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TCP/IP & Routing User Manual

1. Comment stxUDP_AddConn must have been called before using this function 9 3 Notify Codes One notify code transfers a pointer to a UDP information structure This structure is mainly used to pass all important properties regarding to a UDP connection When sevenstaxUDP has posted an NC UDP RECH event to the handler routine of the application some members contain values which describe the connection typedef struct tag UDP INFORMATION IPV4 WANES Ui addrsssr IP address et pose IPV4 dest ip address f owe IP or broadeast multicast UINT16 stx remote port 7 Port number of peer UINTIG Stx dest port Our port number UINT16 st datasize Length of received data UINT8 stx FPTR stx data Boimes to receiveg data UDP_INFORMATION UINT8_stx FPTR_stx data Points to received data The application must only use this pointer and the data referenced to as long as the called function notify handler is active IPV4 remote_ip_address Remote IP address sender might be Unicast Multicast or Broadcast IPV4 dest_ip_address Destination IP address receiver might be Unicast Multicast or Broadcast File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 66 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES UINT16 stx datasize Amount of data in bytes data points to UINT16 stx remote port IP Port number
2. include ethernet h inelude arp h include nie p endif if PPP SUPPORTED 1 include ppp h endif Fife LEPRSUPPORDED Iinelude Mtep lal endif UDP_SUPPORTED 1 include udp h endif alse HTTPSERV SUPPORTED iL include httpserv h endif LE DHCP_SUPPORTED 1 include dhep h endif in AU Ol Pov OR iE is include auto_ip h endif alae DNS SUPPORTED PR DNS SRV SUPPORTED i include dns h endif SL MDNS SUPPORTED 1 include mdns h endif alae NBNS_SUPPORTED 1 include nbns h endif ES NTP_SUPPORTED 1 include ntp h endif File sevenstaxTCPIPRout_UserManual_V53 odt Revision No 5 03 Page 21 79 printed 23 06 08 Public S VENSTAX TCP IP amp Routing User Manual Fee EPP eee tes 5 IP Module Single Device 5 1 Overview Inside sevenstaxTCP IP the single device version of the IP protocol layer is narrow A device with this network layer module has exactly one IP address and is part of one subnet In particular this device can only communicate over one physical interface like Ethernet or a modem The module holds the own IP address subnet mask two DNS servers and a standard gateway When receiving packets the following steps are done gt The IP checksum is checked If the check fails the packet is rejected gt Then the target IP address is checked in relation to the current network configur
3. 2 automatic close This parameter controls generation of additional optional keep alive TCP packets and handling of long time connections without traffic Some application or connection types might need this feature to validate an open TCP connection If set to 0 no keep alive handling nor connection surveillance is executed This is the default behaviour If set to 1 keep alive packets will automatically be sent to the remote client in TCP_KEEP_ALIVE_INTERVAL seconds If set to 2 no keep alive packets will be sent But TCP connections will automatically be closed after TCP_KEEP_ALIVE_INTERVAL seconds without traffic TCP_KEEP_ALIVE_INTERVAL default 7200 If TCP KEEP ALIVE HANDLING is set to 1 this is the time interval in seconds to repeat sending keep alive TCP packets If TCP KEEP ALIVE HANDLING is set to 2 this is the time interval in seconds after which an open TCP connection will be closed because of no traffic TCP CHECK CRC default 1 Enables checking the checksum of received packets File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 62 79 Public l S VENSTAX TCP IP amp Routing User Manual Fee AER RTM_MAXDATA default Max size of TCP send payload The maximum size in bytes of a single TCP packet to be sent Of course stxT CP_WriteBulk handles larger amount of data by fragmenting it into several packets of RTM MAXDATA byte size With the default value exactly o
4. If you like to do some TCP reactions write open close etc due to incoming notify codes execute them AFTER SstxXXX Tick functions This will prevent any interference between your application and the TCP stack Do not write to RX TX buffers sevenstaxTCP IP might be in a state where it waits for some data or builds a packet for transmission Therefore changing buffer contents can cause sevenstaxTCP IP to misbehave 4 4 Include sevenstax Header Files The sevenstax library code contains a lot of header files h to define e g stack usage parameters and special prototypes The sevenstax libraries internally handle all necessary include files for themselves To reduce complexity sevenstax decided not to include header files into header files The user application might use some or all of the sevenstax internet suite features To help the developer to find the correct header files and to include them in an order corresponding to the dependencies sevenstax here gives you a standard dependency list which might be used in the user application File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 20 79 Public TCP IP amp Routing User Manual SEVENSTAX please include these common headers in given order include features h include stxtypes h include protdefs h include pktdesc h include debugstx h add protocol specific headers include ipv4 h FE ETHERNET SUPPORTED 1
5. e Because the DNS protocol needs UDP as the transport layer set UDP SUPPORTED to 1 in features h too Also assure at least 1 free UDP instance with UDP MULTI in udp_defs h e The address of the DNS server can be retrieved via the Internet Service Provider if PPP is used via the DHCP Server if Ethernet is used or manually The primary DNS server should be used preferentially The secondary DNS server should be used only if the primary DNS server is down e Call StxXDNS Init once to set up sevenstaxDNS internal state e After initialization of DNS call stxDNS_QueryStart supplied with the IP address of the DNS server and the name of the server that will be searched The DNS local port is set automatically by the sevenstax software e In your main loop or operating system task call stxDNS_Tick repeatedly in order to keep alive and finish DNS queries e On completion sevenstaxTCP IP will notify the application either with NC DNS IP or NC DNS TIMEOUT e When receiving the event NC DNS IP which means that the DNS server has answered the delivered IP address can be contacted File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 68 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 10 2 Protocol API 10 2 1 stxDNS_Init handler Description Sets up some internal variables and registers the application callback function Must be called before us
6. on port 80 decimal Return Value UINT16 stx The sevenstaxTCP internal connection ID or an error value INVALID CONNECTION ID Subsequent calls into sevenstaxTCP must use this value to identify the connection Also events which the application receives by its handler procedure carry connection IDs Comment stxTCP_Listen only succeeds if a free TCP instance is found 8 2 5 stxTCP WriteBulk uConnld data len SendDynamic Description When a connection is established stxTCP WriteBulk can be used to send data to the remote station This function returns immediately and sends data asynchronously the next time stxTCP_Tick is called Parameter UINT16_stx uConnld connection ID where to send Can be obtained either by a call to stx TCP_Connect or StxTCP_Listen UINT8_stx FPTR_stx data Pointer to the data to send points to the first byte of the data that should be sent UINT32_stx len Size of the data in bytes If bSendDynamic TRUE_stx is used this length should be at least the number of bytes assumed to be sent see comment below BOOL_stx bSendDynamic Get data to send via notify handler Set it to FALSE_stx per default TRUE_stx might be used by an application which dynamically generates send data instead of simply giving a const data pointer sevenstaxTCP will repeatedly call the application notify handler with notify code NC_TCP_GET_TXDATA to request data to send See section 8 3 6 for details Return
7. A simple DNS client is part of sevenstaxTCP IP standard Internet library The application can send a DNS query to get the IP address of server with a known name DNS can be enabled by setting DNS SUPPORTED to 1 in features h see section 2 Supported Protocols The DNS protocol works ahead UDP so UDP_SUPPORTED must be set to 1 too see section 2 Supported Protocols For humans it is more convenient to work with readable names instead of IP addresses For example the URL www yahoo com to access a website instead of using the IP address 64 58 79 230 is much easier to memorize That is the reason why DNS was created A DNS or domain name service converts names to their corresponding IP addresses The modern DNS is organised a bit like a tree There is a root called with certain main branches called top level domains TLD At the root are a few servers e g a root servers net b root servers net which know all addresses of all the servers which handle individual TLDs Top Level Domains such as com edu mil or net Communication with the DNS is done by UDP on port 53 DNS client software so called resolvers must send special packets see RFC 1035 to the DNS server The DNS server on his part sends back a packet containing some records which contain e g the IP address To use sevenstaxTCP IP s integrated DNS resolver within your application the following steps are required In features h set DNS SUPPORTED to 1
8. In this version the function does nothing Parameter Return Value Comment File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 64 79 Public S VENSTAX TCP IP amp Routing User Manual 9 2 3 stxUDP_AddConn hSubConn local port fProcessFunction Description Calling this function will enable one of the possible UDP MULTI UDP instances to be used for sending and or listening UDP packets If fProcessFunction is NULL_stx any incoming UDP data will be transferred to the application via the notify code NC_UDP_RECV If fProcessFunction is NULL_stx incoming UDP data will directly be transferred to the given process function The application will not be notified Parameter CONN_HNDL_TYPE hSubConn only multi device version Connection handle of underlying network layer If NULL_stx no restriction is made concerning the local IP subnet UINT16 stx ocal_port Local UDP port that is to be activated active sending and passive listening UDP PROCESS FCT fProcessFunction The application or stack internal function which will be called directly with a UDP information structure as parameter to process the UDP data If being set to NULL stx the standard UDP notify handler will be called with notify code NC UDP RECH anda UDP information structure The UDP information structure is described below in the chapter Notify Codes Return Value UINT16 stx UDP connection ID to be used
9. STATUS state UINT16 stx size UINTS8 stx FPTR stx data UINT8 stx FPTR stx payload PACKET DESC The packet descriptor is used to hold information about a data packet and for easy passing of this information between internal functions by reference PACKET_STATUS state indicates whether the packet is in use i e under construction or ready for further processing It is for internal use only must not be initialized or changed by the application or lower network components FPTR_stx data points to the location of the first byte in memory This is the place where the packet s data is stored including link layer headers UINT16_stx size specifies the length in bytes of the entire range pointed to by FPTR_stx data FPTR_stx payload points to the first byte of the IP header This is usually the first byte after the end of the link layer header Packet descriptors are also used by sevenstaxPPP and sevenstaxEthernet to deliver packets to higher network protocols such as IPv4 3 2 IPV4 the IP Address typedef union tag IPV4 struct UINT8 stx bl UINT8 stx b2 UINT8 stx b3 UINT8 stx b4 ipb UINT32 stx ipl IPV4 An IP address is actually a 32 bit value which is often shown as 4 decimal values separated by dots for better readability e g 192 168 0 51 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 12 79 Public S VENSTAX TCP IP
10. TCP disconnection states TRUE_stx forces an immediate RST Might be useful in case of any connection problems Return Value BOOL_stx TRUE_stx if a close can be performed FALSE stx otherwise Comment Usually stxTCP_Disconnect only fails when the connection is already in its closed state File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 58 79 Public S VENSTAX TCP IP amp Routing User Manual 8 2 7 stxTCP_GetState uConnld Description This function can be called by the application to get the state of a TCP connection Parameter UINT16_stx uConnld connection ID of TCP connection connection ID was returned by stxTCP_Connect or stxTCP_Listen Return Value TCP_STATUS Status of TCP connection Comment 8 3 Notify Codes With one of the NC TCP XXX codes sevenstaxTCP will call the handler procedure to inform about occurred events Some notify codes transfer a pointer to a TCP information structure This structure is mainly used to pass all important properties regarding to a TCP connection E g when sevenstaxTCP has posted an NC_TCP_CONNECTED event to the handler routine of the application some members remote ip address remote port and local port contain values which describe the connection typedef struct tag TCP INFORMATION UINTS stx FPTR stx data f Points to received data IPV4 WENO Bio eddrsssr IP address Wie pose 20 IPV4 dest ip addres
11. Value BOOL_stx TRUE_stx if stxTCP_WriteBulk has accepted a request to send Otherwise File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 57 79 Public S VENSTAX TCP IP amp Routing User Manual FALSE_stx Succeeds only if a connection is established and no transmission is currently in progress Comment Because sevenstaxTCP is designed to run on small embedded systems it does not copy the data but operates on the source to avoid wasting memory This function is able to send huge amounts of data to the remote station Data is fragmented into RTM_MAXDATA sized pieces and internally sent out using multiple calls NC_TCP_TXREADY is issued only after the last fragment was successfully transmitted and acknowledged Please Note The data and possibly a reference must remain constant until stxTCP_WriteBulk has finished which is signaled by an NC_TCP_TXREADY event see below 8 2 6 stxTCP_Disconnect uConnld bForced Description This function can be called by the application to end a TCP connection sevenstaxTCP does all necessary actions to close a TCP connection gracefully The application receives the result as a call to its handler procedure NC TCP FIN Parameter UINT16_stx uConnld connection ID of TCP connection to be closed connection ID was returned by stxTCP_Connect or stxTCP_Listen BOOL_stx bForced Default FALSE stx should be used to support normal
12. connections are required this specifies the maximum number of simultaneous connections For a single connection TCP set this parameter to 0 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 61 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSERUED TECHNOLOGIES Please keep in mind that RAM requirements increase by about 100 Bytes per defined TCP_MULTI instance TCP_MULTI_TICKS default 1 valid 1 n If multiple connections are needed this specifies the number of connections which are handled by a single call to stx TCP_Tick This value is ignored if TCP MULTI is set to 0 RTM_TIMEOUT default 5000 Retransmission timeout This is the time in milliseconds within a transmitted packet must be acknowledged If sevenstaxTCP does not receive an ACK the packet will be resent RTM_MAXRETRIES default 12 This is the number of attempts sevenstaxTCP will make to transmit a single packet to the other end TCP_CONNECTION_RETRIES default 10 This is the number of attempts sevenstaxTCP will make to establish a connection TCP_SYN_REPEAT default 3000 Delay in ms between SYN TX retries while establishing connection TCP_FINACK_TIMEOUT default 20000 Timeout in ms to wait for ACK of remote to our FINACK TCP_FINACK_REPEAT default 3000 Delay in ms between FINACK TX retries while closing connection TCP_KEEP_ALIVE_HANDLING default 0 off valid 1 sending keep alive packets
13. d must point to the destination IP address of the received packet l must point to the local IP address p must point to the packet descriptor of the received packet File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 29 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 5 5 Adjustable Parameters IP EXTERNAL BROADCAST MASK default 000000FFh valid 00000000h FFFFFFFFh With this macro you can define which local broadcast IP packets which are not identified because of the actually set subnet mask are identified as local broadcasts anyway E g if the local subnet mask is set to 255 255 0 0 you would identify IP packets with target IP x y z 255 as local broadcasts which are external because not based on the local subnet mask if the macro has the default value File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 30 79 Public S VENSTAX TCP IP amp Routing User Manual Ve PEREESUED THSEROUES TES 6 IP Module Multi Device 6 1 Overview Inside sevenstaxTCP IP the multi device version of the IP protocol layer is comprehensive A device with this network layer module can act as a multi homed host This means that it can have more than one IP address and can be part of multiple subnets that are based on one or more physical interfaces like Ethernets or modems PPP The module holds the own IP address and two DNS s
14. generate a compiler error of this kind features h not yet adapted to your system Please check settings in features h The following settings need to be checked or changed for your target system 4 2 1 Alignment and Endianess features h Alignment and endianess are essential settings for a target CPU The following settings take effect in the wordaccess h target specific settings for byte struct handling Please adapt to your target system pragma BYTEALIGN enable this if compiler processor supports byte alignment by default define BYTEALIGNED CO 9 set to 1 GE your target cpu supports byte elicnment define LITTLE ENDIAN 1 set to 1l if your target cpu stores multibyte values in network order 4 2 2 Packing features h stx_pack h stx_unpack h Also packing is an essential setting for a target CPU dealing with multibyte data like IP addresses The following defines are placed before and after every structure which needs packing They can be set globally in the features h define STX PACK PRE e g set it to packed if ARM compiler used piscina Sie INS POST Ae BoC S t ie tee 1 eiciewalowies packed NI LE Gee 5050 a Additionally there are the files stx_pack h and stx_unpack h for those compiler directives than can not be mapped in a define e g pragma pack 1 for packing and pragma pack 0 for unpacking They are included before and after the
15. is a local IP address for the given data link connection Parameter CONN_HNDL_TYPE hSubConn Handle of data link connection CONST stx IPV4 FPTR_stx ps PAddress Pointer to IP address that is to be checked Return Value UINT8_stx 0 IP_MULTI 1 If given IP address is a local IP address UINT8_stx_MAX If given IP address is no local IP address File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 34 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSENDED TECHNOLOGIES 6 2 10 stxIP SetStdGateway psGateway hConn Description Sets manually given IP address and interface as standard gateway Parameter IPV4 FPTR stx psGatewaylP Pointer to IP address of standard gateway CONN HNDL TYPE hConn Handle of local IP subnet over which the interface is given result of stxIP Attach function call Return Value BOOL stx TRUE stx Standard gateway was set successfully FALSE stx Standard gateway could not be set successfully 6 2 11 stxIP DelStdGateway Description Deletes the standard gateway Parameter Return Value 6 2 12 stxIP GetStdGateway void Description Returns current standard gateway Parameter Return Value IPV4 FPTR stx Pointer to standard gateway printed 23 06 08 File sevenstaxTCPIPRout_UserManual_V53 odt Page 35 79 Public Revision No 5 03 S VENSTAX TCP IP amp Routing User Manual 6 2 13 stxIP SaveStdGateway De
16. of entries in the translation table NAT CHECK CHECKSUM default 1 valid 0 1 With this parameter you can enable the checking of the checksum of delivered TCP and UDP packets NAT MASQUERADE EXT IP ADDR default 1 valid 0 1 With this parameter you can enable the feature to masquerade the external IP address see also stxNAT_ SetMasqExtlPFunction File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 50 79 Public TCP IP amp Routing User Manual S VENSTAX 8 TCP Module 8 1 Overview TCP is part of sevenstaxTCP IP standard Internet library It can be enabled by setting TCP_SUPPORTED to 1 in features h see section 2 Supported Protocols 8 1 1 8 1 2 TCP Basics TCP is a connection oriented protocol This means that TCP has to compensate these deranging side effects of the underlying network e Packet loss e Packet duplication e Out of order data delivery To perform these tasks some kind of acknowledging and confirmation must be used For this purpose TCP packets carry additional information such as sequence acknowledge numbers and bit flags Before two Hosts using TCP can exchange data they must synchronize connect to each other This is done by both stations exchanging a special sequence of datagrams where they tell their initial sequence numbers During operation each TCP knows what the other end awaits and tries to deliver the packets that the other TCP has orde
17. of third parties resulting from its use No license is granted under any patents or patent rights of sevenstax This document is an intellectual property of sevenstax GmbH Unauthorized copying and distribution is prohibited Copyright c 2002 2008 by sevenstax GmbH File sevenstaxTCPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 79 79 Public
18. second and third parameters may carry additional information depending on the message Please see the adequate header file for details 4 3 4 Return Value Per default sevenstaxTCP IP does not use the return value of the notify handler function of the application But there are rare cases in which this value is essential e g in conjunction with NC_TCP_GET_TXDATA and NC_HTTP_DYNINFO For details please take a closer look into API documentation of the protocols 4 3 5 Registering a Notify Handler By calling each stxXXX Init function with appropriate parameter the application registers such a handler procedure at sevenstaxTCP IP The application might use always the same handler procedure for all the protocols In such case the notify handler might be a very big switch case construction Another way is to register dedicated notify handler procedures so that each handler already has a dedicated responsibility which might reduce complexity of source code In practise it has been an advantage to distinguish between a common notify handler for all sevenstaxTCP IP protocols and special notify handlers for modules of other sevenstax products e g sevenstaxWebserver 4 3 6 Using the Notify Handler There are some general rules for executing code inside the notify handler procedure Leave as fast as possible When sevenstaxTCP IP signals events it cannot proceed before the handler procedure has exited If you do lengthy tasks inside t
19. stx if route has been changed otherwise FALSE stx File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 37 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSERUED TECHNOLOGIES 6 2 18 stxIP DeleteRoute ulndex Description Deletes a route in the routing table Parameter UINT8 stx ulndex Routing table index result from stxIP AddRoute Return Value BOOL_stx TRUE_stx if route has been deleted otherwise FALSE_stx 6 2 19 stxIP IsRouteEmpty ulndex Description Checks if the denoted routing table entry is empty Parameter UINT8_stx ulndex Routing table index result from stxIP_AddRoute Return Value BOOL_stx TRUE stx if route is empty otherwise FALSE_stx 6 2 20 stxIP SetRoutingToLocalSubnet hConn eRoutingType Description Sets the routing property to the given local IP subnet When activated all packets from another IP subnet that are directed to the given IP subnet are routed The default setting is no routing in which case all these packets are rejected Parameter CONN_HNDL_TYPE hConn Handle of local IP subnet result of stxIP_Attach function call IPV4 ROUTING TYPE eRoutingType Routing type In this version there are the following possibilities 0 IPV4 NO ROUTING no routing 1 IPV4_ ROUTING FORWARD simple forwarding 2 IPV4_ROUTING_NAT network address translation Return Value BOOL_stx TRUE stx if routing property
20. valme Sieypsyjooieere IWS define GET TRGT SEC SHORT gwSecCounter f Arlette y 4 2 4 Controlling sevenstaxTCP IP features features h This file controls features and therefore the resource requirements of sevenstaxTCP IP You can enable disable a complete protocol support by simply writing a 1 or O for the dedicated define Disabled features won t be compiled and linked Features that effect only one module are defined in the module specific header file module defs h Please do not comment out unused features use 0 or 1 only AR PuOLocolse define TCP_SUPPORTED 1 Enables TCP define UDP SUPPORTED I Enables UDP define DNS SUPPORTED 0 Enables simple DNS client define DNS SRV SUPPORTED 1 Enables enhanced DNS server and client define NTP_SUPPORTED L Enables NTP Network Time Protocol deine TCEMPISUERRORTED 1 Enables ICMP Ping responses define HTTPSERV_SUPPORTED 1 Enables HTTP server Ar seriall define PPP SUPPORTED 0 EE define MODEM SUPPORTED 0 Enables Modem driver define NULLMODEM SUPPORTED 0 Enables Nullmodem driver 5 ethernet define ETHERNET SUPPORTED il Enabled Ethernet define MDNS SUPPORTED d EE define BOOTP SUPPORTED 0 Enables BOOTP define DHCP_SUPPORTED 1 Enables DHCP define AUTOIP SUPPORTED 1 Enables Auto TP define NBNS SUPPORTED il Enables NBNS NetBIOS Name Service Pl
21. whole structure type definition You can adapt these files to your application e g if packing should not be disabled for your application So every structure which needs packing is defined as include stx packi ni typedef STX PACK PRE struct tag EXAMPLE PACKET STX PACK POST EXAMPLE PACKET include stx unpack h File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 16 79 Public S VENSTAXx TCP IP amp Routing User Manual 4 2 3 System Time features h sevenstaxTCP IP needs a system time to execute the protocols timing behaviour A simple counter delivering milliseconds must be prepared by the user application Dedicated macros are prepared to easily integrate the user applications time e g as direct variable access or by a function returning that time The easiest way is to simply implement a target cpu timer generating an interrupt every 1 ms and than incrementing the given counters variables below time base for stacks target system specific Please insert your application variables functions here extern unsigned long gdwMilliSecCounter extern unsigned long gdwSecCounter extern unsigned short gwMilliSecCounter extern unsigned short gwSecCounter define GET TRGT MSEC gdwMilliSecCounter M 32 bit value supported e g by TSR define GET TRGT MSEC SHORT gwMilliSecCounter ZS rem define GET TRGT SEC gdwSecCounter f S2 olt
22. 0 79 Public S VENSTAXx TCP IP amp Routing User Manual Parameter 1 points to a TCP INFORMATION structure which describes the incoming data packet All members are valid Parameter 2 is a Connection ID which identifies the connection ReturnValue not used 8 3 5 NC_TCP_TXREADY TCP Info ConnlID This event is posted to signal the application that sevenstaxTCP is ready to accept data for next transmission It occurs after sevenstaxTCP has received an ACK as an answer to the transmitted data After getting NC_TCP_TXREADY the buffer allocated for stxTCP_WriteBulk can be reused freed NC_TCP_TXREADY is issued after sevenstaxTCP has transmitted the entire range of data which was specified through a call to stxTCP_WriteBulk Parameter 1 points to a TCP INFORMATION structure which describes the TCP connection The members remote ip address remote port and local port are valid Parameter 2 is a Connection ID which identifies the connection ReturnValue not used 8 3 6 NC_TCP_GET_TXDATA TCP_TxData ConnlID If stx TCP_WriteBulk was called with parameter bSendDynamic TRUE_stx see section 8 2 5 for details sevenstaxTCP will call the notify handler with NC TCP GET TXDATA to get the next data block to send The application now is responsible to copy the requested data into the given destination address This will repeatedly be done until the application notify handler returns 0 for this call Although th
23. 2 stxIP_Tick Description This function keeps IP alive It must be called as often as possible in order to provide the IP module with processor time Parameter Return Value 6 2 3 stxIP_Attach hSubConn Description Before you can communicate with sevenstaxTCP IP you have to bind IP to a data link protocol e g Ethernet PPP This is done by calling this function in which you specify the data link protocol by a connection handle Result is a new local IP subnet referenced also by a connection handle Parameter CONN_HNDL_TYPE hSubConn Handle of a data link protocol must point to a structure of type CONN_STRUCT_TYPE with the configuration described in the chapter Accesses from IP module into protocol layer below that you can find below Return Value CONN_HNDL_TYPE Connection handle of the new IP local subnet This handle must be used for other API functions that refer to the IP local subnet File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 32 79 Public S VENSTAX TCP IP amp Routing User Manual Sp TEMPERED TERKKOLDENES 6 2 4 stxIP Detach hConn Description Deletes local IP subnet created in stxIP_Attach Parameter CONN_HNDL_TYPE hConn Handle of IP subnet result of stxIP_Attach function call Return Value 6 2 5 stxIP SetLocallPAndSubnetMask hConn psLocallP psSubnetMask Description Sets manually given IP address and subnet mask as local n
24. 3 1 Notify Handler Function Prototype The function prototype of this universal notify handler is defined in protdefs h and looks like this typedef UINT32 stx FCTPTR stx PROTOCOL NOTIFY HANDLER NOTIFY CODE code UINT32 stx paraml UINT32 stx param2 Please note Check your compiler for declaration format of function pointers The notify handler needs to be callable from everywhere within the stack 4 3 2 Notify Codes The first parameter of the notify handler is the NOTIFY CODE This is actually an identifier of the message which sevenstaxTCP IP has sent The sevenstaxTCP IP modules use different notify code areas defined in protdefs h define NC_TCP MIN NOTIFY CODE 400 define NC TCP MAX NOTIFY CODE 419 define NC_UDP MIN NOTIFY CODE 420 define NC UDP MAX NOTIFY CODE 439 The exact definition of a notify code is located in the export header of the dedicated module like tcp h File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 18 79 Public S EVENSTAX TCP IP amp Routing User Manual Va UREESVED THREROUES TES define NC TCP CONNECTED NOTIFY CODEYNC TCP MIN 0 define NC TCP CONNTIMEOUT NOTIFY CODE NC TCP MIN 1 define NC TCP FIN NOTIFY CODE NC TCP MIN 2 You will find a separate list of notify code definitions in the protocol API documentation e g in section 8 3 TCP Notify Codes 4 3 3 Additional param1 and Garam The
25. 4 1 Accesses from Protocol Layer below into IP Module define LOCAL_IP_ADDRESS sLocallP If the local IP address can be set or reset in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro define SUBNET MASK sSubnetMask If the local subnet mask can be set or reset in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro define STD GATEWAY sGatewaylP If the standard gateway can be set or reset in the data link layer the data link layer protocol stack can do this directly by accessing this macro define DNS1 IP ADDRESS sDNS1IP If the first DNS server can be set or reset in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro define DNS2_IP_ADDRESS sDNS2IP If the second DNS server can be set or reset in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro define IP_RECV p stxIP ProcessPacket p Receive function Whenever the link layer has detected an IPv4 packet it must be delivered to the IP module Therefore the link layer has to know the entry point into the IP module where received packets are handled For this reason the function stxIP ProcessPacket is made public by the macro IP RECH It must be called with a packet descriptor see section PACKET_DESC the Packet Descri
26. 6 08 Revision No 5 03 Page 69 79 Public S VENSTAX TCP IP amp Routing User Manual STRING_stx www_name A pointer to the web name e g www yahoo com Return Value BOOL_stx TRUE_stx if the DNS query packet was successfully delivered over UDP FALSE_stx ifa DNS query is already in progress this means that neither the DNS server answered nor a timeout occurred Comment This function internally uses the UDP API of sevenstaxTCP IP Although there are no additional function calls necessary please assure that at least one free UDP instance must be available 10 2 4 stxDNS_QueryStop hConnNetwork Description Stops a pending DNS query and releases UDP port Parameter CONN_HNDL_TYPE hConnNetwork only multi device version connection handle of underlying network layer over which the DNS query ought to be stopped Return Value Comment There is normally no need to call this function because notify codes will be delivered if a timeout occurs But if needed DNS immediately will stop any query by calling this function no notify code will be delivered 10 3 Notify Codes 10 3 1 NC_DNS_IP IP adar After calling stxDNS QueryStart this event occurs when the DNS client has received a valid answer and a record is found which contains the requested IP address Parameter 1 contains the IP address passed in network byte order Parameter 2 is not used and always UINT32_stx_MAX ReturnValue not u
27. 8 1 4 Transmitting TGP EE 53 8 1 5 Terminating a TCP Congechon 53 8 1 6 Server Funpchonalfy cece eeeeeeeeeeeeeeeeeeeesseesesasaaaaaaaaaaaecaeeeeeensseseeeseeseeeeees 54 8 1 7 Single and Multiple ConnectionsS srrnnnnnnrnnrrrnrrrnnrrnrrrrrrrrrerrrrrrerrsrrsersrrssrrrsnnnn 55 8 2 Protocol AP TE 55 G 21 GUTCP geg EE 55 8 22 STOP TICK EE 56 8 2 3 stxTCP_Connect hSubConn ip address Dorf 56 8 2 4 stxTCP_Listen hSubConn oof 57 8 2 5 stxTCP_WriteBulk uConnld data len SendDynamic li 57 8 2 6 stxTCP_Disconnect UConnId bForced le 58 8 2 7 StxTCP GeiziatetuConnidl nnnrnnrrrereeerrenennnee 59 SS NO SOUS uden 59 8 3 1 NC TCP CONNECTED TCP Info Connie 60 8 3 2 NC TCP CONNTIMEOUT TCP Info ConnID J rrrrrerrrnrnnnrvrrvnnrrnrrrrrrrnrrrerrenrr 60 8 3 3 NC TCP FIN AbortReason ConnID le 60 8 3 4 NC TCP RECH TCP Info CGonnifl nn nn rrrnnnnnnnnn 60 8 3 5 NC TCP TXREADY TCP Info ConnID cccccccccccecccecceeeeeeteteeteeseseeeenennenees 61 8 3 6 NC TCP GET TXDATA TCP TxData Connie 61 8 4 Adjustable PA FE ses edeh ee adetnrtetaniaans 61 9 UDP Modules hes 64 Gel EE 64 9 2 Protocol Ab 64 9 2 1 stxUDP_lnit handler DE 64 9 2 2 StXUDP TICK anse E E E ER EEE A E E RER 64 9 2 3 stxUDP_AddConn hSubConn local port fProcessFunction cccccccccceeee 65 9 2 4 stxUDP_DelConn uConnld ere de 65 9 2 5 stxUDP_Write uConnld psRemotelp uRemotePort data datalen 66 9 3 Noty Seier 66 9 3 1
28. AT module a packet can be routed from one to another IP subnet It is used when the sender is not addressable from the target IP subnet In most cases it is used when the packet has to be routed into the Internet When routing into the target IP subnet the internal source IP address must be translated into an external IP address that is reachable from the target IP s subnet Source NAT In case of routing in the other direction the external destination IP address must be translated into the internal IP address Destination NAT In addition the existing internal send port of the transport layer protocol e g TCP UDP is translated into another masqueraded port to assign the returned packets to the internal sender Also the TTL field time to live is decreased by one Because of this change the IP checksum is recalculated for every routed packet The translation information is stored in a translation table Every entry contains the internal IP address the internal transport layer port the masqueraded transport layer port time stamp second counter of the time when the entry was added or used One entry is added automatically when a packet is routed into the target IP subnet When an entry has not been used for a given time it is marked as rewritable As long as this entry has not been rewritten it can be reactivated by an appropriate packet with the old values that are still located there An entry can also be inserted ma
29. AndSubnetMask cccccccscncccssecsnccsvsescccceresseasnececanetevrazacnenenvies 24 5 2 5 SP GetL callP DE 24 5 2 6 stxlP_GetSubnetMask Ju uuanadsmiensm nn mifinni ngseuimennbbedeukete 24 5 2 7 stxIP SetStdGateway psGateway cs ccccccticeesveccsacdenensessaececncaverastercinescneeeesbecees 24 5 2 8 stxlP_DelStdGateway GR D 25 5 29 stxiP G tStdGateway esrssiiorsctiesniraa siina a aE iia 25 5 2 10 stxlP_SaveStdGateway neeesssnsnnossernirnnnssnrrnrnnnneenrrrnnnneennnnnnnnnennnnnnnnnnenna 25 5 2 11 stxIP_RestoreStdGateway Lun ase nasdaneas tea bevanettaaiiaaateecendaeeisaaduodecamiulanendes 25 5 2 12 SHIP _AcCGeSSLINKLocal DOM E cnsbattexseeeia hesieeicineasbiees 26 9 39 ee 26 5 4 Interface to the Protocol Layer DelOW c 2 ccc 0ccccccecessscceteseecsenseasscneeeeeneezscnceeeeeensesees 27 5 4 1 Accesses from Protocol Layer below into IP Module 27 5 4 2 Accesses from IP Module into Protocol Layer below 28 5 5 Adjustable Eegeregie egene 30 6 IP Module Multi De Vice ees deeg idee eege 31 RES EE EE EEE NE EE 31 6 2 Protocol EE 32 6 2 1 SUMP Int handler D 32 02 2 SIPA D 32 6 2 3 SOP AGC hSubConn J xccccresristecseasstasiasnastceczasnnstdave ciauseatangneadesteaveancimensamenvaavess 32 6 2 4 stxlP_Detach hConn E 33 6 2 5 stxIP SetLocallPAndSubnetMask hConn psLocallP psSubnetMask 33 6 2 6 stxIP ResetLocallPAndSubnetMask hConn 1 33 627 stxlP_GetLocallP hConn sisrsiisrssirrisisirrsiriririresi
30. Initial version Last change Last Review Publication File name SEVENSTAX sevenstaxTCP IP amp sevenstaxRouting Revision No State Author 21 08 02 23 06 08 03 18 08 Public User Manual 5 03 Release sevenstax GmbH sevenstaxTCPIPRout UserManual V53 Copyright c 2002 2008 by sevenstax GmbH This document is an intellectual property of sevenstax GmbH Unauthorized copying and distribution is prohibited TCP IP amp Routing User Manual S V ENSTAX Table of Contents 1 E 7 2 Supported Protocols secicocsccesccesesscacieedasccidecea censecietetcndecesbuadecdescasasdenentsendasesznostebeess 9 2 1 Protocols Overview nn narr nnnrnnrnrrnnrnrrrnnnnnnnnnenenneesenserssrrssrnnrrerrnrrnrnnrnnnn 9 2 2 PPP np eege Eed hie een gege 10 2 3 Ethernet Support 10 ZA TEE 10 2 5 Routing Support 10 2 6 TCP SUpport ai ieiiirni nara n n eeaeaa a riaa A E aa E R EAE EE EAEE EE AARAA RE AEA EEEREN EEE 10 2 7 UDP SUPPO dE 10 2 8 DNS SUPPOM srren na e eE E a ar ENEE 11 2 9 ICMP Echo Gupport enesenn aa aE SE Ea EE EEN RE EEATT EENE ENEAN EER 11 210 NTP SUP POM dE 11 3 Internal Data STruclur ssussusadsssstsmmnentriblemummmienja 12 3 1 PACKET DESC the Packet Descrptor 12 3 2 IPV4 the IP Address eet tseeaeaaeeeseeceseeeaeaaaaaaaaaaaaeeeaeeeeeeeeeeeess 12 3 3 CONN HNDL TYPE the Connection Handle Multi Device Version only 13 4 Integration into User Application nnnnnnnnnnnnnnnnnnnnnnnn
31. Interface 7 3 2 1 7 3 2 2 7 3 2 3 StxNAT Init Description Initializes the NAT module Must be called once before using NAT Parameter Return Value stxNAT Tick Description This function keeps NAT alive It must be called as often as possible in order to provide the NAT module with processor time Parameter Return Value StxNAT SetFilterFunction fFilterFunction Description Sets a filter function which can filter out some packets with certain properties concerning destination IP address transport layer protocol e g UDP or destination port of transport layer protocol Parameter NAT FILTER FUNCTION fFilterFunction Filter function Return Value File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 47 79 Public TCP IP amp Routing User Manual S VENSTAX 7 3 2 4 7 3 2 5 7 3 2 6 stxNAT_SetMasqExtlPFunction fMasqExtiPFunction Description Sets a masquerading function which can exchange the external IP address When such a function is set both IP addresses are translated for every routed packet Twice NAT This feature only is active if NAT MASQUERADE_EXT_IP_ADDR is set to 1 Parameter NAT MASQ EXT IP FUNCTION fMasqExtIPFunction Masquerading function Return Value stxNAT_GetSysSecRouted Description Returns the second counter time stamp of the last routed IP packet Parameter Return Value UINT16_stx Se
32. Module into Protocol Layer below 41 6 5 Adjustable Free ck eo cae eege Seege 43 DROUIN D 44 EE a 44 7 2 ge ale Wl IT 44 RE STEEN E 44 7 2 2 Application Programming Inferfac mmmmumrsrmessrrumssamnssraesriseteresiiderdeherernjnnate 44 221 Ee WT td E 44 7 2 2 2 stxForward_Tick DEE 45 7 2 2 3 stxForward_SetFilterFunction fFilterFunction 1 45 7 2 2 4 stxForward_GetSysSecRouted 2 c s ccccsccsicsectecsecssessesseccseeeseessssreneneeeeneesece 45 1 2 3 Notify E 45 7 2 4 Adjustable E 45 STN ME 46 L STEEN E 46 7 3 2 Application Programming Infterface isuussurrrninssmissmnmeueimavin vvs 47 ST MT NN 47 EH ER UE 47 7 3 2 3 stxNAT_SetFilterFunction fFilterFunction li 47 7 3 2 4 stxNAT_SetMasqExtlPFunction fMasqExtIPFunction 1 48 7 3 2 5 stxNAT_GetSysSecRouted E 48 7 3 2 6 stxNAT_GetTTL E 48 7 3 2 7 stxNAT_SetTTL bTime sssesssesserreesssesssrrsessoenrenrsenrenrennessrenrenneasserrennaeesee 49 Ta stxNAT_AddRoutingTableEntryPerm psIPInt uPortint uPortMasq me 7 3 2 9 stxNAT_DelRoutingTableEntryPerm WIdx 1 50 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 4 79 Public TCP IP amp Routing User Manual S V ENSTAXx 8 NO EE 50 21 34 Adjustable FI TM 50 8 TCP Mode Ree 51 CDe UNE EE 51 8 1 1 TCP Basics 51 8 1 2 Connection Establishment rann nnnnnnnrnnrerereenrennee 51 8 1 3 Receiving I CP PAckelS uuuumsurmdnmsmummrete uvnddekmnasnenonmsi itie 52
33. NC_UDP_RECV UDP Info UDPConnID h umurnsmsenmserepsoemensnsvi 67 9 4 Adjustable Kaarte osseageereEseseeeeteeegdeteee eege iaaiiai 67 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 5 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSENDED TECHNOLOGIES 10 DNS Tiny Modne cise acces anisto rnin dk andel 68 10 1 OVOIVIOW tiie cot cacvcadvicasvanecivnceecneveabes sieves sway adda E a e e yicacdeeieehenedevaavanvacdalanveerea seas 68 NO ZAPVOLOCON AP BE 69 TET StXDNS fi handler Lasse 69 1022 SRDS TICK EE 69 10 2 3 stxDNS QueryStart hConnNetwork stx dns ip wwW name 69 10 2 4 stxDNS QueryStop hConnNetwork 1 70 10 3 ee iscrpio aiana ia a Ea EEEE EENEN R L Eer 70 VITNEANE PE TEPPER 70 10 3 2 NC_DNS_TIMEOUT ere 70 10 4 Adjustable Pla ICUS i urne emssiemnlepnntdebenetatindvkahisede 71 11 ICMP Mod le Lasses 72 11 1 Overview 72 11 2 Protocol BE 72 11 3 Notify GO eee 72 11 4 Adj st ble Eeer dee 72 12 NTP UTC 73 W251 OVENI EE 73 12 2 Protocol AP DE 73 12 2 1 stxNTP_Init e e EE 73 1222 SXNTPTiCK ssia EE Ea 74 12 2 3 stxNTP_Query hConnNetwork ntp Server le 74 12 2 4 stxNTP_Transform ntp_seconds seconds minutes hours year month day EE 75 PAGE EE er een EN NN eee eee ere 75 12 31 NE NIP SUCCESS NTP sec sccccscisesceecessiteasvemeeseictapsceessiasszeenceceeeaeeedea 75 1231 NG NTP FAILURE 95 Dh cs ssteneisiaestaadeieerencnbssangabensdesiseviad
34. SE_stx like in sevenstaxEthernet If a protocol stack needs more time to send a packet it must return TRUE_stx as long as the packet is not sent completely define SEND PAYLOAD stxETH GetSendPayload define SEND PAYLOAD stxPPP GetSendPayload With this function macro sevenstaxTCP IP can ask for the buffer size that is available for the sending payload In most cases it is the size of the complete send buffer less File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 28 79 Public S VENSTAX TCP IP amp Routing User Manual the size for the overhead E g for sevenstaxEthernet it is the size of the Ethernet send buffer minus 14 for the Ethernet header size This function prevents sevenstaxTCP IP to write too much data into the send buffer define RCV_PAYLOAD stxETH GetRcvPayload define RCV PAYLOAD stxPPP GetRcvPayload With this function macro sevenstaxTCP IP can ask for the buffer size that is available for the received payload In most cases it is the size of the complete receive buffer less the size for the overhead E g for sevenstaxPPP it is the size of the PPP receive buffer minus 6 for the PPP header and checksum size This function have a bearing only on the TCP module when calculating its window size So if you don t use TCP the value returned by the function doesn t matter define RCV OVERHEAD stxETH GetRcvOverhead define RCV OVERHEAD stxPPP GetRcvOverhea
35. With this macro you can define which local broadcast IP packets not been identified because of the actually set subnet mask are identified as local broadcasts anyway E g if the local subnet mask is set to 255 255 0 0 you would identify IP packets with target IP x y z 255 as local broadcasts which are external because not based on the local subnet mask if the macro has the default value IP_MULTI default 1 valid 1 255 With this macro you can define the maximum number of local IP subnets This value corresponds to the number of successful calls of stxIP_Attach IP_CNT_ROUTING_TAB_ENTRIES default 10 valid 1 255 With this macro you can define the number of entries in the routing table Internally the routing table has one more entry which is a special entry for the standard gateway File sevenstaxTCPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 43 79 Public S VENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 7 Routing 7 1 Overview The normal operation mode of sevenstaxTCP IP is acting as a host that means communication endpoint in the network With help of the sevenstaxRouting modules you can implement a network in which the device can have an intermediary property and so acting as a router The actual routing modules work on the IP layer They contain the routing mechanism NAT network address translation implemented as NAPT network address port translation
36. _UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 44 79 Public S VENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 7 2 2 2 stxForward_Tick Description This function keeps Forwarding alive It must be called as often as possible in order to provide the Forwarding module with processor time In this version this function does nothing Parameter Return Value 7 2 2 3 stxForward SetFilterFunction fFilterFunction Description Sets a filter function which can filter out some packets with certain properties concerning destination IP address transport layer protocol e g UDP or destination port of transport layer protocol Parameter FW FILTER FUNCTION fFilterFunction Filter function Return Value 7 2 2 4 stxForward GetSysSecRouted Description Returns the second counter time stamp of the last routed IP packet Parameter Return Value UINT16 stx Second counter time stamp of last routed IP packet 7 2 3 Notify Codes Currently no notify codes are defined for the Forwarding module 7 24 Adjustable Parameters FW CHECK CHECKSUM default 1 valid 0 1 With this parameter you can enable the checking of the checksum of delivered TCP and UDP packets File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 45 79 Public S VENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 7 3 NAT Module 7 3 1 Overview With the N
37. ain port numbers copied directly from the received packet Parameter 1 points to a TCP INFORMATION structure which describes the newly created connection The members remote_ip_address remote_port and local port are valid Parameter 2 contains a Connection ID which has been returned by stxTCP_Connect ReturnValue not used 8 3 2 NC TCP CONNTIMEOUT TCP Info ConnlID This event occurs if stxTCP Connect failed i e timed out sevenstaxTCP does a few retries to establish a connection and then gives up Parameter 1 points to a TCP INFORMATION structure which describes connection The members remote ip address remote port and local port are valid Parameter 2 is a Connection ID which identifies the connection that failed ReturnValue not used 8 3 3 NC TCP FIN AbortReason ConnlID This event is posted when the TCP connection is terminated This may happen when a web server has finished sending data when an error occurs or after the application has called stxTCP Disconnect Parameter 1 is a ABORT REASON see section 8 1 5 Terminating a TCP Connection Parameter 2 is a Connection ID which identifies the connection that has been closed ReturnValue not used 8 3 4 NC TCP RECV TCP Info ConnlID When sevenstaxTCP has received a data packet TCP RECV is issued to tell the application that data has arrived File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 6
38. amp Routing User Manual Va TEMPERUEE THEKROUSETES IP addresses are stored in network byte order where the first byte ipb b1 is the most significant byte The IPV4 union allows either access to the entire value ipl or partly through ipb b1 to ipb b4 Please Note IP addresses are internally stored as they came over the network network byte order regardless of the processor architecture sevenstaxTCP runs on 3 3 CONN HNDL TYPE the Connection Handle Multi Device Version only typedef struct CONN STRUCT TYPE CONN_HNDL_TYPE hSubConn connection handle of underlying layer CONN MEIH STRUCT TYPE CONST stx FPTR_stx psMeth I DOF Nie Ten OME UN Ciro NEES Cite void FPTRESEX psData pointer to data set UINTS stx HETRESEX pSendBuff send buffer start point CONN STRUCT TYPE typedef struct CONN STRUCT TYPE FPTR stx CONN HNDL TYPE The multi device version of sevenstaxTCP IP works with so called connection structures and connection handles A connection handle is simply a pointer to a connection structure Based on a connection structure of a layer n protocol you can build a connection on layer n 1 by creating a connection structure in which the entry hSubConn points to the connection structure of the protocol on layer n This connection is done by the application with attach functions The highest layer that works with connections handles is layer 4 Access to layer 4 works with connection id
39. and Forwarding The enabling of these routing features can be done per local or remote IP target subnet in the Multi Device IP module with special API functions The translations of the packets are done in the routing modules called from the Multi Device IP module 7 2 Forwarding Module 7 2 1 Overview With the forwarding module a packet can be forwarded from one to another IP subnet It is used when the sender shall remain directly addressable The IP packet leaves unchanged except for the TTL field time to live that is decreased by one Because of this little change the IP checksum is recalculated for every new packet A requirement for successfully routing a packet is that the receive buffer size of the source IP subnet is equal to the send buffer size of the destination IP subnet The module can be configured so that for TCP and UDP packets the checksum is checked and all packets where the check failed are rejected In addition the user can define a filter function to filter out some packets with certain properties concerning destination IP address transport layer protocol e g UDP or destination port of transport layer protocol This module can be activated by defining FORWARD_SUPPORTED with 1 features h 7 2 2 Application Programming Interface 7 2 2 1 stxForward_Init Description Initializes the Forwarding module Must be called once before using Forwarding Parameter Return Value File sevenstaxT CPIPRout
40. as PPP and or Ethernet There are some function prototypes and definitions which must be adjusted according to your application Please note Various functions deal with packet descriptors see section 3 Internal Data Structures for details The link layer has to provide the required packet descriptors User Application Main Loop Notify Handler Procedures While 1 case NC TCP stxIP_Tick break stxTCP_Tick case NC_TCP Se break Ze e Commandes Get Processor time Events with stxTCP_Init stxIP_Tick NotifyCodes stxTCP_WriteBulk stxTCP_Tick and received Data Read Timer GET_TRGT_MSEC sevenstaxTCP Send packets Receive Packets SEND PKT x IP RECV x Link Layer PPP Tx Buffer Rx Buffer Ethernet etc Physical File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 15 79 Public S EVENSTAX TCP IP amp Routing User Manual Sp TEMPERED TERKKOLDENES 4 2 Target Settings The main target configuration file is features h This file is included into all sevenstax modules to control sevenstaxTCP IP s features sevenstaxTCP IP is implemented to run on every controller independently of 8 16 32 bit independently of endianess and compiler behaviour Every effort has been made to support this universal behaviour on most target systems Per default it is prepared and intended to
41. at the location where FPTR_stx data points e Deliver the packet to the network hardware From sevenstaxTCP IP this macro is called with the parameter SENDBUFF define SENDBUFF gETH_sendpacket define SENDBUFF gPPP_sendpacket sevenstaxTCP IP is designed to reuse the send buffer of the link layer in order to save memory Therefore SENDBUFF is by default set to one of the above packet descriptors see section PACKET_DESC the Packet Descriptor for details which contain the send buffers SENDBUFF must be initialised in the following way The member data must point to first byte of the link layer header This might be the first byte of the buffer which the link layer will send off to the network e The member payload must point to the first byte of the IP header This should be for example fourteen bytes behind data when using sevenstaxTCP IP on Ethernet e L tze and estate members are not used at this point and can have any value The buffer can be changed according to the projects needs Therefore the SENDBUFF may be changed to a different packet descriptor but this is normally not required define SEND_BUSY stxETH_SendBusy define SEND_BUSY stxPPP_SendBusy sevenstaxTCP IP needs a data link layer function that indicates if this layer is busy with sending a packet In most cases the data link protocol stack can send a whole packet synchronously inside the call of SEND_PKT in which the function returns always FAL
42. ation of the local IP address and the subnet mask If the target IP address is equal to the local IP address the packet is accepted when the local IP address is not 0 0 0 0 In addition the packet is accepted when it is a global local broadcast or a multicast or All other packets are rejected gt For all unfragmented packets the sub protocol is evaluated If it is one of the protocols TCP UDP ICMP and if the respective protocol is enabled XXX_SUPPORTED macro the packet is delivered to the respective process packet function Note If target s IP address is part of the own subnet packets will be sent directly otherwise they will be sent to the standard gateway This is done on the underlying data link layer so that the target IP address leaves unchanged and is not the standard gateway IP address For some link layer protocols it is necessary to investigate link layer s destination address e g MAC address in Ethernet Using for instance Ethernet it might be necessary to send an ARP request to get destination s MAC address All sevenstax modules use the same send buffer That means an ARP request has to be sent before building an IP packet Because of this a special prepare write function of the link layer has to be defined which can be called from the IP module This is not necessary in every case PPP for instance doesn t need this prepare write function because of the point to point connection File sevens
43. axT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 52 79 Public TCP IP amp Routing User Manual S VENSTAX 8 1 4 8 1 5 data Also the expected sequence number for the next packet will be calculated here 11 If a connection is established and the received sequence number does not match the expected one the own acknowledge number will be set to the expected sequence number and an ACK segment with this number is sent to the peer to force a retransmission At this point the handling of this packet will be aborted 12 If a FINACK is received during an open connection the peer wants to close the connection an ACK and later a FINACK is returned and the connection is aborted Furthermore the application will be notified of the connection s termination after the FINACK No further packet handling will be executed 13 If a FINACK is received after sent FINACK and received ACK we wanted to close the connection an ACK is returned and the connection is aborted Furthermore the application will be notified of the connection s termination No further packet handling will be executed 14 In case an ACK is received while a connection is established a data packet must be acknowledged If the payload of the packet is not empty the packet is delivered to the application via notify code NC_TCP_RECV 15 In case an ACK is received while no connection is established this may indicate that a half open connecti
44. blic S VENSTAX TCP IP amp Routing User Manual Va SERS ENDED TECHNOLOGIES 6 2 16 stxIP AddRoute psNetworkTarget psNetworkMask psGateway hiPInterface Description Adds a route to the routing table Parameter IPV4 FPTR stx psNetworkTarget IP address space e g 192 168 130 0 If NULL stx 0 0 0 0 is inserted IPV4 FPTR stx psNetworkMask Network mask e g 255 255 255 0 If NULL stx 0 0 0 0 is inserted IPV4 FPTR stx psGateway Gateway IP if hosts in the network are not accessible directly CONN HNDL TYPE hiPInterface Local IP subnet and so the physical device over which all packets to the hosts in the given network have to be sent Return Value UINT8_stx Index of routing table entry UINT8_stx_MAxX if no entry was made 6 2 17 stxIP ChangeRoute ulndex psNetworkTarget psNetworkMask psGateway hiPInterface Description Changes a route in the routing table Parameter UINT8 stx ulndex Routing table index result from stxIP AddRoute IPV4 FPTR stx psNetworkTarget IP address space e g 192 168 130 0 If NULL stx 0 0 0 0 is inserted IPV4 FPTR stx psNetworkMask Network mask e g 255 255 255 0 If IPV4 NULL stx 0 0 0 0 is inserted IPV4 FPTR stx psGateway Gateway IP if hosts in the network are not accessible directly CONN HNDL TYPE hlPInterface Local IP subnet and so the physical device over which all packets to the hosts in the given network have to be sent Return Value BOOL stx TRUE
45. cond counter time stamp of last routed IP packet stxNAT_GetTTL Description Returns actual time to live value for an entry in the translation table This function only is available if NAT_ENABLED 1 Parameter Return Value UINT8_stx Actual time to live value for an entry in the translation table File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 48 79 Public TCP IP amp Routing User Manual S V ENSTAX 7 3 2 7 stxNAT_SetTTL bTime Description Sets time to live value for an entry in the translation table This function only is available if NAT_ENABLED 1 Parameter UINT8_stx bTime new time to live value Return Value NAT_ERR NAT ERR OK if value was set successfully NAT ERR INVALID PARAM if value could not be set successfully because it was zero 7 3 2 8 StxNAT AddRoutingTableEntryPerm psIPInt uPortInt uPortMasq pulndex Description Inserts a permanent entry in the translation table port forwarding This function only is available if PFW ENABLED 1 Parameter CONST_stx IPV4 FPTR_stx ps Pint private IP address CONST_stx UINT16 stx uPortint private transport layer port CONST stx UINT16 stx uPortMasq masqueraded transport layer port UINT8_stx FPTR stx pulndex index of translation table UINT8 stx MAX if no free entry was found Return Value NAT ERR NAT ERR OK on successful operation NAT ERR NOT FOUND no free ent
46. ctions sevenstaxTCP IP is focused on systems with very small resources to give them relevant TCP IP functionality Therefore in comparison to a full featured stack implementation of for example a PC software it has some restrictions in usage and capabilities that the user should know Restriction Details 1 Not aware of interrupts Per default sevenstaxTCP IP functions are called inside a tick function which is normally located inside an endless while loop or OS task If parts of sevenstax embedded protocols are called from within an ISR synchronization must be done by the user Not full RFC compliant To give maximum capabilities within small system resources sevenstax embedded protocols fulfill only basic and most relevant parts of the RFC specifications No buffering of any kind Because sevenstaxTCP IP has no data buffers when sending data over a TCP connection using stxTCP_WriteBulk the content must exist and must not be changed until the application receives a feedback NC TCP TXREADY IP fragmentation sevenstaxTCP IP does not support IP fragmentation This is no disadvantage for TCP IP but for UDP packets Only the first part of fragmented UDP packets are received and used sevenstaxTCP IP also never generates fragmented IP packets by itself Replies from name servers DNS Because DNS packets are sent over UDP and sevenstaxTCP IP throws away UDP fragments DNS only w
47. ctions in server mode When a connection is established and the remote client reconnects e g after a possible system crash with the same local port number sevenstaxTCP File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 51 79 Public TCP IP amp Routing User Manual S VENSTAX 8 1 3 sends a RST TCP reset to the client The RST cancels the old connection and a subsequent connection request will succeed Receiving TCP Packets If the lower network layer in most cases an IPv4 implementation e g sevenstaxIP has recognized a TCP packet it calls sevenstaxTCP s receive function stxTCP_ProcessPacket Before calling this function the lower network layer prepares a packet descriptor an internal data structure described below which holds information about the TCP packet Usually the packet resides in the receive buffer of the lower network layer thus sevenstaxTCP doesn t need a buffer itself The stxTCP ProcessPacket function does everything necessary on reception including data delivery to the application handling connection requests and transmitting response packets back to the other end Processing Received TCP Packets 1 In single connection mode The destination port is compared to the local port If they are not equal the packet is rejected 2 In single connection mode and multi device version If the sub connection handle is not NULL_stx and not equal to the
48. d With this function macro sevenstaxTCP IP can ask for the memory overhead for saving a received IP packet In most cases it is the header and footer size of one packet but in some cases it can be more than this because of special data structures necessary to manage received packets E g for sevenstaxPPP the function returns always 6 see above but for sevenstaxEthernet the value is 14 for the header plus 2 because of the ring buffer overhead This function have a bearing only on the TCP module when calculating its optimized window size see chapter TCP So if you don t use this feature the value returned by the function doesn t matter define PREPARE_WRITE t d l stxETH PrepareWrite t d I If there is a need to prepare the write process you can assign a function to this macro E g for Ethernet it is necessary to send an ARP request before sending the packet out t must contain the type of the destination IP address of the packet to send see IPV4 PKT TYPE unicast multicast local broadcast global broadcast d must point to the destination IP address of the packet to send must point to the local IP address define PREPARE RESPONSE s d l p stxETH_PrepareResponse s d I p If there is a need to prepare a response on reception you can assign a function to this macro E g an Ethernet ARP module can save relevant data in the ARP cache as preparation of a response S must point to the source IP of the received packet
49. ease note that some of the features will only be available if the equivalent sevenstax product was bought File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 17 79 Public S EVENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 4 2 5 Standard Lib Functions runtimelib c h sevenstaxTCP IP uses some ANSI C standard library functions for buffer or string manipulation Several simple embedded compilers do not support a complete implementation of these standard libs Or your application might use your own memory or runtime optimized implementation of the standard lib functions To support this sevenstaxTCP IP comes with it s own simple runtime lib in runtimelib c and runtimelib h Please feel free to adapt it to your requirements 4 2 6 Protocol spanning Definitions protdefs h Definitions that are used in multiple protocol stacks are placed here In particular these are definitions for the notify handler system for the interface to the data link layer stacks for handling single and multi device parameters and for connection structures and handles that are used in the multi device stack version 4 3 Notify Handler Application Handler Procedure To signal events to the application sevenstaxTCP IP needs a handler procedure provided by the application a so called callback function Whenever sevenstaxTCP IP has something to report it calls this handler procedure 4
50. efine DNS DEBUG define DNS DETAILS define ICMP_DEBUG define HTTPSERV_DEBUG define NTP_DEBUG ipv4 module tcp module tcp module packet details tep module packet content udp module dns amp dns_srv module dns amp dns sev amp mdns packet details icmp module httpserv amp html page modules ntp module PRPPRPRPRPRPRPRER Each module has a separate macro to map DebugOuts to a common printf function e g tcpdefs h control debug out Hif TE PRDEBUG 1 amp amp DEBUG STX 1 include debugstx h define TCPPRINT a DBGPRINTLN TCP a define TCPPRINT1 a b DBGPRINTLN1 TCP a b define TCPPRINT2 a b c DBGPRINTLN2 TCP a b c All DebugOuts are mapped to the central DBGOUTFCT macro in debugstx h This is the point where the developer might map to an alternative to printf e g to another serial out function or save it in memory Details of DebugOut might be controlled via define switches in features h K coptigure format define DBGFMT TIMESTAMP fl enables preceding timestamp define DBGFMT FILELINE T enables preceding filename line number define DBGFMT MODULE I enables preceding module name like File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 76 79 Public TCP IP amp Routing User Manual S V ENSTAX 14 Restri
51. er PROTOCOL_NOTIFY_HANDLER handler Application handler function to receive notify codes from sevenstaxTCP Return Value Comment Please Note It is advisable to initialize the link layer and set up the receive and transmit packet descriptors before calling stxTCP_Init File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 55 79 Public S VENSTAX TCP IP amp Routing User Manual 8 2 2 stxTCP_Tick Description This function keeps sevenstaxTCP alive It must be called as often as possible in order to provide sevenstaxTCP with processor time It is designed to be very fast thus applications are not slowed down The most time consuming action might be to build an entire TCP packet TCP_MULTI_TICKS per call and deliver it to the link layer Therefore the maximum time stxTCP_Tick will use depends on the size of the biggest packet defined by RTM MAXDATA Parameter Return Value Comment 8 2 3 stxTCP_Connect hSubConn ip address port Description Tries to establish a connection to another TCP Parameter CONN_HNDL_TYPE hSubConn only multi device version Connection handle of underlying network layer If NULL_stx no restriction is made concerning the local IP subnet CONST_stx IPV4 FPTR_stx ip address A pointer to an IPV4 structure which must be initialized to the IP address of the remote peer UINT16_stx port The port number of the remote TCP on which the connecti
52. er to local IP address 5 2 6 stxIP GetSubnetMask Description Returns actually set subnet mask of local subnet Parameter Return Value IPV4 FPTR stx Pointer to subnet mask 5 2 7 stxIP SetStdGateway psGateway Description Sets manually given IP address as standard gateway Parameter IPV4 FPTR stx psGatewaylP Pointer to IP address of standard gateway Return Value BOOL stx TRUE stx Standard gateway was set successfully FALSE stx Standard gateway could not be set successfully File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 24 79 Public S VE NSTAX TCP IP amp Routing User Manual Ker EES 5 2 8 stxIP DelStdGateway Description Deletes the standard gateway Parameter Return Value 5 2 9 stxIP GetStdGateway Description Returns actually set standard gateway Parameter Return Value IPV4 FPTR_stx Pointer to standard gateway 5 2 10 stxIP SaveStdGateway Description Saves actual standard gateway to be restored later Can be useful if a standard gateway is set temporarily so that after deletion the old standard gateway can be restored See also stxIP RestoreStdGateway Parameter Return Value 5 2 11 stxIP RestoreStdGateway Description Restores saved standard gateway Can be useful if a standard gateway is set temporarily so that after deletion the old standard gateway can be restored See also stxIP SaveStdGateway Para
53. erver response Parameter 1 contains the time in seconds since 01 01 1900 This value might be converted by the application with stxNTP_Transform Parameter 2 is not used and always UINT32_stx_MAX ReturnValue not used 12 3 1 NC_NTP_FAILURE This is the opposite to NC_NTP_SUCCESS When an NTP query was made NC_NTP_FAILURE is posted to the handler procedure if the time server does not respond properly Parameter 1 is not used and always UINT32_stx_MAX Parameter 2 is not used and always UINT32_stx_MAX Return Value not used 12 4 Adjustable Parameters Currently there is no NTP parameter available File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 75 79 Public S EVENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 13 Debugging Support At source level sevenstaxTCP IP contains a simple debugging support through macros mapped to printf DebugOut Strings The main switch to enable DebugOuts for all modules is DEBUG_STX 1 in features h e application define DEBUG STX d Main switch sevenstax debugging enabled Each module has a separate switch to enable debug information at compilation time This enables a fine control about the debug information you will get You can control it through the settings in features h protocols define IP_DEBUG define TCP DEBUG define TCPPACKET DEBUG define TCPPACKET DUMP define UDP DEBUG d
54. ervers per local subnet The main difference compared with the single device version is the existence of a routing table The own subnets as well as remote subnets are mapped into this table also the standard gateway One entry contains network target network mask gateway IP interface routing type only with the sevenstaxRouting modules With the first two entries that have IP address format the local or remote subnet is defined The IP interface defines over which local IP subnet and therefore over which physical device a packet targeted to a subnet must be sent If the gateway entry of one routing table entry has a valid IP address packets will not be sent directly into the defined remote subnet In this case the packet will be sent on data link layer to this gateway that represents a router E g for Ethernet an ARP request to the gateway is processed before sending the packet With the routing type entry the device can not only act as a host but also as a router At the moment there are the routing types NAT and Forwarding special modules of sevenstaxRouting The routing type property can be defined for each entry in the routing table that means for every defined local and remote subnet This is done with the help of three special API functions of the IP module When receiving packets the following steps are done gt The IP checksum is checked If the check fails the packet is rejected gt The local IP s
55. etwork setting for given IP local subnet Parameter CONN HNDL TYPE hConn Handle of IP subnet result of stxIP Attach function call IPV4 FPTR stx psLocallP Pointer to local IP address IPV4 psSubnetMask Pointer to subnet mask of local subnet Return Value BOOL stx TRUE sty Given IP settings were set successfully FALSE stx Given IP settings could not be set successfully 6 2 6 stxIP ResetLocallPAndSubnetMask hConn Description Resets local IP address and subnet mask for given IP local subnet Both values are internally set to 0 0 0 0 Parameter CONN HNDL TYPE hConn Handle of IP subnet result of stxIP Attach function call Return Value File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 33 79 Public S VENSTAX TCP IP amp Routing User Manual Tp TEMPERED TERKKOLDENES 6 2 7 stxIP GetLocallP hConn Description Returns current local IP address for given IP local subnet Parameter CONN HNDL TYPE hConn Handle of IP subnet result of stxIP Attach function call Return Value IPV4 FPTR stx Pointer to local IP address 6 2 8 stxIP GetSubnetMask hConn Description Returns current subnet mask of given IP local subnet Parameter CONN HNDL TYPE hConn Handle of IP subnet result of stxIP Attach function call Return Value IPV4 FPTR stx Pointer to subnet mask 6 2 9 stxIP IsLocallP hSubConn psiPAddress Description Checks if given IP address
56. eve high accuracy and reliability NTP uses UDP on port 123 for both transmission and reception To access NTP servers with sevenstaxNTP you should proceed in the following way 1 Set NTP_SUPPORTED to 1 in features h 2 Call stxNTP_Init once to set up sevenstaxNTP s internal state 3 Call stxNTP Query once to start querying the NTP server 4 In your main loop or operating system task call stxNTP_Tick repeatedly in order to keep alive and finish NTP queries 5 After a while the handler procedure receives either an NC_NTP_SUCCESS or NC_NTP_FAILURE event 6 On NC_NTP_SUCCESS call stxNTP_Transform with the 32 bits value in order to convert NTP output into human suitable time values 7 On NC_NTP_FAILURE the query can for example be repeated with another time server s IP address 12 2 Protocol API 12 2 1 stxNTP_Init handler Description Sets up some internal variables and registers the application callback function Must be called once before using any other NTP function Parameter PROTOCOL_NOTIFY_HANDLER handler Application handler function to receive notify codes from sevenstaxNTP module The handler function will be called when NTP data is received or a timeout occurs File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 73 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSENDED TECHNOLOGIES Return Value void Comment 12 2 2 stxNTP Tick De
57. ex Routing table index result from stxIP_AddRoute IPV4_ROUTING_TYPE eRoutingType Routing type In this version there are the following possibilities 0 IPV4 NO ROUTING no routing 1 IPV4 ROUTING FORWARD simple forwarding 2 1IPV4 ROUTING NAT network address translation Return Value BOOL stx TRUE stx if routing property was set FALSE stx if routing property could not be set 6 3 Notify Codes Although sevenstaxTCP IP supports a dedicated notify handler for the IP module currently no notify codes are defined for IP File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 39 79 Public S EVENSTAX TCP IP amp Routing User Manual Sp TEMPERED TERKKOLDENES 6 4 Interface to the Protocol Layer below sevenstaxTCP IP underlying protocols might be PPP and or Ethernet and or any other data link protocol The essential interfaces to handle sending and receiving packets via this sub layer are described here Feel free to adapt this interface to your application if you use another sub layer protocol 6 4 1 Accesses from Protocol Layer below into IP Module define IP SET LOCAL IP AND SUBNET MASK LINK hSubConn plp pSubnet stxIP SetLocallPBAndSubnetMask Link hSubConn plp pSubnet If the local IP address and local subnet mask can be set in the data link layer like in PPP the data link layer protocol stack can do this by accessing this macro The first parameter is the c
58. f BOOL stx FECTPTRESEX Eypedef J clott ups ECTETRIS EX cypedet IOs Sisk T ECTETRISEX Eypedef J clott ups I ECTETRISEX CVSS IAC Sie ECTETRIS CX typedef BOOL stx FCTPTR stx typedef BOOL Ist FECTPTRESEX CONNECTED FCT TYPE WRITESTR FCT TYPE WRITEBYTE FCT TYPE READSTR_FCT_TYPE READBYTE FCT TYPE SENDBUSY FCT TYPE GENERIC FCT TYPE CONN HND CONN HND CONN HND CONN HND UINTS WIG Ss m Li UINTS8 stx void FPTR stx TYPE PE TYPE hConn hConn Szotring veve 2 hConn uChar hConn Pszstring pueoune r hConn EISE hConn hConn uFctCode pData Every function has hConn as first parameter When a function is called with this parameter a connection structure of the layer in which this function is defined is identified The psData member in the connection structure is a pointer to a data structure This data structure is specific to the layer so that it is defined as pointer to void At last pSendBuff is a pointer to the send buffer in where the higher protocol can write the data to send File sevenstaxTCPIPRout_UserManual_V53 odt Revision No 5 03 Page 14 79 printed 23 06 08 Public S VENSTAX TCP IP amp Routing User Manual Va SERSERDED TECHNOLOGIES 4 Integration into User Application 4 1 Overview sevenstaxTCP IP is designed to work in conjunction with different data link layers such
59. for further UDP functions If the same UDP port and in multi device version same sub connection handle has already been registered by previous calls this function will return the same connection ID as before Returns UDP INVALID ID if there are no more free UDP instances defined by UDP_MULTI Comment Please note that it is possible to independently use TCP ports and UDP ports at the same time on both either server listening or client acting mode 9 2 4 stxUDP_DelConn uConnld Description Calling this function disables listening or sending on the given UDP connection ID The corresponding UDP port will be closed Parameter UINT16_stx uConnld UDP connection ID returned by stxUDP_AddConn Return Value Comment File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 65 79 Public S VENSTAX TCP IP amp Routing User Manual 9 2 5 stxUDP Write uConnld psRemotelp uRemotePort data datalen Description Immediately sends a UDP datagram to another host Parameter UINT16_stx uConnld Valid UDP connection ID returned by stxUDP_AddConn IPV4 FPTR_stx psRemotelp The IP Address of the target UINT16_stx uRemotePort The UDP port of the target UINT8_stx FPTR_stx data Pointer to the data to be inserted as UDP payload UINT16 stx datalen Amount of payload bytes to be send Return Value BOOL stx TRUE stx if data has been sent FALSE stx if any error
60. handle CONN HNDL TYPE is a pointer to a connection structure CONN STRUCT TYPE To work properly this structure must have the following configuration hSubConn Don t care any value isn t accessed from IP module e psMeth Must point to a structure of type CONN MEIH STRUCT TYPE with the following contents e fConnected Must point to a function of type CONNECTED FCT TYPE that indicates if a connection over the given connection handle is active e fWriteString Must point to a function of type WRITESTR FCT TYPE over which IP packets can be sent fWriteByte Don t care any value isn t accessed from IP module fReadsString Don t care any value isn t accessed from IP module fReadByte Don t care any value isn t accessed from IP module e fSendBusy Must point to a function of type SENDBUSY_FCT_TYPE that indicates if the protocol stack has still some data to send e fGeneric If there is a need to prepare the write process or to prepare a response on reception this entry must point to a function of type GENERIC_FCT_TYPE E g for Ethernet it is necessary to send an ARP request before sending the packet out Also an Ethernet module can save relevant data in the ARP cache as preparation of a response File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 41 79 Public TCP IP amp Routing User Manual S VENSTAX Preparing a write process The generic functi
61. he handler procedure the receive buffers may overrun packets get lost and must be repeated This will cause considerable delays and might affect performance of the whole system So be sure not to waste much time here Never hold given pointers The optional given two parameters of the notify handler often are pointers to current connection information and or user data They are very connection and TCP process state specific so they are valid only as long as the notify handler is being called and active File sevenstaxTCPIPRout UserManual V53 odt printed 23 06 08 Revision No 5 03 Page 19 79 Public S EVENSTAX TCP IP amp Routing User Manual Tp PERCE ED TERCRU LOU IES After leaving returning from the notify handler you MUST NOT USE these parameters pointers and the referenced data any more because they will be changed in further TCP Stack internal action To use the data referenced by one of the parameters you might process them immediately but in very short time or you might save the content not the pointer into your application Never immediately call back into sevenstaxTCP IP Because the handler procedure is called from inside sevenstaxTCP IP it is dangerous to immediately call back into sevenstaxTCP IP by using sevenstaxTCP IP API functions Doing so can cause deadlocks or even unlimited recursions which will result in stack overflows and thus crash the system or simply unpredictable reactions and data
62. ing any other DNS function Parameter PROTOCOL_NOTIFY_HANDLER handler Application handler function to receive notify codes from sevenstaxTCP IP s DNS module The handler function will be called wnen DNS data is received or a timeout occurs Return Value Comment 10 2 2 stxDNS_Tick Description This function keeps the DNS query alive assuring multiple retries until a timeout occurs It should repeatedly be called by the application like all the other sevenstax Tick functions too independently of a pending DNS query or not Parameter Return Value Comment In case of a timeout this function will call the application notify handler with NC DNS TIMEOUT If the DNS server responds this will be synchronously be signaled by NC DNS IP by the responsible process packet functions 10 2 3 stxDNS_QueryStart hConnNetwork stx dns ip www name Description Instructs sevenstaxTCP IP to transmit DNS queries on UDP port 53 to a known DNS server Multiple DNS queries will be sent by StxDNS Tick The result is posted as a notification code to the handler procedure which can either be NC DNS IP success or NC DNS TIMEOUT failure Parameter CONN HNDL TYPE hConnNetwork only multi device version connection handle of underlying network layer over which the DNS query ought to be started CONST stx IPV4 FPTR stx dns ip IP address of the DNS server to be used File sevenstaxTCPIPRout UserManual V53 odt printed 23 0
63. ink layer like in PPP the data link layer protocol stack can do this directly by accessing this macro The first parameter is the connection handle of the data link layer connection define IP RECV h p stxIP ProcessPacket h p Receive function Whenever the link layer has detected an IPv4 packet it must be delivered to the IP module Therefore the link layer has to know the entry point into the IP module where received packets are handled For this reason the function stx P_ProcessPacket is made public by the macro IP RECH It must be called with the connection handle of File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 40 79 Public S VENSTAX TCP IP amp Routing User Manual Va UREESUED EES the data link connection and with a packet descriptor see section PACKET_DESC the Packet Descriptor for details with the following settings state Not used any value e size Size of the entire packet including link layer headers e data A pointer to the first byte of the link layer header e payload A pointer to the first byte of the IP header The functions returns TRUE_stx if the packet was processed and FALSE_stx if not 6 4 2 Accesses from IP Module into Protocol Layer below All accesses into the protocol layer below data link layer are done via the connection handle of this protocol layer which was connected to the IP module with the function stxIP Attach This connection
64. ional features added 3 02 13 Feb 2003 krz Completely reviewed 3 03 21 Feb 2003 krz Some small corrections 3 11 26 Feb 2003 pe Restrictions reviewed 3 12 22 July 2003 ck New graphics 3 13 24 May 2004 krz Completely reviewed 3 13a 27 May 2004 krz ARP and NotifyCodes updated 3 14 01 June 2004 krf Released 3 15 29 June 2004 krz Format review 3 16 30 July 2004 krz Additional TCP Information in NotifyCodes ARP restrictions removed types extended by _stx prefix corrections 3 17 13 Aug 2004 ck Proof Read 3 18 20 Aug 2004 krz Added header dependencies 3 30 04 May 2006 krz Reviewed for sevenstaxTCP V3 3 4 20 12 Mar 2007 krz Completely reviewed for sevenstaxTCP V4 2 several new and changed API functions new graphics 4 21 20 Oct 2007 krz UDP API changes 5 00 03 Mar 2008 ssu Completely revised for sevenstaxTCP IP amp sevenstaxRouting V5 00 5 01 10 Mar 2008 jma Small corrections 5 02 13 Mar 2008 ttu Completely reviewed 5 03 18 Mar 2008 ttu Formatting changes corrections File sevenstaxTCPIPRout_UserManual_V53 odt Revision No 5 03 printed 23 06 08 Page 78 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERSERUED TECHNOLOGIES The information furnished in this document is believed to be accurate and reliable However no responsibility is assumed by sevenstax for its use nor for any infringements of patents or other rights
65. irnsisiersidrrrvrinnsrrannssisorininraiaireas 34 6 2 8 stxlP_GetSubnetMask hConn E 34 6 2 9 sbxIP IsLocallP hSubConn psiPAddress sccccissssscecsccscsscasserceecssasssorteccstxsoeueas 34 6 2 10 stxIP SetStdGateway psGateway hConn le 35 6 2 11 stxIiP_DelStdGateway d p eapiseesensese mat nm nied 35 62 12 SKIP GelStdGaleway void E yaoentacelextearsesebeaeiobsae 35 6 2 13 stxlP_SaveStdGateway e GN D 36 6 2 14 Set _RestoreSid Gateway CL eegeeeeereruegereedeghEggeeeegeeR de Kee ate canines 36 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 3 79 Public TCP IP amp Routing User Manual S VENSTAX 6 2 15 SIP AccesslinkLocal hConn DON Ke gees ct ecntichseee eee nena 36 6 2 16 stxIP AddRoute psNetworkTarget psNetworkMask psGateway APIMENEGE DEE 37 6 2 17 stxIP ChangeRoute ulndex psNetworkTarget psNetworkMask VINENE AEE EE EE RE EER ERREA 37 6 2 18 stxIP DeleteRoute ulndex EE 38 6 2 19 SoIP _IsRouteEmpty ulndeXx oscsceisszctictessinaseouncstavbesesabessetesesntecnenrceedubidalaneanares 38 6 2 20 stxIP SetRoutingToLocalSubnet hConn eRoutingType 1 38 6 2 21 stxIP SetRoutingToStdGateway eRoutingType le 39 6 2 22 stxIP SetRoutingToRoute ulndex eRoutingType le 39 G NOE ES E 39 6 4 Interface to the Protocol Layer below 2 c cccceseeeeeeseceeeeeecenseeeceeeeeeeeseseceesaneeee 40 6 4 1 Accesses from Protocol Layer below into IP Module 40 6 4 2 Accesses from IP
66. is feature might be used rarely this gives the advantage that the application dynamically might send a very large amount of data without the need to keep the complete databuffer secure until NC_TCP_TXREADY is received On the other hand if there is any TCP retransmission necessary the application must be able to generate this dynamic data again Parameter 1 is a pointer to a TCP_TXDATA structure which contains sevenstaxTCP instructions for the application pSourceData is the application source data pointer which sevenstaxTCP wants to send next Normally this pointer will increase with every call But it will be set back if e g a TCP retransmission is necessary Please assure that your application is able to set this source pointer back to old data pTargetBuffer is the target address to which the application should copy the data uCount is number of bytes which sevenstaxTCP expects to receive Parameter 2 is a Connection ID which identifies the connection ReturnValue returns the number of bytes the application has copied from pSourceData into pTargetBuffer If the last data has been sent the application should return 0 here 8 4 Adjustable Parameters There are some parameters defined in tcpdefs h which can be customized These parameters should properly be adjusted depending on the lower network layer and communication device The following list describes them in detail TCP MULTI default 5 valid 0 n If multiple TCP
67. l_V53 odt printed 23 06 08 Revision No 5 03 Page 7 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ESUED TECHNOLOGIES You should give sevenstaxTCP IP a try when you e want to bring the Internet to small embedded devices which have small memory sizes both RAM amp ROM e want to use TCP IP communication for systems without TCP IP stack e want to build devices which are configurable over a TCP IP network printers etc The sevenstaxTCP IP software stack generally exists in two product versions called single device and multi device In the smaller single device version the stack can work with only one connection device like an Ethernet interface or a GSM modem with PPP On this device you can implement exactly one IP subnet with one IP address In the multi device version the stack can work with multiple connection devices with different IP subnets and IP addresses You can also define routes to reach remote IP subnets far away Thus it is possible to act not only as a host but also as a router File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 8 79 Public l S EVENSTAX TCP IP amp Routing User Manual Ta SENPENSE TEKH TIES tee 2 Supported Protocols This manual deals with the main sevenstax internet suite product sevenstaxTCP IP sevenstaxTCP IP includes the protocols IP TCP ICMP UDP NTP and a simple DNS client sevenstaxTCP IP in this c
68. locally set sub connection handle the packet is rejected 3 Ifa SYN was received A listening instance is searched in multi connection mode If found the checksum is checked if enabled If check was successful all relevant data and status is saved Exit 4 In multi connection state An instance is searched where the remote and local ports matches In multi device version the sub connection handle must also match 5 In single connection state The remote port is compared to the locally set remote port If they are not equal the packet is rejected The checksum is checked if enabled 7 The remote IP address is compared to the locally set remote IP address If they are not equal the packet is rejected 8 If a SYNACK was received after a SYN has been sent an ACK will be returned the alive timer initialized the first acknowledge number calculated and the application notified that the connection is established and data may be transferred At this point no further packet will be handled 9 If a RST was received e g the server has detected a TCP error the connection will be aborted and the application notified of this event No further packet handling will be done 10 If a connection is established the received sequence number will be compared with the expected one This means we have received a packet in the right order which will then be delivered to the upper layer if it carries File sevenst
69. meter Return Value File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 25 79 Public S VENSTAX TCP IP amp Routing User Manual 5 2 12 stxIP AccessLinkLocal bOn Description Controls the access between private and link local IP addresses If local IP address is a private IP address the device can communicate with devices that have a link local IP address 169 254 x y If Local IP address is a link local IP address the device can communicate with devices that have a private IP address The module has a request counter so that this function can be called from many modules If the request counter is at least one the described feature is activated Parameter BOOL_stx bOn If TRUE_stx the access link local request counter is increased If FALSE_stx it is decreased Return Value BOOL_stx TRUE_stx 5 3 Notify Codes Although sevenstaxTCP IP supports a dedicated notify handler for the IP module currently no notify codes are defined for IP File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 26 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ENDED TECHNOLOGIES 5 4 Interface to the Protocol Layer below sevenstaxTCP IP underlying protocols on data link layer might be PPP or Ethernet The essential interfaces to handle sending and receiving packets via this sub layer are implemented as macros in protdefs h 5
70. mple sevenstaxTCP IP cannot be pinged because it doesn t know ICMP but this can be enabled by conditional compilation sevenstaxTCP IP relies on the other end s intelligent control algorithms to improve transmission speed if it has Therefore receiving data with sevenstaxTCP IP is at an acceptable speed To show for what sevenstaxTCP IP is good for see the following details e No receive and transmit buffers sevenstaxTCP IP shares buffers with the lower level network protocol e g sevenstaxPPP or sevenstaxEthernet e Minimum ROM and RAM usage Code size differs from 5K to 9K CISC depending on the compiler and on the processor on which it is executed This makes it an excellent choice for small embedded systems e Pure TCP IP No additional protocols such as ICMP DHCP UDP etc are implemented to save memory But some of them can be enabled by conditional compilation see the chapter Currently Supported Add ons e Sliding windows support on TCP transmission to maximise send performance e Easy integration with existing software Only a few interfaces e Asynchronous behaviour Other software will not be delayed by sevenstaxTCP IP e Trouble free operation under an RTOS environments like CMX and embOS e Shipped as well documented source code ANSI C which makes it easy to modify e Does not follow RFC in all cases but fulfils most MUST criteria e No dedicated reception buffer File sevenstaxT CPIPRout_UserManua
71. n version 4 is a core module and can not be disabled It is available as single device version ipv4 c and as multi device version ipv4md c See section 5 and 6 IP Module Single Device and IP Module Multi Device for details 2 5 Routing Support Routing is part of the sevenstaxRouting product which requires the IP module as multi device version Supported operations are NAT including Port Forwarding and simple Forwarding files nat c nat h natdefs h forward c forward h forwdefs h See section 7 Routing for details 2 6 TCP Support TCP is part of the sevenstaxTCP IP product files tcp c tcp h tcpdefs h TCP is the abbreviation for Transmission Control Protocol a secure and commonly used packet delivery service If you need TCP please define TCP_SUPPORTED 1 in features h See section 8 TCP Module for details 2 7 UDP Support UDP is part of the sevenstaxTCP IP product files udp c udp h udpdefs h UDP is the abbreviation for User Datagram Protocol an unreliable packet delivery service If you need UDP please define UDP SUPPORTED 1 in features h See section 9 UDP Module for details File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 10 79 Public S VENSTAX TCP IP amp Routing User Manual Tp SEMEERUED TERKKOLDENES 2 8 DNS Support DNS is part of the sevenstaxTCP IP product files dns c dns h dnsdefs h A simple DNS client can be used by the application to send a que
72. ne packet fits into the send buffer TCP WINDOW SIZE default Max size of TCP receive payload overhead to save a rcv TCP packet This stands for the maximum number of bytes a TCP can receive This value will be directly written to the TCP header Normally a TCP sets this value dynamically according to its free buffer space With the default value exactly two complete packets fit into the receive buffer File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 63 79 Public S VENSTAX TCP IP amp Routing User Manual Sp TEMPERED TERKKOLDENES 9 UDP Module 9 1 Overview UDP is part of sevenstaxTCP IP standard internet library It can be enabled by setting UDP_SUPPORTED to 1 in features h see section 2 Supported Protocols 9 2 Protocol API 9 2 1 stxUDP Init handler Description Sets up some internal variables initialises internal UDP instances and registers application callback function Must be called before using any other UDP function Parameter PROTOCOL_NOTIFY_HANDLER handler Application handler function to receive notify codes from the UDP module The handler function will be called when UDP data is received for a port that was not registered via stxUDP_AddConn see below Return Value Comment 9 2 2 stxUDP_Tick Description This function keeps sevenstaxUDP alive It must be called as often as possible in order to provide sevenstaxUDP with processor time
73. nnnvnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnr 15 e Ne NEE 15 42 Te Settings eis tees esters aad awe oa bees ean ee ebe 16 4 2 1 Alignment and Endianess features R m mnms emerisnainsseeserssnassnnoesnnnvnnannnanernnevvsevnnnn 16 4 2 2 Packing features h stx pack h Stx uppeckb nr nnnnnnnnn 16 4 2 3 System Time TR QUAI OS Isc ccesecsectepcaceeveiGestsnsesnssaassageneis ee sodeaiccenandesalseiceeetacesaadenayes 17 4 2 4 Controlling sevenstax TCP IP features Ieatures P 17 4 2 5 Standard Lib Functions runtimelb cb 18 4 2 6 Protocol spanning Definitions Droideis hb 18 4 3 Notify Handler Application Handler Procecdure 18 4 3 1 Notify Handler Function Prototype cccccccccceeeeeeeeeeeeeeeeeeeeeeneeeesessasssssneeaeaeeees 18 4 3 2 Notify eee 18 4 3 3 Additional param1 and Garam 19 4 3 4 Return Value esiisa a a Eia E TE E RERE AEE REENER ATTE 19 4 3 5 Registering a Notify Handler 19 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 2 79 Public S VENSTAX TCP IP amp Routing User Manual 4 3 6 Using the EE eege 19 4 4 Include sevenstax Header Files Lusmisnasisssuimisednoimmnhuhietnnnebemndeisbenkebnne 20 5 IP Module Single DEvIte geteegee ageeeeeeegeteeegeee sed gege 22 SEE EN ES 22 9 27 Cie ee EE E ER SAT SUMP Init handler D 23 9 2 2 SOP VICK D 23 5 2 3 stxIP SetLocallPAndSubnetMask psLocallP psSubnetMask rrrrrrrrnnnrnr 23 5 2 4 stxIP ResetLocallP
74. nually to activate a permanent translation This operation is called port forwarding These entries are never rewritten automatically and must be deleted manually A requirement for successfully routing a packet is that the receive buffer size of the source IP subnet is equal to the send buffer size of the destination IP subnet The module can be configured so that for TCP and UDP packets the checksum is checked and all packets where the check failed are rejected In addition the user can define a filter function to filter out some packets with certain properties concerning destination IP address transport layer protocol e g UDP or destination port of transport layer protocol As described above in normal operation only the internal IP address is exchanged during the routing process By registering a special function the external IP address target IP address of packet directed to target IP subnet can additionally be exchanged masqueraded This transformation is called Twice NAT because both IP addresses are exchanged in every routed packet This can be useful for example to reach IP addresses that normally would not be routed as a result of the IP routing table This module can be activated by defining NATPF_SUPPORTED with 1 features h File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 46 79 Public TCP IP amp Routing User Manual S VENSTAX 7 3 2 Application Programming
75. of remote port of sender UINT16 stx local port IP Port number of destination port of receiver Description of the notify codes 9 3 1 NC UDP RECV UDP Info UDPConnID This event is generated as a result of a successfully received UDP packet from the remote machine It is called only if the target port could be found in the active connections see also stx P_AddConn and if the appropriate process function is NULL stx Parameter 1 points to a UDP INFORMATION structure which describes the incoming data packet All members are valid Parameter 2 indicates the ID of the UDP instance on which this data was received ReturnValue not used 9 4 Adjustable Parameters UDP parameters are defined in udpdefs h These parameters should properly be adjusted depending on the application requirements The following list describes them in detail UDP MULTI default 5 valid 1 n If multiple UDP transmissions are required this specifies the maximum number of simultaneous UDP connections Only 4 Bytes RAM are allocated per UDP MULTI Please keep in mind that DNS BOOTP DHCP or mDNS need their own free UDP instances if they are enabled UDP CHECK CRC default 1 Enables checking the checksum of received packets File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 67 79 Public S VENSTAX TCP IP amp Routing User Manual Va PEREESUED THSEROUES TES 10 DNS Tiny Module 10 1 Overview
76. on exists sevenstaxTCP will send an RST which will close the old connection enabling a new one to be established on the same port Transmitting TCP Packets To transmit TCP packets sevenstaxTCP needs to know two things from the lower network layer First it needs the address of the transmit buffer because sevenstaxTCP must know where to assemble a TCP packet Next sevenstaxTCP needs to know the transmit function of the lower layer This function takes the TCP packet and forwards the packet to the network In single device version this function might be an Ethernet or PPP send function thus a function on data link layer In multi device version a send function of the network layer IP layer is called via the sub connection handle Immediately after sevenstaxTCP has built the packet in memory it prepares the packet descriptor in single device version and calls the transmit function to send out the packet Inside sevenstaxTCP there is a function named stxTCP InternalSend which performs all of the above described tasks Terminating a TCP Connection Usually a web server terminates the TCP connection after it has transferred the last byte of the page When the server wants to close the connection it sends a FINACK and enters the FIN_WAIT_1 state see RFC 793 figure 13 Users of sevenstaxTCP must call the function stxTCP Disconnect which initiates the closing process When the connection is closed sevenstaxTCP calls the applicati
77. on is called with function code uFctCode L2 GENERIC FCT PREPARE WRITE IDX The data parameter pData points to a structure of type L2 GENERIC FCT PREPARE WRITE PARA STRUCT with following entries belonging to the packet to send ulPPktType IP packet type enum IPV4 PKT TYPE psDestIP pointer to destination IP address psLocallP pointer to local IP address Preparing a response The generic function is called with function code uFctCode L2 GENERIC FCT PREPARE RESPONSE IDX The data parameter pData points to a structure of type L2 GENERIC FCT PREPARE RESPONSE PARA STRUCT with following entries belonging to the received packet psSrelP pointer to source IP address psDestIP pointer to destination IP address psLocallP pointer to local IP address pPkt pointer to packet descriptor e psData Must point to a structure of type CONN DATA L2 STRUCT TYPE with the following contents e uSizeSendPayload Buffer size that is available for the sending payload In most cases it is the size of the complete send buffer less the size for the overhead E g for Ethernet it is the size of the Ethernet send buffer minus 14 for the Ethernet header size This value prevents sevenstaxTCP IP to write too much data into the send buffer uSizeRcvPayload Buffer size that is available for the received payload In most cases it is the size of the complete receive buffer less the size for the overhead E g for PPP it is the size of the PPP recei
78. on s handler procedure by posting a NC TCP FIN event File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 53 79 Public TCP IP amp Routing User Manual S VENSTAXx There are some other conditions when sevenstaxTCP issues NC TCP FIN as well For example If sevenstaxTCP sends data e g an HTTP request but the packet was not acknowledged after a few retries ACK timeout the TCP connection will also be terminated To separate regular terminations from error conditions the handler procedure is called with different parameters For a detailed description see the following table the constants are defined in tcp h enum ABORT REASON Cause of termination First parameter of Meaning handler procedure ABORT_REASON A successful call to AR_CLOSED Normal operation All data has been stxTCP_Disconnect or the remote successfully transferred TCP has closed the connection 1 stxTCP_Disconnect was called AR_CLOSE_FORCED Error Some data might be received and sevenstaxTCP was in transition state neither in the connected nor in the closed state 2 The other end has send an RST 3 Timeout The remote TCP does not respond to our FINACK s or FIN s Transmitted data was not AR_RTM_EXCEEDED Error Too many retransmissions acknowledged after some retransmissions ARP was not able to resolve the MAC AR NO MACADDRESS Error TCP can not continue Maybe address of the
79. on should be established Ports are something like channels dedicated to particular services E g HTTP resides on port 80 decimal Return Value UINT16 stx The sevenstaxTCP internal connection ID or an error value INVALID CONNECTION ID Subsequent calls into sevenstaxTCP must use this value to identify the connection Also events which the application receives by its handler procedure carry connection IDs Comment Upon a call to StxTCP Connect successful or not the application defined handler procedure is called stxTCP Connect is usually called when sevenstaxTCP acts as a client TCP Server TCPs should call stx TCP_Listen instead File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 56 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 8 2 4 stxTCP Listen hSubConn port Description Puts sevenstaxTCP into the listen state which means that it waits for a connection attempt on the specified port If another TCP sends a SYN sevenstaxTCP handles it properly and enters the connected state Parameter CONN HNDL TYPE hSubConn only multi device version Connection handle of underlying network layer If NULL stx no restriction is made concerning the local IP subnet UINT16 stx port The port number of the local TCP on which the connection should be established Ports are something like channels dedicated to particular services E g HTTP resides
80. onnection handle of the data link layer connection define IP RESET LOCAL IP AND SUBNET MASK LINK hSubConn stxIP ResetLocallPAndSubnetMask Link hSubConn If the local IP address and local subnet mask can be reset in the data link layer like in PPP the data link layer protocol stack can do this by accessing this macro The first parameter is the connection handle of the data link layer connection define IP SET DNS1 IP LINK hSubConn plp stxIP SetDNS1IP Link hSubConn plp If the first DNS server can be set in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro The first parameter is the connection handle of the data link layer connection define IP RESET DNS1 IP LINK hSubConn stxIP ResetDNS1IP Link hSubConn If the first DNS server can be reset in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro The first parameter is the connection handle of the data link layer connection define IP SET DNS2 IP LINK hSubConn pip stxIP SetDNS2IP Link hSubConn plp If the second DNS server can be set in the data link layer like in PPP the data link layer protocol stack can do this directly by accessing this macro The first parameter is the connection handle of the data link layer connection define IP RESET DNS2 IP LINK hSubConn stxIP ResetDNS2IP Link hSubConn If the second DNS server can be reset in the data l
81. ontext is used as a general protocol suite name 2 1 Protocols Overview The following graphic shows the integration of sevenstaxTCP IP red marked inside the other optional sevenstax internet libraries available as separate products httpgen c mdns c nbns c httpprs c dns_lib c xmiprs c httpcint c dns_serv c auto_ip c xmigen c html page c imf c xml c dhepe httpserv c smtp c soapsrv c pop3 c OU ppp c ethernet c ModemDrv X c NICDrv X c File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 9 79 Public TCP IP amp Routing User Manual S VENSTAX 2 2 PPP Support sevenstaxPPP is available as a separate product sevenstaxPPP has been approved in many products and countries worldwide in reliable connections to common public Internet Service Providers ISPs sevenstaxTCP IP connects to PPP if PPP_SUPPORTED 1 is defined in features D 2 3 Ethernet Support sevenstaxEthernet is available as a separate product sevenstaxEthernet offers a very tiny and effective protocol implementation for LAN connections providing implicitly support for ARP and Network Interface Card NIC usage sevenstaxTCP IP connects to Ethernet if ETHERNET_SUPPORTED 1 is defined in features h 2 4 IPv4 Support IP is part of the sevenstaxTCP IP product files ipv4 c ipv4md c ipv4 h ipv4defs h ipv4lib c ipv4lib h IP Internet Protocol i
82. orks if either the reply from the name server is not fragmented or the wanted IP address is in the first fragment For very large sites such as www google com name server replies does not fit into a single UDP packet But in the majority of cases an IP address is included and found in the first fragment IP address from name servers DNS sevenstaxTCP IP only uses the first of potential multiple IP address found in the reply of a name server ICMP The only part of ICMP which is currently implemented into sevenstaxTCP IP are ICMP echo replies PING Use of Ethernet and PPP The single device version of sevenstaxTCP IP does not support use of PPP mode and Ethernet mode at the same time Please use sevenstaxTCP IP MultiDevice if you need several physical interfaces at the same time e g router functionality sevenstaxTCP IP is object of permanent improvement Please contact info sevenstax de to get more information about new TCP IP features that will be available in next release version File sevenstaxTCPIPRout_UserManual_V53 odt Revision No 5 03 printed 23 06 08 Page 77 79 Public TCP IP amp Routing User Manual S VENSTAX 15 Change History Ver Date by Change description 2 88 21 Aug 2002 pe Base version 2 91 12 Dec 2002 pe Improved API documentation 3 01 16 Jan 2003 pe Addit
83. other side Ethernet peer does not exist on the LAN only Connection over network layer has AR_NO_NETWORK Error TCP can not continue terminated 8 1 6 Server Functionality sevenstaxTCP is capable to act as a server This means it can passively wait for connections from other Hosts and send requested data or error messages to them To enable the server functionality the following steps are required After initialization of sevenstaxTCP call stxTCP_Listen This causes sevenstaxTCP to listen on a specified port for incoming connections After being connected which will be indicated by the received notify code NC_TCP_CONNECTED call stxTCP_WriteBulk to send data of nearly any size to the remote TCP When the entire data block was successfully transmitted more data may be sent or the connection may be closed by calling stxTCP Disconnect for a graceful disconnect File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 54 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ENDED TECHNOLOGIES 8 1 7 Single and Multiple Connections In cases where memory is a very limited resource sevenstaxTCP can work in single connection mode This is useful for very small embedded devices with the need of only one TCP connection at a time Set TCP MULTI to 0 or 1 to enable this mode Typically more than one simultaneous connection must exist e g HTTP browser requests seven
84. ptor for details with the following settings e state Not used any value e size Size of the entire packet including link layer headers data A pointer to the first byte of the link layer header e payload A pointer to the first byte of the IP header The function returns TRUE_stx if the packet was processed and FALSE_stx if not File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 27 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ENDED TECHNOLOGIES 5 4 2 Accesses from IP Module into Protocol Layer below The following macros exist for the sevenstaxEthernet and sevenstaxPPP protocol implementations Adapt these macros if you use another sub layer protocol define SEND PKT x stxETH SendipFrame x define SEND PKT x stxPPP SendipFrame x One of these functions is the entry point of the link layer which is responsible for handling data that should be sent off to the network sevenstaxTCP IP requires a function which takes a pointer to a packet descriptor as a single parameter When SEND_PKT is called it has done these things before e It has build a complete IP packet beginning at the location where the packet descriptor s member FPTR_stx payload points to e It has set the packet descriptor s size member to the size of the IP packet The link layer might then do the following e Increase the size member about the length of its own headers e Build its headers
85. red Also it manages a buffer with already transmitted data to repeat transmission if the recipient hasn t acknowledged the packets After both Hosts have finished the connection must be closed This can be done either by exchanging datagrams similar to the connection process or faster by sending a connection reset from any station Of course this is a very much incomplete description of TCP a TCP IP tutorial is beyond the scope of this document Connection Establishment For the purpose of connection establishment sevenstaxTCP has two interfaces named stxTCP Connect client mode and stxTCP Listen server mode how a connection is established is shown in RFC 793 figure 7 NOTE For stxTCP Connect the local port numbers of sevenstaxTCP are pseudo random values sevenstaxTCP tries to send some SYNs to the other end until it receives a SYNACK If for any reason no SYNACK arrives sevenstaxTCP notifies the application through the handler procedure described below that a connection isn t possible When sevenstaxTCP runs as a TCP server like a web server it is also able to respond to connection attempts issued from remote TCPs Instead of calling stxTCP Connect the application should call stxTCP Listen to bring sevenstaxTCP into the listen state For further information refer to the chapter Currently Supported Add ons Server functionality Also sevenstaxTCP has a built in mechanism to handle half open conne
86. reply e Anew checksum is calculated e Source and Destination addresses are swapped e The packet is sent off to the network 11 2 Protocol API Currently there is no public ICMP API function available nor a function to send an ICMP message by the application 11 3 Notify Codes Currently there is no notify code available 11 4 Adjustable Parameters Currently there is no ICMP parameter available File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 72 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 12 NTP Module 12 1 Overview A simple NTP client is part of sevenstaxTCP IP standard Internet library NTP can be used to retrieve the current time NTP can be enabled by setting NTP SUPPORTED to 1 in features h see section 2 Supported Protocols The NTP protocol works ahead UDP so UDP SUPPORTED must also be set to 1 see section 2 Supported Protocols The Network Time Protocol NTP is used to synchronize the time of a computer client or server to another server or reference time source such as a radio or satellite receiver or modem It provides accuracies typically within a millisecond on LANs and up to a few tens of milliseconds on WANs relative to Coordinated Universal Time UTC via a Global Positioning Service GPS receiver for example Typical NTP configurations utilize multiple redundant servers and diverse network paths in order to achi
87. ry found NAT ERR FAILURE masq port is already used for another entry File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 49 79 Public S VENSTAX TCP IP amp Routing User Manual Va PEREESUED TEONNTLOATES 7 3 2 9 stxNAT_DelRoutingTableEntryPerm wIdx Description Deletes a permanent entry port forwarding in the translation table This function only is available if PFW ENABLED 1 Parameter UINT8_stx widx index of translation table result of stxNAT_AddRoutingTableEntryPerm Return Value NAT_ERR NAT_ERR_OK if permanent entry was deleted successfully NAT ERR INVALID PARAM if permanent entry could not be deleted successfully because the index had a wrong value 7 3 3 Notify Codes Currently no notify codes are defined for the Forwarding module 7 3 4 Adjustable Parameters NAT ENABLED default 1 valid 0 1 With this parameter you can enable the normal NAT operation Routing initiated from IP subnet not equal to target IP subnet temporary translation table entries PFW ENABLED default 0 valid 0 1 With this parameter you can enable the port forwarding Routing initiated from target IP subnet or not target IP subnets permanent translation table entries NAT STD TTL default 5 30 sec valid 1 255 6 1530 sec Default TTL time to live value for an entry in the translation table in 1 10 min NAT CNT ROUTING TAB ENTRIES default 40 valid 1 255 Count
88. ry to a DNS server and extract the returned IP address of the response If you need DNS please define DNS SUPPORTED 1 in features h See section 10 DNS Tiny Module for details If you additionally need DNS server functionality please use a separate product called sevenstaxZeroConf which includes a DNS server module and a separate DNS library 2 9 ICMP Echo Support ICMP is part of the sevenstaxTCP IP product files icmp c icmp h icmpdefs h Sometimes it may be useful that a network host responds to ICMP echo requests also known as PING The ICMP support of sevenstaxTCP IP is very simple and small in code size therefore enabling it will not waste much memory sevenstaxTCP IP can be extended to reply to such a request by defining ICMP SUPPORTED 1 in features h See section 11 ICMP Module for details 2 10 NTP Support NTP is part of the sevenstaxTCP IP product files ntp c ntp h ntpdefs h A simple NTP client can be used by the application to send a query to a time server and extract the returned time of the response If you need NTP please define NTP SUPPORTED 1 in features h See section 12 NTP Module for details File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 11 79 Public S VENSTAX TCP IP amp Routing User Manual Ve PEREESUED TEONNTLOATES 3 Internal Data Structures 3 1 PACKET_DESC the Packet Descriptor typedef struct tag PACKET DESC PACKET
89. s Example CONN_STRUCT_TYPE sEthernerConnStruct CONN HNDL TYPE hConnLayer2 CONN HNDL TYPE hConnLayer3 EIER NMR GEES tex uConnTCP UINT16 stx uConnUDP Loco ip amp sEthernetConnStruct stxIP Attach hConnLayer2 SExNCG PIC onnee HE onnk yer Sep SOE stxUDP_AddConn hConnLayer3 67 fct So every protocol knows nothing about the sub layer protocol it only accesses via hSubConn all components of the sub layer connection structure Every connection handle holds in psMeth a pointer to a structure with function pointers typedef struct CONNECTED FCT TYPE fConnected function to return the connected state WRITESTR FCT TYPE fWriteString function to send data buffer via sublayer WRITEBYTE FCT TYPE fWriteByte function to send single byte via sublayer READSTR FCT TYPE fReadString function to read data buffer from sublayer READBYTE FCT TYPE fReadByte function to read single byte from sublayer SENDBUSY_FCT_TYPE fSendBusy function to check busy state of sublayer GENERIC FCT TYPE fiGenerie generic function might be adapted for any purpose CONN METH STRUCT TYPE Not all functions are used in every protocol stack so that some pointers can remain NULL_stx The functions are defined as follows File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 13 79 Public TCP IP amp Routing User Manual SEN NSTAX typede
90. s owe IP or broadcast multicast UINT16 stx datasize Length of received data UINTI6 stx remote port Port number of peer WN srs local port Our port number TCP INFORMATION UINT8 stx FPTR stx data Points to received data The application must only use this pointer and the data referenced to as long as the called function notify handler is active IPV4 remote ip address Remote IP address sender might be Unicast Multicast or Broadcast IPV4 dest ip address Destination IP address receiver might be Unicast Multicast or Broadcast UINT16 stx datasize Amount of data in bytes data points to File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 59 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES UINT16 stx remote port IP Port number of the remote port of sender UINT16 stx local port IP Port number of the destination port of receiver If data arrives on a specific port sevenstaxTCP issues a NC TCP RECH event with an additional pointer to a TCP INFORMATION structure where beside the other members data and datasize describe a newly received packet Below is a description of the notify codes 8 3 1 NC TCP CONNECTED TCP Info ConnlID After calling stxTCP Connect NC TCP CONNECTED is issued in case of success The application can now send and receive data to from sevenstaxTCP Both parameters cont
91. scription Saves actual standard gateway to be restored later Can be useful if a standard gateway is set temporarily so that after deletion the old standard gateway can be restored See also stxIP RestoreStdGateway Parameter Return Value 6 2 14 stxIP RestoreStdGateway Description Restores saved standard gateway Can be useful if a standard gateway is set temporarily so that after deletion the old standard gateway can be restored See also stxIP SaveStdGateway Parameter Return Value 6 2 15 stxIP AccessLinkLocal hConn bOn Description Controls the access between private and link local IP addresses for a local IP subnet If local IP address is a private IP address the device can communicate with devices that have a link local IP address 169 254 x y If Local IP address is a link local IP address the device can communicate with devices that have a private IP address The module has per IP subnet a request counter so that this function can be called from many modules If the request counter of an subnet is at least one the described feature is activated for this subnet Parameter CONN_HNDL_TYPE hConn Handle of IP subnet result of stxIP_Attach function call BOOL_stx bOn If TRUE_stx the access link local request counter is increased If FALSE stx it is decreased Return Value BOOL_stx TRUE_stx File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 36 79 Pu
92. scription This function keeps NTP alive assuring multiple retries until a timeout occurs It should repeatedly be called by the application like all the other sevenstax Tick functions too independently of a pending NTP query or not Parameter Return Value Comment In case of a timeout this function will call the application notify handler with NC NTP FAILURE If the NTP server responds this will be synchronously be signaled by NC NTP SUCCESS by the responsible process packet functions 12 2 3 StxNTP Query hConnNetwork ntp server Description NTP queries will be started by calling this function Sets some internal variables and returns immediately The actual query will be done the next time stxTCP Tick is called After a call to stxNTP Query the application defined handler procedure will either receive an NC NTP SUCCESS got the time or NC NTP FAILURE no response from the time server Parameter CONN HNDL TYPE hConnNetwork only multi device version connection handle of underlying network layer over which the NTP query ought to be started CONST stx IPV4 FPTR stx nip server A pointer to an IPV4 structure representing the IP address of the time server Return Value BOOL_stx TRUE_stx if the query was started FALSE stx if the query could not be started because of no free UDP instance Comment Please note Calls made to stxNTP Query while being in progress will re trigger the query process File se
93. sed 10 3 2 NC_DNS_TIMEOUT FS This event is posted as a negative result when stxDNS QueryStart was called and the DNS resolver timed out There are various reasons for such a failure The most likely reasons are that the DNS server is not able to find the requested host name e g because it does not exist anymore or that the DNS server itself is temporarily not available Parameter 1 is not used and always UINT32_stx_MAX File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 70 79 Public S VENSTAX TCP IP amp Routing User Manual Va TEMPERED TERGKOLDENES Parameter 2 is not used and always UINT32 stx MAX ReturnValue not used 10 4 Adjustable Parameters Currently there is no DNS parameter available for this tiny DNS client module File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 71 79 Public S VENSTAX TCP IP amp Routing User Manual Ve PEREESUED THSEROUES TES 11 ICMP Module 11 1 Overview A simple ICMP responder is part of sevenstaxTCP IP standard internet library sevenstaxICMP automatically responds to an incoming ping with an ICMP packet ICMP can be enabled by setting ICMP SUPPORTED to 1 in features h see section 2 Supported Protocols If an incoming packet is identified as an ICMP echo request sevenstaxICMP does the following steps e The packet is copied to the TX buffer and the type is changed to an ICMP echo
94. staxTCP can be configured to work with up to 65535 connections at a time Multi connection support can be switched on at compile time by setting TCP MULTI to a value of at least 2 With TCP MULTI one can specify the maximum number of connections which sevenstaxTCP can handle This should be well adjusted to save memory because for every connection about 100 bytes RAM are reserved TCP MULTI TICKS is the number of active connections which are handled by a single call to stxTCP_Tick This value also depends a little how frequently stxTCP Tick is called For example If you configure sevenstaxTCP to work with 100 possible connections TCP_MULTI_TICKS can be set to 10 Both defines can be found in tcpdefs h Most of sevenstaxTCP s interfaces have an additional parameter called Connection ID Connection IDs are unique values which help to distinguish between connections They are unique during the lifetime of a connection Connection IDs are automatically recycled newly assigned when a connection ends Please Note TCP_MULTI_TICKS does not affect incoming TCP data Received packets are handled immediately whenever the underlying protocol layer probably IP calls stxTCP_ProcessPacket 8 2 Protocol API 8 2 1 stxTCP_Init handler Description Before sevenstaxTCP can be used this function must be called It initializes all internal states of sevenstaxTCP and also registers the application defined handler procedure Paramet
95. taxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 22 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 5 2 Protocol API 5 2 1 stxIP Init handler Description Initializes the IP module Must be called once before using IP Parameter PROTOCOL NOTIFY HANDLER handler Application defined handler procedure Return Value 5 2 2 stxIP Tick Description This function keeps IP alive It must be called as often as possible in order to provide the IP module with processor time Parameter Return Value 5 2 3 stxIP SetLocallRAndSubnetMask psLocallP psSubnetMask Description Sets manually given IP address and subnet mask as local network setting Parameter IPV4 FPTR stx psLocallP Pointer to local IP address IPV4 psSubnetMask Pointer to subnet mask of local subnet Return Value BOOL stx TRUE sty Given IP settings were set successfully FALSE stx Given IP settings could not be set successfully File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 23 79 Public S VENSTAX TCP IP amp Routing User Manual Ve PEREESUED THSEROUES TES 5 2 4 stxIP ResetLocallPAndSubnetMask Description Resets local IP address and subnet mask Both values are set to 0 0 0 0 Parameter Return Value 5 2 5 stxIP GetLocallP Description Returns actually set local IP address Parameter Return Value IPV4 FPTR_stx Point
96. ubnet over which the packet is received is determined This is important to check if the target IP is equal to the local IP of this local subnet gt Then the target IP address is checked in relation to the current network configuration of the local IP address and the subnet mask If the target IP address is equal to the local IP address the packet is accepted when the local IP address is not 0 0 0 0 In addition the packet is accepted when it is a global local broadcast or a multicast All other packets are rejected gt For all unfragmented packets the sub protocol is evaluated If it is one of the protocols TCP UDP ICMP and if the respective protocol is enabled SUPPORTED the packet is delivered to the respective process packet function 3 Forall packets that are not accepted because of the target IP address or for the packets where the target IP address is equal to the local IP address but which are File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 31 79 Public S VENSTAX TCP IP amp Routing User Manual Va TEMPERS TYRRKOLGS ES not processed by a higher layer protocol it is checked if the packet can be routed only with the sevenstaxRouting modules 6 2 Protocol API 6 2 1 stxIP Init handler Description Initializes the IP module Must be called once before using IP Parameter PROTOCOL NOTIFY HANDLER handler Application defined handler procedure Return Value 6 2
97. ueeesdereacattalereasoars 75 124 Adjustable Parameters eegener eebe eege EES dee 75 13 Debugging UO EE 76 Ae E 77 15 Change IS CON Y seis ieicet x cccetne seas teense edenenneciantianenacdanscacesensecsiectiuessndaansenceencuinsis 78 File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 6 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ENDED TECHNOLOGIES 1 Preface The Internet is today s most commonly used source of information Almost anywhere in the world if there is a telephone jack people using computers can access this vast reservoir of information Normally these computers are big fast and powerful They have large amounts of memory processors faster than light and bloated full featured operating systems Because of this computing power they easily deal with complex network protocols such as PPP and TCP IP In contrast to this connecting smaller devices such as embedded systems to the Internet is somehow a tricky and difficult task The biggest problem is to put such network protocol software into the limited memory space of small microcontrollers But is there always a need to do so The answer is No sometimes it s enough to implement only the basic parts of a protocol This is why sevenstaxTCP IP was made For the reason of smallness the sevenstaxTCP IP has no additional protocols by default which usually belongs to a complete TCP IP suite of protocols For exa
98. ve buffer minus 6 for the PPP header and checksum size Note This value has a bearing only on the TCP module when calculating its window size depending on this value So if you don t use TCP the value doesn t matter uSizeRcvOverhead Memory overhead for saving a received IP packet In most cases it is the header and footer size of one packet but in some cases it can be more than this because of special data structures necessary to manage received packets E g for sevenstaxPPP the function returns always 6 s a but for sevenstaxEthernet the value is 14 for the header plus 2 because of the ring buffer overhead Note This value has a bearing only on the TCP module when calculating its optimized window size depending on this value see chapter TCP So if you File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 42 79 Public S VENSTAX TCP IP amp Routing User Manual Va SURUESED EES don t use TCP or this feature the value returned by the function doesn t matter e pSendBuff Must point into that position in the send buff where a sending IP packet can be placed Note To reduce copying it would be effective to leave space for the eventually existing header of the data link protocol E g for sevenstaxEthernet this pointer points to the beginning of the send buffer plus 14 6 5 Adjustable Parameters IP_EXTERNAL_BROADCAST_MASK default 000000FFh valid 00000000h FFFFFFFFh
99. venstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 74 79 Public S VENSTAX TCP IP amp Routing User Manual Va SERS ERUED TECHNOLOGIES 12 2 4 stxNTP_Transform ntp_seconds seconds minutes hours year month day day_of_week Description Takes the NTP seconds ntp_seconds delivered by the time server and writes the results into the locations for application time variables Parameter UINT32_stx ntp_seconds NTP seconds delivered by the time server UINT8_stx FPTR_stx seconds UINT8_stx FPTR_stx minutes UINT8_stx FPTR_stx hours UINT16_stx FPTR_stx year UINT8_stx FPTR stx month UINT8 stx FPTR_stx day UINT8_stx FPTR stx day of week Addresses of application variables to receive the delivered time values Return Value Comment This function is for convenient conversion of the result of an NTP query which is a 32 bit value of seconds since 1 1 1900 into time and date values The time returned by the servers is UTC Coordinated Universal Time which means it has to be corrected if the local time zone differs from UTC This correction must be done before calling stxNTP Transform The difference between the local time and UTC has to be added to the seconds returned by the server After calling NTP Transform the right values can be read from the parameters as described above 12 3 Notify Codes 12 3 1 NC NTP SUCCESS NTP sec This event indicates a successful reception of a time s
100. was set FALSE stx if routing property could not be set File sevenstaxT CPIPRout_UserManual_V53 odt printed 23 06 08 Revision No 5 03 Page 38 79 Public S VENSTAX TCP IP amp Routing User Manual Va CERSENDED TECHNOLOGIES 6 2 21 stxIP SetRoutingToStdGateway eRoutingType Description Sets the routing property to the IP subnet that is located behind the standard gateway When activated all packets from another IP subnet that are directed to that subnet are routed The default setting is no routing in which case all these packets are rejected This function can for example enable one or more another IP subnets to access the internet Parameter IPV4 ROUTING TYPE eRoutingType Routing type In this version there are the following possibilities 0 IPV4 NO ROUTING no routing 1 IPV4 ROUTING FORWARD simple forwarding 2 1IPV4 ROUTING NAT network address translation Return Value BOOL stx TRUE stx 6 2 22 stxIP SetRoutingToRoute ulndex eRoutingType Description Sets the routing property to an arbitrary local or remote IP subnet except for the subnet behind the standard gateway defined by the index of the routing table As index the result of the call of the function stx P_AddRoute must be used When activated all packets from another IP subnet that are directed to that subnet are routed The default setting is no routing in which case all these packets are rejected Parameter UINT8_stx ulnd

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