jim-tty.c

   1 /*
   2  * Support for tty settings using termios
   3  *
   4  * (c) 2016 Steve Bennett <steveb@workware.net.au>
   5  *
   6  */
   7
   8 /* termios support is required */
   9
  10 #include <jim-tty.h>
  11 #include <termios.h>
  12
  13 static const struct {
  14     unsigned baud;
  15     speed_t speed;
  16 } baudtable[] = {
  17     { 0, B0 },
  18     { 50, B50 },
  19     { 75, B75 },
  20     { 110, B110 },
  21     { 134, B134 },
  22     { 150, B150 },
  23     { 200, B200 },
  24     { 300, B300 },
  25     { 600, B600 },
  26     { 1200, B1200 },
  27     { 1800, B1800 },
  28     { 2400, B2400 },
  29     { 4800, B4800 },
  30     { 9600, B9600 },
  31     { 19200, B19200 },
  32     { 38400, B38400 },
  33     { 57600, B57600 },
  34     { 115200, B115200 },
  35 #ifdef B230400
  36     { 230400, B230400 },
  37 #endif
  38 #ifdef B460800
  39     { 460800, B460800 }
  40 #endif
  41 };
  42
  43 struct flag_name_map {
  44     const char *name;
  45     unsigned value;
  46 };
  47
  48 static const struct flag_name_map parity_map[] = {
  49     { "none", 0 },
  50     { "even", PARENB },
  51     { "odd", PARENB | PARODD },
  52 };
  53 static const struct flag_name_map data_size_map[] = {
  54     { "5", CS5 },
  55     { "6", CS6 },
  56     { "7", CS7 },
  57     { "8", CS8 },
  58 };
  59 static const struct flag_name_map stop_size_map[] = {
  60     { "1", 0 },
  61     { "2", CSTOPB },
  62 };
  63 static const struct flag_name_map input_map[] = {
  64     { "raw", 0 },
  65     { "cooked", ICANON },
  66 };
  67 static const struct flag_name_map output_map[] = {
  68     { "raw", 0 },
  69     { "cooked", OPOST },
  70 };
  71
  72 static const char * const tty_settings_names[] = {
  73     "baud",
  74     "data",
  75     "handshake",
  76     "input",
  77     "output",
  78     "parity",
  79     "stop",
  80     "vmin",
  81     "vtime",
  82     NULL
  83 };
  84
  85 enum {
  86     OPT_BAUD,
  87     OPT_DATA,
  88     OPT_HANDSHAKE,
  89     OPT_INPUT,
  90     OPT_OUTPUT,
  91     OPT_PARITY,
  92     OPT_STOP,
  93     OPT_VMIN,
  94     OPT_VTIME
  95 };
  96
  97
  98 #define ARRAYSIZE(A) (sizeof(A)/sizeof(*(A)))
  99
 100 /**
 101  * Search the flag/name map for an entry with the given name.
 102  * (Actually, just matching the first char)
 103  * Returns a pointer to the entry if found, or NULL if not.
 104  */
 105 static const struct flag_name_map *flag_name_to_value(const struct flag_name_map *map, int len, const char *name)
 106 {
 107     int i;
 108
 109     for (i = 0; i < len; i++) {
 110         /* Only need to compare the first character since all names are unique in the first char */
 111         if (*name == *map[i].name) {
 112             return &map[i];
 113         }
 114     }
 115     return NULL;
 116 }
 117
 118 /**
 119  * Search the flag/name map for an entry with the matching value.
 120  * Returns the corresponding name if found, or NULL if no match.
 121  */
 122 static const char *flag_value_to_name(const struct flag_name_map *map, int len, unsigned value)
 123 {
 124     int i;
 125
 126     for (i = 0; i < len; i++) {
 127         if (value == map[i].value) {
 128             return map[i].name;
 129         }
 130     }
 131     return NULL;
 132 }
 133
 134 /**
 135  * If 'str2' is not NULL, appends 'str1' and 'str2' to the list.
 136  * Otherwise does nothing.
 137  */
 138 static void JimListAddPair(Jim_Interp *interp, Jim_Obj *listObjPtr, const char *str1, const char *str2)
 139 {
 140     if (str2) {
 141         Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, str1, -1));
 142         Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, str2, -1));
 143     }
 144 }
 145
 146 Jim_Obj *Jim_GetTtySettings(Jim_Interp *interp, int fd)
 147 {
 148     struct termios tio;
 149     size_t i;
 150     const char *p;
 151     Jim_Obj *listObjPtr;
 152     speed_t speed;
 153     int baud;
 154
 155     if (tcgetattr(fd, &tio) < 0) {
 156         return NULL;
 157     }
 158
 159     listObjPtr = Jim_NewListObj(interp, NULL, 0);
 160
 161     p = flag_value_to_name(parity_map, ARRAYSIZE(parity_map), tio.c_cflag & (PARENB | PARODD));
 162     JimListAddPair(interp, listObjPtr, "parity", p);
 163     p = flag_value_to_name(data_size_map, ARRAYSIZE(data_size_map), tio.c_cflag & CSIZE);
 164     JimListAddPair(interp, listObjPtr, "data", p);
 165     p = flag_value_to_name(stop_size_map, ARRAYSIZE(stop_size_map), tio.c_cflag & CSTOPB);
 166     JimListAddPair(interp, listObjPtr, "stop", p);
 167     if (tio.c_iflag & (IXON | IXOFF)) {
 168         p = "xonxoff";
 169     }
 170     else if (tio.c_cflag & CRTSCTS) {
 171         p = "rtscts";
 172     }
 173     else {
 174         p = "none";
 175     }
 176     JimListAddPair(interp, listObjPtr, "handshake", p);
 177     p = flag_value_to_name(input_map, ARRAYSIZE(input_map), tio.c_lflag & ICANON);
 178     JimListAddPair(interp, listObjPtr, "input", p);
 179     p = flag_value_to_name(output_map, ARRAYSIZE(output_map), tio.c_oflag & OPOST);
 180     JimListAddPair(interp, listObjPtr, "output", p);
 181
 182     Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, "vmin", -1));
 183     Jim_ListAppendElement(interp, listObjPtr, Jim_NewIntObj(interp, tio.c_cc[VMIN]));
 184     Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, "vtime", -1));
 185     Jim_ListAppendElement(interp, listObjPtr, Jim_NewIntObj(interp, tio.c_cc[VTIME]));
 186
 187     speed = cfgetispeed(&tio);
 188     baud = 0;
 189     for (i = 0; i < sizeof(baudtable) / sizeof(*baudtable); i++) {
 190         if (baudtable[i].speed == speed) {
 191             baud = baudtable[i].baud;
 192             break;
 193         }
 194     }
 195     Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, "baud", -1));
 196     Jim_ListAppendElement(interp, listObjPtr, Jim_NewIntObj(interp, baud));
 197
 198     return listObjPtr;
 199 }
 200
 201 int Jim_SetTtySettings(Jim_Interp *interp, int fd, Jim_Obj *dictObjPtr)
 202 {
 203     int len = Jim_ListLength(interp, dictObjPtr);
 204     int i;
 205
 206     struct termios tio;
 207
 208     if (tcgetattr(fd, &tio) < 0) {
 209         return -1;
 210     }
 211
 212     for (i = 0; i < len; i += 2) {
 213         Jim_Obj *nameObj = Jim_ListGetIndex(interp, dictObjPtr, i);
 214         Jim_Obj *valueObj = Jim_ListGetIndex(interp, dictObjPtr, i + 1);
 215         int opt;
 216         const struct flag_name_map *p;
 217         long l;
 218         size_t j;
 219
 220         if (Jim_GetEnum(interp, nameObj, tty_settings_names, &opt, "setting", JIM_ERRMSG | JIM_ENUM_ABBREV) != JIM_OK) {
 221             return JIM_ERR;
 222         }
 223
 224         switch (opt) {
 225             case OPT_BAUD:
 226                 if (Jim_GetLong(interp, valueObj, &l) != JIM_OK) {
 227                     goto badvalue;
 228                 }
 229                 for (j = 0; j < ARRAYSIZE(baudtable); j++) {
 230                     if (baudtable[j].baud == l) {
 231                         break;
 232                     }
 233                 }
 234                 if (j == ARRAYSIZE(baudtable)) {
 235                     goto badvalue;
 236                 }
 237                 cfsetospeed(&tio, baudtable[j].speed);
 238                 cfsetispeed(&tio, baudtable[j].speed);
 239                 break;
 240
 241             case OPT_PARITY:
 242                 p = flag_name_to_value(parity_map, ARRAYSIZE(parity_map), Jim_String(valueObj));
 243                 if (p == NULL) {
 244 badvalue:
 245                     Jim_SetResultFormatted(interp, "bad value for %#s: %#s", nameObj, valueObj);
 246                     return JIM_ERR;
 247                 }
 248                 tio.c_cflag &= ~(PARENB | PARODD);
 249                 tio.c_cflag |= p->value;
 250                 break;
 251
 252             case OPT_STOP:
 253                 p = flag_name_to_value(stop_size_map, ARRAYSIZE(stop_size_map), Jim_String(valueObj));
 254                 if (p == NULL) {
 255                     goto badvalue;
 256                 }
 257                 tio.c_cflag &= ~CSTOPB;
 258                 tio.c_cflag |= p->value;
 259                 break;
 260
 261             case OPT_DATA:
 262                 p = flag_name_to_value(data_size_map, ARRAYSIZE(data_size_map), Jim_String(valueObj));
 263                 if (p == NULL) {
 264                     goto badvalue;
 265                 }
 266                 tio.c_cflag &= ~CSIZE;
 267                 tio.c_cflag |= p->value;
 268                 break;
 269
 270             case OPT_HANDSHAKE:
 271                 tio.c_iflag &= ~(IXON | IXOFF);
 272                 tio.c_cflag &= ~(CRTSCTS);
 273                 if (Jim_CompareStringImmediate(interp, valueObj, "xonxoff")) {
 274                     tio.c_iflag |= (IXON | IXOFF);
 275                 }
 276                 else if (Jim_CompareStringImmediate(interp, valueObj, "rtscts")) {
 277                     tio.c_cflag |= CRTSCTS;
 278                 }
 279                 else if (!Jim_CompareStringImmediate(interp, valueObj, "none")) {
 280                     goto badvalue;
 281                 }
 282                 break;
 283
 284             case OPT_VMIN:
 285                 if (Jim_GetLong(interp, valueObj, &l) != JIM_OK) {
 286                     goto badvalue;
 287                 }
 288                 tio.c_cc[VMIN] = l;
 289                 break;
 290
 291             case OPT_VTIME:
 292                 if (Jim_GetLong(interp, valueObj, &l) != JIM_OK) {
 293                     goto badvalue;
 294                 }
 295                 tio.c_cc[VTIME] = l;
 296                 break;
 297
 298             case OPT_OUTPUT:
 299                 p = flag_name_to_value(output_map, ARRAYSIZE(output_map), Jim_String(valueObj));
 300                 if (p == NULL) {
 301                     goto badvalue;
 302                 }
 303                 tio.c_oflag &= ~OPOST;
 304                 tio.c_oflag |= p->value;
 305                 break;
 306
 307             case OPT_INPUT:
 308                 p = flag_name_to_value(input_map, ARRAYSIZE(input_map), Jim_String(valueObj));
 309                 if (p == NULL) {
 310                     goto badvalue;
 311                 }
 312                 if (p->value) {
 313                     tio.c_lflag |= (ECHO | ECHOE | ECHOK | ECHONL | ICANON | IEXTEN | ISIG | NOFLSH | TOSTOP);
 314                     tio.c_iflag |= ICRNL;
 315                 }
 316                 else {
 317                     tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL | ICANON | IEXTEN | ISIG | NOFLSH | TOSTOP);
 318                     tio.c_iflag &= ~ICRNL;
 319                 }
 320                 break;
 321
 322         }
 323     }
 324
 325     if (tcsetattr(fd, TCSAFLUSH, &tio) < 0) {
 326         return -1;
 327     }
 328     return 0;
 329 }