X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fjffs2%2Facl.c;fp=fs%2Fjffs2%2Facl.c;h=0ae3cd10702c06be9b14203872ba6cfe110f0ecb;hb=f05f9504c50ed069377d37f02f22e7a16b5921de;hp=0000000000000000000000000000000000000000;hpb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;p=linux-2.6.git

diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
new file mode 100644
index 000000000..0ae3cd107
--- /dev/null
+++ b/fs/jffs2/acl.c
@@ -0,0 +1,485 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2006  NEC Corporation
+ *
+ * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this 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(struct jffs2_acl_header)
+		       + count * sizeof(struct jffs2_acl_entry_short);
+	} else {
+		return sizeof(struct jffs2_acl_header)
+		       + 4 * sizeof(struct jffs2_acl_entry_short)
+		       + (count - 4) * sizeof(struct jffs2_acl_entry);
+	}
+}
+
+static int jffs2_acl_count(size_t size)
+{
+	size_t s;
+
+	size -= sizeof(struct jffs2_acl_header);
+	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
+	if (s < 0) {
+		if (size % sizeof(struct jffs2_acl_entry_short))
+			return -1;
+		return size / sizeof(struct jffs2_acl_entry_short);
+	} else {
+		if (s % sizeof(struct jffs2_acl_entry))
+			return -1;
+		return s / sizeof(struct jffs2_acl_entry) + 4;
+	}
+}
+
+static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
+{
+	void *end = value + size;
+	struct jffs2_acl_header *header = value;
+	struct jffs2_acl_entry *entry;
+	struct posix_acl *acl;
+	uint32_t ver;
+	int i, count;
+
+	if (!value)
+		return NULL;
+	if (size < sizeof(struct jffs2_acl_header))
+		return ERR_PTR(-EINVAL);
+	ver = je32_to_cpu(header->a_version);
+	if (ver != JFFS2_ACL_VERSION) {
+		JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
+		return ERR_PTR(-EINVAL);
+	}
+
+	value += sizeof(struct 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++) {
+		entry = value;
+		if (value + sizeof(struct 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 += sizeof(struct jffs2_acl_entry_short);
+				acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
+				break;
+
+			case ACL_USER:
+			case ACL_GROUP:
+				value += sizeof(struct jffs2_acl_entry);
+				if (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)
+{
+	struct jffs2_acl_header *header;
+	struct jffs2_acl_entry *entry;
+	void *e;
+	size_t i;
+
+	*size = jffs2_acl_size(acl->a_count);
+	header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
+	if (!header)
+		return ERR_PTR(-ENOMEM);
+	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
+	e = header + 1;
+	for (i=0; i < acl->a_count; i++) {
+		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(struct jffs2_acl_entry);
+				break;
+
+			case ACL_USER_OBJ:
+			case ACL_GROUP_OBJ:
+			case ACL_MASK:
+			case ACL_OTHER:
+				e += sizeof(struct jffs2_acl_entry_short);
+				break;
+
+			default:
+				goto fail;
+		}
+	}
+	return header;
+ fail:
+	kfree(header);
+	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 && rc == -ENODATA)
+		rc = 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 jffs2_inode_info *f)
+{
+	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,
+};