Fix and add more decompressors

src/App.h

@@ -310,7 +310,7 @@ public:
             /* Initialize loop's deflate inflate streams */
             if (!loopData->zlibContext) {
                 loopData->zlibContext = new ZlibContext;
-                loopData->inflationStream = new InflationStream;
+                loopData->inflationStream = new InflationStream(CompressOptions::DEDICATED_DECOMPRESSOR);
                 loopData->deflationStream = new DeflationStream(CompressOptions::DEDICATED_COMPRESSOR);
             }
         }

src/HttpResponse.h

@@ -236,14 +236,14 @@ public:
         CompressOptions compressOptions = CompressOptions::DISABLED;
         if (secWebSocketExtensions.length() && webSocketContextData->compression != DISABLED) {
 
-            /* We always want shared inflation, (or the full 15)  */
+            /* Make sure to map SHARED_DECOMPRESSOR to windowBits = 0, not 1  */
             int wantedInflationWindow = 0;
-            if (webSocketContextData->compression & DEDICATED_DECOMPRESSOR) {
+            if ((webSocketContextData->compression & CompressOptions::_DECOMPRESSOR_MASK) != CompressOptions::SHARED_DECOMPRESSOR) {
-                wantedInflationWindow = 15;
+                wantedInflationWindow = (webSocketContextData->compression & CompressOptions::_DECOMPRESSOR_MASK) >> 12;
             }
 
-            /* Map from selected compressor */
+            /* Map from selected compressor (this automatically maps SHARED_COMPRESSOR to windowBits 0, not 1) */
-            int wantedCompressionWindow = (webSocketContextData->compression & 0xFF00) >> 8;
+            int wantedCompressionWindow = (webSocketContextData->compression & CompressOptions::_COMPRESSOR_MASK) >> 8;
 
             auto [negCompression, negCompressionWindow, negInflationWindow, negResponse] =
             negotiateCompression(true, wantedCompressionWindow, wantedInflationWindow,
@@ -252,7 +252,7 @@ public:
             if (negCompression) {
                 perMessageDeflate = true;
 
-                /* Map from windowBits to compressor */
+                /* Map from negotiated windowBits to compressor and decompressor */
                 if (negCompressionWindow == 0) {
                     compressOptions = CompressOptions::SHARED_COMPRESSOR;
                 } else {
@@ -261,11 +261,18 @@ public:
 
                     /* If we are dedicated and have the 3kb then correct any 4kb to 3kb,
                      * (they both share the windowBits = 9) */
-                    if (webSocketContextData->compression == DEDICATED_COMPRESSOR_3KB) {
+                    if (webSocketContextData->compression & DEDICATED_COMPRESSOR_3KB) {
                         compressOptions = DEDICATED_COMPRESSOR_3KB;
                     }
                 }
 
+                /* Here we modify the above compression with negotiated decompressor */
+                if (negInflationWindow == 0) {
+                    compressOptions = CompressOptions(compressOptions | CompressOptions::SHARED_DECOMPRESSOR);
+                } else {
+                    compressOptions = CompressOptions(compressOptions | (negInflationWindow << 12));
+                }
+
                 writeHeader("Sec-WebSocket-Extensions", negResponse);
             }
         }

src/PerMessageDeflate.h

@@ -21,17 +21,34 @@
 #define UWS_PERMESSAGEDEFLATE_H
 
 #include <cstdint>
+#include <cstring>
 
 /* We always define these options no matter if ZLIB is enabled or not */
 namespace uWS {
-    /* Compressor mode is 16 low bit where HIGH8(windowBits), LOW8(memLevel) */
+    /* Compressor mode is 12 lowest bits where HIGH4(windowBits), LOW8(memLevel).
-    enum CompressOptions : uint32_t {
+     * Decompressor mode is 4 highest bits (windowBits).
+     * If compressor or decompressor bits are 1, then they are shared.
+     * If everything is just simply 0, then everything is disabled. */
+    enum CompressOptions : uint16_t {
+        /* These are not actual compression options */
+        _COMPRESSOR_MASK = 0x0FFF,
+        _DECOMPRESSOR_MASK = 0xF000,
+        /* Disabled, shared, shared are "special" values */
         DISABLED = 0,
-        /* Highest bit is shared compressor */
+        SHARED_COMPRESSOR = 1,
-        SHARED_COMPRESSOR = (uint32_t)1 << (uint32_t)31,
+        SHARED_DECOMPRESSOR = 1 << 12,
-        /* Second highest bit is DEDICATED_DECOMPRESSOR */
+        /* Highest 4 bits describe decompressor */
-        DEDICATED_DECOMPRESSOR = (uint32_t)1 << (uint32_t)30,
+        DEDICATED_DECOMPRESSOR_32KB = 15 << 12,
-        /* Lowest 16 bit describe compressor */
+        DEDICATED_DECOMPRESSOR_16KB = 14 << 12,
+        DEDICATED_DECOMPRESSOR_8KB = 13 << 12,
+        DEDICATED_DECOMPRESSOR_4KB = 12 << 12,
+        DEDICATED_DECOMPRESSOR_2KB = 11 << 12,
+        DEDICATED_DECOMPRESSOR_1KB = 10 << 12,
+        DEDICATED_DECOMPRESSOR_512B = 9 << 12,
+        /* Same as 32kb */
+        DEDICATED_DECOMPRESSOR = 15 << 12,
+
+        /* Lowest 12 bit describe compressor */
         DEDICATED_COMPRESSOR_3KB = 9 << 8 | 1,
         DEDICATED_COMPRESSOR_4KB = 9 << 8 | 2,
         DEDICATED_COMPRESSOR_8KB = 10 << 8 | 3,
@@ -66,6 +83,8 @@ struct InflationStream {
     std::optional<std::string_view> inflate(ZlibContext * /*zlibContext*/, std::string_view compressed, size_t maxPayloadLength, bool /*reset*/) {
         return compressed.substr(0, std::min(maxPayloadLength, compressed.length()));
     }
+    InflationStream(CompressOptions /*compressOptions*/) {
+    }
 };
 struct DeflationStream {
     std::string_view deflate(ZlibContext * /*zlibContext*/, std::string_view raw, bool /*reset*/) {
@@ -196,8 +215,10 @@ struct DeflationStream {
 struct InflationStream {
     z_stream inflationStream = {};
 
-    InflationStream() {
+    InflationStream(CompressOptions compressOptions) {
-        inflateInit2(&inflationStream, -15);
+        /* Inflation windowBits are the top 4 bits of the 16 bit compressOptions */
+        //printf("%d\n", -(compressOptions >> 12));
+        inflateInit2(&inflationStream, -(compressOptions >> 12));
     }
 
     ~InflationStream() {
@@ -225,6 +246,11 @@ struct InflationStream {
         }
 #endif
 
+        /* Append tail to chunk */
+        unsigned char tail[4] = {0x00, 0x00, 0xff, 0xff};
+        memcpy((char *)compressed.data() + compressed.length(), tail, 4);
+        compressed = {compressed.data(), compressed.length() + 4};
+
         /* We clear this one here, could be done better */
         zlibContext->dynamicInflationBuffer.clear();
 

src/WebSocketContext.h

@@ -122,7 +122,7 @@ private:
                     if (webSocketData->compressionStatus == WebSocketData::CompressionStatus::COMPRESSED_FRAME) {
                             webSocketData->compressionStatus = WebSocketData::CompressionStatus::ENABLED;
 
-                            /* 9 bytes of padding for libdeflate */
+                            /* 9 bytes of padding for libdeflate, 4 for zlib */
                             webSocketData->fragmentBuffer.append("123456789");
 
                             LoopData *loopData = (LoopData *) us_loop_ext(

src/WebSocketData.h

@@ -56,12 +56,13 @@ public:
         compressionStatus = perMessageDeflate ? ENABLED : DISABLED;
 
         /* Initialize the dedicated sliding window(s) */
-        if (perMessageDeflate && (0 == (compressOptions & CompressOptions::SHARED_COMPRESSOR))) {
+        if (perMessageDeflate) {
-            deflationStream = new DeflationStream(compressOptions);
+            if ((compressOptions & CompressOptions::_COMPRESSOR_MASK) != CompressOptions::SHARED_COMPRESSOR) {
-        }
+                deflationStream = new DeflationStream(compressOptions);
-
+            }
-        if (perMessageDeflate && (compressOptions & CompressOptions::DEDICATED_DECOMPRESSOR)) {
+            if ((compressOptions & CompressOptions::_DECOMPRESSOR_MASK) != CompressOptions::SHARED_DECOMPRESSOR) {
-            inflationStream = new InflationStream();
+                inflationStream = new InflationStream(compressOptions);
+            }
         }
     }