--- /dev/null
+/*
+ * 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,
+};
git://git.onelab.eu / linux-2.6.git / blobdiff