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 < 0xD800) || (*string > 0xDFFF))
                {
                        if (size < 3)
                                break;
                        *buf++ = 0xE0 | (*string >> 12);
                        *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 < 0xD800) \|\| (string > 0xDFFF))
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
98	string++;
99	}
100
101	*buf = '\0';
102
103	return convert_buffer;
104	}
105
106	int
107	vchannel_open()
108	{
109	g_vchannel = WTSVirtualChannelOpen(WTS_CURRENT_SERVER_HANDLE,
110	WTS_CURRENT_SESSION, CHANNELNAME);
111
112	if (g_vchannel == NULL)
113	return -1;
114
115	g_mutex = CreateMutex(NULL, FALSE, "Local\\SeamlessChannel");
116	if (!g_mutex)
117	{
118	WTSVirtualChannelClose(g_vchannel);
119	g_vchannel = NULL;
120	return -1;
121	}
122
123	return 0;
124	}
125
126	void
127	vchannel_close()
128	{
129	if (g_mutex)
130	CloseHandle(g_mutex);
131
132	if (g_vchannel)
133	WTSVirtualChannelClose(g_vchannel);
134
135	g_mutex = NULL;
136	g_vchannel = NULL;
137	}
138
139	int
140	vchannel_is_open()
141	{
142	if (g_vchannel == NULL)
143	return 0;
144	else
145	return 1;
146	}
147
148	int
149	vchannel_read(char *line, size_t length)
150	{
151	static BOOL overflow_mode = FALSE;
152	static char buffer[VCHANNEL_MAX_LINE];
153	static size_t size = 0;
154
155	char *newline;
156	int line_size;
157
158	BOOL result;
159	ULONG bytes_read;
160
161	result = WTSVirtualChannelRead(g_vchannel, 0, buffer + size,
162	sizeof(buffer) - size, &bytes_read);
163
164	if (!result)
165	{
166	errno = EIO;
167	return -1;
168	}
169
170	if (overflow_mode)
171	{
172	newline = strchr(buffer, '\n');
173	if (newline && (newline - buffer) < bytes_read)
174	{
175	size = bytes_read - (newline - buffer) - 1;
176	memmove(buffer, newline + 1, size);
177	overflow_mode = FALSE;
178	}
179	}
180	else
181	size += bytes_read;
182
183	if (overflow_mode)
184	{
185	errno = -EAGAIN;
186	return -1;
187	}
188
189	newline = strchr(buffer, '\n');
190	if (!newline \|\| (newline - buffer) >= size)
191	{
192	if (size == sizeof(buffer))
193	{
194	overflow_mode = TRUE;
195	size = 0;
196	}
197	errno = -EAGAIN;
198	return -1;
199	}
200
201	if ((newline - buffer) >= length)
202	{
203	errno = ENOMEM;
204	return -1;
205	}
206
207	*newline = '\0';
208
209	strcpy(line, buffer);
210	line_size = newline - buffer;
211
212	size -= newline - buffer + 1;
213	memmove(buffer, newline + 1, size);
214
215	return 0;
216	}
217
218	int
219	vchannel_write(const char *format, ...)
220	{
221	BOOL result;
222	va_list argp;
223	char buf[VCHANNEL_MAX_LINE];
224	int size;
225	ULONG bytes_written;
226
227	assert(vchannel_is_open());
228
229	va_start(argp, format);
230	size = _vsnprintf(buf, sizeof(buf), format, argp);
231	va_end(argp);
232
233	assert(size < sizeof(buf));
234
235	WaitForSingleObject(g_mutex, INFINITE);
236	result = WTSVirtualChannelWrite(g_vchannel, buf, (ULONG) strlen(buf), &bytes_written);
237	result = WTSVirtualChannelWrite(g_vchannel, "\n", (ULONG) 1, &bytes_written);
238	ReleaseMutex(g_mutex);
239
240	if (!result)
241	return -1;
242
243	return bytes_written;
244	}
245
246	void
247	vchannel_block()
248	{
249	WaitForSingleObject(g_mutex, INFINITE);
250	}
251
252	void
253	vchannel_unblock()
254	{
255	ReleaseMutex(g_mutex);
256	}
257
258	const char *
259	vchannel_strfilter(char *string)
260	{
261	char *c;
262
263	for (c = string; *c != '\0'; c++)
264	{
265	if (((unsigned char) c < 0x20) \|\| (strchr(INVALID_CHARS, c) != NULL))
266	*c = REPLACEMENT_CHAR;
267	}
268
269	return string;
270	}
271
272	const char *
273	vchannel_strfilter_unicode(const unsigned short *string)
274	{
275	return vchannel_strfilter((char *) unicode_to_utf8(string));
276	}