usr/src/include/arpa/tftp.h

/*      tftp.h  4.2     83/06/11        */

/*
 * Trivial File Transfer Protocol (IEN-133)
 */
#define SEGSIZE         512             /* data segment size */

/*
 * Packet types.
 */
#define RRQ     01                      /* read request */
#define WRQ     02                      /* write request */
#define DATA    03                      /* data packet */
#define ACK     04                      /* acknowledgement */
#define ERROR   05                      /* error code */

struct  tftphdr {
        short   th_opcode;              /* packet type */
        union {
                short   tu_block;       /* block # */
                short   tu_code;        /* error code */
                char    tu_stuff[1];    /* request packet stuff */
        } th_u;
        char    th_data[1];             /* data or error string */
};

#define th_block        th_u.tu_block
#define th_code         th_u.tu_code
#define th_stuff        th_u.tu_stuff
#define th_msg          th_data

/*
 * Error codes.
 */
#define EUNDEF          0               /* not defined */
#define ENOTFOUND       1               /* file not found */
#define EACCESS         2               /* access violation */
#define ENOSPACE        3               /* disk full or allocation exceeded */
#define EBADOP          4               /* illegal TFTP operation */
#define EBADID          5               /* unknown transfer ID */
#define EEXISTS         6               /* file already exists */
#define ENOUSER         7               /* no such user */