mbx.c

广泛使用的邮件服务器！同时

  d.pos = i + j;
  d.chunk = LOCAL->buf;	/* initial buffer chunk */
  d.chunksize = CHUNKSIZE;
  INIT (bs,fd_string,&d,elt->rfc822_size - j);
  return LONGT;			/* success */
}

/* MBX mail modify flags
 * Accepts: MAIL stream
 *	    sequence
 *	    flag(s)
 *	    option flags
 * Unlocks flag lock
 */

void mbx_flag (MAILSTREAM *stream,char *sequence,char *flag,long flags)
{
  time_t tp[2];
  struct stat sbuf;
  unsigned long oldpid = LOCAL->lastpid;
				/* make sure the update takes */
  if (!stream->rdonly && LOCAL && (LOCAL->fd >= 0) && (LOCAL->ld >= 0)) {
    fsync (LOCAL->fd);
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    tp[1] = LOCAL->filetime = sbuf.st_mtime;
				/* we are the last flag updater */
    LOCAL->lastpid = (unsigned long) getpid ();
				/* update header if needed */
    if (((LOCAL->ffuserflag < NUSERFLAGS) &&
	 stream->user_flags[LOCAL->ffuserflag]) || (oldpid != LOCAL->lastpid))
      mbx_update_header (stream);
    tp[0] = time (0);		/* make sure read comes after all that */
    utime (stream->mailbox,tp);
  }
  if (LOCAL->ld >= 0) {		/* unlock now */
    unlockfd (LOCAL->ld,LOCAL->lock);
    LOCAL->ld = -1;
  }
}


/* MBX mail per-message modify flags
 * Accepts: MAIL stream
 *	    message cache element
 */

void mbx_flagmsg (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  if (mbx_flaglock (stream)) mbx_update_status (stream,elt->msgno,NIL);
}

/* MBX mail ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream still alive, NIL if not
 */

long mbx_ping (MAILSTREAM *stream)
{
  unsigned long i,pos;
  long ret = NIL;
  int ld;
  char lock[MAILTMPLEN];
  MESSAGECACHE *elt;
  struct stat sbuf;
  if (stream && LOCAL) {	/* only if stream already open */
    int snarf = stream->inbox && !stream->rdonly;
    ret = LONGT;		/* assume OK */
    fstat (LOCAL->fd,&sbuf);	/* get current file poop */
				/* allow expunge if permitted at ping */
    if (mail_parameters (NIL,GET_EXPUNGEATPING,NIL)) LOCAL->expok = T;
				/* if external modification */
    if (LOCAL->filetime && (LOCAL->filetime < sbuf.st_mtime))
      LOCAL->flagcheck = T;	/* upgrade to flag checking */
				/* new mail or flagcheck handling needed? */
    if (((sbuf.st_size - LOCAL->filesize) || LOCAL->flagcheck ||
	 !stream->nmsgs || snarf) &&
	((ld = lockfd (LOCAL->fd,lock,LOCK_EX)) >= 0)) {
				/* reparse header if not flagchecking */
      if (!LOCAL->flagcheck) ret = mbx_parse (stream);
				/* sweep mailbox for changed message status */
      else if (ret = mbx_parse (stream)) {
	unsigned long recent = 0;
	LOCAL->filetime = sbuf.st_mtime;
	for (i = 1; i <= stream->nmsgs; )
	  if (elt = mbx_elt (stream,i,LOCAL->expok)) {
	    if (elt->recent) ++recent;
	    ++i;
	  }
	mail_recent (stream,recent);
	LOCAL->flagcheck = NIL;	/* got all the updates */
      }
				/* always reparse header at least */
      if (ret && snarf) {	/* snarf new messages if still OK */
	mbx_snarf (stream);
				/* parse snarfed messages */
	ret = mbx_parse (stream);
      }
      unlockfd (ld,lock);	/* release shared parse/append permission */
    }
    if (ret) {			/* must still be alive */
      if (!LOCAL->expunged)	/* look for holes if none known yet */
	for (i = 1, pos = HDRSIZE;
	     !LOCAL->expunged && (i <= stream->nmsgs);
	     i++, pos += elt->private.special.text.size + elt->rfc822_size)
	  if ((elt = mail_elt (stream,i))->private.special.offset != pos)
	    LOCAL->expunged = T;/* found a hole */
				/* burp any holes */
      if (LOCAL->expunged && !stream->rdonly) {
	if (mbx_rewrite (stream,&i,NIL)) fatal ("expunge on check");
	if (i) {		/* any space reclaimed? */
	  LOCAL->expunged = NIL;/* no more pending expunge */
	  sprintf (LOCAL->buf,"Reclaimed %lu bytes of expunged space",i);
	  MM_LOG (LOCAL->buf,(long) NIL);
	}
      }
      LOCAL->expok = NIL;	/* no more expok */
    }
  }
  return ret;			/* return result of the parse */
}

/* MBX mail check mailbox (reparses status too)
 * Accepts: MAIL stream
 */

void mbx_check (MAILSTREAM *stream)
{
  if (LOCAL) LOCAL->expok = T;	/* mark that a check is desired */
  if (mbx_ping (stream)) MM_LOG ("Check completed",(long) NIL);
}


/* MBX mail expunge mailbox
 * Accepts: MAIL stream
 *	    sequence to expunge if non-NIL
 *	    expunge options
 * Returns: T if success, NIL if failure
 */

long mbx_expunge (MAILSTREAM *stream,char *sequence,long options)
{
  long ret;
  unsigned long nexp,reclaimed;
  if (ret = sequence ? ((options & EX_UID) ?
			mail_uid_sequence (stream,sequence) :
			mail_sequence (stream,sequence)) : LONGT) {
    if (!mbx_ping (stream));	/* do nothing if stream dead */
    else if (stream->rdonly)	/* won't do on readonly files! */
      MM_LOG ("Expunge ignored on readonly mailbox",WARN);
				/* if expunged any messages */
    else if (nexp = mbx_rewrite (stream,&reclaimed,sequence ? -1 : 1)) {
      sprintf (LOCAL->buf,"Expunged %lu messages",nexp);
      MM_LOG (LOCAL->buf,(long) NIL);
    }
    else if (reclaimed) {	 /* or if any prior expunged space reclaimed */
      sprintf (LOCAL->buf,"Reclaimed %lu bytes of expunged space",reclaimed);
      MM_LOG (LOCAL->buf,(long) NIL);
    }
    else MM_LOG ("No messages deleted, so no update needed",(long) NIL);
  }
  return ret;
}

/* MBX mail snarf messages from system inbox
 * Accepts: MAIL stream, already locked
 */

void mbx_snarf (MAILSTREAM *stream)
{
  unsigned long i = 0;
  unsigned long j,r,hdrlen,txtlen;
  struct stat sbuf;
  char *hdr,*txt,tmp[MAILTMPLEN];
  MESSAGECACHE *elt;
  MAILSTREAM *sysibx = NIL;
				/* give up if can't get exclusive permission */
  if ((time (0) >= (LOCAL->lastsnarf +
		    (long) mail_parameters (NIL,GET_SNARFINTERVAL,NIL))) &&
      strcmp (sysinbox (),stream->mailbox)) {
    MM_CRITICAL (stream);	/* go critical */
				/* sizes match and anything in sysinbox? */
    if (!stat (sysinbox (),&sbuf) && sbuf.st_size &&
	!fstat (LOCAL->fd,&sbuf) && (sbuf.st_size == LOCAL->filesize) && 
	(sysibx = mail_open (sysibx,sysinbox (),OP_SILENT)) &&
	(!sysibx->rdonly) && (r = sysibx->nmsgs)) {
				/* yes, go to end of file in our mailbox */
      lseek (LOCAL->fd,sbuf.st_size,L_SET);
				/* for each message in sysibx mailbox */
      while (r && (++i <= sysibx->nmsgs)) {
				/* snarf message from system INBOX */
	hdr = cpystr (mail_fetchheader_full (sysibx,i,NIL,&hdrlen,NIL));
	txt = mail_fetchtext_full (sysibx,i,&txtlen,FT_PEEK);
				/* if have a message */
	if (j = hdrlen + txtlen) {
				/* build header line */
	  mail_date (LOCAL->buf,elt = mail_elt (sysibx,i));
	  sprintf (LOCAL->buf + strlen (LOCAL->buf),
		   ",%lu;00000000%04x-00000000\015\012",j,(unsigned)
		   ((fSEEN * elt->seen) +
		    (fDELETED * elt->deleted) + (fFLAGGED * elt->flagged) +
		    (fANSWERED * elt->answered) + (fDRAFT * elt->draft)));
				/* copy message */
	  if ((write (LOCAL->fd,LOCAL->buf,strlen (LOCAL->buf)) < 0) ||
	      (write (LOCAL->fd,hdr,hdrlen) < 0) ||
	      (write (LOCAL->fd,txt,txtlen) < 0)) r = 0;
	}
	fs_give ((void **) &hdr);
      }

				/* make sure all the updates take */
      if (fsync (LOCAL->fd)) r = 0;
      if (r) {			/* delete all the messages we copied */
	if (r == 1) strcpy (tmp,"1");
	else sprintf (tmp,"1:%lu",r);
	mail_setflag (sysibx,tmp,"\\Deleted");
	mail_expunge (sysibx);	/* now expunge all those messages */
      }
      else {
	sprintf (LOCAL->buf,"Can't copy new mail: %s",strerror (errno));
	MM_LOG (LOCAL->buf,WARN);
	ftruncate (LOCAL->fd,sbuf.st_size);
      }
      fstat (LOCAL->fd,&sbuf);	/* yes, get current file size */
      LOCAL->filetime = sbuf.st_mtime;
    }
    if (sysibx) mail_close (sysibx);
    MM_NOCRITICAL (stream);	/* release critical */
    LOCAL->lastsnarf = time (0);/* note time of last snarf */
  }
}

/* MBX mail copy message(s)
 * Accepts: MAIL stream
 *	    sequence
 *	    destination mailbox
 *	    copy options
 * Returns: T if success, NIL if failed
 */

long mbx_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
{
  struct stat sbuf;
  time_t tp[2];
  MESSAGECACHE *elt;
  unsigned long i,j,k,m;
  long ret = LONGT;
  int fd,ld;
  char *s,*t,file[MAILTMPLEN],lock[MAILTMPLEN];
  mailproxycopy_t pc =
    (mailproxycopy_t) mail_parameters (stream,GET_MAILPROXYCOPY,NIL);
  copyuid_t cu = (copyuid_t) mail_parameters (NIL,GET_COPYUID,NIL);
  SEARCHSET *source = cu ? mail_newsearchset () : NIL;
  SEARCHSET *dest = cu ? mail_newsearchset () : NIL;
  MAILSTREAM *dstream = NIL;
  if (!((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
	mail_sequence (stream,sequence))) return NIL;
				/* make sure valid mailbox */
  if ((fd = mbx_isvalid (&dstream,mailbox,file,&ld,lock,
			 cu ? MBXISVALIDUID : MBXISVALIDNOUID)) < 0)
    switch (errno) {
    case ENOENT:		/* no such file? */
      MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before copy",NIL);
      return NIL;
    case EACCES:		/* file protected */
      sprintf (LOCAL->buf,"Can't access destination: %.80s",mailbox);
      MM_LOG (LOCAL->buf,ERROR);
      return NIL;
    case EINVAL:
      if (pc) return (*pc) (stream,sequence,mailbox,options);
      sprintf (LOCAL->buf,"Invalid MBX-format mailbox name: %.80s",mailbox);
      MM_LOG (LOCAL->buf,ERROR);
      return NIL;
    default:
      if (pc) return (*pc) (stream,sequence,mailbox,options);
      sprintf (LOCAL->buf,"Not a MBX-format mailbox: %.80s",mailbox);
      MM_LOG (LOCAL->buf,ERROR);
      return NIL;
    }
  MM_CRITICAL (stream);		/* go critical */
  fstat (fd,&sbuf);		/* get current file size */
  lseek (fd,sbuf.st_size,L_SET);/* move to end of file */

				/* for each requested message */
  for (i = 1; ret && (i <= stream->nmsgs); i++) 
    if ((elt = mail_elt (stream,i))->sequence) {
      lseek (LOCAL->fd,elt->private.special.offset +
	     elt->private.special.text.size,L_SET);
      mail_date(LOCAL->buf,elt);/* build target header */
				/* get target keyword mask */
      for (j = elt->user_flags, k = 0; j; )
	if (s = stream->user_flags[find_rightmost_bit (&j)])
	  for (m = 0; (m < NUSERFLAGS) && (t = dstream->user_flags[m]); m++)
	    if (!compare_cstring (s,t) && (k |= 1 << m)) break;
      sprintf (LOCAL->buf+strlen(LOCAL->buf),",%lu;%08lx%04x-%08lx\015\012",
	       elt->rfc822_size,k,(unsigned)
	       ((fSEEN * elt->seen) + (fDELETED * elt->deleted) +
		(fFLAGGED * elt->flagged) + (fANSWERED * elt->answered) +
		(fDRAFT * elt->draft)),cu ? ++dstream->uid_last : 0);
				/* write target header */
      if (ret = (write (fd,LOCAL->buf,strlen (LOCAL->buf)) > 0)) {
	for (k = elt->rfc822_size; ret && (j = min (k,LOCAL->buflen)); k -= j){
	  read (LOCAL->fd,LOCAL->buf,j);
	  ret = write (fd,LOCAL->buf,j) >= 0;
	}
	if (cu) {		/* need to pass back new UID? */
	  mail_append_set (source,mail_uid (stream,i));
	  mail_append_set (dest,dstream->uid_last);
	}
      }
    }

				/* make sure all the updates take */
  if (!(ret && (ret = !fsync (fd)))) {
    sprintf (LOCAL->buf,"Unable to write message: %s",strerror (errno));
    MM_LOG (LOCAL->buf,ERROR);
    ftruncate (fd,sbuf.st_size);
  }
  if (cu && ret) {		/* return sets if doing COPYUID */
    (*cu) (stream,mailbox,dstream->uid_validity,source,dest);
    lseek (fd,15,L_SET);	/* update UIDLAST */
    sprintf (LOCAL->buf,"%08lx",dstream->uid_last);
    write (fd,LOCAL->buf,8);
  }
  else {			/* flush any sets we may have built */
    mail_free_searchset (&source);
    mail_free_searchset (&dest);
  }
  if (ret) tp[0] = time (0) - 1;/* set atime to now-1 if successful copy */
				/* else preserve \Marked status */
  else tp[0] = (sbuf.st_ctime > sbuf.st_atime) ? sbuf.st_atime : time(0);
  tp[1] = sbuf.st_mtime;	/* preserve mtime */
  utime (file,tp);		/* set the times */
  close (fd);			/* close the file */
  MM_NOCRITICAL (stream);	/* release critical */
  unlockfd (ld,lock);		/* release exclusive parse/append permission */
				/* delete all requested messages */
  if (ret && (options & CP_MOVE) && mbx_flaglock (stream)) {
    for (i = 1; i <= stream->nmsgs; i++) if (mail_elt (stream,i)->sequence) {
				/* mark message deleted */
      mbx_elt (stream,i,NIL)->deleted = T;
				/* recalculate status */
      mbx_update_status (stream,i,NIL);
    }
				/* update flags */
    mbx_flag (stream,NIL,NIL,NIL);
  }
  if (dstream != stream) mail_close (dstream);
  return ret;
}

/* MBX mail append message from stringstruct
 * Accepts: MAIL stream
 *	    destination mailbox
 *	    append callback
 *	    data for callback
 * Returns: T if append successful, else NIL
 */

long mbx_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data)
{
  struct stat sbuf;
  int fd,ld;
  char *flags,*date,tmp[MAILTMPLEN],file[MAILTMPLEN],lock[MAILTMPLEN];
  time_t tp[2];
  FILE *df;
  MESSAGECACHE elt;
  long f;
  unsigned long i,uf;
  STRING *message;
  long ret = NIL;
  MAILSTREAM *dstream = NIL;
  appenduid_t au = (appenduid_t) mail_parameters (NIL,GET_APPENDUID,NIL);