busybox/loginutils/adduser.c

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/* vi: set sw=4 ts=4: */
/*
* adduser - add users to /etc/passwd and /etc/shadow
*
* Copyright (C) 1999 by Lineo, inc. and John Beppu
* Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "busybox.h"
#include "pwd.h"
#include "grp.h"
#define PASSWD_FILE "/etc/passwd"
#define SHADOW_FILE "/etc/shadow"
/* structs __________________________ */
typedef struct {
uid_t u;
gid_t g;
} Id;
/* data _____________________________ */
/* defaults : should this be in an external file? */
static const char default_passwd[] = "x";
static const char default_gecos[] = "Linux User,,,";
static const char default_home_prefix[] = "/home";
static const char default_shell[] = "/bin/sh";
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
#include "shadow.h"
/* shadow in use? */
static int shadow_enabled = 0;
#endif
/* remix */
/* EDR recoded such that the uid may be passed in *p */
static int passwd_study(const char *filename, struct passwd *p)
{
struct passwd *pw;
FILE *passwd;
const int min = 500;
const int max = 65000;
passwd = wfopen(filename, "r");
if (!passwd)
return 4;
/* EDR if uid is out of bounds, set to min */
if ((p->pw_uid > max) || (p->pw_uid < min))
p->pw_uid = min;
/* stuff to do:
* make sure login isn't taken;
* find free uid and gid;
*/
while ((pw = fgetpwent(passwd))) {
if (strcmp(pw->pw_name, p->pw_name) == 0) {
/* return 0; */
return 1;
}
if ((pw->pw_uid >= p->pw_uid) && (pw->pw_uid < max)
&& (pw->pw_uid >= min)) {
p->pw_uid = pw->pw_uid + 1;
}
}
/* EDR check for an already existing gid */
while (getgrgid(p->pw_uid) != NULL)
p->pw_uid++;
/* EDR also check for an existing group definition */
if (getgrnam(p->pw_name) != NULL)
return 3;
/* EDR bounds check */
if ((p->pw_uid > max) || (p->pw_uid < min))
return 2;
/* EDR create new gid always = uid */
p->pw_gid = p->pw_uid;
/* return 1; */
return 0;
}
static void addgroup_wrapper(const char *login, gid_t gid)
{
int argc = 3;
const char *argv0_save;
char group_id[8];
char group_name[32];
char *argv[] = { group_name, "-g", group_id };
argv0_save = applet_name;
applet_name = "addgroup";
safe_strncpy(group_name, login, 32);
sprintf(group_id, "%d", gid);
addgroup_main(argc, argv);
applet_name = argv0_save;
}
static void passwd_wrapper(const char *login)
{
static const char prog[] = "passwd";
execlp(prog, prog, login, NULL);
error_msg_and_die("Failed to execute 'passwd', you must set the password for '%s' manually", login);
}
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/*
* pwd_to_spwd - create entries for new spwd structure
*
* pwd_to_spwd() creates a new (struct spwd) containing the
* information in the pointed-to (struct passwd).
*/
#define DAY (24L*3600L)
#define WEEK (7*DAY)
#define SCALE DAY
static struct spwd *pwd_to_spwd(const struct passwd *pw)
{
static struct spwd sp;
/*
* Nice, easy parts first. The name and passwd map directly
* from the old password structure to the new one.
*/
sp.sp_namp = pw->pw_name;
sp.sp_pwdp = pw->pw_passwd;
/*
* Defaults used if there is no pw_age information.
*/
sp.sp_min = 0;
sp.sp_max = (10000L * DAY) / SCALE;
sp.sp_lstchg = time((time_t *) 0) / SCALE;
/*
* These fields have no corresponding information in the password
* file. They are set to uninitialized values.
*/
sp.sp_warn = -1;
sp.sp_expire = -1;
sp.sp_inact = -1;
sp.sp_flag = -1;
return &sp;
}
#endif
/* putpwent(3) remix */
static int adduser(const char *filename, struct passwd *p)
{
FILE *passwd;
int r;
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
FILE *shadow;
struct spwd *sp;
#endif
/* make sure everything is kosher and setup uid && gid */
passwd = wfopen(filename, "a");
if (passwd == NULL) {
/* return -1; */
return 1;
}
fseek(passwd, 0, SEEK_END);
/* if (passwd_study(filename, p) == 0) { */
r = passwd_study(filename, p);
if (r) {
if (r == 1)
error_msg("%s: login already in use", p->pw_name);
else if (r == 2)
error_msg("illegal uid or no uids left");
else if (r == 3)
error_msg("group name %s already in use", p->pw_name);
else
error_msg("generic error.");
/* return -1; */
return 1;
}
/* add to passwd */
if (putpwent(p, passwd) == -1) {
/* return -1; */
return 1;
}
fclose(passwd);
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/* add to shadow if necessary */
if (shadow_enabled) {
shadow = wfopen(SHADOW_FILE, "a");
if (shadow == NULL) {
/* return -1; */
return 1;
}
fseek(shadow, 0, SEEK_END);
sp = pwd_to_spwd(p);
sp->sp_max = 99999; /* debianish */
sp->sp_warn = 7;
fprintf(shadow, "%s:!:%ld:%ld:%ld:%ld:::\n",
sp->sp_namp, sp->sp_lstchg, sp->sp_min, sp->sp_max,
sp->sp_warn);
fclose(shadow);
}
#endif
/* add to group */
/* addgroup should be responsible for dealing w/ gshadow */
addgroup_wrapper(p->pw_name, p->pw_gid);
/* Clear the umask for this process so it doesn't
* * screw up the permissions on the mkdir and chown. */
umask(0);
/* mkdir */
if (mkdir(p->pw_dir, 0755)) {
perror_msg("%s", p->pw_dir);
}
/* Set the owner and group so it is owned by the new user. */
if (chown(p->pw_dir, p->pw_uid, p->pw_gid)) {
perror_msg("%s", p->pw_dir);
}
/* Now fix up the permissions to 2755. Can't do it before now
* since chown will clear the setgid bit */
if (chmod(p->pw_dir, 02755)) {
perror_msg("%s", p->pw_dir);
}
/* interactively set passwd */
passwd_wrapper(p->pw_name);
return 0;
}
/* return current uid (root is always uid == 0, right?) */
static inline uid_t i_am_not_root(void)
{
return geteuid();
}
/*
* adduser will take a login_name as its first parameter.
*
* home
* shell
* gecos
*
* can be customized via command-line parameters.
* ________________________________________________________________________ */
int adduser_main(int argc, char **argv)
{
int i = 0;
char opt;
const char *login;
const char *gecos;
const char *home = NULL;
const char *shell;
struct passwd pw;
/* init */
if (argc < 2) {
show_usage();
}
gecos = default_gecos;
shell = default_shell;
/* get args */
while ((opt = getopt (argc, argv, "h:g:s:")) != -1)
switch (opt) {
case 'h':
home = argv[++i];
break;
case 'g':
gecos = argv[++i];
break;
case 's':
shell = argv[++i];
break;
default:
show_usage ();
break;
}
/* got root? */
if (i_am_not_root()) {
error_msg_and_die( "Only root may add a user or group to the system.");
}
/* get login */
if (optind >= argc) {
error_msg_and_die( "no user specified");
}
login = argv[optind];
/* create string for $HOME if not specified already */
if (!home) {
home = concat_path_file(default_home_prefix, login);
}
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/* is /etc/shadow in use? */
shadow_enabled = (0 == access(SHADOW_FILE, F_OK));
#endif
/* create a passwd struct */
pw.pw_name = (char *)login;
pw.pw_passwd = (char *)default_passwd;
pw.pw_uid = 0;
pw.pw_gid = 0;
pw.pw_gecos = (char *)gecos;
pw.pw_dir = (char *)home;
pw.pw_shell = (char *)shell;
/* grand finale */
return adduser(PASSWD_FILE, &pw);
}
/* $Id: adduser.c,v 1.1 2002/06/04 20:45:05 sandman Exp $ */