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 #include <sys/cdefs.h>
  17 __FBSDID("$FreeBSD$");
  18
  19 #include <sys/param.h>
  20 #include <sys/fcntl.h>
  21 #include <sys/filio.h>
  22 #include <sys/snoop.h>
  23 #include <sys/stat.h>
  24 #include <sys/linker.h>
  25 #include <sys/module.h>
  26
  27 #include <err.h>
  28 #include <errno.h>
  29 #include <locale.h>
  30 #include <paths.h>
  31 #include <signal.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <sysexits.h>
  36 #include <termcap.h>
  37 #include <termios.h>
  38 #include <time.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(void);
  55 static void     timestamp(const char *);
  56 static void     set_tty(void);
  57 static void     unset_tty(void);
  58 static void     fatal(int, const char *);
  59 static int      open_snp(void);
  60 static void     cleanup(int);
  61 static void     usage(void) __dead2;
  62 static void     setup_scr(void);
  63 static void     attach_snp(void);
  64 static void     detach_snp(void);
  65 static void     set_dev(const char *);
  66 static void     ask_dev(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(void)
  89 {
  90         if (clear_ok)
  91                 tputs(gbuf, 1, putchar);
  92         fflush(stdout);
  93 }
  94
  95 static void
  96 timestamp(const char *buf)
  97 {
  98         time_t          t;
  99         char            btmp[1024];
 100         clear();
 101         printf("\n---------------------------------------------\n");
 102         t = time(NULL);
 103         strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
 104         printf("%s\n", btmp);
 105         printf("%s\n", buf);
 106         printf("---------------------------------------------\n");
 107         fflush(stdout);
 108 }
 109
 110 static void
 111 set_tty(void)
 112 {
 113         struct termios  ntty;
 114
 115         tcgetattr (std_in, &otty);
 116         ntty = otty;
 117         ntty.c_lflag &= ~ICANON;    /* disable canonical operation  */
 118         ntty.c_lflag &= ~ECHO;
 119 #ifdef FLUSHO
 120         ntty.c_lflag &= ~FLUSHO;
 121 #endif
 122 #ifdef PENDIN
 123         ntty.c_lflag &= ~PENDIN;
 124 #endif
 125 #ifdef IEXTEN
 126         ntty.c_lflag &= ~IEXTEN;
 127 #endif
 128         ntty.c_cc[VMIN] = 1;        /* minimum of one character */
 129         ntty.c_cc[VTIME] = 0;       /* timeout value        */
 130
 131         ntty.c_cc[VINTR] = 07;   /* ^G */
 132         ntty.c_cc[VQUIT] = 07;   /* ^G */
 133         tcsetattr (std_in, TCSANOW, &ntty);
 134 }
 135
 136 static void
 137 unset_tty(void)
 138 {
 139         tcsetattr (std_in, TCSANOW, &otty);
 140 }
 141
 142
 143 static void
 144 fatal(int error, const char *buf)
 145 {
 146         unset_tty();
 147         if (buf)
 148                 errx(error, "fatal: %s", buf);
 149         else
 150                 exit(error);
 151 }
 152
 153 static int
 154 open_snp(void)
 155 {
 156         char            snp[] = {_PATH_DEV "snpX"};
 157         char            c;
 158         int             f, mode, pos;
 159
 160         pos = strlen(snp) - 1;
 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[pos] = c;
 169                         if ((f = open(snp, mode)) < 0) {
 170                                 if (errno == EBUSY)
 171                                         continue;
 172                                 err(1, "open %s", snp);
 173                         }
 174                         return f;
 175                 }
 176         else
 177                 if ((f = open(opt_snpdev, mode)) != -1)
 178                         return (f);
 179         fatal(EX_OSFILE, "cannot open snoop device");
 180         return (0);
 181 }
 182
 183
 184 static void
 185 cleanup(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(void)
 197 {
 198         fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
 199         exit(EX_USAGE);
 200 }
 201
 202 static void
 203 setup_scr(void)
 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(void)
 218 {
 219         dev_t           dev;
 220
 221         dev = NODEV;
 222         ioctl(snp_io, SNPSTTY, &dev);
 223 }
 224
 225 static void
 226 attach_snp(void)
 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(const char *name)
 237 {
 238         char            buf[DEV_NAME_LEN];
 239         struct stat     sb;
 240
 241         if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
 242                 snprintf(buf, sizeof buf, "%s", name);
 243         } else {
 244                 if (strlen(name) == 2)
 245                         sprintf(buf, "%s%s", _PATH_TTY, name);
 246                 else
 247                         sprintf(buf, "%s%s", _PATH_DEV, name);
 248         }
 249
 250         if (*name == '\0' || stat(buf, &sb) < 0)
 251                 fatal(EX_DATAERR, "bad device name");
 252
 253         if ((sb.st_mode & S_IFMT) != S_IFCHR)
 254                 fatal(EX_DATAERR, "must be a character device");
 255
 256         snp_tty = sb.st_rdev;
 257         attach_snp();
 258 }
 259
 260 void
 261 ask_dev(char *dbuf, const char *msg)
 262 {
 263         char            buf[DEV_NAME_LEN];
 264         int             len;
 265
 266         clear();
 267         unset_tty();
 268
 269         if (msg)
 270                 printf("%s\n", msg);
 271         if (dbuf)
 272                 printf("Enter device name [%s]:", dbuf);
 273         else
 274                 printf("Enter device name:");
 275
 276         if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
 277                 len = strlen(buf);
 278                 if (buf[len - 1] == '\n')
 279                         buf[len - 1] = '\0';
 280                 if (buf[0] != '\0' && buf[0] != ' ')
 281                         strcpy(dbuf, buf);
 282         }
 283         set_tty();
 284 }
 285
 286 #define READB_LEN       5
 287
 288 int
 289 main(int ac, char *av[])
 290 {
 291         int             ch, res, rv, nread;
 292         size_t          b_size = MIN_SIZE;
 293         char            *buf, chb[READB_LEN];
 294         fd_set          fd_s;
 295
 296         (void) setlocale(LC_TIME, "");
 297
 298         if (isatty(std_out))
 299                 opt_interactive = 1;
 300         else
 301                 opt_interactive = 0;
 302
 303
 304         while ((ch = getopt(ac, av, "Wciotnf:")) != -1)
 305                 switch (ch) {
 306                 case 'W':
 307                         opt_write = 1;
 308                         break;
 309                 case 'c':
 310                         opt_reconn_close = 1;
 311                         break;
 312                 case 'i':
 313                         opt_interactive = 1;
 314                         break;
 315                 case 'o':
 316                         opt_reconn_oflow = 1;
 317                         break;
 318                 case 't':
 319                         opt_timestamp = 1;
 320                         break;
 321                 case 'n':
 322                         opt_no_switch = 1;
 323                         break;
 324                 case 'f':
 325                         opt_snpdev = optarg;
 326                         break;
 327                 case '?':
 328                 default:
 329                         usage();
 330                 }
 331
 332         if (modfind("snp") == -1)
 333                 if (kldload("snp") == -1 || modfind("snp") == -1)
 334                         warn("snp module not available");
 335
 336         signal(SIGINT, cleanup);
 337
 338         snp_io = open_snp();
 339         setup_scr();
 340
 341         if (*(av += optind) == NULL) {
 342                 if (opt_interactive && !opt_no_switch)
 343                         ask_dev(dev_name, MSG_INIT);
 344                 else
 345                         fatal(EX_DATAERR, "no device name given");
 346         } else
 347                 strncpy(dev_name, *av, DEV_NAME_LEN);
 348
 349         set_dev(dev_name);
 350
 351         if (!(buf = (char *) malloc(b_size)))
 352                 fatal(EX_UNAVAILABLE, "malloc failed");
 353
 354         FD_ZERO(&fd_s);
 355
 356         while (1) {
 357                 if (opt_interactive)
 358                         FD_SET(std_in, &fd_s);
 359                 FD_SET(snp_io, &fd_s);
 360                 res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
 361                 if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
 362
 363                         if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
 364                                 fatal(EX_OSERR, "ioctl(FIONREAD)");
 365                         if (nread > READB_LEN)
 366                                 nread = READB_LEN;
 367                         rv = read(std_in, chb, nread);
 368                         if (rv == -1 || rv != nread)
 369                                 fatal(EX_IOERR, "read (stdin) failed");
 370
 371                         switch (chb[0]) {
 372                         case CHR_CLEAR:
 373                                 clear();
 374                                 break;
 375                         case CHR_SWITCH:
 376                                 if (!opt_no_switch) {
 377                                         detach_snp();
 378                                         ask_dev(dev_name, MSG_CHANGE);
 379                                         set_dev(dev_name);
 380                                         break;
 381                                 }
 382                         default:
 383                                 if (opt_write) {
 384                                         rv = write(snp_io, chb, nread);
 385                                         if (rv == -1 || rv != nread) {
 386                                                 detach_snp();
 387                                                 if (opt_no_switch)
 388                                                         fatal(EX_IOERR,
 389                                                           "write failed");
 390                                                 ask_dev(dev_name, MSG_NOWRITE);
 391                                                 set_dev(dev_name);
 392                                         }
 393                                 }
 394
 395                         }
 396                 }
 397                 if (!FD_ISSET(snp_io, &fd_s))
 398                         continue;
 399
 400                 if ((res = ioctl(snp_io, FIONREAD, &nread)) != 0)
 401                         fatal(EX_OSERR, "ioctl(FIONREAD)");
 402
 403                 switch (nread) {
 404                 case SNP_OFLOW:
 405                         if (opt_reconn_oflow)
 406                                 attach_snp();
 407                         else if (opt_interactive && !opt_no_switch) {
 408                                 ask_dev(dev_name, MSG_OFLOW);
 409                                 set_dev(dev_name);
 410                         } else
 411                                 cleanup(-1);
 412                         break;
 413                 case SNP_DETACH:
 414                 case SNP_TTYCLOSE:
 415                         if (opt_reconn_close)
 416                                 attach_snp();
 417                         else if (opt_interactive && !opt_no_switch) {
 418                                 ask_dev(dev_name, MSG_CLOSED);
 419                                 set_dev(dev_name);
 420                         } else
 421                                 cleanup(-1);
 422                         break;
 423                 default:
 424                         if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
 425                                 free(buf);
 426                                 if (!(buf = (char *) malloc(b_size / 2)))
 427                                         fatal(EX_UNAVAILABLE, "malloc failed");
 428                                 b_size = b_size / 2;
 429                         }
 430                         if (nread > b_size) {
 431                                 b_size = (nread % 2) ? (nread + 1) : (nread);
 432                                 free(buf);
 433                                 if (!(buf = (char *) malloc(b_size)))
 434                                         fatal(EX_UNAVAILABLE, "malloc failed");
 435                         }
 436                         rv = read(snp_io, buf, nread);
 437                         if (rv == -1 || rv != nread)
 438                                 fatal(EX_IOERR, "read failed");
 439                         rv = write(std_out, buf, nread);
 440                         if (rv == -1 || rv != nread)
 441                                 fatal(EX_IOERR, "write failed");
 442                 }
 443         }                       /* While */
 444         return(0);
 445 }
 446