File: [local] / src / usr.bin / sudo / Attic / parse.c (download)
Revision 1.7, Tue Jan 8 15:44:25 2002 UTC (22 years, 5 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_3_1_BASE, OPENBSD_3_1 Changes since 1.6: +2 -2 lines
sync with sudo 1.6.4rc2
|
/*
* Copyright (c) 1996, 1998-2002 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* This code is derived from software contributed by Chris Jepeway
* <jepeway@cs.utk.edu>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 4. Products derived from this software may not be called "Sudo" nor
* may "Sudo" appear in their names without specific prior written
* permission from the author.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* 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 <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_H */
#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 lint
static const char rcsid[] = "$Sudo: parse.c,v 1.136 2002/01/08 15:00:18 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;
int pwcheck;
int nopass;
/* Become sudoers file owner */
set_perms(PERM_SUDOERS, 0);
/* 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();
/* If pwcheck *could* be PWCHECK_ALL or PWCHECK_ANY, keep more state. */
if (pwflag > 0)
keepall = TRUE;
/* Need to be root while stat'ing things in the parser. */
set_perms(PERM_ROOT, 0);
error = yyparse();
/* Close the sudoers file now that we are done with it. */
(void) fclose(sudoers_fp);
sudoers_fp = NULL;
if (error || parse_error)
return(VALIDATE_ERROR);
/*
* The pw options may have changed during sudoers parse so we
* wait until now to set this.
*/
if (pwflag)
pwcheck = (pwflag == -1) ? PWCHECK_NEVER : def_ival(pwflag);
else
pwcheck = 0;
/*
* Assume the worst. If the stack is empty the user was
* not mentioned at all.
*/
if (def_flag(I_AUTHENTICATE))
error = VALIDATE_NOT_OK;
else
error = VALIDATE_NOT_OK | FLAG_NOPASS;
if (pwcheck) {
error |= FLAG_NO_CHECK;
} else {
error |= FLAG_NO_HOST;
if (!top)
error |= FLAG_NO_USER;
}
/*
* Only check the actual command if pwcheck flag is not set.
* It is set for the "validate", "list" and "kill" pseudo-commands.
* Always check the host and user.
*/
nopass = -1;
if (pwcheck) {
int found;
if (pwcheck == PWCHECK_NEVER || !def_flag(I_AUTHENTICATE))
nopass = FLAG_NOPASS;
found = 0;
while (top) {
if (host_matches == TRUE) {
found = 1;
if (pwcheck == PWCHECK_ANY && no_passwd == TRUE)
nopass = FLAG_NOPASS;
else if (pwcheck == PWCHECK_ALL && nopass != 0)
nopass = (no_passwd == TRUE) ? FLAG_NOPASS : 0;
}
top--;
}
if (found) {
if (nopass == -1)
nopass = 0;
return(VALIDATE_OK | nopass);
}
} else {
while (top) {
if (host_matches == TRUE) {
error &= ~FLAG_NO_HOST;
if (runas_matches == TRUE) {
if (cmnd_matches == TRUE) {
/*
* User was granted access to cmnd on host.
* If no passwd required return as such.
*/
if (no_passwd == TRUE)
return(VALIDATE_OK | FLAG_NOPASS);
else
return(VALIDATE_OK);
} else if (cmnd_matches == FALSE) {
/*
* User was explicitly denied access to cmnd on host.
*/
if (no_passwd == TRUE)
return(VALIDATE_NOT_OK | FLAG_NOPASS);
else
return(VALIDATE_NOT_OK);
}
}
}
top--;
}
}
/*
* The user was not 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 cmnd names one of the inodes in path.
*/
int
command_matches(cmnd, cmnd_args, path, sudoers_args)
char *cmnd;
char *cmnd_args;
char *path;
char *sudoers_args;
{
int plen;
static struct stat cst;
struct stat pst;
DIR *dirp;
struct dirent *dent;
char buf[MAXPATHLEN];
static char *cmnd_base;
/* Don't bother with pseudo commands like "validate" */
if (strchr(cmnd, '/') == NULL)
return(FALSE);
plen = strlen(path);
/* Only need to stat cmnd once since it never changes */
if (cst.st_dev == 0) {
if (stat(cmnd, &cst) == -1)
return(FALSE);
if ((cmnd_base = strrchr(cmnd, '/')) == NULL)
cmnd_base = cmnd;
else
cmnd_base++;
}
/*
* If the pathname has meta characters in it use fnmatch(3)
* to do the matching
*/
if (has_meta(path)) {
/*
* Return true if fnmatch(3) succeeds 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.
*/
if (fnmatch(path, cmnd, FNM_PATHNAME) != 0)
return(FALSE);
if (!sudoers_args ||
(!cmnd_args && sudoers_args && !strcmp("\"\"", sudoers_args)) ||
(sudoers_args && fnmatch(sudoers_args, cmnd_args ? cmnd_args : "",
0) == 0)) {
if (safe_cmnd)
free(safe_cmnd);
safe_cmnd = estrdup(user_cmnd);
return(TRUE);
} else
return(FALSE);
} else {
/*
* No meta characters
* Check to make sure this is not a directory spec (doesn't end in '/')
*/
if (path[plen - 1] != '/') {
char *p;
/* Only proceed if the basenames of cmnd and path are the same */
if ((p = strrchr(path, '/')) == NULL)
p = path;
else
p++;
if (strcmp(cmnd_base, p) != 0 || stat(path, &pst) == -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 (cst.st_dev != pst.st_dev || cst.st_ino != pst.st_ino)
return(FALSE);
if (!sudoers_args ||
(!cmnd_args && sudoers_args && !strcmp("\"\"", sudoers_args)) ||
(sudoers_args &&
fnmatch(sudoers_args, cmnd_args ? cmnd_args : "", 0) == 0)) {
if (safe_cmnd)
free(safe_cmnd);
safe_cmnd = estrdup(path);
return(TRUE);
} else
return(FALSE);
}
/*
* Grot through path's directory entries, looking for cmnd.
*/
dirp = opendir(path);
if (dirp == NULL)
return(FALSE);
while ((dent = readdir(dirp)) != NULL) {
/* ignore paths > MAXPATHLEN (XXX - log) */
if (plen + NAMLEN(dent) >= sizeof(buf))
continue;
strcpy(buf, path);
strcat(buf, dent->d_name);
/* only stat if basenames are the same */
if (strcmp(cmnd_base, dent->d_name) != 0 || stat(buf, &pst) == -1)
continue;
if (cst.st_dev == pst.st_dev && cst.st_ino == pst.st_ino) {
if (safe_cmnd)
free(safe_cmnd);
safe_cmnd = estrdup(buf);
break;
}
}
closedir(dirp);
return(dent != NULL);
}
}
/*
* 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;
{
int i;
char *m;
struct in_addr addr, mask;
/* If there's an explicit netmask, use it. */
if ((m = strchr(n, '/'))) {
*m++ = '\0';
addr.s_addr = inet_addr(n);
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);
}
*(m - 1) = '/';
for (i = 0; i < num_interfaces; i++)
if ((interfaces[i].addr.s_addr & mask.s_addr) == addr.s_addr)
return(TRUE);
} else {
addr.s_addr = inet_addr(n);
for (i = 0; i < num_interfaces; i++)
if (interfaces[i].addr.s_addr == addr.s_addr ||
(interfaces[i].addr.s_addr & interfaces[i].netmask.s_addr)
== addr.s_addr)
return(TRUE);
}
return(FALSE);
}
/*
* 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 given user belongs to the named group,
* else returns FALSE.
*/
int
usergr_matches(group, user)
char *group;
char *user;
{
struct group *grp;
struct passwd *pw;
char **cur;
/* make sure we have a valid usergroup, sudo style */
if (*group++ != '%')
return(FALSE);
if ((grp = getgrnam(group)) == NULL)
return(FALSE);
/*
* Check against user's real gid as well as group's user list
*/
if ((pw = getpwnam(user)) == NULL)
return(FALSE);
if (grp->gr_gid == pw->pw_gid)
return(TRUE);
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;
{
#ifdef HAVE_GETDOMAINNAME
static char *domain = (char *) -1;
#else
static char *domain = NULL;
#endif /* HAVE_GETDOMAINNAME */
/* make sure we have a valid netgroup, sudo style */
if (*netgr++ != '+')
return(FALSE);
#ifdef HAVE_GETDOMAINNAME
/* get the domain name (if any) */
if (domain == (char *) -1) {
domain = (char *) emalloc(MAXHOSTNAMELEN);
if (getdomainname(domain, MAXHOSTNAMELEN) == -1 || *domain == '\0') {
free(domain);
domain = NULL;
}
}
#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);
}