mix.c

广泛使用的邮件服务器！同时

long mix_unsubscribe (MAILSTREAM *stream,char *mailbox)
{
  return sm_unsubscribe (mailbox);
}

/* MIX mail create mailbox
 * Accepts: mail stream
 *	    mailbox name to create
 * Returns: T on success, NIL on failure
 */

long mix_create (MAILSTREAM *stream,char *mailbox)
{
  DRIVER *test;
  FILE *f;
  int c,i;
  char *t,tmp[MAILTMPLEN],file[MAILTMPLEN];
  char *s = strrchr (mailbox,'/');
  unsigned long now = time (NIL);
  long ret = NIL;
				/* always create \NoSelect if trailing /  */
  if (s && !s[1]) return dummy_create (stream,mailbox);
				/* validate name */
  if (mix_dirfmttest (s ? s + 1 : mailbox))
    sprintf(tmp,"Can't create mailbox %.80s: invalid MIX-format name",mailbox);
				/* must not already exist */
  else if ((test = mail_valid (NIL,mailbox,NIL)) &&
	   strcmp (test->name,"dummy"))
    sprintf (tmp,"Can't create mailbox %.80s: mailbox already exists",mailbox);
				/* create directory and metadata */
  else if (!dummy_create_path (stream,
			       mix_file (file,mix_dir (tmp,mailbox),MIXMETA),
			       get_dir_protection (mailbox)))
    sprintf (tmp,"Can't create mailbox %.80s: %.80s",mailbox,strerror (errno));
  else if (!(f = fopen (file,"w")))
    sprintf (tmp,"Can't re-open metadata %.80s: %.80s",mailbox,
	     strerror (errno));
  else {			/* success, write initial metadata */
    fprintf (f,SEQFMT,now);
    fprintf (f,MTAFMT,now,0,now);
    for (i = 0, c = 'K'; (i < NUSERFLAGS) &&
	   (t = (stream && stream->user_flags[i]) ? stream->user_flags[i] :
	    default_user_flag (i)) && *t; ++i) {
      putc (c,f);		/* write another keyword */
      fputs (t,f);
      c = ' ';			/* delimiter is now space */
    }
    fclose (f);
    set_mbx_protections (mailbox,file);
				/* point to suffix */
    s = file + strlen (file) - (sizeof (MIXMETA) - 1);
    strcpy (s,MIXINDEX);	/* create index */
    if (!dummy_create_path (stream,file,get_dir_protection (mailbox)))
      sprintf (tmp,"Can't create mix mailbox index: %.80s",strerror (errno));
    else {
      set_mbx_protections (mailbox,file);
      strcpy (s,MIXSTATUS);	/* create status */
      if (!dummy_create_path (stream,file,get_dir_protection (mailbox)))
	sprintf (tmp,"Can't create mix mailbox status: %.80s",
		 strerror (errno));
      else {
	set_mbx_protections (mailbox,file);
	sprintf (s,"%08lx",now);/* message file */
	if (!dummy_create_path (stream,file,get_dir_protection (mailbox)))
	  sprintf (tmp,"Can't create mix mailbox data: %.80s",
		   strerror (errno));
	else {
	  set_mbx_protections (mailbox,file);
	  ret = LONGT;	/* declare success at this point */
	}
      }
    }
  }
  if (!ret) MM_LOG (tmp,ERROR);	/* some error */
  return ret;
}

/* MIX mail delete mailbox
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long mix_delete (MAILSTREAM *stream,char *mailbox)
{
  DIR *dirp;
  struct direct *d;
  int fd = -1;
  char *s,tmp[MAILTMPLEN];
  if (!mix_isvalid (mailbox,tmp))
    sprintf (tmp,"Can't delete mailbox %.80s: no such mailbox",mailbox);
  else if (((fd = open (tmp,O_RDWR,NIL)) < 0) || flock (fd,LOCK_EX|LOCK_NB))
    sprintf (tmp,"Can't lock mailbox for delete: %.80s",mailbox);
				/* delete metadata */
  else if (unlink (tmp)) sprintf (tmp,"Can't delete mailbox %.80s index: %80s",
				  mailbox,strerror (errno));
  else {
    close (fd);			/* close descriptor on deleted metadata */
				/* get directory name */
    *(s = strrchr (tmp,'/')) = '\0';
    if (dirp = opendir (tmp)) {	/* open directory */
      *s++ = '/';		/* restore delimiter */
				/* massacre messages */
      while (d = readdir (dirp)) if (mix_dirfmttest (d->d_name)) {
	strcpy (s,d->d_name);	/* make path */
	unlink (tmp);		/* sayonara */
      }
      closedir (dirp);		/* flush directory */
      *(s = strrchr (tmp,'/')) = '\0';
      if (rmdir (tmp)) {	/* try to remove the directory */
	sprintf (tmp,"Can't delete name %.80s: %.80s",
		 mailbox,strerror (errno));
	MM_LOG (tmp,WARN);
      }
    }
    return T;			/* always success */
  }
  if (fd >= 0) close (fd);	/* close any descriptor on metadata */
  MM_LOG (tmp,ERROR);		/* something failed */
  return NIL;
}

/* MIX mail rename mailbox
 * Accepts: MIX mail stream
 *	    old mailbox name
 *	    new mailbox name
 * Returns: T on success, NIL on failure
 */

long mix_rename (MAILSTREAM *stream,char *old,char *newname)
{
  char c,*s,tmp[MAILTMPLEN],tmp1[MAILTMPLEN];
  struct stat sbuf;
  int fd = -1;
  if (!mix_isvalid (old,tmp))
    sprintf (tmp,"Can't rename mailbox %.80s: no such mailbox",old);
  else if (((fd = open (tmp,O_RDWR,NIL)) < 0) || flock (fd,LOCK_EX|LOCK_NB))
    sprintf (tmp,"Can't lock mailbox for rename: %.80s",old);
  else if (mix_dirfmttest ((s = strrchr (newname,'/')) ? s + 1 : newname))
    sprintf (tmp,"Can't rename to mailbox %.80s: invalid MIX-format name",
	     newname);
				/* new mailbox name must not be valid */
  else if (mix_isvalid (newname,tmp))
    sprintf (tmp,"Can't rename to mailbox %.80s: destination already exists",
	     newname);
  else {
    mix_dir (tmp,old);		/* build old directory name */
    mix_dir (tmp1,newname);	/* and new directory name */
				/* easy if not INBOX */
    if (compare_cstring (old,"INBOX")) {
				/* found superior to destination name? */
      if (s = strrchr (tmp1,'/')) {
	c = *++s;		/* remember first character of inferior */
	*s = '\0';		/* tie off to get just superior */
				/* name doesn't exist, create it */
	if ((stat (tmp1,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
	    !dummy_create_path (stream,tmp1,get_dir_protection (newname)))
	  return NIL;
	*s = c;			/* restore full name */
      }
      if (!rename (tmp,tmp1)) {
	close (fd);		/* close descriptor on metadata */
	return LONGT;
      }
    }

				/* RFC 3501 requires this */
    else if (dummy_create_path (stream,strcat (tmp1,"/"),
				get_dir_protection (newname))) {
      void *a;
      int i,n,lasterror;
      char *src,*dst;
      struct direct **names = NIL;
      size_t srcl = strlen (tmp);
      size_t dstl = strlen (tmp1);
				/* rename each mix file to new directory */
      for (i = lasterror = 0,n = scandir (tmp,&names,mix_rselect,alphasort);
	   i < n; ++i) {
	size_t len = strlen (names[i]->d_name);
	sprintf (src = (char *) fs_get (srcl + len + 2),"%s/%s",
		 tmp,names[i]->d_name);
	sprintf (dst = (char *) fs_get (dstl + len + 1),"%s%s",
		 tmp1,names[i]->d_name);
	if (rename (src,dst)) lasterror = errno;
	fs_give ((void **) &src);
	fs_give ((void **) &dst);
	fs_give ((void **) &names[i]);
      }
				/* free directory list */
      if (a = (void *) names) fs_give ((void **) &a);
      if (lasterror) errno = lasterror;
      else {
	close (fd);		/* close descriptor on metadata */
	return mix_create (NIL,"INBOX");
      }
    }
    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %.80s",
	     old,newname,strerror (errno));
  }
  if (fd >= 0) close (fd);	/* close any descriptor on metadata */
  MM_LOG (tmp,ERROR);		/* something failed */
  return NIL;
}


/* MIX test for mix name
 * Accepts: candidate directory name
 * Returns: T if mix file name, NIL otherwise
 */

int mix_rselect (struct direct *name)
{
  return mix_dirfmttest (name->d_name);
}

/* MIX mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *mix_open (MAILSTREAM *stream)
{
  short silent;
				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return user_flags (&mixproto);
  if (stream->local) fatal ("mix recycle stream");
  stream->local = memset (fs_get (sizeof (MIXLOCAL)),0,sizeof (MIXLOCAL));
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
				/* make temporary buffer */
  LOCAL->buf = (char *) fs_get (CHUNKSIZE);
  LOCAL->buflen = CHUNKSIZE - 1;
				/* set stream->mailbox to be directory name */
  mix_dir (LOCAL->buf,stream->mailbox);
  fs_give ((void **) &stream->mailbox);
  stream->mailbox = cpystr (LOCAL->buf);
  LOCAL->msgfd = -1;		/* currently no file open */
  if (!(((!stream->rdonly &&	/* open metadata file */
	  ((LOCAL->mfd = open (mix_file (LOCAL->buf,stream->mailbox,MIXMETA),
			       O_RDWR,NIL)) >= 0)) ||
	 ((stream->rdonly = T) &&
	  ((LOCAL->mfd = open (mix_file (LOCAL->buf,stream->mailbox,MIXMETA),
			       O_RDONLY,NIL)) >= 0))) &&
	!flock (LOCAL->mfd,LOCK_SH))) {
    MM_LOG ("Error opening mix metadata file",ERROR);
    mix_abort (stream);
    stream = NIL;		/* open fails */
  }
  else {			/* metadata open, complete open */
    LOCAL->index = cpystr (mix_file (LOCAL->buf,stream->mailbox,MIXINDEX));
    LOCAL->status = cpystr (mix_file (LOCAL->buf,stream->mailbox,MIXSTATUS));
    LOCAL->sortcache = cpystr (mix_file (LOCAL->buf,stream->mailbox,
					 MIXSORTCACHE));
    stream->sequence++;		/* bump sequence number */
				/* parse mailbox */
    stream->nmsgs = stream->recent = 0;
    if (silent = stream->silent) LOCAL->internal = T;
    stream->silent = T;
    if (mix_ping (stream)) {	/* do initial ping */
				/* try burping in case we are exclusive */
      if (!stream->rdonly) mix_expunge (stream,"",NIL);
      if (!(stream->nmsgs || stream->silent))
	MM_LOG ("Mailbox is empty",(long) NIL);
      stream->silent = silent;	/* now notify upper level */
      mail_exists (stream,stream->nmsgs);
      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 =	/* can we create new user flags? */
	(stream->user_flags[NUSERFLAGS-1] || stream->rdonly) ? NIL : T;
    }
    else {			/* got murdelyzed in ping */
      mix_abort (stream);
      stream = NIL;
    }
  }
  return stream;		/* return stream to caller */
}

/* MIX mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mix_close (MAILSTREAM *stream,long options)
{
  if (LOCAL) {			/* only if a file is open */
    int silent = stream->silent;
    stream->silent = T;		/* note this stream is dying */
				/* burp-only or expunge */
    mix_expunge (stream,(options & CL_EXPUNGE) ? NIL : "",NIL);
    mix_abort (stream);
    stream->silent = silent;	/* reset silent state */
  }
}


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

void mix_abort (MAILSTREAM *stream)
{
  if (LOCAL) {			/* only if a file is open */
				/* close current message file if open */
    if (LOCAL->msgfd >= 0) close (LOCAL->msgfd);
				/* close current metadata file if open */
    if (LOCAL->mfd >= 0) close (LOCAL->mfd);
    if (LOCAL->index) fs_give ((void **) &LOCAL->index);
    if (LOCAL->status) fs_give ((void **) &LOCAL->status);
    if (LOCAL->sortcache) fs_give ((void **) &LOCAL->sortcache);
				/* free local scratch 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 */
  }
}

/* MIX 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 *mix_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		  long flags)
{
  unsigned long i,j,k;
  int fd;
  char *s,tmp[MAILTMPLEN];
  MESSAGECACHE *elt;
  if (length) *length = 0;	/* default return */
  if (flags & FT_UID) return "";/* UID call "impossible" */
  elt = mail_elt (stream,msgno);/* get elt */
				/* is message in current message file? */
  if ((LOCAL->msgfd < 0) || (elt->private.spare.data != LOCAL->curmsg)) {
    if (LOCAL->msgfd >= 0) close (LOCAL->msgfd);
    if ((LOCAL->msgfd = open (mix_file_data (LOCAL->buf,stream->mailbox,
					     elt->private.spare.data),
					     O_RDONLY,NIL)) < 0) return "";
				/* got file */
    LOCAL->curmsg = elt->private.spare.data;
  }    
  lseek (LOCAL->msgfd,elt->private.special.offset,L_SET);
				/* size of special data and header */
  j = elt->private.msg.header.offset + elt->private.msg.header.text.size;
  if (j > LOCAL->buflen) {	/* is buffer big enough? */
				/* no, make one that is */
    fs_give ((void **) &LOCAL->buf);
    LOCAL->buf = (char *) fs_get ((LOCAL->buflen = j) + 1);
  }
  /* Maybe someday validate internaldate too */
				/* slurp special data + header, validate */
  if ((read (LOCAL->msgfd,LOCAL->buf,j) == j) &&
      !strncmp (LOCAL->buf,MSGTOK,MSGTSZ) &&
      (elt->private.uid == strtoul ((char *) LOCAL->buf + MSGTSZ,&s,16)) &&
      (*s++ == ':') && (s = strchr (s,':')) &&
      (k = strtoul (s+1,&s,16)) && (*s++ == ':') &&
      (s < (char *) (LOCAL->buf + elt->private.msg.header.offset))) {
				/* won, set offset and size of message */
    i = elt->private.msg.header.offset;
    *length = elt->private.msg.header.text.size;
    if (k != elt->rfc822_size) {
      sprintf (tmp,"Inconsistency in mix message size, uid=%lx (%lu != %lu)",
	       elt->private.uid,elt->rfc822_size,k);
      MM_LOG (tmp,WARN);
    }
  }
  else {			/* document the problem */
    LOCAL->buf[100] = '\0';	/* tie off buffer at no more than 100 octets */
				/* or at newline, whichever is first */
    if (s = strpbrk (LOCAL->buf,"\015\012")) *s = '\0';
    sprintf (tmp,"Error reading mix message header, uid=%lx, s=%.0lx, h=%s",
	     elt->private.uid,elt->rfc822_size,LOCAL->buf);
    MM_LOG (tmp,ERROR);
    *length = i = j = 0;	/* default to empty */
  }
  LOCAL->buf[j] = '\0';		/* tie off buffer at the end */