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 #include <asm/hyperv-tlfs.h>
  31
  32 #include "hyperv_vmbus.h"
  33 #include "hv_utils_transport.h"
  34
  35 /*
  36  * Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
  37  */
  38 #define WS2008_SRV_MAJOR        1
  39 #define WS2008_SRV_MINOR        0
  40 #define WS2008_SRV_VERSION     (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)
  41
  42 #define WIN7_SRV_MAJOR   3
  43 #define WIN7_SRV_MINOR   0
  44 #define WIN7_SRV_VERSION     (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)
  45
  46 #define WIN8_SRV_MAJOR   4
  47 #define WIN8_SRV_MINOR   0
  48 #define WIN8_SRV_VERSION     (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
  49
  50 #define KVP_VER_COUNT 3
  51 static const int kvp_versions[] = {
  52         WIN8_SRV_VERSION,
  53         WIN7_SRV_VERSION,
  54         WS2008_SRV_VERSION
  55 };
  56
  57 #define FW_VER_COUNT 2
  58 static const int fw_versions[] = {
  59         UTIL_FW_VERSION,
  60         UTIL_WS2K8_FW_VERSION
  61 };
  62
  63 /*
  64  * Global state maintained for transaction that is being processed. For a class
  65  * of integration services, including the "KVP service", the specified protocol
  66  * is a "request/response" protocol which means that there can only be single
  67  * outstanding transaction from the host at any given point in time. We use
  68  * this to simplify memory management in this driver - we cache and process
  69  * only one message at a time.
  70  *
  71  * While the request/response protocol is guaranteed by the host, we further
  72  * ensure this by serializing packet processing in this driver - we do not
  73  * read additional packets from the VMBUS until the current packet is fully
  74  * handled.
  75  */
  76
  77 static struct {
  78         int state;   /* hvutil_device_state */
  79         int recv_len; /* number of bytes received. */
  80         struct hv_kvp_msg  *kvp_msg; /* current message */
  81         struct vmbus_channel *recv_channel; /* chn we got the request */
  82         u64 recv_req_id; /* request ID. */
  83 } kvp_transaction;
  84
  85 /*
  86  * This state maintains the version number registered by the daemon.
  87  */
  88 static int dm_reg_value;
  89
  90 static void kvp_send_key(struct work_struct *dummy);
  91
  92
  93 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
  94 static void kvp_timeout_func(struct work_struct *dummy);
  95 static void kvp_host_handshake_func(struct work_struct *dummy);
  96 static void kvp_register(int);
  97
  98 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
  99 static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
 100 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
 101
 102 static const char kvp_devname[] = "vmbus/hv_kvp";
 103 static u8 *recv_buffer;
 104 static struct hvutil_transport *hvt;
 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         tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
 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         tasklet_schedule(&kvp_transaction.recv_channel->callback_event);
 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_ADAPTER_ID_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                 fallthrough;
 358
 359         case KVP_OP_GET_IP_INFO:
 360                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 361                                 MAX_ADAPTER_ID_SIZE,
 362                                 UTF16_LITTLE_ENDIAN,
 363                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 364                                 MAX_ADAPTER_ID_SIZE);
 365
 366                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 367         }
 368 }
 369
 370
 371
 372
 373 static void
 374 kvp_send_key(struct work_struct *dummy)
 375 {
 376         struct hv_kvp_msg *message;
 377         struct hv_kvp_msg *in_msg;
 378         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 379         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 380         __u32 val32;
 381         __u64 val64;
 382         int rc;
 383
 384         /* The transaction state is wrong. */
 385         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 386                 return;
 387
 388         message = kzalloc(sizeof(*message), GFP_KERNEL);
 389         if (!message)
 390                 return;
 391
 392         message->kvp_hdr.operation = operation;
 393         message->kvp_hdr.pool = pool;
 394         in_msg = kvp_transaction.kvp_msg;
 395
 396         /*
 397          * The key/value strings sent from the host are encoded
 398          * in utf16; convert it to utf8 strings.
 399          * The host assures us that the utf16 strings will not exceed
 400          * the max lengths specified. We will however, reserve room
 401          * for the string terminating character - in the utf16s_utf8s()
 402          * function we limit the size of the buffer where the converted
 403          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
 404          * that the strings can be properly terminated!
 405          */
 406
 407         switch (message->kvp_hdr.operation) {
 408         case KVP_OP_SET_IP_INFO:
 409                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 410                 break;
 411         case KVP_OP_GET_IP_INFO:
 412                 /*
 413                  * We only need to pass on the info of operation, adapter_id
 414                  * and addr_family to the userland kvp daemon.
 415                  */
 416                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 417                 break;
 418         case KVP_OP_SET:
 419                 switch (in_msg->body.kvp_set.data.value_type) {
 420                 case REG_SZ:
 421                         /*
 422                          * The value is a string - utf16 encoding.
 423                          */
 424                         message->body.kvp_set.data.value_size =
 425                                 utf16s_to_utf8s(
 426                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 427                                 in_msg->body.kvp_set.data.value_size,
 428                                 UTF16_LITTLE_ENDIAN,
 429                                 message->body.kvp_set.data.value,
 430                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 431                         break;
 432
 433                 case REG_U32:
 434                         /*
 435                          * The value is a 32 bit scalar.
 436                          * We save this as a utf8 string.
 437                          */
 438                         val32 = in_msg->body.kvp_set.data.value_u32;
 439                         message->body.kvp_set.data.value_size =
 440                                 sprintf(message->body.kvp_set.data.value,
 441                                         "%u", val32) + 1;
 442                         break;
 443
 444                 case REG_U64:
 445                         /*
 446                          * The value is a 64 bit scalar.
 447                          * We save this as a utf8 string.
 448                          */
 449                         val64 = in_msg->body.kvp_set.data.value_u64;
 450                         message->body.kvp_set.data.value_size =
 451                                 sprintf(message->body.kvp_set.data.value,
 452                                         "%llu", val64) + 1;
 453                         break;
 454
 455                 }
 456
 457                 /*
 458                  * The key is always a string - utf16 encoding.
 459                  */
 460                 message->body.kvp_set.data.key_size =
 461                         utf16s_to_utf8s(
 462                         (wchar_t *)in_msg->body.kvp_set.data.key,
 463                         in_msg->body.kvp_set.data.key_size,
 464                         UTF16_LITTLE_ENDIAN,
 465                         message->body.kvp_set.data.key,
 466                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 467
 468                 break;
 469
 470         case KVP_OP_GET:
 471                 message->body.kvp_get.data.key_size =
 472                         utf16s_to_utf8s(
 473                         (wchar_t *)in_msg->body.kvp_get.data.key,
 474                         in_msg->body.kvp_get.data.key_size,
 475                         UTF16_LITTLE_ENDIAN,
 476                         message->body.kvp_get.data.key,
 477                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 478                 break;
 479
 480         case KVP_OP_DELETE:
 481                 message->body.kvp_delete.key_size =
 482                         utf16s_to_utf8s(
 483                         (wchar_t *)in_msg->body.kvp_delete.key,
 484                         in_msg->body.kvp_delete.key_size,
 485                         UTF16_LITTLE_ENDIAN,
 486                         message->body.kvp_delete.key,
 487                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 488                 break;
 489
 490         case KVP_OP_ENUMERATE:
 491                 message->body.kvp_enum_data.index =
 492                         in_msg->body.kvp_enum_data.index;
 493                 break;
 494         }
 495
 496         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 497         rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
 498         if (rc) {
 499                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 500                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 501                         kvp_respond_to_host(message, HV_E_FAIL);
 502                         kvp_transaction.state = HVUTIL_READY;
 503                 }
 504         }
 505
 506         kfree(message);
 507 }
 508
 509 /*
 510  * Send a response back to the host.
 511  */
 512
 513 static void
 514 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 515 {
 516         struct hv_kvp_msg  *kvp_msg;
 517         struct hv_kvp_exchg_msg_value  *kvp_data;
 518         char    *key_name;
 519         char    *value;
 520         struct icmsg_hdr *icmsghdrp;
 521         int     keylen = 0;
 522         int     valuelen = 0;
 523         u32     buf_len;
 524         struct vmbus_channel *channel;
 525         u64     req_id;
 526         int ret;
 527
 528         /*
 529          * Copy the global state for completing the transaction. Note that
 530          * only one transaction can be active at a time.
 531          */
 532
 533         buf_len = kvp_transaction.recv_len;
 534         channel = kvp_transaction.recv_channel;
 535         req_id = kvp_transaction.recv_req_id;
 536
 537         icmsghdrp = (struct icmsg_hdr *)
 538                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 539
 540         if (channel->onchannel_callback == NULL)
 541                 /*
 542                  * We have raced with util driver being unloaded;
 543                  * silently return.
 544                  */
 545                 return;
 546
 547         icmsghdrp->status = error;
 548
 549         /*
 550          * If the error parameter is set, terminate the host's enumeration
 551          * on this pool.
 552          */
 553         if (error) {
 554                 /*
 555                  * Something failed or we have timed out;
 556                  * terminate the current host-side iteration.
 557                  */
 558                 goto response_done;
 559         }
 560
 561         kvp_msg = (struct hv_kvp_msg *)
 562                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 563                         sizeof(struct icmsg_hdr)];
 564
 565         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 566         case KVP_OP_GET_IP_INFO:
 567                 ret = process_ob_ipinfo(msg_to_host,
 568                                  (struct hv_kvp_ip_msg *)kvp_msg,
 569                                  KVP_OP_GET_IP_INFO);
 570                 if (ret < 0)
 571                         icmsghdrp->status = HV_E_FAIL;
 572
 573                 goto response_done;
 574         case KVP_OP_SET_IP_INFO:
 575                 goto response_done;
 576         case KVP_OP_GET:
 577                 kvp_data = &kvp_msg->body.kvp_get.data;
 578                 goto copy_value;
 579
 580         case KVP_OP_SET:
 581         case KVP_OP_DELETE:
 582                 goto response_done;
 583
 584         default:
 585                 break;
 586         }
 587
 588         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 589         key_name = msg_to_host->body.kvp_enum_data.data.key;
 590
 591         /*
 592          * The windows host expects the key/value pair to be encoded
 593          * in utf16. Ensure that the key/value size reported to the host
 594          * will be less than or equal to the MAX size (including the
 595          * terminating character).
 596          */
 597         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 598                                 (wchar_t *) kvp_data->key,
 599                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 600         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 601
 602 copy_value:
 603         value = msg_to_host->body.kvp_enum_data.data.value;
 604         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 605                                 (wchar_t *) kvp_data->value,
 606                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 607         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 608
 609         /*
 610          * If the utf8s to utf16s conversion failed; notify host
 611          * of the error.
 612          */
 613         if ((keylen < 0) || (valuelen < 0))
 614                 icmsghdrp->status = HV_E_FAIL;
 615
 616         kvp_data->value_type = REG_SZ; /* all our values are strings */
 617
 618 response_done:
 619         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 620
 621         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 622                                 VM_PKT_DATA_INBAND, 0);
 623 }
 624
 625 /*
 626  * This callback is invoked when we get a KVP message from the host.
 627  * The host ensures that only one KVP transaction can be active at a time.
 628  * KVP implementation in Linux needs to forward the key to a user-mde
 629  * component to retrieve the corresponding value. Consequently, we cannot
 630  * respond to the host in the context of this callback. Since the host
 631  * guarantees that at most only one transaction can be active at a time,
 632  * we stash away the transaction state in a set of global variables.
 633  */
 634
 635 void hv_kvp_onchannelcallback(void *context)
 636 {
 637         struct vmbus_channel *channel = context;
 638         u32 recvlen;
 639         u64 requestid;
 640
 641         struct hv_kvp_msg *kvp_msg;
 642
 643         struct icmsg_hdr *icmsghdrp;
 644         int kvp_srv_version;
 645         static enum {NEGO_NOT_STARTED,
 646                      NEGO_IN_PROGRESS,
 647                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
 648
 649         if (kvp_transaction.state < HVUTIL_READY) {
 650                 /*
 651                  * If userspace daemon is not connected and host is asking
 652                  * us to negotiate we need to delay to not lose messages.
 653                  * This is important for Failover IP setting.
 654                  */
 655                 if (host_negotiatied == NEGO_NOT_STARTED) {
 656                         host_negotiatied = NEGO_IN_PROGRESS;
 657                         schedule_delayed_work(&kvp_host_handshake_work,
 658                                       HV_UTIL_NEGO_TIMEOUT * HZ);
 659                 }
 660                 return;
 661         }
 662         if (kvp_transaction.state > HVUTIL_READY)
 663                 return;
 664
 665         if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen, &requestid)) {
 666                 pr_err_ratelimited("KVP request received. Could not read into recv buf\n");
 667                 return;
 668         }
 669
 670         if (!recvlen)
 671                 return;
 672
 673         /* Ensure recvlen is big enough to read header data */
 674         if (recvlen < ICMSG_HDR) {
 675                 pr_err_ratelimited("KVP request received. Packet length too small: %d\n",
 676                                    recvlen);
 677                 return;
 678         }
 679
 680         icmsghdrp = (struct icmsg_hdr *)&recv_buffer[sizeof(struct vmbuspipe_hdr)];
 681
 682         if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 683                 if (vmbus_prep_negotiate_resp(icmsghdrp,
 684                                 recv_buffer, recvlen,
 685                                 fw_versions, FW_VER_COUNT,
 686                                 kvp_versions, KVP_VER_COUNT,
 687                                 NULL, &kvp_srv_version)) {
 688                         pr_info("KVP IC version %d.%d\n",
 689                                 kvp_srv_version >> 16,
 690                                 kvp_srv_version & 0xFFFF);
 691                 }
 692         } else if (icmsghdrp->icmsgtype == ICMSGTYPE_KVPEXCHANGE) {
 693                 /*
 694                  * recvlen is not checked against sizeof(struct kvp_msg) because kvp_msg contains
 695                  * a union of structs and the msg type received is not known. Code using this
 696                  * struct should provide validation when accessing its fields.
 697                  */
 698                 kvp_msg = (struct hv_kvp_msg *)&recv_buffer[ICMSG_HDR];
 699
 700                 /*
 701                  * Stash away this global state for completing the
 702                  * transaction; note transactions are serialized.
 703                  */
 704
 705                 kvp_transaction.recv_len = recvlen;
 706                 kvp_transaction.recv_req_id = requestid;
 707                 kvp_transaction.kvp_msg = kvp_msg;
 708
 709                 if (kvp_transaction.state < HVUTIL_READY) {
 710                         /* Userspace is not registered yet */
 711                         kvp_respond_to_host(NULL, HV_E_FAIL);
 712                         return;
 713                 }
 714                 kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 715
 716                 /*
 717                  * Get the information from the
 718                  * user-mode component.
 719                  * component. This transaction will be
 720                  * completed when we get the value from
 721                  * the user-mode component.
 722                  * Set a timeout to deal with
 723                  * user-mode not responding.
 724                  */
 725                 schedule_work(&kvp_sendkey_work);
 726                 schedule_delayed_work(&kvp_timeout_work,
 727                                         HV_UTIL_TIMEOUT * HZ);
 728
 729                 return;
 730
 731         } else {
 732                 pr_err_ratelimited("KVP request received. Invalid msg type: %d\n",
 733                                    icmsghdrp->icmsgtype);
 734                 return;
 735         }
 736
 737         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 738                 | ICMSGHDRFLAG_RESPONSE;
 739
 740         vmbus_sendpacket(channel, recv_buffer,
 741                          recvlen, requestid,
 742                          VM_PKT_DATA_INBAND, 0);
 743
 744         host_negotiatied = NEGO_FINISHED;
 745         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 746 }
 747
 748 static void kvp_on_reset(void)
 749 {
 750         if (cancel_delayed_work_sync(&kvp_timeout_work))
 751                 kvp_respond_to_host(NULL, HV_E_FAIL);
 752         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 753 }
 754
 755 int
 756 hv_kvp_init(struct hv_util_service *srv)
 757 {
 758         recv_buffer = srv->recv_buffer;
 759         kvp_transaction.recv_channel = srv->channel;
 760         kvp_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 4;
 761
 762         /*
 763          * When this driver loads, the user level daemon that
 764          * processes the host requests may not yet be running.
 765          * Defer processing channel callbacks until the daemon
 766          * has registered.
 767          */
 768         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 769
 770         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 771                                     kvp_on_msg, kvp_on_reset);
 772         if (!hvt)
 773                 return -EFAULT;
 774
 775         return 0;
 776 }
 777
 778 static void hv_kvp_cancel_work(void)
 779 {
 780         cancel_delayed_work_sync(&kvp_host_handshake_work);
 781         cancel_delayed_work_sync(&kvp_timeout_work);
 782         cancel_work_sync(&kvp_sendkey_work);
 783 }
 784
 785 int hv_kvp_pre_suspend(void)
 786 {
 787         struct vmbus_channel *channel = kvp_transaction.recv_channel;
 788
 789         tasklet_disable(&channel->callback_event);
 790
 791         /*
 792          * If there is a pending transtion, it's unnecessary to tell the host
 793          * that the transaction will fail, because that is implied when
 794          * util_suspend() calls vmbus_close() later.
 795          */
 796         hv_kvp_cancel_work();
 797
 798         /*
 799          * Forece the state to READY to handle the ICMSGTYPE_NEGOTIATE message
 800          * later. The user space daemon may go out of order and its write()
 801          * may fail with EINVAL: this doesn't matter since the daemon will
 802          * reset the device by closing and re-opening it.
 803          */
 804         kvp_transaction.state = HVUTIL_READY;
 805         return 0;
 806 }
 807
 808 int hv_kvp_pre_resume(void)
 809 {
 810         struct vmbus_channel *channel = kvp_transaction.recv_channel;
 811
 812         tasklet_enable(&channel->callback_event);
 813
 814         return 0;
 815 }
 816
 817 void hv_kvp_deinit(void)
 818 {
 819         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 820
 821         hv_kvp_cancel_work();
 822
 823         hvutil_transport_destroy(hvt);
 824 }