misc.c

   1 /*
   2  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
   3  * Copyright (c) 2005 Damien Miller.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "includes.h"
  27 RCSID("$OpenBSD: misc.c,v 1.34 2005/07/08 09:26:18 dtucker Exp $");
  28
  29 #include "misc.h"
  30 #include "log.h"
  31 #include "xmalloc.h"
  32
  33 /* remove newline at end of string */
  34 char *
  35 chop(char *s)
  36 {
  37         char *t = s;
  38         while (*t) {
  39                 if (*t == '\n' || *t == '\r') {
  40                         *t = '\0';
  41                         return s;
  42                 }
  43                 t++;
  44         }
  45         return s;
  46
  47 }
  48
  49 /* set/unset filedescriptor to non-blocking */
  50 int
  51 set_nonblock(int fd)
  52 {
  53         int val;
  54
  55         val = fcntl(fd, F_GETFL, 0);
  56         if (val < 0) {
  57                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  58                 return (-1);
  59         }
  60         if (val & O_NONBLOCK) {
  61                 debug3("fd %d is O_NONBLOCK", fd);
  62                 return (0);
  63         }
  64         debug2("fd %d setting O_NONBLOCK", fd);
  65         val |= O_NONBLOCK;
  66         if (fcntl(fd, F_SETFL, val) == -1) {
  67                 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
  68                     strerror(errno));
  69                 return (-1);
  70         }
  71         return (0);
  72 }
  73
  74 int
  75 unset_nonblock(int fd)
  76 {
  77         int val;
  78
  79         val = fcntl(fd, F_GETFL, 0);
  80         if (val < 0) {
  81                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  82                 return (-1);
  83         }
  84         if (!(val & O_NONBLOCK)) {
  85                 debug3("fd %d is not O_NONBLOCK", fd);
  86                 return (0);
  87         }
  88         debug("fd %d clearing O_NONBLOCK", fd);
  89         val &= ~O_NONBLOCK;
  90         if (fcntl(fd, F_SETFL, val) == -1) {
  91                 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
  92                     fd, strerror(errno));
  93                 return (-1);
  94         }
  95         return (0);
  96 }
  97
  98 /* disable nagle on socket */
  99 void
 100 set_nodelay(int fd)
 101 {
 102         int opt;
 103         socklen_t optlen;
 104
 105         optlen = sizeof opt;
 106         if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
 107                 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
 108                 return;
 109         }
 110         if (opt == 1) {
 111                 debug2("fd %d is TCP_NODELAY", fd);
 112                 return;
 113         }
 114         opt = 1;
 115         debug2("fd %d setting TCP_NODELAY", fd);
 116         if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
 117                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 118 }
 119
 120 /* Characters considered whitespace in strsep calls. */
 121 #define WHITESPACE " \t\r\n"
 122
 123 /* return next token in configuration line */
 124 char *
 125 strdelim(char **s)
 126 {
 127         char *old;
 128         int wspace = 0;
 129
 130         if (*s == NULL)
 131                 return NULL;
 132
 133         old = *s;
 134
 135         *s = strpbrk(*s, WHITESPACE "=");
 136         if (*s == NULL)
 137                 return (old);
 138
 139         /* Allow only one '=' to be skipped */
 140         if (*s[0] == '=')
 141                 wspace = 1;
 142         *s[0] = '\0';
 143
 144         *s += strspn(*s + 1, WHITESPACE) + 1;
 145         if (*s[0] == '=' && !wspace)
 146                 *s += strspn(*s + 1, WHITESPACE) + 1;
 147
 148         return (old);
 149 }
 150
 151 struct passwd *
 152 pwcopy(struct passwd *pw)
 153 {
 154         struct passwd *copy = xmalloc(sizeof(*copy));
 155
 156         memset(copy, 0, sizeof(*copy));
 157         copy->pw_name = xstrdup(pw->pw_name);
 158         copy->pw_passwd = xstrdup(pw->pw_passwd);
 159         copy->pw_gecos = xstrdup(pw->pw_gecos);
 160         copy->pw_uid = pw->pw_uid;
 161         copy->pw_gid = pw->pw_gid;
 162 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
 163         copy->pw_expire = pw->pw_expire;
 164 #endif
 165 #ifdef HAVE_PW_CHANGE_IN_PASSWD
 166         copy->pw_change = pw->pw_change;
 167 #endif
 168 #ifdef HAVE_PW_CLASS_IN_PASSWD
 169         copy->pw_class = xstrdup(pw->pw_class);
 170 #endif
 171         copy->pw_dir = xstrdup(pw->pw_dir);
 172         copy->pw_shell = xstrdup(pw->pw_shell);
 173         return copy;
 174 }
 175
 176 /*
 177  * Convert ASCII string to TCP/IP port number.
 178  * Port must be >0 and <=65535.
 179  * Return 0 if invalid.
 180  */
 181 int
 182 a2port(const char *s)
 183 {
 184         long port;
 185         char *endp;
 186
 187         errno = 0;
 188         port = strtol(s, &endp, 0);
 189         if (s == endp || *endp != '\0' ||
 190             (errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) ||
 191             port <= 0 || port > 65535)
 192                 return 0;
 193
 194         return port;
 195 }
 196
 197 #define SECONDS         1
 198 #define MINUTES         (SECONDS * 60)
 199 #define HOURS           (MINUTES * 60)
 200 #define DAYS            (HOURS * 24)
 201 #define WEEKS           (DAYS * 7)
 202
 203 /*
 204  * Convert a time string into seconds; format is
 205  * a sequence of:
 206  *      time[qualifier]
 207  *
 208  * Valid time qualifiers are:
 209  *      <none>  seconds
 210  *      s|S     seconds
 211  *      m|M     minutes
 212  *      h|H     hours
 213  *      d|D     days
 214  *      w|W     weeks
 215  *
 216  * Examples:
 217  *      90m     90 minutes
 218  *      1h30m   90 minutes
 219  *      2d      2 days
 220  *      1w      1 week
 221  *
 222  * Return -1 if time string is invalid.
 223  */
 224 long
 225 convtime(const char *s)
 226 {
 227         long total, secs;
 228         const char *p;
 229         char *endp;
 230
 231         errno = 0;
 232         total = 0;
 233         p = s;
 234
 235         if (p == NULL || *p == '\0')
 236                 return -1;
 237
 238         while (*p) {
 239                 secs = strtol(p, &endp, 10);
 240                 if (p == endp ||
 241                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 242                     secs < 0)
 243                         return -1;
 244
 245                 switch (*endp++) {
 246                 case '\0':
 247                         endp--;
 248                 case 's':
 249                 case 'S':
 250                         break;
 251                 case 'm':
 252                 case 'M':
 253                         secs *= MINUTES;
 254                         break;
 255                 case 'h':
 256                 case 'H':
 257                         secs *= HOURS;
 258                         break;
 259                 case 'd':
 260                 case 'D':
 261                         secs *= DAYS;
 262                         break;
 263                 case 'w':
 264                 case 'W':
 265                         secs *= WEEKS;
 266                         break;
 267                 default:
 268                         return -1;
 269                 }
 270                 total += secs;
 271                 if (total < 0)
 272                         return -1;
 273                 p = endp;
 274         }
 275
 276         return total;
 277 }
 278
 279 /*
 280  * Search for next delimiter between hostnames/addresses and ports.
 281  * Argument may be modified (for termination).
 282  * Returns *cp if parsing succeeds.
 283  * *cp is set to the start of the next delimiter, if one was found.
 284  * If this is the last field, *cp is set to NULL.
 285  */
 286 char *
 287 hpdelim(char **cp)
 288 {
 289         char *s, *old;
 290
 291         if (cp == NULL || *cp == NULL)
 292                 return NULL;
 293
 294         old = s = *cp;
 295         if (*s == '[') {
 296                 if ((s = strchr(s, ']')) == NULL)
 297                         return NULL;
 298                 else
 299                         s++;
 300         } else if ((s = strpbrk(s, ":/")) == NULL)
 301                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 302
 303         switch (*s) {
 304         case '\0':
 305                 *cp = NULL;     /* no more fields*/
 306                 break;
 307
 308         case ':':
 309         case '/':
 310                 *s = '\0';      /* terminate */
 311                 *cp = s + 1;
 312                 break;
 313
 314         default:
 315                 return NULL;
 316         }
 317
 318         return old;
 319 }
 320
 321 char *
 322 cleanhostname(char *host)
 323 {
 324         if (*host == '[' && host[strlen(host) - 1] == ']') {
 325                 host[strlen(host) - 1] = '\0';
 326                 return (host + 1);
 327         } else
 328                 return host;
 329 }
 330
 331 char *
 332 colon(char *cp)
 333 {
 334         int flag = 0;
 335
 336         if (*cp == ':')         /* Leading colon is part of file name. */
 337                 return (0);
 338         if (*cp == '[')
 339                 flag = 1;
 340
 341         for (; *cp; ++cp) {
 342                 if (*cp == '@' && *(cp+1) == '[')
 343                         flag = 1;
 344                 if (*cp == ']' && *(cp+1) == ':' && flag)
 345                         return (cp+1);
 346                 if (*cp == ':' && !flag)
 347                         return (cp);
 348                 if (*cp == '/')
 349                         return (0);
 350         }
 351         return (0);
 352 }
 353
 354 /* function to assist building execv() arguments */
 355 void
 356 addargs(arglist *args, char *fmt, ...)
 357 {
 358         va_list ap;
 359         char buf[1024];
 360         u_int nalloc;
 361
 362         va_start(ap, fmt);
 363         vsnprintf(buf, sizeof(buf), fmt, ap);
 364         va_end(ap);
 365
 366         nalloc = args->nalloc;
 367         if (args->list == NULL) {
 368                 nalloc = 32;
 369                 args->num = 0;
 370         } else if (args->num+2 >= nalloc)
 371                 nalloc *= 2;
 372
 373         args->list = xrealloc(args->list, nalloc * sizeof(char *));
 374         args->nalloc = nalloc;
 375         args->list[args->num++] = xstrdup(buf);
 376         args->list[args->num] = NULL;
 377 }
 378
 379 /*
 380  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 381  * Warning: this calls getpw*.
 382  */
 383 char *
 384 tilde_expand_filename(const char *filename, uid_t uid)
 385 {
 386         const char *path;
 387         char user[128], ret[MAXPATHLEN];
 388         struct passwd *pw;
 389         u_int len, slash;
 390
 391         if (*filename != '~')
 392                 return (xstrdup(filename));
 393         filename++;
 394
 395         path = strchr(filename, '/');
 396         if (path != NULL && path > filename) {          /* ~user/path */
 397                 slash = path - filename;
 398                 if (slash > sizeof(user) - 1)
 399                         fatal("tilde_expand_filename: ~username too long");
 400                 memcpy(user, filename, slash);
 401                 user[slash] = '\0';
 402                 if ((pw = getpwnam(user)) == NULL)
 403                         fatal("tilde_expand_filename: No such user %s", user);
 404         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 405                 fatal("tilde_expand_filename: No such uid %d", uid);
 406
 407         if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
 408                 fatal("tilde_expand_filename: Path too long");
 409
 410         /* Make sure directory has a trailing '/' */
 411         len = strlen(pw->pw_dir);
 412         if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
 413             strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
 414                 fatal("tilde_expand_filename: Path too long");
 415
 416         /* Skip leading '/' from specified path */
 417         if (path != NULL)
 418                 filename = path + 1;
 419         if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
 420                 fatal("tilde_expand_filename: Path too long");
 421
 422         return (xstrdup(ret));
 423 }
 424
 425 /*
 426  * Expand a string with a set of %[char] escapes. A number of escapes may be
 427  * specified as (char *escape_chars, char *replacement) pairs. The list must
 428  * be terminated by a NULL escape_char. Returns replaced string in memory
 429  * allocated by xmalloc.
 430  */
 431 char *
 432 percent_expand(const char *string, ...)
 433 {
 434 #define EXPAND_MAX_KEYS 16
 435         struct {
 436                 const char *key;
 437                 const char *repl;
 438         } keys[EXPAND_MAX_KEYS];
 439         u_int num_keys, i, j;
 440         char buf[4096];
 441         va_list ap;
 442
 443         /* Gather keys */
 444         va_start(ap, string);
 445         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 446                 keys[num_keys].key = va_arg(ap, char *);
 447                 if (keys[num_keys].key == NULL)
 448                         break;
 449                 keys[num_keys].repl = va_arg(ap, char *);
 450                 if (keys[num_keys].repl == NULL)
 451                         fatal("percent_expand: NULL replacement");
 452         }
 453         va_end(ap);
 454
 455         if (num_keys >= EXPAND_MAX_KEYS)
 456                 fatal("percent_expand: too many keys");
 457
 458         /* Expand string */
 459         *buf = '\0';
 460         for (i = 0; *string != '\0'; string++) {
 461                 if (*string != '%') {
 462  append:
 463                         buf[i++] = *string;
 464                         if (i >= sizeof(buf))
 465                                 fatal("percent_expand: string too long");
 466                         buf[i] = '\0';
 467                         continue;
 468                 }
 469                 string++;
 470                 if (*string == '%')
 471                         goto append;
 472                 for (j = 0; j < num_keys; j++) {
 473                         if (strchr(keys[j].key, *string) != NULL) {
 474                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 475                                 if (i >= sizeof(buf))
 476                                         fatal("percent_expand: string too long");
 477                                 break;
 478                         }
 479                 }
 480                 if (j >= num_keys)
 481                         fatal("percent_expand: unknown key %%%c", *string);
 482         }
 483         return (xstrdup(buf));
 484 #undef EXPAND_MAX_KEYS
 485 }
 486
 487 /*
 488  * Read an entire line from a public key file into a static buffer, discarding
 489  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 490  */
 491 int
 492 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 493    u_long *lineno)
 494 {
 495         while (fgets(buf, bufsz, f) != NULL) {
 496                 (*lineno)++;
 497                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 498                         return 0;
 499                 } else {
 500                         debug("%s: %s line %lu exceeds size limit", __func__,
 501                             filename, *lineno);
 502                         /* discard remainder of line */
 503                         while (fgetc(f) != '\n' && !feof(f))
 504                                 ;       /* nothing */
 505                 }
 506         }
 507         return -1;
 508 }
 509
 510 char *
 511 tohex(const u_char *d, u_int l)
 512 {
 513         char b[3], *r;
 514         u_int i, hl;
 515
 516         hl = l * 2 + 1;
 517         r = xmalloc(hl);
 518         *r = '\0';
 519         for (i = 0; i < l; i++) {
 520                 snprintf(b, sizeof(b), "%02x", d[i]);
 521                 strlcat(r, b, hl);
 522         }
 523         return (r);
 524 }
 525