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linux-next/fs/lockd/xdr4.c
Chuck Lever 3460f29a27 lockd: Introduce new-style XDR functions for NLMv4
We'd like to prevent local buffer overflows caused by malicious or
broken servers.  New xdr_stream style decoders can do that.

For efficiency, we also want to be able to pass xdr_streams from
call_encode() to all XDR encoding functions, rather than building
an xdr_stream in every XDR encoding function in the kernel.

Same idea as the NLM v3 XDR overhaul.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:23 -05:00

335 lines
7.3 KiB
C

/*
* linux/fs/lockd/xdr4.c
*
* XDR support for lockd and the lock client.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
* Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/nfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>
#define NLMDBG_FACILITY NLMDBG_XDR
static inline loff_t
s64_to_loff_t(__s64 offset)
{
return (loff_t)offset;
}
static inline s64
loff_t_to_s64(loff_t offset)
{
s64 res;
if (offset > NLM4_OFFSET_MAX)
res = NLM4_OFFSET_MAX;
else if (offset < -NLM4_OFFSET_MAX)
res = -NLM4_OFFSET_MAX;
else
res = offset;
return res;
}
/*
* XDR functions for basic NLM types
*/
static __be32 *
nlm4_decode_cookie(__be32 *p, struct nlm_cookie *c)
{
unsigned int len;
len = ntohl(*p++);
if(len==0)
{
c->len=4;
memset(c->data, 0, 4); /* hockeypux brain damage */
}
else if(len<=NLM_MAXCOOKIELEN)
{
c->len=len;
memcpy(c->data, p, len);
p+=XDR_QUADLEN(len);
}
else
{
dprintk("lockd: bad cookie size %d (only cookies under "
"%d bytes are supported.)\n",
len, NLM_MAXCOOKIELEN);
return NULL;
}
return p;
}
static __be32 *
nlm4_encode_cookie(__be32 *p, struct nlm_cookie *c)
{
*p++ = htonl(c->len);
memcpy(p, c->data, c->len);
p+=XDR_QUADLEN(c->len);
return p;
}
static __be32 *
nlm4_decode_fh(__be32 *p, struct nfs_fh *f)
{
memset(f->data, 0, sizeof(f->data));
f->size = ntohl(*p++);
if (f->size > NFS_MAXFHSIZE) {
dprintk("lockd: bad fhandle size %d (should be <=%d)\n",
f->size, NFS_MAXFHSIZE);
return NULL;
}
memcpy(f->data, p, f->size);
return p + XDR_QUADLEN(f->size);
}
/*
* Encode and decode owner handle
*/
static __be32 *
nlm4_decode_oh(__be32 *p, struct xdr_netobj *oh)
{
return xdr_decode_netobj(p, oh);
}
static __be32 *
nlm4_decode_lock(__be32 *p, struct nlm_lock *lock)
{
struct file_lock *fl = &lock->fl;
__u64 len, start;
__s64 end;
if (!(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len, NLM_MAXSTRLEN))
|| !(p = nlm4_decode_fh(p, &lock->fh))
|| !(p = nlm4_decode_oh(p, &lock->oh)))
return NULL;
lock->svid = ntohl(*p++);
locks_init_lock(fl);
fl->fl_owner = current->files;
fl->fl_pid = (pid_t)lock->svid;
fl->fl_flags = FL_POSIX;
fl->fl_type = F_RDLCK; /* as good as anything else */
p = xdr_decode_hyper(p, &start);
p = xdr_decode_hyper(p, &len);
end = start + len - 1;
fl->fl_start = s64_to_loff_t(start);
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = s64_to_loff_t(end);
return p;
}
/*
* Encode result of a TEST/TEST_MSG call
*/
static __be32 *
nlm4_encode_testres(__be32 *p, struct nlm_res *resp)
{
s64 start, len;
dprintk("xdr: before encode_testres (p %p resp %p)\n", p, resp);
if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
return NULL;
*p++ = resp->status;
if (resp->status == nlm_lck_denied) {
struct file_lock *fl = &resp->lock.fl;
*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
*p++ = htonl(resp->lock.svid);
/* Encode owner handle. */
if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
return NULL;
start = loff_t_to_s64(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
len = 0;
else
len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
p = xdr_encode_hyper(p, start);
p = xdr_encode_hyper(p, len);
dprintk("xdr: encode_testres (status %u pid %d type %d start %Ld end %Ld)\n",
resp->status, (int)resp->lock.svid, fl->fl_type,
(long long)fl->fl_start, (long long)fl->fl_end);
}
dprintk("xdr: after encode_testres (p %p resp %p)\n", p, resp);
return p;
}
/*
* First, the server side XDR functions
*/
int
nlm4svc_decode_testargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
return 0;
exclusive = ntohl(*p++);
if (!(p = nlm4_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_encode_testres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm4_encode_testres(p, resp)))
return 0;
return xdr_ressize_check(rqstp, p);
}
int
nlm4svc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
return 0;
argp->block = ntohl(*p++);
exclusive = ntohl(*p++);
if (!(p = nlm4_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
argp->reclaim = ntohl(*p++);
argp->state = ntohl(*p++);
argp->monitor = 1; /* monitor client by default */
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
return 0;
argp->block = ntohl(*p++);
exclusive = ntohl(*p++);
if (!(p = nlm4_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
if (!(p = nlm4_decode_cookie(p, &argp->cookie))
|| !(p = nlm4_decode_lock(p, &argp->lock)))
return 0;
argp->lock.fl.fl_type = F_UNLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
memset(lock, 0, sizeof(*lock));
locks_init_lock(&lock->fl);
lock->svid = ~(u32) 0;
lock->fl.fl_pid = (pid_t)lock->svid;
if (!(p = nlm4_decode_cookie(p, &argp->cookie))
|| !(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len, NLM_MAXSTRLEN))
|| !(p = nlm4_decode_fh(p, &lock->fh))
|| !(p = nlm4_decode_oh(p, &lock->oh)))
return 0;
argp->fsm_mode = ntohl(*p++);
argp->fsm_access = ntohl(*p++);
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_encode_shareres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
return 0;
*p++ = resp->status;
*p++ = xdr_zero; /* sequence argument */
return xdr_ressize_check(rqstp, p);
}
int
nlm4svc_encode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
return 0;
*p++ = resp->status;
return xdr_ressize_check(rqstp, p);
}
int
nlm4svc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len, NLM_MAXSTRLEN)))
return 0;
argp->state = ntohl(*p++);
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
{
if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
return 0;
argp->state = ntohl(*p++);
memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
p += XDR_QUADLEN(SM_PRIV_SIZE);
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm4_decode_cookie(p, &resp->cookie)))
return 0;
resp->status = *p++;
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_argsize_check(rqstp, p);
}
int
nlm4svc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_ressize_check(rqstp, p);
}