perm.c revision 7767
142004Sabial/* 242004Sabial * perm.c - check user permission for at(1) 342004Sabial * Copyright (C) 1994 Thomas Koenig 442004Sabial * 542004Sabial * Redistribution and use in source and binary forms, with or without 642004Sabial * modification, are permitted provided that the following conditions 742004Sabial * are met: 842004Sabial * 1. Redistributions of source code must retain the above copyright 942004Sabial * notice, this list of conditions and the following disclaimer. 1042004Sabial * 2. The name of the author(s) may not be used to endorse or promote 1142004Sabial * products derived from this software without specific prior written 1242004Sabial * permission. 1342004Sabial * 1442004Sabial * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 1542004Sabial * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1642004Sabial * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1742004Sabial * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1842004Sabial * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1942004Sabial * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2042004Sabial * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2142004Sabial * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2242004Sabial * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26/* System Headers */ 27 28#include <sys/types.h> 29#include <errno.h> 30#include <pwd.h> 31#include <stddef.h> 32#include <stdio.h> 33#include <stdlib.h> 34#include <string.h> 35#include <unistd.h> 36 37/* Local headers */ 38 39#include "privs.h" 40#include "at.h" 41 42/* Macros */ 43 44#define MAXUSERID 10 45 46/* Structures and unions */ 47 48 49/* File scope variables */ 50 51static char rcsid[] = "$Id: perm.c,v 1.1 1994/05/10 18:23:08 kernel Exp $"; 52 53/* Function declarations */ 54 55static int check_for_user(FILE *fp,const char *name); 56 57/* Local functions */ 58 59static int check_for_user(FILE *fp,const char *name) 60{ 61 char *buffer; 62 size_t len; 63 int found = 0; 64 65 len = strlen(name); 66 buffer = mymalloc(len+2); 67 68 while(fgets(buffer, len+2, fp) != NULL) 69 { 70 if ((strncmp(name, buffer, len) == 0) && 71 (buffer[len] == '\n')) 72 { 73 found = 1; 74 break; 75 } 76 } 77 fclose(fp); 78 free(buffer); 79 return found; 80} 81/* Global functions */ 82int check_permission() 83{ 84 FILE *fp; 85 uid_t uid = geteuid(); 86 struct passwd *pentry; 87 88 if (uid==0) 89 return 1; 90 91 if ((pentry = getpwuid(uid)) == NULL) 92 { 93 perror("Cannot access user database"); 94 exit(EXIT_FAILURE); 95 } 96 97 PRIV_START 98 99 fp=fopen(PERM_PATH "at.allow","r"); 100 101 PRIV_END 102 103 if (fp != NULL) 104 { 105 return check_for_user(fp, pentry->pw_name); 106 } 107 else 108 { 109 110 PRIV_START 111 112 fp=fopen(PERM_PATH "at.deny", "r"); 113 114 PRIV_END 115 116 if (fp != NULL) 117 { 118 return !check_for_user(fp, pentry->pw_name); 119 } 120 perror("at.deny"); 121 } 122 return 0; 123} 124