selinuxfs.c 28.2 KB
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/* Updated: Karl MacMillan <kmacmillan@tresys.com>
 *
 * 	Added conditional policy language extensions
 *
 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *	This program is free software; you can redistribute it and/or modify
 *  	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation, version 2.
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/security.h>
#include <linux/major.h>
#include <linux/seq_file.h>
#include <linux/percpu.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>

/* selinuxfs pseudo filesystem for exporting the security policy API.
   Based on the proc code and the fs/nfsd/nfsctl.c code. */

#include "flask.h"
#include "avc.h"
#include "avc_ss.h"
#include "security.h"
#include "objsec.h"
#include "conditional.h"

unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;

static int __init checkreqprot_setup(char *str)
{
	selinux_checkreqprot = simple_strtoul(str,NULL,0) ? 1 : 0;
	return 1;
}
__setup("checkreqprot=", checkreqprot_setup);


static DECLARE_MUTEX(sel_sem);

/* global data for booleans */
static struct dentry *bool_dir = NULL;
static int bool_num = 0;
static int *bool_pending_values = NULL;

extern void selnl_notify_setenforce(int val);

/* Check whether a task is allowed to use a security operation. */
static int task_has_security(struct task_struct *tsk,
			     u32 perms)
{
	struct task_security_struct *tsec;

	tsec = tsk->security;
	if (!tsec)
		return -EACCES;

	return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
			    SECCLASS_SECURITY, perms, NULL);
}

enum sel_inos {
	SEL_ROOT_INO = 2,
	SEL_LOAD,	/* load policy */
	SEL_ENFORCE,	/* get or set enforcing status */
	SEL_CONTEXT,	/* validate context */
	SEL_ACCESS,	/* compute access decision */
	SEL_CREATE,	/* compute create labeling decision */
	SEL_RELABEL,	/* compute relabeling decision */
	SEL_USER,	/* compute reachable user contexts */
	SEL_POLICYVERS,	/* return policy version for this kernel */
	SEL_COMMIT_BOOLS, /* commit new boolean values */
	SEL_MLS,	/* return if MLS policy is enabled */
	SEL_DISABLE,	/* disable SELinux until next reboot */
	SEL_AVC,	/* AVC management directory */
	SEL_MEMBER,	/* compute polyinstantiation membership decision */
	SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
};

#define TMPBUFLEN	12
static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
				size_t count, loff_t *ppos)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t length;

	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
				 size_t count, loff_t *ppos)

{
	char *page;
	ssize_t length;
	int new_value;

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	if (count >= PAGE_SIZE)
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		return -ENOMEM;
	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}
	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;
	length = -EFAULT;
	if (copy_from_user(page, buf, count))
		goto out;

	length = -EINVAL;
	if (sscanf(page, "%d", &new_value) != 1)
		goto out;

	if (new_value != selinux_enforcing) {
		length = task_has_security(current, SECURITY__SETENFORCE);
		if (length)
			goto out;
		selinux_enforcing = new_value;
		if (selinux_enforcing)
			avc_ss_reset(0);
		selnl_notify_setenforce(selinux_enforcing);
	}
	length = count;
out:
	free_page((unsigned long) page);
	return length;
}
#else
#define sel_write_enforce NULL
#endif

static struct file_operations sel_enforce_ops = {
	.read		= sel_read_enforce,
	.write		= sel_write_enforce,
};

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static ssize_t sel_write_disable(struct file * file, const char __user * buf,
				 size_t count, loff_t *ppos)

{
	char *page;
	ssize_t length;
	int new_value;
	extern int selinux_disable(void);

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	if (count >= PAGE_SIZE)
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		return -ENOMEM;
	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}
	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;
	length = -EFAULT;
	if (copy_from_user(page, buf, count))
		goto out;

	length = -EINVAL;
	if (sscanf(page, "%d", &new_value) != 1)
		goto out;

	if (new_value) {
		length = selinux_disable();
		if (length < 0)
			goto out;
	}

	length = count;
out:
	free_page((unsigned long) page);
	return length;
}
#else
#define sel_write_disable NULL
#endif

static struct file_operations sel_disable_ops = {
	.write		= sel_write_disable,
};

static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
                                   size_t count, loff_t *ppos)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t length;

	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static struct file_operations sel_policyvers_ops = {
	.read		= sel_read_policyvers,
};

/* declaration for sel_write_load */
static int sel_make_bools(void);

static ssize_t sel_read_mls(struct file *filp, char __user *buf,
				size_t count, loff_t *ppos)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t length;

	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static struct file_operations sel_mls_ops = {
	.read		= sel_read_mls,
};

static ssize_t sel_write_load(struct file * file, const char __user * buf,
			      size_t count, loff_t *ppos)

{
	int ret;
	ssize_t length;
	void *data = NULL;

	down(&sel_sem);

	length = task_has_security(current, SECURITY__LOAD_POLICY);
	if (length)
		goto out;

	if (*ppos != 0) {
		/* No partial writes. */
		length = -EINVAL;
		goto out;
	}

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	if ((count > 64 * 1024 * 1024)
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	    || (data = vmalloc(count)) == NULL) {
		length = -ENOMEM;
		goto out;
	}

	length = -EFAULT;
	if (copy_from_user(data, buf, count) != 0)
		goto out;

	length = security_load_policy(data, count);
	if (length)
		goto out;

	ret = sel_make_bools();
	if (ret)
		length = ret;
	else
		length = count;
out:
	up(&sel_sem);
	vfree(data);
	return length;
}

static struct file_operations sel_load_ops = {
	.write		= sel_write_load,
};

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static ssize_t sel_write_context(struct file * file, char *buf, size_t size)
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{
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	char *canon;
	u32 sid, len;
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	ssize_t length;

	length = task_has_security(current, SECURITY__CHECK_CONTEXT);
	if (length)
		return length;

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	length = security_context_to_sid(buf, size, &sid);
	if (length < 0)
		return length;
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	length = security_sid_to_context(sid, &canon, &len);
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	if (length < 0)
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		return length;

	if (len > SIMPLE_TRANSACTION_LIMIT) {
		printk(KERN_ERR "%s:  context size (%u) exceeds payload "
		       "max\n", __FUNCTION__, len);
		length = -ERANGE;
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		goto out;
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	}
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	memcpy(buf, canon, len);
	length = len;
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out:
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	kfree(canon);
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	return length;
}

static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
				     size_t count, loff_t *ppos)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t length;

	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static ssize_t sel_write_checkreqprot(struct file * file, const char __user * buf,
				      size_t count, loff_t *ppos)
{
	char *page;
	ssize_t length;
	unsigned int new_value;

	length = task_has_security(current, SECURITY__SETCHECKREQPROT);
	if (length)
		return length;

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	if (count >= PAGE_SIZE)
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		return -ENOMEM;
	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}
	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;
	length = -EFAULT;
	if (copy_from_user(page, buf, count))
		goto out;

	length = -EINVAL;
	if (sscanf(page, "%u", &new_value) != 1)
		goto out;

	selinux_checkreqprot = new_value ? 1 : 0;
	length = count;
out:
	free_page((unsigned long) page);
	return length;
}
static struct file_operations sel_checkreqprot_ops = {
	.read		= sel_read_checkreqprot,
	.write		= sel_write_checkreqprot,
};

/*
 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 */
static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
static ssize_t sel_write_member(struct file * file, char *buf, size_t size);

static ssize_t (*write_op[])(struct file *, char *, size_t) = {
	[SEL_ACCESS] = sel_write_access,
	[SEL_CREATE] = sel_write_create,
	[SEL_RELABEL] = sel_write_relabel,
	[SEL_USER] = sel_write_user,
	[SEL_MEMBER] = sel_write_member,
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	[SEL_CONTEXT] = sel_write_context,
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};

static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
	ino_t ino =  file->f_dentry->d_inode->i_ino;
	char *data;
	ssize_t rv;

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	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
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		return -EINVAL;

	data = simple_transaction_get(file, buf, size);
	if (IS_ERR(data))
		return PTR_ERR(data);

	rv =  write_op[ino](file, data, size);
	if (rv>0) {
		simple_transaction_set(file, rv);
		rv = size;
	}
	return rv;
}

static struct file_operations transaction_ops = {
	.write		= selinux_transaction_write,
	.read		= simple_transaction_read,
	.release	= simple_transaction_release,
};

/*
 * payload - write methods
 * If the method has a response, the response should be put in buf,
 * and the length returned.  Otherwise return 0 or and -error.
 */

static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
{
	char *scon, *tcon;
	u32 ssid, tsid;
	u16 tclass;
	u32 req;
	struct av_decision avd;
	ssize_t length;

	length = task_has_security(current, SECURITY__COMPUTE_AV);
	if (length)
		return length;

	length = -ENOMEM;
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	scon = kzalloc(size+1, GFP_KERNEL);
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	if (!scon)
		return length;

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	tcon = kzalloc(size+1, GFP_KERNEL);
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	if (!tcon)
		goto out;

	length = -EINVAL;
	if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
		goto out2;

	length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
	if (length < 0)
		goto out2;
	length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
	if (length < 0)
		goto out2;

	length = security_compute_av(ssid, tsid, tclass, req, &avd);
	if (length < 0)
		goto out2;

	length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
			  "%x %x %x %x %u",
			  avd.allowed, avd.decided,
			  avd.auditallow, avd.auditdeny,
			  avd.seqno);
out2:
	kfree(tcon);
out:
	kfree(scon);
	return length;
}

static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
{
	char *scon, *tcon;
	u32 ssid, tsid, newsid;
	u16 tclass;
	ssize_t length;
	char *newcon;
	u32 len;

	length = task_has_security(current, SECURITY__COMPUTE_CREATE);
	if (length)
		return length;

	length = -ENOMEM;
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	scon = kzalloc(size+1, GFP_KERNEL);
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	if (!scon)
		return length;

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	tcon = kzalloc(size+1, GFP_KERNEL);
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	if (!tcon)
		goto out;

	length = -EINVAL;
	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
		goto out2;

	length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
	if (length < 0)
		goto out2;
	length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
	if (length < 0)
		goto out2;

	length = security_transition_sid(ssid, tsid, tclass, &newsid);
	if (length < 0)
		goto out2;

	length = security_sid_to_context(newsid, &newcon, &len);
	if (length < 0)
		goto out2;

	if (len > SIMPLE_TRANSACTION_LIMIT) {
		printk(KERN_ERR "%s:  context size (%u) exceeds payload "
		       "max\n", __FUNCTION__, len);
		length = -ERANGE;
		goto out3;
	}

	memcpy(buf, newcon, len);
	length = len;
out3:
	kfree(newcon);
out2:
	kfree(tcon);
out:
	kfree(scon);
	return length;
}

static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
{
	char *scon, *tcon;
	u32 ssid, tsid, newsid;
	u16 tclass;
	ssize_t length;
	char *newcon;
	u32 len;

	length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
	if (length)
		return length;

	length = -ENOMEM;
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	scon = kzalloc(size+1, GFP_KERNEL);
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	if (!scon)
		return length;

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	tcon = kzalloc(size+1, GFP_KERNEL);
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	if (!tcon)
		goto out;

	length = -EINVAL;
	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
		goto out2;

	length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
	if (length < 0)
		goto out2;
	length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
	if (length < 0)
		goto out2;

	length = security_change_sid(ssid, tsid, tclass, &newsid);
	if (length < 0)
		goto out2;

	length = security_sid_to_context(newsid, &newcon, &len);
	if (length < 0)
		goto out2;

	if (len > SIMPLE_TRANSACTION_LIMIT) {
		length = -ERANGE;
		goto out3;
	}

	memcpy(buf, newcon, len);
	length = len;
out3:
	kfree(newcon);
out2:
	kfree(tcon);
out:
	kfree(scon);
	return length;
}

static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
{
	char *con, *user, *ptr;
	u32 sid, *sids;
	ssize_t length;
	char *newcon;
	int i, rc;
	u32 len, nsids;

	length = task_has_security(current, SECURITY__COMPUTE_USER);
	if (length)
		return length;

	length = -ENOMEM;
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	con = kzalloc(size+1, GFP_KERNEL);
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	if (!con)
		return length;

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	user = kzalloc(size+1, GFP_KERNEL);
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	if (!user)
		goto out;

	length = -EINVAL;
	if (sscanf(buf, "%s %s", con, user) != 2)
		goto out2;

	length = security_context_to_sid(con, strlen(con)+1, &sid);
	if (length < 0)
		goto out2;

	length = security_get_user_sids(sid, user, &sids, &nsids);
	if (length < 0)
		goto out2;

	length = sprintf(buf, "%u", nsids) + 1;
	ptr = buf + length;
	for (i = 0; i < nsids; i++) {
		rc = security_sid_to_context(sids[i], &newcon, &len);
		if (rc) {
			length = rc;
			goto out3;
		}
		if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
			kfree(newcon);
			length = -ERANGE;
			goto out3;
		}
		memcpy(ptr, newcon, len);
		kfree(newcon);
		ptr += len;
		length += len;
	}
out3:
	kfree(sids);
out2:
	kfree(user);
out:
	kfree(con);
	return length;
}

static ssize_t sel_write_member(struct file * file, char *buf, size_t size)
{
	char *scon, *tcon;
	u32 ssid, tsid, newsid;
	u16 tclass;
	ssize_t length;
	char *newcon;
	u32 len;

	length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
	if (length)
		return length;

	length = -ENOMEM;
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	scon = kzalloc(size+1, GFP_KERNEL);
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	if (!scon)
		return length;

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	tcon = kzalloc(size+1, GFP_KERNEL);
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	if (!tcon)
		goto out;

	length = -EINVAL;
	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
		goto out2;

	length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
	if (length < 0)
		goto out2;
	length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
	if (length < 0)
		goto out2;

	length = security_member_sid(ssid, tsid, tclass, &newsid);
	if (length < 0)
		goto out2;

	length = security_sid_to_context(newsid, &newcon, &len);
	if (length < 0)
		goto out2;

	if (len > SIMPLE_TRANSACTION_LIMIT) {
		printk(KERN_ERR "%s:  context size (%u) exceeds payload "
		       "max\n", __FUNCTION__, len);
		length = -ERANGE;
		goto out3;
	}

	memcpy(buf, newcon, len);
	length = len;
out3:
	kfree(newcon);
out2:
	kfree(tcon);
out:
	kfree(scon);
	return length;
}

static struct inode *sel_make_inode(struct super_block *sb, int mode)
{
	struct inode *ret = new_inode(sb);

	if (ret) {
		ret->i_mode = mode;
		ret->i_uid = ret->i_gid = 0;
		ret->i_blksize = PAGE_CACHE_SIZE;
		ret->i_blocks = 0;
		ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
	}
	return ret;
}

#define BOOL_INO_OFFSET 30

static ssize_t sel_read_bool(struct file *filep, char __user *buf,
			     size_t count, loff_t *ppos)
{
	char *page = NULL;
	ssize_t length;
	ssize_t end;
	ssize_t ret;
	int cur_enforcing;
	struct inode *inode;

	down(&sel_sem);

	ret = -EFAULT;

	/* check to see if this file has been deleted */
	if (!filep->f_op)
		goto out;

725
	if (count > PAGE_SIZE) {
L
Linus Torvalds 已提交
726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785
		ret = -EINVAL;
		goto out;
	}
	if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
		ret = -ENOMEM;
		goto out;
	}

	inode = filep->f_dentry->d_inode;
	cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
	if (cur_enforcing < 0) {
		ret = cur_enforcing;
		goto out;
	}

	length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
			  bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
	if (length < 0) {
		ret = length;
		goto out;
	}

	if (*ppos >= length) {
		ret = 0;
		goto out;
	}
	if (count + *ppos > length)
		count = length - *ppos;
	end = count + *ppos;
	if (copy_to_user(buf, (char *) page + *ppos, count)) {
		ret = -EFAULT;
		goto out;
	}
	*ppos = end;
	ret = count;
out:
	up(&sel_sem);
	if (page)
		free_page((unsigned long)page);
	return ret;
}

static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
			      size_t count, loff_t *ppos)
{
	char *page = NULL;
	ssize_t length = -EFAULT;
	int new_value;
	struct inode *inode;

	down(&sel_sem);

	length = task_has_security(current, SECURITY__SETBOOL);
	if (length)
		goto out;

	/* check to see if this file has been deleted */
	if (!filep->f_op)
		goto out;

786
	if (count >= PAGE_SIZE) {
L
Linus Torvalds 已提交
787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
		length = -ENOMEM;
		goto out;
	}
	if (*ppos != 0) {
		/* No partial writes. */
		goto out;
	}
	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page) {
		length = -ENOMEM;
		goto out;
	}

	if (copy_from_user(page, buf, count))
		goto out;

	length = -EINVAL;
	if (sscanf(page, "%d", &new_value) != 1)
		goto out;

	if (new_value)
		new_value = 1;

	inode = filep->f_dentry->d_inode;
	bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
	length = count;

out:
	up(&sel_sem);
	if (page)
		free_page((unsigned long) page);
	return length;
}

static struct file_operations sel_bool_ops = {
	.read           = sel_read_bool,
	.write          = sel_write_bool,
};

static ssize_t sel_commit_bools_write(struct file *filep,
				      const char __user *buf,
				      size_t count, loff_t *ppos)
{
	char *page = NULL;
	ssize_t length = -EFAULT;
	int new_value;

	down(&sel_sem);

	length = task_has_security(current, SECURITY__SETBOOL);
	if (length)
		goto out;

	/* check to see if this file has been deleted */
	if (!filep->f_op)
		goto out;

844
	if (count >= PAGE_SIZE) {
L
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		length = -ENOMEM;
		goto out;
	}
	if (*ppos != 0) {
		/* No partial writes. */
		goto out;
	}
	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page) {
		length = -ENOMEM;
		goto out;
	}

	if (copy_from_user(page, buf, count))
		goto out;

	length = -EINVAL;
	if (sscanf(page, "%d", &new_value) != 1)
		goto out;

865
	if (new_value && bool_pending_values) {
L
Linus Torvalds 已提交
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		security_set_bools(bool_num, bool_pending_values);
	}

	length = count;

out:
	up(&sel_sem);
	if (page)
		free_page((unsigned long) page);
	return length;
}

static struct file_operations sel_commit_bools_ops = {
	.write          = sel_commit_bools_write,
};

/* delete booleans - partial revoke() from
 * fs/proc/generic.c proc_kill_inodes */
static void sel_remove_bools(struct dentry *de)
{
	struct list_head *p, *node;
	struct super_block *sb = de->d_sb;

	spin_lock(&dcache_lock);
	node = de->d_subdirs.next;
	while (node != &de->d_subdirs) {
E
Eric Dumazet 已提交
892
		struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
L
Linus Torvalds 已提交
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909
		list_del_init(node);

		if (d->d_inode) {
			d = dget_locked(d);
			spin_unlock(&dcache_lock);
			d_delete(d);
			simple_unlink(de->d_inode, d);
			dput(d);
			spin_lock(&dcache_lock);
		}
		node = de->d_subdirs.next;
	}

	spin_unlock(&dcache_lock);

	file_list_lock();
	list_for_each(p, &sb->s_files) {
E
Eric Dumazet 已提交
910
		struct file * filp = list_entry(p, struct file, f_u.fu_list);
L
Linus Torvalds 已提交
911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
		struct dentry * dentry = filp->f_dentry;

		if (dentry->d_parent != de) {
			continue;
		}
		filp->f_op = NULL;
	}
	file_list_unlock();
}

#define BOOL_DIR_NAME "booleans"

static int sel_make_bools(void)
{
	int i, ret = 0;
	ssize_t len;
	struct dentry *dentry = NULL;
	struct dentry *dir = bool_dir;
	struct inode *inode = NULL;
	struct inode_security_struct *isec;
	char **names = NULL, *page;
	int num;
	int *values = NULL;
	u32 sid;

	/* remove any existing files */
J
Jesper Juhl 已提交
937
	kfree(bool_pending_values);
938
	bool_pending_values = NULL;
L
Linus Torvalds 已提交
939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982

	sel_remove_bools(dir);

	if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
		return -ENOMEM;

	ret = security_get_bools(&num, &names, &values);
	if (ret != 0)
		goto out;

	for (i = 0; i < num; i++) {
		dentry = d_alloc_name(dir, names[i]);
		if (!dentry) {
			ret = -ENOMEM;
			goto err;
		}
		inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
		if (!inode) {
			ret = -ENOMEM;
			goto err;
		}

		len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
		if (len < 0) {
			ret = -EINVAL;
			goto err;
		} else if (len >= PAGE_SIZE) {
			ret = -ENAMETOOLONG;
			goto err;
		}
		isec = (struct inode_security_struct*)inode->i_security;
		if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
			goto err;
		isec->sid = sid;
		isec->initialized = 1;
		inode->i_fop = &sel_bool_ops;
		inode->i_ino = i + BOOL_INO_OFFSET;
		d_add(dentry, inode);
	}
	bool_num = num;
	bool_pending_values = values;
out:
	free_page((unsigned long)page);
	if (names) {
J
Jesper Juhl 已提交
983 984
		for (i = 0; i < num; i++)
			kfree(names[i]);
L
Linus Torvalds 已提交
985 986 987 988
		kfree(names);
	}
	return ret;
err:
989
	kfree(values);
L
Linus Torvalds 已提交
990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017
	d_genocide(dir);
	ret = -ENOMEM;
	goto out;
}

#define NULL_FILE_NAME "null"

struct dentry *selinux_null = NULL;

static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
					    size_t count, loff_t *ppos)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t length;

	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static ssize_t sel_write_avc_cache_threshold(struct file * file,
					     const char __user * buf,
					     size_t count, loff_t *ppos)

{
	char *page;
	ssize_t ret;
	int new_value;

1018
	if (count >= PAGE_SIZE) {
L
Linus Torvalds 已提交
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
		ret = -ENOMEM;
		goto out;
	}

	if (*ppos != 0) {
		/* No partial writes. */
		ret = -EINVAL;
		goto out;
	}

	page = (char*)get_zeroed_page(GFP_KERNEL);
	if (!page) {
		ret = -ENOMEM;
		goto out;
	}

	if (copy_from_user(page, buf, count)) {
		ret = -EFAULT;
		goto out_free;
	}

	if (sscanf(page, "%u", &new_value) != 1) {
		ret = -EINVAL;
		goto out;
	}

	if (new_value != avc_cache_threshold) {
		ret = task_has_security(current, SECURITY__SETSECPARAM);
		if (ret)
			goto out_free;
		avc_cache_threshold = new_value;
	}
	ret = count;
out_free:
	free_page((unsigned long)page);
out:
	return ret;
}

static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
				       size_t count, loff_t *ppos)
{
	char *page;
	ssize_t ret = 0;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (!page) {
		ret = -ENOMEM;
		goto out;
	}
	ret = avc_get_hash_stats(page);
	if (ret >= 0)
		ret = simple_read_from_buffer(buf, count, ppos, page, ret);
	free_page((unsigned long)page);
out:
	return ret;
}

static struct file_operations sel_avc_cache_threshold_ops = {
	.read		= sel_read_avc_cache_threshold,
	.write		= sel_write_avc_cache_threshold,
};

static struct file_operations sel_avc_hash_stats_ops = {
	.read		= sel_read_avc_hash_stats,
};

#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
{
	int cpu;

	for (cpu = *idx; cpu < NR_CPUS; ++cpu) {
		if (!cpu_possible(cpu))
			continue;
		*idx = cpu + 1;
		return &per_cpu(avc_cache_stats, cpu);
	}
	return NULL;
}

static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
{
	loff_t n = *pos - 1;

	if (*pos == 0)
		return SEQ_START_TOKEN;

	return sel_avc_get_stat_idx(&n);
}

static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return sel_avc_get_stat_idx(pos);
}

static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
{
	struct avc_cache_stats *st = v;

	if (v == SEQ_START_TOKEN)
		seq_printf(seq, "lookups hits misses allocations reclaims "
			   "frees\n");
	else
		seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
			   st->hits, st->misses, st->allocations,
			   st->reclaims, st->frees);
	return 0;
}

static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
{ }

static struct seq_operations sel_avc_cache_stats_seq_ops = {
	.start		= sel_avc_stats_seq_start,
	.next		= sel_avc_stats_seq_next,
	.show		= sel_avc_stats_seq_show,
	.stop		= sel_avc_stats_seq_stop,
};

static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
{
	return seq_open(file, &sel_avc_cache_stats_seq_ops);
}

static struct file_operations sel_avc_cache_stats_ops = {
	.open		= sel_open_avc_cache_stats,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
#endif

static int sel_make_avc_files(struct dentry *dir)
{
	int i, ret = 0;
	static struct tree_descr files[] = {
		{ "cache_threshold",
		  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
		{ "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
		{ "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
#endif
	};

1164
	for (i = 0; i < ARRAY_SIZE(files); i++) {
L
Linus Torvalds 已提交
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
		struct inode *inode;
		struct dentry *dentry;

		dentry = d_alloc_name(dir, files[i].name);
		if (!dentry) {
			ret = -ENOMEM;
			goto err;
		}

		inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
		if (!inode) {
			ret = -ENOMEM;
			goto err;
		}
		inode->i_fop = files[i].ops;
		d_add(dentry, inode);
	}
out:
	return ret;
err:
	d_genocide(dir);
	goto out;
}

static int sel_make_dir(struct super_block *sb, struct dentry *dentry)
{
	int ret = 0;
	struct inode *inode;

	inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
	if (!inode) {
		ret = -ENOMEM;
		goto out;
	}
	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	d_add(dentry, inode);
out:
	return ret;
}

static int sel_fill_super(struct super_block * sb, void * data, int silent)
{
	int ret;
	struct dentry *dentry;
	struct inode *inode;
	struct inode_security_struct *isec;

	static struct tree_descr selinux_files[] = {
		[SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
		[SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1216
		[SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
L
Linus Torvalds 已提交
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
		[SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
		[SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
		[SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
		[SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
		[SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
		[SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
		[SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
		[SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
		[SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
		[SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
		/* last one */ {""}
	};
	ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
	if (ret)
		return ret;

	dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
	if (!dentry)
		return -ENOMEM;

	inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
	if (!inode)
		goto out;
	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	d_add(dentry, inode);
	bool_dir = dentry;
	ret = sel_make_bools();
	if (ret)
		goto out;

	dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
	if (!dentry)
		return -ENOMEM;

	inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
	if (!inode)
		goto out;
	isec = (struct inode_security_struct*)inode->i_security;
	isec->sid = SECINITSID_DEVNULL;
	isec->sclass = SECCLASS_CHR_FILE;
	isec->initialized = 1;

	init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
	d_add(dentry, inode);
	selinux_null = dentry;

	dentry = d_alloc_name(sb->s_root, "avc");
	if (!dentry)
		return -ENOMEM;

	ret = sel_make_dir(sb, dentry);
	if (ret)
		goto out;

	ret = sel_make_avc_files(dentry);
	if (ret)
		goto out;

	return 0;
out:
	dput(dentry);
	printk(KERN_ERR "%s:  failed while creating inodes\n", __FUNCTION__);
	return -ENOMEM;
}

static struct super_block *sel_get_sb(struct file_system_type *fs_type,
				      int flags, const char *dev_name, void *data)
{
	return get_sb_single(fs_type, flags, data, sel_fill_super);
}

static struct file_system_type sel_fs_type = {
	.name		= "selinuxfs",
	.get_sb		= sel_get_sb,
	.kill_sb	= kill_litter_super,
};

struct vfsmount *selinuxfs_mount;

static int __init init_sel_fs(void)
{
	int err;

	if (!selinux_enabled)
		return 0;
	err = register_filesystem(&sel_fs_type);
	if (!err) {
		selinuxfs_mount = kern_mount(&sel_fs_type);
		if (IS_ERR(selinuxfs_mount)) {
			printk(KERN_ERR "selinuxfs:  could not mount!\n");
			err = PTR_ERR(selinuxfs_mount);
			selinuxfs_mount = NULL;
		}
	}
	return err;
}

__initcall(init_sel_fs);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
void exit_sel_fs(void)
{
	unregister_filesystem(&sel_fs_type);
}
#endif