The Tcpdump Group git mirrors - tcpdump/blob - util.c

   1 /*
   2  * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #ifndef lint
  23 static const char rcsid[] _U_ =
  24     "@(#) $Header: /tcpdump/master/tcpdump/util.c,v 1.94 2004-06-15 23:05:06 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <sys/stat.h>
  34
  35 #include <errno.h>
  36 #ifdef HAVE_FCNTL_H
  37 #include <fcntl.h>
  38 #endif
  39 #include <pcap.h>
  40 #include <stdio.h>
  41 #include <stdarg.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 #include "interface.h"
  46
  47 /*
  48  * Print out a filename (or other ascii string).
  49  * If ep is NULL, assume no truncation check is needed.
  50  * Return true if truncated.
  51  */
  52 int
  53 fn_print(register const u_char *s, register const u_char *ep)
  54 {
  55         register int ret;
  56         register u_char c;
  57
  58         ret = 1;                        /* assume truncated */
  59         while (ep == NULL || s < ep) {
  60                 c = *s++;
  61                 if (c == '\0') {
  62                         ret = 0;
  63                         break;
  64                 }
  65                 if (!isascii(c)) {
  66                         c = toascii(c);
  67                         putchar('M');
  68                         putchar('-');
  69                 }
  70                 if (!isprint(c)) {
  71                         c ^= 0x40;      /* DEL to ?, others to alpha */
  72                         putchar('^');
  73                 }
  74                 putchar(c);
  75         }
  76         return(ret);
  77 }
  78
  79 /*
  80  * Print out a counted filename (or other ascii string).
  81  * If ep is NULL, assume no truncation check is needed.
  82  * Return true if truncated.
  83  */
  84 int
  85 fn_printn(register const u_char *s, register u_int n,
  86           register const u_char *ep)
  87 {
  88         register u_char c;
  89
  90         while (n > 0 && (ep == NULL || s < ep)) {
  91                 n--;
  92                 c = *s++;
  93                 if (!isascii(c)) {
  94                         c = toascii(c);
  95                         putchar('M');
  96                         putchar('-');
  97                 }
  98                 if (!isprint(c)) {
  99                         c ^= 0x40;      /* DEL to ?, others to alpha */
 100                         putchar('^');
 101                 }
 102                 putchar(c);
 103         }
 104         return (n == 0) ? 0 : 1;
 105 }
 106
 107 /*
 108  * Print the timestamp
 109  */
 110 void
 111 ts_print(register const struct timeval *tvp)
 112 {
 113         register int s;
 114         struct tm *tm;
 115         time_t Time;
 116         static unsigned b_sec;
 117         static unsigned b_usec;
 118
 119         switch (tflag) {
 120
 121         case 0: /* Default */
 122                 s = (tvp->tv_sec + thiszone) % 86400;
 123                 (void)printf("%02d:%02d:%02d.%06u ",
 124                              s / 3600, (s % 3600) / 60, s % 60,
 125                              (unsigned)tvp->tv_usec);
 126                 break;
 127
 128         case 1: /* No time stamp */
 129                 break;
 130
 131         case 2: /* Unix timeval style */
 132                 (void)printf("%u.%06u ",
 133                              (unsigned)tvp->tv_sec,
 134                              (unsigned)tvp->tv_usec);
 135                 break;
 136
 137         case 3: /* Microseconds since previous packet */
 138                 if (b_sec == 0) {
 139                         printf("000000 ");
 140                 } else {
 141                         int d_usec = tvp->tv_usec - b_usec;
 142                         int d_sec = tvp->tv_sec - b_sec;
 143
 144                         while (d_usec < 0) {
 145                                 d_usec += 1000000;
 146                                 d_sec--;
 147                         }
 148                         if (d_sec)
 149                                 printf("%d. ", d_sec);
 150                         printf("%06d ", d_usec);
 151                 }
 152                 b_sec = tvp->tv_sec;
 153                 b_usec = tvp->tv_usec;
 154                 break;
 155
 156         case 4: /* Default + Date*/
 157                 s = (tvp->tv_sec + thiszone) % 86400;
 158                 Time = (tvp->tv_sec + thiszone) - s;
 159                 tm = gmtime (&Time);
 160                 if (!tm)
 161                         printf("Date fail  ");
 162                 else
 163                         printf("%04d-%02d-%02d ",
 164                                    tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday);
 165                 printf("%02d:%02d:%02d.%06u ",
 166                            s / 3600, (s % 3600) / 60, s % 60, (unsigned)tvp->tv_usec);
 167                 break;
 168         }
 169 }
 170
 171 /*
 172  * Print a relative number of seconds (e.g. hold time, prune timer)
 173  * in the form 5m1s.  This does no truncation, so 32230861 seconds
 174  * is represented as 1y1w1d1h1m1s.
 175  */
 176 void
 177 relts_print(int secs)
 178 {
 179         static const char *lengths[] = {"y", "w", "d", "h", "m", "s"};
 180         static const int seconds[] = {31536000, 604800, 86400, 3600, 60, 1};
 181         const char **l = lengths;
 182         const int *s = seconds;
 183
 184         if (secs == 0) {
 185                 (void)printf("0s");
 186                 return;
 187         }
 188         if (secs < 0) {
 189                 (void)printf("-");
 190                 secs = -secs;
 191         }
 192         while (secs > 0) {
 193                 if (secs >= *s) {
 194                         (void)printf("%d%s", secs / *s, *l);
 195                         secs -= (secs / *s) * *s;
 196                 }
 197                 s++;
 198                 l++;
 199         }
 200 }
 201
 202 /*
 203  *  this is a generic routine for printing unknown data;
 204  *  we pass on the linefeed plus indentation string to
 205  *  get a proper output - returns 0 on error
 206  */
 207
 208 int
 209 print_unknown_data(const u_char *cp,const char *ident,int len)
 210 {
 211         hex_print(ident,cp,len);
 212         return(1); /* everything is ok */
 213 }
 214
 215 /*
 216  * Convert a token value to a string; use "fmt" if not found.
 217  */
 218 const char *
 219 tok2strbuf(register const struct tok *lp, register const char *fmt,
 220            register int v, char *buf, size_t bufsize)
 221 {
 222         while (lp->s != NULL) {
 223                 if (lp->v == v)
 224                         return (lp->s);
 225                 ++lp;
 226         }
 227         if (fmt == NULL)
 228                 fmt = "#%d";
 229
 230         (void)snprintf(buf, bufsize, fmt, v);
 231         return (const char *)buf;
 232 }
 233
 234 /*
 235  * Convert a token value to a string; use "fmt" if not found.
 236  */
 237 const char *
 238 tok2str(register const struct tok *lp, register const char *fmt,
 239         register int v)
 240 {
 241         static char buf[4][128];
 242         static int idx = 0;
 243         char *ret;
 244
 245         ret = buf[idx];
 246         idx = (idx+1) & 3;
 247         return tok2strbuf(lp, fmt, v, ret, sizeof(buf[0]));
 248 }
 249
 250 /*
 251  * Convert a bit token value to a string; use "fmt" if not found.
 252  * this is useful for parsing bitfields, the output strings are comma seperated
 253  */
 254 char *
 255 bittok2str(register const struct tok *lp, register const char *fmt,
 256            register int v)
 257 {
 258         static char buf[256]; /* our stringbuffer */
 259         int buflen=0;
 260         register int rotbit; /* this is the bit we rotate through all bitpositions */
 261         register int tokval;
 262
 263         while (lp->s != NULL) {
 264             tokval=lp->v;   /* load our first value */
 265             rotbit=1;
 266             while (rotbit != 0) {
 267                 /*
 268                  * lets AND the rotating bit with our token value
 269                  * and see if we have got a match
 270                  */
 271                 if (tokval == (v&rotbit)) {
 272                     /* ok we have found something */
 273                     buflen+=snprintf(buf+buflen, sizeof(buf)-buflen, "%s, ",lp->s);
 274                     break;
 275                 }
 276                 rotbit=rotbit<<1; /* no match - lets shift and try again */
 277             }
 278             lp++;
 279         }
 280
 281         if (buflen != 0) { /* did we find anything */
 282             /* yep, set the the trailing zero 2 bytes before to eliminate the last comma & whitespace */
 283             buf[buflen-2] = '\0';
 284             return (buf);
 285         }
 286         else {
 287             /* bummer - lets print the "unknown" message as advised in the fmt string if we got one */
 288             if (fmt == NULL)
 289                 fmt = "#%d";
 290             (void)snprintf(buf, sizeof(buf), fmt, v);
 291             return (buf);
 292         }
 293 }
 294
 295 /*
 296  * Convert a value to a string using an array; the macro
 297  * tok2strary() in <interface.h> is the public interface to
 298  * this function and ensures that the second argument is
 299  * correct for bounds-checking.
 300  */
 301 const char *
 302 tok2strary_internal(register const char **lp, int n, register const char *fmt,
 303         register int v)
 304 {
 305         static char buf[128];
 306
 307         if (v >= 0 && v < n && lp[v] != NULL)
 308                 return lp[v];
 309         if (fmt == NULL)
 310                 fmt = "#%d";
 311         (void)snprintf(buf, sizeof(buf), fmt, v);
 312         return (buf);
 313 }
 314
 315 /*
 316  * Convert a 32-bit netmask to prefixlen if possible
 317  * the function returns the prefix-len; if plen == -1
 318  * then conversion was not possible;
 319  */
 320
 321 int
 322 mask2plen (u_int32_t mask)
 323 {
 324         u_int32_t bitmasks[33] = {
 325                 0x00000000,
 326                 0x80000000, 0xc0000000, 0xe0000000, 0xf0000000,
 327                 0xf8000000, 0xfc000000, 0xfe000000, 0xff000000,
 328                 0xff800000, 0xffc00000, 0xffe00000, 0xfff00000,
 329                 0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000,
 330                 0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000,
 331                 0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00,
 332                 0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0,
 333                 0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff
 334         };
 335         int prefix_len = 32;
 336
 337         /* let's see if we can transform the mask into a prefixlen */
 338         while (prefix_len >= 0) {
 339                 if (bitmasks[prefix_len] == mask)
 340                         break;
 341                 prefix_len--;
 342         }
 343         return (prefix_len);
 344 }
 345
 346 /* VARARGS */
 347 void
 348 error(const char *fmt, ...)
 349 {
 350         va_list ap;
 351
 352         (void)fprintf(stderr, "%s: ", program_name);
 353         va_start(ap, fmt);
 354         (void)vfprintf(stderr, fmt, ap);
 355         va_end(ap);
 356         if (*fmt) {
 357                 fmt += strlen(fmt);
 358                 if (fmt[-1] != '\n')
 359                         (void)fputc('\n', stderr);
 360         }
 361         exit(1);
 362         /* NOTREACHED */
 363 }
 364
 365 /* VARARGS */
 366 void
 367 warning(const char *fmt, ...)
 368 {
 369         va_list ap;
 370
 371         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 372         va_start(ap, fmt);
 373         (void)vfprintf(stderr, fmt, ap);
 374         va_end(ap);
 375         if (*fmt) {
 376                 fmt += strlen(fmt);
 377                 if (fmt[-1] != '\n')
 378                         (void)fputc('\n', stderr);
 379         }
 380 }
 381
 382 /*
 383  * Copy arg vector into a new buffer, concatenating arguments with spaces.
 384  */
 385 char *
 386 copy_argv(register char **argv)
 387 {
 388         register char **p;
 389         register u_int len = 0;
 390         char *buf;
 391         char *src, *dst;
 392
 393         p = argv;
 394         if (*p == 0)
 395                 return 0;
 396
 397         while (*p)
 398                 len += strlen(*p++) + 1;
 399
 400         buf = (char *)malloc(len);
 401         if (buf == NULL)
 402                 error("copy_argv: malloc");
 403
 404         p = argv;
 405         dst = buf;
 406         while ((src = *p++) != NULL) {
 407                 while ((*dst++ = *src++) != '\0')
 408                         ;
 409                 dst[-1] = ' ';
 410         }
 411         dst[-1] = '\0';
 412
 413         return buf;
 414 }
 415
 416 /*
 417  * On Windows, we need to open the file in binary mode, so that
 418  * we get all the bytes specified by the size we get from "fstat()".
 419  * On UNIX, that's not necessary.  O_BINARY is defined on Windows;
 420  * we define it as 0 if it's not defined, so it does nothing.
 421  */
 422 #ifndef O_BINARY
 423 #define O_BINARY        0
 424 #endif
 425
 426 char *
 427 read_infile(char *fname)
 428 {
 429         register int i, fd, cc;
 430         register char *cp;
 431         struct stat buf;
 432
 433         fd = open(fname, O_RDONLY|O_BINARY);
 434         if (fd < 0)
 435                 error("can't open %s: %s", fname, pcap_strerror(errno));
 436
 437         if (fstat(fd, &buf) < 0)
 438                 error("can't stat %s: %s", fname, pcap_strerror(errno));
 439
 440         cp = malloc((u_int)buf.st_size + 1);
 441         if (cp == NULL)
 442                 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
 443                         fname, pcap_strerror(errno));
 444         cc = read(fd, cp, (u_int)buf.st_size);
 445         if (cc < 0)
 446                 error("read %s: %s", fname, pcap_strerror(errno));
 447         if (cc != buf.st_size)
 448                 error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
 449
 450         close(fd);
 451         /* replace "# comment" with spaces */
 452         for (i = 0; i < cc; i++) {
 453                 if (cp[i] == '#')
 454                         while (i < cc && cp[i] != '\n')
 455                                 cp[i++] = ' ';
 456         }
 457         cp[cc] = '\0';
 458         return (cp);
 459 }
 460
 461 void
 462 safeputs(const char *s)
 463 {
 464         while (*s) {
 465                 safeputchar(*s);
 466                 s++;
 467         }
 468 }
 469
 470 void
 471 safeputchar(int c)
 472 {
 473         unsigned char ch;
 474
 475         ch = (unsigned char)(c & 0xff);
 476         if (ch < 0x80 && isprint(ch))
 477                 printf("%c", ch);
 478         else
 479                 printf("\\%03o", ch);
 480 }