+ return StrLength(ReplyBuf);
+}
+
+
+
+struct xrds {
+ int nesting_level;
+ int in_xrd;
+ int current_service_priority;
+ int selected_service_priority; /* more here later */
+};
+
+
+void xrds_xml_start(void *data, const char *supplied_el, const char **attr) {
+ struct xrds *xrds = (struct xrds *) data;
+ int i;
+
+ ++xrds->nesting_level;
+
+ if (!strcasecmp(supplied_el, "XRD")) {
+ ++xrds->in_xrd;
+ syslog(LOG_DEBUG, "*** XRD CONTAINER BEGIN ***");
+ }
+
+ else if (!strcasecmp(supplied_el, "service")) {
+ xrds->current_service_priority = 0;
+ for (i=0; attr[i] != NULL; i+=2) {
+ if (!strcasecmp(attr[i], "priority")) {
+ xrds->current_service_priority = atoi(attr[i+1]);
+ }
+ }
+ }
+}
+
+
+void xrds_xml_end(void *data, const char *supplied_el) {
+ struct xrds *xrds = (struct xrds *) data;
+
+ --xrds->nesting_level;
+
+ if (!strcasecmp(supplied_el, "XRD")) {
+ --xrds->in_xrd;
+ syslog(LOG_DEBUG, "*** XRD CONTAINER END ***");
+ }
+
+ else if (!strcasecmp(supplied_el, "service")) {
+ /* this is where we should evaluate the service and do stuff */
+ xrds->current_service_priority = 0;
+ }
+}
+
+
+void xrds_xml_chardata(void *data, const XML_Char *s, int len) {
+ struct xrds *xrds = (struct xrds *) data;
+
+ if (xrds) ; /* this is only here to silence the warning for now */
+
+ /* StrBufAppendBufPlain (xrds->CData, s, len, 0); */
+}
+
+
+/*
+ * Parse an XRDS document.
+ * If OpenID stuff is discovered, populate FIXME something and return nonzero
+ * If nothing useful happened, return 0.
+ */
+int parse_xrds_document(StrBuf *ReplyBuf) {
+ struct xrds xrds;
+
+ memset(&xrds, 0, sizeof (struct xrds));
+ XML_Parser xp = XML_ParserCreate(NULL);
+ if (xp) {
+ XML_SetUserData(xp, &xrds);
+ XML_SetElementHandler(xp, xrds_xml_start, xrds_xml_end);
+ XML_SetCharacterDataHandler(xp, xrds_xml_chardata);
+ XML_Parse(xp, ChrPtr(ReplyBuf), StrLength(ReplyBuf), 0);
+ XML_Parse(xp, "", 0, 1);
+ XML_ParserFree(xp);
+ }
+ else {
+ syslog(LOG_ALERT, "Cannot create XML parser");
+ }
+
+ return(0); /* FIXME return nonzero if something wonderful happened */
+}
+
+
+/* Attempt to perform Yadis discovery as specified in Yadis 1.0 section 6.2.5.
+ * If successful, returns nonzero and calls parse_xrds_document() to act upon the received data.
+ * If Yadis fails, returns 0 and does nothing else.
+ */
+int perform_yadis_discovery(StrBuf *YadisURL) {
+ int docbytes = (-1);
+ StrBuf *ReplyBuf = NULL;
+ int r;
+ CURL *curl;
+ CURLcode result;
+ char errmsg[1024] = "";
+ struct curl_slist *my_headers = NULL;
+
+ if (YadisURL == NULL) return(0);
+ if (StrLength(YadisURL) == 0) return(0);
+
+ ReplyBuf = NewStrBuf ();
+ if (ReplyBuf == 0) return(0);
+
+ curl = ctdl_openid_curl_easy_init(errmsg);
+ if (!curl) return(0);
+
+ curl_easy_setopt(curl, CURLOPT_URL, ChrPtr(YadisURL));
+ curl_easy_setopt(curl, CURLOPT_WRITEDATA, ReplyBuf);
+ curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlFillStrBuf_callback);
+
+ my_headers = curl_slist_append(my_headers, "Accept:"); /* disable the default Accept: header */
+ my_headers = curl_slist_append(my_headers, "Accept: application/xrds+xml");
+ curl_easy_setopt(curl, CURLOPT_HTTPHEADER, my_headers);
+
+ result = curl_easy_perform(curl);
+ if (result) {
+ syslog(LOG_DEBUG, "libcurl error %d: %s", result, errmsg);
+ }
+ curl_slist_free_all(my_headers);
+ curl_easy_cleanup(curl);
+
+ docbytes = StrLength(ReplyBuf);
+
+ /* FIXME here we need to handle Yadis 1.0 section 6.2.5.
+ *
+ * The response from the server will be one of:
+ *
+ * Option 1: An HTML document with a <head> element that includes a <meta> element with http-equiv
+ * attribute, X-XRDS-Location,
+ *
+ * Option 2: HTTP response-headers that include an X-XRDS-Location response-header, together with a
+ * document (NOTE: we can probably recurse for this)
+ *
+ * Option 3:. HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
+ * a contenttype response-header specifying MIME media type, application/xrds+xml, or both.
+ *
+ */
+
+ /*
+ * Option 4: the returned web page may *be* an XRDS document. Try to parse it.
+ */
+ r = 0;
+ if (docbytes >= 0) {
+ r = parse_xrds_document(ReplyBuf);
+ FreeStrBuf(&ReplyBuf);
+ }
+
+ return(r);