swh:1:snp:2ca5d6eff8f04a671c0d5b13646cede522c64b7d
Tip revision: 8bf02e254c7213087c4aa19aa24943b312279ed2 authored by Jacques Vidrine on 27 November 2003, 16:40:03 UTC
Correct a remote denial-of-service attack in named(8).
Correct a remote denial-of-service attack in named(8).
Tip revision: 8bf02e2
coda_subr.c
/*
*
* Coda: an Experimental Distributed File System
* Release 3.1
*
* Copyright (c) 1987-1998 Carnegie Mellon University
* All Rights Reserved
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation, and
* that credit is given to Carnegie Mellon University in all documents
* and publicity pertaining to direct or indirect use of this code or its
* derivatives.
*
* CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
* SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
* FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
* DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
* RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
* ANY DERIVATIVE WORK.
*
* Carnegie Mellon encourages users of this software to return any
* improvements or extensions that they make, and to grant Carnegie
* Mellon the rights to redistribute these changes without encumbrance.
*
* @(#) src/sys/coda/coda_subr.c,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
* $FreeBSD$
*
*/
/*
* Mach Operating System
* Copyright (c) 1989 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
/*
* This code was written for the Coda file system at Carnegie Mellon
* University. Contributers include David Steere, James Kistler, and
* M. Satyanarayanan.
*/
/* NOTES: rvb
* 1. Added coda_unmounting to mark all cnodes as being UNMOUNTING. This has to
* be done before dounmount is called. Because some of the routines that
* dounmount calls before coda_unmounted might try to force flushes to venus.
* The vnode pager does this.
* 2. coda_unmounting marks all cnodes scanning coda_cache.
* 3. cfs_checkunmounting (under DEBUG) checks all cnodes by chasing the vnodes
* under the /coda mount point.
* 4. coda_cacheprint (under DEBUG) prints names with vnode/cnode address
*/
#include <vcoda.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/select.h>
#include <sys/mount.h>
#include <coda/coda.h>
#include <coda/cnode.h>
#include <coda/coda_subr.h>
#include <coda/coda_namecache.h>
int coda_active = 0;
int coda_reuse = 0;
int coda_new = 0;
struct cnode *coda_freelist = NULL;
struct cnode *coda_cache[CODA_CACHESIZE];
#define coda_hash(fid) (((fid)->Volume + (fid)->Vnode) & (CODA_CACHESIZE-1))
#define CNODE_NEXT(cp) ((cp)->c_next)
#define ODD(vnode) ((vnode) & 0x1)
/*
* Allocate a cnode.
*/
struct cnode *
coda_alloc(void)
{
struct cnode *cp;
if (coda_freelist) {
cp = coda_freelist;
coda_freelist = CNODE_NEXT(cp);
coda_reuse++;
}
else {
CODA_ALLOC(cp, struct cnode *, sizeof(struct cnode));
/* NetBSD vnodes don't have any Pager info in them ('cause there are
no external pagers, duh!) */
#define VNODE_VM_INFO_INIT(vp) /* MT */
VNODE_VM_INFO_INIT(CTOV(cp));
coda_new++;
}
bzero(cp, sizeof (struct cnode));
return(cp);
}
/*
* Deallocate a cnode.
*/
void
coda_free(cp)
register struct cnode *cp;
{
CNODE_NEXT(cp) = coda_freelist;
coda_freelist = cp;
}
/*
* Put a cnode in the hash table
*/
void
coda_save(cp)
struct cnode *cp;
{
CNODE_NEXT(cp) = coda_cache[coda_hash(&cp->c_fid)];
coda_cache[coda_hash(&cp->c_fid)] = cp;
}
/*
* Remove a cnode from the hash table
*/
void
coda_unsave(cp)
struct cnode *cp;
{
struct cnode *ptr;
struct cnode *ptrprev = NULL;
ptr = coda_cache[coda_hash(&cp->c_fid)];
while (ptr != NULL) {
if (ptr == cp) {
if (ptrprev == NULL) {
coda_cache[coda_hash(&cp->c_fid)]
= CNODE_NEXT(ptr);
} else {
CNODE_NEXT(ptrprev) = CNODE_NEXT(ptr);
}
CNODE_NEXT(cp) = (struct cnode *)NULL;
return;
}
ptrprev = ptr;
ptr = CNODE_NEXT(ptr);
}
}
/*
* Lookup a cnode by fid. If the cnode is dying, it is bogus so skip it.
* NOTE: this allows multiple cnodes with same fid -- dcs 1/25/95
*/
struct cnode *
coda_find(fid)
ViceFid *fid;
{
struct cnode *cp;
cp = coda_cache[coda_hash(fid)];
while (cp) {
if ((cp->c_fid.Vnode == fid->Vnode) &&
(cp->c_fid.Volume == fid->Volume) &&
(cp->c_fid.Unique == fid->Unique) &&
(!IS_UNMOUNTING(cp)))
{
coda_active++;
return(cp);
}
cp = CNODE_NEXT(cp);
}
return(NULL);
}
/*
* coda_kill is called as a side effect to vcopen. To prevent any
* cnodes left around from an earlier run of a venus or warden from
* causing problems with the new instance, mark any outstanding cnodes
* as dying. Future operations on these cnodes should fail (excepting
* coda_inactive of course!). Since multiple venii/wardens can be
* running, only kill the cnodes for a particular entry in the
* coda_mnttbl. -- DCS 12/1/94 */
int
coda_kill(whoIam, dcstat)
struct mount *whoIam;
enum dc_status dcstat;
{
int hash, count = 0;
struct cnode *cp;
/*
* Algorithm is as follows:
* Second, flush whatever vnodes we can from the name cache.
*
* Finally, step through whatever is left and mark them dying.
* This prevents any operation at all.
*/
/* This is slightly overkill, but should work. Eventually it'd be
* nice to only flush those entries from the namecache that
* reference a vnode in this vfs. */
coda_nc_flush(dcstat);
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
#ifdef DEBUG
printf("coda_kill: vp %p, cp %p\n", CTOV(cp), cp);
#endif
count++;
CODADEBUG(CODA_FLUSH,
myprintf(("Live cnode fid %lx.%lx.%lx flags %d count %d\n",
(cp->c_fid).Volume,
(cp->c_fid).Vnode,
(cp->c_fid).Unique,
cp->c_flags,
CTOV(cp)->v_usecount)); );
}
}
}
return count;
}
/*
* There are two reasons why a cnode may be in use, it may be in the
* name cache or it may be executing.
*/
void
coda_flush(dcstat)
enum dc_status dcstat;
{
int hash;
struct cnode *cp;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_FLUSH]++;
coda_nc_flush(dcstat); /* flush files from the name cache */
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
if (!ODD(cp->c_fid.Vnode)) /* only files can be executed */
coda_vmflush(cp);
}
}
}
/*
* As a debugging measure, print out any cnodes that lived through a
* name cache flush.
*/
void
coda_testflush(void)
{
int hash;
struct cnode *cp;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash];
cp != NULL;
cp = CNODE_NEXT(cp)) {
myprintf(("Live cnode fid %lx.%lx.%lx count %d\n",
(cp->c_fid).Volume,(cp->c_fid).Vnode,
(cp->c_fid).Unique, CTOV(cp)->v_usecount));
}
}
}
/*
* First, step through all cnodes and mark them unmounting.
* NetBSD kernels may try to fsync them now that venus
* is dead, which would be a bad thing.
*
*/
void
coda_unmounting(whoIam)
struct mount *whoIam;
{
int hash;
struct cnode *cp;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
if (cp->c_flags & (C_LOCKED|C_WANTED)) {
printf("coda_unmounting: Unlocking %p\n", cp);
cp->c_flags &= ~(C_LOCKED|C_WANTED);
wakeup((caddr_t) cp);
}
cp->c_flags |= C_UNMOUNTING;
}
}
}
}
#ifdef DEBUG
void
coda_checkunmounting(mp)
struct mount *mp;
{
register struct vnode *vp, *nvp;
struct cnode *cp;
int count = 0, bad = 0;
loop:
for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
if (vp->v_mount != mp)
goto loop;
nvp = TAILQ_NEXT(vp, v_nmntvnodes);
cp = VTOC(vp);
count++;
if (!(cp->c_flags & C_UNMOUNTING)) {
bad++;
printf("vp %p, cp %p missed\n", vp, cp);
cp->c_flags |= C_UNMOUNTING;
}
}
}
void
coda_cacheprint(whoIam)
struct mount *whoIam;
{
int hash;
struct cnode *cp;
int count = 0;
printf("coda_cacheprint: coda_ctlvp %p, cp %p", coda_ctlvp, VTOC(coda_ctlvp));
coda_nc_name(VTOC(coda_ctlvp));
printf("\n");
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL; cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
printf("coda_cacheprint: vp %p, cp %p", CTOV(cp), cp);
coda_nc_name(cp);
printf("\n");
count++;
}
}
}
printf("coda_cacheprint: count %d\n", count);
}
#endif
/*
* There are 6 cases where invalidations occur. The semantics of each
* is listed here.
*
* CODA_FLUSH -- flush all entries from the name cache and the cnode cache.
* CODA_PURGEUSER -- flush all entries from the name cache for a specific user
* This call is a result of token expiration.
*
* The next two are the result of callbacks on a file or directory.
* CODA_ZAPDIR -- flush the attributes for the dir from its cnode.
* Zap all children of this directory from the namecache.
* CODA_ZAPFILE -- flush the attributes for a file.
*
* The fifth is a result of Venus detecting an inconsistent file.
* CODA_PURGEFID -- flush the attribute for the file
* If it is a dir (odd vnode), purge its
* children from the namecache
* remove the file from the namecache.
*
* The sixth allows Venus to replace local fids with global ones
* during reintegration.
*
* CODA_REPLACE -- replace one ViceFid with another throughout the name cache
*/
int handleDownCall(opcode, out)
int opcode; union outputArgs *out;
{
int error;
/* Handle invalidate requests. */
switch (opcode) {
case CODA_FLUSH : {
coda_flush(IS_DOWNCALL);
CODADEBUG(CODA_FLUSH,coda_testflush();) /* print remaining cnodes */
return(0);
}
case CODA_PURGEUSER : {
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_PURGEUSER]++;
/* XXX - need to prevent fsync's */
coda_nc_purge_user(out->coda_purgeuser.cred.cr_uid, IS_DOWNCALL);
return(0);
}
case CODA_ZAPFILE : {
struct cnode *cp;
error = 0;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_ZAPFILE]++;
cp = coda_find(&out->coda_zapfile.CodaFid);
if (cp != NULL) {
vref(CTOV(cp));
cp->c_flags &= ~C_VATTR;
if (CTOV(cp)->v_flag & VTEXT)
error = coda_vmflush(cp);
CODADEBUG(CODA_ZAPFILE, myprintf(("zapfile: fid = (%lx.%lx.%lx),
refcnt = %d, error = %d\n",
cp->c_fid.Volume,
cp->c_fid.Vnode,
cp->c_fid.Unique,
CTOV(cp)->v_usecount - 1, error)););
if (CTOV(cp)->v_usecount == 1) {
cp->c_flags |= C_PURGING;
}
vrele(CTOV(cp));
}
return(error);
}
case CODA_ZAPDIR : {
struct cnode *cp;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_ZAPDIR]++;
cp = coda_find(&out->coda_zapdir.CodaFid);
if (cp != NULL) {
vref(CTOV(cp));
cp->c_flags &= ~C_VATTR;
coda_nc_zapParentfid(&out->coda_zapdir.CodaFid, IS_DOWNCALL);
CODADEBUG(CODA_ZAPDIR, myprintf(("zapdir: fid = (%lx.%lx.%lx),
refcnt = %d\n",cp->c_fid.Volume,
cp->c_fid.Vnode,
cp->c_fid.Unique,
CTOV(cp)->v_usecount - 1)););
if (CTOV(cp)->v_usecount == 1) {
cp->c_flags |= C_PURGING;
}
vrele(CTOV(cp));
}
return(0);
}
case CODA_PURGEFID : {
struct cnode *cp;
error = 0;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_PURGEFID]++;
cp = coda_find(&out->coda_purgefid.CodaFid);
if (cp != NULL) {
vref(CTOV(cp));
if (ODD(out->coda_purgefid.CodaFid.Vnode)) { /* Vnode is a directory */
coda_nc_zapParentfid(&out->coda_purgefid.CodaFid,
IS_DOWNCALL);
}
cp->c_flags &= ~C_VATTR;
coda_nc_zapfid(&out->coda_purgefid.CodaFid, IS_DOWNCALL);
if (!(ODD(out->coda_purgefid.CodaFid.Vnode))
&& (CTOV(cp)->v_flag & VTEXT)) {
error = coda_vmflush(cp);
}
CODADEBUG(CODA_PURGEFID, myprintf(("purgefid: fid = (%lx.%lx.%lx), refcnt = %d, error = %d\n",
cp->c_fid.Volume, cp->c_fid.Vnode,
cp->c_fid.Unique,
CTOV(cp)->v_usecount - 1, error)););
if (CTOV(cp)->v_usecount == 1) {
cp->c_flags |= C_PURGING;
}
vrele(CTOV(cp));
}
return(error);
}
case CODA_REPLACE : {
struct cnode *cp = NULL;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_REPLACE]++;
cp = coda_find(&out->coda_replace.OldFid);
if (cp != NULL) {
/* remove the cnode from the hash table, replace the fid, and reinsert */
vref(CTOV(cp));
coda_unsave(cp);
cp->c_fid = out->coda_replace.NewFid;
coda_save(cp);
CODADEBUG(CODA_REPLACE, myprintf(("replace: oldfid = (%lx.%lx.%lx), newfid = (%lx.%lx.%lx), cp = %p\n",
out->coda_replace.OldFid.Volume,
out->coda_replace.OldFid.Vnode,
out->coda_replace.OldFid.Unique,
cp->c_fid.Volume, cp->c_fid.Vnode,
cp->c_fid.Unique, cp));)
vrele(CTOV(cp));
}
return (0);
}
default:
myprintf(("handleDownCall: unknown opcode %d\n", opcode));
return (EINVAL);
}
}
/* coda_grab_vnode: lives in either cfs_mach.c or cfs_nbsd.c */
int
coda_vmflush(cp)
struct cnode *cp;
{
return 0;
}
/*
* kernel-internal debugging switches
*/
void coda_debugon(void)
{
codadebug = -1;
coda_nc_debug = -1;
coda_vnop_print_entry = 1;
coda_psdev_print_entry = 1;
coda_vfsop_print_entry = 1;
}
void coda_debugoff(void)
{
codadebug = 0;
coda_nc_debug = 0;
coda_vnop_print_entry = 0;
coda_psdev_print_entry = 0;
coda_vfsop_print_entry = 0;
}
/*
* Utilities used by both client and server
* Standard levels:
* 0) no debugging
* 1) hard failures
* 2) soft failures
* 3) current test software
* 4) main procedure entry points
* 5) main procedure exit points
* 6) utility procedure entry points
* 7) utility procedure exit points
* 8) obscure procedure entry points
* 9) obscure procedure exit points
* 10) random stuff
* 11) all <= 1
* 12) all <= 2
* 13) all <= 3
* ...
*/