1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright 2001 Mark R V Murray 5 * All rights reserved. 6 * Copyright (c) 2001 Networks Associates Technology, Inc. 7 * All rights reserved. 8 * 9 * Portions of this software were developed for the FreeBSD Project by 10 * ThinkSec AS and NAI Labs, the Security Research Division of Network 11 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 12 * ("CBOSS"), as part of the DARPA CHATS research program. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. The name of the author may not be used to endorse or promote 23 * products derived from this software without specific prior written 24 * permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/types.h> 43 #include <sys/stat.h> 44 #include <fcntl.h> 45 #include <login_cap.h> 46 #include <pwd.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <unistd.h> 50 51 #define PAM_SM_ACCOUNT 52 53 #include <security/pam_appl.h> 54 #include <security/pam_modules.h> 55 #include <security/pam_mod_misc.h> 56 57 #define _PATH_NOLOGIN "/var/run/nologin" 58 59 static char nologin_def[] = _PATH_NOLOGIN; 60 61 PAM_EXTERN int 62 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, 63 int argc __unused, const char *argv[] __unused) 64 { 65 login_cap_t *lc; 66 struct passwd *pwd; 67 struct stat st; 68 int retval, fd; 69 ssize_t ss; 70 const char *user, *nologin; 71 char *mtmp; 72 73 retval = pam_get_user(pamh, &user, NULL); 74 if (retval != PAM_SUCCESS) 75 return (retval); 76 77 PAM_LOG("Got user: %s", user); 78 79 pwd = getpwnam(user); 80 if (pwd == NULL) 81 return (PAM_USER_UNKNOWN); 82 83 /* 84 * login_getpwclass(3) will select the "root" class by default 85 * if pwd->pw_uid is 0. That class should have "ignorenologin" 86 * capability so that super-user can bypass nologin. 87 */ 88 lc = login_getpwclass(pwd); 89 if (lc == NULL) { 90 PAM_LOG("Unable to get login class for user %s", user); 91 return (PAM_SERVICE_ERR); 92 } 93 94 if (login_getcapbool(lc, "ignorenologin", 0)) { 95 login_close(lc); 96 return (PAM_SUCCESS); 97 } 98 99 nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def); 100 101 fd = open(nologin, O_RDONLY, 0); 102 if (fd < 0) { 103 login_close(lc); 104 return (PAM_SUCCESS); 105 } 106 107 PAM_LOG("Opened %s file", nologin); 108 109 if (fstat(fd, &st) == 0) { 110 mtmp = malloc(st.st_size + 1); 111 if (mtmp != NULL) { 112 ss = read(fd, mtmp, st.st_size); 113 if (ss > 0) { 114 mtmp[ss] = '\0'; 115 pam_error(pamh, "%s", mtmp); 116 } 117 free(mtmp); 118 } 119 } 120 121 PAM_VERBOSE_ERROR("Administrator refusing you: %s", nologin); 122 123 close(fd); 124 login_close(lc); 125 126 return (PAM_AUTH_ERR); 127 } 128 129 PAM_MODULE_ENTRY("pam_nologin"); 130