mh.c

这是用C编写IMAP源代码

/* MH mail unsubscribe to mailbox
 * Accepts: mail stream
 *	    mailbox to delete from subscription list
 * Returns: T on success, NIL on failure
 */

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

long mh_create (MAILSTREAM *stream,char *mailbox)
{
  char *s,tmp[MAILTMPLEN];
				/* assume error */
  sprintf (tmp,"Can't create mailbox %.80s: invalid MH-format name",mailbox);
  if (mailbox[0] == '#' && (mailbox[1] == 'm' || mailbox[1] == 'M') &&
      (mailbox[2] == 'h' || mailbox[2] == 'H') && mailbox[3] == '/')
				/* make sure valid name */
    for (s = mailbox + 4; s && *s;) {
      if (isdigit (*s)) s++;	/* digit, check this node further... */
				/* all digit node, barf */
      else if (*s == '/') s = NIL;
				/* non-digit in node, skip to next node */
      else if (s = strchr (s+1,'/')) s++;
      else tmp[0] = NIL;	/* no more nodes, good name */
    }
  if (tmp[0]) {			/* was there an error in the name? */
    mm_log (tmp,ERROR);		/* yes, log it */
    return NIL;
  }
				/* must not already exist */
  if (mh_isvalid (mailbox,tmp,NIL)) {
    sprintf (tmp,"Can't create mailbox %.80s: mailbox already exists",mailbox);
    mm_log (tmp,ERROR);
    return NIL;
  }
  if (!mh_path) return NIL;	/* sorry */
  if (!(mh_file (tmp,mailbox) &&/* try to make it */
	dummy_create_path (stream,strcat (tmp,"/"),
			   get_dir_protection (mailbox)))) {
    sprintf (tmp,"Can't create mailbox %.80s: %s",mailbox,strerror (errno));
    mm_log (tmp,ERROR);
    return NIL;
  }
  return T;			/* return success */
}

/* MH mail delete mailbox
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long mh_delete (MAILSTREAM *stream,char *mailbox)
{
  DIR *dirp;
  struct direct *d;
  int i;
  char tmp[MAILTMPLEN];
  if (!(mailbox[0] == '#' && (mailbox[1] == 'm' || mailbox[1] == 'M') &&
	(mailbox[2] == 'h' || mailbox[2] == 'H') && mailbox[3] == '/')) {
    sprintf (tmp,"Can't delete mailbox %.80s: invalid MH-format name",mailbox);
    mm_log (tmp,ERROR);
    return NIL;
  }
				/* is mailbox valid? */
  if (!mh_isvalid (mailbox,tmp,NIL)){
    sprintf (tmp,"Can't delete mailbox %.80s: no such mailbox",mailbox);
    mm_log (tmp,ERROR);
    return NIL;
  }
				/* get name of directory */
  i = strlen (mh_file (tmp,mailbox));
  if (dirp = opendir (tmp)) {	/* open directory */
    tmp[i++] = '/';		/* now apply trailing delimiter */
    while (d = readdir (dirp))	/* massacre all numeric or comma files */
      if (mh_select (d) || (*d->d_name == ',') ||
	  !strcmp (d->d_name,MHSEQUENCE)) {
	strcpy (tmp + i,d->d_name);
	unlink (tmp);		/* sayonara */
      }
    closedir (dirp);		/* flush directory */
  }
				/* try to remove the directory */
  if (rmdir (mh_file (tmp,mailbox))) {
    sprintf (tmp,"Can't delete mailbox %.80s: %s",mailbox,strerror (errno));
    mm_log (tmp,WARN);
  }
  return T;			/* return success */
}

/* MH mail rename mailbox
 * Accepts: MH mail stream
 *	    old mailbox name
 *	    new mailbox name
 * Returns: T on success, NIL on failure
 */

long mh_rename (MAILSTREAM *stream,char *old,char *newname)
{
  char c,*s,tmp[MAILTMPLEN],tmp1[MAILTMPLEN];
  struct stat sbuf;
  if (!(old[0] == '#' && (old[1] == 'm' || old[1] == 'M') &&
	(old[2] == 'h' || old[2] == 'H') && old[3] == '/'))
    sprintf (tmp,"Can't delete mailbox %.80s: invalid MH-format name",old);
				/* old mailbox name must be valid */
  else if (!mh_isvalid (old,tmp,NIL))
    sprintf (tmp,"Can't rename mailbox %.80s: no such mailbox",old);
  else if (!(newname[0] == '#' && (newname[1] == 'm' || newname[1] == 'M') &&
	(newname[2] == 'h' || newname[2] == 'H') && newname[3] == '/'))
    sprintf (tmp,"Can't rename to mailbox %.80s: invalid MH-format name",
	     newname);
				/* new mailbox name must not be valid */
  else if (mh_isvalid (newname,tmp,NIL))
    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 (mh_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 (mh_file (tmp,old),tmp1)) return T;
    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %s",
	     old,newname,strerror (errno));
  }
  mm_log (tmp,ERROR);		/* something failed */
  return NIL;
}

/* MH mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *mh_open (MAILSTREAM *stream)
{
  char tmp[MAILTMPLEN];
  if (!stream) return &mhproto;	/* return prototype for OP_PROTOTYPE call */
  if (stream->local) fatal ("mh recycle stream");
  stream->local = fs_get (sizeof (MHLOCAL));
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"#MHINBOX");
  mh_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->cachedtexts = 0;	/* no cached texts */
  stream->sequence++;		/* bump sequence number */
				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
  if (!mh_ping (stream)) return NIL;
  if (!(stream->nmsgs || stream->silent))
    mm_log ("Mailbox is empty",(long) NIL);
  return stream;		/* return stream to caller */
}

/* MH mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mh_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) mh_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 */
  }
}


/* MH mail fetch fast information
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 */

void mh_fast (MAILSTREAM *stream,char *sequence,long flags)
{
  unsigned long i,j;
				/* ugly and slow */
  if (stream && LOCAL && ((flags & FT_UID) ?
			  mail_uid_sequence (stream,sequence) :
			  mail_sequence (stream,sequence)))
    for (i = 1; i <= stream->nmsgs; i++)
      if (mail_elt (stream,i)->sequence) mh_header (stream,i,&j,NIL);
}

/* MH 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 *mh_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		 long flags)
{
  unsigned long i,hdrsize;
  int fd;
  unsigned char *t;
  struct stat sbuf;
  struct tm *tm;
  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;
    }
				/* build message file name */
    sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);
    if ((fd = open (LOCAL->buf,O_RDONLY,NIL)) < 0) return "";
    fstat (fd,&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;
				/* is buffer big enough? */
    if (sbuf.st_size > LOCAL->buflen) {
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get ((LOCAL->buflen = sbuf.st_size) + 1);
    }
				/* slurp message */
    read (fd,LOCAL->buf,sbuf.st_size);
				/* tie off file */
    LOCAL->buf[sbuf.st_size] = '\0';
    close (fd);			/* flush message file */
				/* find end of header */
    for (i = 0,t = LOCAL->buf; *t && !(i && (*t == '\n')); i = (*t++ == '\n'));
				/* number of header bytes */
    hdrsize = (*t ? ++t : t) - LOCAL->buf;
    elt->rfc822_size =		/* size of entire message in CRLF form */
      (elt->private.msg.header.text.size =
       strcrlfcpy (&elt->private.msg.header.text.data,&i,LOCAL->buf,
		   hdrsize)) +
	 (elt->private.msg.text.text.size =
	  strcrlfcpy (&elt->private.msg.text.text.data,&i,t,
		      sbuf.st_size - hdrsize));
				/* add to cached size */
    LOCAL->cachedtexts += elt->rfc822_size;
  }
  *length = elt->private.msg.header.text.size;
  return (char *) elt->private.msg.header.text.data;
}

/* MH 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 mh_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);/* get elt */
				/* snarf message if don't have it yet */
  if (!elt->private.msg.text.text.data) {
    mh_header (stream,msgno,&i,flags);
    if (!elt->private.msg.text.text.data) return NIL;
  }
  if (!(flags & FT_PEEK)) {	/* mark as seen */
    mail_elt (stream,msgno)->seen = T;
    mm_flags (stream,msgno);
  }
  if (!elt->private.msg.text.text.data) return NIL;
  INIT (bs,mail_string,elt->private.msg.text.text.data,
	elt->private.msg.text.text.size);
  return T;
}

/* MH mail ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream alive, else NIL
 */

long mh_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)) { /* directory exists? */
    if (stream->inbox) return T;
    sprintf (tmp,"Can't open mailbox %.80s: no such mailbox",stream->mailbox);
    mm_log (tmp,ERROR);
    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,mh_select,mh_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) {
	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 */
	}
	else {			/* see if already read */
	  sprintf (tmp,"%s/%s",LOCAL->dir,names[i]->d_name);
	  stat (tmp,&sbuf);	/* get inode poop */
	  if (sbuf.st_atime > sbuf.st_mtime) elt->seen = T;
	}
      }
      fs_give ((void **) &names[i]);
    }
				/* free directory */
    if (s = (void *) names) fs_give ((void **) &s);
  }

				/* if INBOX, snarf from system INBOX  */
  if (stream->inbox && strcmp (sysinbox (),stream->mailbox)) {
    old = stream->uid_last;