+ int lablen, labstart, i, needquote, c, r, neednorm;
+ const unsigned char *p;
+ char *str;
+ findlabel_state fls;
+ adns_status st;
+ vbuf *vb;
+
+ vb= &pai->qu->vb;
+ vb->used= 0;
+ adns__findlabel_start(&fls, pai->ads,
+ -1, pai->qu,
+ pai->dgram, pai->dglen, max,
+ *cbyte_io, cbyte_io);
+ st= adns__findlabel_next(&fls,&lablen,&labstart);
+ if (!lablen) {
+ adns__vbuf_appendstr(vb,"<>");
+ goto x_ok;
+ }
+
+ neednorm= 1;
+ for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++) {
+ c= *p++;
+ if ((c&~128) < 32 || (c&~128) == 127) return adns_s_invaliddata;
+ if (c == '.' && !neednorm) neednorm= 1;
+ else if (strchr("()<>@,;:\\\".[]",c)) needquote++;
+ else neednorm= 0;
+ }
+
+ if (needquote || neednorm) {
+ r= adns__vbuf_ensure(vb, lablen+needquote+4); if (!r) R_NOMEM;
+ adns__vbuf_appendq(vb,"\"",1);
+ for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++, p++) {
+ c= *p;
+ if (strchr("()<>@,;:\\\".[]",c)) adns__vbuf_appendq(vb,"\\",1);
+ adns__vbuf_appendq(vb,p,1);
+ }
+ adns__vbuf_appendq(vb,"\"",1);
+ } else {
+ r= adns__vbuf_append(vb, pai->dgram+labstart, lablen); if (!r) R_NOMEM;
+ }
+
+ r= adns__vbuf_appendstr(vb,"@"); if (!r) R_NOMEM;
+
+ st= adns__parse_domain_more(&fls,pai->ads, pai->qu,vb,0, pai->dgram);
+ if (st) return st;
+
+ x_ok:
+ str= adns__alloc_interim(pai->qu, vb->used+1); if (!str) R_NOMEM;
+ memcpy(str,vb->buf,vb->used);
+ str[vb->used]= 0;
+ *mb_r= str;
+ return adns_s_ok;