freebsd-skq/sys/rpc/clnt_rc.c
dfr 2fb03513fc Implement support for RPCSEC_GSS authentication to both the NFS client
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager.  I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.

The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.

To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.

As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.

Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.

The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.

Sponsored by:	Isilon Systems
MFC after:	1 month
2008-11-03 10:38:00 +00:00

478 lines
11 KiB
C

/*-
* 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>
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;
struct rc_data {
struct mtx rc_lock;
struct sockaddr_storage rc_addr; /* server address */
struct netconfig* rc_nconf; /* network type */
rpcprog_t rc_prog; /* program number */
rpcvers_t rc_vers; /* version number */
size_t rc_sendsz;
size_t rc_recvsz;
struct timeval rc_timeout;
struct timeval rc_retry;
int rc_retries;
int rc_privport;
char *rc_waitchan;
int rc_intr;
int rc_connecting;
int rc_closed;
struct ucred *rc_ucred;
CLIENT* rc_client; /* underlying RPC client */
struct rpc_err rc_err;
};
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;
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;
mtx_lock(&rc->rc_lock);
again:
if (rc->rc_closed) {
mtx_unlock(&rc->rc_lock);
return (RPC_CANTSEND);
}
if (rc->rc_connecting) {
while (!rc->rc_closed && !rc->rc_client) {
error = msleep(rc, &rc->rc_lock,
rc->rc_intr ? PCATCH : 0, "rpcrecon", 0);
if (error) {
mtx_unlock(&rc->rc_lock);
return (RPC_INTR);
}
}
/*
* If the other guy failed to connect, we might as
* well have another go.
*/
if (!rc->rc_client && !rc->rc_connecting)
goto again;
mtx_unlock(&rc->rc_lock);
return (RPC_SUCCESS);
} else {
rc->rc_connecting = TRUE;
}
mtx_unlock(&rc->rc_lock);
so = __rpc_nconf2socket(rc->rc_nconf);
if (!so) {
stat = rpc_createerr.cf_stat = RPC_TLIERROR;
rpc_createerr.cf_error.re_errno = 0;
goto out;
}
if (rc->rc_privport)
bindresvport(so, NULL);
oldcred = td->td_ucred;
td->td_ucred = rc->rc_ucred;
if (rc->rc_nconf->nc_semantics == NC_TPI_CLTS)
rc->rc_client = clnt_dg_create(so,
(struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
rc->rc_sendsz, rc->rc_recvsz);
else
rc->rc_client = clnt_vc_create(so,
(struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
rc->rc_sendsz, rc->rc_recvsz);
td->td_ucred = oldcred;
if (!rc->rc_client) {
soclose(so);
rc->rc_err = rpc_createerr.cf_error;
stat = rpc_createerr.cf_stat;
goto out;
}
CLNT_CONTROL(rc->rc_client, CLSET_FD_CLOSE, 0);
CLNT_CONTROL(rc->rc_client, CLSET_CONNECT, &one);
CLNT_CONTROL(rc->rc_client, CLSET_TIMEOUT, &rc->rc_timeout);
CLNT_CONTROL(rc->rc_client, CLSET_RETRY_TIMEOUT, &rc->rc_retry);
CLNT_CONTROL(rc->rc_client, CLSET_WAITCHAN, rc->rc_waitchan);
CLNT_CONTROL(rc->rc_client, CLSET_INTERRUPTIBLE, &rc->rc_intr);
stat = RPC_SUCCESS;
out:
mtx_lock(&rc->rc_lock);
if (rc->rc_closed) {
if (rc->rc_client) {
CLNT_CLOSE(rc->rc_client);
CLNT_RELEASE(rc->rc_client);
rc->rc_client = NULL;
}
}
rc->rc_connecting = FALSE;
wakeup(rc);
mtx_unlock(&rc->rc_lock);
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;
tries = 0;
do {
if (rc->rc_closed) {
return (RPC_CANTSEND);
}
if (!rc->rc_client) {
stat = clnt_reconnect_connect(cl);
if (stat == RPC_SYSTEMERROR) {
(void) tsleep(&fake_wchan, 0,
"rpccon", hz);
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);
}
CLNT_RELEASE(client);
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)) {
break;
}
}
if (stat == RPC_TIMEDOUT || stat == RPC_CANTSEND
|| stat == RPC_CANTRECV) {
tries++;
if (tries >= rc->rc_retries)
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.
*/
if (rc->rc_client == client) {
CLNT_RELEASE(rc->rc_client);
rc->rc_client = NULL;
}
mtx_unlock(&rc->rc_lock);
} else {
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;
}
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)
{
}
static bool_t
clnt_reconnect_control(CLIENT *cl, u_int request, void *info)
{
struct rc_data *rc = (struct rc_data *)cl->cl_private;
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;
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;
if (rc->rc_client)
CLNT_DESTROY(rc->rc_client);
crfree(rc->rc_ucred);
mtx_destroy(&rc->rc_lock);
mem_free(rc, sizeof(*rc));
mem_free(cl, sizeof (CLIENT));
}