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         [SER_BT_CONN_DIALOG] = "dialog",
 118         [SER_BT_CONN_NOTIFY] = "notify",
 119 };
 120
 121 static enum ser_bt_conn_t lookup_conn_name(const char *name)
 122 {
 123         size_t idx;
 124         const char *item;
 125
 126         if (!name || !*name)
 127                 return SER_BT_CONN_UNKNOWN;
 128         idx = ARRAY_SIZE(ser_bt_conn_names);
 129         while (idx-- > 0) {
 130                 item = ser_bt_conn_names[idx];
 131                 if (strcmp(item, name) == 0)
 132                         return idx;
 133         }
 134
 135         return SER_BT_CONN_UNKNOWN;
 136 }
 137
 138 static const char *conn_name_text(enum ser_bt_conn_t type)
 139 {
 140         if (type >= ARRAY_SIZE(ser_bt_conn_names))
 141                 type = SER_BT_CONN_UNKNOWN;
 142
 143         return ser_bt_conn_names[type];
 144 }
 145
 146 /**
 147  * Parse conn= specs for serial over Bluetooth communication.
 148  *
 149  * @param[in] serial The serial port that is about to get opened.
 150  * @param[in] spec The caller provided conn= specification.
 151  * @param[out] conn_type The type of BT comm (BT RFCOMM, BLE notify).
 152  * @param[out] remote_addr The remote device address.
 153  * @param[out] rfcomm_channel The RFCOMM channel (if applicable).
 154  * @param[out] read_hdl The BLE notify read handle (if applicable).
 155  * @param[out] write_hdl The BLE notify write handle (if applicable).
 156  * @param[out] cccd_hdl The BLE notify CCCD handle (if applicable).
 157  * @param[out] cccd_val The BLE notify CCCD value (if applicable).
 158  *
 159  * @return 0 upon success, non-zero upon failure.
 160  *
 161  * Summary of parsing rules as they are implemented:
 162  * - Implementor's note: Automatic scan for available devices is not
 163  *   yet implemented. So strictly speaking some parts of the input
 164  *   spec are optional, but fallbacks may not take effect ATM.
 165  * - Insist on the "bt" prefix. Accept "bt" alone without any other
 166  *   additional field.
 167  * - The first field that follows is the connection type. Supported
 168  *   types are 'rfcomm', 'ble122', 'cc254x', and potentially others
 169  *   in a future implementation.
 170  * - The next field is the remote device's address, either separated
 171  *   by colons or dashes or spaces, or not separated at all.
 172  * - Other parameters (RFCOMM channel, notify handles and write values)
 173  *   get derived from the connection type.
 174  * - More fields after the remote address are options which override
 175  *   builtin defaults (RFCOMM channels, BLE handles, etc).
 176  *
 177  * Supported formats resulting from these rules:
 178  *   bt/<conn>/<addr>[/<param>]...
 179  *
 180  * Examples:
 181  *   bt/rfcomm/11-22-33-44-55-66
 182  *   bt/rfcomm/11-22-33-44-55-66/channel=2
 183  *   bt/ble122/88:6b:12:34:56:78
 184  *   bt/cc254x/0123456789ab
 185  *
 186  * It's assumed that users easily can create those conn= specs from
 187  * available information, or that scan routines will create such specs
 188  * that copy'n'paste results (or GUI choices from previous scan results)
 189  * can get processed here.
 190  */
 191 static int ser_bt_parse_conn_spec(
 192         struct sr_serial_dev_inst *serial, const char *spec,
 193         enum ser_bt_conn_t *conn_type, const char **remote_addr,
 194         size_t *rfcomm_channel,
 195         uint16_t *read_hdl, uint16_t *write_hdl,
 196         uint16_t *cccd_hdl, uint16_t *cccd_val,
 197         uint16_t *ble_mtu)
 198 {
 199         char **fields, *field;
 200         enum ser_bt_conn_t type;
 201         const char *addr;
 202         int ret_parse, ret;
 203         size_t fields_count, field_idx;
 204         char *endp;
 205         unsigned long parm_val;
 206
 207         if (conn_type)
 208                 *conn_type = SER_BT_CONN_UNKNOWN;
 209         if (remote_addr)
 210                 *remote_addr = NULL;
 211         if (rfcomm_channel)
 212                 *rfcomm_channel = 0;
 213         if (read_hdl)
 214                 *read_hdl = 0;
 215         if (write_hdl)
 216                 *write_hdl = 0;
 217         if (cccd_hdl)
 218                 *cccd_hdl = 0;
 219         if (cccd_val)
 220                 *cccd_val = 0;
 221         if (ble_mtu)
 222                 *ble_mtu = 0;
 223
 224         if (!serial || !spec || !spec[0])
 225                 return SR_ERR_ARG;
 226
 227         /* Evaluate the mandatory first three fields. */
 228         fields = g_strsplit_set(spec, "/", 0);
 229         if (!fields)
 230                 return SR_ERR_ARG;
 231         if (g_strv_length(fields) < 3) {
 232                 g_strfreev(fields);
 233                 return SR_ERR_ARG;
 234         }
 235         field = fields[0];
 236         if (strcmp(field, SER_BT_CONN_PREFIX) != 0) {
 237                 g_strfreev(fields);
 238                 return SR_ERR_ARG;
 239         }
 240         field = fields[1];
 241         type = lookup_conn_name(field);
 242         if (!type) {
 243                 g_strfreev(fields);
 244                 return SR_ERR_ARG;
 245         }
 246         if (conn_type)
 247                 *conn_type = type;
 248         field = fields[2];
 249         if (!field || !*field) {
 250                 g_strfreev(fields);
 251                 return SR_ERR_ARG;
 252         }
 253         addr = g_strdup(field);
 254         if (remote_addr)
 255                 *remote_addr = addr;
 256
 257         /* Derive default parameters that match the connection type. */
 258         /* TODO Lookup defaults from a table? */
 259         switch (type) {
 260         case SER_BT_CONN_RFCOMM:
 261                 if (rfcomm_channel)
 262                         *rfcomm_channel = 1;
 263                 break;
 264         case SER_BT_CONN_BLE122:
 265                 if (read_hdl)
 266                         *read_hdl = 8;
 267                 if (write_hdl)
 268                         *write_hdl = 0;
 269                 if (cccd_hdl)
 270                         *cccd_hdl = 9;
 271                 if (cccd_val)
 272                         *cccd_val = 0x0003;
 273                 break;
 274         case SER_BT_CONN_NRF51:
 275                 /* TODO
 276                  * Are these values appropriate? Check the learn article at
 277                  * https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend?view=all
 278                  */
 279                 if (read_hdl)
 280                         *read_hdl = 13;
 281                 if (write_hdl)
 282                         *write_hdl = 11;
 283                 if (cccd_hdl)
 284                         *cccd_hdl = 14;
 285                 if (cccd_val)
 286                         *cccd_val = 0x0001;
 287                 /* TODO 'random' type, sec-level=high */
 288                 break;
 289         case SER_BT_CONN_CC254x:
 290                 /* TODO Are these values appropriate? Just guessing here. */
 291                 if (read_hdl)
 292                         *read_hdl = 20;
 293                 if (write_hdl)
 294                         *write_hdl = 0;
 295                 if (cccd_hdl)
 296                         *cccd_hdl = 21;
 297                 if (cccd_val)
 298                         *cccd_val = 0x0001;
 299                 break;
 300         case SER_BT_CONN_AC6328:
 301                 if (read_hdl)
 302                         *read_hdl = 12;
 303                 if (write_hdl)
 304                         *write_hdl = 15;
 305                 if (cccd_hdl)
 306                         *cccd_hdl = 13;
 307                 if (cccd_val)
 308                         *cccd_val = 0x0001;
 309                 break;
 310         case SER_BT_CONN_DIALOG:
 311                 if (read_hdl)
 312                         *read_hdl = 23;
 313                 if (write_hdl)
 314                         *write_hdl = 18;
 315                 if (cccd_hdl)
 316                         *cccd_hdl = 0;
 317                 if (cccd_val)
 318                         *cccd_val = 0x0001;
 319                 if (ble_mtu)
 320                         *ble_mtu = 400;
 321                 break;
 322         case SER_BT_CONN_NOTIFY:
 323                 /* All other values must be provided externally. */
 324                 if (cccd_val)
 325                         *cccd_val = 0x0001;
 326                 break;
 327         default:
 328                 return SR_ERR_ARG;
 329         }
 330
 331         /*
 332          * Preset a successful return value for the conn= parse call.
 333          * Scan optional additional fields which specify more params.
 334          * Update the defaults which were setup above. Pessimize the
 335          * routine's return value in error paths.
 336          */
 337         ret_parse = SR_OK;
 338         fields_count = g_strv_length(fields);
 339         for (field_idx = 3; field_idx < fields_count; field_idx++) {
 340                 field = fields[field_idx];
 341                 if (!field || !*field)
 342                         continue;
 343                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_CHANNEL)) {
 344                         field += strlen(SER_BT_PARAM_PREFIX_CHANNEL);
 345                         endp = NULL;
 346                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 347                         if (ret != SR_OK || !endp || *endp != '\0') {
 348                                 ret_parse = SR_ERR_ARG;
 349                                 break;
 350                         }
 351                         if (rfcomm_channel)
 352                                 *rfcomm_channel = parm_val;
 353                         continue;
 354                 }
 355                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_RX)) {
 356                         field += strlen(SER_BT_PARAM_PREFIX_HDL_RX);
 357                         endp = NULL;
 358                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 359                         if (ret != SR_OK || !endp || *endp != '\0') {
 360                                 ret_parse = SR_ERR_ARG;
 361                                 break;
 362                         }
 363                         if (read_hdl)
 364                                 *read_hdl = parm_val;
 365                         continue;
 366                 }
 367                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_TX)) {
 368                         field += strlen(SER_BT_PARAM_PREFIX_HDL_TX);
 369                         endp = NULL;
 370                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 371                         if (ret != SR_OK || !endp || *endp != '\0') {
 372                                 ret_parse = SR_ERR_ARG;
 373                                 break;
 374                         }
 375                         if (write_hdl)
 376                                 *write_hdl = parm_val;
 377                         continue;
 378                 }
 379                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_HDL_CCCD)) {
 380                         field += strlen(SER_BT_PARAM_PREFIX_HDL_CCCD);
 381                         endp = NULL;
 382                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 383                         if (ret != SR_OK || !endp || *endp != '\0') {
 384                                 ret_parse = SR_ERR_ARG;
 385                                 break;
 386                         }
 387                         if (cccd_hdl)
 388                                 *cccd_hdl = parm_val;
 389                         continue;
 390                 }
 391                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_VAL_CCCD)) {
 392                         field += strlen(SER_BT_PARAM_PREFIX_VAL_CCCD);
 393                         endp = NULL;
 394                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 395                         if (ret != SR_OK || !endp || *endp != '\0') {
 396                                 ret_parse = SR_ERR_ARG;
 397                                 break;
 398                         }
 399                         if (cccd_val)
 400                                 *cccd_val = parm_val;
 401                         continue;
 402                 }
 403                 if (g_str_has_prefix(field, SER_BT_PARAM_PREFIX_BLE_MTU)) {
 404                         field += strlen(SER_BT_PARAM_PREFIX_BLE_MTU);
 405                         endp = NULL;
 406                         ret = sr_atoul_base(field, &parm_val, &endp, 0);
 407                         if (ret != SR_OK || !endp || *endp != '\0') {
 408                                 ret_parse = SR_ERR_ARG;
 409                                 break;
 410                         }
 411                         if (ble_mtu)
 412                                 *ble_mtu = parm_val;
 413                         continue;
 414                 }
 415                 return SR_ERR_DATA;
 416         }
 417
 418         g_strfreev(fields);
 419         return ret_parse;
 420 }
 421
 422 static void ser_bt_mask_databits(struct sr_serial_dev_inst *serial,
 423         uint8_t *data, size_t len)
 424 {
 425         uint32_t mask32;
 426         uint8_t mask;
 427         size_t idx;
 428
 429         if ((serial->comm_params.data_bits % 8) == 0)
 430                 return;
 431
 432         mask32 = (1UL << serial->comm_params.data_bits) - 1;
 433         mask = mask32 & 0xff;
 434         for (idx = 0; idx < len; idx++)
 435                 data[idx] &= mask;
 436 }
 437
 438 static int ser_bt_data_cb(void *cb_data, uint8_t *data, size_t dlen)
 439 {
 440         struct sr_serial_dev_inst *serial;
 441
 442         serial = cb_data;
 443         if (!serial)
 444                 return -1;
 445
 446         if (!data && dlen)
 447                 return -1;
 448         if (!data || !dlen)
 449                 return 0;
 450
 451         ser_bt_mask_databits(serial, data, dlen);
 452         sr_ser_queue_rx_data(serial, data, dlen);
 453
 454         return 0;
 455 }
 456
 457 /* }}} */
 458 /* {{{ wrap serial-over-BT operations in a common serial.c API */
 459
 460 /* See if a serial port's name refers to a BT type. */
 461 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
 462 {
 463         size_t off;
 464         char sep;
 465
 466         if (!serial)
 467                 return 0;
 468         if (!serial->port || !*serial->port)
 469                 return 0;
 470
 471         /* Accept either "bt" alone, or "bt/" as a prefix. */
 472         if (!g_str_has_prefix(serial->port, SER_BT_CONN_PREFIX))
 473                 return 0;
 474         off = strlen(SER_BT_CONN_PREFIX);
 475         sep = serial->port[off];
 476         if (sep != '\0' && sep != '/')
 477                 return 0;
 478
 479         return 1;
 480 }
 481
 482 /* The open() wrapper for BT ports. */
 483 static int ser_bt_open(struct sr_serial_dev_inst *serial, int flags)
 484 {
 485         enum ser_bt_conn_t conn_type;
 486         const char *remote_addr;
 487         size_t rfcomm_channel;
 488         uint16_t read_hdl, write_hdl, cccd_hdl, cccd_val;
 489         uint16_t ble_mtu;
 490         int rc;
 491         struct sr_bt_desc *desc;
 492
 493         (void)flags;
 494
 495         /* Derive BT specific parameters from the port spec. */
 496         rc = ser_bt_parse_conn_spec(serial, serial->port,
 497                         &conn_type, &remote_addr,
 498                         &rfcomm_channel,
 499                         &read_hdl, &write_hdl,
 500                         &cccd_hdl, &cccd_val,
 501                         &ble_mtu);
 502         if (rc != SR_OK)
 503                 return SR_ERR_ARG;
 504
 505         if (!conn_type || !remote_addr || !remote_addr[0]) {
 506                 /* TODO Auto-search for available connections? */
 507                 return SR_ERR_NA;
 508         }
 509
 510         /* Create the connection. Only store params after successful use. */
 511         desc = sr_bt_desc_new();
 512         if (!desc)
 513                 return SR_ERR;
 514         serial->bt_desc = desc;
 515         rc = sr_bt_config_addr_remote(desc, remote_addr);
 516         if (rc < 0)
 517                 return SR_ERR;
 518         serial->bt_addr_remote = g_strdup(remote_addr);
 519         switch (conn_type) {
 520         case SER_BT_CONN_RFCOMM:
 521                 rc = sr_bt_config_rfcomm(desc, rfcomm_channel);
 522                 if (rc < 0)
 523                         return SR_ERR;
 524                 serial->bt_rfcomm_channel = rfcomm_channel;
 525                 break;
 526         case SER_BT_CONN_BLE122:
 527         case SER_BT_CONN_NRF51:
 528         case SER_BT_CONN_CC254x:
 529         case SER_BT_CONN_AC6328:
 530         case SER_BT_CONN_DIALOG:
 531         case SER_BT_CONN_NOTIFY:
 532                 rc = sr_bt_config_notify(desc,
 533                         read_hdl, write_hdl, cccd_hdl, cccd_val,
 534                         ble_mtu);
 535                 if (rc < 0)
 536                         return SR_ERR;
 537                 serial->bt_notify_handle_read = read_hdl;
 538                 serial->bt_notify_handle_write = write_hdl;
 539                 serial->bt_notify_handle_cccd = cccd_hdl;
 540                 serial->bt_notify_value_cccd = cccd_val;
 541                 serial->bt_ble_mtu = ble_mtu;
 542                 break;
 543         default:
 544                 /* Unsupported type, or incomplete implementation. */
 545                 return SR_ERR_ARG;
 546         }
 547         serial->bt_conn_type = conn_type;
 548
 549         /* Make sure the receive buffer can accept input data. */
 550         if (!serial->rcv_buffer)
 551                 serial->rcv_buffer = g_string_sized_new(SER_BT_CHUNK_SIZE);
 552         rc = sr_bt_config_cb_data(desc, ser_bt_data_cb, serial);
 553         if (rc < 0)
 554                 return SR_ERR;
 555
 556         /* Open the connection. */
 557         switch (conn_type) {
 558         case SER_BT_CONN_RFCOMM:
 559                 rc = sr_bt_connect_rfcomm(desc);
 560                 if (rc < 0)
 561                         return SR_ERR;
 562                 break;
 563         case SER_BT_CONN_BLE122:
 564         case SER_BT_CONN_NRF51:
 565         case SER_BT_CONN_CC254x:
 566         case SER_BT_CONN_AC6328:
 567         case SER_BT_CONN_DIALOG:
 568         case SER_BT_CONN_NOTIFY:
 569                 rc = sr_bt_connect_ble(desc);
 570                 if (rc < 0)
 571                         return SR_ERR;
 572                 rc = sr_bt_start_notify(desc);
 573                 if (rc < 0)
 574                         return SR_ERR;
 575                 break;
 576         default:
 577                 return SR_ERR_ARG;
 578         }
 579
 580         return SR_OK;
 581 }
 582
 583 static int ser_bt_close(struct sr_serial_dev_inst *serial)
 584 {
 585         if (!serial)
 586                 return SR_ERR_ARG;
 587
 588         if (!serial->bt_desc)
 589                 return SR_OK;
 590
 591         sr_bt_disconnect(serial->bt_desc);
 592         sr_bt_desc_free(serial->bt_desc);
 593         serial->bt_desc = NULL;
 594
 595         g_free(serial->bt_addr_local);
 596         serial->bt_addr_local = NULL;
 597         g_free(serial->bt_addr_remote);
 598         serial->bt_addr_remote = NULL;
 599         g_slist_free_full(serial->bt_source_args, g_free);
 600         serial->bt_source_args = NULL;
 601
 602         return SR_OK;
 603 }
 604
 605 /* Flush, discards pending RX data, empties buffers. */
 606 static int ser_bt_flush(struct sr_serial_dev_inst *serial)
 607 {
 608         (void)serial;
 609         /* EMPTY */
 610
 611         return SR_OK;
 612 }
 613
 614 /* Drain, waits for completion of pending TX data. */
 615 static int ser_bt_drain(struct sr_serial_dev_inst *serial)
 616 {
 617         (void)serial;
 618         /* EMPTY */     /* TODO? */
 619
 620         return SR_ERR_BUG;
 621 }
 622
 623 static int ser_bt_write(struct sr_serial_dev_inst *serial,
 624                 const void *buf, size_t count,
 625                 int nonblocking, unsigned int timeout_ms)
 626 {
 627         ssize_t wrlen;
 628
 629         /*
 630          * TODO Support chunked transmission when callers' requests
 631          * exceed the BT channel's capacity? See ser_hid_write().
 632          */
 633
 634         switch (serial->bt_conn_type) {
 635         case SER_BT_CONN_RFCOMM:
 636                 (void)nonblocking;
 637                 (void)timeout_ms;
 638                 wrlen = sr_bt_write(serial->bt_desc, buf, count);
 639                 if (wrlen < 0)
 640                         return SR_ERR_IO;
 641                 return wrlen;
 642         case SER_BT_CONN_BLE122:
 643         case SER_BT_CONN_NRF51:
 644         case SER_BT_CONN_CC254x:
 645         case SER_BT_CONN_AC6328:
 646         case SER_BT_CONN_DIALOG:
 647         case SER_BT_CONN_NOTIFY:
 648                 /*
 649                  * Assume that when applications call the serial layer's
 650                  * write routine, then the BLE chip/module does support
 651                  * a TX handle. Just call the serial-BT library's write
 652                  * routine.
 653                  */
 654                 (void)nonblocking;
 655                 (void)timeout_ms;
 656                 wrlen = sr_bt_write(serial->bt_desc, buf, count);
 657                 if (wrlen < 0)
 658                         return SR_ERR_IO;
 659                 return wrlen;
 660         default:
 661                 return SR_ERR_ARG;
 662         }
 663         /* UNREACH */
 664 }
 665
 666 static int ser_bt_read(struct sr_serial_dev_inst *serial,
 667                 void *buf, size_t count,
 668                 int nonblocking, unsigned int timeout_ms)
 669 {
 670         gint64 deadline_us, now_us;
 671         uint8_t buffer[SER_BT_CHUNK_SIZE];
 672         ssize_t rdlen;
 673         int rc;
 674         size_t dlen;
 675
 676         /*
 677          * Immediately satisfy the caller's request from the RX buffer
 678          * if the requested amount of data is available already.
 679          */
 680         if (sr_ser_has_queued_data(serial) >= count)
 681                 return sr_ser_unqueue_rx_data(serial, buf, count);
 682
 683         /*
 684          * When a timeout was specified, then determine the deadline
 685          * where to stop reception.
 686          */
 687         deadline_us = 0;
 688         if (timeout_ms) {
 689                 now_us = g_get_monotonic_time();
 690                 deadline_us = now_us + timeout_ms * 1000;
 691         }
 692
 693         /*
 694          * Keep receiving from the port until the caller's requested
 695          * amount of data has become available, or the timeout has
 696          * expired. In the absence of a timeout, stop reading when an
 697          * attempt no longer yields receive data.
 698          */
 699         while (TRUE) {
 700                 /* Run another attempt to receive data. */
 701                 switch (serial->bt_conn_type) {
 702                 case SER_BT_CONN_RFCOMM:
 703                         rdlen = sr_bt_read(serial->bt_desc, buffer, sizeof(buffer));
 704                         if (rdlen <= 0)
 705                                 break;
 706                         rc = ser_bt_data_cb(serial, buffer, rdlen);
 707                         if (rc < 0)
 708                                 rdlen = -1;
 709                         break;
 710                 case SER_BT_CONN_BLE122:
 711                 case SER_BT_CONN_NRF51:
 712                 case SER_BT_CONN_CC254x:
 713                 case SER_BT_CONN_AC6328:
 714                 case SER_BT_CONN_DIALOG:
 715                 case SER_BT_CONN_NOTIFY:
 716                         dlen = sr_ser_has_queued_data(serial);
 717                         rc = sr_bt_check_notify(serial->bt_desc);
 718                         if (rc < 0)
 719                                 rdlen = -1;
 720                         else if (sr_ser_has_queued_data(serial) != dlen)
 721                                 rdlen = +1;
 722                         else
 723                                 rdlen = 0;
 724                         break;
 725                 default:
 726                         rdlen = -1;
 727                         break;
 728                 }
 729
 730                 /*
 731                  * Stop upon receive errors, or timeout expiration. Only
 732                  * stop upon empty reception in the absence of a timeout.
 733                  */
 734                 if (rdlen < 0)
 735                         break;
 736                 if (nonblocking && !rdlen)
 737                         break;
 738                 if (deadline_us) {
 739                         now_us = g_get_monotonic_time();
 740                         if (now_us > deadline_us)
 741                                 break;
 742                 }
 743
 744                 /* Also stop when sufficient data has become available. */
 745                 if (sr_ser_has_queued_data(serial) >= count)
 746                         break;
 747         }
 748
 749         /*
 750          * Satisfy the caller's demand for receive data from previously
 751          * queued incoming data.
 752          */
 753         dlen = sr_ser_has_queued_data(serial);
 754         if (dlen > count)
 755                 dlen = count;
 756         if (!dlen)
 757                 return 0;
 758
 759         return sr_ser_unqueue_rx_data(serial, buf, dlen);
 760 }
 761
 762 struct bt_source_args_t {
 763         /* The application callback. */
 764         sr_receive_data_callback cb;
 765         void *cb_data;
 766         /* The serial device, to store RX data. */
 767         struct sr_serial_dev_inst *serial;
 768 };
 769
 770 /*
 771  * Gets periodically invoked by the glib main loop. "Drives" (checks)
 772  * progress of BT communication, and invokes the application's callback
 773  * which processes RX data (when some has become available), as well as
 774  * handles application level timeouts.
 775  */
 776 static int bt_source_cb(int fd, int revents, void *cb_data)
 777 {
 778         struct bt_source_args_t *args;
 779         struct sr_serial_dev_inst *serial;
 780         uint8_t rx_buf[SER_BT_CHUNK_SIZE];
 781         ssize_t rdlen;
 782         size_t dlen;
 783         int rc;
 784
 785         args = cb_data;
 786         if (!args)
 787                 return -1;
 788         serial = args->serial;
 789         if (!serial)
 790                 return -1;
 791         if (!serial->bt_conn_type)
 792                 return -1;
 793
 794         /*
 795          * Drain receive data which the channel might have pending.
 796          * This is "a copy" of the "background part" of ser_bt_read(),
 797          * without the timeout support code, and not knowing how much
 798          * data the application is expecting.
 799          */
 800         do {
 801                 switch (serial->bt_conn_type) {
 802                 case SER_BT_CONN_RFCOMM:
 803                         rdlen = sr_bt_read(serial->bt_desc, rx_buf, sizeof(rx_buf));
 804                         if (rdlen <= 0)
 805                                 break;
 806                         rc = ser_bt_data_cb(serial, rx_buf, rdlen);
 807                         if (rc < 0)
 808                                 rdlen = -1;
 809                         break;
 810                 case SER_BT_CONN_BLE122:
 811                 case SER_BT_CONN_NRF51:
 812                 case SER_BT_CONN_CC254x:
 813                 case SER_BT_CONN_AC6328:
 814                 case SER_BT_CONN_DIALOG:
 815                 case SER_BT_CONN_NOTIFY:
 816                         dlen = sr_ser_has_queued_data(serial);
 817                         rc = sr_bt_check_notify(serial->bt_desc);
 818                         if (rc < 0)
 819                                 rdlen = -1;
 820                         else if (sr_ser_has_queued_data(serial) != dlen)
 821                                 rdlen = +1;
 822                         else
 823                                 rdlen = 0;
 824                         break;
 825                 default:
 826                         rdlen = -1;
 827                         break;
 828                 }
 829         } while (rdlen > 0);
 830
 831         /*
 832          * When RX data became available (now or earlier), pass this
 833          * condition to the application callback. Always periodically
 834          * run the application callback, since it handles timeouts and
 835          * might carry out other tasks as well like signalling progress.
 836          */
 837         if (sr_ser_has_queued_data(args->serial))
 838                 revents |= G_IO_IN;
 839         rc = args->cb(fd, revents, args->cb_data);
 840
 841         return rc;
 842 }
 843
 844 /* TODO Can we use the Bluetooth socket's file descriptor? Probably not portably. */
 845 #define WITH_MAXIMUM_TIMEOUT_VALUE      0
 846 static int ser_bt_setup_source_add(struct sr_session *session,
 847                 struct sr_serial_dev_inst *serial,
 848                 int events, int timeout,
 849                 sr_receive_data_callback cb, void *cb_data)
 850 {
 851         struct bt_source_args_t *args;
 852         int rc;
 853
 854         (void)events;
 855
 856         /* Optionally enforce a minimum poll period. */
 857         if (WITH_MAXIMUM_TIMEOUT_VALUE && timeout > WITH_MAXIMUM_TIMEOUT_VALUE)
 858                 timeout = WITH_MAXIMUM_TIMEOUT_VALUE;
 859
 860         /* Allocate status container for background data reception. */
 861         args = g_malloc0(sizeof(*args));
 862         args->cb = cb;
 863         args->cb_data = cb_data;
 864         args->serial = serial;
 865
 866         /*
 867          * Have a periodic timer installed. Register the allocated block
 868          * with the serial device, since the GSource's finalizer won't
 869          * free the memory, and we haven't bothered to create a custom
 870          * BT specific GSource.
 871          */
 872         rc = sr_session_source_add(session, -1, events, timeout, bt_source_cb, args);
 873         if (rc != SR_OK) {
 874                 g_free(args);
 875                 return rc;
 876         }
 877         serial->bt_source_args = g_slist_append(serial->bt_source_args, args);
 878
 879         return SR_OK;
 880 }
 881
 882 static int ser_bt_setup_source_remove(struct sr_session *session,
 883                 struct sr_serial_dev_inst *serial)
 884 {
 885         (void)serial;
 886
 887         (void)sr_session_source_remove(session, -1);
 888         /* Release callback args here already? */
 889
 890         return SR_OK;
 891 }
 892
 893 struct bt_scan_args_t {
 894         GSList *port_list;
 895         sr_ser_list_append_t append;
 896         GSList *addr_list;
 897         const char *bt_type;
 898 };
 899
 900 static void scan_cb(void *cb_args, const char *addr, const char *name)
 901 {
 902         struct bt_scan_args_t *scan_args;
 903         GSList *l;
 904         char addr_text[20];
 905         const struct scan_supported_item *item;
 906         enum ser_bt_conn_t type;
 907         char *port_name, *port_desc;
 908         char *addr_copy;
 909
 910         scan_args = cb_args;
 911         if (!scan_args)
 912                 return;
 913         sr_info("BT scan, found: %s - %s\n", addr, name);
 914
 915         /* Check whether the device was seen before. */
 916         for (l = scan_args->addr_list; l; l = l->next) {
 917                 if (strcmp(addr, l->data) == 0)
 918                         return;
 919         }
 920
 921         /* Substitute colons in the address by dashes. */
 922         if (!addr || !*addr)
 923                 return;
 924         snprintf(addr_text, sizeof(addr_text), "%s", addr);
 925         g_strcanon(addr_text, "0123456789abcdefABCDEF", '-');
 926
 927         /* Create a port name, and a description. */
 928         item = scan_is_supported(name);
 929         type = item ? item->type : SER_BT_CONN_UNKNOWN;
 930         port_name = g_strdup_printf("%s/%s/%s%s",
 931                 SER_BT_CONN_PREFIX, conn_name_text(type), addr_text,
 932                 (item && item->add_params) ? item->add_params : "");
 933         port_desc = g_strdup_printf("%s (%s)", name, scan_args->bt_type);
 934
 935         scan_args->port_list = scan_args->append(scan_args->port_list, port_name, port_desc);
 936         g_free(port_name);
 937         g_free(port_desc);
 938
 939         /* Keep track of the handled address. */
 940         addr_copy = g_strdup(addr);
 941         scan_args->addr_list = g_slist_append(scan_args->addr_list, addr_copy);
 942 }
 943
 944 static GSList *ser_bt_list(GSList *list, sr_ser_list_append_t append)
 945 {
 946         static const int scan_duration = 3;
 947
 948         struct bt_scan_args_t scan_args;
 949         struct sr_bt_desc *desc;
 950
 951         /*
 952          * Implementor's note: This "list" routine is best-effort. We
 953          * assume that registering callbacks always succeeds. Silently
 954          * ignore failure to scan for devices. Just return those which
 955          * we happen to find.
 956          */
 957
 958         desc = sr_bt_desc_new();
 959         if (!desc)
 960                 return list;
 961
 962         memset(&scan_args, 0, sizeof(scan_args));
 963         scan_args.port_list = list;
 964         scan_args.append = append;
 965
 966         scan_args.addr_list = NULL;
 967         scan_args.bt_type = "BT";
 968         (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
 969         (void)sr_bt_scan_bt(desc, scan_duration);
 970         g_slist_free_full(scan_args.addr_list, g_free);
 971
 972         scan_args.addr_list = NULL;
 973         scan_args.bt_type = "BLE";
 974         (void)sr_bt_config_cb_scan(desc, scan_cb, &scan_args);
 975         (void)sr_bt_scan_le(desc, scan_duration);
 976         g_slist_free_full(scan_args.addr_list, g_free);
 977
 978         sr_bt_desc_free(desc);
 979
 980         return scan_args.port_list;
 981 }
 982
 983 static struct ser_lib_functions serlib_bt = {
 984         .open = ser_bt_open,
 985         .close = ser_bt_close,
 986         .flush = ser_bt_flush,
 987         .drain = ser_bt_drain,
 988         .write = ser_bt_write,
 989         .read = ser_bt_read,
 990         /*
 991          * Bluetooth communication has no concept of bitrate, so ignore
 992          * these arguments silently. Neither need we pass the frame format
 993          * down to internal BT comm routines, nor need we keep the values
 994          * here, since the caller will cache/register them already.
 995          */
 996         .set_params = std_dummy_set_params,
 997         .set_handshake = std_dummy_set_handshake,
 998         .setup_source_add = ser_bt_setup_source_add,
 999         .setup_source_remove = ser_bt_setup_source_remove,
1000         .list = ser_bt_list,
1001         .get_frame_format = NULL,
1002 };
1003 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = &serlib_bt;
1004
1005 /* }}} */
1006 #else
1007
1008 SR_PRIV int ser_name_is_bt(struct sr_serial_dev_inst *serial)
1009 {
1010         (void)serial;
1011
1012         return 0;
1013 }
1014
1015 SR_PRIV struct ser_lib_functions *ser_lib_funcs_bt = NULL;
1016
1017 #endif
1018 #endif
1019
1020 /** @} */