#include <linux/capability.h> #include <linux/fs.h> #include <linux/posix_acl.h> #include <linux/reiserfs_fs.h> #include <linux/errno.h> #include <linux/pagemap.h> #include <linux/xattr.h> #include <linux/posix_acl_xattr.h> #include <linux/reiserfs_xattr.h> #include <linux/reiserfs_acl.h> #include <asm/uaccess.h> static int reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl); static int xattr_set_acl(struct inode *inode, int type, const void *value, size_t size) { struct posix_acl *acl; int error; if (!reiserfs_posixacl(inode->i_sb)) return -EOPNOTSUPP; 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); } else if (acl) { error = posix_acl_valid(acl); if (error) goto release_and_out; } } else acl = NULL; error = reiserfs_set_acl(inode, type, acl); release_and_out: posix_acl_release(acl); return error; } static int xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size) { struct posix_acl *acl; int error; if (!reiserfs_posixacl(inode->i_sb)) return -EOPNOTSUPP; acl = reiserfs_get_acl(inode, type); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl == NULL) return -ENODATA; error = posix_acl_to_xattr(acl, buffer, size); posix_acl_release(acl); return error; } /* * Convert from filesystem to in-memory representation. */ static struct posix_acl *posix_acl_from_disk(const void *value, size_t size) { const char *end = (char *)value + size; int n, count; struct posix_acl *acl; if (!value) return NULL; if (size < sizeof(reiserfs_acl_header)) return ERR_PTR(-EINVAL); if (((reiserfs_acl_header *) value)->a_version != cpu_to_le32(REISERFS_ACL_VERSION)) return ERR_PTR(-EINVAL); value = (char *)value + sizeof(reiserfs_acl_header); count = reiserfs_acl_count(size); if (count < 0) return ERR_PTR(-EINVAL); if (count == 0) return NULL; acl = posix_acl_alloc(count, GFP_NOFS); if (!acl) return ERR_PTR(-ENOMEM); for (n = 0; n < count; n++) { reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) goto fail; acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: value = (char *)value + sizeof(reiserfs_acl_entry_short); acl->a_entries[n].e_id = ACL_UNDEFINED_ID; break; case ACL_USER: case ACL_GROUP: value = (char *)value + sizeof(reiserfs_acl_entry); if ((char *)value > end) goto fail; acl->a_entries[n].e_id = le32_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); } /* * Convert from in-memory to filesystem representation. */ static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size) { reiserfs_acl_header *ext_acl; char *e; int n; *size = reiserfs_acl_size(acl->a_count); ext_acl = (reiserfs_acl_header *) kmalloc(sizeof(reiserfs_acl_header) + acl->a_count * sizeof(reiserfs_acl_entry), GFP_NOFS); if (!ext_acl) return ERR_PTR(-ENOMEM); ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); e = (char *)ext_acl + sizeof(reiserfs_acl_header); for (n = 0; n < acl->a_count; n++) { reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); switch (acl->a_entries[n].e_tag) { case ACL_USER: case ACL_GROUP: entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); e += sizeof(reiserfs_acl_entry); break; case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: e += sizeof(reiserfs_acl_entry_short); break; default: goto fail; } } return (char *)ext_acl; fail: kfree(ext_acl); return ERR_PTR(-EINVAL); } /* * Inode operation get_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) { char *name, *value; struct posix_acl *acl, **p_acl; size_t size; int retval; struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); switch (type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; p_acl = &reiserfs_i->i_acl_access; break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; p_acl = &reiserfs_i->i_acl_default; break; default: return ERR_PTR(-EINVAL); } if (IS_ERR(*p_acl)) { if (PTR_ERR(*p_acl) == -ENODATA) return NULL; } else if (*p_acl != NULL) return posix_acl_dup(*p_acl); size = reiserfs_xattr_get(inode, name, NULL, 0); if ((int)size < 0) { if (size == -ENODATA || size == -ENOSYS) { *p_acl = ERR_PTR(-ENODATA); return NULL; } return ERR_PTR(size); } value = kmalloc(size, GFP_NOFS); if (!value) return ERR_PTR(-ENOMEM); retval = reiserfs_xattr_get(inode, name, value, size); if (retval == -ENODATA || retval == -ENOSYS) { /* This shouldn't actually happen as it should have been caught above.. but just in case */ acl = NULL; *p_acl = ERR_PTR(-ENODATA); } else if (retval < 0) { acl = ERR_PTR(retval); } else { acl = posix_acl_from_disk(value, retval); *p_acl = posix_acl_dup(acl); } kfree(value); return acl; } /* * Inode operation set_posix_acl(). * * inode->i_mutex: down * BKL held [before 2.5.x] */ static int reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) { char *name; void *value = NULL; struct posix_acl **p_acl; size_t size; int error; struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; switch (type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; p_acl = &reiserfs_i->i_acl_access; if (acl) { mode_t mode = inode->i_mode; error = posix_acl_equiv_mode(acl, &mode); if (error < 0) return error; else { inode->i_mode = mode; if (error == 0) acl = NULL; } } break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; p_acl = &reiserfs_i->i_acl_default; if (!S_ISDIR(inode->i_mode)) return acl ? -EACCES : 0; break; default: return -EINVAL; } if (acl) { value = posix_acl_to_disk(acl, &size); if (IS_ERR(value)) return (int)PTR_ERR(value); error = reiserfs_xattr_set(inode, name, value, size, 0); } else { error = reiserfs_xattr_del(inode, name); if (error == -ENODATA) { /* This may seem odd here, but it means that the ACL was set * with a value representable with mode bits. If there was * an ACL before, reiserfs_xattr_del already dirtied the inode. */ mark_inode_dirty(inode); error = 0; } } kfree(value); if (!error) { /* Release the old one */ if (!IS_ERR(*p_acl) && *p_acl) posix_acl_release(*p_acl); if (acl == NULL) *p_acl = ERR_PTR(-ENODATA); else *p_acl = posix_acl_dup(acl); } return error; } /* dir->i_mutex: locked, * inode is new and not released into the wild yet */ int reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry, struct inode *inode) { struct posix_acl *acl; int err = 0; /* ACLs only get applied to files and directories */ if (S_ISLNK(inode->i_mode)) return 0; /* ACLs can only be used on "new" objects, so if it's an old object * there is nothing to inherit from */ if (get_inode_sd_version(dir) == STAT_DATA_V1) goto apply_umask; /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This * would be useless since permissions are ignored, and a pain because * it introduces locking cycles */ if (is_reiserfs_priv_object(dir)) { reiserfs_mark_inode_private(inode); goto apply_umask; } acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT); if (IS_ERR(acl)) { if (PTR_ERR(acl) == -ENODATA) goto apply_umask; return PTR_ERR(acl); } if (acl) { struct posix_acl *acl_copy; mode_t mode = inode->i_mode; int need_acl; /* Copy the default ACL to the default ACL of a new directory */ if (S_ISDIR(inode->i_mode)) { err = reiserfs_set_acl(inode, ACL_TYPE_DEFAULT, acl); if (err) goto cleanup; } /* Now we reconcile the new ACL and the mode, potentially modifying both */ acl_copy = posix_acl_clone(acl, GFP_NOFS); if (!acl_copy) { err = -ENOMEM; goto cleanup; } need_acl = posix_acl_create_masq(acl_copy, &mode); if (need_acl >= 0) { if (mode != inode->i_mode) { inode->i_mode = mode; } /* If we need an ACL.. */ if (need_acl > 0) { err = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, acl_copy); if (err) goto cleanup_copy; } } cleanup_copy: posix_acl_release(acl_copy); cleanup: posix_acl_release(acl); } else { apply_umask: /* no ACL, apply umask */ inode->i_mode &= ~current->fs->umask; } return err; } /* Looks up and caches the result of the default ACL. * We do this so that we don't need to carry the xattr_sem into * reiserfs_new_inode if we don't need to */ int reiserfs_cache_default_acl(struct inode *inode) { int ret = 0; if (reiserfs_posixacl(inode->i_sb) && !is_reiserfs_priv_object(inode)) { struct posix_acl *acl; reiserfs_read_lock_xattr_i(inode); reiserfs_read_lock_xattrs(inode->i_sb); acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); reiserfs_read_unlock_xattrs(inode->i_sb); reiserfs_read_unlock_xattr_i(inode); ret = acl ? 1 : 0; posix_acl_release(acl); } return ret; } int reiserfs_acl_chmod(struct inode *inode) { struct posix_acl *acl, *clone; int error; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; if (get_inode_sd_version(inode) == STAT_DATA_V1 || !reiserfs_posixacl(inode->i_sb)) { return 0; } reiserfs_read_lock_xattrs(inode->i_sb); acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); reiserfs_read_unlock_xattrs(inode->i_sb); if (!acl) return 0; if (IS_ERR(acl)) return PTR_ERR(acl); clone = posix_acl_clone(acl, GFP_NOFS); posix_acl_release(acl); if (!clone) return -ENOMEM; error = posix_acl_chmod_masq(clone, inode->i_mode); if (!error) { int lock = !has_xattr_dir(inode); reiserfs_write_lock_xattr_i(inode); if (lock) reiserfs_write_lock_xattrs(inode->i_sb); else reiserfs_read_lock_xattrs(inode->i_sb); error = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, clone); if (lock) reiserfs_write_unlock_xattrs(inode->i_sb); else reiserfs_read_unlock_xattrs(inode->i_sb); reiserfs_write_unlock_xattr_i(inode); } posix_acl_release(clone); return error; } static int posix_acl_access_get(struct inode *inode, const char *name, void *buffer, size_t size) { if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) return -EINVAL; return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size); } static int posix_acl_access_set(struct inode *inode, const char *name, const void *value, size_t size, int flags) { if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) return -EINVAL; return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); } static int posix_acl_access_del(struct inode *inode, const char *name) { struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); struct posix_acl **acl = &reiserfs_i->i_acl_access; if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1) return -EINVAL; if (!IS_ERR(*acl) && *acl) { posix_acl_release(*acl); *acl = ERR_PTR(-ENODATA); } return 0; } static int posix_acl_access_list(struct inode *inode, const char *name, int namelen, char *out) { int len = namelen; if (!reiserfs_posixacl(inode->i_sb)) return 0; if (out) memcpy(out, name, len); return len; } struct reiserfs_xattr_handler posix_acl_access_handler = { .prefix = POSIX_ACL_XATTR_ACCESS, .get = posix_acl_access_get, .set = posix_acl_access_set, .del = posix_acl_access_del, .list = posix_acl_access_list, }; static int posix_acl_default_get(struct inode *inode, const char *name, void *buffer, size_t size) { if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) return -EINVAL; return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size); } static int posix_acl_default_set(struct inode *inode, const char *name, const void *value, size_t size, int flags) { if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) return -EINVAL; return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); } static int posix_acl_default_del(struct inode *inode, const char *name) { struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode); struct posix_acl **acl = &reiserfs_i->i_acl_default; if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1) return -EINVAL; if (!IS_ERR(*acl) && *acl) { posix_acl_release(*acl); *acl = ERR_PTR(-ENODATA); } return 0; } static int posix_acl_default_list(struct inode *inode, const char *name, int namelen, char *out) { int len = namelen; if (!reiserfs_posixacl(inode->i_sb)) return 0; if (out) memcpy(out, name, len); return len; } struct reiserfs_xattr_handler posix_acl_default_handler = { .prefix = POSIX_ACL_XATTR_DEFAULT, .get = posix_acl_default_get, .set = posix_acl_default_set, .del = posix_acl_default_del, .list = posix_acl_default_list, };