1 /*- 2 * Copyright 2001 Mark R V Murray 3 * All rights reserved. 4 * Copyright (c) 2001 Networks Associates Technology, Inc. 5 * All rights reserved. 6 * 7 * Portions of this software were developed for the FreeBSD Project by 8 * ThinkSec AS and NAI Labs, the Security Research Division of Network 9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 10 * ("CBOSS"), as part of the DARPA CHATS research program. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. The name of the author may not be used to endorse or promote 21 * products derived from this software without specific prior written 22 * permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $FreeBSD: src/lib/libpam/modules/pam_nologin/pam_nologin.c,v 1.13 2007/06/14 13:07:06 yar Exp $ 37 */ 38 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 #include <fcntl.h> 42 #include <login_cap.h> 43 #include <pwd.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 48 #define PAM_SM_ACCOUNT 49 50 #include <security/pam_appl.h> 51 #include <security/pam_modules.h> 52 #include <security/pam_mod_misc.h> 53 54 #define _PATH_NOLOGIN "/var/run/nologin" 55 56 static char nologin_def[] = _PATH_NOLOGIN; 57 58 PAM_EXTERN int 59 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, 60 int argc __unused, const char *argv[] __unused) 61 { 62 login_cap_t *lc; 63 struct passwd *pwd; 64 struct stat st; 65 int retval, fd; 66 ssize_t ss; 67 const char *user, *nologin; 68 char *mtmp; 69 70 retval = pam_get_user(pamh, &user, NULL); 71 if (retval != PAM_SUCCESS) 72 return (retval); 73 74 PAM_LOG("Got user: %s", user); 75 76 pwd = getpwnam(user); 77 if (pwd == NULL) 78 return (PAM_USER_UNKNOWN); 79 80 /* 81 * login_getpwclass(3) will select the "root" class by default 82 * if pwd->pw_uid is 0. That class should have "ignorenologin" 83 * capability so that super-user can bypass nologin. 84 */ 85 lc = login_getpwclass(pwd); 86 if (lc == NULL) { 87 PAM_LOG("Unable to get login class for user %s", user); 88 return (PAM_SERVICE_ERR); 89 } 90 91 if (login_getcapbool(lc, "ignorenologin", 0)) { 92 login_close(lc); 93 return (PAM_SUCCESS); 94 } 95 96 nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def); 97 98 fd = open(nologin, O_RDONLY, 0); 99 if (fd < 0) { 100 login_close(lc); 101 return (PAM_SUCCESS); 102 } 103 104 PAM_LOG("Opened %s file", nologin); 105 106 if (fstat(fd, &st) == 0) { 107 mtmp = malloc(st.st_size + 1); 108 if (mtmp != NULL) { 109 ss = read(fd, mtmp, st.st_size); 110 if (ss > 0) { 111 mtmp[ss] = '\0'; 112 pam_error(pamh, "%s", mtmp); 113 } 114 free(mtmp); 115 } 116 } 117 118 PAM_VERBOSE_ERROR("Administrator refusing you: %s", nologin); 119 120 close(fd); 121 login_close(lc); 122 123 return (PAM_AUTH_ERR); 124 } 125 126 PAM_MODULE_ENTRY("pam_nologin"); 127