GUACAMOLE-623: Add support for setting terminal font for Kubernetes via "argv".

src/protocols/kubernetes/Makefile.am

@@ -29,6 +29,7 @@ ACLOCAL_AMFLAGS = -I m4
 lib_LTLIBRARIES = libguac-client-kubernetes.la
 
 libguac_client_kubernetes_la_SOURCES = \
+    argv.c                             \
     client.c                           \
     clipboard.c                        \
     input.c                            \
@@ -41,6 +42,7 @@ libguac_client_kubernetes_la_SOURCES = \
     user.c
 
 noinst_HEADERS = \
+    argv.h       \
     client.h     \
     clipboard.h  \
     input.h      \

src/protocols/kubernetes/argv.c

@@ -0,0 +1,195 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "config.h"
+#include "argv.h"
+#include "kubernetes.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
+#include <guacamole/user.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * All Kubernetes connection settings which may be updated by unprivileged
+ * users through "argv" streams.
+ */
+typedef enum guac_kubernetes_argv_setting {
+
+    /**
+     * The color scheme of the terminal.
+     */
+    GUAC_KUBERNETES_ARGV_SETTING_COLOR_SCHEME,
+
+    /**
+     * The name of the font family used by the terminal.
+     */
+    GUAC_KUBERNETES_ARGV_SETTING_FONT_NAME,
+
+    /**
+     * The size of the font used by the terminal, in points.
+     */
+    GUAC_KUBERNETES_ARGV_SETTING_FONT_SIZE
+
+} guac_kubernetes_argv_setting;
+
+/**
+ * The value or current status of a connection parameter received over an
+ * "argv" stream.
+ */
+typedef struct guac_kubernetes_argv {
+
+    /**
+     * The specific setting being updated.
+     */
+    guac_kubernetes_argv_setting setting;
+
+    /**
+     * Buffer space for containing the received argument value.
+     */
+    char buffer[GUAC_KUBERNETES_ARGV_MAX_LENGTH];
+
+    /**
+     * The number of bytes received so far.
+     */
+    int length;
+
+} guac_kubernetes_argv;
+
+/**
+ * Handler for "blob" instructions which appends the data from received blobs
+ * to the end of the in-progress argument value buffer.
+ *
+ * @see guac_user_blob_handler
+ */
+static int guac_kubernetes_argv_blob_handler(guac_user* user,
+        guac_stream* stream, void* data, int length) {
+
+    guac_kubernetes_argv* argv = (guac_kubernetes_argv*) stream->data;
+
+    /* Calculate buffer size remaining, including space for null terminator,
+     * adjusting received length accordingly */
+    int remaining = sizeof(argv->buffer) - argv->length - 1;
+    if (length > remaining)
+        length = remaining;
+
+    /* Append received data to end of buffer */
+    memcpy(argv->buffer + argv->length, data, length);
+    argv->length += length;
+
+    return 0;
+
+}
+
+/**
+ * Handler for "end" instructions which applies the changes specified by the
+ * argument value buffer associated with the stream.
+ *
+ * @see guac_user_end_handler
+ */
+static int guac_kubernetes_argv_end_handler(guac_user* user,
+        guac_stream* stream) {
+
+    int size;
+
+    guac_client* client = user->client;
+    guac_kubernetes_client* kubernetes_client = (guac_kubernetes_client*) client->data;
+    guac_terminal* terminal = kubernetes_client->term;
+
+    /* Append null terminator to value */
+    guac_kubernetes_argv* argv = (guac_kubernetes_argv*) stream->data;
+    argv->buffer[argv->length] = '\0';
+
+    /* Apply changes to chosen setting */
+    switch (argv->setting) {
+
+        /* Update color scheme */
+        case GUAC_KUBERNETES_ARGV_SETTING_COLOR_SCHEME:
+            guac_terminal_apply_color_scheme(terminal, argv->buffer);
+            break;
+
+        /* Update font name */
+        case GUAC_KUBERNETES_ARGV_SETTING_FONT_NAME:
+            guac_terminal_apply_font(terminal, argv->buffer, -1, 0);
+            break;
+
+        /* Update font size */
+        case GUAC_KUBERNETES_ARGV_SETTING_FONT_SIZE:
+
+            /* Update only if font size is sane */
+            size = atoi(argv->buffer);
+            if (size > 0) {
+                guac_terminal_apply_font(terminal, NULL, size,
+                        kubernetes_client->settings->resolution);
+            }
+
+            break;
+
+    }
+
+    /* Update Kubernetes terminal size */
+    guac_kubernetes_resize(client, terminal->term_height,
+            terminal->term_width);
+
+    free(argv);
+    return 0;
+
+}
+
+int guac_kubernetes_argv_handler(guac_user* user, guac_stream* stream,
+        char* mimetype, char* name) {
+
+    guac_kubernetes_argv_setting setting;
+
+    /* Allow users to update the color scheme and font details */
+    if (strcmp(name, "color-scheme") == 0)
+        setting = GUAC_KUBERNETES_ARGV_SETTING_COLOR_SCHEME;
+    else if (strcmp(name, "font-name") == 0)
+        setting = GUAC_KUBERNETES_ARGV_SETTING_FONT_NAME;
+    else if (strcmp(name, "font-size") == 0)
+        setting = GUAC_KUBERNETES_ARGV_SETTING_FONT_SIZE;
+
+    /* No other connection parameters may be updated */
+    else {
+        guac_protocol_send_ack(user->socket, stream, "Not allowed.",
+                GUAC_PROTOCOL_STATUS_CLIENT_FORBIDDEN);
+        guac_socket_flush(user->socket);
+        return 0;
+    }
+
+    guac_kubernetes_argv* argv = malloc(sizeof(guac_kubernetes_argv));
+    argv->setting = setting;
+    argv->length = 0;
+
+    /* Prepare stream to receive argument value */
+    stream->blob_handler = guac_kubernetes_argv_blob_handler;
+    stream->end_handler = guac_kubernetes_argv_end_handler;
+    stream->data = argv;
+
+    /* Signal stream is ready */
+    guac_protocol_send_ack(user->socket, stream, "Ready for updated "
+            "parameter.", GUAC_PROTOCOL_STATUS_SUCCESS);
+    guac_socket_flush(user->socket);
+    return 0;
+
+}
+

src/protocols/kubernetes/argv.h

@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+
+#ifndef GUAC_KUBERNETES_ARGV_H
+#define GUAC_KUBERNETES_ARGV_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+/**
+ * The maximum number of bytes to allow for any argument value received via an
+ * argv stream, including null terminator.
+ */
+#define GUAC_KUBERNETES_ARGV_MAX_LENGTH 16384
+
+/**
+ * Handles an incoming stream from a Guacamole "argv" instruction, updating the
+ * given connection parameter if that parameter is allowed to be updated.
+ */
+guac_user_argv_handler guac_kubernetes_argv_handler;
+
+#endif
+

src/protocols/kubernetes/user.c

@@ -17,6 +17,7 @@
  * under the License.
  */
 
+#include "argv.h"
 #include "clipboard.h"
 #include "common/cursor.h"
 #include "input.h"
@@ -87,6 +88,9 @@ int guac_kubernetes_user_join_handler(guac_user* user, int argc, char** argv) {
         /* STDIN redirection */
         user->pipe_handler = guac_kubernetes_pipe_handler;
 
+        /* Updates to connection parameters */
+        user->argv_handler = guac_kubernetes_argv_handler;
+
         /* Display size change events */
         user->size_handler = guac_kubernetes_user_size_handler;