#include <u.h>#include <libc.h>#include <ip.h>#include <auth.h>#include "ppp.h" enum{	PAD	= 128,}; Block*resetb(Block *bp){	bp->rptr = bp->base+PAD;	bp->wptr = bp->rptr;	return bp;} Block*allocb(int len){	Block *bp; 	len += PAD;	bp = mallocz(sizeof(Block)+len, 0);	bp->base = (uchar*)bp+sizeof(Block);	bp->lim = bp->base+len;	return resetb(bp);} voidfreeb(Block *bp){	if(bp == nil)		return;	bp->rptr = (void*)0xdeadbabe;	bp->wptr = (void*)0xdeadbabe;	if(bp->base == (uchar*)bp + sizeof(Block))		free(bp);}