wifi-tally_Oostendam/nodemcu-firmware/app/mqtt/mqtt_msg.c

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2021-09-27 19:52:27 +00:00
/*
* Copyright (c) 2014, Stephen Robinson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <string.h>
#include "mqtt_msg.h"
#define MQTT_MAX_FIXED_HEADER_SIZE 3
enum mqtt_connect_flag
{
MQTT_CONNECT_FLAG_USERNAME = 1 << 7,
MQTT_CONNECT_FLAG_PASSWORD = 1 << 6,
MQTT_CONNECT_FLAG_WILL_RETAIN = 1 << 5,
MQTT_CONNECT_FLAG_WILL = 1 << 2,
MQTT_CONNECT_FLAG_CLEAN_SESSION = 1 << 1
};
struct __attribute((__packed__)) mqtt_connect_variable_header
{
uint8_t lengthMsb;
uint8_t lengthLsb;
uint8_t magic[4];
uint8_t version;
uint8_t flags;
uint8_t keepaliveMsb;
uint8_t keepaliveLsb;
};
static int append_string(mqtt_message_buffer_t *msgb, const char* string, int len)
{
if(msgb->message.length + len + 2 > msgb->buffer_length)
return -1;
msgb->buffer[msgb->message.length++] = len >> 8;
msgb->buffer[msgb->message.length++] = len & 0xff;
memcpy(msgb->buffer + msgb->message.length, string, len);
msgb->message.length += len;
return len + 2;
}
static uint16_t append_message_id(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
if(msgb->message.length + 2 > msgb->buffer_length)
return 0;
msgb->buffer[msgb->message.length++] = message_id >> 8;
msgb->buffer[msgb->message.length++] = message_id & 0xff;
return 1;
}
static int init_message(mqtt_message_buffer_t* msgb)
{
msgb->message.length = MQTT_MAX_FIXED_HEADER_SIZE;
return MQTT_MAX_FIXED_HEADER_SIZE;
}
static mqtt_message_t* fail_message(mqtt_message_buffer_t* msgb)
{
msgb->message.data = msgb->buffer;
msgb->message.length = 0;
return &msgb->message;
}
static mqtt_message_t* fini_message(mqtt_message_buffer_t* msgb, int type, int dup, int qos, int retain)
{
int remaining_length = msgb->message.length - MQTT_MAX_FIXED_HEADER_SIZE;
if(remaining_length > 127)
{
msgb->buffer[0] = ((type & 0x0f) << 4) | ((dup & 1) << 3) | ((qos & 3) << 1) | (retain & 1);
msgb->buffer[1] = 0x80 | (remaining_length % 128);
msgb->buffer[2] = remaining_length / 128;
msgb->message.length = remaining_length + 3;
msgb->message.data = msgb->buffer;
}
else
{
msgb->buffer[1] = ((type & 0x0f) << 4) | ((dup & 1) << 3) | ((qos & 3) << 1) | (retain & 1);
msgb->buffer[2] = remaining_length;
msgb->message.length = remaining_length + 2;
msgb->message.data = msgb->buffer + 1;
}
return &msgb->message;
}
void mqtt_msg_init(mqtt_message_buffer_t* msgb, uint8_t* buffer, uint16_t buffer_length)
{
memset(msgb, 0, sizeof(msgb));
msgb->buffer = buffer;
msgb->buffer_length = buffer_length;
}
// Returns total length of message, or -1 if not enough bytes are available
int32_t mqtt_get_total_length(uint8_t* buffer, uint16_t buffer_length)
{
int i;
int totlen = 0;
if(buffer_length == 1)
return -1;
for(i = 1; i < buffer_length; ++i)
{
totlen += (buffer[i] & 0x7f) << (7 * (i - 1));
if((buffer[i] & 0x80) == 0)
{
++i;
break;
}
if(i == buffer_length)
return -1;
}
totlen += i;
return totlen;
}
const char* mqtt_get_publish_topic(uint8_t* buffer, uint16_t* buffer_length)
{
int i;
int totlen = 0;
int topiclen;
for(i = 1; i < *buffer_length; ++i)
{
totlen += (buffer[i] & 0x7f) << (7 * (i -1));
if((buffer[i] & 0x80) == 0)
{
++i;
break;
}
}
totlen += i;
if(i + 2 > *buffer_length)
return NULL;
topiclen = buffer[i++] << 8;
topiclen |= buffer[i++];
if(i + topiclen > *buffer_length)
return NULL;
*buffer_length = topiclen;
return (const char*)(buffer + i);
}
const char* mqtt_get_publish_data(uint8_t* buffer, uint16_t* buffer_length)
{
int i;
int totlen = 0;
int topiclen;
for(i = 1; i < *buffer_length; ++i)
{
totlen += (buffer[i] & 0x7f) << (7 * (i - 1));
if((buffer[i] & 0x80) == 0)
{
++i;
break;
}
}
totlen += i;
if(i + 2 > *buffer_length)
return NULL;
topiclen = buffer[i++] << 8;
topiclen |= buffer[i++];
if(i + topiclen > *buffer_length){
*buffer_length = 0;
return NULL;
}
i += topiclen;
if(mqtt_get_qos(buffer) > 0)
{
if(i + 2 > *buffer_length)
return NULL;
i += 2;
}
if(totlen < i)
return NULL;
if(totlen <= *buffer_length)
*buffer_length = totlen - i;
else
*buffer_length = *buffer_length - i;
return (const char*)(buffer + i);
}
uint16_t mqtt_get_id(uint8_t* buffer, uint16_t buffer_length)
{
if(buffer_length < 1)
return 0;
switch(mqtt_get_type(buffer))
{
case MQTT_MSG_TYPE_PUBLISH:
{
int i;
int topiclen;
if(mqtt_get_qos(buffer) <= 0)
return 0;
for(i = 1; i < buffer_length; ++i)
{
if((buffer[i] & 0x80) == 0)
{
++i;
break;
}
}
if(i + 2 > buffer_length)
return 0;
topiclen = buffer[i++] << 8;
topiclen |= buffer[i++];
if(i + topiclen > buffer_length)
return 0;
i += topiclen;
if(i + 2 > buffer_length)
return 0;
return (buffer[i] << 8) | buffer[i + 1];
}
case MQTT_MSG_TYPE_PUBACK:
case MQTT_MSG_TYPE_PUBREC:
case MQTT_MSG_TYPE_PUBREL:
case MQTT_MSG_TYPE_PUBCOMP:
case MQTT_MSG_TYPE_SUBACK:
case MQTT_MSG_TYPE_UNSUBACK:
case MQTT_MSG_TYPE_SUBSCRIBE:
{
// This requires the remaining length to be encoded in 1 byte,
// which it should be.
if(buffer_length >= 4 && (buffer[1] & 0x80) == 0)
return (buffer[2] << 8) | buffer[3];
else
return 0;
}
default:
return 0;
}
}
mqtt_message_t* mqtt_msg_connect(mqtt_message_buffer_t* msgb, mqtt_connect_info_t* info)
{
struct mqtt_connect_variable_header* variable_header;
init_message(msgb);
if(msgb->message.length + sizeof(*variable_header) > msgb->buffer_length)
return fail_message(msgb);
variable_header = (void*)(msgb->buffer + msgb->message.length);
msgb->message.length += sizeof(*variable_header);
variable_header->lengthMsb = 0;
variable_header->lengthLsb = 4;
memcpy(variable_header->magic, "MQTT", 4);
variable_header->version = 4;
variable_header->flags = 0;
variable_header->keepaliveMsb = info->keepalive >> 8;
variable_header->keepaliveLsb = info->keepalive & 0xff;
if(info->clean_session)
variable_header->flags |= MQTT_CONNECT_FLAG_CLEAN_SESSION;
if(info->client_id != NULL && info->client_id[0] != '\0')
{
if(append_string(msgb, info->client_id, strlen(info->client_id)) < 0)
return fail_message(msgb);
}
else
return fail_message(msgb);
if(info->will_topic != NULL && info->will_topic[0] != '\0')
{
if(append_string(msgb, info->will_topic, strlen(info->will_topic)) < 0)
return fail_message(msgb);
if(append_string(msgb, info->will_message, strlen(info->will_message)) < 0)
return fail_message(msgb);
variable_header->flags |= MQTT_CONNECT_FLAG_WILL;
if(info->will_retain)
variable_header->flags |= MQTT_CONNECT_FLAG_WILL_RETAIN;
variable_header->flags |= (info->will_qos & 3) << 3;
}
if(info->username != NULL && info->username[0] != '\0')
{
if(append_string(msgb, info->username, strlen(info->username)) < 0)
return fail_message(msgb);
variable_header->flags |= MQTT_CONNECT_FLAG_USERNAME;
}
if(info->password != NULL && info->password[0] != '\0')
{
if(append_string(msgb, info->password, strlen(info->password)) < 0)
return fail_message(msgb);
variable_header->flags |= MQTT_CONNECT_FLAG_PASSWORD;
}
return fini_message(msgb, MQTT_MSG_TYPE_CONNECT, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_publish(mqtt_message_buffer_t* msgb, const char* topic, const char* data, int data_length, int qos, int retain, uint16_t message_id)
{
init_message(msgb);
if(topic == NULL || topic[0] == '\0')
return fail_message(msgb);
if(append_string(msgb, topic, strlen(topic)) < 0)
return fail_message(msgb);
if(qos > 0)
{
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
}
if(msgb->message.length + data_length > msgb->buffer_length)
return fail_message(msgb);
memcpy(msgb->buffer + msgb->message.length, data, data_length);
msgb->message.length += data_length;
return fini_message(msgb, MQTT_MSG_TYPE_PUBLISH, 0, qos, retain);
}
mqtt_message_t* mqtt_msg_puback(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
init_message(msgb);
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PUBACK, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_pubrec(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
init_message(msgb);
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PUBREC, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_pubrel(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
init_message(msgb);
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PUBREL, 0, 1, 0);
}
mqtt_message_t* mqtt_msg_pubcomp(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
init_message(msgb);
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PUBCOMP, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_subscribe_init(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
init_message(msgb);
if(!append_message_id(msgb, message_id))
return fail_message(msgb);
return &msgb->message;
}
mqtt_message_t* mqtt_msg_subscribe_topic(mqtt_message_buffer_t* msgb, const char* topic, int qos)
{
if(topic == NULL || topic[0] == '\0')
return fail_message(msgb);
if(append_string(msgb, topic, strlen(topic)) < 0)
return fail_message(msgb);
if(msgb->message.length + 1 > msgb->buffer_length)
return fail_message(msgb);
msgb->buffer[msgb->message.length++] = qos;
return &msgb->message;
}
mqtt_message_t* mqtt_msg_subscribe_fini(mqtt_message_buffer_t* msgb)
{
return fini_message(msgb, MQTT_MSG_TYPE_SUBSCRIBE, 0, 1, 0);
}
mqtt_message_t* mqtt_msg_subscribe(mqtt_message_buffer_t* msgb, const char* topic, int qos, uint16_t message_id)
{
mqtt_message_t* result;
result = mqtt_msg_subscribe_init(msgb, message_id);
if (result->length != 0) {
result = mqtt_msg_subscribe_topic(msgb, topic, qos);
}
if (result->length != 0) {
result = mqtt_msg_subscribe_fini(msgb);
}
return result;
}
mqtt_message_t* mqtt_msg_unsubscribe_init(mqtt_message_buffer_t* msgb, uint16_t message_id)
{
return mqtt_msg_subscribe_init(msgb, message_id);
}
mqtt_message_t* mqtt_msg_unsubscribe_topic(mqtt_message_buffer_t* msgb, const char* topic)
{
if(topic == NULL || topic[0] == '\0')
return fail_message(msgb);
if(append_string(msgb, topic, strlen(topic)) < 0)
return fail_message(msgb);
return &msgb->message;
}
mqtt_message_t* mqtt_msg_unsubscribe_fini(mqtt_message_buffer_t* msgb)
{
return fini_message(msgb, MQTT_MSG_TYPE_UNSUBSCRIBE, 0, 1, 0);
}
mqtt_message_t* mqtt_msg_unsubscribe(mqtt_message_buffer_t* msgb, const char* topic, uint16_t message_id)
{
mqtt_message_t* result;
result = mqtt_msg_unsubscribe_init(msgb, message_id);
if (result->length != 0) {
result = mqtt_msg_unsubscribe_topic(msgb, topic);
}
if (result->length != 0) {
result = mqtt_msg_unsubscribe_fini(msgb);
}
return result;
}
mqtt_message_t* mqtt_msg_pingreq(mqtt_message_buffer_t* msgb)
{
init_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PINGREQ, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_pingresp(mqtt_message_buffer_t* msgb)
{
init_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_PINGRESP, 0, 0, 0);
}
mqtt_message_t* mqtt_msg_disconnect(mqtt_message_buffer_t* msgb)
{
init_message(msgb);
return fini_message(msgb, MQTT_MSG_TYPE_DISCONNECT, 0, 0, 0);
}