/*-
* Copyright (c) 2009-2011 Robert N. M. Watson
* Copyright (c) 2011 Jonathan Anderson
* All rights reserved.
*
* 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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, WHETHER 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>
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/errno.h>
#include <err.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "cap_test.h"
/*
* Test openat(2) in a variety of sitations to ensure that it obeys Capsicum
* "strict relative" rules:
*
* 1. Use strict relative lookups in capability mode or when operating
* relative to a capability.
* 2. When performing strict relative lookups, absolute paths (including
* symlinks to absolute paths) are not allowed, nor are paths containing
* '..' components.
*/
int
test_relative(void)
{
int success = PASSED;
int fd, etc, etc_cap, etc_cap_ro, etc_cap_base, etc_cap_all;
cap_rights_t baserights = CAP_READ | CAP_WRITE | CAP_SEEK | CAP_LOOKUP;
cap_rights_t rights;
REQUIRE(etc = open("/etc/", O_RDONLY));
CHECK_SYSCALL_SUCCEEDS(cap_getrights, etc, &rights);
CHECK_RIGHTS(rights, CAP_ALL);
MAKE_CAPABILITY(etc_cap, etc, CAP_READ);
MAKE_CAPABILITY(etc_cap_ro, etc, CAP_READ | CAP_LOOKUP);
MAKE_CAPABILITY(etc_cap_base, etc, baserights);
MAKE_CAPABILITY(etc_cap_all, etc, CAP_MASK_VALID);
/*
* openat(2) with regular file descriptors in non-capability mode
* should Just Work (tm).
*/
CHECK_SYSCALL_SUCCEEDS(openat, etc, "/etc/passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, AT_FDCWD, "/etc/passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc, "../etc/passwd", O_RDONLY);
/*
* Lookups relative to capabilities should be strictly relative.
*
* When not in capability mode, we don't actually require CAP_LOOKUP.
*/
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_ro, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_base, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_all, "passwd", O_RDONLY);
CHECK_NOTCAPABLE(openat, etc_cap_ro, "../etc/passwd", O_RDONLY);
CHECK_NOTCAPABLE(openat, etc_cap_base, "../etc/passwd", O_RDONLY);
/*
* This requires discussion: do we treat a capability with
* CAP_MASK_VALID *exactly* like a non-capability file descriptor
* (currently, the implementation says yes)?
*/
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_all, "../etc/passwd", O_RDONLY);
/*
* A file opened relative to a capability should itself be a capability.
*/
CHECK_SYSCALL_SUCCEEDS(cap_getrights, etc_cap_base, &rights);
REQUIRE(fd = openat(etc_cap_base, "passwd", O_RDONLY));
CHECK_SYSCALL_SUCCEEDS(cap_getrights, fd, &rights);
CHECK_RIGHTS(rights, baserights);
/*
* Enter capability mode; now ALL lookups are strictly relative.
*/
REQUIRE(cap_enter());
/*
* Relative lookups on regular files or capabilities with CAP_LOOKUP
* ought to succeed.
*/
CHECK_SYSCALL_SUCCEEDS(openat, etc, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_ro, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_base, "passwd", O_RDONLY);
CHECK_SYSCALL_SUCCEEDS(openat, etc_cap_all, "passwd", O_RDONLY);
/*
* Lookup relative to capabilities without CAP_LOOKUP should fail.
*/
CHECK_NOTCAPABLE(openat, etc_cap, "passwd", O_RDONLY);
/*
* Absolute lookups should fail.
*/
CHECK_CAPMODE(openat, AT_FDCWD, "/etc/passwd", O_RDONLY);
CHECK_NOTCAPABLE(openat, etc, "/etc/passwd", O_RDONLY);
/*
* Lookups containing '..' should fail in capability mode.
*/
CHECK_NOTCAPABLE(openat, etc, "../etc/passwd", O_RDONLY);
CHECK_NOTCAPABLE(openat, etc_cap_ro, "../etc/passwd", O_RDONLY);
CHECK_NOTCAPABLE(openat, etc_cap_base, "../etc/passwd", O_RDONLY);
REQUIRE(fd = openat(etc, "passwd", O_RDONLY));
CHECK_SYSCALL_SUCCEEDS(cap_getrights, fd, &rights);
/*
* A file opened relative to a capability should itself be a capability.
*/
REQUIRE(fd = openat(etc_cap_base, "passwd", O_RDONLY));
CHECK_SYSCALL_SUCCEEDS(cap_getrights, fd, &rights);
CHECK_RIGHTS(rights, baserights);
return success;
}
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