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/*
* perm.c - check user permission for at(1)
* Copyright (C) 1994 Thomas Koenig
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/* System Headers */
#include <sys/types.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* Local headers */
#include "privs.h"
#include "at.h"
/* Macros */
#if defined(DEBUG_PERM_C)
#define ETCDIR "../test/etc"
#undef PRIV_START
#define PRIV_START while(0)
#undef PRIV_END
#define PRIV_END while(0)
#endif
/* Structures and unions */
/* File scope variables */
static const char *svnid = "$Id$";
/* Function declarations */
static int user_in_file(const char *path, const char *name);
/* Local functions */
/*
*/
static int
user_in_file(const char *path, const char *name)
{
FILE *fp;
char buffer[256];
int found = 0;
int c = '\n';
PRIV_START;
fp = fopen( path, "r");
PRIV_END;
if ( fp == NULL )
return -1;
while ( !found && fgets(buffer, sizeof(buffer), fp) != NULL) {
size_t llen = strlen(buffer);
c = buffer[llen-1];
if (c == '\n')
buffer[llen-1] = '\0';
while (c != '\n' && c != EOF)
c = fgetc(fp);
found = (strcmp(buffer, name)==0);
}
fclose(fp);
if (c == EOF) {
fprintf(stderr, "%s: incomplete last line.\n", path);
}
return found;
}
/* Global functions */
int
check_permission()
{
uid_t uid = geteuid();
struct passwd *pentry;
int allow = 0, deny = 1;
if (uid == 0)
return 1;
if ((pentry = getpwuid(uid)) == NULL) {
perror("Cannot access user database");
exit(EXIT_FAILURE);
}
allow = user_in_file(ETCDIR "/at.allow", pentry->pw_name);
if (allow==0 || allow==1)
return allow;
/* There was an error while looking for pw_name in at.allow.
* Check at.deny only when at.allow doesn't exist.
*/
deny = user_in_file(ETCDIR "/at.deny", pentry->pw_name);
return deny == 0;
}
#if defined(DEBUG_PERM_C)
int
main(int argc, char *argv[])
{
printf("check_permission() ==> %d\n", check_permission());
return 0;
}
#endif
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