flocksim.c

广泛使用的邮件服务器！同时

	mm_nocritical ((st == stream) ? stream : NIL);
	break;

      case 'D':			/* mm_diskerror() */
	st = (MAILSTREAM *) strtoul (event+1,&s,16);
	if (s && (*s++ == ' ')) {
	  i = strtoul (s,&s,10);
	  if (s && (*s++ == ' ')) {
	    j = (long) strtoul (s,NIL,10);
	    if (st == stream)	/* let's hope it's on usable stream */
	      putc (mm_diskerror (stream,(long) i,j) ? '+' : '-',po);
	    else if (j) {	/* serious diskerror on slave-created stream */
	      mm_log ("Retrying disk write to avoid mailbox corruption!",WARN);
	      sleep (5);	/* give some time for it to clear up */
	      putc ('-',po);	/* don't abort */
	    }
	    else {		/* recoverable on slave-created stream */
	      mm_log ("Error on disk write",ERROR);
	      putc ('+',po);	/* so abort it */
	    }
	    fflush (po);	/* force it out either way */
	    break;
	  }
	}
	sprintf (tmp,"Invalid diskerror event arguments: %.500s",event);
	fatal (tmp);
      case 'F':			/* mm_fatal() */
	mm_fatal (event+1);
	break;
      default:			/* random lossage */
	sprintf (tmp,"Unknown event from execution process: %.500s",event);
	fatal (tmp);
      }
    }
    fclose (pi); fclose (po);	/* done with the pipes */
				/* get slave status */
    grim_pid_reap_status (pid,NIL,&ret);
    if (ret & 0177) {		/* signal or stopped */
      sprintf (tmp,"Execution process terminated abnormally (%lx)",ret);
      mm_log (tmp,ERROR);
      ret = NIL;
    }
    else ret >>= 8;		/* return exit code */
    (*bn) (BLOCK_NONSENSITIVE,blockdata);
  }
  return ret;			/* return status */
}

/* Safe driver calls */


/* Safely delete mailbox
 * Accepts: driver to call under slave
 *	    MAIL stream
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long safe_delete (DRIVER *dtb,MAILSTREAM *stream,char *mbx)
{
  long ret = master (stream,NIL,NIL);
  if (lockslavep) exit ((*dtb->mbxdel) (stream,mbx));
  return ret;
}


/* Safely rename mailbox
 * Accepts: driver to call under slave
 *	    MAIL stream
 *	    old mailbox name
 *	    new mailbox name (or NIL for delete)
 * Returns: T on success, NIL on failure
 */

long safe_rename (DRIVER *dtb,MAILSTREAM *stream,char *old,char *newname)
{
  long ret = master (stream,NIL,NIL);
  if (lockslavep) exit ((*dtb->mbxren) (stream,old,newname));
  return ret;
}


/* Safely get status of mailbox
 * Accepts: driver to call under slave
 *	    MAIL stream
 *	    mailbox name
 *	    status flags
 * Returns: T on success, NIL on failure
 */

long safe_status (DRIVER *dtb,MAILSTREAM *stream,char *mbx,long flags)
{
  long ret = master (stream,NIL,NIL);
  if (lockslavep) exit ((*dtb->status) (stream,mbx,flags));
  return ret;
}


/* Scan file for contents
 * Accepts: driver to call under slave
 *	    file name
 *	    desired contents
 *	    length of contents
 *	    length of file
 * Returns: NIL if contents not found, T if found
 */

long safe_scan_contents (DRIVER *dtb,char *name,char *contents,
			 unsigned long csiz,unsigned long fsiz)
{
  long ret = master (NIL,NIL,NIL);
  if (lockslavep) exit (scan_contents (dtb,name,contents,csiz,fsiz));
  return ret;
}

/* Safely copy message to mailbox
 * Accepts: driver to call under slave
 *	    MAIL stream
 *	    sequence
 *	    destination mailbox
 *	    copy options
 * Returns: T if success, NIL if failed
 */

long safe_copy (DRIVER *dtb,MAILSTREAM *stream,char *seq,char *mbx,long flags)
{
  mailproxycopy_t pc =
    (mailproxycopy_t) mail_parameters (stream,GET_MAILPROXYCOPY,NIL);
  long ret = master (stream,NIL,NIL);
  if (lockslavep) {
				/* don't do proxycopy in slave */
    if (pc) mail_parameters (stream,SET_MAILPROXYCOPY,(void *) slaveproxycopy);
    exit ((*dtb->copy) (stream,seq,mbx,flags));
  }
				/* do any proxycopy in master */
  if (lockproxycopy && pc) return (*pc) (stream,seq,mbx,flags);
  return ret;
}


/* Append package for slave */

typedef struct append_data {
  int first;			/* flag indicating first message */
  char *flags;			/* message flags */
  char *date;			/* message date */
  char *msg;			/* message text */
  STRING message;		/* message stringstruct */
} APPENDDATA;


/* Safely append message to mailbox
 * Accepts: driver to call under slave
 *	    MAIL stream
 *	    destination mailbox
 *	    append callback
 *	    data for callback
 * Returns: T if append successful, else NIL
 */

long safe_append (DRIVER *dtb,MAILSTREAM *stream,char *mbx,append_t af,
		  void *data)
{
  long ret = master (stream,af,data);
  if (lockslavep) {
    APPENDDATA ad;
    ad.first = T;		/* initialize initial append package */
    ad.flags = ad.date = ad.msg = NIL;
    exit ((*dtb->append) (stream,mbx,slave_append,&ad));
  }
  return ret;
}

/* Slave callbacks */


/* Message exists (i.e. there are that many messages in the mailbox)
 * Accepts: MAIL stream
 *	    message number
 */

void slave_exists (MAILSTREAM *stream,unsigned long number)
{
  /* this event never passed by slaves */
}


/* Message expunged
 * Accepts: MAIL stream
 *	    message number
 */

void slave_expunged (MAILSTREAM *stream,unsigned long number)
{
  /* this event never passed by slaves */
}


/* Message status changed
 * Accepts: MAIL stream
 *	    message number
 */

void slave_flags (MAILSTREAM *stream,unsigned long number)
{
  /* this event never passed by slaves */
}

/* Mailbox status
 * Accepts: MAIL stream
 *	    mailbox name
 *	    mailbox status
 */

void slave_status (MAILSTREAM *stream,char *mailbox,MAILSTATUS *status)
{
  int i,c;
  fprintf (slaveout,"S%lx %lu %lu %lu %lu %lu %lu ",
	  (unsigned long) stream,status->flags,status->messages,status->recent,
	  status->unseen,status->uidnext,status->uidvalidity,mailbox);
				/* yow!  are we paranoid enough yet? */
  for (i = 0; (i < 500) && (c = *mailbox++); ++i) switch (c) {
  case '\r': case '\n':		/* newline in a mailbox name? */
    c = ' ';
  default:
    putc (c,slaveout);
  }
  putc ('\n',slaveout);
  fflush (slaveout);
}

/* Notification event
 * Accepts: MAIL stream
 *	    string to log
 *	    error flag
 */

void slave_notify (MAILSTREAM *stream,char *string,long errflg)
{
  int i,c;
  fprintf (slaveout,"N%lx %lu ",(unsigned long) stream,errflg);
				/* prevent more than 500 bytes */
  for (i = 0; (i < 500) && (c = *string++); ++i) switch (c) {
  case '\r': case '\n':		/* or embedded newline */
    c = ' ';
  default:
    putc (c,slaveout);
  }
  putc ('\n',slaveout);
  fflush (slaveout);
}


/* Log an event for the user to see
 * Accepts: string to log
 *	    error flag
 */

void slave_log (char *string,long errflg)
{
  int i,c;
  fprintf (slaveout,"L%lu ",errflg);
				/* prevent more than 500 bytes */
  for (i = 0; (i < 500) && (c = *string++); ++i) switch (c) {
  case '\r': case '\n':		/* or embedded newline */
    c = ' ';
  default:
    putc (c,slaveout);
  }
  putc ('\n',slaveout);
  fflush (slaveout);
}

/* About to enter critical code
 * Accepts: stream
 */

void slave_critical (MAILSTREAM *stream)
{
  fprintf (slaveout,"C%lx\n",(unsigned long) stream);
  fflush (slaveout);
}


/* About to exit critical code
 * Accepts: stream
 */

void slave_nocritical (MAILSTREAM *stream)
{
  fprintf (slaveout,"X%lx\n",(unsigned long) stream);
  fflush (slaveout);
}

/* Disk error found
 * Accepts: stream
 *	    system error code
 *	    flag indicating that mailbox may be clobbered
 * Returns: abort flag
 */

long slave_diskerror (MAILSTREAM *stream,long errcode,long serious)
{
  char tmp[MAILTMPLEN];
  int c;
  long ret = NIL;
  fprintf (slaveout,"D%lx %lu %lu\n",(unsigned long) stream,errcode,serious);
  fflush (slaveout);
  switch (c = getc (slavein)) {
  case EOF:			/* pipe broken */
    slave_fatal ("Pipe broken reading diskerror response");
  case '+':			/* user wants to abort */
    ret = LONGT;
  case '-':			/* no abort */
    break;
  default:
    sprintf (tmp,"Unknown master response for diskerror: %c",c);
    slave_fatal (tmp);
  }
  return ret;
}


/* Log a fatal error event
 * Accepts: string to log
 * Does not return
 */

void slave_fatal (char *string)
{
  int i,c;
  syslog (LOG_ALERT,"IMAP toolkit slave process crash: %.500s",string);
  putc ('F',slaveout);
				/* prevent more than 500 bytes */
  for (i = 0; (i < 500) && (c = *string++); ++i) switch (c) {
  case '\r': case '\n':		/* newline in a mailbox name? */
    c = ' ';
  default:
    putc (c,slaveout);
  }
  putc ('\n',slaveout);
  fflush (slaveout);
  abort ();			/* die */
}

/* Append read buffer
 * Accepts: number of bytes to read
 *	    error message if fails
 * Returns: read-in string
 */

static char *slave_append_read (unsigned long n,char *error)
{
#if 0
  unsigned long i;
#endif
  int c;
  char *t,tmp[MAILTMPLEN];
  char *s = (char *) fs_get (n + 1);
  s[n] = '\0';
#if 0
  /* This doesn't work on Solaris with GCC.  I think that it's a C library
   * bug, since the problem only shows up if the application does fread()
   * on some other file
   */
  for (t = s; n && ((i = fread (t,1,n,slavein)); t += i,n -= i);
#else
  for (t = s; n && ((c = getc (slavein)) != EOF); *t++ = c,--n);
#endif
  if (n) {
    sprintf(tmp,"Pipe broken reading %.100s with %lu bytes remaining",error,n);
    slave_fatal (tmp);
  }
  return s;
}

/* Append message callback
 * Accepts: MAIL stream
 *	    append data package
 *	    pointer to return initial flags
 *	    pointer to return message internal date
 *	    pointer to return stringstruct of message or NIL to stop
 * Returns: T if success (have message or stop), NIL if error
 */

long slave_append (MAILSTREAM *stream,void *data,char **flags,char **date,
		   STRING **message)
{
  char tmp[MAILTMPLEN];
  unsigned long n;
  int c;
  APPENDDATA *ad = (APPENDDATA *) data;
				/* flush text of previous message */
  if (ad->flags) fs_give ((void **) &ad->flags);
  if (ad->date) fs_give ((void **) &ad->date);
  if (ad->msg) fs_give ((void **) &ad->msg);
  *flags = *date = NIL;		/* assume no flags or date */
  fputs ("A\n",slaveout);	/* tell master we're doing append callback */
  fflush (slaveout);
  switch (c = getc (slavein)) {	/* what did master say? */
  case '+':			/* have message, get size of flags */
    for (n = 0; isdigit (c = getc (slavein)); n *= 10, n += (c - '0'));
    if (c != ' ') {
      if (c == EOF) sprintf (tmp,"Pipe broken after flag size %lu",n);
      sprintf (tmp,"Missing delimiter after flag size %lu: %c",n,c);
      slave_fatal (tmp);
    }
    if (n) *flags = ad->flags = slave_append_read (n,"flags");
				/* get size of date */
    for (n = 0; isdigit (c = getc (slavein)); n *= 10, n += (c - '0'));
    if (c != ' ') {
      if (c == EOF) sprintf (tmp,"Pipe broken after date size %lu",n);
      else sprintf (tmp,"Missing delimiter after date size %lu: %c",n,c);
      slave_fatal (tmp);
    }
    if (n) *date = ad->date = slave_append_read (n,"date");
				/* get size of message */
    for (n = 0; isdigit (c = getc (slavein)); n *= 10, n += (c - '0'));
    if (c != ' ') {
      if (c == EOF) sprintf (tmp,"Pipe broken after message size %lu",n);
      sprintf (tmp,"Missing delimiter after message size %lu: %c",n,c);
      slave_fatal (tmp);
    }
    if (n) {			/* make buffer for message */
      ad->msg = slave_append_read (n,"message");
				/* initialize stringstruct */
      INIT (&ad->message,mail_string,(void *) ad->msg,n);
      ad->first = NIL;		/* no longer first message */
      *message = &ad->message;	/* return message */
    }
    else *message = NIL;	/* empty message */
    return LONGT;
  case '-':			/* error */
    *message = NIL;		/* set stop */
    break;
  case EOF:			/* end of file */
    slave_fatal ("Pipe broken reading append response");
  default:			/* unknown event */
    sprintf (tmp,"Unknown master response for append: %c",c);
    slave_fatal (tmp);
  }
  return NIL;			/* return failure */
}

/* Proxy copy across mailbox formats
 * Accepts: mail stream
 *	    sequence to copy on this stream
 *	    destination mailbox
 *	    option flags
 * Returns: T if success, else NIL
 */

long slaveproxycopy (MAILSTREAM *stream,char *sequence,char *mailbox,
		     long options)
{
  fputs ("&\n",slaveout);	/* redo copy as append */
  fflush (slaveout);
  return NIL;			/* failure for now */
}