Add an endpoint to check connectivity to WOPI server

The endpoint is accessible at /hosting/wopiAccessCheck

You send it a POST with input json:
{
	"callbackUrl: "<url-to-my-wopi-host>"
}

For instance:
curl -ki https://localhost:9980/hosting/wopiAccessCheck --header "Content-Type: application/json" -d '{"callbackUrl":"https://cool.local"}'

Returns json such as:
{
	"status": 0,
	"details": "OK"
}
With status and details giving hints to what went wrong if it did.

The callbackUrl needs just to be an HTTPS endpoint, it does not need to
be the wopi service but can be only a healthcheck url for instance.

Signed-off-by: Méven Car <meven.car@collabora.com>
Change-Id: Ibdef0bbf0d2fd98e3d293a06dfcfc79478d618e5

wsd/ClientRequestDispatcher.cpp

@@ -9,10 +9,15 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+#include <Poco/Net/HTTPRequest.h>
+#include <Poco/Net/HTTPResponse.h>
+#include <Poco/Net/WebSocket.h>
 #include <config.h>
 #include <config_version.h>
 
 #include <ClientRequestDispatcher.hpp>
+#include <cstdio>
+#include <istream>
 
 #if ENABLE_FEATURE_LOCK
 #include "CommandControl.hpp"
@@ -49,9 +54,15 @@
 #include <Poco/MemoryStream.h>
 #include <Poco/Net/HTMLForm.h>
 #include <Poco/Net/NetException.h>
+#include <Poco/Net/DNS.h>
 #include <Poco/Net/PartHandler.h>
+#if !MOBILEAPP
+#include <Poco/Net/SSLException.h>
+#include <Poco/Net/HTTPSClientSession.h>
+#endif // !MOBILEAPP
 #include <Poco/SAX/InputSource.h>
 #include <Poco/StreamCopier.h>
+#include <Poco/Timespan.h>
 
 #include <map>
 #include <memory>
@@ -797,6 +808,8 @@ void ClientRequestDispatcher::handleIncomingMessage(SocketDisposition& dispositi
                 handleWopiDiscoveryRequest(requestDetails, socket);
             else if (requestDetails.equals(1, "capabilities"))
                 handleCapabilitiesRequest(request, socket);
+            else if (requestDetails.equals(1, "wopiAccessCheck"))
+                handleWopiAccessCheckRequest(request, message, socket);
         }
         else if (requestDetails.isGet("/robots.txt"))
             handleRobotsTxtRequest(request, socket);
@@ -990,6 +1003,155 @@ void ClientRequestDispatcher::handleWopiDiscoveryRequest(
     LOG_INF("Sent discovery.xml successfully.");
 }
 
+void ClientRequestDispatcher::handleWopiAccessCheckRequest(const Poco::Net::HTTPRequest& request,
+                                                           Poco::MemoryInputStream& message,
+                                                           const std::shared_ptr<StreamSocket>& socket)
+{
+    assert(socket && "Must have a valid socket");
+
+    LOG_DBG("Wopi Access Check request: " << request.getURI());
+
+    // Poco::JSON
+    Poco::JSON::Parser jsonParser;
+    Poco::Dynamic::Var parsingResult;
+    Poco::JSON::Object::Ptr object;
+    Poco::URI uri;
+
+    std::string text(std::istreambuf_iterator<char>(message), {});
+    try
+    {
+        parsingResult = jsonParser.parse(text);
+        object = parsingResult.extract<Poco::JSON::Object::Ptr>();
+
+        auto callbackUrlStr = object->getValue<std::string>("callbackUrl");
+
+        uri = Poco::URI(callbackUrlStr);
+    }
+    catch (const std::exception& exception)
+    {
+        LOG_ERR_S("Wopi Access Check request error, json object expected got ["
+                  << text << "] on request to URL: " << request.getURI() << exception.what());
+
+        HttpHelper::sendErrorAndShutdown(http::StatusCode::BadRequest, socket);
+        return;
+    }
+
+    enum class CheckStatus
+    {
+        Ok = 0,
+        NotHttpSucess,
+        HostNotFound,
+        HostUnReachable,
+        UnspecifiedError,
+        ConnectionAborted,
+        ConnectionRefused,
+        InvalidCertificate,
+        CertificateValidation,
+        NotHttps,
+        NoScheme,
+        Timeout,
+    };
+    std::map<CheckStatus, std::string> checkStatusNames = {
+        { CheckStatus::Ok, "Ok" },
+        { CheckStatus::NotHttpSucess, "NOT_HTTP_SUCESS" },
+        { CheckStatus::HostNotFound, "HOST_NOT_FOUND" },
+        { CheckStatus::HostUnReachable, "HOST_UNREACHABLE" },
+        { CheckStatus::UnspecifiedError, "UNSPECIFIED_ERROR" },
+        { CheckStatus::ConnectionAborted, "CONNECTION_ABORTED" },
+        { CheckStatus::ConnectionRefused, "CONNECTION_REFUSED" },
+        { CheckStatus::InvalidCertificate, "INVALID_CERTIFICATE" },
+        { CheckStatus::NotHttps, "NOT_HTTPS" },
+        { CheckStatus::NoScheme, "NO_SCHEME" },
+        { CheckStatus::Timeout, "TIMEOUT" }
+    };
+
+    CheckStatus result = CheckStatus::Ok;
+
+    if (uri.getScheme().empty())
+    {
+        result = CheckStatus::NoScheme;
+    }
+    else if (uri.getScheme() != "https")
+    {
+        result = CheckStatus::NotHttps;
+    }
+    else
+    {
+        // request the url
+        try
+        {
+            const auto hostAddress(Poco::Net::DNS::resolve(uri.getHost()));
+
+            Poco::Net::HTTPSClientSession httpSession(uri.getHost(), 443);
+            httpSession.setConnectTimeout(Poco::Timespan(0, 300));
+            Poco::Net::HTTPRequest httpRequest(Poco::Net::HTTPRequest::HTTP_GET,
+                                               uri.getPathAndQuery());
+            httpSession.sendRequest(httpRequest);
+            Poco::Net::HTTPResponse response;
+            std::istream* responseStream = &httpSession.receiveResponse(response);
+
+            std::cout << responseStream->rdbuf();
+            if (response.getStatus() != 200)
+            {
+                result = CheckStatus::NotHttpSucess;
+            }
+        }
+        catch (Poco::Net::HostNotFoundException& hostNotfound)
+        {
+            result = CheckStatus::HostNotFound;
+        }
+        catch (Poco::Net::NoAddressFoundException& noAddressFound)
+        {
+            result = CheckStatus::HostUnReachable;
+        }
+        catch (Poco::Net::ConnectionAbortedException& connectionAborted)
+        {
+            result = CheckStatus::ConnectionAborted;
+        }
+        catch (Poco::Net::ConnectionRefusedException& exception)
+        {
+            result = CheckStatus::ConnectionRefused;
+        }
+        catch (Poco::Net::InvalidCertificateException& invalidCertification)
+        {
+            result = CheckStatus::InvalidCertificate;
+        }
+        catch (Poco::Net::CertificateValidationException& certificateValidation)
+        {
+            result = CheckStatus::CertificateValidation;
+        }
+        catch (Poco::TimeoutException& timeout)
+        {
+            result = CheckStatus::Timeout;
+        }
+        catch (Poco::Exception& exception)
+        {
+            LOG_ERR_S("Wopi Access Check request error, query to callback ["
+                      << uri.toString() << "] failed:" << exception.what() << exception.className()
+                      << exception.name() << exception.message());
+
+            result = CheckStatus::UnspecifiedError;
+        }
+    }
+
+    // construct the result
+    Poco::JSON::Object::Ptr status = new Poco::JSON::Object;
+    status->set("status", (int)result);
+    status->set("details", checkStatusNames[result]);
+
+    std::ostringstream ostrJSON;
+    status->stringify(ostrJSON);
+    const auto output = ostrJSON.str();
+
+    http::Response httpResponse(http::StatusCode::OK);
+    FileServerRequestHandler::hstsHeaders(httpResponse);
+    httpResponse.set("Last-Modified", Util::getHttpTimeNow());
+    httpResponse.setBody(output, "application/json");
+    httpResponse.set("X-Content-Type-Options", "nosniff");
+    socket->sendAndShutdown(httpResponse);
+    LOG_INF("Sent capabilities.json successfully.");
+}
+
 void ClientRequestDispatcher::handleClipboardRequest(const Poco::Net::HTTPRequest& request,
                                                      Poco::MemoryInputStream& message,
                                                      SocketDisposition& disposition,

wsd/ClientRequestDispatcher.hpp

@@ -67,6 +67,10 @@ class ClientRequestDispatcher final : public SimpleSocketHandler
     void handleCapabilitiesRequest(const Poco::Net::HTTPRequest& request,
                                    const std::shared_ptr<StreamSocket>& socket);
 
+    void handleWopiAccessCheckRequest(const Poco::Net::HTTPRequest& request,
+                                   Poco::MemoryInputStream& message,
+                                   const std::shared_ptr<StreamSocket>& socket);
+
     static void handleClipboardRequest(const Poco::Net::HTTPRequest& request,
                                        Poco::MemoryInputStream& message,
                                        SocketDisposition& disposition,