diff options
Diffstat (limited to 'netwerk/protocol/http/Http2Compression.cpp')
| -rw-r--r-- | netwerk/protocol/http/Http2Compression.cpp | 1443 |
1 files changed, 1443 insertions, 0 deletions
diff --git a/netwerk/protocol/http/Http2Compression.cpp b/netwerk/protocol/http/Http2Compression.cpp new file mode 100644 index 0000000000..8dba007688 --- /dev/null +++ b/netwerk/protocol/http/Http2Compression.cpp @@ -0,0 +1,1443 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set sw=2 ts=8 et tw=80 : */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +// HttpLog.h should generally be included first +#include "HttpLog.h" + +// Log on level :5, instead of default :4. +#undef LOG +#define LOG(args) LOG5(args) +#undef LOG_ENABLED +#define LOG_ENABLED() LOG5_ENABLED() + +#include "Http2Compression.h" +#include "Http2HuffmanIncoming.h" +#include "Http2HuffmanOutgoing.h" +#include "mozilla/StaticPtr.h" +#include "nsCharSeparatedTokenizer.h" +#include "nsIMemoryReporter.h" +#include "nsHttpHandler.h" + +namespace mozilla { +namespace net { + +static nsDeque<nvPair>* gStaticHeaders = nullptr; + +class HpackStaticTableReporter final : public nsIMemoryReporter { + public: + NS_DECL_THREADSAFE_ISUPPORTS + + HpackStaticTableReporter() = default; + + NS_IMETHOD + CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData, + bool aAnonymize) override { + MOZ_COLLECT_REPORT("explicit/network/hpack/static-table", KIND_HEAP, + UNITS_BYTES, + gStaticHeaders->SizeOfIncludingThis(MallocSizeOf), + "Memory usage of HPACK static table."); + + return NS_OK; + } + + private: + MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf) + + ~HpackStaticTableReporter() = default; +}; + +NS_IMPL_ISUPPORTS(HpackStaticTableReporter, nsIMemoryReporter) + +class HpackDynamicTableReporter final : public nsIMemoryReporter { + public: + NS_DECL_THREADSAFE_ISUPPORTS + + explicit HpackDynamicTableReporter(Http2BaseCompressor* aCompressor) + : mCompressor(aCompressor) {} + + NS_IMETHOD + CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData, + bool aAnonymize) override { + if (mCompressor) { + MOZ_COLLECT_REPORT("explicit/network/hpack/dynamic-tables", KIND_HEAP, + UNITS_BYTES, + mCompressor->SizeOfExcludingThis(MallocSizeOf), + "Aggregate memory usage of HPACK dynamic tables."); + } + return NS_OK; + } + + private: + MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf) + + ~HpackDynamicTableReporter() = default; + + Http2BaseCompressor* mCompressor; + + friend class Http2BaseCompressor; +}; + +NS_IMPL_ISUPPORTS(HpackDynamicTableReporter, nsIMemoryReporter) + +StaticRefPtr<HpackStaticTableReporter> gStaticReporter; + +void Http2CompressionCleanup() { + // this happens after the socket thread has been destroyed + delete gStaticHeaders; + gStaticHeaders = nullptr; + UnregisterStrongMemoryReporter(gStaticReporter); + gStaticReporter = nullptr; +} + +static void AddStaticElement(const nsCString& name, const nsCString& value) { + nvPair* pair = new nvPair(name, value); + gStaticHeaders->Push(pair); +} + +static void AddStaticElement(const nsCString& name) { + AddStaticElement(name, ""_ns); +} + +static void InitializeStaticHeaders() { + MOZ_ASSERT(OnSocketThread(), "not on socket thread"); + if (!gStaticHeaders) { + gStaticHeaders = new nsDeque<nvPair>(); + gStaticReporter = new HpackStaticTableReporter(); + RegisterStrongMemoryReporter(gStaticReporter); + AddStaticElement(":authority"_ns); + AddStaticElement(":method"_ns, "GET"_ns); + AddStaticElement(":method"_ns, "POST"_ns); + AddStaticElement(":path"_ns, "/"_ns); + AddStaticElement(":path"_ns, "/index.html"_ns); + AddStaticElement(":scheme"_ns, "http"_ns); + AddStaticElement(":scheme"_ns, "https"_ns); + AddStaticElement(":status"_ns, "200"_ns); + AddStaticElement(":status"_ns, "204"_ns); + AddStaticElement(":status"_ns, "206"_ns); + AddStaticElement(":status"_ns, "304"_ns); + AddStaticElement(":status"_ns, "400"_ns); + AddStaticElement(":status"_ns, "404"_ns); + AddStaticElement(":status"_ns, "500"_ns); + AddStaticElement("accept-charset"_ns); + AddStaticElement("accept-encoding"_ns, "gzip, deflate"_ns); + AddStaticElement("accept-language"_ns); + AddStaticElement("accept-ranges"_ns); + AddStaticElement("accept"_ns); + AddStaticElement("access-control-allow-origin"_ns); + AddStaticElement("age"_ns); + AddStaticElement("allow"_ns); + AddStaticElement("authorization"_ns); + AddStaticElement("cache-control"_ns); + AddStaticElement("content-disposition"_ns); + AddStaticElement("content-encoding"_ns); + AddStaticElement("content-language"_ns); + AddStaticElement("content-length"_ns); + AddStaticElement("content-location"_ns); + AddStaticElement("content-range"_ns); + AddStaticElement("content-type"_ns); + AddStaticElement("cookie"_ns); + AddStaticElement("date"_ns); + AddStaticElement("etag"_ns); + AddStaticElement("expect"_ns); + AddStaticElement("expires"_ns); + AddStaticElement("from"_ns); + AddStaticElement("host"_ns); + AddStaticElement("if-match"_ns); + AddStaticElement("if-modified-since"_ns); + AddStaticElement("if-none-match"_ns); + AddStaticElement("if-range"_ns); + AddStaticElement("if-unmodified-since"_ns); + AddStaticElement("last-modified"_ns); + AddStaticElement("link"_ns); + AddStaticElement("location"_ns); + AddStaticElement("max-forwards"_ns); + AddStaticElement("proxy-authenticate"_ns); + AddStaticElement("proxy-authorization"_ns); + AddStaticElement("range"_ns); + AddStaticElement("referer"_ns); + AddStaticElement("refresh"_ns); + AddStaticElement("retry-after"_ns); + AddStaticElement("server"_ns); + AddStaticElement("set-cookie"_ns); + AddStaticElement("strict-transport-security"_ns); + AddStaticElement("transfer-encoding"_ns); + AddStaticElement("user-agent"_ns); + AddStaticElement("vary"_ns); + AddStaticElement("via"_ns); + AddStaticElement("www-authenticate"_ns); + } +} + +size_t nvPair::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const { + return mName.SizeOfExcludingThisIfUnshared(aMallocSizeOf) + + mValue.SizeOfExcludingThisIfUnshared(aMallocSizeOf); +} + +size_t nvPair::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const { + return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf); +} + +nvFIFO::nvFIFO() : mByteCount(0), mTable() { InitializeStaticHeaders(); } + +nvFIFO::~nvFIFO() { Clear(); } + +void nvFIFO::AddElement(const nsCString& name, const nsCString& value) { + nvPair* pair = new nvPair(name, value); + mByteCount += pair->Size(); + mTable.PushFront(pair); +} + +void nvFIFO::AddElement(const nsCString& name) { AddElement(name, ""_ns); } + +void nvFIFO::RemoveElement() { + nvPair* pair = mTable.Pop(); + if (pair) { + mByteCount -= pair->Size(); + delete pair; + } +} + +uint32_t nvFIFO::ByteCount() const { return mByteCount; } + +uint32_t nvFIFO::Length() const { + return mTable.GetSize() + gStaticHeaders->GetSize(); +} + +uint32_t nvFIFO::VariableLength() const { return mTable.GetSize(); } + +size_t nvFIFO::StaticLength() const { return gStaticHeaders->GetSize(); } + +void nvFIFO::Clear() { + mByteCount = 0; + while (mTable.GetSize()) { + delete mTable.Pop(); + } +} + +const nvPair* nvFIFO::operator[](size_t index) const { + // NWGH - ensure index > 0 + // NWGH - subtract 1 from index here + if (index >= (mTable.GetSize() + gStaticHeaders->GetSize())) { + MOZ_ASSERT(false); + NS_WARNING("nvFIFO Table Out of Range"); + return nullptr; + } + if (index >= gStaticHeaders->GetSize()) { + return mTable.ObjectAt(index - gStaticHeaders->GetSize()); + } + return gStaticHeaders->ObjectAt(index); +} + +Http2BaseCompressor::Http2BaseCompressor() + : mOutput(nullptr), + mMaxBuffer(kDefaultMaxBuffer), + mMaxBufferSetting(kDefaultMaxBuffer), + mSetInitialMaxBufferSizeAllowed(true), + mPeakSize(0), + mPeakCount(0), + mDumpTables(false) { + mDynamicReporter = new HpackDynamicTableReporter(this); + RegisterStrongMemoryReporter(mDynamicReporter); +} + +Http2BaseCompressor::~Http2BaseCompressor() { + if (mPeakSize) { + Telemetry::Accumulate(mPeakSizeID, mPeakSize); + } + if (mPeakCount) { + Telemetry::Accumulate(mPeakCountID, mPeakCount); + } + UnregisterStrongMemoryReporter(mDynamicReporter); + mDynamicReporter->mCompressor = nullptr; + mDynamicReporter = nullptr; +} + +void Http2BaseCompressor::ClearHeaderTable() { mHeaderTable.Clear(); } + +size_t Http2BaseCompressor::SizeOfExcludingThis( + mozilla::MallocSizeOf aMallocSizeOf) const { + size_t size = 0; + for (uint32_t i = mHeaderTable.StaticLength(); i < mHeaderTable.Length(); + ++i) { + size += mHeaderTable[i]->SizeOfIncludingThis(aMallocSizeOf); + } + return size; +} + +void Http2BaseCompressor::MakeRoom(uint32_t amount, const char* direction) { + uint32_t countEvicted = 0; + uint32_t bytesEvicted = 0; + + // make room in the header table + while (mHeaderTable.VariableLength() && + ((mHeaderTable.ByteCount() + amount) > mMaxBuffer)) { + // NWGH - remove the "- 1" here + uint32_t index = mHeaderTable.Length() - 1; + LOG(("HTTP %s header table index %u %s %s removed for size.\n", direction, + index, mHeaderTable[index]->mName.get(), + mHeaderTable[index]->mValue.get())); + ++countEvicted; + bytesEvicted += mHeaderTable[index]->Size(); + mHeaderTable.RemoveElement(); + } + + if (!strcmp(direction, "decompressor")) { + Telemetry::Accumulate(Telemetry::HPACK_ELEMENTS_EVICTED_DECOMPRESSOR, + countEvicted); + Telemetry::Accumulate(Telemetry::HPACK_BYTES_EVICTED_DECOMPRESSOR, + bytesEvicted); + Telemetry::Accumulate( + Telemetry::HPACK_BYTES_EVICTED_RATIO_DECOMPRESSOR, + (uint32_t)((100.0 * (double)bytesEvicted) / (double)amount)); + } else { + Telemetry::Accumulate(Telemetry::HPACK_ELEMENTS_EVICTED_COMPRESSOR, + countEvicted); + Telemetry::Accumulate(Telemetry::HPACK_BYTES_EVICTED_COMPRESSOR, + bytesEvicted); + Telemetry::Accumulate( + Telemetry::HPACK_BYTES_EVICTED_RATIO_COMPRESSOR, + (uint32_t)((100.0 * (double)bytesEvicted) / (double)amount)); + } +} + +void Http2BaseCompressor::DumpState(const char* preamble) { + if (!LOG_ENABLED()) { + return; + } + + if (!mDumpTables) { + return; + } + + LOG(("%s", preamble)); + + LOG(("Header Table")); + uint32_t i; + uint32_t length = mHeaderTable.Length(); + uint32_t staticLength = mHeaderTable.StaticLength(); + // NWGH - make i = 1; i <= length; ++i + for (i = 0; i < length; ++i) { + const nvPair* pair = mHeaderTable[i]; + // NWGH - make this <= staticLength + LOG(("%sindex %u: %s %s", i < staticLength ? "static " : "", i, + pair->mName.get(), pair->mValue.get())); + } +} + +void Http2BaseCompressor::SetMaxBufferSizeInternal(uint32_t maxBufferSize) { + MOZ_ASSERT(maxBufferSize <= mMaxBufferSetting); + + uint32_t removedCount = 0; + + LOG(("Http2BaseCompressor::SetMaxBufferSizeInternal %u called", + maxBufferSize)); + + while (mHeaderTable.VariableLength() && + (mHeaderTable.ByteCount() > maxBufferSize)) { + mHeaderTable.RemoveElement(); + ++removedCount; + } + + mMaxBuffer = maxBufferSize; +} + +nsresult Http2BaseCompressor::SetInitialMaxBufferSize(uint32_t maxBufferSize) { + MOZ_ASSERT(mSetInitialMaxBufferSizeAllowed); + + if (mSetInitialMaxBufferSizeAllowed) { + mMaxBufferSetting = maxBufferSize; + return NS_OK; + } + + return NS_ERROR_FAILURE; +} + +void Http2BaseCompressor::SetDumpTables(bool dumpTables) { + mDumpTables = dumpTables; +} + +nsresult Http2Decompressor::DecodeHeaderBlock(const uint8_t* data, + uint32_t datalen, + nsACString& output, bool isPush) { + mSetInitialMaxBufferSizeAllowed = false; + mOffset = 0; + mData = data; + mDataLen = datalen; + mOutput = &output; + // Add in some space to hopefully not have to reallocate while decompressing + // the headers. 512 bytes seems like a good enough number. + mOutput->Truncate(); + mOutput->SetCapacity(datalen + 512); + mHeaderStatus.Truncate(); + mHeaderHost.Truncate(); + mHeaderScheme.Truncate(); + mHeaderPath.Truncate(); + mHeaderMethod.Truncate(); + mSeenNonColonHeader = false; + mIsPush = isPush; + + nsresult rv = NS_OK; + nsresult softfail_rv = NS_OK; + while (NS_SUCCEEDED(rv) && (mOffset < mDataLen)) { + bool modifiesTable = true; + const char* preamble = "Decompressor state after ?"; + if (mData[mOffset] & 0x80) { + rv = DoIndexed(); + preamble = "Decompressor state after indexed"; + } else if (mData[mOffset] & 0x40) { + rv = DoLiteralWithIncremental(); + preamble = "Decompressor state after literal with incremental"; + } else if (mData[mOffset] & 0x20) { + rv = DoContextUpdate(); + preamble = "Decompressor state after context update"; + } else if (mData[mOffset] & 0x10) { + modifiesTable = false; + rv = DoLiteralNeverIndexed(); + preamble = "Decompressor state after literal never index"; + } else { + modifiesTable = false; + rv = DoLiteralWithoutIndex(); + preamble = "Decompressor state after literal without index"; + } + DumpState(preamble); + if (rv == NS_ERROR_ILLEGAL_VALUE) { + if (modifiesTable) { + // Unfortunately, we can't count on our peer now having the same state + // as us, so let's terminate the session and we can try again later. + return NS_ERROR_FAILURE; + } + + // This is an http-level error that we can handle by resetting the stream + // in the upper layers. Let's note that we saw this, then continue + // decompressing until we either hit the end of the header block or find a + // hard failure. That way we won't get an inconsistent compression state + // with the server. + softfail_rv = rv; + rv = NS_OK; + } else if (rv == NS_ERROR_NET_RESET) { + // This happens when we detect connection-based auth being requested in + // the response headers. We'll paper over it for now, and the session will + // handle this as if it received RST_STREAM with HTTP_1_1_REQUIRED. + softfail_rv = rv; + rv = NS_OK; + } + } + + if (NS_FAILED(rv)) { + return rv; + } + + return softfail_rv; +} + +nsresult Http2Decompressor::DecodeInteger(uint32_t prefixLen, uint32_t& accum) { + accum = 0; + + if (prefixLen) { + uint32_t mask = (1 << prefixLen) - 1; + + accum = mData[mOffset] & mask; + ++mOffset; + + if (accum != mask) { + // the simple case for small values + return NS_OK; + } + } + + uint32_t factor = 1; // 128 ^ 0 + + // we need a series of bytes. The high bit signifies if we need another one. + // The first one is a a factor of 128 ^ 0, the next 128 ^1, the next 128 ^2, + // .. + + if (mOffset >= mDataLen) { + NS_WARNING("Ran out of data to decode integer"); + // This is session-fatal. + return NS_ERROR_FAILURE; + } + bool chainBit = mData[mOffset] & 0x80; + accum += (mData[mOffset] & 0x7f) * factor; + + ++mOffset; + factor = factor * 128; + + while (chainBit) { + // really big offsets are just trawling for overflows + if (accum >= 0x800000) { + NS_WARNING("Decoding integer >= 0x800000"); + // This is not strictly fatal to the session, but given the fact that + // the value is way to large to be reasonable, let's just tell our peer + // to go away. + return NS_ERROR_FAILURE; + } + + if (mOffset >= mDataLen) { + NS_WARNING("Ran out of data to decode integer"); + // This is session-fatal. + return NS_ERROR_FAILURE; + } + chainBit = mData[mOffset] & 0x80; + accum += (mData[mOffset] & 0x7f) * factor; + ++mOffset; + factor = factor * 128; + } + return NS_OK; +} + +static bool HasConnectionBasedAuth(const nsACString& headerValue) { + for (const nsACString& authMethod : + nsCCharSeparatedTokenizer(headerValue, '\n').ToRange()) { + if (authMethod.LowerCaseEqualsLiteral("ntlm")) { + return true; + } + if (authMethod.LowerCaseEqualsLiteral("negotiate")) { + return true; + } + } + + return false; +} + +nsresult Http2Decompressor::OutputHeader(const nsACString& name, + const nsACString& value) { + // exclusions + if (!mIsPush && + (name.EqualsLiteral("connection") || name.EqualsLiteral("host") || + name.EqualsLiteral("keep-alive") || + name.EqualsLiteral("proxy-connection") || name.EqualsLiteral("te") || + name.EqualsLiteral("transfer-encoding") || + name.EqualsLiteral("upgrade") || name.Equals(("accept-encoding")))) { + nsCString toLog(name); + LOG(("HTTP Decompressor illegal response header found, not gatewaying: %s", + toLog.get())); + return NS_OK; + } + + // Look for upper case characters in the name. + for (const char* cPtr = name.BeginReading(); cPtr && cPtr < name.EndReading(); + ++cPtr) { + if (*cPtr <= 'Z' && *cPtr >= 'A') { + nsCString toLog(name); + LOG(("HTTP Decompressor upper case response header found. [%s]\n", + toLog.get())); + return NS_ERROR_ILLEGAL_VALUE; + } + } + + // Look for CR OR LF in value - could be smuggling Sec 10.3 + // can map to space safely + for (const char* cPtr = value.BeginReading(); + cPtr && cPtr < value.EndReading(); ++cPtr) { + if (*cPtr == '\r' || *cPtr == '\n') { + char* wPtr = const_cast<char*>(cPtr); + *wPtr = ' '; + } + } + + // Status comes first + if (name.EqualsLiteral(":status")) { + nsAutoCString status("HTTP/2 "_ns); + status.Append(value); + status.AppendLiteral("\r\n"); + mOutput->Insert(status, 0); + mHeaderStatus = value; + } else if (name.EqualsLiteral(":authority")) { + mHeaderHost = value; + } else if (name.EqualsLiteral(":scheme")) { + mHeaderScheme = value; + } else if (name.EqualsLiteral(":path")) { + mHeaderPath = value; + } else if (name.EqualsLiteral(":method")) { + mHeaderMethod = value; + } + + // http/2 transport level headers shouldn't be gatewayed into http/1 + bool isColonHeader = false; + for (const char* cPtr = name.BeginReading(); cPtr && cPtr < name.EndReading(); + ++cPtr) { + if (*cPtr == ':') { + isColonHeader = true; + break; + } else if (*cPtr != ' ' && *cPtr != '\t') { + isColonHeader = false; + break; + } + } + + if (isColonHeader) { + // :status is the only pseudo-header field allowed in received HEADERS + // frames, PUSH_PROMISE allows the other pseudo-header fields + if (!name.EqualsLiteral(":status") && !mIsPush) { + LOG(("HTTP Decompressor found illegal response pseudo-header %s", + name.BeginReading())); + return NS_ERROR_ILLEGAL_VALUE; + } + if (mSeenNonColonHeader) { + LOG(("HTTP Decompressor found illegal : header %s", name.BeginReading())); + return NS_ERROR_ILLEGAL_VALUE; + } + LOG(("HTTP Decompressor not gatewaying %s into http/1", + name.BeginReading())); + return NS_OK; + } + + LOG(("Http2Decompressor::OutputHeader %s %s", name.BeginReading(), + value.BeginReading())); + mSeenNonColonHeader = true; + mOutput->Append(name); + mOutput->AppendLiteral(": "); + mOutput->Append(value); + mOutput->AppendLiteral("\r\n"); + + // Need to check if the server is going to try to speak connection-based auth + // with us. If so, we need to kill this via h2, and dial back with http/1.1. + // Technically speaking, the server should've just reset or goaway'd us with + // HTTP_1_1_REQUIRED, but there are some busted servers out there, so we need + // to check on our own to work around them. + if (name.EqualsLiteral("www-authenticate") || + name.EqualsLiteral("proxy-authenticate")) { + if (HasConnectionBasedAuth(value)) { + LOG3(("Http2Decompressor %p connection-based auth found in %s", this, + name.BeginReading())); + return NS_ERROR_NET_RESET; + } + } + return NS_OK; +} + +nsresult Http2Decompressor::OutputHeader(uint32_t index) { + // NWGH - make this < index + // bounds check + if (mHeaderTable.Length() <= index) { + LOG(("Http2Decompressor::OutputHeader index too large %u", index)); + // This is session-fatal. + return NS_ERROR_FAILURE; + } + + return OutputHeader(mHeaderTable[index]->mName, mHeaderTable[index]->mValue); +} + +nsresult Http2Decompressor::CopyHeaderString(uint32_t index, nsACString& name) { + // NWGH - make this < index + // bounds check + if (mHeaderTable.Length() <= index) { + // This is session-fatal. + return NS_ERROR_FAILURE; + } + + name = mHeaderTable[index]->mName; + return NS_OK; +} + +nsresult Http2Decompressor::CopyStringFromInput(uint32_t bytes, + nsACString& val) { + if (mOffset + bytes > mDataLen) { + // This is session-fatal. + return NS_ERROR_FAILURE; + } + + val.Assign(reinterpret_cast<const char*>(mData) + mOffset, bytes); + mOffset += bytes; + return NS_OK; +} + +nsresult Http2Decompressor::DecodeFinalHuffmanCharacter( + const HuffmanIncomingTable* table, uint8_t& c, uint8_t& bitsLeft) { + MOZ_ASSERT(mOffset <= mDataLen); + if (mOffset > mDataLen) { + NS_WARNING("DecodeFinalHuffmanCharacter would read beyond end of buffer"); + return NS_ERROR_FAILURE; + } + uint8_t mask = (1 << bitsLeft) - 1; + uint8_t idx = mData[mOffset - 1] & mask; + idx <<= (8 - bitsLeft); + // Don't update bitsLeft yet, because we need to check that value against the + // number of bits used by our encoding later on. We'll update when we are sure + // how many bits we've actually used. + + if (table->IndexHasANextTable(idx)) { + // Can't chain to another table when we're all out of bits in the encoding + LOG(("DecodeFinalHuffmanCharacter trying to chain when we're out of bits")); + return NS_ERROR_FAILURE; + } + + const HuffmanIncomingEntry* entry = table->Entry(idx); + + if (bitsLeft < entry->mPrefixLen) { + // We don't have enough bits to actually make a match, this is some sort of + // invalid coding + LOG(("DecodeFinalHuffmanCharacter does't have enough bits to match")); + return NS_ERROR_FAILURE; + } + + // This is a character! + if (entry->mValue == 256) { + // EOS + LOG(("DecodeFinalHuffmanCharacter actually decoded an EOS")); + return NS_ERROR_FAILURE; + } + c = static_cast<uint8_t>(entry->mValue & 0xFF); + bitsLeft -= entry->mPrefixLen; + + return NS_OK; +} + +uint8_t Http2Decompressor::ExtractByte(uint8_t bitsLeft, + uint32_t& bytesConsumed) { + MOZ_DIAGNOSTIC_ASSERT(mOffset < mDataLen); + uint8_t rv; + + if (bitsLeft) { + // Need to extract bitsLeft bits from the previous byte, and 8 - bitsLeft + // bits from the current byte + uint8_t mask = (1 << bitsLeft) - 1; + rv = (mData[mOffset - 1] & mask) << (8 - bitsLeft); + rv |= (mData[mOffset] & ~mask) >> bitsLeft; + } else { + rv = mData[mOffset]; + } + + // We always update these here, under the assumption that all 8 bits we got + // here will be used. These may be re-adjusted later in the case that we don't + // use up all 8 bits of the byte. + ++mOffset; + ++bytesConsumed; + + return rv; +} + +nsresult Http2Decompressor::DecodeHuffmanCharacter( + const HuffmanIncomingTable* table, uint8_t& c, uint32_t& bytesConsumed, + uint8_t& bitsLeft) { + uint8_t idx = ExtractByte(bitsLeft, bytesConsumed); + + if (table->IndexHasANextTable(idx)) { + if (mOffset >= mDataLen) { + if (!bitsLeft || (mOffset > mDataLen)) { + // TODO - does this get me into trouble in the new world? + // No info left in input to try to consume, we're done + LOG(("DecodeHuffmanCharacter all out of bits to consume, can't chain")); + return NS_ERROR_FAILURE; + } + + // We might get lucky here! + return DecodeFinalHuffmanCharacter(table->NextTable(idx), c, bitsLeft); + } + + // We're sorry, Mario, but your princess is in another castle + return DecodeHuffmanCharacter(table->NextTable(idx), c, bytesConsumed, + bitsLeft); + } + + const HuffmanIncomingEntry* entry = table->Entry(idx); + if (entry->mValue == 256) { + LOG(("DecodeHuffmanCharacter found an actual EOS")); + return NS_ERROR_FAILURE; + } + c = static_cast<uint8_t>(entry->mValue & 0xFF); + + // Need to adjust bitsLeft (and possibly other values) because we may not have + // consumed all of the bits of the byte we extracted. + if (entry->mPrefixLen <= bitsLeft) { + bitsLeft -= entry->mPrefixLen; + --mOffset; + --bytesConsumed; + } else { + bitsLeft = 8 - (entry->mPrefixLen - bitsLeft); + } + MOZ_ASSERT(bitsLeft < 8); + + return NS_OK; +} + +nsresult Http2Decompressor::CopyHuffmanStringFromInput(uint32_t bytes, + nsACString& val) { + if (mOffset + bytes > mDataLen) { + LOG(("CopyHuffmanStringFromInput not enough data")); + return NS_ERROR_FAILURE; + } + + uint32_t bytesRead = 0; + uint8_t bitsLeft = 0; + nsAutoCString buf; + nsresult rv; + uint8_t c; + + while (bytesRead < bytes) { + uint32_t bytesConsumed = 0; + rv = DecodeHuffmanCharacter(&HuffmanIncomingRoot, c, bytesConsumed, + bitsLeft); + if (NS_FAILED(rv)) { + LOG(("CopyHuffmanStringFromInput failed to decode a character")); + return rv; + } + + bytesRead += bytesConsumed; + buf.Append(c); + } + + if (bytesRead > bytes) { + LOG(("CopyHuffmanStringFromInput read more bytes than was allowed!")); + return NS_ERROR_FAILURE; + } + + if (bitsLeft) { + // The shortest valid code is 4 bits, so we know there can be at most one + // character left that our loop didn't decode. Check to see if that's the + // case, and if so, add it to our output. + rv = DecodeFinalHuffmanCharacter(&HuffmanIncomingRoot, c, bitsLeft); + if (NS_SUCCEEDED(rv)) { + buf.Append(c); + } + } + + if (bitsLeft > 7) { + LOG(("CopyHuffmanStringFromInput more than 7 bits of padding")); + return NS_ERROR_FAILURE; + } + + if (bitsLeft) { + // Any bits left at this point must belong to the EOS symbol, so make sure + // they make sense (ie, are all ones) + uint8_t mask = (1 << bitsLeft) - 1; + uint8_t bits = mData[mOffset - 1] & mask; + if (bits != mask) { + LOG( + ("CopyHuffmanStringFromInput ran out of data but found possible " + "non-EOS symbol")); + return NS_ERROR_FAILURE; + } + } + + val = buf; + LOG(("CopyHuffmanStringFromInput decoded a full string!")); + return NS_OK; +} + +nsresult Http2Decompressor::DoIndexed() { + // this starts with a 1 bit pattern + MOZ_ASSERT(mData[mOffset] & 0x80); + + // This is a 7 bit prefix + + uint32_t index; + nsresult rv = DecodeInteger(7, index); + if (NS_FAILED(rv)) { + return rv; + } + + LOG(("HTTP decompressor indexed entry %u\n", index)); + + if (index == 0) { + return NS_ERROR_FAILURE; + } + // NWGH - remove this line, since we'll keep everything 1-indexed + index--; // Internally, we 0-index everything, since this is, y'know, C++ + + return OutputHeader(index); +} + +nsresult Http2Decompressor::DoLiteralInternal(nsACString& name, + nsACString& value, + uint32_t namePrefixLen) { + // guts of doliteralwithoutindex and doliteralwithincremental + MOZ_ASSERT(((mData[mOffset] & 0xF0) == 0x00) || // withoutindex + ((mData[mOffset] & 0xF0) == 0x10) || // neverindexed + ((mData[mOffset] & 0xC0) == 0x40)); // withincremental + + // first let's get the name + uint32_t index; + nsresult rv = DecodeInteger(namePrefixLen, index); + if (NS_FAILED(rv)) { + return rv; + } + + // sanity check + if (mOffset >= mDataLen) { + NS_WARNING("Http2 Decompressor ran out of data"); + // This is session-fatal + return NS_ERROR_FAILURE; + } + + bool isHuffmanEncoded; + + if (!index) { + // name is embedded as a literal + uint32_t nameLen; + isHuffmanEncoded = mData[mOffset] & (1 << 7); + rv = DecodeInteger(7, nameLen); + if (NS_SUCCEEDED(rv)) { + if (isHuffmanEncoded) { + rv = CopyHuffmanStringFromInput(nameLen, name); + } else { + rv = CopyStringFromInput(nameLen, name); + } + } + LOG(("Http2Decompressor::DoLiteralInternal literal name %s", + name.BeginReading())); + } else { + // NWGH - make this index, not index - 1 + // name is from headertable + rv = CopyHeaderString(index - 1, name); + LOG(("Http2Decompressor::DoLiteralInternal indexed name %d %s", index, + name.BeginReading())); + } + if (NS_FAILED(rv)) { + return rv; + } + + // sanity check + if (mOffset >= mDataLen) { + NS_WARNING("Http2 Decompressor ran out of data"); + // This is session-fatal + return NS_ERROR_FAILURE; + } + + // now the value + uint32_t valueLen; + isHuffmanEncoded = mData[mOffset] & (1 << 7); + rv = DecodeInteger(7, valueLen); + if (NS_SUCCEEDED(rv)) { + if (isHuffmanEncoded) { + rv = CopyHuffmanStringFromInput(valueLen, value); + } else { + rv = CopyStringFromInput(valueLen, value); + } + } + if (NS_FAILED(rv)) { + return rv; + } + + int32_t newline = 0; + while ((newline = value.FindChar('\n', newline)) != -1) { + if (value[newline + 1] == ' ' || value[newline + 1] == '\t') { + LOG(("Http2Decompressor::Disallowing folded header value %s", + value.BeginReading())); + return NS_ERROR_ILLEGAL_VALUE; + } + // Increment this to avoid always finding the same newline and looping + // forever + ++newline; + } + + LOG(("Http2Decompressor::DoLiteralInternal value %s", value.BeginReading())); + return NS_OK; +} + +nsresult Http2Decompressor::DoLiteralWithoutIndex() { + // this starts with 0000 bit pattern + MOZ_ASSERT((mData[mOffset] & 0xF0) == 0x00); + + nsAutoCString name, value; + nsresult rv = DoLiteralInternal(name, value, 4); + + LOG(("HTTP decompressor literal without index %s %s\n", name.get(), + value.get())); + + if (NS_SUCCEEDED(rv)) { + rv = OutputHeader(name, value); + } + return rv; +} + +nsresult Http2Decompressor::DoLiteralWithIncremental() { + // this starts with 01 bit pattern + MOZ_ASSERT((mData[mOffset] & 0xC0) == 0x40); + + nsAutoCString name, value; + nsresult rv = DoLiteralInternal(name, value, 6); + if (NS_SUCCEEDED(rv)) { + rv = OutputHeader(name, value); + } + // Let NET_RESET continue on so that we don't get out of sync, as it is just + // used to kill the stream, not the session. + if (NS_FAILED(rv) && rv != NS_ERROR_NET_RESET) { + return rv; + } + + uint32_t room = nvPair(name, value).Size(); + if (room > mMaxBuffer) { + ClearHeaderTable(); + LOG( + ("HTTP decompressor literal with index not inserted due to size %u %s " + "%s\n", + room, name.get(), value.get())); + DumpState("Decompressor state after ClearHeaderTable"); + return rv; + } + + MakeRoom(room, "decompressor"); + + // Incremental Indexing implicitly adds a row to the header table. + mHeaderTable.AddElement(name, value); + + uint32_t currentSize = mHeaderTable.ByteCount(); + if (currentSize > mPeakSize) { + mPeakSize = currentSize; + } + + uint32_t currentCount = mHeaderTable.VariableLength(); + if (currentCount > mPeakCount) { + mPeakCount = currentCount; + } + + LOG(("HTTP decompressor literal with index 0 %s %s\n", name.get(), + value.get())); + + return rv; +} + +nsresult Http2Decompressor::DoLiteralNeverIndexed() { + // This starts with 0001 bit pattern + MOZ_ASSERT((mData[mOffset] & 0xF0) == 0x10); + + nsAutoCString name, value; + nsresult rv = DoLiteralInternal(name, value, 4); + + LOG(("HTTP decompressor literal never indexed %s %s\n", name.get(), + value.get())); + + if (NS_SUCCEEDED(rv)) { + rv = OutputHeader(name, value); + } + return rv; +} + +nsresult Http2Decompressor::DoContextUpdate() { + // This starts with 001 bit pattern + MOZ_ASSERT((mData[mOffset] & 0xE0) == 0x20); + + // Getting here means we have to adjust the max table size, because the + // compressor on the other end has signaled to us through HPACK (not H2) + // that it's using a size different from the currently-negotiated size. + // This change could either come about because we've sent a + // SETTINGS_HEADER_TABLE_SIZE, or because the encoder has decided that + // the current negotiated size doesn't fit its needs (for whatever reason) + // and so it needs to change it (either up to the max allowed by our SETTING, + // or down to some value below that) + uint32_t newMaxSize; + nsresult rv = DecodeInteger(5, newMaxSize); + LOG(("Http2Decompressor::DoContextUpdate new maximum size %u", newMaxSize)); + if (NS_FAILED(rv)) { + return rv; + } + + if (newMaxSize > mMaxBufferSetting) { + // This is fatal to the session - peer is trying to use a table larger + // than we have made available. + return NS_ERROR_FAILURE; + } + + SetMaxBufferSizeInternal(newMaxSize); + + return NS_OK; +} + +///////////////////////////////////////////////////////////////// + +nsresult Http2Compressor::EncodeHeaderBlock( + const nsCString& nvInput, const nsACString& method, const nsACString& path, + const nsACString& host, const nsACString& scheme, + const nsACString& protocol, bool simpleConnectForm, nsACString& output) { + mSetInitialMaxBufferSizeAllowed = false; + mOutput = &output; + output.Truncate(); + mParsedContentLength = -1; + + bool isWebsocket = (!simpleConnectForm && !protocol.IsEmpty()); + + // first thing's first - context size updates (if necessary) + if (mBufferSizeChangeWaiting) { + if (mLowestBufferSizeWaiting < mMaxBufferSetting) { + EncodeTableSizeChange(mLowestBufferSizeWaiting); + } + EncodeTableSizeChange(mMaxBufferSetting); + mBufferSizeChangeWaiting = false; + } + + // colon headers first + if (!simpleConnectForm) { + ProcessHeader(nvPair(":method"_ns, method), false, false); + ProcessHeader(nvPair(":path"_ns, path), true, false); + ProcessHeader(nvPair(":authority"_ns, host), false, false); + ProcessHeader(nvPair(":scheme"_ns, scheme), false, false); + if (isWebsocket) { + ProcessHeader(nvPair(":protocol"_ns, protocol), false, false); + } + } else { + ProcessHeader(nvPair(":method"_ns, method), false, false); + ProcessHeader(nvPair(":authority"_ns, host), false, false); + } + + // now the non colon headers + const char* beginBuffer = nvInput.BeginReading(); + + // This strips off the HTTP/1 method+path+version + int32_t crlfIndex = nvInput.Find("\r\n"); + while (true) { + int32_t startIndex = crlfIndex + 2; + + crlfIndex = nvInput.Find("\r\n", false, startIndex); + if (crlfIndex == -1) { + break; + } + + int32_t colonIndex = + nvInput.Find(":", false, startIndex, crlfIndex - startIndex); + if (colonIndex == -1) { + break; + } + + nsDependentCSubstring name = + Substring(beginBuffer + startIndex, beginBuffer + colonIndex); + // all header names are lower case in http/2 + ToLowerCase(name); + + // exclusions + if (name.EqualsLiteral("connection") || name.EqualsLiteral("host") || + name.EqualsLiteral("keep-alive") || + name.EqualsLiteral("proxy-connection") || name.EqualsLiteral("te") || + name.EqualsLiteral("transfer-encoding") || + name.EqualsLiteral("upgrade") || + name.EqualsLiteral("sec-websocket-key")) { + continue; + } + + // colon headers are for http/2 and this is http/1 input, so that + // is probably a smuggling attack of some kind + bool isColonHeader = false; + for (const char* cPtr = name.BeginReading(); + cPtr && cPtr < name.EndReading(); ++cPtr) { + if (*cPtr == ':') { + isColonHeader = true; + break; + } else if (*cPtr != ' ' && *cPtr != '\t') { + isColonHeader = false; + break; + } + } + if (isColonHeader) { + continue; + } + + int32_t valueIndex = colonIndex + 1; + + while (valueIndex < crlfIndex && beginBuffer[valueIndex] == ' ') + ++valueIndex; + + nsDependentCSubstring value = + Substring(beginBuffer + valueIndex, beginBuffer + crlfIndex); + + if (name.EqualsLiteral("content-length")) { + int64_t len; + nsCString tmp(value); + if (nsHttp::ParseInt64(tmp.get(), nullptr, &len)) { + mParsedContentLength = len; + } + } + + if (name.EqualsLiteral("cookie")) { + // cookie crumbling + bool haveMoreCookies = true; + int32_t nextCookie = valueIndex; + while (haveMoreCookies) { + int32_t semiSpaceIndex = + nvInput.Find("; ", false, nextCookie, crlfIndex - nextCookie); + if (semiSpaceIndex == -1) { + haveMoreCookies = false; + semiSpaceIndex = crlfIndex; + } + nsDependentCSubstring cookie = + Substring(beginBuffer + nextCookie, beginBuffer + semiSpaceIndex); + // cookies less than 20 bytes are not indexed + ProcessHeader(nvPair(name, cookie), false, cookie.Length() < 20); + nextCookie = semiSpaceIndex + 2; + } + } else { + // allow indexing of every non-cookie except authorization + ProcessHeader(nvPair(name, value), false, + name.EqualsLiteral("authorization")); + } + } + + // NB: This is a *really* ugly hack, but to do this in the right place (the + // transaction) would require totally reworking how/when the transaction + // creates its request stream, which is not worth the effort and risk of + // breakage just to add one header only to h2 connections. + if (!simpleConnectForm && !isWebsocket) { + // Add in TE: trailers for regular requests + nsAutoCString te("te"); + nsAutoCString trailers("trailers"); + ProcessHeader(nvPair(te, trailers), false, false); + } + + mOutput = nullptr; + DumpState("Compressor state after EncodeHeaderBlock"); + return NS_OK; +} + +void Http2Compressor::DoOutput(Http2Compressor::outputCode code, + const class nvPair* pair, uint32_t index) { + // start Byte needs to be calculated from the offset after + // the opcode has been written out in case the output stream + // buffer gets resized/relocated + uint32_t offset = mOutput->Length(); + uint8_t* startByte; + + switch (code) { + case kNeverIndexedLiteral: + LOG( + ("HTTP compressor %p neverindex literal with name reference %u %s " + "%s\n", + this, index, pair->mName.get(), pair->mValue.get())); + + // In this case, the index will have already been adjusted to be 1-based + // instead of 0-based. + EncodeInteger(4, index); // 0001 4 bit prefix + startByte = + reinterpret_cast<unsigned char*>(mOutput->BeginWriting()) + offset; + *startByte = (*startByte & 0x0f) | 0x10; + + if (!index) { + HuffmanAppend(pair->mName); + } + + HuffmanAppend(pair->mValue); + break; + + case kPlainLiteral: + LOG(("HTTP compressor %p noindex literal with name reference %u %s %s\n", + this, index, pair->mName.get(), pair->mValue.get())); + + // In this case, the index will have already been adjusted to be 1-based + // instead of 0-based. + EncodeInteger(4, index); // 0000 4 bit prefix + startByte = + reinterpret_cast<unsigned char*>(mOutput->BeginWriting()) + offset; + *startByte = *startByte & 0x0f; + + if (!index) { + HuffmanAppend(pair->mName); + } + + HuffmanAppend(pair->mValue); + break; + + case kIndexedLiteral: + LOG(("HTTP compressor %p literal with name reference %u %s %s\n", this, + index, pair->mName.get(), pair->mValue.get())); + + // In this case, the index will have already been adjusted to be 1-based + // instead of 0-based. + EncodeInteger(6, index); // 01 2 bit prefix + startByte = + reinterpret_cast<unsigned char*>(mOutput->BeginWriting()) + offset; + *startByte = (*startByte & 0x3f) | 0x40; + + if (!index) { + HuffmanAppend(pair->mName); + } + + HuffmanAppend(pair->mValue); + break; + + case kIndex: + LOG(("HTTP compressor %p index %u %s %s\n", this, index, + pair->mName.get(), pair->mValue.get())); + // NWGH - make this plain old index instead of index + 1 + // In this case, we are passed the raw 0-based C index, and need to + // increment to make it 1-based and comply with the spec + EncodeInteger(7, index + 1); + startByte = + reinterpret_cast<unsigned char*>(mOutput->BeginWriting()) + offset; + *startByte = *startByte | 0x80; // 1 1 bit prefix + break; + } +} + +// writes the encoded integer onto the output +void Http2Compressor::EncodeInteger(uint32_t prefixLen, uint32_t val) { + uint32_t mask = (1 << prefixLen) - 1; + uint8_t tmp; + + if (val < mask) { + // 1 byte encoding! + tmp = val; + mOutput->Append(reinterpret_cast<char*>(&tmp), 1); + return; + } + + if (mask) { + val -= mask; + tmp = mask; + mOutput->Append(reinterpret_cast<char*>(&tmp), 1); + } + + uint32_t q, r; + do { + q = val / 128; + r = val % 128; + tmp = r; + if (q) { + tmp |= 0x80; // chain bit + } + val = q; + mOutput->Append(reinterpret_cast<char*>(&tmp), 1); + } while (q); +} + +void Http2Compressor::HuffmanAppend(const nsCString& value) { + nsAutoCString buf; + uint8_t bitsLeft = 8; + uint32_t length = value.Length(); + uint32_t offset; + uint8_t* startByte; + + for (uint32_t i = 0; i < length; ++i) { + uint8_t idx = static_cast<uint8_t>(value[i]); + uint8_t huffLength = HuffmanOutgoing[idx].mLength; + uint32_t huffValue = HuffmanOutgoing[idx].mValue; + + if (bitsLeft < 8) { + // Fill in the least significant <bitsLeft> bits of the previous byte + // first + uint32_t val; + if (huffLength >= bitsLeft) { + val = huffValue & ~((1 << (huffLength - bitsLeft)) - 1); + val >>= (huffLength - bitsLeft); + } else { + val = huffValue << (bitsLeft - huffLength); + } + val &= ((1 << bitsLeft) - 1); + offset = buf.Length() - 1; + startByte = reinterpret_cast<unsigned char*>(buf.BeginWriting()) + offset; + *startByte = *startByte | static_cast<uint8_t>(val & 0xFF); + if (huffLength >= bitsLeft) { + huffLength -= bitsLeft; + bitsLeft = 8; + } else { + bitsLeft -= huffLength; + huffLength = 0; + } + } + + while (huffLength >= 8) { + uint32_t mask = ~((1 << (huffLength - 8)) - 1); + uint8_t val = ((huffValue & mask) >> (huffLength - 8)) & 0xFF; + buf.Append(reinterpret_cast<char*>(&val), 1); + huffLength -= 8; + } + + if (huffLength) { + // Fill in the most significant <huffLength> bits of the next byte + bitsLeft = 8 - huffLength; + uint8_t val = (huffValue & ((1 << huffLength) - 1)) << bitsLeft; + buf.Append(reinterpret_cast<char*>(&val), 1); + } + } + + if (bitsLeft != 8) { + // Pad the last <bitsLeft> bits with ones, which corresponds to the EOS + // encoding + uint8_t val = (1 << bitsLeft) - 1; + offset = buf.Length() - 1; + startByte = reinterpret_cast<unsigned char*>(buf.BeginWriting()) + offset; + *startByte = *startByte | val; + } + + // Now we know how long our encoded string is, we can fill in our length + uint32_t bufLength = buf.Length(); + offset = mOutput->Length(); + EncodeInteger(7, bufLength); + startByte = + reinterpret_cast<unsigned char*>(mOutput->BeginWriting()) + offset; + *startByte = *startByte | 0x80; + + // Finally, we can add our REAL data! + mOutput->Append(buf); + LOG( + ("Http2Compressor::HuffmanAppend %p encoded %d byte original on %d " + "bytes.\n", + this, length, bufLength)); +} + +void Http2Compressor::ProcessHeader(const nvPair inputPair, bool noLocalIndex, + bool neverIndex) { + uint32_t newSize = inputPair.Size(); + uint32_t headerTableSize = mHeaderTable.Length(); + uint32_t matchedIndex = 0u; + uint32_t nameReference = 0u; + bool match = false; + + LOG(("Http2Compressor::ProcessHeader %s %s", inputPair.mName.get(), + inputPair.mValue.get())); + + // NWGH - make this index = 1; index <= headerTableSize; ++index + for (uint32_t index = 0; index < headerTableSize; ++index) { + if (mHeaderTable[index]->mName.Equals(inputPair.mName)) { + // NWGH - make this nameReference = index + nameReference = index + 1; + if (mHeaderTable[index]->mValue.Equals(inputPair.mValue)) { + match = true; + matchedIndex = index; + break; + } + } + } + + // We need to emit a new literal + if (!match || noLocalIndex || neverIndex) { + if (neverIndex) { + DoOutput(kNeverIndexedLiteral, &inputPair, nameReference); + DumpState("Compressor state after literal never index"); + return; + } + + if (noLocalIndex || (newSize > (mMaxBuffer / 2)) || (mMaxBuffer < 128)) { + DoOutput(kPlainLiteral, &inputPair, nameReference); + DumpState("Compressor state after literal without index"); + return; + } + + // make sure to makeroom() first so that any implied items + // get preserved. + MakeRoom(newSize, "compressor"); + DoOutput(kIndexedLiteral, &inputPair, nameReference); + + mHeaderTable.AddElement(inputPair.mName, inputPair.mValue); + LOG(("HTTP compressor %p new literal placed at index 0\n", this)); + DumpState("Compressor state after literal with index"); + return; + } + + // emit an index + DoOutput(kIndex, &inputPair, matchedIndex); + + DumpState("Compressor state after index"); +} + +void Http2Compressor::EncodeTableSizeChange(uint32_t newMaxSize) { + uint32_t offset = mOutput->Length(); + EncodeInteger(5, newMaxSize); + uint8_t* startByte = + reinterpret_cast<uint8_t*>(mOutput->BeginWriting()) + offset; + *startByte = *startByte | 0x20; +} + +void Http2Compressor::SetMaxBufferSize(uint32_t maxBufferSize) { + mMaxBufferSetting = maxBufferSize; + SetMaxBufferSizeInternal(maxBufferSize); + if (!mBufferSizeChangeWaiting) { + mBufferSizeChangeWaiting = true; + mLowestBufferSizeWaiting = maxBufferSize; + } else if (maxBufferSize < mLowestBufferSizeWaiting) { + mLowestBufferSizeWaiting = maxBufferSize; + } +} + +} // namespace net +} // namespace mozilla |