG_SZ; /* all our values are strings */
 616
 617 response_done:
 618         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 619
 620         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 621                                 VM_PKT_DATA_INBAND, 0);
 622 }
 623
 624 /*
 625  * This callback is invoked when we get a KVP message from the host.
 626  * The host ensures that only one KVP transaction can be active at a time.
 627  * KVP implementation in Linux needs to forward the key to a user-mde
 628  * component to retrieve the corresponding value. Consequently, we cannot
 629  * respond to the host in the context of this callback. Since the host
 630  * guarantees that at most only one transaction can be active at a time,
 631  * we stash away the transaction state in a set of global variables.
 632  */
 633
 634 void hv_kvp_onchannelcallback(void *context)
 635 {
 636         struct vmbus_channel *channel = context;
 637         u32 recvlen;
 638         u64 requestid;
 639
 640         struct hv_kvp_msg *kvp_msg;
 641
 642         struct icmsg_hdr *icmsghdrp;
 643         int kvp_srv_version;
 644         static enum {NEGO_NOT_STARTED,
 645                      NEGO_IN_PROGRESS,
 646                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
 647
 648         if (kvp_transaction.state < HVUTIL_READY) {
 649                 /*
 650                  * If userspace daemon is not connected and host is asking
 651                  * us to negotiate we need to delay to not lose messages.
 652                  * This is important for Failover IP setting.
 653                  */
 654                 if (host_negotiatied == NEGO_NOT_STARTED) {
 655                         host_negotiatied = NEGO_IN_PROGRESS;
 656                         schedule_delayed_work(&kvp_host_handshake_work,
 657                                       HV_UTIL_NEGO_TIMEOUT * HZ);
 658                 }
 659                 return;
 660         }
 661         if (kvp_transaction.state > HVUTIL_READY)
 662                 return;
 663
 664         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 665                          &requestid);
 666
 667         if (recvlen > 0) {
 668                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 669                         sizeof(struct vmbuspipe_hdr)];
 670
 671                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 672                         if (vmbus_prep_negotiate_resp(icmsghdrp,
 673                                  recv_buffer, fw_versions, FW_VER_COUNT,
 674                                  kvp_versions, KVP_VER_COUNT,
 675                                  NULL, &kvp_srv_version)) {
 676                                 pr_info("KVP IC version %d.%d\n",
 677                                         kvp_srv_version >> 16,
 678                                         kvp_srv_version & 0xFFFF);
 679                         }
 680                 } else {
 681                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 682                                 sizeof(struct vmbuspipe_hdr) +
 683                                 sizeof(struct icmsg_hdr)];
 684
 685                         /*
 686                          * Stash away this global state for completing the
 687                          * transaction; note transactions are serialized.
 688                          */
 689
 690                         kvp_transaction.recv_len = recvlen;
 691                         kvp_transaction.recv_req_id = requestid;
 692                         kvp_transaction.kvp_msg = kvp_msg;
 693
 694                         if (kvp_transaction.state < HVUTIL_READY) {
 695                                 /* Userspace is not registered yet */
 696                                 kvp_respond_to_host(NULL, HV_E_FAIL);
 697                                 return;
 698                         }
 699                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 700
 701                         /*
 702                          * Get the information from the
 703                          * user-mode component.
 704                          * component. This transaction will be
 705                          * completed when we get the value from
 706                          * the user-mode component.
 707                          * Set a timeout to deal with
 708                          * user-mode not responding.
 709                          */
 710                         schedule_work(&kvp_sendkey_work);
 711                         schedule_delayed_work(&kvp_timeout_work,
 712                                               HV_UTIL_TIMEOUT * HZ);
 713
 714                         return;
 715
 716                 }
 717
 718                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 719                         | ICMSGHDRFLAG_RESPONSE;
 720
 721                 vmbus_sendpacket(channel, recv_buffer,
 722                                        recvlen, requestid,
 723                                        VM_PKT_DATA_INBAND, 0);
 724
 725                 host_negotiatied = NEGO_FINISHED;
 726                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 727         }
 728
 729 }
 730
 731 static void kvp_on_reset(void)
 732 {
 733         if (cancel_delayed_work_sync(&kvp_timeout_work))
 734                 kvp_respond_to_host(NULL, HV_E_FAIL);
 735         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 736 }
 737
 738 int
 739 hv_kvp_init(struct hv_util_service *srv)
 740 {
 741         recv_buffer = srv->recv_buffer;
 742         kvp_transaction.recv_channel = srv->channel;
 743
 744         /*
 745          * When this driver loads, the user level daemon that
 746          * processes the host requests may not yet be running.
 747          * Defer processing channel callbacks until the daemon
 748          * has registered.
 749          */
 750         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 751
 752         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 753                                     kvp_on_msg, kvp_on_reset);
 754         if (!hvt)
 755                 return -EFAULT;
 756
 757         return 0;
 758 }
 759
 760 void hv_kvp_deinit(void)
 761 {
 762         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 763         cancel_delayed_work_sync(&kvp_host_handshake_work);
 764         cancel_delayed_work_sync(&kvp_timeout_work);
 765         cancel_work_sync(&kvp_sendkey_work);
 766         hvutil_transport_destroy(hvt);
 767 }