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deb-mbse/unix/mbuseradd.c
2005-08-31 20:22:20 +00:00

476 lines
12 KiB
C

/*****************************************************************************
*
* $Id$
* Purpose ...............: setuid root version of useradd
*
*****************************************************************************
* Copyright (C) 1997-2005
*
* Michiel Broek FIDO: 2:280/2802
* Beekmansbos 10
* 1971 BV IJmuiden
* the Netherlands
*
* This file is part of MBSE BBS.
*
* This BBS 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, or (at your option) any
* later version.
*
* MBSE BBS 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 MBSE BBS; see the file COPYING. If not, write to the Free
* Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*****************************************************************************/
#include "../config.h"
#include <stdio.h>
#include <stdlib.h>
#include <pwd.h>
#include <sys/types.h>
#include <grp.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <syslog.h>
#include <time.h>
#if defined(__OpenBSD__)
#include <sys/sysctl.h>
#endif
#include "xmalloc.h"
#include "mbuseradd.h"
/*
* Milliseconds timer, returns 0 on success.
*/
int msleep(int msecs)
{
int rc;
struct timespec req, rem;
rem.tv_sec = 0;
rem.tv_nsec = 0;
req.tv_sec = msecs / 1000;
req.tv_nsec = (msecs % 1000) * 1000000;
while (1) {
rc = nanosleep(&req, &rem);
if (rc == 0)
break;
if ((errno == EINVAL) || (errno == EFAULT))
break;
/*
* Error was EINTR, run timer again to complete.
*/
req.tv_sec = rem.tv_sec;
req.tv_nsec = rem.tv_nsec;
rem.tv_sec = 0;
rem.tv_nsec = 0;
}
return rc;
}
int execute(char **args, char *in, char *out, char *err)
{
char buf[PATH_MAX];
int i, pid, status = 0, rc = 0;
memset(&buf, 0, sizeof(buf));
for (i = 0; i < 16; i++) {
if (args[i])
snprintf(buf + strlen(buf), PATH_MAX - strlen(buf), " %s", args[i]);
else
break;
}
syslog(LOG_WARNING, "Execute:%s", buf);
fflush(stdout);
fflush(stderr);
if ((pid = fork()) == 0) {
msleep(150);
if (in) {
close(0);
if (open(in, O_RDONLY) != 0) {
syslog(LOG_WARNING, "Reopen of stdin to %s failed", in);
_exit(-1);
}
}
if (out) {
close(1);
if (open(out, O_WRONLY | O_APPEND | O_CREAT,0600) != 1) {
syslog(LOG_WARNING, "Reopen of stdout to %s failed", out);
_exit(-1);
}
}
if (err) {
close(2);
if (open(err, O_WRONLY | O_APPEND | O_CREAT,0600) != 2) {
syslog(LOG_WARNING, "Reopen of stderr to %s failed", err);
_exit(-1);
}
}
rc = execv(args[0],args);
syslog(LOG_WARNING, "Exec \"%s\" returned %d", args[0], rc);
_exit(-1);
}
do {
rc = wait(&status);
} while (((rc > 0) && (rc != pid)) || ((rc == -1) && (errno == EINTR)));
return 0;
}
void makedir(char *path, mode_t mode, uid_t owner, gid_t group)
{
if (mkdir(path, mode) != 0) {
syslog(LOG_WARNING, "Can't create directory %s:%s", path, strerror(errno));
exit(2);
}
if ((chown(path, owner, group)) == -1) {
syslog(LOG_WARNING, "Unable to change ownership of %s", path);
exit(2);
}
}
/*
* Internal version of basename to make this better portable.
*/
char *Basename(char *str)
{
char *cp = strrchr(str, '/');
return cp ? cp+1 : str;
}
/*
* Function will create the users name in the passwd file
* Note that this function must run setuid root!
*/
int main(int argc, char *argv[])
{
char *temp, *shell, *homedir, *args[16], *parent;
int i;
struct passwd *pwent, *pwuser;
struct group *gr;
pid_t ppid;
#if defined(__OpenBSD__)
#define ARG_SIZE 60
static char **s, buf[ARG_SIZE];
size_t siz = 100;
char **p;
int mib[4];
#else
FILE *fp;
#endif
if (argc != 5)
Help();
/*
* First simple check for argument overflow
*/
for (i = 1; i < 5; i++) {
if (strlen(argv[i]) > 80) {
fprintf(stderr, "mbuseradd: Argument %d is too long\n", i);
exit(1);
}
}
/*
* Check calling username
*/
ppid = getuid();
pwent = getpwuid(ppid);
if (!pwent) {
fprintf(stderr, "mbuseradd: Cannot determine your user name.\n");
exit(1);
}
if (strcmp(pwent->pw_name, (char *)"mbse") && strcmp(pwent->pw_name, (char *)"bbs")) {
fprintf(stderr, "mbuseradd: only users `mbse' and `bbs' may do this.\n");
exit(1);
}
/*
* Get my groupname, this must be "bbs", other users may not
* use this program, not even root.
*/
gr = getgrgid(pwent->pw_gid);
if (!gr) {
fprintf(stderr, "mbuseradd: Cannot determine group name.\n");
exit(1);
}
if (strcmp(gr->gr_name, (char *)"bbs")) {
fprintf(stderr, "mbuseradd: You are not a member of group `bbs'.\n");
exit(1);
}
/*
* Find out the name of our parent.
*/
temp = calloc(PATH_MAX, sizeof(char));
ppid = getppid();
#if defined(__OpenBSD__)
/*
* Systems that use sysctl to get process information
*/
mib[0] = CTL_KERN;
mib[1] = KERN_PROC_ARGS;
mib[2] = ppid;
mib[3] = KERN_PROC_ARGV;
if ((s = realloc(s, siz)) == NULL) {
fprintf(stderr, "mbuseradd: no memory\n");
exit(1);
}
if (sysctl(mib, 4, s, &siz, NULL, 0) == -1) {
perror("");
fprintf(stderr, "mbuseradd: sysctl call failed\n");
exit(1);
}
buf[0] = '\0';
for (p = s; *p != NULL; p++) {
if (p != s)
strlcat(buf, " ", sizeof(buf));
strlcat(buf, *p, sizeof(buf));
}
printf("%s\n", buf);
parent = xstrcpy(buf);
#else
/*
* Systems with /proc filesystem like Linux, FreeBSD
*/
snprintf(temp, PATH_MAX, "/proc/%d/cmdline", ppid);
if ((fp = fopen(temp, "r")) == NULL) {
fprintf(stderr, "mbuseradd: can't read %s\n", temp);
exit(1);
}
fgets(temp, PATH_MAX-1, fp);
fclose(fp);
parent = xstrcpy(Basename(temp));
#endif
if (strcmp((char *)"-mbnewusr", parent)) {
fprintf(stderr, "mbuseradd: illegal parent\n");
free(temp);
free(parent);
exit(1);
}
memset(args, 0, sizeof(args));
shell = calloc(PATH_MAX, sizeof(char));
homedir = calloc(PATH_MAX, sizeof(char));
if (setuid(0) == -1 || setgid(1) == -1) {
perror("");
fprintf(stderr, "mbuseradd: Unable to setuid(root) or setgid(root)\n");
fprintf(stderr, "Make sure that this program is set to -rwsr-sr-x\n");
fprintf(stderr, "Owner must be root and group root\n");
exit(1);
}
umask(0000);
/*
* We don't log into MBSE BBS logfiles but to the system logfiles,
* because we are modifying system files not belonging to MBSE BBS.
*/
openlog("mbuseradd", LOG_PID|LOG_CONS|LOG_NOWAIT, LOG_AUTH);
syslog(LOG_WARNING, "mbuseradd %s %s %s %s", argv[1], argv[2], argv[3], argv[4]);
/*
* Build command to add user entry to the /etc/passwd and /etc/shadow
* files. We use the systems own useradd program.
*/
#if defined(__linux__) || defined(__NetBSD__) || defined(__OpenBSD__)
if ((access("/usr/bin/useradd", R_OK)) == 0)
args[0] = (char *)"/usr/bin/useradd";
else if ((access("/bin/useradd", R_OK)) == 0)
args[0] = (char *)"/bin/useradd";
else if ((access("/usr/sbin/useradd", R_OK)) == 0)
args[0] = (char *)"/usr/sbin/useradd";
else if ((access("/sbin/useradd", R_OK)) == 0)
args[0] = (char *)"/sbin/useradd";
else {
syslog(LOG_WARNING, "Can't find useradd");
exit(1);
}
#elif __FreeBSD__
if ((access("/usr/sbin/pw", X_OK)) == 0)
args[0] = (char *)"/usr/sbin/pw";
else if ((access("/sbin/pw", X_OK)) == 0)
args[0] = (char *)"/sbin/pw";
else {
syslog(LOG_WARNING, "Can't find pw");
exit(1);
}
#else
#error "Don't know how to add a user on this OS"
#endif
snprintf(shell, PATH_MAX, "%s/bin/mbsebbs", getenv("MBSE_ROOT"));
snprintf(homedir, PATH_MAX, "%s/%s", argv[4], argv[2]);
#if defined(__linux__)
args[1] = (char *)"-c";
args[2] = argv[3];
args[3] = (char *)"-d";
args[4] = homedir;
args[5] = (char *)"-g";
args[6] = argv[1];
args[7] = (char *)"-s";
args[8] = shell;
args[9] = argv[2];
args[10] = NULL;
#elif defined(__NetBSD__) || defined(__OpenBSD__)
args[1] = (char *)"-c";
args[2] = argv[3];
args[3] = (char *)"-d";
args[4] = homedir;
args[5] = (char *)"-g";
args[6] = argv[1];
args[7] = (char *)"-s";
args[8] = shell;
args[9] = (char *)"-m";
args[10] = argv[2];
args[11] = NULL;
#elif defined(__FreeBSD__)
args[1] = (char *)"useradd";
args[2] = argv[2];
args[3] = (char *)"-c";
args[4] = argv[3];
args[5] = (char *)"-d";
args[6] = homedir;
args[7] = (char *)"-g";
args[8] = argv[1];
args[9] = (char *)"-s";
args[10] = shell;
args[11] = NULL;
#else
#error "Don't know how to add a user on this OS"
#endif
if (execute(args, (char *)"/dev/tty", (char *)"/dev/tty", (char *)"/dev/tty") != 0) {
syslog(LOG_WARNING, "Failed to create unix account");
exit(1);
}
syslog(LOG_WARNING, "Created Unix account");
/*
* Now create directories and files for this user.
*/
if ((pwent = getpwnam((char *)"mbse")) == NULL) {
syslog(LOG_WARNING, "Can't get password entry for \"mbse\"");
exit(2);
}
/*
*
* Check bbs users base home directory
*/
if ((access(argv[4], R_OK)) != 0) {
syslog(LOG_WARNING, "No bbs base homedirectory, creating..");
makedir(argv[4], 0770, pwent->pw_uid, pwent->pw_gid);
}
/*
* Now create users home directory. Check for an existing directory,
* some systems have already created a home directory. If one is found
* it is removed to create a fresh one.
*/
if ((access(homedir, R_OK)) == 0) {
if ((access("/bin/rm", X_OK)) == 0)
args[0] = (char *)"/bin/rm";
else if ((access("/usr/bin/rm", X_OK)) == 0)
args[0] = (char *)"/usr/bin/rm";
else {
syslog(LOG_WARNING, "Can't find rm");
exit(2);
}
args[1] = (char *)"-Rf";
args[2] = homedir;
args[3] = NULL;
i = execute(args, (char *)"/dev/tty", (char *)"/dev/tty", (char *)"/dev/tty");
if (i != 0) {
syslog(LOG_WARNING, "Unable remove old home directory");
exit(2);
}
}
/*
* Create users home directory.
*/
if ((pwuser = getpwnam(argv[2])) == NULL) {
syslog(LOG_WARNING, "Can't get passwd entry for %s", argv[2]);
exit(2);
}
makedir(homedir, 0770, pwuser->pw_uid, pwent->pw_gid);
/*
* Create Maildir and subdirs for Qmail.
*/
snprintf(temp, PATH_MAX, "%s/%s/Maildir", argv[4], argv[2]);
makedir(temp, 0700, pwuser->pw_uid, pwent->pw_gid);
snprintf(temp, PATH_MAX, "%s/%s/Maildir/cur", argv[4], argv[2]);
makedir(temp, 0700, pwuser->pw_uid, pwent->pw_gid);
snprintf(temp, PATH_MAX, "%s/%s/Maildir/new", argv[4], argv[2]);
makedir(temp, 0700, pwuser->pw_uid, pwent->pw_gid);
snprintf(temp, PATH_MAX, "%s/%s/Maildir/tmp", argv[4], argv[2]);
makedir(temp, 0700, pwuser->pw_uid, pwent->pw_gid);
#ifdef _VPOPMAIL_PATH
snprintf(temp, PATH_MAX, "%s/vadduser", _VPOPMAIL_PATH);
args[0] = temp;
args[1] = argv[2];
args[2] = argv[2];
args[3] = NULL;
if (execute(args, (char *)"/dev/tty", (char *)"/dev/tty", (char *)"/dev/tty") != 0) {
syslog(LOG_WARNING, "Failed to create vpopmail account");
} else {
syslog(LOG_WARNING, "Created vpopmail account");
}
#endif
free(shell);
free(temp);
free(homedir);
syslog(LOG_WARNING, "Added system account for user\"%s\"", argv[2]);
exit(0);
}
void Help()
{
fprintf(stderr, "\nmbuseradd commandline:\n\n");
fprintf(stderr, "mbuseradd [gid] [name] [comment] [usersdir]\n");
exit(1);
}