+static int run_slot(struct active_request_slot *slot)
+{
+ int err = 0;
+ struct slot_results results;
+
+ slot->results = &results;
+ slot->curl_result = curl_easy_perform(slot->curl);
+ finish_active_slot(slot);
+
+ if (results.curl_result != CURLE_OK) {
+ err |= error("RPC failed; result=%d, HTTP code = %ld",
+ results.curl_result, results.http_code);
+ }
+
+ return err;
+}
+
+static int probe_rpc(struct rpc_state *rpc)
+{
+ struct active_request_slot *slot;
+ struct curl_slist *headers = NULL;
+ struct strbuf buf = STRBUF_INIT;
+ int err;
+
+ slot = get_active_slot();
+
+ headers = curl_slist_append(headers, rpc->hdr_content_type);
+ headers = curl_slist_append(headers, rpc->hdr_accept);
+
+ curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+ curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
+ curl_easy_setopt(slot->curl, CURLOPT_URL, rpc->service_url);
+ curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
+ curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, "0000");
+ curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, 4);
+ curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
+ curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+ curl_easy_setopt(slot->curl, CURLOPT_FILE, &buf);
+
+ err = run_slot(slot);
+
+ curl_slist_free_all(headers);
+ strbuf_release(&buf);
+ return err;
+}
+