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sudo/gram.y
2005-01-27 15:42:30 +00:00

627 lines
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%{
/*
* Copyright (c) 1996, 1998-2004 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F39502-99-1-0512.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
# include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#if defined(YYBISON) && defined(HAVE_ALLOCA_H) && !defined(__GNUC__)
# include <alloca.h>
#endif /* YYBISON && HAVE_ALLOCA_H && !__GNUC__ */
#include "sudo.h"
#include "parse.h"
#ifndef lint
__unused static const char rcsid[] = "$Sudo$";
#endif /* lint */
/*
* Globals
*/
extern int sudolineno;
extern char *sudoers;
int parse_error;
int pedantic = FALSE;
int verbose = FALSE;
int errorlineno = -1;
char *errorfile = NULL;
struct defaults *defaults;
struct userspec *userspecs;
/*
* Local protoypes
*/
static void add_defaults __P((int, struct member *, struct defaults *));
static void add_userspec __P((struct member *, struct privilege *));
void yyerror __P((const char *));
void
yyerror(s)
const char *s;
{
/* Save the line the first error occurred on. */
if (errorlineno == -1) {
errorlineno = sudolineno ? sudolineno - 1 : 0;
errorfile = estrdup(sudoers);
}
if (verbose && s != NULL) {
#ifndef TRACELEXER
(void) fprintf(stderr, ">>> %s: %s near line %d <<<\n", sudoers, s,
sudolineno ? sudolineno - 1 : 0);
#else
(void) fprintf(stderr, "<*> ");
#endif
}
parse_error = TRUE;
}
%}
%union {
struct cmndspec *cmndspec;
struct defaults *defaults;
struct member *member;
struct privilege *privilege;
struct sudo_command command;
struct cmndtag tag;
char *string;
int tok;
}
%start file /* special start symbol */
%token <command> COMMAND /* absolute pathname w/ optional args */
%token <string> ALIAS /* an UPPERCASE alias name */
%token <string> DEFVAR /* a Defaults variable name */
%token <string> NTWKADDR /* w.x.y.z */
%token <string> NETGROUP /* a netgroup (+NAME) */
%token <string> USERGROUP /* a usergroup (%NAME) */
%token <string> WORD /* a word */
%token <tok> DEFAULTS /* Defaults entry */
%token <tok> DEFAULTS_HOST /* Host-specific defaults entry */
%token <tok> DEFAULTS_USER /* User-specific defaults entry */
%token <tok> DEFAULTS_RUNAS /* Runas-specific defaults entry */
%token <tok> DEFAULTS_CMND /* Command-specific defaults entry */
%token <tok> RUNAS /* ( runas_list ) */
%token <tok> NOPASSWD /* no passwd req for command */
%token <tok> PASSWD /* passwd req for command (default) */
%token <tok> NOEXEC /* preload dummy execve() for cmnd */
%token <tok> EXEC /* don't preload dummy execve() */
%token <tok> MONITOR /* monitor children of cmnd */
%token <tok> NOMONITOR /* disable monitoring of children */
%token <tok> ALL /* ALL keyword */
%token <tok> COMMENT /* comment and/or carriage return */
%token <tok> HOSTALIAS /* Host_Alias keyword */
%token <tok> CMNDALIAS /* Cmnd_Alias keyword */
%token <tok> USERALIAS /* User_Alias keyword */
%token <tok> RUNASALIAS /* Runas_Alias keyword */
%token <tok> ':' '=' ',' '!' '+' '-' /* union member tokens */
%token <tok> ERROR
%type <cmndspec> cmndspec
%type <cmndspec> cmndspeclist
%type <defaults> defaults_entry
%type <defaults> defaults_list
%type <member> cmnd
%type <member> opcmnd
%type <member> cmndlist
%type <member> host
%type <member> hostlist
%type <member> ophost
%type <member> oprunasuser
%type <member> opuser
%type <member> runaslist
%type <member> runasspec
%type <member> runasuser
%type <member> user
%type <member> userlist
%type <privilege> privilege
%type <privilege> privileges
%type <tag> cmndtag
%%
file : { ; }
| line
;
line : entry
| line entry
;
entry : COMMENT {
;
}
| error COMMENT {
yyerrok;
}
| userlist privileges {
add_userspec($1, $2);
}
| USERALIAS useraliases {
;
}
| HOSTALIAS hostaliases {
;
}
| CMNDALIAS cmndaliases {
;
}
| RUNASALIAS runasaliases {
;
}
| DEFAULTS defaults_list {
add_defaults(DEFAULTS, NULL, $2);
}
| DEFAULTS_USER userlist defaults_list {
add_defaults(DEFAULTS_USER, $2, $3);
}
| DEFAULTS_RUNAS runaslist defaults_list {
add_defaults(DEFAULTS_RUNAS, $2, $3);
}
| DEFAULTS_HOST hostlist defaults_list {
add_defaults(DEFAULTS_HOST, $2, $3);
}
| DEFAULTS_CMND cmndlist defaults_list {
add_defaults(DEFAULTS_CMND, $2, $3);
}
;
defaults_list : defaults_entry
| defaults_list ',' defaults_entry {
LIST_APPEND($1, $3);
$$ = $1;
}
;
defaults_entry : DEFVAR {
NEW_DEFAULT($$, $1, NULL, TRUE);
}
| '!' DEFVAR {
NEW_DEFAULT($$, $2, NULL, FALSE);
}
| DEFVAR '=' WORD {
NEW_DEFAULT($$, $1, $3, TRUE);
}
| DEFVAR '+' WORD {
NEW_DEFAULT($$, $1, $3, '+');
}
| DEFVAR '-' WORD {
NEW_DEFAULT($$, $1, $3, '-');
}
;
privileges : privilege
| privileges ':' privilege {
LIST_APPEND($1, $3);
$$ = $1;
}
;
privilege : hostlist '=' cmndspeclist {
struct cmndtag tags;
struct privilege *p = emalloc(sizeof(*p));
struct cmndspec *cs;
p->hostlist = $1;
p->cmndlist = $3;
tags.nopasswd = tags.noexec = tags.monitor = UNSPEC;
/* propagate tags */
for (cs = $3; cs != NULL; cs = cs->next) {
if (cs->tags.nopasswd == UNSPEC)
cs->tags.nopasswd = tags.nopasswd;
if (cs->tags.noexec == UNSPEC)
cs->tags.noexec = tags.noexec;
if (cs->tags.monitor == UNSPEC)
cs->tags.monitor = tags.monitor;
memcpy(&tags, &cs->tags, sizeof(tags));
}
p->last = NULL;
p->next = NULL;
$$ = p;
}
;
ophost : host {
$$ = $1;
$$->negated = FALSE;
}
| '!' host {
$$ = $2;
$$->negated = TRUE;
}
;
host : ALIAS {
NEW_MEMBER($$, $1, ALIAS);
}
| ALL {
NEW_MEMBER($$, NULL, ALL);
}
| NETGROUP {
NEW_MEMBER($$, $1, NETGROUP);
}
| NTWKADDR {
NEW_MEMBER($$, $1, NTWKADDR);
}
| WORD {
NEW_MEMBER($$, $1, WORD);
}
;
cmndspeclist : cmndspec
| cmndspeclist ',' cmndspec {
LIST_APPEND($1, $3);
$$ = $1;
}
;
cmndspec : runasspec cmndtag opcmnd {
struct cmndspec *cs = emalloc(sizeof(*cs));
cs->runaslist = $1;
cs->tags = $2;
cs->cmnd = $3;
cs->last = NULL;
cs->next = NULL;
$$ = cs;
}
;
opcmnd : cmnd {
$$ = $1;
$$->negated = FALSE;
}
| '!' cmnd {
$$ = $2;
$$->negated = TRUE;
}
;
runasspec : /* empty */ {
$$ = NULL;
}
| RUNAS runaslist {
$$ = $2;
}
;
runaslist : oprunasuser
| runaslist ',' oprunasuser {
LIST_APPEND($1, $3);
$$ = $1;
}
;
oprunasuser : runasuser {
$$ = $1;
$$->negated = FALSE;
}
| '!' runasuser {
$$ = $2;
$$->negated = TRUE;
}
;
runasuser : ALIAS {
NEW_MEMBER($$, $1, ALIAS);
}
| ALL {
NEW_MEMBER($$, NULL, ALL);
}
| NETGROUP {
NEW_MEMBER($$, $1, NETGROUP);
}
| USERGROUP {
NEW_MEMBER($$, $1, USERGROUP);
}
| WORD {
NEW_MEMBER($$, $1, WORD);
}
;
cmndtag : /* empty */ {
$$.nopasswd = $$.noexec = $$.monitor = UNSPEC;
}
| cmndtag NOPASSWD {
$$.nopasswd = TRUE;
}
| cmndtag PASSWD {
$$.nopasswd = FALSE;
}
| cmndtag NOEXEC {
$$.noexec = TRUE;
}
| cmndtag EXEC {
$$.noexec = FALSE;
}
| cmndtag MONITOR {
$$.monitor = TRUE;
}
| cmndtag NOMONITOR {
$$.monitor = FALSE;
}
;
cmnd : ALL {
NEW_MEMBER($$, NULL, ALL);
}
| ALIAS {
NEW_MEMBER($$, $1, ALIAS);
}
| COMMAND {
struct sudo_command *c = emalloc(sizeof(*c));
c->cmnd = $1.cmnd;
c->args = $1.args;
NEW_MEMBER($$, (char *)c, COMMAND);
}
;
hostaliases : hostalias
| hostaliases ':' hostalias
;
hostalias : ALIAS '=' hostlist {
char *s;
if ((s = alias_add($1, HOSTALIAS, $3)) != NULL) {
yyerror(s);
YYERROR;
}
}
;
hostlist : ophost
| hostlist ',' ophost {
LIST_APPEND($1, $3);
$$ = $1;
}
;
cmndaliases : cmndalias
| cmndaliases ':' cmndalias
;
cmndalias : ALIAS '=' cmndlist {
char *s;
if ((s = alias_add($1, CMNDALIAS, $3)) != NULL) {
yyerror(s);
YYERROR;
}
}
;
cmndlist : opcmnd
| cmndlist ',' opcmnd {
LIST_APPEND($1, $3);
$$ = $1;
}
;
runasaliases : runasalias
| runasaliases ':' runasalias
;
runasalias : ALIAS '=' runaslist {
char *s;
if ((s = alias_add($1, RUNASALIAS, $3)) != NULL) {
yyerror(s);
YYERROR;
}
}
;
useraliases : useralias
| useraliases ':' useralias
;
useralias : ALIAS '=' userlist {
char *s;
if ((s = alias_add($1, USERALIAS, $3)) != NULL) {
yyerror(s);
YYERROR;
}
}
;
userlist : opuser
| userlist ',' opuser {
LIST_APPEND($1, $3);
$$ = $1;
}
;
opuser : user {
$$ = $1;
$$->negated = FALSE;
}
| '!' user {
$$ = $2;
$$->negated = TRUE;
}
;
user : ALIAS {
NEW_MEMBER($$, $1, ALIAS);
}
| ALL {
NEW_MEMBER($$, NULL, ALL);
}
| NETGROUP {
NEW_MEMBER($$, $1, NETGROUP);
}
| USERGROUP {
NEW_MEMBER($$, $1, USERGROUP);
}
| WORD {
NEW_MEMBER($$, $1, WORD);
}
;
%%
/*
* Add a list of defaults structures to the defaults list.
* The binding, if non-NULL, specifies a list of hosts, users, or
* runas users the entries apply to (specified by the type).
*/
static void
add_defaults(type, binding, defs)
int type;
struct member *binding;
struct defaults *defs;
{
struct defaults *d;
/*
* Set type and binding (who it applies to) for new entries.
*/
for (d = defs; d != NULL; d = d->next) {
d->type = type;
d->binding = binding;
}
if (defaults == NULL)
defaults = defs;
else
LIST_APPEND(defaults, defs);
}
/*
* Allocate a new struct userspec, populate it, and insert it at the
* and of the userspecs list.
*/
static void
add_userspec(members, privs)
struct member *members;
struct privilege *privs;
{
struct userspec *u;
u = emalloc(sizeof(*u));
u->user = members;
u->privileges = privs;
u->last = NULL;
u->next = NULL;
if (userspecs == NULL)
userspecs = u;
else
LIST_APPEND(userspecs, u);
}
/*
* Free up space used by data structures from a previous parser run and sets
* the current sudoers file to path.
*/
void
init_parser(path, quiet)
char *path;
int quiet;
{
struct defaults *d;
struct member *m, *lastbinding;
struct userspec *us;
struct privilege *priv;
struct cmndspec *cs;
VOID *next;
for (us = userspecs; us != NULL; us = next) {
for (m = us->user; m != NULL; m = next) {
next = m->next;
if (m->name != NULL)
free(m->name);
free(m);
}
for (priv = us->privileges; priv != NULL; priv = next) {
for (m = priv->hostlist; m != NULL; m = next) {
next = m->next;
if (m->name != NULL)
free(m->name);
free(m);
}
for (cs = priv->cmndlist; cs != NULL; cs = next) {
for (m = cs->runaslist; m != NULL; m = next) {
next = m->next;
if (m->name != NULL)
free(m->name);
free(m);
}
if (cs->cmnd->name != NULL)
free(cs->cmnd->name);
free(cs->cmnd);
next = cs->next;
free(cs);
}
next = priv->next;
free(priv);
}
next = us->next;
free(us);
}
userspecs = NULL;
lastbinding = NULL;
for (d = defaults; d != NULL; d = next) {
if (d->binding != lastbinding) {
for (m = d->binding; m != NULL; m = next) {
next = m->next;
if (m->name != NULL)
free(m->name);
free(m);
}
lastbinding = d->binding;
}
next = d->next;
free(d->var);
if (d->val != NULL)
free(d->val);
free(d);
}
defaults = NULL;
init_aliases();
if (sudoers != NULL)
free(sudoers);
sudoers = estrdup(path);
parse_error = FALSE;
errorlineno = -1;
sudolineno = 1;
verbose = !quiet;
}