sys-utils/ldattach.c

   1 /* line discipline loading daemon
   2  * open a serial device and attach a line discipline on it
   3  *
   4  * Usage:
   5  *      ldattach GIGASET_M101 /dev/ttyS0
   6  *
   7  * =====================================================================
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  * =====================================================================
  13  */
  14
  15 #include <errno.h>
  16 #include <fcntl.h>
  17 #include <getopt.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/ioctl.h>
  22 #include <sys/stat.h>
  23 #include <sys/types.h>
  24 #include <termios.h>
  25 #include <unistd.h>
  26
  27 #include "c.h"
  28 #include "nls.h"
  29 #include "strutils.h"
  30 #include "closestream.h"
  31
  32 #ifndef N_GIGASET_M101
  33 # define N_GIGASET_M101 16
  34 #endif
  35
  36 #ifndef N_PPS
  37 # define N_PPS 18
  38 #endif
  39
  40 /* attach a line discipline ioctl */
  41 #ifndef TIOCSETD
  42 # define TIOCSETD   0x5423
  43 #endif
  44
  45 static int debug = 0;
  46
  47 struct ld_table {
  48         const char *name;
  49         int value;
  50 };
  51
  52 /* currently supported line disciplines, plus some aliases */
  53 static const struct ld_table ld_discs[] = {
  54         { "TTY",                N_TTY },
  55         { "SLIP",               N_SLIP },
  56         { "MOUSE",              N_MOUSE },
  57         { "PPP",                N_PPP },
  58         { "STRIP",              N_STRIP },
  59         { "AX25",               N_AX25 },
  60         { "X25",                N_X25 },
  61         { "6PACK",              N_6PACK },
  62         { "R3964",              N_R3964 },
  63         { "IRDA",               N_IRDA },
  64         { "HDLC",               N_HDLC },
  65         { "SYNC_PPP",           N_SYNC_PPP },
  66         { "SYNCPPP",            N_SYNC_PPP },
  67         { "HCI",                N_HCI },
  68         { "PPS",                N_PPS },
  69         { "M101",               N_GIGASET_M101 },
  70         { "GIGASET",            N_GIGASET_M101 },
  71         { "GIGASET_M101",       N_GIGASET_M101 },
  72         { NULL,                 0 }
  73 };
  74
  75 /* known c_iflag names */
  76 static const struct ld_table ld_iflags[] =
  77 {
  78         { "IGNBRK",     IGNBRK },
  79         { "BRKINT",     BRKINT },
  80         { "IGNPAR",     IGNPAR },
  81         { "PARMRK",     PARMRK },
  82         { "INPCK",      INPCK },
  83         { "ISTRIP",     ISTRIP },
  84         { "INLCR",      INLCR },
  85         { "IGNCR",      IGNCR },
  86         { "ICRNL",      ICRNL },
  87         { "IUCLC",      IUCLC },
  88         { "IXON",       IXON },
  89         { "IXANY",      IXANY },
  90         { "IXOFF",      IXOFF },
  91         { "IMAXBEL",    IMAXBEL },
  92         { "IUTF8",      IUTF8 },
  93         { NULL,         0 }
  94 };
  95
  96 static void dbg(char *fmt, ...)
  97 {
  98         va_list args;
  99
 100         if (debug == 0)
 101                 return;
 102         fflush(NULL);
 103         fprintf(stderr, "%s: ", program_invocation_short_name);
 104         va_start(args, fmt);
 105         vfprintf(stderr, fmt, args);
 106         va_end(args);
 107         fprintf(stderr, "\n");
 108         fflush(NULL);
 109         return;
 110 }
 111
 112 static int lookup_table(const struct ld_table *tab, const char *str)
 113 {
 114         const struct ld_table *t;
 115
 116         for (t = tab; t && t->name; t++)
 117                 if (!strcasecmp(t->name, str))
 118                         return t->value;
 119         return -1;
 120 }
 121
 122 static void print_table(FILE * out, const struct ld_table *tab)
 123 {
 124         const struct ld_table *t;
 125         int i;
 126
 127         for (t = tab, i = 1; t && t->name; t++, i++) {
 128                 fprintf(out, "  %-10s", t->name);
 129                 if (!(i % 6))
 130                         fputc('\n', out);
 131         }
 132 }
 133
 134 static int parse_iflag(char *str, int *set_iflag, int *clr_iflag)
 135 {
 136         int iflag;
 137         char *s;
 138
 139         for (s = strtok(str, ","); s != NULL; s = strtok(NULL, ",")) {
 140                 if (*s == '-')
 141                         s++;
 142                 if ((iflag = lookup_table(ld_iflags, s)) < 0)
 143                         iflag = strtos32_or_err(s, _("invalid iflag"));
 144                 if (s > str && *(s - 1) == '-')
 145                         *clr_iflag |= iflag;
 146                 else
 147                         *set_iflag |= iflag;
 148         }
 149         dbg("iflag (set/clear): %d/%d", *set_iflag, *clr_iflag);
 150         return 0;
 151 }
 152
 153
 154 static void __attribute__ ((__noreturn__)) usage(int exitcode)
 155 {
 156         FILE *out = exitcode == EXIT_SUCCESS ? stdout : stderr;
 157
 158         fputs(USAGE_HEADER, out);
 159         fprintf(out, _(" %s [options] <ldisc> <device>\n"), program_invocation_short_name);
 160         fputs(USAGE_OPTIONS, out);
 161
 162         fputs(_(" -d, --debug             print verbose messages to stderr\n"), out);
 163         fputs(_(" -s, --speed <value>     set serial line speed\n"), out);
 164         fputs(_(" -7, --sevenbits         set character size to 7 bits\n"), out);
 165         fputs(_(" -8, --eightbits         set character size to 8 bits\n"), out);
 166         fputs(_(" -n, --noparity          set parity to none\n"), out);
 167         fputs(_(" -e, --evenparity        set parity to even\n"), out);
 168         fputs(_(" -o, --oddparity         set parity to odd\n"), out);
 169         fputs(_(" -1, --onestopbit        set stop bits to one\n"), out);
 170         fputs(_(" -2, --twostopbits       set stop bits to two\n"), out);
 171         fputs(_(" -i, --iflag [-]<iflag>  set input mode flag\n"), out);
 172
 173         fputs(USAGE_SEPARATOR, out);
 174         fputs(USAGE_HELP, out);
 175         fputs(USAGE_VERSION, out);
 176         fputs(_("\nKnown <ldisc> names:\n"), out);
 177         print_table(out, ld_discs);
 178         fputs(_("\nKnown <iflag> names:\n"), out);
 179         print_table(out, ld_iflags);
 180         fputc('\n', out);
 181         fprintf(out, USAGE_MAN_TAIL("ldattach(8)"));
 182         exit(exitcode);
 183 }
 184
 185 static int my_cfsetspeed(struct termios *ts, int speed)
 186 {
 187         /* Standard speeds
 188          * -- cfsetspeed() is able to translate number to Bxxx constants
 189          */
 190         if (cfsetspeed(ts, speed) == 0)
 191                 return 0;
 192
 193         /* Nonstandard speeds
 194          * -- we have to bypass glibc and set the speed manually (because glibc
 195          *    checks for speed and supports Bxxx bit rates only)...
 196          */
 197 #ifdef _HAVE_STRUCT_TERMIOS_C_ISPEED
 198 # define BOTHER 0010000         /* non standard rate */
 199         dbg("using non-standard speeds");
 200         ts->c_ospeed = ts->c_ispeed = speed;
 201         ts->c_cflag &= ~CBAUD;
 202         ts->c_cflag |= BOTHER;
 203         return 0;
 204 #else
 205         return -1;
 206 #endif
 207 }
 208
 209 int main(int argc, char **argv)
 210 {
 211         int tty_fd;
 212         struct termios ts;
 213         int speed = 0, bits = '-', parity = '-', stop = '-';
 214         int set_iflag = 0, clr_iflag = 0;
 215         int ldisc;
 216         int optc;
 217         char *dev;
 218         static const struct option opttbl[] = {
 219                 {"speed", required_argument, NULL, 's'},
 220                 {"sevenbits", no_argument, NULL, '7'},
 221                 {"eightbits", no_argument, NULL, '8'},
 222                 {"noparity", no_argument, NULL, 'n'},
 223                 {"evenparity", no_argument, NULL, 'e'},
 224                 {"oddparity", no_argument, NULL, 'o'},
 225                 {"onestopbit", no_argument, NULL, '1'},
 226                 {"twostopbits", no_argument, NULL, '2'},
 227                 {"iflag", required_argument, NULL, 'i'},
 228                 {"help", no_argument, NULL, 'h'},
 229                 {"version", no_argument, NULL, 'V'},
 230                 {"debug", no_argument, NULL, 'd'},
 231                 {NULL, 0, NULL, 0}
 232         };
 233
 234         setlocale(LC_ALL, "");
 235         bindtextdomain(PACKAGE, LOCALEDIR);
 236         textdomain(PACKAGE);
 237         atexit(close_stdout);
 238
 239         /* parse options */
 240         if (argc == 0)
 241                 usage(EXIT_SUCCESS);
 242         while ((optc =
 243                 getopt_long(argc, argv, "dhV78neo12s:i:", opttbl,
 244                             NULL)) >= 0) {
 245                 switch (optc) {
 246                 case 'd':
 247                         debug = 1;
 248                         break;
 249                 case '1':
 250                 case '2':
 251                         stop = optc;
 252                         break;
 253                 case '7':
 254                 case '8':
 255                         bits = optc;
 256                         break;
 257                 case 'n':
 258                 case 'e':
 259                 case 'o':
 260                         parity = optc;
 261                         break;
 262                 case 's':
 263                         speed = strtos32_or_err(optarg, _("invalid speed argument"));
 264                         break;
 265                 case 'i':
 266                         parse_iflag(optarg, &set_iflag, &clr_iflag);
 267                         break;
 268                 case 'V':
 269                         printf(UTIL_LINUX_VERSION);
 270                         return EXIT_SUCCESS;
 271                 case 'h':
 272                         usage(EXIT_SUCCESS);
 273                 default:
 274                         warnx(_("invalid option"));
 275                         usage(EXIT_FAILURE);
 276                 }
 277         }
 278
 279         if (argc - optind != 2)
 280                 usage(EXIT_FAILURE);
 281
 282         /* parse line discipline specification */
 283         ldisc = lookup_table(ld_discs, argv[optind]);
 284         if (ldisc < 0)
 285                 ldisc = strtos32_or_err(argv[optind], _("invalid line discipline argument"));
 286
 287         /* open device */
 288         dev = argv[optind + 1];
 289         if ((tty_fd = open(dev, O_RDWR | O_NOCTTY)) < 0)
 290                 err(EXIT_FAILURE, _("cannot open %s"), dev);
 291         if (!isatty(tty_fd))
 292                 errx(EXIT_FAILURE, _("%s is not a serial line"), dev);
 293
 294         dbg("opened %s", dev);
 295
 296         /* set line speed and format */
 297         if (tcgetattr(tty_fd, &ts) < 0)
 298                 err(EXIT_FAILURE,
 299                     _("cannot get terminal attributes for %s"), dev);
 300         cfmakeraw(&ts);
 301         if (speed && my_cfsetspeed(&ts, speed) < 0)
 302                 errx(EXIT_FAILURE, _("speed %d unsupported"), speed);
 303
 304         switch (stop) {
 305         case '1':
 306                 ts.c_cflag &= ~CSTOPB;
 307                 break;
 308         case '2':
 309                 ts.c_cflag |= CSTOPB;
 310                 break;
 311         case '-':
 312                 break;
 313         default:
 314                 abort();
 315         }
 316         switch (bits) {
 317         case '7':
 318                 ts.c_cflag = (ts.c_cflag & ~CSIZE) | CS7;
 319                 break;
 320         case '8':
 321                 ts.c_cflag = (ts.c_cflag & ~CSIZE) | CS8;
 322                 break;
 323         case '-':
 324                 break;
 325         default:
 326                 abort();
 327         }
 328         switch (parity) {
 329         case 'n':
 330                 ts.c_cflag &= ~(PARENB | PARODD);
 331                 break;
 332         case 'e':
 333                 ts.c_cflag |= PARENB;
 334                 ts.c_cflag &= ~PARODD;
 335                 break;
 336         case 'o':
 337                 ts.c_cflag |= (PARENB | PARODD);
 338                 break;
 339         case '-':
 340                 break;
 341         default:
 342                 abort();
 343         }
 344
 345         ts.c_cflag |= CREAD;    /* just to be on the safe side */
 346         ts.c_iflag |= set_iflag;
 347         ts.c_iflag &= ~clr_iflag;
 348
 349         if (tcsetattr(tty_fd, TCSAFLUSH, &ts) < 0)
 350                 err(EXIT_FAILURE,
 351                     _("cannot set terminal attributes for %s"), dev);
 352
 353         dbg("set to raw %d %c%c%c: cflag=0x%x",
 354             speed, bits, parity, stop, ts.c_cflag);
 355
 356         /* Attach the line discpline. */
 357         if (ioctl(tty_fd, TIOCSETD, &ldisc) < 0)
 358                 err(EXIT_FAILURE, _("cannot set line discipline"));
 359
 360         dbg("line discipline set to %d", ldisc);
 361
 362         /* Go into background if not in debug mode. */
 363         if (!debug && daemon(0, 0) < 0)
 364                 err(EXIT_FAILURE, _("cannot daemonize"));
 365
 366         /* Sleep to keep the line discipline active. */
 367         pause();
 368
 369         exit(EXIT_SUCCESS);
 370 }