| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: parser.y,v 1.4 1997/09/17 10:26:52 mdw Exp $ |
| 4 | * |
| 5 | * Parser for `become.conf' files |
| 6 | * |
| 7 | * (c) 1997 EBI |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of `become' |
| 13 | * |
| 14 | * `Become' is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * `Become' is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with `become'; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: parser.y,v $ |
| 32 | * Revision 1.4 1997/09/17 10:26:52 mdw |
| 33 | * Use rewritten class handler. Makes the expression parsers considerably |
| 34 | * simpler. |
| 35 | * |
| 36 | * Revision 1.3 1997/09/09 18:17:06 mdw |
| 37 | * Allow default port to be given as a service name or port number. |
| 38 | * |
| 39 | * Revision 1.2 1997/08/04 10:24:24 mdw |
| 40 | * Sources placed under CVS control. |
| 41 | * |
| 42 | * Revision 1.1 1997/07/21 13:47:45 mdw |
| 43 | * Initial revision |
| 44 | * |
| 45 | */ |
| 46 | |
| 47 | /*----- Header files ------------------------------------------------------*/ |
| 48 | %{ |
| 49 | |
| 50 | /* --- ANSI headers --- */ |
| 51 | |
| 52 | #include <stdio.h> |
| 53 | #include <stdlib.h> |
| 54 | #include <string.h> |
| 55 | |
| 56 | /* --- Unix headers --- */ |
| 57 | |
| 58 | #include <sys/types.h> |
| 59 | #include <sys/socket.h> |
| 60 | |
| 61 | #include <netinet/in.h> |
| 62 | |
| 63 | #include <arpa/inet.h> |
| 64 | |
| 65 | #include <netdb.h> |
| 66 | #include <pwd.h> |
| 67 | #include <unistd.h> |
| 68 | |
| 69 | /* --- Local headers --- */ |
| 70 | |
| 71 | #include "class.h" |
| 72 | #include "daemon.h" |
| 73 | #include "lexer.h" |
| 74 | #include "name.h" |
| 75 | #include "rule.h" |
| 76 | #include "sym.h" |
| 77 | #include "userdb.h" |
| 78 | #include "utils.h" |
| 79 | |
| 80 | %} |
| 81 | /*----- Stack type --------------------------------------------------------*/ |
| 82 | |
| 83 | %union { |
| 84 | long i; |
| 85 | char *s; |
| 86 | name *n; |
| 87 | class_node *c; |
| 88 | } |
| 89 | |
| 90 | /*----- Token and rule declarations ---------------------------------------*/ |
| 91 | |
| 92 | /* --- Tokens --- */ |
| 93 | |
| 94 | %token BADTOKEN |
| 95 | %token USER |
| 96 | %token COMMAND |
| 97 | %token HOST |
| 98 | %token ALLOW |
| 99 | %token PORT |
| 100 | %token KEYFILE |
| 101 | %token <i> INT |
| 102 | %token <s> WORD |
| 103 | %token <s> STRING |
| 104 | %token ARROW |
| 105 | |
| 106 | %left ',' |
| 107 | %left '-' |
| 108 | %left '|' |
| 109 | %left '&' |
| 110 | |
| 111 | /* --- Rules --- */ |
| 112 | |
| 113 | %type <c> user_class command_class host_class |
| 114 | %type <c> user_class_opt command_class_opt host_class_opt |
| 115 | %type <n> name |
| 116 | |
| 117 | /*----- Error reporting ---------------------------------------------------*/ |
| 118 | %{ |
| 119 | |
| 120 | #define YYDEBUG 1 |
| 121 | #define YYERROR_VERBOSE |
| 122 | |
| 123 | /* --- @yyprint@ --- * |
| 124 | * |
| 125 | * Arguments: @FILE *fp@ = pointer to stream to write on |
| 126 | * @int type@ = pointer to token type |
| 127 | * @YYSTYPE v@ = token value |
| 128 | * |
| 129 | * Returns: --- |
| 130 | * |
| 131 | * Use: Displays the semantic value of a token. |
| 132 | */ |
| 133 | |
| 134 | #define YYPRINT(fp, type, value) yyprint(fp, type, value) |
| 135 | |
| 136 | static void yyprint(FILE *fp, int type, YYSTYPE v) |
| 137 | { |
| 138 | switch (type) { |
| 139 | case INT: |
| 140 | fprintf(fp, " %li", v.i); |
| 141 | break; |
| 142 | case WORD: |
| 143 | case STRING: |
| 144 | fprintf(fp, " `%s'", v.s); |
| 145 | break; |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | /* --- @yyerror@ --- * |
| 150 | * |
| 151 | * Arguments: @const char *msg@ = pointer to error message |
| 152 | * |
| 153 | * Returns: --- |
| 154 | * |
| 155 | * Use: Reports parse errors. |
| 156 | */ |
| 157 | |
| 158 | static void yyerror(const char *msg) |
| 159 | { |
| 160 | moan("%s at line %i", msg, lex_line); |
| 161 | } |
| 162 | |
| 163 | %} |
| 164 | %% |
| 165 | /*----- The actual grammar ------------------------------------------------*/ |
| 166 | |
| 167 | /* --- Simple driver things --- */ |
| 168 | |
| 169 | file : /* empty */ |
| 170 | | file statement |
| 171 | ; |
| 172 | |
| 173 | statement : user_spec |
| 174 | | command_spec |
| 175 | | host_spec |
| 176 | | allow_spec |
| 177 | | port_spec |
| 178 | | key_spec |
| 179 | | error ';' |
| 180 | ; |
| 181 | |
| 182 | /* --- Main statement types --- */ |
| 183 | |
| 184 | user_spec : USER name '=' user_class ';' { |
| 185 | if ($2->c) |
| 186 | class_dec($2->c); |
| 187 | $2->c = $4; |
| 188 | } |
| 189 | ; |
| 190 | |
| 191 | command_spec : COMMAND name '=' command_class ';' { |
| 192 | if ($2->c) |
| 193 | class_dec($2->c); |
| 194 | $2->c = $4; |
| 195 | } |
| 196 | ; |
| 197 | |
| 198 | host_spec : HOST name '=' host_class ';' { |
| 199 | if ($2->c) |
| 200 | class_dec($2->c); |
| 201 | $2->c = $4; |
| 202 | } |
| 203 | ; |
| 204 | |
| 205 | port_spec : PORT STRING ';' { |
| 206 | struct servent *s = getservbyname($2, "udp"); |
| 207 | if (!s) { |
| 208 | moan("unknown service `%s' at line %i", |
| 209 | $2, lex_line); |
| 210 | YYERROR; |
| 211 | } |
| 212 | daemon_usePort(s->s_port); |
| 213 | } |
| 214 | | PORT INT ';' { daemon_usePort(htons($2)); } |
| 215 | ; |
| 216 | |
| 217 | key_spec : KEYFILE STRING ';' { daemon_readKey($2); } |
| 218 | |
| 219 | /* --- Parsing allow specifications --- */ |
| 220 | |
| 221 | allow_spec : ALLOW host_class_opt user_class ARROW |
| 222 | user_class_opt command_class_opt ';' { |
| 223 | rule_add($2, $3, $5, $6); |
| 224 | } |
| 225 | |
| 226 | host_class_opt : /* empty */ { $$ = class_all; } |
| 227 | | '[' host_class ']' { $$ = $2; } |
| 228 | ; |
| 229 | |
| 230 | user_class_opt : /* empty */ { $$ = class_all; } |
| 231 | | user_class { $$ = $1; } |
| 232 | ; |
| 233 | |
| 234 | command_class_opt : /* empty */ { $$ = class_all; } |
| 235 | | ':' command_class { $$ = $2; } |
| 236 | ; |
| 237 | |
| 238 | /* --- Names get translated into symbols quickly --- */ |
| 239 | |
| 240 | name : WORD { |
| 241 | unsigned f; |
| 242 | name *n = name_find($1, 1, &f); |
| 243 | if (!f) |
| 244 | n->c = 0; |
| 245 | $$ = n; |
| 246 | } |
| 247 | |
| 248 | /*----- Various class expression types ------------------------------------* |
| 249 | * |
| 250 | * Unfortunately, all these need to handle token types slightly differently |
| 251 | * and I can't be bothered to remember the current state. |
| 252 | */ |
| 253 | |
| 254 | /* --- User class expressions --- */ |
| 255 | |
| 256 | user_class : user_class ',' user_class { |
| 257 | if (($$ = class_union($1, $3)) == 0) { |
| 258 | yyerror("type mismatch"); |
| 259 | YYERROR; |
| 260 | } |
| 261 | } |
| 262 | | user_class '-' user_class { |
| 263 | if (($$ = class_diff($1, $3)) == 0) { |
| 264 | yyerror("type mismatch"); |
| 265 | YYERROR; |
| 266 | } |
| 267 | } |
| 268 | | user_class '&' user_class { |
| 269 | if (($$ = class_isect($1, $3)) == 0) { |
| 270 | yyerror("type mismatch"); |
| 271 | YYERROR; |
| 272 | } |
| 273 | } |
| 274 | | user_class '|' user_class { |
| 275 | if (($$ = class_union($1, $3)) == 0) { |
| 276 | yyerror("type mismatch"); |
| 277 | YYERROR; |
| 278 | } |
| 279 | } |
| 280 | | INT { $$ = class_fromUser(clType_user, $1); } |
| 281 | | STRING { |
| 282 | struct passwd *pw; |
| 283 | if ((pw = userdb_userByName($1)) == 0) { |
| 284 | moan("user `%s' not known at line %i", |
| 285 | $1, lex_line); |
| 286 | YYERROR; |
| 287 | } else |
| 288 | $$ = class_fromUser(clType_user, pw->pw_uid); |
| 289 | } |
| 290 | | WORD { |
| 291 | name *n = name_find($1, 0, 0); |
| 292 | if (!n || !n->c) { |
| 293 | moan("class `%s' not found at line %i", |
| 294 | $1, lex_line); |
| 295 | YYERROR; |
| 296 | } else if (~n->c->type & clType_user) { |
| 297 | yyerror("type mismatch"); |
| 298 | YYERROR; |
| 299 | } else { |
| 300 | $$ = n->c; |
| 301 | class_inc(n->c); |
| 302 | } |
| 303 | } |
| 304 | | '(' user_class ')' { $$ = $2; } |
| 305 | ; |
| 306 | |
| 307 | /* --- Command class expressions --- */ |
| 308 | |
| 309 | command_class : command_class ',' command_class { |
| 310 | if (($$ = class_union($1, $3)) == 0) { |
| 311 | yyerror("type mismatch"); |
| 312 | YYERROR; |
| 313 | } |
| 314 | } |
| 315 | | command_class '-' command_class { |
| 316 | if (($$ = class_diff($1, $3)) == 0) { |
| 317 | yyerror("type mismatch"); |
| 318 | YYERROR; |
| 319 | } |
| 320 | } |
| 321 | | command_class '&' command_class { |
| 322 | if (($$ = class_isect($1, $3)) == 0) { |
| 323 | yyerror("type mismatch"); |
| 324 | YYERROR; |
| 325 | } |
| 326 | } |
| 327 | | command_class '|' command_class { |
| 328 | if (($$ = class_union($1, $3)) == 0) { |
| 329 | yyerror("type mismatch"); |
| 330 | YYERROR; |
| 331 | } |
| 332 | } |
| 333 | | STRING { $$ = class_fromString(clType_command, $1); } |
| 334 | | WORD { |
| 335 | name *n = name_find($1, 0, 0); |
| 336 | if (!n || !n->c) { |
| 337 | moan("class `%s' not found at line %i", |
| 338 | $1, lex_line); |
| 339 | YYERROR; |
| 340 | } else if (~n->c->type & clType_command) { |
| 341 | yyerror("type mismatch"); |
| 342 | YYERROR; |
| 343 | } else { |
| 344 | $$ = n->c; |
| 345 | class_inc(n->c); |
| 346 | } |
| 347 | } |
| 348 | | '(' command_class ')' { $$ = $2; } |
| 349 | ; |
| 350 | |
| 351 | /* --- Host class expressions --- */ |
| 352 | |
| 353 | host_class : host_class ',' host_class { |
| 354 | if (($$ = class_union($1, $3)) == 0) { |
| 355 | yyerror("type mismatch"); |
| 356 | YYERROR; |
| 357 | } |
| 358 | } |
| 359 | | host_class '-' host_class { |
| 360 | if (($$ = class_diff($1, $3)) == 0) { |
| 361 | yyerror("type mismatch"); |
| 362 | YYERROR; |
| 363 | } |
| 364 | } |
| 365 | | host_class '&' host_class { |
| 366 | if (($$ = class_isect($1, $3)) == 0) { |
| 367 | yyerror("type mismatch"); |
| 368 | YYERROR; |
| 369 | } |
| 370 | } |
| 371 | | host_class '|' host_class { |
| 372 | if (($$ = class_union($1, $3)) == 0) { |
| 373 | yyerror("type mismatch"); |
| 374 | YYERROR; |
| 375 | } |
| 376 | } |
| 377 | | STRING { $$ = class_fromString(clType_host, $1); } |
| 378 | | WORD { |
| 379 | name *n = name_find($1, 0, 0); |
| 380 | if (!n || !n->c) { |
| 381 | moan("class `%s' not found at line %i", |
| 382 | $1, lex_line); |
| 383 | YYERROR; |
| 384 | } else if (~n->c->type & clType_host) { |
| 385 | yyerror("type mismatch"); |
| 386 | YYERROR; |
| 387 | } else { |
| 388 | $$ = n->c; |
| 389 | class_inc(n->c); |
| 390 | } |
| 391 | } |
| 392 | | '(' host_class ')' { $$ = $2; } |
| 393 | ; |
| 394 | |
| 395 | /*----- That's all, folks -------------------------------------------------*/ |