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4df6c5e1fc
freebsd-skq/sys/rpc/svc.c
rmacklem 4df6c5e1fc Fix two races in the server side krpc w.r.t upcalls: 
Add a flag so that soupcall_clear() is only called once to cancel
  an upcall.
  Move the test for xprt_registered in the upcall down to after the
  mtx_lock() of the pool mutex, to catch the case where it is
  unregistered while the upcall is waiting for the mutex.
Also, move the mtx_destroy() of the pool mutex to after SVC_RELEASE(),
so that it isn't destroyed before the upcalls are disabled.

Reviewed by:	dfr, jhb
Tested by:	pho
Approved by:	kib (mentor)
2009-06-04 14:13:06 +00:00

1316 lines
30 KiB
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/* $NetBSD: svc.c,v 1.21 2000/07/06 03:10:35 christos Exp $ */
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#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/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(SVCPOOL *pool);
static void xprt_unregister_locked(SVCXPRT *xprt);
/* *************** SVCXPRT related stuff **************** */
static int svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS);
static int svcpool_maxthread_sysctl(SYSCTL_HANDLER_ARGS);
SVCPOOL*
svcpool_create(const char *name, struct sysctl_oid_list *sysctl_base)
{
SVCPOOL *pool;
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_xlist);
TAILQ_INIT(&pool->sp_active);
TAILQ_INIT(&pool->sp_callouts);
LIST_INIT(&pool->sp_threads);
LIST_INIT(&pool->sp_idlethreads);
pool->sp_minthreads = 1;
pool->sp_maxthreads = 1;
pool->sp_threadcount = 0;
/*
* 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", "");
SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"maxthreads", CTLTYPE_INT | CTLFLAG_RW,
pool, 0, svcpool_maxthread_sysctl, "I", "");
SYSCTL_ADD_INT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
"threads", CTLFLAG_RD, &pool->sp_threadcount, 0, "");
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_UINT(&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_UINT(&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)
{
SVCXPRT *xprt, *nxprt;
struct svc_callout *s;
struct svcxprt_list cleanup;
TAILQ_INIT(&cleanup);
mtx_lock(&pool->sp_lock);
while (TAILQ_FIRST(&pool->sp_xlist)) {
xprt = TAILQ_FIRST(&pool->sp_xlist);
xprt_unregister_locked(xprt);
TAILQ_INSERT_TAIL(&cleanup, xprt, xp_link);
}
while (TAILQ_FIRST(&pool->sp_callouts)) {
s = TAILQ_FIRST(&pool->sp_callouts);
mtx_unlock(&pool->sp_lock);
svc_unreg(pool, s->sc_prog, s->sc_vers);
mtx_lock(&pool->sp_lock);
}
TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
SVC_RELEASE(xprt);
}
mtx_destroy(&pool->sp_lock);
if (pool->sp_rcache)
replay_freecache(pool->sp_rcache);
sysctl_ctx_free(&pool->sp_sysctl);
free(pool, M_RPC);
}
static bool_t
svcpool_active(SVCPOOL *pool)
{
enum svcpool_state state = pool->sp_state;
if (state == SVCPOOL_INIT || state == SVCPOOL_CLOSING)
return (FALSE);
return (TRUE);
}
/*
* Sysctl handler to set the minimum thread count on a pool
*/
static int
svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS)
{
SVCPOOL *pool;
int newminthreads, error, n;
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);
if (newminthreads > pool->sp_minthreads
&& svcpool_active(pool)) {
/*
* If the pool is running and we are
* increasing, create some more threads now.
*/
n = newminthreads - pool->sp_threadcount;
if (n > 0) {
mtx_unlock(&pool->sp_lock);
while (n--)
svc_new_thread(pool);
mtx_lock(&pool->sp_lock);
}
}
pool->sp_minthreads = newminthreads;
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;
SVCTHREAD *st;
int newmaxthreads, error;
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);
if (newmaxthreads < pool->sp_maxthreads
&& svcpool_active(pool)) {
/*
* If the pool is running and we are
* decreasing, wake up some idle threads to
* encourage them to exit.
*/
LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink)
cv_signal(&st->st_cond);
}
pool->sp_maxthreads = newmaxthreads;
mtx_unlock(&pool->sp_lock);
}
return (error);
}
/*
* Activate a transport handle.
*/
void
xprt_register(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
mtx_lock(&pool->sp_lock);
xprt->xp_registered = TRUE;
xprt->xp_active = FALSE;
TAILQ_INSERT_TAIL(&pool->sp_xlist, xprt, xp_link);
mtx_unlock(&pool->sp_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)
{
SVCPOOL *pool = xprt->xp_pool;
if (xprt->xp_active) {
TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
xprt->xp_active = FALSE;
}
TAILQ_REMOVE(&pool->sp_xlist, xprt, xp_link);
xprt->xp_registered = FALSE;
}
void
xprt_unregister(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
mtx_lock(&pool->sp_lock);
xprt_unregister_locked(xprt);
mtx_unlock(&pool->sp_lock);
SVC_RELEASE(xprt);
}
static void
xprt_assignthread(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
SVCTHREAD *st;
/*
* Attempt to assign a service thread to this
* transport.
*/
LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink) {
if (st->st_xprt == NULL && STAILQ_EMPTY(&st->st_reqs))
break;
}
if (st) {
SVC_ACQUIRE(xprt);
xprt->xp_thread = st;
st->st_xprt = xprt;
cv_signal(&st->st_cond);
} 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 (pool->sp_state == SVCPOOL_ACTIVE
&& pool->sp_lastcreatetime < time_uptime
&& pool->sp_threadcount < pool->sp_maxthreads) {
pool->sp_state = SVCPOOL_THREADWANTED;
}
}
}
void
xprt_active(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
mtx_lock(&pool->sp_lock);
if (!xprt->xp_registered) {
/*
* Race with xprt_unregister - we lose.
*/
mtx_unlock(&pool->sp_lock);
return;
}
if (!xprt->xp_active) {
TAILQ_INSERT_TAIL(&pool->sp_active, xprt, xp_alink);
xprt->xp_active = TRUE;
xprt_assignthread(xprt);
}
mtx_unlock(&pool->sp_lock);
}
void
xprt_inactive_locked(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
if (xprt->xp_active) {
TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
xprt->xp_active = FALSE;
}
}
void
xprt_inactive(SVCXPRT *xprt)
{
SVCPOOL *pool = xprt->xp_pool;
mtx_lock(&pool->sp_lock);
xprt_inactive_locked(xprt);
mtx_unlock(&pool->sp_lock);
}
/*
* 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);
}
/* ********************** 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);
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;
MGET(m, M_WAIT, MT_DATA);
MCLGET(m, M_WAIT);
m->m_len = 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;
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);
if (r->rq_addr) {
free(r->rq_addr, M_SONAME);
r->rq_addr = NULL;
}
goto call_done;
default:
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) {
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(SVCPOOL *pool)
{
SVCXPRT *xprt, *nxprt;
time_t timo;
struct svcxprt_list cleanup;
TAILQ_INIT(&cleanup);
TAILQ_FOREACH_SAFE(xprt, &pool->sp_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(&pool->sp_lock);
TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
SVC_RELEASE(xprt);
}
mtx_lock(&pool->sp_lock);
}
static void
svc_assign_waiting_sockets(SVCPOOL *pool)
{
SVCXPRT *xprt;
TAILQ_FOREACH(xprt, &pool->sp_active, xp_alink) {
if (!xprt->xp_thread) {
xprt_assignthread(xprt);
}
}
}
static bool_t
svc_request_space_available(SVCPOOL *pool)
{
mtx_assert(&pool->sp_lock, MA_OWNED);
if (pool->sp_space_throttled) {
/*
* Below the low-water yet? If so, assign any waiting sockets.
*/
if (pool->sp_space_used < pool->sp_space_low) {
pool->sp_space_throttled = FALSE;
svc_assign_waiting_sockets(pool);
return TRUE;
}
return FALSE;
} else {
if (pool->sp_space_used
>= pool->sp_space_high) {
pool->sp_space_throttled = TRUE;
pool->sp_space_throttle_count++;
return FALSE;
}
return TRUE;
}
}
static void
svc_run_internal(SVCPOOL *pool, bool_t ismaster)
{
SVCTHREAD *st, *stpref;
SVCXPRT *xprt;
enum xprt_stat stat;
struct svc_req *rqstp;
int error;
st = mem_alloc(sizeof(*st));
st->st_xprt = NULL;
STAILQ_INIT(&st->st_reqs);
cv_init(&st->st_cond, "rpcsvc");
mtx_lock(&pool->sp_lock);
LIST_INSERT_HEAD(&pool->sp_threads, st, st_link);
/*
* If we are a new thread which was spawned to cope with
* increased load, set the state back to SVCPOOL_ACTIVE.
*/
if (pool->sp_state == SVCPOOL_THREADSTARTING)
pool->sp_state = SVCPOOL_ACTIVE;
while (pool->sp_state != SVCPOOL_CLOSING) {
/*
* Check for idle transports once per second.
*/
if (time_uptime > pool->sp_lastidlecheck) {
pool->sp_lastidlecheck = time_uptime;
svc_checkidle(pool);
}
xprt = st->st_xprt;
if (!xprt && STAILQ_EMPTY(&st->st_reqs)) {
/*
* Enforce maxthreads count.
*/
if (pool->sp_threadcount > pool->sp_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)) {
TAILQ_FOREACH(xprt, &pool->sp_active,
xp_alink) {
if (!xprt->xp_thread) {
SVC_ACQUIRE(xprt);
xprt->xp_thread = st;
st->st_xprt = xprt;
break;
}
}
}
if (st->st_xprt)
continue;
LIST_INSERT_HEAD(&pool->sp_idlethreads, st, st_ilink);
error = cv_timedwait_sig(&st->st_cond, &pool->sp_lock,
5 * hz);
LIST_REMOVE(st, st_ilink);
/*
* Reduce worker thread count when idle.
*/
if (error == EWOULDBLOCK) {
if (!ismaster
&& (pool->sp_threadcount
> pool->sp_minthreads)
&& !st->st_xprt
&& STAILQ_EMPTY(&st->st_reqs))
break;
}
if (error == EWOULDBLOCK)
continue;
if (error) {
if (pool->sp_state != SVCPOOL_CLOSING) {
mtx_unlock(&pool->sp_lock);
svc_exit(pool);
mtx_lock(&pool->sp_lock);
}
break;
}
if (pool->sp_state == SVCPOOL_THREADWANTED) {
pool->sp_state = SVCPOOL_THREADSTARTING;
pool->sp_lastcreatetime = time_uptime;
mtx_unlock(&pool->sp_lock);
svc_new_thread(pool);
mtx_lock(&pool->sp_lock);
}
continue;
}
if (xprt) {
/*
* Drain the transport socket and queue up any
* RPCs.
*/
xprt->xp_lastactive = time_uptime;
stat = XPRT_IDLE;
do {
if (!svc_request_space_available(pool))
break;
rqstp = NULL;
mtx_unlock(&pool->sp_lock);
stat = svc_getreq(xprt, &rqstp);
mtx_lock(&pool->sp_lock);
if (rqstp) {
/*
* See if the application has
* a preference for some other
* thread.
*/
stpref = st;
if (pool->sp_assign)
stpref = pool->sp_assign(st,
rqstp);
pool->sp_space_used +=
rqstp->rq_size;
if (pool->sp_space_used
> pool->sp_space_used_highest)
pool->sp_space_used_highest =
pool->sp_space_used;
rqstp->rq_thread = stpref;
STAILQ_INSERT_TAIL(&stpref->st_reqs,
rqstp, rq_link);
stpref->st_reqcount++;
/*
* If we assigned the request
* to another thread, make
* sure its awake and continue
* reading from the
* socket. Otherwise, try to
* find some other thread to
* read from the socket and
* execute the request
* immediately.
*/
if (stpref != st) {
cv_signal(&stpref->st_cond);
continue;
} else {
break;
}
}
} while (stat == XPRT_MOREREQS
&& pool->sp_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.
*/
xprt->xp_thread = NULL;
st->st_xprt = NULL;
if (xprt->xp_active) {
xprt_assignthread(xprt);
TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
TAILQ_INSERT_TAIL(&pool->sp_active, xprt,
xp_alink);
}
mtx_unlock(&pool->sp_lock);
SVC_RELEASE(xprt);
mtx_lock(&pool->sp_lock);
}
/*
* Execute what we have queued.
*/
while ((rqstp = STAILQ_FIRST(&st->st_reqs)) != NULL) {
size_t sz = rqstp->rq_size;
mtx_unlock(&pool->sp_lock);
svc_executereq(rqstp);
mtx_lock(&pool->sp_lock);
pool->sp_space_used -= sz;
}
}
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"));
LIST_REMOVE(st, st_link);
pool->sp_threadcount--;
mtx_unlock(&pool->sp_lock);
cv_destroy(&st->st_cond);
mem_free(st, sizeof(*st));
if (!ismaster)
wakeup(pool);
}
static void
svc_thread_start(void *arg)
{
svc_run_internal((SVCPOOL *) arg, FALSE);
kthread_exit();
}
static void
svc_new_thread(SVCPOOL *pool)
{
struct thread *td;
pool->sp_threadcount++;
kthread_add(svc_thread_start, pool,
pool->sp_proc, &td, 0, 0,
"%s: service", pool->sp_name);
}
void
svc_run(SVCPOOL *pool)
{
int i;
struct proc *p;
struct thread *td;
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;
pool->sp_lastcreatetime = time_uptime;
pool->sp_threadcount = 1;
for (i = 1; i < pool->sp_minthreads; i++) {
svc_new_thread(pool);
}
svc_run_internal(pool, TRUE);
mtx_lock(&pool->sp_lock);
while (pool->sp_threadcount > 0)
msleep(pool, &pool->sp_lock, 0, "svcexit", 0);
mtx_unlock(&pool->sp_lock);
}
void
svc_exit(SVCPOOL *pool)
{
SVCTHREAD *st;
mtx_lock(&pool->sp_lock);
pool->sp_state = SVCPOOL_CLOSING;
LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink)
cv_signal(&st->st_cond);
mtx_unlock(&pool->sp_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;
SVCXPRT *xprt;
SVCPOOL *pool;
st = rqstp->rq_thread;
xprt = rqstp->rq_xprt;
if (xprt)
pool = xprt->xp_pool;
else
pool = NULL;
if (st) {
mtx_lock(&pool->sp_lock);
KASSERT(rqstp == STAILQ_FIRST(&st->st_reqs),
("Freeing request out of order"));
STAILQ_REMOVE_HEAD(&st->st_reqs, rq_link);
st->st_reqcount--;
if (pool->sp_done)
pool->sp_done(st, rqstp);
mtx_unlock(&pool->sp_lock);
}
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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