seamlessrdp/ServerExe/vchannel.c

/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Seamless windows - Virtual channel handling

   Copyright (C) Pierre Ossman <ossman@cendio.se> 2006

   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; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>

#include <windows.h>
#include <wtsapi32.h>
#include <cchannel.h>

#include "vchannel.h"

#define CHANNELNAME "seamrdp"

#define INVALID_CHARS ","
#define REPLACEMENT_CHAR '_'

static HANDLE g_mutex = NULL;
static HANDLE g_vchannel = NULL;

void
debug(char *format, ...)
{
        va_list argp;
        char buf[256];

        sprintf(buf, "DEBUG,");

        va_start(argp, format);
        _vsnprintf(buf + sizeof("DEBUG,") - 1, sizeof(buf) - sizeof("DEBUG,") + 1, format, argp);
        va_end(argp);

        vchannel_strfilter(buf + sizeof("DEBUG,"));

        vchannel_write(buf);
}

#define CONVERT_BUFFER_SIZE 1024
static char convert_buffer[CONVERT_BUFFER_SIZE];

const char *
unicode_to_utf8(const unsigned short *string)
{
        unsigned char *buf;
        size_t size;

        buf = (unsigned char *) convert_buffer;
        size = sizeof(convert_buffer) - 1;

        /* We do not handle characters outside BMP (i.e. we can't do UTF-16) */
        while (*string != 0x0000)
        {
                if (*string < 0x80)
                {
                        if (size < 1)
                                break;
                        *buf++ = (unsigned char) *string;
                        size--;
                }
                else if (*string < 0x800)
                {
                        if (size < 2)
                                break;
                        *buf++ = 0xC0 | (*string >> 6);
                        *buf++ = 0x80 | (*string & 0x3F);
                        size -= 2;
                }
                else if (*string < 0x10000)
                {
                        if (size < 3)
                                break;
                        *buf++ = 0xE0 | (*string >> 12);
                        *buf++ = 0x80 | (*string >> 6 & 0x3F);
                        *buf++ = 0x80 | (*string & 0x3F);
                        size -= 2;
                }
                else if (*string < 0x200000)
                {
                        if (size < 4)
                                break;
                        *buf++ = 0xF0 | (*string >> 18);
                        *buf++ = 0x80 | (*string >> 12 & 0x3F);
                        *buf++ = 0x80 | (*string >> 6 & 0x3F);
                        *buf++ = 0x80 | (*string & 0x3F);
                        size -= 2;
                }

                string++;
        }

        *buf = '\0';

        return convert_buffer;
}

int
vchannel_open()
{
        g_vchannel = WTSVirtualChannelOpen(WTS_CURRENT_SERVER_HANDLE,
                                           WTS_CURRENT_SESSION, CHANNELNAME);

        if (g_vchannel == NULL)
                return -1;

        g_mutex = CreateMutex(NULL, FALSE, "Local\\SeamlessChannel");
        if (!g_mutex)
        {
                WTSVirtualChannelClose(g_vchannel);
                g_vchannel = NULL;
                return -1;
        }

        return 0;
}

void
vchannel_close()
{
        if (g_mutex)
                CloseHandle(g_mutex);

        if (g_vchannel)
                WTSVirtualChannelClose(g_vchannel);

        g_mutex = NULL;
        g_vchannel = NULL;
}

int
vchannel_is_open()
{
        if (g_vchannel == NULL)
                return 0;
        else
                return 1;
}

int
vchannel_read(char *line, size_t length)
{
        static BOOL overflow_mode = FALSE;
        static char buffer[VCHANNEL_MAX_LINE];
        static size_t size = 0;

        char *newline;
        int line_size;

        BOOL result;
        ULONG bytes_read;

        result = WTSVirtualChannelRead(g_vchannel, 0, buffer + size,
                                       sizeof(buffer) - size, &bytes_read);

        if (!result)
        {
                errno = EIO;
                return -1;
        }

        if (overflow_mode)
        {
                newline = strchr(buffer, '\n');
                if (newline && (newline - buffer) < bytes_read)
                {
                        size = bytes_read - (newline - buffer) - 1;
                        memmove(buffer, newline + 1, size);
                        overflow_mode = FALSE;
                }
        }
        else
                size += bytes_read;

        if (overflow_mode)
        {
                errno = -EAGAIN;
                return -1;
        }

        newline = strchr(buffer, '\n');
        if (!newline || (newline - buffer) >= size)
        {
                if (size == sizeof(buffer))
                {
                        overflow_mode = TRUE;
                        size = 0;
                }
                errno = -EAGAIN;
                return -1;
        }

        if ((newline - buffer) >= length)
        {
                errno = ENOMEM;
                return -1;
        }

        *newline = '\0';

        strcpy(line, buffer);
        line_size = newline - buffer;

        size -= newline - buffer + 1;
        memmove(buffer, newline + 1, size);

        return 0;
}

int
vchannel_write(const char *format, ...)
{
        BOOL result;
        va_list argp;
        char buf[VCHANNEL_MAX_LINE];
        int size;
        ULONG bytes_written;

        assert(vchannel_is_open());

        va_start(argp, format);
        size = _vsnprintf(buf, sizeof(buf), format, argp);
        va_end(argp);

        assert(size < sizeof(buf));

        WaitForSingleObject(g_mutex, INFINITE);
        result = WTSVirtualChannelWrite(g_vchannel, buf, (ULONG) strlen(buf), &bytes_written);
        result = WTSVirtualChannelWrite(g_vchannel, "\n", (ULONG) 1, &bytes_written);
        ReleaseMutex(g_mutex);

        if (!result)
                return -1;

        return bytes_written;
}

void
vchannel_block()
{
        WaitForSingleObject(g_mutex, INFINITE);
}

void
vchannel_unblock()
{
        ReleaseMutex(g_mutex);
}

const char *
vchannel_strfilter(char *string)
{
        char *c;

        for (c = string; *c != '\0'; c++)
        {
                if (((unsigned char) *c < 0x20) || (strchr(INVALID_CHARS, *c) != NULL))
                        *c = REPLACEMENT_CHAR;
        }

        return string;
}

const char *
vchannel_strfilter_unicode(const unsigned short *string)
{
        return vchannel_strfilter((char *) unicode_to_utf8(string));
}
1	/* -- c-basic-offset: 8 --
2	rdesktop: A Remote Desktop Protocol client.
3	Seamless windows - Virtual channel handling
4
5	Copyright (C) Pierre Ossman <ossman@cendio.se> 2006
6
7	This program is free software; you can redistribute it and/or modify
8	it under the terms of the GNU General Public License as published by
9	the Free Software Foundation; either version 2 of the License, or
10	(at your option) any later version.
11
12	This program is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.
16
17	You should have received a copy of the GNU General Public License
18	along with this program; if not, write to the Free Software
19	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20	*/
21
22	#include <assert.h>
23	#include <stdio.h>
24	#include <stdarg.h>
25	#include <errno.h>
26
27	#include <windows.h>
28	#include <wtsapi32.h>
29	#include <cchannel.h>
30
31	#include "vchannel.h"
32
33	#define CHANNELNAME "seamrdp"
34
35	#define INVALID_CHARS ","
36	#define REPLACEMENT_CHAR '_'
37
38	static HANDLE g_mutex = NULL;
39	static HANDLE g_vchannel = NULL;
40
41	void
42	debug(char *format, ...)
43	{
44	va_list argp;
45	char buf[256];
46
47	sprintf(buf, "DEBUG,");
48
49	va_start(argp, format);
50	_vsnprintf(buf + sizeof("DEBUG,") - 1, sizeof(buf) - sizeof("DEBUG,") + 1, format, argp);
51	va_end(argp);
52
53	vchannel_strfilter(buf + sizeof("DEBUG,"));
54
55	vchannel_write(buf);
56	}
57
58	#define CONVERT_BUFFER_SIZE 1024
59	static char convert_buffer[CONVERT_BUFFER_SIZE];
60
61	const char *
62	unicode_to_utf8(const unsigned short *string)
63	{
64	unsigned char *buf;
65	size_t size;
66
67	buf = (unsigned char *) convert_buffer;
68	size = sizeof(convert_buffer) - 1;
69
70	/* We do not handle characters outside BMP (i.e. we can't do UTF-16) */
71	while (*string != 0x0000)
72	{
73	if (*string < 0x80)
74	{
75	if (size < 1)
76	break;
77	buf++ = (unsigned char) string;
78	size--;
79	}
80	else if (*string < 0x800)
81	{
82	if (size < 2)
83	break;
84	buf++ = 0xC0 \| (string >> 6);
85	buf++ = 0x80 \| (string & 0x3F);
86	size -= 2;
87	}
88	else if (*string < 0x10000)
89	{
90	if (size < 3)
91	break;
92	buf++ = 0xE0 \| (string >> 12);
93	buf++ = 0x80 \| (string >> 6 & 0x3F);
94	buf++ = 0x80 \| (string & 0x3F);
95	size -= 2;
96	}
97	else if (*string < 0x200000)
98	{
99	if (size < 4)
100	break;
101	buf++ = 0xF0 \| (string >> 18);
102	buf++ = 0x80 \| (string >> 12 & 0x3F);
103	buf++ = 0x80 \| (string >> 6 & 0x3F);
104	buf++ = 0x80 \| (string & 0x3F);
105	size -= 2;
106	}
107
108	string++;
109	}
110
111	*buf = '\0';
112
113	return convert_buffer;
114	}
115
116	int
117	vchannel_open()
118	{
119	g_vchannel = WTSVirtualChannelOpen(WTS_CURRENT_SERVER_HANDLE,
120	WTS_CURRENT_SESSION, CHANNELNAME);
121
122	if (g_vchannel == NULL)
123	return -1;
124
125	g_mutex = CreateMutex(NULL, FALSE, "Local\\SeamlessChannel");
126	if (!g_mutex)
127	{
128	WTSVirtualChannelClose(g_vchannel);
129	g_vchannel = NULL;
130	return -1;
131	}
132
133	return 0;
134	}
135
136	void
137	vchannel_close()
138	{
139	if (g_mutex)
140	CloseHandle(g_mutex);
141
142	if (g_vchannel)
143	WTSVirtualChannelClose(g_vchannel);
144
145	g_mutex = NULL;
146	g_vchannel = NULL;
147	}
148
149	int
150	vchannel_is_open()
151	{
152	if (g_vchannel == NULL)
153	return 0;
154	else
155	return 1;
156	}
157
158	int
159	vchannel_read(char *line, size_t length)
160	{
161	static BOOL overflow_mode = FALSE;
162	static char buffer[VCHANNEL_MAX_LINE];
163	static size_t size = 0;
164
165	char *newline;
166	int line_size;
167
168	BOOL result;
169	ULONG bytes_read;
170
171	result = WTSVirtualChannelRead(g_vchannel, 0, buffer + size,
172	sizeof(buffer) - size, &bytes_read);
173
174	if (!result)
175	{
176	errno = EIO;
177	return -1;
178	}
179
180	if (overflow_mode)
181	{
182	newline = strchr(buffer, '\n');
183	if (newline && (newline - buffer) < bytes_read)
184	{
185	size = bytes_read - (newline - buffer) - 1;
186	memmove(buffer, newline + 1, size);
187	overflow_mode = FALSE;
188	}
189	}
190	else
191	size += bytes_read;
192
193	if (overflow_mode)
194	{
195	errno = -EAGAIN;
196	return -1;
197	}
198
199	newline = strchr(buffer, '\n');
200	if (!newline \|\| (newline - buffer) >= size)
201	{
202	if (size == sizeof(buffer))
203	{
204	overflow_mode = TRUE;
205	size = 0;
206	}
207	errno = -EAGAIN;
208	return -1;
209	}
210
211	if ((newline - buffer) >= length)
212	{
213	errno = ENOMEM;
214	return -1;
215	}
216
217	*newline = '\0';
218
219	strcpy(line, buffer);
220	line_size = newline - buffer;
221
222	size -= newline - buffer + 1;
223	memmove(buffer, newline + 1, size);
224
225	return 0;
226	}
227
228	int
229	vchannel_write(const char *format, ...)
230	{
231	BOOL result;
232	va_list argp;
233	char buf[VCHANNEL_MAX_LINE];
234	int size;
235	ULONG bytes_written;
236
237	assert(vchannel_is_open());
238
239	va_start(argp, format);
240	size = _vsnprintf(buf, sizeof(buf), format, argp);
241	va_end(argp);
242
243	assert(size < sizeof(buf));
244
245	WaitForSingleObject(g_mutex, INFINITE);
246	result = WTSVirtualChannelWrite(g_vchannel, buf, (ULONG) strlen(buf), &bytes_written);
247	result = WTSVirtualChannelWrite(g_vchannel, "\n", (ULONG) 1, &bytes_written);
248	ReleaseMutex(g_mutex);
249
250	if (!result)
251	return -1;
252
253	return bytes_written;
254	}
255
256	void
257	vchannel_block()
258	{
259	WaitForSingleObject(g_mutex, INFINITE);
260	}
261
262	void
263	vchannel_unblock()
264	{
265	ReleaseMutex(g_mutex);
266	}
267
268	const char *
269	vchannel_strfilter(char *string)
270	{
271	char *c;
272
273	for (c = string; *c != '\0'; c++)
274	{
275	if (((unsigned char) c < 0x20) \|\| (strchr(INVALID_CHARS, c) != NULL))
276	*c = REPLACEMENT_CHAR;
277	}
278
279	return string;
280	}
281
282	const char *
283	vchannel_strfilter_unicode(const unsigned short *string)
284	{
285	return vchannel_strfilter((char *) unicode_to_utf8(string));
286	}