/*
* @msg: the complete incoming message, whose header to decode
*
* Decodes the header part of the message, but does not
* validate the decoded fields in the header. It expects
* bufferLength to refer to length of the data packet. Upon
* return bufferOffset will refer to the amount of the packet
* consumed by decoding of the header.
*
* returns 0 if successfully decoded, -1 upon fatal error
*/
int virNetMessageDecodeHeader(virNetMessagePtr msg)
{
XDR xdr;
int ret = -1;
if (msg->bufferLength < VIR_NET_MESSAGE_LEN_MAX) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Unable to decode header until len is received"));
return -1;
}
msg->bufferOffset = VIR_NET_MESSAGE_LEN_MAX;
/* Parse the header. */
xdrmem_create(&xdr,
msg->buffer + msg->bufferOffset,
msg->bufferLength - msg->bufferOffset,
XDR_DECODE);
if (!xdr_virNetMessageHeader(&xdr, &msg->header)) {
virReportError(VIR_ERR_RPC, "%s", _("Unable to decode message header"));
goto cleanup;
}
msg->bufferOffset += xdr_getpos(&xdr);
ret = 0;
cleanup:
xdr_destroy(&xdr);
return ret;
}
/*
* @msg: the outgoing message, whose header to encode
*
* Encodes the length word and header of the message, setting the
* message offset ready to encode the payload. Leaves space
* for the length field later. Upon return bufferLength will
* refer to the total available space for message, while
* bufferOffset will refer to current space used by header
*
* returns 0 if successfully encoded, -1 upon fatal error
*/
int virNetMessageEncodeHeader(virNetMessagePtr msg)
{
XDR xdr;
int ret = -1;
unsigned int len = 0;
msg->bufferLength = VIR_NET_MESSAGE_MAX + VIR_NET_MESSAGE_LEN_MAX;
if (VIR_REALLOC_N(msg->buffer, msg->bufferLength) < 0) {
virReportOOMError();
return ret;
}
msg->bufferOffset = 0;
/* Format the header. */
xdrmem_create(&xdr,
msg->buffer,
msg->bufferLength,
XDR_ENCODE);
/* The real value is filled in shortly */
if (!xdr_u_int(&xdr, &len)) {
virReportError(VIR_ERR_RPC, "%s", _("Unable to encode message length"));
goto cleanup;
}
if (!xdr_virNetMessageHeader(&xdr, &msg->header)) {
virReportError(VIR_ERR_RPC, "%s", _("Unable to encode message header"));
goto cleanup;
}
len = xdr_getpos(&xdr);
xdr_setpos(&xdr, 0);
/* Fill in current length - may be re-written later
* if a payload is added
*/
if (!xdr_u_int(&xdr, &len)) {
virReportError(VIR_ERR_RPC, "%s", _("Unable to re-encode message length"));
goto cleanup;
}
msg->bufferOffset += len;
ret = 0;
cleanup:
xdr_destroy(&xdr);
return ret;
}
