From ed2ed0f7ae0604de83c3a08ef72471cfec6445bd Mon Sep 17 00:00:00 2001
From: Benjamin Sergeant <bsergean@gmail.com>
Date: Fri, 14 Aug 2020 18:13:34 -0700
Subject: [PATCH] (ixwebsocket client) handle HTTP redirects

---
 docs/CHANGELOG.md                    |  4 ++
 ixwebsocket/IXWebSocketHandshake.cpp | 22 ++++----
 ixwebsocket/IXWebSocketTransport.cpp | 78 ++++++++++++++++++----------
 ixwebsocket/IXWebSocketVersion.h     |  2 +-
 4 files changed, 69 insertions(+), 37 deletions(-)

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 279d0d8e..92ec03e6 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All changes to this project will be documented in this file.
 
+## [10.2.0] - 2020-08-14
+
+(ixwebsocket client) handle HTTP redirects
+
 ## [10.2.0] - 2020-08-13
 
 (ws) upgrade to latest version of nlohmann json (3.9.1 from 3.2.0)
diff --git a/ixwebsocket/IXWebSocketHandshake.cpp b/ixwebsocket/IXWebSocketHandshake.cpp
index 2c972c80..4ff676d8 100644
--- a/ixwebsocket/IXWebSocketHandshake.cpp
+++ b/ixwebsocket/IXWebSocketHandshake.cpp
@@ -170,20 +170,11 @@ namespace ix
         {
             std::stringstream ss;
             ss << "Expecting HTTP/1.1, got " << httpVersion << ". "
-               << "Rejecting connection to " << host << ":" << port << ", status: " << status
+               << "Rejecting connection to " << url << ", status: " << status
                << ", HTTP Status line: " << line;
             return WebSocketInitResult(false, status, ss.str());
         }
 
-        // We want an 101 HTTP status
-        if (status != 101)
-        {
-            std::stringstream ss;
-            ss << "Expecting status 101 (Switching Protocol), got " << status
-               << " status connecting to " << host << ":" << port << ", HTTP Status line: " << line;
-            return WebSocketInitResult(false, status, ss.str());
-        }
-
         auto result = parseHttpHeaders(_socket, isCancellationRequested);
         auto headersValid = result.first;
         auto headers = result.second;
@@ -193,6 +184,17 @@ namespace ix
             return WebSocketInitResult(false, status, "Error parsing HTTP headers");
         }
 
+        // We want an 101 HTTP status for websocket, otherwise it could be
+        // a redirection (like 301)
+        if (status != 101)
+        {
+            std::stringstream ss;
+            ss << "Expecting status 101 (Switching Protocol), got " << status
+               << " status connecting to " << url << ", HTTP Status line: " << line;
+
+            return WebSocketInitResult(false, status, ss.str(), headers, path);
+        }
+
         // Check the presence of the connection field
         if (headers.find("connection") == headers.end())
         {
diff --git a/ixwebsocket/IXWebSocketTransport.cpp b/ixwebsocket/IXWebSocketTransport.cpp
index 730249fd..43e9c53b 100644
--- a/ixwebsocket/IXWebSocketTransport.cpp
+++ b/ixwebsocket/IXWebSocketTransport.cpp
@@ -107,36 +107,62 @@ namespace ix
 
         std::string protocol, host, path, query;
         int port;
+        std::string remoteUrl(url);
 
-        if (!UrlParser::parse(url, protocol, host, path, query, port))
+        WebSocketInitResult result;
+        const int maxRedirections = 10;
+
+        for (int i = 0; i < maxRedirections; ++i)
         {
-            std::stringstream ss;
-            ss << "Could not parse url: '" << url << "'";
-            return WebSocketInitResult(false, 0, ss.str());
+            if (!UrlParser::parse(remoteUrl, protocol, host, path, query, port))
+            {
+                std::stringstream ss;
+                ss << "Could not parse url: '" << url << "'";
+                return WebSocketInitResult(false, 0, ss.str());
+            }
+
+            std::string errorMsg;
+            bool tls = protocol == "wss";
+            _socket = createSocket(tls, -1, errorMsg, _socketTLSOptions);
+            _perMessageDeflate = std::make_unique<WebSocketPerMessageDeflate>();
+
+            if (!_socket)
+            {
+                return WebSocketInitResult(false, 0, errorMsg);
+            }
+
+            WebSocketHandshake webSocketHandshake(_requestInitCancellation,
+                                                  _socket,
+                                                  _perMessageDeflate,
+                                                  _perMessageDeflateOptions,
+                                                  _enablePerMessageDeflate);
+
+            result = webSocketHandshake.clientHandshake(
+                remoteUrl, headers, host, path, port, timeoutSecs);
+
+            if (result.http_status >= 300 && result.http_status < 400)
+            {
+                auto it = result.headers.find("Location");
+                if (it == result.headers.end())
+                {
+                    std::stringstream ss;
+                    ss << "Missing Location Header for HTTP Redirect response. "
+                       << "Rejecting connection to " << url << ", status: " << result.http_status;
+                    result.errorStr = ss.str();
+                    break;
+                }
+
+                remoteUrl = it->second;
+                continue;
+            }
+
+            if (result.success)
+            {
+                setReadyState(ReadyState::OPEN);
+            }
+            return result;
         }
 
-        std::string errorMsg;
-        bool tls = protocol == "wss";
-        _socket = createSocket(tls, -1, errorMsg, _socketTLSOptions);
-        _perMessageDeflate = std::make_unique<WebSocketPerMessageDeflate>();
-
-        if (!_socket)
-        {
-            return WebSocketInitResult(false, 0, errorMsg);
-        }
-
-        WebSocketHandshake webSocketHandshake(_requestInitCancellation,
-                                              _socket,
-                                              _perMessageDeflate,
-                                              _perMessageDeflateOptions,
-                                              _enablePerMessageDeflate);
-
-        auto result =
-            webSocketHandshake.clientHandshake(url, headers, host, path, port, timeoutSecs);
-        if (result.success)
-        {
-            setReadyState(ReadyState::OPEN);
-        }
         return result;
     }
 
diff --git a/ixwebsocket/IXWebSocketVersion.h b/ixwebsocket/IXWebSocketVersion.h
index c4224a6c..8ffbff54 100644
--- a/ixwebsocket/IXWebSocketVersion.h
+++ b/ixwebsocket/IXWebSocketVersion.h
@@ -6,4 +6,4 @@
 
 #pragma once
 
-#define IX_WEBSOCKET_VERSION "10.2.0"
+#define IX_WEBSOCKET_VERSION "10.2.1"