1 // Copyright (c) 2012 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 "ipc/ipc_message.h" 6 7 #include "base/atomic_sequence_num.h" 8 #include "base/logging.h" 9 #include "build/build_config.h" 10 11 #if defined(OS_POSIX) 12 #include "base/file_descriptor_posix.h" 13 #include "ipc/file_descriptor_set_posix.h" 14 #endif 15 16 namespace { 17 18 base::StaticAtomicSequenceNumber g_ref_num; 19 20 // Create a reference number for identifying IPC messages in traces. The return 21 // values has the reference number stored in the upper 24 bits, leaving the low 22 // 8 bits set to 0 for use as flags. 23 inline uint32 GetRefNumUpper24() { 24 base::debug::TraceLog* trace_log = base::debug::TraceLog::GetInstance(); 25 int32 pid = trace_log ? trace_log->process_id() : 0; 26 int32 count = g_ref_num.GetNext(); 27 // The 24 bit hash is composed of 14 bits of the count and 10 bits of the 28 // Process ID. With the current trace event buffer cap, the 14-bit count did 29 // not appear to wrap during a trace. Note that it is not a big deal if 30 // collisions occur, as this is only used for debugging and trace analysis. 31 return ((pid << 14) | (count & 0x3fff)) << 8; 32 } 33 34 } // namespace 35 36 namespace IPC { 37 38 //------------------------------------------------------------------------------ 39 40 Message::~Message() { 41 } 42 43 Message::Message() 44 : Pickle(sizeof(Header)) { 45 header()->routing = header()->type = 0; 46 header()->flags = GetRefNumUpper24(); 47 #if defined(OS_POSIX) 48 header()->num_fds = 0; 49 header()->pad = 0; 50 #endif 51 Init(); 52 } 53 54 Message::Message(int32 routing_id, uint32 type, PriorityValue priority) 55 : Pickle(sizeof(Header)) { 56 header()->routing = routing_id; 57 header()->type = type; 58 DCHECK((priority & 0xffffff00) == 0); 59 header()->flags = priority | GetRefNumUpper24(); 60 #if defined(OS_POSIX) 61 header()->num_fds = 0; 62 header()->pad = 0; 63 #endif 64 Init(); 65 } 66 67 Message::Message(const char* data, int data_len) : Pickle(data, data_len) { 68 Init(); 69 } 70 71 Message::Message(const Message& other) : Pickle(other) { 72 Init(); 73 #if defined(OS_POSIX) 74 file_descriptor_set_ = other.file_descriptor_set_; 75 #endif 76 } 77 78 void Message::Init() { 79 dispatch_error_ = false; 80 #ifdef IPC_MESSAGE_LOG_ENABLED 81 received_time_ = 0; 82 dont_log_ = false; 83 log_data_ = NULL; 84 #endif 85 } 86 87 Message& Message::operator=(const Message& other) { 88 *static_cast<Pickle*>(this) = other; 89 #if defined(OS_POSIX) 90 file_descriptor_set_ = other.file_descriptor_set_; 91 #endif 92 return *this; 93 } 94 95 void Message::SetHeaderValues(int32 routing, uint32 type, uint32 flags) { 96 // This should only be called when the message is already empty. 97 DCHECK(payload_size() == 0); 98 99 header()->routing = routing; 100 header()->type = type; 101 header()->flags = flags; 102 } 103 104 #ifdef IPC_MESSAGE_LOG_ENABLED 105 void Message::set_sent_time(int64 time) { 106 DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0); 107 header()->flags |= HAS_SENT_TIME_BIT; 108 WriteInt64(time); 109 } 110 111 int64 Message::sent_time() const { 112 if ((header()->flags & HAS_SENT_TIME_BIT) == 0) 113 return 0; 114 115 const char* data = end_of_payload(); 116 data -= sizeof(int64); 117 return *(reinterpret_cast<const int64*>(data)); 118 } 119 120 void Message::set_received_time(int64 time) const { 121 received_time_ = time; 122 } 123 #endif 124 125 #if defined(OS_POSIX) 126 bool Message::WriteFile(base::ScopedFD descriptor) { 127 // We write the index of the descriptor so that we don't have to 128 // keep the current descriptor as extra decoding state when deserialising. 129 WriteInt(file_descriptor_set()->size()); 130 return file_descriptor_set()->AddToOwn(descriptor.Pass()); 131 } 132 133 bool Message::WriteBorrowingFile(const base::PlatformFile& descriptor) { 134 // We write the index of the descriptor so that we don't have to 135 // keep the current descriptor as extra decoding state when deserialising. 136 WriteInt(file_descriptor_set()->size()); 137 return file_descriptor_set()->AddToBorrow(descriptor); 138 } 139 140 bool Message::ReadFile(PickleIterator* iter, base::ScopedFD* descriptor) const { 141 int descriptor_index; 142 if (!ReadInt(iter, &descriptor_index)) 143 return false; 144 145 FileDescriptorSet* file_descriptor_set = file_descriptor_set_.get(); 146 if (!file_descriptor_set) 147 return false; 148 149 base::PlatformFile file = 150 file_descriptor_set->TakeDescriptorAt(descriptor_index); 151 if (file < 0) 152 return false; 153 154 descriptor->reset(file); 155 return true; 156 } 157 158 bool Message::HasFileDescriptors() const { 159 return file_descriptor_set_.get() && !file_descriptor_set_->empty(); 160 } 161 162 void Message::EnsureFileDescriptorSet() { 163 if (file_descriptor_set_.get() == NULL) 164 file_descriptor_set_ = new FileDescriptorSet; 165 } 166 167 #endif 168 169 } // namespace IPC 170