| /* |
| * JFFS2 -- Journalling Flash File System, Version 2. |
| * |
| * Copyright © 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/sched.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); |
| if (size < 4 * sizeof(struct jffs2_acl_entry_short)) { |
| if (size % sizeof(struct jffs2_acl_entry_short)) |
| return -1; |
| return size / sizeof(struct jffs2_acl_entry_short); |
| } else { |
| s = size - 4 * sizeof(struct jffs2_acl_entry_short); |
| 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_get_acl(struct inode *inode, int type) |
| { |
| struct posix_acl *acl; |
| char *value = NULL; |
| int rc, xprefix; |
| |
| acl = get_cached_acl(inode, type); |
| if (acl != ACL_NOT_CACHED) |
| return acl; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| xprefix = JFFS2_XPREFIX_ACL_ACCESS; |
| break; |
| case ACL_TYPE_DEFAULT: |
| xprefix = JFFS2_XPREFIX_ACL_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| 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)) |
| set_cached_acl(inode, type, acl); |
| return acl; |
| } |
| |
| static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl) |
| { |
| char *value = NULL; |
| size_t size = 0; |
| int rc; |
| |
| 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; |
| kfree(value); |
| |
| return rc; |
| } |
| |
| static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl) |
| { |
| 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) { |
| struct iattr attr; |
| |
| attr.ia_valid = ATTR_MODE | ATTR_CTIME; |
| attr.ia_mode = mode; |
| attr.ia_ctime = CURRENT_TIME_SEC; |
| rc = jffs2_do_setattr(inode, &attr); |
| if (rc < 0) |
| return rc; |
| } |
| 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; |
| } |
| rc = __jffs2_set_acl(inode, xprefix, acl); |
| if (!rc) |
| set_cached_acl(inode, type, acl); |
| return rc; |
| } |
| |
| 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_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode) |
| { |
| struct posix_acl *acl, *clone; |
| int rc; |
| |
| cache_no_acl(inode); |
| |
| if (S_ISLNK(*i_mode)) |
| return 0; /* Symlink always has no-ACL */ |
| |
| acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| |
| if (!acl) { |
| *i_mode &= ~current_umask(); |
| } else { |
| if (S_ISDIR(*i_mode)) |
| set_cached_acl(inode, ACL_TYPE_DEFAULT, acl); |
| |
| clone = posix_acl_clone(acl, GFP_KERNEL); |
| if (!clone) |
| return -ENOMEM; |
| rc = posix_acl_create_masq(clone, (mode_t *)i_mode); |
| if (rc < 0) { |
| posix_acl_release(clone); |
| return rc; |
| } |
| if (rc > 0) |
| set_cached_acl(inode, ACL_TYPE_ACCESS, clone); |
| |
| posix_acl_release(clone); |
| } |
| return 0; |
| } |
| |
| int jffs2_init_acl_post(struct inode *inode) |
| { |
| int rc; |
| |
| if (inode->i_default_acl) { |
| rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl); |
| if (rc) |
| return rc; |
| } |
| |
| if (inode->i_acl) { |
| rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl); |
| if (rc) |
| return rc; |
| } |
| |
| return 0; |
| } |
| |
| 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 dentry *dentry, char *list, |
| size_t list_size, const char *name, size_t name_len, int type) |
| { |
| 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 dentry *dentry, char *list, |
| size_t list_size, const char *name, size_t name_len, int type) |
| { |
| 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 dentry *dentry, const char *name, |
| void *buffer, size_t size, int type) |
| { |
| struct posix_acl *acl; |
| int rc; |
| |
| if (name[0] != '\0') |
| return -EINVAL; |
| |
| acl = jffs2_get_acl(dentry->d_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_setxattr(struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags, int type) |
| { |
| struct posix_acl *acl; |
| int rc; |
| |
| if (name[0] != '\0') |
| return -EINVAL; |
| if (!is_owner_or_cap(dentry->d_inode)) |
| 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(dentry->d_inode, type, acl); |
| out: |
| posix_acl_release(acl); |
| return rc; |
| } |
| |
| struct xattr_handler jffs2_acl_access_xattr_handler = { |
| .prefix = POSIX_ACL_XATTR_ACCESS, |
| .flags = ACL_TYPE_DEFAULT, |
| .list = jffs2_acl_access_listxattr, |
| .get = jffs2_acl_getxattr, |
| .set = jffs2_acl_setxattr, |
| }; |
| |
| struct xattr_handler jffs2_acl_default_xattr_handler = { |
| .prefix = POSIX_ACL_XATTR_DEFAULT, |
| .flags = ACL_TYPE_DEFAULT, |
| .list = jffs2_acl_default_listxattr, |
| .get = jffs2_acl_getxattr, |
| .set = jffs2_acl_setxattr, |
| }; |