freebsd-dev/sys/rpc/clnt_bck.c
Enji Cooper ea85a1540a Deobfuscate cleanup path in clnt_bck_create(..)
Similar to r300836, cl and ct will always be non-NULL as they're allocated
using the mem_alloc routines, which always use `malloc(..., M_WAITOK)`.

Deobfuscating the cleanup path fixes a leak where if cl was NULL and
ct was not, ct would not be free'd, and also removes a duplicate test for
cl not being NULL.

Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D6801
MFC after: 1 week
Reported by: Coverity
CID: 1229999
Reviewed by: cem
Sponsored by: EMC / Isilon Storage Division
2016-06-10 17:53:28 +00:00

589 lines
15 KiB
C

/* $NetBSD: clnt_vc.c,v 1.4 2000/07/14 08:40:42 fvdl Exp $ */
/*-
* Copyright (c) 2009, Sun Microsystems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Sun Microsystems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid2 = "@(#)clnt_tcp.c 1.37 87/10/05 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)clnt_tcp.c 2.2 88/08/01 4.0 RPCSRC";
static char sccsid3[] = "@(#)clnt_vc.c 1.19 89/03/16 Copyr 1988 Sun Micro";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* clnt_tcp.c, Implements a TCP/IP based, client side RPC.
*
* Copyright (C) 1984, Sun Microsystems, Inc.
*
* TCP based RPC supports 'batched calls'.
* A sequence of calls may be batched-up in a send buffer. The rpc call
* return immediately to the client even though the call was not necessarily
* sent. The batching occurs if the results' xdr routine is NULL (0) AND
* the rpc timeout value is zero (see clnt.h, rpc).
*
* Clients should NOT casually batch calls that in fact return results; that is,
* the server side should be aware that a call is batched and not produce any
* return message. Batched calls that produce many result messages can
* deadlock (netlock) the client and the server....
*
* Now go hang yourself.
*/
/*
* This code handles the special case of a NFSv4.n backchannel for
* callback RPCs. It is similar to clnt_vc.c, but uses the TCP
* connection provided by the client to the server.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/syslog.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <net/vnet.h>
#include <netinet/tcp.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>
#include <rpc/krpc.h>
struct cmessage {
struct cmsghdr cmsg;
struct cmsgcred cmcred;
};
static void clnt_bck_geterr(CLIENT *, struct rpc_err *);
static bool_t clnt_bck_freeres(CLIENT *, xdrproc_t, void *);
static void clnt_bck_abort(CLIENT *);
static bool_t clnt_bck_control(CLIENT *, u_int, void *);
static void clnt_bck_close(CLIENT *);
static void clnt_bck_destroy(CLIENT *);
static struct clnt_ops clnt_bck_ops = {
.cl_abort = clnt_bck_abort,
.cl_geterr = clnt_bck_geterr,
.cl_freeres = clnt_bck_freeres,
.cl_close = clnt_bck_close,
.cl_destroy = clnt_bck_destroy,
.cl_control = clnt_bck_control
};
/*
* Create a client handle for a connection.
* Default options are set, which the user can change using clnt_control()'s.
* This code handles the special case of an NFSv4.1 session backchannel
* call, which is sent on a TCP connection created against the server
* by a client.
*/
void *
clnt_bck_create(
struct socket *so, /* Server transport socket. */
const rpcprog_t prog, /* program number */
const rpcvers_t vers) /* version number */
{
CLIENT *cl; /* client handle */
struct ct_data *ct = NULL; /* client handle */
struct timeval now;
struct rpc_msg call_msg;
static uint32_t disrupt;
XDR xdrs;
if (disrupt == 0)
disrupt = (uint32_t)(long)so;
cl = (CLIENT *)mem_alloc(sizeof (*cl));
ct = (struct ct_data *)mem_alloc(sizeof (*ct));
mtx_init(&ct->ct_lock, "ct->ct_lock", NULL, MTX_DEF);
ct->ct_threads = 0;
ct->ct_closing = FALSE;
ct->ct_closed = FALSE;
ct->ct_upcallrefs = 0;
ct->ct_closeit = FALSE;
/*
* Set up private data struct
*/
ct->ct_wait.tv_sec = -1;
ct->ct_wait.tv_usec = -1;
/*
* Initialize call message
*/
getmicrotime(&now);
ct->ct_xid = ((uint32_t)++disrupt) ^ __RPC_GETXID(&now);
call_msg.rm_xid = ct->ct_xid;
call_msg.rm_direction = CALL;
call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
call_msg.rm_call.cb_prog = (uint32_t)prog;
call_msg.rm_call.cb_vers = (uint32_t)vers;
/*
* pre-serialize the static part of the call msg and stash it away
*/
xdrmem_create(&xdrs, ct->ct_mcallc, MCALL_MSG_SIZE,
XDR_ENCODE);
if (!xdr_callhdr(&xdrs, &call_msg))
goto err;
ct->ct_mpos = XDR_GETPOS(&xdrs);
XDR_DESTROY(&xdrs);
ct->ct_waitchan = "rpcbck";
ct->ct_waitflag = 0;
cl->cl_refs = 1;
cl->cl_ops = &clnt_bck_ops;
cl->cl_private = ct;
cl->cl_auth = authnone_create();
TAILQ_INIT(&ct->ct_pending);
return (cl);
err:
mtx_destroy(&ct->ct_lock);
mem_free(ct, sizeof (struct ct_data));
mem_free(cl, sizeof (CLIENT));
return (NULL);
}
enum clnt_stat
clnt_bck_call(
CLIENT *cl, /* client handle */
struct rpc_callextra *ext, /* call metadata */
rpcproc_t proc, /* procedure number */
struct mbuf *args, /* pointer to args */
struct mbuf **resultsp, /* pointer to results */
struct timeval utimeout,
SVCXPRT *xprt)
{
struct ct_data *ct = (struct ct_data *) cl->cl_private;
AUTH *auth;
struct rpc_err *errp;
enum clnt_stat stat;
XDR xdrs;
struct rpc_msg reply_msg;
bool_t ok;
int nrefreshes = 2; /* number of times to refresh cred */
struct timeval timeout;
uint32_t xid;
struct mbuf *mreq = NULL, *results;
struct ct_request *cr;
int error;
cr = malloc(sizeof(struct ct_request), M_RPC, M_WAITOK);
mtx_lock(&ct->ct_lock);
if (ct->ct_closing || ct->ct_closed) {
mtx_unlock(&ct->ct_lock);
free(cr, M_RPC);
return (RPC_CANTSEND);
}
ct->ct_threads++;
if (ext) {
auth = ext->rc_auth;
errp = &ext->rc_err;
} else {
auth = cl->cl_auth;
errp = &ct->ct_error;
}
cr->cr_mrep = NULL;
cr->cr_error = 0;
if (ct->ct_wait.tv_usec == -1)
timeout = utimeout; /* use supplied timeout */
else
timeout = ct->ct_wait; /* use default timeout */
call_again:
mtx_assert(&ct->ct_lock, MA_OWNED);
ct->ct_xid++;
xid = ct->ct_xid;
mtx_unlock(&ct->ct_lock);
/*
* Leave space to pre-pend the record mark.
*/
mreq = m_gethdr(M_WAITOK, MT_DATA);
mreq->m_data += sizeof(uint32_t);
KASSERT(ct->ct_mpos + sizeof(uint32_t) <= MHLEN,
("RPC header too big"));
bcopy(ct->ct_mcallc, mreq->m_data, ct->ct_mpos);
mreq->m_len = ct->ct_mpos;
/*
* The XID is the first thing in the request.
*/
*mtod(mreq, uint32_t *) = htonl(xid);
xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
errp->re_status = stat = RPC_SUCCESS;
if ((!XDR_PUTINT32(&xdrs, &proc)) ||
(!AUTH_MARSHALL(auth, xid, &xdrs,
m_copym(args, 0, M_COPYALL, M_WAITOK)))) {
errp->re_status = stat = RPC_CANTENCODEARGS;
mtx_lock(&ct->ct_lock);
goto out;
}
mreq->m_pkthdr.len = m_length(mreq, NULL);
/*
* Prepend a record marker containing the packet length.
*/
M_PREPEND(mreq, sizeof(uint32_t), M_WAITOK);
*mtod(mreq, uint32_t *) =
htonl(0x80000000 | (mreq->m_pkthdr.len - sizeof(uint32_t)));
cr->cr_xid = xid;
mtx_lock(&ct->ct_lock);
/*
* Check to see if the client end has already started to close down
* the connection. The svc code will have set ct_error.re_status
* to RPC_CANTRECV if this is the case.
* If the client starts to close down the connection after this
* point, it will be detected later when cr_error is checked,
* since the request is in the ct_pending queue.
*/
if (ct->ct_error.re_status == RPC_CANTRECV) {
if (errp != &ct->ct_error) {
errp->re_errno = ct->ct_error.re_errno;
errp->re_status = RPC_CANTRECV;
}
stat = RPC_CANTRECV;
goto out;
}
TAILQ_INSERT_TAIL(&ct->ct_pending, cr, cr_link);
mtx_unlock(&ct->ct_lock);
/*
* sosend consumes mreq.
*/
sx_xlock(&xprt->xp_lock);
error = sosend(xprt->xp_socket, NULL, NULL, mreq, NULL, 0, curthread);
if (error != 0) printf("sosend=%d\n", error);
mreq = NULL;
if (error == EMSGSIZE) {
printf("emsgsize\n");
SOCKBUF_LOCK(&xprt->xp_socket->so_snd);
sbwait(&xprt->xp_socket->so_snd);
SOCKBUF_UNLOCK(&xprt->xp_socket->so_snd);
sx_xunlock(&xprt->xp_lock);
AUTH_VALIDATE(auth, xid, NULL, NULL);
mtx_lock(&ct->ct_lock);
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
goto call_again;
}
sx_xunlock(&xprt->xp_lock);
reply_msg.acpted_rply.ar_verf.oa_flavor = AUTH_NULL;
reply_msg.acpted_rply.ar_verf.oa_base = cr->cr_verf;
reply_msg.acpted_rply.ar_verf.oa_length = 0;
reply_msg.acpted_rply.ar_results.where = NULL;
reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
mtx_lock(&ct->ct_lock);
if (error) {
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
errp->re_errno = error;
errp->re_status = stat = RPC_CANTSEND;
goto out;
}
/*
* Check to see if we got an upcall while waiting for the
* lock. In both these cases, the request has been removed
* from ct->ct_pending.
*/
if (cr->cr_error) {
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
errp->re_errno = cr->cr_error;
errp->re_status = stat = RPC_CANTRECV;
goto out;
}
if (cr->cr_mrep) {
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
goto got_reply;
}
/*
* Hack to provide rpc-based message passing
*/
if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
errp->re_status = stat = RPC_TIMEDOUT;
goto out;
}
error = msleep(cr, &ct->ct_lock, ct->ct_waitflag, ct->ct_waitchan,
tvtohz(&timeout));
TAILQ_REMOVE(&ct->ct_pending, cr, cr_link);
if (error) {
/*
* The sleep returned an error so our request is still
* on the list. Turn the error code into an
* appropriate client status.
*/
errp->re_errno = error;
switch (error) {
case EINTR:
stat = RPC_INTR;
break;
case EWOULDBLOCK:
stat = RPC_TIMEDOUT;
break;
default:
stat = RPC_CANTRECV;
}
errp->re_status = stat;
goto out;
} else {
/*
* We were woken up by the svc thread. If the
* upcall had a receive error, report that,
* otherwise we have a reply.
*/
if (cr->cr_error) {
errp->re_errno = cr->cr_error;
errp->re_status = stat = RPC_CANTRECV;
goto out;
}
}
got_reply:
/*
* Now decode and validate the response. We need to drop the
* lock since xdr_replymsg may end up sleeping in malloc.
*/
mtx_unlock(&ct->ct_lock);
if (ext && ext->rc_feedback)
ext->rc_feedback(FEEDBACK_OK, proc, ext->rc_feedback_arg);
xdrmbuf_create(&xdrs, cr->cr_mrep, XDR_DECODE);
ok = xdr_replymsg(&xdrs, &reply_msg);
cr->cr_mrep = NULL;
if (ok) {
if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
(reply_msg.acpted_rply.ar_stat == SUCCESS))
errp->re_status = stat = RPC_SUCCESS;
else
stat = _seterr_reply(&reply_msg, errp);
if (stat == RPC_SUCCESS) {
results = xdrmbuf_getall(&xdrs);
if (!AUTH_VALIDATE(auth, xid,
&reply_msg.acpted_rply.ar_verf, &results)) {
errp->re_status = stat = RPC_AUTHERROR;
errp->re_why = AUTH_INVALIDRESP;
} else {
KASSERT(results,
("auth validated but no result"));
*resultsp = results;
}
} /* end successful completion */
/*
* If unsuccessful AND error is an authentication error
* then refresh credentials and try again, else break
*/
else if (stat == RPC_AUTHERROR)
/* maybe our credentials need to be refreshed ... */
if (nrefreshes > 0 && AUTH_REFRESH(auth, &reply_msg)) {
nrefreshes--;
XDR_DESTROY(&xdrs);
mtx_lock(&ct->ct_lock);
goto call_again;
}
/* end of unsuccessful completion */
/* end of valid reply message */
} else
errp->re_status = stat = RPC_CANTDECODERES;
XDR_DESTROY(&xdrs);
mtx_lock(&ct->ct_lock);
out:
mtx_assert(&ct->ct_lock, MA_OWNED);
KASSERT(stat != RPC_SUCCESS || *resultsp,
("RPC_SUCCESS without reply"));
if (mreq != NULL)
m_freem(mreq);
if (cr->cr_mrep != NULL)
m_freem(cr->cr_mrep);
ct->ct_threads--;
if (ct->ct_closing)
wakeup(ct);
mtx_unlock(&ct->ct_lock);
if (auth && stat != RPC_SUCCESS)
AUTH_VALIDATE(auth, xid, NULL, NULL);
free(cr, M_RPC);
return (stat);
}
static void
clnt_bck_geterr(CLIENT *cl, struct rpc_err *errp)
{
struct ct_data *ct = (struct ct_data *) cl->cl_private;
*errp = ct->ct_error;
}
static bool_t
clnt_bck_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
{
XDR xdrs;
bool_t dummy;
xdrs.x_op = XDR_FREE;
dummy = (*xdr_res)(&xdrs, res_ptr);
return (dummy);
}
/*ARGSUSED*/
static void
clnt_bck_abort(CLIENT *cl)
{
}
static bool_t
clnt_bck_control(CLIENT *cl, u_int request, void *info)
{
return (TRUE);
}
static void
clnt_bck_close(CLIENT *cl)
{
struct ct_data *ct = (struct ct_data *) cl->cl_private;
mtx_lock(&ct->ct_lock);
if (ct->ct_closed) {
mtx_unlock(&ct->ct_lock);
return;
}
if (ct->ct_closing) {
while (ct->ct_closing)
msleep(ct, &ct->ct_lock, 0, "rpcclose", 0);
KASSERT(ct->ct_closed, ("client should be closed"));
mtx_unlock(&ct->ct_lock);
return;
}
ct->ct_closing = FALSE;
ct->ct_closed = TRUE;
mtx_unlock(&ct->ct_lock);
wakeup(ct);
}
static void
clnt_bck_destroy(CLIENT *cl)
{
struct ct_data *ct = (struct ct_data *) cl->cl_private;
clnt_bck_close(cl);
mtx_destroy(&ct->ct_lock);
mem_free(ct, sizeof(struct ct_data));
if (cl->cl_netid && cl->cl_netid[0])
mem_free(cl->cl_netid, strlen(cl->cl_netid) +1);
if (cl->cl_tp && cl->cl_tp[0])
mem_free(cl->cl_tp, strlen(cl->cl_tp) +1);
mem_free(cl, sizeof(CLIENT));
}
/*
* This call is done by the svc code when a backchannel RPC reply is
* received.
*/
void
clnt_bck_svccall(void *arg, struct mbuf *mrep, uint32_t xid)
{
struct ct_data *ct = (struct ct_data *)arg;
struct ct_request *cr;
int foundreq;
mtx_lock(&ct->ct_lock);
ct->ct_upcallrefs++;
/*
* See if we can match this reply to a request.
*/
foundreq = 0;
TAILQ_FOREACH(cr, &ct->ct_pending, cr_link) {
if (cr->cr_xid == xid) {
/*
* This one matches. We leave the reply mbuf list in
* cr->cr_mrep. Set the XID to zero so that we will
* ignore any duplicated replies.
*/
cr->cr_xid = 0;
cr->cr_mrep = mrep;
cr->cr_error = 0;
foundreq = 1;
wakeup(cr);
break;
}
}
ct->ct_upcallrefs--;
if (ct->ct_upcallrefs < 0)
panic("rpcvc svccall refcnt");
if (ct->ct_upcallrefs == 0)
wakeup(&ct->ct_upcallrefs);
mtx_unlock(&ct->ct_lock);
if (foundreq == 0)
m_freem(mrep);
}