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

ulab-next
Laxmikant Rashinkar 12 years ago
parent c5ebc9ae51
commit 1d1e804a1c

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gtcp-proxy is a 'man in the middle' program to monitor data flowing between
two network connections.

Binary file not shown.

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/**
* 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();
}

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/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2013
*
* 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 "gtcp.h"
/**
* Return a newly created socket or -1 on error
*****************************************************************************/
int tcp_socket_create(void)
{
int rv;
int option_value;
#if defined(_WIN32)
int option_len;
#else
unsigned int option_len;
#endif
/* in win32 a socket is an unsigned int, in linux, its an int */
if ((rv = (int) socket(PF_INET, SOCK_STREAM, 0)) < 0)
return -1;
option_len = sizeof(option_value);
if (getsockopt(rv, SOL_SOCKET, SO_REUSEADDR, (char *) &option_value,
&option_len) == 0)
{
if (option_value == 0)
{
option_value = 1;
option_len = sizeof(option_value);
setsockopt(rv, SOL_SOCKET, SO_REUSEADDR, (char *) &option_value,
option_len);
}
}
option_len = sizeof(option_value);
if (getsockopt(rv, SOL_SOCKET, SO_SNDBUF, (char *) &option_value,
&option_len) == 0)
{
if (option_value < (1024 * 32))
{
option_value = 1024 * 32;
option_len = sizeof(option_value);
setsockopt(rv, SOL_SOCKET, SO_SNDBUF, (char *) &option_value,
option_len);
}
}
return rv;
}
/**
* Place specifed socket in non blocking mode
*****************************************************************************/
void tcp_set_non_blocking(int skt)
{
unsigned long i;
#if defined(_WIN32)
i = 1;
ioctlsocket(skt, FIONBIO, &i);
#else
i = fcntl(skt, F_GETFL);
i = i | O_NONBLOCK;
fcntl(skt, F_SETFL, i);
#endif
}
/**
* Assign name to socket
*
* @param skt the socket to bind
* @param port the port to bind to
*
* @return 0 on success, -1 on error
*****************************************************************************/
int tcp_bind(int skt, char *port)
{
struct sockaddr_in s;
memset(&s, 0, sizeof(struct sockaddr_in));
s.sin_family = AF_INET;
s.sin_port = htons((uint16_t) atoi(port));
s.sin_addr.s_addr = INADDR_ANY;
return bind(skt, (struct sockaddr *) &s, sizeof(struct sockaddr_in));
}
/**
* Listen for incoming connections
*
* @param skt the socket to listen on
*
* @return 0 on success, -1 on error
*****************************************************************************/
int tcp_listen(int skt)
{
return listen(skt, 2);
}
/**
* Accept incoming connection
*
* @param skt socket to accept incoming connection on
*
* @return 0 on success, -1 on error
*****************************************************************************/
int tcp_accept(int skt)
{
int ret ;
char ipAddr[256] ;
struct sockaddr_in s;
#if defined(_WIN32)
int i;
#else
unsigned int i;
#endif
i = sizeof(struct sockaddr_in);
memset(&s, 0, i);
return accept(skt, (struct sockaddr *)&s, &i);
}
/**
* Check if the socket would block
*
* @return TRUE if would block, else FALSE
*****************************************************************************/
int tcp_last_error_would_block()
{
#if defined(_WIN32)
return WSAGetLastError() == WSAEWOULDBLOCK;
#else
return (errno == EWOULDBLOCK) || (errno == EAGAIN) || (errno == EINPROGRESS);
#endif
}
/**
* Close specified socket
*****************************************************************************/
void tcp_close(int skt)
{
if (skt <= 0)
return;
#if defined(_WIN32)
closesocket(skt);
#else
close(skt);
#endif
}
/**
* Create a new socket
*
* @return new socket or -1 on error
*****************************************************************************/
int tcp_socket(void)
{
int rv;
int option_value;
#if defined(_WIN32)
int option_len;
#else
unsigned int option_len;
#endif
/* in win32 a socket is an unsigned int, in linux, its an int */
if ((rv = (int) socket(PF_INET, SOCK_STREAM, 0)) < 0)
return -1;
option_len = sizeof(option_value);
if (getsockopt(rv, SOL_SOCKET, SO_REUSEADDR, (char *) &option_value,
&option_len) == 0)
{
if (option_value == 0)
{
option_value = 1;
option_len = sizeof(option_value);
setsockopt(rv, SOL_SOCKET, SO_REUSEADDR, (char *) &option_value,
option_len);
}
}
option_len = sizeof(option_value);
if (getsockopt(rv, SOL_SOCKET, SO_SNDBUF, (char *) &option_value,
&option_len) == 0)
{
if (option_value < (1024 * 32))
{
option_value = 1024 * 32;
option_len = sizeof(option_value);
setsockopt(rv, SOL_SOCKET, SO_SNDBUF, (char *) &option_value,
option_len);
}
}
return rv;
}
/**
* Connect to a server
*
* @param skt opaque socket obj
* @param address connect to this server
* @param port using this port
*
* @return 0 on success, -1 on error
*****************************************************************************/
int tcp_connect(int skt, const char *hostname, const char *port)
{
struct sockaddr_in s;
struct hostent *h;
memset(&s, 0, sizeof(struct sockaddr_in));
s.sin_family = AF_INET;
s.sin_port = htons((uint16_t) atoi(port));
s.sin_addr.s_addr = inet_addr(hostname);
if (s.sin_addr.s_addr == INADDR_NONE)
{
h = gethostbyname(hostname);
if (h != 0)
{
if (h->h_name != 0)
{
if (h->h_addr_list != 0)
{
if ((*(h->h_addr_list)) != 0)
{
s.sin_addr.s_addr = *((int *)(*(h->h_addr_list)));
}
}
}
}
}
return connect(skt, (struct sockaddr *) &s, sizeof(struct sockaddr_in));
}
/**
* Return 1 if we can write to the socket, 0 otherwise
*****************************************************************************/
int tcp_can_send(int skt, int millis)
{
fd_set wfds;
struct timeval time;
int rv;
time.tv_sec = millis / 1000;
time.tv_usec = (millis * 1000) % 1000000;
FD_ZERO(&wfds);
if (skt > 0)
{
FD_SET(((unsigned int) skt), &wfds);
rv = select(skt + 1, 0, &wfds, 0, &time);
if (rv > 0)
{
return tcp_socket_ok(skt);
}
}
return 0;
}
/**
* Return 1 if socket is OK, 0 otherwise
*****************************************************************************/
int tcp_socket_ok(int skt)
{
int opt;
#if defined(_WIN32)
int opt_len;
#else
unsigned int opt_len;
#endif
opt_len = sizeof(opt);
if (getsockopt(skt, SOL_SOCKET, SO_ERROR, (char *) (&opt), &opt_len) == 0)
{
if (opt == 0)
return 1;
}
return 0;
}
/**
* Check if specified sockets can be operated on without blocking
*
* @return 1 if they can be operated on or 0 if blocking would occur
*****************************************************************************/
int tcp_select(int sck1, int sck2)
{
fd_set rfds;
struct timeval time;
int max = 0;
int rv = 0;
memset(&rfds, 0, sizeof(fd_set));
memset(&time, 0, sizeof(struct timeval));
time.tv_sec = 0;
time.tv_usec = 0;
FD_ZERO(&rfds);
if (sck1 > 0)
FD_SET(((unsigned int) sck1), &rfds);
if (sck2 > 0)
FD_SET(((unsigned int) sck2), &rfds);
max = sck1;
if (sck2 > max)
max = sck2;
rv = select(max + 1, &rfds, 0, 0, &time);
if (rv > 0)
{
rv = 0;
if (FD_ISSET(((unsigned int) sck1), &rfds))
rv = rv | 1;
if (FD_ISSET(((unsigned int)sck2), &rfds))
rv = rv | 2;
}
else
{
rv = 0;
}
return rv;
}
int tcp_recv(int skt, void *ptr, int len, int flags)
{
#if defined(_WIN32)
return recv(skt, (char *) ptr, len, flags);
#else
return recv(skt, ptr, len, flags);
#endif
}
int tcp_send(int skt, const void *ptr, int len, int flags)
{
#if defined(_WIN32)
return send(skt, (const char *)ptr, len, flags);
#else
return send(skt, ptr, len, flags);
#endif
}

@ -0,0 +1,48 @@
/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2013
*
* 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.
*/
#ifndef _GTCP_H
#define _GTCP_H
#include <stdint.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
int tcp_socket_create(void);
void tcp_set_non_blocking(int skt);
int tcp_bind(int skt, char *port);
int tcp_listen(int skt);
int tcp_accept(int skt);
int tcp_last_error_would_block();
void tcp_close(int skt);
int tcp_socket(void);
int tcp_connect(int skt, const char *hostname, const char *port);
int tcp_can_send(int skt, int millis);
int tcp_socket_ok(int skt);
int tcp_select(int sck1, int sck2);
int tcp_recv(int skt, void *ptr, int len, int flags);
int tcp_send(int skt, const void *ptr, int len, int flags);
#endif
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