mbx.c

广泛使用的邮件服务器！同时

{
  if (stream) dummy_lsub (NIL,ref,pat);
}

/* MBX mail create mailbox
 * Accepts: MAIL stream
 *	    mailbox name to create
 * Returns: T on success, NIL on failure
 */

long mbx_create (MAILSTREAM *stream,char *mailbox)
{
  char *s,*t,mbx[MAILTMPLEN],tmp[HDRSIZE];
  long ret = NIL;
  int i,fd;
  if (!(s = mbx_file (mbx,mailbox))) {
    sprintf (mbx,"Can't create %.80s: invalid name",mailbox);
    MM_LOG (mbx,ERROR);
  }
				/* create underlying file */
  else if (dummy_create_path (stream,s,get_dir_protection (mailbox))) {
				/* done if made directory */
    if ((s = strrchr (s,'/')) && !s[1]) return T;
    if ((fd = open (mbx,O_WRONLY|O_BINARY,NIL)) < 0) {
      sprintf (tmp,"Can't reopen mailbox node %.80s: %s",mbx,strerror (errno));
      MM_LOG (tmp,ERROR);
      unlink (mbx);		/* delete the file */
    }
    else {
      memset (tmp,'\0',HDRSIZE);/* initialize header */
      sprintf (s = tmp,"*mbx*\015\012%08lx00000000\015\012",
	       (unsigned long) time (0));
      for (i = 0; i < NUSERFLAGS; ++i) {
	t = (stream && stream->user_flags[i]) ? stream->user_flags[i] :
	  ((t = default_user_flag (i)) ? t : "");
	sprintf (s += strlen (s),"%s\015\012",t);
      }
      if (write (fd,tmp,HDRSIZE) != HDRSIZE) {
	sprintf (tmp,"Can't initialize mailbox node %.80s: %s",
		 mbx,strerror (errno));
	MM_LOG (tmp,ERROR);
	unlink (mbx);		/* delete the file */
      }
      else ret = T;		/* success */
      close (fd);		/* close file */
    }
  }
				/* set proper protections */
  return ret ? set_mbx_protections (mailbox,mbx) : NIL;
}


/* MBX mail delete mailbox
 * Accepts: MAIL stream
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long mbx_delete (MAILSTREAM *stream,char *mailbox)
{
  return mbx_rename (stream,mailbox,NIL);
}

/* MBX mail rename mailbox
 * Accepts: MAIL stream
 *	    old mailbox name
 *	    new mailbox name (or NIL for delete)
 * Returns: T on success, NIL on failure
 */

long mbx_rename (MAILSTREAM *stream,char *old,char *newname)
{
  long ret = LONGT;
  char c,*s,tmp[MAILTMPLEN],file[MAILTMPLEN],lock[MAILTMPLEN];
  int fd,ld;
  struct stat sbuf;
  if (!mbx_file (file,old) ||
      (newname && (!((s = mailboxfile (tmp,newname)) && *s) ||
		   ((s = strrchr (tmp,'/')) && !s[1])))) {
    sprintf (tmp,newname ?
	     "Can't rename mailbox %.80s to %.80s: invalid name" :
	     "Can't delete mailbox %.80s: invalid name",
	     old,newname);
    MM_LOG (tmp,ERROR);
    return NIL;
  }
  else if ((fd = open (file,O_RDWR|O_BINARY,NIL)) < 0) {
    sprintf (tmp,"Can't open mailbox %.80s: %s",old,strerror (errno));
    MM_LOG (tmp,ERROR);
    return NIL;
  }
				/* get parse/append permission */
  if ((ld = lockfd (fd,lock,LOCK_EX)) < 0) {
    MM_LOG ("Unable to lock rename mailbox",ERROR);
    return NIL;
  }
				/* lock out other users */
  if (flock (fd,LOCK_EX|LOCK_NB)) {
    close (fd);			/* couldn't lock, give up on it then */
    sprintf (tmp,"Mailbox %.80s is in use by another process",old);
    MM_LOG (tmp,ERROR);
    unlockfd (ld,lock);		/* release exclusive parse/append permission */
    return NIL;
  }

  if (newname) {		/* want rename? */
				/* found superior to destination name? */
    if (s = strrchr (tmp,'/')) {
      c = *++s;			/* remember first character of inferior */
      *s = '\0';		/* tie off to get just superior */
				/* superior name doesn't exist, create it */
      if ((stat (tmp,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
	  !dummy_create_path (stream,tmp,get_dir_protection (newname)))
	ret = NIL;
      else *s = c;		/* restore full name */
    }
				/* rename the file */
    if (ret && rename (file,tmp)) {
      sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %s",old,newname,
	       strerror (errno));
      MM_LOG (tmp,ERROR);
      ret = NIL;		/* set failure */
    }
  }
  else if (unlink (file)) {
    sprintf (tmp,"Can't delete mailbox %.80s: %s",old,strerror (errno));
    MM_LOG (tmp,ERROR);
    ret = NIL;			/* set failure */
  }
  flock (fd,LOCK_UN);		/* release lock on the file */
  unlockfd (ld,lock);		/* release exclusive parse/append permission */
  close (fd);			/* close the file */
				/* recreate file if renamed INBOX */
  if (ret && !compare_cstring (old,"INBOX")) mbx_create (NIL,"INBOX");
  return ret;			/* return success */
}

/* MBX Mail status
 * Accepts: mail stream
 *	    mailbox name
 *	    status flags
 * Returns: T on success, NIL on failure
 */

long mbx_status (MAILSTREAM *stream,char *mbx,long flags)
{
  MAILSTATUS status;
  unsigned long i;
  MAILSTREAM *tstream = NIL;
  MAILSTREAM *systream = NIL;
				/* make temporary stream (unless this mbx) */
  if (!stream && !(stream = tstream =
		   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 */
}

/* MBX mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *mbx_open (MAILSTREAM *stream)
{
  int fd,ld;
  short silent;
  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 (&mbxproto);
  if (stream->local) fatal ("mbx recycle stream");
				/* canonicalize the mailbox name */
  if (!mbx_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|O_BINARY,NIL)) < 0) {
    if ((fd = open (tmp,O_RDONLY|O_BINARY,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 = memset (fs_get (sizeof (MBXLOCAL)),NIL,sizeof (MBXLOCAL));
  LOCAL->fd = fd;		/* bind the file */
  LOCAL->ld = -1;		/* no flaglock */
  LOCAL->buf = (char *) fs_get (CHUNKSIZE);
  LOCAL->buflen = CHUNKSIZE - 1;
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
  fs_give ((void **) &stream->mailbox);
  stream->mailbox = cpystr (tmp);
				/* get parse/append permission */
  if ((ld = lockfd (LOCAL->fd,tmp,LOCK_EX)) < 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 = HDRSIZE;	/* initialize parsed file size */
				/* time not set up yet */
  LOCAL->lastsnarf = LOCAL->filetime = 0;
  LOCAL->expok = LOCAL->flagcheck = NIL;
  stream->sequence++;		/* bump sequence number */
				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
  silent = stream->silent;	/* defer events */
  stream->silent = T;
  if (mbx_ping (stream) && !stream->nmsgs)
    MM_LOG ("Mailbox is empty",(long) NIL);
  stream->silent = silent;	/* now notify upper level */
  mail_exists (stream,stream->nmsgs);
  mail_recent (stream,stream->recent);
  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;
  stream->kwd_create = (stream->user_flags[NUSERFLAGS-1] || stream->rdonly) ?
    NIL : T;			/* can we create new user flags? */
  return stream;		/* return stream to caller */
}

/* MBX mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mbx_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 */
				/* do an expunge if requested */
    if (options & CL_EXPUNGE) mbx_expunge (stream,NIL,NIL);
    else {			/* otherwise do a checkpoint to purge */
      LOCAL->expok = T;		/*  possible expunged messages */
      mbx_ping (stream);
    }
    stream->silent = silent;	/* restore previous status */
    mbx_abort (stream);
  }
}


/* MBX mail abort stream
 * Accepts: MAIL stream
 */

void mbx_abort (MAILSTREAM *stream)
{
  if (stream && LOCAL) {	/* only if a file is open */
    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);
				/* nuke the local data */
    fs_give ((void **) &stream->local);
    stream->dtb = NIL;		/* log out the DTB */
  }
}


/* MBX mail fetch flags
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 * Sniffs at file to see if some other process changed the flags
 */

void mbx_flags (MAILSTREAM *stream,char *sequence,long flags)
{
  MESSAGECACHE *elt;
  unsigned long i;
  if (mbx_ping (stream) && 	/* ping mailbox, get new status for messages */
      ((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 && !elt->valid)
	mbx_elt (stream,i,NIL);
}

/* MBX 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 *mbx_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		  long flags)
{
  unsigned long i;
  char *s;
  *length = 0;			/* default to empty */
  if (flags & FT_UID) return "";/* UID call "impossible" */
				/* get header position, possibly header */
  i = mbx_hdrpos (stream,msgno,length,&s);
  if (!s) {			/* mbx_hdrpos() returned header? */
    lseek (LOCAL->fd,i,L_SET);	/* no, get to header position */
				/* is buffer big enough? */
    if (*length > LOCAL->buflen) {
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get ((LOCAL->buflen = *length) + 1);
    }
				/* slurp the data */
    read (LOCAL->fd,s = LOCAL->buf,*length);
  }
  s[*length] = '\0';		/* tie off string */
  return s;
}

/* MBX mail fetch message text (body only)
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned header text length
 *	    option flags
 * Returns: T on success, NIL on failure
 */

long mbx_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags)
{
  FDDATA d;
  unsigned long i,j;
  MESSAGECACHE *elt;
				/* UID call "impossible" */
  if (flags & FT_UID) return NIL;
				/* get message status */
  elt = mbx_elt (stream,msgno,NIL);
				/* if message not seen */
  if (!(flags & FT_PEEK) && !elt->seen && mbx_flaglock (stream)) {
    elt->seen = T;		/* mark message as seen */
				/* recalculate status */
    mbx_update_status (stream,msgno,NIL);
    MM_FLAGS (stream,msgno);
				/* update flags */
    mbx_flag (stream,NIL,NIL,NIL);
  }
  if (!LOCAL) return NIL;	/* mbx_flaglock() could have aborted */
				/* find header position */
  i = mbx_hdrpos (stream,msgno,&j,NIL);
  d.fd = LOCAL->fd;		/* set up file descriptor */