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 "ipc/file_descriptor_set_posix.h" 13 #endif 14 15 namespace { 16 17 base::StaticAtomicSequenceNumber g_ref_num; 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 = g_ref_num.GetNext(); 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 << 14) | (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 Init(); 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 Init(); 64 } 65 66 Message::Message(const char* data, int data_len) : Pickle(data, data_len) { 67 Init(); 68 } 69 70 Message::Message(const Message& other) : Pickle(other) { 71 Init(); 72 #if defined(OS_POSIX) 73 file_descriptor_set_ = other.file_descriptor_set_; 74 #endif 75 } 76 77 void Message::Init() { 78 dispatch_error_ = false; 79 #ifdef IPC_MESSAGE_LOG_ENABLED 80 received_time_ = 0; 81 dont_log_ = false; 82 log_data_ = NULL; 83 #endif 84 } 85 86 Message& Message::operator=(const Message& other) { 87 *static_cast<Pickle*>(this) = other; 88 #if defined(OS_POSIX) 89 file_descriptor_set_ = other.file_descriptor_set_; 90 #endif 91 return *this; 92 } 93 94 void Message::SetHeaderValues(int32 routing, uint32 type, uint32 flags) { 95 // This should only be called when the message is already empty. 96 DCHECK(payload_size() == 0); 97 98 header()->routing = routing; 99 header()->type = type; 100 header()->flags = flags; 101 } 102 103 #ifdef IPC_MESSAGE_LOG_ENABLED 104 void Message::set_sent_time(int64 time) { 105 DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0); 106 header()->flags |= HAS_SENT_TIME_BIT; 107 WriteInt64(time); 108 } 109 110 int64 Message::sent_time() const { 111 if ((header()->flags & HAS_SENT_TIME_BIT) == 0) 112 return 0; 113 114 const char* data = end_of_payload(); 115 data -= sizeof(int64); 116 return *(reinterpret_cast<const int64*>(data)); 117 } 118 119 void Message::set_received_time(int64 time) const { 120 received_time_ = time; 121 } 122 #endif 123 124 #if defined(OS_POSIX) 125 bool Message::WriteFileDescriptor(const base::FileDescriptor& descriptor) { 126 // We write the index of the descriptor so that we don't have to 127 // keep the current descriptor as extra decoding state when deserialising. 128 WriteInt(file_descriptor_set()->size()); 129 if (descriptor.auto_close) { 130 return file_descriptor_set()->AddAndAutoClose(descriptor.fd); 131 } else { 132 return file_descriptor_set()->Add(descriptor.fd); 133 } 134 } 135 136 bool Message::ReadFileDescriptor(PickleIterator* iter, 137 base::FileDescriptor* descriptor) const { 138 int descriptor_index; 139 if (!ReadInt(iter, &descriptor_index)) 140 return false; 141 142 FileDescriptorSet* file_descriptor_set = file_descriptor_set_.get(); 143 if (!file_descriptor_set) 144 return false; 145 146 descriptor->fd = file_descriptor_set->GetDescriptorAt(descriptor_index); 147 descriptor->auto_close = true; 148 149 return descriptor->fd >= 0; 150 } 151 152 bool Message::HasFileDescriptors() const { 153 return file_descriptor_set_.get() && !file_descriptor_set_->empty(); 154 } 155 156 void Message::EnsureFileDescriptorSet() { 157 if (file_descriptor_set_.get() == NULL) 158 file_descriptor_set_ = new FileDescriptorSet; 159 } 160 161 #endif 162 163 } // namespace IPC 164