1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "remoting/host/win/wts_terminal_monitor.h"
6
7 #include <windows.h>
8 #include <wtsapi32.h>
9
10 #include "base/basictypes.h"
11 #include "base/logging.h"
12 #include "base/strings/utf_string_conversions.h"
13
14 namespace remoting {
15
16 // Session id that does not represent any session.
17 const uint32 kInvalidSessionId = 0xffffffffu;
18
19 const char* WtsTerminalMonitor::kConsole = "console";
20
~WtsTerminalMonitor()21 WtsTerminalMonitor::~WtsTerminalMonitor() {
22 }
23
24 // static
LookupTerminalId(uint32 session_id,std::string * terminal_id)25 bool WtsTerminalMonitor::LookupTerminalId(uint32 session_id,
26 std::string* terminal_id) {
27 // Fast path for the case when |session_id| is currently attached to
28 // the physical console.
29 if (session_id == WTSGetActiveConsoleSessionId()) {
30 *terminal_id = kConsole;
31 return true;
32 }
33
34 // RdpClient sets the terminal ID as the initial program's working directory.
35 DWORD bytes;
36 wchar_t* working_directory;
37 if (!WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE,
38 session_id,
39 WTSWorkingDirectory,
40 &working_directory,
41 &bytes)) {
42 return false;
43 }
44
45 bool result = base::WideToUTF8(working_directory,
46 (bytes / sizeof(wchar_t)) - 1,
47 terminal_id);
48 WTSFreeMemory(working_directory);
49 return result;
50 }
51
52 // static
LookupSessionId(const std::string & terminal_id)53 uint32 WtsTerminalMonitor::LookupSessionId(const std::string& terminal_id) {
54 // Use the fast path if the caller wants to get id of the session attached to
55 // the physical console.
56 if (terminal_id == kConsole)
57 return WTSGetActiveConsoleSessionId();
58
59 // Enumerate all sessions and try to match the client endpoint.
60 WTS_SESSION_INFO* session_info;
61 DWORD session_info_count;
62 if (!WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &session_info,
63 &session_info_count)) {
64 PLOG(ERROR) << "Failed to enumerate all sessions";
65 return kInvalidSessionId;
66 }
67 for (DWORD i = 0; i < session_info_count; ++i) {
68 uint32 session_id = session_info[i].SessionId;
69
70 std::string id;
71 if (LookupTerminalId(session_id, &id) && terminal_id == id) {
72 WTSFreeMemory(session_info);
73 return session_id;
74 }
75 }
76
77 // |terminal_id| is not associated with any session.
78 WTSFreeMemory(session_info);
79 return kInvalidSessionId;
80 }
81
WtsTerminalMonitor()82 WtsTerminalMonitor::WtsTerminalMonitor() {
83 }
84
85 } // namespace remoting
86