Protocol design: Implementation of variable long frames

/*   *author  : davidlin           *Date    : 2014-12-25pm           *Email   : [email protected] or [email protected]           *world   : the city of sz,  in China          *Ver      : 000.000.001          *For      : threads for rxtx!       *history :      editor      time             do          *            1) linpeng       2014-12-25       created this file!          *           2)            */               signaling frames, the length of the data frame is different, The length of different data frames is more and more diverse, so the variable-length implementation of frames in communication protocols is of great practical significance. How to achieve:         1. Through the shift of the frame tail;         2. Increments the length item by layer. Like a 2-layer protocol typedef struct net_packet_t {    ip_packet_t     The ip;    size_t    size;    //is used to obtain the IP packet length};typedef  struct ip_packet_t {    char head;    char  pay[max];    //need to shift and grow longer     size_t chksum;    char tail;}; Phy_tx (&net,  net.size);     //send format, sent according to the actual length of the frame

Protocol design: Implementation of variable long frames