xref: /curl/lib/mqtt.h (revision bdae2759)
1 #ifndef HEADER_CURL_MQTT_H
2 #define HEADER_CURL_MQTT_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) Björn Stenberg, <bjorn@haxx.se>
11  *
12  * This software is licensed as described in the file COPYING, which
13  * you should have received as part of this distribution. The terms
14  * are also available at https://curl.se/docs/copyright.html.
15  *
16  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17  * copies of the Software, and permit persons to whom the Software is
18  * furnished to do so, under the terms of the COPYING file.
19  *
20  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21  * KIND, either express or implied.
22  *
23  * SPDX-License-Identifier: curl
24  *
25  ***************************************************************************/
26 
27 #ifndef CURL_DISABLE_MQTT
28 extern const struct Curl_handler Curl_handler_mqtt;
29 #endif
30 
31 enum mqttstate {
32   MQTT_FIRST,             /* 0 */
33   MQTT_REMAINING_LENGTH,  /* 1 */
34   MQTT_CONNACK,           /* 2 */
35   MQTT_SUBACK,            /* 3 */
36   MQTT_SUBACK_COMING,     /* 4 - the SUBACK remainder */
37   MQTT_PUBWAIT,    /* 5 - wait for publish */
38   MQTT_PUB_REMAIN,  /* 6 - wait for the remainder of the publish */
39 
40   MQTT_NOSTATE /* 7 - never used an actual state */
41 };
42 
43 struct mqtt_conn {
44   enum mqttstate state;
45   enum mqttstate nextstate; /* switch to this after remaining length is
46                                done */
47   unsigned int packetid;
48 };
49 
50 /* protocol-specific transfer-related data */
51 struct MQTT {
52   char *sendleftovers;
53   size_t nsend; /* size of sendleftovers */
54 
55   /* when receiving */
56   size_t npacket; /* byte counter */
57   unsigned char firstbyte;
58   size_t remaining_length;
59   struct dynbuf recvbuf;
60   unsigned char pkt_hd[4]; /* for decoding the arriving packet length */
61 };
62 
63 #endif /* HEADER_CURL_MQTT_H */
64