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/* $NetBSD: perm.c,v 1.4 2016/03/13 00:32:09 dholland Exp $ */
/*
* perm.c - check user permission for at(1)
* Copyright (C) 1994 Thomas Koenig
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author(s) may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* System Headers */
#include <sys/types.h>
#include <errno.h>
#include <pwd.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* Local headers */
#include "at.h"
#include "panic.h"
#include "pathnames.h"
#include "privs.h"
#include "perm.h"
/* File scope variables */
#ifndef lint
#if 0
static char rcsid[] = "$OpenBSD: perm.c,v 1.1 1997/03/01 23:40:12 millert Exp $";
#else
__RCSID("$NetBSD: perm.c,v 1.4 2016/03/13 00:32:09 dholland Exp $");
#endif
#endif
/* Local functions */
static bool
check_for_user(FILE *fp, const char *name)
{
char *buffer;
size_t len;
bool found = false;
len = strlen(name);
if ((buffer = malloc(len + 2)) == NULL)
panic("Insufficient virtual memory");
while (fgets(buffer, (int)len + 2, fp) != NULL) {
if (strncmp(name, buffer, len) == 0 && buffer[len] == '\n') {
found = true;
break;
}
}
(void)fclose(fp);
free(buffer);
return found;
}
/* Global functions */
bool
check_permission(void)
{
FILE *fp;
uid_t uid = geteuid();
struct passwd *pentry;
if (uid == 0)
return true;
if ((pentry = getpwuid(uid)) == NULL) {
perror("Cannot access user database");
exit(EXIT_FAILURE);
}
privs_enter();
fp = fopen(_PATH_AT_ALLOW, "r");
privs_exit();
if (fp != NULL) {
return check_for_user(fp, pentry->pw_name);
} else {
privs_enter();
fp = fopen(_PATH_AT_DENY, "r");
privs_exit();
if (fp != NULL)
return !check_for_user(fp, pentry->pw_name);
}
return false;
}
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