Initial commit: Basic Gemini client.

1 files changed, 220 insertions, 0 deletions

diff --git a/geminiclient.cpp b/geminiclient.cpp
new file mode 100644
index 0000000..4a914a3
--- /dev/null
+++ b/geminiclient.cpp
@@ -0,0 +1,220 @@
+#include "geminiclient.hpp"
+
+#include <QDebug>
+
+GeminiClient::GeminiClient(QObject *parent) : QObject(parent)
+{
+    connect(&socket, &QSslSocket::encrypted, this, &GeminiClient::socketEncrypted);
+    connect(&socket, &QSslSocket::readyRead, this, &GeminiClient::socketReadyRead);
+    connect(&socket, &QSslSocket::disconnected, this, &GeminiClient::socketDisconnected);
+}
+
+bool GeminiClient::startRequest(const QUrl &url)
+{
+    if(socket.isOpen())
+        return false;
+
+    socket.connectToHostEncrypted(url.host(), url.port(1965));
+
+    buffer.resize(0);
+    body.resize(0);
+    is_receiving_body = false;
+
+    if(not socket.isOpen())
+        return false;
+
+    target_url = url;
+
+    return true;
+}
+
+bool GeminiClient::isInProgress() const
+{
+    return socket.isOpen();
+}
+
+bool GeminiClient::cancelRequest()
+{
+    socket.close();
+    return true;
+}
+
+void GeminiClient::socketEncrypted()
+{
+    QString request = target_url.toString() + "\r\n";
+
+    QByteArray request_bytes = request.toUtf8();
+
+    qint64 offset = 0;
+    while(offset < request_bytes.size()) {
+        auto const len = socket.write(request_bytes.constData() + offset, request_bytes.size() - offset);
+        if(len <= 0)
+        {
+            socket.close();
+            return;
+        }
+        offset += len;
+    }
+}
+
+void GeminiClient::socketReadyRead()
+{
+    QByteArray response = socket.readAll();
+
+    if(is_receiving_body)
+    {
+        body.append(response);
+    }
+    else
+    {
+        for(int i = 0; i < response.size(); i++)
+        {
+            if(response[i] == '\n') {
+                buffer.append(response.data(), i);
+                body.append(response.data() + i + 1, response.size() - i - 1);
+
+                // "XY " <META> <CR> <LF>
+                if(buffer.size() <= 5) {
+                    socket.close();
+                    qDebug() << buffer;
+                    emit protocolViolation("Line is too short for valid protocol");
+                    return;
+                }
+                if(buffer[buffer.size() - 1] != '\r') {
+                    socket.close();
+                    qDebug() << buffer;
+                    emit protocolViolation("Line does not end with <CR> <LF>");
+                    return;
+                }
+                if(not isdigit(buffer[0])) {
+                    socket.close();
+                    qDebug() << buffer;
+                    emit protocolViolation("First character is not a digit.");
+                    return;
+                }
+                if(not isdigit(buffer[1])) {
+                    socket.close();
+                    qDebug() << buffer;
+                    emit protocolViolation("Second character is not a digit.");
+                    return;
+                }
+                // TODO: Implement stricter version
+                // if(buffer[2] != ' ') {
+                if(not isspace(buffer[2])) {
+                    socket.close();
+                    qDebug() << buffer;
+                    emit protocolViolation("Third character is not a space.");
+                    return;
+                }
+
+                QString meta = QString::fromUtf8(buffer.data() + 3, buffer.size() - 4);
+
+                int primary_code = buffer[0] - '0';
+                int secondary_code = buffer[1] - '0';
+
+                qDebug() << primary_code << secondary_code << meta;
+
+                // We don't need to receive any data after that.
+                if(primary_code != 2)
+                    socket.close();
+
+                switch(primary_code)
+                {
+                case 1: // requesting input
+                    emit inputRequired(meta);
+                    return;
+
+                case 2: // success
+                    is_receiving_body = true;
+                    mime_type = QString(meta);
+                    return;
+
+                case 3: { // redirect
+                    QUrl new_url(meta);
+                    if(new_url.isValid()) {
+                        if(new_url.isRelative())
+                            new_url =  target_url.resolved(new_url);
+                        assert(not new_url.isRelative());
+
+                        emit redirected(new_url, (secondary_code == 1));
+                    }
+                    else {
+                        emit protocolViolation("Invalid URL for redirection!");
+                    }
+                    return;
+                }
+
+                case 4: { // temporary failure
+                    TemporaryFailure type = TemporaryFailure::unspecified;
+                    switch(secondary_code)
+                    {
+                    case 1: type = TemporaryFailure::server_unavailable; break;
+                    case 2: type = TemporaryFailure::cgi_error; break;
+                    case 3: type = TemporaryFailure::proxy_error; break;
+                    case 4: type = TemporaryFailure::slow_down; break;
+                    }
+                    emit temporaryFailure(type, meta);
+                    return;
+                }
+
+                case 5: { // permanent failure
+                    PermanentFailure type = PermanentFailure::unspecified;
+                    switch(secondary_code)
+                    {
+                    case 1: type = PermanentFailure::not_found; break;
+                    case 2: type = PermanentFailure::gone; break;
+                    case 3: type = PermanentFailure::proxy_request_required; break;
+                    case 9: type = PermanentFailure::bad_request; break;
+                    }
+                    emit permanentFailure(type, meta);
+                    return;
+                }
+
+                case 6: // client certificate required
+                    switch(secondary_code)
+                    {
+                    case 1:
+                        emit transientCertificateRequested(meta);
+                        return;
+
+                    case 2:
+                        emit authorisedCertificateRequested(meta);
+                        return;
+
+                    case 3:
+                        emit certificateRejected(CertificateRejection::not_accepted, meta);
+                        return;
+
+                    case 4:
+                        emit certificateRejected(CertificateRejection::future_certificate_rejected, meta);
+                        return;
+
+                    case 5:
+                        emit certificateRejected(CertificateRejection::expired_certificate_rejected, meta);
+                        return;
+
+                    default:
+                        emit certificateRejected(CertificateRejection::unspecified, meta);
+                        return;
+                    }
+                    return;
+
+                default:
+                    emit protocolViolation("Unspecified status code used!");
+                    return;
+                }
+
+                assert(false and "unreachable");
+            }
+        }
+        buffer.append(response);
+    }
+}
+
+void GeminiClient::socketDisconnected()
+{
+    if(is_receiving_body) {
+        body.append(socket.readAll());
+        emit requestComplete(body, mime_type);
+    }
+}