mail.c

广泛使用的邮件服务器！同时

    else {			/* can save memory doing it this way */
      hdr = (*stream->dtb->header) (stream,msgno,&hdrsize,flags | FT_INTERNAL);
      if (hdrsize) {		/* in case null header */
	c = hdr[hdrsize];	/* preserve what's there */
	hdr[hdrsize] = '\0';	/* tie off header */
	rfc822_parse_msg (env,NIL,hdr,hdrsize,NIL,BADHOST,stream->dtb->flags);
	hdr[hdrsize] = c;	/* restore in case cached data */
      }
      else *env = mail_newenvelope ();
    }
  }
				/* if need date, have date in envelope? */
  if (!elt->day && *env && (*env)->date) mail_parse_date (elt,(*env)->date);
				/* sigh, fill in bogus default */
  if (!elt->day) elt->day = elt->month = 1;
  if (body) *body = *b;		/* return the body */
  return *env;			/* return the envelope */
}

/* Mail mark single message (internal use only)
 * Accepts: mail stream
 *	    elt to mark
 *	    fetch flags
 */

static void markseen (MAILSTREAM *stream,MESSAGECACHE *elt,long flags)
{
  unsigned long i;
  char sequence[20];
  MESSAGECACHE *e;
				/* non-peeking and needs to set \Seen? */
  if (!(flags & FT_PEEK) && !elt->seen) {
    if (stream->dtb->flagmsg){	/* driver wants per-message call? */
      elt->valid = NIL;		/* do pre-alteration driver call */
      (*stream->dtb->flagmsg) (stream,elt);
				/* set seen, do post-alteration driver call */
      elt->seen = elt->valid = T;
      (*stream->dtb->flagmsg) (stream,elt);
    }
    if (stream->dtb->flag) {	/* driver wants one-time call?  */
				/* better safe than sorry, save seq bits */
      for (i = 1; i <= stream->nmsgs; i++) {
	e = mail_elt (stream,i);
	e->private.sequence = e->sequence;
      }
				/* call driver to set the message */
      sprintf (sequence,"%lu",elt->msgno);
      (*stream->dtb->flag) (stream,sequence,"\\Seen",ST_SET);
				/* restore sequence bits */
      for (i = 1; i <= stream->nmsgs; i++) {
	e = mail_elt (stream,i);
	e->sequence = e->private.sequence;
      }
    }
				/* notify mail program of flag change */
    MM_FLAGS (stream,elt->msgno);
  }
}

/* Mail fetch message
 * Accepts: mail stream
 *	    message # to fetch
 *	    pointer to returned length
 *	    flags
 * Returns: message text
 */

char *mail_fetch_message (MAILSTREAM *stream,unsigned long msgno,
			  unsigned long *len,long flags)
{
  GETS_DATA md;
  SIZEDTEXT *t;
  STRING bs;
  MESSAGECACHE *elt;
  char *s,*u;
  unsigned long i,j;
  if (len) *len = 0;		/* default return size */
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return "";		/* must get UID/msgno map first */
  }
				/* initialize message data identifier */
  INIT_GETS (md,stream,msgno,"",0,0);
				/* is data already cached? */
  if ((t = &(elt = mail_elt (stream,msgno))->private.msg.full.text)->data) {
    markseen (stream,elt,flags);/* mark message seen */
    return mail_fetch_text_return (&md,t,len);
  }
  if (!stream->dtb) return "";	/* not in cache, must have live driver */
  if (stream->dtb->msgdata) return
    ((*stream->dtb->msgdata) (stream,msgno,"",0,0,NIL,flags) && t->data) ?
      mail_fetch_text_return (&md,t,len) : "";
				/* ugh, have to do this the crufty way */
  u = mail_fetch_header (stream,msgno,NIL,NIL,&i,flags);
				/* copy in case text method stomps on it */
  s = (char *) memcpy (fs_get ((size_t) i),u,(size_t) i);
  if ((*stream->dtb->text) (stream,msgno,&bs,flags)) {
    t = &stream->text;		/* build combined copy */
    if (t->data) fs_give ((void **) &t->data);
    t->data = (unsigned char *) fs_get ((t->size = i + SIZE (&bs)) + 1);
    if (!elt->rfc822_size) elt->rfc822_size = t->size;
    else if (elt->rfc822_size != t->size) {
      char tmp[MAILTMPLEN];
      sprintf (tmp,"Calculated RFC822.SIZE (%lu) != reported size (%lu)",
	       t->size,elt->rfc822_size);
      mm_log (tmp,WARN);	/* bug trap */
    }
    memcpy (t->data,s,(size_t) i);
    for (u = (char *) t->data + i, j = SIZE (&bs); j;) {
      memcpy (u,bs.curpos,bs.cursize);
      u += bs.cursize;		/* update text */
      j -= bs.cursize;
      bs.curpos += (bs.cursize -1);
      bs.cursize = 0;
      (*bs.dtb->next) (&bs);	/* advance to next buffer's worth */
    } 
    *u = '\0';			/* tie off data */
    u = mail_fetch_text_return (&md,t,len);
  }
  else u = "";
  fs_give ((void **) &s);	/* finished with copy of header */
  return u;
}

/* Mail fetch message header
 * Accepts: mail stream
 *	    message # to fetch
 *	    MIME section specifier (#.#.#...#)
 *	    list of lines to fetch
 *	    pointer to returned length
 *	    flags
 * Returns: message header in RFC822 format
 *
 * Note: never calls a mailgets routine
 */

char *mail_fetch_header (MAILSTREAM *stream,unsigned long msgno,char *section,
			 STRINGLIST *lines,unsigned long *len,long flags)
{
  STRING bs;
  BODY *b = NIL;
  SIZEDTEXT *t = NIL,rt;
  MESSAGE *m = NIL;
  MESSAGECACHE *elt;
  char tmp[MAILTMPLEN];
  if (len) *len = 0;		/* default return size */
  if (section && (strlen (section) > (MAILTMPLEN - 20))) return "";
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return "";		/* must get UID/msgno map first */
  }
  elt = mail_elt (stream,msgno);/* get cache data */
  if (section && *section) {	/* nested body header wanted? */
    if (!((b = mail_body (stream,msgno,section)) &&
	  (b->type == TYPEMESSAGE) && !strcmp (b->subtype,"RFC822")))
      return "";		/* lose if no body or not MESSAGE/RFC822 */
    m = b->nested.msg;		/* point to nested message */
  }
				/* else top-level message header wanted */
  else m = &elt->private.msg;
  if (m->header.text.data && mail_match_lines (lines,m->lines,flags)) {
    if (lines) textcpy (t = &stream->text,&m->header.text);
    else t = &m->header.text;	/* in cache, and cache is valid */
    markseen (stream,elt,flags);/* mark message seen */
  }

  else if (stream->dtb) {	/* not in cache, has live driver? */
    if (stream->dtb->msgdata) {	/* has driver section fetch? */
				/* build driver section specifier */
      if (section && *section) sprintf (tmp,"%s.HEADER",section);
      else strcpy (tmp,"HEADER");
      if ((*stream->dtb->msgdata) (stream,msgno,tmp,0,0,lines,flags)) {
	t = &m->header.text;	/* fetch data */
				/* don't need to postprocess lines */
	if (m->lines) lines = NIL;
	else if (lines) textcpy (t = &stream->text,&m->header.text);
      }
    }
    else if (b) {		/* nested body wanted? */
      if (stream->private.search.text) {
	rt.data = (unsigned char *) stream->private.search.text +
	  b->nested.msg->header.offset;
	rt.size = b->nested.msg->header.text.size;
	t = &rt;
      }
      else if ((*stream->dtb->text) (stream,msgno,&bs,flags & ~FT_INTERNAL)) {
	if ((bs.dtb->next == mail_string_next) && !lines) {
	  rt.data = (unsigned char *) bs.curpos + b->nested.msg->header.offset;
	  rt.size = b->nested.msg->header.text.size;
	  if (stream->private.search.string)
	    stream->private.search.text = bs.curpos;
	  t = &rt;		/* special hack to avoid extra copy */
	}
	else textcpyoffstring (t = &stream->text,&bs,
			       b->nested.msg->header.offset,
			       b->nested.msg->header.text.size);
      }
    }
    else {			/* top-level header fetch */
				/* mark message seen */
      markseen (stream,elt,flags);
      if (rt.data = (unsigned char *)
	  (*stream->dtb->header) (stream,msgno,&rt.size,flags)) {
				/* make a safe copy if need to filter */
	if (lines) textcpy (t = &stream->text,&rt);
	else t = &rt;		/* top level header */
      }
    }
  }
  if (!t || !t->data) return "";/* error if no string */
				/* filter headers if requested */
  if (lines) t->size = mail_filter ((char *) t->data,t->size,lines,flags);
  if (len) *len = t->size;	/* return size if requested */
  return (char *) t->data;	/* and text */
}

/* Mail fetch message text
 * Accepts: mail stream
 *	    message # to fetch
 *	    MIME section specifier (#.#.#...#)
 *	    pointer to returned length
 *	    flags
 * Returns: message text
 */

char *mail_fetch_text (MAILSTREAM *stream,unsigned long msgno,char *section,
		       unsigned long *len,long flags)
{
  GETS_DATA md;
  PARTTEXT *p;
  STRING bs;
  MESSAGECACHE *elt;
  BODY *b = NIL;
  char tmp[MAILTMPLEN];
  unsigned long i;
  if (len) *len = 0;		/* default return size */
  memset (&stream->private.string,NIL,sizeof (STRING));
  if (section && (strlen (section) > (MAILTMPLEN - 20))) return "";
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return "";		/* must get UID/msgno map first */
  }
  elt = mail_elt (stream,msgno);/* get cache data */
  if (section && *section) {	/* nested body text wanted? */
    if (!((b = mail_body (stream,msgno,section)) &&
	  (b->type == TYPEMESSAGE) && !strcmp (b->subtype,"RFC822")))
      return "";		/* lose if no body or not MESSAGE/RFC822 */
    p = &b->nested.msg->text;	/* point at nested message */
				/* build IMAP-format section specifier */
    sprintf (tmp,"%s.TEXT",section);
    flags &= ~FT_INTERNAL;	/* can't win with this set */
  }
  else {			/* top-level message text wanted */
    p = &elt->private.msg.text;
    strcpy (tmp,"TEXT");
  }
				/* initialize message data identifier */
  INIT_GETS (md,stream,msgno,section,0,0);
  if (p->text.data) {		/* is data already cached? */
    markseen (stream,elt,flags);/* mark message seen */
    return mail_fetch_text_return (&md,&p->text,len);
  }
  if (!stream->dtb) return "";	/* not in cache, must have live driver */
  if (stream->dtb->msgdata) return
    ((*stream->dtb->msgdata) (stream,msgno,tmp,0,0,NIL,flags) && p->text.data)?
      mail_fetch_text_return (&md,&p->text,len) : "";
  if (!(*stream->dtb->text) (stream,msgno,&bs,flags)) return "";
  if (section && *section) {	/* nested is more complex */
    SETPOS (&bs,p->offset);
    i = p->text.size;		/* just want this much */
  }
  else i = SIZE (&bs);		/* want entire text */
  return mail_fetch_string_return (&md,&bs,i,len,flags);
}

/* Mail fetch message body part MIME headers
 * Accepts: mail stream
 *	    message # to fetch
 *	    MIME section specifier (#.#.#...#)
 *	    pointer to returned length
 *	    flags
 * Returns: message text
 */

char *mail_fetch_mime (MAILSTREAM *stream,unsigned long msgno,char *section,
		       unsigned long *len,long flags)
{
  PARTTEXT *p;
  STRING bs;
  BODY *b;
  char tmp[MAILTMPLEN];
  if (len) *len = 0;		/* default return size */
  if (section && (strlen (section) > (MAILTMPLEN - 20))) return "";
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return "";		/* must get UID/msgno map first */
  }
  flags &= ~FT_INTERNAL;	/* can't win with this set */
  if (!(section && *section && (b = mail_body (stream,msgno,section))))
    return "";			/* not valid section */
				/* in cache? */
  if ((p = &b->mime)->text.data) {
				/* mark message seen */
    markseen (stream,mail_elt (stream,msgno),flags);
    if (len) *len = p->text.size;
    return (char *) p->text.data;
  }
  if (!stream->dtb) return "";	/* not in cache, must have live driver */
  if (stream->dtb->msgdata) {	/* has driver fetch? */
				/* build driver section specifier */
    sprintf (tmp,"%s.MIME",section);
    if ((*stream->dtb->msgdata) (stream,msgno,tmp,0,0,NIL,flags) &&
	p->text.data) {
      if (len) *len = p->text.size;
      return (char *) p->text.data;
    }
    else return "";
  }
  if (len) *len = b->mime.text.size;
  if (!b->mime.text.size) {	/* empty MIME header -- mark seen anyway */
    markseen (stream,mail_elt (stream,msgno),flags);
    return "";
  }
				/* have to get it from offset */
  if (stream->private.search.text)
    return stream->private.search.text + b->mime.offset;
  if (!(*stream->dtb->text) (stream,msgno,&bs,flags)) {
    if (len) *len = 0;
    return "";
  }
  if (bs.dtb->next == mail_string_next) {
    if (stream->private.search.string) stream->private.search.text = bs.curpos;
    return bs.curpos + b->mime.offset;
  }
  return textcpyoffstring (&stream->text,&bs,b->mime.offset,b->mime.text.size);
}

/* Mail fetch message body part
 * Accepts: mail stream
 *	    message # to fetch
 *	    MIME section specifier (#.#.#...#)
 *	    pointer to returned length
 *	    flags
 * Returns: message body
 */

char *mail_fetch_body (MAILSTREAM *stream,unsigned long msgno,char *section,
		       unsigned long *len,long flags)
{
  GETS_DATA md;
  PARTTEXT *p;
  STRING bs;
  BODY *b;
  SIZEDTEXT *t;
  char *s,tmp[MAILTMPLEN];
  memset (&stream->private.string,NIL,sizeof (STRING));
  if (!(section && *section))	/* top-level text wanted? */
    return mail_fetch_message (stream,msgno,len,flags);
  else if (strlen (section) > (MAILTMPLEN - 20)) return "";
  flags &= ~FT_INTERNAL;	/* can't win with this set */
				/* initialize message data identifier */
  INIT_GETS (md,stream,msgno,section,0,0);
				/* kludge for old section 0 header */
  if (!strcmp (s = strcpy (tmp,section),"0") ||
      ((s = strstr (tmp,".0")) && !s[2])) {
    SIZEDTEXT ht;
    *s = '\0';			/* tie off section */
				/* this silly way so it does mailgets */
    ht.data = (unsigned char *) mail_fetch_header (stream,msgno,
						   tmp[0] ? tmp : NIL,NIL,
						   &ht.size,flags);
				/* may have UIDs here */
    md.flags = (flags & FT_UID) ? MG_UID : NIL;
    return mail_fetch_text_return (&md,&ht,len);
  }
  if (len) *len = 0;		/* default return size */
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return "";		/* must get UID/msgno map first */
  }
				/* must have body */
  if (!(b = mail_body (stream,msgno,section))) return "";
				/* have cached text? */
  if ((t = &(p = &b->contents)->text)->data) {
				/* mark message seen */
    markseen (stream,mail_elt (stream,msgno),flags);
    return mail_fetch_text_return (&md,t,len);
  }
  if (!stream->dtb) return "";	/* not in cache, must have live driver */
  if (stream->dtb->msgdata) return
    ((*stream->dtb->msgdata)(stream,msgno,section,0,0,NIL,flag