usr.sbin/watch/watch.c

   1 /*
   2  * Copyright (c) 1995 Ugen J.S.Antsilevich
   3  *
   4  * Redistribution and use in source forms, with and without modification,
   5  * are permitted provided that this entire comment appears intact.
   6  *
   7  * Redistribution in binary form may occur without any restrictions.
   8  * Obviously, it would be nice if you gave credit where credit is due
   9  * but requiring it would be too onerous.
  10  *
  11  * This software is provided ``AS IS'' without any warranties of any kind.
  12  *
  13  * Snoop stuff.
  14  */
  15
  16 #ifndef lint
  17 static const char rcsid[] =
  18   "$FreeBSD$";
  19 #endif /* not lint */
  20
  21 #include <sys/param.h>
  22 #include <sys/fcntl.h>
  23 #include <sys/filio.h>
  24 #include <sys/snoop.h>
  25 #include <sys/stat.h>
  26 #include <sys/linker.h>
  27 #include <sys/module.h>
  28
  29 #include <err.h>
  30 #include <locale.h>
  31 #include <paths.h>
  32 #include <signal.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <sysexits.h>
  37 #include <termcap.h>
  38 #include <termios.h>
  39 #include <unistd.h>
  40
  41 #define MSG_INIT        "Snoop started."
  42 #define MSG_OFLOW       "Snoop stopped due to overflow. Reconnecting."
  43 #define MSG_CLOSED      "Snoop stopped due to tty close. Reconnecting."
  44 #define MSG_CHANGE      "Snoop device change by user request."
  45 #define MSG_NOWRITE     "Snoop device change due to write failure."
  46
  47
  48 #define DEV_NAME_LEN    1024    /* for /dev/ttyXX++ */
  49 #define MIN_SIZE        256
  50
  51 #define CHR_SWITCH      24      /* Ctrl+X        */
  52 #define CHR_CLEAR       23      /* Ctrl+V        */
  53
  54 static void     clear __P((void));
  55 static void     timestamp  __P((const char *));
  56 static void     set_tty __P((void));
  57 static void     unset_tty __P((void));
  58 static void     fatal __P((int, const char *));
  59 static int      open_snp __P((void));
  60 static void     cleanup __P((int));
  61 static void     usage __P((void));
  62 static void     setup_scr __P((void));
  63 static void     attach_snp __P((void));
  64 static void     detach_snp __P((void));
  65 static void     set_dev __P((const char *));
  66 static void     ask_dev __P((char *, const char *));
  67
  68 int             opt_reconn_close = 0;
  69 int             opt_reconn_oflow = 0;
  70 int             opt_interactive = 1;
  71 int             opt_timestamp = 0;
  72 int             opt_write = 0;
  73 int             opt_no_switch = 0;
  74 const char      *opt_snpdev;
  75
  76 char            dev_name[DEV_NAME_LEN];
  77 int             snp_io;
  78 dev_t           snp_tty;
  79 int             std_in = 0, std_out = 1;
  80
  81
  82 int             clear_ok = 0;
  83 struct termios  otty;
  84 char            tbuf[1024], gbuf[1024];
  85
  86
  87 static void
  88 clear()
  89 {
  90         if (clear_ok)
  91                 tputs(gbuf, 1, putchar);
  92         fflush(stdout);
  93 }
  94
  95 static void
  96 timestamp(buf)
  97         const char     *buf;
  98 {
  99         time_t          t;
 100         char            btmp[1024];
 101         clear();
 102         printf("\n---------------------------------------------\n");
 103         t = time(NULL);
 104         strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
 105         printf("%s\n", btmp);
 106         printf("%s\n", buf);
 107         printf("---------------------------------------------\n");
 108         fflush(stdout);
 109 }
 110
 111 static void
 112 set_tty()
 113 {
 114         struct termios  ntty;
 115
 116         tcgetattr (std_in, &otty);
 117         ntty = otty;
 118         ntty.c_lflag &= ~ICANON;    /* disable canonical operation  */
 119         ntty.c_lflag &= ~ECHO;
 120 #ifdef FLUSHO
 121         ntty.c_lflag &= ~FLUSHO;
 122 #endif
 123 #ifdef PENDIN
 124         ntty.c_lflag &= ~PENDIN;
 125 #endif
 126 #ifdef IEXTEN
 127         ntty.c_lflag &= ~IEXTEN;
 128 #endif
 129         ntty.c_cc[VMIN] = 1;        /* minimum of one character */
 130         ntty.c_cc[VTIME] = 0;       /* timeout value        */
 131
 132         ntty.c_cc[VINTR] = 07;   /* ^G */
 133         ntty.c_cc[VQUIT] = 07;   /* ^G */
 134         tcsetattr (std_in, TCSANOW, &ntty);
 135 }
 136
 137 static void
 138 unset_tty()
 139 {
 140         tcsetattr (std_in, TCSANOW, &otty);
 141 }
 142
 143
 144 static void
 145 fatal(error, buf)
 146         int                   error;
 147         const char           *buf;
 148 {
 149         unset_tty();
 150         if (buf)
 151                 errx(error, "fatal: %s", buf);
 152         else
 153                 exit(error);
 154 }
 155
 156 static int
 157 open_snp()
 158 {
 159         char            snp[] = {_PATH_DEV "snpX"};
 160         char            c;
 161         int             f, mode;
 162
 163         if (opt_write)
 164                 mode = O_RDWR;
 165         else
 166                 mode = O_RDONLY;
 167
 168         if (opt_snpdev == NULL)
 169                 for (c = '0'; c <= '9'; c++) {
 170                         snp[8] = c;
 171                         if ((f = open(snp, mode)) < 0)
 172                                 continue;
 173                         return f;
 174                 }
 175         else
 176                 if ((f = open(opt_snpdev, mode)) != -1)
 177                         return (f);
 178         fatal(EX_OSFILE, "cannot open snoop device");
 179         return (0);
 180 }
 181
 182
 183 static void
 184 cleanup(signo)
 185         int             signo __unused;
 186 {
 187         if (opt_timestamp)
 188                 timestamp("Logging Exited.");
 189         close(snp_io);
 190         unset_tty();
 191         exit(EX_OK);
 192 }
 193
 194
 195 static void
 196 usage()
 197 {
 198         fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
 199         exit(EX_USAGE);
 200 }
 201
 202 static void
 203 setup_scr()
 204 {
 205         char           *cbuf = gbuf, *term;
 206         if (!opt_interactive)
 207                 return;
 208         if ((term = getenv("TERM")))
 209                 if (tgetent(tbuf, term) == 1)
 210                         if (tgetstr("cl", &cbuf))
 211                                 clear_ok = 1;
 212         set_tty();
 213         clear();
 214 }
 215
 216 static void
 217 detach_snp()
 218 {
 219         dev_t           dev;
 220
 221         dev = NODEV;
 222         ioctl(snp_io, SNPSTTY, &dev);
 223 }
 224
 225 static void
 226 attach_snp()
 227 {
 228         if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
 229                 fatal(EX_UNAVAILABLE, "cannot attach to tty");
 230         if (opt_timestamp)
 231                 timestamp("Logging Started.");
 232 }
 233
 234
 235 static void
 236 set_dev(name)
 237         const char     *name;
 238 {
 239         char            buf[DEV_NAME_LEN];
 240         struct stat     sb;
 241
 242         if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
 243                 snprintf(buf, sizeof buf, "%s", name);
 244         }
 245         else {
 246                 if (strlen(name) == 2)
 247                         sprintf(buf, "%s%s", _PATH_TTY, name);
 248                 else
 249                         sprintf(buf, "%s%s", _PATH_DEV, name);
 250         }
 251
 252         if (*name == '\0' || stat(buf, &sb) < 0)
 253                 fatal(EX_DATAERR, "bad device name");
 254
 255         if ((sb.st_mode & S_IFMT) != S_IFCHR)
 256                 fatal(EX_DATAERR, "must be a character device");
 257
 258         snp_tty = sb.st_rdev;
 259         attach_snp();
 260 }
 261
 262 void
 263 ask_dev(dbuf, msg)
 264         char           *dbuf;
 265         const char     *msg;
 266 {
 267         char            buf[DEV_NAME_LEN];
 268         int             len;
 269
 270         clear();
 271         unset_tty();
 272
 273         if (msg)
 274                 printf("%s\n", msg);
 275         if (dbuf)
 276                 printf("Enter device name [%s]:", dbuf);
 277         else
 278                 printf("Enter device name:");
 279
 280         if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
 281                 len = strlen(buf);
 282                 if (buf[len - 1] == '\n')
 283                         buf[len - 1] = '\0';
 284                 if (buf[0] != '\0' && buf[0] != ' ')
 285                         strcpy(dbuf, buf);
 286         }
 287         set_tty();
 288 }
 289
 290 #define READB_LEN       5
 291
 292 int
 293 main(ac, av)
 294         int             ac;
 295         char          **av;
 296 {
 297         int             res, idata, rv;
 298         size_t          nread, b_size = MIN_SIZE;
 299         char            ch, *buf, chb[READB_LEN];
 300         fd_set          fd_s;
 301
 302         (void) setlocale(LC_TIME, "");
 303
 304         if (isatty(std_out))
 305                 opt_interactive = 1;
 306         else
 307                 opt_interactive = 0;
 308
 309
 310         while ((ch = getopt(ac, av, "Wciotnf:")) != -1)
 311                 switch (ch) {
 312                 case 'W':
 313                         opt_write = 1;
 314                         break;
 315                 case 'c':
 316                         opt_reconn_close = 1;
 317                         break;
 318                 case 'i':
 319                         opt_interactive = 1;
 320                         break;
 321                 case 'o':
 322                         opt_reconn_oflow = 1;
 323                         break;
 324                 case 't':
 325                         opt_timestamp = 1;
 326                         break;
 327                 case 'n':
 328                         opt_no_switch = 1;
 329                         break;
 330                 case 'f':
 331                         opt_snpdev = optarg;
 332                         break;
 333                 case '?':
 334                 default:
 335                         usage();
 336                 }
 337
 338         if (modfind("snp") == -1)
 339                 if (kldload("snp") == -1 || modfind("snp") == -1)
 340                         warn("snp module not available");
 341
 342         signal(SIGINT, cleanup);
 343
 344         setup_scr();
 345         snp_io = open_snp();
 346
 347         if (*(av += optind) == NULL) {
 348                 if (opt_interactive && !opt_no_switch)
 349                         ask_dev(dev_name, MSG_INIT);
 350                 else
 351                         fatal(EX_DATAERR, "no device name given");
 352         } else
 353                 strncpy(dev_name, *av, DEV_NAME_LEN);
 354
 355         set_dev(dev_name);
 356
 357         if (!(buf = (char *) malloc(b_size)))
 358                 fatal(EX_UNAVAILABLE, "malloc failed");
 359
 360         FD_ZERO(&fd_s);
 361
 362         while (1) {
 363                 if (opt_interactive)
 364                         FD_SET(std_in, &fd_s);
 365                 FD_SET(snp_io, &fd_s);
 366                 res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
 367                 if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
 368
 369                         if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
 370                                 fatal(EX_OSERR, "ioctl(FIONREAD)");
 371                         if (nread > READB_LEN)
 372                                 nread = READB_LEN;
 373                         rv = read(std_in, chb, nread);
 374                         if (rv == -1 || (unsigned)rv != nread)
 375                                 fatal(EX_IOERR, "read (stdin) failed");
 376
 377                         switch (chb[0]) {
 378                         case CHR_CLEAR:
 379                                 clear();
 380                                 break;
 381                         case CHR_SWITCH:
 382                                 if (!opt_no_switch) {
 383                                         detach_snp();
 384                                         ask_dev(dev_name, MSG_CHANGE);
 385                                         set_dev(dev_name);
 386                                         break;
 387                                 }
 388                         default:
 389                                 if (opt_write) {
 390                                         rv = write(snp_io, chb, nread);
 391                                         if (rv == -1 || (unsigned)rv != nread) {
 392                                                 detach_snp();
 393                                                 if (opt_no_switch)
 394                                                         fatal(EX_IOERR, "write failed");
 395                                                 ask_dev(dev_name, MSG_NOWRITE);
 396                                                 set_dev(dev_name);
 397                                         }
 398                                 }
 399
 400                         }
 401                 }
 402                 if (!FD_ISSET(snp_io, &fd_s))
 403                         continue;
 404
 405                 if ((res = ioctl(snp_io, FIONREAD, &idata)) != 0)
 406                         fatal(EX_OSERR, "ioctl(FIONREAD)");
 407
 408                 switch (idata) {
 409                 case SNP_OFLOW:
 410                         if (opt_reconn_oflow)
 411                                 attach_snp();
 412                         else if (opt_interactive && !opt_no_switch) {
 413                                 ask_dev(dev_name, MSG_OFLOW);
 414                                 set_dev(dev_name);
 415                         } else
 416                                 cleanup(-1);
 417                 case SNP_DETACH:
 418                 case SNP_TTYCLOSE:
 419                         if (opt_reconn_close)
 420                                 attach_snp();
 421                         else if (opt_interactive && !opt_no_switch) {
 422                                 ask_dev(dev_name, MSG_CLOSED);
 423                                 set_dev(dev_name);
 424                         } else
 425                                 cleanup(-1);
 426                 default:
 427                         nread = (unsigned)idata;
 428                         if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
 429                                 free(buf);
 430                                 if (!(buf = (char *) malloc(b_size / 2)))
 431                                         fatal(EX_UNAVAILABLE, "malloc failed");
 432                                 b_size = b_size / 2;
 433                         }
 434                         if (nread > b_size) {
 435                                 b_size = (nread % 2) ? (nread + 1) : (nread);
 436                                 free(buf);
 437                                 if (!(buf = (char *) malloc(b_size)))
 438                                         fatal(EX_UNAVAILABLE, "malloc failed");
 439                         }
 440                         rv = read(snp_io, buf, nread);
 441                         if (rv == -1 || (unsigned)rv != nread)
 442                                 fatal(EX_IOERR, "read failed");
 443                         rv = write(std_out, buf, nread);
 444                         if (rv == -1 || (unsigned)rv != nread)
 445                                 fatal(EX_IOERR, "write failed");
 446                 }
 447         }                       /* While */
 448         return(0);
 449 }
 450