mmdf.c

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  if ((t = dummy_file (file,name)) && !stat (t,&sbuf)) {
    if (!sbuf.st_size)errno = 0;/* empty file */
    else if ((fd = open (file,O_RDONLY,NIL)) >= 0) {
				/* error -1 for invalid format */
      if (!(ret = mmdf_isvalid_fd (fd,tmp))) errno = -1;
      close (fd);		/* close the file */
				/* \Marked status? */
      if ((sbuf.st_ctime > sbuf.st_atime) || (sbuf.st_mtime > sbuf.st_atime)) {
	tp[0] = sbuf.st_atime;	/* preserve atime and mtime */
	tp[1] = sbuf.st_mtime;
	utime (file,tp);	/* set the times */
      }
    }
  }
  return ret;			/* return what we should */
}

/* MMDF mail test for valid mailbox
 * Accepts: file descriptor
 *	    scratch buffer
 * Returns: T if valid, NIL otherwise
 */

long mmdf_isvalid_fd (int fd,char *tmp)
{
  int ret = NIL;
  memset (tmp,'\0',MAILTMPLEN);
  if (read (fd,tmp,MAILTMPLEN-1) >= 0) ret = ISMMDF (tmp) ? T : NIL;
  return ret;			/* return what we should */
}


/* MMDF manipulate driver parameters
 * Accepts: function code
 *	    function-dependent value
 * Returns: function-dependent return value
 */

void *mmdf_parameters (long function,void *value)
{
  void *ret = NIL;
  switch ((int) function) {
  case GET_INBOXPATH:
    if (value) ret = dummy_file ((char *) value,"INBOX");
    break;
  }
  return ret;
}

/* MMDF mail scan mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 *	    string to scan
 */

void mmdf_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
{
  if (stream) dummy_scan (NIL,ref,pat,contents);
}


/* MMDF mail list mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void mmdf_list (MAILSTREAM *stream,char *ref,char *pat)
{
  if (stream) dummy_list (NIL,ref,pat);
}


/* MMDF mail list subscribed mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

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

long mmdf_create (MAILSTREAM *stream,char *mailbox)
{
  char *s,mbx[MAILTMPLEN],tmp[MAILTMPLEN];
  long ret = NIL;
  int i,fd;
  time_t ti = time (0);
  if (!(s = dummy_file (mbx,mailbox))) {
    sprintf (tmp,"Can't create %.80s: invalid name",mailbox);
    MM_LOG (tmp,ERROR);
  }
				/* create underlying file */
  else if (dummy_create_path (stream,s,get_dir_protection (mailbox))) {
				/* done if dir-only or whiner */
    if (((s = strrchr (s,'/')) && !s[1]) ||
	mail_parameters (NIL,GET_USERHASNOLIFE,NIL)) ret = T;
    else if ((fd = open (mbx,O_WRONLY,
		    (long) mail_parameters (NIL,GET_MBXPROTECTION,NIL))) < 0) {
      sprintf (tmp,"Can't reopen mailbox node %.80s: %s",mbx,strerror (errno));
      MM_LOG (tmp,ERROR);
      unlink (mbx);		/* delete the file */
    }
    else {			/* initialize header */
      memset (tmp,'\0',MAILTMPLEN);
      sprintf (tmp,"%sFrom %s %sDate: ",mmdfhdr,pseudo_from,ctime (&ti));
      rfc822_date (s = tmp + strlen (tmp));
      sprintf (s += strlen (s),	/* write the pseudo-header */
	       "\nFrom: %s <%s@%s>\nSubject: %s\nX-IMAP: %010lu 0000000000",
	       pseudo_name,pseudo_from,mylocalhost (),pseudo_subject,
	       (unsigned long) ti);
      for (i = 0; i < NUSERFLAGS; ++i) if (default_user_flag (i))
	sprintf (s += strlen (s)," %s",default_user_flag (i));
      sprintf (s += strlen (s),"\nStatus: RO\n\n%s\n%s",pseudo_msg,mmdfhdr);
      if (write (fd,tmp,strlen (tmp)) > 0) ret = T;
      else {
	sprintf (tmp,"Can't initialize mailbox node %.80s: %s",mbx,
		 strerror (errno));
	MM_LOG (tmp,ERROR);
	unlink (mbx);		/* delete the file */
      }
      close (fd);		/* close file */
    }
  }
				/* set proper protections */
  return ret ? set_mbx_protections (mailbox,mbx) : NIL;
}

/* MMDF mail delete mailbox
 * Accepts: MAIL stream
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long mmdf_delete (MAILSTREAM *stream,char *mailbox)
{
  return mmdf_rename (stream,mailbox,NIL);
}


/* MMDF mail rename mailbox
 * Accepts: MAIL stream
 *	    old mailbox name
 *	    new mailbox name (or NIL for delete)
 * Returns: T on success, NIL on failure
 */

long mmdf_rename (MAILSTREAM *stream,char *old,char *newname)
{
  long ret = NIL;
  char c,*s = NIL;
  char tmp[MAILTMPLEN],file[MAILTMPLEN],lock[MAILTMPLEN];
  DOTLOCK lockx;
  int fd,ld;
  long i;
  struct stat sbuf;
  MM_CRITICAL (stream);	/* get the c-client lock */
  if (!dummy_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);
				/* lock out other c-clients */
  else if ((ld = lockname (lock,file,LOCK_EX|LOCK_NB,&i)) < 0)
    sprintf (tmp,"Mailbox %.80s is in use by another process",old);

  else {
    if ((fd = mmdf_lock (file,O_RDWR,
			 (long) mail_parameters (NIL,GET_MBXPROTECTION,NIL),
			 &lockx,LOCK_EX)) < 0)
       sprintf (tmp,"Can't lock mailbox %.80s: %s",old,strerror (errno));
    else {
      if (newname) {		/* want rename? */
				/* found superior to destination name? */
	if (s = strrchr (s,'/')) {
	  c = *++s;		/* remember first character of inferior */
	  *s = '\0';		/* tie off to get just 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))) {
	    mmdf_unlock (fd,NIL,&lockx);
	    mmdf_unlock (ld,NIL,NIL);
	    unlink (lock);
	    MM_NOCRITICAL (stream);
	    return ret;		/* return success or failure */
	  }
	  *s = c;		/* restore full name */
	}
	if (rename (file,tmp))
	  sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %s",old,newname,
		   strerror (errno));
	else ret = T;		/* set success */
      }
      else if (unlink (file))
	sprintf (tmp,"Can't delete mailbox %.80s: %s",old,strerror (errno));
      else ret = T;		/* set success */
      mmdf_unlock (fd,NIL,&lockx);
    }
    mmdf_unlock (ld,NIL,NIL);	/* flush the lock */
    unlink (lock);
  }
  MM_NOCRITICAL (stream);	/* no longer critical */
  if (!ret) MM_LOG (tmp,ERROR);	/* log error */
  return ret;			/* return success or failure */
}

/* MMDF mail open
 * Accepts: Stream to open
 * Returns: Stream on success, NIL on failure
 */

MAILSTREAM *mmdf_open (MAILSTREAM *stream)
{
  long i;
  int fd;
  char tmp[MAILTMPLEN];
  DOTLOCK lock;
  long retry;
				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return user_flags (&mmdfproto);
  retry = stream->silent ? 1 : KODRETRY;
  if (stream->local) fatal ("mmdf recycle stream");
  stream->local = memset (fs_get (sizeof (MMDFLOCAL)),0,sizeof (MMDFLOCAL));
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
				/* canonicalize the stream mailbox name */
  if (!dummy_file (tmp,stream->mailbox)) {
    sprintf (tmp,"Can't open - invalid name: %.80s",stream->mailbox);
    MM_LOG (tmp,ERROR);
    return NIL;
  }
				/* flush old name */
  fs_give ((void **) &stream->mailbox);
				/* save canonical name */
  stream->mailbox = cpystr (tmp);
  LOCAL->fd = LOCAL->ld = -1;	/* no file or state locking yet */
  LOCAL->buf = (char *) fs_get (CHUNKSIZE);
  LOCAL->buflen = CHUNKSIZE - 1;
  LOCAL->text.data = (unsigned char *) fs_get (CHUNKSIZE);
  LOCAL->text.size = CHUNKSIZE - 1;
  LOCAL->linebuf = (char *) fs_get (CHUNKSIZE);
  LOCAL->linebuflen = CHUNKSIZE - 1;
  stream->sequence++;		/* bump sequence number */

				/* make lock for read/write access */
  if (!stream->rdonly) while (retry) {
				/* try to lock file */
    if ((fd = lockname (tmp,stream->mailbox,LOCK_EX|LOCK_NB,&i)) < 0) {
				/* suppressing kiss-of-death? */
      if (stream->nokod) retry = 0;
				/* no, first time through? */
      else if (retry-- == KODRETRY) {
				/* learned other guy's PID and can signal? */
	if (i && !kill ((int) i,SIGUSR2)) {
	  sprintf (tmp,"Trying to get mailbox lock from process %ld",i);
	  MM_LOG (tmp,WARN);
	}
	else retry = 0;		/* give up */
      }
      if (!stream->silent) {	/* nothing if silent stream */
	if (retry) sleep (1);	/* wait a second before trying again */
	else MM_LOG ("Mailbox is open by another process, access is readonly",
		     WARN);
      }
    }
    else {			/* got the lock, nobody else can alter state */
      LOCAL->ld = fd;		/* note lock's fd and name */
      LOCAL->lname = cpystr (tmp);
				/* make sure mode OK (don't use fchmod()) */
      chmod (LOCAL->lname,(long) mail_parameters (NIL,GET_LOCKPROTECTION,NIL));
      if (stream->silent) i = 0;/* silent streams won't accept KOD */
      else {			/* note our PID in the lock */
	sprintf (tmp,"%d",getpid ());
	write (fd,tmp,(i = strlen (tmp))+1);
      }
      ftruncate (fd,i);		/* make sure tied off */
      fsync (fd);		/* make sure it's available */
      retry = 0;		/* no more need to try */
    }
  }

				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
				/* will we be able to get write access? */
  if ((LOCAL->ld >= 0) && access (stream->mailbox,W_OK) && (errno == EACCES)) {
    MM_LOG ("Can't get write access to mailbox, access is readonly",WARN);
    flock (LOCAL->ld,LOCK_UN);	/* release the lock */
    close (LOCAL->ld);		/* close the lock file */
    LOCAL->ld = -1;		/* no more lock fd */
    unlink (LOCAL->lname);	/* delete it */
  }
				/* reset UID validity */
  stream->uid_validity = stream->uid_last = 0;
  if (stream->silent && !stream->rdonly && (LOCAL->ld < 0))
    mmdf_abort (stream);	/* abort if can't get RW silent stream */
				/* parse mailbox */
  else if (mmdf_parse (stream,&lock,LOCK_SH)) {
    mmdf_unlock (LOCAL->fd,stream,&lock);
    mail_unlock (stream);
    MM_NOCRITICAL (stream);	/* done with critical */
  }
  if (!LOCAL) return NIL;	/* failure if stream died */
				/* make sure upper level knows readonly */
  stream->rdonly = (LOCAL->ld < 0);
				/* notify about empty mailbox */
  if (!(stream->nmsgs || stream->silent)) MM_LOG ("Mailbox is empty",NIL);
  if (!stream->rdonly) {	/* flags stick if readwrite */
    stream->perm_seen = stream->perm_deleted =
      stream->perm_flagged = stream->perm_answered = stream->perm_draft = T;
    if (!stream->uid_nosticky) {/* users with lives get permanent keywords */
      stream->perm_user_flags = 0xffffffff;
				/* and maybe can create them too! */
      stream->kwd_create = stream->user_flags[NUSERFLAGS-1] ? NIL : T;
    }
  }
  return stream;		/* return stream alive to caller */
}


/* MMDF mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mmdf_close (MAILSTREAM *stream,long options)
{
  int silent = stream->silent;
  stream->silent = T;		/* go silent */
				/* expunge if requested */
  if (options & CL_EXPUNGE) mmdf_expunge (stream,NIL,NIL);
				/* else dump final checkpoint */
  else if (LOCAL->dirty) mmdf_check (stream);
  stream->silent = silent;	/* restore old silence state */
  mmdf_abort (stream);		/* now punt the file and local data */
}

/* MMDF mail fetch message header
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned header text length
 *	    option flags
 * Returns: message header in RFC822 format
 */

				/* lines to filter from header */
static STRINGLIST *mmdf_hlines = NIL;

char *mmdf_header (MAILSTREAM *stream,unsigned long msgno,
		   unsigned long *length,long flags)
{
  MESSAGECACHE *elt;
  unsigned char *s,*t,*tl;
  *length = 0;			/* default to empty */
  if (flags & FT_UID) return "";/* UID call "impossible" */
  elt = mail_elt (stream,msgno);/* get cache */
  if (!mmdf_hlines) {		/* once only code */
    STRINGLIST *lines = mmdf_hlines = mail_newstringlist ();
    lines->text.size = strlen ((char *) (lines->text.data =
					 (unsigned char *) "Status"));
    lines = lines->next = mail_newstringlist ();