freebsd-nq/usr.bin/at/perm.c
Pedro F. Giffuni 1de7b4b805 various: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:37:16 +00:00

128 lines
2.9 KiB
C

/*-
* perm.c - check user permission for at(1)
*
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/* System Headers */
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* Local headers */
#include "at.h"
#include "perm.h"
#include "privs.h"
/* Macros */
#define MAXUSERID 10
/* Structures and unions */
/* Function declarations */
static int check_for_user(FILE *fp,const char *name);
/* Local functions */
static int check_for_user(FILE *fp,const char *name)
{
char *buffer;
size_t len;
int found = 0;
len = strlen(name);
if ((buffer = malloc(len+2)) == NULL)
errx(EXIT_FAILURE, "virtual memory exhausted");
while(fgets(buffer, len+2, fp) != NULL)
{
if ((strncmp(name, buffer, len) == 0) &&
(buffer[len] == '\n'))
{
found = 1;
break;
}
}
fclose(fp);
free(buffer);
return found;
}
/* Global functions */
int check_permission(void)
{
FILE *fp;
uid_t uid = geteuid();
struct passwd *pentry;
if (uid==0)
return 1;
if ((pentry = getpwuid(uid)) == NULL)
err(EXIT_FAILURE, "cannot access user database");
PRIV_START
fp=fopen(PERM_PATH "at.allow","r");
PRIV_END
if (fp != NULL)
{
return check_for_user(fp, pentry->pw_name);
}
else if (errno == ENOENT)
{
PRIV_START
fp=fopen(PERM_PATH "at.deny", "r");
PRIV_END
if (fp != NULL)
{
return !check_for_user(fp, pentry->pw_name);
}
else if (errno != ENOENT)
warn("at.deny");
}
else
warn("at.allow");
return 0;
}