mqtt: add new experimental protocol

Closes #5173

1 files changed, 49 insertions, 0 deletions

diff --git a/lib/mqtt.h b/lib/mqtt.h
new file mode 100644
index 000000000..b5e447be5
--- /dev/null
+++ b/lib/mqtt.h
@@ -0,0 +1,49 @@
+#ifndef HEADER_CURL_MQTT_H
+#define HEADER_CURL_MQTT_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2019 - 2020, Björn Stenberg, <bjorn@haxx.se>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#ifdef CURL_ENABLE_MQTT
+extern const struct Curl_handler Curl_handler_mqtt;
+#endif
+
+struct mqtt_conn {
+  enum {
+    MQTT_CONNACK,
+    MQTT_SUBACK,
+    MQTT_SUBWAIT,    /* wait for subscribe response */
+    MQTT_SUB_REMAIN  /* wait for the remainder of the subscribe response */
+  } state;
+  unsigned int packetid;
+};
+
+/* protocol-specific transfer-related data */
+struct MQTT {
+  char *sendleftovers;
+  size_t nsend; /* size of sendleftovers */
+
+  /* when receving a PUBLISH */
+  size_t npacket; /* byte counter */
+  unsigned char firstbyte;
+};
+
+#endif /* HEADER_CURL_MQTT_H */