first checkin for gtcp-proxy, a man-in-the-middle program to monitor network traffice

1 files changed, 678 insertions, 0 deletions

diff --git a/tests/gtcp_proxy/gtcp-proxy.c b/tests/gtcp_proxy/gtcp-proxy.c
new file mode 100644
index 00000000..39555c76
--- /dev/null
+++ b/tests/gtcp_proxy/gtcp-proxy.c
@@ -0,0 +1,678 @@
+/**
+ * xrdp: A Remote Desktop Protocol server.
+ *
+ * Copyright (C) Laxmikant Rashinkar 2013 LK.Rashinkar@gmail.com
+ *
+ * Licensed 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 <stdio.h>
+#include <gtk/gtk.h>
+#include <pthread.h>
+
+#include "gtcp.h"
+
+#define WINDOW_TITLE    "Tcp Proxy Version 1.0"
+#define CONTEXT_ID      1
+#define MSG_INFO        GTK_MESSAGE_INFO
+#define MSG_WARN        GTK_MESSAGE_WARNING
+#define MSG_ERROR       GTK_MESSAGE_ERROR
+#define MAIN_THREAD_YES 0
+#define MAIN_THREAD_NO  1
+
+/* globals */
+pthread_t g_tid;
+int       g_keep_running   = 1;
+int       g_loc_io_count   = 0;  /* bytes read from local port  */
+int       g_rem_io_count   = 0;  /* bytes read from remote port */
+
+GtkWidget *g_btn_start;
+GtkWidget *g_tbx_loc_port;
+GtkWidget *g_tbx_rem_ip;
+GtkWidget *g_tbx_rem_port;
+GtkWidget *g_tbx_loc_stats;
+GtkWidget *g_tbx_rem_stats;
+GtkWidget *g_statusbar;
+GtkWidget *g_txtvu_loc_port;
+GtkWidget *g_txtvu_rem_port;
+
+/* forward declarations */
+static void *tcp_proxy(void *arg);
+
+static void show_msg(int not_main_thread, int style,
+                     const gchar *title, const gchar *msg);
+
+static void show_status(int not_main_thread, char *msg);
+static void clear_status(int not_main_thread);
+static void enable_btn_start(int main_thread);
+static void disable_btn_start(int main_thread);
+
+/* getters */
+static char *get_local_port();
+static char *get_remote_ip();
+static char *get_remote_port();
+
+/* setters */
+static void show_loc_port_stats(int main_thread, int count);
+static void show_rem_port_stats(int main_thread, int count);
+
+/* handlers */
+static gboolean on_delete_event(GtkWidget *widget, GdkEvent *ev, gpointer data);
+static void on_destroy(GtkWidget *widget, gpointer data);
+static void on_start_clicked(GtkWidget *widget, gpointer data);
+static void on_clear_clicked(GtkWidget *widget, gpointer data);
+static void on_quit_clicked(GtkWidget *widget, gpointer data);
+
+int main(int argc, char **argv)
+{
+    /* init threads */
+    g_thread_init(NULL);
+    gdk_threads_init();
+
+    /* setup GTK */
+    gtk_init(&argc, &argv);
+
+    /* create labels and right justify them */
+    GtkWidget *lbl_loc_port    = gtk_label_new("Local port");
+    GtkWidget *lbl_rem_ip      = gtk_label_new("Remote IP");
+    GtkWidget *lbl_rem_port    = gtk_label_new("Remote port");
+    GtkWidget *lbl_loc_stats   = gtk_label_new("Local port recv stats");
+    GtkWidget *lbl_rem_stats   = gtk_label_new("Remote port recv stats");
+
+    gtk_misc_set_alignment(GTK_MISC(lbl_loc_port), 1.0, 0.5);
+    gtk_misc_set_alignment(GTK_MISC(lbl_rem_ip), 1.0, 0.5);
+    gtk_misc_set_alignment(GTK_MISC(lbl_rem_port), 1.0, 0.5);
+    gtk_misc_set_alignment(GTK_MISC(lbl_loc_stats), 1.0, 0.5);
+    gtk_misc_set_alignment(GTK_MISC(lbl_rem_stats), 1.0, 0.5);
+
+    /* create text boxes */
+    g_tbx_loc_port   = gtk_entry_new();
+    g_tbx_rem_ip     = gtk_entry_new();
+    g_tbx_rem_port   = gtk_entry_new();
+    g_tbx_loc_stats  = gtk_entry_new();
+    g_tbx_rem_stats  = gtk_entry_new();
+
+    /* stat text boxes are read only */
+    gtk_entry_set_editable(GTK_ENTRY(g_tbx_loc_stats), FALSE);
+    gtk_entry_set_editable(GTK_ENTRY(g_tbx_rem_stats), FALSE);
+
+    /* enable when debugging */
+#if 0
+    gtk_entry_set_text(GTK_ENTRY(g_tbx_loc_port), "1234");
+    gtk_entry_set_text(GTK_ENTRY(g_tbx_rem_ip), "192.168.2.20");
+    gtk_entry_set_text(GTK_ENTRY(g_tbx_rem_port), "43222");
+#endif
+
+    /* setup buttons inside a HBox */
+    g_btn_start          = gtk_button_new_with_label("Start listening");
+    GtkWidget *btn_clear = gtk_button_new_with_label("Clear receive stats");
+    GtkWidget *btn_quit  = gtk_button_new_with_label("Quit application");
+
+    GtkWidget *hbox = gtk_hbox_new(FALSE, 5);
+    gtk_box_pack_start_defaults(GTK_BOX(hbox), g_btn_start);
+    gtk_box_pack_start_defaults(GTK_BOX(hbox), btn_clear);
+    gtk_box_pack_start_defaults(GTK_BOX(hbox), btn_quit);
+
+#if 0
+    g_txtvu_loc_port = gtk_text_view_new();
+    g_txtvu_rem_port = gtk_text_view_new();
+#endif
+
+    /* create table */
+    GtkWidget *table = gtk_table_new(8, 3, FALSE);
+
+    int row = 0;
+
+    /* insert labels into table */
+    gtk_table_attach(GTK_TABLE(table), lbl_loc_port, 0, 1, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), lbl_rem_ip, 0, 1, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), lbl_rem_port, 0, 1, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), lbl_loc_stats, 0, 1, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), lbl_rem_stats, 0, 1, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    row = 0;
+
+    /* insert text boxes into table */
+    gtk_table_attach(GTK_TABLE(table), g_tbx_loc_port, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), g_tbx_rem_ip, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), g_tbx_rem_port, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), g_tbx_loc_stats, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+    gtk_table_attach(GTK_TABLE(table), g_tbx_rem_stats, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+    row++;
+
+    /* insert hbox with buttons into table */
+    gtk_table_attach(GTK_TABLE(table), hbox, 1, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+
+#if 0
+    /* text view to display hexdumps */
+    gtk_table_attach(GTK_TABLE(table), g_txtvu_loc_port, 0, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+    row++;
+#endif
+
+    /* status bar to display messages */
+    g_statusbar = gtk_statusbar_new();
+    gtk_statusbar_set_has_resize_grip(GTK_STATUSBAR(g_statusbar), TRUE);
+    gtk_table_attach(GTK_TABLE(table), g_statusbar, 0, 2, row, row + 1,
+                     GTK_FILL, GTK_FILL, 5, 0);
+
+    /* setup main window */
+    GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+    gtk_container_set_border_width(GTK_CONTAINER(window), 5);
+    gtk_window_set_default_size(GTK_WINDOW(window), 640, 480);
+    gtk_window_set_title(GTK_WINDOW(window), WINDOW_TITLE);
+    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
+    gtk_window_set_resizable(GTK_WINDOW(window), FALSE);
+
+    gtk_container_add(GTK_CONTAINER(window), table);
+    gtk_widget_show_all(window);
+
+    /* setup callbacks */
+    g_signal_connect(window, "delete-event", G_CALLBACK(on_delete_event), NULL);
+    g_signal_connect(window, "destroy", G_CALLBACK(on_destroy), NULL);
+
+    g_signal_connect(g_btn_start, "clicked", G_CALLBACK(on_start_clicked), NULL);
+    g_signal_connect(btn_clear, "clicked", G_CALLBACK(on_clear_clicked), NULL);
+    g_signal_connect(btn_quit, "clicked", G_CALLBACK(on_quit_clicked), NULL);
+
+    gdk_threads_enter();
+    gtk_main();
+    gdk_threads_leave();
+
+    return 0;
+}
+
+/**
+ * Start listening on specifed local socket; when we get a connection,
+ * connect to specified remote server and transfer data between local
+ * and remote server
+ *****************************************************************************/
+
+static void *tcp_proxy(void *arg)
+{
+    char buf[1024 * 32];
+
+    int lis_skt = -1;
+    int acc_skt = -1;
+    int con_skt = -1;
+    int sel     = 0;
+    int rv      = 0;
+    int i       = 0;
+    int count   = 0;
+    int sent    = 0;
+
+    /* create listener socket */
+    if ((lis_skt = tcp_socket_create()) < 0)
+    {
+        show_msg(MAIN_THREAD_NO, MSG_ERROR, "Creating socket",
+                 "\nOperation failed. System out of resources");
+        enable_btn_start(MAIN_THREAD_NO);
+        return NULL;
+    }
+
+    /* place it in non blocking mode */
+    tcp_set_non_blocking(lis_skt);
+
+    if ((rv = tcp_bind(lis_skt, get_local_port())) != 0)
+    {
+        show_msg(MAIN_THREAD_NO, MSG_ERROR, "Bind error",
+                 "\nUnable to bind socket, cannot continue");
+        tcp_close(lis_skt);
+        enable_btn_start(MAIN_THREAD_NO);
+        return NULL;
+    }
+
+    /* listen for incoming connection */
+    if (tcp_listen(lis_skt))
+    {
+        show_msg(MAIN_THREAD_NO, MSG_ERROR, "Listen error",
+                 "\nUnable to listen on socket, cannot continue");
+        tcp_close(lis_skt);
+        enable_btn_start(MAIN_THREAD_NO);
+        return NULL;
+    }
+
+    show_status(MAIN_THREAD_NO, "Waiting for client connections");
+
+    /* accept incoming connection */
+    while (g_keep_running)
+    {
+        acc_skt = tcp_accept(lis_skt);
+        if (acc_skt > 0)
+        {
+            /* client connected */
+            show_status(MAIN_THREAD_NO, "Client connected");
+            tcp_close(lis_skt);
+            lis_skt = -1;
+            break;
+        }
+        if ((acc_skt < 0) && (tcp_last_error_would_block()))
+        {
+            /* no connection, try again */
+            usleep(250);
+            continue;
+        }
+        else
+        {
+            tcp_close(lis_skt);
+            lis_skt = -1;
+            enable_btn_start(MAIN_THREAD_NO);
+            return NULL;
+        }
+    }
+
+    /* we have a client connection, try connecting to server */
+    if ((con_skt = tcp_socket()) < 0)
+    {
+        show_msg(MAIN_THREAD_NO, MSG_ERROR, "Creating socket",
+                 "\nOperation failed. System out of resources");
+        tcp_close(lis_skt);
+        tcp_close(acc_skt);
+        enable_btn_start(MAIN_THREAD_NO);
+        return NULL;
+    }
+
+    /* place it in non blocking mode */
+    tcp_set_non_blocking(con_skt);
+
+    rv = tcp_connect(con_skt, get_remote_ip(), get_remote_port());
+#if 0
+    if (rv < 0)
+    {
+        show_status(MAIN_THREAD_NO, "Could not connect to server");
+        tcp_close(lis_skt);
+        tcp_close(acc_skt);
+        enable_btn_start(MAIN_THREAD_NO);
+        return NULL;
+    }
+#endif
+
+    if ((rv < 0) && (tcp_last_error_would_block(con_skt)))
+    {
+        for (i = 0; i < 100; i++)
+        {
+            if (tcp_can_send(con_skt, 100))
+                break;
+
+            usleep(100);
+        }
+
+        if (i == 100)
+        {
+            show_status(MAIN_THREAD_NO, "Could not connect to server");
+            tcp_close(lis_skt);
+            tcp_close(acc_skt);
+            enable_btn_start(MAIN_THREAD_NO);
+            return NULL;
+        }
+    }
+
+    show_status(MAIN_THREAD_NO, "Connected to server");
+    rv = 0;
+
+    while (g_keep_running && rv == 0)
+    {
+        if ((sel = tcp_select(con_skt, acc_skt)) == 0)
+        {
+            usleep(10);
+            continue;
+        }
+
+        if (sel & 1)
+        {
+            /* can read from con_skt without blocking */
+            count = tcp_recv(con_skt, buf, 1024 * 16, 0);
+            rv = count < 1;
+
+            if (rv == 0)
+            {
+                g_loc_io_count += count;
+                show_loc_port_stats(MAIN_THREAD_NO, g_loc_io_count);
+
+                /* TODO: hexdump data here */
+
+                sent = 0;
+
+                while ((sent < count) && (rv == 0) && (g_keep_running))
+                {
+                    i = tcp_send(acc_skt, buf + sent, count - sent, 0);
+
+                    if ((i == -1) && tcp_last_error_would_block(acc_skt))
+                    {
+                        tcp_can_send(acc_skt, 1000);
+                    }
+                    else if (i < 1)
+                    {
+                        rv = 1;
+                    }
+                    else
+                    {
+                        sent += i;
+                    }
+                }
+            }
+        }
+
+        if (sel & 2)
+        {
+            /* can read from acc_skt without blocking */
+            count = tcp_recv(acc_skt, buf, 1024 * 16, 0);
+            rv = count < 1;
+
+            if (rv == 0)
+            {
+                g_rem_io_count += count;
+                show_rem_port_stats(MAIN_THREAD_NO, g_rem_io_count);
+
+                /* TODO: hexdump data here */
+
+                sent = 0;
+
+                while ((sent < count) && (rv == 0) && (g_keep_running))
+                {
+                    i = tcp_send(con_skt, buf + sent, count - sent, 0);
+
+                    if ((i == -1) && tcp_last_error_would_block(con_skt))
+                    {
+                        tcp_can_send(con_skt, 1000);
+                    }
+                    else if (i < 1)
+                    {
+                        rv = 1;
+                    }
+                    else
+                    {
+                        sent += i;
+                    }
+                }
+            }
+        }
+    }
+
+    tcp_close(lis_skt);
+    tcp_close(con_skt);
+    tcp_close(acc_skt);
+
+    show_status(MAIN_THREAD_NO, "Connection closed");
+    enable_btn_start(MAIN_THREAD_NO);
+    return NULL;
+}
+
+/**
+ * Display a message using specified style dialog
+ *
+ * @param  style  information, warning or error
+ * @param  title  text to be displayed in title bar
+ * @param  msg    message to be displayed
+ *****************************************************************************/
+
+static void show_msg(int not_main_window, int style,
+                     const gchar *title, const gchar *msg)
+{
+    GtkWidget *dialog;
+
+    if (not_main_window)
+        gdk_threads_enter();
+
+    dialog = gtk_message_dialog_new(GTK_WINDOW(NULL),
+                                    GTK_DIALOG_DESTROY_WITH_PARENT,
+                                    style,
+                                    GTK_BUTTONS_OK,
+                                    "%s", msg);
+
+    gtk_window_set_title(GTK_WINDOW(dialog), title);
+    gtk_dialog_run(GTK_DIALOG(dialog));
+    gtk_widget_destroy(dialog);
+
+    if (not_main_window)
+        gdk_threads_leave();
+}
+
+/**
+ * Write message to status bar
+ *****************************************************************************/
+
+static void show_status(int not_main_thread, char *msg)
+{
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_statusbar_push(GTK_STATUSBAR(g_statusbar), CONTEXT_ID, msg);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * Clear status bar
+ *****************************************************************************/
+
+static void clear_status(int not_main_thread)
+{
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_statusbar_remove_all(GTK_STATUSBAR(g_statusbar), CONTEXT_ID);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * Enable 'Start Listening' button
+ *****************************************************************************/
+
+static void enable_btn_start(int not_main_thread)
+{
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_widget_set_sensitive(GTK_WIDGET(g_btn_start), TRUE);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * Disable 'Start Listening' button
+ *****************************************************************************/
+
+static void disable_btn_start(int not_main_thread)
+{
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_widget_set_sensitive(GTK_WIDGET(g_btn_start), FALSE);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * Return local port setting
+ *****************************************************************************/
+
+static char *get_local_port()
+{
+    const char *cptr = gtk_entry_get_text(GTK_ENTRY(g_tbx_loc_port));
+    return (char *) cptr;
+}
+
+/**
+ * Return remote IP setting
+ *****************************************************************************/
+
+static char *get_remote_ip()
+{
+    const char *cptr = gtk_entry_get_text(GTK_ENTRY(g_tbx_rem_ip));
+    return (char *) cptr;
+}
+
+/**
+ * Return remote port setting
+ *****************************************************************************/
+
+static char *get_remote_port()
+{
+    const char *cptr = gtk_entry_get_text(GTK_ENTRY(g_tbx_rem_port));
+    return (char *) cptr;
+}
+
+/**
+ * Update local port stat counter
+ *****************************************************************************/
+
+static void show_loc_port_stats(int not_main_thread, int count)
+{
+    char buf[128];
+
+    sprintf(buf, "%d", count);
+
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_entry_set_text(GTK_ENTRY(g_tbx_loc_stats), buf);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * Update remote port stat counter
+ *****************************************************************************/
+
+static void show_rem_port_stats(int not_main_thread, int count)
+{
+    char buf[128];
+
+    sprintf(buf, "%d", count);
+
+    if (not_main_thread)
+        gdk_threads_enter();
+
+    gtk_entry_set_text(GTK_ENTRY(g_tbx_rem_stats), buf);
+
+    if (not_main_thread)
+        gdk_threads_leave();
+}
+
+/**
+ * User clicked on window close button
+ *****************************************************************************/
+
+static gboolean on_delete_event(GtkWidget *widget, GdkEvent *ev, gpointer data)
+{
+    return FALSE;
+}
+
+/**
+ * Close application
+ *****************************************************************************/
+
+static void on_destroy(GtkWidget *widget, gpointer data)
+{
+    /* this will destory all windows and return control to gtk_main() */
+    gtk_main_quit();
+}
+
+/**
+ * Start a thread that listens for incoming connections
+ *****************************************************************************/
+
+static void on_start_clicked(GtkWidget *widget, gpointer data)
+{
+    /* local port must be specified */
+    if (gtk_entry_get_text_length(GTK_ENTRY(g_tbx_loc_port)) == 0)
+    {
+        show_msg(MAIN_THREAD_YES, MSG_ERROR, "Invalid entry",
+                 "\nYou must enter a value for Local Port");
+        return;
+    }
+
+    /* remote IP must be specified */
+    if (gtk_entry_get_text_length(GTK_ENTRY(g_tbx_rem_ip)) == 0)
+    {
+        show_msg(MAIN_THREAD_YES, MSG_ERROR, "Invalid entry",
+                 "\nYou must enter a value for Remote IP");
+        return;
+    }
+
+    /* remote port must be specified */
+    if (gtk_entry_get_text_length(GTK_ENTRY(g_tbx_rem_port)) == 0)
+    {
+        show_msg(MAIN_THREAD_YES, MSG_ERROR, "Invalid entry",
+                 "\nYou must enter a value for Remote Port");
+        return;
+    }
+
+    if (pthread_create(&g_tid, NULL, tcp_proxy, NULL))
+    {
+        show_msg(MAIN_THREAD_YES, MSG_ERROR, "Starting listener",
+                 "\nThread create error. System out of resources");
+        return;
+    }
+
+    disable_btn_start(MAIN_THREAD_YES);
+}
+
+/**
+ * Clear stat counters
+ *****************************************************************************/
+
+static void on_clear_clicked(GtkWidget *widget, gpointer data)
+{
+    g_loc_io_count = 0;
+    g_rem_io_count = 0;
+    show_loc_port_stats(MAIN_THREAD_YES, g_loc_io_count);
+    show_rem_port_stats(MAIN_THREAD_YES, g_rem_io_count);
+}
+
+/**
+ * Quit application
+ *****************************************************************************/
+
+static void on_quit_clicked(GtkWidget *widget, gpointer data)
+{
+    /* this will destory all windows and return control to gtk_main() */
+    gtk_main_quit();
+}