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
*
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#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 <getopt.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "busybox.h"
/* 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";
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/* 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;
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passwd = bb_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;
}
}
if (p->pw_gid == 0) {
/* 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 create new gid always = uid */
p->pw_gid = p->pw_uid;
}
/* EDR bounds check */
if ((p->pw_uid > max) || (p->pw_uid < min))
return 2;
/* return 1; */
return 0;
}
static void addgroup_wrapper(const char *login, gid_t gid)
{
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char *cmd;
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bb_xasprintf(&cmd, "addgroup -g %d %s", gid, login);
system(cmd);
free(cmd);
}
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static void passwd_wrapper(const char *login) __attribute__ ((noreturn));
static void passwd_wrapper(const char *login)
{
static const char prog[] = "passwd";
execlp(prog, prog, login, NULL);
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bb_error_msg_and_die("Failed to execute '%s', you must set the password for '%s' manually", prog, login);
}
/* putpwent(3) remix */
static int adduser(const char *filename, struct passwd *p, int makehome, int setpass)
{
FILE *passwd;
int r;
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
FILE *shadow;
struct spwd *sp;
#endif
int new_group = 1;
/* if using a pre-existing group, don't create one */
if (p->pw_gid != 0)
new_group = 0;
/* make sure everything is kosher and setup uid && gid */
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passwd = bb_wfopen(filename, "a");
if (passwd == NULL) {
return 1;
}
fseek(passwd, 0, SEEK_END);
/* if (passwd_study(filename, p) == 0) { */
r = passwd_study(filename, p);
if (r) {
if (r == 1)
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bb_error_msg("%s: login already in use", p->pw_name);
else if (r == 2)
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bb_error_msg("illegal uid or no uids left");
else if (r == 3)
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bb_error_msg("group name %s already in use", p->pw_name);
else
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bb_error_msg("generic error.");
return 1;
}
/* add to passwd */
if (putpwent(p, passwd) == -1) {
return 1;
}
fclose(passwd);
#ifdef CONFIG_FEATURE_SHADOWPASSWDS
/* add to shadow if necessary */
if (shadow_enabled) {
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shadow = bb_wfopen(bb_path_shadow_file, "a");
if (shadow == NULL) {
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
if (new_group) {
/* 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);
if (makehome) {
/* mkdir */
if (mkdir(p->pw_dir, 0755)) {
bb_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)) {
bb_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)) {
bb_perror_msg("%s", p->pw_dir);
}
}
if (setpass) {
/* interactively set passwd */
passwd_wrapper(p->pw_name);
}
return 0;
}
/* return current uid (root is always uid == 0, right?) */
#ifndef CONFIG_ADDGROUP
static inline void if_i_am_not_root(void)
#else
void if_i_am_not_root(void)
#endif
{
if (geteuid()) {
bb_error_msg_and_die( "Only root may add a user or group to the system.");
}
}
#define SETPASS (1 << 4)
#define MAKEHOME (1 << 6)
/*
* 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)
{
struct passwd pw;
const char *login;
const char *gecos = default_gecos;
const char *home = NULL;
const char *shell = DEFAULT_SHELL;
const char *usegroup = NULL;
int flags;
int setpass = 1;
int makehome = 1;
/* init */
if (argc < 2) {
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bb_show_usage();
}
/* get args */
flags = bb_getopt_ulflags(argc, argv, "h:g:s:G:DSH", &home, &gecos, &shell, &usegroup);
if (flags & SETPASS) {
setpass = 0;
}
if (flags & MAKEHOME) {
makehome = 0;
}
/* got root? */
if_i_am_not_root();
/* get login */
if (optind >= argc) {
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bb_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? */
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shadow_enabled = (0 == access(bb_path_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;
if (usegroup) {
/* Add user to a group that already exists */
pw.pw_gid = my_getgrnam(usegroup);
/* exits on error */
}
/* grand finale */
return adduser(bb_path_passwd_file, &pw, makehome, setpass);
}