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|
/*
* Copyright (c) 2004-2005, 2007-2008 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.
*/
#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 */
#include <ctype.h>
#include <pwd.h>
#include <grp.h>
#include "sudo.h"
#include "parse.h"
#include "lbuf.h"
#include <gram.h>
#ifndef lint
__unused static const char rcsid[] = "$Sudo: parse.c,v 1.239 2009/03/28 13:07:16 millert Exp $";
#endif /* lint */
/* Characters that must be quoted in sudoers */
#define SUDOERS_QUOTED ":\\,=#\""
/* sudoers nsswitch routines */
struct sudo_nss sudo_nss_file = {
&sudo_nss_file,
NULL,
sudo_file_open,
sudo_file_close,
sudo_file_parse,
sudo_file_setdefs,
sudo_file_lookup,
sudo_file_display_cmnd,
sudo_file_display_defaults,
sudo_file_display_bound_defaults,
sudo_file_display_privs
};
/*
* Parser externs.
*/
extern FILE *yyin;
extern char *errorfile;
extern int errorlineno, parse_error;
/*
* Local prototypes.
*/
static void print_member __P((struct lbuf *, char *, int, int, int));
static int display_bound_defaults __P((int, struct lbuf *));
int
sudo_file_open(nss)
struct sudo_nss *nss;
{
if (def_ignore_local_sudoers)
return(-1);
nss->handle = open_sudoers(_PATH_SUDOERS, NULL);
return(nss->handle ? 0 : -1);
}
int
sudo_file_close(nss)
struct sudo_nss *nss;
{
/* Free parser data structures and close sudoers file. */
init_parser(NULL, 0);
if (nss->handle != NULL) {
fclose(nss->handle);
nss->handle = NULL;
yyin = NULL;
}
return(0);
}
/*
* Parse the specified sudoers file.
*/
int
sudo_file_parse(nss)
struct sudo_nss *nss;
{
if (nss->handle == NULL)
return(-1);
init_parser(_PATH_SUDOERS, 0);
yyin = nss->handle;
if (yyparse() != 0 || parse_error) {
log_error(NO_EXIT, "parse error in %s near line %d",
errorfile, errorlineno);
return(-1);
}
return(0);
}
/*
* Wrapper around update_defaults() for nsswitch code.
*/
int
sudo_file_setdefs(nss)
struct sudo_nss *nss;
{
if (nss->handle == NULL)
return(-1);
if (!update_defaults(SETDEF_GENERIC|SETDEF_HOST|SETDEF_USER))
return(-1);
return(0);
}
/*
* Look up the user in the parsed sudoers file and check to see if they are
* allowed to run the specified command on this host as the target user.
*/
int
sudo_file_lookup(nss, validated, pwflag)
struct sudo_nss *nss;
int validated;
int pwflag;
{
int match, host_match, runas_match, cmnd_match;
struct cmndspec *cs;
struct cmndtag *tags = NULL;
struct privilege *priv;
struct userspec *us;
if (nss->handle == NULL)
return(validated);
/*
* Only check the actual command if pwflag is not set.
* It is set for the "validate", "list" and "kill" pseudo-commands.
* Always check the host and user.
*/
if (pwflag) {
int nopass;
enum def_tupple pwcheck;
pwcheck = (pwflag == -1) ? never : sudo_defs_table[pwflag].sd_un.tuple;
nopass = (pwcheck == all) ? TRUE : FALSE;
if (list_pw == NULL)
SET(validated, FLAG_NO_CHECK);
CLR(validated, FLAG_NO_USER);
CLR(validated, FLAG_NO_HOST);
match = DENY;
tq_foreach_fwd(&userspecs, us) {
if (userlist_matches(sudo_user.pw, &us->users) != ALLOW)
continue;
tq_foreach_fwd(&us->privileges, priv) {
if (hostlist_matches(&priv->hostlist) != ALLOW)
continue;
tq_foreach_fwd(&priv->cmndlist, cs) {
/* Only check the command when listing another user. */
if (user_uid == 0 || list_pw == NULL ||
user_uid == list_pw->pw_uid ||
cmnd_matches(cs->cmnd) == ALLOW)
match = ALLOW;
if ((pwcheck == any && cs->tags.nopasswd == TRUE) ||
(pwcheck == all && cs->tags.nopasswd != TRUE))
nopass = cs->tags.nopasswd;
}
}
}
if (match == ALLOW || user_uid == 0) {
/* User has an entry for this host. */
SET(validated, VALIDATE_OK);
} else if (match == DENY)
SET(validated, VALIDATE_NOT_OK);
if (pwcheck == always && def_authenticate)
SET(validated, FLAG_CHECK_USER);
else if (pwcheck == never || nopass == TRUE)
def_authenticate = FALSE;
return(validated);
}
/* Need to be runas user while stat'ing things. */
set_perms(PERM_RUNAS);
match = UNSPEC;
tq_foreach_rev(&userspecs, us) {
if (userlist_matches(sudo_user.pw, &us->users) != ALLOW)
continue;
CLR(validated, FLAG_NO_USER);
tq_foreach_rev(&us->privileges, priv) {
host_match = hostlist_matches(&priv->hostlist);
if (host_match == ALLOW)
CLR(validated, FLAG_NO_HOST);
else
continue;
tq_foreach_rev(&priv->cmndlist, cs) {
runas_match = runaslist_matches(&cs->runasuserlist,
&cs->runasgrouplist);
if (runas_match == ALLOW) {
cmnd_match = cmnd_matches(cs->cmnd);
if (cmnd_match != UNSPEC) {
match = cmnd_match;
tags = &cs->tags;
#ifdef HAVE_SELINUX
/* Set role and type if not specified on command line. */
if (user_role == NULL)
user_role = cs->role ? estrdup(cs->role) : def_role;
if (user_type == NULL)
user_type = cs->type ? estrdup(cs->type) : def_type;
#endif /* HAVE_SELINUX */
goto matched2;
}
}
}
}
}
matched2:
if (match == ALLOW) {
SET(validated, VALIDATE_OK);
CLR(validated, VALIDATE_NOT_OK);
if (tags != NULL) {
if (tags->nopasswd != UNSPEC)
def_authenticate = !tags->nopasswd;
if (tags->noexec != UNSPEC)
def_noexec = tags->noexec;
if (tags->setenv != UNSPEC)
def_setenv = tags->setenv;
}
} else if (match == DENY) {
SET(validated, VALIDATE_NOT_OK);
CLR(validated, VALIDATE_OK);
}
set_perms(PERM_ROOT);
return(validated);
}
#define TAG_CHANGED(t) \
(cs->tags.t != UNSPEC && cs->tags.t != IMPLIED && cs->tags.t != tags->t)
static void
sudo_file_append_cmnd(cs, tags, lbuf)
struct cmndspec *cs;
struct cmndtag *tags;
struct lbuf *lbuf;
{
struct member *m;
#ifdef HAVE_SELINUX
if (cs->role)
lbuf_append(lbuf, "ROLE=", cs->role, " ", NULL);
if (cs->type)
lbuf_append(lbuf, "TYPE=", cs->type, " ", NULL);
#endif /* HAVE_SELINUX */
if (TAG_CHANGED(setenv)) {
lbuf_append(lbuf, cs->tags.setenv ? "SETENV: " :
"NOSETENV: ", NULL);
tags->setenv = cs->tags.setenv;
}
if (TAG_CHANGED(noexec)) {
lbuf_append(lbuf, cs->tags.noexec ? "NOEXEC: " :
"EXEC: ", NULL);
tags->noexec = cs->tags.noexec;
}
if (TAG_CHANGED(nopasswd)) {
lbuf_append(lbuf, cs->tags.nopasswd ? "NOPASSWD: " :
"PASSWD: ", NULL);
tags->nopasswd = cs->tags.nopasswd;
}
m = cs->cmnd;
print_member(lbuf, m->name, m->type, m->negated,
CMNDALIAS);
}
static int
sudo_file_display_priv_short(pw, us, lbuf)
struct passwd *pw;
struct userspec *us;
struct lbuf *lbuf;
{
struct cmndspec *cs;
struct member *m;
struct privilege *priv;
struct cmndtag tags;
int nfound = 0;
tq_foreach_fwd(&us->privileges, priv) {
tags.noexec = UNSPEC;
tags.setenv = UNSPEC;
tags.nopasswd = UNSPEC;
lbuf_append(lbuf, " ", NULL);
tq_foreach_fwd(&priv->cmndlist, cs) {
if (cs != tq_first(&priv->cmndlist))
lbuf_append(lbuf, ", ", NULL);
lbuf_append(lbuf, "(", NULL);
if (!tq_empty(&cs->runasuserlist)) {
tq_foreach_fwd(&cs->runasuserlist, m) {
if (m != tq_first(&cs->runasuserlist))
lbuf_append(lbuf, ", ", NULL);
print_member(lbuf, m->name, m->type, m->negated,
RUNASALIAS);
}
} else {
lbuf_append(lbuf, def_runas_default, NULL);
}
if (!tq_empty(&cs->runasgrouplist)) {
lbuf_append(lbuf, " : ", NULL);
tq_foreach_fwd(&cs->runasgrouplist, m) {
if (m != tq_first(&cs->runasgrouplist))
lbuf_append(lbuf, ", ", NULL);
print_member(lbuf, m->name, m->type, m->negated,
RUNASALIAS);
}
}
lbuf_append(lbuf, ") ", NULL);
sudo_file_append_cmnd(cs, &tags, lbuf);
nfound++;
}
lbuf_print(lbuf); /* forces a newline */
}
return(nfound);
}
static int
sudo_file_display_priv_long(pw, us, lbuf)
struct passwd *pw;
struct userspec *us;
struct lbuf *lbuf;
{
struct cmndspec *cs;
struct member *m;
struct privilege *priv;
struct cmndtag tags;
int nfound = 0;
tq_foreach_fwd(&us->privileges, priv) {
tags.noexec = UNSPEC;
tags.setenv = UNSPEC;
tags.nopasswd = UNSPEC;
lbuf_print(lbuf); /* force a newline */
lbuf_append(lbuf, "Sudoers entry:", NULL);
lbuf_print(lbuf);
tq_foreach_fwd(&priv->cmndlist, cs) {
lbuf_append(lbuf, " RunAsUsers: ", NULL);
if (!tq_empty(&cs->runasuserlist)) {
tq_foreach_fwd(&cs->runasuserlist, m) {
if (m != tq_first(&cs->runasuserlist))
lbuf_append(lbuf, ", ", NULL);
print_member(lbuf, m->name, m->type, m->negated,
RUNASALIAS);
}
} else {
lbuf_append(lbuf, def_runas_default, NULL);
}
lbuf_print(lbuf);
if (!tq_empty(&cs->runasgrouplist)) {
lbuf_append(lbuf, " RunAsGroups: ", NULL);
tq_foreach_fwd(&cs->runasgrouplist, m) {
if (m != tq_first(&cs->runasgrouplist))
lbuf_append(lbuf, ", ", NULL);
print_member(lbuf, m->name, m->type, m->negated,
RUNASALIAS);
}
lbuf_print(lbuf);
}
lbuf_append(lbuf, " Commands: ", NULL);
lbuf_print(lbuf);
lbuf_append(lbuf, "\t", NULL);
sudo_file_append_cmnd(cs, &tags, lbuf);
lbuf_print(lbuf);
nfound++;
}
}
return(nfound);
}
int
sudo_file_display_privs(nss, pw, lbuf)
struct sudo_nss *nss;
struct passwd *pw;
struct lbuf *lbuf;
{
struct userspec *us;
int nfound = 0;
if (nss->handle == NULL)
return(-1);
tq_foreach_fwd(&userspecs, us) {
/* XXX - why only check the first privilege here? */
if (userlist_matches(pw, &us->users) != ALLOW ||
hostlist_matches(&us->privileges.first->hostlist) != ALLOW)
continue;
if (long_list)
nfound += sudo_file_display_priv_long(pw, us, lbuf);
else
nfound += sudo_file_display_priv_short(pw, us, lbuf);
}
return(nfound);
}
/*
* Display matching Defaults entries for the given user on this host.
*/
int
sudo_file_display_defaults(nss, pw, lbuf)
struct sudo_nss *nss;
struct passwd *pw;
struct lbuf *lbuf;
{
struct defaults *d;
char *prefix = NULL;
int nfound = 0;
if (nss->handle == NULL)
return(-1);
if (lbuf->len == 0)
prefix = " ";
else
prefix = ", ";
tq_foreach_fwd(&defaults, d) {
switch (d->type) {
case DEFAULTS_HOST:
if (hostlist_matches(&d->binding) != ALLOW)
continue;
break;
case DEFAULTS_USER:
if (userlist_matches(pw, &d->binding) != ALLOW)
continue;
break;
case DEFAULTS_RUNAS:
case DEFAULTS_CMND:
continue;
}
lbuf_append(lbuf, prefix, NULL);
if (d->val != NULL) {
lbuf_append(lbuf, d->var, d->op == '+' ? "+=" :
d->op == '-' ? "-=" : "=", NULL);
if (strpbrk(d->val, " \t") != NULL) {
lbuf_append(lbuf, "\"", NULL);
lbuf_append_quoted(lbuf, "\"", d->val, NULL);
lbuf_append(lbuf, "\"", NULL);
} else
lbuf_append_quoted(lbuf, SUDOERS_QUOTED, d->val, NULL);
} else
lbuf_append(lbuf, d->op == FALSE ? "!" : "", d->var, NULL);
prefix = ", ";
nfound++;
}
return(nfound);
}
/*
* Display Defaults entries that are per-runas or per-command
*/
int
sudo_file_display_bound_defaults(nss, pw, lbuf)
struct sudo_nss *nss;
struct passwd *pw;
struct lbuf *lbuf;
{
int nfound = 0;
/* XXX - should only print ones that match what the user can do. */
nfound += display_bound_defaults(DEFAULTS_RUNAS, lbuf);
nfound += display_bound_defaults(DEFAULTS_CMND, lbuf);
return(nfound);
}
/*
* Display Defaults entries of the given type.
*/
static int
display_bound_defaults(dtype, lbuf)
int dtype;
struct lbuf *lbuf;
{
struct defaults *d;
struct member *m, *binding = NULL;
char *dname, *dsep;
int atype, nfound = 0;
switch (dtype) {
case DEFAULTS_HOST:
atype = HOSTALIAS;
dname = "host";
dsep = "@";
break;
case DEFAULTS_USER:
atype = USERALIAS;
dname = "user";
dsep = ":";
break;
case DEFAULTS_RUNAS:
atype = RUNASALIAS;
dname = "runas";
dsep = ">";
break;
case DEFAULTS_CMND:
atype = CMNDALIAS;
dname = "cmnd";
dsep = "!";
break;
default:
return(-1);
}
/* printf("Per-%s Defaults entries:\n", dname); */
tq_foreach_fwd(&defaults, d) {
if (d->type != dtype)
continue;
nfound++;
if (binding != tq_first(&d->binding)) {
binding = tq_first(&d->binding);
lbuf_append(lbuf, " Defaults", dsep, NULL);
for (m = binding; m != NULL; m = m->next) {
if (m != binding)
lbuf_append(lbuf, ",", NULL);
print_member(lbuf, m->name, m->type, m->negated, atype);
lbuf_append(lbuf, " ", NULL);
}
} else
lbuf_append(lbuf, ", ", NULL);
if (d->val != NULL) {
lbuf_append(lbuf, d->var, d->op == '+' ? "+=" :
d->op == '-' ? "-=" : "=", d->val, NULL);
} else
lbuf_append(lbuf, d->op == FALSE ? "!" : "", d->var, NULL);
}
return(nfound);
}
int
sudo_file_display_cmnd(nss, pw)
struct sudo_nss *nss;
struct passwd *pw;
{
struct cmndspec *cs;
struct member *match;
struct privilege *priv;
struct userspec *us;
int rval = 1;
int host_match, runas_match, cmnd_match;
if (nss->handle == NULL)
return(rval);
match = NULL;
tq_foreach_rev(&userspecs, us) {
if (userlist_matches(pw, &us->users) != ALLOW)
continue;
tq_foreach_rev(&us->privileges, priv) {
host_match = hostlist_matches(&priv->hostlist);
if (host_match != ALLOW)
continue;
tq_foreach_rev(&priv->cmndlist, cs) {
runas_match = runaslist_matches(&cs->runasuserlist,
&cs->runasgrouplist);
if (runas_match == ALLOW) {
cmnd_match = cmnd_matches(cs->cmnd);
if (cmnd_match != UNSPEC) {
match = host_match && runas_match ?
cs->cmnd : NULL;
goto matched;
}
}
}
}
}
matched:
if (match != NULL && !match->negated) {
printf("%s%s%s\n", safe_cmnd, user_args ? " " : "",
user_args ? user_args : "");
rval = 0;
}
return(rval);
}
/*
* Print the contents of a struct member to stdout
*/
static void
_print_member(lbuf, name, type, negated, alias_type)
struct lbuf *lbuf;
char *name;
int type, negated, alias_type;
{
struct alias *a;
struct member *m;
struct sudo_command *c;
switch (type) {
case ALL:
lbuf_append(lbuf, negated ? "!ALL" : "ALL", NULL);
break;
case COMMAND:
c = (struct sudo_command *) name;
if (negated)
lbuf_append(lbuf, "!", NULL);
lbuf_append_quoted(lbuf, SUDOERS_QUOTED, c->cmnd, NULL);
if (c->args) {
lbuf_append(lbuf, " ", NULL);
lbuf_append_quoted(lbuf, SUDOERS_QUOTED, c->args, NULL);
}
break;
case ALIAS:
if ((a = alias_find(name, alias_type)) != NULL) {
tq_foreach_fwd(&a->members, m) {
if (m != tq_first(&a->members))
lbuf_append(lbuf, ", ", NULL);
_print_member(lbuf, m->name, m->type,
negated ? !m->negated : m->negated, alias_type);
}
break;
}
/* FALLTHROUGH */
default:
lbuf_append(lbuf, negated ? "!" : "", name, NULL);
break;
}
}
static void
print_member(lbuf, name, type, negated, alias_type)
struct lbuf *lbuf;
char *name;
int type, negated, alias_type;
{
alias_seqno++;
_print_member(lbuf, name, type, negated, alias_type);
}
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