int
FileRepConnServer_ReceiveMessageLength(uint32 *len)
{
int32 length;
if (pq_getbytes((char*) &length, 4) == EOF) {
ereport(WARNING,
(errcode_for_socket_access(),
errmsg("receive EOF on connection: %m")));
return STATUS_ERROR;
}
length = ntohl(length);
if (length < 4) {
ereport(WARNING,
(errmsg("receive unexpected message length on connection")));
return STATUS_ERROR;
}
length -= 4;
*len = length;
return STATUS_OK;
}
/*
* readLogMessage - read log message sent from client
*/
static void
readLogMessage(void *buf, int plen)
{
int32 len;
if (pq_getbytes((char *) &len, 4) == EOF)
{
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("QDSYNC: incomplete log packet")));
}
len = ntohl(len);
len -= 4;
pq_getbytes(buf, len);
elog(DEBUG4, "QDSYNC: readLogMessage: plen %d len: %d", plen, len);
}
static int
Wrappered_pq_getbytes(char *s, size_t len)
{
#if (PG_VERSION_NUM >= 90401) \
|| ((PG_VERSION_NUM >= 90306) && (PG_VERSION_NUM < 90400)) \
|| ((PG_VERSION_NUM >= 90210) && (PG_VERSION_NUM < 90300)) \
|| ((PG_VERSION_NUM >= 90115) && (PG_VERSION_NUM < 90200)) \
|| ((PG_VERSION_NUM >= 90019) && (PG_VERSION_NUM < 90100))
pq_startmsgread();
#endif
return pq_getbytes(s, len);
}
int
FileRepConnServer_ReceiveMessageData(
char *data,
uint32 length)
{
if (pq_getbytes(data, length) == EOF)
{
ereport(WARNING,
(errcode_for_socket_access(),
errmsg("receive EOF on connection: %m")));
return STATUS_ERROR;
}
return STATUS_OK;
}
/* --------------------------------
* pq_getmessage - get a message with length word from connection
*
* The return value is placed in an expansible StringInfo, which has
* already been initialized by the caller.
* Only the message body is placed in the StringInfo; the length word
* is removed. Also, s->cursor is initialized to zero for convenience
* in scanning the message contents.
*
* If maxlen is not zero, it is an upper limit on the length of the
* message we are willing to accept. We abort the connection (by
* returning EOF) if client tries to send more than that.
*
* returns 0 if OK, EOF if trouble
* --------------------------------
*/
int
pq_getmessage(StringInfo s, int maxlen)
{
int32 len;
resetStringInfo(s);
/* Read message length word */
if (pq_getbytes((char *) &len, 4) == EOF)
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected EOF within message length word")));
return EOF;
}
len = ntohl(len);
if (len < 4 ||
(maxlen > 0 && len > maxlen))
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid message length")));
return EOF;
}
len -= 4; /* discount length itself */
if (len > 0)
{
/*
* Allocate space for message. If we run out of room (ridiculously
* large message), we will elog(ERROR), but we want to discard the
* message body so as not to lose communication sync.
*/
PG_TRY();
{
enlargeStringInfo(s, len);
}
PG_CATCH();
{
if (pq_discardbytes(len) == EOF)
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete message from client")));
PG_RE_THROW();
}
PG_END_TRY();
/* And grab the message */
if (pq_getbytes(s->data, len) == EOF)
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete message from client")));
return EOF;
}
s->len = len;
/* Place a trailing null per StringInfo convention */
s->data[len] = '\0';
}
return 0;
}
/*
* Receive Startup packet
* Response Client Authentication
*/
int
FileRepConnServer_ReceiveStartupPacket(void)
{
uint32 length;
int status = STATUS_OK;
char *buf = NULL;
pq_init();
status = FileRepConnServer_ReceiveMessageLength(&length);
if (status != STATUS_OK) {
goto exit;
}
if (length < (uint32) sizeof(ProtocolVersion) ||
length > MAX_STARTUP_PACKET_LENGTH) {
status = STATUS_ERROR;
ereport(WARNING,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid length of startup packet"),
FileRep_errcontext()));
goto exit;
}
buf = (char *)malloc(length +1);
if (buf == NULL) {
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("not enough memory to allocate buffer for startup packet"),
FileRep_errcontext()));
}
memset(buf, 0, length + 1);
if (pq_getbytes(buf, length) == EOF) {
status = STATUS_ERROR;
ereport(WARNING,
(errcode_for_socket_access(),
errmsg("receive EOF on connection: %m"),
FileRep_errcontext()));
goto exit;
}
port->proto = ntohl(*((ProtocolVersion *) buf));
if (PG_PROTOCOL_MAJOR(port->proto) >= 3) {
/* uint32 offset = sizeof(ProtocolVersion);*/
/*
* tell the client that it is authorized (no pg_hba.conf and
* password are required).
*/
StringInfoData buf;
/* sends AUTH_REQ_OK back to client */
FakeClientAuthentication(port);
/* send to client that we are ready to receive data */
/* similar to ReadyForQuery(DestRemoteExecute); */
pq_beginmessage(&buf, 'Z');
pq_sendbyte(&buf, 'I');
pq_endmessage(&buf);
pq_flush();
} else {
ereport(WARNING,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("not supported version"),
FileRep_errcontext()));
}
exit:
if (buf) {
free(buf);
buf = NULL;
}
return status;
}
