agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 1 | // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "base/file_descriptor_shuffle.h" |
| 6 | |
| 7 | #include <errno.h> |
| 8 | #include <unistd.h> |
| 9 | |
agl@chromium.org | d263ad7 | 2009-05-02 06:37:31 +0900 | [diff] [blame] | 10 | #include "base/eintr_wrapper.h" |
agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 11 | #include "base/logging.h" |
| 12 | |
| 13 | namespace base { |
| 14 | |
| 15 | bool PerformInjectiveMultimap(const InjectiveMultimap& m_in, |
| 16 | InjectionDelegate* delegate) { |
| 17 | InjectiveMultimap m(m_in); |
| 18 | std::vector<int> extra_fds; |
| 19 | |
| 20 | for (InjectiveMultimap::iterator i = m.begin(); i != m.end(); ++i) { |
| 21 | int temp_fd = -1; |
| 22 | |
| 23 | // We DCHECK the injectiveness of the mapping. |
dkegel@google.com | 44a1720 | 2009-06-07 04:59:36 +0900 | [diff] [blame] | 24 | for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { |
| 25 | DCHECK(i->dest != j->dest) << "Both fd " << i->source |
| 26 | << " and " << j->source << " map to " << i->dest; |
| 27 | } |
agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 28 | |
| 29 | const bool is_identity = i->source == i->dest; |
| 30 | |
| 31 | for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { |
| 32 | if (!is_identity && i->dest == j->source) { |
| 33 | if (temp_fd == -1) { |
| 34 | if (!delegate->Duplicate(&temp_fd, i->dest)) |
| 35 | return false; |
| 36 | extra_fds.push_back(temp_fd); |
| 37 | } |
| 38 | |
| 39 | j->source = temp_fd; |
| 40 | j->close = false; |
| 41 | } |
| 42 | |
| 43 | if (i->close && i->source == j->dest) |
| 44 | i->close = false; |
| 45 | |
| 46 | if (i->close && i->source == j->source) { |
| 47 | i->close = false; |
| 48 | j->close = true; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | if (!is_identity) { |
| 53 | if (!delegate->Move(i->source, i->dest)) |
| 54 | return false; |
| 55 | } |
| 56 | |
| 57 | if (!is_identity && i->close) |
| 58 | delegate->Close(i->source); |
| 59 | } |
| 60 | |
| 61 | for (std::vector<int>::const_iterator |
| 62 | i = extra_fds.begin(); i != extra_fds.end(); ++i) { |
| 63 | delegate->Close(*i); |
| 64 | } |
| 65 | |
| 66 | return true; |
| 67 | } |
| 68 | |
| 69 | bool FileDescriptorTableInjection::Duplicate(int* result, int fd) { |
agl@chromium.org | d263ad7 | 2009-05-02 06:37:31 +0900 | [diff] [blame] | 70 | *result = HANDLE_EINTR(dup(fd)); |
agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 71 | return *result >= 0; |
| 72 | } |
| 73 | |
| 74 | bool FileDescriptorTableInjection::Move(int src, int dest) { |
agl@chromium.org | d263ad7 | 2009-05-02 06:37:31 +0900 | [diff] [blame] | 75 | return HANDLE_EINTR(dup2(src, dest)) != -1; |
agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 76 | } |
| 77 | |
| 78 | void FileDescriptorTableInjection::Close(int fd) { |
agl@chromium.org | d263ad7 | 2009-05-02 06:37:31 +0900 | [diff] [blame] | 79 | HANDLE_EINTR(close(fd)); |
agl@chromium.org | f9d9126 | 2009-05-01 04:40:03 +0900 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | } // namespace base |