1 /**
2  * @file
3  * MQTT client (private interface)
4  */
5 
6 /*
7  * Copyright (c) 2016 Erik Andersson
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without modification,
11  * are permitted provided that the following conditions are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright notice,
14  *    this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright notice,
16  *    this list of conditions and the following disclaimer in the documentation
17  *    and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30  * OF SUCH DAMAGE.
31  *
32  * This file is part of the lwIP TCP/IP stack.
33  *
34  * Author: Erik Andersson
35  *
36  */
37 #ifndef LWIP_HDR_APPS_MQTT_PRIV_H
38 #define LWIP_HDR_APPS_MQTT_PRIV_H
39 
40 #include "lwip/apps/mqtt.h"
41 #include "lwip/altcp.h"
42 
43 #ifdef __cplusplus
44 extern "C" {
45 #endif
46 
47 /** Pending request item, binds application callback to pending server requests */
48 struct mqtt_request_t
49 {
50   /** Next item in list, NULL means this is the last in chain,
51       next pointing at itself means request is unallocated */
52   struct mqtt_request_t *next;
53   /** Callback to upper layer */
54   mqtt_request_cb_t cb;
55   void *arg;
56   /** MQTT packet identifier */
57   u16_t pkt_id;
58   /** Expire time relative to element before this  */
59   u16_t timeout_diff;
60 };
61 
62 /** Ring buffer */
63 struct mqtt_ringbuf_t {
64   u16_t put;
65   u16_t get;
66   u8_t buf[MQTT_OUTPUT_RINGBUF_SIZE];
67 };
68 
69 /** MQTT client */
70 struct mqtt_client_s
71 {
72   /** Timers and timeouts */
73   u16_t cyclic_tick;
74   u16_t keep_alive;
75   u16_t server_watchdog;
76   /** Packet identifier generator*/
77   u16_t pkt_id_seq;
78   /** Packet identifier of pending incoming publish */
79   u16_t inpub_pkt_id;
80   /** Connection state */
81   u8_t conn_state;
82   struct altcp_pcb *conn;
83   /** Connection callback */
84   void *connect_arg;
85   mqtt_connection_cb_t connect_cb;
86   /** Pending requests to server */
87   struct mqtt_request_t *pend_req_queue;
88   struct mqtt_request_t req_list[MQTT_REQ_MAX_IN_FLIGHT];
89   void *inpub_arg;
90   /** Incoming data callback */
91   mqtt_incoming_data_cb_t data_cb;
92   mqtt_incoming_publish_cb_t pub_cb;
93   /** Input */
94   u32_t msg_idx;
95   u8_t rx_buffer[MQTT_VAR_HEADER_BUFFER_LEN];
96   /** Output ring-buffer */
97   struct mqtt_ringbuf_t output;
98 };
99 
100 #ifdef __cplusplus
101 }
102 #endif
103 
104 #endif /* LWIP_HDR_APPS_MQTT_PRIV_H */
105