/*
* Copyright (c) 1996, 1998-2005, 2007
* 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 <sys/socket.h>
#include <sys/stat.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 */
#ifdef HAVE_FNMATCH
# include <fnmatch.h>
#endif /* HAVE_FNMATCH */
#ifdef HAVE_EXTENDED_GLOB
# include <glob.h>
#endif /* HAVE_EXTENDED_GLOB */
#ifdef HAVE_NETGROUP_H
# include <netgroup.h>
#endif /* HAVE_NETGROUP_H */
#include <ctype.h>
#include <pwd.h>
#include <grp.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#ifdef HAVE_DIRENT_H
# include <dirent.h>
# define NAMLEN(dirent) strlen((dirent)->d_name)
#else
# define dirent direct
# define NAMLEN(dirent) (dirent)->d_namlen
# ifdef HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# ifdef HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# ifdef HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#include "sudo.h"
#include "parse.h"
#include "interfaces.h"
#ifndef HAVE_FNMATCH
# include "emul/fnmatch.h"
#endif /* HAVE_FNMATCH */
#ifndef HAVE_EXTENDED_GLOB
# include "emul/glob.h"
#endif /* HAVE_EXTENDED_GLOB */
#ifndef lint
__unused static const char rcsid[] = "$Sudo: parse.c,v 1.160.2.15 2007/12/04 15:26:40 millert Exp $";
#endif /* lint */
/*
* Globals
*/
int parse_error = FALSE;
extern int keepall;
extern FILE *yyin, *yyout;
/*
* Prototypes
*/
static int has_meta __P((char *));
void init_parser __P((void));
/*
* Look up the user in the sudoers file and check to see if they are
* allowed to run the specified command on this host as the target user.
*/
int
sudoers_lookup(pwflag)
int pwflag;
{
int error, nopass;
/* We opened _PATH_SUDOERS in check_sudoers() so just rewind it. */
rewind(sudoers_fp);
yyin = sudoers_fp;
yyout = stdout;
/* Allocate space for data structures in the parser. */
init_parser();
/* Keep more state for pseudo-commands so that listpw and verifypw work */
if (pwflag > 0)
keepall = TRUE;
/* Need to be runas user while stat'ing things in the parser. */
set_perms(PERM_RUNAS);
error = yyparse();
/* Close the sudoers file now that we are done with it. */
(void) fclose(sudoers_fp);
sudoers_fp = NULL;
if (error || parse_error) {
set_perms(PERM_ROOT);
return(VALIDATE_ERROR);
}
/*
* Assume the worst. If the stack is empty the user was
* not mentioned at all.
*/
if (def_authenticate)
error = VALIDATE_NOT_OK;
else
error = VALIDATE_NOT_OK | FLAG_NOPASS;
if (pwflag) {
SET(error, FLAG_NO_CHECK);
} else {
SET(error, FLAG_NO_HOST);
if (!top)
SET(error, FLAG_NO_USER);
}
/*
* 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.
*/
nopass = -1;
if (pwflag) {
int found;
enum def_tupple pwcheck;
pwcheck = (pwflag == -1) ? never : sudo_defs_table[pwflag].sd_un.tuple;
if (pwcheck == always && def_authenticate)
nopass = FLAG_CHECK_USER;
else if (pwcheck == never || !def_authenticate)
nopass = FLAG_NOPASS;
found = 0;
while (top) {
if (host_matches == TRUE) {
found = 1;
if (pwcheck == any && no_passwd == TRUE)
nopass = FLAG_NOPASS;
else if (pwcheck == all && nopass != 0)
nopass = (no_passwd == TRUE) ? FLAG_NOPASS : 0;
}
top--;
}
if (found) {
set_perms(PERM_ROOT);
if (nopass == -1)
nopass = 0;
return(VALIDATE_OK | nopass);
}
} else {
while (top) {
if (host_matches == TRUE) {
CLR(error, FLAG_NO_HOST);
if (runas_matches == TRUE && cmnd_matches == TRUE) {
/*
* User was granted access to cmnd on host as user.
*/
set_perms(PERM_ROOT);
return(VALIDATE_OK |
(no_passwd == TRUE ? FLAG_NOPASS : 0) |
(no_execve == TRUE ? FLAG_NOEXEC : 0) |
(setenv_ok >= TRUE ? FLAG_SETENV : 0));
} else if ((runas_matches == TRUE && cmnd_matches == FALSE) ||
(runas_matches == FALSE && cmnd_matches == TRUE)) {
/*
* User was explicitly denied access to cmnd on host.
*/
set_perms(PERM_ROOT);
return(VALIDATE_NOT_OK |
(no_passwd == TRUE ? FLAG_NOPASS : 0) |
(no_execve == TRUE ? FLAG_NOEXEC : 0) |
(setenv_ok >= TRUE ? FLAG_SETENV : 0));
}
}
top--;
}
}
set_perms(PERM_ROOT);
/*
* The user was neither explicitly granted nor denied access.
*/
if (nopass == -1)
nopass = 0;
return(error | nopass);
}
/*
* If path doesn't end in /, return TRUE iff cmnd & path name the same inode;
* otherwise, return TRUE if user_cmnd names one of the inodes in path.
*/
int
command_matches(sudoers_cmnd, sudoers_args)
char *sudoers_cmnd;
char *sudoers_args;
{
struct stat sudoers_stat;
struct dirent *dent;
char **ap, *base, buf[PATH_MAX];
glob_t gl;
DIR *dirp;
/* Check for pseudo-commands */
if (strchr(user_cmnd, '/') == NULL) {
/*
* Return true if both sudoers_cmnd and user_cmnd are "sudoedit" AND
* a) there are no args in sudoers OR
* b) there are no args on command line and none req by sudoers OR
* c) there are args in sudoers and on command line and they match
*/
if (strcmp(sudoers_cmnd, "sudoedit") != 0 ||
strcmp(user_cmnd, "sudoedit") != 0)
return(FALSE);
if (!sudoers_args ||
(!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) ||
(sudoers_args &&
fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) {
efree(safe_cmnd);
safe_cmnd = estrdup(sudoers_cmnd);
return(TRUE);
} else
return(FALSE);
}
/*
* If sudoers_cmnd has meta characters in it, use fnmatch(3)
* to do the matching.
*/
if (has_meta(sudoers_cmnd)) {
/*
* Return true if we find a match in the glob(3) results AND
* a) there are no args in sudoers OR
* b) there are no args on command line and none required by sudoers OR
* c) there are args in sudoers and on command line and they match
* else return false.
*
* Could optimize patterns ending in "/*" to "/user_base"
*/
#define GLOB_FLAGS (GLOB_NOSORT | GLOB_MARK | GLOB_BRACE | GLOB_TILDE)
if (glob(sudoers_cmnd, GLOB_FLAGS, NULL, &gl) != 0) {
globfree(&gl);
return(FALSE);
}
/* For each glob match, compare basename, st_dev and st_ino. */
for (ap = gl.gl_pathv; *ap != NULL; ap++) {
/* only stat if basenames are the same */
if ((base = strrchr(*ap, '/')) != NULL)
base++;
else
base = *ap;
if (strcmp(user_base, base) != 0 ||
stat(*ap, &sudoers_stat) == -1)
continue;
if (user_stat->st_dev == sudoers_stat.st_dev &&
user_stat->st_ino == sudoers_stat.st_ino) {
efree(safe_cmnd);
safe_cmnd = estrdup(*ap);
break;
}
}
globfree(&gl);
if (*ap == NULL)
return(FALSE);
if (!sudoers_args ||
(!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) ||
(sudoers_args &&
fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) {
efree(safe_cmnd);
safe_cmnd = estrdup(user_cmnd);
return(TRUE);
} else
return(FALSE);
} else {
size_t dlen = strlen(sudoers_cmnd);
/*
* No meta characters
* Check to make sure this is not a directory spec (doesn't end in '/')
*/
if (sudoers_cmnd[dlen - 1] != '/') {
/* Only proceed if user_base and basename(sudoers_cmnd) match */
if ((base = strrchr(sudoers_cmnd, '/')) == NULL)
base = sudoers_cmnd;
else
base++;
if (strcmp(user_base, base) != 0 ||
stat(sudoers_cmnd, &sudoers_stat) == -1)
return(FALSE);
/*
* Return true if inode/device matches AND
* a) there are no args in sudoers OR
* b) there are no args on command line and none req by sudoers OR
* c) there are args in sudoers and on command line and they match
*/
if (user_stat->st_dev != sudoers_stat.st_dev ||
user_stat->st_ino != sudoers_stat.st_ino)
return(FALSE);
if (!sudoers_args ||
(!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) ||
(sudoers_args &&
fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) {
efree(safe_cmnd);
safe_cmnd = estrdup(sudoers_cmnd);
return(TRUE);
} else
return(FALSE);
}
/*
* Grot through sudoers_cmnd's directory entries, looking for user_base.
*/
dirp = opendir(sudoers_cmnd);
if (dirp == NULL)
return(FALSE);
if (strlcpy(buf, sudoers_cmnd, sizeof(buf)) >= sizeof(buf))
return(FALSE);
while ((dent = readdir(dirp)) != NULL) {
/* ignore paths > PATH_MAX (XXX - log) */
buf[dlen] = '\0';
if (strlcat(buf, dent->d_name, sizeof(buf)) >= sizeof(buf))
continue;
/* only stat if basenames are the same */
if (strcmp(user_base, dent->d_name) != 0 ||
stat(buf, &sudoers_stat) == -1)
continue;
if (user_stat->st_dev == sudoers_stat.st_dev &&
user_stat->st_ino == sudoers_stat.st_ino) {
efree(safe_cmnd);
safe_cmnd = estrdup(buf);
break;
}
}
closedir(dirp);
return(dent != NULL);
}
}
static int
addr_matches_if(n)
char *n;
{
int i;
struct in_addr addr;
struct interface *ifp;
#ifdef HAVE_IN6_ADDR
struct in6_addr addr6;
int j;
#endif
int family;
#ifdef HAVE_IN6_ADDR
if (inet_pton(AF_INET6, n, &addr6) > 0) {
family = AF_INET6;
} else
#endif
{
family = AF_INET;
addr.s_addr = inet_addr(n);
}
for (i = 0; i < num_interfaces; i++) {
ifp = &interfaces[i];
if (ifp->family != family)
continue;
switch(family) {
case AF_INET:
if (ifp->addr.ip4.s_addr == addr.s_addr ||
(ifp->addr.ip4.s_addr & ifp->netmask.ip4.s_addr)
== addr.s_addr)
return(TRUE);
break;
#ifdef HAVE_IN6_ADDR
case AF_INET6:
if (memcmp(ifp->addr.ip6.s6_addr, addr6.s6_addr,
sizeof(addr6.s6_addr)) == 0)
return(TRUE);
for (j = 0; j < sizeof(addr6.s6_addr); j++) {
if ((ifp->addr.ip6.s6_addr[j] & ifp->netmask.ip6.s6_addr[j]) != addr6.s6_addr[j])
break;
}
if (j == sizeof(addr6.s6_addr))
return(TRUE);
#endif /* HAVE_IN6_ADDR */
}
}
return(FALSE);
}
static int
addr_matches_if_netmask(n, m)
char *n;
char *m;
{
int i;
struct in_addr addr, mask;
struct interface *ifp;
#ifdef HAVE_IN6_ADDR
struct in6_addr addr6, mask6;
int j;
#endif
int family;
#ifdef HAVE_IN6_ADDR
if (inet_pton(AF_INET6, n, &addr6) > 0)
family = AF_INET6;
else
#endif
{
family = AF_INET;
addr.s_addr = inet_addr(n);
}
if (family == AF_INET) {
if (strchr(m, '.'))
mask.s_addr = inet_addr(m);
else {
i = 32 - atoi(m);
mask.s_addr = 0xffffffff;
mask.s_addr >>= i;
mask.s_addr <<= i;
mask.s_addr = htonl(mask.s_addr);
}
}
#ifdef HAVE_IN6_ADDR
else {
if (inet_pton(AF_INET6, m, &mask6) <= 0) {
j = atoi(m);
for (i = 0; i < 16; i++) {
if (j < i * 8)
mask6.s6_addr[i] = 0;
else if (i * 8 + 8 <= j)
mask6.s6_addr[i] = 0xff;
else
mask6.s6_addr[i] = 0xff00 >> (j - i * 8);
}
}
}
#endif /* HAVE_IN6_ADDR */
for (i = 0; i < num_interfaces; i++) {
ifp = &interfaces[i];
if (ifp->family != family)
continue;
switch(family) {
case AF_INET:
if ((ifp->addr.ip4.s_addr & mask.s_addr) == addr.s_addr)
return(TRUE);
#ifdef HAVE_IN6_ADDR
case AF_INET6:
for (j = 0; j < sizeof(addr6.s6_addr); j++) {
if ((ifp->addr.ip6.s6_addr[j] & mask6.s6_addr[j]) != addr6.s6_addr[j])
break;
}
if (j == sizeof(addr6.s6_addr))
return(TRUE);
#endif /* HAVE_IN6_ADDR */
}
}
return(FALSE);
}
/*
* Returns TRUE if "n" is one of our ip addresses or if
* "n" is a network that we are on, else returns FALSE.
*/
int
addr_matches(n)
char *n;
{
char *m;
int retval;
/* If there's an explicit netmask, use it. */
if ((m = strchr(n, '/'))) {
*m++ = '\0';
retval = addr_matches_if_netmask(n, m);
*(m - 1) = '/';
} else
retval = addr_matches_if(n);
return(retval);
}
/*
* Returns 0 if the hostname matches the pattern and non-zero otherwise.
*/
int
hostname_matches(shost, lhost, pattern)
char *shost;
char *lhost;
char *pattern;
{
if (has_meta(pattern)) {
if (strchr(pattern, '.'))
return(fnmatch(pattern, lhost, FNM_CASEFOLD));
else
return(fnmatch(pattern, shost, FNM_CASEFOLD));
} else {
if (strchr(pattern, '.'))
return(strcasecmp(lhost, pattern));
else
return(strcasecmp(shost, pattern));
}
}
/*
* Returns TRUE if the user/uid from sudoers matches the specified user/uid,
* else returns FALSE.
*/
int
userpw_matches(sudoers_user, user, pw)
char *sudoers_user;
char *user;
struct passwd *pw;
{
if (pw != NULL && *sudoers_user == '#') {
uid_t uid = atoi(sudoers_user + 1);
if (uid == pw->pw_uid)
return(1);
}
return(strcmp(sudoers_user, user) == 0);
}
/*
* Returns TRUE if the given user belongs to the named group,
* else returns FALSE.
* XXX - reduce the number of passwd/group lookups
*/
int
usergr_matches(group, user, pw)
char *group;
char *user;
struct passwd *pw;
{
struct group *grp;
gid_t pw_gid;
char **cur;
int i;
/* make sure we have a valid usergroup, sudo style */
if (*group++ != '%')
return(FALSE);
/* look up user's primary gid in the passwd file */
if (pw == NULL && (pw = getpwnam(user)) == NULL)
return(FALSE);
pw_gid = pw->pw_gid;
if ((grp = getgrnam(group)) == NULL)
return(FALSE);
/* check against user's primary (passwd file) gid */
if (grp->gr_gid == pw_gid)
return(TRUE);
/*
* If the user has a supplementary group vector, check it first.
*/
if (strcmp(user, user_name) == 0) {
for (i = 0; i < user_ngroups; i++) {
if (grp->gr_gid == user_groups[i])
return(TRUE);
}
}
if (grp->gr_mem != NULL) {
for (cur = grp->gr_mem; *cur; cur++) {
if (strcmp(*cur, user) == 0)
return(TRUE);
}
}
return(FALSE);
}
/*
* Returns TRUE if "host" and "user" belong to the netgroup "netgr",
* else return FALSE. Either of "host", "shost" or "user" may be NULL
* in which case that argument is not checked...
*/
int
netgr_matches(netgr, host, shost, user)
char *netgr;
char *host;
char *shost;
char *user;
{
static char *domain;
#ifdef HAVE_GETDOMAINNAME
static int initialized;
#endif
/* make sure we have a valid netgroup, sudo style */
if (*netgr++ != '+')
return(FALSE);
#ifdef HAVE_GETDOMAINNAME
/* get the domain name (if any) */
if (!initialized) {
domain = (char *) emalloc(MAXHOSTNAMELEN);
if (getdomainname(domain, MAXHOSTNAMELEN) == -1 || *domain == '\0') {
efree(domain);
domain = NULL;
}
initialized = 1;
}
#endif /* HAVE_GETDOMAINNAME */
#ifdef HAVE_INNETGR
if (innetgr(netgr, host, user, domain))
return(TRUE);
else if (host != shost && innetgr(netgr, shost, user, domain))
return(TRUE);
#endif /* HAVE_INNETGR */
return(FALSE);
}
/*
* Returns TRUE if "s" has shell meta characters in it,
* else returns FALSE.
*/
static int
has_meta(s)
char *s;
{
char *t;
for (t = s; *t; t++) {
if (*t == '\\' || *t == '?' || *t == '*' || *t == '[' || *t == ']')
return(TRUE);
}
return(FALSE);
}