error_t pppSendEchoRep(PppContext *context,
const PppEchoPacket *echoReqPacket, PppProtocol protocol)
{
error_t error;
size_t length;
size_t offset;
NetBuffer *buffer;
PppEchoPacket *echoRepPacket;
//Retrieve the length of the Echo-Request packet
length = ntohs(echoReqPacket->length);
//Make sure the length is valid
if(length < sizeof(PppEchoPacket))
return ERROR_INVALID_LENGTH;
if(length > context->peerConfig.mru)
return ERROR_INVALID_LENGTH;
//Allocate a buffer memory to hold the Echo-Reply packet
buffer = pppAllocBuffer(sizeof(PppEchoPacket), &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Echo-Reply packet
echoRepPacket = netBufferAt(buffer, offset);
//Format packet header
echoRepPacket->code = PPP_CODE_CODE_REJ;
echoRepPacket->identifier = echoReqPacket->identifier;
echoRepPacket->length = htons(length);
echoRepPacket->magicNumber = context->localConfig.magicNumber;
//The data field of the Echo-Request packet is copied into the data
//field of the Echo-Reply packet
error = netBufferAppend(buffer, echoReqPacket->data, length - sizeof(PppEchoPacket));
//Check status code
if(!error)
{
//Debug message
TRACE_INFO("Sending Echo-Reply packet (%" PRIuSIZE " bytes)...\r\n", length);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, protocol);
}
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
error_t pppSendProtocolRej(PppContext *context, uint8_t identifier,
uint16_t protocol, const uint8_t *information, size_t length)
{
error_t error;
size_t offset;
NetBuffer *buffer;
PppProtocolRejPacket *protocolRejPacket;
//Calculate the length of the Protocol-Reject packet
length += sizeof(PppProtocolRejPacket);
//The Rejected-Information must be truncated to comply with
//the peer's established MRU
length = MIN(length, context->peerConfig.mru);
//Allocate a buffer memory to hold the Protocol-Reject packet
buffer = pppAllocBuffer(sizeof(PppProtocolRejPacket), &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Protocol-Reject packet
protocolRejPacket = netBufferAt(buffer, offset);
//Format packet header
protocolRejPacket->code = PPP_CODE_PROTOCOL_REJ;
protocolRejPacket->identifier = identifier;
protocolRejPacket->length = htons(length);
protocolRejPacket->rejectedProtocol = htons(protocol);
//The Rejected-Information field contains a copy of the
//packet which is being rejected
error = netBufferAppend(buffer, information,
length - sizeof(PppProtocolRejPacket));
//Check status code
if(!error)
{
//Debug message
TRACE_INFO("Sending Protocol-Reject packet (%" PRIuSIZE " bytes)...\r\n", length);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, PPP_PROTOCOL_LCP);
}
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
error_t chapSendResponse(PppContext *context, const uint8_t *value)
{
error_t error;
size_t n;
size_t length;
size_t offset;
NetBuffer *buffer;
ChapResponsePacket *responsePacket;
//Retrieve the length of the username
n = strlen(context->username);
//Calculate the length of the Response packet
length = sizeof(ChapResponsePacket) + MD5_DIGEST_SIZE + n;
//Allocate a buffer memory to hold the Response packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Response packet
responsePacket = netBufferAt(buffer, offset);
//Format packet header
responsePacket->code = CHAP_CODE_RESPONSE;
responsePacket->identifier = context->chapFsm.peerIdentifier;
responsePacket->length = htons(length);
responsePacket->valueSize = MD5_DIGEST_SIZE;
//Copy the Response value
memcpy(responsePacket->value, value, MD5_DIGEST_SIZE);
//The Name field is one or more octets representing the
//identification of the system transmitting the packet
memcpy(responsePacket->value + MD5_DIGEST_SIZE, context->username, n);
//Debug message
TRACE_INFO("Sending CHAP Response packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) responsePacket, length, PPP_PROTOCOL_CHAP);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, PPP_PROTOCOL_CHAP);
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
error_t pppSendTerminateAck(PppContext *context,
uint8_t identifier, PppProtocol protocol)
{
error_t error;
size_t length;
size_t offset;
NetBuffer *buffer;
PppTerminatePacket *terminateAckPacket;
//Length of the Terminate-Ack packet
length = sizeof(PppTerminatePacket);
//Allocate a buffer memory to hold the Terminate-Ack packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Terminate-Ack packet
terminateAckPacket = netBufferAt(buffer, offset);
//Format packet header
terminateAckPacket->code = PPP_CODE_TERMINATE_ACK;
terminateAckPacket->identifier = identifier;
terminateAckPacket->length = htons(length);
//Debug message
TRACE_INFO("Sending Terminate-Ack packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) terminateAckPacket, length, protocol);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, protocol);
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
error_t chapSendFailure(PppContext *context)
{
error_t error;
size_t length;
size_t offset;
NetBuffer *buffer;
PppPacket *failurePacket;
//Retrieve the length of the Failure packet
length = sizeof(PppPacket);
//Allocate a buffer memory to hold the Failure packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Failure packet
failurePacket = netBufferAt(buffer, offset);
//Format packet header
failurePacket->code = CHAP_CODE_FAILURE;
failurePacket->identifier = context->chapFsm.localIdentifier;
failurePacket->length = htons(length);
//Debug message
TRACE_INFO("Sending CHAP Failure packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) failurePacket, length, PPP_PROTOCOL_CHAP);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, PPP_PROTOCOL_CHAP);
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}
error_t lcpSendConfigureReq(PppContext *context)
{
error_t error;
size_t length;
size_t offset;
NetBuffer *buffer;
PppConfigurePacket *configureReqPacket;
//Debug message
TRACE_INFO("LCP Send-Configure-Request callback\r\n");
//Calculate the maximum size of the Configure-Request packet
length = sizeof(PppConfigurePacket) +
sizeof(LcpMruOption) + sizeof(LcpAccmOption);
//Allocate a buffer memory to hold the packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Configure-Request packet
configureReqPacket = netBufferAt(buffer, offset);
//Format packet header
configureReqPacket->code = PPP_CODE_CONFIGURE_REQ;
configureReqPacket->identifier = ++context->lcpFsm.identifier;
configureReqPacket->length = sizeof(PppConfigurePacket);
//Make sure the Maximum-Receive-Unit option has not been previously rejected
if(!context->localConfig.mruRejected)
{
//Convert MRU to network byte order
uint16_t value = htons(context->localConfig.mru);
//Add option
pppAddOption(configureReqPacket, LCP_OPTION_MRU, &value, sizeof(uint16_t));
}
//Make sure the Async-Control-Character-Map option has not been previously rejected
if(!context->localConfig.accmRejected)
{
//Convert ACCM to network byte order
uint32_t value = htonl(context->localConfig.accm);
//Add option
pppAddOption(configureReqPacket, LCP_OPTION_ACCM, &value, sizeof(uint32_t));
}
//Save packet length
length = configureReqPacket->length;
//Convert length field to network byte order
configureReqPacket->length = htons(length);
//Adjust the length of the multi-part buffer
netBufferSetLength(buffer, offset + length);
//Debug message
TRACE_INFO("Sending Configure-Request packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) configureReqPacket, length, PPP_PROTOCOL_LCP);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, PPP_PROTOCOL_LCP);
//The restart counter is decremented each time a Configure-Request is sent
if(context->lcpFsm.restartCounter > 0)
context->lcpFsm.restartCounter--;
//Save the time at which the packet was sent
context->lcpFsm.timestamp = osGetSystemTime();
//Free previously allocated memory block
netBufferFree(buffer);
//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;
}
error_t chapSendChallenge(PppContext *context)
{
error_t error;
size_t n;
size_t length;
size_t offset;
NetBuffer *buffer;
ChapChallengePacket *challengePacket;
//Retrieve the length of the username
n = strlen(context->username);
//Calculate the length of the Challenge packet
length = sizeof(ChapChallengePacket) + MD5_DIGEST_SIZE + n;
//Allocate a buffer memory to hold the Challenge packet
buffer = pppAllocBuffer(length, &offset);
//Failed to allocate memory?
if(!buffer) return ERROR_OUT_OF_MEMORY;
//Point to the Challenge packet
challengePacket = netBufferAt(buffer, offset);
//Format packet header
challengePacket->code = CHAP_CODE_CHALLENGE;
challengePacket->identifier = ++context->chapFsm.localIdentifier;
challengePacket->length = htons(length);
challengePacket->valueSize = MD5_DIGEST_SIZE;
//Make sure that the callback function has been registered
if(context->settings.randCallback != NULL)
{
//Generate a random challenge value
error = context->settings.randCallback(
context->chapFsm.challenge, MD5_DIGEST_SIZE);
}
else
{
//Report an error
error = ERROR_FAILURE;
}
//Check status code
if(!error)
{
//Copy the challenge value
memcpy(challengePacket->value, context->chapFsm.challenge, MD5_DIGEST_SIZE);
//The Name field is one or more octets representing the
//identification of the system transmitting the packet
memcpy(challengePacket->value + MD5_DIGEST_SIZE, context->username, n);
//Debug message
TRACE_INFO("Sending CHAP Challenge packet (%" PRIuSIZE " bytes)...\r\n", length);
//Dump packet contents for debugging purpose
pppDumpPacket((PppPacket *) challengePacket, length, PPP_PROTOCOL_CHAP);
//Send PPP frame
error = pppSendFrame(context->interface, buffer, offset, PPP_PROTOCOL_CHAP);
//The restart counter is decremented each time a Challenge packet is sent
if(context->chapFsm.restartCounter > 0)
context->chapFsm.restartCounter--;
//Save the time at which the packet was sent
context->chapFsm.timestamp = osGetSystemTime();
}
//Free previously allocated memory block
netBufferFree(buffer);
//Return status code
return error;
}