1 /* $NetBSD: perm.c,v 1.2 2000/10/04 19:24:59 mjl Exp $ */ 2 3 /* 4 * perm.c - check user permission for at(1) 5 * Copyright (C) 1994 Thomas Koenig 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. The name of the author(s) may not be used to endorse or promote 13 * products derived from this software without specific prior written 14 * permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* System Headers */ 29 30 #include <sys/types.h> 31 #include <errno.h> 32 #include <pwd.h> 33 #include <stddef.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 /* Local headers */ 40 41 #include "at.h" 42 #include "panic.h" 43 #include "pathnames.h" 44 #include "privs.h" 45 #include "perm.h" 46 47 /* File scope variables */ 48 49 #ifndef lint 50 #if 0 51 static char rcsid[] = "$OpenBSD: perm.c,v 1.1 1997/03/01 23:40:12 millert Exp $"; 52 #else 53 __RCSID("$NetBSD: perm.c,v 1.2 2000/10/04 19:24:59 mjl Exp $"); 54 #endif 55 #endif 56 57 /* Function declarations */ 58 59 static int check_for_user (FILE *, const char *); 60 61 /* Local functions */ 62 63 static int 64 check_for_user(FILE *fp, const char *name) 65 { 66 char *buffer; 67 size_t len; 68 int found = 0; 69 70 len = strlen(name); 71 if ((buffer = malloc(len + 2)) == NULL) 72 panic("Insufficient virtual memory"); 73 74 while (fgets(buffer, len + 2, fp) != NULL) { 75 if (strncmp(name, buffer, len) == 0 && buffer[len] == '\n') { 76 found = 1; 77 break; 78 } 79 } 80 (void)fclose(fp); 81 free(buffer); 82 return (found); 83 } 84 85 86 /* Global functions */ 87 88 int 89 check_permission(void) 90 { 91 FILE *fp; 92 uid_t uid = geteuid(); 93 struct passwd *pentry; 94 95 if (uid==0) 96 return 1; 97 98 if ((pentry = getpwuid(uid)) == NULL) { 99 perror("Cannot access user database"); 100 exit(EXIT_FAILURE); 101 } 102 103 PRIV_START 104 105 fp = fopen(_PATH_AT_ALLOW, "r"); 106 107 PRIV_END 108 109 if (fp != NULL) { 110 return (check_for_user(fp, pentry->pw_name)); 111 } else { 112 PRIV_START 113 114 fp = fopen(_PATH_AT_DENY, "r"); 115 116 PRIV_END 117 118 if (fp != NULL) 119 return (!check_for_user(fp, pentry->pw_name)); 120 } 121 return (0); 122 } 123