support/serial.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2
   3 /* serial port functions
   4  *
   5  * Author: Chris Toshok <toshok@ximian.com>
   6  */
   7
   8 #include "map.h"
   9 #include "mph.h"
  10
  11 #include <termios.h>
  12 #include <unistd.h>
  13 #include <fcntl.h>
  14 #include <string.h>
  15 #include <errno.h>
  16 #if defined(HAVE_POLL_H)
  17 #include <poll.h>
  18 #elif defined(HAVE_SYS_POLL_H)
  19 #include <sys/poll.h>
  20 #endif
  21 #include <sys/ioctl.h>
  22
  23 /* This is for ASYNC_*, serial_struct on linux */
  24 #if defined(HAVE_LINUX_SERIAL_H)
  25 #include <linux/serial.h>
  26 #endif
  27
  28 #include <glib.h>
  29
  30 /* This is for FIONREAD on solaris */
  31 #if defined(sun)
  32 #include <sys/filio.h>
  33 #endif
  34
  35 /* sys/time.h (for timeval) is required when using osx 10.3 (but not 10.4) */
  36 /* IOKit is a private framework in iOS, so exclude there */
  37 #if defined(__APPLE__) && !defined(HOST_IOS)
  38 #include <sys/time.h>
  39 #include <IOKit/IOKitLib.h>
  40 #include <IOKit/serial/IOSerialKeys.h>
  41 #include <IOKit/serial/ioss.h>
  42 #include <IOKit/IOBSD.h>
  43 #endif
  44
  45 /* This is a copy of System.IO.Ports.Handshake */
  46 typedef enum {
  47         NoneHandshake = 0,
  48         XOnXOff = 1,
  49         RequestToSend = 2,
  50         RequestToSendXOnXOff = 3
  51 } MonoHandshake;
  52
  53 /* This is a copy of System.IO.Ports.Parity */
  54 typedef enum {
  55         NoneParity = 0,
  56         Odd = 1,
  57         Even = 2,
  58         Mark = 3,
  59         Space = 4
  60 } MonoParity;
  61
  62 /* This is a copy of System.IO.Ports.StopBits */
  63 typedef enum {
  64         NoneStopBits = 0,
  65         One = 1,
  66         Two = 2,
  67         OnePointFive = 3
  68 } MonoStopBits;
  69
  70 /* This is a copy of System.IO.Ports.SerialSignal */
  71 typedef enum {
  72         NoneSignal,
  73         Cd = 1, /* Carrier detect */
  74         Cts = 2, /* Clear to send */
  75         Dsr = 4, /* Data set ready */
  76         Dtr = 8, /* Data terminal ready */
  77         Rts = 16  /* Request to send */
  78 } MonoSerialSignal;
  79
  80 /*
  81  * Silence the compiler, we do not need these prototypes to be public, since these are only
  82  * used by P/Invoke
  83  */
  84
  85 int              open_serial (char *devfile);
  86 int              close_serial (int unix_fd);
  87 guint32          read_serial (int fd, guchar *buffer, int offset, int count);
  88 int              write_serial (int fd, guchar *buffer, int offset, int count, int timeout);
  89 int              discard_buffer (int fd, gboolean input);
  90 gint32           get_bytes_in_buffer (int fd, gboolean input);
  91 gboolean         is_baud_rate_legal (int baud_rate);
  92 int              setup_baud_rate (int baud_rate, gboolean *custom_baud_rate);
  93 gboolean         set_attributes (int fd, int baud_rate, MonoParity parity, int dataBits, MonoStopBits stopBits, MonoHandshake handshake);
  94 MonoSerialSignal get_signals (int fd, gint32 *error);
  95 gint32           set_signal (int fd, MonoSerialSignal signal, gboolean value);
  96 int              breakprop (int fd);
  97 gboolean         poll_serial (int fd, gint32 *error, int timeout);
  98 void            *list_serial_devices (void);
  99
 100 int
 101 open_serial (char *devfile)
 102 {
 103         int fd;
 104         fd = open (devfile, O_RDWR | O_NOCTTY | O_NONBLOCK);
 105
 106         return fd;
 107 }
 108
 109 int
 110 close_serial (int unix_fd)
 111 {
 112         // Linus writes: do not retry close after EINTR
 113         return close (unix_fd);
 114 }
 115
 116 guint32
 117 read_serial (int fd, guchar *buffer, int offset, int count)
 118 {
 119         guint32 n;
 120
 121         n = read (fd, buffer + offset, count);
 122
 123         return (guint32) n;
 124 }
 125
 126 int
 127 write_serial (int fd, guchar *buffer, int offset, int count, int timeout)
 128 {
 129         struct pollfd pinfo;
 130         guint32 n;
 131
 132         pinfo.fd = fd;
 133         pinfo.events = POLLOUT;
 134         pinfo.revents = POLLOUT;
 135
 136         n = count;
 137
 138         while (n > 0)
 139         {
 140                 ssize_t t;
 141
 142                 if (timeout != 0) {
 143                         int c;
 144
 145                         while ((c = poll (&pinfo, 1, timeout)) == -1 && errno == EINTR)
 146                                 ;
 147                         if (c == -1)
 148                                 return -1;
 149                 }
 150
 151                 do {
 152                         t = write (fd, buffer + offset, n);
 153                 } while (t == -1 && errno == EINTR);
 154
 155                 if (t < 0)
 156                         return -1;
 157
 158                 offset += t;
 159                 n -= t;
 160         }
 161
 162         return 0;
 163 }
 164
 165 int
 166 discard_buffer (int fd, gboolean input)
 167 {
 168         return tcflush(fd, input ? TCIFLUSH : TCOFLUSH);
 169 }
 170
 171 gint32
 172 get_bytes_in_buffer (int fd, gboolean input)
 173 {
 174         gint32 retval;
 175
 176         if (ioctl (fd, input ? FIONREAD : TIOCOUTQ, &retval) == -1) {
 177                 return -1;
 178         }
 179
 180         return retval;
 181 }
 182
 183 gboolean
 184 is_baud_rate_legal (int baud_rate)
 185 {
 186         gboolean ignore = FALSE;
 187         return setup_baud_rate (baud_rate, &ignore) != -1;
 188 }
 189
 190 int
 191 setup_baud_rate (int baud_rate, gboolean *custom_baud_rate)
 192 {
 193         switch (baud_rate)
 194         {
 195 /*Some values are not defined on OSX and *BSD */
 196 #if defined(B921600)
 197         case 921600:
 198             baud_rate = B921600;
 199             break;
 200 #endif
 201 #if defined(B460800)
 202         case 460800:
 203             baud_rate = B460800;
 204             break;
 205 #endif
 206         case 230400:
 207             baud_rate = B230400;
 208             break;
 209         case 115200:
 210             baud_rate = B115200;
 211             break;
 212         case 57600:
 213             baud_rate = B57600;
 214             break;
 215         case 38400:
 216             baud_rate = B38400;
 217             break;
 218         case 19200:
 219             baud_rate = B19200;
 220             break;
 221         case 9600:
 222                 baud_rate = B9600;
 223                 break;
 224         case 4800:
 225             baud_rate = B4800;
 226                 break;
 227         case 2400:
 228             baud_rate = B2400;
 229                 break;
 230         case 1800:
 231             baud_rate = B1800;
 232                 break;
 233         case 1200:
 234             baud_rate = B1200;
 235                 break;
 236         case 600:
 237             baud_rate = B600;
 238             break;
 239         case 300:
 240             baud_rate = B300;
 241             break;
 242         case 200:
 243             baud_rate = B200;
 244             break;
 245         case 150:
 246             baud_rate = B150;
 247             break;
 248         case 134:
 249             baud_rate = B134;
 250             break;
 251         case 110:
 252             baud_rate = B110;
 253             break;
 254         case 75:
 255             baud_rate = B75;
 256             break;
 257         case 50:
 258 #ifdef B50
 259             baud_rate = B50;
 260 #else
 261             baud_rate = -1;
 262             break;
 263 #endif
 264         case 0:
 265 #ifdef B0
 266             baud_rate = B0;
 267 #else
 268             baud_rate = -1;
 269 #endif
 270             break;
 271         default:
 272                 *custom_baud_rate = TRUE;
 273                 break;
 274         }
 275         return baud_rate;
 276 }
 277
 278 gboolean
 279 set_attributes (int fd, int baud_rate, MonoParity parity, int dataBits, MonoStopBits stopBits, MonoHandshake handshake)
 280 {
 281         struct termios newtio;
 282         gboolean custom_baud_rate = FALSE;
 283
 284         if (tcgetattr (fd, &newtio) == -1)
 285                 return FALSE;
 286
 287         newtio.c_cflag |=  (CLOCAL | CREAD);
 288         newtio.c_lflag &= ~(ICANON | ECHO | ECHOE | ECHOK | ECHONL | ISIG | IEXTEN );
 289         newtio.c_oflag &= ~(OPOST);
 290         newtio.c_iflag = IGNBRK;
 291
 292         /* setup baudrate */
 293         baud_rate = setup_baud_rate (baud_rate, &custom_baud_rate);
 294
 295         /* char lenght */
 296         newtio.c_cflag &= ~CSIZE;
 297         switch (dataBits)
 298         {
 299         case 5:
 300             newtio.c_cflag |= CS5;
 301             break;
 302         case 6:
 303             newtio.c_cflag |= CS6;
 304             break;
 305         case 7:
 306             newtio.c_cflag |= CS7;
 307             break;
 308         case 8:
 309         default:
 310                 newtio.c_cflag |= CS8;
 311                 break;
 312         }
 313
 314         /* stopbits */
 315         switch (stopBits)
 316         {
 317         case NoneStopBits:
 318                 /* Unhandled */
 319                 break;
 320         case One: /* One */
 321                 /* do nothing, the default is one stop bit */
 322             newtio.c_cflag &= ~CSTOPB;
 323                 break;
 324         case Two: /* Two */
 325                 newtio.c_cflag |= CSTOPB;
 326                 break;
 327         case OnePointFive: /* OnePointFive */
 328                 /* XXX unhandled */
 329                 break;
 330         }
 331
 332         /* parity */
 333         newtio.c_iflag &= ~(INPCK | ISTRIP );
 334
 335         switch (parity)
 336         {
 337         case NoneParity: /* None */
 338             newtio.c_cflag &= ~(PARENB | PARODD);
 339             break;
 340
 341         case Odd: /* Odd */
 342             newtio.c_cflag |= PARENB | PARODD;
 343             break;
 344
 345         case Even: /* Even */
 346             newtio.c_cflag &= ~(PARODD);
 347             newtio.c_cflag |= (PARENB);
 348             break;
 349
 350         case Mark: /* Mark */
 351             /* XXX unhandled */
 352             break;
 353         case Space: /* Space */
 354             /* XXX unhandled */
 355             break;
 356         }
 357
 358         newtio.c_iflag &= ~(IXOFF | IXON);
 359 #ifdef CRTSCTS
 360         newtio.c_cflag &= ~CRTSCTS;
 361 #endif /* def CRTSCTS */
 362
 363         switch (handshake)
 364         {
 365         case NoneHandshake: /* None */
 366                 /* do nothing */
 367                 break;
 368         case RequestToSend: /* RequestToSend (RTS) */
 369 #ifdef CRTSCTS
 370                 newtio.c_cflag |= CRTSCTS;
 371 #endif /* def CRTSCTS */
 372                 break;
 373         case RequestToSendXOnXOff: /* RequestToSendXOnXOff (RTS + XON/XOFF) */
 374 #ifdef CRTSCTS
 375                 newtio.c_cflag |= CRTSCTS;
 376 #endif /* def CRTSCTS */
 377                 /* fall through */
 378         case XOnXOff: /* XOnXOff */
 379             newtio.c_iflag |= IXOFF | IXON;
 380                 break;
 381         }
 382
 383         if (custom_baud_rate == FALSE) {
 384                 if (cfsetospeed (&newtio, baud_rate) < 0 || cfsetispeed (&newtio, baud_rate) < 0)
 385                         return FALSE;
 386         } else {
 387 #if __linux__ || (defined(__APPLE__) && !defined(HOST_IOS))
 388
 389                 /* On Linux to set a custom baud rate, we must set the
 390                  * "standard" baud_rate to 38400.   On Apple we set it purely
 391                  * so that tcsetattr has something to use (and report back later), but
 392                  * the Apple specific API is still opaque to these APIs, see:
 393                  * https://developer.apple.com/library/mac/samplecode/SerialPortSample/Listings/SerialPortSample_SerialPortSample_c.html#//apple_ref/doc/uid/DTS10000454-SerialPortSample_SerialPortSample_c-DontLinkElementID_4
 394                  */
 395                 if (cfsetospeed (&newtio, B38400) < 0 || cfsetispeed (&newtio, B38400) < 0)
 396                         return FALSE;
 397 #endif
 398         }
 399
 400         if (tcsetattr (fd, TCSANOW, &newtio) < 0)
 401                 return FALSE;
 402
 403         if (custom_baud_rate == TRUE){
 404 #if defined(HAVE_LINUX_SERIAL_H)
 405                 struct serial_struct ser;
 406
 407                 if (ioctl (fd, TIOCGSERIAL, &ser) < 0)
 408                 {
 409                         return FALSE;
 410                 }
 411
 412                 ser.custom_divisor = ser.baud_base / baud_rate;
 413                 ser.flags &= ~ASYNC_SPD_MASK;
 414                 ser.flags |= ASYNC_SPD_CUST;
 415
 416                 if (ioctl (fd, TIOCSSERIAL, &ser) < 0)
 417                 {
 418                         return FALSE;
 419                 }
 420 #elif defined(__APPLE__) && !defined(HOST_IOS)
 421                 speed_t speed = baud_rate;
 422                 if (ioctl(fd, IOSSIOSPEED, &speed) == -1)
 423                         return FALSE;
 424 #else
 425                 /* Don't know how to set custom baud rate on this platform. */
 426                 return FALSE;
 427 #endif
 428         }
 429
 430         return TRUE;
 431 }
 432
 433
 434 static gint32
 435 get_signal_code (MonoSerialSignal signal)
 436 {
 437         switch (signal) {
 438                 case Cd:
 439                         return TIOCM_CAR;
 440                 case Cts:
 441                         return TIOCM_CTS;
 442                 case Dsr:
 443                         return TIOCM_DSR;
 444                 case Dtr:
 445                         return TIOCM_DTR;
 446                 case Rts:
 447                         return TIOCM_RTS;
 448                 default:
 449                         return 0;
 450         }
 451
 452         /* Not reached */
 453         return 0;
 454 }
 455
 456 static MonoSerialSignal
 457 get_mono_signal_codes (int signals)
 458 {
 459         MonoSerialSignal retval = NoneSignal;
 460
 461         if ((signals & TIOCM_CAR) != 0)
 462                 retval |= Cd;
 463         if ((signals & TIOCM_CTS) != 0)
 464                 retval |= Cts;
 465         if ((signals & TIOCM_DSR) != 0)
 466                 retval |= Dsr;
 467         if ((signals & TIOCM_DTR) != 0)
 468                 retval |= Dtr;
 469         if ((signals & TIOCM_RTS) != 0)
 470                 retval |= Rts;
 471
 472         return retval;
 473 }
 474
 475 MonoSerialSignal
 476 get_signals (int fd, gint32 *error)
 477 {
 478         int signals;
 479
 480         *error = 0;
 481
 482         if (ioctl (fd, TIOCMGET, &signals) == -1) {
 483                 *error = -1;
 484                 return NoneSignal;
 485         }
 486
 487         return get_mono_signal_codes (signals);
 488 }
 489
 490 gint32
 491 set_signal (int fd, MonoSerialSignal signal, gboolean value)
 492 {
 493         int signals, expected, activated;
 494
 495         expected = get_signal_code (signal);
 496         if (ioctl (fd, TIOCMGET, &signals) == -1)
 497                 return -1;
 498
 499         activated = (signals & expected) != 0;
 500         if (activated == value) /* Already set */
 501                 return 1;
 502
 503         if (value)
 504                 signals |= expected;
 505         else
 506                 signals &= ~expected;
 507
 508         if (ioctl (fd, TIOCMSET, &signals) == -1)
 509                 return -1;
 510
 511         return 1;
 512 }
 513
 514 int
 515 breakprop (int fd)
 516 {
 517         return tcsendbreak (fd, 0);
 518 }
 519
 520 gboolean
 521 poll_serial (int fd, gint32 *error, int timeout)
 522 {
 523         struct pollfd pinfo;
 524
 525         *error = 0;
 526
 527         pinfo.fd = fd;
 528         pinfo.events = POLLIN;
 529         pinfo.revents = 0;
 530
 531         while (poll (&pinfo, 1, timeout) == -1 && errno == EINTR) {
 532                 /* EINTR is an OK condition, we should not throw in the upper layer an IOException */
 533                 if (errno != EINTR){
 534                         *error = -1;
 535                         return FALSE;
 536                 }
 537         }
 538
 539         return (pinfo.revents & POLLIN) != 0 ? 1 : 0;
 540 }
 541
 542 /*
 543  * mono internals should not be used here.
 544  * this serial stuff needs to be implemented with icalls.
 545  * make this at least compile until the code is moved elsewhere
 546  * defined(linux) is wrong, too
 547  */
 548 void*
 549 list_serial_devices (void)
 550 {
 551         return NULL;
 552 }
 553
 554 #if 0
 555 MonoArray *
 556 list_serial_devices (void)
 557 {
 558         MonoArray *array;
 559 #if defined(linux)
 560         /* Linux serial files are of the form ttyS[0-9]+ */
 561         GSList *l, *list = NULL;
 562         GDir* dir = g_dir_open ("/dev", 0, NULL);
 563         const char *filename;
 564         int i = 0;
 565
 566         while ((filename = g_dir_read_name (dir))) {
 567                 if (filename) {
 568                         if (!strncmp (filename, "ttyS", 4))
 569                                 list = g_slist_append (list, g_strconcat ("/dev/", filename, NULL));
 570                 }
 571         }
 572
 573         g_dir_close (dir);
 574
 575         array = mono_array_new (mono_domain_get (), mono_get_string_class (), g_slist_length (list));
 576         for (l = list; l; l = l->next) {
 577                 mono_array_set (array, gpointer, i++, mono_string_new (mono_domain_get (), (char*)l->data));
 578                 g_free (l->data);
 579         }
 580
 581         g_slist_free (list);
 582
 583 #else
 584 #warning "list_serial_devices isn't ported to this OS"
 585 #endif
 586
 587         return array;
 588 }
 589 #endif
 590