MQTT / MQTTPacket

Basic C library for MQTT packet serialization and deserialization

Dependents:   MQTT MQTT MQTT MQTT ... more

Fork of MQTTPacket by MQTT

This library is part of the EclipseTM Paho project; specifically the embedded client.

A basic MQTT library in C for packet serialization and deserialization

Diff: MQTTPacket.c

Revision:
18:bf36e077e7b8
Parent:
17:c5bd28cc139a
Child:
19:99773f597e90
--- a/MQTTPacket.c	Fri Aug 01 17:25:52 2014 +0000
+++ b/MQTTPacket.c	Mon Sep 29 11:31:13 2014 +0000
@@ -311,3 +311,143 @@
 	return rc;
 }
 
+
+const char* MQTTPacket_names[] =
+{
+	"RESERVED", "CONNECT", "CONNACK", "PUBLISH", "PUBACK", "PUBREC", "PUBREL",
+	"PUBCOMP", "SUBSCRIBE", "SUBACK", "UNSUBSCRIBE", "UNSUBACK",
+	"PINGREQ", "PINGRESP", "DISCONNECT"
+};
+
+
+char* MQTTPacket_toString(char* strbuf, int strbuflen, unsigned char* buf, int buflen)
+{
+	int index = 0;
+	int rem_length = 0;
+	MQTTHeader header = {0};
+	int strindex = 0;
+
+	header.byte = buf[index++];
+	index += MQTTPacket_decodeBuf(&buf[index], &rem_length);
+
+	switch (header.bits.type)
+	{
+	case CONNECT:
+	{
+		MQTTPacket_connectData data;
+		if (MQTTDeserialize_connect(&data, buf, buflen) == 1)
+		{
+			strindex = snprintf(strbuf, strbuflen,
+				"CONNECT MQTT version %d, client id %.*s, clean session %d, keep alive %hd",
+				(int)data.MQTTVersion, data.clientID.lenstring.len, data.clientID.lenstring.data,
+				(int)data.cleansession, data.keepAliveInterval);
+			if (data.willFlag)
+				strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", will QoS %d, will retain %d, will topic %.*s, will message %.*s",
+				data.will.qos, data.will.retained,
+				data.will.topicName.lenstring.len, data.will.topicName.lenstring.data,
+				data.will.message.lenstring.len, data.will.message.lenstring.data);
+			if (data.username.lenstring.data && data.username.lenstring.len > 0)
+			{
+				printf("user name\n");
+				strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", user name %.*s", data.username.lenstring.len, data.username.lenstring.data);
+			}
+			if (data.password.lenstring.data && data.password.lenstring.len > 0)
+				strindex += snprintf(&strbuf[strindex], strbuflen - strindex,
+				", password %.*s", data.password.lenstring.len, data.password.lenstring.data);
+		}
+	}
+	break;
+	case CONNACK:
+	{
+		unsigned char sessionPresent, connack_rc;
+		if (MQTTDeserialize_connack(&sessionPresent, &connack_rc, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+			"CONNACK session present %d, rc %d", sessionPresent, connack_rc);
+	}
+	break;
+	case PUBLISH:
+	{
+		unsigned char dup, retained, *payload;
+		unsigned short packetid;
+		int qos, payloadlen;
+		MQTTString topicName = MQTTString_initializer;
+		if (MQTTDeserialize_publish(&dup, &qos, &retained, &packetid, &topicName,
+				&payload, &payloadlen, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"PUBLISH dup %d, QoS %d, retained %d, packet id %d, topic %.*s, payload length %d, payload %.*s",
+				dup, qos, retained, packetid,
+				(topicName.lenstring.len < 20) ? topicName.lenstring.len : 20, topicName.lenstring.data,
+				payloadlen, (payloadlen < 20) ? payloadlen : 20, payload);
+	}
+	break;
+	case PUBACK:
+	case PUBREC:
+	case PUBREL:
+	case PUBCOMP:
+	{
+		unsigned char packettype, dup;
+		unsigned short packetid;
+		if (MQTTDeserialize_ack(&packettype, &dup, &packetid, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"%s dup %d, packet id %d",
+				MQTTPacket_names[packettype], dup, packetid);
+	}
+	break;
+	case SUBSCRIBE:
+	{
+		unsigned char dup;
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		MQTTString topicFilters[1];
+		int requestedQoSs[1];
+		if (MQTTDeserialize_subscribe(&dup, &packetid, maxcount, &count,
+				topicFilters, requestedQoSs, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"SUBSCRIBE dup %d, packet id %d count %d topic %.*s qos %d",
+				dup, packetid, count,
+				topicFilters[0].lenstring.len, topicFilters[0].lenstring.data,
+				requestedQoSs[0]);
+	}
+	break;
+	case SUBACK:
+	{
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		int grantedQoSs[1];
+		if (MQTTDeserialize_suback(&packetid, maxcount, &count, grantedQoSs, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"SUBACK packet id %d count %d topic %.*s granted qos %d",
+				packetid, count, grantedQoSs[0]);
+	}
+	break;
+	case UNSUBSCRIBE:
+	{
+		unsigned char dup;
+		unsigned short packetid;
+		int maxcount = 1, count = 0;
+		MQTTString topicFilters[1];
+		if (MQTTDeserialize_unsubscribe(&dup, &packetid, maxcount, &count, topicFilters, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"UNSUBSCRIBE dup %d, packet id %d count %d topic %.*s",
+				dup, packetid, count,
+				topicFilters[0].lenstring.len, topicFilters[0].lenstring.data);
+	}
+	break;
+	case UNSUBACK:
+	{
+		unsigned short packetid;
+		if (MQTTDeserialize_unsuback(&packetid, buf, buflen) == 1)
+			strindex = snprintf(strbuf, strbuflen,
+				"UNSUBACK packet id %d", packetid);
+	}
+	break;
+	case PINGREQ:
+	case PINGRESP:
+	case DISCONNECT:
+		strindex = snprintf(strbuf, strbuflen, "%s", MQTTPacket_names[header.bits.type]);
+		break;
+	}
+	return strbuf;
+}