void chown_tty (const struct passwd *info) { struct group *grent; gid_t gid; /* * See if login.defs has some value configured for the port group * ID. Otherwise, use the user's primary group ID. */ grent = getgr_nam_gid (getdef_str ("TTYGROUP")); if (NULL != grent) { gid = grent->gr_gid; } else { gid = info->pw_gid; } /* * Change the permissions on the TTY to be owned by the user with * the group as determined above. */ if ( (fchown (STDIN_FILENO, info->pw_uid, gid) != 0) || (fchmod (STDIN_FILENO, getdef_num ("TTYPERM", 0600)) != 0)) { int err = errno; fprintf (stderr, _("Unable to change owner or mode of tty stdin: %s"), strerror (err)); SYSLOG ((LOG_WARN, "unable to change owner or mode of tty stdin for user `%s': %s\n", info->pw_name, strerror (err))); if (EROFS != err) { closelog (); exit (EXIT_FAILURE); } } #ifdef __linux__ /* * Please don't add code to chown /dev/vcs* to the user logging in - * it's a potential security hole. I wouldn't like the previous user * to hold the file descriptor open and watch my screen. We don't * have the *BSD revoke() system call yet, and vhangup() only works * for tty devices (which vcs* is not). --marekm */ #endif }
static int get_groups (char *list) { char *cp; const struct group *grp; int errors = 0; int ngroups = 0; /* * Initialize the list to be empty */ user_groups[0] = (char *) 0; if (!*list) return 0; /* * So long as there is some data to be converted, strip off each * name and look it up. A mix of numerical and string values for * group identifiers is permitted. */ do { /* * Strip off a single name from the list */ if ((cp = strchr (list, ','))) *cp++ = '\0'; /* * Names starting with digits are treated as numerical GID * values, otherwise the string is looked up as is. */ grp = getgr_nam_gid (list); /* * There must be a match, either by GID value or by * string name. */ if (!grp) { fprintf (stderr, _("%s: unknown group %s\n"), Prog, list); errors++; } list = cp; /* * If the group doesn't exist, don't dump core. Instead, * try the next one. --marekm */ if (!grp) continue; #ifdef USE_NIS /* * Don't add this group if they are an NIS group. Tell the * user to go to the server for this group. */ if (__isgrNIS ()) { fprintf (stderr, _("%s: group `%s' is a NIS group.\n"), Prog, grp->gr_name); continue; } #endif if (ngroups == sys_ngroups) { fprintf (stderr, _ ("%s: too many groups specified (max %d).\n"), Prog, ngroups); break; } /* * Add the group name to the user's list of groups. */ user_groups[ngroups++] = xstrdup (grp->gr_name); } while (list); user_groups[ngroups] = (char *) 0; /* * Any errors in finding group names are fatal */ if (errors) return -1; return 0; }
/* * process_flags - perform command line argument setting * * process_flags() interprets the command line arguments and sets the * values that the user will be created with accordingly. The values * are checked for sanity. */ static void process_flags (int argc, char **argv) { const struct group *grp; const struct passwd *pwd; const struct spwd *spwd = NULL; int anyflag = 0; int arg; if (argc == 1 || argv[argc - 1][0] == '-') usage (); if (!(pwd = getpwnam (argv[argc - 1]))) { fprintf (stderr, _("%s: user %s does not exist\n"), Prog, argv[argc - 1]); exit (E_NOTFOUND); } user_name = argv[argc - 1]; user_id = pwd->pw_uid; user_gid = pwd->pw_gid; user_comment = xstrdup (pwd->pw_gecos); user_home = xstrdup (pwd->pw_dir); user_shell = xstrdup (pwd->pw_shell); #ifdef WITH_AUDIT user_newname = user_name; user_newid = user_id; user_newgid = user_gid; user_newcomment = user_comment; user_newhome = user_home; user_newshell = user_shell; #endif #ifdef USE_NIS /* * Now make sure it isn't an NIS user. */ if (__ispwNIS ()) { char *nis_domain; char *nis_master; fprintf (stderr, _("%s: user %s is a NIS user\n"), Prog, user_name); if (!yp_get_default_domain (&nis_domain) && !yp_master (nis_domain, "passwd.byname", &nis_master)) { fprintf (stderr, _("%s: %s is the NIS master\n"), Prog, nis_master); } exit (E_NOTFOUND); } #endif if (is_shadow_pwd && (spwd = getspnam (user_name))) { user_expire = spwd->sp_expire; user_inactive = spwd->sp_inact; #ifdef WITH_AUDIT user_newexpire = user_expire; user_newinactive = user_inactive; #endif } { /* * Parse the command line options. */ int c; static struct option long_options[] = { {"append", required_argument, NULL, 'a'}, {"comment", required_argument, NULL, 'c'}, {"home", required_argument, NULL, 'd'}, {"expiredate", required_argument, NULL, 'e'}, {"inactive", required_argument, NULL, 'f'}, {"gid", required_argument, NULL, 'g'}, {"groups", required_argument, NULL, 'G'}, {"help", no_argument, NULL, 'h'}, {"login", required_argument, NULL, 'l'}, {"lock", no_argument, NULL, 'L'}, {"move-home", no_argument, NULL, 'm'}, {"non-unique", no_argument, NULL, 'o'}, {"password", required_argument, NULL, 'p'}, {"shell", required_argument, NULL, 's'}, {"uid", required_argument, NULL, 'u'}, {"unlock", no_argument, NULL, 'U'}, {NULL, 0, NULL, '\0'} }; while ((c = getopt_long (argc, argv, "ac:d:e:f:g:G:l:Lmop:s:u:U", long_options, NULL)) != -1) { switch (c) { case 'a': aflg++; break; case 'c': if (!VALID (optarg)) { fprintf (stderr, _("%s: invalid field `%s'\n"), Prog, optarg); exit (E_BAD_ARG); } #ifdef WITH_AUDIT user_newcomment = optarg; #else user_comment = optarg; #endif cflg++; break; case 'd': if (!VALID (optarg)) { fprintf (stderr, _("%s: invalid field `%s'\n"), Prog, optarg); exit (E_BAD_ARG); } dflg++; user_newhome = optarg; break; case 'e': if (*optarg) { #ifdef WITH_AUDIT user_newexpire = strtoday (optarg); if (user_newexpire == -1) { #else user_expire = strtoday (optarg); if (user_expire == -1) { #endif fprintf (stderr, _ ("%s: invalid date `%s'\n"), Prog, optarg); exit (E_BAD_ARG); } #ifdef WITH_AUDIT user_newexpire *= DAY / SCALE; #else user_expire *= DAY / SCALE; #endif } else #ifdef WITH_AUDIT user_newexpire = -1; #else user_expire = -1; #endif eflg++; break; case 'f': #ifdef WITH_AUDIT user_newinactive = get_number (optarg); #else user_inactive = get_number (optarg); #endif fflg++; break; case 'g': grp = getgr_nam_gid (optarg); if (!grp) { fprintf (stderr, _("%s: unknown group %s\n"), Prog, optarg); exit (E_NOTFOUND); } user_newgid = grp->gr_gid; gflg++; break; case 'G': if (get_groups (optarg)) exit (E_NOTFOUND); Gflg++; break; case 'l': if (!check_user_name (optarg)) { fprintf (stderr, _("%s: invalid field `%s'\n"), Prog, optarg); exit (E_BAD_ARG); } /* * If the name does not really change, we mustn't * set the flag as this will cause rather serious * problems later! */ if (strcmp (user_name, optarg)) lflg++; user_newname = optarg; break; case 'L': if (Uflg || pflg) usage (); Lflg++; break; case 'm': if (!dflg) usage (); mflg++; break; case 'o': if (!uflg) usage (); oflg++; break; case 'p': if (Lflg || Uflg) usage (); user_pass = optarg; pflg++; break; case 's': if (!VALID (optarg)) { fprintf (stderr, _("%s: invalid field `%s'\n"), Prog, optarg); exit (E_BAD_ARG); } #ifdef WITH_AUDIT user_newshell = optarg; #else user_shell = optarg; #endif sflg++; break; case 'u': user_newid = get_id (optarg); uflg++; break; case 'U': if (Lflg && pflg) usage (); Uflg++; break; default: usage (); } anyflag++; } } if (anyflag == 0) { fprintf (stderr, _("%s: no flags given\n"), Prog); exit (E_USAGE); } if (!is_shadow_pwd && (eflg || fflg)) { fprintf (stderr, _ ("%s: shadow passwords required for -e and -f\n"), Prog); exit (E_USAGE); } if (optind != argc - 1) usage (); if (aflg && (!Gflg)) { fprintf (stderr, _("%s: -a flag is ONLY allowed with the -G flag\n"), Prog); usage (); exit (E_USAGE); } if (dflg && strcmp (user_home, user_newhome) == 0) dflg = mflg = 0; if (uflg && user_id == user_newid) uflg = oflg = 0; if (lflg && getpwnam (user_newname)) { fprintf (stderr, _("%s: user %s exists\n"), Prog, user_newname); exit (E_NAME_IN_USE); } if (uflg && !oflg && getpwuid (user_newid)) { fprintf (stderr, _("%s: uid %lu is not unique\n"), Prog, (unsigned long) user_newid); exit (E_UID_IN_USE); } } /* * close_files - close all of the files that were opened * * close_files() closes all of the files that were opened for this new * user. This causes any modified entries to be written out. */ static void close_files (void) { if (!pw_close ()) { fprintf (stderr, _("%s: cannot rewrite password file\n"), Prog); fail_exit (E_PW_UPDATE); } if (is_shadow_pwd && !spw_close ()) { fprintf (stderr, _("%s: cannot rewrite shadow password file\n"), Prog); fail_exit (E_PW_UPDATE); } if (is_shadow_pwd) spw_unlock (); (void) pw_unlock (); /* * Close the DBM and/or flat files */ endpwent (); endspent (); endgrent (); #ifdef SHADOWGRP endsgent (); #endif } /* * open_files - lock and open the password files * * open_files() opens the two password files. */ static void open_files (void) { if (!pw_lock ()) { fprintf (stderr, _("%s: unable to lock password file\n"), Prog); exit (E_PW_UPDATE); } if (!pw_open (O_RDWR)) { fprintf (stderr, _("%s: unable to open password file\n"), Prog); fail_exit (E_PW_UPDATE); } if (is_shadow_pwd && !spw_lock ()) { fprintf (stderr, _("%s: cannot lock shadow password file\n"), Prog); fail_exit (E_PW_UPDATE); } if (is_shadow_pwd && !spw_open (O_RDWR)) { fprintf (stderr, _("%s: cannot open shadow password file\n"), Prog); fail_exit (E_PW_UPDATE); } } /* * usr_update - create the user entries * * usr_update() creates the password file entries for this user and * will update the group entries if required. */ static void usr_update (void) { struct passwd pwent; const struct passwd *pwd; struct spwd spent; const struct spwd *spwd = NULL; /* * Locate the entry in /etc/passwd, which MUST exist. */ pwd = pw_locate (user_name); if (!pwd) { fprintf (stderr, _("%s: %s not found in /etc/passwd\n"), Prog, user_name); fail_exit (E_NOTFOUND); } pwent = *pwd; new_pwent (&pwent); /* * Locate the entry in /etc/shadow. It doesn't have to exist, and * won't be created if it doesn't. */ if (is_shadow_pwd && (spwd = spw_locate (user_name))) { spent = *spwd; new_spent (&spent); } if (lflg || uflg || gflg || cflg || dflg || sflg || pflg || Lflg || Uflg) { if (!pw_update (&pwent)) { fprintf (stderr, _("%s: error changing password entry\n"), Prog); fail_exit (E_PW_UPDATE); } if (lflg && !pw_remove (user_name)) { fprintf (stderr, _("%s: error removing password entry\n"), Prog); fail_exit (E_PW_UPDATE); } } if (spwd && (lflg || eflg || fflg || pflg || Lflg || Uflg)) { if (!spw_update (&spent)) { fprintf (stderr, _ ("%s: error adding new shadow password entry\n"), Prog); fail_exit (E_PW_UPDATE); } if (lflg && !spw_remove (user_name)) { fprintf (stderr, _ ("%s: error removing shadow password entry\n"), Prog); fail_exit (E_PW_UPDATE); } } } /* * move_home - move the user's home directory * * move_home() moves the user's home directory to a new location. The * files will be copied if the directory cannot simply be renamed. */ static void move_home (void) { struct stat sb; if (mflg && stat (user_home, &sb) == 0) { /* * Don't try to move it if it is not a directory * (but /dev/null for example). --marekm */ if (!S_ISDIR (sb.st_mode)) return; if (access (user_newhome, F_OK) == 0) { fprintf (stderr, _("%s: directory %s exists\n"), Prog, user_newhome); fail_exit (E_HOMEDIR); } else if (rename (user_home, user_newhome)) { if (errno == EXDEV) { if (mkdir (user_newhome, sb.st_mode & 0777)) { fprintf (stderr, _ ("%s: can't create %s\n"), Prog, user_newhome); } if (chown (user_newhome, sb.st_uid, sb.st_gid)) { fprintf (stderr, _("%s: can't chown %s\n"), Prog, user_newhome); rmdir (user_newhome); fail_exit (E_HOMEDIR); } if (copy_tree (user_home, user_newhome, uflg ? user_newid : -1, gflg ? user_newgid : -1) == 0) { if (remove_tree (user_home) != 0 || rmdir (user_home) != 0) fprintf (stderr, _ ("%s: warning: failed to completely remove old home directory %s"), Prog, user_home); #ifdef WITH_AUDIT audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "moving home directory", user_newname, user_newid, 1); #endif return; } (void) remove_tree (user_newhome); (void) rmdir (user_newhome); } fprintf (stderr, _ ("%s: cannot rename directory %s to %s\n"), Prog, user_home, user_newhome); fail_exit (E_HOMEDIR); } #ifdef WITH_AUDIT audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "moving home directory", user_newname, user_newid, 1); #endif } if (uflg || gflg) { #ifdef WITH_AUDIT audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "changing home directory owner", user_newname, user_newid, 1); #endif chown (dflg ? user_newhome : user_home, uflg ? user_newid : user_id, gflg ? user_newgid : user_gid); } } /* * update_files - update the lastlog and faillog files */ static void update_files (void) { struct lastlog ll; struct faillog fl; int fd; /* * Relocate the "lastlog" entries for the user. The old entry is * left alone in case the UID was shared. It doesn't hurt anything * to just leave it be. */ if ((fd = open (LASTLOG_FILE, O_RDWR)) != -1) { lseek (fd, (off_t) user_id * sizeof ll, SEEK_SET); if (read (fd, (char *) &ll, sizeof ll) == sizeof ll) { lseek (fd, (off_t) user_newid * sizeof ll, SEEK_SET); write (fd, (char *) &ll, sizeof ll); } close (fd); } /* * Relocate the "faillog" entries in the same manner. */ if ((fd = open (FAILLOG_FILE, O_RDWR)) != -1) { lseek (fd, (off_t) user_id * sizeof fl, SEEK_SET); if (read (fd, (char *) &fl, sizeof fl) == sizeof fl) { lseek (fd, (off_t) user_newid * sizeof fl, SEEK_SET); write (fd, (char *) &fl, sizeof fl); } close (fd); } } #ifndef NO_MOVE_MAILBOX /* * This is the new and improved code to carefully chown/rename the user's * mailbox. Maybe I am too paranoid but the mail spool dir sometimes * happens to be mode 1777 (this makes mail user agents work without * being setgid mail, but is NOT recommended; they all should be fixed * to use movemail). --marekm */ static void move_mailbox (void) { const char *maildir; char mailfile[1024], newmailfile[1024]; int fd; struct stat st; maildir = getdef_str ("MAIL_DIR"); #ifdef MAIL_SPOOL_DIR if (!maildir && !getdef_str ("MAIL_FILE")) maildir = MAIL_SPOOL_DIR; #endif if (!maildir) return; /* * O_NONBLOCK is to make sure open won't hang on mandatory locks. * We do fstat/fchown to make sure there are no races (someone * replacing /var/spool/mail/luser with a hard link to /etc/passwd * between stat and chown). --marekm */ snprintf (mailfile, sizeof mailfile, "%s/%s", maildir, user_name); fd = open (mailfile, O_RDONLY | O_NONBLOCK, 0); if (fd < 0) { /* no need for warnings if the mailbox doesn't exist */ if (errno != ENOENT) perror (mailfile); return; } if (fstat (fd, &st) < 0) { perror ("fstat"); close (fd); return; } if (st.st_uid != user_id) { /* better leave it alone */ fprintf (stderr, _("%s: warning: %s not owned by %s\n"), Prog, mailfile, user_name); close (fd); return; } if (uflg) { if (fchown (fd, user_newid, (gid_t) - 1) < 0) { perror (_("failed to change mailbox owner")); } #ifdef WITH_AUDIT else { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "changing mail file owner", user_newname, user_newid, 1); } #endif } close (fd); if (lflg) { snprintf (newmailfile, sizeof newmailfile, "%s/%s", maildir, user_newname); if (link (mailfile, newmailfile) || unlink (mailfile)) { perror (_("failed to rename mailbox")); } #ifdef WITH_AUDIT else { audit_logger (AUDIT_USER_CHAUTHTOK, Prog, "changing mail file name", user_newname, user_newid, 1); } #endif } } #endif /* * main - usermod command */ int main (int argc, char **argv) { int grp_err = 0; #ifdef USE_PAM pam_handle_t *pamh = NULL; struct passwd *pampw; int retval; #endif #ifdef WITH_AUDIT audit_help_open (); #endif /* * Get my name so that I can use it to report errors. */ Prog = Basename (argv[0]); setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); sys_ngroups = sysconf (_SC_NGROUPS_MAX); user_groups = malloc ((1 + sys_ngroups) * sizeof (char *)); user_groups[0] = (char *) 0; OPENLOG ("usermod"); is_shadow_pwd = spw_file_present (); #ifdef SHADOWGRP is_shadow_grp = sgr_file_present (); #endif process_flags (argc, argv); #ifdef USE_PAM retval = PAM_SUCCESS; pampw = getpwuid (getuid ()); if (pampw == NULL) { retval = PAM_USER_UNKNOWN; } if (retval == PAM_SUCCESS) { retval = pam_start ("usermod", pampw->pw_name, &conv, &pamh); } if (retval == PAM_SUCCESS) { retval = pam_authenticate (pamh, 0); if (retval != PAM_SUCCESS) { pam_end (pamh, retval); } } if (retval == PAM_SUCCESS) { retval = pam_acct_mgmt (pamh, 0); if (retval != PAM_SUCCESS) { pam_end (pamh, retval); } } if (retval != PAM_SUCCESS) { fprintf (stderr, _("%s: PAM authentication failed\n"), Prog); exit (1); } #endif /* USE_PAM */ /* * Do the hard stuff - open the files, change the user entries, * change the home directory, then close and update the files. */ open_files (); usr_update (); nscd_flush_cache ("passwd"); nscd_flush_cache ("group"); close_files (); if (Gflg || lflg) grp_err = grp_update (); if (mflg) move_home (); #ifndef NO_MOVE_MAILBOX if (lflg || uflg) move_mailbox (); #endif if (uflg) { update_files (); /* * Change the UID on all of the files owned by `user_id' to * `user_newid' in the user's home directory. */ chown_tree (dflg ? user_newhome : user_home, user_id, user_newid, user_gid, gflg ? user_newgid : user_gid); } if (grp_err) exit (E_GRP_UPDATE); #ifdef USE_PAM if (retval == PAM_SUCCESS) pam_end (pamh, PAM_SUCCESS); #endif /* USE_PAM */ exit (E_SUCCESS); /* NOT REACHED */ }