qga/service-win32.c

   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 }