NSM: move to xdr_stream-based XDR encoders and decoders
Introduce xdr_stream-based XDR encoder and decoder functions, which are
more careful about preventing RPC buffer overflows.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 0fc9836..81e1cc1 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -193,21 +193,26 @@
* Status Monitor wire protocol.
*/
-static __be32 *xdr_encode_nsm_string(__be32 *p, char *string)
+static int encode_nsm_string(struct xdr_stream *xdr, const char *string)
{
- size_t len = strlen(string);
+ const u32 len = strlen(string);
+ __be32 *p;
- if (len > SM_MAXSTRLEN)
- len = SM_MAXSTRLEN;
- return xdr_encode_opaque(p, string, len);
+ if (unlikely(len > SM_MAXSTRLEN))
+ return -EIO;
+ p = xdr_reserve_space(xdr, sizeof(u32) + len);
+ if (unlikely(p == NULL))
+ return -EIO;
+ xdr_encode_opaque(p, string, len);
+ return 0;
}
/*
* "mon_name" specifies the host to be monitored.
*/
-static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp)
+static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
{
- return xdr_encode_nsm_string(p, argp->mon_name);
+ return encode_nsm_string(xdr, argp->mon_name);
}
/*
@@ -216,30 +221,35 @@
* (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
* has changed.
*/
-static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp)
+static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
- p = xdr_encode_nsm_string(p, utsname()->nodename);
- if (!p)
- return ERR_PTR(-EIO);
+ int status;
+ __be32 *p;
+ status = encode_nsm_string(xdr, utsname()->nodename);
+ if (unlikely(status != 0))
+ return status;
+ p = xdr_reserve_space(xdr, 3 * sizeof(u32));
+ if (unlikely(p == NULL))
+ return -EIO;
*p++ = htonl(argp->prog);
*p++ = htonl(argp->vers);
*p++ = htonl(argp->proc);
-
- return p;
+ return 0;
}
/*
* The "mon_id" argument specifies the non-private arguments
* of an NSMPROC_MON or NSMPROC_UNMON call.
*/
-static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp)
+static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
- p = xdr_encode_mon_name(p, argp);
- if (!p)
- return ERR_PTR(-EIO);
+ int status;
- return xdr_encode_my_id(p, argp);
+ status = encode_mon_name(xdr, argp);
+ if (unlikely(status != 0))
+ return status;
+ return encode_my_id(xdr, argp);
}
/*
@@ -250,55 +260,71 @@
* Linux provides the raw IP address of the monitored host,
* left in network byte order.
*/
-static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp)
+static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
+ if (unlikely(p == NULL))
+ return -EIO;
*p++ = argp->addr;
*p++ = 0;
*p++ = 0;
*p++ = 0;
-
- return p;
-}
-
-static int
-xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
-{
- p = xdr_encode_mon_id(p, argp);
- if (IS_ERR(p))
- return PTR_ERR(p);
-
- p = xdr_encode_priv(p, argp);
- if (IS_ERR(p))
- return PTR_ERR(p);
-
- rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
return 0;
}
-static int
-xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
+static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
+ const struct nsm_args *argp)
{
- p = xdr_encode_mon_id(p, argp);
- if (IS_ERR(p))
- return PTR_ERR(p);
- rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
- return 0;
+ struct xdr_stream xdr;
+ int status;
+
+ xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+ status = encode_mon_id(&xdr, argp);
+ if (unlikely(status))
+ return status;
+ return encode_priv(&xdr, argp);
}
-static int
-xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
+static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
+ const struct nsm_args *argp)
{
+ struct xdr_stream xdr;
+
+ xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+ return encode_mon_id(&xdr, argp);
+}
+
+static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
+ struct nsm_res *resp)
+{
+ struct xdr_stream xdr;
+
+ xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+ p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
+ if (unlikely(p == NULL))
+ return -EIO;
resp->status = ntohl(*p++);
- resp->state = ntohl(*p++);
- dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
+ resp->state = ntohl(*p);
+
+ dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
resp->status, resp->state);
return 0;
}
-static int
-xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
+static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
+ struct nsm_res *resp)
{
- resp->state = ntohl(*p++);
+ struct xdr_stream xdr;
+
+ xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+ p = xdr_inline_decode(&xdr, sizeof(u32));
+ if (unlikely(p == NULL))
+ return -EIO;
+ resp->state = ntohl(*p);
+
+ dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
return 0;
}
@@ -314,8 +340,8 @@
static struct rpc_procinfo nsm_procedures[] = {
[NSMPROC_MON] = {
.p_proc = NSMPROC_MON,
- .p_encode = (kxdrproc_t) xdr_encode_mon,
- .p_decode = (kxdrproc_t) xdr_decode_stat_res,
+ .p_encode = (kxdrproc_t)xdr_enc_mon,
+ .p_decode = (kxdrproc_t)xdr_dec_stat_res,
.p_arglen = SM_mon_sz,
.p_replen = SM_monres_sz,
.p_statidx = NSMPROC_MON,
@@ -323,8 +349,8 @@
},
[NSMPROC_UNMON] = {
.p_proc = NSMPROC_UNMON,
- .p_encode = (kxdrproc_t) xdr_encode_unmon,
- .p_decode = (kxdrproc_t) xdr_decode_stat,
+ .p_encode = (kxdrproc_t)xdr_enc_unmon,
+ .p_decode = (kxdrproc_t)xdr_dec_stat,
.p_arglen = SM_mon_id_sz,
.p_replen = SM_unmonres_sz,
.p_statidx = NSMPROC_UNMON,