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1 // Copyright (c) 2009 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/file_descriptor_shuffle.h" | 5 #include "base/file_descriptor_shuffle.h" |
6 | 6 |
7 #include <errno.h> | 7 #include <errno.h> |
8 #include <unistd.h> | 8 #include <unistd.h> |
9 | 9 |
10 #include "base/eintr_wrapper.h" | 10 #include "base/eintr_wrapper.h" |
11 #include "base/logging.h" | 11 #include "base/logging.h" |
12 | 12 |
13 namespace base { | 13 namespace base { |
14 | 14 |
15 bool PerformInjectiveMultimap(const InjectiveMultimap& m_in, | 15 bool PerformInjectiveMultimapDestructive( |
16 InjectionDelegate* delegate) { | 16 InjectiveMultimap* m, InjectionDelegate* delegate) { |
17 InjectiveMultimap m(m_in); | 17 static const size_t kMaxExtraFDs = 16; |
18 std::vector<int> extra_fds; | 18 int extra_fds[kMaxExtraFDs]; |
| 19 unsigned next_extra_fd = 0; |
19 | 20 |
20 for (InjectiveMultimap::iterator i = m.begin(); i != m.end(); ++i) { | 21 // DANGER: this function may not allocate. |
| 22 |
| 23 for (InjectiveMultimap::iterator i = m->begin(); i != m->end(); ++i) { |
21 int temp_fd = -1; | 24 int temp_fd = -1; |
22 | 25 |
23 // We DCHECK the injectiveness of the mapping. | 26 // We DCHECK the injectiveness of the mapping. |
24 for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { | 27 for (InjectiveMultimap::iterator j = i + 1; j != m->end(); ++j) { |
25 DCHECK(i->dest != j->dest) << "Both fd " << i->source | 28 DCHECK(i->dest != j->dest) << "Both fd " << i->source |
26 << " and " << j->source << " map to " << i->dest; | 29 << " and " << j->source << " map to " << i->dest; |
27 } | 30 } |
28 | 31 |
29 const bool is_identity = i->source == i->dest; | 32 const bool is_identity = i->source == i->dest; |
30 | 33 |
31 for (InjectiveMultimap::iterator j = i + 1; j != m.end(); ++j) { | 34 for (InjectiveMultimap::iterator j = i + 1; j != m->end(); ++j) { |
32 if (!is_identity && i->dest == j->source) { | 35 if (!is_identity && i->dest == j->source) { |
33 if (temp_fd == -1) { | 36 if (temp_fd == -1) { |
34 if (!delegate->Duplicate(&temp_fd, i->dest)) | 37 if (!delegate->Duplicate(&temp_fd, i->dest)) |
35 return false; | 38 return false; |
36 extra_fds.push_back(temp_fd); | 39 if (next_extra_fd < kMaxExtraFDs) { |
| 40 extra_fds[next_extra_fd++] = temp_fd; |
| 41 } else { |
| 42 RAW_LOG(ERROR, "PerformInjectiveMultimapDestructive overflowed " |
| 43 "extra_fds. Leaking file descriptors!"); |
| 44 } |
37 } | 45 } |
38 | 46 |
39 j->source = temp_fd; | 47 j->source = temp_fd; |
40 j->close = false; | 48 j->close = false; |
41 } | 49 } |
42 | 50 |
43 if (i->close && i->source == j->dest) | 51 if (i->close && i->source == j->dest) |
44 i->close = false; | 52 i->close = false; |
45 | 53 |
46 if (i->close && i->source == j->source) { | 54 if (i->close && i->source == j->source) { |
47 i->close = false; | 55 i->close = false; |
48 j->close = true; | 56 j->close = true; |
49 } | 57 } |
50 } | 58 } |
51 | 59 |
52 if (!is_identity) { | 60 if (!is_identity) { |
53 if (!delegate->Move(i->source, i->dest)) | 61 if (!delegate->Move(i->source, i->dest)) |
54 return false; | 62 return false; |
55 } | 63 } |
56 | 64 |
57 if (!is_identity && i->close) | 65 if (!is_identity && i->close) |
58 delegate->Close(i->source); | 66 delegate->Close(i->source); |
59 } | 67 } |
60 | 68 |
61 for (std::vector<int>::const_iterator | 69 for (unsigned i = 0; i < next_extra_fd; i++) |
62 i = extra_fds.begin(); i != extra_fds.end(); ++i) { | 70 delegate->Close(extra_fds[i]); |
63 delegate->Close(*i); | |
64 } | |
65 | 71 |
66 return true; | 72 return true; |
67 } | 73 } |
68 | 74 |
| 75 bool PerformInjectiveMultimap(const InjectiveMultimap& m_in, |
| 76 InjectionDelegate* delegate) { |
| 77 InjectiveMultimap m(m_in); |
| 78 return PerformInjectiveMultimapDestructive(&m, delegate); |
| 79 } |
| 80 |
69 bool FileDescriptorTableInjection::Duplicate(int* result, int fd) { | 81 bool FileDescriptorTableInjection::Duplicate(int* result, int fd) { |
70 *result = HANDLE_EINTR(dup(fd)); | 82 *result = HANDLE_EINTR(dup(fd)); |
71 return *result >= 0; | 83 return *result >= 0; |
72 } | 84 } |
73 | 85 |
74 bool FileDescriptorTableInjection::Move(int src, int dest) { | 86 bool FileDescriptorTableInjection::Move(int src, int dest) { |
75 return HANDLE_EINTR(dup2(src, dest)) != -1; | 87 return HANDLE_EINTR(dup2(src, dest)) != -1; |
76 } | 88 } |
77 | 89 |
78 void FileDescriptorTableInjection::Close(int fd) { | 90 void FileDescriptorTableInjection::Close(int fd) { |
79 int ret = HANDLE_EINTR(close(fd)); | 91 int ret = HANDLE_EINTR(close(fd)); |
80 DPCHECK(ret == 0); | 92 DPCHECK(ret == 0); |
81 } | 93 } |
82 | 94 |
83 } // namespace base | 95 } // namespace base |
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