mx.c

这是用C编写IMAP源代码


/* MX mail rename mailbox
 * Accepts: MX mail stream
 *	    old mailbox name
 *	    new mailbox name
 * Returns: T on success, NIL on failure
 */

long mx_rename (MAILSTREAM *stream,char *old,char *newname)
{
  char c,*s,tmp[MAILTMPLEN],tmp1[MAILTMPLEN];
  struct stat sbuf;
  if (!mx_isvalid (old,tmp))
    sprintf (tmp,"Can't rename mailbox %.80s: no such mailbox",old);
				/* new mailbox name must not be valid */
  else if (mx_isvalid (newname,tmp))
    sprintf (tmp,"Can't rename to mailbox %.80s: destination already exists",
	     newname);
				/* success if can rename the directory */
  else {			/* found superior to destination name? */
    if (s = strrchr (mx_file (tmp1,newname),'/')) {
      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 (mx_file (tmp,old),tmp1)) {
				/* recreate file if renamed INBOX */
      if (!compare_cstring (old,"INBOX")) mx_create (NIL,"INBOX");
      return T;
    }
    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %s",
	     old,newname,strerror (errno));
  }
  MM_LOG (tmp,ERROR);		/* something failed */
  return NIL;
}

/* MX mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *mx_open (MAILSTREAM *stream)
{
  char tmp[MAILTMPLEN];
				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return user_flags (&mxproto);
  if (stream->local) fatal ("mx recycle stream");
  stream->local = fs_get (sizeof (MXLOCAL));
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
  mx_file (tmp,stream->mailbox);/* get directory name */
  LOCAL->dir = cpystr (tmp);	/* copy directory name for later */
				/* make temporary buffer */
  LOCAL->buf = (char *) fs_get ((LOCAL->buflen = MAXMESSAGESIZE) + 1);
  LOCAL->scantime = 0;		/* not scanned yet */
  LOCAL->fd = -1;		/* no index yet */
  LOCAL->cachedtexts = 0;	/* no cached texts */
  stream->sequence++;		/* bump sequence number */
				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
  if (mx_ping (stream) && !(stream->nmsgs || stream->silent))
    MM_LOG ("Mailbox is empty",(long) NIL);
  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 */
}

/* MX mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mx_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 */
    if (options & CL_EXPUNGE) mx_expunge (stream);
    if (LOCAL->dir) fs_give ((void **) &LOCAL->dir);
				/* 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 */
    stream->silent = silent;	/* reset silent state */
  }
}

/* MX mail fetch fast information
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 */

void mx_fast (MAILSTREAM *stream,char *sequence,long flags)
{
  unsigned long i;
  MESSAGECACHE *elt;
  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) mx_fast_work (stream,elt);
}


/* MX mail fetch fast information
 * Accepts: MAIL stream
 *	    message cache element
 * Returns: name of message file
 */

char *mx_fast_work (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  struct stat sbuf;
  struct tm *tm;
				/* build message file name */
  sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);
  if (!elt->rfc822_size) {	/* have size yet? */
    stat (LOCAL->buf,&sbuf);	/* get size of message */
				/* make plausible IMAPish date string */
    tm = gmtime (&sbuf.st_mtime);
    elt->day = tm->tm_mday; elt->month = tm->tm_mon + 1;
    elt->year = tm->tm_year + 1900 - BASEYEAR;
    elt->hours = tm->tm_hour; elt->minutes = tm->tm_min;
    elt->seconds = tm->tm_sec;
    elt->zhours = 0; elt->zminutes = 0; elt->zoccident = 0;
    elt->rfc822_size = sbuf.st_size;
  }
  return LOCAL->buf;		/* return file name */
}

/* MX 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 *mx_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		 long flags)
{
  unsigned long i;
  int fd;
  MESSAGECACHE *elt;
  *length = 0;			/* default to empty */
  if (flags & FT_UID) return "";/* UID call "impossible" */
  elt = mail_elt (stream,msgno);/* get elt */
  if (!elt->private.msg.header.text.data) {
				/* purge cache if too big */
    if (LOCAL->cachedtexts > max (stream->nmsgs * 4096,2097152)) {
      mail_gc (stream,GC_TEXTS);/* just can't keep that much */
      LOCAL->cachedtexts = 0;
    }
    if ((fd = open (mx_fast_work (stream,elt),O_RDONLY,NIL)) < 0) return "";
				/* is buffer big enough? */
    if (elt->rfc822_size > LOCAL->buflen) {
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get ((LOCAL->buflen = elt->rfc822_size) + 1);
    }
				/* slurp message */
    read (fd,LOCAL->buf,elt->rfc822_size);
				/* tie off file */
    LOCAL->buf[elt->rfc822_size] = '\0';
    close (fd);			/* flush message file */
				/* find end of header */
    if (elt->rfc822_size < 4) i = 0;
    else for (i = 4; (i < elt->rfc822_size) &&
	      !((LOCAL->buf[i - 4] == '\015') &&
		(LOCAL->buf[i - 3] == '\012') &&
		(LOCAL->buf[i - 2] == '\015') &&
		(LOCAL->buf[i - 1] == '\012')); i++);
				/* copy header */
    cpytxt (&elt->private.msg.header.text,LOCAL->buf,i);
    cpytxt (&elt->private.msg.text.text,LOCAL->buf+i,elt->rfc822_size - i);
				/* add to cached size */
    LOCAL->cachedtexts += elt->rfc822_size;
  }
  *length = elt->private.msg.header.text.size;
  return (char *) elt->private.msg.header.text.data;
}

/* MX mail fetch message text (body only)
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned stringstruct
 *	    option flags
 * Returns: T on success, NIL on failure
 */

long mx_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags)
{
  unsigned long i;
  MESSAGECACHE *elt;
				/* UID call "impossible" */
  if (flags & FT_UID) return NIL;
  elt = mail_elt (stream,msgno);
				/* snarf message if don't have it yet */
  if (!elt->private.msg.text.text.data) {
    mx_header (stream,msgno,&i,flags);
    if (!elt->private.msg.text.text.data) return NIL;
  }
				/* mark as seen */
  if (!(flags & FT_PEEK) && mx_lockindex (stream)) {
    elt->seen = T;
    mx_unlockindex (stream);
    MM_FLAGS (stream,msgno);
  }
  INIT (bs,mail_string,elt->private.msg.text.text.data,
	elt->private.msg.text.text.size);
  return T;
}

/* MX mail modify flags
 * Accepts: MAIL stream
 *	    sequence
 *	    flag(s)
 *	    option flags
 */

void mx_flag (MAILSTREAM *stream,char *sequence,char *flag,long flags)
{
  mx_unlockindex (stream);	/* finished with index */
}


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

void mx_flagmsg (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  mx_lockindex (stream);	/* lock index if not already locked */
}

/* MX mail ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream alive, else NIL
 */

long mx_ping (MAILSTREAM *stream)
{
  MAILSTREAM *sysibx = NIL;
  MESSAGECACHE *elt,*selt;
  struct stat sbuf;
  char *s,tmp[MAILTMPLEN];
  int fd;
  unsigned long i,j,r,old;
  long nmsgs = stream->nmsgs;
  long recent = stream->recent;
  int silent = stream->silent;
  if (stat (LOCAL->dir,&sbuf)) return NIL;
  stream->silent = T;		/* don't pass up mm_exists() events yet */
  if (sbuf.st_ctime != LOCAL->scantime) {
    struct direct **names = NIL;
    long nfiles = scandir (LOCAL->dir,&names,mx_select,mx_numsort);
    if (nfiles < 0) nfiles = 0;	/* in case error */
    old = stream->uid_last;
				/* note scanned now */
    LOCAL->scantime = sbuf.st_ctime;
				/* scan directory */
    for (i = 0; i < nfiles; ++i) {
				/* if newly seen, add to list */
      if ((j = atoi (names[i]->d_name)) > old) {
				/* swell the cache */
	mail_exists (stream,++nmsgs);
	stream->uid_last = (elt = mail_elt (stream,nmsgs))->private.uid = j;
	elt->valid = T;		/* note valid flags */
	if (old) {		/* other than the first pass? */
	  elt->recent = T;	/* yup, mark as recent */
	  recent++;		/* bump recent count */
	}
      }
      fs_give ((void **) &names[i]);
    }
				/* free directory */
    if (s = (void *) names) fs_give ((void **) &s);
  }
  stream->nmsgs = nmsgs;	/* don't upset mail_uid() */

				/* if INBOX, snarf from system INBOX  */
  if (mx_lockindex (stream) && stream->inbox) {
    old = stream->uid_last;
				/* paranoia check */
    if (!strcmp (sysinbox (),stream->mailbox)) {
      stream->silent = silent;
      return NIL;
    }
    MM_CRITICAL (stream);	/* go critical */
    stat (sysinbox (),&sbuf);	/* see if anything there */
				/* can get sysinbox mailbox? */
    if (sbuf.st_size && (sysibx = mail_open (sysibx,sysinbox (),OP_SILENT))
	&& (!sysibx->rdonly) && (r = sysibx->nmsgs)) {
      for (i = 1; i <= r; ++i) {/* for each message in sysinbox mailbox */
				/* build file name we will use */
	sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,++old);
				/* snarf message from Berkeley mailbox */
	selt = mail_elt (sysibx,i);
	if (((fd = open (LOCAL->buf,O_WRONLY|O_CREAT|O_EXCL,
			 S_IREAD|S_IWRITE)) >= 0) &&
	    (s = mail_fetchheader_full (sysibx,i,NIL,&j,FT_PEEK)) &&
	    (write (fd,s,j) == j) &&
	    (s = mail_fetchtext_full (sysibx,i,&j,FT_PEEK)) &&
	    (write (fd,s,j) == j) && !fsync (fd) && !close (fd)) {
				/* swell the cache */
	  mail_exists (stream,++nmsgs);
	  stream->uid_last =	/* create new elt, note its file number */
	    (elt = mail_elt (stream,nmsgs))->private.uid = old;
	  recent++;		/* bump recent count */
				/* set up initial flags and date */
	  elt->valid = elt->recent = T;
	  elt->seen = selt->seen;
	  elt->deleted = selt->deleted;
	  elt->flagged = selt->flagged;
	  elt->answered = selt->answered;
	  elt->draft = selt->draft;
	  elt->day = selt->day;elt->month = selt->month;elt->year = selt->year;
	  elt->hours = selt->hours;elt->minutes = selt->minutes;
	  elt->seconds = selt->seconds;
	  elt->zhours = selt->zhours; elt->zminutes = selt->zminutes;
	  elt->zoccident = selt->zoccident;
	  mx_setdate (LOCAL->buf,elt);
	}
	else {			/* failed to snarf */
	  if (fd) {		/* did it ever get opened? */
	    close (fd);		/* close descriptor */
	    unlink (LOCAL->buf);/* flush this file */
	  }
	  stream->silent = silent;
	  return NIL;		/* note that something is badly wrong */
	}
	sprintf (tmp,"%lu",i);	/* delete it from the sysinbox */
	mail_flag (sysibx,tmp,"\\Deleted",ST_SET);
      }
      stat (LOCAL->dir,&sbuf);	/* update scan time */
      LOCAL->scantime = sbuf.st_ctime;      
      mail_expunge (sysibx);	/* now expunge all those messages */
    }
    if (sysibx) mail_close (sysibx);
    MM_NOCRITICAL (stream);	/* release critical */
  }
  mx_unlockindex (stream);	/* done with index */
  stream->silent = silent;	/* can pass up events now */
  mail_exists (stream,nmsgs);	/* notify upper level of mailbox size */
  mail_recent (stream,recent);
  return T;			/* return that we are alive */
}

/* MX mail check mailbox
 * Accepts: MAIL stream
 */

void mx_check (MAILSTREAM *stream)
{
  if (mx_ping (stream)) MM_LOG ("Check completed",(long) NIL);
}


/* MX mail expunge mailbox
 * Accepts: MAIL stream
 */

void mx_expunge (MAILSTREAM *stream)
{
  MESSAGECACHE *elt;
  unsigned long i = 1;
  unsigned long n = 0;
  unsigned long recent = stream->recent;
  if (mx_lockindex (stream)) {	/* lock the index */
    MM_CRITICAL (stream);	/* go critical */
    while (i <= stream->nmsgs) {/* for each message */