/* ------------------------------------------------------------------- * Vehicular Ad Hoc Networks: Regular Broadcasting of messages. * Skeleton for VANET-protocols. This should be considered as an * example to create other VANET protocols! * Apart from channel load, the "protocol" as it is now does not do * anything useful. * * Dan Jungels (daniel.jungels@epfl.ch) * LCA - EPFL * * * Packet Headers for the protocol * Originally written for ns2.29 * * 2005-12-15: release of first version (dj) * 2005-12-23: update and cleanup, public release (dj) * 2006-01-05: bugfix in the packet header (dj) * ------------------------------------------------------------------- */#ifndef vanetrbc_header_h#define vanetrbc_header_h// Message types#define VANETTYPE_REGBC         1// define your own message types here// Header Macros#define HDR_VANET(p)        ((struct hdr_vanet*)hdr_vanet::access(p))#define HDR_VANET_RBC(p)    ((struct hdr_vanet_rbc*)hdr_vanet::access(p))// define the header macros for your own message types here// general VANET header, shared by all types.// this is an easy method to access the msgtype-variable (since you don't// know which specific packet-header you have received, before having read// this variable), thus preventing you from making "unknown" castsstruct hdr_vanet {        u_int8_t vn_msgtype;    // type of the message (don't change!)        // Header access methods (don't change!)    static int offset_;     // required by PacketHeaderManager    inline static int& offset() {        return offset_;    }    inline static hdr_vanet* access(const Packet* p) {        return (hdr_vanet*) p->access(offset_);    }    // end of Header access methods.    };struct hdr_vanet_rbc {  // TYPE: Regular broadcast        u_int8_t rbc_msgtype;   // type of the message (don't change!).                            // It is mandatory to copy *first* all the                            // variables that you use in the general header                            // (above) to every specific header with the same                            // type (i.e. u_int8_t), so that you don't                            // overwrite the memory location when writing                            // data to the specific headers! (the name may be                            // different, a good convention is to always use                            // a specific prefix per specific header)        // here you may add or remove fields as you wish, for the specific packet    // header    double rbc_timestamp;   // timestamp at which the message was sent                            // (you may change or remove this)    u_int32_t rbc_senderID; // the sender's ID                            // (you may change or remove this)        char rbc_message[150];  // to store some data in it... (not really used                            // for the moment. but maybe later. you may                            // also include some cryptographic stuff, etc).    double rbc_posx;        // sender's position    double rbc_posy;            // calculate the size of the header (don't remove, but update)    inline int size() {        // The same comment as above applies.        int sz = sizeof(u_int8_t)       // 1 on x86                + sizeof(double)        // 8 on x86                + sizeof(u_int32_t)     // 4 on x86                + 150*sizeof(char)      // ...*1 on x86                + sizeof(double)        // 8 on x86                + sizeof(double);       // 8 on x86        return sz;    }};// ! add your packet types here// for size calculation of header-space reservation (don't remove!)union hdr_all_vanet {    hdr_vanet vh;    hdr_vanet_rbc rbc;    // also add you packet types here, if you have added some above};#endif