/*-
* 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));
}
