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freebsd-dev/sys/rpc/svc.c
Alexander Motin 82dcc80db1 Fix race in r267221. 
MFC after:	2 weeks
2014-06-09 15:00:43 +00:00

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/* $NetBSD: svc.c,v 1.21 2000/07/06 03:10:35 christos 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 = "@(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)svc.c 2.4 88/08/11 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* svc.c, Server-side remote procedure call interface.
*
* There are two sets of procedures here. The xprt routines are
* for handling transport handles. The svc routines handle the
* list of service routines.
*
* Copyright (C) 1984, Sun Microsystems, Inc.
*/
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/smp.h>
#include <sys/sx.h>
#include <sys/ucred.h>
#include <rpc/rpc.h>
#include <rpc/rpcb_clnt.h>
#include <rpc/replay.h>
#include <rpc/rpc_com.h>
#define SVC_VERSQUIET 0x0001 /* keep quiet about vers mismatch */
#define version_keepquiet(xp) (SVC_EXT(xp)->xp_flags & SVC_VERSQUIET)
static struct svc_callout *svc_find(SVCPOOL *pool, rpcprog_t, rpcvers_t,
char *);
static void svc_new_thread(SVCGROUP *grp);
static void xprt_unregister_locked(SVCXPRT *xprt);
static void svc_change_space_used(SVCPOOL *pool, int delta);
static bool_t svc_request_space_available(SVCPOOL *pool);
/* *************** SVCXPRT related stuff **************** */
static int svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS);
static int svcpool_maxthread_sysctl(SYSCTL_HANDLER_ARGS);
static int svcpool_threads_sysctl(SYSCTL_HANDLER_ARGS);
SVCPOOL*
svcpool_create(const char *name, struct sysctl_oid_list *sysctl_base)
{
SVCPOOL *pool;
SVCGROUP *grp;
int g;
pool = malloc(sizeof(SVCPOOL), M_RPC, M_WAITOK|M_ZERO);
mtx_init(&pool->sp_lock, "sp_lock", NULL, MTX_DEF);
pool->sp_name = name;
pool->sp_state = SVCPOOL_INIT;
pool->sp_proc = NULL;
TAILQ_INIT(&pool->sp_callouts);
TAILQ_INIT(&pool->sp_lcallouts);
pool->sp_minthreads = 1;
pool->sp_maxthreads = 1;
pool->sp_groupcount = 1;
for (g = 0; g < SVC_MAXGROUPS; g++) {
grp = &pool->sp_groups[g];
mtx_init(&grp->sg_lock, "sg_lock", NULL, MTX_DEF);
grp->sg_pool = pool;
grp->sg_state = SVCPOOL_ACTIVE;
TAILQ_INIT(&grp->sg_xlist);
TAILQ_INIT(&grp->sg_active);
LIST_INIT(&grp->sg_idlethreads);
grp->sg_minthreads = 1;
grp->sg_maxthreads = 1;
}
/*
* Don't use more than a quarter of mbuf clusters or more than
* 45Mb buffering requests.
*/
pool->sp_space_high = nmbclusters * MCLBYTES / 4;
if (pool->sp_space_high > 45 << 20)
pool->sp_space_high = 45 << 20;
pool->sp_space_low = 2 * pool->sp_space_high / 3;
sysctl_ctx_init(&pool->sp_sysctl);
if (sysctl_base) {
SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"minthreads", CTLTYPE_INT | CTLFLAG_RW,
pool, 0, svcpool_minthread_sysctl, "I",
"Minimal number of threads");
SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"maxthreads", CTLTYPE_INT | CTLFLAG_RW,
pool, 0, svcpool_maxthread_sysctl, "I",
"Maximal number of threads");
SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"threads", CTLTYPE_INT | CTLFLAG_RD,
pool, 0, svcpool_threads_sysctl, "I",
"Current number of threads");
SYSCTL_ADD_INT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"groups", CTLFLAG_RD, &pool->sp_groupcount, 0,
"Number of thread groups");
SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_used", CTLFLAG_RD,
&pool->sp_space_used, 0,
"Space in parsed but not handled requests.");
SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_used_highest", CTLFLAG_RD,
&pool->sp_space_used_highest, 0,
"Highest space used since reboot.");
SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_high", CTLFLAG_RW,
&pool->sp_space_high, 0,
"Maximum space in parsed but not handled requests.");
SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_low", CTLFLAG_RW,
&pool->sp_space_low, 0,
"Low water mark for request space.");
SYSCTL_ADD_INT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_throttled", CTLFLAG_RD,
&pool->sp_space_throttled, 0,
"Whether nfs requests are currently throttled");
SYSCTL_ADD_INT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"request_space_throttle_count", CTLFLAG_RD,
&pool->sp_space_throttle_count, 0,
"Count of times throttling based on request space has occurred");
}
return pool;
}
void
svcpool_destroy(SVCPOOL *pool)
{
SVCGROUP *grp;
SVCXPRT *xprt, *nxprt;
struct svc_callout *s;
struct svc_loss_callout *sl;
struct svcxprt_list cleanup;
int g;
TAILQ_INIT(&cleanup);
for (g = 0; g < SVC_MAXGROUPS; g++) {
grp = &pool->sp_groups[g];
mtx_lock(&grp->sg_lock);
while ((xprt = TAILQ_FIRST(&grp->sg_xlist)) != NULL) {
xprt_unregister_locked(xprt);
TAILQ_INSERT_TAIL(&cleanup, xprt, xp_link);
}
mtx_unlock(&grp->sg_lock);
}
TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
SVC_RELEASE(xprt);
}
mtx_lock(&pool->sp_lock);
while ((s = TAILQ_FIRST(&pool->sp_callouts)) != NULL) {
mtx_unlock(&pool->sp_lock);
svc_unreg(pool, s->sc_prog, s->sc_vers);
mtx_lock(&pool->sp_lock);
}
while ((sl = TAILQ_FIRST(&pool->sp_lcallouts)) != NULL) {
mtx_unlock(&pool->sp_lock);
svc_loss_unreg(pool, sl->slc_dispatch);
mtx_lock(&pool->sp_lock);
}
mtx_unlock(&pool->sp_lock);
for (g = 0; g < SVC_MAXGROUPS; g++) {
grp = &pool->sp_groups[g];
mtx_destroy(&grp->sg_lock);
}
mtx_destroy(&pool->sp_lock);
if (pool->sp_rcache)
replay_freecache(pool->sp_rcache);
sysctl_ctx_free(&pool->sp_sysctl);
free(pool, M_RPC);
}
/*
* Sysctl handler to get the present thread count on a pool
*/
static int
svcpool_threads_sysctl(SYSCTL_HANDLER_ARGS)
{
SVCPOOL *pool;
int threads, error, g;
pool = oidp->oid_arg1;
threads = 0;
mtx_lock(&pool->sp_lock);
for (g = 0; g < pool->sp_groupcount; g++)
threads += pool->sp_groups[g].sg_threadcount;
mtx_unlock(&pool->sp_lock);
error = sysctl_handle_int(oidp, &threads, 0, req);
return (error);
}
/*
* Sysctl handler to set the minimum thread count on a pool
*/
static int
svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS)
{
SVCPOOL *pool;
int newminthreads, error, g;
pool = oidp->oid_arg1;
newminthreads = pool->sp_minthreads;
error = sysctl_handle_int(oidp, &newminthreads, 0, req);
if (error == 0 && newminthreads != pool->sp_minthreads) {
if (newminthreads > pool->sp_maxthreads)
return (EINVAL);
mtx_lock(&pool->sp_lock);
pool->sp_minthreads = newminthreads;
for (g = 0; g < pool->sp_groupcount; g++) {
pool->sp_groups[g].sg_minthreads = max(1,
pool->sp_minthreads / pool->sp_groupcount);
}
mtx_unlock(&pool->sp_lock);
}
return (error);
}
/*
* Sysctl handler to set the maximum thread count on a pool
*/
static int
svcpool_maxthread_sysctl(SYSCTL_HANDLER_ARGS)
{
SVCPOOL *pool;
int newmaxthreads, error, g;
pool = oidp->oid_arg1;
newmaxthreads = pool->sp_maxthreads;
error = sysctl_handle_int(oidp, &newmaxthreads, 0, req);
if (error == 0 && newmaxthreads != pool->sp_maxthreads) {
if (newmaxthreads < pool->sp_minthreads)
return (EINVAL);
mtx_lock(&pool->sp_lock);
pool->sp_maxthreads = newmaxthreads;
for (g = 0; g < pool->sp_groupcount; g++) {
pool->sp_groups[g].sg_maxthreads = max(1,
pool->sp_maxthreads / pool->sp_groupcount);
}
mtx_unlock(&pool->sp_lock);
}
return (error);
}
/*
* Activate a transport handle.
*/
void
xprt_register(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
SVCGROUP *grp;
int g;
SVC_ACQUIRE(xprt);
g = atomic_fetchadd_int(&pool->sp_nextgroup, 1) % pool->sp_groupcount;
xprt->xp_group = grp = &pool->sp_groups[g];
mtx_lock(&grp->sg_lock);
xprt->xp_registered = TRUE;
xprt->xp_active = FALSE;
TAILQ_INSERT_TAIL(&grp->sg_xlist, xprt, xp_link);
mtx_unlock(&grp->sg_lock);
}
/*
* De-activate a transport handle. Note: the locked version doesn't
* release the transport - caller must do that after dropping the pool
* lock.
*/
static void
xprt_unregister_locked(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
mtx_assert(&grp->sg_lock, MA_OWNED);
KASSERT(xprt->xp_registered == TRUE,
("xprt_unregister_locked: not registered"));
xprt_inactive_locked(xprt);
TAILQ_REMOVE(&grp->sg_xlist, xprt, xp_link);
xprt->xp_registered = FALSE;
}
void
xprt_unregister(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
mtx_lock(&grp->sg_lock);
if (xprt->xp_registered == FALSE) {
/* Already unregistered by another thread */
mtx_unlock(&grp->sg_lock);
return;
}
xprt_unregister_locked(xprt);
mtx_unlock(&grp->sg_lock);
SVC_RELEASE(xprt);
}
/*
* Attempt to assign a service thread to this transport.
*/
static int
xprt_assignthread(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
SVCTHREAD *st;
mtx_assert(&grp->sg_lock, MA_OWNED);
st = LIST_FIRST(&grp->sg_idlethreads);
if (st) {
LIST_REMOVE(st, st_ilink);
SVC_ACQUIRE(xprt);
xprt->xp_thread = st;
st->st_xprt = xprt;
cv_signal(&st->st_cond);
return (TRUE);
} else {
/*
* See if we can create a new thread. The
* actual thread creation happens in
* svc_run_internal because our locking state
* is poorly defined (we are typically called
* from a socket upcall). Don't create more
* than one thread per second.
*/
if (grp->sg_state == SVCPOOL_ACTIVE
&& grp->sg_lastcreatetime < time_uptime
&& grp->sg_threadcount < grp->sg_maxthreads) {
grp->sg_state = SVCPOOL_THREADWANTED;
}
}
return (FALSE);
}
void
xprt_active(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
mtx_lock(&grp->sg_lock);
if (!xprt->xp_registered) {
/*
* Race with xprt_unregister - we lose.
*/
mtx_unlock(&grp->sg_lock);
return;
}
if (!xprt->xp_active) {
xprt->xp_active = TRUE;
if (xprt->xp_thread == NULL) {
if (!svc_request_space_available(xprt->xp_pool) ||
!xprt_assignthread(xprt))
TAILQ_INSERT_TAIL(&grp->sg_active, xprt,
xp_alink);
}
}
mtx_unlock(&grp->sg_lock);
}
void
xprt_inactive_locked(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
mtx_assert(&grp->sg_lock, MA_OWNED);
if (xprt->xp_active) {
if (xprt->xp_thread == NULL)
TAILQ_REMOVE(&grp->sg_active, xprt, xp_alink);
xprt->xp_active = FALSE;
}
}
void
xprt_inactive(SVCXPRT *xprt)
{
SVCGROUP *grp = xprt->xp_group;
mtx_lock(&grp->sg_lock);
xprt_inactive_locked(xprt);
mtx_unlock(&grp->sg_lock);
}
/*
* Variant of xprt_inactive() for use only when sure that port is
* assigned to thread. For example, withing receive handlers.
*/
void
xprt_inactive_self(SVCXPRT *xprt)
{
KASSERT(xprt->xp_thread != NULL,
("xprt_inactive_self(%p) with NULL xp_thread", xprt));
xprt->xp_active = FALSE;
}
/*
* Add a service program to the callout list.
* The dispatch routine will be called when a rpc request for this
* program number comes in.
*/
bool_t
svc_reg(SVCXPRT *xprt, const rpcprog_t prog, const rpcvers_t vers,
void (*dispatch)(struct svc_req *, SVCXPRT *),
const struct netconfig *nconf)
{
SVCPOOL *pool = xprt->xp_pool;
struct svc_callout *s;
char *netid = NULL;
int flag = 0;
/* VARIABLES PROTECTED BY svc_lock: s, svc_head */
if (xprt->xp_netid) {
netid = strdup(xprt->xp_netid, M_RPC);
flag = 1;
} else if (nconf && nconf->nc_netid) {
netid = strdup(nconf->nc_netid, M_RPC);
flag = 1;
} /* must have been created with svc_raw_create */
if ((netid == NULL) && (flag == 1)) {
return (FALSE);
}
mtx_lock(&pool->sp_lock);
if ((s = svc_find(pool, prog, vers, netid)) != NULL) {
if (netid)
free(netid, M_RPC);
if (s->sc_dispatch == dispatch)
goto rpcb_it; /* he is registering another xptr */
mtx_unlock(&pool->sp_lock);
return (FALSE);
}
s = malloc(sizeof (struct svc_callout), M_RPC, M_NOWAIT);
if (s == NULL) {
if (netid)
free(netid, M_RPC);
mtx_unlock(&pool->sp_lock);
return (FALSE);
}
s->sc_prog = prog;
s->sc_vers = vers;
s->sc_dispatch = dispatch;
s->sc_netid = netid;
TAILQ_INSERT_TAIL(&pool->sp_callouts, s, sc_link);
if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
((SVCXPRT *) xprt)->xp_netid = strdup(netid, M_RPC);
rpcb_it:
mtx_unlock(&pool->sp_lock);
/* now register the information with the local binder service */
if (nconf) {
bool_t dummy;
struct netconfig tnc;
struct netbuf nb;
tnc = *nconf;
nb.buf = &xprt->xp_ltaddr;
nb.len = xprt->xp_ltaddr.ss_len;
dummy = rpcb_set(prog, vers, &tnc, &nb);
return (dummy);
}
return (TRUE);
}
/*
* Remove a service program from the callout list.
*/
void
svc_unreg(SVCPOOL *pool, const rpcprog_t prog, const rpcvers_t vers)
{
struct svc_callout *s;
/* unregister the information anyway */
(void) rpcb_unset(prog, vers, NULL);
mtx_lock(&pool->sp_lock);
while ((s = svc_find(pool, prog, vers, NULL)) != NULL) {
TAILQ_REMOVE(&pool->sp_callouts, s, sc_link);
if (s->sc_netid)
mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
mem_free(s, sizeof (struct svc_callout));
}
mtx_unlock(&pool->sp_lock);
}
/*
* Add a service connection loss program to the callout list.
* The dispatch routine will be called when some port in ths pool die.
*/
bool_t
svc_loss_reg(SVCXPRT *xprt, void (*dispatch)(SVCXPRT *))
{
SVCPOOL *pool = xprt->xp_pool;
struct svc_loss_callout *s;
mtx_lock(&pool->sp_lock);
TAILQ_FOREACH(s, &pool->sp_lcallouts, slc_link) {
if (s->slc_dispatch == dispatch)
break;
}
if (s != NULL) {
mtx_unlock(&pool->sp_lock);
return (TRUE);
}
s = malloc(sizeof (struct svc_callout), M_RPC, M_NOWAIT);
if (s == NULL) {
mtx_unlock(&pool->sp_lock);
return (FALSE);
}
s->slc_dispatch = dispatch;
TAILQ_INSERT_TAIL(&pool->sp_lcallouts, s, slc_link);
mtx_unlock(&pool->sp_lock);
return (TRUE);
}
/*
* Remove a service connection loss program from the callout list.
*/
void
svc_loss_unreg(SVCPOOL *pool, void (*dispatch)(SVCXPRT *))
{
struct svc_loss_callout *s;
mtx_lock(&pool->sp_lock);
TAILQ_FOREACH(s, &pool->sp_lcallouts, slc_link) {
if (s->slc_dispatch == dispatch) {
TAILQ_REMOVE(&pool->sp_lcallouts, s, slc_link);
free(s, M_RPC);
break;
}
}
mtx_unlock(&pool->sp_lock);
}
/* ********************** CALLOUT list related stuff ************* */
/*
* Search the callout list for a program number, return the callout
* struct.
*/
static struct svc_callout *
svc_find(SVCPOOL *pool, rpcprog_t prog, rpcvers_t vers, char *netid)
{
struct svc_callout *s;
mtx_assert(&pool->sp_lock, MA_OWNED);
TAILQ_FOREACH(s, &pool->sp_callouts, sc_link) {
if (s->sc_prog == prog && s->sc_vers == vers
&& (netid == NULL || s->sc_netid == NULL ||
strcmp(netid, s->sc_netid) == 0))
break;
}
return (s);
}
/* ******************* REPLY GENERATION ROUTINES ************ */
static bool_t
svc_sendreply_common(struct svc_req *rqstp, struct rpc_msg *rply,
struct mbuf *body)
{
SVCXPRT *xprt = rqstp->rq_xprt;
bool_t ok;
if (rqstp->rq_args) {
m_freem(rqstp->rq_args);
rqstp->rq_args = NULL;
}
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
rply, svc_getrpccaller(rqstp), body);
if (!SVCAUTH_WRAP(&rqstp->rq_auth, &body))
return (FALSE);
ok = SVC_REPLY(xprt, rply, rqstp->rq_addr, body, &rqstp->rq_reply_seq);
if (rqstp->rq_addr) {
free(rqstp->rq_addr, M_SONAME);
rqstp->rq_addr = NULL;
}
return (ok);
}
/*
* Send a reply to an rpc request
*/
bool_t
svc_sendreply(struct svc_req *rqstp, xdrproc_t xdr_results, void * xdr_location)
{
struct rpc_msg rply;
struct mbuf *m;
XDR xdrs;
bool_t ok;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = SUCCESS;
rply.acpted_rply.ar_results.where = NULL;
rply.acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
m = m_getcl(M_WAITOK, MT_DATA, 0);
xdrmbuf_create(&xdrs, m, XDR_ENCODE);
ok = xdr_results(&xdrs, xdr_location);
XDR_DESTROY(&xdrs);
if (ok) {
return (svc_sendreply_common(rqstp, &rply, m));
} else {
m_freem(m);
return (FALSE);
}
}
bool_t
svc_sendreply_mbuf(struct svc_req *rqstp, struct mbuf *m)
{
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = SUCCESS;
rply.acpted_rply.ar_results.where = NULL;
rply.acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;
return (svc_sendreply_common(rqstp, &rply, m));
}
/*
* No procedure error reply
*/
void
svcerr_noproc(struct svc_req *rqstp)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = PROC_UNAVAIL;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, svc_getrpccaller(rqstp), NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Can't decode args error reply
*/
void
svcerr_decode(struct svc_req *rqstp)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = GARBAGE_ARGS;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, (struct sockaddr *) &xprt->xp_rtaddr, NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Some system error
*/
void
svcerr_systemerr(struct svc_req *rqstp)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = SYSTEM_ERR;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, svc_getrpccaller(rqstp), NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Authentication error reply
*/
void
svcerr_auth(struct svc_req *rqstp, enum auth_stat why)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_DENIED;
rply.rjcted_rply.rj_stat = AUTH_ERROR;
rply.rjcted_rply.rj_why = why;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, svc_getrpccaller(rqstp), NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Auth too weak error reply
*/
void
svcerr_weakauth(struct svc_req *rqstp)
{
svcerr_auth(rqstp, AUTH_TOOWEAK);
}
/*
* Program unavailable error reply
*/
void
svcerr_noprog(struct svc_req *rqstp)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = PROG_UNAVAIL;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, svc_getrpccaller(rqstp), NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Program version mismatch error reply
*/
void
svcerr_progvers(struct svc_req *rqstp, rpcvers_t low_vers, rpcvers_t high_vers)
{
SVCXPRT *xprt = rqstp->rq_xprt;
struct rpc_msg rply;
rply.rm_xid = rqstp->rq_xid;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = rqstp->rq_verf;
rply.acpted_rply.ar_stat = PROG_MISMATCH;
rply.acpted_rply.ar_vers.low = (uint32_t)low_vers;
rply.acpted_rply.ar_vers.high = (uint32_t)high_vers;
if (xprt->xp_pool->sp_rcache)
replay_setreply(xprt->xp_pool->sp_rcache,
&rply, svc_getrpccaller(rqstp), NULL);
svc_sendreply_common(rqstp, &rply, NULL);
}
/*
* Allocate a new server transport structure. All fields are
* initialized to zero and xp_p3 is initialized to point at an
* extension structure to hold various flags and authentication
* parameters.
*/
SVCXPRT *
svc_xprt_alloc()
{
SVCXPRT *xprt;
SVCXPRT_EXT *ext;
xprt = mem_alloc(sizeof(SVCXPRT));
memset(xprt, 0, sizeof(SVCXPRT));
ext = mem_alloc(sizeof(SVCXPRT_EXT));
memset(ext, 0, sizeof(SVCXPRT_EXT));
xprt->xp_p3 = ext;
refcount_init(&xprt->xp_refs, 1);
return (xprt);
}
/*
* Free a server transport structure.
*/
void
svc_xprt_free(xprt)
SVCXPRT *xprt;
{
mem_free(xprt->xp_p3, sizeof(SVCXPRT_EXT));
mem_free(xprt, sizeof(SVCXPRT));
}
/* ******************* SERVER INPUT STUFF ******************* */
/*
* Read RPC requests from a transport and queue them to be
* executed. We handle authentication and replay cache replies here.
* Actually dispatching the RPC is deferred till svc_executereq.
*/
static enum xprt_stat
svc_getreq(SVCXPRT *xprt, struct svc_req **rqstp_ret)
{
SVCPOOL *pool = xprt->xp_pool;
struct svc_req *r;
struct rpc_msg msg;
struct mbuf *args;
struct svc_loss_callout *s;
enum xprt_stat stat;
/* now receive msgs from xprtprt (support batch calls) */
r = malloc(sizeof(*r), M_RPC, M_WAITOK|M_ZERO);
msg.rm_call.cb_cred.oa_base = r->rq_credarea;
msg.rm_call.cb_verf.oa_base = &r->rq_credarea[MAX_AUTH_BYTES];
r->rq_clntcred = &r->rq_credarea[2*MAX_AUTH_BYTES];
if (SVC_RECV(xprt, &msg, &r->rq_addr, &args)) {
enum auth_stat why;
/*
* Handle replays and authenticate before queuing the
* request to be executed.
*/
SVC_ACQUIRE(xprt);
r->rq_xprt = xprt;
if (pool->sp_rcache) {
struct rpc_msg repmsg;
struct mbuf *repbody;
enum replay_state rs;
rs = replay_find(pool->sp_rcache, &msg,
svc_getrpccaller(r), &repmsg, &repbody);
switch (rs) {
case RS_NEW:
break;
case RS_DONE:
SVC_REPLY(xprt, &repmsg, r->rq_addr,
repbody, &r->rq_reply_seq);
if (r->rq_addr) {
free(r->rq_addr, M_SONAME);
r->rq_addr = NULL;
}
m_freem(args);
goto call_done;
default:
m_freem(args);
goto call_done;
}
}
r->rq_xid = msg.rm_xid;
r->rq_prog = msg.rm_call.cb_prog;
r->rq_vers = msg.rm_call.cb_vers;
r->rq_proc = msg.rm_call.cb_proc;
r->rq_size = sizeof(*r) + m_length(args, NULL);
r->rq_args = args;
if ((why = _authenticate(r, &msg)) != AUTH_OK) {
/*
* RPCSEC_GSS uses this return code
* for requests that form part of its
* context establishment protocol and
* should not be dispatched to the
* application.
*/
if (why != RPCSEC_GSS_NODISPATCH)
svcerr_auth(r, why);
goto call_done;
}
if (!SVCAUTH_UNWRAP(&r->rq_auth, &r->rq_args)) {
svcerr_decode(r);
goto call_done;
}
/*
* Everything checks out, return request to caller.
*/
*rqstp_ret = r;
r = NULL;
}
call_done:
if (r) {
svc_freereq(r);
r = NULL;
}
if ((stat = SVC_STAT(xprt)) == XPRT_DIED) {
TAILQ_FOREACH(s, &pool->sp_lcallouts, slc_link)
(*s->slc_dispatch)(xprt);
xprt_unregister(xprt);
}
return (stat);
}
static void
svc_executereq(struct svc_req *rqstp)
{
SVCXPRT *xprt = rqstp->rq_xprt;
SVCPOOL *pool = xprt->xp_pool;
int prog_found;
rpcvers_t low_vers;
rpcvers_t high_vers;
struct svc_callout *s;
/* now match message with a registered service*/
prog_found = FALSE;
low_vers = (rpcvers_t) -1L;
high_vers = (rpcvers_t) 0L;
TAILQ_FOREACH(s, &pool->sp_callouts, sc_link) {
if (s->sc_prog == rqstp->rq_prog) {
if (s->sc_vers == rqstp->rq_vers) {
/*
* We hand ownership of r to the
* dispatch method - they must call
* svc_freereq.
*/
(*s->sc_dispatch)(rqstp, xprt);
return;
} /* found correct version */
prog_found = TRUE;
if (s->sc_vers < low_vers)
low_vers = s->sc_vers;
if (s->sc_vers > high_vers)
high_vers = s->sc_vers;
} /* found correct program */
}
/*
* if we got here, the program or version
* is not served ...
*/
if (prog_found)
svcerr_progvers(rqstp, low_vers, high_vers);
else
svcerr_noprog(rqstp);
svc_freereq(rqstp);
}
static void
svc_checkidle(SVCGROUP *grp)
{
SVCXPRT *xprt, *nxprt;
time_t timo;
struct svcxprt_list cleanup;
TAILQ_INIT(&cleanup);
TAILQ_FOREACH_SAFE(xprt, &grp->sg_xlist, xp_link, nxprt) {
/*
* Only some transports have idle timers. Don't time
* something out which is just waking up.
*/
if (!xprt->xp_idletimeout || xprt->xp_thread)
continue;
timo = xprt->xp_lastactive + xprt->xp_idletimeout;
if (time_uptime > timo) {
xprt_unregister_locked(xprt);
TAILQ_INSERT_TAIL(&cleanup, xprt, xp_link);
}
}
mtx_unlock(&grp->sg_lock);
TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
SVC_RELEASE(xprt);
}
mtx_lock(&grp->sg_lock);
}
static void
svc_assign_waiting_sockets(SVCPOOL *pool)
{
SVCGROUP *grp;
SVCXPRT *xprt;
int g;
for (g = 0; g < pool->sp_groupcount; g++) {
grp = &pool->sp_groups[g];
mtx_lock(&grp->sg_lock);
while ((xprt = TAILQ_FIRST(&grp->sg_active)) != NULL) {
if (xprt_assignthread(xprt))
TAILQ_REMOVE(&grp->sg_active, xprt, xp_alink);
else
break;
}
mtx_unlock(&grp->sg_lock);
}
}
static void
svc_change_space_used(SVCPOOL *pool, int delta)
{
unsigned int value;
value = atomic_fetchadd_int(&pool->sp_space_used, delta) + delta;
if (delta > 0) {
if (value >= pool->sp_space_high && !pool->sp_space_throttled) {
pool->sp_space_throttled = TRUE;
pool->sp_space_throttle_count++;
}
if (value > pool->sp_space_used_highest)
pool->sp_space_used_highest = value;
} else {
if (value < pool->sp_space_low && pool->sp_space_throttled) {
pool->sp_space_throttled = FALSE;
svc_assign_waiting_sockets(pool);
}
}
}
static bool_t
svc_request_space_available(SVCPOOL *pool)
{
if (pool->sp_space_throttled)
return (FALSE);
return (TRUE);
}
static void
svc_run_internal(SVCGROUP *grp, bool_t ismaster)
{
SVCPOOL *pool = grp->sg_pool;
SVCTHREAD *st, *stpref;
SVCXPRT *xprt;
enum xprt_stat stat;
struct svc_req *rqstp;
size_t sz;
int error;
st = mem_alloc(sizeof(*st));
mtx_init(&st->st_lock, "st_lock", NULL, MTX_DEF);
st->st_pool = pool;
st->st_xprt = NULL;
STAILQ_INIT(&st->st_reqs);
cv_init(&st->st_cond, "rpcsvc");
mtx_lock(&grp->sg_lock);
/*
* If we are a new thread which was spawned to cope with
* increased load, set the state back to SVCPOOL_ACTIVE.
*/
if (grp->sg_state == SVCPOOL_THREADSTARTING)
grp->sg_state = SVCPOOL_ACTIVE;
while (grp->sg_state != SVCPOOL_CLOSING) {
/*
* Create new thread if requested.
*/
if (grp->sg_state == SVCPOOL_THREADWANTED) {
grp->sg_state = SVCPOOL_THREADSTARTING;
grp->sg_lastcreatetime = time_uptime;
mtx_unlock(&grp->sg_lock);
svc_new_thread(grp);
mtx_lock(&grp->sg_lock);
continue;
}
/*
* Check for idle transports once per second.
*/
if (time_uptime > grp->sg_lastidlecheck) {
grp->sg_lastidlecheck = time_uptime;
svc_checkidle(grp);
}
xprt = st->st_xprt;
if (!xprt) {
/*
* Enforce maxthreads count.
*/
if (grp->sg_threadcount > grp->sg_maxthreads)
break;
/*
* Before sleeping, see if we can find an
* active transport which isn't being serviced
* by a thread.
*/
if (svc_request_space_available(pool) &&
(xprt = TAILQ_FIRST(&grp->sg_active)) != NULL) {
TAILQ_REMOVE(&grp->sg_active, xprt, xp_alink);
SVC_ACQUIRE(xprt);
xprt->xp_thread = st;
st->st_xprt = xprt;
continue;
}
LIST_INSERT_HEAD(&grp->sg_idlethreads, st, st_ilink);
if (ismaster || (!ismaster &&
grp->sg_threadcount > grp->sg_minthreads))
error = cv_timedwait_sig(&st->st_cond,
&grp->sg_lock, 5 * hz);
else
error = cv_wait_sig(&st->st_cond,
&grp->sg_lock);
if (st->st_xprt == NULL)
LIST_REMOVE(st, st_ilink);
/*
* Reduce worker thread count when idle.
*/
if (error == EWOULDBLOCK) {
if (!ismaster
&& (grp->sg_threadcount
> grp->sg_minthreads)
&& !st->st_xprt)
break;
} else if (error) {
mtx_unlock(&grp->sg_lock);
svc_exit(pool);
mtx_lock(&grp->sg_lock);
break;
}
continue;
}
mtx_unlock(&grp->sg_lock);
/*
* Drain the transport socket and queue up any RPCs.
*/
xprt->xp_lastactive = time_uptime;
do {
if (!svc_request_space_available(pool))
break;
rqstp = NULL;
stat = svc_getreq(xprt, &rqstp);
if (rqstp) {
svc_change_space_used(pool, rqstp->rq_size);
/*
* See if the application has a preference
* for some other thread.
*/
if (pool->sp_assign) {
stpref = pool->sp_assign(st, rqstp);
rqstp->rq_thread = stpref;
STAILQ_INSERT_TAIL(&stpref->st_reqs,
rqstp, rq_link);
mtx_unlock(&stpref->st_lock);
if (stpref != st)
rqstp = NULL;
} else {
rqstp->rq_thread = st;
STAILQ_INSERT_TAIL(&st->st_reqs,
rqstp, rq_link);
}
}
} while (rqstp == NULL && stat == XPRT_MOREREQS
&& grp->sg_state != SVCPOOL_CLOSING);
/*
* Move this transport to the end of the active list to
* ensure fairness when multiple transports are active.
* If this was the last queued request, svc_getreq will end
* up calling xprt_inactive to remove from the active list.
*/
mtx_lock(&grp->sg_lock);
xprt->xp_thread = NULL;
st->st_xprt = NULL;
if (xprt->xp_active) {
if (!svc_request_space_available(pool) ||
!xprt_assignthread(xprt))
TAILQ_INSERT_TAIL(&grp->sg_active,
xprt, xp_alink);
}
mtx_unlock(&grp->sg_lock);
SVC_RELEASE(xprt);
/*
* Execute what we have queued.
*/
sz = 0;
mtx_lock(&st->st_lock);
while ((rqstp = STAILQ_FIRST(&st->st_reqs)) != NULL) {
STAILQ_REMOVE_HEAD(&st->st_reqs, rq_link);
mtx_unlock(&st->st_lock);
sz += rqstp->rq_size;
svc_executereq(rqstp);
mtx_lock(&st->st_lock);
}
mtx_unlock(&st->st_lock);
svc_change_space_used(pool, -sz);
mtx_lock(&grp->sg_lock);
}
if (st->st_xprt) {
xprt = st->st_xprt;
st->st_xprt = NULL;
SVC_RELEASE(xprt);
}
KASSERT(STAILQ_EMPTY(&st->st_reqs), ("stray reqs on exit"));
mtx_destroy(&st->st_lock);
cv_destroy(&st->st_cond);
mem_free(st, sizeof(*st));
grp->sg_threadcount--;
if (!ismaster)
wakeup(grp);
mtx_unlock(&grp->sg_lock);
}
static void
svc_thread_start(void *arg)
{
svc_run_internal((SVCGROUP *) arg, FALSE);
kthread_exit();
}
static void
svc_new_thread(SVCGROUP *grp)
{
SVCPOOL *pool = grp->sg_pool;
struct thread *td;
grp->sg_threadcount++;
kthread_add(svc_thread_start, grp, pool->sp_proc, &td, 0, 0,
"%s: service", pool->sp_name);
}
void
svc_run(SVCPOOL *pool)
{
int g, i;
struct proc *p;
struct thread *td;
SVCGROUP *grp;
p = curproc;
td = curthread;
snprintf(td->td_name, sizeof(td->td_name),
"%s: master", pool->sp_name);
pool->sp_state = SVCPOOL_ACTIVE;
pool->sp_proc = p;
/* Choose group count based on number of threads and CPUs. */
pool->sp_groupcount = max(1, min(SVC_MAXGROUPS,
min(pool->sp_maxthreads / 2, mp_ncpus) / 6));
for (g = 0; g < pool->sp_groupcount; g++) {
grp = &pool->sp_groups[g];
grp->sg_minthreads = max(1,
pool->sp_minthreads / pool->sp_groupcount);
grp->sg_maxthreads = max(1,
pool->sp_maxthreads / pool->sp_groupcount);
grp->sg_lastcreatetime = time_uptime;
}
/* Starting threads */
for (g = 0; g < pool->sp_groupcount; g++) {
grp = &pool->sp_groups[g];
for (i = ((g == 0) ? 1 : 0); i < grp->sg_minthreads; i++)
svc_new_thread(grp);
}
pool->sp_groups[0].sg_threadcount++;
svc_run_internal(&pool->sp_groups[0], TRUE);
/* Waiting for threads to stop. */
for (g = 0; g < pool->sp_groupcount; g++) {
grp = &pool->sp_groups[g];
mtx_lock(&grp->sg_lock);
while (grp->sg_threadcount > 0)
msleep(grp, &grp->sg_lock, 0, "svcexit", 0);
mtx_unlock(&grp->sg_lock);
}
}
void
svc_exit(SVCPOOL *pool)
{
SVCGROUP *grp;
SVCTHREAD *st;
int g;
pool->sp_state = SVCPOOL_CLOSING;
for (g = 0; g < pool->sp_groupcount; g++) {
grp = &pool->sp_groups[g];
mtx_lock(&grp->sg_lock);
if (grp->sg_state != SVCPOOL_CLOSING) {
grp->sg_state = SVCPOOL_CLOSING;
LIST_FOREACH(st, &grp->sg_idlethreads, st_ilink)
cv_signal(&st->st_cond);
}
mtx_unlock(&grp->sg_lock);
}
}
bool_t
svc_getargs(struct svc_req *rqstp, xdrproc_t xargs, void *args)
{
struct mbuf *m;
XDR xdrs;
bool_t stat;
m = rqstp->rq_args;
rqstp->rq_args = NULL;
xdrmbuf_create(&xdrs, m, XDR_DECODE);
stat = xargs(&xdrs, args);
XDR_DESTROY(&xdrs);
return (stat);
}
bool_t
svc_freeargs(struct svc_req *rqstp, xdrproc_t xargs, void *args)
{
XDR xdrs;
if (rqstp->rq_addr) {
free(rqstp->rq_addr, M_SONAME);
rqstp->rq_addr = NULL;
}
xdrs.x_op = XDR_FREE;
return (xargs(&xdrs, args));
}
void
svc_freereq(struct svc_req *rqstp)
{
SVCTHREAD *st;
SVCPOOL *pool;
st = rqstp->rq_thread;
if (st) {
pool = st->st_pool;
if (pool->sp_done)
pool->sp_done(st, rqstp);
}
if (rqstp->rq_auth.svc_ah_ops)
SVCAUTH_RELEASE(&rqstp->rq_auth);
if (rqstp->rq_xprt) {
SVC_RELEASE(rqstp->rq_xprt);
}
if (rqstp->rq_addr)
free(rqstp->rq_addr, M_SONAME);
if (rqstp->rq_args)
m_freem(rqstp->rq_args);
free(rqstp, M_RPC);
}
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