xref: /openbmc/qemu/qga/service-win32.c (revision 709395f8)
1 /*
2  * QEMU Guest Agent helpers for win32 service management
3  *
4  * Copyright IBM Corp. 2012
5  *
6  * Authors:
7  *  Gal Hammer        <ghammer@redhat.com>
8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 #include "qemu/osdep.h"
14 #include <windows.h>
15 #include "qga/service-win32.h"
16 
17 static int printf_win_error(const char *text)
18 {
19     DWORD err = GetLastError();
20     char *message;
21     int n;
22 
23     FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
24         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
25         NULL,
26         err,
27         MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
28         (char *)&message, 0,
29         NULL);
30     n = fprintf(stderr, "%s. (Error: %d) %s", text, (int)err, message);
31     LocalFree(message);
32 
33     return n;
34 }
35 
36 /* Windows command line escaping. Based on
37  * <http://blogs.msdn.com/b/oldnewthing/archive/2010/09/17/10063629.aspx> and
38  * <http://msdn.microsoft.com/en-us/library/windows/desktop/17w5ykft%28v=vs.85%29.aspx>.
39  *
40  * The caller is responsible for initializing @buffer; prior contents are lost.
41  */
42 static const char *win_escape_arg(const char *to_escape, GString *buffer)
43 {
44     size_t backslash_count;
45     const char *c;
46 
47     /* open with a double quote */
48     g_string_assign(buffer, "\"");
49 
50     backslash_count = 0;
51     for (c = to_escape; *c != '\0'; ++c) {
52         switch (*c) {
53         case '\\':
54             /* The meaning depends on the first non-backslash character coming
55              * up.
56              */
57             ++backslash_count;
58             break;
59 
60         case '"':
61             /* We must escape each pending backslash, then escape the double
62              * quote. This creates a case of "odd number of backslashes [...]
63              * followed by a double quotation mark".
64              */
65             while (backslash_count) {
66                 --backslash_count;
67                 g_string_append(buffer, "\\\\");
68             }
69             g_string_append(buffer, "\\\"");
70             break;
71 
72         default:
73             /* Any pending backslashes are without special meaning, flush them.
74              * "Backslashes are interpreted literally, unless they immediately
75              * precede a double quotation mark."
76              */
77             while (backslash_count) {
78                 --backslash_count;
79                 g_string_append_c(buffer, '\\');
80             }
81             g_string_append_c(buffer, *c);
82         }
83     }
84 
85     /* We're about to close with a double quote in string delimiter role.
86      * Double all pending backslashes, creating a case of "even number of
87      * backslashes [...] followed by a double quotation mark".
88      */
89     while (backslash_count) {
90         --backslash_count;
91         g_string_append(buffer, "\\\\");
92     }
93     g_string_append_c(buffer, '"');
94 
95     return buffer->str;
96 }
97 
98 int ga_install_service(const char *path, const char *logfile,
99                        const char *state_dir)
100 {
101     int ret = EXIT_FAILURE;
102     SC_HANDLE manager;
103     SC_HANDLE service;
104     TCHAR module_fname[MAX_PATH];
105     GString *esc;
106     GString *cmdline;
107     SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION };
108 
109     if (GetModuleFileName(NULL, module_fname, MAX_PATH) == 0) {
110         printf_win_error("No full path to service's executable");
111         return EXIT_FAILURE;
112     }
113 
114     esc     = g_string_new("");
115     cmdline = g_string_new("");
116 
117     g_string_append_printf(cmdline, "%s -d",
118                            win_escape_arg(module_fname, esc));
119 
120     if (path) {
121         g_string_append_printf(cmdline, " -p %s", win_escape_arg(path, esc));
122     }
123     if (logfile) {
124         g_string_append_printf(cmdline, " -l %s -v",
125                                win_escape_arg(logfile, esc));
126     }
127     if (state_dir) {
128         g_string_append_printf(cmdline, " -t %s",
129                                win_escape_arg(state_dir, esc));
130     }
131 
132     g_debug("service's cmdline: %s", cmdline->str);
133 
134     manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
135     if (manager == NULL) {
136         printf_win_error("No handle to service control manager");
137         goto out_strings;
138     }
139 
140     service = CreateService(manager, QGA_SERVICE_NAME, QGA_SERVICE_DISPLAY_NAME,
141         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START,
142         SERVICE_ERROR_NORMAL, cmdline->str, NULL, NULL, NULL, NULL, NULL);
143     if (service == NULL) {
144         printf_win_error("Failed to install service");
145         goto out_manager;
146     }
147 
148     ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &desc);
149     fprintf(stderr, "Service was installed successfully.\n");
150     ret = EXIT_SUCCESS;
151     CloseServiceHandle(service);
152 
153 out_manager:
154     CloseServiceHandle(manager);
155 
156 out_strings:
157     g_string_free(cmdline, TRUE);
158     g_string_free(esc, TRUE);
159     return ret;
160 }
161 
162 int ga_uninstall_service(void)
163 {
164     SC_HANDLE manager;
165     SC_HANDLE service;
166 
167     manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
168     if (manager == NULL) {
169         printf_win_error("No handle to service control manager");
170         return EXIT_FAILURE;
171     }
172 
173     service = OpenService(manager, QGA_SERVICE_NAME, DELETE);
174     if (service == NULL) {
175         printf_win_error("No handle to service");
176         CloseServiceHandle(manager);
177         return EXIT_FAILURE;
178     }
179 
180     if (DeleteService(service) == FALSE) {
181         printf_win_error("Failed to delete service");
182     } else {
183         fprintf(stderr, "Service was deleted successfully.\n");
184     }
185 
186     CloseServiceHandle(service);
187     CloseServiceHandle(manager);
188 
189     return EXIT_SUCCESS;
190 }
191