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 <stdlib.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <getopt.h>
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <fcntl.h>
  22 #include <sys/ioctl.h>
  23 #include <errno.h>
  24 #include <termios.h>
  25 #include <unistd.h>
  26 #include <err.h>
  27
  28 #include "c.h"
  29 #include "nls.h"
  30
  31 #define dbg(format, arg...) \
  32         do { if (debug) fprintf(stderr , "%s:" format "\n" , progname , ## arg); } while (0)
  33
  34 #ifndef N_GIGASET_M101
  35 # define N_GIGASET_M101 16
  36 #endif
  37
  38 #ifndef N_PPS
  39 # define N_PPS 18
  40 #endif
  41
  42 /* attach a line discipline ioctl */
  43 #ifndef TIOCSETD
  44 # define TIOCSETD   0x5423
  45 #endif
  46
  47 static const char *progname;
  48 static int debug = 0;
  49
  50 struct ld_table {
  51         const char      *name;
  52         int             value;
  53 };
  54
  55 /* currently supported line disciplines, plus some aliases */
  56 static const struct ld_table ld_discs[] =
  57 {
  58         { "TTY",        N_TTY },
  59         { "SLIP",       N_SLIP },
  60         { "MOUSE",      N_MOUSE },
  61         { "PPP",        N_PPP },
  62         { "STRIP",      N_STRIP },
  63         { "AX25",       N_AX25 },
  64         { "X25",        N_X25 },
  65         { "6PACK",      N_6PACK },
  66         { "R3964",      N_R3964 },
  67         { "IRDA",       N_IRDA },
  68         { "HDLC",       N_HDLC },
  69         { "SYNC_PPP",   N_SYNC_PPP },
  70         { "SYNCPPP",    N_SYNC_PPP },
  71         { "HCI",        N_HCI },
  72         { "GIGASET_M101",       N_GIGASET_M101 },
  73         { "GIGASET",    N_GIGASET_M101 },
  74         { "M101",       N_GIGASET_M101 },
  75         { "PPS",        N_PPS },
  76         { NULL, 0 }
  77 };
  78
  79 static int lookup_table(const struct ld_table *tab, const char *str)
  80 {
  81     const struct ld_table *t;
  82
  83     for (t = tab; t && t->name; t++)
  84         if (!strcasecmp(t->name, str))
  85             return t->value;
  86     return -1;
  87 }
  88
  89 static void print_table(FILE *out, const struct ld_table *tab)
  90 {
  91     const struct ld_table *t;
  92     int i;
  93
  94     for (t = tab, i = 1; t && t->name; t++, i++) {
  95         fprintf(out, "  %-10s", t->name);
  96         if (!(i % 3))
  97                 fputc('\n', out);
  98     }
  99 }
 100
 101 static void __attribute__((__noreturn__)) usage(int exitcode)
 102 {
 103     fprintf(stderr,
 104             _("\nUsage: %s [ -dhV78neo12 ] [ -s <speed> ] <ldisc> <device>\n"),
 105             progname);
 106     fputs(_("\nKnown <ldisc> names:\n"), stderr);
 107     print_table(stderr, ld_discs);
 108
 109     exit(exitcode);
 110 }
 111
 112 static int my_cfsetspeed(struct termios *ts, int speed)
 113 {
 114         /* Standard speeds
 115          * -- cfsetspeed() is able to translate number to Bxxx constants
 116          */
 117         if (cfsetspeed(ts, speed) == 0)
 118                 return 0;
 119
 120         /* Nonstandard speeds
 121          * -- we have to bypass glibc and set the speed manually (because
 122          *    glibc checks for speed and supports Bxxx bit rates only)...
 123          */
 124 #ifdef _HAVE_STRUCT_TERMIOS_C_ISPEED
 125 # define BOTHER 0010000               /* non standard rate */
 126         dbg("using non-standard speeds");
 127         ts->c_ospeed = ts->c_ispeed = speed;
 128         ts->c_cflag &= ~CBAUD;
 129         ts->c_cflag |= BOTHER;
 130         return 0;
 131 #else
 132         return -1;
 133 #endif
 134 }
 135
 136 int main(int argc, char **argv)
 137 {
 138     int tty_fd;
 139     struct termios ts;
 140     int speed = 0, bits = '-', parity = '-', stop = '-';
 141     int ldisc;
 142     int optc;
 143     char *end;
 144     char *dev;
 145     static const struct option opttbl[] = {
 146         {"speed", 1, 0, 's'},
 147         {"sevenbits", 0, 0, '7'},
 148         {"eightbits", 0, 0, '8'},
 149         {"noparity", 0, 0, 'n'},
 150         {"evenparity", 0, 0, 'e'},
 151         {"oddparity", 0, 0, 'o'},
 152         {"onestopbit", 0, 0, '1'},
 153         {"twostopbits", 0, 0, '2'},
 154         {"help", 0, 0, 'h'},
 155         {"version", 0, 0, 'V'},
 156         {"debug", 0, 0, 'd'},
 157         {0, 0, 0, 0}
 158     };
 159
 160     setlocale(LC_ALL, "");
 161     bindtextdomain(PACKAGE, LOCALEDIR);
 162     textdomain(PACKAGE);
 163
 164     /* parse options */
 165     progname = program_invocation_short_name;
 166
 167     if (argc == 0)
 168         usage(EXIT_SUCCESS);
 169     while ((optc = getopt_long(argc, argv, "dhV78neo12s:", opttbl, NULL)) >= 0) {
 170         switch (optc) {
 171         case 'd':
 172             debug++;
 173             break;
 174         case '1':
 175         case '2':
 176             stop = optc;
 177             break;
 178         case '7':
 179         case '8':
 180             bits = optc;
 181             break;
 182         case 'n':
 183         case 'e':
 184         case 'o':
 185             parity = optc;
 186             break;
 187         case 's':
 188             speed = strtol(optarg, &end, 10);
 189             if (*end || speed <= 0)
 190                 errx(EXIT_FAILURE, _("invalid speed: %s"), optarg);
 191             break;
 192         case 'V':
 193             printf(_("ldattach from %s\n"), PACKAGE_STRING);
 194             break;
 195         case 'h':
 196             usage(EXIT_SUCCESS);
 197         default:
 198             warnx(_("invalid option"));
 199             usage(EXIT_FAILURE);
 200         }
 201     }
 202
 203     if (argc - optind != 2)
 204         usage(EXIT_FAILURE);
 205
 206     /* parse line discipline specification */
 207     ldisc = lookup_table(ld_discs, argv[optind]);
 208     if (ldisc < 0) {
 209         ldisc = strtol(argv[optind], &end, 0);
 210         if (*end || ldisc < 0)
 211             errx(EXIT_FAILURE, _("invalid line discipline: %s"), argv[optind]);
 212     }
 213
 214     /* open device */
 215     dev = argv[optind+1];
 216     if ((tty_fd = open(dev, O_RDWR|O_NOCTTY)) < 0)
 217         err(EXIT_FAILURE, _("cannot open %s"), dev);
 218     if (!isatty(tty_fd))
 219         errx(EXIT_FAILURE, _("%s is not a serial line"), dev);
 220
 221     dbg("opened %s", dev);
 222
 223     /* set line speed and format */
 224     if (tcgetattr(tty_fd, &ts) < 0)
 225         err(EXIT_FAILURE, _("cannot get terminal attributes for %s"), dev);
 226     cfmakeraw(&ts);
 227     if (speed && my_cfsetspeed(&ts, speed) < 0)
 228         errx(EXIT_FAILURE, _("speed %d unsupported"), speed);
 229     switch (stop) {
 230     case '1':
 231         ts.c_cflag &= ~CSTOPB;
 232         break;
 233     case '2':
 234         ts.c_cflag |= CSTOPB;
 235         break;
 236     }
 237     switch (bits) {
 238     case '7':
 239         ts.c_cflag = (ts.c_cflag & ~CSIZE) | CS7;
 240         break;
 241     case '8':
 242         ts.c_cflag = (ts.c_cflag & ~CSIZE) | CS8;
 243         break;
 244     }
 245     switch (parity) {
 246     case 'n':
 247         ts.c_cflag &= ~(PARENB|PARODD);
 248         break;
 249     case 'e':
 250         ts.c_cflag |= PARENB;
 251         ts.c_cflag &= ~PARODD;
 252         break;
 253     case 'o':
 254         ts.c_cflag |= (PARENB|PARODD);
 255         break;
 256     }
 257     ts.c_cflag |= CREAD;        /* just to be on the safe side */
 258     if (tcsetattr(tty_fd, TCSAFLUSH, &ts) < 0)
 259         err(EXIT_FAILURE, _("cannot set terminal attributes for %s"), dev);
 260
 261     dbg("set to raw %d %c%c%c: cflag=0x%x",
 262         speed, bits, parity, stop, ts.c_cflag);
 263
 264     /* Attach the line discpline. */
 265     if (ioctl(tty_fd, TIOCSETD, &ldisc) < 0)
 266         err(EXIT_FAILURE, _("cannot set line discipline"));
 267
 268     dbg("line discipline set to %d", ldisc);
 269
 270     /* Go into background if not in debug mode. */
 271     if (!debug && daemon(0, 0) < 0)
 272         err(EXIT_FAILURE, _("cannot daemonize"));
 273
 274     /* Sleep to keep the line discipline active. */
 275     pause();
 276
 277     exit(EXIT_SUCCESS);
 278 }