kern/src/ns/convM2D.c

/* Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
 * Portions Copyright © 1997-1999 Vita Nuova Limited
 * Portions Copyright © 2000-2007 Vita Nuova Holdings Limited
 *                                (www.vitanuova.com)
 * Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
 *
 * Modified for the Akaros operating system:
 * Copyright (c) 2013-2014 The Regents of the University of California
 * Copyright (c) 2013-2015 Google Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#include <vfs.h>
#include <kfs.h>
#include <slab.h>
#include <kmalloc.h>
#include <kref.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <error.h>
#include <cpio.h>
#include <pmap.h>
#include <smp.h>
#include <ip.h>

int statcheck(uint8_t * buf, unsigned int nbuf)
{
	uint8_t *ebuf;
	int i;

	ebuf = buf + nbuf;

	if (nbuf < STATFIXLEN || nbuf != BIT16SZ + GBIT16(buf)){
		printk("nbuf %d, STATFIXLEN %d ", nbuf, STATFIXLEN);
		printk("BIT16SZ %d, GBIT16(buf) %d ",
			BIT16SZ, GBIT16(buf));
		printk("This is bad!\n");
		return -1;
	}

	buf += STATFIXLEN - 4 * BIT16SZ;

	for (i = 0; i < 4; i++) {
		if (buf + BIT16SZ > ebuf)
			return -1;
		buf += BIT16SZ + GBIT16(buf);
	}

	if (buf != ebuf){
		return -1;
	}

	return 0;
}

static char nullstring[] = "";

unsigned int
convM2D(uint8_t * buf, unsigned int nbuf, struct dir *d, char *strs)
{
	uint8_t *p, *ebuf;
	char *sv[4];
	int i, ns;

	if (nbuf < STATFIXLEN)
		return 0;

	p = buf;
	ebuf = buf + nbuf;

	p += BIT16SZ;	/* ignore size */
	d->type = GBIT16(p);
	p += BIT16SZ;
	d->dev = GBIT32(p);
	p += BIT32SZ;
	d->qid.type = GBIT8(p);
	p += BIT8SZ;
	d->qid.vers = GBIT32(p);
	p += BIT32SZ;
	d->qid.path = GBIT64(p);
	p += BIT64SZ;
	d->mode = GBIT32(p);
	p += BIT32SZ;
	d->atime = GBIT32(p);
	p += BIT32SZ;
	d->mtime = GBIT32(p);
	p += BIT32SZ;
	d->length = GBIT64(p);
	p += BIT64SZ;

	for (i = 0; i < 4; i++) {
		if (p + BIT16SZ > ebuf)
			return 0;
		ns = GBIT16(p);
		p += BIT16SZ;
		if (p + ns > ebuf)
			return 0;
		if (strs) {
			sv[i] = strs;
			memmove(strs, p, ns);
			strs += ns;
			*strs++ = '\0';
		}
		p += ns;
	}

	if (strs) {
		d->name = sv[0];
		d->uid = sv[1];
		d->gid = sv[2];
		d->muid = sv[3];
	} else {
		d->name = nullstring;
		d->uid = nullstring;
		d->gid = nullstring;
		d->muid = nullstring;
	}

	return p - buf;
}