/* * six-byte packet header for asynch lines. * headers for other devices take up the same * or less space. If this changes the header * struct will have to become a union. */ struct header { char sync; /* sync byte */ char ksize; /* encoded packet size */ unsigned short sum; /* block check of data packet */ char cntl; /* control byte */ char ccntl; /* block check of header */ }; #define HDRSIZ 6 /* * Control structure for a packet driver connection. */ struct pack { short p_state; /* line state */ short p_bits; /* mask for getepack */ short p_rsize; /* input packet size */ short p_xsize; /* output packet size */ struct header p_ihbuf; /* input header */ struct header p_ohbuf; /* output header */ char *p_rptr; char p_mode; char **p_ipool; /* head link to input buffer pool */ char **p_io; /* input buffer given to driver */ char p_xcount; /* # active output buffers */ char p_rcount; char p_nout,p_tout; char p_lpsize; /* log(psize/32) */ char p_timer; char p_obusy; char p_srxmit; char p_rwindow; /* window size */ char p_swindow; char p_msg; /* control msg */ char p_rmsg; /* repeated control msg */ char p_ps,p_pr; /* last packet sent, recv'd */ char p_rpr; /* copy of remote pr */ char p_nxtps; /* next output seq number */ char p_imap; /* bit map of input buffers */ char p_pscopy; /* newest output packet */ char *p_ob[8]; /* output buffers */ char *p_ib[8]; /* input buffers */ char p_os[8]; /* output buffer status */ char p_is[8]; /* input buffer status */ short p_osum[8]; /* output checksums */ short p_isum[8]; /* input checksums */ DSYSTEM; }; #define CHECK 0125252 #define SYN 020 #define MOD8 7 #define NOTCNTL(a) (a & 0300) #define MIN(a,b) ((a