[become] / src / parser.y

/* -*-c-*-
 *
 * $Id: parser.y,v 1.5 1998/01/12 16:46:22 mdw Exp $
 *
 * Parser for `become.conf' files
 *
 * (c) 1998 EBI
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of `become'
 *
 * `Become' is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * `Become' is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with `become'; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------*
 *
 * $Log: parser.y,v $
 * Revision 1.5  1998/01/12 16:46:22  mdw
 * Fix copyright date.
 *
 * Revision 1.4  1997/09/17  10:26:52  mdw
 * Use rewritten class handler.  Makes the expression parsers considerably
 * simpler.
 *
 * Revision 1.3  1997/09/09 18:17:06  mdw
 * Allow default port to be given as a service name or port number.
 *
 * Revision 1.2  1997/08/04 10:24:24  mdw
 * Sources placed under CVS control.
 *
 * Revision 1.1  1997/07/21  13:47:45  mdw
 * Initial revision
 *
 */

/*----- Header files ------------------------------------------------------*/
%{

/* --- ANSI headers --- */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* --- Unix headers --- */

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <netdb.h>
#include <pwd.h>
#include <unistd.h>

/* --- Local headers --- */

#include "class.h"
#include "daemon.h"
#include "lexer.h"
#include "name.h"
#include "rule.h"
#include "sym.h"
#include "userdb.h"
#include "utils.h"

%}
/*----- Stack type --------------------------------------------------------*/

%union {
  long i;
  char *s;
  name *n;
  class_node *c;
}

/*----- Token and rule declarations ---------------------------------------*/

/* --- Tokens --- */

%token BADTOKEN
%token USER
%token COMMAND
%token HOST
%token ALLOW
%token PORT
%token KEYFILE
%token <i> INT
%token <s> WORD
%token <s> STRING
%token ARROW

%left ','
%left '-'
%left '|'
%left '&'

/* --- Rules --- */

%type <c> user_class command_class host_class
%type <c> user_class_opt command_class_opt host_class_opt
%type <n> name

/*----- Error reporting ---------------------------------------------------*/
%{

#define YYDEBUG 1
#define YYERROR_VERBOSE

/* --- @yyprint@ --- *
 *
 * Arguments:	@FILE *fp@ = pointer to stream to write on
 *		@int type@ = pointer to token type
 *		@YYSTYPE v@ = token value
 *
 * Returns:	---
 *
 * Use:		Displays the semantic value of a token.
 */

#define YYPRINT(fp, type, value) yyprint(fp, type, value)

static void yyprint(FILE *fp, int type, YYSTYPE v)
{
  switch (type) {
    case INT:
      fprintf(fp, " %li", v.i);
      break;
    case WORD:
    case STRING:
      fprintf(fp, " `%s'", v.s);
      break;
  }
}

/* --- @yyerror@ --- *
 *
 * Arguments:	@const char *msg@ = pointer to error message
 *
 * Returns:	---
 *
 * Use:		Reports parse errors.
 */

static void yyerror(const char *msg)
{
  moan("%s at line %i", msg, lex_line);
}

%}
%%
/*----- The actual grammar ------------------------------------------------*/

/* --- Simple driver things --- */

file		: /* empty */
		| file statement
		;

statement	: user_spec
		| command_spec
		| host_spec
		| allow_spec
		| port_spec
		| key_spec
		| error ';'
		;

/* --- Main statement types --- */

user_spec	: USER name '=' user_class ';' {
			  if ($2->c)
			    class_dec($2->c);
			  $2->c = $4;
			}
		;

command_spec	: COMMAND name '=' command_class ';' {
			  if ($2->c)
			    class_dec($2->c);
			  $2->c = $4;
			}
		;

host_spec	: HOST name '=' host_class ';' {
			  if ($2->c)
			    class_dec($2->c);
			  $2->c = $4;
			}
		;

port_spec	: PORT STRING ';' {
			  struct servent *s = getservbyname($2, "udp");
			  if (!s) {
			    moan("unknown service `%s' at line %i",
				 $2, lex_line);
			    YYERROR;
			  }
			  daemon_usePort(s->s_port);
			}
		| PORT INT ';' { daemon_usePort(htons($2)); }
		;

key_spec	: KEYFILE STRING ';' { daemon_readKey($2); }

/* --- Parsing allow specifications --- */

allow_spec	: ALLOW host_class_opt user_class ARROW
		   user_class_opt command_class_opt ';' {
			  rule_add($2, $3, $5, $6);
			}

host_class_opt	: /* empty */ { $$ = class_all; }
		| '[' host_class ']' { $$ = $2; }
		;

user_class_opt	: /* empty */ { $$ = class_all; }
		| user_class { $$ = $1; }
		;

command_class_opt : /* empty */ { $$ = class_all; }
		| ':' command_class { $$ = $2; }
		;

/* --- Names get translated into symbols quickly --- */

name		: WORD	{
			  unsigned f;
			  name *n = name_find($1, 1, &f);
			  if (!f)
			    n->c = 0;
 			  $$ = n;
			}

/*----- Various class expression types ------------------------------------*
 *
 * Unfortunately, all these need to handle token types slightly differently
 * and I can't be bothered to remember the current state.
 */

/* --- User class expressions --- */

user_class	: user_class ',' user_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| user_class '-' user_class {
			  if (($$ = class_diff($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| user_class '&' user_class {
			  if (($$ = class_isect($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| user_class '|' user_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| INT	{ $$ = class_fromUser(clType_user, $1); }
		| STRING {
			  struct passwd *pw;
			  if ((pw = userdb_userByName($1)) == 0) {
			    moan("user `%s' not known at line %i",
				 $1, lex_line);
			    YYERROR;
			  } else
			    $$ = class_fromUser(clType_user, pw->pw_uid);
			}
		| WORD	{
			  name *n = name_find($1, 0, 0);
			  if (!n || !n->c) {
			    moan("class `%s' not found at line %i",
				 $1, lex_line);
			    YYERROR;
			  } else if (~n->c->type & clType_user) {
			    yyerror("type mismatch");
			    YYERROR;
			  } else {
			    $$ = n->c;
			    class_inc(n->c);
			  }
			}
		| '(' user_class ')' { $$ = $2; }
		;

/* --- Command class expressions --- */

command_class	: command_class ',' command_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| command_class '-' command_class {
			  if (($$ = class_diff($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| command_class '&' command_class {
			  if (($$ = class_isect($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| command_class '|' command_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| STRING { $$ = class_fromString(clType_command, $1); }
		| WORD	{
			  name *n = name_find($1, 0, 0);
			  if (!n || !n->c) {
			    moan("class `%s' not found at line %i",
				 $1, lex_line);
			    YYERROR;
			  } else if (~n->c->type & clType_command) {
			    yyerror("type mismatch");
			    YYERROR;
			  } else {
			    $$ = n->c;
			    class_inc(n->c);
			  }
			}
		| '(' command_class ')' { $$ = $2; }
		;

/* --- Host class expressions --- */

host_class	: host_class ',' host_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| host_class '-' host_class {
			  if (($$ = class_diff($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| host_class '&' host_class {
			  if (($$ = class_isect($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| host_class '|' host_class {
			  if (($$ = class_union($1, $3)) == 0) {
			    yyerror("type mismatch");
			    YYERROR;
			  }
			}
		| STRING { $$ = class_fromString(clType_host, $1); }
		| WORD	{
			  name *n = name_find($1, 0, 0);
			  if (!n || !n->c) {
			    moan("class `%s' not found at line %i",
				 $1, lex_line);
			    YYERROR;
			  } else if (~n->c->type & clType_host) {
			    yyerror("type mismatch");
			    YYERROR;
			  } else {
			    $$ = n->c;
			    class_inc(n->c);
			  }
			}
		| '(' host_class ')' { $$ = $2; }
		;

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
c4f2d992	1	/* --c--
c4f2d992	2	*
c758e654	3	* $Id: parser.y,v 1.5 1998/01/12 16:46:22 mdw Exp $
c4f2d992	4	*
	5	* Parser for `become.conf' files
	6	*
c758e654	7	* (c) 1998 EBI
c4f2d992	8	*/
c4f2d992	9
03f996bd	10	/----- Licensing notice --------------------------------------------------
c4f2d992	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
03f996bd	25	* along with `become'; if not, write to the Free Software Foundation,
03f996bd	26	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
c4f2d992	27	*/
	28
	29	/----- Revision history --------------------------------------------------
	30	*
	31	* $Log: parser.y,v $
c758e654	32	* Revision 1.5 1998/01/12 16:46:22 mdw
	33	* Fix copyright date.
	34	*
	35	* Revision 1.4 1997/09/17 10:26:52 mdw
c327f3bc	36	* Use rewritten class handler. Makes the expression parsers considerably
	37	* simpler.
	38	*
f3debbd8	39	* Revision 1.3 1997/09/09 18:17:06 mdw
	40	* Allow default port to be given as a service name or port number.
	41	*
03f996bd	42	* Revision 1.2 1997/08/04 10:24:24 mdw
	43	* Sources placed under CVS control.
	44	*
	45	* Revision 1.1 1997/07/21 13:47:45 mdw
c4f2d992	46	* Initial revision
	47	*
	48	*/
	49
	50	/----- Header files ------------------------------------------------------/
	51	%{
	52
	53	/* --- ANSI headers --- */
	54
	55	#include <stdio.h>
	56	#include <stdlib.h>
	57	#include <string.h>
	58
	59	/* --- Unix headers --- */
	60
	61	#include <sys/types.h>
f3debbd8	62	#include <sys/socket.h>
	63
	64	#include <netinet/in.h>
c4f2d992	65
f3debbd8	66	#include <arpa/inet.h>
	67
	68	#include <netdb.h>
c4f2d992	69	#include <pwd.h>
	70	#include <unistd.h>
	71
	72	/* --- Local headers --- */
	73
	74	#include "class.h"
	75	#include "daemon.h"
	76	#include "lexer.h"
	77	#include "name.h"
	78	#include "rule.h"
c4f2d992	79	#include "sym.h"
	80	#include "userdb.h"
	81	#include "utils.h"
	82
	83	%}
	84	/----- Stack type --------------------------------------------------------/
	85
	86	%union {
	87	long i;
	88	char *s;
	89	name *n;
c327f3bc	90	class_node *c;
c4f2d992	91	}
	92
	93	/----- Token and rule declarations ---------------------------------------/
	94
	95	/* --- Tokens --- */
	96
	97	%token BADTOKEN
	98	%token USER
	99	%token COMMAND
	100	%token HOST
	101	%token ALLOW
	102	%token PORT
	103	%token KEYFILE
	104	%token <i> INT
	105	%token <s> WORD
	106	%token <s> STRING
	107	%token ARROW
	108
	109	%left ','
	110	%left '-'
	111	%left '\|'
	112	%left '&'
	113
	114	/* --- Rules --- */
	115
	116	%type <c> user_class command_class host_class
	117	%type <c> user_class_opt command_class_opt host_class_opt
	118	%type <n> name
	119
	120	/----- Error reporting ---------------------------------------------------/
	121	%{
	122
	123	#define YYDEBUG 1
	124	#define YYERROR_VERBOSE
	125
	126	/* --- @yyprint@ --- *
	127	*
	128	* Arguments: @FILE *fp@ = pointer to stream to write on
	129	* @int type@ = pointer to token type
	130	* @YYSTYPE v@ = token value
	131	*
	132	* Returns: ---
	133	*
	134	* Use: Displays the semantic value of a token.
	135	*/
	136
	137	#define YYPRINT(fp, type, value) yyprint(fp, type, value)
	138
	139	static void yyprint(FILE *fp, int type, YYSTYPE v)
	140	{
	141	switch (type) {
	142	case INT:
	143	fprintf(fp, " %li", v.i);
	144	break;
	145	case WORD:
	146	case STRING:
	147	fprintf(fp, " `%s'", v.s);
	148	break;
	149	}
	150	}
	151
	152	/* --- @yyerror@ --- *
	153	*
	154	* Arguments: @const char *msg@ = pointer to error message
155	*
156	* Returns: ---
157	*
158	* Use: Reports parse errors.
159	*/
160
161	static void yyerror(const char *msg)
162	{
163	moan("%s at line %i", msg, lex_line);
164	}
165
166	%}
167	%%
168	/----- The actual grammar ------------------------------------------------/
169
170	/* --- Simple driver things --- */
171
172	file : /* empty */
173	\| file statement
174	;
175
176	statement : user_spec
177	\| command_spec
178	\| host_spec
179	\| allow_spec
180	\| port_spec
181	\| key_spec
182	\| error ';'
183	;
184
185	/* --- Main statement types --- */
186
187	user_spec : USER name '=' user_class ';' {
188	if ($2->c)
189	class_dec($2->c);
190	$2->c = $4;
191	}
192	;
193
194	command_spec : COMMAND name '=' command_class ';' {
195	if ($2->c)
196	class_dec($2->c);
197	$2->c = $4;
198	}
199	;
200
201	host_spec : HOST name '=' host_class ';' {
202	if ($2->c)
203	class_dec($2->c);
204	$2->c = $4;
205	}
206	;
207
f3debbd8	208	port_spec : PORT STRING ';' {
	209	struct servent *s = getservbyname($2, "udp");
	210	if (!s) {
	211	moan("unknown service `%s' at line %i",
	212	$2, lex_line);
	213	YYERROR;
	214	}
	215	daemon_usePort(s->s_port);
	216	}
	217	\| PORT INT ';' { daemon_usePort(htons($2)); }
c4f2d992	218	;
	219
	220	key_spec : KEYFILE STRING ';' { daemon_readKey($2); }
	221
	222	/* --- Parsing allow specifications --- */
	223
	224	allow_spec : ALLOW host_class_opt user_class ARROW
	225	user_class_opt command_class_opt ';' {
	226	rule_add($2, $3, $5, $6);
	227	}
	228
	229	host_class_opt : /* empty */ { $$ = class_all; }
	230	\| '[' host_class ']' { $$ = $2; }
	231	;
	232
	233	user_class_opt : /* empty */ { $$ = class_all; }
	234	\| user_class { $$ = $1; }
	235	;
	236
	237	command_class_opt : /* empty */ { $$ = class_all; }
	238	\| ':' command_class { $$ = $2; }
	239	;
	240
	241	/* --- Names get translated into symbols quickly --- */
	242
	243	name : WORD {
	244	unsigned f;
	245	name *n = name_find($1, 1, &f);
	246	if (!f)
	247	n->c = 0;
	248	$$ = n;
	249	}
	250
	251	/----- Various class expression types ------------------------------------
	252	*
	253	* Unfortunately, all these need to handle token types slightly differently
	254	* and I can't be bothered to remember the current state.
	255	*/
	256
	257	/* --- User class expressions --- */
	258
	259	user_class : user_class ',' user_class {
c327f3bc	260	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	261	yyerror("type mismatch");
c4f2d992	262	YYERROR;
c4f2d992	263	}
	264	}
	265	\| user_class '-' user_class {
c327f3bc	266	if (($$ = class_diff($1, $3)) == 0) {
c4f2d992	267	yyerror("type mismatch");
c4f2d992	268	YYERROR;
c4f2d992	269	}
	270	}
	271	\| user_class '&' user_class {
c327f3bc	272	if (($$ = class_isect($1, $3)) == 0) {
c4f2d992	273	yyerror("type mismatch");
c4f2d992	274	YYERROR;
c4f2d992	275	}
	276	}
	277	\| user_class '\|' user_class {
c327f3bc	278	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	279	yyerror("type mismatch");
c4f2d992	280	YYERROR;
c4f2d992	281	}
c4f2d992	282	}
c327f3bc	283	\| INT { $$ = class_fromUser(clType_user, $1); }
c4f2d992	284	\| STRING {
c4f2d992	285	struct passwd *pw;
c4f2d992	286	if ((pw = userdb_userByName($1)) == 0) {
	287	moan("user `%s' not known at line %i",
	288	$1, lex_line);
	289	YYERROR;
c327f3bc	290	} else
c327f3bc	291	$$ = class_fromUser(clType_user, pw->pw_uid);
c4f2d992	292	}
	293	\| WORD {
	294	name *n = name_find($1, 0, 0);
	295	if (!n \|\| !n->c) {
	296	moan("class `%s' not found at line %i",
	297	$1, lex_line);
	298	YYERROR;
	299	} else if (~n->c->type & clType_user) {
	300	yyerror("type mismatch");
	301	YYERROR;
	302	} else {
	303	$$ = n->c;
	304	class_inc(n->c);
	305	}
	306	}
	307	\| '(' user_class ')' { $$ = $2; }
	308	;
	309
	310	/* --- Command class expressions --- */
	311
	312	command_class : command_class ',' command_class {
c327f3bc	313	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	314	yyerror("type mismatch");
c4f2d992	315	YYERROR;
c4f2d992	316	}
	317	}
	318	\| command_class '-' command_class {
c327f3bc	319	if (($$ = class_diff($1, $3)) == 0) {
c4f2d992	320	yyerror("type mismatch");
c4f2d992	321	YYERROR;
c4f2d992	322	}
	323	}
	324	\| command_class '&' command_class {
c327f3bc	325	if (($$ = class_isect($1, $3)) == 0) {
c4f2d992	326	yyerror("type mismatch");
c4f2d992	327	YYERROR;
c4f2d992	328	}
	329	}
	330	\| command_class '\|' command_class {
c327f3bc	331	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	332	yyerror("type mismatch");
c4f2d992	333	YYERROR;
c4f2d992	334	}
c4f2d992	335	}
c327f3bc	336	\| STRING { $$ = class_fromString(clType_command, $1); }
c4f2d992	337	\| WORD {
	338	name *n = name_find($1, 0, 0);
	339	if (!n \|\| !n->c) {
	340	moan("class `%s' not found at line %i",
	341	$1, lex_line);
	342	YYERROR;
	343	} else if (~n->c->type & clType_command) {
	344	yyerror("type mismatch");
	345	YYERROR;
	346	} else {
	347	$$ = n->c;
	348	class_inc(n->c);
	349	}
	350	}
	351	\| '(' command_class ')' { $$ = $2; }
	352	;
	353
	354	/* --- Host class expressions --- */
	355
c327f3bc	356	host_class : host_class ',' host_class {
c327f3bc	357	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	358	yyerror("type mismatch");
c4f2d992	359	YYERROR;
c4f2d992	360	}
	361	}
	362	\| host_class '-' host_class {
c327f3bc	363	if (($$ = class_diff($1, $3)) == 0) {
c4f2d992	364	yyerror("type mismatch");
c4f2d992	365	YYERROR;
c4f2d992	366	}
	367	}
	368	\| host_class '&' host_class {
c327f3bc	369	if (($$ = class_isect($1, $3)) == 0) {
c4f2d992	370	yyerror("type mismatch");
c4f2d992	371	YYERROR;
c4f2d992	372	}
	373	}
	374	\| host_class '\|' host_class {
c327f3bc	375	if (($$ = class_union($1, $3)) == 0) {
c4f2d992	376	yyerror("type mismatch");
c4f2d992	377	YYERROR;
c4f2d992	378	}
c4f2d992	379	}
c327f3bc	380	\| STRING { $$ = class_fromString(clType_host, $1); }
c4f2d992	381	\| WORD {
	382	name *n = name_find($1, 0, 0);
	383	if (!n \|\| !n->c) {
	384	moan("class `%s' not found at line %i",
	385	$1, lex_line);
	386	YYERROR;
	387	} else if (~n->c->type & clType_host) {
	388	yyerror("type mismatch");
	389	YYERROR;
	390	} else {
	391	$$ = n->c;
	392	class_inc(n->c);
	393	}
	394	}
	395	\| '(' host_class ')' { $$ = $2; }
	396	;
	397
	398	/----- That's all, folks -------------------------------------------------/