/**
* Helper function to read packet data from some source into a buffer
* @param buf the buffer into which the packet will be serialized
* @param buflen the length in bytes of the supplied buffer
* @param getfn pointer to a function which will read any number of bytes from the needed source
* @return integer MQTT packet type, or -1 on error
*/
int MQTTPacket_read(unsigned char* buf, int buflen, int (*getfn)(unsigned char*, int))
{
int rc = -1;
MQTTHeader header = {0};
int len = 0;
int rem_len = 0;
/* 1. read the header byte. This has the packet type in it */
if ((*getfn)(buf, 1) != 1)
goto exit;
len = 1;
/* 2. read the remaining length. This is variable in itself */
MQTTPacket_decode(getfn, &rem_len);
len += MQTTPacket_encode(buf + 1, rem_len); /* put the original remaining length back into the buffer */
/* 3. read the rest of the buffer using a callback to supply the rest of the data */
if ((*getfn)(buf + len, rem_len) != rem_len)
goto exit;
header.byte = buf[0];
rc = header.bits.type;
exit:
return rc;
}
/**
* Reads one MQTT packet from a socket.
* @param socket a socket from which to read an MQTT packet
* @param error pointer to the error code which is completed if no packet is returned
* @return the packet structure or NULL if there was an error
*/
void* MQTTPacket_Factory(int socket, int* error)
{
char* data = NULL;
static Header header;
int remaining_length, ptype;
void* pack = NULL;
int actual_len = 0;
FUNC_ENTRY;
*error = SOCKET_ERROR; /* indicate whether an error occurred, or not */
/* read the packet data from the socket */
if ((*error = Socket_getch(socket, &(header.byte))) != TCPSOCKET_COMPLETE) /* first byte is the header byte */
goto exit; /* packet not read, *error indicates whether SOCKET_ERROR occurred */
/* now read the remaining length, so we know how much more to read */
if ((*error = MQTTPacket_decode(socket, &remaining_length)) != TCPSOCKET_COMPLETE)
goto exit; /* packet not read, *error indicates whether SOCKET_ERROR occurred */
/* now read the rest, the variable header and payload */
if ((data = Socket_getdata(socket, remaining_length, &actual_len)) == NULL)
{
*error = SOCKET_ERROR;
goto exit; /* socket error */
}
if (actual_len != remaining_length)
*error = TCPSOCKET_INTERRUPTED;
else
{
ptype = header.bits.type;
if (ptype < CONNECT || ptype > DISCONNECT || new_packets[ptype] == NULL)
Log(TRACE_MIN, 2, NULL, ptype);
else
{
if ((pack = (*new_packets[ptype])(header.byte, data, remaining_length)) == NULL)
*error = BAD_MQTT_PACKET;
#if !defined(NO_PERSISTENCE)
else if (header.bits.type == PUBLISH && header.bits.qos == 2)
{
int buf0len;
char *buf = malloc(10);
buf[0] = header.byte;
buf0len = 1 + MQTTPacket_encode(&buf[1], remaining_length);
*error = MQTTPersistence_put(socket, buf, buf0len, 1,
&data, &remaining_length, header.bits.type, ((Publish *)pack)->msgId, 1);
free(buf);
}
#endif
}
}
exit:
FUNC_EXIT_RC(*error);
return pack;
}
MQTTReturnCode MQTTPacket_decodeBuf(unsigned char *buf, uint32_t *value, uint32_t *readBytesLen) {
bufptr = buf;
return MQTTPacket_decode(bufchar, value, readBytesLen);
}
int MQTTPacket_decodeBuf(unsigned char* buf, int* value)
{
bufptr = buf;
return MQTTPacket_decode(bufchar, value);
}
void* MQTTPacket_Factory(networkHandles* net, int* error)
{
static Header header;
int ptype;
void* pack = NULL;
FUNC_ENTRY;
*error = SOCKET_ERROR; // Indicate whether an error occurred, or not
/* read the packet data from the socket */
#if defined(OPENSSL)
*error = (net->ssl) ? SSLSocket_getch(net->ssl, net->socket, &header.byte) : Socket_getch(net->socket, &header.byte);
#else
*error = Socket_getch(net->socket, &header.byte);
#endif
if (*error != TCPSOCKET_COMPLETE)
{ // First byte is the header byte
goto exit; // packet not read, *error indicates whether SOCKET_ERROR occurred.
}
// Now read the remaining length, so we know how much more to read
size_t remaining_length;
if ((*error = MQTTPacket_decode(net, &remaining_length)) != TCPSOCKET_COMPLETE) {
goto exit; // Packet not read, *error indicates whether SOCKET_ERROR occurred.
}
// Now read the rest, the variable header and payload.
size_t actual_len = 0;
#if defined(OPENSSL)
char* data = (net->ssl) ? SSLSocket_getdata(net->ssl, net->socket, remaining_length, &actual_len) : Socket_getdata(net->socket, remaining_length, &actual_len);
#else
char* data = Socket_getdata(net->socket, remaining_length, &actual_len);
#endif
if (data == NULL)
{
*error = SOCKET_ERROR;
goto exit; // Socket error
}
if (actual_len != remaining_length)
{
*error = TCPSOCKET_INTERRUPTED;
}
else
{
ptype = header.bits.type;
if (ptype < CONNECT || ptype > DISCONNECT || new_packets[ptype] == NULL)
Log(TRACE_MIN, 2, NULL, ptype);
else
{
if ((pack = (*new_packets[ptype])(header.byte, data, remaining_length)) == NULL)
*error = BAD_MQTT_PACKET;
#if !defined(NO_PERSISTENCE)
else if (header.bits.type == PUBLISH && header.bits.qos == 2)
{
int buf0len;
char *buf = malloc(10);
buf[0] = header.byte;
buf0len = 1 + MQTTPacket_encode(&buf[1], remaining_length);
size_t remaining_length_new = remaining_length;
*error = MQTTPersistence_put(net->socket, buf, buf0len, 1, &data, &remaining_length_new, header.bits.type, ((Publish *)pack)->msgId, 1);
free(buf);
}
#endif
}
}
if (pack)
time(&(net->lastReceived));
exit:
FUNC_EXIT_RC(*error);
return pack;
}