/* * 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, };