SUNRPC: Introduce new xdr_stream-based encoders to rpcb_clnt.c

Replace the open-coded encode logic for rpcbind arguments with an
xdr_stream-based implementation, similar to what NFSv4 uses, to
better protect against buffer overflows.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2009-08-09 15:09:40 -04:00 committed by Trond Myklebust
parent 4116092b92
commit 6f2c2db7a4
1 changed files with 75 additions and 1 deletions

View File

@ -708,6 +708,30 @@ static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
return 0;
}
static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
const struct rpcbind_args *rpcb)
{
struct rpc_task *task = req->rq_task;
struct xdr_stream xdr;
dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
task->tk_pid, task->tk_msg.rpc_proc->p_name,
rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
p = xdr_reserve_space(&xdr, sizeof(__be32) * RPCB_mappingargs_sz);
if (unlikely(p == NULL))
return -EIO;
*p++ = htonl(rpcb->r_prog);
*p++ = htonl(rpcb->r_vers);
*p++ = htonl(rpcb->r_prot);
*p = htonl(rpcb->r_port);
return 0;
}
static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
unsigned short *portp)
{
@ -746,6 +770,56 @@ static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
return 0;
}
static int encode_rpcb_string(struct xdr_stream *xdr, const char *string,
const u32 maxstrlen)
{
u32 len;
__be32 *p;
if (unlikely(string == NULL))
return -EIO;
len = strlen(string);
if (unlikely(len > maxstrlen))
return -EIO;
p = xdr_reserve_space(xdr, sizeof(__be32) + len);
if (unlikely(p == NULL))
return -EIO;
xdr_encode_opaque(p, string, len);
return 0;
}
static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
const struct rpcbind_args *rpcb)
{
struct rpc_task *task = req->rq_task;
struct xdr_stream xdr;
dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
task->tk_pid, task->tk_msg.rpc_proc->p_name,
rpcb->r_prog, rpcb->r_vers,
rpcb->r_netid, rpcb->r_addr);
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
p = xdr_reserve_space(&xdr,
sizeof(__be32) * (RPCB_program_sz + RPCB_version_sz));
if (unlikely(p == NULL))
return -EIO;
*p++ = htonl(rpcb->r_prog);
*p = htonl(rpcb->r_vers);
if (encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN))
return -EIO;
if (encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN))
return -EIO;
if (encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN))
return -EIO;
return 0;
}
static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
unsigned short *portp)
{
@ -812,7 +886,7 @@ out_err:
#define PROC(proc, argtype, restype) \
[RPCBPROC_##proc] = { \
.p_proc = RPCBPROC_##proc, \
.p_encode = (kxdrproc_t) rpcb_encode_##argtype, \
.p_encode = (kxdrproc_t) rpcb_enc_##argtype, \
.p_decode = (kxdrproc_t) rpcb_decode_##restype, \
.p_arglen = RPCB_##argtype##args_sz, \
.p_replen = RPCB_##restype##res_sz, \