[net-next-2.6.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@kernel.org>
 * 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>

/*
 * 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	*
72c2d582	6	* Integrated into 2.1.97+, Andrew G. Morgan <morgan@kernel.org>
1da177e4 LT	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
1da177e4 LT	17	/*
	18	* This lock protects task->cap_* for all tasks including current.
	19	* Locking rule: acquire this prior to tasklist_lock.
	20	*/
	21	static DEFINE_SPINLOCK(task_capability_lock);
	22
	23	/*
	24	* For sys_getproccap() and sys_setproccap(), any of the three
	25	* capability set pointers may be NULL -- indicating that that set is
	26	* uninteresting and/or not to be changed.
	27	*/
	28
207a7ba8	29	/**
1da177e4	30	* sys_capget - get the capabilities of a given process.
207a7ba8 RD	31	* @header: pointer to struct that contains capability version and
	32	* target pid data
	33	* @dataptr: pointer to struct that contains the effective, permitted,
	34	* and inheritable capabilities that are returned
	35	*
	36	* Returns 0 on success and < 0 on error.
1da177e4 LT	37	*/
	38	asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
	39	{
	40	int ret = 0;
	41	pid_t pid;
	42	__u32 version;
36c8b586	43	struct task_struct *target;
1da177e4 LT	44	struct __user_cap_data_struct data;
	45
	46	if (get_user(version, &header->version))
	47	return -EFAULT;
	48
	49	if (version != _LINUX_CAPABILITY_VERSION) {
	50	if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
	51	return -EFAULT;
	52	return -EINVAL;
	53	}
	54
	55	if (get_user(pid, &header->pid))
	56	return -EFAULT;
	57
	58	if (pid < 0)
	59	return -EINVAL;
	60
	61	spin_lock(&task_capability_lock);
	62	read_lock(&tasklist_lock);
	63
	64	if (pid && pid != current->pid) {
	65	target = find_task_by_pid(pid);
	66	if (!target) {
	67	ret = -ESRCH;
	68	goto out;
	69	}
	70	} else
	71	target = current;
	72
	73	ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
	74
	75	out:
	76	read_unlock(&tasklist_lock);
	77	spin_unlock(&task_capability_lock);
	78
	79	if (!ret && copy_to_user(dataptr, &data, sizeof data))
	80	return -EFAULT;
	81
	82	return ret;
	83	}
	84
	85	/*
	86	* cap_set_pg - set capabilities for all processes in a given process
	87	* group. We call this holding task_capability_lock and tasklist_lock.
	88	*/
41487c65	89	static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
1da177e4 LT	90	kernel_cap_t *inheritable,
	91	kernel_cap_t *permitted)
	92	{
36c8b586	93	struct task_struct g, target;
1da177e4 LT	94	int ret = -EPERM;
1da177e4 LT	95	int found = 0;
41487c65	96	struct pid *pgrp;
1da177e4	97
41487c65 EB	98	pgrp = find_pid(pgrp_nr);
41487c65 EB	99	do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
1da177e4 LT	100	target = g;
	101	while_each_thread(g, target) {
	102	if (!security_capset_check(target, effective,
	103	inheritable,
	104	permitted)) {
	105	security_capset_set(target, effective,
	106	inheritable,
	107	permitted);
	108	ret = 0;
	109	}
	110	found = 1;
	111	}
41487c65	112	} while_each_pid_task(pgrp, PIDTYPE_PGID, g);
1da177e4 LT	113
	114	if (!found)
	115	ret = 0;
	116	return ret;
	117	}
	118
	119	/*
	120	* cap_set_all - set capabilities for all processes other than init
	121	* and self. We call this holding task_capability_lock and tasklist_lock.
	122	*/
	123	static inline int cap_set_all(kernel_cap_t *effective,
	124	kernel_cap_t *inheritable,
	125	kernel_cap_t *permitted)
	126	{
36c8b586	127	struct task_struct g, target;
1da177e4 LT	128	int ret = -EPERM;
	129	int found = 0;
	130
	131	do_each_thread(g, target) {
f400e198	132	if (target == current \|\| is_init(target))
1da177e4 LT	133	continue;
	134	found = 1;
	135	if (security_capset_check(target, effective, inheritable,
	136	permitted))
	137	continue;
	138	ret = 0;
	139	security_capset_set(target, effective, inheritable, permitted);
	140	} while_each_thread(g, target);
	141
	142	if (!found)
	143	ret = 0;
	144	return ret;
	145	}
	146
207a7ba8 RD	147	/**
	148	* sys_capset - set capabilities for a process or a group of processes
	149	* @header: pointer to struct that contains capability version and
	150	* target pid data
	151	* @data: pointer to struct that contains the effective, permitted,
	152	* and inheritable capabilities
	153	*
	154	* Set capabilities for a given process, all processes, or all
1da177e4 LT	155	* processes in a given process group.
	156	*
	157	* The restrictions on setting capabilities are specified as:
	158	*
	159	* [pid is for the 'target' task. 'current' is the calling task.]
	160	*
	161	* I: any raised capabilities must be a subset of the (old current) permitted
	162	* P: any raised capabilities must be a subset of the (old current) permitted
	163	* E: must be set to a subset of (new target) permitted
207a7ba8 RD	164	*
207a7ba8 RD	165	* Returns 0 on success and < 0 on error.
1da177e4 LT	166	*/
	167	asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
	168	{
	169	kernel_cap_t inheritable, permitted, effective;
	170	__u32 version;
36c8b586	171	struct task_struct *target;
1da177e4 LT	172	int ret;
	173	pid_t pid;
	174
	175	if (get_user(version, &header->version))
	176	return -EFAULT;
	177
	178	if (version != _LINUX_CAPABILITY_VERSION) {
	179	if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
	180	return -EFAULT;
	181	return -EINVAL;
	182	}
	183
	184	if (get_user(pid, &header->pid))
	185	return -EFAULT;
	186
	187	if (pid && pid != current->pid && !capable(CAP_SETPCAP))
	188	return -EPERM;
	189
	190	if (copy_from_user(&effective, &data->effective, sizeof(effective)) \|\|
	191	copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) \|\|
	192	copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
	193	return -EFAULT;
	194
	195	spin_lock(&task_capability_lock);
	196	read_lock(&tasklist_lock);
	197
	198	if (pid > 0 && pid != current->pid) {
	199	target = find_task_by_pid(pid);
	200	if (!target) {
	201	ret = -ESRCH;
	202	goto out;
	203	}
	204	} else
	205	target = current;
	206
	207	ret = 0;
	208
	209	/* having verified that the proposed changes are legal,
	210	we now put them into effect. */
	211	if (pid < 0) {
	212	if (pid == -1) /* all procs other than current and init */
	213	ret = cap_set_all(&effective, &inheritable, &permitted);
	214
	215	else /* all procs in process group */
	216	ret = cap_set_pg(-pid, &effective, &inheritable,
	217	&permitted);
	218	} else {
	219	ret = security_capset_check(target, &effective, &inheritable,
	220	&permitted);
	221	if (!ret)
	222	security_capset_set(target, &effective, &inheritable,
	223	&permitted);
	224	}
	225
	226	out:
	227	read_unlock(&tasklist_lock);
	228	spin_unlock(&task_capability_lock);
	229
	230	return ret;
	231	}
12b5989b CW	232
	233	int __capable(struct task_struct *t, int cap)
	234	{
	235	if (security_capable(t, cap) == 0) {
	236	t->flags \|= PF_SUPERPRIV;
	237	return 1;
	238	}
	239	return 0;
	240	}
12b5989b CW	241
	242	int capable(int cap)
	243	{
	244	return __capable(current, cap);
	245	}
	246	EXPORT_SYMBOL(capable);