#21 Check WS response headers

src/protocol/websocket.cpp

@@ -5,6 +5,7 @@
  */
 
 #include <string>
+#include <unordered_map>
 #include <algorithm>
 #include "websocket.hpp"
 #include <ftl/lib/loguru.hpp>
@@ -228,7 +229,6 @@ void WebSocketBase<SocketT>::connect(const ftl::URI& uri, int timeout) {
     http += "Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==\r\n";
     http += "Sec-WebSocket-Version: 13\r\n";
     http += "\r\n";
-    // TODO(Seb): check/process HTTP response code
 
     int rc = SocketT::send(http.c_str(), static_cast<int>(http.length()));
     if (rc != static_cast<int>(http.length())) {
@@ -252,7 +252,8 @@ void WebSocketBase<SocketT>::connect(const ftl::URI& uri, int timeout) {
                         + uri.getHost() + ": " + line);
     }
 
-    // TODO(Seb): verify response headers,
+    std::unordered_map<std::string, std::string> headers;
+
     while (true) {
         for (i = 0; i < 2 || (i < 255 && line[i-2] != '\r' && line[i-1] != '\n'); ++i) {
             if (SocketT::recv(line+i, 1) == 0) {
@@ -260,7 +261,23 @@ void WebSocketBase<SocketT>::connect(const ftl::URI& uri, int timeout) {
             }
         }
         if (line[0] == '\r' && line[1] == '\n') { break; }
-    }
+
+        // Split the headers into a map for checking
+        line[i] = 0;
+        const std::string cppline(line);
+        const auto ix = cppline.find(":");
+        const auto label = cppline.substr(0, ix);
+        const auto value = cppline.substr(ix + 2, cppline.size() - ix - 4);
+        headers[label] = value;
+    }
+
+    // Validate some of the headers
+    if (headers.count("Connection") == 0 || headers.at("Connection") != "upgrade")
+        throw FTL_Error("Missing WS connection header");
+    if (headers.count("Upgrade") == 0 || headers.at("Upgrade") != "websocket")
+        throw FTL_Error("Missing WS Upgrade");
+    if (headers.count("Sec-WebSocket-Accept") == 0)
+        throw FTL_Error("Missing WS accept header");
 }
 
 template<typename SocketT>