Luis Hector Chavez | 645501c | 2016-12-28 10:56:26 -0800 | [diff] [blame^] | 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 <limits.h> |
| 8 | #include <stddef.h> |
| 9 | #include <stdint.h> |
| 10 | |
| 11 | #include "base/atomic_sequence_num.h" |
| 12 | #include "base/logging.h" |
| 13 | #include "build/build_config.h" |
| 14 | #include "ipc/attachment_broker.h" |
| 15 | #include "ipc/ipc_message_attachment.h" |
| 16 | #include "ipc/ipc_message_attachment_set.h" |
| 17 | #include "ipc/placeholder_brokerable_attachment.h" |
| 18 | |
| 19 | #if defined(OS_POSIX) |
| 20 | #include "base/file_descriptor_posix.h" |
| 21 | #include "ipc/ipc_platform_file_attachment_posix.h" |
| 22 | #endif |
| 23 | |
| 24 | namespace { |
| 25 | |
| 26 | base::StaticAtomicSequenceNumber g_ref_num; |
| 27 | |
| 28 | // Create a reference number for identifying IPC messages in traces. The return |
| 29 | // values has the reference number stored in the upper 24 bits, leaving the low |
| 30 | // 8 bits set to 0 for use as flags. |
| 31 | inline uint32_t GetRefNumUpper24() { |
| 32 | base::trace_event::TraceLog* trace_log = |
| 33 | base::trace_event::TraceLog::GetInstance(); |
| 34 | uint32_t pid = trace_log ? trace_log->process_id() : 0; |
| 35 | uint32_t count = g_ref_num.GetNext(); |
| 36 | // The 24 bit hash is composed of 14 bits of the count and 10 bits of the |
| 37 | // Process ID. With the current trace event buffer cap, the 14-bit count did |
| 38 | // not appear to wrap during a trace. Note that it is not a big deal if |
| 39 | // collisions occur, as this is only used for debugging and trace analysis. |
| 40 | return ((pid << 14) | (count & 0x3fff)) << 8; |
| 41 | } |
| 42 | |
| 43 | } // namespace |
| 44 | |
| 45 | namespace IPC { |
| 46 | |
| 47 | //------------------------------------------------------------------------------ |
| 48 | |
| 49 | Message::~Message() { |
| 50 | } |
| 51 | |
| 52 | Message::Message() : base::Pickle(sizeof(Header)) { |
| 53 | header()->routing = header()->type = 0; |
| 54 | header()->flags = GetRefNumUpper24(); |
| 55 | #if USE_ATTACHMENT_BROKER |
| 56 | header()->num_brokered_attachments = 0; |
| 57 | #endif |
| 58 | #if defined(OS_POSIX) |
| 59 | header()->num_fds = 0; |
| 60 | header()->pad = 0; |
| 61 | #endif |
| 62 | Init(); |
| 63 | } |
| 64 | |
| 65 | Message::Message(int32_t routing_id, uint32_t type, PriorityValue priority) |
| 66 | : base::Pickle(sizeof(Header)) { |
| 67 | header()->routing = routing_id; |
| 68 | header()->type = type; |
| 69 | DCHECK((priority & 0xffffff00) == 0); |
| 70 | header()->flags = priority | GetRefNumUpper24(); |
| 71 | #if USE_ATTACHMENT_BROKER |
| 72 | header()->num_brokered_attachments = 0; |
| 73 | #endif |
| 74 | #if defined(OS_POSIX) |
| 75 | header()->num_fds = 0; |
| 76 | header()->pad = 0; |
| 77 | #endif |
| 78 | Init(); |
| 79 | } |
| 80 | |
| 81 | Message::Message(const char* data, int data_len) |
| 82 | : base::Pickle(data, data_len) { |
| 83 | Init(); |
| 84 | } |
| 85 | |
| 86 | Message::Message(const Message& other) : base::Pickle(other) { |
| 87 | Init(); |
| 88 | attachment_set_ = other.attachment_set_; |
| 89 | sender_pid_ = other.sender_pid_; |
| 90 | } |
| 91 | |
| 92 | void Message::Init() { |
| 93 | dispatch_error_ = false; |
| 94 | sender_pid_ = base::kNullProcessId; |
| 95 | #ifdef IPC_MESSAGE_LOG_ENABLED |
| 96 | received_time_ = 0; |
| 97 | dont_log_ = false; |
| 98 | log_data_ = NULL; |
| 99 | #endif |
| 100 | } |
| 101 | |
| 102 | Message& Message::operator=(const Message& other) { |
| 103 | *static_cast<base::Pickle*>(this) = other; |
| 104 | attachment_set_ = other.attachment_set_; |
| 105 | sender_pid_ = other.sender_pid_; |
| 106 | return *this; |
| 107 | } |
| 108 | |
| 109 | void Message::SetHeaderValues(int32_t routing, uint32_t type, uint32_t flags) { |
| 110 | // This should only be called when the message is already empty. |
| 111 | DCHECK(payload_size() == 0); |
| 112 | |
| 113 | header()->routing = routing; |
| 114 | header()->type = type; |
| 115 | header()->flags = flags; |
| 116 | } |
| 117 | |
| 118 | void Message::EnsureMessageAttachmentSet() { |
| 119 | if (attachment_set_.get() == NULL) |
| 120 | attachment_set_ = new MessageAttachmentSet; |
| 121 | } |
| 122 | |
| 123 | #ifdef IPC_MESSAGE_LOG_ENABLED |
| 124 | void Message::set_sent_time(int64_t time) { |
| 125 | DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0); |
| 126 | header()->flags |= HAS_SENT_TIME_BIT; |
| 127 | WriteInt64(time); |
| 128 | } |
| 129 | |
| 130 | int64_t Message::sent_time() const { |
| 131 | if ((header()->flags & HAS_SENT_TIME_BIT) == 0) |
| 132 | return 0; |
| 133 | |
| 134 | const char* data = end_of_payload(); |
| 135 | data -= sizeof(int64_t); |
| 136 | return *(reinterpret_cast<const int64_t*>(data)); |
| 137 | } |
| 138 | |
| 139 | void Message::set_received_time(int64_t time) const { |
| 140 | received_time_ = time; |
| 141 | } |
| 142 | #endif |
| 143 | |
| 144 | Message::NextMessageInfo::NextMessageInfo() |
| 145 | : message_size(0), message_found(false), pickle_end(nullptr), |
| 146 | message_end(nullptr) {} |
| 147 | Message::NextMessageInfo::~NextMessageInfo() {} |
| 148 | |
| 149 | Message::SerializedAttachmentIds |
| 150 | Message::SerializedIdsOfBrokerableAttachments() { |
| 151 | DCHECK(HasBrokerableAttachments()); |
| 152 | std::vector<scoped_refptr<IPC::BrokerableAttachment>> attachments( |
| 153 | attachment_set_->GetBrokerableAttachments()); |
| 154 | CHECK_LE(attachments.size(), std::numeric_limits<size_t>::max() / |
| 155 | BrokerableAttachment::kNonceSize); |
| 156 | size_t size = attachments.size() * BrokerableAttachment::kNonceSize; |
| 157 | char* buffer = static_cast<char*>(malloc(size)); |
| 158 | for (size_t i = 0; i < attachments.size(); ++i) { |
| 159 | char* start_range = buffer + i * BrokerableAttachment::kNonceSize; |
| 160 | BrokerableAttachment::AttachmentId id = attachments[i]->GetIdentifier(); |
| 161 | id.SerializeToBuffer(start_range, BrokerableAttachment::kNonceSize); |
| 162 | } |
| 163 | SerializedAttachmentIds ids; |
| 164 | ids.buffer = buffer; |
| 165 | ids.size = size; |
| 166 | return ids; |
| 167 | } |
| 168 | |
| 169 | // static |
| 170 | void Message::FindNext(const char* range_start, |
| 171 | const char* range_end, |
| 172 | NextMessageInfo* info) { |
| 173 | DCHECK(info); |
| 174 | info->message_found = false; |
| 175 | info->message_size = 0; |
| 176 | |
| 177 | size_t pickle_size = 0; |
| 178 | if (!base::Pickle::PeekNext(sizeof(Header), |
| 179 | range_start, range_end, &pickle_size)) |
| 180 | return; |
| 181 | |
| 182 | bool have_entire_pickle = |
| 183 | static_cast<size_t>(range_end - range_start) >= pickle_size; |
| 184 | |
| 185 | #if USE_ATTACHMENT_BROKER |
| 186 | // TODO(dskiba): determine message_size when entire pickle is not available |
| 187 | |
| 188 | if (!have_entire_pickle) |
| 189 | return; |
| 190 | |
| 191 | const char* pickle_end = range_start + pickle_size; |
| 192 | |
| 193 | // The data is not copied. |
| 194 | Message message(range_start, static_cast<int>(pickle_size)); |
| 195 | size_t num_attachments = message.header()->num_brokered_attachments; |
| 196 | |
| 197 | // Check for possible overflows. |
| 198 | size_t max_size_t = std::numeric_limits<size_t>::max(); |
| 199 | if (num_attachments >= max_size_t / BrokerableAttachment::kNonceSize) |
| 200 | return; |
| 201 | |
| 202 | size_t attachment_length = num_attachments * BrokerableAttachment::kNonceSize; |
| 203 | if (pickle_size > max_size_t - attachment_length) |
| 204 | return; |
| 205 | |
| 206 | // Check whether the range includes the attachments. |
| 207 | size_t buffer_length = static_cast<size_t>(range_end - range_start); |
| 208 | if (buffer_length < attachment_length + pickle_size) |
| 209 | return; |
| 210 | |
| 211 | for (size_t i = 0; i < num_attachments; ++i) { |
| 212 | const char* attachment_start = |
| 213 | pickle_end + i * BrokerableAttachment::kNonceSize; |
| 214 | BrokerableAttachment::AttachmentId id(attachment_start, |
| 215 | BrokerableAttachment::kNonceSize); |
| 216 | info->attachment_ids.push_back(id); |
| 217 | } |
| 218 | info->message_end = |
| 219 | pickle_end + num_attachments * BrokerableAttachment::kNonceSize; |
| 220 | info->message_size = info->message_end - range_start; |
| 221 | #else |
| 222 | info->message_size = pickle_size; |
| 223 | |
| 224 | if (!have_entire_pickle) |
| 225 | return; |
| 226 | |
| 227 | const char* pickle_end = range_start + pickle_size; |
| 228 | |
| 229 | info->message_end = pickle_end; |
| 230 | #endif // USE_ATTACHMENT_BROKER |
| 231 | |
| 232 | info->pickle_end = pickle_end; |
| 233 | info->message_found = true; |
| 234 | } |
| 235 | |
| 236 | bool Message::AddPlaceholderBrokerableAttachmentWithId( |
| 237 | BrokerableAttachment::AttachmentId id) { |
| 238 | scoped_refptr<PlaceholderBrokerableAttachment> attachment( |
| 239 | new PlaceholderBrokerableAttachment(id)); |
| 240 | return attachment_set()->AddAttachment(attachment); |
| 241 | } |
| 242 | |
| 243 | bool Message::WriteAttachment( |
| 244 | scoped_refptr<base::Pickle::Attachment> attachment) { |
| 245 | bool brokerable; |
| 246 | size_t index; |
| 247 | bool success = attachment_set()->AddAttachment( |
| 248 | make_scoped_refptr(static_cast<MessageAttachment*>(attachment.get())), |
| 249 | &index, &brokerable); |
| 250 | DCHECK(success); |
| 251 | |
| 252 | // NOTE: If you add more data to the pickle, make sure to update |
| 253 | // PickleSizer::AddAttachment. |
| 254 | |
| 255 | // Write the type of descriptor. |
| 256 | WriteBool(brokerable); |
| 257 | |
| 258 | // Write the index of the descriptor so that we don't have to |
| 259 | // keep the current descriptor as extra decoding state when deserialising. |
| 260 | WriteInt(static_cast<int>(index)); |
| 261 | |
| 262 | #if USE_ATTACHMENT_BROKER |
| 263 | if (brokerable) |
| 264 | header()->num_brokered_attachments++; |
| 265 | #endif |
| 266 | |
| 267 | return success; |
| 268 | } |
| 269 | |
| 270 | bool Message::ReadAttachment( |
| 271 | base::PickleIterator* iter, |
| 272 | scoped_refptr<base::Pickle::Attachment>* attachment) const { |
| 273 | bool brokerable; |
| 274 | if (!iter->ReadBool(&brokerable)) |
| 275 | return false; |
| 276 | |
| 277 | int index; |
| 278 | if (!iter->ReadInt(&index)) |
| 279 | return false; |
| 280 | |
| 281 | MessageAttachmentSet* attachment_set = attachment_set_.get(); |
| 282 | if (!attachment_set) |
| 283 | return false; |
| 284 | |
| 285 | *attachment = brokerable |
| 286 | ? attachment_set->GetBrokerableAttachmentAt(index) |
| 287 | : attachment_set->GetNonBrokerableAttachmentAt(index); |
| 288 | |
| 289 | return nullptr != attachment->get(); |
| 290 | } |
| 291 | |
| 292 | bool Message::HasAttachments() const { |
| 293 | return attachment_set_.get() && !attachment_set_->empty(); |
| 294 | } |
| 295 | |
| 296 | bool Message::HasMojoHandles() const { |
| 297 | return attachment_set_.get() && attachment_set_->num_mojo_handles() > 0; |
| 298 | } |
| 299 | |
| 300 | bool Message::HasBrokerableAttachments() const { |
| 301 | return attachment_set_.get() && |
| 302 | attachment_set_->num_brokerable_attachments() > 0; |
| 303 | } |
| 304 | |
| 305 | } // namespace IPC |