/* lkfs: read kfs under linux,	-markus, Aug 1996 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include "dat.h"

char *tagname[]=
{
	"Tnone",
	"Tsuper",
	"Tdir",
	"Tind1",
	"Tind2",
	"Tfile",
	"Tfree",
	"Tbuck",
	"Tvirgo",
	"Tcache",
	"MAXTAG"
};

#define        QPDIR   0x80000000L
#define        QPNONE  0
#define        QPROOT  1
#define        QPSUPER 2
#define        QID(a,b)        (Qid){a,b}

#define WMAGIC "kfs wren device\n"
#define superblock 1
#define rootblock 2

#define dprint if(debug)printf

int	RBUFSIZE;
int	BUFSIZE;
int	DIRPERBUF;
int	INDPERBUF;
int	INDPERBUF2;
int	FEPERBUF;

int	fd;
char	buf[8*1024];
Tag	*tag;
int	verbose=0;
int	debug=0;

void panic(char *msg){
	if(errno)perror(msg);
	else fprintf(stderr,msg);
	exit(1);
}
void getblock(long addr){
	int i;
	static long oaddr=0;
	if(addr==oaddr)
		return;
	dprint("\t<< getting block#%-5ld ",addr);
	i = lseek(fd, addr*RBUFSIZE, SEEK_SET) < 0
		|| read(fd, buf, RBUFSIZE) != RBUFSIZE;
	if(i) panic("getblock: seek/read");
	tag = (Tag*)(buf+BUFSIZE);
	dprint("   Tag={%d,%s,%ld} >>\n",
		tag->pad,
		(tag->tag < MAXTAG)?tagname[tag->tag]:"BADTAG",
		tag->path);
	oaddr=addr;
}
long indfetch(long x, long y){
	getblock(x);
	return ((long *)buf)[y];
}
long dnodebuf(Dentry *d, long a) {
	long addr = 0;              
	dprint("\t<< dnodebuf #%ld >>\n",a);
	if(a < 0) {
		fprintf(stderr,"dnodebuf: neg\n");
		return 0;
	}               
	if(a < NDBLOCK) { 
		addr = d->dblock[a];
		return addr;
	}
	a -= NDBLOCK;   
	if(a < INDPERBUF) {
		addr = d->iblock;
		addr = indfetch(addr, a);
		return addr;
	}
	a -= INDPERBUF;
	if(a < INDPERBUF2) {
		addr = d->diblock;
		addr = indfetch(addr, a/INDPERBUF);
		addr = indfetch(addr, a%INDPERBUF);
		return addr;
	}
	fprintf(stderr,"dnodebuf: trip indirect\n");
	return 0;
}
void dentrydump(Dentry *d){
	int i;
	if(!(d->mode & DALLOC))
		return;
	printf("%o ", d->mode);
	printf("%5d ", d->uid);
	printf("%5d ", d->gid);
	printf("%-25s ", d->name);
	printf("%7ld ", d->size);
	printf("%ld ", d->mtime);
	if(verbose)
		printf("%ld ", d->atime);
	printf("(%ld.%ld) ", ~QPDIR&(d->qid.path),d->qid.version);
	if(verbose){
		printf("[ ");
		for(i=0;i<NDBLOCK && d->dblock[i];i++)
			printf("%ld ", d->dblock[i]);
		if(d->iblock) printf("ib=%ld ",d->iblock);
		if(d->diblock) printf("dib=%ld ",d->diblock);
		printf("]");
	}
	printf("\n");
}
void blockdump(long block, long size){
	int slot;
	Dentry *dp;
	Superb *sb;
	long limit;
	if(block)
		getblock(block);
	switch(tag->tag){
	case Tdir:
		for(slot=0;slot<DIRPERBUF;slot++){
			dp=(Dentry*)buf+slot%DIRPERBUF;
			dentrydump(dp);
		}
		break;
	case Tfile:
		limit = (size < BUFSIZE) ? size : BUFSIZE;
		dprint("\t<< filedata (limit=%ld) >>\n",limit);
		for(slot=0;slot<limit;slot++){
			putc((int)(buf[slot]), stdout);
		}
		if(debug && size < BUFSIZE){
			printf("<<<EOF>>>\n");
		}
		break;
	case Tsuper:
		sb=(Superb*)buf;
		printf("fstart=%ld\n", sb->super.fstart);
		printf("fsize=%ld\n", sb->super.fsize);
		printf("tfree=%ld\n", sb->super.tfree);
		printf("qidgen=%ld\n", sb->super.qidgen);
		printf("fsok=%ld\n", sb->super.fsok);
		printf("nfree=%ld (freelist)\n", sb->fbuf.nfree);
		break;
	default:
		break;
	}
}
void allblocksdump(Dentry *dp){
	int i;
	long block;
	for(i=0;;i++){
		block=dnodebuf(dp,i);
		if(!block)
			break;
		blockdump(block, dp->size - (i*BUFSIZE));
	}
}
void init(char *file){
	int i;
	fd = open(file, O_RDONLY);
	if(fd<0)
		panic("open");
        lseek(fd, 0, 0); 
        i = read(fd, buf, sizeof buf);
        if(i<sizeof buf)
		panic("can't read");
        if(strncmp(buf+256, WMAGIC, strlen(WMAGIC)) != 0)
                panic("badmagic!");
	RBUFSIZE = atol(buf+256+strlen(WMAGIC));
	if(RBUFSIZE % 512)
		panic("init: bad buffersize\n");
	BUFSIZE = RBUFSIZE - sizeof(Tag);
	DIRPERBUF = BUFSIZE / sizeof(Dentry);
	INDPERBUF = BUFSIZE / sizeof(long);
	INDPERBUF2 = INDPERBUF * INDPERBUF;
	FEPERBUF = (BUFSIZE - sizeof(Super1) - sizeof(long)) / sizeof(long);
	if(debug){
		printf("RBUFSIZE=%d\n",RBUFSIZE);
		printf("BUFSIZE=%d\n",BUFSIZE);
		printf("DIRPERBUF=%d\n",DIRPERBUF);
		printf("INDPERBUF=%d\n",INDPERBUF);
		printf("FEPERBUF=%d\n",FEPERBUF);
	}
	getblock(superblock);
	if(tag->tag != Tsuper || tag->path != QPSUPER)
		panic("bad tag/path for superblock");
	if(verbose)
		blockdump(0,0);
	getblock(rootblock);
	if(tag->tag != Tdir || tag->path != QPROOT)
		panic("bad tag/path for rootblock");
	if(verbose)
		blockdump(0,0);
}
Dentry lookup(Dentry *dir, char *name){
	int slot;
	Dentry *dp;
	Dentry ret;
	int i;
	long block;
	memset(&ret,0,sizeof(Dentry));
	if(!(dir->mode & DALLOC)){
		dprint("lookup: not DALLOC\n");
		return ret;
	}
	dprint("lookup: looking for %s in %s\n",name,dir->name);
	for(i=0;;i++){
		block=dnodebuf(dir,i);
		if(!block)
			break;
		getblock(block);
		if(tag->tag==Tdir){
			for(slot=0;slot<DIRPERBUF;slot++){
				dp = (Dentry*)buf+slot%DIRPERBUF;
				if(strcmp(name, dp->name)==0)
					return *dp;
			}
		}else{
			dprint("lookup: %s points to tag!=Tdir\n",dir->name);
			break;
		}
	}
	return ret;
}
int main(int argc, char ** argv){
	Dentry d, root;
	Dentry *curr=0;
	int found;
	char *name=0;
	if(argc<2)
		panic("bad args: usage: lkfs filesys name ...");
	init(argv[1]);
	getblock(rootblock);
	memmove(&root,buf,sizeof(Dentry));
	curr=&root;
	found=1;
	if(argc>2)
	for(name=strtok(argv[2],"/"); name; name=strtok(NULL,"/")){
		found=0;
		d=lookup(curr,name);
		if(!(d.mode & DALLOC)){
			dprint("main: not found: %s\n",name);
			break;
		}
		curr=&d;
		found=1;
		dprint("main: found %s\n",name);
	}
	if(found)
		allblocksdump(curr);
	else
		fprintf(stderr, "main: not found\n");
	return 0;
}