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freebsd-skq/sys/rpc/clnt_rc.c
rmacklem a523dc02f9 Add TLS support to the kernel RPC. 
An internet draft titled "Towards Remote Procedure Call Encryption By Default"
describes how TLS is to be used for Sun RPC, with NFS as an intended use case.
This patch adds client and server support for this to the kernel RPC,
using KERN_TLS and upcalls to daemons for the handshake, peer reset and
other non-application data record cases.

The upcalls to the daemons use three fields to uniquely identify the
TCP connection. They are the time.tv_sec, time.tv_usec of the connection
establshment, plus a 64bit sequence number. The time fields avoid problems
with re-use of the sequence number after a daemon restart.
For the server side, once a Null RPC with AUTH_TLS is received, kernel
reception on the socket is blocked and an upcall to the rpctlssd(8) daemon
is done to perform the TLS handshake.  Upon completion, the completion
status of the handshake is stored in xp_tls as flag bits and the reply to
the Null RPC is sent.
For the client, if CLSET_TLS has been set, a new TCP connection will
send the Null RPC with AUTH_TLS to initiate the handshake.  The client
kernel RPC code will then block kernel I/O on the socket and do an upcall
to the rpctlscd(8) daemon to perform the handshake.
If the upcall is successful, ct_rcvstate will be maintained to indicate
if/when an upcall is being done.

If non-application data records are received, the code does an upcall to
the appropriate daemon, which will do a SSL_read() of 0 length to handle
the record(s).

When the socket is being shut down, upcalls are done to the daemons, so
that they can perform SSL_shutdown() calls to perform the "peer reset".

The rpctlssd(8) and rpctlscd(8) daemons require a patched version of the
openssl library and, as such, will not be committed to head at this time.

Although the changes done by this patch are fairly numerous, there should
be no semantics change to the kernel RPC at this time.
A future commit to the NFS code will optionally enable use of TLS for NFS.
2020-08-22 03:57:55 +00:00

549 lines
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2008 Isilon Inc http://www.isilon.com/
* Authors: Doug Rabson <dfr@rabson.org>
* Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.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/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>
#include <rpc/krpc.h>
#include <rpc/rpcsec_tls.h>
static enum clnt_stat clnt_reconnect_call(CLIENT *, struct rpc_callextra *,
rpcproc_t, struct mbuf *, struct mbuf **, struct timeval);
static void clnt_reconnect_geterr(CLIENT *, struct rpc_err *);
static bool_t clnt_reconnect_freeres(CLIENT *, xdrproc_t, void *);
static void clnt_reconnect_abort(CLIENT *);
static bool_t clnt_reconnect_control(CLIENT *, u_int, void *);
static void clnt_reconnect_close(CLIENT *);
static void clnt_reconnect_destroy(CLIENT *);
static struct clnt_ops clnt_reconnect_ops = {
.cl_call = clnt_reconnect_call,
.cl_abort = clnt_reconnect_abort,
.cl_geterr = clnt_reconnect_geterr,
.cl_freeres = clnt_reconnect_freeres,
.cl_close = clnt_reconnect_close,
.cl_destroy = clnt_reconnect_destroy,
.cl_control = clnt_reconnect_control
};
static int fake_wchan;
CLIENT *
clnt_reconnect_create(
struct netconfig *nconf, /* network type */
struct sockaddr *svcaddr, /* servers address */
rpcprog_t program, /* program number */
rpcvers_t version, /* version number */
size_t sendsz, /* buffer recv size */
size_t recvsz) /* buffer send size */
{
CLIENT *cl = NULL; /* client handle */
struct rc_data *rc = NULL; /* private data */
if (svcaddr == NULL) {
rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
return (NULL);
}
cl = mem_alloc(sizeof (CLIENT));
rc = mem_alloc(sizeof (*rc));
mtx_init(&rc->rc_lock, "rc->rc_lock", NULL, MTX_DEF);
(void) memcpy(&rc->rc_addr, svcaddr, (size_t)svcaddr->sa_len);
rc->rc_nconf = nconf;
rc->rc_prog = program;
rc->rc_vers = version;
rc->rc_sendsz = sendsz;
rc->rc_recvsz = recvsz;
rc->rc_timeout.tv_sec = -1;
rc->rc_timeout.tv_usec = -1;
rc->rc_retry.tv_sec = 3;
rc->rc_retry.tv_usec = 0;
rc->rc_retries = INT_MAX;
rc->rc_privport = FALSE;
rc->rc_waitchan = "rpcrecv";
rc->rc_intr = 0;
rc->rc_connecting = FALSE;
rc->rc_closed = FALSE;
rc->rc_ucred = crdup(curthread->td_ucred);
rc->rc_client = NULL;
rc->rc_tls = false;
cl->cl_refs = 1;
cl->cl_ops = &clnt_reconnect_ops;
cl->cl_private = (caddr_t)(void *)rc;
cl->cl_auth = authnone_create();
cl->cl_tp = NULL;
cl->cl_netid = NULL;
return (cl);
}
static enum clnt_stat
clnt_reconnect_connect(CLIENT *cl)
{
struct thread *td = curthread;
struct rc_data *rc = (struct rc_data *)cl->cl_private;
struct socket *so;
enum clnt_stat stat;
int error;
int one = 1;
struct ucred *oldcred;
CLIENT *newclient = NULL;
uint64_t ssl[3];
uint32_t reterr;
mtx_lock(&rc->rc_lock);
while (rc->rc_connecting) {
error = msleep(rc, &rc->rc_lock,
rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
if (error) {
mtx_unlock(&rc->rc_lock);
return (RPC_INTR);
}
}
if (rc->rc_closed) {
mtx_unlock(&rc->rc_lock);
return (RPC_CANTSEND);
}
if (rc->rc_client) {
mtx_unlock(&rc->rc_lock);
return (RPC_SUCCESS);
}
/*
* My turn to attempt a connect. The rc_connecting variable
* serializes the following code sequence, so it is guaranteed
* that rc_client will still be NULL after it is re-locked below,
* since that is the only place it is set non-NULL.
*/
rc->rc_connecting = TRUE;
mtx_unlock(&rc->rc_lock);
oldcred = td->td_ucred;
td->td_ucred = rc->rc_ucred;
so = __rpc_nconf2socket(rc->rc_nconf);
if (!so) {
stat = rpc_createerr.cf_stat = RPC_TLIERROR;
rpc_createerr.cf_error.re_errno = 0;
td->td_ucred = oldcred;
goto out;
}
if (rc->rc_privport)
bindresvport(so, NULL);
if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
newclient = clnt_dg_create(so,
(struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
rc->rc_sendsz, rc->rc_recvsz);
else {
/*
* I do not believe a timeout of less than 1sec would make
* sense here since short delays can occur when a server is
* temporarily overloaded.
*/
if (rc->rc_timeout.tv_sec > 0 && rc->rc_timeout.tv_usec >= 0) {
error = so_setsockopt(so, SOL_SOCKET, SO_SNDTIMEO,
&rc->rc_timeout, sizeof(struct timeval));
if (error != 0) {
stat = rpc_createerr.cf_stat = RPC_CANTSEND;
rpc_createerr.cf_error.re_errno = error;
td->td_ucred = oldcred;
goto out;
}
}
newclient = clnt_vc_create(so,
(struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
if (rc->rc_tls && newclient != NULL) {
stat = rpctls_connect(newclient, so, ssl, &reterr);
if (stat != RPC_SUCCESS || reterr != RPCTLSERR_OK) {
if (stat == RPC_SUCCESS)
stat = RPC_FAILED;
stat = rpc_createerr.cf_stat = stat;
rpc_createerr.cf_error.re_errno = 0;
CLNT_CLOSE(newclient);
CLNT_RELEASE(newclient);
newclient = NULL;
td->td_ucred = oldcred;
goto out;
}
}
}
td->td_ucred = oldcred;
if (!newclient) {
soclose(so);
rc->rc_err = rpc_createerr.cf_error;
stat = rpc_createerr.cf_stat;
goto out;
}
CLNT_CONTROL(newclient, CLSET_FD_CLOSE, 0);
CLNT_CONTROL(newclient, CLSET_CONNECT, &one);
CLNT_CONTROL(newclient, CLSET_TIMEOUT, &rc->rc_timeout);
CLNT_CONTROL(newclient, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
CLNT_CONTROL(newclient, CLSET_WAITCHAN, rc->rc_waitchan);
CLNT_CONTROL(newclient, CLSET_INTERRUPTIBLE, &rc->rc_intr);
if (rc->rc_tls)
CLNT_CONTROL(newclient, CLSET_TLS, ssl);
if (rc->rc_backchannel != NULL)
CLNT_CONTROL(newclient, CLSET_BACKCHANNEL, rc->rc_backchannel);
stat = RPC_SUCCESS;
out:
mtx_lock(&rc->rc_lock);
KASSERT(rc->rc_client == NULL, ("rc_client not null"));
if (!rc->rc_closed) {
rc->rc_client = newclient;
newclient = NULL;
}
rc->rc_connecting = FALSE;
wakeup(rc);
mtx_unlock(&rc->rc_lock);
if (newclient) {
/*
* It has been closed, so discard the new client.
* nb: clnt_[dg|vc]_close()/clnt_[dg|vc]_destroy() cannot
* be called with the rc_lock mutex held, since they may
* msleep() while holding a different mutex.
*/
CLNT_CLOSE(newclient);
CLNT_RELEASE(newclient);
}
return (stat);
}
static enum clnt_stat
clnt_reconnect_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)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
CLIENT *client;
enum clnt_stat stat;
int tries, error;
tries = 0;
do {
mtx_lock(&rc->rc_lock);
if (rc->rc_closed) {
mtx_unlock(&rc->rc_lock);
return (RPC_CANTSEND);
}
if (!rc->rc_client) {
mtx_unlock(&rc->rc_lock);
stat = clnt_reconnect_connect(cl);
if (stat == RPC_SYSTEMERROR) {
error = tsleep(&fake_wchan,
rc->rc_intr ? PCATCH : 0, "rpccon", hz);
if (error == EINTR || error == ERESTART)
return (RPC_INTR);
tries++;
if (tries >= rc->rc_retries)
return (stat);
continue;
}
if (stat != RPC_SUCCESS)
return (stat);
mtx_lock(&rc->rc_lock);
}
if (!rc->rc_client) {
mtx_unlock(&rc->rc_lock);
stat = RPC_FAILED;
continue;
}
CLNT_ACQUIRE(rc->rc_client);
client = rc->rc_client;
mtx_unlock(&rc->rc_lock);
stat = CLNT_CALL_MBUF(client, ext, proc, args,
resultsp, utimeout);
if (stat != RPC_SUCCESS) {
if (!ext)
CLNT_GETERR(client, &rc->rc_err);
}
if (stat == RPC_TIMEDOUT) {
/*
* Check for async send misfeature for NLM
* protocol.
*/
if ((rc->rc_timeout.tv_sec == 0
&& rc->rc_timeout.tv_usec == 0)
|| (rc->rc_timeout.tv_sec == -1
&& utimeout.tv_sec == 0
&& utimeout.tv_usec == 0)) {
CLNT_RELEASE(client);
break;
}
}
if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
|| stat == RPC_CANTRECV) {
tries++;
if (tries >= rc->rc_retries) {
CLNT_RELEASE(client);
break;
}
if (ext && ext->rc_feedback)
ext->rc_feedback(FEEDBACK_RECONNECT, proc,
ext->rc_feedback_arg);
mtx_lock(&rc->rc_lock);
/*
* Make sure that someone else hasn't already
* reconnected by checking if rc_client has changed.
* If not, we are done with the client and must
* do CLNT_RELEASE(client) twice to dispose of it,
* because there is both an initial refcnt and one
* acquired by CLNT_ACQUIRE() above.
*/
if (rc->rc_client == client) {
rc->rc_client = NULL;
mtx_unlock(&rc->rc_lock);
CLNT_RELEASE(client);
} else {
mtx_unlock(&rc->rc_lock);
}
CLNT_RELEASE(client);
} else {
CLNT_RELEASE(client);
break;
}
} while (stat != RPC_SUCCESS);
KASSERT(stat != RPC_SUCCESS || *resultsp,
("RPC_SUCCESS without reply"));
return (stat);
}
static void
clnt_reconnect_geterr(CLIENT *cl, struct rpc_err *errp)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
*errp = rc->rc_err;
}
/*
* Since this function requires that rc_client be valid, it can
* only be called when that is guaranteed to be the case.
*/
static bool_t
clnt_reconnect_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
return (CLNT_FREERES(rc->rc_client, xdr_res, res_ptr));
}
/*ARGSUSED*/
static void
clnt_reconnect_abort(CLIENT *h)
{
}
/*
* CLNT_CONTROL() on the client returned by clnt_reconnect_create() must
* always be called before CLNT_CALL_MBUF() by a single thread only.
*/
static bool_t
clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
SVCXPRT *xprt;
if (info == NULL) {
return (FALSE);
}
switch (request) {
case CLSET_TIMEOUT:
rc->rc_timeout = *(struct timeval *)info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, request, info);
break;
case CLGET_TIMEOUT:
*(struct timeval *)info = rc->rc_timeout;
break;
case CLSET_RETRY_TIMEOUT:
rc->rc_retry = *(struct timeval *)info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, request, info);
break;
case CLGET_RETRY_TIMEOUT:
*(struct timeval *)info = rc->rc_retry;
break;
case CLGET_VERS:
*(uint32_t *)info = rc->rc_vers;
break;
case CLSET_VERS:
rc->rc_vers = *(uint32_t *) info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, CLSET_VERS, info);
break;
case CLGET_PROG:
*(uint32_t *)info = rc->rc_prog;
break;
case CLSET_PROG:
rc->rc_prog = *(uint32_t *) info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, request, info);
break;
case CLSET_WAITCHAN:
rc->rc_waitchan = (char *)info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, request, info);
break;
case CLGET_WAITCHAN:
*(const char **) info = rc->rc_waitchan;
break;
case CLSET_INTERRUPTIBLE:
rc->rc_intr = *(int *) info;
if (rc->rc_client)
CLNT_CONTROL(rc->rc_client, request, info);
break;
case CLGET_INTERRUPTIBLE:
*(int *) info = rc->rc_intr;
break;
case CLSET_RETRIES:
rc->rc_retries = *(int *) info;
break;
case CLGET_RETRIES:
*(int *) info = rc->rc_retries;
break;
case CLSET_PRIVPORT:
rc->rc_privport = *(int *) info;
break;
case CLGET_PRIVPORT:
*(int *) info = rc->rc_privport;
break;
case CLSET_BACKCHANNEL:
xprt = (SVCXPRT *)info;
xprt_register(xprt);
rc->rc_backchannel = info;
break;
case CLSET_TLS:
rc->rc_tls = true;
break;
default:
return (FALSE);
}
return (TRUE);
}
static void
clnt_reconnect_close(CLIENT *cl)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
CLIENT *client;
mtx_lock(&rc->rc_lock);
if (rc->rc_closed) {
mtx_unlock(&rc->rc_lock);
return;
}
rc->rc_closed = TRUE;
client = rc->rc_client;
rc->rc_client = NULL;
mtx_unlock(&rc->rc_lock);
if (client) {
CLNT_CLOSE(client);
CLNT_RELEASE(client);
}
}
static void
clnt_reconnect_destroy(CLIENT *cl)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
SVCXPRT *xprt;
if (rc->rc_client)
CLNT_DESTROY(rc->rc_client);
if (rc->rc_backchannel) {
xprt = (SVCXPRT *)rc->rc_backchannel;
xprt_unregister(xprt);
SVC_RELEASE(xprt);
}
crfree(rc->rc_ucred);
mtx_destroy(&rc->rc_lock);
mem_free(rc, sizeof(*rc));
mem_free(cl, sizeof (CLIENT));
}
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