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freebsd/sys/netsmb/smb_dev.c
Pawel Jakub Dawidek 7008be5bd7 Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

	struct cap_rights {
		uint64_t	cr_rights[CAP_RIGHTS_VERSION + 2];
	};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

	#define	CAP_PDKILL	CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

	#define	CAP_LOOKUP	CAPRIGHT(0, 0x0000000000000400ULL)
	#define	CAP_FCHMOD	CAPRIGHT(0, 0x0000000000002000ULL)

	#define	CAP_FCHMODAT	(CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

	cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
	void cap_rights_set(cap_rights_t *rights, ...);
	void cap_rights_clear(cap_rights_t *rights, ...);
	bool cap_rights_is_set(const cap_rights_t *rights, ...);

	bool cap_rights_is_valid(const cap_rights_t *rights);
	void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
	void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
	bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

	cap_rights_t rights;

	cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

	#define	cap_rights_set(rights, ...)				\
		__cap_rights_set((rights), __VA_ARGS__, 0ULL)
	void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

	cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by:	The FreeBSD Foundation
2013-09-05 00:09:56 +00:00

415 lines
9.3 KiB
C

/*-
* Copyright (c) 2000-2001 Boris Popov
* 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/capability.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/file.h> /* Must come after sys/malloc.h */
#include <sys/filedesc.h>
#include <sys/mbuf.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <net/if.h>
#include <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>
#include <netsmb/smb_dev.h>
static struct cdev *nsmb_dev;
static d_open_t nsmb_dev_open;
static d_ioctl_t nsmb_dev_ioctl;
MODULE_DEPEND(netsmb, libiconv, 1, 1, 2);
MODULE_VERSION(netsmb, NSMB_VERSION);
static int smb_version = NSMB_VERSION;
struct sx smb_lock;
SYSCTL_DECL(_net_smb);
SYSCTL_INT(_net_smb, OID_AUTO, version, CTLFLAG_RD, &smb_version, 0, "");
static MALLOC_DEFINE(M_NSMBDEV, "NETSMBDEV", "NET/SMB device");
static struct cdevsw nsmb_cdevsw = {
.d_version = D_VERSION,
.d_open = nsmb_dev_open,
.d_ioctl = nsmb_dev_ioctl,
.d_name = NSMB_NAME
};
static int
nsmb_dev_init(void)
{
nsmb_dev = make_dev(&nsmb_cdevsw, 0, UID_ROOT, GID_OPERATOR,
0600, "nsmb");
if (nsmb_dev == NULL)
return (ENOMEM);
return (0);
}
static void
nsmb_dev_destroy(void)
{
MPASS(nsmb_dev != NULL);
destroy_dev(nsmb_dev);
nsmb_dev = NULL;
}
static struct smb_dev *
smbdev_alloc(struct cdev *dev)
{
struct smb_dev *sdp;
sdp = malloc(sizeof(struct smb_dev), M_NSMBDEV, M_WAITOK | M_ZERO);
sdp->dev = dev;
sdp->sd_level = -1;
sdp->sd_flags |= NSMBFL_OPEN;
sdp->refcount = 1;
return (sdp);
}
void
sdp_dtor(void *arg)
{
struct smb_dev *dev;
dev = (struct smb_dev *)arg;
SMB_LOCK();
sdp_trydestroy(dev);
SMB_UNLOCK();
}
static int
nsmb_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct smb_dev *sdp;
int error;
sdp = smbdev_alloc(dev);
error = devfs_set_cdevpriv(sdp, sdp_dtor);
if (error) {
free(sdp, M_NSMBDEV);
return (error);
}
return (0);
}
void
sdp_trydestroy(struct smb_dev *sdp)
{
struct smb_vc *vcp;
struct smb_share *ssp;
struct smb_cred *scred;
SMB_LOCKASSERT();
if (!sdp)
panic("No smb_dev upon device close");
MPASS(sdp->refcount > 0);
sdp->refcount--;
if (sdp->refcount)
return;
scred = malloc(sizeof(struct smb_cred), M_NSMBDEV, M_WAITOK);
smb_makescred(scred, curthread, NULL);
ssp = sdp->sd_share;
if (ssp != NULL) {
smb_share_lock(ssp);
smb_share_rele(ssp, scred);
}
vcp = sdp->sd_vc;
if (vcp != NULL) {
smb_vc_lock(vcp);
smb_vc_rele(vcp, scred);
}
free(scred, M_NSMBDEV);
free(sdp, M_NSMBDEV);
return;
}
static int
nsmb_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct smb_dev *sdp;
struct smb_vc *vcp;
struct smb_share *ssp;
struct smb_cred *scred;
int error = 0;
error = devfs_get_cdevpriv((void **)&sdp);
if (error)
return (error);
scred = malloc(sizeof(struct smb_cred), M_NSMBDEV, M_WAITOK);
SMB_LOCK();
smb_makescred(scred, td, NULL);
switch (cmd) {
case SMBIOC_OPENSESSION:
if (sdp->sd_vc) {
error = EISCONN;
goto out;
}
error = smb_usr_opensession((struct smbioc_ossn*)data,
scred, &vcp);
if (error)
break;
sdp->sd_vc = vcp;
smb_vc_unlock(vcp);
sdp->sd_level = SMBL_VC;
break;
case SMBIOC_OPENSHARE:
if (sdp->sd_share) {
error = EISCONN;
goto out;
}
if (sdp->sd_vc == NULL) {
error = ENOTCONN;
goto out;
}
error = smb_usr_openshare(sdp->sd_vc,
(struct smbioc_oshare*)data, scred, &ssp);
if (error)
break;
sdp->sd_share = ssp;
smb_share_unlock(ssp);
sdp->sd_level = SMBL_SHARE;
break;
case SMBIOC_REQUEST:
if (sdp->sd_share == NULL) {
error = ENOTCONN;
goto out;
}
error = smb_usr_simplerequest(sdp->sd_share,
(struct smbioc_rq*)data, scred);
break;
case SMBIOC_T2RQ:
if (sdp->sd_share == NULL) {
error = ENOTCONN;
goto out;
}
error = smb_usr_t2request(sdp->sd_share,
(struct smbioc_t2rq*)data, scred);
break;
case SMBIOC_SETFLAGS: {
struct smbioc_flags *fl = (struct smbioc_flags*)data;
int on;
if (fl->ioc_level == SMBL_VC) {
if (fl->ioc_mask & SMBV_PERMANENT) {
on = fl->ioc_flags & SMBV_PERMANENT;
if ((vcp = sdp->sd_vc) == NULL) {
error = ENOTCONN;
goto out;
}
error = smb_vc_get(vcp, scred);
if (error)
break;
if (on && (vcp->obj.co_flags & SMBV_PERMANENT) == 0) {
vcp->obj.co_flags |= SMBV_PERMANENT;
smb_vc_ref(vcp);
} else if (!on && (vcp->obj.co_flags & SMBV_PERMANENT)) {
vcp->obj.co_flags &= ~SMBV_PERMANENT;
smb_vc_rele(vcp, scred);
}
smb_vc_put(vcp, scred);
} else
error = EINVAL;
} else if (fl->ioc_level == SMBL_SHARE) {
if (fl->ioc_mask & SMBS_PERMANENT) {
on = fl->ioc_flags & SMBS_PERMANENT;
if ((ssp = sdp->sd_share) == NULL) {
error = ENOTCONN;
goto out;
}
error = smb_share_get(ssp, scred);
if (error)
break;
if (on && (ssp->obj.co_flags & SMBS_PERMANENT) == 0) {
ssp->obj.co_flags |= SMBS_PERMANENT;
smb_share_ref(ssp);
} else if (!on && (ssp->obj.co_flags & SMBS_PERMANENT)) {
ssp->obj.co_flags &= ~SMBS_PERMANENT;
smb_share_rele(ssp, scred);
}
smb_share_put(ssp, scred);
} else
error = EINVAL;
break;
} else
error = EINVAL;
break;
}
case SMBIOC_LOOKUP:
if (sdp->sd_vc || sdp->sd_share) {
error = EISCONN;
goto out;
}
vcp = NULL;
ssp = NULL;
error = smb_usr_lookup((struct smbioc_lookup*)data, scred, &vcp, &ssp);
if (error)
break;
if (vcp) {
sdp->sd_vc = vcp;
smb_vc_unlock(vcp);
sdp->sd_level = SMBL_VC;
}
if (ssp) {
sdp->sd_share = ssp;
smb_share_unlock(ssp);
sdp->sd_level = SMBL_SHARE;
}
break;
case SMBIOC_READ: case SMBIOC_WRITE: {
struct smbioc_rw *rwrq = (struct smbioc_rw*)data;
struct uio auio;
struct iovec iov;
if ((ssp = sdp->sd_share) == NULL) {
error = ENOTCONN;
goto out;
}
iov.iov_base = rwrq->ioc_base;
iov.iov_len = rwrq->ioc_cnt;
auio.uio_iov = &iov;
auio.uio_iovcnt = 1;
auio.uio_offset = rwrq->ioc_offset;
auio.uio_resid = rwrq->ioc_cnt;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_rw = (cmd == SMBIOC_READ) ? UIO_READ : UIO_WRITE;
auio.uio_td = td;
if (cmd == SMBIOC_READ)
error = smb_read(ssp, rwrq->ioc_fh, &auio, scred);
else
error = smb_write(ssp, rwrq->ioc_fh, &auio, scred);
rwrq->ioc_cnt -= auio.uio_resid;
break;
}
default:
error = ENODEV;
}
out:
free(scred, M_NSMBDEV);
SMB_UNLOCK();
return error;
}
static int
nsmb_dev_load(module_t mod, int cmd, void *arg)
{
int error = 0;
switch (cmd) {
case MOD_LOAD:
error = smb_sm_init();
if (error)
break;
error = smb_iod_init();
if (error) {
smb_sm_done();
break;
}
error = nsmb_dev_init();
if (error)
break;
sx_init(&smb_lock, "samba device lock");
break;
case MOD_UNLOAD:
smb_iod_done();
error = smb_sm_done();
if (error)
break;
nsmb_dev_destroy();
sx_destroy(&smb_lock);
break;
default:
error = EINVAL;
break;
}
return error;
}
DEV_MODULE (dev_netsmb, nsmb_dev_load, 0);
int
smb_dev2share(int fd, int mode, struct smb_cred *scred,
struct smb_share **sspp, struct smb_dev **ssdp)
{
cap_rights_t rights;
struct file *fp, *fptmp;
struct smb_dev *sdp;
struct smb_share *ssp;
struct thread *td;
int error;
td = curthread;
error = fget(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
if (error)
return (error);
fptmp = td->td_fpop;
td->td_fpop = fp;
error = devfs_get_cdevpriv((void **)&sdp);
td->td_fpop = fptmp;
fdrop(fp, td);
if (error || sdp == NULL)
return (error);
SMB_LOCK();
*ssdp = sdp;
ssp = sdp->sd_share;
if (ssp == NULL) {
SMB_UNLOCK();
return (ENOTCONN);
}
error = smb_share_get(ssp, scred);
if (error == 0) {
sdp->refcount++;
*sspp = ssp;
}
SMB_UNLOCK();
return error;
}