libjaylink/transport_tcp.c

   1 /*
   2  * This file is part of the libjaylink project.
   3  *
   4  * Copyright (C) 2015-2017 Marc Schink <jaylink-dev@marcschink.de>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <stdint.h>
  22 #include <string.h>
  23 #include <sys/types.h>
  24
  25 #ifdef _WIN32
  26 #include <winsock2.h>
  27 #include <ws2tcpip.h>
  28 #else
  29 #include <sys/time.h>
  30 #include <sys/types.h>
  31 #include <sys/socket.h>
  32 #include <netdb.h>
  33 #include <netinet/in.h>
  34 #endif
  35
  36 #include "libjaylink.h"
  37 #include "libjaylink-internal.h"
  38
  39 /**
  40  * @file
  41  *
  42  * Transport abstraction layer (TCP/IP).
  43  */
  44
  45 /** @cond PRIVATE */
  46 #define CMD_SERVER              0x00
  47 #define CMD_CLIENT              0x07
  48
  49 /**
  50  * Response status code indicating that the maximum number of simultaneous
  51  * connections on the device has been reached.
  52  */
  53 #define RESP_MAX_CONNECTIONS    0xfe
  54
  55 /** Buffer size in bytes. */
  56 #define BUFFER_SIZE     2048
  57
  58 /** Timeout of a receive operation in milliseconds. */
  59 #define RECV_TIMEOUT    5000
  60 /** Timeout of a send operation in milliseconds. */
  61 #define SEND_TIMEOUT    5000
  62
  63 /** String of the port number for the J-Link TCP/IP protocol. */
  64 #define PORT_STRING     "19020"
  65
  66 /** Size of the server's hello message in bytes. */
  67 #define SERVER_HELLO_SIZE       4
  68 /**
  69  * Maximum length of the server name including trailing null-terminator in
  70  * bytes.
  71  */
  72 #define SERVER_NAME_MAX_LENGTH  256
  73 /** @endcond */
  74
  75 static int initialize_handle(struct jaylink_device_handle *devh)
  76 {
  77         struct jaylink_context *ctx;
  78
  79         ctx = devh->dev->ctx;
  80
  81         devh->buffer_size = BUFFER_SIZE;
  82         devh->buffer = malloc(devh->buffer_size);
  83
  84         if (!devh->buffer) {
  85                 log_err(ctx, "Transport buffer malloc failed.");
  86                 return JAYLINK_ERR_MALLOC;
  87         }
  88
  89         devh->read_length = 0;
  90         devh->bytes_available = 0;
  91         devh->read_pos = 0;
  92
  93         devh->write_length = 0;
  94         devh->write_pos = 0;
  95
  96         return JAYLINK_OK;
  97 }
  98
  99 static void cleanup_handle(struct jaylink_device_handle *devh)
 100 {
 101         free(devh->buffer);
 102 }
 103
 104 static int _recv(struct jaylink_device_handle *devh, uint8_t *buffer,
 105                 size_t length)
 106 {
 107         struct jaylink_context *ctx;
 108         size_t tmp;
 109
 110         ctx = devh->dev->ctx;
 111
 112         while (length > 0) {
 113                 tmp = length;
 114
 115                 if (!socket_recv(devh->sock, buffer, &tmp, 0)) {
 116                         log_err(ctx, "Failed to receive data from device.");
 117                         return JAYLINK_ERR_IO;
 118                 } else if (!tmp) {
 119                         log_err(ctx, "Failed to receive data from device: "
 120                                 "remote connection closed.");
 121                         return JAYLINK_ERR_IO;
 122                 }
 123
 124                 buffer += tmp;
 125                 length -= tmp;
 126
 127                 log_dbg(ctx, "Received %zu bytes from device.", tmp);
 128         }
 129
 130         return JAYLINK_OK;
 131 }
 132
 133 static int handle_server_hello(struct jaylink_device_handle *devh)
 134 {
 135         int ret;
 136         struct jaylink_context *ctx;
 137         uint8_t buf[SERVER_HELLO_SIZE];
 138         char name[SERVER_NAME_MAX_LENGTH];
 139         uint16_t proto_version;
 140         size_t length;
 141
 142         ctx = devh->dev->ctx;
 143
 144         ret = _recv(devh, buf, sizeof(buf));
 145
 146         if (ret != JAYLINK_OK) {
 147                 log_err(ctx, "Failed to receive hello message.");
 148                 return ret;
 149         }
 150
 151         if (buf[0] == RESP_MAX_CONNECTIONS) {
 152                 log_err(ctx, "Maximum number of connections reached.");
 153                 return JAYLINK_ERR;
 154         }
 155
 156         if (buf[0] != CMD_SERVER) {
 157                 log_err(ctx, "Invalid hello message received.");
 158                 return JAYLINK_ERR_PROTO;
 159         }
 160
 161         proto_version = buffer_get_u16(buf, 1);
 162
 163         log_dbg(ctx, "Protocol version: 0x%04x.", proto_version);
 164
 165         length = buf[3];
 166         ret = _recv(devh, (uint8_t *)name, length);
 167
 168         if (ret != JAYLINK_OK) {
 169                 log_err(ctx, "Failed to receive server name.");
 170                 return ret;
 171         }
 172
 173         name[length] = '\0';
 174
 175         log_dbg(ctx, "Server name: %s.", name);
 176
 177         return JAYLINK_OK;
 178 }
 179
 180 JAYLINK_PRIV int transport_tcp_open(struct jaylink_device_handle *devh)
 181 {
 182         int ret;
 183         struct jaylink_context *ctx;
 184         struct jaylink_device *dev;
 185         struct addrinfo hints;
 186         struct addrinfo *info;
 187         struct addrinfo *rp;
 188         struct timeval timeout;
 189         int sock;
 190
 191         dev = devh->dev;
 192         ctx = dev->ctx;
 193
 194         log_dbg(ctx, "Trying to open device (IPv4 address = %s).",
 195                 dev->ipv4_address);
 196
 197         ret = initialize_handle(devh);
 198
 199         if (ret != JAYLINK_OK) {
 200                 log_err(ctx, "Initialize device handle failed.");
 201                 return ret;
 202         }
 203
 204         memset(&hints, 0, sizeof(struct addrinfo));
 205         hints.ai_family = AF_INET;
 206         hints.ai_socktype = SOCK_STREAM;
 207         hints.ai_protocol = IPPROTO_TCP;
 208
 209         ret = getaddrinfo(dev->ipv4_address, PORT_STRING, &hints, &info);
 210
 211         if (ret != 0) {
 212                 log_err(ctx, "Address lookup failed.");
 213                 cleanup_handle(devh);
 214                 return JAYLINK_ERR;
 215         }
 216
 217         sock = -1;
 218
 219         for (rp = info; rp != NULL; rp = rp->ai_next) {
 220                 sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 221
 222                 if (sock < 0)
 223                         continue;
 224
 225                 if (!connect(sock, info->ai_addr, info->ai_addrlen))
 226                         break;
 227
 228                 socket_close(sock);
 229                 sock = -1;
 230         }
 231
 232         freeaddrinfo(info);
 233
 234         if (sock < 0) {
 235                 log_err(ctx, "Failed to open device.");
 236                 cleanup_handle(devh);
 237                 return JAYLINK_ERR;
 238         }
 239
 240         log_dbg(ctx, "Device opened successfully.");
 241
 242         timeout.tv_sec = RECV_TIMEOUT / 1000;
 243         timeout.tv_usec = (RECV_TIMEOUT % 1000) * 1000;
 244
 245         if (!socket_set_option(sock, SOL_SOCKET, SO_RCVTIMEO, &timeout,
 246                         sizeof(struct timeval))) {
 247                 log_err(ctx, "Failed to set socket receive timeout.");
 248                 socket_close(sock);
 249                 cleanup_handle(devh);
 250                 return JAYLINK_ERR;
 251         }
 252
 253         timeout.tv_sec = SEND_TIMEOUT / 1000;
 254         timeout.tv_usec = (SEND_TIMEOUT % 1000) * 1000;
 255
 256         if (!socket_set_option(sock, SOL_SOCKET, SO_SNDTIMEO, &timeout,
 257                         sizeof(struct timeval))) {
 258                 log_err(ctx, "Failed to set socket send timeout.");
 259                 socket_close(sock);
 260                 cleanup_handle(devh);
 261                 return JAYLINK_ERR;
 262         }
 263
 264         devh->sock = sock;
 265
 266         ret = handle_server_hello(devh);
 267
 268         if (ret != JAYLINK_OK) {
 269                 socket_close(sock);
 270                 cleanup_handle(devh);
 271                 return ret;
 272         }
 273
 274         return JAYLINK_OK;
 275 }
 276
 277 JAYLINK_PRIV int transport_tcp_close(struct jaylink_device_handle *devh)
 278 {
 279         struct jaylink_context *ctx;
 280
 281         ctx = devh->dev->ctx;
 282
 283         log_dbg(ctx, "Closing device (IPv4 address = %s).",
 284                 devh->dev->ipv4_address);
 285
 286         cleanup_handle(devh);
 287
 288         log_dbg(ctx, "Device closed successfully.");
 289
 290         return JAYLINK_OK;
 291 }
 292
 293 JAYLINK_PRIV int transport_tcp_start_write(struct jaylink_device_handle *devh,
 294                 size_t length, bool has_command)
 295 {
 296         struct jaylink_context *ctx;
 297
 298         if (!length)
 299                 return JAYLINK_ERR_ARG;
 300
 301         ctx = devh->dev->ctx;
 302
 303         log_dbg(ctx, "Starting write operation (length = %zu bytes).", length);
 304
 305         if (devh->write_pos > 0)
 306                 log_warn(ctx, "Last write operation left %zu bytes in the "
 307                         "buffer.", devh->write_pos);
 308
 309         if (devh->write_length > 0)
 310                 log_warn(ctx, "Last write operation was not performed.");
 311
 312         devh->write_length = length;
 313         devh->write_pos = 0;
 314
 315         if (has_command) {
 316                 devh->buffer[0] = CMD_CLIENT;
 317                 devh->write_pos++;
 318         }
 319
 320         return JAYLINK_OK;
 321 }
 322
 323 JAYLINK_PRIV int transport_tcp_start_read(struct jaylink_device_handle *devh,
 324                 size_t length)
 325 {
 326         struct jaylink_context *ctx;
 327
 328         if (!length)
 329                 return JAYLINK_ERR_ARG;
 330
 331         ctx = devh->dev->ctx;
 332
 333         log_dbg(ctx, "Starting read operation (length = %zu bytes).", length);
 334
 335         if (devh->bytes_available > 0)
 336                 log_dbg(ctx, "Last read operation left %zu bytes in the "
 337                         "buffer.", devh->bytes_available);
 338
 339         if (devh->read_length > 0)
 340                 log_warn(ctx, "Last read operation left %zu bytes.",
 341                         devh->read_length);
 342
 343         devh->read_length = length;
 344
 345         return JAYLINK_OK;
 346 }
 347
 348 JAYLINK_PRIV int transport_tcp_start_write_read(
 349                 struct jaylink_device_handle *devh, size_t write_length,
 350                 size_t read_length, bool has_command)
 351 {
 352         struct jaylink_context *ctx;
 353
 354         if (!read_length || !write_length)
 355                 return JAYLINK_ERR_ARG;
 356
 357         ctx = devh->dev->ctx;
 358
 359         log_dbg(ctx, "Starting write / read operation (length = "
 360                 "%zu / %zu bytes).", write_length, read_length);
 361
 362         if (devh->write_pos > 0)
 363                 log_warn(ctx, "Last write operation left %zu bytes in the "
 364                         "buffer.", devh->write_pos);
 365
 366         if (devh->write_length > 0)
 367                 log_warn(ctx, "Last write operation was not performed.");
 368
 369         if (devh->bytes_available > 0)
 370                 log_warn(ctx, "Last read operation left %zu bytes in the "
 371                         "buffer.", devh->bytes_available);
 372
 373         if (devh->read_length > 0)
 374                 log_warn(ctx, "Last read operation left %zu bytes.",
 375                         devh->read_length);
 376
 377         devh->write_length = write_length;
 378         devh->write_pos = 0;
 379
 380         if (has_command) {
 381                 devh->buffer[0] = CMD_CLIENT;
 382                 devh->write_pos++;
 383         }
 384
 385         devh->read_length = read_length;
 386         devh->bytes_available = 0;
 387         devh->read_pos = 0;
 388
 389         return JAYLINK_OK;
 390 }
 391
 392 static int _send(struct jaylink_device_handle *devh, const uint8_t *buffer,
 393                 size_t length)
 394 {
 395         struct jaylink_context *ctx;
 396         size_t tmp;
 397
 398         ctx = devh->dev->ctx;
 399
 400         while (length > 0) {
 401                 tmp = length;
 402
 403                 if (!socket_send(devh->sock, buffer, &tmp, 0)) {
 404                         log_err(ctx, "Failed to send data to device.");
 405                         return JAYLINK_ERR_IO;
 406                 }
 407
 408                 buffer += tmp;
 409                 length -= tmp;
 410
 411                 log_dbg(ctx, "Sent %zu bytes to device.", tmp);
 412         }
 413
 414         return JAYLINK_OK;
 415 }
 416
 417 static bool adjust_buffer(struct jaylink_device_handle *devh, size_t size)
 418 {
 419         struct jaylink_context *ctx;
 420         uint8_t *buffer;
 421         size_t num;
 422
 423         ctx = devh->dev->ctx;
 424
 425         /* Adjust buffer size to a multiple of BUFFER_SIZE bytes. */
 426         num = size / BUFFER_SIZE;
 427
 428         if (size % BUFFER_SIZE > 0)
 429                 num++;
 430
 431         size = num * BUFFER_SIZE;
 432         buffer = realloc(devh->buffer, size);
 433
 434         if (!buffer) {
 435                 log_err(ctx, "Failed to adjust buffer size to %zu bytes.",
 436                         size);
 437                 return false;
 438         }
 439
 440         devh->buffer = buffer;
 441         devh->buffer_size = size;
 442
 443         log_dbg(ctx, "Adjusted buffer size to %zu bytes.", size);
 444
 445         return true;
 446 }
 447
 448 JAYLINK_PRIV int transport_tcp_write(struct jaylink_device_handle *devh,
 449                 const uint8_t *buffer, size_t length)
 450 {
 451         int ret;
 452         struct jaylink_context *ctx;
 453         size_t tmp;
 454
 455         ctx = devh->dev->ctx;
 456
 457         if (length > devh->write_length) {
 458                 log_err(ctx, "Requested to write %zu bytes but only %zu bytes "
 459                         "are expected for the write operation.", length,
 460                         devh->write_length);
 461                 return JAYLINK_ERR_ARG;
 462         }
 463
 464         /*
 465          * Store data in the buffer if the expected number of bytes for the
 466          * write operation is not reached.
 467          */
 468         if (length < devh->write_length) {
 469                 if (devh->write_pos + length > devh->buffer_size) {
 470                         if (!adjust_buffer(devh, devh->write_pos + length))
 471                                 return JAYLINK_ERR_MALLOC;
 472                 }
 473
 474                 memcpy(devh->buffer + devh->write_pos, buffer, length);
 475
 476                 devh->write_length -= length;
 477                 devh->write_pos += length;
 478
 479                 log_dbg(ctx, "Wrote %zu bytes into buffer.", length);
 480                 return JAYLINK_OK;
 481         }
 482
 483         /*
 484          * Expected number of bytes for this write operation is reached and
 485          * therefore the write operation will be performed.
 486          */
 487         devh->write_length = 0;
 488
 489         /* Send data directly to the device if the buffer is empty. */
 490         if (!devh->write_pos)
 491                 return _send(devh, buffer, length);
 492
 493         tmp = MIN(length, devh->buffer_size - devh->write_pos);
 494
 495         /*
 496          * Fill up the internal buffer in order to reduce the number of
 497          * messages sent to the device for performance reasons.
 498          */
 499         memcpy(devh->buffer + devh->write_pos, buffer, tmp);
 500
 501         length -= tmp;
 502         buffer += tmp;
 503
 504         log_dbg(ctx, "Buffer filled up with %zu bytes.", tmp);
 505
 506         ret = _send(devh, devh->buffer, devh->write_pos + tmp);
 507
 508         devh->write_pos = 0;
 509
 510         if (ret != JAYLINK_OK)
 511                 return ret;
 512
 513         if (!length)
 514                 return JAYLINK_OK;
 515
 516         return _send(devh, buffer, length);
 517 }
 518
 519 JAYLINK_PRIV int transport_tcp_read(struct jaylink_device_handle *devh,
 520                 uint8_t *buffer, size_t length)
 521 {
 522         int ret;
 523         struct jaylink_context *ctx;
 524
 525         ctx = devh->dev->ctx;
 526
 527         if (length > devh->read_length) {
 528                 log_err(ctx, "Requested to read %zu bytes but only %zu bytes "
 529                         "are expected for the read operation.", length,
 530                         devh->read_length);
 531                 return JAYLINK_ERR_ARG;
 532         }
 533
 534         if (length <= devh->bytes_available) {
 535                 memcpy(buffer, devh->buffer + devh->read_pos, length);
 536
 537                 devh->read_length -= length;
 538                 devh->bytes_available -= length;
 539                 devh->read_pos += length;
 540
 541                 log_dbg(ctx, "Read %zu bytes from buffer.", length);
 542                 return JAYLINK_OK;
 543         }
 544
 545         if (devh->bytes_available) {
 546                 memcpy(buffer, devh->buffer + devh->read_pos,
 547                         devh->bytes_available);
 548
 549                 buffer += devh->bytes_available;
 550                 length -= devh->bytes_available;
 551                 devh->read_length -= devh->bytes_available;
 552
 553                 log_dbg(ctx, "Read %zu bytes from buffer to flush it.",
 554                         devh->bytes_available);
 555
 556                 devh->bytes_available = 0;
 557                 devh->read_pos = 0;
 558         }
 559
 560         ret = _recv(devh, buffer, length);
 561
 562         if (ret != JAYLINK_OK)
 563                 return ret;
 564
 565         devh->read_length -= length;
 566
 567         return JAYLINK_OK;
 568 }