GUACAMOLE-860: Add TN5250 packet processing.

Makefile.am

@@ -39,6 +39,7 @@ DIST_SUBDIRS =               \
     src/protocols/rdp        \
     src/protocols/ssh        \
     src/protocols/telnet     \
+    src/protocols/tn5250     \
     src/protocols/vnc
 
 SUBDIRS =        \
@@ -73,6 +74,10 @@ if ENABLE_TELNET
 SUBDIRS += src/protocols/telnet
 endif
 
+if ENABLE_TN5250
+SUBDIRS += src/protocols/tn5250
+endif
+
 if ENABLE_VNC
 SUBDIRS += src/protocols/vnc
 endif

configure.ac

@@ -1004,6 +1004,9 @@ fi
 AM_CONDITIONAL([ENABLE_TELNET], [test "x${have_libtelnet}"  = "xyes" \
                                    -a "x${have_terminal}" = "xyes"])
 
+AM_CONDITIONAL([ENABLE_TN5250], [test "x${have_libtelnet}"  = "xyes" \
+                                   -a "x${have_terminal}" = "xyes"])
+
 AC_SUBST(TELNET_LIBS)
 
 #
@@ -1190,6 +1193,7 @@ AC_CONFIG_FILES([Makefile
                  src/protocols/rdp/tests/Makefile
                  src/protocols/ssh/Makefile
                  src/protocols/telnet/Makefile
+                 src/protocols/tn5250/Makefile
                  src/protocols/vnc/Makefile])
 AC_OUTPUT
 
@@ -1201,6 +1205,7 @@ AM_COND_IF([ENABLE_KUBERNETES], [build_kubernetes=yes], [build_kubernetes=no])
 AM_COND_IF([ENABLE_RDP],        [build_rdp=yes],        [build_rdp=no])
 AM_COND_IF([ENABLE_SSH],        [build_ssh=yes],        [build_ssh=no])
 AM_COND_IF([ENABLE_TELNET],     [build_telnet=yes],     [build_telnet=no])
+AM_COND_IF([ENABLE_TN5250],     [build_tn5250=yes],     [build_tn5250=no])
 AM_COND_IF([ENABLE_VNC],        [build_vnc=yes],        [build_vnc=no])
 
 #
@@ -1262,6 +1267,7 @@ $PACKAGE_NAME version $PACKAGE_VERSION
       RDP ........... ${build_rdp}
       SSH ........... ${build_ssh}
       Telnet ........ ${build_telnet}
+      TN5250 ........ ${build_tn5250}
       VNC ........... ${build_vnc}
 
    Services / tools:

src/protocols/tn5250/Makefile.am

@@ -0,0 +1,67 @@
+#
+# 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.
+#
+# NOTE: Parts of this file (Makefile.am) are automatically transcluded verbatim
+# into Makefile.in. Though the build system (GNU Autotools) automatically adds
+# its own license boilerplate to the generated Makefile.in, that boilerplate
+# does not apply to the transcluded portions of Makefile.am which are licensed
+# to you by the ASF under the Apache License, Version 2.0, as described above.
+#
+
+AUTOMAKE_OPTIONS = foreign
+ACLOCAL_AMFLAGS = -I m4
+
+lib_LTLIBRARIES = libguac-client-tn5250.la
+
+libguac_client_tn5250_la_SOURCES = \
+    argv.c                         \
+    client.c                       \
+    clipboard.c                    \
+    input.c                        \
+    pipe.c                         \
+    settings.c                     \
+    tn5250.c                       \
+    user.c                         \
+    lib5250/lib5250.c
+
+noinst_HEADERS =       \
+    argv.h             \
+    client.h           \
+    clipboard.h        \
+    input.h            \
+    pipe.h             \
+    settings.h         \
+    tn5250.h           \
+    user.h             \
+    lib5250/lib5250.h
+
+libguac_client_tn5250_la_CFLAGS = \
+    -Werror -Wall -Iinclude       \
+    @LIBGUAC_INCLUDE@             \
+    @TERMINAL_INCLUDE@
+
+libguac_client_tn5250_la_LIBADD = \
+    @COMMON_LTLIB@                \
+    @LIBGUAC_LTLIB@               \
+    @TERMINAL_LTLIB@
+
+libguac_client_tn5250_la_LDFLAGS = \
+    -version-info 0:0:0            \
+    @PTHREAD_LIBS@                 \
+    @TELNET_LIBS@
+

src/protocols/tn5250/argv.c

@@ -0,0 +1,84 @@
+/*
+ * 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 "tn5250.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
+#include <guacamole/user.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int guac_tn5250_argv_callback(guac_user* user, const char* mimetype,
+        const char* name, const char* value, void* data) {
+
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_terminal* terminal = tn5250_client->term;
+
+    /* Update color scheme */
+    if (strcmp(name, GUAC_TN5250_ARGV_COLOR_SCHEME) == 0)
+        guac_terminal_apply_color_scheme(terminal, value);
+
+    /* Update font name */
+    else if (strcmp(name, GUAC_TN5250_ARGV_FONT_NAME) == 0)
+        guac_terminal_apply_font(terminal, value, -1, 0);
+
+    /* Update only if font size is sane */
+    else if (strcmp(name, GUAC_TN5250_ARGV_FONT_SIZE) == 0) {
+        int size = atoi(value);
+        if (size > 0)
+            guac_terminal_apply_font(terminal, NULL, size,
+                    tn5250_client->settings->resolution);
+    }
+
+    return 0;
+
+}
+
+void* guac_tn5250_send_current_argv(guac_user* user, void* data) {
+
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) data;
+    guac_terminal* terminal = tn5250_client->term;
+
+    /* Send current color scheme */
+    guac_user_stream_argv(user, user->socket, "text/plain",
+            GUAC_TN5250_ARGV_COLOR_SCHEME,
+            guac_terminal_get_color_scheme(terminal));
+
+    /* Send current font name */
+    guac_user_stream_argv(user, user->socket, "text/plain",
+            GUAC_TN5250_ARGV_FONT_NAME,
+            guac_terminal_get_font_name(terminal));
+
+    /* Send current font size */
+    char font_size[64];
+    sprintf(font_size, "%i", guac_terminal_get_font_size(terminal));
+    guac_user_stream_argv(user, user->socket, "text/plain",
+            GUAC_TN5250_ARGV_FONT_SIZE, font_size);
+
+    return NULL;
+
+}
+

src/protocols/tn5250/argv.h

@@ -0,0 +1,73 @@
+/*
+ * 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_TN5250_ARGV_H
+#define GUAC_TN5250_ARGV_H
+
+#include "config.h"
+
+#include <guacamole/argv.h>
+#include <guacamole/user.h>
+
+/**
+ * The name of the parameter that specifies/updates the color scheme used by
+ * the terminal emulator.
+ */
+#define GUAC_TN5250_ARGV_COLOR_SCHEME "color-scheme"
+
+/**
+ * The name of the parameter that specifies/updates the name of the font used
+ * by the terminal emulator.
+ */
+#define GUAC_TN5250_ARGV_FONT_NAME "font-name"
+
+/**
+ * The name of the parameter that specifies/updates the font size used by the
+ * terminal emulator.
+ */
+#define GUAC_TN5250_ARGV_FONT_SIZE "font-size"
+
+/**
+ * Handles a received argument value from a Guacamole "argv" instruction,
+ * updating the given connection parameter.
+ */
+guac_argv_callback guac_tn5250_argv_callback;
+
+/**
+ * Sends the current values of all non-sensitive parameters which may be set
+ * while the connection is running to the given user. Note that the user
+ * receiving these values will not necessarily be able to set new values
+ * themselves if their connection is read-only. This function can be used as
+ * the callback for guac_client_foreach_user() and guac_client_for_owner()
+ *
+ * @param user
+ *     The user that should receive the values of all non-sensitive parameters
+ *     which may be set while the connection is running.
+ *
+ * @param data
+ *     The guac_n5250_client instance associated with the current connection.
+ *
+ * @return
+ *     Always NULL.
+ */
+void* guac_tn5250_send_current_argv(guac_user* user, void* data);
+
+#endif
+

src/protocols/tn5250/client.c

@@ -0,0 +1,105 @@
+/*
+ * 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 "client.h"
+#include "settings.h"
+#include "tn5250.h"
+#include "user.h"
+
+#include <langinfo.h>
+#include <locale.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <guacamole/argv.h>
+#include <guacamole/client.h>
+#include <guacamole/recording.h>
+
+int guac_client_init(guac_client* client) {
+
+    guac_client_log(client, GUAC_LOG_INFO, "%s: Starting initialization of TN5250 client.", __func__);
+
+    /* Set client args */
+    client->args = GUAC_TN5250_CLIENT_ARGS;
+
+    /* Allocate client instance data */
+    guac_tn5250_client* tn5250_client = calloc(1, sizeof(guac_tn5250_client));
+    client->data = tn5250_client;
+
+    /* Init tn5250 client */
+    tn5250_client->socket_fd = -1;
+    tn5250_client->echo_enabled = 1;
+
+    /* Set handlers */
+    client->join_handler = guac_tn5250_user_join_handler;
+    client->free_handler = guac_tn5250_client_free_handler;
+    client->leave_handler = guac_tn5250_user_leave_handler;
+
+    /* Register handlers for argument values that may be sent after the handshake */
+    guac_argv_register(GUAC_TN5250_ARGV_COLOR_SCHEME, guac_tn5250_argv_callback, NULL, GUAC_ARGV_OPTION_ECHO);
+    guac_argv_register(GUAC_TN5250_ARGV_FONT_NAME, guac_tn5250_argv_callback, NULL, GUAC_ARGV_OPTION_ECHO);
+    guac_argv_register(GUAC_TN5250_ARGV_FONT_SIZE, guac_tn5250_argv_callback, NULL, GUAC_ARGV_OPTION_ECHO);
+
+    /* Set locale and warn if not UTF-8 */
+    setlocale(LC_CTYPE, "");
+    if (strcmp(nl_langinfo(CODESET), "UTF-8") != 0) {
+        guac_client_log(client, GUAC_LOG_INFO,
+                "Current locale does not use UTF-8. Some characters may "
+                "not render correctly.");
+    }
+
+    /* Success */
+    return 0;
+
+}
+
+int guac_tn5250_client_free_handler(guac_client* client) {
+
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+
+    /* Close tn5250 connection */
+    if (tn5250_client->socket_fd != -1)
+        close(tn5250_client->socket_fd);
+
+    /* Clean up recording, if in progress */
+    if (tn5250_client->recording != NULL)
+        guac_recording_free(tn5250_client->recording);
+
+    /* Kill terminal */
+    guac_terminal_free(tn5250_client->term);
+
+    /* Wait for and free telnet session, if connected */
+    if (tn5250_client->tn5250 != NULL) {
+        pthread_join(tn5250_client->client_thread, NULL);
+        telnet_free(tn5250_client->tn5250);
+    }
+
+    /* Free settings */
+    if (tn5250_client->settings != NULL)
+        guac_tn5250_settings_free(tn5250_client->settings);
+
+    free(tn5250_client);
+    return 0;
+
+}
+

src/protocols/tn5250/client.h

@@ -0,0 +1,39 @@
+/*
+ * 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_TN5250_CLIENT_H
+#define GUAC_TN5250_CLIENT_H
+
+#include "config.h"
+#include "terminal/terminal.h"
+
+#include <pthread.h>
+#include <regex.h>
+#include <sys/types.h>
+
+#include <libtelnet.h>
+
+/**
+ * Free handler. Required by libguac and called when the guac_client is
+ * disconnected and must be cleaned up.
+ */
+guac_client_free_handler guac_tn5250_client_free_handler;
+
+#endif
+

src/protocols/tn5250/clipboard.c

@@ -0,0 +1,61 @@
+/*
+ * 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 "clipboard.h"
+#include "tn5250.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/client.h>
+#include <guacamole/stream.h>
+#include <guacamole/user.h>
+
+int guac_tn5250_clipboard_handler(guac_user* user, guac_stream* stream,
+        char* mimetype) {
+
+    /* Clear clipboard and prepare for new data */
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_terminal_clipboard_reset(tn5250_client->term, mimetype);
+
+    /* Set handlers for clipboard stream */
+    stream->blob_handler = guac_tn5250_clipboard_blob_handler;
+    stream->end_handler = guac_tn5250_clipboard_end_handler;
+
+    return 0;
+}
+
+int guac_tn5250_clipboard_blob_handler(guac_user* user, guac_stream* stream,
+        void* data, int length) {
+
+    /* Append new data */
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_terminal_clipboard_append(tn5250_client->term, data, length);
+
+    return 0;
+}
+
+int guac_tn5250_clipboard_end_handler(guac_user* user, guac_stream* stream) {
+
+    /* Nothing to do - clipboard is implemented within client */
+
+    return 0;
+}
+

src/protocols/tn5250/clipboard.h

@@ -0,0 +1,43 @@
+/*
+ * 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_TN5250_CLIPBOARD_H
+#define GUAC_TN5250_CLIPBOARD_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+/**
+ * Handler for inbound clipboard streams.
+ */
+guac_user_clipboard_handler guac_tn5250_clipboard_handler;
+
+/**
+ * Handler for data received along clipboard streams.
+ */
+guac_user_blob_handler guac_tn5250_clipboard_blob_handler;
+
+/**
+ * Handler for end-of-stream related to clipboard.
+ */
+guac_user_end_handler guac_tn5250_clipboard_end_handler;
+
+#endif
+

src/protocols/tn5250/input.c

@@ -0,0 +1,138 @@
+/*
+ * 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 "input.h"
+#include "terminal/terminal.h"
+#include "tn5250.h"
+
+#include <guacamole/client.h>
+#include <guacamole/recording.h>
+#include <guacamole/user.h>
+#include <libtelnet.h>
+
+#include <regex.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int guac_tn5250_user_mouse_handler(guac_user* user, int x, int y, int mask) {
+
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+    guac_terminal* term = tn5250_client->term;
+
+    /* Skip if terminal not yet ready */
+    if (term == NULL)
+        return 0;
+
+    /* Report mouse position within recording */
+    if (tn5250_client->recording != NULL)
+        guac_recording_report_mouse(tn5250_client->recording, x, y,
+                mask);
+
+    /* Send mouse if not searching for password or username */
+    if (settings->password_regex == NULL && settings->username_regex == NULL)
+        guac_terminal_send_mouse(term, user, x, y, mask);
+
+    return 0;
+
+}
+
+int guac_tn5250_user_key_handler(guac_user* user, int keysym, int pressed) {
+
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+    guac_terminal* term = tn5250_client->term;
+
+    /* Report key state within recording */
+    if (tn5250_client->recording != NULL)
+        guac_recording_report_key(tn5250_client->recording,
+                keysym, pressed);
+
+    /* Skip if terminal not yet ready */
+    if (term == NULL)
+        return 0;
+
+    /* Stop searching for password */
+    if (settings->password_regex != NULL) {
+
+        guac_client_log(client, GUAC_LOG_DEBUG,
+                "Stopping password prompt search due to user input.");
+
+        regfree(settings->password_regex);
+        free(settings->password_regex);
+        settings->password_regex = NULL;
+
+    }
+
+    /* Stop searching for username */
+    if (settings->username_regex != NULL) {
+
+        guac_client_log(client, GUAC_LOG_DEBUG,
+                "Stopping username prompt search due to user input.");
+
+        regfree(settings->username_regex);
+        free(settings->username_regex);
+        settings->username_regex = NULL;
+
+    }
+
+    /* Intercept and handle Pause / Break / Ctrl+0 as "IAC BRK" */
+    if (pressed && (
+                keysym == 0xFF13                  /* Pause */
+             || keysym == 0xFF6B                  /* Break */
+             || (
+                    guac_terminal_get_mod_ctrl(term)
+                    && keysym == '0'
+                )                                 /* Ctrl + 0 */
+       )) {
+
+        /* Send IAC BRK */
+        telnet_iac(tn5250_client->tn5250, TELNET_BREAK);
+
+        return 0;
+    }
+
+    /* Send key */
+    guac_terminal_send_key(term, keysym, pressed);
+
+    return 0;
+
+}
+
+int guac_tn5250_user_size_handler(guac_user* user, int width, int height) {
+
+    /* Get terminal */
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_terminal* terminal = tn5250_client->term;
+
+    /* Skip if terminal not yet ready */
+    if (terminal == NULL)
+        return 0;
+
+    /* Resize terminal */
+    guac_terminal_resize(terminal, width, height);
+
+    return 0;
+}
+

src/protocols/tn5250/input.h

@@ -0,0 +1,46 @@
+/*
+ * 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_TN5250_INPUT_H
+#define GUAC_TN5250_INPUT_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+/**
+ * Handler for key events. Required by libguac and called whenever key events
+ * are received.
+ */
+guac_user_key_handler guac_tn5250_user_key_handler;
+
+/**
+ * Handler for mouse events. Required by libguac and called whenever mouse
+ * events are received.
+ */
+guac_user_mouse_handler guac_tn5250_user_mouse_handler;
+
+/**
+ * Handler for size events. Required by libguac and called whenever the remote
+ * display (window) is resized.
+ */
+guac_user_size_handler guac_tn5250_user_size_handler;
+
+#endif
+

src/protocols/tn5250/lib5250/lib5250.c

@@ -0,0 +1,105 @@
+/*
+ * 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 "lib5250.h"
+#include "tn5250.h"
+
+#include <guacamole/client.h>
+
+#include <arpa/inet.h>
+
+int guac_lib5250_process_packet(const char* data, guac_client* client) {
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "%s: Processing expected TN5250 SNA data.", __func__);
+
+    guac_lib5250_packet* packet = (guac_lib5250_packet*) data;
+
+    if (ntohs(packet->type) != GUAC_LIB5250_SNA_GDS) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                "%s: Unexpected SNA packet typing parsing TN5250 packet: 0x%x",
+                __func__, ntohs(packet->type));
+        return 1;
+    }
+
+    switch (packet->opcode) {
+
+        case GUAC_LIB5250_OPCODE_NOOP:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode no-op.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_INVITE:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode invite.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_OUTPUT:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode output.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_PUTGET:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode put/get.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_SAVESCREEN:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode save screen.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_RESTORESCREEN:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode restore screen.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_READIMMEDIATE:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode read immediate.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_READSCREEN:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode read screen.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_CANCELINVITE:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode cancel invite.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_MSGON:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode msg on.", __func__);
+            break;
+
+        case GUAC_LIB5250_OPCODE_MSGOFF:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received opcode msg off.", __func__);
+            break;
+
+        default:
+            guac_client_log(client, GUAC_LOG_TRACE, "%s: Received unknown opcode.", __func__);
+
+    }
+
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: SNA data length: %d bytes.", __func__, ntohs(packet->len));
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: Packet type: 0x%x", __func__, ntohs(packet->type));
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: Reserved space: 0x%x", __func__, ntohs(packet->reserved));
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: Variable header length: 0x%x.", __func__, packet->varlen);
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: SNA Flags: 0x%x", __func__, packet->flags);
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: SNA Rerved flags: 0x%x", __func__, packet->reserved_flags);
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: SNA Opcode: 0x%x", __func__, packet->opcode);
+
+    guac_client_log(client, GUAC_LOG_TRACE, "%s: WHOLE ENCHILADA: 0x%x", __func__, packet);
+
+    guac_client_log(client, GUAC_LOG_WARNING, "%s: Everything else is unimplemented, now.", __func__);
+    return 0;
+
+}

src/protocols/tn5250/lib5250/lib5250.h

@@ -0,0 +1,207 @@
+/*
+ * 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_LIB5250_H
+#define GUAC_LIB5250_H
+
+#include "config.h"
+#include "tn5250.h"
+
+#include <guacamole/client.h>
+
+#include <stdint.h>
+
+/**
+ * The General Data Stream SNA packet type.
+ */
+#define GUAC_LIB5250_SNA_GDS 0x12a0
+
+/**
+ * An enum that represents all of the available terminal types according to
+ * RFC1205, the specification that documents the Telnet 5250 (TN5250)
+ * standard.
+ */
+typedef enum guac_lib5250_terminal {
+
+    /* 24 x 80 Double-Byte Character Set color display */
+    GUAC_LIB5250_TERMINAL_IBM_5555_C01,
+
+    /* 24 x 80 Double-Byte Character Set (DBCS) */
+    GUAC_LIB5250_TERMINAL_IBM_5555_B01,
+
+    /* 27 x 132 color display */
+    GUAC_LIB5250_TERMINAL_IBM_3477_FC,
+
+    /* 27 x 132 monochrome display */
+    GUAC_LIB5250_TERMINAL_IBM_3477_FG,
+
+    /* 27 x 132 monochrome display */
+    GUAC_LIB5250_TERMINAL_IBM_3180_2,
+
+    /* 24 x 80 color display */
+    GUAC_LIB5250_TERMINAL_IBM_3179_2,
+
+    /* 24 x 80 monochrome display */
+    GUAC_LIB5250_TERMINAL_IBM_3196_A1,
+
+    /* 24 x 80 color display */
+    GUAC_LIB5250_TERMINAL_IBM_5292_2,
+
+    /* 24 x 80 monochrome display */
+    GUAC_LIB5250_TERMINAL_IBM_5291_1,
+
+    /* 24 x 80 monochrome display */
+    GUAC_LIB5250_TERMINAL_IBM_5251_11
+
+} guac_lib5250_terminal;
+
+/**
+ * A data type that captures a terminal type, from the guac_lib5250_terminal
+ * enum, and the capabilities associated with that terminal.
+ */
+typedef struct guac_lib5250_terminal_cap {
+
+    /* The name of the terminal. */
+    guac_lib5250_terminal name;
+
+    /* The number of rows supported on the terminal. */
+    unsigned int rows;
+
+    /* The number of columns supports on the terminal. */
+    unsigned int cols;
+
+    /* 1 if the terminal supports colors, 0 if it is monochrome. */
+    unsigned int color;
+
+    /* The number of bytes-per-character the terminal supports. This must
+     * be either 1 or 2. */
+    unsigned int charbytes;
+
+} guac_lib5250_terminal_cap;
+
+/**
+ * A list of the possible TN5250 opcodes, which can be sent to the client to
+ * direct it to do something with the terminal. These are documented in RFC1205.
+ */
+typedef enum guac_lib5250_opcode {
+    
+    /* No Operation */
+    GUAC_LIB5250_OPCODE_NOOP = 0x00,
+
+    /* Invite terminal */
+    GUAC_LIB5250_OPCODE_INVITE = 0x01,
+
+    /* Output only */
+    GUAC_LIB5250_OPCODE_OUTPUT = 0x02,
+
+    /* Put/Get */
+    GUAC_LIB5250_OPCODE_PUTGET = 0x03,
+
+    /* Save screen */
+    GUAC_LIB5250_OPCODE_SAVESCREEN = 0x04,
+
+    /* Restore screen */
+    GUAC_LIB5250_OPCODE_RESTORESCREEN = 0x05,
+
+    /* Read immediate */
+    GUAC_LIB5250_OPCODE_READIMMEDIATE = 0x06,
+
+    /* Read screen */
+    GUAC_LIB5250_OPCODE_READSCREEN = 0x08,
+
+    /* Cancel invite */
+    GUAC_LIB5250_OPCODE_CANCELINVITE = 0x0A,
+
+    /* Message light on */
+    GUAC_LIB5250_OPCODE_MSGON = 0x0B,
+
+    /* Message light off */
+    GUAC_LIB5250_OPCODE_MSGOFF = 0x0C
+
+} guac_lib5250_opcode;
+
+/**
+ * A data type that defines the structure of the packet for 5250 communication
+ * across telnet. The structure of this packet is based off of the definition
+ * in RFC1205.
+ */
+typedef struct guac_lib5250_packet {
+   
+    /* The length of the entire logical record. */
+    uint16_t len;
+
+    /* The SNA record type. This should always be 0x12A0, which is the
+     * General Data Stream record. */
+    uint16_t type;
+
+    /* Empty space, should be zerod. */
+    uint16_t reserved;
+
+    /* The length of the variable portion of the header, in octets. According
+     * to the RFC, this should always be 0x04. */
+    uint8_t varlen;
+
+    /* Flags associated with the header, as documented in the RFC. The
+     * bits are as follows:
+     * Bit 0: ERR - Data stream output error.
+     * Bit 1: ATN - Indicates Attention key was pressed.
+     * Bit 2-4: Reserved, zeros.
+     * Bit 5: SRQ - System Request key has been pressed.
+     * Bit 6: TRQ - Test Request key has been pressed.
+     * Bit 7: HLP - Help in Error State, with actual help code sent as data after
+     *              the header.
+     */
+    uint8_t flags;
+
+    /* At present, the remaining 8 bits of flags are not used at all. As old
+     * as RFC1205 is, I doubt that's likely to change. These bits should be
+     * all zeroes.
+     */
+    uint8_t reserved_flags;
+
+    /* The operation code, as requested by the sender. Valid values for this
+     * are in the gauc_lib5250_opcode enum.
+     */
+    uint8_t opcode;
+
+    /* What remains is the data in the packet, which should consume the
+     * remainder of the space that the header did not take up. The packet
+     * should also be terminated with a Telnet IAC EOR record, 0xffef.
+     */
+    void* data;
+
+} guac_lib5250_packet __attribute__ ((aligned));
+
+/**
+ * Parses the packet that libtelnet has received and then takes action
+ * based on the contents of the packet.
+ *
+ * @param data
+ *     The data buffer delivered by libtelnet, which should be binary telnet
+ *     data that is the actual TN5250 protocol.
+ *
+ * @param client
+ *     The Guacamole client associated with this connection.
+ *
+ * @return
+ *     Zero if the data was successfully processed, non-zero otherwise.
+ */
+int guac_lib5250_process_packet(const char* data, guac_client* client);
+
+#endif // GUAC_LIB5250_H

src/protocols/tn5250/pipe.c

@@ -0,0 +1,50 @@
+/*
+ * 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 "pipe.h"
+#include "tn5250.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
+#include <guacamole/user.h>
+
+#include <string.h>
+
+int guac_tn5250_pipe_handler(guac_user* user, guac_stream* stream,
+        char* mimetype, char* name) {
+
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+
+    /* Redirect STDIN if pipe has required name */
+    if (strcmp(name, GUAC_TN5250_STDIN_PIPE_NAME) == 0) {
+        guac_terminal_send_stream(tn5250_client->term, user, stream);
+        return 0;
+    }
+
+    /* No other inbound pipe streams are supported */
+    guac_protocol_send_ack(user->socket, stream, "No such input stream.",
+            GUAC_PROTOCOL_STATUS_RESOURCE_NOT_FOUND);
+    guac_socket_flush(user->socket);
+    return 0;
+
+}
+

src/protocols/tn5250/pipe.h

@@ -0,0 +1,42 @@
+/*
+ * 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_TN5250_PIPE_H
+#define GUAC_TN5250_PIPE_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+/**
+ * The name reserved for the inbound pipe stream which forces the terminal
+ * emulator's STDIN to be received from the pipe.
+ */
+#define GUAC_TN5250_STDIN_PIPE_NAME "STDIN"
+
+/**
+ * Handles an incoming stream from a Guacamole "pipe" instruction. If the pipe
+ * is named "STDIN", the the contents of the pipe stream are redirected to
+ * STDIN of the terminal emulator for as long as the pipe is open.
+ */
+guac_user_pipe_handler guac_tn5250_pipe_handler;
+
+#endif
+

src/protocols/tn5250/settings.c

@@ -0,0 +1,501 @@
+/*
+ * 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 "common/defaults.h"
+#include "settings.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/user.h>
+#include <guacamole/wol-constants.h>
+
+#include <sys/types.h>
+#include <regex.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+/* Client plugin arguments */
+const char* GUAC_TN5250_CLIENT_ARGS[] = {
+    "hostname",
+    "port",
+    "username",
+    "username-regex",
+    "password",
+    "password-regex",
+    GUAC_TN5250_ARGV_FONT_NAME,
+    GUAC_TN5250_ARGV_FONT_SIZE,
+    GUAC_TN5250_ARGV_COLOR_SCHEME,
+    "typescript-path",
+    "typescript-name",
+    "create-typescript-path",
+    "recording-path",
+    "recording-name",
+    "recording-exclude-output",
+    "recording-exclude-mouse",
+    "recording-include-keys",
+    "create-recording-path",
+    "read-only",
+    "backspace",
+    "terminal-type",
+    "scrollback",
+    "login-success-regex",
+    "login-failure-regex",
+    "disable-copy",
+    "disable-paste",
+    NULL
+};
+
+enum TN5250_ARGS_IDX {
+    
+    /**
+     * The hostname to connect to. Required.
+     */
+    IDX_HOSTNAME,
+
+    /**
+     * The port to connect to. Optional.
+     */
+    IDX_PORT,
+
+    /**
+     * The name of the user to login as. Optional.
+     */
+    IDX_USERNAME,
+
+    /**
+     * The regular expression to use when searching for the username/login
+     * prompt. Optional.
+     */
+    IDX_USERNAME_REGEX,
+
+    /**
+     * The password to use when logging in. Optional.
+     */
+    IDX_PASSWORD,
+
+    /**
+     * The regular expression to use when searching for the password prompt.
+     * Optional.
+     */
+    IDX_PASSWORD_REGEX,
+
+    /**
+     * The name of the font to use within the terminal.
+     */
+    IDX_FONT_NAME,
+
+    /**
+     * The size of the font to use within the terminal, in points.
+     */
+    IDX_FONT_SIZE,
+
+    /**
+     * The color scheme to use, as a series of semicolon-separated color-value
+     * pairs: "background: <color>", "foreground: <color>", or
+     * "color<n>: <color>", where <n> is a number from 0 to 255, and <color> is
+     * "color<n>" or an X11 color code (e.g. "aqua" or "rgb:12/34/56").
+     * The color scheme can also be one of the special values: "black-white",
+     * "white-black", "gray-black", or "green-black".
+     */
+    IDX_COLOR_SCHEME,
+
+    /**
+     * The full absolute path to the directory in which typescripts should be
+     * written.
+     */
+    IDX_TYPESCRIPT_PATH,
+
+    /**
+     * The name that should be given to typescripts which are written in the
+     * given path. Each typescript will consist of two files: "NAME" and
+     * "NAME.timing".
+     */
+    IDX_TYPESCRIPT_NAME,
+
+    /**
+     * Whether the specified typescript path should automatically be created
+     * if it does not yet exist.
+     */
+    IDX_CREATE_TYPESCRIPT_PATH,
+
+    /**
+     * The full absolute path to the directory in which screen recordings
+     * should be written.
+     */
+    IDX_RECORDING_PATH,
+
+    /**
+     * The name that should be given to screen recordings which are written in
+     * the given path.
+     */
+    IDX_RECORDING_NAME,
+
+    /**
+     * Whether output which is broadcast to each connected client (graphics,
+     * streams, etc.) should NOT be included in the session recording. Output
+     * is included by default, as it is necessary for any recording which must
+     * later be viewable as video.
+     */
+    IDX_RECORDING_EXCLUDE_OUTPUT,
+
+    /**
+     * Whether changes to mouse state, such as position and buttons pressed or
+     * released, should NOT be included in the session recording. Mouse state
+     * is included by default, as it is necessary for the mouse cursor to be
+     * rendered in any resulting video.
+     */
+    IDX_RECORDING_EXCLUDE_MOUSE,
+
+    /**
+     * Whether keys pressed and released should be included in the session
+     * recording. Key events are NOT included by default within the recording,
+     * as doing so has privacy and security implications.  Including key events
+     * may be necessary in certain auditing contexts, but should only be done
+     * with caution. Key events can easily contain sensitive information, such
+     * as passwords, credit card numbers, etc.
+     */
+    IDX_RECORDING_INCLUDE_KEYS,
+
+    /**
+     * Whether the specified screen recording path should automatically be
+     * created if it does not yet exist.
+     */
+    IDX_CREATE_RECORDING_PATH,
+
+    /**
+     * "true" if this connection should be read-only (user input should be
+     * dropped), "false" or blank otherwise.
+     */
+    IDX_READ_ONLY,
+
+    /**
+     * ASCII code, as an integer to use for the backspace key, or
+     * GUAC_TERMINAL_DEFAULT_BACKSPACE if not specified.
+     */
+    IDX_BACKSPACE,
+
+    /**
+     * The terminal emulator type that is passed to the remote system (e.g.
+     * "xterm" or "xterm-256color"). "linux" is used if unspecified.
+     */
+    IDX_TERMINAL_TYPE,
+
+    /**
+     * The maximum size of the scrollback buffer in rows.
+     */
+    IDX_SCROLLBACK,
+
+    /**
+     * The regular expression to use when searching for whether login was
+     * successful. This parameter is optional. If given, the
+     * "login-failure-regex" parameter must also be specified, and the first
+     * frame of the Guacamole connection will be withheld until login
+     * success/failure has been determined.
+     */
+    IDX_LOGIN_SUCCESS_REGEX,
+
+    /**
+     * The regular expression to use when searching for whether login was
+     * unsuccessful. This parameter is optional. If given, the
+     * "login-success-regex" parameter must also be specified, and the first
+     * frame of the Guacamole connection will be withheld until login
+     * success/failure has been determined.
+     */
+    IDX_LOGIN_FAILURE_REGEX,
+
+    /**
+     * Whether outbound clipboard access should be blocked. If set to "true",
+     * it will not be possible to copy data from the terminal to the client
+     * using the clipboard. By default, clipboard access is not blocked.
+     */
+    IDX_DISABLE_COPY,
+
+    /**
+     * Whether inbound clipboard access should be blocked. If set to "true", it
+     * will not be possible to paste data from the client to the terminal using
+     * the clipboard. By default, clipboard access is not blocked.
+     */
+    IDX_DISABLE_PASTE,
+
+    TN5250_ARGS_COUNT
+};
+
+/**
+ * Compiles the given regular expression, returning NULL if compilation fails
+ * or of the given regular expression is NULL. The returned regex_t must be
+ * freed with regfree() AND free(), or with guac_tn5250_regex_free().
+ *
+ * @param user
+ *     The user who provided the setting associated with the given regex
+ *     pattern. Error messages will be logged on behalf of this user.
+ *
+ * @param pattern
+ *     The regular expression pattern to compile.
+ *
+ * @return
+ *     The compiled regular expression, or NULL if compilation fails or NULL
+ *     was originally provided for the pattern.
+ */
+static regex_t* guac_tn5250_compile_regex(guac_user* user, char* pattern) {
+
+    /* Nothing to compile if no pattern provided */
+    if (pattern == NULL)
+        return NULL;
+
+    int compile_result;
+    regex_t* regex = malloc(sizeof(regex_t));
+
+    /* Compile regular expression */
+    compile_result = regcomp(regex, pattern,
+            REG_EXTENDED | REG_NOSUB | REG_ICASE | REG_NEWLINE);
+
+    /* Notify of failure to parse/compile */
+    if (compile_result != 0) {
+        guac_user_log(user, GUAC_LOG_ERROR, "Regular expression '%s' "
+                "could not be compiled.", pattern);
+        free(regex);
+        return NULL;
+    }
+
+    return regex;
+}
+
+void guac_tn5250_regex_free(regex_t** regex) {
+    if (*regex != NULL) {
+        regfree(*regex);
+        free(*regex);
+        *regex = NULL;
+    }
+}
+
+guac_tn5250_settings* guac_tn5250_parse_args(guac_user* user,
+        int argc, const char** argv) {
+
+    /* Validate arg count */
+    if (argc != TN5250_ARGS_COUNT) {
+        guac_user_log(user, GUAC_LOG_WARNING, "Incorrect number of connection "
+                "parameters provided: expected %i, got %i.",
+                TN5250_ARGS_COUNT, argc);
+        return NULL;
+    }
+
+    guac_tn5250_settings* settings = calloc(1, sizeof(guac_tn5250_settings));
+
+    /* Read parameters */
+    settings->hostname =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_HOSTNAME, "");
+
+    /* Read username */
+    settings->username =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_USERNAME, NULL);
+
+    /* Read username regex only if username is specified */
+    if (settings->username != NULL) {
+        settings->username_regex = guac_tn5250_compile_regex(user,
+            guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                    IDX_USERNAME_REGEX, GUAC_TN5250_DEFAULT_USERNAME_REGEX));
+    }
+
+    /* Read password */
+    settings->password =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_PASSWORD, NULL);
+
+    /* Read password regex only if password is specified */
+    if (settings->password != NULL) {
+        settings->password_regex = guac_tn5250_compile_regex(user,
+            guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                    IDX_PASSWORD_REGEX, GUAC_TN5250_DEFAULT_PASSWORD_REGEX));
+    }
+
+    /* Read optional login success detection regex */
+    settings->login_success_regex = guac_tn5250_compile_regex(user,
+            guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                    IDX_LOGIN_SUCCESS_REGEX, NULL));
+
+    /* Read optional login failure detection regex */
+    settings->login_failure_regex = guac_tn5250_compile_regex(user,
+            guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                    IDX_LOGIN_FAILURE_REGEX, NULL));
+
+    /* Both login success and login failure regexes must be provided if either
+     * is present at all */
+    if (settings->login_success_regex != NULL
+            && settings->login_failure_regex == NULL) {
+        guac_tn5250_regex_free(&settings->login_success_regex);
+        guac_user_log(user, GUAC_LOG_WARNING, "Ignoring provided value for "
+                "\"%s\" as \"%s\" must also be provided.",
+                GUAC_TN5250_CLIENT_ARGS[IDX_LOGIN_SUCCESS_REGEX],
+                GUAC_TN5250_CLIENT_ARGS[IDX_LOGIN_FAILURE_REGEX]);
+    }
+    else if (settings->login_failure_regex != NULL
+            && settings->login_success_regex == NULL) {
+        guac_tn5250_regex_free(&settings->login_failure_regex);
+        guac_user_log(user, GUAC_LOG_WARNING, "Ignoring provided value for "
+                "\"%s\" as \"%s\" must also be provided.",
+                GUAC_TN5250_CLIENT_ARGS[IDX_LOGIN_FAILURE_REGEX],
+                GUAC_TN5250_CLIENT_ARGS[IDX_LOGIN_SUCCESS_REGEX]);
+    }
+
+    /* Read-only mode */
+    settings->read_only =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_READ_ONLY, false);
+
+    /* Read maximum scrollback size */
+    settings->max_scrollback =
+        guac_user_parse_args_int(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_SCROLLBACK, GUAC_TERMINAL_DEFAULT_MAX_SCROLLBACK);
+
+    /* Read font name */
+    settings->font_name =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_FONT_NAME, GUAC_TERMINAL_DEFAULT_FONT_NAME);
+
+    /* Read font size */
+    settings->font_size =
+        guac_user_parse_args_int(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_FONT_SIZE, GUAC_TERMINAL_DEFAULT_FONT_SIZE);
+
+    /* Copy requested color scheme */
+    settings->color_scheme =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_COLOR_SCHEME, GUAC_TERMINAL_DEFAULT_COLOR_SCHEME);
+
+    /* Pull width/height/resolution directly from user */
+    settings->width      = user->info.optimal_width;
+    settings->height     = user->info.optimal_height;
+    settings->resolution = user->info.optimal_resolution;
+
+    /* Read port */
+    settings->port =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_PORT, GUAC_TN5250_DEFAULT_PORT);
+
+    /* Read typescript path */
+    settings->typescript_path =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_TYPESCRIPT_PATH, NULL);
+
+    /* Read typescript name */
+    settings->typescript_name =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_TYPESCRIPT_NAME, GUAC_TN5250_DEFAULT_TYPESCRIPT_NAME);
+
+    /* Parse path creation flag */
+    settings->create_typescript_path =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_CREATE_TYPESCRIPT_PATH, false);
+
+    /* Read recording path */
+    settings->recording_path =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_RECORDING_PATH, NULL);
+
+    /* Read recording name */
+    settings->recording_name =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_RECORDING_NAME, GUAC_TN5250_DEFAULT_RECORDING_NAME);
+
+    /* Parse output exclusion flag */
+    settings->recording_exclude_output =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_RECORDING_EXCLUDE_OUTPUT, false);
+
+    /* Parse mouse exclusion flag */
+    settings->recording_exclude_mouse =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_RECORDING_EXCLUDE_MOUSE, false);
+
+    /* Parse key event inclusion flag */
+    settings->recording_include_keys =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_RECORDING_INCLUDE_KEYS, false);
+
+    /* Parse path creation flag */
+    settings->create_recording_path =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_CREATE_RECORDING_PATH, false);
+
+    /* Parse backspace key code */
+    settings->backspace =
+        guac_user_parse_args_int(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_BACKSPACE, GUAC_TERMINAL_DEFAULT_BACKSPACE);
+
+    /* Read terminal emulator type. */
+    settings->terminal_type =
+        guac_user_parse_args_string(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_TERMINAL_TYPE, "linux");
+
+    /* Parse clipboard copy disable flag */
+    settings->disable_copy =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_DISABLE_COPY, false);
+
+    /* Parse clipboard paste disable flag */
+    settings->disable_paste =
+        guac_user_parse_args_boolean(user, GUAC_TN5250_CLIENT_ARGS, argv,
+                IDX_DISABLE_PASTE, false);
+
+    /* Parsing was successful */
+    return settings;
+
+}
+
+void guac_tn5250_settings_free(guac_tn5250_settings* settings) {
+
+    /* Free network connection information */
+    free(settings->hostname);
+    free(settings->port);
+
+    /* Free credentials */
+    free(settings->username);
+    free(settings->password);
+
+    /* Free various regexes */
+    guac_tn5250_regex_free(&settings->username_regex);
+    guac_tn5250_regex_free(&settings->password_regex);
+    guac_tn5250_regex_free(&settings->login_success_regex);
+    guac_tn5250_regex_free(&settings->login_failure_regex);
+
+    /* Free display preferences */
+    free(settings->font_name);
+    free(settings->color_scheme);
+
+    /* Free typescript settings */
+    free(settings->typescript_name);
+    free(settings->typescript_path);
+
+    /* Free screen recording settings */
+    free(settings->recording_name);
+    free(settings->recording_path);
+
+    /* Free terminal emulator type. */
+    free(settings->terminal_type);
+
+    /* Free overall structure */
+    free(settings);
+
+}
+

src/protocols/tn5250/settings.h

@@ -0,0 +1,321 @@
+/*
+ * 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_TN5250_SETTINGS_H
+#define GUAC_TN5250_SETTINGS_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+#include <sys/types.h>
+#include <regex.h>
+#include <stdbool.h>
+/**
+ * The port to connect to when initiating any tn5250 connection, if no other
+ * port is specified.
+ */
+#define GUAC_TN5250_DEFAULT_PORT "23"
+
+/**
+ * The filename to use for the typescript, if not specified.
+ */
+#define GUAC_TN5250_DEFAULT_TYPESCRIPT_NAME "typescript" 
+
+/**
+ * The filename to use for the screen recording, if not specified.
+ */
+#define GUAC_TN5250_DEFAULT_RECORDING_NAME "recording"
+
+/**
+ * The regular expression to use when searching for the username/login prompt
+ * if no other regular expression is specified.
+ */
+#define GUAC_TN5250_DEFAULT_USERNAME_REGEX "[Ll]ogin:"
+
+/**
+ * The regular expression to use when searching for the password prompt if no
+ * other regular expression is specified.
+ */
+#define GUAC_TN5250_DEFAULT_PASSWORD_REGEX "[Pp]assword:"
+
+/**
+ * Settings for the TN5250 connection. The values for this structure are parsed
+ * from the arguments given during the Guacamole protocol handshake using the
+ * guac_tn5250_parse_args() function.
+ */
+typedef struct guac_tn5250_settings {
+
+    /**
+     * The hostname of the tn5250 server to connect to.
+     */
+    char* hostname;
+
+    /**
+     * The port of the tn5250 server to connect to.
+     */
+    char* port;
+
+    /**
+     * The name of the user to login as, if any. If no username is specified,
+     * this will be NULL.
+     */
+    char* username;
+
+    /**
+     * The regular expression to use when searching for the username/login
+     * prompt. If no username is specified, this will be NULL. If a username
+     * is specified, this will either be the specified username regex, or the
+     * default username regex.
+     */
+    regex_t* username_regex;
+
+    /**
+     * The password to give when authenticating, if any. If no password is
+     * specified, this will be NULL.
+     */
+    char* password;
+
+    /**
+     * The regular expression to use when searching for the password prompt. If
+     * no password is specified, this will be NULL. If a password is specified,
+     * this will either be the specified password regex, or the default
+     * password regex.
+     */
+    regex_t* password_regex;
+
+    /**
+     * The regular expression to use when searching for whether login was
+     * successful. If no such regex is specified, or if no login failure regex
+     * was specified, this will be NULL.
+     */
+    regex_t* login_success_regex;
+
+    /**
+     * The regular expression to use when searching for whether login failed.
+     * If no such regex is specified, or if no login success regex was
+     * specified, this will be NULL.
+     */
+    regex_t* login_failure_regex;
+
+    /**
+     * Whether this connection is read-only, and user input should be dropped.
+     */
+    bool read_only;
+
+    /**
+     * The maximum size of the scrollback buffer in rows.
+     */
+    int max_scrollback;
+
+    /**
+     * The name of the font to use for display rendering.
+     */
+    char* font_name;
+
+    /**
+     * The size of the font to use, in points.
+     */
+    int font_size;
+
+    /**
+     * The name of the color scheme to use.
+     */
+    char* color_scheme; 
+
+    /**
+     * The desired width of the terminal display, in pixels.
+     */
+    int width;
+
+    /**
+     * The desired height of the terminal display, in pixels.
+     */
+    int height;
+
+    /**
+     * The desired screen resolution, in DPI.
+     */
+    int resolution;
+
+    /**
+     * Whether outbound clipboard access should be blocked. If set, it will not
+     * be possible to copy data from the terminal to the client using the
+     * clipboard.
+     */
+    bool disable_copy;
+
+    /**
+     * Whether inbound clipboard access should be blocked. If set, it will not
+     * be possible to paste data from the client to the terminal using the
+     * clipboard.
+     */
+    bool disable_paste;
+
+    /**
+     * The path in which the typescript should be saved, if enabled. If no
+     * typescript should be saved, this will be NULL.
+     */
+    char* typescript_path;
+
+    /**
+     * The filename to use for the typescript, if enabled.
+     */
+    char* typescript_name;
+
+    /**
+     * Whether the typescript path should be automatically created if it does
+     * not already exist.
+     */
+    bool create_typescript_path;
+
+    /**
+     * The path in which the screen recording should be saved, if enabled. If
+     * no screen recording should be saved, this will be NULL.
+     */
+    char* recording_path;
+
+    /**
+     * The filename to use for the screen recording, if enabled.
+     */
+    char* recording_name;
+
+    /**
+     * Whether the screen recording path should be automatically created if it
+     * does not already exist.
+     */
+    bool create_recording_path;
+
+    /**
+     * Whether output which is broadcast to each connected client (graphics,
+     * streams, etc.) should NOT be included in the session recording. Output
+     * is included by default, as it is necessary for any recording which must
+     * later be viewable as video.
+     */
+    bool recording_exclude_output;
+
+    /**
+     * Whether changes to mouse state, such as position and buttons pressed or
+     * released, should NOT be included in the session recording. Mouse state
+     * is included by default, as it is necessary for the mouse cursor to be
+     * rendered in any resulting video.
+     */
+    bool recording_exclude_mouse;
+
+    /**
+     * Whether keys pressed and released should be included in the session
+     * recording. Key events are NOT included by default within the recording,
+     * as doing so has privacy and security implications.  Including key events
+     * may be necessary in certain auditing contexts, but should only be done
+     * with caution. Key events can easily contain sensitive information, such
+     * as passwords, credit card numbers, etc.
+     */
+    bool recording_include_keys;
+
+    /**
+     * The ASCII code, as an integer, that the tn5250 client will use when the
+     * backspace key is pressed.  By default, this is 127, ASCII delete, if
+     * not specified in the client settings.
+     */
+    int backspace;
+
+    /**
+     * The terminal emulator type that is passed to the remote system.
+     */
+    char* terminal_type;
+    
+    /**
+     * Whether or not to send the magic Wake-on-LAN (WoL) packet prior to
+     * continuing the connection.
+     */
+    bool wol_send_packet;
+    
+    /**
+     * The MAC address to put in the magic WoL packet for the remote host to
+     * wake.
+     */
+    char* wol_mac_addr;
+    
+    /**
+     * The broadcast address to which to send the magic WoL packet to wake
+     * the remote host.
+     */
+    char* wol_broadcast_addr;
+    
+    /**
+     * The UDP port to use when sending the WoL packet.
+     */
+    unsigned short wol_udp_port;
+    
+    /**
+     * The number of seconds to wait after sending the magic WoL packet before
+     * continuing the connection.
+     */
+    int wol_wait_time;
+
+} guac_tn5250_settings;
+
+/**
+ * Parses all given args, storing them in a newly-allocated settings object. If
+ * the args fail to parse, NULL is returned.
+ *
+ * @param user
+ *     The user who submitted the given arguments while joining the
+ *     connection.
+ *
+ * @param argc
+ *     The number of arguments within the argv array.
+ *
+ * @param argv
+ *     The values of all arguments provided by the user.
+ *
+ * @return
+ *     A newly-allocated settings object which must be freed with
+ *     guac_tn5250_settings_free() when no longer needed. If the arguments fail
+ *     to parse, NULL is returned.
+ */
+guac_tn5250_settings* guac_tn5250_parse_args(guac_user* user,
+        int argc, const char** argv);
+
+/**
+ * Frees the regex pointed to by the given pointer, assigning the value NULL to
+ * that pointer once the regex is freed. If the pointer already contains NULL,
+ * this function has no effect.
+ *
+ * @param regex
+ *     The address of the pointer to the regex that should be freed.
+ */
+void guac_tn5250_regex_free(regex_t** regex);
+
+/**
+ * Frees the given guac_tn5250_settings object, having been previously
+ * allocated via guac_tn5250_parse_args().
+ *
+ * @param settings
+ *     The settings object to free.
+ */
+void guac_tn5250_settings_free(guac_tn5250_settings* settings);
+
+/**
+ * NULL-terminated array of accepted client args.
+ */
+extern const char* GUAC_TN5250_CLIENT_ARGS[];
+
+#endif
+

src/protocols/tn5250/tn5250.c

@@ -0,0 +1,770 @@
+/*
+ * 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 "tn5250.h"
+#include "lib5250/lib5250.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/client.h>
+#include <guacamole/protocol.h>
+#include <guacamole/recording.h>
+#include <guacamole/timestamp.h>
+#include <guacamole/wol.h>
+#include <libtelnet.h>
+
+#include <errno.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <poll.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+/**
+ * Support levels for various telnet options, required for connection
+ * negotiation by telnet_init(), part of libtelnet. According to RFC1205,
+ * support for BINARY, TERMINAL TYPE (TTYPE), and END OF RECORD (EOR) must be
+ * enabled for TN5250 to operate. TERMINAL is only supported
+ * client-side (WILL), while BINARY and END OF RECORD should be agreed upon
+ * between client and server.
+ */
+static const telnet_telopt_t __telnet_options[] = {
+    { TELNET_TELOPT_BINARY,      TELNET_WILL, TELNET_DO   },
+    { TELNET_TELOPT_ECHO,        TELNET_WONT, TELNET_DO   },
+    { TELNET_TELOPT_EOR,         TELNET_WILL, TELNET_DO   },
+    { TELNET_TELOPT_TTYPE,       TELNET_WILL, TELNET_DONT },
+    { TELNET_TELOPT_NEW_ENVIRON, TELNET_WILL, TELNET_DONT },
+    { -1, 0, 0 }
+};
+
+/**
+ * Write the entire buffer given to the specified file descriptor, retrying
+ * the write automatically if necessary. This function will return a value
+ * not equal to the buffer's size if an error occurs which prevents all
+ * future writes.
+ *
+ * @param fd
+ *     The file descriptor to write to.
+ *
+ * @param buffer
+ *     The buffer to write.
+ *
+ * @param size
+ *     The number of bytes from the buffer to write.
+ *
+ * @return
+ *     Return a value equal to the buffer's size on success, or a value not
+ *     equal to the buffer's size or a negative value on failure.
+ */
+static int __guac_tn5250_write_all(int fd, const char* buffer, int size) {
+
+    int remaining = size;
+    while (remaining > 0) {
+
+        /* Attempt to write data */
+        int ret_val = write(fd, buffer, remaining);
+        if (ret_val <= 0)
+            return -1;
+
+        /* If successful, contine with what data remains (if any) */
+        remaining -= ret_val;
+        buffer += ret_val;
+
+    }
+
+    return size;
+
+}
+
+/**
+ * Matches the given line against the given regex, returning true and sending
+ * the given value if a match is found. An enter keypress is automatically
+ * sent after the value is sent.
+ *
+ * @param client
+ *     The guac_client associated with the tn5250 session.
+ *
+ * @param regex
+ *     The regex to search for within the given line buffer.
+ *
+ * @param value
+ *     The string value to send through STDIN of the tn5250 session if a
+ *     match is found, or NULL if no value should be sent.
+ *
+ * @param line_buffer
+ *     The line of character data to test.
+ *
+ * @return
+ *     true if a match is found, false otherwise.
+ */
+static bool guac_tn5250_regex_exec(guac_client* client, regex_t* regex,
+        const char* value, const char* line_buffer) {
+
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+
+    /* Send value upon match */
+    if (regexec(regex, line_buffer, 0, NULL, 0) == 0) {
+
+        /* Send value */
+        if (value != NULL) {
+            guac_terminal_send_string(tn5250_client->term, value);
+            guac_terminal_send_string(tn5250_client->term, "\x0D");
+        }
+
+        /* Stop searching for prompt */
+        return true;
+
+    }
+
+    return false;
+
+}
+
+/**
+ * Matches the given line against the various stored regexes, automatically
+ * sending the configured username, password, or reporting login
+ * success/failure depending on context. If no search is in progress, either
+ * because no regexes have been defined or because all applicable searches have
+ * completed, this function has no effect.
+ *
+ * @param client
+ *     The guac_client associated with the tn5250 session.
+ *
+ * @param line_buffer
+ *     The line of character data to test.
+ */
+static void guac_tn5250_search_line(guac_client* client, const char* line_buffer) {
+
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+
+    /* Continue search for username prompt */
+    if (settings->username_regex != NULL) {
+        if (guac_tn5250_regex_exec(client, settings->username_regex,
+                    settings->username, line_buffer)) {
+            guac_client_log(client, GUAC_LOG_DEBUG, "Username sent");
+            guac_tn5250_regex_free(&settings->username_regex);
+        }
+    }
+
+    /* Continue search for password prompt */
+    if (settings->password_regex != NULL) {
+        if (guac_tn5250_regex_exec(client, settings->password_regex,
+                    settings->password, line_buffer)) {
+
+            guac_client_log(client, GUAC_LOG_DEBUG, "Password sent");
+
+            /* Do not continue searching for username/password once password is sent */
+            guac_tn5250_regex_free(&settings->username_regex);
+            guac_tn5250_regex_free(&settings->password_regex);
+
+        }
+    }
+
+    /* Continue search for login success */
+    if (settings->login_success_regex != NULL) {
+        if (guac_tn5250_regex_exec(client, settings->login_success_regex,
+                    NULL, line_buffer)) {
+
+            /* Allow terminal to render now that login has been deemed successful */
+            guac_client_log(client, GUAC_LOG_DEBUG, "Login successful");
+            guac_terminal_start(tn5250_client->term);
+
+            /* Stop all searches */
+            guac_tn5250_regex_free(&settings->username_regex);
+            guac_tn5250_regex_free(&settings->password_regex);
+            guac_tn5250_regex_free(&settings->login_success_regex);
+            guac_tn5250_regex_free(&settings->login_failure_regex);
+
+        }
+    }
+
+    /* Continue search for login failure */
+    if (settings->login_failure_regex != NULL) {
+        if (guac_tn5250_regex_exec(client, settings->login_failure_regex,
+                    NULL, line_buffer)) {
+
+            /* Advise that login has failed and connection should be closed */
+            guac_client_abort(client,
+                    GUAC_PROTOCOL_STATUS_CLIENT_UNAUTHORIZED,
+                    "Login failed");
+
+            /* Stop all searches */
+            guac_tn5250_regex_free(&settings->username_regex);
+            guac_tn5250_regex_free(&settings->password_regex);
+            guac_tn5250_regex_free(&settings->login_success_regex);
+            guac_tn5250_regex_free(&settings->login_failure_regex);
+
+        }
+    }
+
+}
+
+/**
+ * Searches for a line matching the various stored regexes, automatically
+ * sending the configured username, password, or reporting login
+ * success/failure depending on context. If no search is in progress, either
+ * because no regexes have been defined or because all applicable searches
+ * have completed, this function has no effect.
+ *
+ * @param client
+ *     The guac_client associated with the tn5250 session.
+ *
+ * @param buffer
+ *     The buffer of received data to search through.
+ *
+ * @param size
+ *     The size of the given buffer, in bytes.
+ */
+static void guac_tn5250_search(guac_client* client, const char* buffer, int size) {
+
+    static char line_buffer[1024] = {0};
+    static int length = 0;
+
+    /* Append all characters in buffer to current line */
+    const char* current = buffer;
+    for (int i = 0; i < size; i++) {
+
+        char c = *(current++);
+
+        /* Attempt pattern match and clear buffer upon reading newline */
+        if (c == '\n') {
+            if (length > 0) {
+                line_buffer[length] = '\0';
+                guac_tn5250_search_line(client, line_buffer);
+                length = 0;
+            }
+        }
+
+        /* Append all non-newline characters to line buffer as long as space
+         * remains */
+        else if (length < sizeof(line_buffer) - 1)
+            line_buffer[length++] = c;
+
+    }
+
+    /* Attempt pattern match if an unfinished line remains (may be a prompt) */
+    if (length > 0) {
+        line_buffer[length] = '\0';
+        guac_tn5250_search_line(client, line_buffer);
+    }
+
+}
+
+/**
+ * Event handler, as defined by libtelnet. This function is passed to
+ * telnet_init() and will be called for every event fired by libtelnet,
+ * including feature enable/disable and receipt/transmission of data.
+ *
+ * @param tn5250
+ *     The telnet_t object associated with the event.
+ *
+ * @param event
+ *     The telnet_event_t that has fired.
+ *
+ * @param data
+ *     User data provided to the event.
+ */
+static void __guac_tn5250_event_handler(telnet_t* tn5250, telnet_event_t* event, void* data) {
+
+    guac_client* client = (guac_client*) data;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+
+    switch (event->type) {
+
+        /* Terminal output received */
+        case TELNET_EV_DATA:
+            guac_client_log(client, GUAC_LOG_TRACE,
+                    "%s: Received %d bytes of data from remote side.", __func__, event->data.size);
+            if (tn5250_client->binary_mode) {
+                guac_client_log(client, GUAC_LOG_TRACE,
+                        "%s: Receiving binary data, which will not go directly to the terminal.",
+                        __func__);
+                if (guac_lib5250_process_packet(event->data.buffer, client)) {
+                    return;
+                }
+            }
+            else {
+                guac_client_log(client, GUAC_LOG_TRACE,
+                        "%s: Writing ASCII output directly to terminal.", __func__);
+                guac_terminal_write(tn5250_client->term, event->data.buffer, event->data.size);
+                guac_tn5250_search(client, event->data.buffer, event->data.size);
+            }
+            break;
+
+        /* Data destined for remote end */
+        case TELNET_EV_SEND:
+            guac_client_log(client, GUAC_LOG_TRACE,
+                    "%s: Sending %d bytes of data to remote side.", __func__, event->data.size);
+            if (__guac_tn5250_write_all(tn5250_client->socket_fd, event->data.buffer, event->data.size)
+                    != event->data.size)
+                guac_client_stop(client);
+            break;
+
+        /* Remote feature enabled */
+        case TELNET_EV_WILL:
+            if (event->neg.telopt == TELNET_TELOPT_ECHO)
+                tn5250_client->echo_enabled = 0; /* Disable local echo, as remote will echo */
+
+            if (event->neg.telopt == TELNET_TELOPT_EOR) {
+                guac_client_log(client, GUAC_LOG_DEBUG,
+                        "%s: Received End of Record support from remote side.",
+                        __func__);
+            }
+            if (event->neg.telopt == TELNET_TELOPT_BINARY) {
+                guac_client_log(client, GUAC_LOG_DEBUG,
+                        "%s: Received Binary support from remote side.",
+                        __func__);
+            }
+            break;
+
+        /* Remote feature disabled */
+        case TELNET_EV_WONT:
+            if (event->neg.telopt == TELNET_TELOPT_ECHO)
+                tn5250_client->echo_enabled = 1; /* Enable local echo, as remote won't echo */
+
+            /* END OF RECORD are require for TN5250 - stop if remote
+             * side does not support it. */
+            if (event->neg.telopt == TELNET_TELOPT_EOR) {
+                guac_client_log(client, GUAC_LOG_ERROR, "%s: Unexpected lack of "
+                        " END OF RECORD support on the remote side.", __func__);
+                guac_client_stop(client);
+
+            }
+
+            if (event->neg.telopt == TELNET_TELOPT_BINARY) {
+                guac_client_log(client, GUAC_LOG_DEBUG, "%s: End of binary data.",
+                        __func__);
+                tn5250_client->binary_mode = 0;
+            }
+            break;
+
+        /* Local feature enable */
+        case TELNET_EV_DO:
+            if (event->neg.telopt == TELNET_TELOPT_EOR)
+                guac_client_log(client, GUAC_LOG_DEBUG,
+                        "%s: Local EOR support enabled.",
+                        __func__);
+
+            /* Sending a DO BINARY means the next data we receive from the 
+             * server should be binary data. */
+            if (event->neg.telopt == TELNET_TELOPT_BINARY) {
+                guac_client_log(client, GUAC_LOG_DEBUG,
+                        "%s: Local BINARY support enabled, "
+                        "expecting next data to be binary.",
+                        __func__);
+                tn5250_client->binary_mode = 1;
+            }
+            break;
+
+        /* Terminal type request */
+        case TELNET_EV_TTYPE:
+            guac_client_log(client, GUAC_LOG_DEBUG,
+                    "%s: Received TERMINAL TYPE request from the remote side.", __func__);
+            if (event->ttype.cmd == TELNET_TTYPE_SEND) {
+                guac_client_log(client, GUAC_LOG_DEBUG,
+                        "%s: Sending terminal type \"%s\" to remote side.", __func__, settings->terminal_type);
+
+                /* Apparently sending the TERMINAL TYPE to an IBMi system over
+                 * telnet requires both sending the TERM environment variable
+                 * and responding to the actual telnet TTYPE inquiry. */
+                telnet_begin_newenviron(tn5250, TELNET_ENVIRON_IS);
+                telnet_newenviron_value(tn5250, TELNET_ENVIRON_VAR, "TERM");
+                telnet_newenviron_value(tn5250, TELNET_ENVIRON_VALUE, settings->terminal_type);
+                telnet_finish_sb(tn5250);
+                telnet_ttype_is(tn5250_client->tn5250, settings->terminal_type);
+            }
+            break;
+
+        /* Environment request */
+        case TELNET_EV_ENVIRON:
+            guac_client_log(client, GUAC_LOG_DEBUG,
+                    "%s: Received environment request from the remote side.",
+                    __func__);
+            /* Only send USER if entire environment was requested */
+            if (event->environ.size == 0) {
+                guac_client_log(client, GUAC_LOG_TRACE, "%s: Sending username to remote server: %s", __func__, settings->username);
+                guac_tn5250_send_user(tn5250, settings->username);
+            }
+
+            break;
+
+        /* Generic IAC received */
+        case TELNET_EV_IAC:
+            if (event->iac.cmd == TELNET_EOR) {
+                guac_client_log(client, GUAC_LOG_TRACE, "%s: Receive END OF RECORD from remote side.", __func__);
+                break;
+            }
+            guac_client_log(client, GUAC_LOG_DEBUG,
+                    "%s: Received generic IAC data: 0x%x",
+                    __func__, event->iac.cmd);
+            break;
+
+        /* For subnegotiation, we need to break and let the libtelnet internals
+         * finish handling the request. */
+        case TELNET_EV_SUBNEGOTIATION:
+            guac_client_log(client, GUAC_LOG_TRACE,
+                    "%s: Received subnegotiation, sending on to libtelnet.",
+                    __func__);
+            break;
+
+        /* Connection warnings */
+        case TELNET_EV_WARNING:
+            guac_client_log(client, GUAC_LOG_WARNING, "%s", event->error.msg);
+            break;
+
+        /* Connection errors */
+        case TELNET_EV_ERROR:
+            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                    "Telnet connection closing with error: %s", event->error.msg);
+            break;
+
+        /* Ignore other events */
+        default:
+            guac_client_log(client, GUAC_LOG_WARNING,
+                    "%s: Unknown or unsupported telnet command received: 0x%x",
+                    __func__, event->type);
+            break;
+
+    }
+
+}
+
+/**
+ * Input thread, started by the main tn5250 client thread. This thread
+ * continuously reads from the terminal's STDIN and transfers all read
+ * data to the tn5250 connection.
+ *
+ * @param data
+ *     The current guac_client instance.
+ *
+ * @return
+ *     Always NULL.
+ */
+static void* __guac_tn5250_input_thread(void* data) {
+
+    guac_client* client = (guac_client*) data;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+
+    char buffer[8192];
+    int bytes_read;
+
+    /* Write all data read */
+    while ((bytes_read = guac_terminal_read_stdin(tn5250_client->term, buffer, sizeof(buffer))) > 0) {
+        telnet_send(tn5250_client->tn5250, buffer, bytes_read);
+        if (tn5250_client->echo_enabled)
+            guac_terminal_write(tn5250_client->term, buffer, bytes_read);
+    }
+
+    return NULL;
+
+}
+
+/**
+ * Connects to the tn5250 server specified within the data associated
+ * with the given guac_client, which will have been populated by
+ * guac_client_init.
+ *
+ * @return
+ *     The connected tn5250 instance, if successful, or NULL if the
+ *     connection fails for any reason.
+ */
+static telnet_t* __guac_tn5250_create_session(guac_client* client) {
+
+    int retval;
+
+    int fd;
+    struct addrinfo* addresses;
+    struct addrinfo* current_address;
+
+    char connected_address[1024];
+    char connected_port[64];
+
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+
+    struct addrinfo hints = {
+        .ai_family   = AF_UNSPEC,
+        .ai_socktype = SOCK_STREAM,
+        .ai_protocol = IPPROTO_TCP
+    };
+
+    /* Get socket */
+    fd = socket(AF_INET, SOCK_STREAM, 0);
+
+    /* Get addresses connection */
+    if ((retval = getaddrinfo(settings->hostname, settings->port,
+                    &hints, &addresses))) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error parsing given address or port: %s",
+                gai_strerror(retval));
+        return NULL;
+
+    }
+
+    /* Attempt connection to each address until success */
+    current_address = addresses;
+    while (current_address != NULL) {
+
+        int retval;
+
+        /* Resolve hostname */
+        if ((retval = getnameinfo(current_address->ai_addr,
+                current_address->ai_addrlen,
+                connected_address, sizeof(connected_address),
+                connected_port, sizeof(connected_port),
+                NI_NUMERICHOST | NI_NUMERICSERV)))
+            guac_client_log(client, GUAC_LOG_DEBUG, "Unable to resolve host: %s", gai_strerror(retval));
+
+        /* Connect */
+        if (connect(fd, current_address->ai_addr,
+                        current_address->ai_addrlen) == 0) {
+
+            guac_client_log(client, GUAC_LOG_DEBUG, "Successfully connected to "
+                    "host %s, port %s", connected_address, connected_port);
+
+            /* Done if successful connect */
+            break;
+
+        }
+
+        /* Otherwise log information regarding bind failure */
+        else
+            guac_client_log(client, GUAC_LOG_DEBUG, "Unable to connect to "
+                    "host %s, port %s: %s",
+                    connected_address, connected_port, strerror(errno));
+
+        current_address = current_address->ai_next;
+
+    }
+
+    /* If unable to connect to anything, fail */
+    if (current_address == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_NOT_FOUND,
+                "Unable to connect to any addresses.");
+        return NULL;
+    }
+
+    /* Free addrinfo */
+    freeaddrinfo(addresses);
+
+    /* Open tn5250 session */
+    telnet_t* tn5250 = telnet_init(__telnet_options, __guac_tn5250_event_handler, 0, client);
+    if (tn5250 == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Telnet client allocation failed.");
+        return NULL;
+    }
+
+    /* Save file descriptor */
+    tn5250_client->socket_fd = fd;
+
+    return tn5250;
+
+}
+
+/**
+ * Sends a 16-bit value over the given tn5250 connection with the byte order
+ * required by the tn5250 protocol.
+ *
+ * @param tn5250
+ *     The tn5250 connection to use.
+ *
+ * @param value
+ *     The value to send.
+ */
+/*
+static void __guac_tn5250_send_uint16(telnet_t* tn5250, uint16_t value) {
+
+    unsigned char buffer[2];
+    buffer[0] = (value >> 8) & 0xFF;
+    buffer[1] =  value       & 0xFF;
+
+    telnet_send(tn5250, (char*) buffer, 2);
+
+}
+*/
+
+/**
+ * Sends an 8-bit value over the given tn5250 connection.
+ *
+ * @param tn5250
+ *     The tn5250 connection to use.
+ *
+ * @param value
+ *     The value to send.
+ */
+/*
+static void __guac_tn5250_send_uint8(telnet_t* tn5250, uint8_t value) {
+    telnet_send(tn5250, (char*) (&value), 1);
+}
+*/
+
+void guac_tn5250_send_user(telnet_t* tn5250, const char* username) {
+
+    /* IAC SB NEW-ENVIRON IS */
+    telnet_begin_newenviron(tn5250, TELNET_ENVIRON_IS);
+
+    /* Only send username if defined */
+    if (username != NULL) {
+
+        telnet_newenviron_value(tn5250, TELNET_ENVIRON_VAR, "USER");
+        telnet_newenviron_value(tn5250, TELNET_ENVIRON_VALUE, username);
+
+    }
+
+    /* IAC SB */
+    telnet_finish_sb(tn5250);
+
+}
+
+/**
+ * Waits for data on the given file descriptor for up to one second. The
+ * return value is identical to that of select(): 0 on timeout, < 0 on
+ * error, and > 0 on success.
+ *
+ * @param socket_fd The file descriptor to wait for.
+ * @return A value greater than zero on success, zero on timeout, and
+ *         less than zero on error.
+ */
+static int __guac_tn5250_wait(int socket_fd) {
+
+    /* Build array of file descriptors */
+    struct pollfd fds[] = {{
+        .fd      = socket_fd,
+        .events  = POLLIN,
+        .revents = 0,
+    }};
+
+    /* Wait for one second */
+    return poll(fds, 1, 1000);
+
+}
+
+void* guac_tn5250_client_thread(void* data) {
+
+    guac_client* client = (guac_client*) data;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+    guac_tn5250_settings* settings = tn5250_client->settings;
+
+    pthread_t input_thread;
+    char buffer[8192];
+    int wait_result;
+
+    /* Set up screen recording, if requested */
+    if (settings->recording_path != NULL) {
+        tn5250_client->recording = guac_recording_create(client,
+                settings->recording_path,
+                settings->recording_name,
+                settings->create_recording_path,
+                !settings->recording_exclude_output,
+                !settings->recording_exclude_mouse,
+                0, /* Touch events not supported */
+                settings->recording_include_keys);
+    }
+
+    /* Create terminal options with required parameters */
+    guac_terminal_options* options = guac_terminal_options_create(
+            settings->width, settings->height, settings->resolution);
+
+    /* Set optional parameters */
+    options->disable_copy = settings->disable_copy;
+    options->max_scrollback = settings->max_scrollback;
+    options->font_name = settings->font_name;
+    options->font_size = settings->font_size;
+    options->color_scheme = settings->color_scheme;
+    options->backspace = settings->backspace;
+
+    /* Create terminal */
+    tn5250_client->term = guac_terminal_create(client, options);
+
+    /* Free options struct now that it's been used */
+    free(options);
+
+    /* Fail if terminal init failed */
+    if (tn5250_client->term == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
+                "Terminal initialization failed");
+        return NULL;
+    }
+
+    /* Send current values of exposed arguments to owner only */
+    guac_client_for_owner(client, guac_tn5250_send_current_argv,
+            tn5250_client);
+
+    /* Set up typescript, if requested */
+    if (settings->typescript_path != NULL) {
+        guac_terminal_create_typescript(tn5250_client->term,
+                settings->typescript_path,
+                settings->typescript_name,
+                settings->create_typescript_path);
+    }
+
+    /* Open tn5250 session */
+    tn5250_client->tn5250 = __guac_tn5250_create_session(client);
+    if (tn5250_client->tn5250 == NULL) {
+        /* Already aborted within __guac_tn5250_create_session() */
+        return NULL;
+    }
+
+    /* Logged in */
+    guac_client_log(client, GUAC_LOG_INFO, "Telnet connection successful.");
+
+    /* Allow terminal to render if login success/failure detection is not
+     * enabled */
+    if (settings->login_success_regex == NULL
+            && settings->login_failure_regex == NULL)
+        guac_terminal_start(tn5250_client->term);
+
+    /* Start input thread */
+    if (pthread_create(&(input_thread), NULL, __guac_tn5250_input_thread, (void*) client)) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to start input thread");
+        return NULL;
+    }
+
+    /* While data available, write to terminal */
+    while ((wait_result = __guac_tn5250_wait(tn5250_client->socket_fd)) >= 0) {
+
+        /* Resume waiting of no data available */
+        if (wait_result == 0)
+            continue;
+
+        int bytes_read = read(tn5250_client->socket_fd, buffer, sizeof(buffer));
+        if (bytes_read <= 0)
+            break;
+
+        telnet_recv(tn5250_client->tn5250, buffer, bytes_read);
+
+    }
+
+    /* Kill client and Wait for input thread to die */
+    guac_client_stop(client);
+    pthread_join(input_thread, NULL);
+
+    guac_client_log(client, GUAC_LOG_INFO, "Telnet connection ended.");
+    return NULL;
+
+}
+

src/protocols/tn5250/tn5250.h

@@ -0,0 +1,95 @@
+/*
+ * 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_TN5250_H
+#define GUAC_TN5250_H
+
+#include "config.h"
+#include "settings.h"
+#include "terminal/terminal.h"
+
+#include <guacamole/recording.h>
+#include <libtelnet.h>
+
+#include <stdint.h>
+
+/**
+ * TN5250-specific client data.
+ */
+typedef struct guac_tn5250_client {
+
+    /**
+     * Telnet connection settings.
+     */
+    guac_tn5250_settings* settings;
+
+    /**
+     * The TN5250 client thread.
+     */
+    pthread_t client_thread;
+
+    /**
+     * The file descriptor of the socket connected to the tn5250 server,
+     * or -1 if no connection has been established.
+     */
+    int socket_fd;
+
+    /**
+     * TN5250 connection, used by the telnet client thread.
+     */
+    telnet_t* tn5250;
+
+    /**
+     * Whether all user input should be automatically echoed to the
+     * terminal.
+     */
+    int echo_enabled;
+
+    /**
+     * The terminal which will render all output from the tn5250 client.
+     */
+    guac_terminal* term;
+
+    /**
+     * The in-progress session recording, or NULL if no recording is in
+     * progress.
+     */
+    guac_recording* recording;
+
+    /**
+     * Indicates whether or not the TN5250 client is now in binary mode and
+     * subsequent data should be binary.
+     */
+    int binary_mode;
+
+} guac_tn5250_client;
+
+/**
+ * Main tn5250 client thread, handling transfer of TN5250 output to STDOUT.
+ */
+void* guac_tn5250_client_thread(void* data);
+
+/**
+ * Sends the given username by setting the remote USER environment variable
+ * using the telnet NEW-ENVIRON option.
+ */
+void guac_tn5250_send_user(telnet_t* tn5250, const char* username);
+
+#endif
+

src/protocols/tn5250/user.c

@@ -0,0 +1,122 @@
+/*
+ * 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 "clipboard.h"
+#include "input.h"
+#include "pipe.h"
+#include "settings.h"
+#include "tn5250.h"
+#include "terminal/terminal.h"
+#include "user.h"
+
+#include <guacamole/client.h>
+#include <guacamole/socket.h>
+#include <guacamole/user.h>
+
+#include <pthread.h>
+#include <string.h>
+
+int guac_tn5250_user_join_handler(guac_user* user, int argc, char** argv) {
+
+    guac_client* client = user->client;
+    guac_tn5250_client* tn5250_client = (guac_tn5250_client*) client->data;
+
+    /* Parse provided arguments */
+    guac_tn5250_settings* settings = guac_tn5250_parse_args(user,
+            argc, (const char**) argv);
+
+    /* Fail if settings cannot be parsed */
+    if (settings == NULL) {
+        guac_user_log(user, GUAC_LOG_INFO,
+                "Badly formatted client arguments.");
+        return 1;
+    }
+
+    /* Store settings at user level */
+    user->data = settings;
+
+    /* Connect via tn5250 if owner */
+    if (user->owner) {
+
+        /* Store owner's settings at client level */
+        tn5250_client->settings = settings;
+
+        /* Start client thread */
+        if (pthread_create(&(tn5250_client->client_thread), NULL,
+                    guac_tn5250_client_thread, (void*) client)) {
+            guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
+                    "Unable to start tn5250 client thread");
+            return 1;
+        }
+
+    }
+
+    /* If not owner, synchronize with current display */
+    else {
+        guac_terminal_dup(tn5250_client->term, user, user->socket);
+        guac_tn5250_send_current_argv(user, tn5250_client);
+        guac_socket_flush(user->socket);
+    }
+
+    /* Only handle events if not read-only */
+    if (!settings->read_only) {
+
+        /* General mouse/keyboard events */
+        user->key_handler = guac_tn5250_user_key_handler;
+        user->mouse_handler = guac_tn5250_user_mouse_handler;
+
+        /* Inbound (client to server) clipboard transfer */
+        if (!settings->disable_paste)
+            user->clipboard_handler = guac_tn5250_clipboard_handler;
+
+        /* STDIN redirection */
+        user->pipe_handler = guac_tn5250_pipe_handler;
+
+        /* Updates to connection parameters */
+        user->argv_handler = guac_argv_handler;
+
+        /* Display size change events */
+        user->size_handler = guac_tn5250_user_size_handler;
+
+    }
+
+    return 0;
+
+}
+
+int guac_tn5250_user_leave_handler(guac_user* user) {
+
+    guac_tn5250_client* tn5250_client =
+        (guac_tn5250_client*) user->client->data;
+
+    /* Remove the user from the terminal */
+    guac_terminal_remove_user(tn5250_client->term, user);
+
+    /* Free settings if not owner (owner settings will be freed with client) */
+    if (!user->owner) {
+        guac_tn5250_settings* settings = (guac_tn5250_settings*) user->data;
+        guac_tn5250_settings_free(settings);
+    }
+
+    return 0;
+}
+

src/protocols/tn5250/user.h

@@ -0,0 +1,38 @@
+/*
+ * 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_TN5250_USER_H
+#define GUAC_TN5250_USER_H
+
+#include "config.h"
+
+#include <guacamole/user.h>
+
+/**
+ * Handler for joining users.
+ */
+guac_user_join_handler guac_tn5250_user_join_handler;
+
+/**
+ * Handler for leaving users.
+ */
+guac_user_leave_handler guac_tn5250_user_leave_handler;
+
+#endif
+