| // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/file_descriptor_shuffle.h" |
| |
| #include <errno.h> |
| #include <unistd.h> |
| |
| #include "base/eintr_wrapper.h" |
| #include "base/logging.h" |
| |
| namespace base { |
| |
| bool PerformInjectiveMultimap(const InjectiveMultimap& m_in, |
| InjectionDelegate* delegate) { |
| InjectiveMultimap m(m_in); |
| std::vector<int> extra_fds; |
| |
| for (InjectiveMultimap::iterator i = m.begin(); i != m.end(); ++i) { |
| int temp_fd = -1; |
| |
| // We DCHECK the injectiveness of the mapping. |
| for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { |
| DCHECK(i->dest != j->dest) << "Both fd " << i->source |
| << " and " << j->source << " map to " << i->dest; |
| } |
| |
| const bool is_identity = i->source == i->dest; |
| |
| for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { |
| if (!is_identity && i->dest == j->source) { |
| if (temp_fd == -1) { |
| if (!delegate->Duplicate(&temp_fd, i->dest)) |
| return false; |
| extra_fds.push_back(temp_fd); |
| } |
| |
| j->source = temp_fd; |
| j->close = false; |
| } |
| |
| if (i->close && i->source == j->dest) |
| i->close = false; |
| |
| if (i->close && i->source == j->source) { |
| i->close = false; |
| j->close = true; |
| } |
| } |
| |
| if (!is_identity) { |
| if (!delegate->Move(i->source, i->dest)) |
| return false; |
| } |
| |
| if (!is_identity && i->close) |
| delegate->Close(i->source); |
| } |
| |
| for (std::vector<int>::const_iterator |
| i = extra_fds.begin(); i != extra_fds.end(); ++i) { |
| delegate->Close(*i); |
| } |
| |
| return true; |
| } |
| |
| bool FileDescriptorTableInjection::Duplicate(int* result, int fd) { |
| *result = HANDLE_EINTR(dup(fd)); |
| return *result >= 0; |
| } |
| |
| bool FileDescriptorTableInjection::Move(int src, int dest) { |
| return HANDLE_EINTR(dup2(src, dest)) != -1; |
| } |
| |
| void FileDescriptorTableInjection::Close(int fd) { |
| HANDLE_EINTR(close(fd)); |
| } |
| |
| } // namespace base |