1: #ifndef __AITMQTT_H
2: #define __AITMQTT_H
3:
4:
5: #define MQTT_DATA_MAX 268435455
6: #define MQTT_CONN_STR "MQIsdp"
7: #define MQTT_PROTO_VER 3
8: #define MQTT_KEEPALIVE 10
9:
10: /* FIXED HEADER */
11:
12: struct mqtthdr {
13: struct {
14: unsigned char retain:1,
15: qos:2,
16: dup:1,
17: type:4;
18: } mqtt_msg;
19: unsigned char mqtt_len[1]; /* may be grow to 4 bytes */
20: } __packed;
21:
22: #define MQTT_TYPE_UNKNOWN 0 /* reserved */
23: #define MQTT_TYPE_CONNECT 1 /* client request to connect to server */
24: #define MQTT_TYPE_CONNACK 2 /* connect acknowledgment */
25: #define MQTT_TYPE_PUBLISH 3 /* publish message */
26: #define MQTT_TYPE_PUBACK 4 /* publish acknowledgment */
27: #define MQTT_TYPE_PUBREC 5 /* publish received (assured delivery part 1) */
28: #define MQTT_TYPE_PUBREL 6 /* publish release (assured delivery part 2) */
29: #define MQTT_TYPE_PUBCOMP 7 /* publish complete (assured delivery part 3) */
30: #define MQTT_TYPE_SUBSCRIBE 8 /* client subscribe request */
31: #define MQTT_TYPE_SUBACK 9 /* subscribe acknowledgment */
32: #define MQTT_TYPE_UNSUBSCRIBE 10 /* client unsubscribe request */
33: #define MQTT_TYPE_UNSUBACK 11 /* unsubscribe acknowledgment */
34: #define MQTT_TYPE_PINGREQ 12 /* PING request */
35: #define MQTT_TYPE_PINGRESP 13 /* PING response */
36: #define MQTT_TYPE_DISCONNECT 14 /* client is disconnecting */
37: #define MQTT_TYPE_RESERVED 15 /* reserved */
38:
39: #define MQTT_FLAG_DUP 1 /* This flag is set when the client or server attempts to re-deliver
40: a PUBLISH, PUBREL, SUBSCRIBE or UNSUBSCRIBE message.
41: This applies to messages where the value of QoS is greater than
42: zero (0), and an acknowledgment is required.
43: When the DUP bit is set, the variable header includes a Message ID.
44:
45: The recipient should treat this flag as a hint as to whether
46: the message may have been previously received.
47: It should not be relied on to detect duplicates. */
48:
49: #define MQTT_QOS_ONCE 0 /* At most once, Fire and Forget, <=1 */
50: #define MQTT_QOS_ACK 1 /* At least once, Acknowledged delivery, >=1 */
51: #define MQTT_QOS_EXACTLY 2 /* Exactly once, Assured delivery, =1 */
52: #define MQTT_QOS_RESERVED 3 /* reserved */
53:
54: #define MQTT_FLAG_RETAIN 1 /* This flag is only used on PUBLISH messages.
55:
56: When a client sends a PUBLISH to a server,
57: if the Retain flag is set (1),
58: the server should hold on to the message after it has been
59: delivered to the current subscribers.
60: When a new subscription is established on a topic,
61: the last retained message on that topic should be sent to
62: the subscriber with the Retain flag set.
63: If there is no retained message, nothing is sent
64: This is useful where publishers send messages on a
65: "report by exception" basis, where it might be some time between messages.
66: This allows new subscribers to instantly receive data with the retained,
67: or Last Known Good, value.
68:
69: When a server sends a PUBLISH to a client as a result of
70: a subscription that already existed when the original PUBLISH arrived,
71: the Retain flag should not be set, regardless of the Retain flag
72: of the original PUBLISH. This allows a client to distinguish messages
73: that are being received because they were retained and those
74: that are being received "live".
75:
76: Retained messages should be kept over restarts of the server.
77: A server may delete a retained message if it receives a message
78: with a zero-length payload and the Retain flag set on the same topic. */
79:
80: /* VARIABLE HEADERS */
81:
82: #define MQTT_RETCODE_ACCEPTED 0
83: #define MQTT_RETCODE_REFUSE_VER 1
84: #define MQTT_RETCODE_REFUSE_ID 2
85: #define MQTT_RETCODE_REFUSE_UNAVAIL 3
86: #define MQTT_RETCODE_REFUSE_USERPASS 4
87: #define MQTT_RETCODE_DENIED 5
88:
89:
90: typedef union {
91: struct {
92: unsigned short m:8,
93: l:8;
94: } sb;
95: unsigned short val;
96: } mqtt_v_t;
97:
98: typedef struct {
99: mqtt_v_t var_sb;
100: unsigned char var_data[0];
101: } __packed mqtthdr_var_t;
102: #define MQTTHDR_VAR_SIZEOF(x) (assert((x)), sizeof(mqtt_v_t) + ntohs((x)->var_sb.val))
103:
104: typedef unsigned char mqtthdr_protover_t;
105: typedef unsigned char mqtthdr_retcode_t;
106:
107: typedef struct {
108: unsigned char reserved:1,
109: clean_sess:1,
110: will_flg:1,
111: will_qos:2,
112: will_retain:1,
113: password:1,
114: username:1;
115: } __packed mqtthdr_connflgs_t;
116:
117:
118: /* MQTT Message buffer */
119:
120: typedef struct {
121: void *msg_base;
122: unsigned short msg_len;
123: } mqtt_msg_t;
124:
125:
126: // -------------------------------------------------------
127: // mqtt_GetErrno() Get error code of last operation
128: inline int mqtt_GetErrno();
129: // mqtt_GetError() Get error text of last operation
130: inline const char *mqtt_GetError();
131: // -------------------------------------------------------
132:
133:
134: /*
135: * mqtt_msgAlloc() Allocate memory for MQTT Message
136: * @len = >0 Allocate buffer with length
137: * return: NULL error or Message, after use must call mqtt_msgFree() with all!=0
138: */
139: inline mqtt_msg_t *mqtt_msgAlloc(unsigned short len);
140: /*
141: * mqtt_msgFree() Free MQTT message
142: * @msg = Message buffer
143: * @all = !=0 Destroy entire message, if MQTT Message allocated with mqtt_msgAlloc()
144: * return: none
145: */
146: inline void mqtt_msgFree(mqtt_msg_t ** __restrict msg, int all);
147: /*
148: * mqtt_msgRealloc() Reallocate MQTT message buffer
149: * @msg = MQTT message
150: * @len = new length
151: * return: -1 error or >-1 old buffer length
152: */
153: inline int mqtt_msgRealloc(mqtt_msg_t * __restrict msg, unsigned short len);
154:
155: /*
156: * mqtt_encodeLen() Encode number to MQTT length field
157: * @num = number for encode
158: * return: -1 error or >-1 length
159: */
160: inline unsigned int mqtt_encodeLen(unsigned int num);
161: /*
162: * mqtt_decodeLen() Decode length from MQTT packet
163: * @len = length
164: * @n = sizeof bytes, if !=NULL
165: * return: -1 error, >-1 length of message
166: */
167: inline unsigned int mqtt_decodeLen(unsigned int len, char *n);
168: /*
169: * mqtt_sizeLen Return sizeof len field
170: * @len = length
171: * return: -1 error, >-1 sizeof len in bytes
172: */
173: inline char mqtt_sizeLen(unsigned int len);
174: /*
175: * mqtt_str2var Create MQTT variable from string
176: * @csStr = string
177: * @strLen = string length
178: * return: NULL error or != ok variable, must be free after use!
179: */
180: inline mqtthdr_var_t *mqtt_str2var(const unsigned char *csStr, unsigned short strLen);
181:
182:
183: #endif
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