src/serial_bt.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2018-2019 Gerhard Sittig <gerhard.sittig@gmx.net>
   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 3 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 <config.h>
  21 #include <glib.h>
  22 #include <libsigrok/libsigrok.h>
  23 #include "libsigrok-internal.h"
  24 #include <string.h>
  25 #include <memory.h>
  26
  27 #define LOG_PREFIX "serial-bt"
  28
  29 #ifdef HAVE_SERIAL_COMM
  30 #ifdef HAVE_BLUETOOTH
  31
  32 #define SER_BT_CONN_PREFIX      "bt"
  33 #define SER_BT_CHUNK_SIZE       1200
  34
  35 #define SER_BT_PARAM_PREFIX_CHANNEL     "channel="
  36 #define SER_BT_PARAM_PREFIX_HDL_RX      "handle_rx="
  37 #define SER_BT_PARAM_PREFIX_HDL_TX      "handle_tx="
  38 #define SER_BT_PARAM_PREFIX_HDL_CCCD    "handle_cccd="
  39 #define SER_BT_PARAM_PREFIX_VAL_CCCD    "value_cccd="
  40 #define SER_BT_PARAM_PREFIX_BLE_MTU     "mtu="
  41
  42 /**
  43  * @file
  44  *
  45  * Serial port handling, wraps the external BT/BLE dependencies.
  46  */
  47
  48 /**
  49  * @defgroup grp_serial_bt Serial port handling, BT/BLE group
  50  *
  51  * Make serial-over-BT communication appear like a regular serial port.
  52  *
  53  * @{
  54  */
  55
  56 /* {{{ support for serial-over-BT channels */
  57
  58 /*
  59  * This builtin database of known devices (keyed by their names as
  60  * provided during BT/BLE scans) can help improve the presentation of
  61  * scan results. Ideally users could take the output and pass it to
  62  * subsequent program invocations, not having to "come up with" the
  63  * conn= spec, or only having to touch it up minimally. GUI dialogs
  64  * could present scan results such that users just need to pick an
  65  * item to open a connection.
  66  *
  67  * The current implementation guesses connection types from device
  68  * names, and optionally amends them with additional parameters if
  69  * experience shows that individual devices need these extra specs.
  70  *
  71  * This database may have to move to a separate source file should
  72  * its size grow to amounts that are considered inappropriate here
  73  * in the serial transport's BT dispatcher. For now the item count
  74  * is small.
  75  */
  76
  77 static const struct scan_supported_item {
  78         const char *name;
  79         enum ser_bt_conn_t type;
  80         const char *add_params;
  81 } scan_supported_items[] = {
  82         { "121GW", SER_BT_CONN_BLE122, NULL, },
  83         { "Adafruit Bluefruit LE 8134", SER_BT_CONN_NRF51, NULL, },
  84         { "DL24M_BLE", SER_BT_CONN_AC6328, NULL, },
  85         { "DL24M_SPP", SER_BT_CONN_RFCOMM, "/channel=2", },
  86         { "HC-05", SER_BT_CONN_RFCOMM, NULL, },
  87         { "UC96_BLE", SER_BT_CONN_AC6328, NULL, },
  88         { "UC96_SPP", SER_BT_CONN_RFCOMM, "/channel=2", },
  89         { "UM25C", SER_BT_CONN_RFCOMM, NULL, },
  90         { NULL, SER_BT_CONN_UNKNOWN, NULL, },
  91 };
  92
  93 static const struct scan_supported_item *scan_is_supported(const char *name)
  94 {
  95         size_t idx;
  96         const struct scan_supported_item *item;
  97
  98         for (idx = 0; idx < ARRAY_SIZE(scan_supported_items); idx++) {
  99                 item = &scan_supported_items[idx];
 100                 if (!item->name)
 101                         break;
 102                 if (strcmp(name, item->name) != 0)
 103                         continue;
 104                 return item;
 105         }
 106
 107         return NULL;
 108 }
 109
 110 static const char *ser_bt_conn_names[SER_BT_CONN_MAX] = {
 111         [SER_BT_CONN_UNKNOWN] = "<type>",
 112         [SER_BT_CONN_RFCOMM] = "rfcomm",
 113         [SER_BT_CONN_BLE122] = "ble122",
 114         [SER_BT_CONN_NRF51] = "nrf51",
 115         [SER_BT_CONN_CC254x] = "cc254x",
 116         [SER_BT_CONN_AC6328] = "ac6328",
 117 };
 118
 119 static enum ser_bt_conn_t lookup_conn_name(const char *name)
 120 {
 121         size_t idx;
 122         const char *item;
 123
 124         if (!name || !*name)
 125                 return SER_BT_CONN_UNKNOWN;
 126         idx = ARRAY_SIZE(ser_bt_conn_names);
 127         while (idx-- > 0) {
 128                 item = ser_bt_conn_names[idx];
 129                 if (strcmp(item, name) == 0)
 130                         return idx;
 131         }
 132
 133         return SER_BT_CONN_UNKNOWN;
 134 }
 135
 136 static const char *conn_name_text(enum ser_bt_conn_t type)
 137 {
 138         if (type >= ARRAY_SIZE(ser_bt_conn_names))
 139                 type = SER_BT_CONN_UNKNOWN;
 140
 141         return ser_bt_conn_names[type];
 142 }
 143
 144 /**
 145  * Parse conn= specs for serial over Bluetooth communication.
 146  *
 147  * @param[in] serial The serial port that is about to get opened.
 148  * @param[in] spec The caller provided conn= specification.
 149  * @param[out] conn_type The type of BT comm (BT RFCOMM, BLE notify).
 150  * @param[out] remote_addr The remote device address.
 151  * @param[out] rfcomm_channel The RFCOMM channel (if applicable).
 152  * @param[out] read_hdl The BLE notify read handle (if applicable).
 153  * @param[out] write_hdl The BLE notify write handle (if applicable).
 154  * @param[out] cccd_hdl The BLE notify CCCD handle (if applicable).
 155  * @param[out] cccd_val The BLE notify CCCD value (if applicable).
 156  *
 157  * @return 0 upon success, non-zero upon failure.
 158  *
 159  * Summary of parsing rules as they are implemented:
 160  * - Implementor's note: Automatic scan for available devices is not
 161  *   yet implemented. So strictly speaking some parts of the input
 162  *   spec are optional, but fallbacks may not take effect ATM.
 163  * - Insist on the "bt" prefix. Accept "bt" alone without any other
 164  *   additional field.
 165  * - The first field that follows is the connection type. Supported
 166  *   types are 'rfcomm', 'ble122', 'cc254x', and potentially others
 167  *   in a future implementation.
 168  * - The next field is the remote device's address, either separated
 169  *   by colons or dashes or spaces, or not separated at all.
 170  * - Other parameters (RFCOMM channel, notify handles and write values)
 171  *   get derived from the connection type.
 172  * - More fields after the remote address are options which override
 173  *   builtin defaults (RFCOMM channels, BLE handles, etc).
 174  *
 175  * Supported formats resulting from these rules:
 176  *   bt/<conn>/<addr>[/<param>]...
 177  *
 178  * Examples:
 179  *   bt/rfcomm/11-22-33-44-55-66
 180  *   bt/rfcomm/11-22-33-44-55-66/channel=2
 181  *   bt/ble122/88:6b:12:34:56:78
 182  *   bt/cc254x/0123456789ab
 183  *
 184  * It's assumed that users easily can create those conn= specs from
 185  * available information, or that scan routines will create such specs
 186  * that copy'n'paste results (or GUI choices from previous scan results)
 187  * can get processed here.
 188  */
 189 static int ser_bt_parse_conn_spec(
 190         struct sr_serial_dev_inst *serial, const char *spec,
 191         enum ser_bt_conn_t *conn_type, const char **remote_addr,
 192         size_t *rfcomm_channel,
 193         uint16_t *read_hdl, uint16_t *write_hdl,
 194         uint16_t *cccd_hdl, uint16_t *cccd_val,
 195         uint16_t *ble_mtu)
 196 {
 197         char **fields, *field;
 198         enum ser_bt_conn_t type;
 199         const char *addr;
 200         int ret_parse, ret;
 201         size_t fields_count, field_idx;
 202         char *endp;
 203         unsigned long parm_val;
 204
 205         if (conn_type)
 206                 *conn_type = SER_BT_CONN_UNKNOWN;
 207         if (remote_addr)
 208                 *remote_addr = NULL;
 209         if (rfcomm_channel)
 210                 *rfcomm_channel = 0;
 211         if (read_hdl)
 212                 *read_hdl = 0;
 213         if (write_hdl)
 214                 *write_hdl = 0;
 215         if (cccd_hdl)
 216                 *cccd_hdl = 0;
 217         if (cccd_val)
 218                 *cccd_val = 0;
 219         if (ble_mtu)
 220                 *ble_mtu = 0;
 221
 222         if (!serial || !spec || !spec[0])
 223                 return SR_ERR_ARG;
 224
 225         /* Evaluate the mandatory first three fields. */
 226         fields = g_strsplit_set(spec, "/", 0);
 227         if (!fields)
 228                 return SR_ERR_ARG;
 229         if (g_strv_length(fields) < 3) {
 230                 g_strfreev(fields);
 231                 return SR_ERR_ARG;
 232         }
 233         field = fields[0];
 234         if (strcmp(field, SER_BT_CONN_PREFIX) != 0) {
 235                 g_strfreev(fields);
 236                 return SR_ERR_ARG;
 237         }
 238         field = fields[1];
 239         type = lookup_conn_name(field);
 240         if (!type) {
 241                 g_strfreev(fields);
 242                 return SR_ERR_ARG;
 243         }
 244         if (conn_type)
 245                 *conn_type = type;
 246         field = fields[2];
 247         if (!field || !*field) {
 248                 g_strfreev(fields);
 249                 return SR_ERR_ARG;
 250         }
 251         addr = g_strdup(field);
 252         if (remote_addr)
 253                 *remote_addr = addr;
 254
 255         /* Derive default parameters that match the connection type. */
 256         /* TODO Lookup defaults from a table? */
 257         switch (type) {
 258         case SER_BT_CONN_RFCOMM:
 259                 if (rfcomm_channel)
 260                         *rfcomm_channel = 1;
 261                 break;
 262         case SER_BT_CONN_BLE122:
 263                 if (read_hdl)
 264                         *read_hdl = 8;
 265                 if (write_hdl)
 266                         *write_hdl = 0;
 267                 if (cccd_hdl)
 268                         *cccd_hdl = 9;
 269                 if (cccd_val)
 270                         *cccd_val = 0x0003;
 271                 break;
 272         case SER_BT_CONN_NRF51:
 273                 /* TODO
 274                  * Are these values appropriate? Check the learn article at
 275                  * https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend?view=all
 276                  */
 277                 if (read_hdl)
 278                         *read_hdl = 13;
 279                 if (write_hdl)
 280                         *write_hdl = 11;
 281                 if (cccd_hdl)
 282                         *cccd_hdl = 14;
 283                 if (cccd_val)
 284                         *cccd_val = 0x0001;
 285                 /* TODO 'random' type, sec-level=high */
 286                 break;
 287         case SER_BT_CONN_CC254x:
 288                 /* TODO Are these values appropriate? Just guessing here. */
 289                 if (read_hdl)
 290                         *read_hdl = 20;
 291                 if (write_hdl)
 292                         *write_hdl = 0;
 293                 if (cccd_hdl)
 294                         *cccd_hdl = 21;
 295                 if (cccd_val)
 296                         *cccd_val = 0x0001;
 297                 break;
 298         case SER_BT_CONN_AC6328:
 299                 if (read_hdl)
 300                         *read_hdl = 12;
 301                 if (write_hdl)
 302                         *write_hdl = 15;
 303                 if (cccd_hdl)
 304                         *cccd_hdl = 13;
 305                 if (cccd_val)
 306                         *cccd_val = 0x0001;
 307                 break;
 308         default:
 309                 return SR_ERR_ARG;
 310         }
 311
 312         /*
 313          * Preset a successful return value for the conn= parse call.
 314          * Scan optional additional fields which specify more params.
 315          * Update the defaults which were setup above. Pessimize the
 316          * routine's return value in error paths.
 317          */
 318         ret_parse = SR_OK;
 319         fields_count = g_strv_length(fields);
 320         for (field_idx = 3; field_idx < fields_count; field_idx++) {
 321                 field = fields[field_idx];
 322                 if (!field || !*field)
 323                         continue;
 324                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_CHANNEL)) {
 325                         field += strlen(SER_BT_PARAM_PREFIX_CHANNEL);
 326                         endp = NULL;
 327                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 328                         if (ret != SR_OK || !endp || *endp != '\0') {
 329                                 ret_parse = SR_ERR_ARG;
 330                                 break;
 331                         }
 332                         if (rfcomm_channel)
 333                                 *rfcomm_channel = parm_val;
 334                         continue;
 335                 }
 336                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_RX)) {
 337                         field += strlen(SER_BT_PARAM_PREFIX_HDL_RX);
 338                         endp = NULL;
 339                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 340                         if (ret != SR_OK || !endp || *endp != '\0') {
 341                                 ret_parse = SR_ERR_ARG;
 342                                 break;
 343                         }
 344                         if (read_hdl)
 345                                 *read_hdl = parm_val;
 346                         continue;
 347                 }
 348                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_TX)) {
 349                         field += strlen(SER_BT_PARAM_PREFIX_HDL_TX);
 350                         endp = NULL;
 351                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 352                         if (ret != SR_OK || !endp || *endp != '\0') {
 353                                 ret_parse = SR_ERR_ARG;
 354                                 break;
 355                         }
 356                         if (write_hdl)
 357                                 *write_hdl = parm_val;
 358                         continue;
 359                 }
 360                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_CCCD)) {
 361                         field += strlen(SER_BT_PARAM_PREFIX_HDL_CCCD);
 362                         endp = NULL;
 363                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 364                         if (ret != SR_OK || !endp || *endp != '\0') {
 365                                 ret_parse = SR_ERR_ARG;
 366                                 break;
 367                         }
 368                         if (cccd_hdl)
 369                                 *cccd_hdl = parm_val;
 370                         continue;
 371                 }
 372                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_VAL_CCCD)) {
 373                         field += strlen(SER_BT_PARAM_PREFIX_VAL_CCCD);
 374                         endp = NULL;
 375                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 376                         if (ret != SR_OK || !endp || *endp != '\0') {
 377                                 ret_parse = SR_ERR_ARG;
 378                                 break;
 379                         }
 380                         if (cccd_val)
 381                                 *cccd_val = parm_val;
 382                         continue;
 383                 }
 384                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_BLE_MTU)) {
 385                         field += strlen(SER_BT_PARAM_PREFIX_BLE_MTU);
 386                         endp = NULL;
 387                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 388                         if (ret != SR_OK || !endp || *endp != '\0') {
 389                                 ret_parse = SR_ERR_ARG;
 390                                 break;
 391                         }
 392                         if (ble_mtu)
 393                                 *ble_mtu = parm_val;
 394                         continue;
 395                 }
 396                 return SR_ERR_DATA;
 397         }
 398
 399         g_strfreev(fields);
 400         return ret_parse;
 401 }
 402
 403 static void ser_bt_mask_databits(struct sr_serial_dev_inst *serial,
 404         uint8_t *data, size_t len)
 405 {
 406         uint32_t mask32;
 407         uint8_t mask;
 408         size_t idx;
 409
 410         if ((serial->comm_params.data_bits % 8) == 0)
 411                 return;
 412
 413         mask32 = (1UL << serial->comm_params.data_bits) - 1;
 414         mask = mask32 & 0xff;
 415         for (idx = 0; idx < len; idx++)
 416                 data[idx] &= mask;
 417 }
 418
 419 static int ser_bt_data_cb(void *cb_data, uint8_t *data, size_t dlen)
 420 {
 421         struct sr_serial_dev_inst *serial;
 422
 423         serial = cb_data;
 424         if (!serial)
 425                 return -1;
 426
 427         if (!data && dlen)
 428                 return -1;
 429         if (!data || !dlen)
 430                 return 0;
 431
 432         ser_bt_mask_databits(serial, data, dlen);
 433         sr_ser_queue_rx_data(serial, data, dlen);
 434
 435         return 0;
 436 }
 437
 438 /* }}} */
 439 /* {{{ wrap serial-over-BT operations in a common serial.c API */
 440
 441 /* See if a serial port's name refers to a BT type. */
 442 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
 443 {
 444         size_t off;
 445         char sep;
 446
 447         if (!serial)
 448                 return 0;
 449         if (!serial->port || !*serial->port)
 450                 return 0;
 451
 452         /* Accept either "bt" alone, or "bt/" as a prefix. */
 453         if (!g_str_has_prefix(serial->port, SER_BT_CONN_PREFIX))
 454                 return 0;
 455         off = strlen(SER_BT_CONN_PREFIX);
 456         sep = serial->port[off];
 457         if (sep != '\0' && sep != '/')
 458                 return 0;
 459
 460         return 1;
 461 }
 462
 463 /* The open() wrapper for BT ports. */
 464 static int ser_bt_open(struct sr_serial_dev_inst *serial, int flags)
 465 {
 466         enum ser_bt_conn_t conn_type;
 467         const char *remote_addr;
 468         size_t rfcomm_channel;
 469         uint16_t read_hdl, write_hdl, cccd_hdl, cccd_val;
 470         uint16_t ble_mtu;
 471         int rc;
 472         struct sr_bt_desc *desc;
 473
 474         (void)flags;
 475
 476         /* Derive BT specific parameters from the port spec. */
 477         rc = ser_bt_parse_conn_spec(serial, serial->port,
 478                         &conn_type, &remote_addr,
 479                         &rfcomm_channel,
 480                         &read_hdl, &write_hdl,
 481                         &cccd_hdl, &cccd_val,
 482                         &ble_mtu);
 483         if (rc != SR_OK)
 484                 return SR_ERR_ARG;
 485
 486         if (!conn_type || !remote_addr || !remote_addr[0]) {
 487                 /* TODO Auto-search for available connections? */
 488                 return SR_ERR_NA;
 489         }
 490
 491         /* Create the connection. Only store params after successful use. */
 492         desc = sr_bt_desc_new();
 493         if (!desc)
 494                 return SR_ERR;
 495         serial->bt_desc = desc;
 496         rc = sr_bt_config_addr_remote(desc, remote_addr);
 497         if (rc < 0)
 498                 return SR_ERR;
 499         serial->bt_addr_remote = g_strdup(remote_addr);
 500         switch (conn_type) {
 501         case SER_BT_CONN_RFCOMM:
 502                 rc = sr_bt_config_rfcomm(desc, rfcomm_channel);
 503                 if (rc < 0)
 504                         return SR_ERR;
 505                 serial->bt_rfcomm_channel = rfcomm_channel;
 506                 break;
 507         case SER_BT_CONN_BLE122:
 508         case SER_BT_CONN_NRF51:
 509         case SER_BT_CONN_CC254x:
 510         case SER_BT_CONN_AC6328:
 511                 rc = sr_bt_config_notify(desc,
 512                         read_hdl, write_hdl, cccd_hdl, cccd_val,
 513                         ble_mtu);
 514                 if (rc < 0)
 515                         return SR_ERR;
 516                 serial->bt_notify_handle_read = read_hdl;
 517                 serial->bt_notify_handle_write = write_hdl;
 518                 serial->bt_notify_handle_cccd = cccd_hdl;
 519                 serial->bt_notify_value_cccd = cccd_val;
 520                 serial->bt_ble_mtu = ble_mtu;
 521                 break;
 522         default:
 523                 /* Unsupported type, or incomplete implementation. */
 524                 return SR_ERR_ARG;
 525         }
 526         serial->bt_conn_type = conn_type;
 527
 528         /* Make sure the receive buffer can accept input data. */
 529         if (!serial->rcv_buffer)
 530                 serial->rcv_buffer = g_string_sized_new(SER_BT_CHUNK_SIZE);
 531         rc = sr_bt_config_cb_data(desc, ser_bt_data_cb, serial);
 532         if (rc < 0)
 533                 return SR_ERR;
 534
 535         /* Open the connection. */
 536         switch (conn_type) {
 537         case SER_BT_CONN_RFCOMM:
 538                 rc = sr_bt_connect_rfcomm(desc);
 539                 if (rc < 0)
 540                         return SR_ERR;
 541                 break;
 542         case SER_BT_CONN_BLE122:
 543         case SER_BT_CONN_NRF51:
 544         case SER_BT_CONN_CC254x:
 545         case SER_BT_CONN_AC6328:
 546                 rc = sr_bt_connect_ble(desc);
 547                 if (rc < 0)
 548                         return SR_ERR;
 549                 rc = sr_bt_start_notify(desc);
 550                 if (rc < 0)
 551                         return SR_ERR;
 552                 break;
 553         default:
 554                 return SR_ERR_ARG;
 555         }
 556
 557         return SR_OK;
 558 }
 559
 560 static int ser_bt_close(struct sr_serial_dev_inst *serial)
 561 {
 562         if (!serial)
 563                 return SR_ERR_ARG;
 564
 565         if (!serial->bt_desc)
 566                 return SR_OK;
 567
 568         sr_bt_disconnect(serial->bt_desc);
 569         sr_bt_desc_free(serial->bt_desc);
 570         serial->bt_desc = NULL;
 571
 572         g_free(serial->bt_addr_local);
 573         serial->bt_addr_local = NULL;
 574         g_free(serial->bt_addr_remote);
 575         serial->bt_addr_remote = NULL;
 576         g_slist_free_full(serial->bt_source_args, g_free);
 577         serial->bt_source_args = NULL;
 578
 579         return SR_OK;
 580 }
 581
 582 /* Flush, discards pending RX data, empties buffers. */
 583 static int ser_bt_flush(struct sr_serial_dev_inst *serial)
 584 {
 585         (void)serial;
 586         /* EMPTY */
 587
 588         return SR_OK;
 589 }
 590
 591 /* Drain, waits for completion of pending TX data. */
 592 static int ser_bt_drain(struct sr_serial_dev_inst *serial)
 593 {
 594         (void)serial;
 595         /* EMPTY */     /* TODO? */
 596
 597         return SR_ERR_BUG;
 598 }
 599
 600 static int ser_bt_write(struct sr_serial_dev_inst *serial,
 601                 const void *buf, size_t count,
 602                 int nonblocking, unsigned int timeout_ms)
 603 {
 604         ssize_t wrlen;
 605
 606         /*
 607          * TODO Support chunked transmission when callers' requests
 608          * exceed the BT channel's capacity? See ser_hid_write().
 609          */
 610
 611         switch (serial->bt_conn_type) {
 612         case SER_BT_CONN_RFCOMM:
 613                 (void)nonblocking;
 614                 (void)timeout_ms;
 615                 wrlen = sr_bt_write(serial->bt_desc, buf, count);
 616                 if (wrlen < 0)
 617                         return SR_ERR_IO;
 618                 return wrlen;
 619         case SER_BT_CONN_BLE122:
 620         case SER_BT_CONN_NRF51:
 621         case SER_BT_CONN_CC254x:
 622         case SER_BT_CONN_AC6328:
 623                 /*
 624                  * Assume that when applications call the serial layer's
 625                  * write routine, then the BLE chip/module does support
 626                  * a TX handle. Just call the serial-BT library's write
 627                  * routine.
 628                  */
 629                 (void)nonblocking;
 630                 (void)timeout_ms;
 631                 wrlen = sr_bt_write(serial->bt_desc, buf, count);
 632                 if (wrlen < 0)
 633                         return SR_ERR_IO;
 634                 return wrlen;
 635         default:
 636                 return SR_ERR_ARG;
 637         }
 638         /* UNREACH */
 639 }
 640
 641 static int ser_bt_read(struct sr_serial_dev_inst *serial,
 642                 void *buf, size_t count,
 643                 int nonblocking, unsigned int timeout_ms)
 644 {
 645         gint64 deadline_us, now_us;
 646         uint8_t buffer[SER_BT_CHUNK_SIZE];
 647         ssize_t rdlen;
 648         int rc;
 649         size_t dlen;
 650
 651         /*
 652          * Immediately satisfy the caller's request from the RX buffer
 653          * if the requested amount of data is available already.
 654          */
 655         if (sr_ser_has_queued_data(serial) >= count)
 656                 return sr_ser_unqueue_rx_data(serial, buf, count);
 657
 658         /*
 659          * When a timeout was specified, then determine the deadline
 660          * where to stop reception.
 661          */
 662         deadline_us = 0;
 663         if (timeout_ms) {
 664                 now_us = g_get_monotonic_time();
 665                 deadline_us = now_us + timeout_ms * 1000;
 666         }
 667
 668         /*
 669          * Keep receiving from the port until the caller's requested
 670          * amount of data has become available, or the timeout has
 671          * expired. In the absence of a timeout, stop reading when an
 672          * attempt no longer yields receive data.
 673          */
 674         while (TRUE) {
 675                 /* Run another attempt to receive data. */
 676                 switch (serial->bt_conn_type) {
 677                 case SER_BT_CONN_RFCOMM:
 678                         rdlen = sr_bt_read(serial->bt_desc, buffer, sizeof(buffer));
 679                         if (rdlen <= 0)
 680                                 break;
 681                         rc = ser_bt_data_cb(serial, buffer, rdlen);
 682                         if (rc < 0)
 683                                 rdlen = -1;
 684                         break;
 685                 case SER_BT_CONN_BLE122:
 686                 case SER_BT_CONN_NRF51:
 687                 case SER_BT_CONN_CC254x:
 688                 case SER_BT_CONN_AC6328:
 689                         dlen = sr_ser_has_queued_data(serial);
 690                         rc = sr_bt_check_notify(serial->bt_desc);
 691                         if (rc < 0)
 692                                 rdlen = -1;
 693                         else if (sr_ser_has_queued_data(serial) != dlen)
 694                                 rdlen = +1;
 695                         else
 696                                 rdlen = 0;
 697                         break;
 698                 default:
 699                         rdlen = -1;
 700                         break;
 701                 }
 702
 703                 /*
 704                  * Stop upon receive errors, or timeout expiration. Only
 705                  * stop upon empty reception in the absence of a timeout.
 706                  */
 707                 if (rdlen < 0)
 708                         break;
 709                 if (nonblocking && !rdlen)
 710                         break;
 711                 if (deadline_us) {
 712                         now_us = g_get_monotonic_time();
 713                         if (now_us > deadline_us)
 714                                 break;
 715                 }
 716
 717                 /* Also stop when sufficient data has become available. */
 718                 if (sr_ser_has_queued_data(serial) >= count)
 719                         break;
 720         }
 721
 722         /*
 723          * Satisfy the caller's demand for receive data from previously
 724          * queued incoming data.
 725          */
 726         dlen = sr_ser_has_queued_data(serial);
 727         if (dlen > count)
 728                 dlen = count;
 729         if (!dlen)
 730                 return 0;
 731
 732         return sr_ser_unqueue_rx_data(serial, buf, dlen);
 733 }
 734
 735 struct bt_source_args_t {
 736         /* The application callback. */
 737         sr_receive_data_callback cb;
 738         void *cb_data;
 739         /* The serial device, to store RX data. */
 740         struct sr_serial_dev_inst *serial;
 741 };
 742
 743 /*
 744  * Gets periodically invoked by the glib main loop. "Drives" (checks)
 745  * progress of BT communication, and invokes the application's callback
 746  * which processes RX data (when some has become available), as well as
 747  * handles application level timeouts.
 748  */
 749 static int bt_source_cb(int fd, int revents, void *cb_data)
 750 {
 751         struct bt_source_args_t *args;
 752         struct sr_serial_dev_inst *serial;
 753         uint8_t rx_buf[SER_BT_CHUNK_SIZE];
 754         ssize_t rdlen;
 755         size_t dlen;
 756         int rc;
 757
 758         args = cb_data;
 759         if (!args)
 760                 return -1;
 761         serial = args->serial;
 762         if (!serial)
 763                 return -1;
 764         if (!serial->bt_conn_type)
 765                 return -1;
 766
 767         /*
 768          * Drain receive data which the channel might have pending.
 769          * This is "a copy" of the "background part" of ser_bt_read(),
 770          * without the timeout support code, and not knowing how much
 771          * data the application is expecting.
 772          */
 773         do {
 774                 switch (serial->bt_conn_type) {
 775                 case SER_BT_CONN_RFCOMM:
 776                         rdlen = sr_bt_read(serial->bt_desc, rx_buf, sizeof(rx_buf));
 777                         if (rdlen <= 0)
 778                                 break;
 779                         rc = ser_bt_data_cb(serial, rx_buf, rdlen);
 780                         if (rc < 0)
 781                                 rdlen = -1;
 782                         break;
 783                 case SER_BT_CONN_BLE122:
 784                 case SER_BT_CONN_NRF51:
 785                 case SER_BT_CONN_CC254x:
 786                 case SER_BT_CONN_AC6328:
 787                         dlen = sr_ser_has_queued_data(serial);
 788                         rc = sr_bt_check_notify(serial->bt_desc);
 789                         if (rc < 0)
 790                                 rdlen = -1;
 791                         else if (sr_ser_has_queued_data(serial) != dlen)
 792                                 rdlen = +1;
 793                         else
 794                                 rdlen = 0;
 795                         break;
 796                 default:
 797                         rdlen = -1;
 798                         break;
 799                 }
 800         } while (rdlen > 0);
 801
 802         /*
 803          * When RX data became available (now or earlier), pass this
 804          * condition to the application callback. Always periodically
 805          * run the application callback, since it handles timeouts and
 806          * might carry out other tasks as well like signalling progress.
 807          */
 808         if (sr_ser_has_queued_data(args->serial))
 809                 revents |= G_IO_IN;
 810         rc = args->cb(fd, revents, args->cb_data);
 811
 812         return rc;
 813 }
 814
 815 /* TODO Can we use the Bluetooth socket's file descriptor? Probably not portably. */
 816 #define WITH_MAXIMUM_TIMEOUT_VALUE      0
 817 static int ser_bt_setup_source_add(struct sr_session *session,
 818                 struct sr_serial_dev_inst *serial,
 819                 int events, int timeout,
 820                 sr_receive_data_callback cb, void *cb_data)
 821 {
 822         struct bt_source_args_t *args;
 823         int rc;
 824
 825         (void)events;
 826
 827         /* Optionally enforce a minimum poll period. */
 828         if (WITH_MAXIMUM_TIMEOUT_VALUE && timeout > WITH_MAXIMUM_TIMEOUT_VALUE)
 829                 timeout = WITH_MAXIMUM_TIMEOUT_VALUE;
 830
 831         /* Allocate status container for background data reception. */
 832         args = g_malloc0(sizeof(*args));
 833         args->cb = cb;
 834         args->cb_data = cb_data;
 835         args->serial = serial;
 836
 837         /*
 838          * Have a periodic timer installed. Register the allocated block
 839          * with the serial device, since the GSource's finalizer won't
 840          * free the memory, and we haven't bothered to create a custom
 841          * BT specific GSource.
 842          */
 843         rc = sr_session_source_add(session, -1, events, timeout, bt_source_cb, args);
 844         if (rc != SR_OK) {
 845                 g_free(args);
 846                 return rc;
 847         }
 848         serial->bt_source_args = g_slist_append(serial->bt_source_args, args);
 849
 850         return SR_OK;
 851 }
 852
 853 static int ser_bt_setup_source_remove(struct sr_session *session,
 854                 struct sr_serial_dev_inst *serial)
 855 {
 856         (void)serial;
 857
 858         (void)sr_session_source_remove(session, -1);
 859         /* Release callback args here already? */
 860
 861         return SR_OK;
 862 }
 863
 864 struct bt_scan_args_t {
 865         GSList *port_list;
 866         sr_ser_list_append_t append;
 867         GSList *addr_list;
 868         const char *bt_type;
 869 };
 870
 871 static void scan_cb(void *cb_args, const char *addr, const char *name)
 872 {
 873         struct bt_scan_args_t *scan_args;
 874         GSList *l;
 875         char addr_text[20];
 876         const struct scan_supported_item *item;
 877         enum ser_bt_conn_t type;
 878         char *port_name, *port_desc;
 879         char *addr_copy;
 880
 881         scan_args = cb_args;
 882         if (!scan_args)
 883                 return;
 884         sr_info("BT scan, found: %s - %s\n", addr, name);
 885
 886         /* Check whether the device was seen before. */
 887         for (l = scan_args->addr_list; l; l = l->next) {
 888                 if (strcmp(addr, l->data) == 0)
 889                         return;
 890         }
 891
 892         /* Substitute colons in the address by dashes. */
 893         if (!addr || !*addr)
 894                 return;
 895         snprintf(addr_text, sizeof(addr_text), "%s", addr);
 896         g_strcanon(addr_text, "0123456789abcdefABCDEF", '-');
 897
 898         /* Create a port name, and a description. */
 899         item = scan_is_supported(name);
 900         type = item ? item->type : SER_BT_CONN_UNKNOWN;
 901         port_name = g_strdup_printf("%s/%s/%s%s",
 902                 SER_BT_CONN_PREFIX, conn_name_text(type), addr_text,
 903                 (item && item->add_params) ? item->add_params : "");
 904         port_desc = g_strdup_printf("%s (%s)", name, scan_args->bt_type);
 905
 906         scan_args->port_list = scan_args->append(scan_args->port_list, port_name, port_desc);
 907         g_free(port_name);
 908         g_free(port_desc);
 909
 910         /* Keep track of the handled address. */
 911         addr_copy = g_strdup(addr);
 912         scan_args->addr_list = g_slist_append(scan_args->addr_list, addr_copy);
 913 }
 914
 915 static GSList *ser_bt_list(GSList *list, sr_ser_list_append_t append)
 916 {
 917         static const int scan_duration = 3;
 918
 919         struct bt_scan_args_t scan_args;
 920         struct sr_bt_desc *desc;
 921
 922         /*
 923          * Implementor's note: This "list" routine is best-effort. We
 924          * assume that registering callbacks always succeeds. Silently
 925          * ignore failure to scan for devices. Just return those which
 926          * we happen to find.
 927          */
 928
 929         desc = sr_bt_desc_new();
 930         if (!desc)
 931                 return list;
 932
 933         memset(&scan_args, 0, sizeof(scan_args));
 934         scan_args.port_list = list;
 935         scan_args.append = append;
 936
 937         scan_args.addr_list = NULL;
 938         scan_args.bt_type = "BT";
 939         (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
 940         (void)sr_bt_scan_bt(desc, scan_duration);
 941         g_slist_free_full(scan_args.addr_list, g_free);
 942
 943         scan_args.addr_list = NULL;
 944         scan_args.bt_type = "BLE";
 945         (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
 946         (void)sr_bt_scan_le(desc, scan_duration);
 947         g_slist_free_full(scan_args.addr_list, g_free);
 948
 949         sr_bt_desc_free(desc);
 950
 951         return scan_args.port_list;
 952 }
 953
 954 static struct ser_lib_functions serlib_bt = {
 955         .open = ser_bt_open,
 956         .close = ser_bt_close,
 957         .flush = ser_bt_flush,
 958         .drain = ser_bt_drain,
 959         .write = ser_bt_write,
 960         .read = ser_bt_read,
 961         /*
 962          * Bluetooth communication has no concept of bitrate, so ignore
 963          * these arguments silently. Neither need we pass the frame format
 964          * down to internal BT comm routines, nor need we keep the values
 965          * here, since the caller will cache/register them already.
 966          */
 967         .set_params = std_dummy_set_params,
 968         .set_handshake = std_dummy_set_handshake,
 969         .setup_source_add = ser_bt_setup_source_add,
 970         .setup_source_remove = ser_bt_setup_source_remove,
 971         .list = ser_bt_list,
 972         .get_frame_format = NULL,
 973 };
 974 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = &serlib_bt;
 975
 976 /* }}} */
 977 #else
 978
 979 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
 980 {
 981         (void)serial;
 982
 983         return 0;
 984 }
 985
 986 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = NULL;
 987
 988 #endif
 989 #endif
 990
 991 /** @} */