int _mosquitto_send_real_publish(struct mosquitto *mosq, uint16_t mid, const char *topic, uint32_t payloadlen, const void *payload, int qos, bool retain, bool dup)
{
struct _mosquitto_packet *packet = NULL;
int packetlen;
int rc;
assert(mosq);
assert(topic);
packetlen = 2+strlen(topic) + payloadlen;
if(qos > 0) packetlen += 2; /* For message id */
packet = _mosquitto_calloc(1, sizeof(struct _mosquitto_packet));
if(!packet) return MOSQ_ERR_NOMEM;
packet->mid = mid;
packet->command = PUBLISH | ((dup&0x1)<<3) | (qos<<1) | retain;
packet->remaining_length = packetlen;
rc = _mosquitto_packet_alloc(packet);
if(rc){
_mosquitto_free(packet);
return rc;
}
/* Variable header (topic string) */
_mosquitto_write_string(packet, topic, strlen(topic));
if(qos > 0){
_mosquitto_write_uint16(packet, mid);
}
/* Payload */
if(payloadlen){
_mosquitto_write_bytes(packet, payload, payloadlen);
}
return _mosquitto_packet_queue(mosq, packet);
}
int _mosquitto_send_suback(struct mosquitto *context, uint16_t mid, uint32_t payloadlen, const void *payload)
{//给当前客户端发送一个回包，内容在参数payload上面
struct _mosquitto_packet *packet = NULL;
int rc;
_mosquitto_log_printf(NULL, MOSQ_LOG_DEBUG, "Sending SUBACK to %s", context->id);
packet = _mosquitto_calloc(1, sizeof(struct _mosquitto_packet));
if(!packet) return MOSQ_ERR_NOMEM;
packet->command = SUBACK;
packet->remaining_length = 2+payloadlen;
rc = _mosquitto_packet_alloc(packet);
if(rc){
_mosquitto_free(packet);
return rc;
}
_mosquitto_write_uint16(packet, mid);
if(payloadlen){
_mosquitto_write_bytes(packet, payload, payloadlen);
}
return _mosquitto_packet_queue(context, packet);
}
void _mosquitto_write_string(struct _mosquitto_packet *packet, const char *str, uint16_t length)
{
assert(packet);
_mosquitto_write_uint16(packet, length);
_mosquitto_write_bytes(packet, str, length);
}
