/***************************************************************************** * * $Id$ * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(__OpenBSD__) || defined(__NetBSD__) #include #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]; #elif defined(__NetBSD__) #define ARG_SIZE 60 static char **s; size_t siz = 100; 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)); } parent = xstrcpy(buf); #elif defined(__NetBSD__) /* * 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); } parent = xstrcpy((char *)s); #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 \"%s\"\n", parent); 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); }