1 /*- 2 * Copyright (c) 1996 by 3 * Sean Eric Fagan <sef@kithrup.com> 4 * David Nugent <davidn@blaze.net.au> 5 * All rights reserved. 6 * 7 * Portions copyright (c) 1995,1997 by 8 * Berkeley Software Design, Inc. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, is permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice immediately at the beginning of the file, without modification, 16 * 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. This work was done expressly for inclusion into FreeBSD. Other use 21 * is permitted provided this notation is included. 22 * 4. Absolutely no warranty of function or purpose is made by the authors. 23 * 5. Modifications may be freely made to this file providing the above 24 * conditions are met. 25 * 26 * Low-level routines relating to the user capabilities database 27 * 28 * $FreeBSD: head/lib/libutil/login_auth.c 255007 2013-08-28 21:10:37Z jilles $ 29 */ 30 31 #include <sys/types.h> 32 33 #include <fcntl.h> 34 #include <login_cap.h> 35 #include <paths.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 40 41 /* 42 * auth_checknologin() 43 * Checks for the existance of a nologin file in the login_cap 44 * capability <lc>. If there isn't one specified, then it checks 45 * to see if this class should just ignore nologin files. Lastly, 46 * it tries to print out the default nologin file, and, if such 47 * exists, it exits. 48 */ 49 50 void 51 auth_checknologin(login_cap_t *lc) 52 { 53 const char *file; 54 55 /* Do we ignore a nologin file? */ 56 if (login_getcapbool(lc, "ignorenologin", 0)) 57 return; 58 59 /* Note that <file> will be "" if there is no nologin capability */ 60 if ((file = login_getcapstr(lc, "nologin", "", NULL)) == NULL) 61 exit(1); 62 63 /* 64 * *file is true IFF there was a "nologin" capability 65 * Note that auth_cat() returns 1 only if the specified 66 * file exists, and is readable. E.g., /.nologin exists. 67 */ 68 if ((*file && auth_cat(file)) || auth_cat(_PATH_NOLOGIN)) 69 exit(1); 70 } 71 72 73 /* 74 * auth_cat() 75 * Checks for the readability of <file>; if it can be opened for 76 * reading, it prints it out to stdout, and then exits. Otherwise, 77 * it returns 0 (meaning no nologin file). 78 */ 79 80 int 81 auth_cat(const char *file) 82 { 83 int fd, count; 84 char buf[BUFSIZ]; 85 86 if ((fd = open(file, O_RDONLY | O_CLOEXEC)) < 0) 87 return 0; 88 while ((count = read(fd, buf, sizeof(buf))) > 0) 89 (void)write(fileno(stdout), buf, count); 90 close(fd); 91 sleep(5); /* wait an arbitrary time to drain */ 92 return 1; 93 } 94