Files
sudo/parse.yacc
1995-04-09 02:27:40 +00:00

400 lines
7.6 KiB
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%{
/*
* CU sudo version 1.3.1
*
* This program 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 1, or (at your option)
* any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Please send bugs, changes, problems to sudo-bugs@cs.colorado.edu
*
*******************************************************************
*
* parse.yacc -- yacc parser and alias manipulation routines for sudo.
*
* Chris Jepeway <jepeway@cs.utk.edu>
*/
#ifndef lint
static char rcsid[] = "$Id$";
#endif /* lint */
#include "config.h"
#include <stdio.h>
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif /* STDC_HEADERS */
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_LSEARCH
#include <search.h>
#endif /* HAVE_LSEARCH */
#include "sudo.h"
#include "options.h"
#ifndef HAVE_LSEARCH
#include "search.h"
#endif /* HAVE_LSEARCH */
extern int sudolineno, parse_error;
int errorlineno = -1;
static int user_matched;
/*
* Alias types
*/
#define HOST 1
#define CMND 2
#define USER 3
/*
* the matching stack
*/
#define MATCHSTACKSIZE (20)
struct matchstack match[MATCHSTACKSIZE];
int top = 0;
#define push \
if (top > MATCHSTACKSIZE) \
yyerror("matching stack overflow\n"); \
else {\
match[top].user = -1; \
match[top].cmnd = -1; \
match[top].host = -1; \
top++; \
}
#define pop \
if (top == 0) \
yyerror("matching stack underflow\n"); \
else \
top--;
extern int path_matches __P((char *, char *));
extern int addr_matches __P((char *));
static int find_alias __P((char *, int));
static int add_alias __P((char *, int));
static int more_aliases __P((int));
int yyerror(s)
char *s;
{
/* save the line the first error occured on */
if (errorlineno == -1)
errorlineno = sudolineno;
#ifndef TRACELEXER
fprintf(stderr, ">>> sudoers file: %s, line %d <<<\n", s, sudolineno);
#else
fprintf(stderr, "<*> ");
#endif
parse_error = TRUE;
}
%}
%union {
char string[MAXCOMMANDLENGTH+1];
int tok;
}
%start file /* special start symbol */
%token <string> ALIAS /* an UPPERCASE alias name */
%token <string> NTWKADDR /* w.x.y.z */
%token <string> PATH /* an absolute pathname */
%token <string> NAME /* a mixed-case name */
%token <tok> COMMENT /* comment and/or carriage return */
%token <tok> ALL /* ALL keyword */
%token <tok> HOSTALIAS /* Host_Alias keyword */
%token <tok> CMNDALIAS /* Cmnd_Alias keyword */
%token <tok> USERALIAS /* User_Alias keyword */
%token <tok> ':' '=' ',' '!' '.' /* union member tokens */
%token <tok> ERROR
%type <string> fqdn cmnd
%%
file : entry
| file entry
;
entry : COMMENT
{ ; }
| error COMMENT
{ yyerrok; }
| NAME {
user_matched = strcmp($1, user) == 0;
} privileges
| USERALIAS useraliases
{ ; }
| HOSTALIAS hostaliases
{ ; }
| CMNDALIAS cmndaliases
{ ; }
;
privileges : privilege
| privileges ':' privilege
;
privilege : { push; } hostspec '=' opcmndlist {
if (user_matched)
user_matches = TRUE;
else
pop;
}
;
hostspec : ALL {
host_matches = TRUE;
}
| NTWKADDR {
if (addr_matches($1))
host_matches = TRUE;
}
| NAME {
if (strcmp(host, $1) == 0)
host_matches = TRUE;
}
| ALIAS {
if (find_alias($1, HOST))
host_matches = TRUE;
}
| fqdn {
#ifdef HAVE_STRCASECMP
if (strcasecmp($1, host) == 0)
host_matches = TRUE;
#else
if (strcmp($1, host) == 0)
host_matches = TRUE;
#endif /* HAVE_STRCASECMP */
}
;
fqdn : NAME '.' NAME {
strcpy($$, $1);
strcat($$, ".");
strcat($$, $3);
}
| fqdn '.' NAME {
strcpy($$, $1);
strcat($$, ".");
strcat($$, $3);
}
;
opcmndlist : opcmnd
| opcmndlist ',' opcmnd
;
opcmnd : cmnd
{ ; }
| '!' { push; } opcmnd {
int cmnd_matched = cmnd_matches;
pop;
if (cmnd_matched == TRUE)
cmnd_matches = FALSE;
else if (cmnd_matched == FALSE)
cmnd_matches = TRUE;
}
;
cmnd : ALL { cmnd_matches = TRUE; }
| ALIAS {
if (find_alias($1, CMND))
cmnd_matches = TRUE;
}
| PATH {
if (path_matches(cmnd, $1))
cmnd_matches = TRUE;
}
;
hostaliases : hostalias
| hostaliases ':' hostalias
;
hostalias : ALIAS { push; } '=' hostlist {
if (host_matches == TRUE && !add_alias($1, HOST))
YYERROR;
pop;
}
;
hostlist : hostspec
| hostlist ',' hostspec
;
cmndaliases : cmndalias
| cmndaliases ':' cmndalias
;
cmndalias : ALIAS { push; } '=' cmndlist {
if (cmnd_matches == TRUE && !add_alias($1, CMND))
YYERROR;
pop;
}
;
cmndlist : cmnd
{ ; }
| cmndlist ',' cmnd
;
useraliases : useralias
| useraliases ':' useralias
;
useralias : ALIAS { push; } '=' userlist {
if (user_matches == TRUE && !add_alias($1, CMND))
YYERROR;
pop;
}
;
userlist : user
{ ; }
| userlist ',' user
;
user : NAME {
/* XXX need to set user_matched */
user_matches = strcmp($1, user) == 0;
}
;
%%
typedef struct {
int type;
char name[1024];
} aliasinfo;
#define MOREALIASES (32)
aliasinfo *aliases;
int naliases = 0;
int nslots = 0;
static int
aliascmp(a1, a2)
const VOID *a1, *a2;
{
int r;
aliasinfo *ai1, *ai2;
ai1 = (aliasinfo *) a1;
ai2 = (aliasinfo *) a2;
r = strcmp(ai1->name, ai2->name);
if (r == 0)
r = ai1->type - ai2->type;
return(r);
}
static int
add_alias(alias, type)
char *alias;
int type;
{
aliasinfo ai, *aip;
char s[512];
int ok;
ok = FALSE; /* assume failure */
ai.type = type;
strcpy(ai.name, alias);
if (lfind((const void *)&ai, (void *)aliases, (size_t *)&naliases, sizeof(ai), aliascmp) != NULL) {
sprintf(s, "Alias `%s' already defined", alias);
yyerror(s);
} else {
if (naliases == nslots && !more_aliases(nslots)) {
(void) sprintf(s, "Out of memory defining alias `%s'", alias);
yyerror(s);
}
aip = (aliasinfo *) lsearch((const void *)&ai, (void *)aliases, (size_t *)&naliases, sizeof(ai),
aliascmp);
if (aip != NULL) {
ok = TRUE;
} else {
(void) sprintf(s, "Aliases corrupted defining alias `%s'", alias);
yyerror(s);
}
}
return(ok);
}
static int
find_alias(alias, type)
char *alias;
int type;
{
aliasinfo ai;
strcpy(ai.name, alias);
ai.type = type;
return(lfind((const void *)&ai, (void *)aliases, (size_t *)&naliases, sizeof(ai), aliascmp) != NULL);
}
static int
more_aliases(nslots)
int nslots;
{
aliasinfo *aip;
if (nslots == 0)
aip = (aliasinfo *) malloc(MOREALIASES * sizeof(*aip));
else
aip = (aliasinfo *) realloc(aliases,
(nslots + MOREALIASES) * sizeof(*aip));
if (aip != NULL) {
aliases = aip;
nslots += MOREALIASES;
}
return(aip != NULL);
}
int
dumpaliases()
{
int n = naliases;
while (n--)
printf("%s\t%s\n", aliases[n].type == HOST ? "HOST" : "CMND",
aliases[n].name);
}
void
reset_aliases()
{
(void) free(aliases);
naliases = nslots = 0;
}