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openvpn-gui
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Parse and display messages received by echo msg commands 

Process four new echo commands to construct messages to be
displayed to the user:

      echo msg message-text
      echo msg-n message-text
      echo msg-window message-title
      echo msg-notify message-title

Note: All rules of push and echo processing apply and determine
what is received as echo commands by the GUI. In addition,
'url-encoded' characters (% followed by two hex digits) are
decoded and displayed.

The message is constructed in the GUI by concatenating the text
specified in one or more "echo msg text" or "echo msg-n text"
commands. In case of "echo msg text" text is appended with a new
line. An empty text in this case will
just add a new line.

The message ends and gets displayed when one of the following
are receieved:

    echo msg-window title
    echo msg-notify title

where "title" becomes the title of the message window. In case of
msg-window, a modeless window shows the message, in the latter case
a notification balloon is shown.

Example: when pushed from the server:

    push "echo msg I say let the world go to hell%2C"
    push "echo msg I must have my cup of tea."
    push "echo msg-window Notes from the underground"

will display a modeless window with title
"Notes from the underground" and a two line body
    --
    I say let the world go to hell,
    I must have my cup of tea.
    --

Note that the message itself is not quoted in the above examples
and so it relies on the server's option-parser combining
individual words into a space separated string. Number of words
on a line is limited by the maximum number of parameters allowed
in openvpn commands (16). This limitation may be avoided by quoting
the text that follows so that the option parser sees it as one
parameter.

The comma character is not allowed in pushed strings, so
it has to be sent encoded as %2C as shown above.
Such encoding of arbitrary bytes is suppored. For example,
newlines may be embedded as %0A, though discouraged. Instead
use multiple "echo msg" commands to separate lines by new line.

An example with embedded spaces and multiple lines concatenated
without a new line in between (note use of single quotes):

    push "echo msg-n I swear to you gentlemen%2C that to be"
    push "echo msg-n ' overly conscious is a sickness%2C ' "
    push "echo msg-n a real%2C thorough sickness."
    push "echo msg-notify Quote of the Day"

    will show up as a notification that displays for an
    OS-dependent interval as:

    --
    Quote of the Day

    I swear to you gentlemen, that to be overly conscious
    is a sickness, a real, thorough sickness.
    --

where the location of the line break is automatically determined
by the notification API and is OS version-dependent.

Commands like "echo msg ..." in the config file are also
processed the same way. It gets displayed when the GUI connects
to the management interface and receives all pending echo.
Pushed message(s) get displayed when the client daemon
processes push-reply and passes on echo directives to the
GUI.

TODO: The actual window that displays the messages is
implemented in the next commit.

Signed-off-by: Selva Nair <selva.nair@gmail.com>
pull/391/head
Selva Nair 2017-11-26 17:38:11 -05:00
parent 2aa61fee24
commit 00732e1d9e
10 changed files with 366 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Makefile.am
View File

@ -92,6 +92,7 @@ openvpn_gui_SOURCES = \
chartable.h \
save_pass.c save_pass.h \
env_set.c env_set.h \
echo.c echo.h \
openvpn-gui-res.h
openvpn_gui_LDFLAGS = -mwindows

247
echo.c Normal file
View File

@ -0,0 +1,247 @@
/*
* OpenVPN-GUI -- A Windows GUI for OpenVPN.
*
* Copyright (C) 2017 Selva Nair <selva.nair@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <windows.h>
#include <wchar.h>
#include "main.h"
#include "options.h"
#include "misc.h"
#include "openvpn.h"
#include "echo.h"
#include "tray.h"
/* echo msg types */
#define ECHO_MSG_WINDOW (1)
#define ECHO_MSG_NOTIFY (2)
struct echo_msg_history {
struct echo_msg_fp fp;
struct echo_msg_history *next;
};
/* We use a global message window for all messages
*/
static HWND echo_msg_window;
/* Forward declarations */
static void
AddMessageBoxText(HWND hwnd, const wchar_t *text, const wchar_t *title, BOOL show);
void
echo_msg_init(void)
{
/* TODO: create a message box and save handle in echo_msg_window */
return;
}
/* compute a digest of the message and add it to the msg struct */
static void
echo_msg_add_fp(struct echo_msg *msg, time_t timestamp)
{
msg->fp.timestamp = timestamp;
/* digest not implemented */
return;
}
/* Add message to history -- update if already present */
static void
echo_msg_save(struct echo_msg *msg)
{
/* Not implemented */
return;
}
/* persist echo msg history to the registry */
void
echo_msg_persist(connection_t *c)
{
/* Not implemented */
return;
}
/* load echo msg history from registry */
void
echo_msg_load(connection_t *c)
{
/* Not implemented */
return;
}
/* Return true if the message is same as recently shown */
static BOOL
echo_msg_repeated(const struct echo_msg *msg)
{
/* Not implemented */
return false;
}
/* Append a line of echo msg */
static void
echo_msg_append(connection_t *c, time_t UNUSED timestamp, const char *msg, BOOL addnl)
{
wchar_t *eol = L"";
wchar_t *wmsg = NULL;
if (!(wmsg = Widen(msg)))
{
WriteStatusLog(c, L"GUI> ", L"Error: out of memory while processing echo msg", false);
goto out;
}
size_t len = c->echo_msg.txtlen + wcslen(wmsg) + 1; /* including null terminator */
if (addnl)
{
eol = L"\r\n";
len += 2;
}
WCHAR *s = realloc(c->echo_msg.text, len*sizeof(WCHAR));
if (!s)
{
WriteStatusLog(c, L"GUI> ", L"Error: out of memory while processing echo msg", false);
goto out;
}
swprintf(s + c->echo_msg.txtlen, len - c->echo_msg.txtlen, L"%s%s", wmsg, eol);
s[len-1] = L'\0';
c->echo_msg.text = s;
c->echo_msg.txtlen = len - 1; /* exclude null terminator */
out:
free(wmsg);
return;
}
/* Called when echo msg-window or echo msg-notify is received */
static void
echo_msg_display(connection_t *c, time_t timestamp, const char *title, int type)
{
WCHAR *wtitle = Widen(title);
if (wtitle)
{
c->echo_msg.title = wtitle;
}
else
{
WriteStatusLog(c, L"GUI> ", L"Error: out of memory converting echo message title to widechar", false);
c->echo_msg.title = L"Message from server";
}
echo_msg_add_fp(&c->echo_msg, timestamp); /* add fingerprint: digest+timestamp */
/* Check whether the message is muted */
if (c->flags & FLAG_DISABLE_ECHO_MSG || echo_msg_repeated(&c->echo_msg))
{
return;
}
if (type == ECHO_MSG_WINDOW)
{
HWND h = echo_msg_window;
if (h)
{
AddMessageBoxText(h, c->echo_msg.text, c->echo_msg.title, true);
}
}
else /* notify */
{
ShowTrayBalloon(c->echo_msg.title, c->echo_msg.text);
}
/* save or update history */
echo_msg_save(&c->echo_msg);
}
void
echo_msg_process(connection_t *c, time_t timestamp, const char *s)
{
wchar_t errmsg[256] = L"";
char *msg = url_decode(s);
if (!msg)
{
WriteStatusLog(c, L"GUI> ", L"Error in url_decode of echo message", false);
return;
}
if (strbegins(msg, "msg "))
{
echo_msg_append(c, timestamp, msg + 4, true);
}
else if (streq(msg, "msg")) /* empty msg is treated as a new line */
{
echo_msg_append(c, timestamp, msg+3, true);
}
else if (strbegins(msg, "msg-n "))
{
echo_msg_append(c, timestamp, msg + 6, false);
}
else if (strbegins(msg, "msg-window "))
{
echo_msg_display(c, timestamp, msg + 11, ECHO_MSG_WINDOW);
echo_msg_clear(c, false);
}
else if (strbegins(msg, "msg-notify "))
{
echo_msg_display(c, timestamp, msg + 11, ECHO_MSG_NOTIFY);
echo_msg_clear(c, false);
}
else
{
_sntprintf_0(errmsg, L"WARNING: Unknown ECHO directive '%hs' ignored.", msg);
WriteStatusLog(c, L"GUI> ", errmsg, false);
}
free(msg);
}
void
echo_msg_clear(connection_t *c, BOOL clear_history)
{
CLEAR(c->echo_msg.fp);
free(c->echo_msg.text);
free(c->echo_msg.title);
c->echo_msg.text = NULL;
c->echo_msg.txtlen = 0;
c->echo_msg.title = NULL;
if (clear_history)
{
echo_msg_persist(c);
struct echo_msg_history *head = c->echo_msg.history;
struct echo_msg_history *next;
while (head)
{
next = head->next;
free(head);
head = next;
}
CLEAR(c->echo_msg);
}
}
/* Add new message to the message box window and optionally show it */
static void
AddMessageBoxText(HWND hwnd, const wchar_t *text, const wchar_t *title, BOOL show)
{
/* Not implemented */
return;
}

57
echo.h Normal file
View File

@ -0,0 +1,57 @@
/*
* OpenVPN-GUI -- A Windows GUI for OpenVPN.
*
* Copyright (C) 2017 Selva Nair <selva.nair@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef ECHO_H
#define ECHO_H
#include <wchar.h>
/* data structures and methods for handling echo msg */
#define HASHLEN 20
/* message finger print consists of a SHA1 hash and a timestamp */
struct echo_msg_fp {
BYTE digest[HASHLEN];
time_t timestamp;
};
struct echo_msg_history;
struct echo_msg {
struct echo_msg_fp fp; /* keep this as the first element */
wchar_t *title;
wchar_t *text;
int txtlen;
int type;
struct echo_msg_history *history;
};
/* init echo message -- call on program start */
void echo_msg_init();
/* Process echo msg and related commands received from mgmt iterface. */
void echo_msg_process(connection_t *c, time_t timestamp, const char *msg);
/* Clear echo msg buffers and optionally history */
void echo_msg_clear(connection_t *c, BOOL clear_history);
/* Load echo msg history from the registry */
void echo_msg_load(connection_t *c);
#endif

3
main.c
View File

@ -49,6 +49,7 @@
#include "manage.h"
#include "misc.h"
#include "save_pass.h"
#include "echo.h"
#ifndef DISABLE_CHANGE_PASSWORD
#include <openssl/evp.h>
@ -510,6 +511,8 @@ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM
ChangeWindowMessageFilterEx(hwnd, WM_COPYDATA, MSGFLT_ALLOW, NULL);
#endif
echo_msg_init();
CreatePopupMenus(); /* Create popup menus */
ShowTrayIcon();
if (o.service_only)

32
misc.c
View File

@ -488,3 +488,35 @@ CloseHandleEx(LPHANDLE handle)
*handle = INVALID_HANDLE_VALUE;
}
}
/*
* Decode url encoded characters in buffer src and
* return the result in a newly allocated buffer. The
* caller should free the returned pointer. Returns
* NULL on memory allocation error.
*/
char *
url_decode(const char *src)
{
const char *s = src;
char *out = malloc(strlen(src) + 1); /* output is guaranteed to be not longer than src */
char *o;
if (!out)
return NULL;
for (o = out; *s; o++)
{
unsigned int c = *s++;
if (c == '%' && isxdigit(s[0]) && isxdigit(s[1]))
{
sscanf(s, "%2x", &c);
s += 2;
}
/* We passthough all other chars including % not followed by 2 hex digits */
*o = (char)c;
}
*o = '\0';
return out;
}

5
misc.h
View File

@ -48,4 +48,9 @@ void CloseSemaphore(HANDLE sem);
/* Close a handle if not null or invalid */
void CloseHandleEx(LPHANDLE h);
/* Decode url encoded charcters in src and return the result as a newly
* allocated string. Returns NULL on error.
*/
char *url_decode(const char *src);
#endif

2
openvpn-gui.vcxproj
View File

@ -137,6 +137,7 @@
</ItemDefinitionGroup>
<ItemGroup>
<ClCompile Include="access.c" />
<ClCompile Include="echo.c" />
<ClCompile Include="env_set.c" />
<ClCompile Include="localization.c" />
<ClCompile Include="main.c" />
@ -158,6 +159,7 @@
<ClInclude Include="access.h" />
<ClInclude Include="chartable.h" />
<ClInclude Include="config-msvc.h" />
<ClInclude Include="echo.h" />
<ClInclude Include="env_set.h" />
<ClInclude Include="localization.h" />
<ClInclude Include="main.h" />

6
openvpn-gui.vcxproj.filters
View File

@ -18,6 +18,9 @@
<ClCompile Include="access.c">
<Filter>Source Files</Filter>
</ClCompile>
<ClCompile Include="echo.c">
<Filter>Source Files</Filter>
</ClCompile>
<ClCompile Include="env_set.c">
<Filter>Source Files</Filter>
</ClCompile>
@ -74,6 +77,9 @@
<ClInclude Include="chartable.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="echo.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="env_set.h">
<Filter>Header Files</Filter>
</ClInclude>

10
openvpn.c
View File

@ -55,6 +55,7 @@
#include "access.h"
#include "save_pass.h"
#include "env_set.h"
#include "echo.h"
extern options_t o;
@ -324,6 +325,7 @@ OnStateChange(connection_t *c, char *data)
c->failed_psw_attempts++;
}
echo_msg_clear(c, false); /* do not clear history */
// We change the state to reconnecting only if there was a prior successful connection.
if (c->state == connected)
{
@ -991,6 +993,10 @@ OnEcho(connection_t *c, char *msg)
{
process_setenv(c, timestamp, msg);
}
else if (strbegins(msg, "msg"))
{
echo_msg_process(c, timestamp, msg);
}
else
{
wchar_t errmsg[256];
@ -1580,6 +1586,7 @@ Cleanup (connection_t *c)
free_dynamic_cr (c);
env_item_del_all(c->es);
c->es = NULL;
echo_msg_clear(c, true); /* clear history */
if (c->hProcess)
CloseHandle (c->hProcess);
@ -1832,6 +1839,9 @@ ThreadOpenVPNStatus(void *p)
if (o.silent_connection == 0)
ShowWindow(c->hwndStatus, SW_SHOW);
/* Load echo msg histroy from registry */
echo_msg_load(c);
/* Run the message loop for the status window */
while (WM_QUIT != msg.message)
{

3
options.h
View File

@ -33,6 +33,7 @@ typedef struct connection connection_t;
#include <lmcons.h>
#include "manage.h"
#include "echo.h"
#define MAX_NAME (UNLEN + 1)
@ -87,6 +88,7 @@ typedef struct {
#define FLAG_SAVE_KEY_PASS (1<<4)
#define FLAG_SAVE_AUTH_PASS (1<<5)
#define FLAG_DISABLE_SAVE_PASS (1<<6)
#define FLAG_DISABLE_ECHO_MSG (1<<7)
#define CONFIG_VIEW_AUTO (0)
#define CONFIG_VIEW_FLAT (1)
@ -155,6 +157,7 @@ struct connection {
unsigned long long int bytes_in;
unsigned long long int bytes_out;
struct env_item *es; /* Pointer to the head of config-specific env variables list */
struct echo_msg echo_msg; /* Message echo-ed from server or client config and related data */
};
/* All options used within OpenVPN GUI */