[thirdparty/linux.git] / kernel / capability.c

/*
 * linux/kernel/capability.c
 *
 * Copyright (C) 1997  Andrew Main <zefram@fysh.org>
 *
 * Integrated into 2.1.97+,  Andrew G. Morgan <morgan@transmeta.com>
 * 30 May 2002:	Cleanup, Robert M. Love <rml@tech9.net>
 */ 

#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>

unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
kernel_cap_t cap_bset = CAP_INIT_EFF_SET;

/*
 * This lock protects task->cap_* for all tasks including current.
 * Locking rule: acquire this prior to tasklist_lock.
 */
static DEFINE_SPINLOCK(task_capability_lock);

/*
 * For sys_getproccap() and sys_setproccap(), any of the three
 * capability set pointers may be NULL -- indicating that that set is
 * uninteresting and/or not to be changed.
 */

/**
 * sys_capget - get the capabilities of a given process.
 * @header: pointer to struct that contains capability version and
 *	target pid data
 * @dataptr: pointer to struct that contains the effective, permitted,
 *	and inheritable capabilities that are returned
 *
 * Returns 0 on success and < 0 on error.
 */
asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
{
     int ret = 0;
     pid_t pid;
     __u32 version;
     struct task_struct *target;
     struct __user_cap_data_struct data;

     if (get_user(version, &header->version))
	     return -EFAULT;

     if (version != _LINUX_CAPABILITY_VERSION) {
	     if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
		     return -EFAULT; 
             return -EINVAL;
     }

     if (get_user(pid, &header->pid))
	     return -EFAULT;

     if (pid < 0) 
             return -EINVAL;

     spin_lock(&task_capability_lock);
     read_lock(&tasklist_lock); 

     if (pid && pid != current->pid) {
	     target = find_task_by_pid(pid);
	     if (!target) {
	          ret = -ESRCH;
	          goto out;
	     }
     } else
	     target = current;

     ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);

out:
     read_unlock(&tasklist_lock); 
     spin_unlock(&task_capability_lock);

     if (!ret && copy_to_user(dataptr, &data, sizeof data))
          return -EFAULT; 

     return ret;
}

/*
 * cap_set_pg - set capabilities for all processes in a given process
 * group.  We call this holding task_capability_lock and tasklist_lock.
 */
static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
			      kernel_cap_t *inheritable,
			      kernel_cap_t *permitted)
{
	struct task_struct *g, *target;
	int ret = -EPERM;
	int found = 0;
	struct pid *pgrp;

	pgrp = find_pid(pgrp_nr);
	do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
		target = g;
		while_each_thread(g, target) {
			if (!security_capset_check(target, effective,
							inheritable,
							permitted)) {
				security_capset_set(target, effective,
							inheritable,
							permitted);
				ret = 0;
			}
			found = 1;
		}
	} while_each_pid_task(pgrp, PIDTYPE_PGID, g);

	if (!found)
	     ret = 0;
	return ret;
}

/*
 * cap_set_all - set capabilities for all processes other than init
 * and self.  We call this holding task_capability_lock and tasklist_lock.
 */
static inline int cap_set_all(kernel_cap_t *effective,
			       kernel_cap_t *inheritable,
			       kernel_cap_t *permitted)
{
     struct task_struct *g, *target;
     int ret = -EPERM;
     int found = 0;

     do_each_thread(g, target) {
             if (target == current || is_init(target))
                     continue;
             found = 1;
	     if (security_capset_check(target, effective, inheritable,
						permitted))
		     continue;
	     ret = 0;
	     security_capset_set(target, effective, inheritable, permitted);
     } while_each_thread(g, target);

     if (!found)
	     ret = 0;
     return ret;
}

/**
 * sys_capset - set capabilities for a process or a group of processes
 * @header: pointer to struct that contains capability version and
 *	target pid data
 * @data: pointer to struct that contains the effective, permitted,
 *	and inheritable capabilities
 *
 * Set capabilities for a given process, all processes, or all
 * processes in a given process group.
 *
 * The restrictions on setting capabilities are specified as:
 *
 * [pid is for the 'target' task.  'current' is the calling task.]
 *
 * I: any raised capabilities must be a subset of the (old current) permitted
 * P: any raised capabilities must be a subset of the (old current) permitted
 * E: must be set to a subset of (new target) permitted
 *
 * Returns 0 on success and < 0 on error.
 */
asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
{
     kernel_cap_t inheritable, permitted, effective;
     __u32 version;
     struct task_struct *target;
     int ret;
     pid_t pid;

     if (get_user(version, &header->version))
	     return -EFAULT; 

     if (version != _LINUX_CAPABILITY_VERSION) {
	     if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
		     return -EFAULT; 
             return -EINVAL;
     }

     if (get_user(pid, &header->pid))
	     return -EFAULT; 

     if (pid && pid != current->pid && !capable(CAP_SETPCAP))
             return -EPERM;

     if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
	 copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
	 copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
	     return -EFAULT; 

     spin_lock(&task_capability_lock);
     read_lock(&tasklist_lock);

     if (pid > 0 && pid != current->pid) {
          target = find_task_by_pid(pid);
          if (!target) {
               ret = -ESRCH;
               goto out;
          }
     } else
               target = current;

     ret = 0;

     /* having verified that the proposed changes are legal,
           we now put them into effect. */
     if (pid < 0) {
             if (pid == -1)  /* all procs other than current and init */
                     ret = cap_set_all(&effective, &inheritable, &permitted);

             else            /* all procs in process group */
                     ret = cap_set_pg(-pid, &effective, &inheritable,
		     					&permitted);
     } else {
	     ret = security_capset_check(target, &effective, &inheritable,
	     						&permitted);
	     if (!ret)
		     security_capset_set(target, &effective, &inheritable,
		     					&permitted);
     }

out:
     read_unlock(&tasklist_lock);
     spin_unlock(&task_capability_lock);

     return ret;
}

int __capable(struct task_struct *t, int cap)
{
	if (security_capable(t, cap) == 0) {
		t->flags |= PF_SUPERPRIV;
		return 1;
	}
	return 0;
}

int capable(int cap)
{
	return __capable(current, cap);
}
EXPORT_SYMBOL(capable);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/kernel/capability.c
	3	*
	4	* Copyright (C) 1997 Andrew Main <zefram@fysh.org>
	5	*
	6	* Integrated into 2.1.97+, Andrew G. Morgan <morgan@transmeta.com>
	7	* 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
	8	*/
	9
c59ede7b	10	#include <linux/capability.h>
1da177e4 LT	11	#include <linux/mm.h>
	12	#include <linux/module.h>
	13	#include <linux/security.h>
	14	#include <linux/syscalls.h>
	15	#include <asm/uaccess.h>
	16
	17	unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
	18	kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
	19
1da177e4 LT	20	/*
	21	* This lock protects task->cap_* for all tasks including current.
	22	* Locking rule: acquire this prior to tasklist_lock.
	23	*/
	24	static DEFINE_SPINLOCK(task_capability_lock);
	25
	26	/*
	27	* For sys_getproccap() and sys_setproccap(), any of the three
	28	* capability set pointers may be NULL -- indicating that that set is
	29	* uninteresting and/or not to be changed.
	30	*/
	31
207a7ba8	32	/**
1da177e4	33	* sys_capget - get the capabilities of a given process.
207a7ba8 RD	34	* @header: pointer to struct that contains capability version and
	35	* target pid data
	36	* @dataptr: pointer to struct that contains the effective, permitted,
	37	* and inheritable capabilities that are returned
	38	*
	39	* Returns 0 on success and < 0 on error.
1da177e4 LT	40	*/
	41	asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
	42	{
	43	int ret = 0;
	44	pid_t pid;
	45	__u32 version;
36c8b586	46	struct task_struct *target;
1da177e4 LT	47	struct __user_cap_data_struct data;
	48
	49	if (get_user(version, &header->version))
	50	return -EFAULT;
	51
	52	if (version != _LINUX_CAPABILITY_VERSION) {
	53	if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
	54	return -EFAULT;
	55	return -EINVAL;
	56	}
	57
	58	if (get_user(pid, &header->pid))
	59	return -EFAULT;
	60
	61	if (pid < 0)
	62	return -EINVAL;
	63
	64	spin_lock(&task_capability_lock);
	65	read_lock(&tasklist_lock);
	66
	67	if (pid && pid != current->pid) {
	68	target = find_task_by_pid(pid);
	69	if (!target) {
	70	ret = -ESRCH;
	71	goto out;
	72	}
	73	} else
	74	target = current;
	75
	76	ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
	77
	78	out:
	79	read_unlock(&tasklist_lock);
	80	spin_unlock(&task_capability_lock);
	81
	82	if (!ret && copy_to_user(dataptr, &data, sizeof data))
	83	return -EFAULT;
	84
	85	return ret;
	86	}
	87
	88	/*
	89	* cap_set_pg - set capabilities for all processes in a given process
	90	* group. We call this holding task_capability_lock and tasklist_lock.
	91	*/
41487c65	92	static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
1da177e4 LT	93	kernel_cap_t *inheritable,
	94	kernel_cap_t *permitted)
	95	{
36c8b586	96	struct task_struct g, target;
1da177e4 LT	97	int ret = -EPERM;
1da177e4 LT	98	int found = 0;
41487c65	99	struct pid *pgrp;
1da177e4	100
41487c65 EB	101	pgrp = find_pid(pgrp_nr);
41487c65 EB	102	do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
1da177e4 LT	103	target = g;
	104	while_each_thread(g, target) {
	105	if (!security_capset_check(target, effective,
	106	inheritable,
	107	permitted)) {
	108	security_capset_set(target, effective,
	109	inheritable,
	110	permitted);
	111	ret = 0;
	112	}
	113	found = 1;
	114	}
41487c65	115	} while_each_pid_task(pgrp, PIDTYPE_PGID, g);
1da177e4 LT	116
	117	if (!found)
	118	ret = 0;
	119	return ret;
	120	}
	121
	122	/*
	123	* cap_set_all - set capabilities for all processes other than init
	124	* and self. We call this holding task_capability_lock and tasklist_lock.
	125	*/
	126	static inline int cap_set_all(kernel_cap_t *effective,
	127	kernel_cap_t *inheritable,
	128	kernel_cap_t *permitted)
	129	{
36c8b586	130	struct task_struct g, target;
1da177e4 LT	131	int ret = -EPERM;
	132	int found = 0;
	133
	134	do_each_thread(g, target) {
f400e198	135	if (target == current \|\| is_init(target))
1da177e4 LT	136	continue;
	137	found = 1;
	138	if (security_capset_check(target, effective, inheritable,
	139	permitted))
	140	continue;
	141	ret = 0;
	142	security_capset_set(target, effective, inheritable, permitted);
	143	} while_each_thread(g, target);
	144
	145	if (!found)
	146	ret = 0;
	147	return ret;
	148	}
	149
207a7ba8 RD	150	/**
	151	* sys_capset - set capabilities for a process or a group of processes
	152	* @header: pointer to struct that contains capability version and
	153	* target pid data
	154	* @data: pointer to struct that contains the effective, permitted,
	155	* and inheritable capabilities
	156	*
	157	* Set capabilities for a given process, all processes, or all
1da177e4 LT	158	* processes in a given process group.
	159	*
	160	* The restrictions on setting capabilities are specified as:
	161	*
	162	* [pid is for the 'target' task. 'current' is the calling task.]
	163	*
	164	* I: any raised capabilities must be a subset of the (old current) permitted
	165	* P: any raised capabilities must be a subset of the (old current) permitted
	166	* E: must be set to a subset of (new target) permitted
207a7ba8 RD	167	*
207a7ba8 RD	168	* Returns 0 on success and < 0 on error.
1da177e4 LT	169	*/
	170	asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
	171	{
	172	kernel_cap_t inheritable, permitted, effective;
	173	__u32 version;
36c8b586	174	struct task_struct *target;
1da177e4 LT	175	int ret;
	176	pid_t pid;
	177
	178	if (get_user(version, &header->version))
	179	return -EFAULT;
	180
	181	if (version != _LINUX_CAPABILITY_VERSION) {
	182	if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
	183	return -EFAULT;
	184	return -EINVAL;
	185	}
	186
	187	if (get_user(pid, &header->pid))
	188	return -EFAULT;
	189
	190	if (pid && pid != current->pid && !capable(CAP_SETPCAP))
	191	return -EPERM;
	192
	193	if (copy_from_user(&effective, &data->effective, sizeof(effective)) \|\|
	194	copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) \|\|
	195	copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
	196	return -EFAULT;
	197
	198	spin_lock(&task_capability_lock);
	199	read_lock(&tasklist_lock);
	200
	201	if (pid > 0 && pid != current->pid) {
	202	target = find_task_by_pid(pid);
	203	if (!target) {
	204	ret = -ESRCH;
	205	goto out;
	206	}
	207	} else
	208	target = current;
	209
	210	ret = 0;
	211
	212	/* having verified that the proposed changes are legal,
	213	we now put them into effect. */
	214	if (pid < 0) {
	215	if (pid == -1) /* all procs other than current and init */
	216	ret = cap_set_all(&effective, &inheritable, &permitted);
	217
	218	else /* all procs in process group */
	219	ret = cap_set_pg(-pid, &effective, &inheritable,
	220	&permitted);
	221	} else {
	222	ret = security_capset_check(target, &effective, &inheritable,
	223	&permitted);
	224	if (!ret)
	225	security_capset_set(target, &effective, &inheritable,
	226	&permitted);
	227	}
	228
	229	out:
	230	read_unlock(&tasklist_lock);
	231	spin_unlock(&task_capability_lock);
	232
	233	return ret;
	234	}
12b5989b CW	235
	236	int __capable(struct task_struct *t, int cap)
	237	{
	238	if (security_capable(t, cap) == 0) {
	239	t->flags \|= PF_SUPERPRIV;
	240	return 1;
	241	}
	242	return 0;
	243	}
12b5989b CW	244
	245	int capable(int cap)
	246	{
	247	return __capable(current, cap);
	248	}
	249	EXPORT_SYMBOL(capable);