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 <time.h>
  40 #include <unistd.h>
  41
  42 #define MSG_INIT        "Snoop started."
  43 #define MSG_OFLOW       "Snoop stopped due to overflow. Reconnecting."
  44 #define MSG_CLOSED      "Snoop stopped due to tty close. Reconnecting."
  45 #define MSG_CHANGE      "Snoop device change by user request."
  46 #define MSG_NOWRITE     "Snoop device change due to write failure."
  47
  48
  49 #define DEV_NAME_LEN    1024    /* for /dev/ttyXX++ */
  50 #define MIN_SIZE        256
  51
  52 #define CHR_SWITCH      24      /* Ctrl+X        */
  53 #define CHR_CLEAR       23      /* Ctrl+V        */
  54
  55 static void     clear(void);
  56 static void     timestamp(const char *);
  57 static void     set_tty(void);
  58 static void     unset_tty(void);
  59 static void     fatal(int, const char *);
  60 static int      open_snp(void);
  61 static void     cleanup(int);
  62 static void     usage(void) __dead2;
  63 static void     setup_scr(void);
  64 static void     attach_snp(void);
  65 static void     detach_snp(void);
  66 static void     set_dev(const char *);
  67 static void     ask_dev(char *, const char *);
  68
  69 int             opt_reconn_close = 0;
  70 int             opt_reconn_oflow = 0;
  71 int             opt_interactive = 1;
  72 int             opt_timestamp = 0;
  73 int             opt_write = 0;
  74 int             opt_no_switch = 0;
  75 const char      *opt_snpdev;
  76
  77 char            dev_name[DEV_NAME_LEN];
  78 int             snp_io;
  79 dev_t           snp_tty;
  80 int             std_in = 0, std_out = 1;
  81
  82
  83 int             clear_ok = 0;
  84 struct termios  otty;
  85 char            tbuf[1024], gbuf[1024];
  86
  87
  88 static void
  89 clear(void)
  90 {
  91         if (clear_ok)
  92                 tputs(gbuf, 1, putchar);
  93         fflush(stdout);
  94 }
  95
  96 static void
  97 timestamp(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(void)
 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(void)
 139 {
 140         tcsetattr (std_in, TCSANOW, &otty);
 141 }
 142
 143
 144 static void
 145 fatal(int error, const char *buf)
 146 {
 147         unset_tty();
 148         if (buf)
 149                 errx(error, "fatal: %s", buf);
 150         else
 151                 exit(error);
 152 }
 153
 154 static int
 155 open_snp(void)
 156 {
 157         char            snp[] = {_PATH_DEV "snpX"};
 158         char            c;
 159         int             f, mode;
 160
 161         if (opt_write)
 162                 mode = O_RDWR;
 163         else
 164                 mode = O_RDONLY;
 165
 166         if (opt_snpdev == NULL)
 167                 for (c = '0'; c <= '9'; c++) {
 168                         snp[8] = c;
 169                         if ((f = open(snp, mode)) < 0)
 170                                 continue;
 171                         return f;
 172                 }
 173         else
 174                 if ((f = open(opt_snpdev, mode)) != -1)
 175                         return (f);
 176         fatal(EX_OSFILE, "cannot open snoop device");
 177         return (0);
 178 }
 179
 180
 181 static void
 182 cleanup(int signo __unused)
 183 {
 184         if (opt_timestamp)
 185                 timestamp("Logging Exited.");
 186         close(snp_io);
 187         unset_tty();
 188         exit(EX_OK);
 189 }
 190
 191
 192 static void
 193 usage(void)
 194 {
 195         fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
 196         exit(EX_USAGE);
 197 }
 198
 199 static void
 200 setup_scr(void)
 201 {
 202         char           *cbuf = gbuf, *term;
 203         if (!opt_interactive)
 204                 return;
 205         if ((term = getenv("TERM")))
 206                 if (tgetent(tbuf, term) == 1)
 207                         if (tgetstr("cl", &cbuf))
 208                                 clear_ok = 1;
 209         set_tty();
 210         clear();
 211 }
 212
 213 static void
 214 detach_snp(void)
 215 {
 216         dev_t           dev;
 217
 218         dev = NODEV;
 219         ioctl(snp_io, SNPSTTY, &dev);
 220 }
 221
 222 static void
 223 attach_snp(void)
 224 {
 225         if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
 226                 fatal(EX_UNAVAILABLE, "cannot attach to tty");
 227         if (opt_timestamp)
 228                 timestamp("Logging Started.");
 229 }
 230
 231
 232 static void
 233 set_dev(const char *name)
 234 {
 235         char            buf[DEV_NAME_LEN];
 236         struct stat     sb;
 237
 238         if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
 239                 snprintf(buf, sizeof buf, "%s", name);
 240         } else {
 241                 if (strlen(name) == 2)
 242                         sprintf(buf, "%s%s", _PATH_TTY, name);
 243                 else
 244                         sprintf(buf, "%s%s", _PATH_DEV, name);
 245         }
 246
 247         if (*name == '\0' || stat(buf, &sb) < 0)
 248                 fatal(EX_DATAERR, "bad device name");
 249
 250         if ((sb.st_mode & S_IFMT) != S_IFCHR)
 251                 fatal(EX_DATAERR, "must be a character device");
 252
 253         snp_tty = sb.st_rdev;
 254         attach_snp();
 255 }
 256
 257 void
 258 ask_dev(char *dbuf, const char *msg)
 259 {
 260         char            buf[DEV_NAME_LEN];
 261         int             len;
 262
 263         clear();
 264         unset_tty();
 265
 266         if (msg)
 267                 printf("%s\n", msg);
 268         if (dbuf)
 269                 printf("Enter device name [%s]:", dbuf);
 270         else
 271                 printf("Enter device name:");
 272
 273         if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
 274                 len = strlen(buf);
 275                 if (buf[len - 1] == '\n')
 276                         buf[len - 1] = '\0';
 277                 if (buf[0] != '\0' && buf[0] != ' ')
 278                         strcpy(dbuf, buf);
 279         }
 280         set_tty();
 281 }
 282
 283 #define READB_LEN       5
 284
 285 int
 286 main(int ac, char *av[])
 287 {
 288         int             res, idata, rv;
 289         size_t          nread, b_size = MIN_SIZE;
 290         char            ch, *buf, chb[READB_LEN];
 291         fd_set          fd_s;
 292
 293         (void) setlocale(LC_TIME, "");
 294
 295         if (isatty(std_out))
 296                 opt_interactive = 1;
 297         else
 298                 opt_interactive = 0;
 299
 300
 301         while ((ch = getopt(ac, av, "Wciotnf:")) != -1)
 302                 switch (ch) {
 303                 case 'W':
 304                         opt_write = 1;
 305                         break;
 306                 case 'c':
 307                         opt_reconn_close = 1;
 308                         break;
 309                 case 'i':
 310                         opt_interactive = 1;
 311                         break;
 312                 case 'o':
 313                         opt_reconn_oflow = 1;
 314                         break;
 315                 case 't':
 316                         opt_timestamp = 1;
 317                         break;
 318                 case 'n':
 319                         opt_no_switch = 1;
 320                         break;
 321                 case 'f':
 322                         opt_snpdev = optarg;
 323                         break;
 324                 case '?':
 325                 default:
 326                         usage();
 327                 }
 328
 329         if (modfind("snp") == -1)
 330                 if (kldload("snp") == -1 || modfind("snp") == -1)
 331                         warn("snp module not available");
 332
 333         signal(SIGINT, cleanup);
 334
 335         setup_scr();
 336         snp_io = open_snp();
 337
 338         if (*(av += optind) == NULL) {
 339                 if (opt_interactive && !opt_no_switch)
 340                         ask_dev(dev_name, MSG_INIT);
 341                 else
 342                         fatal(EX_DATAERR, "no device name given");
 343         } else
 344                 strncpy(dev_name, *av, DEV_NAME_LEN);
 345
 346         set_dev(dev_name);
 347
 348         if (!(buf = (char *) malloc(b_size)))
 349                 fatal(EX_UNAVAILABLE, "malloc failed");
 350
 351         FD_ZERO(&fd_s);
 352
 353         while (1) {
 354                 if (opt_interactive)
 355                         FD_SET(std_in, &fd_s);
 356                 FD_SET(snp_io, &fd_s);
 357                 res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
 358                 if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
 359
 360                         if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
 361                                 fatal(EX_OSERR, "ioctl(FIONREAD)");
 362                         if (nread > READB_LEN)
 363                                 nread = READB_LEN;
 364                         rv = read(std_in, chb, nread);
 365                         if (rv == -1 || (unsigned)rv != nread)
 366                                 fatal(EX_IOERR, "read (stdin) failed");
 367
 368                         switch (chb[0]) {
 369                         case CHR_CLEAR:
 370                                 clear();
 371                                 break;
 372                         case CHR_SWITCH:
 373                                 if (!opt_no_switch) {
 374                                         detach_snp();
 375                                         ask_dev(dev_name, MSG_CHANGE);
 376                                         set_dev(dev_name);
 377                                         break;
 378                                 }
 379                         default:
 380                                 if (opt_write) {
 381                                         rv = write(snp_io, chb, nread);
 382                                         if (rv == -1 || (unsigned)rv != nread) {
 383                                                 detach_snp();
 384                                                 if (opt_no_switch)
 385                                                         fatal(EX_IOERR,
 386                                                           "write failed");
 387                                                 ask_dev(dev_name, MSG_NOWRITE);
 388                                                 set_dev(dev_name);
 389                                         }
 390                                 }
 391
 392                         }
 393                 }
 394                 if (!FD_ISSET(snp_io, &fd_s))
 395                         continue;
 396
 397                 if ((res = ioctl(snp_io, FIONREAD, &idata)) != 0)
 398                         fatal(EX_OSERR, "ioctl(FIONREAD)");
 399
 400                 switch (idata) {
 401                 case SNP_OFLOW:
 402                         if (opt_reconn_oflow)
 403                                 attach_snp();
 404                         else if (opt_interactive && !opt_no_switch) {
 405                                 ask_dev(dev_name, MSG_OFLOW);
 406                                 set_dev(dev_name);
 407                         } else
 408                                 cleanup(-1);
 409                         break;
 410                 case SNP_DETACH:
 411                 case SNP_TTYCLOSE:
 412                         if (opt_reconn_close)
 413                                 attach_snp();
 414                         else if (opt_interactive && !opt_no_switch) {
 415                                 ask_dev(dev_name, MSG_CLOSED);
 416                                 set_dev(dev_name);
 417                         } else
 418                                 cleanup(-1);
 419                         break;
 420                 default:
 421                         nread = (unsigned)idata;
 422                         if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
 423                                 free(buf);
 424                                 if (!(buf = (char *) malloc(b_size / 2)))
 425                                         fatal(EX_UNAVAILABLE, "malloc failed");
 426                                 b_size = b_size / 2;
 427                         }
 428                         if (nread > b_size) {
 429                                 b_size = (nread % 2) ? (nread + 1) : (nread);
 430                                 free(buf);
 431                                 if (!(buf = (char *) malloc(b_size)))
 432                                         fatal(EX_UNAVAILABLE, "malloc failed");
 433                         }
 434                         rv = read(snp_io, buf, nread);
 435                         if (rv == -1 || (unsigned)rv != nread)
 436                                 fatal(EX_IOERR, "read failed");
 437                         rv = write(std_out, buf, nread);
 438                         if (rv == -1 || (unsigned)rv != nread)
 439                                 fatal(EX_IOERR, "write failed");
 440                 }
 441         }                       /* While */
 442         return(0);
 443 }
 444