git.gag.com Git - debian/sudo/blob - toke.l

   1 %{
   2 /*
   3  * Copyright (c) 1996, 1998-2005, 2007-2010
   4  *      Todd C. Miller <Todd.Miller@courtesan.com>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  18  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  19  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  20  *
  21  * Sponsored in part by the Defense Advanced Research Projects
  22  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  23  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
  24  */
  25
  26 #include <config.h>
  27
  28 #include <sys/types.h>
  29 #include <sys/param.h>
  30 #include <sys/stat.h>
  31 #include <stdio.h>
  32 #ifdef STDC_HEADERS
  33 # include <stdlib.h>
  34 # include <stddef.h>
  35 #else
  36 # ifdef HAVE_STDLIB_H
  37 #  include <stdlib.h>
  38 # endif
  39 #endif /* STDC_HEADERS */
  40 #ifdef HAVE_STRING_H
  41 # include <string.h>
  42 #endif /* HAVE_STRING_H */
  43 #ifdef HAVE_STRINGS_H
  44 # include <strings.h>
  45 #endif /* HAVE_STRINGS_H */
  46 #ifdef HAVE_UNISTD_H
  47 # include <unistd.h>
  48 #endif /* HAVE_UNISTD_H */
  49 #if defined(HAVE_MALLOC_H) && !defined(STDC_HEADERS)
  50 # include <malloc.h>
  51 #endif /* HAVE_MALLOC_H && !STDC_HEADERS */
  52 #ifdef HAVE_DIRENT_H
  53 # include <dirent.h>
  54 # define NAMLEN(dirent) strlen((dirent)->d_name)
  55 #else
  56 # define dirent direct
  57 # define NAMLEN(dirent) (dirent)->d_namlen
  58 # ifdef HAVE_SYS_NDIR_H
  59 #  include <sys/ndir.h>
  60 # endif
  61 # ifdef HAVE_SYS_DIR_H
  62 #  include <sys/dir.h>
  63 # endif
  64 # ifdef HAVE_NDIR_H
  65 #  include <ndir.h>
  66 # endif
  67 #endif
  68 #include <ctype.h>
  69 #include "sudo.h"
  70 #include "parse.h"
  71 #include <gram.h>
  72
  73 extern YYSTYPE yylval;
  74 extern int parse_error;
  75 int sudolineno = 1;
  76 char *sudoers;
  77 static int sawspace = 0;
  78 static int arg_len = 0;
  79 static int arg_size = 0;
  80
  81 static int append               __P((char *, int));
  82 static int _fill                __P((char *, int, int));
  83 static int fill_cmnd            __P((char *, int));
  84 static int fill_args            __P((char *, int, int));
  85 static int _push_include        __P((char *, int));
  86 static int pop_include          __P((void));
  87 static int ipv6_valid           __P((const char *s));
  88 static char *parse_include      __P((char *));
  89 extern void yyerror             __P((const char *));
  90
  91 #define fill(a, b)              _fill(a, b, 0)
  92
  93 #define push_include(_p)        (_push_include((_p), FALSE))
  94 #define push_includedir(_p)     (_push_include((_p), TRUE))
  95
  96 /* realloc() to size + COMMANDARGINC to make room for command args */
  97 #define COMMANDARGINC   64
  98
  99 #ifdef TRACELEXER
 100 #define LEXTRACE(msg)   fputs(msg, stderr)
 101 #else
 102 #define LEXTRACE(msg)
 103 #endif
 104 %}
 105
 106 HEX16                   [0-9A-Fa-f]{1,4}
 107 OCTET                   (1?[0-9]{1,2})|(2[0-4][0-9])|(25[0-5])
 108 IPV4ADDR                {OCTET}(\.{OCTET}){3}
 109 IPV6ADDR                ({HEX16}?:){2,7}{HEX16}?|({HEX16}?:){2,6}:{IPV4ADDR}
 110
 111 HOSTNAME                [[:alnum:]_-]+
 112 WORD                    ([^#>!=:,\(\) \t\n\\]|\\[^\n])+
 113 ID                      #-?[0-9]+
 114 PATH                    \/(\\[\,:= \t#]|[^\,:=\\ \t\n#])+
 115 ENVAR                   ([^#!=, \t\n\\\"]|\\[^\n])([^#=, \t\n\\\"]|\\[^\n])*
 116 DEFVAR                  [a-z_]+
 117
 118 %option nounput
 119 %option noyywrap
 120
 121 %s      GOTDEFS
 122 %x      GOTCMND
 123 %x      STARTDEFS
 124 %x      INDEFS
 125 %x      INSTR
 126
 127 %%
 128 <GOTDEFS>[[:blank:]]+   BEGIN STARTDEFS;
 129
 130 <STARTDEFS>{DEFVAR}     {
 131                             BEGIN INDEFS;
 132                             LEXTRACE("DEFVAR ");
 133                             if (!fill(yytext, yyleng))
 134                                 yyterminate();
 135                             return(DEFVAR);
 136                         }
 137
 138 <INDEFS>{
 139     ,                   {
 140                             BEGIN STARTDEFS;
 141                             LEXTRACE(", ");
 142                             return(',');
 143                         }                       /* return ',' */
 144
 145     =                   {
 146                             LEXTRACE("= ");
 147                             return('=');
 148                         }                       /* return '=' */
 149
 150     \+=                 {
 151                             LEXTRACE("+= ");
 152                             return('+');
 153                         }                       /* return '+' */
 154
 155     -=                  {
 156                             LEXTRACE("-= ");
 157                             return('-');
 158                         }                       /* return '-' */
 159
 160     \"                  {
 161                             LEXTRACE("BEGINSTR ");
 162                             yylval.string = NULL;
 163                             BEGIN INSTR;
 164                         }
 165
 166     {ENVAR}             {
 167                             LEXTRACE("WORD(2) ");
 168                             if (!fill(yytext, yyleng))
 169                                 yyterminate();
 170                             return(WORD);
 171                         }
 172 }
 173
 174 <INSTR>{
 175     \\[[:blank:]]*\n[[:blank:]]*        {
 176                             /* Line continuation char followed by newline. */
 177                             ++sudolineno;
 178                             LEXTRACE("\n");
 179                         }
 180
 181     \"                  {
 182                             LEXTRACE("ENDSTR ");
 183                             BEGIN INDEFS;
 184                             return(WORD);
 185                         }
 186
 187     \\                  {
 188                             LEXTRACE("BACKSLASH ");
 189                             if (!append(yytext, yyleng))
 190                                 yyterminate();
 191                         }
 192
 193     ([^\"\n\\]|\\\")+   {
 194                             LEXTRACE("STRBODY ");
 195                             if (!append(yytext, yyleng))
 196                                 yyterminate();
 197                         }
 198 }
 199
 200 <GOTCMND>{
 201     \\[\*\?\[\]\!]      {
 202                             /* quoted fnmatch glob char, pass verbatim */
 203                             LEXTRACE("QUOTEDCHAR ");
 204                             if (!fill_args(yytext, 2, sawspace))
 205                                 yyterminate();
 206                             sawspace = FALSE;
 207                         }
 208
 209     \\[:\\,= \t#]       {
 210                             /* quoted sudoers special char, strip backslash */
 211                             LEXTRACE("QUOTEDCHAR ");
 212                             if (!fill_args(yytext + 1, 1, sawspace))
 213                                 yyterminate();
 214                             sawspace = FALSE;
 215                         }
 216
 217     [#:\,=\n]           {
 218                             BEGIN INITIAL;
 219                             yyless(0);
 220                             return(COMMAND);
 221                         }                       /* end of command line args */
 222
 223     [^#\\:, \t\n]+      {
 224                             LEXTRACE("ARG ");
 225                             if (!fill_args(yytext, yyleng, sawspace))
 226                                 yyterminate();
 227                             sawspace = FALSE;
 228                         }                       /* a command line arg */
 229 }
 230
 231 <INITIAL>^#include[[:blank:]]+\/.*\n {
 232                             char *path;
 233
 234                             if ((path = parse_include(yytext)) == NULL)
 235                                 yyterminate();
 236
 237                             LEXTRACE("INCLUDE\n");
 238
 239                             /* Push current buffer and switch to include file */
 240                             if (!push_include(path))
 241                                 yyterminate();
 242                         }
 243
 244 <INITIAL>^#includedir[[:blank:]]+\/.*\n {
 245                             char *path;
 246
 247                             if ((path = parse_include(yytext)) == NULL)
 248                                 yyterminate();
 249
 250                             LEXTRACE("INCLUDEDIR\n");
 251
 252                             /*
 253                              * Push current buffer and switch to include file.
 254                              * We simply ignore empty directories.
 255                              */
 256                             if (!push_includedir(path) && parse_error)
 257                                 yyterminate();
 258                         }
 259
 260 <INITIAL>^[[:blank:]]*Defaults([:@>\!]\!?{WORD})? {
 261                             int n;
 262                             for (n = 0; isblank((unsigned char)yytext[n]); n++)
 263                                 continue;
 264                             n += 8;
 265                             BEGIN GOTDEFS;
 266                             switch (yytext[n++]) {
 267                                 case ':':
 268                                     yyless(n);
 269                                     LEXTRACE("DEFAULTS_USER ");
 270                                     return(DEFAULTS_USER);
 271                                 case '>':
 272                                     yyless(n);
 273                                     LEXTRACE("DEFAULTS_RUNAS ");
 274                                     return(DEFAULTS_RUNAS);
 275                                 case '@':
 276                                     yyless(n);
 277                                     LEXTRACE("DEFAULTS_HOST ");
 278                                     return(DEFAULTS_HOST);
 279                                 case '!':
 280                                     yyless(n);
 281                                     LEXTRACE("DEFAULTS_CMND ");
 282                                     return(DEFAULTS_CMND);
 283                                 default:
 284                                     LEXTRACE("DEFAULTS ");
 285                                     return(DEFAULTS);
 286                             }
 287                         }
 288
 289 <INITIAL>^[[:blank:]]*(Host|Cmnd|User|Runas)_Alias      {
 290                             int n;
 291                             for (n = 0; isblank((unsigned char)yytext[n]); n++)
 292                                 continue;
 293                             switch (yytext[n]) {
 294                                 case 'H':
 295                                     LEXTRACE("HOSTALIAS ");
 296                                     return(HOSTALIAS);
 297                                 case 'C':
 298                                     LEXTRACE("CMNDALIAS ");
 299                                     return(CMNDALIAS);
 300                                 case 'U':
 301                                     LEXTRACE("USERALIAS ");
 302                                     return(USERALIAS);
 303                                 case 'R':
 304                                     LEXTRACE("RUNASALIAS ");
 305                                     return(RUNASALIAS);
 306                             }
 307                         }
 308
 309 NOPASSWD[[:blank:]]*:   {
 310                                 /* cmnd does not require passwd for this user */
 311                                 LEXTRACE("NOPASSWD ");
 312                                 return(NOPASSWD);
 313                         }
 314
 315 PASSWD[[:blank:]]*:     {
 316                                 /* cmnd requires passwd for this user */
 317                                 LEXTRACE("PASSWD ");
 318                                 return(PASSWD);
 319                         }
 320
 321 NOEXEC[[:blank:]]*:     {
 322                                 LEXTRACE("NOEXEC ");
 323                                 return(NOEXEC);
 324                         }
 325
 326 EXEC[[:blank:]]*:       {
 327                                 LEXTRACE("EXEC ");
 328                                 return(EXEC);
 329                         }
 330
 331 SETENV[[:blank:]]*:     {
 332                                 LEXTRACE("SETENV ");
 333                                 return(SETENV);
 334                         }
 335
 336 NOSETENV[[:blank:]]*:   {
 337                                 LEXTRACE("NOSETENV ");
 338                                 return(NOSETENV);
 339                         }
 340
 341 \+{WORD}                {
 342                             /* netgroup */
 343                             if (!fill(yytext, yyleng))
 344                                 yyterminate();
 345                             LEXTRACE("NETGROUP ");
 346                             return(NETGROUP);
 347                         }
 348
 349 \%:?{WORD}              {
 350                             /* UN*X group */
 351                             if (!fill(yytext, yyleng))
 352                                 yyterminate();
 353                             LEXTRACE("USERGROUP ");
 354                             return(USERGROUP);
 355                         }
 356
 357 {IPV4ADDR}(\/{IPV4ADDR})? {
 358                             if (!fill(yytext, yyleng))
 359                                 yyterminate();
 360                             LEXTRACE("NTWKADDR ");
 361                             return(NTWKADDR);
 362                         }
 363
 364 {IPV4ADDR}\/([12][0-9]*|3[0-2]*) {
 365                             if (!fill(yytext, yyleng))
 366                                 yyterminate();
 367                             LEXTRACE("NTWKADDR ");
 368                             return(NTWKADDR);
 369                         }
 370
 371 {IPV6ADDR}(\/{IPV6ADDR})? {
 372                             if (!ipv6_valid(yytext)) {
 373                                 LEXTRACE("ERROR ");
 374                                 return(ERROR);
 375                             }
 376                             if (!fill(yytext, yyleng))
 377                                 yyterminate();
 378                             LEXTRACE("NTWKADDR ");
 379                             return(NTWKADDR);
 380                         }
 381
 382 {IPV6ADDR}\/([0-9]|[1-9][0-9]|1[01][0-9]|12[0-8]) {
 383                             if (!ipv6_valid(yytext)) {
 384                                 LEXTRACE("ERROR ");
 385                                 return(ERROR);
 386                             }
 387                             if (!fill(yytext, yyleng))
 388                                 yyterminate();
 389                             LEXTRACE("NTWKADDR ");
 390                             return(NTWKADDR);
 391                         }
 392
 393 [[:upper:]][[:upper:][:digit:]_]* {
 394                             if (strcmp(yytext, "ALL") == 0) {
 395                                 LEXTRACE("ALL ");
 396                                 return(ALL);
 397                             }
 398 #ifdef HAVE_SELINUX
 399                             /* XXX - restrict type/role to initial state */
 400                             if (strcmp(yytext, "TYPE") == 0) {
 401                                 LEXTRACE("TYPE ");
 402                                 return(TYPE);
 403                             }
 404                             if (strcmp(yytext, "ROLE") == 0) {
 405                                 LEXTRACE("ROLE ");
 406                                 return(ROLE);
 407                             }
 408 #endif /* HAVE_SELINUX */
 409                             if (!fill(yytext, yyleng))
 410                                 yyterminate();
 411                             LEXTRACE("ALIAS ");
 412                             return(ALIAS);
 413                         }
 414
 415 <GOTDEFS>({PATH}|sudoedit) {
 416                             /* no command args allowed for Defaults!/path */
 417                             if (!fill_cmnd(yytext, yyleng))
 418                                 yyterminate();
 419                             LEXTRACE("COMMAND ");
 420                             return(COMMAND);
 421                         }
 422
 423 sudoedit                {
 424                             BEGIN GOTCMND;
 425                             LEXTRACE("COMMAND ");
 426                             if (!fill_cmnd(yytext, yyleng))
 427                                 yyterminate();
 428                         }                       /* sudo -e */
 429
 430 {PATH}                  {
 431                             /* directories can't have args... */
 432                             if (yytext[yyleng - 1] == '/') {
 433                                 LEXTRACE("COMMAND ");
 434                                 if (!fill_cmnd(yytext, yyleng))
 435                                     yyterminate();
 436                                 return(COMMAND);
 437                             } else {
 438                                 BEGIN GOTCMND;
 439                                 LEXTRACE("COMMAND ");
 440                                 if (!fill_cmnd(yytext, yyleng))
 441                                     yyterminate();
 442                             }
 443                         }                       /* a pathname */
 444
 445 <INITIAL,GOTDEFS>\"[^"\n]+\" {
 446                             /* a quoted user/group name */
 447                             if (!fill(yytext + 1, yyleng - 2))
 448                                 yyterminate();
 449                             switch (yytext[1]) {
 450                             case '%':
 451                                 LEXTRACE("USERGROUP ");
 452                                 return(USERGROUP);
 453                             case '+':
 454                                 LEXTRACE("NETGROUP ");
 455                                 return(NETGROUP);
 456                             default:
 457                                 LEXTRACE("WORD(4) ");
 458                                 return(WORD);
 459                             }
 460                         }
 461
 462 <INITIAL,GOTDEFS>({ID}|{WORD}) {
 463                             /* a word */
 464                             if (!fill(yytext, yyleng))
 465                                 yyterminate();
 466                             LEXTRACE("WORD(5) ");
 467                             return(WORD);
 468                         }
 469
 470 \(                      {
 471                             LEXTRACE("( ");
 472                             return ('(');
 473                         }
 474
 475 \)                      {
 476                             LEXTRACE(") ");
 477                             return(')');
 478                         }
 479
 480 ,                       {
 481                             LEXTRACE(", ");
 482                             return(',');
 483                         }                       /* return ',' */
 484
 485 =                       {
 486                             LEXTRACE("= ");
 487                             return('=');
 488                         }                       /* return '=' */
 489
 490 :                       {
 491                             LEXTRACE(": ");
 492                             return(':');
 493                         }                       /* return ':' */
 494
 495 <*>!+                   {
 496                             if (yyleng % 2 == 1)
 497                                 return('!');    /* return '!' */
 498                         }
 499
 500 <*>\n                   {
 501                             BEGIN INITIAL;
 502                             ++sudolineno;
 503                             LEXTRACE("\n");
 504                             return(COMMENT);
 505                         }                       /* return newline */
 506
 507 <*>[[:blank:]]+         {                       /* throw away space/tabs */
 508                             sawspace = TRUE;    /* but remember for fill_args */
 509                         }
 510
 511 <*>\\[[:blank:]]*\n     {
 512                             sawspace = TRUE;    /* remember for fill_args */
 513                             ++sudolineno;
 514                             LEXTRACE("\n\t");
 515                         }                       /* throw away EOL after \ */
 516
 517 <INITIAL,STARTDEFS,INDEFS>#(-[^\n0-9].*|[^\n0-9-].*)?\n {
 518                             BEGIN INITIAL;
 519                             ++sudolineno;
 520                             LEXTRACE("\n");
 521                             return(COMMENT);
 522                         }                       /* comment, not uid/gid */
 523
 524 <*>.                    {
 525                             LEXTRACE("ERROR ");
 526                             return(ERROR);
 527                         }       /* parse error */
 528
 529 <*><<EOF>>              {
 530                             if (YY_START != INITIAL) {
 531                                 BEGIN INITIAL;
 532                                 LEXTRACE("ERROR ");
 533                                 return(ERROR);
 534                             }
 535                             if (!pop_include())
 536                                 yyterminate();
 537                         }
 538
 539 %%
 540 static unsigned char
 541 hexchar(s)
 542     const char *s;
 543 {
 544     int i;
 545     int result = 0;
 546
 547     s += 2; /* skip \\x */
 548     for (i = 0; i < 2; i++) {
 549         switch (*s) {
 550         case 'A':
 551         case 'a':
 552             result += 10;
 553             break;
 554         case 'B':
 555         case 'b':
 556             result += 11;
 557             break;
 558         case 'C':
 559         case 'c':
 560             result += 12;
 561             break;
 562         case 'D':
 563         case 'd':
 564             result += 13;
 565             break;
 566         case 'E':
 567         case 'e':
 568             result += 14;
 569             break;
 570         case 'F':
 571         case 'f':
 572             result += 15;
 573             break;
 574         default:
 575             result += *s - '0';
 576             break;
 577         }
 578         if (i == 0) {
 579             result *= 16;
 580             s++;
 581         }
 582     }
 583     return((unsigned char)result);
 584 }
 585
 586 static int
 587 _fill(src, len, olen)
 588     char *src;
 589     int len, olen;
 590 {
 591     char *dst;
 592
 593     dst = olen ? realloc(yylval.string, olen + len + 1) : malloc(len + 1);
 594     if (dst == NULL) {
 595         yyerror("unable to allocate memory");
 596         return(FALSE);
 597     }
 598     yylval.string = dst;
 599
 600     /* Copy the string and collapse any escaped characters. */
 601     dst += olen;
 602     while (len--) {
 603         if (*src == '\\' && len) {
 604             if (src[1] == 'x' && len >= 3 &&
 605                 isxdigit((unsigned char) src[2]) &&
 606                 isxdigit((unsigned char) src[3])) {
 607                 *dst++ = hexchar(src);
 608                 src += 4;
 609                 len -= 3;
 610             } else {
 611                 src++;
 612                 len--;
 613                 *dst++ = *src++;
 614             }
 615         } else {
 616             *dst++ = *src++;
 617         }
 618     }
 619     *dst = '\0';
 620     return(TRUE);
 621 }
 622
 623 static int
 624 append(src, len)
 625     char *src;
 626     int len;
 627 {
 628     int olen = 0;
 629
 630     if (yylval.string != NULL)
 631         olen = strlen(yylval.string);
 632
 633     return(_fill(src, len, olen));
 634 }
 635
 636 #define SPECIAL(c) \
 637     ((c) == ',' || (c) == ':' || (c) == '=' || (c) == ' ' || (c) == '\t' || (c) == '#')
 638
 639 static int
 640 fill_cmnd(src, len)
 641     char *src;
 642     int len;
 643 {
 644     char *dst;
 645     int i;
 646
 647     arg_len = arg_size = 0;
 648
 649     dst = yylval.command.cmnd = (char *) malloc(len + 1);
 650     if (yylval.command.cmnd == NULL) {
 651         yyerror("unable to allocate memory");
 652         return(FALSE);
 653     }
 654
 655     /* Copy the string and collapse any escaped sudo-specific characters. */
 656     for (i = 0; i < len; i++) {
 657         if (src[i] == '\\' && i != len - 1 && SPECIAL(src[i + 1]))
 658             *dst++ = src[++i];
 659         else
 660             *dst++ = src[i];
 661     }
 662     *dst = '\0';
 663
 664     yylval.command.args = NULL;
 665     return(TRUE);
 666 }
 667
 668 static int
 669 fill_args(s, len, addspace)
 670     char *s;
 671     int len;
 672     int addspace;
 673 {
 674     int new_len;
 675     char *p;
 676
 677     if (yylval.command.args == NULL) {
 678         addspace = 0;
 679         new_len = len;
 680     } else
 681         new_len = arg_len + len + addspace;
 682
 683     if (new_len >= arg_size) {
 684         /* Allocate more space than we need for subsequent args */
 685         while (new_len >= (arg_size += COMMANDARGINC))
 686             ;
 687
 688         p = yylval.command.args ?
 689             (char *) realloc(yylval.command.args, arg_size) :
 690             (char *) malloc(arg_size);
 691         if (p == NULL) {
 692             efree(yylval.command.args);
 693             yyerror("unable to allocate memory");
 694             return(FALSE);
 695         } else
 696             yylval.command.args = p;
 697     }
 698
 699     /* Efficiently append the arg (with a leading space if needed). */
 700     p = yylval.command.args + arg_len;
 701     if (addspace)
 702         *p++ = ' ';
 703     if (strlcpy(p, s, arg_size - (p - yylval.command.args)) != len) {
 704         yyerror("fill_args: buffer overflow");  /* paranoia */
 705         return(FALSE);
 706     }
 707     arg_len = new_len;
 708     return(TRUE);
 709 }
 710
 711 struct path_list {
 712     char *path;
 713     struct path_list *next;
 714 };
 715
 716 struct include_stack {
 717     YY_BUFFER_STATE bs;
 718     char *path;
 719     struct path_list *more; /* more files in case of includedir */
 720     int lineno;
 721     int keepopen;
 722 };
 723
 724 static int
 725 pl_compare(v1, v2)
 726     const void *v1;
 727     const void *v2;
 728 {
 729     const struct path_list * const *p1 = v1;
 730     const struct path_list * const *p2 = v2;
 731
 732     return(strcmp((*p1)->path, (*p2)->path));
 733 }
 734
 735 static char *
 736 switch_dir(stack, dirpath)
 737     struct include_stack *stack;
 738     char *dirpath;
 739 {
 740     DIR *dir;
 741     int i, count = 0;
 742     char *path = NULL;
 743     struct dirent *dent;
 744     struct stat sb;
 745     struct path_list *pl, *first = NULL;
 746     struct path_list **sorted = NULL;
 747
 748     if (!(dir = opendir(dirpath))) {
 749         yyerror(dirpath);
 750         return(NULL);
 751     }
 752     while ((dent = readdir(dir))) {
 753         /* Ignore files that end in '~' or have a '.' in them. */
 754         if (dent->d_name[0] == '\0' || dent->d_name[NAMLEN(dent) - 1] == '~'
 755             || strchr(dent->d_name, '.') != NULL) {
 756             continue;
 757         }
 758         if (asprintf(&path, "%s/%s", dirpath, dent->d_name) == -1) {
 759             closedir(dir);
 760             goto bad;
 761         }
 762         if (stat(path, &sb) != 0 || !S_ISREG(sb.st_mode)) {
 763             efree(path);
 764             continue;
 765         }
 766         pl = malloc(sizeof(*pl));
 767         if (pl == NULL)
 768             goto bad;
 769         pl->path = path;
 770         pl->next = first;
 771         first = pl;
 772         count++;
 773     }
 774     closedir(dir);
 775
 776     if (count == 0)
 777         goto done;
 778
 779     /* Sort the list as an array. */
 780     sorted = malloc(sizeof(*sorted) * count);
 781     if (sorted == NULL)
 782         goto bad;
 783     pl = first;
 784     for (i = 0; i < count; i++) {
 785         sorted[i] = pl;
 786         pl = pl->next;
 787     }
 788     qsort(sorted, count, sizeof(*sorted), pl_compare);
 789
 790     /* Apply sorting to the list. */
 791     first = sorted[0];
 792     sorted[count - 1]->next = NULL;
 793     for (i = 1; i < count; i++)
 794         sorted[i - 1]->next = sorted[i];
 795     efree(sorted);
 796
 797     /* Pull out the first element for parsing, leave the rest for later. */
 798     if (count) {
 799         path = first->path;
 800         pl = first->next;
 801         efree(first);
 802         stack->more = pl;
 803     } else {
 804         path = NULL;
 805     }
 806 done:
 807     efree(dirpath);
 808     return(path);
 809 bad:
 810     while (first != NULL) {
 811         pl = first;
 812         first = pl->next;
 813         free(pl->path);
 814         free(pl);
 815     }
 816     efree(sorted);
 817     efree(dirpath);
 818     efree(path);
 819     return(NULL);
 820 }
 821
 822 #define MAX_SUDOERS_DEPTH       128
 823 #define SUDOERS_STACK_INCREMENT 16
 824
 825 static size_t istacksize, idepth;
 826 static struct include_stack *istack;
 827 static int keepopen;
 828
 829 void
 830 init_lexer()
 831 {
 832     struct path_list *pl;
 833
 834     while (idepth) {
 835         idepth--;
 836         while ((pl = istack[idepth].more) != NULL) {
 837             istack[idepth].more = pl->next;
 838             efree(pl->path);
 839             efree(pl);
 840         }
 841         efree(istack[idepth].path);
 842         if (idepth && !istack[idepth].keepopen)
 843             fclose(istack[idepth].bs->yy_input_file);
 844         yy_delete_buffer(istack[idepth].bs);
 845     }
 846     efree(istack);
 847     istack = NULL;
 848     istacksize = idepth = 0;
 849     keepopen = FALSE;
 850 }
 851
 852 static int
 853 _push_include(path, isdir)
 854     char *path;
 855     int isdir;
 856 {
 857     struct path_list *pl;
 858     FILE *fp;
 859
 860     /* push current state onto stack */
 861     if (idepth >= istacksize) {
 862         if (idepth > MAX_SUDOERS_DEPTH) {
 863             yyerror("too many levels of includes");
 864             return(FALSE);
 865         }
 866         istacksize += SUDOERS_STACK_INCREMENT;
 867         istack = (struct include_stack *) realloc(istack,
 868             sizeof(*istack) * istacksize);
 869         if (istack == NULL) {
 870             yyerror("unable to allocate memory");
 871             return(FALSE);
 872         }
 873     }
 874     if (isdir) {
 875         if (!(path = switch_dir(&istack[idepth], path))) {
 876             /* switch_dir() called yyerror() for us */
 877             return(FALSE);
 878         }
 879         while ((fp = open_sudoers(path, FALSE, &keepopen)) == NULL) {
 880             /* Unable to open path in includedir, go to next one, if any. */
 881             efree(path);
 882             if ((pl = istack[idepth].more) == NULL)
 883                 return(FALSE);
 884             path = pl->path;
 885             istack[idepth].more = pl->next;
 886             efree(pl);
 887         }
 888     } else {
 889         if ((fp = open_sudoers(path, TRUE, &keepopen)) == NULL) {
 890             yyerror(path);
 891             return(FALSE);
 892         }
 893         istack[idepth].more = NULL;
 894     }
 895     /* Push the old (current) file and open the new one. */
 896     istack[idepth].path = sudoers; /* push old path */
 897     istack[idepth].bs = YY_CURRENT_BUFFER;
 898     istack[idepth].lineno = sudolineno;
 899     istack[idepth].keepopen = keepopen;
 900     idepth++;
 901     sudolineno = 1;
 902     sudoers = path;
 903     yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
 904
 905     return(TRUE);
 906 }
 907
 908 static int
 909 pop_include()
 910 {
 911     struct path_list *pl;
 912     FILE *fp;
 913
 914     if (idepth == 0)
 915         return(FALSE);
 916
 917     if (!keepopen)
 918         fclose(YY_CURRENT_BUFFER->yy_input_file);
 919     yy_delete_buffer(YY_CURRENT_BUFFER);
 920     /* If we are in an include dir, move to the next file. */
 921     while ((pl = istack[idepth - 1].more) != NULL) {
 922         fp = open_sudoers(pl->path, FALSE, &keepopen);
 923         if (fp != NULL) {
 924             istack[idepth - 1].more = pl->next;
 925             efree(sudoers);
 926             sudoers = pl->path;
 927             sudolineno = 1;
 928             yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
 929             efree(pl);
 930             break;
 931         }
 932         /* Unable to open path in include dir, go to next one. */
 933         istack[idepth - 1].more = pl->next;
 934         efree(pl->path);
 935         efree(pl);
 936     }
 937     /* If no path list, just pop the last dir on the stack. */
 938     if (pl == NULL) {
 939         idepth--;
 940         yy_switch_to_buffer(istack[idepth].bs);
 941         efree(sudoers);
 942         sudoers = istack[idepth].path;
 943         sudolineno = istack[idepth].lineno;
 944         keepopen = istack[idepth].keepopen;
 945     }
 946     return(TRUE);
 947 }
 948
 949 static char *
 950 parse_include(base)
 951     char *base;
 952 {
 953     char *cp, *ep, *path;
 954     int len = 0, subst = 0;
 955     size_t shost_len = 0;
 956
 957     /* Pull out path from #include line. */
 958     cp = base + sizeof("#include");
 959     if (*cp == 'i')
 960         cp += 3; /* includedir */
 961     while (isblank((unsigned char) *cp))
 962         cp++;
 963     ep = cp;
 964     while (*ep != '\0' && !isspace((unsigned char) *ep)) {
 965         if (ep[0] == '%' && ep[1] == 'h') {
 966             shost_len = strlen(user_shost);
 967             len += shost_len - 2;
 968             subst = 1;
 969         }
 970         ep++;
 971     }
 972
 973     /* Make a copy of path and return it. */
 974     len += (int)(ep - cp);
 975     if ((path = malloc(len + 1)) == NULL)
 976         yyerror("unable to allocate memory");
 977     if (subst) {
 978         /* substitute for %h */
 979         char *pp = path;
 980         while (cp < ep) {
 981             if (cp[0] == '%' && cp[1] == 'h') {
 982                 memcpy(pp, user_shost, shost_len);
 983                 pp += shost_len;
 984                 cp += 2;
 985                 continue;
 986             }
 987             *pp++ = *cp++;
 988         }
 989         *pp = '\0';
 990     } else {
 991         memcpy(path, cp, len);
 992         path[len] = '\0';
 993     }
 994
 995     /* Push any excess characters (e.g. comment, newline) back to the lexer */
 996     if (*ep != '\0')
 997         yyless((int)(ep - base));
 998
 999     return(path);
1000 }
1001
1002 /*
1003  * Check to make sure an IPv6 address does not contain multiple instances
1004  * of the string "::".  Assumes strlen(s) >= 1.
1005  * Returns TRUE if address is valid else FALSE.
1006  */
1007 static int
1008 ipv6_valid(s)
1009     const char *s;
1010 {
1011     int nmatch = 0;
1012
1013     for (; *s != '\0'; s++) {
1014         if (s[0] == ':' && s[1] == ':') {
1015             if (++nmatch > 1)
1016                 break;
1017         }
1018         if (s[0] == '/')
1019             nmatch = 0;                 /* reset if we hit netmask */
1020     }
1021
1022     return (nmatch <= 1);
1023 }