error_t lcpProcessConfigureReq(PppContext *context,
const PppConfigurePacket *configureReqPacket)
{
error_t error;
size_t length;
bool_t notRecognizable;
bool_t notAcceptable;
PppOption *option;
//Debug message
TRACE_INFO("\r\nLCP Receive-Configure-Request event\r\n");
//Initialize variables
error = NO_ERROR;
notRecognizable = FALSE;
notAcceptable = FALSE;
//Retrieve the length of the option list
length = ntohs(configureReqPacket->length) - sizeof(PppConfigurePacket);
//Point to the first option
option = (PppOption *) configureReqPacket->options;
//Parse configuration options
while(length > 0)
{
//Parse current option
error = lcpParseOption(context, option, length, NULL);
//Any error to report?
if(error == ERROR_INVALID_TYPE)
{
//Option not recognizable
notRecognizable = TRUE;
//Catch error
error = NO_ERROR;
}
else if(error == ERROR_INVALID_VALUE)
{
//Option not acceptable for configuration
notAcceptable = TRUE;
//Catch error
error = NO_ERROR;
}
else if(error)
{
//Malformed Configure-Request packet
break;
}
//Remaining bytes to process
length -= option->length;
//Jump to the next option
option = (PppOption *) ((uint8_t *) option + option->length);
}
//Valid Configure-Request packet received from the peer?
if(!error)
{
//Check flags
if(notRecognizable)
{
//If some configuration options received in the Configure-Request are not
//recognizable or not acceptable for negociation, then the implementation
//must transmit a Configure-Reject
pppRcvConfigureReqEvent(context, &context->lcpFsm, &lcpCallbacks,
configureReqPacket, PPP_CODE_CONFIGURE_REJ);
}
else if(notAcceptable)
{
//If all configuration options are recognizable, but some values are not
//acceptable, then the implementation must transmit a Configure-Nak
pppRcvConfigureReqEvent(context, &context->lcpFsm, &lcpCallbacks,
configureReqPacket, PPP_CODE_CONFIGURE_NAK);
}
else
{
//If every configuration option received in the Configure-Request is
//recognizable and all values are acceptable, then the implementation
//must transmit a Configure-Ack
pppRcvConfigureReqEvent(context, &context->lcpFsm, &lcpCallbacks,
configureReqPacket, PPP_CODE_CONFIGURE_ACK);
}
}
//Return status code
return error;
}
error_t pppSendConfigureAckNak(PppContext *context,
const PppConfigurePacket *configureReqPacket, PppProtocol protocol, PppCode code)
{
error_t error;
size_t length;
size_t offset;
NetBuffer *buffer;
PppConfigurePacket *configureAckNakPacket;
PppOption *option;
//Initialize status code
error = NO_ERROR;
//Retrieve the length of the Configure-Request packet
length = ntohs(configureReqPacket->length);
//Allocate a buffer memory to hold the Configure-Ack, Nak or Reject packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the beginning of the packet
configureAckNakPacket = netBufferAt(buffer, offset);
//Format packet header
configureAckNakPacket->code = code;
configureAckNakPacket->identifier = configureReqPacket->identifier;
configureAckNakPacket->length = sizeof(PppConfigurePacket);
//Retrieve the length of the option list
length -= sizeof(PppConfigurePacket);
//Point to the first option
option = (PppOption *) configureReqPacket->options;
//Parse configuration options
while(length > 0)
{
//LCP protocol?
if(protocol == PPP_PROTOCOL_LCP)
{
//Parse LCP option
lcpParseOption(context, option, length, configureAckNakPacket);
}
#if (IPV4_SUPPORT)
//IPCP protocol?
else if(protocol == PPP_PROTOCOL_IPCP)
{
//Parse IPCP option
ipcpParseOption(context, option, length, configureAckNakPacket);
}
#endif
//Remaining bytes to process
length -= option->length;
//Jump to the next option
option = (PppOption *) ((uint8_t *) option + option->length);
}
//Adjust the length of the multi-part buffer
netBufferSetLength(buffer, offset + configureAckNakPacket->length);
//Convert length field to network byte order
configureAckNakPacket->length = htons(configureAckNakPacket->length);
//Debug message
if(code == PPP_CODE_CONFIGURE_ACK)
{
TRACE_INFO("Sending Configure-Ack packet (%" PRIuSIZE " bytes)...\r\n",
ntohs(configureAckNakPacket->length));
}
else if(code == PPP_CODE_CONFIGURE_NAK)
{
TRACE_INFO("Sending Configure-Nak packet (%" PRIuSIZE " bytes)...\r\n",
ntohs(configureAckNakPacket->length));
}
else if(code == PPP_CODE_CONFIGURE_REJ)
{
TRACE_INFO("Sending Configure-Reject packet (%" PRIuSIZE " bytes)...\r\n",
ntohs(configureAckNakPacket->length));
}
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) configureAckNakPacket,
ntohs(configureAckNakPacket->length), protocol);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, protocol);
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
