ref: 887ae1a17b54babf6a0946872bf6faaac1427be1
dir: /sys/src/cmd/aux/olefs.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <auth.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
/* little endian */
#define SHORT(p) (((uchar*)(p))[0] | (((uchar*)(p))[1] << 8))
#define LONG(p) ((ulong)SHORT(p) |(((ulong)SHORT((p)+2)) << 16))
typedef struct Ofile Ofile;
typedef struct Odir Odir;
enum {
/* special block map entries */
Bspecial = 0xFFFFFFFD,
Bendchain = 0xFFFFFFFE,
Bunused = 0xFFFFFFFF,
Blocksize = 0x200,
Odirsize = 0x80,
/* Odir types */
Tstorage = 1,
Tstream = 2,
Troot = 5,
};
/*
* the file consists of chains of blocks of size 0x200.
* to find what block follows block n, you look at
* blockmap[n]. that block follows it unless it is Bspecial
* or Bendchain.
*
* it's like the MS-DOS file system allocation tables.
*/
struct Ofile {
Biobuf *b;
ulong nblock;
ulong *blockmap;
ulong rootblock;
ulong smapblock;
ulong *smallmap;
};
/* Odir headers are found in directory listings in the Olefile */
/* prev and next form a binary tree of directory entries */
struct Odir {
Ofile *f;
Rune name[32+1];
uchar type;
uchar isroot;
ulong left;
ulong right;
ulong dir;
ulong start;
ulong size;
};
void*
emalloc(ulong sz)
{
void *v;
v = malloc(sz);
assert(v != nil);
return v;
}
int
convM2OD(Odir *f, void *buf, int nbuf)
{
int i;
char *p;
int len;
if(nbuf < Odirsize)
return -1;
/*
* the short at 0x40 is the length of the name.
* when zero, it means there is no Odir here.
*/
p = buf;
len = SHORT(p+0x40);
if(len == 0)
return 0;
if(len > 32) /* shouldn't happen */
len = 32;
for(i=0; i<len; i++)
f->name[i] = SHORT(p+i*2);
f->name[len] = 0;
f->type = p[0x42];
f->left = LONG(p+0x44);
f->right = LONG(p+0x48);
f->dir = LONG(p+0x4C);
f->start = LONG(p+0x74);
f->size = LONG(p+0x78);
/* BUG: grab time in ms format from here */
return 1;
}
int
oreadblock(Ofile *f, int block, ulong off, char *buf, int nbuf)
{
int n;
if(block < 0 || block >= f->nblock) {
werrstr("attempt to read %x/%lux\n", block, f->nblock);
return -1;
}
if(off >= Blocksize){
print("offset too far into block\n");
return 0;
}
if(off+nbuf > Blocksize)
nbuf = Blocksize-off;
/* blocks start numbering at -1 [sic] */
off += (block+1)*Blocksize;
if(Bseek(f->b, off, 0) != off){
print("seek failed\n");
return -1;
}
n = Bread(f->b, buf, nbuf);
if(n < 0)
print("Bread failed: %r");
return n;
}
int
chainlen(Ofile *f, ulong start)
{
int i;
for(i=0; start < 0xFFFF0000; i++)
start = f->blockmap[start];
return i;
}
/*
* read nbuf bytes starting at offset off from the
* chain whose first block is block. the chain is linked
* together via the blockmap as described above,
* like the MS-DOS file allocation tables.
*/
int
oreadchain(Ofile *f, ulong block, int off, char *buf, int nbuf)
{
int i;
int offblock;
offblock = off/Blocksize;
for(i=0; i<offblock && block < 0xFFFF0000; i++)
block = f->blockmap[block];
return oreadblock(f, block, off%Blocksize, buf, nbuf);
}
int
oreadfile(Odir *d, int off, char *buf, int nbuf)
{
/*
* if d->size < 0x1000 then d->start refers
* to a small depot block, else a big one.
* if this is the root entry, it's a big one
* no matter what.
*/
if(off >= d->size)
return 0;
if(off+nbuf > d->size)
nbuf = d->size-off;
if(d->size >= 0x1000
|| memcmp(d->name, L"Root Entry", 11*sizeof(Rune)) == 0)
return oreadchain(d->f, d->start, off, buf, nbuf);
else { /* small block */
off += d->start*64;
return oreadchain(d->f, d->f->smapblock, off, buf, nbuf);
}
}
int
oreaddir(Ofile *f, int entry, Odir *d)
{
char buf[Odirsize];
if(oreadchain(f, f->rootblock, entry*Odirsize, buf, Odirsize) != Odirsize)
return -1;
d->f = f;
return convM2OD(d, buf, Odirsize);
}
void
dumpdir(Ofile *f, ulong dnum)
{
Odir d;
if(oreaddir(f, dnum, &d) != 1) {
fprint(2, "dumpdir %lux failed\n", dnum);
return;
}
fprint(2, "%.8lux type %d size %lud l %.8lux r %.8lux d %.8lux (%S)\n", dnum, d.type, d.size, d.left, d.right, d.dir, d.name);
if(d.left != (ulong)-1)
dumpdir(f, d.left);
if(d.right != (ulong)-1)
dumpdir(f, d.right);
if(d.dir != (ulong)-1)
dumpdir(f, d.dir);
}
Ofile*
oleopen(char *fn)
{
int i, j, k, block;
int ndepot;
ulong u;
Odir rootdir;
ulong extrablock;
uchar buf[Blocksize];
Ofile *f;
Biobuf *b;
static char magic[] = {
0xD0, 0xCF, 0x11, 0xE0,
0xA1, 0xB1, 0x1A, 0xE1
};
b = Bopen(fn, OREAD);
if(b == nil)
return nil;
/* the first bytes are magic */
if(Bread(b, buf, sizeof magic) != sizeof magic
|| memcmp(buf, magic, sizeof magic) != 0) {
Bterm(b);
werrstr("bad magic: not OLE file");
return nil;
}
f = emalloc(sizeof *f);
f->b = b;
/*
* the header contains a list of depots, which are
* block maps. we assimilate them into one large map,
* kept in main memory.
*/
Bseek(b, 0, 0);
if(Bread(b, buf, Blocksize) != Blocksize) {
Bterm(b);
free(f);
print("short read\n");
return nil;
}
ndepot = LONG(buf+0x2C);
f->nblock = ndepot*(Blocksize/4);
// fprint(2, "ndepot = %d f->nblock = %lud\n", ndepot, f->nblock);
f->rootblock = LONG(buf+0x30);
f->smapblock = LONG(buf+0x3C);
f->blockmap = emalloc(sizeof(f->blockmap[0])*f->nblock);
extrablock = LONG(buf+0x44);
u = 0;
/* the big block map fills to the end of the first 512-byte block */
for(i=0; i<ndepot && i<(0x200-0x4C)/4; i++) {
if(Bseek(b, 0x4C+4*i, 0) != 0x4C+4*i
|| Bread(b, buf, 4) != 4) {
print("bseek %d fail\n", 0x4C+4*i);
goto Die;
}
block = LONG(buf);
if((ulong)block == Bendchain) {
ndepot = i;
f->nblock = ndepot*(Blocksize/4);
break;
}
if(Bseek(b, (block+1)*Blocksize, 0) != (block+1)*Blocksize) {
print("Xbseek %d fail\n", (block+1)*Blocksize);
goto Die;
}
for(j=0; j<Blocksize/4; j++) {
if(Bread(b, buf, 4) != 4) {
print("Bread fail seek block %x, %d i %d ndepot %d\n", block, (block+1)*Blocksize, i, ndepot);
goto Die;
}
f->blockmap[u++] = LONG(buf);
}
}
/*
* if the first block can't hold it, it continues in the block at LONG(hdr+0x44).
* if that in turn is not big enough, there's a next block number at the end of
* each block.
*/
while(i < ndepot) {
for(k=0; k<(0x200-4)/4 && i<ndepot; i++, k++) {
if(Bseek(b, 0x200+extrablock*Blocksize+4*i, 0) != 0x200+extrablock*0x200+4*i
|| Bread(b, buf, 4) != 4) {
print("bseek %d fail\n", 0x4C+4*i);
goto Die;
}
block = LONG(buf);
if((ulong)block == Bendchain) {
ndepot = i;
f->nblock = ndepot*(Blocksize/4);
goto Break2;
}
if(Bseek(b, (block+1)*Blocksize, 0) != (block+1)*Blocksize) {
print("Xbseek %d fail\n", (block+1)*Blocksize);
goto Die;
}
for(j=0; j<Blocksize/4; j++) {
if(Bread(b, buf, 4) != 4) {
print("Bread fail seek block %x, %d i %d ndepot %d\n", block, (block+1)*Blocksize, i, ndepot);
goto Die;
}
f->blockmap[u++] = LONG(buf);
}
}
if(Bseek(b, 0x200+extrablock*Blocksize+Blocksize-4, 0) != 0x200+extrablock*Blocksize+Blocksize-4
|| Bread(b, buf, 4) != 4) {
print("bseek %d fail\n", 0x4C+4*i);
goto Die;
}
extrablock = LONG(buf);
}
Break2:;
if(oreaddir(f, 0, &rootdir) <= 0){
print("oreaddir could not read root\n");
goto Die;
}
f->smapblock = rootdir.start;
return f;
Die:
Bterm(b);
free(f->blockmap);
free(f);
return nil;
}
void
oleread(Req *r)
{
Odir *d;
char *p;
int e, n;
long c;
vlong o;
o = r->ifcall.offset;
d = r->fid->file->aux;
if(d == nil) {
respond(r, "cannot happen");
return;
}
c = r->ifcall.count;
if(o >= d->size) {
r->ofcall.count = 0;
respond(r, nil);
return;
}
if(o+c > d->size)
c = d->size-o;
/*
* oreadfile returns so little data, it will
* help to read as much as we can.
*/
e = c+o;
n = 0;
for(p=r->ofcall.data; o<e; o+=n, p+=n) {
n = oreadfile(d, o, p, e-o);
if(n <= 0)
break;
}
if(n == -1 && o == r->ifcall.offset)
respond(r, "error reading word file");
else {
r->ofcall.count = o - r->ifcall.offset;
respond(r, nil);
}
}
Odir*
copydir(Odir *d)
{
Odir *e;
e = emalloc(sizeof(*d));
*e = *d;
return e;
}
void
filldir(File *t, Ofile *f, int dnum, int nrecur)
{
Odir d;
int i;
Rune rbuf[40];
char buf[UTFmax*nelem(rbuf)];
File *nt;
if(dnum == 0xFFFFFFFF || oreaddir(f, dnum, &d) != 1)
return;
/*
* i hope there are no broken files with
* circular trees. i hate infinite loops.
*/
if(nrecur > 100)
sysfatal("tree too large in office file: probably circular");
filldir(t, f, d.left, nrecur+1);
/* add current tree entry */
runestrecpy(rbuf, rbuf+sizeof rbuf, d.name);
for(i=0; rbuf[i]; i++)
if(rbuf[i] == L' ')
rbuf[i] = L'␣';
else if(rbuf[i] <= 0x20 || rbuf[i] == L'/'
|| (0x80 <= rbuf[i] && rbuf[i] <= 0x9F))
rbuf[i] = ':';
snprint(buf, sizeof buf, "%S", rbuf);
if(d.dir == 0xFFFFFFFF) {
/* make file */
nt = createfile(t, buf, nil, 0444, nil);
if(nt == nil)
sysfatal("nt nil: create %s: %r", buf);
nt->aux = copydir(&d);
nt->length = d.size;
} else /* make directory */
nt = createfile(t, buf, nil, DMDIR|0777, nil);
filldir(t, f, d.right, nrecur+1);
if(d.dir != 0xFFFFFFFF)
filldir(nt, f, d.dir, nrecur+1);
closefile(nt);
}
Srv olesrv = {
.read= oleread,
};
void
main(int argc, char **argv)
{
char *mtpt;
Ofile *f;
Odir d;
mtpt = "/mnt/doc";
ARGBEGIN{
case 'm':
mtpt = ARGF();
break;
default:
goto Usage;
}ARGEND
if(argc != 1) {
Usage:
fprint(2, "usage: olefs file\n");
exits("usage");
}
f = oleopen(argv[0]);
if(f == nil) {
print("error opening %s: %r\n", argv[0]);
exits("open");
}
// dumpdir(f, 0);
if(oreaddir(f, 0, &d) != 1) {
fprint(2, "oreaddir error: %r\n");
exits("oreaddir");
}
olesrv.tree = alloctree(nil, nil, DMDIR|0777, nil);
filldir(olesrv.tree->root, f, d.dir, 0);
postmountsrv(&olesrv, nil, mtpt, MREPL);
exits(0);
}