[mirror_ubuntu-bionic-kernel.git] / fs / jffs2 / acl.c

/*-------------------------------------------------------------------------*
 *  File: fs/jffs2/acl.c
 *  POSIX ACL support on JFFS2 FileSystem
 *
 *  Implemented by KaiGai Kohei <kaigai@ak.jp.nec.com>
 *  Copyright (C) 2006 NEC Corporation
 *
 *  For licensing information, see the file 'LICENCE' in the jffs2 directory.
 *-------------------------------------------------------------------------*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/mtd/mtd.h>
#include "nodelist.h"

static size_t jffs2_acl_size(int count)
{
	if (count <= 4) {
		return sizeof(jffs2_acl_header)
		       + count * sizeof(jffs2_acl_entry_short);
	} else {
		return sizeof(jffs2_acl_header)
		       + 4 * sizeof(jffs2_acl_entry_short)
		       + (count - 4) * sizeof(jffs2_acl_entry);
	}
}

static int jffs2_acl_count(size_t size)
{
	size_t s;

	size -= sizeof(jffs2_acl_header);
	s = size - 4 * sizeof(jffs2_acl_entry_short);
	if (s < 0) {
		if (size % sizeof(jffs2_acl_entry_short))
			return -1;
		return size / sizeof(jffs2_acl_entry_short);
	} else {
		if (s % sizeof(jffs2_acl_entry))
			return -1;
		return s / sizeof(jffs2_acl_entry) + 4;
	}
}

static struct posix_acl *jffs2_acl_from_medium(const void *value, size_t size)
{
	const char *end = (char *)value + size;
	struct posix_acl *acl;
	uint32_t ver;
	int i, count;

	if (!value)
		return NULL;
	if (size < sizeof(jffs2_acl_header))
		return ERR_PTR(-EINVAL);
	ver = je32_to_cpu(((jffs2_acl_header *)value)->a_version);
	if (ver != JFFS2_ACL_VERSION) {
		JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
		return ERR_PTR(-EINVAL);
	}

	value = (char *)value + sizeof(jffs2_acl_header);
	count = jffs2_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;

	acl = posix_acl_alloc(count, GFP_KERNEL);
	if (!acl)
		return ERR_PTR(-ENOMEM);

	for (i=0; i < count; i++) {
		jffs2_acl_entry *entry = (jffs2_acl_entry *)value;
		if ((char *)value + sizeof(jffs2_acl_entry_short) > end)
			goto fail;
		acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
		acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
		switch (acl->a_entries[i].e_tag) {
			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				value = (char *)value + sizeof(jffs2_acl_entry_short);
				acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
				break;

			case ACL_USER:
			case ACL_GROUP:
				value = (char *)value + sizeof(jffs2_acl_entry);
				if ((char *)value > end)
					goto fail;
				acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
				break;

			default:
				goto fail;
		}
	}
	if (value != end)
		goto fail;
	return acl;
 fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
{
	jffs2_acl_header *jffs2_acl;
	char *e;
	size_t i;

	*size = jffs2_acl_size(acl->a_count);
	jffs2_acl = (jffs2_acl_header *)kmalloc(sizeof(jffs2_acl_header)
						+ acl->a_count * sizeof(jffs2_acl_entry),
						GFP_KERNEL);
	if (!jffs2_acl)
		return ERR_PTR(-ENOMEM);
	jffs2_acl->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
	e = (char *)jffs2_acl + sizeof(jffs2_acl_header);
	for (i=0; i < acl->a_count; i++) {
		jffs2_acl_entry *entry = (jffs2_acl_entry *)e;
		entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
		entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
		switch(acl->a_entries[i].e_tag) {
			case ACL_USER:
			case ACL_GROUP:
				entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
				e += sizeof(jffs2_acl_entry);
				break;

			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				e += sizeof(jffs2_acl_entry_short);
				break;

			default:
				goto fail;
		}
	}
	return (char *)jffs2_acl;
 fail:
	kfree(jffs2_acl);
	return ERR_PTR(-EINVAL);
}

static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
{
	struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;

	spin_lock(&inode->i_lock);
	if (*i_acl != JFFS2_ACL_NOT_CACHED)
		acl = posix_acl_dup(*i_acl);
	spin_unlock(&inode->i_lock);
	return acl;
}

static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*i_acl != JFFS2_ACL_NOT_CACHED)
		posix_acl_release(*i_acl);
	*i_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl;
	char *value = NULL;
	int rc, xprefix;

	switch (type) {
	case ACL_TYPE_ACCESS:
		acl = jffs2_iget_acl(inode, &f->i_acl_access);
		if (acl != JFFS2_ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		acl = jffs2_iget_acl(inode, &f->i_acl_default);
		if (acl != JFFS2_ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}
	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	if (rc > 0) {
		value = kmalloc(rc, GFP_KERNEL);
		if (!value)
			return ERR_PTR(-ENOMEM);
		rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	}
	if (rc > 0) {
		acl = jffs2_acl_from_medium(value, rc);
	} else if (rc == -ENODATA || rc == -ENOSYS) {
		acl = NULL;
	} else {
		acl = ERR_PTR(rc);
	}
	if (value)
		kfree(value);
	if (!IS_ERR(acl)) {
		switch (type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, acl);
			break;
		}
	}
	return acl;
}

static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	size_t size = 0;
	char *value = NULL;
	int rc, xprefix;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	switch (type) {
	case ACL_TYPE_ACCESS:
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		if (acl) {
			mode_t mode = inode->i_mode;
			rc = posix_acl_equiv_mode(acl, &mode);
			if (rc < 0)
				return rc;
			if (inode->i_mode != mode) {
				inode->i_mode = mode;
				jffs2_dirty_inode(inode);
			}
			if (rc == 0)
				acl = NULL;
		}
		break;
	case ACL_TYPE_DEFAULT:
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;
	default:
		return -EINVAL;
	}
	if (acl) {
		value = jffs2_acl_to_medium(acl, &size);
		if (IS_ERR(value))
			return PTR_ERR(value);
	}

	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
	if (value)
		kfree(value);
	if (!rc) {
		switch(type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, acl);
			break;
		}
	}
	return rc;
}

static int jffs2_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		rc = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return rc;
	}
	return -EAGAIN;
}

int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	return generic_permission(inode, mask, jffs2_check_acl);
}

int jffs2_init_acl(struct inode *inode, struct inode *dir)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl = NULL, *clone;
	mode_t mode;
	int rc = 0;

	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	if (!S_ISLNK(inode->i_mode)) {
		acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (!acl)
			inode->i_mode &= ~current->fs->umask;
	}
	if (acl) {
		if (S_ISDIR(inode->i_mode)) {
			rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
			if (rc)
				goto cleanup;
		}
		clone = posix_acl_clone(acl, GFP_KERNEL);
		rc = -ENOMEM;
		if (!clone)
			goto cleanup;
		mode = inode->i_mode;
		rc = posix_acl_create_masq(clone, &mode);
		if (rc >= 0) {
			inode->i_mode = mode;
			if (rc > 0)
				rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
		}
		posix_acl_release(clone);
	}
 cleanup:
	posix_acl_release(acl);
	return rc;
}

void jffs2_clear_acl(struct inode *inode)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);

	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_access);
		f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	}
	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_default);
		f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	}
}

int jffs2_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int rc;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);
	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;
	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!rc)
		rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	posix_acl_release(clone);
	return rc;
}

static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
					 const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_ACCESS);
	return retlen;
}

static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
					  const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	return retlen;
}

static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl)
		return -ENODATA;
	rc = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return rc;
}

static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
{
	struct posix_acl *acl;
	int rc;

	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (acl) {
			rc = posix_acl_valid(acl);
			if (rc)
				goto out;
		}
	} else {
		acl = NULL;
	}
	rc = jffs2_set_acl(inode, type, acl);
 out:
	posix_acl_release(acl);
	return rc;
}

static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
				     const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
				      const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

struct xattr_handler jffs2_acl_access_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.list	= jffs2_acl_access_listxattr,
	.get	= jffs2_acl_access_getxattr,
	.set	= jffs2_acl_access_setxattr,
};

struct xattr_handler jffs2_acl_default_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.list	= jffs2_acl_default_listxattr,
	.get	= jffs2_acl_default_getxattr,
	.set	= jffs2_acl_default_setxattr,
};
Commit	Line	Data
aa98d7cf KK	1	/-------------------------------------------------------------------------
	2	* File: fs/jffs2/acl.c
	3	* POSIX ACL support on JFFS2 FileSystem
	4	*
	5	* Implemented by KaiGai Kohei <kaigai@ak.jp.nec.com>
	6	* Copyright (C) 2006 NEC Corporation
	7	*
	8	* For licensing information, see the file 'LICENCE' in the jffs2 directory.
	9	-------------------------------------------------------------------------/
	10	#include <linux/kernel.h>
	11	#include <linux/slab.h>
	12	#include <linux/fs.h>
	13	#include <linux/time.h>
	14	#include <linux/crc32.h>
	15	#include <linux/jffs2.h>
	16	#include <linux/xattr.h>
	17	#include <linux/posix_acl_xattr.h>
	18	#include <linux/mtd/mtd.h>
	19	#include "nodelist.h"
	20
	21	static size_t jffs2_acl_size(int count)
	22	{
	23	if (count <= 4) {
	24	return sizeof(jffs2_acl_header)
	25	+ count * sizeof(jffs2_acl_entry_short);
	26	} else {
	27	return sizeof(jffs2_acl_header)
	28	+ 4 * sizeof(jffs2_acl_entry_short)
	29	+ (count - 4) * sizeof(jffs2_acl_entry);
	30	}
	31	}
	32
	33	static int jffs2_acl_count(size_t size)
	34	{
	35	size_t s;
	36
	37	size -= sizeof(jffs2_acl_header);
	38	s = size - 4 * sizeof(jffs2_acl_entry_short);
	39	if (s < 0) {
	40	if (size % sizeof(jffs2_acl_entry_short))
	41	return -1;
	42	return size / sizeof(jffs2_acl_entry_short);
	43	} else {
	44	if (s % sizeof(jffs2_acl_entry))
	45	return -1;
	46	return s / sizeof(jffs2_acl_entry) + 4;
	47	}
	48	}
	49
	50	static struct posix_acl jffs2_acl_from_medium(const void value, size_t size)
	51	{
	52	const char end = (char )value + size;
	53	struct posix_acl *acl;
	54	uint32_t ver;
	55	int i, count;
	56
	57	if (!value)
	58	return NULL;
	59	if (size < sizeof(jffs2_acl_header))
	60	return ERR_PTR(-EINVAL);
	61	ver = je32_to_cpu(((jffs2_acl_header *)value)->a_version);
	62	if (ver != JFFS2_ACL_VERSION) {
	63	JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
	64	return ERR_PTR(-EINVAL);
65	}
66
67	value = (char *)value + sizeof(jffs2_acl_header);
68	count = jffs2_acl_count(size);
69	if (count < 0)
70	return ERR_PTR(-EINVAL);
71	if (count == 0)
72	return NULL;
73
74	acl = posix_acl_alloc(count, GFP_KERNEL);
75	if (!acl)
76	return ERR_PTR(-ENOMEM);
77
78	for (i=0; i < count; i++) {
79	jffs2_acl_entry entry = (jffs2_acl_entry )value;
80	if ((char *)value + sizeof(jffs2_acl_entry_short) > end)
81	goto fail;
82	acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
83	acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
84	switch (acl->a_entries[i].e_tag) {
85	case ACL_USER_OBJ:
86	case ACL_GROUP_OBJ:
87	case ACL_MASK:
88	case ACL_OTHER:
89	value = (char *)value + sizeof(jffs2_acl_entry_short);
90	acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
91	break;
92
93	case ACL_USER:
94	case ACL_GROUP:
95	value = (char *)value + sizeof(jffs2_acl_entry);
96	if ((char *)value > end)
97	goto fail;
98	acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
99	break;
100
101	default:
102	goto fail;
103	}
104	}
105	if (value != end)
106	goto fail;
107	return acl;
108	fail:
109	posix_acl_release(acl);
110	return ERR_PTR(-EINVAL);
111	}
112
113	static void jffs2_acl_to_medium(const struct posix_acl acl, size_t *size)
114	{
115	jffs2_acl_header *jffs2_acl;
116	char *e;
117	size_t i;
118
119	*size = jffs2_acl_size(acl->a_count);
120	jffs2_acl = (jffs2_acl_header *)kmalloc(sizeof(jffs2_acl_header)
121	+ acl->a_count * sizeof(jffs2_acl_entry),
122	GFP_KERNEL);
123	if (!jffs2_acl)
124	return ERR_PTR(-ENOMEM);
125	jffs2_acl->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
126	e = (char *)jffs2_acl + sizeof(jffs2_acl_header);
127	for (i=0; i < acl->a_count; i++) {
128	jffs2_acl_entry entry = (jffs2_acl_entry )e;
129	entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
130	entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
131	switch(acl->a_entries[i].e_tag) {
132	case ACL_USER:
133	case ACL_GROUP:
134	entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
135	e += sizeof(jffs2_acl_entry);
136	break;
137
138	case ACL_USER_OBJ:
139	case ACL_GROUP_OBJ:
140	case ACL_MASK:
141	case ACL_OTHER:
142	e += sizeof(jffs2_acl_entry_short);
143	break;
144
145	default:
146	goto fail;
147	}
148	}
149	return (char *)jffs2_acl;
150	fail:
151	kfree(jffs2_acl);
152	return ERR_PTR(-EINVAL);
153	}
154
155	static struct posix_acl jffs2_iget_acl(struct inode inode, struct posix_acl **i_acl)
156	{
157	struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;
158
159	spin_lock(&inode->i_lock);
160	if (*i_acl != JFFS2_ACL_NOT_CACHED)
161	acl = posix_acl_dup(*i_acl);
162	spin_unlock(&inode->i_lock);
163	return acl;
164	}
165
166	static void jffs2_iset_acl(struct inode inode, struct posix_acl i_acl, struct posix_acl acl)
167	{
168	spin_lock(&inode->i_lock);
169	if (*i_acl != JFFS2_ACL_NOT_CACHED)
170	posix_acl_release(*i_acl);
171	*i_acl = posix_acl_dup(acl);
172	spin_unlock(&inode->i_lock);
173	}
174
175	static struct posix_acl jffs2_get_acl(struct inode inode, int type)
176	{
177	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
178	struct posix_acl *acl;
179	char *value = NULL;
180	int rc, xprefix;
181
182	switch (type) {
183	case ACL_TYPE_ACCESS:
184	acl = jffs2_iget_acl(inode, &f->i_acl_access);
185	if (acl != JFFS2_ACL_NOT_CACHED)
186	return acl;
187	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
188	break;
189	case ACL_TYPE_DEFAULT:
190	acl = jffs2_iget_acl(inode, &f->i_acl_default);
191	if (acl != JFFS2_ACL_NOT_CACHED)
192	return acl;
193	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
194	break;
195	default:
196	return ERR_PTR(-EINVAL);
197	}
198	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
199	if (rc > 0) {
200	value = kmalloc(rc, GFP_KERNEL);
201	if (!value)
202	return ERR_PTR(-ENOMEM);
203	rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
204	}
205	if (rc > 0) {
206	acl = jffs2_acl_from_medium(value, rc);
207	} else if (rc == -ENODATA \|\| rc == -ENOSYS) {
208	acl = NULL;
209	} else {
210	acl = ERR_PTR(rc);
211	}
212	if (value)
213	kfree(value);
214	if (!IS_ERR(acl)) {
215	switch (type) {
216	case ACL_TYPE_ACCESS:
217	jffs2_iset_acl(inode, &f->i_acl_access, acl);
218	break;
219	case ACL_TYPE_DEFAULT:
220	jffs2_iset_acl(inode, &f->i_acl_default, acl);
221	break;
222	}
223	}
224	return acl;
225	}
226
227	static int jffs2_set_acl(struct inode inode, int type, struct posix_acl acl)
228	{
229	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
230	size_t size = 0;
231	char *value = NULL;
232	int rc, xprefix;
233
234	if (S_ISLNK(inode->i_mode))
235	return -EOPNOTSUPP;
236
237	switch (type) {
238	case ACL_TYPE_ACCESS:
239	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
240	if (acl) {
241	mode_t mode = inode->i_mode;
242	rc = posix_acl_equiv_mode(acl, &mode);
243	if (rc < 0)
244	return rc;
245	if (inode->i_mode != mode) {
246	inode->i_mode = mode;
247	jffs2_dirty_inode(inode);
248	}
249	if (rc == 0)
250	acl = NULL;
251	}
252	break;
253	case ACL_TYPE_DEFAULT:
254	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
255	if (!S_ISDIR(inode->i_mode))
256	return acl ? -EACCES : 0;
257	break;
258	default:
259	return -EINVAL;
260	}
261	if (acl) {
262	value = jffs2_acl_to_medium(acl, &size);
263	if (IS_ERR(value))
264	return PTR_ERR(value);
265	}
266
267	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
268	if (value)
269	kfree(value);
270	if (!rc) {
271	switch(type) {
272	case ACL_TYPE_ACCESS:
273	jffs2_iset_acl(inode, &f->i_acl_access, acl);
274	break;
275	case ACL_TYPE_DEFAULT:
276	jffs2_iset_acl(inode, &f->i_acl_default, acl);
277	break;
278	}
279	}
280	return rc;
281	}
282
283	static int jffs2_check_acl(struct inode *inode, int mask)
284	{
285	struct posix_acl *acl;
286	int rc;
287
288	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
289	if (IS_ERR(acl))
290	return PTR_ERR(acl);
291	if (acl) {
292	rc = posix_acl_permission(inode, acl, mask);
293	posix_acl_release(acl);
294	return rc;
295	}
296	return -EAGAIN;
297	}
298
299	int jffs2_permission(struct inode inode, int mask, struct nameidata nd)
300	{
301	return generic_permission(inode, mask, jffs2_check_acl);
302	}
303
304	int jffs2_init_acl(struct inode inode, struct inode dir)
305	{
306	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
307	struct posix_acl acl = NULL, clone;
308	mode_t mode;
309	int rc = 0;
310
311	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
312	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
313	if (!S_ISLNK(inode->i_mode)) {
314	acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
315	if (IS_ERR(acl))
316	return PTR_ERR(acl);
317	if (!acl)
318	inode->i_mode &= ~current->fs->umask;
319	}
320	if (acl) {
321	if (S_ISDIR(inode->i_mode)) {
322	rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
323	if (rc)
324	goto cleanup;
325	}
326	clone = posix_acl_clone(acl, GFP_KERNEL);
327	rc = -ENOMEM;
328	if (!clone)
329	goto cleanup;
330	mode = inode->i_mode;
331	rc = posix_acl_create_masq(clone, &mode);
332	if (rc >= 0) {
333	inode->i_mode = mode;
334	if (rc > 0)
335	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
336	}
337	posix_acl_release(clone);
338	}
339	cleanup:
340	posix_acl_release(acl);
341	return rc;
342	}
343
344	void jffs2_clear_acl(struct inode *inode)
345	{
346	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
347
348	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
349	posix_acl_release(f->i_acl_access);
350	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
351	}
352	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
353	posix_acl_release(f->i_acl_default);
354	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
355	}
356	}
357
358	int jffs2_acl_chmod(struct inode *inode)
359	{
360	struct posix_acl acl, clone;
361	int rc;
362
363	if (S_ISLNK(inode->i_mode))
364	return -EOPNOTSUPP;
365	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
366	if (IS_ERR(acl) \|\| !acl)
367	return PTR_ERR(acl);
368	clone = posix_acl_clone(acl, GFP_KERNEL);
369	posix_acl_release(acl);
370	if (!clone)
371	return -ENOMEM;
372	rc = posix_acl_chmod_masq(clone, inode->i_mode);
373	if (!rc)
374	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
375	posix_acl_release(clone);
376	return rc;
377	}
378
379	static size_t jffs2_acl_access_listxattr(struct inode inode, char list, size_t list_size,
380	const char *name, size_t name_len)
381	{
382	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
383
384	if (list && retlen <= list_size)
385	strcpy(list, POSIX_ACL_XATTR_ACCESS);
386	return retlen;
387	}
388
389	static size_t jffs2_acl_default_listxattr(struct inode inode, char list, size_t list_size,
390	const char *name, size_t name_len)
391	{
392	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
393
394	if (list && retlen <= list_size)
395	strcpy(list, POSIX_ACL_XATTR_DEFAULT);
396	return retlen;
397	}
398
399	static int jffs2_acl_getxattr(struct inode inode, int type, void buffer, size_t size)
400	{
401	struct posix_acl *acl;
402	int rc;
403
404	acl = jffs2_get_acl(inode, type);
405	if (IS_ERR(acl))
406	return PTR_ERR(acl);
407	if (!acl)
408	return -ENODATA;
409	rc = posix_acl_to_xattr(acl, buffer, size);
410	posix_acl_release(acl);
411
412	return rc;
413	}
414
415	static int jffs2_acl_access_getxattr(struct inode inode, const char name, void *buffer, size_t size)
416	{
417	if (name[0] != '\0')
418	return -EINVAL;
419	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
420	}
421
422	static int jffs2_acl_default_getxattr(struct inode inode, const char name, void *buffer, size_t size)
423	{
424	if (name[0] != '\0')
425	return -EINVAL;
426	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
427	}
428
429	static int jffs2_acl_setxattr(struct inode inode, int type, const void value, size_t size)
430	{
431	struct posix_acl *acl;
432	int rc;
433
434	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
435	return -EPERM;
436
437	if (value) {
438	acl = posix_acl_from_xattr(value, size);
439	if (IS_ERR(acl))
440	return PTR_ERR(acl);
441	if (acl) {
442	rc = posix_acl_valid(acl);
443	if (rc)
444	goto out;
445	}
446	} else {
447	acl = NULL;
448	}
449	rc = jffs2_set_acl(inode, type, acl);
450	out:
451	posix_acl_release(acl);
452	return rc;
453	}
454
455	static int jffs2_acl_access_setxattr(struct inode inode, const char name,
456	const void *buffer, size_t size, int flags)
457	{
458	if (name[0] != '\0')
459	return -EINVAL;
460	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
461	}
462
463	static int jffs2_acl_default_setxattr(struct inode inode, const char name,
464	const void *buffer, size_t size, int flags)
465	{
466	if (name[0] != '\0')
467	return -EINVAL;
468	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
469	}
470
471	struct xattr_handler jffs2_acl_access_xattr_handler = {
472	.prefix = POSIX_ACL_XATTR_ACCESS,
473	.list = jffs2_acl_access_listxattr,
474	.get = jffs2_acl_access_getxattr,
475	.set = jffs2_acl_access_setxattr,
476	};
477
478	struct xattr_handler jffs2_acl_default_xattr_handler = {
479	.prefix = POSIX_ACL_XATTR_DEFAULT,
480	.list = jffs2_acl_default_listxattr,
481	.get = jffs2_acl_default_getxattr,
482	.set = jffs2_acl_default_setxattr,
483	};