dummy.c

这是用C编写IMAP源代码

  unsigned long csiz;
  struct stat sbuf;
  char *s,tmp[MAILTMPLEN];
				/* don't \NoSelect dir if it has a driver */
  if ((attributes & LATT_NOSELECT) && (d = mail_valid (NIL,name,NIL)) &&
      (d != &dummydriver)) attributes &= ~LATT_NOSELECT;
  if (!contents ||		/* notify main program */
      (!(attributes & LATT_NOSELECT) && (csiz = strlen (contents)) &&
       (s = mailboxfile (tmp,name)) &&
       (*s || (s = mail_parameters (NIL,GET_INBOXPATH,tmp))) &&
       !stat (s,&sbuf) && (csiz <= sbuf.st_size) &&
       SAFE_SCAN_CONTENTS (d,tmp,contents,csiz,sbuf.st_size)))
    mm_list (stream,delimiter,name,attributes);
  return T;
}

/* Dummy create mailbox
 * Accepts: mail stream
 *	    mailbox name to create
 * Returns: T on success, NIL on failure
 */

long dummy_create (MAILSTREAM *stream,char *mailbox)
{
  char *s,tmp[MAILTMPLEN];
  long ret = NIL;
				/* validate name */
  if (!(compare_cstring (mailbox,"INBOX") && (s = dummy_file (tmp,mailbox)))) {
    sprintf (tmp,"Can't create %.80s: invalid name",mailbox);
    MM_LOG (tmp,ERROR);
  }
				/* create the name, done if made directory */
  else if ((ret = dummy_create_path (stream,tmp,get_dir_protection(mailbox)))&&
	   (s = strrchr (s,'/')) && !s[1]) return T;
  return ret ? set_mbx_protections (mailbox,tmp) : NIL;
}

/* Dummy create path
 * Accepts: mail stream
 *	    path name to create
 *	    directory mode
 * Returns: T on success, NIL on failure
 */

long dummy_create_path (MAILSTREAM *stream,char *path,long dirmode)
{
  struct stat sbuf;
  char c,*s,tmp[MAILTMPLEN];
  int fd;
  long ret = NIL;
  char *t = strrchr (path,'/');
  int wantdir = t && !t[1];
  int mask = umask (0);
  if (wantdir) *t = '\0';	/* flush trailing delimiter for directory */
  if (s = strrchr (path,'/')) {	/* found superior to this name? */
    c = *++s;			/* remember first character of inferior */
    *s = '\0';			/* tie off to get just superior */
				/* name doesn't exist, create it */
    if ((stat (path,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
	!dummy_create_path (stream,path,dirmode)) {
      umask (mask);		/* restore mask */
      return NIL;
    }
    *s = c;			/* restore full name */
  }
  if (wantdir) {		/* want to create directory? */
    ret = !mkdir (path,(int) dirmode);
    *t = '/';			/* restore directory delimiter */
  }
				/* create file */
  else if ((fd = open (path,O_WRONLY|O_CREAT|O_EXCL,
		       (int) mail_parameters(NIL,GET_MBXPROTECTION,NIL))) >= 0)
    ret = !close (fd);
  if (!ret) {			/* error? */
    sprintf (tmp,"Can't create mailbox node %.80s: %.80s",path,strerror (errno));
    MM_LOG (tmp,ERROR);
  }
  umask (mask);			/* restore mask */
  return ret;			/* return status */
}

/* Dummy delete mailbox
 * Accepts: mail stream
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long dummy_delete (MAILSTREAM *stream,char *mailbox)
{
  struct stat sbuf;
  char *s,tmp[MAILTMPLEN];
  if (!(s = dummy_file (tmp,mailbox))) {
    sprintf (tmp,"Can't delete - invalid name: %.80s",s);
    MM_LOG (tmp,ERROR);
  }
				/* no trailing / (workaround BSD kernel bug) */
  if ((s = strrchr (tmp,'/')) && !s[1]) *s = '\0';
  if (stat (tmp,&sbuf) || ((sbuf.st_mode & S_IFMT) == S_IFDIR) ?
      rmdir (tmp) : unlink (tmp)) {
    sprintf (tmp,"Can't delete mailbox %.80s: %.80s",mailbox,strerror (errno));
    MM_LOG (tmp,ERROR);
    return NIL;
  }
  return T;			/* return success */
}

/* Mail rename mailbox
 * Accepts: mail stream
 *	    old mailbox name
 *	    new mailbox name
 * Returns: T on success, NIL on failure
 */

long dummy_rename (MAILSTREAM *stream,char *old,char *newname)
{
  struct stat sbuf;
  char c,*s,tmp[MAILTMPLEN],mbx[MAILTMPLEN],oldname[MAILTMPLEN];
				/* no trailing / allowed */
  if (!dummy_file (oldname,old) || !(s = dummy_file (mbx,newname)) ||
      ((s = strrchr (s,'/')) && !s[1])) {
    sprintf (mbx,"Can't rename %.80s to %.80s: invalid name",old,newname);
    MM_LOG (mbx,ERROR);
    return NIL;
  }
  if (s) {			/* found superior to destination name? */
    c = *++s;			/* remember first character of inferior */
    *s = '\0';			/* tie off to get just superior */
				/* name doesn't exist, create it */
    if ((stat (mbx,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
	!dummy_create (stream,mbx)) return NIL;
    *s = c;			/* restore full name */
  }
				/* rename of non-ex INBOX creates dest */
  if (!compare_cstring (old,"INBOX") && stat (oldname,&sbuf))
    return dummy_create (NIL,mbx);
  if (rename (oldname,mbx)) {
    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %.80s",old,newname,
	     strerror (errno));
    MM_LOG (tmp,ERROR);
    return NIL;
  }
  return T;			/* return success */
}

/* Dummy open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *dummy_open (MAILSTREAM *stream)
{
  int fd;
  char err[MAILTMPLEN],tmp[MAILTMPLEN];
  struct stat sbuf;
				/* OP_PROTOTYPE call */
  if (!stream) return &dummyproto;
  err[0] = '\0';		/* no error message yet */
				/* can we open the file? */
  if (!dummy_file (tmp,stream->mailbox))
    sprintf (err,"Can't open this name: %.80s",stream->mailbox);
  else if ((fd = open (tmp,O_RDONLY,NIL)) < 0) {
				/* no, error unless INBOX */
    if (compare_cstring (stream->mailbox,"INBOX"))
      sprintf (err,"%.80s: %.80s",strerror (errno),stream->mailbox);
  }
  else {			/* file had better be empty then */
    fstat (fd,&sbuf);		/* sniff at its size */
    close (fd);
    if ((sbuf.st_mode & S_IFMT) != S_IFREG)
      sprintf (err,"Can't open %.80s: not a selectable mailbox",
	       stream->mailbox);
    else if (sbuf.st_size)	/* bogus format if non-empty */
      sprintf (err,"Can't open %.80s (file %.80s): not in valid mailbox format",
	       stream->mailbox,tmp);
  }
  if (err[0]) {			/* if an error happened */
    MM_LOG (err,stream->silent ? WARN : ERROR);
    return NIL;
  }
  else if (!stream->silent) {	/* only if silence not requested */
    mail_exists (stream,0);	/* say there are 0 messages */
    mail_recent (stream,0);	/* and certainly no recent ones! */
    stream->uid_validity = time (0);
  }
  stream->inbox = T;		/* note that it's an INBOX */
  return stream;		/* return success */
}


/* Dummy close
 * Accepts: MAIL stream
 *	    options
 */

void dummy_close (MAILSTREAM *stream,long options)
{
				/* return silently */
}

/* Dummy ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream alive, else NIL
 */

long dummy_ping (MAILSTREAM *stream)
{
  MAILSTREAM *test;
  if (time (0) >=		/* time to do another test? */
      ((time_t) (stream->gensym +
		 (long) mail_parameters (NIL,GET_SNARFINTERVAL,NIL)))) {
				/* has mailbox format changed? */
    if ((test = mail_open (NIL,stream->mailbox,OP_PROTOTYPE)) &&
	(test->dtb != stream->dtb) &&
	(test = mail_open (NIL,stream->mailbox,NIL))) {
				/* preserve some resources */
      test->original_mailbox = stream->original_mailbox;
      stream->original_mailbox = NIL;
      test->sparep = stream->sparep;
      stream->sparep = NIL;
      test->sequence = stream->sequence;
      mail_close ((MAILSTREAM *) /* flush resources used by dummy stream */
		  memcpy (fs_get (sizeof (MAILSTREAM)),stream,
			  sizeof (MAILSTREAM)));
				/* swap the streams */
      memcpy (stream,test,sizeof (MAILSTREAM));
      fs_give ((void **) &test);/* flush test now that copied */
				/* make sure application knows */
      mail_exists (stream,stream->recent = stream->nmsgs);
    }
				/* still hasn't changed */
    else stream->gensym = time (0);
  }
  return T;
}


/* Dummy check mailbox
 * Accepts: MAIL stream
 * No-op for readonly files, since read/writer can expunge it from under us!
 */

void dummy_check (MAILSTREAM *stream)
{
  dummy_ping (stream);		/* invoke ping */
}


/* Dummy expunge mailbox
 * Accepts: MAIL stream
 */

void dummy_expunge (MAILSTREAM *stream)
{
				/* return silently */
}

/* Dummy copy message(s)
 * Accepts: MAIL stream
 *	    sequence
 *	    destination mailbox
 *	    options
 * Returns: T if copy successful, else NIL
 */

long dummy_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
{
  if ((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
      mail_sequence (stream,sequence)) fatal ("Impossible dummy_copy");
  return NIL;
}


/* Dummy append message string
 * Accepts: mail stream
 *	    destination mailbox
 *	    append callback function
 *	    data for callback
 * Returns: T on success, NIL on failure
 */

long dummy_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data)
{
  struct stat sbuf;
  int fd = -1;
  int e;
  char tmp[MAILTMPLEN];
  MAILSTREAM *ts = default_proto (T);
  if (compare_cstring (mailbox,"INBOX") && dummy_file (tmp,mailbox) &&
      ((fd = open (tmp,O_RDONLY,NIL)) < 0)) {
    if ((e = errno) == ENOENT)	/* failed, was it no such file? */
      MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before append",NIL);
    sprintf (tmp,"%.80s: %.80s",strerror (e),mailbox);
    MM_LOG (tmp,ERROR);		/* pass up error */
    return NIL;			/* always fails */
  }
  if (fd >= 0) {		/* found file? */
    fstat (fd,&sbuf);		/* get its size */
    close (fd);			/* toss out the fd */
    if (sbuf.st_size) ts = NIL;	/* non-empty file? */
  }
  if (ts) return (*ts->dtb->append) (stream,mailbox,af,data);
  sprintf (tmp,"Indeterminate mailbox format: %.80s",mailbox);
  MM_LOG (tmp,ERROR);
  return NIL;
}

/* Dummy mail generate file string
 * Accepts: temporary buffer to write into
 *	    mailbox name string
 * Returns: local file string or NIL if failure
 */

char *dummy_file (char *dst,char *name)
{
  char *s = mailboxfile (dst,name);
				/* return our standard inbox */
  return (s && !*s) ? strcpy (dst,sysinbox ()) : s;
}


/* Dummy canonicalize name
 * Accepts: buffer to write name
 *	    reference
 *	    pattern
 * Returns: T if success, NIL if failure
 */

long dummy_canonicalize (char *tmp,char *ref,char *pat)
{
  if (ref) {			/* preliminary reference check */
    if (*ref == '{') return NIL;/* remote reference not allowed */
    else if (!*ref) ref = NIL;	/* treat empty reference as no reference */
  }
  switch (*pat) {
  case '#':			/* namespace name */
    if (mailboxfile (tmp,pat)) strcpy (tmp,pat);
    else return NIL;		/* unknown namespace */
    break;
  case '{':			/* remote names not allowed */
    return NIL;
  case '/':			/* rooted name */
  case '~':			/* home directory name */
    if (!ref || (*ref != '#')) {/* non-namespace reference? */
      strcpy (tmp,pat);		/* yes, ignore */
      break;
    }
				/* fall through */
  default:			/* apply reference for all other names */
    if (!ref) strcpy (tmp,pat);	/* just copy if no namespace */
    else if ((*ref != '#') || mailboxfile (tmp,ref)) {
				/* wants root of name? */
      if (*pat == '/') strcpy (strchr (strcpy (tmp,ref),'/'),pat);
				/* otherwise just append */
      else sprintf (tmp,"%s%s",ref,pat);
    }
    else return NIL;		/* unknown namespace */
  }
  return T;
}