/*
* 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) 2002-2018 Free Software Foundation, Inc.
* This file is part of the GNU C Library.
* Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
*
* The GNU C Library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* The GNU C Library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with the GNU C Library; if not, see
* <http://www.gnu.org/licenses/>.
*
* Copyright (c) 2010, Oracle America, Inc.
*
* 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 the "Oracle America, 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.
*/
#include <errno.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/svc.h>
#include <rpc/pmap_clnt.h>
#include <sys/poll.h>
#include <time.h>
#include <shlib-compat.h>
#define xports RPC_THREAD_VARIABLE(svc_xports_s)
#define NULL_SVC ((struct svc_callout *)0)
#define RQCRED_SIZE 400 /* this size is excessive */
/* The services list
Each entry represents a set of procedures (an rpc program).
The dispatch routine takes request structs and runs the
appropriate procedure. */
struct svc_callout {
struct svc_callout *sc_next;
rpcprog_t sc_prog;
rpcvers_t sc_vers;
void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
bool_t sc_mapped;
};
#define svc_head RPC_THREAD_VARIABLE(svc_head_s)
/* *************** SVCXPRT related stuff **************** */
/* Activate a transport handle. */
void
xprt_register (SVCXPRT *xprt)
{
register int sock = xprt->xp_sock;
register int i;
if (xports == NULL)
{
xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *));
if (xports == NULL) /* Don't add handle */
return;
}
if (sock < _rpc_dtablesize ())
{
struct pollfd *new_svc_pollfd;
xports[sock] = xprt;
if (sock < FD_SETSIZE)
FD_SET (sock, &svc_fdset);
/* Check if we have an empty slot */
for (i = 0; i < svc_max_pollfd; ++i)
if (svc_pollfd[i].fd == -1)
{
svc_pollfd[i].fd = sock;
svc_pollfd[i].events = (POLLIN | POLLPRI |
POLLRDNORM | POLLRDBAND);
return;
}
new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
sizeof (struct pollfd)
* (svc_max_pollfd + 1));
if (new_svc_pollfd == NULL) /* Out of memory */
return;
svc_pollfd = new_svc_pollfd;
++svc_max_pollfd;
svc_pollfd[svc_max_pollfd - 1].fd = sock;
svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
POLLRDNORM | POLLRDBAND);
}
}
libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)
/* De-activate a transport handle. */
void
xprt_unregister (SVCXPRT *xprt)
{
register int sock = xprt->xp_sock;
register int i;
if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
{
xports[sock] = (SVCXPRT *) 0;
if (sock < FD_SETSIZE)
FD_CLR (sock, &svc_fdset);
for (i = 0; i < svc_max_pollfd; ++i)
if (svc_pollfd[i].fd == sock)
svc_pollfd[i].fd = -1;
}
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (xprt_unregister)
#else
libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
#endif
/* ********************** CALLOUT list related stuff ************* */
/* Search the callout list for a program number, return the callout
struct. */
static struct svc_callout *
svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
{
register struct svc_callout *s, *p;
p = NULL_SVC;
for (s = svc_head; s != NULL_SVC; s = s->sc_next)
{
if ((s->sc_prog == prog) && (s->sc_vers == vers))
goto done;
p = s;
}
done:
*prev = p;
return s;
}
/* 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_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
void (*dispatch) (struct svc_req *, SVCXPRT *),
rpcproc_t protocol)
{
struct svc_callout *prev;
register struct svc_callout *s;
if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
{
if (s->sc_dispatch == dispatch)
goto pmap_it; /* he is registering another xptr */
return FALSE;
}
s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
if (s == (struct svc_callout *) 0)
return FALSE;
s->sc_prog = prog;
s->sc_vers = vers;
s->sc_dispatch = dispatch;
s->sc_next = svc_head;
s->sc_mapped = FALSE;
svc_head = s;
pmap_it:
/* now register the information with the local binder service */
if (protocol)
{
if (! pmap_set (prog, vers, protocol, xprt->xp_port))
return FALSE;
s->sc_mapped = TRUE;
}
return TRUE;
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_register)
#else
libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
#endif
/* Remove a service program from the callout list. */
void
svc_unregister (rpcprog_t prog, rpcvers_t vers)
{
struct svc_callout *prev;
register struct svc_callout *s;
if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
return;
bool is_mapped = s->sc_mapped;
if (prev == NULL_SVC)
svc_head = s->sc_next;
else
prev->sc_next = s->sc_next;
s->sc_next = NULL_SVC;
mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
/* now unregister the information with the local binder service */
if (is_mapped)
pmap_unset (prog, vers);
}
libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)
/* ******************* REPLY GENERATION ROUTINES ************ */
/* Send a reply to an rpc request */
bool_t
svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
caddr_t xdr_location)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = SUCCESS;
rply.acpted_rply.ar_results.where = xdr_location;
rply.acpted_rply.ar_results.proc = xdr_results;
return SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_sendreply)
#else
libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
#endif
/* No procedure error reply */
void
svcerr_noproc (register SVCXPRT *xprt)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = PROC_UNAVAIL;
SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_noproc)
#else
libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
#endif
/* Can't decode args error reply */
void
svcerr_decode (register SVCXPRT *xprt)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = GARBAGE_ARGS;
SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_decode)
#else
libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
#endif
/* Some system error */
void
svcerr_systemerr (register SVCXPRT *xprt)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = SYSTEM_ERR;
SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_systemerr)
#else
libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
#endif
/* Authentication error reply */
void
svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_DENIED;
rply.rjcted_rply.rj_stat = AUTH_ERROR;
rply.rjcted_rply.rj_why = why;
SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)
/* Auth too weak error reply */
void
svcerr_weakauth (SVCXPRT *xprt)
{
svcerr_auth (xprt, AUTH_TOOWEAK);
}
libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)
/* Program unavailable error reply */
void
svcerr_noprog (register SVCXPRT *xprt)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = PROG_UNAVAIL;
SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)
/* Program version mismatch error reply */
void
svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
rpcvers_t high_vers)
{
struct rpc_msg rply;
rply.rm_direction = REPLY;
rply.rm_reply.rp_stat = MSG_ACCEPTED;
rply.acpted_rply.ar_verf = xprt->xp_verf;
rply.acpted_rply.ar_stat = PROG_MISMATCH;
rply.acpted_rply.ar_vers.low = low_vers;
rply.acpted_rply.ar_vers.high = high_vers;
SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)
/* ******************* SERVER INPUT STUFF ******************* */
/*
* Get server side input from some transport.
*
* Statement of authentication parameters management:
* This function owns and manages all authentication parameters, specifically
* the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
* the "cooked" credentials (rqst->rq_clntcred).
* However, this function does not know the structure of the cooked
* credentials, so it make the following assumptions:
* a) the structure is contiguous (no pointers), and
* b) the cred structure size does not exceed RQCRED_SIZE bytes.
* In all events, all three parameters are freed upon exit from this routine.
* The storage is trivially management on the call stack in user land, but
* is mallocated in kernel land.
*/
void
svc_getreq (int rdfds)
{
fd_set readfds;
FD_ZERO (&readfds);
readfds.fds_bits[0] = rdfds;
svc_getreqset (&readfds);
}
libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)
void
svc_getreqset (fd_set *readfds)
{
register fd_mask mask;
register fd_mask *maskp;
register int setsize;
register int sock;
register int bit;
setsize = _rpc_dtablesize ();
if (setsize > FD_SETSIZE)
setsize = FD_SETSIZE;
maskp = readfds->fds_bits;
for (sock = 0; sock < setsize; sock += NFDBITS)
for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
svc_getreq_common (sock + bit - 1);
}
libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)
void
svc_getreq_poll (struct pollfd *pfdp, int pollretval)
{
if (pollretval == 0)
return;
register int fds_found;
for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
{
register struct pollfd *p = &pfdp[i];
if (p->fd != -1 && p->revents)
{
/* fd has input waiting */
if (p->revents & POLLNVAL)
xprt_unregister (xports[p->fd]);
else
svc_getreq_common (p->fd);
if (++fds_found >= pollretval)
break;
}
}
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_getreq_poll)
#else
libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
#endif
void
svc_getreq_common (const int fd)
{
enum xprt_stat stat;
struct rpc_msg msg;
register SVCXPRT *xprt;
char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
msg.rm_call.cb_cred.oa_base = cred_area;
msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
xprt = xports[fd];
/* Do we control fd? */
if (xprt == NULL)
return;
/* now receive msgs from xprtprt (support batch calls) */
do
{
if (SVC_RECV (xprt, &msg))
{
/* now find the exported program and call it */
struct svc_callout *s;
struct svc_req r;
enum auth_stat why;
rpcvers_t low_vers;
rpcvers_t high_vers;
int prog_found;
r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
r.rq_xprt = xprt;
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_cred = msg.rm_call.cb_cred;
/* first authenticate the message */
/* Check for null flavor and bypass these calls if possible */
if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
{
r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
r.rq_xprt->xp_verf.oa_length = 0;
}
else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
{
svcerr_auth (xprt, why);
goto call_done;
}
/* now match message with a registered service */
prog_found = FALSE;
low_vers = 0 - 1;
high_vers = 0;
for (s = svc_head; s != NULL_SVC; s = s->sc_next)
{
if (s->sc_prog == r.rq_prog)
{
if (s->sc_vers == r.rq_vers)
{
(*s->sc_dispatch) (&r, xprt);
goto call_done;
}
/* 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 (xprt, low_vers, high_vers);
else
svcerr_noprog (xprt);
/* Fall through to ... */
}
call_done:
if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
{
SVC_DESTROY (xprt);
break;
}
}
while (stat == XPRT_MOREREQS);
}
libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)
/* If there are no file descriptors available, then accept will fail.
We want to delay here so the connection request can be dequeued;
otherwise we can bounce between polling and accepting, never giving the
request a chance to dequeue and eating an enormous amount of cpu time
in svc_run if we're polling on many file descriptors. */
void
__svc_accept_failed (void)
{
if (errno == EMFILE)
{
struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 };
__nanosleep (&ts, NULL);
}
}
void
__rpc_thread_svc_cleanup (void)
{
struct svc_callout *svcp;
while ((svcp = svc_head) != NULL)
svc_unregister (svcp->sc_prog, svcp->sc_vers);
}