saop/win32-service.c

/**
 * saop: smtp authentication over pop3
 * Copyright (C) 2007 Juan José Gutiérrez de Quevedo <juanjo@iteisa.com>
 *
 * 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; version 2 of the License
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * @author Juan José Gutiérrez de Quevedo <juanjo@iteisa.com>
 */
#include <stdio.h>
#include <windows.h>

#define SERVICE_NAME "saop: smtp authentication over pop3"
#define SERVICE_SHORT_NAME "saop"
#define SERVICE_DESCRIPTION_TEXT "Adds LOGIN authentication to an SMTP server. Users are authenticated against a pop3 server, an imap4 server or a file"

/* macros */
#define ChangeServiceStatus(x,y,z) y.dwCurrentState=z; SetServiceStatus(x,&y);
#define MIN(x,y) (((x)<(y))?(x):(y))
#define cmp(x,y) strncmp(x,y,strlen(y))
#define msgbox(x,y) MessageBox(NULL,x,"Error from " SERVICE_NAME,MB_OK|y)
#define winerror(x) msgbox(x,MB_ICONERROR)
#define winmessage(x) msgbox(x,MB_ICONINFORMATION)
#define _(x) x

/**
 * The docs on microsoft's web don't seem very clear, so I have
 * looked at the stunnel source code to understand how this thing
 * works. What you see here is still original source, but is 
 * "inspired" by stunnel's source code (gui.c mainly).
 * It's the real minimum needed to install, start and stop services
 */

extern int quit;

extern int saop_main(int,char **);

SERVICE_STATUS service_status;
SERVICE_STATUS_HANDLE service_status_handle;

int WINAPI WinMain(HINSTANCE,HINSTANCE,LPSTR,int);
static void WINAPI service_main(DWORD,LPTSTR*);
static void WINAPI handler(DWORD);
static int service_install();
static int service_uninstall();

int WINAPI WinMain(HINSTANCE instance,HINSTANCE previous_instance,LPSTR cmdline,int cmdshow)
{
  if(!cmp(cmdline,"-service"))
  {
    SERVICE_TABLE_ENTRY service_table[]={
      {SERVICE_NAME,service_main},
      {NULL,NULL}
    };

    if(0==StartServiceCtrlDispatcher(service_table))
    {
      winerror("Error starting service dispatcher.");
      return -1;
    }
  }
  else if(!cmp(cmdline,"-install"))
    service_install();
  else if(!cmp(cmdline,"-uninstall"))
    service_uninstall();
  else
    saop_main(0,NULL);

  return 0;
}

static int service_install()
{
  SC_HANDLE scm,service_handle;
  SERVICE_DESCRIPTION sd;
  char filename[1024];
  char exepath[2048];

  if(NULL==(scm=OpenSCManager(NULL,NULL,SC_MANAGER_CREATE_SERVICE)))
  {
    winerror(_("Error opening connection to the Service Manager."));
    exit(-1);
  }
  if(0==GetModuleFileName(NULL,filename,sizeof(filename)))
  {
    winerror(_("Error getting the file name of the process."));
    exit(-1);
  }

  snprintf(exepath,sizeof(exepath),"\"%s\" -service",filename);

  service_handle=CreateService(
    scm,                        /* scm handle */
    SERVICE_SHORT_NAME,         /* service name */
    SERVICE_NAME,               /* display name */
    SERVICE_ALL_ACCESS,         /* desired access */
    SERVICE_WIN32_OWN_PROCESS,  /* service type */
    SERVICE_AUTO_START,         /* start type */
    SERVICE_ERROR_NORMAL,       /* error control */
    exepath,                    /* executable path with arguments */
    NULL,                       /* load group */
    NULL,                       /* tag for group id */
    NULL,                       /* dependencies */
    NULL,                       /* user name */
    NULL);                      /* password */

  if(NULL==service_handle)
  {
    winerror("Error creating service. Already installed?");
    exit(-1);
  }
  else
    winmessage("Service successfully installed.");

  /*
   * createservice doesn't have a field for description
   * so we use ChangeServiceConfig2
   */
  sd.lpDescription=SERVICE_DESCRIPTION_TEXT;
  ChangeServiceConfig2(service_handle,SERVICE_CONFIG_DESCRIPTION,(void *)&sd);

  CloseServiceHandle(service_handle);
  CloseServiceHandle(scm);

  return 0;
}

static int service_uninstall()
{
  SC_HANDLE scm,service_handle;
  SERVICE_STATUS status;

  if(NULL==(scm=OpenSCManager(NULL,NULL,SC_MANAGER_CREATE_SERVICE)))
  {
    winerror(_("Error opening connection to the Service Manager."));
    exit(-1);
  }

  if(NULL==(service_handle=OpenService(scm,SERVICE_SHORT_NAME,SERVICE_QUERY_STATUS|DELETE)))
  {
    winerror(_("Error opening service."));
    CloseServiceHandle(scm);
    exit(-1);
  }

  if(0==QueryServiceStatus(service_handle,&status))
  {
    winerror(_("Error querying service."));
    CloseServiceHandle(scm);
    CloseServiceHandle(service_handle);
    exit(-1);
  }

  if(SERVICE_STOPPED!=status.dwCurrentState)
  {
    winerror(SERVICE_NAME _(" is still running. Stop it before trying to uninstall it."));
    CloseServiceHandle(scm);
    CloseServiceHandle(service_handle);
    exit(-1);
  }

  if(0==DeleteService(service_handle))
  {
    winerror(_("Error deleting service."));
    CloseServiceHandle(scm);
    CloseServiceHandle(service_handle);
    exit(-1);
  }

  CloseServiceHandle(scm);
  CloseServiceHandle(service_handle);
  winmessage(_("Service successfully uninstalled."));
  return 0;
}

static void WINAPI service_main(DWORD argc,LPTSTR *argv)
{
  /* configure service_status structure */
  service_status.dwServiceType=SERVICE_WIN32;
  service_status.dwControlsAccepted=0;
  service_status.dwWin32ExitCode=NO_ERROR;
  service_status.dwServiceSpecificExitCode=NO_ERROR;
  service_status.dwCheckPoint=0;
  service_status.dwWaitHint=0;
  service_status.dwControlsAccepted|=SERVICE_ACCEPT_STOP;

  service_status_handle=RegisterServiceCtrlHandler(SERVICE_NAME,handler);

  if(0!=service_status_handle)
  {
    /* set service status */
    ChangeServiceStatus(service_status_handle,service_status,SERVICE_RUNNING);

    /* now start our main program */
    quit=0;
    saop_main(argc,argv);

    /* when we are here, we have been stopped */
    ChangeServiceStatus(service_status_handle,service_status,SERVICE_STOP_PENDING);
    ChangeServiceStatus(service_status_handle,service_status,SERVICE_STOPPED);
  }
}

static void WINAPI handler(DWORD code)
{
  if(SERVICE_CONTROL_STOP==code)
  {
    quit=1;
    ChangeServiceStatus(service_status_handle,service_status,SERVICE_STOP_PENDING);
  }
}