tenex.c

广泛使用的邮件服务器！同时

		   mail_open (NIL,mbx,OP_READONLY|OP_SILENT))) return NIL;
  status.flags = flags;		/* return status values */
  status.messages = stream->nmsgs;
  status.recent = stream->recent;
  if (flags & SA_UNSEEN)	/* must search to get unseen messages */
    for (i = 1,status.unseen = 0; i <= stream->nmsgs; i++)
      if (!mail_elt (stream,i)->seen) status.unseen++;
  status.uidnext = stream->uid_last + 1;
  status.uidvalidity = stream->uid_validity;
				/* calculate post-snarf results */
  if (!status.recent && stream->inbox &&
      (systream = mail_open (NIL,sysinbox (),OP_READONLY|OP_SILENT))) {
    status.messages += systream->nmsgs;
    status.recent += systream->recent;
    if (flags & SA_UNSEEN)	/* must search to get unseen messages */
      for (i = 1; i <= systream->nmsgs; i++)
	if (!mail_elt (systream,i)->seen) status.unseen++;
				/* kludge but probably good enough */
    status.uidnext += systream->nmsgs;
  }
  MM_STATUS(stream,mbx,&status);/* pass status to main program */
  if (tstream) mail_close (tstream);
  if (systream) mail_close (systream);
  return T;			/* success */
}

/* Tenex mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *tenex_open (MAILSTREAM *stream)
{
  int fd,ld;
  char tmp[MAILTMPLEN];
  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return user_flags (&tenexproto);
  if (stream->local) fatal ("tenex recycle stream");
  user_flags (stream);		/* set up user flags */
				/* canonicalize the mailbox name */
  if (!tenex_file (tmp,stream->mailbox)) {
    sprintf (tmp,"Can't open - invalid name: %.80s",stream->mailbox);
    MM_LOG (tmp,ERROR);
  }
  if (stream->rdonly ||
      (fd = open (tmp,O_RDWR,NIL)) < 0) {
    if ((fd = open (tmp,O_RDONLY,NIL)) < 0) {
      sprintf (tmp,"Can't open mailbox: %s",strerror (errno));
      MM_LOG (tmp,ERROR);
      return NIL;
    }
    else if (!stream->rdonly) {	/* got it, but readonly */
      MM_LOG ("Can't get write access to mailbox, access is readonly",WARN);
      stream->rdonly = T;
    }
  }
  stream->local = fs_get (sizeof (TENEXLOCAL));
  LOCAL->buf = (char *) fs_get (CHUNKSIZE);
  LOCAL->buflen = CHUNKSIZE - 1;
  LOCAL->text.data = (unsigned char *) fs_get (CHUNKSIZE);
  LOCAL->text.size = CHUNKSIZE - 1;

				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
  LOCAL->fd = fd;		/* bind the file */
				/* flush old name */
  fs_give ((void **) &stream->mailbox);
				/* save canonical name */
  stream->mailbox = cpystr (tmp);
				/* get shared parse permission */
  if ((ld = lockfd (fd,tmp,LOCK_SH)) < 0) {
    MM_LOG ("Unable to lock open mailbox",ERROR);
    return NIL;
  }
  (*bn) (BLOCK_FILELOCK,NIL);
  flock (LOCAL->fd,LOCK_SH);	/* lock the file */
  (*bn) (BLOCK_NONE,NIL);
  unlockfd (ld,tmp);		/* release shared parse permission */
  LOCAL->filesize = 0;		/* initialize parsed file size */
				/* time not set up yet */
  LOCAL->lastsnarf = LOCAL->filetime = 0;
  LOCAL->mustcheck = LOCAL->shouldcheck = NIL;
  stream->sequence++;		/* bump sequence number */
				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
  if (tenex_ping (stream) && !stream->nmsgs)
    MM_LOG ("Mailbox is empty",(long) NIL);
  if (!LOCAL) return NIL;	/* failure if stream died */
  stream->perm_seen = stream->perm_deleted =
    stream->perm_flagged = stream->perm_answered = stream->perm_draft =
      stream->rdonly ? NIL : T;
  stream->perm_user_flags = stream->rdonly ? NIL : 0xffffffff;
  return stream;		/* return stream to caller */
}

/* Tenex mail close
 * Accepts: MAIL stream
 *	    close options
 */

void tenex_close (MAILSTREAM *stream,long options)
{
  if (stream && LOCAL) {	/* only if a file is open */
    int silent = stream->silent;
    stream->silent = T;		/* note this stream is dying */
    if (options & CL_EXPUNGE) tenex_expunge (stream,NIL,NIL);
    stream->silent = silent;	/* restore previous status */
    flock (LOCAL->fd,LOCK_UN);	/* unlock local file */
    close (LOCAL->fd);		/* close the local file */
				/* free local text buffer */
    if (LOCAL->buf) fs_give ((void **) &LOCAL->buf);
    if (LOCAL->text.data) fs_give ((void **) &LOCAL->text.data);
				/* nuke the local data */
    fs_give ((void **) &stream->local);
    stream->dtb = NIL;		/* log out the DTB */
  }
}

/* Tenex mail fetch fast data
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 */

void tenex_fast (MAILSTREAM *stream,char *sequence,long flags)
{
  STRING bs;
  MESSAGECACHE *elt;
  unsigned long i;
  if (stream && LOCAL &&
      ((flags & FT_UID) ? mail_uid_sequence (stream,sequence) :
       mail_sequence (stream,sequence)))
    for (i = 1; i <= stream->nmsgs; i++)
      if ((elt = mail_elt (stream,i))->sequence) {
	if (!elt->rfc822_size) { /* have header size yet? */
	  lseek (LOCAL->fd,elt->private.special.offset +
		 elt->private.special.text.size,L_SET);
				/* resize bigbuf if necessary */
	  if (LOCAL->buflen < elt->private.msg.full.text.size) {
	    fs_give ((void **) &LOCAL->buf);
	    LOCAL->buflen = elt->private.msg.full.text.size;
	    LOCAL->buf = (char *) fs_get (LOCAL->buflen + 1);
	  }
				/* tie off string */
	  LOCAL->buf[elt->private.msg.full.text.size] = '\0';
				/* read in the message */
	  read (LOCAL->fd,LOCAL->buf,elt->private.msg.full.text.size);
	  INIT (&bs,mail_string,(void *) LOCAL->buf,
		elt->private.msg.full.text.size);
				/* calculate its CRLF size */
	  elt->rfc822_size = strcrlflen (&bs);
	}
	tenex_elt (stream,i);	/* get current flags from file */
      }
}


/* Tenex mail fetch flags
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 * Sniffs at file to get flags
 */

void tenex_flags (MAILSTREAM *stream,char *sequence,long flags)
{
  unsigned long i;
  if (stream && LOCAL &&
      ((flags & FT_UID) ? mail_uid_sequence (stream,sequence) :
       mail_sequence (stream,sequence)))
    for (i = 1; i <= stream->nmsgs; i++)
      if (mail_elt (stream,i)->sequence) tenex_elt (stream,i);
}

/* TENEX mail fetch message header
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned header text length
 *	    option flags
 * Returns: message header in RFC822 format
 */

char *tenex_header (MAILSTREAM *stream,unsigned long msgno,
		    unsigned long *length,long flags)
{
  char *s;
  unsigned long i;
  *length = 0;			/* default to empty */
  if (flags & FT_UID) return "";/* UID call "impossible" */
				/* get to header position */
  lseek (LOCAL->fd,tenex_hdrpos (stream,msgno,&i),L_SET);
  if (flags & FT_INTERNAL) {
    if (i > LOCAL->buflen) {	/* resize if not enough space */
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get (LOCAL->buflen = i + 1);
    }
				/* slurp the data */
    read (LOCAL->fd,LOCAL->buf,*length = i);
  }
  else {
    s = (char *) fs_get (i + 1);/* get readin buffer */
    s[i] = '\0';		/* tie off string */
    read (LOCAL->fd,s,i);	/* slurp the data */
				/* make CRLF copy of string */
    *length = strcrlfcpy (&LOCAL->buf,&LOCAL->buflen,s,i);
    fs_give ((void **) &s);	/* free readin buffer */
  }
  return (char *) LOCAL->buf;
}

/* TENEX mail fetch message text (body only)
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned stringstruct
 *	    option flags
 * Returns: T, always
 */

long tenex_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags)
{
  char *s;
  unsigned long i,j;
  MESSAGECACHE *elt;
				/* UID call "impossible" */
  if (flags & FT_UID) return NIL;
				/* get message status */
  elt = tenex_elt (stream,msgno);
				/* if message not seen */
  if (!(flags & FT_PEEK) && !elt->seen) {
    elt->seen = T;		/* mark message as seen */
				/* recalculate status */
    tenex_update_status (stream,msgno,T);
    MM_FLAGS (stream,msgno);
  }
  if (flags & FT_INTERNAL) {	/* if internal representation wanted */
				/* find header position */
    i = tenex_hdrpos (stream,msgno,&j);
    if (i > LOCAL->buflen) {	/* resize if not enough space */
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get (LOCAL->buflen = i + 1);
    }
				/* go to text position */
    lseek (LOCAL->fd,i + j,L_SET);
				/* slurp the data */
    read (LOCAL->fd,LOCAL->buf,i);
				/* set up stringstruct for internal */
    INIT (bs,mail_string,LOCAL->buf,i);
  }
  else {			/* normal form, previous text cached? */
    if (elt->private.uid == LOCAL->uid)
      i = elt->private.msg.text.text.size;
    else {			/* not cached, cache it now */
      LOCAL->uid = elt->private.uid;
				/* find header position */
      i = tenex_hdrpos (stream,msgno,&j);
				/* go to text position */
      lseek (LOCAL->fd,i + j,L_SET);
      s = (char *) fs_get ((i = tenex_size (stream,msgno) - j) + 1);
      s[i] = '\0';		/* tie off string */
      read (LOCAL->fd,s,i);	/* slurp the data */
				/* make CRLF copy of string */
      i = elt->private.msg.text.text.size =
	strcrlfcpy (&LOCAL->text.data,&LOCAL->text.size,s,i);
      fs_give ((void **) &s);	/* free readin buffer */
    }
				/* set up stringstruct */
    INIT (bs,mail_string,LOCAL->text.data,i);
  }
  return T;			/* success */
}

/* Tenex mail modify flags
 * Accepts: MAIL stream
 *	    sequence
 *	    flag(s)
 *	    option flags
 */

void tenex_flag (MAILSTREAM *stream,char *sequence,char *flag,long flags)
{
  time_t tp[2];
  struct stat sbuf;
  if (!stream->rdonly) {	/* make sure the update takes */
    fsync (LOCAL->fd);
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    tp[1] = LOCAL->filetime = sbuf.st_mtime;
    tp[0] = time (0);		/* make sure read comes after all that */
    utime (stream->mailbox,tp);
  }
}


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

void tenex_flagmsg (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  struct stat sbuf;
				/* maybe need to do a checkpoint? */
  if (LOCAL->filetime && !LOCAL->shouldcheck) {
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    if (LOCAL->filetime < sbuf.st_mtime) LOCAL->shouldcheck = T;
    LOCAL->filetime = 0;	/* don't do this test for any other messages */
  }
				/* recalculate status */
  tenex_update_status (stream,elt->msgno,NIL);
}

/* Tenex mail ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream still alive, NIL if not
 */

long tenex_ping (MAILSTREAM *stream)
{
  unsigned long i = 1;
  long r = T;
  int ld;
  char lock[MAILTMPLEN];
  struct stat sbuf;
  if (stream && LOCAL) {	/* only if stream already open */
    fstat (LOCAL->fd,&sbuf);	/* get current file poop */
    if (LOCAL->filetime && !(LOCAL->mustcheck || LOCAL->shouldcheck) &&
	(LOCAL->filetime < sbuf.st_mtime)) LOCAL->shouldcheck = T;
				/* check for changed message status */
    if (LOCAL->mustcheck || LOCAL->shouldcheck) {
      LOCAL->filetime = sbuf.st_mtime;
      if (LOCAL->shouldcheck)	/* babble when we do this unilaterally */
	MM_NOTIFY (stream,"[CHECK] Checking for flag updates",NIL);
      while (i <= stream->nmsgs) tenex_elt (stream,i++);
      LOCAL->mustcheck = LOCAL->shouldcheck = NIL;
    }
				/* get shared parse/append permission */
    if ((sbuf.st_size != LOCAL->filesize) &&
	((ld = lockfd (LOCAL->fd,lock,LOCK_SH)) >= 0)) {
				/* parse resulting mailbox */
      r = (tenex_parse (stream)) ? T : NIL;
      unlockfd (ld,lock);	/* release shared parse/append permission */
    }
    if (LOCAL) {		/* stream must still be alive */
				/* snarf if this is a read-write inbox */
      if (stream->inbox && !stream->rdonly) {
	tenex_snarf (stream);
	fstat (LOCAL->fd,&sbuf);/* see if file changed now */
	if ((sbuf.st_size != LOCAL->filesize) &&
	    ((ld = lockfd (LOCAL->fd,lock,LOCK_SH)) >= 0)) {
				/* parse resulting mailbox */
	  r = (tenex_parse (stream)) ? T : NIL;
	  unlockfd (ld,lock);	/* release shared parse/append permission */
	}
      }
    }
  }
  return r;			/* return result of the parse */
}


/* Tenex mail check mailbox (reparses status too)
 * Accepts: MAIL stream
 */

void tenex_check (MAILSTREAM *stream)
{
				/* mark that a check is desired */
  if (LOCAL) LOCAL->mustcheck = T;