d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
f0ea3689a9
freebsd-dev/sys/dev/ipmi/ipmi_linux.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

117 lines
4.1 KiB
C
Raw Blame History

/*-
* Copyright (c) 2009 IronPort Systems Inc. <ambrisko@ironport.com>
* 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("$FreeBSD$");
/*
* Linux ioctl handler for the ipmi device driver
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capability.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/file.h>
#include <sys/proc.h>
#ifdef __amd64__
#include <machine/../linux32/linux.h>
#include <machine/../linux32/linux32_proto.h>
#else
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#endif
#include <compat/linux/linux_ioctl.h>
#include <sys/ioccom.h>
#include <sys/ipmi.h>
/* There are multiple ioctl number ranges that need to be handled */
#define IPMI_LINUX_IOCTL_MIN 0x690b
#define IPMI_LINUX_IOCTL_MAX 0x6915
/* Linux versions of ioctl's */
#define L_IPMICTL_RECEIVE_MSG_TRUNC _IOWR(IPMI_IOC_MAGIC, 11, struct ipmi_recv)
#define L_IPMICTL_RECEIVE_MSG _IOWR(IPMI_IOC_MAGIC, 12, struct ipmi_recv)
#define L_IPMICTL_SEND_COMMAND _IOW(IPMI_IOC_MAGIC, 13, struct ipmi_req)
#define L_IPMICTL_REGISTER_FOR_CMD _IOW(IPMI_IOC_MAGIC, 14, struct ipmi_cmdspec)
#define L_IPMICTL_UNREGISTER_FOR_CMD _IOW(IPMI_IOC_MAGIC, 15, struct ipmi_cmdspec)
#define L_IPMICTL_SET_GETS_EVENTS_CMD _IOW(IPMI_IOC_MAGIC, 16, int)
#define L_IPMICTL_SET_MY_ADDRESS_CMD _IOW(IPMI_IOC_MAGIC, 17, unsigned int)
#define L_IPMICTL_GET_MY_ADDRESS_CMD _IOW(IPMI_IOC_MAGIC, 18, unsigned int)
#define L_IPMICTL_SET_MY_LUN_CMD _IOW(IPMI_IOC_MAGIC, 19, unsigned int)
#define L_IPMICTL_GET_MY_LUN_CMD _IOW(IPMI_IOC_MAGIC, 20, unsigned int)
static linux_ioctl_function_t ipmi_linux_ioctl;
static struct linux_ioctl_handler ipmi_linux_handler = {ipmi_linux_ioctl,
IPMI_LINUX_IOCTL_MIN,
IPMI_LINUX_IOCTL_MAX};
SYSINIT (ipmi_linux_register, SI_SUB_KLD, SI_ORDER_MIDDLE,
linux_ioctl_register_handler, &ipmi_linux_handler);
SYSUNINIT(ipmi_linux_unregister, SI_SUB_KLD, SI_ORDER_MIDDLE,
linux_ioctl_unregister_handler, &ipmi_linux_handler);
static int
ipmi_linux_modevent(module_t mod, int type, void *data)
{
/* Do we care about any specific load/unload actions? */
return (0);
}
DEV_MODULE(ipmi_linux, ipmi_linux_modevent, NULL);
MODULE_DEPEND(ipmi_linux, linux, 1, 1, 1);
static int
ipmi_linux_ioctl(struct thread *td, struct linux_ioctl_args *args)
{
cap_rights_t rights;
struct file *fp;
u_long cmd;
int error;
error = fget(td, args->fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
if (error != 0)
return (error);
cmd = args->cmd;
switch(cmd) {
case L_IPMICTL_GET_MY_ADDRESS_CMD:
cmd = IPMICTL_GET_MY_ADDRESS_CMD;
break;
case L_IPMICTL_GET_MY_LUN_CMD:
cmd = IPMICTL_GET_MY_LUN_CMD;
break;
}
/*
* Pass the ioctl off to our standard handler.
*/
error = (fo_ioctl(fp, cmd, (caddr_t)args->arg, td->td_ucred, td));
fdrop(fp, td);
return (error);
}
Reference in New Issue View Git Blame Copy Permalink