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| 1 // Copyright 2014 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 "mojo/edk/system/transport_data.h" | |
| 6 | |
| 7 #include <string.h> | |
| 8 | |
| 9 #include "base/compiler_specific.h" | |
| 10 #include "base/logging.h" | |
| 11 #include "mojo/edk/system/channel.h" | |
| 12 #include "mojo/edk/system/constants.h" | |
| 13 #include "mojo/edk/system/message_in_transit.h" | |
| 14 | |
| 15 namespace mojo { | |
| 16 namespace system { | |
| 17 | |
| 18 // The maximum amount of space needed per platform handle. | |
| 19 // (|{Channel,RawChannel}::GetSerializedPlatformHandleSize()| should always | |
| 20 // return a value which is at most this. This is only used to calculate | |
| 21 // |TransportData::kMaxBufferSize|. This value should be a multiple of the | |
| 22 // alignment in order to simplify calculations, even though the actual amount of | |
| 23 // space needed need not be a multiple of the alignment. | |
| 24 const size_t kMaxSizePerPlatformHandle = 8; | |
| 25 static_assert(kMaxSizePerPlatformHandle % MessageInTransit::kMessageAlignment == | |
| 26 0, | |
| 27 "kMaxSizePerPlatformHandle not a multiple of alignment"); | |
| 28 | |
| 29 STATIC_CONST_MEMBER_DEFINITION const size_t | |
| 30 TransportData::kMaxSerializedDispatcherSize; | |
| 31 STATIC_CONST_MEMBER_DEFINITION const size_t | |
| 32 TransportData::kMaxSerializedDispatcherPlatformHandles; | |
| 33 | |
| 34 // static | |
| 35 const size_t TransportData::kMaxPlatformHandles = | |
| 36 kMaxMessageNumHandles * kMaxSerializedDispatcherPlatformHandles; | |
| 37 | |
| 38 // In additional to the header, for each attached (Mojo) handle there'll be a | |
| 39 // handle table entry and serialized dispatcher data. | |
| 40 // Note: This definition must follow the one for |kMaxPlatformHandles|; | |
| 41 // otherwise, we get a static initializer with gcc (but not clang). | |
| 42 // static | |
| 43 const size_t TransportData::kMaxBufferSize = | |
| 44 sizeof(Header) + | |
| 45 kMaxMessageNumHandles * | |
| 46 (sizeof(HandleTableEntry) + kMaxSerializedDispatcherSize) + | |
| 47 kMaxPlatformHandles * kMaxSizePerPlatformHandle; | |
| 48 | |
| 49 struct TransportData::PrivateStructForCompileAsserts { | |
| 50 static_assert(sizeof(Header) % MessageInTransit::kMessageAlignment == 0, | |
| 51 "sizeof(MessageInTransit::Header) not a multiple of alignment"); | |
| 52 static_assert(kMaxSerializedDispatcherSize % | |
| 53 MessageInTransit::kMessageAlignment == | |
| 54 0, | |
| 55 "kMaxSerializedDispatcherSize not a multiple of alignment"); | |
| 56 static_assert(sizeof(HandleTableEntry) % | |
| 57 MessageInTransit::kMessageAlignment == | |
| 58 0, | |
| 59 "sizeof(MessageInTransit::HandleTableEntry) not a multiple of " | |
| 60 "alignment"); | |
| 61 }; | |
| 62 | |
| 63 TransportData::TransportData(scoped_ptr<DispatcherVector> dispatchers, | |
| 64 Channel* channel) { | |
| 65 DCHECK(dispatchers); | |
| 66 DCHECK(channel); | |
| 67 | |
| 68 const size_t num_handles = dispatchers->size(); | |
| 69 DCHECK_GT(num_handles, 0u); | |
| 70 | |
| 71 // The offset to the start of the (Mojo) handle table. | |
| 72 const size_t handle_table_start_offset = sizeof(Header); | |
| 73 // The offset to the start of the serialized dispatcher data. | |
| 74 const size_t serialized_dispatcher_start_offset = | |
| 75 handle_table_start_offset + num_handles * sizeof(HandleTableEntry); | |
| 76 // The estimated size of the secondary buffer. We compute this estimate below. | |
| 77 // It must be at least as big as the (eventual) actual size. | |
| 78 size_t estimated_size = serialized_dispatcher_start_offset; | |
| 79 size_t estimated_num_platform_handles = 0; | |
| 80 #if DCHECK_IS_ON | |
| 81 std::vector<size_t> all_max_sizes(num_handles); | |
| 82 std::vector<size_t> all_max_platform_handles(num_handles); | |
| 83 #endif | |
| 84 for (size_t i = 0; i < num_handles; i++) { | |
| 85 if (Dispatcher* dispatcher = (*dispatchers)[i].get()) { | |
| 86 size_t max_size = 0; | |
| 87 size_t max_platform_handles = 0; | |
| 88 Dispatcher::TransportDataAccess::StartSerialize( | |
| 89 dispatcher, channel, &max_size, &max_platform_handles); | |
| 90 | |
| 91 DCHECK_LE(max_size, kMaxSerializedDispatcherSize); | |
| 92 estimated_size += MessageInTransit::RoundUpMessageAlignment(max_size); | |
| 93 DCHECK_LE(estimated_size, kMaxBufferSize); | |
| 94 | |
| 95 DCHECK_LE(max_platform_handles, kMaxSerializedDispatcherPlatformHandles); | |
| 96 estimated_num_platform_handles += max_platform_handles; | |
| 97 DCHECK_LE(estimated_num_platform_handles, kMaxPlatformHandles); | |
| 98 | |
| 99 #if DCHECK_IS_ON | |
| 100 all_max_sizes[i] = max_size; | |
| 101 all_max_platform_handles[i] = max_platform_handles; | |
| 102 #endif | |
| 103 } | |
| 104 } | |
| 105 | |
| 106 size_t size_per_platform_handle = 0; | |
| 107 if (estimated_num_platform_handles > 0) { | |
| 108 size_per_platform_handle = channel->GetSerializedPlatformHandleSize(); | |
| 109 DCHECK_LE(size_per_platform_handle, kMaxSizePerPlatformHandle); | |
| 110 estimated_size += estimated_num_platform_handles * size_per_platform_handle; | |
| 111 estimated_size = MessageInTransit::RoundUpMessageAlignment(estimated_size); | |
| 112 DCHECK_LE(estimated_size, kMaxBufferSize); | |
| 113 } | |
| 114 | |
| 115 buffer_.reset(static_cast<char*>( | |
| 116 base::AlignedAlloc(estimated_size, MessageInTransit::kMessageAlignment))); | |
| 117 // Entirely clear out the secondary buffer, since then we won't have to worry | |
| 118 // about clearing padding or unused space (e.g., if a dispatcher fails to | |
| 119 // serialize). | |
| 120 memset(buffer_.get(), 0, estimated_size); | |
| 121 | |
| 122 if (estimated_num_platform_handles > 0) { | |
| 123 DCHECK(!platform_handles_); | |
| 124 platform_handles_.reset(new embedder::PlatformHandleVector()); | |
| 125 } | |
| 126 | |
| 127 Header* header = reinterpret_cast<Header*>(buffer_.get()); | |
| 128 header->num_handles = static_cast<uint32_t>(num_handles); | |
| 129 // (Okay to leave |platform_handle_table_offset|, |num_platform_handles|, and | |
| 130 // |unused| be zero; we'll set the former two later if necessary.) | |
| 131 | |
| 132 HandleTableEntry* handle_table = reinterpret_cast<HandleTableEntry*>( | |
| 133 buffer_.get() + handle_table_start_offset); | |
| 134 size_t current_offset = serialized_dispatcher_start_offset; | |
| 135 for (size_t i = 0; i < num_handles; i++) { | |
| 136 Dispatcher* dispatcher = (*dispatchers)[i].get(); | |
| 137 if (!dispatcher) { | |
| 138 static_assert(Dispatcher::kTypeUnknown == 0, | |
| 139 "Value of Dispatcher::kTypeUnknown must be 0"); | |
| 140 continue; | |
| 141 } | |
| 142 | |
| 143 #if DCHECK_IS_ON | |
| 144 size_t old_platform_handles_size = | |
| 145 platform_handles_ ? platform_handles_->size() : 0; | |
| 146 #endif | |
| 147 | |
| 148 void* destination = buffer_.get() + current_offset; | |
| 149 size_t actual_size = 0; | |
| 150 if (Dispatcher::TransportDataAccess::EndSerializeAndClose( | |
| 151 dispatcher, | |
| 152 channel, | |
| 153 destination, | |
| 154 &actual_size, | |
| 155 platform_handles_.get())) { | |
| 156 handle_table[i].type = static_cast<int32_t>(dispatcher->GetType()); | |
| 157 handle_table[i].offset = static_cast<uint32_t>(current_offset); | |
| 158 handle_table[i].size = static_cast<uint32_t>(actual_size); | |
| 159 // (Okay to not set |unused| since we cleared the entire buffer.) | |
| 160 | |
| 161 #if DCHECK_IS_ON | |
| 162 DCHECK_LE(actual_size, all_max_sizes[i]); | |
| 163 DCHECK_LE(platform_handles_ | |
| 164 ? (platform_handles_->size() - old_platform_handles_size) | |
| 165 : 0, | |
| 166 all_max_platform_handles[i]); | |
| 167 #endif | |
| 168 } else { | |
| 169 // Nothing to do on failure, since |buffer_| was cleared, and | |
| 170 // |kTypeUnknown| is zero. The handle was simply closed. | |
| 171 LOG(ERROR) << "Failed to serialize handle to remote message pipe"; | |
| 172 } | |
| 173 | |
| 174 current_offset += MessageInTransit::RoundUpMessageAlignment(actual_size); | |
| 175 DCHECK_LE(current_offset, estimated_size); | |
| 176 DCHECK_LE(platform_handles_ ? platform_handles_->size() : 0, | |
| 177 estimated_num_platform_handles); | |
| 178 } | |
| 179 | |
| 180 if (platform_handles_ && platform_handles_->size() > 0) { | |
| 181 header->platform_handle_table_offset = | |
| 182 static_cast<uint32_t>(current_offset); | |
| 183 header->num_platform_handles = | |
| 184 static_cast<uint32_t>(platform_handles_->size()); | |
| 185 current_offset += platform_handles_->size() * size_per_platform_handle; | |
| 186 current_offset = MessageInTransit::RoundUpMessageAlignment(current_offset); | |
| 187 } | |
| 188 | |
| 189 // There's no aligned realloc, so it's no good way to release unused space (if | |
| 190 // we overshot our estimated space requirements). | |
| 191 buffer_size_ = current_offset; | |
| 192 | |
| 193 // |dispatchers_| will be destroyed as it goes out of scope. | |
| 194 } | |
| 195 | |
| 196 #if defined(OS_POSIX) | |
| 197 TransportData::TransportData( | |
| 198 embedder::ScopedPlatformHandleVectorPtr platform_handles) | |
| 199 : buffer_size_(sizeof(Header)), platform_handles_(platform_handles.Pass()) { | |
| 200 buffer_.reset(static_cast<char*>( | |
| 201 base::AlignedAlloc(buffer_size_, MessageInTransit::kMessageAlignment))); | |
| 202 memset(buffer_.get(), 0, buffer_size_); | |
| 203 } | |
| 204 #endif // defined(OS_POSIX) | |
| 205 | |
| 206 TransportData::~TransportData() { | |
| 207 } | |
| 208 | |
| 209 // static | |
| 210 const char* TransportData::ValidateBuffer( | |
| 211 size_t serialized_platform_handle_size, | |
| 212 const void* buffer, | |
| 213 size_t buffer_size) { | |
| 214 DCHECK(buffer); | |
| 215 DCHECK_GT(buffer_size, 0u); | |
| 216 | |
| 217 // Always make sure that the buffer size is sane; if it's not, someone's | |
| 218 // messing with us. | |
| 219 if (buffer_size < sizeof(Header) || buffer_size > kMaxBufferSize || | |
| 220 buffer_size % MessageInTransit::kMessageAlignment != 0) | |
| 221 return "Invalid message secondary buffer size"; | |
| 222 | |
| 223 const Header* header = static_cast<const Header*>(buffer); | |
| 224 const size_t num_handles = header->num_handles; | |
| 225 | |
| 226 #if !defined(OS_POSIX) | |
| 227 // On POSIX, we send control messages with platform handles (but no handles) | |
| 228 // attached (see the comments for | |
| 229 // |TransportData(embedder::ScopedPlatformHandleVectorPtr)|. (This check isn't | |
| 230 // important security-wise anyway.) | |
| 231 if (num_handles == 0) | |
| 232 return "Message has no handles attached, but secondary buffer present"; | |
| 233 #endif | |
| 234 | |
| 235 // Sanity-check |num_handles| (before multiplying it against anything). | |
| 236 if (num_handles > kMaxMessageNumHandles) | |
| 237 return "Message handle payload too large"; | |
| 238 | |
| 239 if (buffer_size < sizeof(Header) + num_handles * sizeof(HandleTableEntry)) | |
| 240 return "Message secondary buffer too small"; | |
| 241 | |
| 242 if (header->num_platform_handles == 0) { | |
| 243 // Then |platform_handle_table_offset| should also be zero. | |
| 244 if (header->platform_handle_table_offset != 0) { | |
| 245 return "Message has no handles attached, but platform handle table " | |
| 246 "present"; | |
| 247 } | |
| 248 } else { | |
| 249 // |num_handles| has already been validated, so the multiplication is okay. | |
| 250 if (header->num_platform_handles > | |
| 251 num_handles * kMaxSerializedDispatcherPlatformHandles) | |
| 252 return "Message has too many platform handles attached"; | |
| 253 | |
| 254 static const char kInvalidPlatformHandleTableOffset[] = | |
| 255 "Message has invalid platform handle table offset"; | |
| 256 // This doesn't check that the platform handle table doesn't alias other | |
| 257 // stuff, but it doesn't matter, since it's all read-only. | |
| 258 if (header->platform_handle_table_offset % | |
| 259 MessageInTransit::kMessageAlignment != | |
| 260 0) | |
| 261 return kInvalidPlatformHandleTableOffset; | |
| 262 | |
| 263 // ">" instead of ">=" since the size per handle may be zero. | |
| 264 if (header->platform_handle_table_offset > buffer_size) | |
| 265 return kInvalidPlatformHandleTableOffset; | |
| 266 | |
| 267 // We already checked |platform_handle_table_offset| and | |
| 268 // |num_platform_handles|, so the addition and multiplication are okay. | |
| 269 if (header->platform_handle_table_offset + | |
| 270 header->num_platform_handles * serialized_platform_handle_size > | |
| 271 buffer_size) | |
| 272 return kInvalidPlatformHandleTableOffset; | |
| 273 } | |
| 274 | |
| 275 const HandleTableEntry* handle_table = | |
| 276 reinterpret_cast<const HandleTableEntry*>( | |
| 277 static_cast<const char*>(buffer) + sizeof(Header)); | |
| 278 static const char kInvalidSerializedDispatcher[] = | |
| 279 "Message contains invalid serialized dispatcher"; | |
| 280 for (size_t i = 0; i < num_handles; i++) { | |
| 281 size_t offset = handle_table[i].offset; | |
| 282 if (offset % MessageInTransit::kMessageAlignment != 0) | |
| 283 return kInvalidSerializedDispatcher; | |
| 284 | |
| 285 size_t size = handle_table[i].size; | |
| 286 if (size > kMaxSerializedDispatcherSize || size > buffer_size) | |
| 287 return kInvalidSerializedDispatcher; | |
| 288 | |
| 289 // Note: This is an overflow-safe check for |offset + size > buffer_size| | |
| 290 // (we know that |size <= buffer_size| from the previous check). | |
| 291 if (offset > buffer_size - size) | |
| 292 return kInvalidSerializedDispatcher; | |
| 293 } | |
| 294 | |
| 295 return nullptr; | |
| 296 } | |
| 297 | |
| 298 // static | |
| 299 void TransportData::GetPlatformHandleTable(const void* transport_data_buffer, | |
| 300 size_t* num_platform_handles, | |
| 301 const void** platform_handle_table) { | |
| 302 DCHECK(transport_data_buffer); | |
| 303 DCHECK(num_platform_handles); | |
| 304 DCHECK(platform_handle_table); | |
| 305 | |
| 306 const Header* header = static_cast<const Header*>(transport_data_buffer); | |
| 307 *num_platform_handles = header->num_platform_handles; | |
| 308 *platform_handle_table = static_cast<const char*>(transport_data_buffer) + | |
| 309 header->platform_handle_table_offset; | |
| 310 } | |
| 311 | |
| 312 // static | |
| 313 scoped_ptr<DispatcherVector> TransportData::DeserializeDispatchers( | |
| 314 const void* buffer, | |
| 315 size_t buffer_size, | |
| 316 embedder::ScopedPlatformHandleVectorPtr platform_handles, | |
| 317 Channel* channel) { | |
| 318 DCHECK(buffer); | |
| 319 DCHECK_GT(buffer_size, 0u); | |
| 320 DCHECK(channel); | |
| 321 | |
| 322 const Header* header = static_cast<const Header*>(buffer); | |
| 323 const size_t num_handles = header->num_handles; | |
| 324 scoped_ptr<DispatcherVector> dispatchers(new DispatcherVector(num_handles)); | |
| 325 | |
| 326 const HandleTableEntry* handle_table = | |
| 327 reinterpret_cast<const HandleTableEntry*>( | |
| 328 static_cast<const char*>(buffer) + sizeof(Header)); | |
| 329 for (size_t i = 0; i < num_handles; i++) { | |
| 330 size_t offset = handle_table[i].offset; | |
| 331 size_t size = handle_table[i].size; | |
| 332 // Should already have been checked by |ValidateBuffer()|: | |
| 333 DCHECK_EQ(offset % MessageInTransit::kMessageAlignment, 0u); | |
| 334 DCHECK_LE(offset, buffer_size); | |
| 335 DCHECK_LE(offset + size, buffer_size); | |
| 336 | |
| 337 const void* source = static_cast<const char*>(buffer) + offset; | |
| 338 (*dispatchers)[i] = Dispatcher::TransportDataAccess::Deserialize( | |
| 339 channel, handle_table[i].type, source, size, platform_handles.get()); | |
| 340 } | |
| 341 | |
| 342 return dispatchers.Pass(); | |
| 343 } | |
| 344 | |
| 345 } // namespace system | |
| 346 } // namespace mojo | |
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Chromium Code Reviews
Issue 623883002:
Revert "Move mojo edk into mojo/edk" (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master