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);
}


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;
}
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
59	int
60	vchannel_open()
61	{
62	g_vchannel = WTSVirtualChannelOpen(WTS_CURRENT_SERVER_HANDLE,
63	WTS_CURRENT_SESSION, CHANNELNAME);
64
65	if (g_vchannel == NULL)
66	return -1;
67
68	g_mutex = CreateMutex(NULL, FALSE, "Local\\SeamlessChannel");
69	if (!g_mutex)
70	{
71	WTSVirtualChannelClose(g_vchannel);
72	g_vchannel = NULL;
73	return -1;
74	}
75
76	return 0;
77	}
78
79	void
80	vchannel_close()
81	{
82	if (g_mutex)
83	CloseHandle(g_mutex);
84
85	if (g_vchannel)
86	WTSVirtualChannelClose(g_vchannel);
87
88	g_mutex = NULL;
89	g_vchannel = NULL;
90	}
91
92	int
93	vchannel_is_open()
94	{
95	if (g_vchannel == NULL)
96	return 0;
97	else
98	return 1;
99	}
100
101	int
102	vchannel_read(char *line, size_t length)
103	{
104	static BOOL overflow_mode = FALSE;
105	static char buffer[VCHANNEL_MAX_LINE];
106	static size_t size = 0;
107
108	char *newline;
109	int line_size;
110
111	BOOL result;
112	ULONG bytes_read;
113
114	result = WTSVirtualChannelRead(g_vchannel, 0, buffer + size,
115	sizeof(buffer) - size, &bytes_read);
116
117	if (!result)
118	{
119	errno = EIO;
120	return -1;
121	}
122
123	if (overflow_mode)
124	{
125	newline = strchr(buffer, '\n');
126	if (newline && (newline - buffer) < bytes_read)
127	{
128	size = bytes_read - (newline - buffer) - 1;
129	memmove(buffer, newline + 1, size);
130	overflow_mode = FALSE;
131	}
132	}
133	else
134	size += bytes_read;
135
136	if (overflow_mode)
137	{
138	errno = -EAGAIN;
139	return -1;
140	}
141
142	newline = strchr(buffer, '\n');
143	if (!newline \|\| (newline - buffer) >= size)
144	{
145	if (size == sizeof(buffer))
146	{
147	overflow_mode = TRUE;
148	size = 0;
149	}
150	errno = -EAGAIN;
151	return -1;
152	}
153
154	if ((newline - buffer) >= length)
155	{
156	errno = ENOMEM;
157	return -1;
158	}
159
160	*newline = '\0';
161
162	strcpy(line, buffer);
163	line_size = newline - buffer;
164
165	size -= newline - buffer + 1;
166	memmove(buffer, newline + 1, size);
167
168	return 0;
169	}
170
171	int
172	vchannel_write(const char *format, ...)
173	{
174	BOOL result;
175	va_list argp;
176	char buf[VCHANNEL_MAX_LINE];
177	int size;
178	ULONG bytes_written;
179
180	assert(vchannel_is_open());
181
182	va_start(argp, format);
183	size = _vsnprintf(buf, sizeof(buf), format, argp);
184	va_end(argp);
185
186	assert(size < sizeof(buf));
187
188	WaitForSingleObject(g_mutex, INFINITE);
189	result = WTSVirtualChannelWrite(g_vchannel, buf, (ULONG) strlen(buf), &bytes_written);
190	result = WTSVirtualChannelWrite(g_vchannel, "\n", (ULONG) 1, &bytes_written);
191	ReleaseMutex(g_mutex);
192
193	if (!result)
194	return -1;
195
196	return bytes_written;
197	}
198
199	void
200	vchannel_block()
201	{
202	WaitForSingleObject(g_mutex, INFINITE);
203	}
204
205	void
206	vchannel_unblock()
207	{
208	ReleaseMutex(g_mutex);
209	}
210
211	const char *
212	vchannel_strfilter(char *string)
213	{
214	char *c;
215
216	for (c = string; *c != '\0'; c++)
217	{
218	if (((unsigned char) c < 0x20) \|\| (strchr(INVALID_CHARS, c) != NULL))
219	*c = REPLACEMENT_CHAR;
220	}
221
222	return string;
223	}