freebsd-skq/sys/security/mac/mac_posix_shm.c
Konstantin Belousov 940cb0e2bb Implement read(2)/write(2) and neccessary lseek(2) for posix shmfd.
Add MAC framework entries for posix shm read and write.

Do not allow implicit extension of the underlying memory segment past
the limit set by ftruncate(2) by either of the syscalls.  Read and
write returns short i/o, lseek(2) fails with EINVAL when resulting
offset does not fit into the limit.

Discussed with:	alc
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2013-08-21 17:45:00 +00:00

265 lines
7.0 KiB
C

/*-
* Copyright (c) 2003-2006 SPARTA, Inc.
* Copyright (c) 2009-2011 Robert N. M. Watson
* All rights reserved.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS"). *
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* 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>
__FBSDID("$FreeBSD$");
#include "opt_kdtrace.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mman.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sdt.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
static struct label *
mac_posixshm_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(posixshm_init_label, label);
return (label);
}
void
mac_posixshm_init(struct shmfd *shmfd)
{
if (mac_labeled & MPC_OBJECT_POSIXSHM)
shmfd->shm_label = mac_posixshm_label_alloc();
else
shmfd->shm_label = NULL;
}
static void
mac_posixshm_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(posixshm_destroy_label, label);
mac_labelzone_free(label);
}
void
mac_posixshm_destroy(struct shmfd *shmfd)
{
if (shmfd->shm_label != NULL) {
mac_posixshm_label_free(shmfd->shm_label);
shmfd->shm_label = NULL;
}
}
void
mac_posixshm_create(struct ucred *cred, struct shmfd *shmfd)
{
MAC_POLICY_PERFORM_NOSLEEP(posixshm_create, cred, shmfd,
shmfd->shm_label);
}
MAC_CHECK_PROBE_DEFINE2(posixshm_check_create, "struct ucred *",
"const char *");
int
mac_posixshm_check_create(struct ucred *cred, const char *path)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_create, cred, path);
MAC_CHECK_PROBE2(posixshm_check_create, error, cred, path);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(posixshm_check_mmap, "struct ucred *",
"struct shmfd *", "int", "int");
int
mac_posixshm_check_mmap(struct ucred *cred, struct shmfd *shmfd, int prot,
int flags)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_mmap, cred, shmfd,
shmfd->shm_label, prot, flags);
MAC_CHECK_PROBE4(posixshm_check_mmap, error, cred, shmfd, prot,
flags);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_open, "struct ucred *",
"struct shmfd *", "accmode_t accmode");
int
mac_posixshm_check_open(struct ucred *cred, struct shmfd *shmfd,
accmode_t accmode)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_open, cred, shmfd,
shmfd->shm_label, accmode);
MAC_CHECK_PROBE3(posixshm_check_open, error, cred, shmfd, accmode);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_stat, "struct ucred *",
"struct ucred *", "struct shmfd *");
int
mac_posixshm_check_stat(struct ucred *active_cred, struct ucred *file_cred,
struct shmfd *shmfd)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_stat, active_cred, file_cred,
shmfd, shmfd->shm_label);
MAC_CHECK_PROBE3(posixshm_check_stat, error, active_cred, file_cred,
shmfd);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_truncate, "struct ucred *",
"struct ucred *", "struct shmfd *");
int
mac_posixshm_check_truncate(struct ucred *active_cred, struct ucred *file_cred,
struct shmfd *shmfd)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_truncate, active_cred,
file_cred, shmfd, shmfd->shm_label);
MAC_CHECK_PROBE3(posixshm_check_truncate, error, active_cred,
file_cred, shmfd);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(posixshm_check_unlink, "struct ucred *",
"struct shmfd *");
int
mac_posixshm_check_unlink(struct ucred *cred, struct shmfd *shmfd)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_unlink, cred, shmfd,
shmfd->shm_label);
MAC_CHECK_PROBE2(posixshm_check_unlink, error, cred, shmfd);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_setmode, "struct ucred *",
"struct shmfd *", "mode_t");
int
mac_posixshm_check_setmode(struct ucred *cred, struct shmfd *shmfd, mode_t mode)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_setmode, cred, shmfd,
shmfd->shm_label, mode);
MAC_CHECK_PROBE3(posixshm_check_setmode, error, cred, shmfd, mode);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(posixshm_check_setowner, "struct ucred *",
"struct shmfd *", "uid_t", "gid_t");
int
mac_posixshm_check_setowner(struct ucred *cred, struct shmfd *shmfd, uid_t uid,
gid_t gid)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_setowner, cred, shmfd,
shmfd->shm_label, uid, gid);
MAC_CHECK_PROBE4(posixshm_check_setowner, error, cred, shmfd,
uid, gid);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_read, "struct ucred *",
"struct ucred *", "struct shmfd *");
int
mac_posixshm_check_read(struct ucred *active_cred, struct ucred *file_cred,
struct shmfd *shmfd)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_read, active_cred,
file_cred, shmfd, shmfd->shm_label);
MAC_CHECK_PROBE3(posixshm_check_read, error, active_cred,
file_cred, shmfd);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(posixshm_check_write, "struct ucred *",
"struct ucred *", "struct shmfd *");
int
mac_posixshm_check_write(struct ucred *active_cred, struct ucred *file_cred,
struct shmfd *shmfd)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_write, active_cred,
file_cred, shmfd, shmfd->shm_label);
MAC_CHECK_PROBE3(posixshm_check_write, error, active_cred,
file_cred, shmfd);
return (error);
}