diff options
Diffstat (limited to 'Kernel/FileSystem')
| -rw-r--r-- | Kernel/FileSystem/VirtualFileSystem.cpp | 111 |
1 files changed, 50 insertions, 61 deletions
diff --git a/Kernel/FileSystem/VirtualFileSystem.cpp b/Kernel/FileSystem/VirtualFileSystem.cpp index c402a16383..b572af0303 100644 --- a/Kernel/FileSystem/VirtualFileSystem.cpp +++ b/Kernel/FileSystem/VirtualFileSystem.cpp @@ -674,8 +674,6 @@ Custody& VFS::root_custody() KResultOr<NonnullRefPtr<Custody>> VFS::resolve_path(StringView path, Custody& base, RefPtr<Custody>* parent_custody, int options, int symlink_recursion_level) { - // FIXME: resolve_path currently doesn't deal with .. and . . If path is ../. and base is /home/anon, it returns - // /home/anon/../. instead of /home . if (symlink_recursion_level >= symlink_recursion_limit) return KResult(-ELOOP); @@ -683,7 +681,6 @@ KResultOr<NonnullRefPtr<Custody>> VFS::resolve_path(StringView path, Custody& ba return KResult(-EINVAL); auto parts = path.split_view('/', true); - InodeIdentifier crumb_id; auto& current_root = current->process().root_directory(); @@ -691,99 +688,91 @@ KResultOr<NonnullRefPtr<Custody>> VFS::resolve_path(StringView path, Custody& ba if (path[0] == '/') { custody_chain.append(current_root); - crumb_id = current_root.inode().identifier(); } else { for (auto* custody = &base; custody; custody = custody->parent()) { // FIXME: Prepending here is not efficient! Fix this. custody_chain.prepend(*custody); } - crumb_id = base.inode().identifier(); } - if (parent_custody) - *parent_custody = custody_chain.last(); - - int mount_flags = custody_chain.last().mount_flags(); - for (int i = 0; i < parts.size(); ++i) { - bool inode_was_root_at_head_of_loop = current_root.inode().identifier() == crumb_id; - auto crumb_inode = get_inode(crumb_id); - if (!crumb_inode) - return KResult(-EIO); - auto metadata = crumb_inode->metadata(); - if (!metadata.is_directory()) + auto& current_parent = custody_chain.last(); + auto parent_metadata = current_parent.inode().metadata(); + if (!parent_metadata.is_directory()) return KResult(-ENOTDIR); - if (!metadata.may_execute(current->process())) + // Ensure the current user is allowed to resolve paths inside this directory. + if (!parent_metadata.may_execute(current->process())) return KResult(-EACCES); auto& part = parts[i]; - if (part.is_empty()) + bool have_more_parts = i + 1 < parts.size(); + + if (part == "..") { + // If we encounter a "..", take a step back, but don't go beyond the root. + if (custody_chain.size() > 1) + custody_chain.take_last(); continue; + } else if (part == "." || part.is_empty()) { + continue; + } - auto& current_parent = custody_chain.last(); - crumb_id = crumb_inode->lookup(part); - if (!crumb_id.is_valid()) { - if (i != parts.size() - 1) { - // We didn't find the filename we were looking for, - // and we didn't even reach the last path part. - // (ENOENT with non-null parent_custody) signals to caller that + // Okay, let's look up this part. + auto child_id = current_parent.inode().lookup(part); + + if (!child_id.is_valid()) { + if (parent_custody) { + // ENOENT with a non-null parent custody signals to caller that // we found the immediate parent of the file, but the file itself // does not exist yet. - // Since this is not the immediate parent, clear parent_custody. - if (parent_custody) - *parent_custody = nullptr; + *parent_custody = have_more_parts ? nullptr : ¤t_parent; } return KResult(-ENOENT); } - if (auto mount = find_mount_for_host(crumb_id)) { - crumb_id = mount->guest(); - mount_flags = mount->flags(); - } - if (inode_was_root_at_head_of_loop && crumb_id.is_root_inode() && crumb_id != current_root.inode().identifier() && part == "..") { - auto mount = find_mount_for_guest(crumb_id); - auto dir_inode = get_inode(mount->host()); - ASSERT(dir_inode); - crumb_id = dir_inode->lookup(".."); + + int mount_flags_for_child = current_parent.mount_flags(); + // See if there's something mounted on the child; in that case + // we would need to return the guest inode, not the host inode. + if (auto mount = find_mount_for_host(child_id)) { + child_id = mount->guest(); + mount_flags_for_child = mount->flags(); } - crumb_inode = get_inode(crumb_id); - ASSERT(crumb_inode); + auto child_inode = get_inode(child_id); + ASSERT(child_inode); - custody_chain.append(Custody::create(&custody_chain.last(), part, *crumb_inode, mount_flags)); + custody_chain.append(Custody::create(¤t_parent, part, *child_inode, mount_flags_for_child)); - metadata = crumb_inode->metadata(); - if (metadata.is_directory()) { - if (i != parts.size() - 1) { - if (parent_custody) - *parent_custody = custody_chain.last(); - } - } - if (metadata.is_symlink()) { - if (i == parts.size() - 1) { + if (child_inode->metadata().is_symlink()) { + if (!have_more_parts) { if (options & O_NOFOLLOW) return KResult(-ELOOP); if (options & O_NOFOLLOW_NOERROR) - return custody_chain.last(); + break; } - auto symlink_contents = crumb_inode->read_entire(); - if (!symlink_contents) + auto symlink_contents = child_inode->read_entire(); + if (!symlink_contents) { + if (parent_custody) + *parent_custody = nullptr; return KResult(-ENOENT); + } auto symlink_path = StringView(symlink_contents.data(), symlink_contents.size()); auto symlink_target = resolve_path(symlink_path, current_parent, parent_custody, options, symlink_recursion_level + 1); - if (symlink_target.is_error()) + if (symlink_target.is_error() || !have_more_parts) return symlink_target; - bool have_more_parts = i + 1 < parts.size(); - if (i + 1 == parts.size() - 1 && parts[i + 1].is_empty()) - have_more_parts = false; - - if (!have_more_parts) - return symlink_target; + // Now, resolve the remaining path relative to the symlink target. + // We prepend a "." to it to ensure that it's not empty and that + // any initial slashes it might have get interpreted properly. + StringBuilder remaining_path; + remaining_path.append('.'); + remaining_path.append(path.substring_view_starting_after_substring(part)); - StringView remaining_path = path.substring_view_starting_from_substring(parts[i + 1]); - return resolve_path(remaining_path, *symlink_target.value(), parent_custody, options, symlink_recursion_level + 1); + return resolve_path(remaining_path.to_string(), *symlink_target.value(), parent_custody, options, symlink_recursion_level + 1); } } + + if (parent_custody) + *parent_custody = custody_chain.last().parent(); return custody_chain.last(); } |