Allow for any websocket protocol containing mqtt

I've see various variations, like mqtt and mqttv31. The 3.1.1 specs are clear what it should be, but the 3.1 specs aren't. So, allowing anything with mqtt in it.
halfgaar · Jul 3, 2022 · c24becf · c24becf
1 parent 1ca1bdf
commit c24becf
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Showing 3 changed files with 12 additions and 8 deletions.
diff --git a/iowrapper.cpp b/iowrapper.cpp
@@ -371,7 +371,8 @@ ssize_t IoWrapper::readWebsocketAndOrSsl(int fd, void *buf, size_t nbytes, IoWra
                 {
                     std::string websocketKey;
                     int websocketVersion;
-                    if (parseHttpHeader(websocketPendingBytes, websocketKey, websocketVersion))
+                    std::string subprotocol;
+                    if (parseHttpHeader(websocketPendingBytes, websocketKey, websocketVersion, subprotocol))
                     {
                         if (websocketKey.empty())
                             throw BadHttpRequest("No websocket key specified.");
@@ -380,7 +381,7 @@ ssize_t IoWrapper::readWebsocketAndOrSsl(int fd, void *buf, size_t nbytes, IoWra
 
                         const std::string acceptString = generateWebsocketAcceptString(websocketKey);
 
-                        std::string answer = generateWebsocketAnswer(acceptString);
+                        std::string answer = generateWebsocketAnswer(acceptString, subprotocol);
                         parentClient->writeText(answer);
                         websocketState = WebsocketState::Upgrading;
                         websocketPendingBytes.reset();

diff --git a/utils.cpp b/utils.cpp
@@ -348,7 +348,7 @@ bool isPowerOfTwo(int n)
     return (n != 0) && (n & (n - 1)) == 0;
 }
 
-bool parseHttpHeader(CirBuf &buf, std::string &websocket_key, int &websocket_version)
+bool parseHttpHeader(CirBuf &buf, std::string &websocket_key, int &websocket_version, std::string &subprotocol)
 {
     const std::string s(buf.tailPtr(), buf.usedBytes());
     std::istringstream is(s);
@@ -397,8 +397,11 @@ bool parseHttpHeader(CirBuf &buf, std::string &websocket_key, int &websocket_ver
             websocket_key = value;
         else if (name == "sec-websocket-version")
             websocket_version = stoi(value);
-        else if (name == "sec-websocket-protocol" && value_lower == "mqtt")
+        else if (name == "sec-websocket-protocol" && strContains(value_lower, "mqtt"))
+        {
+            subprotocol = value;
             subprotocol_seen = true;
+        }
     }
 
     if (doubleEmptyLine)
@@ -489,14 +492,14 @@ std::string generateBadHttpRequestReponse(const std::string &msg)
     return oss.str();
 }
 
-std::string generateWebsocketAnswer(const std::string &acceptString)
+std::string generateWebsocketAnswer(const std::string &acceptString, const std::string &subprotocol)
 {
     std::ostringstream oss;
     oss << "HTTP/1.1 101 Switching Protocols\r\n";
     oss << "Upgrade: websocket\r\n";
     oss << "Connection: Upgrade\r\n";
     oss << "Sec-WebSocket-Accept: " << acceptString << "\r\n";
-    oss << "Sec-WebSocket-Protocol: mqtt\r\n";
+    oss << "Sec-WebSocket-Protocol: " << subprotocol << "\r\n";
     oss << "\r\n";
     oss.flush();
     return oss.str();

diff --git a/utils.h b/utils.h
@@ -77,15 +77,15 @@ std::string str_tolower(std::string s);
 bool stringTruthiness(const std::string &val);
 bool isPowerOfTwo(int val);
 
-bool parseHttpHeader(CirBuf &buf, std::string &websocket_key, int &websocket_version);
+bool parseHttpHeader(CirBuf &buf, std::string &websocket_key, int &websocket_version, std::string &subprotocol);
 
 std::vector<char> base64Decode(const std::string &s);
 std::string base64Encode(const unsigned char *input, const int length);
 std::string generateWebsocketAcceptString(const std::string &websocketKey);
 
 std::string generateInvalidWebsocketVersionHttpHeaders(const int wantedVersion);
 std::string generateBadHttpRequestReponse(const std::string &msg);
-std::string generateWebsocketAnswer(const std::string &acceptString);
+std::string generateWebsocketAnswer(const std::string &acceptString, const std::string &subprotocol);
 
 void testSsl(const std::string &fullchain, const std::string &privkey);