/*****************************************************************************
Function:
static void DHCPReplyToDiscovery(BOOTP_HEADER *Header, int netIx)
Summary:
Replies to a DHCP Discover message.
Description:
This function replies to a DHCP Discover message by sending out a
DHCP Offer message.
Precondition:
None
Parameters:
Header - the BootP header this is in response to.
netIx - interface index
Returns:
None
***************************************************************************/
static void DHCPReplyToDiscovery(BOOTP_HEADER *Header, int netIx)
{
uint8_t i;
NET_CONFIG* pConfig;
UDP_SOCKET s;
// Set the correct socket to active and ensure that
// enough space is available to generate the DHCP response
s = MySocket[netIx];
if(UDPIsPutReady(s) < 300u)
return;
pConfig = UDPSocketGetNet(s);
// Begin putting the BOOTP Header and DHCP options
UDPPut(s, BOOT_REPLY); // Message Type: 2 (BOOTP Reply)
// Reply with the same Hardware Type, Hardware Address Length, Hops, and Transaction ID fields
UDPPutArray(s, (uint8_t*)&(Header->HardwareType), 7);
UDPPut(s, 0x00); // Seconds Elapsed: 0 (Not used)
UDPPut(s, 0x00); // Seconds Elapsed: 0 (Not used)
UDPPutArray(s, (uint8_t*)&(Header->BootpFlags), sizeof(Header->BootpFlags));
UDPPut(s, 0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
UDPPut(s, 0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
UDPPut(s, 0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
UDPPut(s, 0x00); // Your (client) IP Address: 0.0.0.0 (none yet assigned)
UDPPutArray(s, (uint8_t*)&DHCPNextLease[netIx], sizeof(IP_ADDR)); // Lease IP address to give out
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPutArray(s, (uint8_t*)&(Header->ClientMAC), sizeof(MAC_ADDR)); // Client MAC address: Same as given by client
for(i = 0; i < 64+128+(16-sizeof(MAC_ADDR)); i++) // Remaining 10 bytes of client hardware address, server host name: Null string (not used)
UDPPut(s, 0x00); // Boot filename: Null string (not used)
UDPPut(s, 0x63); // Magic Cookie: 0x63538263
UDPPut(s, 0x82); // Magic Cookie: 0x63538263
UDPPut(s, 0x53); // Magic Cookie: 0x63538263
UDPPut(s, 0x63); // Magic Cookie: 0x63538263
// Options: DHCP Offer
UDPPut(s, DHCP_MESSAGE_TYPE);
UDPPut(s, 1);
UDPPut(s, DHCP_OFFER_MESSAGE);
// Option: Subnet Mask
UDPPut(s, DHCP_SUBNET_MASK);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyMask, sizeof(IP_ADDR));
// Option: Lease duration
UDPPut(s, DHCP_IP_LEASE_TIME);
UDPPut(s, 4);
UDPPut(s, (DHCP_LEASE_DURATION>>24) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION>>16) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION>>8) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION) & 0xFF);
// Option: Server identifier
UDPPut(s, DHCP_SERVER_IDENTIFIER);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// Option: Router/Gateway address
UDPPut(s, DHCP_ROUTER);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// Option: DNS server address
UDPPut(s, DHCP_DNS);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// No more options, mark ending
UDPPut(s, DHCP_END_OPTION);
// Add zero padding to ensure compatibility with old BOOTP relays that discard small packets (<300 UDP octets)
while(UDPGetTxCount(s) < 300u)
UDPPut(s, 0);
// Force remote destination address to be the broadcast address, regardless
// of what the node's source IP address was (to ensure we don't try to
// unicast to 0.0.0.0).
memset((void*)&UDPSocketDcpt[s].remoteNode, 0xFF, sizeof(NODE_INFO));
// Transmit the packet
UDPFlush(s);
}
/*****************************************************************************
Function:
static void DHCPReplyToRequest(BOOTP_HEADER *Header, bool bAccept, int netIx)
Summary:
Replies to a DHCP Request message.
Description:
This function replies to a DHCP Request message by sending out a
DHCP Acknowledge message.
Precondition:
None
Parameters:
Header - the BootP header this is in response to.
bAccept - whether or not we've accepted this request
netIx - interface index
Returns:
None
Internal:
Needs to support more than one simultaneous lease in the future.
***************************************************************************/
static void DHCPReplyToRequest(BOOTP_HEADER *Header, bool bAccept, int netIx)
{
uint8_t i;
NET_CONFIG* pConfig;
UDP_SOCKET s;
// Set the correct socket to active and ensure that
// enough space is available to generate the DHCP response
s = MySocket[netIx];
if(UDPIsPutReady(s) < 300u)
return;
pConfig = UDPSocketGetNet(s);
// Search through all remaining options and look for the Requested IP address field
// Obtain options
while(UDPIsGetReady(s))
{
uint8_t Option, Len;
uint32_t dw;
// Get option type
if(!UDPGet(s, &Option))
break;
if(Option == DHCP_END_OPTION)
break;
// Get option length
UDPGet(s, &Len);
// Process option
if((Option == DHCP_PARAM_REQUEST_IP_ADDRESS) && (Len == 4u))
{
// Get the requested IP address and see if it is the one we have on offer. If not, we should send back a NAK, but since there could be some other DHCP server offering this address, we'll just silently ignore this request.
UDPGetArray(s, (uint8_t*)&dw, 4);
Len -= 4;
if(dw != DHCPNextLease[netIx].Val)
{
bAccept = false;
}
break;
}
// Remove the unprocessed bytes that we don't care about
while(Len--)
{
UDPGet(s, &i);
}
}
// Begin putting the BOOTP Header and DHCP options
UDPPut(s, BOOT_REPLY); // Message Type: 2 (BOOTP Reply)
// Reply with the same Hardware Type, Hardware Address Length, Hops, and Transaction ID fields
UDPPutArray(s, (uint8_t*)&(Header->HardwareType), 7);
UDPPut(s, 0x00); // Seconds Elapsed: 0 (Not used)
UDPPut(s, 0x00); // Seconds Elapsed: 0 (Not used)
UDPPutArray(s, (uint8_t*)&(Header->BootpFlags), sizeof(Header->BootpFlags));
UDPPutArray(s, (uint8_t*)&(Header->ClientIP), sizeof(IP_ADDR));// Your (client) IP Address:
UDPPutArray(s, (uint8_t*)&DHCPNextLease[netIx], sizeof(IP_ADDR)); // Lease IP address to give out
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Next Server IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPut(s, 0x00); // Relay Agent IP Address: 0.0.0.0 (not used)
UDPPutArray(s, (uint8_t*)&(Header->ClientMAC), sizeof(MAC_ADDR)); // Client MAC address: Same as given by client
for(i = 0; i < 64+128+(16-sizeof(MAC_ADDR)); i++) // Remaining 10 bytes of client hardware address, server host name: Null string (not used)
UDPPut(s, 0x00); // Boot filename: Null string (not used)
UDPPut(s, 0x63); // Magic Cookie: 0x63538263
UDPPut(s, 0x82); // Magic Cookie: 0x63538263
UDPPut(s, 0x53); // Magic Cookie: 0x63538263
UDPPut(s, 0x63); // Magic Cookie: 0x63538263
// Options: DHCP lease ACKnowledge
if(bAccept)
{
UDPPut(s, DHCP_OPTION_ACK_MESSAGE);
UDPPut(s, 1);
UDPPut(s, DHCP_ACK_MESSAGE);
}
else // Send a NACK
{
UDPPut(s, DHCP_OPTION_ACK_MESSAGE);
UDPPut(s, 1);
UDPPut(s, DHCP_NAK_MESSAGE);
}
// Option: Lease duration
UDPPut(s, DHCP_IP_LEASE_TIME);
UDPPut(s, 4);
UDPPut(s, (DHCP_LEASE_DURATION>>24) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION>>16) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION>>8) & 0xFF);
UDPPut(s, (DHCP_LEASE_DURATION) & 0xFF);
// Option: Server identifier
UDPPut(s, DHCP_SERVER_IDENTIFIER);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// Option: Subnet Mask
UDPPut(s, DHCP_SUBNET_MASK);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyMask, sizeof(IP_ADDR));
// Option: Router/Gateway address
UDPPut(s, DHCP_ROUTER);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// Option: DNS server address
UDPPut(s, DHCP_DNS);
UDPPut(s, sizeof(IP_ADDR));
UDPPutArray(s, (uint8_t*)&pConfig->MyIPAddr, sizeof(IP_ADDR));
// No more options, mark ending
UDPPut(s, DHCP_END_OPTION);
// Add zero padding to ensure compatibility with old BOOTP relays that discard small packets (<300 UDP octets)
while(UDPGetTxCount(s) < 300u)
UDPPut(s, 0);
// Force remote destination address to be the broadcast address, regardless
// of what the node's source IP address was (to ensure we don't try to
// unicast to 0.0.0.0).
memset((void*)&UDPSocketDcpt[s].remoteNode, 0xFF, sizeof(NODE_INFO));
// Transmit the packet
UDPFlush(s);
}
/*****************************************************************************
Function:
int sendto(SOCKET s, const char* buf, int len, int flags, const struct sockaddr* to, int tolen)
Summary:
This function used to send the data for both connection oriented and connection-less
sockets.
Description:
The sendto function is used to send outgoing data on a socket.
The destination address is given by to and tolen. Both
Datagram and stream sockets are supported.
Precondition:
socket function should be called.
Parameters:
s - Socket descriptor returned from a previous call to socket.
buf - application data buffer containing data to transmit.
len - length of data in bytes.
flags - message flags. Currently this field is not supported.
to - Optional pointer to the the sockaddr structure containing the
destination address. If NULL, the currently bound remote port and IP
address are used as the destination.
tolen - length of the sockaddr structure.
Returns:
On success, sendto returns number of bytes sent. In case of
error returns SOCKET_ERROR (and errno set accordingly).
Remarks:
None.
***************************************************************************/
int sendto( SOCKET s, const char* buf, int len, int flags, const struct sockaddr* to, int tolen )
{
struct BSDSocket *socket;
UDP_SOCKET_DCPT* udpSkt;
int size = SOCKET_ERROR;
NODE_INFO remoteInfo;
uint16_t wRemotePort;
struct sockaddr_in local;
if( s >= BSD_SOCKET_COUNT )
{
errno = EBADF;
return SOCKET_ERROR;
}
socket = &BSDSocketArray[s];
if(socket->bsdState == SKT_CLOSED)
{
errno = EBADF;
return SOCKET_ERROR;
}
if(socket->SocketType == SOCK_DGRAM) //UDP
{
// Decide the destination IP address and port
remoteInfo.IPAddr.Val = socket->remoteIP;
wRemotePort = socket->remotePort;
if(to)
{
if((unsigned int)tolen != sizeof(struct sockaddr_in))
{
errno = EFAULT;
return SOCKET_ERROR;
}
wRemotePort = ((struct sockaddr_in*)to)->sin_port;
remoteInfo.IPAddr.Val = ((struct sockaddr_in*)to)->sin_addr.s_addr;
// Implicitly bind the socket if it isn't already
if(socket->bsdState == SKT_CREATED)
{
memset(&local, 0x00, sizeof(local));
if(bind(s, (struct sockaddr*)&local, sizeof(local)) == SOCKET_ERROR)
return SOCKET_ERROR;
}
}
if(remoteInfo.IPAddr.Val == IP_ADDR_ANY)
remoteInfo.IPAddr.Val = 0xFFFFFFFFu;
// Set the remote IP and MAC address if it is different from what we already have stored in the UDP socket
udpSkt = UDPSocketDcpt + socket->SocketID;
if(TCPIP_IPV4_GetDestAddress(udpSkt->pTxPkt).Val != remoteInfo.IPAddr.Val)
{
TCPIP_IPV4_SetDestAddress(udpSkt->pTxPkt, remoteInfo.IPAddr.Val);
if(!ARPIsResolved(UDPSocketGetNet(socket->SocketID), &remoteInfo.IPAddr, &((IPV4_PACKET*)udpSkt->pTxPkt)->remoteMACAddr))
{
errno = EINPROGRESS;
return SOCKET_ERROR;
}
}
// Select the UDP socket and see if we can write to it
if(UDPIsTxPutReady(socket->SocketID, len))
{
// Set the proper remote port
udpSkt->remotePort = wRemotePort;
// Write data and send UDP datagram
size = UDPPutArray(socket->SocketID, (uint8_t*)buf, len);
UDPFlush(socket->SocketID);
return size;
}
}
else if(socket->SocketType == SOCK_STREAM) //TCP will only send to the already established socket.
{
if(socket->bsdState != SKT_EST)
{
errno = ENOTCONN;
return SOCKET_ERROR;
}
if(HandlePossibleTCPDisconnection(s))
{
errno = ECONNRESET;
return SOCKET_ERROR;
}
// Handle special case were 0 return value is okay
if(len == 0)
return 0;
// Write data to the socket. If one or more bytes were written, then
// return this value. Otherwise, fail and return SOCKET_ERROR.
size = TCPPutArray(socket->SocketID, (uint8_t*)buf, len);
if(size)
return size;
}
errno = EWOULDBLOCK;
return SOCKET_ERROR;
}
