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014bd22934cf35a890777e223741fa5dc2b541b9
sudo/sudo.c
Todd C. Miller 014bd22934 -u flag was being ignored
1999-08-04 07:53:04 +00:00

1037 lines
26 KiB
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/*
* Copyright (c) 1994-1996,1998-1999 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* 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.
*
* For a brief history of sudo, please see the HISTORY file included
* with this distribution.
*/
#define _SUDO_SUDO_C
#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 */
#ifdef HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <pwd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <grp.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netdb.h>
#include "sudo.h"
#include "interfaces.h"
#include "version.h"
#ifndef STDC_HEADERS
extern char *getenv __P((char *));
#endif /* STDC_HEADERS */
#ifndef lint
static const char rcsid[] = "$Sudo$";
#endif /* lint */
/*
* Local type declarations
*/
struct env_table {
char *name;
int len;
};
/*
* Prototypes
*/
static int parse_args __P((void));
static void usage __P((int));
static void usage_excl __P((int));
static void check_sudoers __P((void));
static int init_vars __P((int));
static void add_env __P((int));
static void clean_env __P((char **, struct env_table *));
extern int user_is_exempt __P((void));
extern struct passwd *sudo_getpwuid __P((uid_t));
extern void list_matches __P((void));
/*
* Globals
*/
int Argc;
char **Argv;
int NewArgc = 0;
char **NewArgv = NULL;
struct sudo_user sudo_user;
FILE *sudoers_fp = NULL;
static char *runas_homedir = NULL; /* XXX */
struct interface *interfaces;
int num_interfaces;
extern int errorlineno;
/*
* Table of "bad" envariables to remove and len for strncmp()
*/
static struct env_table badenv_table[] = {
{ "IFS=", 4 },
{ "LOCALDOMAIN=", 12 },
{ "RES_OPTIONS=", 12 },
{ "HOSTALIASES=", 12 },
{ "LD_", 3 },
{ "_RLD", 4 },
#ifdef __hpux
{ "SHLIB_PATH=", 11 },
#endif /* __hpux */
#ifdef _AIX
{ "LIBPATH=", 8 },
#endif /* _AIX */
#ifdef HAVE_KERB4
{ "KRB_CONF", 8 },
#endif /* HAVE_KERB4 */
#ifdef HAVE_KERB5
{ "KRB5_CONFIG", 11 },
#endif /* HAVE_KERB5 */
{ "ENV=", 4 },
{ "BASH_ENV=", 9 },
{ (char *) NULL, 0 }
};
int
main(argc, argv)
int argc;
char **argv;
{
int validated;
int fd;
int cmnd_status;
int sudo_mode;
#ifdef POSIX_SIGNALS
sigset_t set, oset;
#else
int omask;
#endif /* POSIX_SIGNALS */
extern char **environ;
extern int printmatches;
/* Must be done as the first thing... */
#if defined(HAVE_GETPRPWNAM) && defined(HAVE_SET_AUTH_PARAMETERS)
(void) set_auth_parameters(argc, argv);
# ifdef HAVE_INITPRIVS
initprivs();
# endif
#endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */
Argv = argv;
Argc = argc;
if (geteuid() != 0) {
(void) fprintf(stderr, "Sorry, %s must be setuid root.\n", Argv[0]);
exit(1);
}
/* Initialize syslog(3) if we are using it. */
#if (LOGGING & SLOG_SYSLOG)
# ifdef Syslog_facility
openlog(Syslog_ident, Syslog_options, Syslog_facility);
# else
openlog(Syslog_ident, Syslog_options);
# endif /* Syslog_facility */
#endif /* LOGGING & SLOG_SYSLOG */
/*
* Block signals so the user cannot kill us at some point and
* avoid the logging.
* XXX - this list is not complete!
*/
#ifdef POSIX_SIGNALS
(void) sigemptyset(&set);
(void) sigaddset(&set, SIGHUP);
(void) sigaddset(&set, SIGINT);
(void) sigaddset(&set, SIGQUIT);
(void) sigaddset(&set, SIGILL);
(void) sigaddset(&set, SIGTSTP);
(void) sigprocmask(SIG_BLOCK, &set, &oset);
#else
omask = sigblock(sigmask(SIGHUP)|sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGILL)|sigmask(SIGTSTP));
#endif /* POSIX_SIGNALS */
/*
* Close any open fd's other than stdin, stdout and stderr.
*/
#ifdef HAVE_SYSCONF
for (fd = sysconf(_SC_OPEN_MAX) - 1; fd > 2; fd--)
(void) close(fd);
#else
for (fd = getdtablesize() - 1; fd > 2; fd--)
(void) close(fd);
#endif /* HAVE_SYSCONF */
/*
* Set the prompt based on $SUDO_PROMPT (can be overridden by `-p')
*/
if ((user_prompt = getenv("SUDO_PROMPT")) == NULL)
user_prompt = PASSPROMPT;
/* Parse our arguments. */
sudo_mode = parse_args();
switch (sudo_mode) {
case MODE_VERSION:
case MODE_HELP:
(void) printf("Sudo version %s\n", version);
if (sudo_mode == MODE_VERSION)
exit(0);
else
usage(0);
break;
case MODE_VALIDATE:
user_cmnd = "validate";
break;
case MODE_KILL:
case MODE_INVALIDATE:
user_cmnd = "kill";
break;
case MODE_SHELL:
user_cmnd = "shell";
break;
case MODE_LIST:
user_cmnd = "list";
printmatches = 1;
break;
}
/* Must have a command to run... */
if (user_cmnd == NULL && NewArgc == 0)
usage(1);
clean_env(environ, badenv_table);
cmnd_status = init_vars(sudo_mode);
set_perms(PERM_USER, sudo_mode);
check_sudoers(); /* check mode/owner on _PATH_SUDO_SUDOERS */
if (sudo_mode == MODE_KILL || sudo_mode == MODE_INVALIDATE) {
remove_timestamp((sudo_mode == MODE_KILL));
exit(0);
}
add_env(!(sudo_mode & MODE_SHELL)); /* add in SUDO_* envariables */
/* Validate the user but don't search for pseudo-commands. */
validated = sudoers_lookup((sudo_mode != MODE_VALIDATE && sudo_mode != MODE_LIST));
switch (validated) {
case VALIDATE_OK:
check_user();
/* fallthrough */
case VALIDATE_OK_NOPASS:
/* Finally tell the user if the command did not exist. */
if (cmnd_status == NOT_FOUND_DOT) {
(void) fprintf(stderr, "%s: ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.\n", Argv[0], user_cmnd, user_cmnd, user_cmnd);
exit(1);
} else if (cmnd_status == NOT_FOUND) {
(void) fprintf(stderr, "%s: %s: command not found\n", Argv[0],
user_cmnd);
exit(1);
}
log_auth(validated, 1);
if (sudo_mode == MODE_VALIDATE)
exit(0);
else if (sudo_mode == MODE_LIST) {
list_matches();
exit(0);
}
/* Become specified user or root. */
set_perms(PERM_RUNAS, sudo_mode);
/* Set $HOME for `sudo -H' */
if ((sudo_mode & MODE_RESET_HOME) && runas_homedir)
(void) sudo_setenv("HOME", runas_homedir);
/* This *must* have been set if we got a match but... */
if (safe_cmnd == NULL) {
log_error(MSG_ONLY,
"internal error, cmnd_safe never got set for %s; %s",
user_cmnd,
"please report this error to sudo-bugs@courtesan.com");
}
#if (LOGGING & SLOG_SYSLOG)
closelog();
#endif
/* Reset signal mask. */
#ifdef POSIX_SIGNALS
(void) sigprocmask(SIG_SETMASK, &oset, NULL);
#else
(void) sigsetmask(omask);
#endif /* POSIX_SIGNALS */
#ifndef PROFILING
if ((sudo_mode & MODE_BACKGROUND) && fork() > 0)
exit(0);
else
EXEC(safe_cmnd, NewArgv); /* run the command */
#else
exit(0);
#endif /* PROFILING */
/*
* If we got here then the exec() failed...
*/
(void) fprintf(stderr, "%s: unable to exec %s: %s\n",
Argv[0], safe_cmnd, strerror(errno));
exit(-1);
break;
case VALIDATE_NO_USER:
check_user();
log_auth(validated, 1);
exit(1);
break;
case VALIDATE_NOT_OK:
check_user();
case VALIDATE_NOT_OK_NOPASS:
/*
* We'd like to not leak path info at all here, but that can
* *really* confuse the users. To really close the leak we'd
* have to say "not allowed to run foo" even when the problem
* is just "no foo in path" since the user can trivially set
* their path to just contain a single dir.
*/
#ifndef DONT_LEAK_PATH_INFO
log_auth(validated,
!(cmnd_status == NOT_FOUND_DOT || cmnd_status == NOT_FOUND));
if (cmnd_status == NOT_FOUND)
(void) fprintf(stderr, "%s: %s: command not found\n", Argv[0],
user_cmnd);
else if (cmnd_status == NOT_FOUND_DOT)
(void) fprintf(stderr, "%s: ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.\n", Argv[0], user_cmnd, user_cmnd, user_cmnd);
exit(1);
break;
#endif /* DONT_LEAK_PATH_INFO */
case VALIDATE_ERROR:
log_error(0, "parse error in %s around line %d", _PATH_SUDO_SUDOERS,
errorlineno);
break;
default:
log_auth(validated, 1);
exit(1);
break;
}
exit(0); /* not reached */
}
/*
* Initialize timezone, set umask, fill in ``sudo_user'' struct and
* load the ``interfaces'' array.
*/
static int
init_vars(sudo_mode)
int sudo_mode;
{
char *p, thost[MAXHOSTNAMELEN];
#ifdef FQDN
struct hostent *hp;
#endif /* FQDN */
#ifdef NO_ROOT_SUDO
if (getuid() == 0) {
(void) fputs("You are already root, you don't need to use sudo.\n",
stderr);
exit(1);
}
#endif
/* Sanity check command from user. */
if (user_cmnd == NULL && strlen(NewArgv[0]) >= MAXPATHLEN) {
(void) fprintf(stderr, "%s: %s: Pathname too long\n", Argv[0],
NewArgv[0]);
exit(1);
}
#ifdef HAVE_TZSET
(void) tzset(); /* set the timezone if applicable */
#endif /* HAVE_TZSET */
#ifdef SECURE_PATH
/* Replace the PATH envariable with a secure one. */
if (!user_is_exempt() && sudo_setenv("PATH", SECURE_PATH)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
#endif /* SECURE_PATH */
#ifdef SUDO_UMASK
(void) umask((mode_t)SUDO_UMASK);
#endif /* SUDO_UMASK */
/* Default values for runas and cmnd, overridden later. */
if (user_runas == NULL)
user_runas = RUNAS_DEFAULT;
if (user_cmnd == NULL)
user_cmnd = NewArgv[0];
(void) strcpy(user_cwd, "unknown");
/*
* We avoid gethostbyname() if possible since we don't want
* sudo to block if DNS or NIS is hosed.
* "host" is the (possibly fully-qualified) hostname and
* "shost" is the unqualified form of the hostname.
*/
if ((gethostname(thost, sizeof(thost)))) {
user_host = "localhost";
log_error(USE_ERRNO|MSG_ONLY, "can't get hostname");
} else
user_host = estrdup(thost);
#ifdef FQDN
if (!(hp = gethostbyname(user_host)))
log_error(USE_ERRNO|MSG_ONLY|NO_EXIT,
"unable to lookup %s via gethostbyname()", user_host);
else
user_host = estrdup(hp->h_name);
#endif /* FQDN */
if ((p = strchr(user_host, '.'))) {
*p = '\0';
user_shost = estrdup(user_host);
*p = '.';
} else {
user_shost = user_host;
}
if ((p = ttyname(STDIN_FILENO)) || (p = ttyname(STDOUT_FILENO))) {
if (strncmp(p, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
p += sizeof(_PATH_DEV) - 1;
user_tty = estrdup(p);
} else
user_tty = "unknown";
/*
* Get a local copy of the user's struct passwd with the shadow password
* if necessary. It is assumed that euid is 0 at this point so we
* can read the shadow passwd file if necessary.
*/
if ((sudo_user.pw = sudo_getpwuid(getuid())) == NULL) {
/* Need to make a fake struct passwd for logging to work. */
struct passwd pw;
char pw_name[MAX_UID_T_LEN + 1];
pw.pw_uid = getuid();
(void) sprintf(pw_name, "%ld", (long) pw.pw_uid);
pw.pw_name = pw_name;
sudo_user.pw = &pw;
log_error(0, "uid %ld does not exist in the passwd file!",
(long) pw.pw_uid);
}
/* It is now safe to use log_error() and set_perms() */
/*
* Get current working directory. Try as user, fall back to root.
*/
set_perms(PERM_USER, sudo_mode);
if (!getcwd(user_cwd, sizeof(user_cwd))) {
set_perms(PERM_ROOT, sudo_mode);
if (!getcwd(user_cwd, sizeof(user_cwd))) {
(void) fprintf(stderr, "%s: Can't get working directory!\n",
Argv[0]);
(void) strcpy(user_cwd, "unknown");
}
} else
set_perms(PERM_ROOT, sudo_mode);
/*
* Load the list of local ip addresses and netmasks into
* the interfaces array.
*/
load_interfaces();
/*
* If we were given the '-s' option (run shell) we need to redo
* NewArgv and NewArgc.
*/
if ((sudo_mode & MODE_SHELL)) {
char **dst, **src = NewArgv;
NewArgv = (char **) emalloc (sizeof(char *) * (++NewArgc + 1));
if (user_shell && *user_shell) {
NewArgv[0] = user_shell;
} else {
(void) fprintf(stderr, "%s: Unable to determine shell.", Argv[0]);
exit(1);
}
/* copy the args from Argv */
for (dst = NewArgv + 1; (*dst = *src) != NULL; ++src, ++dst)
;
}
/* Resolve the path and return. */
if ((sudo_mode & MODE_RUN))
return(find_path(NewArgv[0], &user_cmnd));
else
return(FOUND);
}
/*
* Command line argument parsing, can't use getopt(3).
*/
static int
parse_args()
{
int rval = MODE_RUN; /* what mode is suod to be run in? */
int excl = 0; /* exclusive arg, no others allowed */
#ifdef HAVE_KERB5
extern char *realm; /* kerb5 realm (may be user-specified */
#endif /* HAVE_KERB5 */
NewArgv = Argv + 1;
NewArgc = Argc - 1;
#ifdef SHELL_IF_NO_ARGS
if (Argc < 2) { /* no options and no command */
rval |= MODE_SHELL;
return(rval);
}
#else
if (Argc < 2) /* no options and no command */
usage(1);
#endif /* SHELL_IF_NO_ARGS */
while (NewArgc > 0 && NewArgv[0][0] == '-') {
if (NewArgv[0][1] != '\0' && NewArgv[0][2] != '\0') {
(void) fprintf(stderr, "%s: Please use single character options\n",
Argv[0]);
usage(1);
}
switch (NewArgv[0][1]) {
#ifdef HAVE_KERB5
case 'r':
/* Must have an associated realm. */
if (NewArgv[1] == NULL)
usage(1);
realm = NewArgv[1];
/* Shift Argv over and adjust Argc. */
NewArgc--;
NewArgv++;
break;
#endif /* HAVE_KERB5 */
case 'p':
/* Must have an associated prompt. */
if (NewArgv[1] == NULL)
usage(1);
user_prompt = NewArgv[1];
/* Shift Argv over and adjust Argc. */
NewArgc--;
NewArgv++;
break;
case 'u':
/* Must have an associated runas user. */
if (NewArgv[1] == NULL)
usage(1);
user_runas = NewArgv[1];
/* Shift Argv over and adjust Argc. */
NewArgc--;
NewArgv++;
break;
case 'b':
rval |= MODE_BACKGROUND;
break;
case 'v':
rval = MODE_VALIDATE;
if (excl && excl != 'v')
usage_excl(1);
excl = 'v';
break;
case 'k':
rval = MODE_INVALIDATE;
if (excl && excl != 'k')
usage_excl(1);
excl = 'k';
break;
case 'K':
rval = MODE_KILL;
if (excl && excl != 'K')
usage_excl(1);
excl = 'K';
break;
case 'l':
rval = MODE_LIST;
if (excl && excl != 'l')
usage_excl(1);
excl = 'l';
break;
case 'V':
rval = MODE_VERSION;
if (excl && excl != 'V')
usage_excl(1);
excl = 'V';
break;
case 'h':
rval = MODE_HELP;
if (excl && excl != 'h')
usage_excl(1);
excl = 'h';
break;
case 's':
rval |= MODE_SHELL;
#ifdef SHELL_SETS_HOME
rval |= MODE_RESET_HOME;
#endif /* SHELL_SETS_HOME */
break;
case 'H':
rval |= MODE_RESET_HOME;
break;
case '-':
NewArgc--;
NewArgv++;
#ifdef SHELL_IF_NO_ARGS
if (rval == MODE_RUN)
rval |= MODE_SHELL;
#endif /* SHELL_IF_NO_ARGS */
return(rval);
case '\0':
(void) fprintf(stderr, "%s: '-' requires an argument\n",
Argv[0]);
usage(1);
default:
(void) fprintf(stderr, "%s: Illegal option %s\n", Argv[0],
NewArgv[0]);
usage(1);
}
NewArgc--;
NewArgv++;
}
if (NewArgc > 0 && !(rval & MODE_RUN))
usage(1);
return(rval);
}
/*
* Add sudo-specific variables into the environment.
* Sets ``cmnd_args'' as a side effect.
*/
static void
add_env(contiguous)
int contiguous;
{
char idstr[MAX_UID_T_LEN + 1];
size_t size;
char *buf;
/* Add the SUDO_COMMAND envariable (cmnd + args). */
size = strlen(user_cmnd) + 1;
if (NewArgc > 1) {
char *to, **from;
if (contiguous) {
size += (size_t) (NewArgv[NewArgc-1] - NewArgv[1]) +
strlen(NewArgv[NewArgc-1]) + 1;
} else {
for (from = &NewArgv[1]; *from; from++)
size += strlen(*from) + 1;
}
buf = (char *) emalloc(size);
/*
* Copy the command and it's arguments info buf.
*/
(void) strcpy(buf, user_cmnd);
to = buf + strlen(user_cmnd);
for (from = &NewArgv[1]; *from; from++) {
*to++ = ' ';
(void) strcpy(to, *from);
to += strlen(*from);
}
} else {
buf = user_cmnd;
}
if (sudo_setenv("SUDO_COMMAND", buf)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
if (NewArgc > 1)
free(buf);
/* Grab a pointer to the flat arg string from the environment. */
if (NewArgc > 1 && (user_args = getenv("SUDO_COMMAND"))) {
if ((user_args = strchr(user_args, ' ')))
user_args++;
else
user_args = NULL;
}
/* Add the SUDO_USER environment variable. */
if (sudo_setenv("SUDO_USER", user_name)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
/* Add the SUDO_UID environment variable. */
(void) sprintf(idstr, "%ld", (long) user_uid);
if (sudo_setenv("SUDO_UID", idstr)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
/* Add the SUDO_GID environment variable. */
(void) sprintf(idstr, "%ld", (long) user_gid);
if (sudo_setenv("SUDO_GID", idstr)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
/* Set PS1 if SUDO_PS1 is set. */
if ((buf = getenv("SUDO_PS1")))
if (sudo_setenv("PS1", buf)) {
(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
exit(1);
}
}
/*
* Sanity check sudoers mode/owner/type.
* Leaves a file pointer to the sudoers file open in ``fp''.
*/
static void
check_sudoers()
{
struct stat statbuf;
int rootstat, i;
char c;
/*
* Fix the mode and group on sudoers file from old default.
* Only works if filesystem is readable/writable by root.
*/
set_perms(PERM_ROOT, 0);
if ((rootstat = lstat(_PATH_SUDO_SUDOERS, &statbuf)) == 0 &&
SUDOERS_UID == statbuf.st_uid && SUDOERS_MODE != 0400 &&
(statbuf.st_mode & 0007777) == 0400) {
if (chmod(_PATH_SUDO_SUDOERS, SUDOERS_MODE) == 0) {
(void) fprintf(stderr, "%s: fixed mode on %s\n",
Argv[0], _PATH_SUDO_SUDOERS);
if (statbuf.st_gid != SUDOERS_GID) {
if (!chown(_PATH_SUDO_SUDOERS,(uid_t) -1,SUDOERS_GID)) {
(void) fprintf(stderr, "%s: set group on %s\n",
Argv[0], _PATH_SUDO_SUDOERS);
statbuf.st_gid = SUDOERS_GID;
} else {
(void) fprintf(stderr,"%s: Unable to set group on %s: %s\n",
Argv[0], _PATH_SUDO_SUDOERS, strerror(errno));
}
}
} else {
(void) fprintf(stderr, "%s: Unable to fix mode on %s: %s\n",
Argv[0], _PATH_SUDO_SUDOERS, strerror(errno));
}
}
/*
* Sanity checks on sudoers file. Must be done as sudoers
* file owner. We already did a stat as root, so use that
* data if we can't stat as sudoers file owner.
*/
set_perms(PERM_SUDOERS, 0);
if (rootstat != 0 && lstat(_PATH_SUDO_SUDOERS, &statbuf) != 0)
log_error(USE_ERRNO, "can't stat %s", _PATH_SUDO_SUDOERS);
else if (!S_ISREG(statbuf.st_mode))
log_error(0, "%s is not a regular file", _PATH_SUDO_SUDOERS);
else if ((statbuf.st_mode & 07777) != SUDOERS_MODE)
log_error(0, "%s is mode 0%o, should be 0%o", _PATH_SUDO_SUDOERS,
(statbuf.st_mode & 07777), SUDOERS_MODE);
else if (statbuf.st_uid != SUDOERS_UID)
log_error(0, "%s is owned by uid %ld, should be %d", _PATH_SUDO_SUDOERS,
(long) statbuf.st_uid, SUDOERS_UID);
else if (statbuf.st_gid != SUDOERS_GID)
log_error(0, "%s is owned by gid %ld, should be %d", _PATH_SUDO_SUDOERS,
(long) statbuf.st_gid, SUDOERS_GID);
else {
/* Solaris sometimes returns EAGAIN so try 10 times */
for (i = 0; i < 10 ; i++) {
errno = 0;
if ((sudoers_fp = fopen(_PATH_SUDO_SUDOERS, "r")) == NULL ||
fread(&c, sizeof(c), 1, sudoers_fp) != 1) {
sudoers_fp = NULL;
if (errno != EAGAIN && errno != EWOULDBLOCK)
break;
} else
break;
sleep(1);
}
if (sudoers_fp == NULL)
log_error(USE_ERRNO, "can't open %s", _PATH_SUDO_SUDOERS);
}
set_perms(PERM_ROOT, 0);
set_perms(PERM_USER, 0);
}
/*
* Remove environment variables that match the entries in badenv_table.
*/
static void
clean_env(envp, badenv_table)
char **envp;
struct env_table *badenv_table;
{
struct env_table *bad;
char **cur;
/*
* Remove any envars that match entries in badenv_table.
*/
for (cur = envp; *cur; cur++) {
for (bad = badenv_table; bad->name; bad++) {
if (strncmp(*cur, bad->name, bad->len) == 0) {
/* Got a match so remove it. */
char **move;
for (move = cur; *move; move++)
*move = *(move + 1);
cur--;
break;
}
}
}
}
/*
* Set real and effective uids and gids based on perm.
*/
void
set_perms(perm, sudo_mode)
int perm;
int sudo_mode;
{
struct passwd *pw;
switch (perm) {
case PERM_ROOT:
if (setuid(0)) {
perror("setuid(0)");
exit(1);
}
break;
case PERM_USER:
(void) setgid(user_gid);
if (geteuid() != user_uid && seteuid(user_uid)) {
perror("seteuid(user_uid)");
exit(1);
}
break;
case PERM_FULL_USER:
if (setuid(0)) {
perror("setuid(0)");
exit(1);
}
(void) setgid(user_gid);
if (setuid(user_uid)) {
perror("setuid(user_uid)");
exit(1);
}
break;
case PERM_RUNAS:
if (setuid(0)) {
perror("setuid(0)");
exit(1);
}
/* XXX - add group/gid support */
if (*user_runas == '#') {
if (setuid(atoi(user_runas + 1))) {
(void) fprintf(stderr,
"%s: cannot set uid to %s: %s\n",
Argv[0], user_runas, strerror(errno));
exit(1);
}
} else {
if (!(pw = getpwnam(user_runas))) {
(void) fprintf(stderr,
"%s: no passwd entry for %s!\n",
Argv[0], user_runas);
exit(1);
}
/* Set $USER and $LOGNAME to target user */
if (sudo_setenv("USER", pw->pw_name)) {
(void) fprintf(stderr,
"%s: cannot allocate memory!\n",
Argv[0]);
exit(1);
}
if (sudo_setenv("LOGNAME", pw->pw_name)) {
(void) fprintf(stderr,
"%s: cannot allocate memory!\n",
Argv[0]);
exit(1);
}
if (setgid(pw->pw_gid)) {
(void) fprintf(stderr,
"%s: cannot set gid to %ld: %s\n",
Argv[0], (long) pw->pw_gid,
strerror(errno));
exit(1);
}
/*
* Initialize group vector only if are
* going to run as a non-root user.
*/
if (strcmp(user_runas, "root") != 0 &&
initgroups(user_runas, pw->pw_gid)
== -1) {
(void) fprintf(stderr,
"%s: cannot set group vector: %s\n",
Argv[0], strerror(errno));
exit(1);
}
if (setuid(pw->pw_uid)) {
(void) fprintf(stderr,
"%s: cannot set uid to %ld: %s\n",
Argv[0], (long) pw->pw_uid,
strerror(errno));
exit(1);
}
if (sudo_mode & MODE_RESET_HOME)
runas_homedir = pw->pw_dir;
}
break;
case PERM_SUDOERS:
if (setuid(0)) {
perror("setuid(0)");
exit(1);
}
if (setgid(SUDOERS_GID)) {
perror("setgid(SUDOERS_GID)");
exit(1);
}
/*
* If SUDOERS_UID == 0 and SUDOERS_MODE
* is group readable we use a non-zero
* uid in order to avoid NFS lossage.
* Using uid 1 is a bit bogus but should
* work on all OS's.
*/
if (SUDOERS_UID == 0) {
if ((SUDOERS_MODE & 040) && seteuid(1)) {
perror("seteuid(1)");
exit(1);
}
} else {
if (seteuid(SUDOERS_UID)) {
perror("seteuid(SUDOERS_UID)");
exit(1);
}
}
break;
}
}
/*
* Tell which options are mutually exclusive and exit.
*/
static void
usage_excl(exit_val)
int exit_val;
{
(void) fprintf(stderr,
"Only one of the -v, -k, -K, -l, -V and -h options may be used\n");
usage(exit_val);
}
/*
* Give usage message and exit.
*/
static void
usage(exit_val)
int exit_val;
{
(void) fprintf(stderr,
"usage: %s -V | -h | -l | -v | -k | -K | -H | [-b] [-p prompt]\n%*s",
Argv[0], strlen(Argv[0]) + 8, " ");
#ifdef HAVE_KERB5
(void) fprintf(stderr, "[-r realm] ");
#endif /* HAVE_KERB5 */
(void) fprintf(stderr, "[-u username/#uid] -s | <command>\n");
exit(exit_val);
}
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