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/atomicops.h" 8 #include "base/logging.h" 9 #include "build/build_config.h" 10 11 #if defined(OS_POSIX) 12 #include "ipc/file_descriptor_set_posix.h" 13 #endif 14 15 namespace { 16 17 base::subtle::Atomic32 g_ref_num = 0; 18 19 // Create a reference number for identifying IPC messages in traces. The return 20 // values has the reference number stored in the upper 24 bits, leaving the low 21 // 8 bits set to 0 for use as flags. 22 inline uint32 GetRefNumUpper24() { 23 base::debug::TraceLog* trace_log = base::debug::TraceLog::GetInstance(); 24 int32 pid = trace_log ? trace_log->process_id() : 0; 25 int32 count = base::subtle::NoBarrier_AtomicIncrement(&g_ref_num, 1); 26 // The 24 bit hash is composed of 14 bits of the count and 10 bits of the 27 // Process ID. With the current trace event buffer cap, the 14-bit count did 28 // not appear to wrap during a trace. Note that it is not a big deal if 29 // collisions occur, as this is only used for debugging and trace analysis. 30 return ((pid << 22) | (count & 0x3fff)) << 8; 31 } 32 33 } // namespace 34 35 namespace IPC { 36 37 //------------------------------------------------------------------------------ 38 39 Message::~Message() { 40 } 41 42 Message::Message() 43 : Pickle(sizeof(Header)) { 44 header()->routing = header()->type = 0; 45 header()->flags = GetRefNumUpper24(); 46 #if defined(OS_POSIX) 47 header()->num_fds = 0; 48 header()->pad = 0; 49 #endif 50 InitLoggingVariables(); 51 } 52 53 Message::Message(int32 routing_id, uint32 type, PriorityValue priority) 54 : Pickle(sizeof(Header)) { 55 header()->routing = routing_id; 56 header()->type = type; 57 DCHECK((priority & 0xffffff00) == 0); 58 header()->flags = priority | GetRefNumUpper24(); 59 #if defined(OS_POSIX) 60 header()->num_fds = 0; 61 header()->pad = 0; 62 #endif 63 InitLoggingVariables(); 64 } 65 66 Message::Message(const char* data, int data_len) : Pickle(data, data_len) { 67 InitLoggingVariables(); 68 } 69 70 Message::Message(const Message& other) : Pickle(other) { 71 InitLoggingVariables(); 72 #if defined(OS_POSIX) 73 file_descriptor_set_ = other.file_descriptor_set_; 74 #endif 75 } 76 77 void Message::InitLoggingVariables() { 78 #ifdef IPC_MESSAGE_LOG_ENABLED 79 received_time_ = 0; 80 dont_log_ = false; 81 log_data_ = NULL; 82 #endif 83 } 84 85 Message& Message::operator=(const Message& other) { 86 *static_cast<Pickle*>(this) = other; 87 #if defined(OS_POSIX) 88 file_descriptor_set_ = other.file_descriptor_set_; 89 #endif 90 return *this; 91 } 92 93 void Message::SetHeaderValues(int32 routing, uint32 type, uint32 flags) { 94 // This should only be called when the message is already empty. 95 DCHECK(payload_size() == 0); 96 97 header()->routing = routing; 98 header()->type = type; 99 header()->flags = flags; 100 } 101 102 #ifdef IPC_MESSAGE_LOG_ENABLED 103 void Message::set_sent_time(int64 time) { 104 DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0); 105 header()->flags |= HAS_SENT_TIME_BIT; 106 WriteInt64(time); 107 } 108 109 int64 Message::sent_time() const { 110 if ((header()->flags & HAS_SENT_TIME_BIT) == 0) 111 return 0; 112 113 const char* data = end_of_payload(); 114 data -= sizeof(int64); 115 return *(reinterpret_cast<const int64*>(data)); 116 } 117 118 void Message::set_received_time(int64 time) const { 119 received_time_ = time; 120 } 121 #endif 122 123 #if defined(OS_POSIX) 124 bool Message::WriteFileDescriptor(const base::FileDescriptor& descriptor) { 125 // We write the index of the descriptor so that we don't have to 126 // keep the current descriptor as extra decoding state when deserialising. 127 WriteInt(file_descriptor_set()->size()); 128 if (descriptor.auto_close) { 129 return file_descriptor_set()->AddAndAutoClose(descriptor.fd); 130 } else { 131 return file_descriptor_set()->Add(descriptor.fd); 132 } 133 } 134 135 bool Message::ReadFileDescriptor(PickleIterator* iter, 136 base::FileDescriptor* descriptor) const { 137 int descriptor_index; 138 if (!ReadInt(iter, &descriptor_index)) 139 return false; 140 141 FileDescriptorSet* file_descriptor_set = file_descriptor_set_.get(); 142 if (!file_descriptor_set) 143 return false; 144 145 descriptor->fd = file_descriptor_set->GetDescriptorAt(descriptor_index); 146 descriptor->auto_close = true; 147 148 return descriptor->fd >= 0; 149 } 150 151 bool Message::HasFileDescriptors() const { 152 return file_descriptor_set_.get() && !file_descriptor_set_->empty(); 153 } 154 155 void Message::EnsureFileDescriptorSet() { 156 if (file_descriptor_set_.get() == NULL) 157 file_descriptor_set_ = new FileDescriptorSet; 158 } 159 160 #endif 161 162 } // namespace IPC 163