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 <stdlib.h>
  14 #include <stdio.h>
  15 #include <glib.h>
  16 #include <windows.h>
  17 #include "qga/service-win32.h"
  18
  19 static int printf_win_error(const char *text)
  20 {
  21     DWORD err = GetLastError();
  22     char *message;
  23     int n;
  24
  25     FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
  26         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
  27         NULL,
  28         err,
  29         MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
  30         (char *)&message, 0,
  31         NULL);
  32     n = fprintf(stderr, "%s. (Error: %d) %s", text, (int)err, message);
  33     LocalFree(message);
  34
  35     return n;
  36 }
  37
  38 /* Windows command line escaping. Based on
  39  * <http://blogs.msdn.com/b/oldnewthing/archive/2010/09/17/10063629.aspx> and
  40  * <http://msdn.microsoft.com/en-us/library/windows/desktop/17w5ykft%28v=vs.85%29.aspx>.
  41  *
  42  * The caller is responsible for initializing @buffer; prior contents are lost.
  43  */
  44 static const char *win_escape_arg(const char *to_escape, GString *buffer)
  45 {
  46     size_t backslash_count;
  47     const char *c;
  48
  49     /* open with a double quote */
  50     g_string_assign(buffer, "\"");
  51
  52     backslash_count = 0;
  53     for (c = to_escape; *c != '\0'; ++c) {
  54         switch (*c) {
  55         case '\\':
  56             /* The meaning depends on the first non-backslash character coming
  57              * up.
  58              */
  59             ++backslash_count;
  60             break;
  61
  62         case '"':
  63             /* We must escape each pending backslash, then escape the double
  64              * quote. This creates a case of "odd number of backslashes [...]
  65              * followed by a double quotation mark".
  66              */
  67             while (backslash_count) {
  68                 --backslash_count;
  69                 g_string_append(buffer, "\\\\");
  70             }
  71             g_string_append(buffer, "\\\"");
  72             break;
  73
  74         default:
  75             /* Any pending backslashes are without special meaning, flush them.
  76              * "Backslashes are interpreted literally, unless they immediately
  77              * precede a double quotation mark."
  78              */
  79             while (backslash_count) {
  80                 --backslash_count;
  81                 g_string_append_c(buffer, '\\');
  82             }
  83             g_string_append_c(buffer, *c);
  84         }
  85     }
  86
  87     /* We're about to close with a double quote in string delimiter role.
  88      * Double all pending backslashes, creating a case of "even number of
  89      * backslashes [...] followed by a double quotation mark".
  90      */
  91     while (backslash_count) {
  92         --backslash_count;
  93         g_string_append(buffer, "\\\\");
  94     }
  95     g_string_append_c(buffer, '"');
  96
  97     return buffer->str;
  98 }
  99
 100 int ga_install_service(const char *path, const char *logfile,
 101                        const char *state_dir)
 102 {
 103     int ret = EXIT_FAILURE;
 104     SC_HANDLE manager;
 105     SC_HANDLE service;
 106     TCHAR module_fname[MAX_PATH];
 107     GString *esc;
 108     GString *cmdline;
 109     SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION };
 110
 111     if (GetModuleFileName(NULL, module_fname, MAX_PATH) == 0) {
 112         printf_win_error("No full path to service's executable");
 113         return EXIT_FAILURE;
 114     }
 115
 116     esc     = g_string_new("");
 117     cmdline = g_string_new("");
 118
 119     g_string_append_printf(cmdline, "%s -d",
 120                            win_escape_arg(module_fname, esc));
 121
 122     if (path) {
 123         g_string_append_printf(cmdline, " -p %s", win_escape_arg(path, esc));
 124     }
 125     if (logfile) {
 126         g_string_append_printf(cmdline, " -l %s -v",
 127                                win_escape_arg(logfile, esc));
 128     }
 129     if (state_dir) {
 130         g_string_append_printf(cmdline, " -t %s",
 131                                win_escape_arg(state_dir, esc));
 132     }
 133
 134     g_debug("service's cmdline: %s", cmdline->str);
 135
 136     manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 137     if (manager == NULL) {
 138         printf_win_error("No handle to service control manager");
 139         goto out_strings;
 140     }
 141
 142     service = CreateService(manager, QGA_SERVICE_NAME, QGA_SERVICE_DISPLAY_NAME,
 143         SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START,
 144         SERVICE_ERROR_NORMAL, cmdline->str, NULL, NULL, NULL, NULL, NULL);
 145     if (service == NULL) {
 146         printf_win_error("Failed to install service");
 147         goto out_manager;
 148     }
 149
 150     ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &desc);
 151     fprintf(stderr, "Service was installed successfully.\n");
 152     ret = EXIT_SUCCESS;
 153     CloseServiceHandle(service);
 154
 155 out_manager:
 156     CloseServiceHandle(manager);
 157
 158 out_strings:
 159     g_string_free(cmdline, TRUE);
 160     g_string_free(esc, TRUE);
 161     return ret;
 162 }
 163
 164 int ga_uninstall_service(void)
 165 {
 166     SC_HANDLE manager;
 167     SC_HANDLE service;
 168
 169     manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
 170     if (manager == NULL) {
 171         printf_win_error("No handle to service control manager");
 172         return EXIT_FAILURE;
 173     }
 174
 175     service = OpenService(manager, QGA_SERVICE_NAME, DELETE);
 176     if (service == NULL) {
 177         printf_win_error("No handle to service");
 178         CloseServiceHandle(manager);
 179         return EXIT_FAILURE;
 180     }
 181
 182     if (DeleteService(service) == FALSE) {
 183         printf_win_error("Failed to delete service");
 184     } else {
 185         fprintf(stderr, "Service was deleted successfully.\n");
 186     }
 187
 188     CloseServiceHandle(service);
 189     CloseServiceHandle(manager);
 190
 191     return EXIT_SUCCESS;
 192 }