portmap.c   [plain text]

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
 * Reserved.  This file contains Original Code and/or Modifications of
 * Original Code as defined in and that are subject to the Apple Public
 * Source License Version 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
 * this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License."
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1990, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)portmap.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

/*
@(#)portmap.c	2.3 88/08/11 4.0 RPCSRC
static char sccsid[] = "@(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
*/

/*
 * portmap.c, Implements the program,version to port number mapping for
 * rpc.
 */

/*
 * 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
 */

#include <errno.h>
#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <netinfo/nibind_prot.h>

#define NETINFO_TAG_NETWORK "network"
#define NETINFO_NETWORK_DIR_PATH "/var/db/netinfo/network.nidb"
#define NETINFO_STAT_LATENCY 30

static int have_tag_network = 0;
static struct timeval last_network_stat = {0, 0};

void reg_service();
void reap();
static void callit();
struct pmaplist *pmaplist;
int debugging = 0;
extern int errno;
extern int svc_maxfd;

extern int get_myaddress();

static void
portmap_svc_run()
{
	fd_set readfds;
	int status;
	
	for (;;)
	{
		readfds = svc_fdset;
		switch ((status = select(svc_maxfd+1, &readfds, NULL, NULL, NULL)))
		{
			case -1:
				if (errno == EINTR) continue;

				if ((errno == EFAULT) || (errno == EINVAL))
				{
					syslog(LOG_ERR, "aborting - select error %d (%s)",
						errno, strerror(errno));
					return;
				}

				syslog(LOG_NOTICE, "ignoring select error %d (%s)",
					errno, strerror(errno));
				continue;

			case 0:
				continue;

			default:
				svc_getreqset(&readfds);
		}
	}
}

int
main(argc, argv)
	int argc;
	char **argv;
{
	SVCXPRT *xprt;
	int sock, c;
	struct sockaddr_in addr;
	int len = sizeof(struct sockaddr_in);
	register struct pmaplist *pml;

	while ((c = getopt(argc, argv, "d")) != EOF) {
		switch (c) {

		case 'd':
			debugging = 1;
			break;

		default:
			(void) fprintf(stderr, "usage: %s [-d]\n", argv[0]);
			exit(1);
		}
	}

	if (!debugging && daemon(0, 0)) {
		(void) fprintf(stderr, "portmap: fork: %s", strerror(errno));
		exit(1);
	}

	openlog("portmap", debugging ? LOG_PID | LOG_PERROR : LOG_PID,
	    LOG_DAEMON);

	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
		syslog(LOG_ERR, "cannot create udp socket: %m");
		exit(1);
	}

	addr.sin_addr.s_addr = 0;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PMAPPORT);
	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
		syslog(LOG_ERR, "cannot bind udp: %m");
		exit(1);
	}

	if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
		syslog(LOG_ERR, "couldn't do udp_create");
		exit(1);
	}
	/* make an entry for ourself */
	pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
	pml->pml_next = 0;
	pml->pml_map.pm_prog = PMAPPROG;
	pml->pml_map.pm_vers = PMAPVERS;
	pml->pml_map.pm_prot = IPPROTO_UDP;
	pml->pml_map.pm_port = PMAPPORT;
	pmaplist = pml;

	if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
		syslog(LOG_ERR, "cannot create tcp socket: %m");
		exit(1);
	}
	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
		syslog(LOG_ERR, "cannot bind udp: %m");
		exit(1);
	}
	if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
	    == (SVCXPRT *)NULL) {
		syslog(LOG_ERR, "couldn't do tcp_create");
		exit(1);
	}
	/* make an entry for ourself */
	pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
	pml->pml_map.pm_prog = PMAPPROG;
	pml->pml_map.pm_vers = PMAPVERS;
	pml->pml_map.pm_prot = IPPROTO_TCP;
	pml->pml_map.pm_port = PMAPPORT;
	pml->pml_next = pmaplist;
	pmaplist = pml;

	(void)svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE);

	/* initialize "network.nidb" timer */
	gettimeofday(&last_network_stat, NULL);

	(void)signal(SIGCHLD, reap);
	portmap_svc_run();
	syslog(LOG_ERR, "run_svc returned unexpectedly");
	abort();
}

#ifndef lint
/* need to override perror calls in rpc library */
__private_extern__
void
perror(what)
	const char *what;
{

	syslog(LOG_ERR, "%s: %m", what);
}
#endif

static struct pmaplist *
find_service(prog, vers, prot)
	u_long prog, vers, prot;
{
	register struct pmaplist *hit = NULL;
	register struct pmaplist *pml;

	for (pml = pmaplist; pml != NULL; pml = pml->pml_next) {
		if ((pml->pml_map.pm_prog != prog) ||
			(pml->pml_map.pm_prot != prot))
			continue;
		hit = pml;
		if (pml->pml_map.pm_vers == vers)
		    break;
	}
	return (hit);
}

/* 
 * 1 OK, 0 not
 */
void
reg_service(rqstp, xprt)
	struct svc_req *rqstp;
	SVCXPRT *xprt;
{
	struct pmap reg;
	struct pmaplist *pml, *prevpml, *fnd;
	int ans, port;
	caddr_t t;
	
	if (debugging)
		(void) fprintf(stderr, "server: about do a switch\n");
	switch (rqstp->rq_proc) {

	case PMAPPROC_NULL:
		/*
		 * Null proc call
		 */
		if (!svc_sendreply(xprt, xdr_void, (caddr_t)0) && debugging) {
			abort();
		}
		break;

	case PMAPPROC_SET:
		/*
		 * Set a program,version to port mapping
		 */
		if (!svc_getargs(xprt, xdr_pmap, &reg))
			svcerr_decode(xprt);
		else {
			/*
			 * check to see if already used
			 * find_service returns a hit even if
			 * the versions don't match, so check for it
			 */
			fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
			if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
				if (fnd->pml_map.pm_port == reg.pm_port) {
					ans = 1;
					goto done;
				}
				else {
					ans = 0;
					goto done;
				}
			} else {
				/* 
				 * add to END of list
				 */
				pml = (struct pmaplist *)
				    malloc((u_int)sizeof(struct pmaplist));
				pml->pml_map = reg;
				pml->pml_next = 0;
				if (pmaplist == 0) {
					pmaplist = pml;
				} else {
					for (fnd= pmaplist; fnd->pml_next != 0;
					    fnd = fnd->pml_next);
					fnd->pml_next = pml;
				}
				ans = 1;
			}
		done:
			if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
			    debugging) {
				(void) fprintf(stderr, "svc_sendreply\n");
				abort();
			}
		}
		break;

	case PMAPPROC_UNSET:
		/*
		 * Remove a program,version to port mapping.
		 */
		if (!svc_getargs(xprt, xdr_pmap, &reg))
			svcerr_decode(xprt);
		else {
			ans = 0;
			for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
				if ((pml->pml_map.pm_prog != reg.pm_prog) ||
					(pml->pml_map.pm_vers != reg.pm_vers)) {
					/* both pml & prevpml move forwards */
					prevpml = pml;
					pml = pml->pml_next;
					continue;
				}
				/* found it; pml moves forward, prevpml stays */
				ans = 1;
				t = (caddr_t)pml;
				pml = pml->pml_next;
				if (prevpml == NULL)
					pmaplist = pml;
				else
					prevpml->pml_next = pml;
				free(t);
			}
			if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
			    debugging) {
				(void) fprintf(stderr, "svc_sendreply\n");
				abort();
			}
		}
		break;

	case PMAPPROC_GETPORT:
		/*
		 * Lookup the mapping for a program,version and return its port
		 */
		if (!svc_getargs(xprt, xdr_pmap, &reg))
			svcerr_decode(xprt);
		else {
			fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
			if (fnd)
				port = fnd->pml_map.pm_port;
			else
				port = 0;
			if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&port)) &&
			    debugging) {
				(void) fprintf(stderr, "svc_sendreply\n");
				abort();
			}
		}
		break;

	case PMAPPROC_DUMP:
		/*
		 * Return the current set of mapped program,version
		 */
		if (!svc_getargs(xprt, xdr_void, NULL))
			svcerr_decode(xprt);
		else {
			if ((!svc_sendreply(xprt, xdr_pmaplist,
			    (caddr_t)&pmaplist)) && debugging) {
				(void) fprintf(stderr, "svc_sendreply\n");
				abort();
			}
		}
		break;

	case PMAPPROC_CALLIT:
		/*
		 * Calls a procedure on the local machine.  If the requested
		 * procedure is not registered this procedure does not return
		 * error information!!
		 * This procedure is only supported on rpc/udp and calls via 
		 * rpc/udp.  It passes null authentication parameters.
		 */
		callit(rqstp, xprt);
		break;

	default:
		svcerr_noproc(xprt);
		break;
	}
}


/*
 * Stuff for the rmtcall service
 */
#define ARGSIZE 9000

struct encap_parms {
	u_long arglen;
	char *args;
};

static bool_t
xdr_encap_parms(xdrs, epp)
	XDR *xdrs;
	struct encap_parms *epp;
{
	return (xdr_bytes(xdrs, &(epp->args), (int *)&(epp->arglen), ARGSIZE));
}

struct rmtcallargs {
	u_long	rmt_prog;
	u_long	rmt_vers;
	u_long	rmt_port;
	u_long	rmt_proc;
	struct encap_parms rmt_args;
};

static bool_t
xdr_rmtcall_args(xdrs, cap)
	register XDR *xdrs;
	register struct rmtcallargs *cap;
{

	/* does not get a port number */
	if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
	    xdr_u_long(xdrs, &(cap->rmt_vers)) &&
	    xdr_u_long(xdrs, &(cap->rmt_proc))) {
		return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
	}
	return (FALSE);
}

static bool_t
xdr_rmtcall_result(xdrs, cap)
	register XDR *xdrs;
	register struct rmtcallargs *cap;
{
	if (xdr_u_long(xdrs, &(cap->rmt_port)))
		return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
	return (FALSE);
}

/*
 * only worries about the struct encap_parms part of struct rmtcallargs.
 * The arglen must already be set!!
 */
static bool_t
xdr_opaque_parms(xdrs, cap)
	XDR *xdrs;
	struct rmtcallargs *cap;
{

	return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
}

/*
 * This routine finds and sets the length of incoming opaque paraters
 * and then calls xdr_opaque_parms.
 */
static bool_t
xdr_len_opaque_parms(xdrs, cap)
	register XDR *xdrs;
	struct rmtcallargs *cap;
{
	register u_int beginpos, lowpos, highpos, currpos, pos;

	beginpos = lowpos = pos = xdr_getpos(xdrs);
	highpos = lowpos + ARGSIZE;
	while ((int)(highpos - lowpos) >= 0) {
		currpos = (lowpos + highpos) / 2;
		if (xdr_setpos(xdrs, currpos)) {
			pos = currpos;
			lowpos = currpos + 1;
		} else {
			highpos = currpos - 1;
		}
	}
	xdr_setpos(xdrs, beginpos);
	cap->rmt_args.arglen = pos - beginpos;
	return (xdr_opaque_parms(xdrs, cap));
}

/*
 * Call a remote procedure service
 * This procedure is very quiet when things go wrong.
 * The proc is written to support broadcast rpc.  In the broadcast case,
 * a machine should shut-up instead of complain, less the requestor be
 * overrun with complaints at the expense of not hearing a valid reply ...
 *
 * This now forks so that the program & process that it calls can call 
 * back to the portmapper.
 */
static void
callit(rqstp, xprt)
	struct svc_req *rqstp;
	SVCXPRT *xprt;
{
	struct rmtcallargs a;
	struct pmaplist *pml;
	u_short port;
	struct sockaddr_in me;
	int pid, so = -1;
	CLIENT *client;
	struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
	struct timeval timeout;
	char buf[ARGSIZE];
	char tag[MAXPATHLEN];
	int off, taglen;
	unsigned int delta;
	struct stat sb;
	struct timeval now;

	timeout.tv_sec = 5;
	timeout.tv_usec = 0;
	a.rmt_args.args = buf;
	if (!svc_getargs(xprt, xdr_rmtcall_args, &a))
		return;

	/*
	 * Drop NIBIND_BIND calls for the parent tag "network" if the database 
	 * doesn't exist.  This prevents excessive fork() calls.
	 */
	if ((have_tag_network == 0) && (a.rmt_prog == NIBIND_PROG) && (a.rmt_proc == NIBIND_BIND))
	{
		/* Skip sender address and child tag */
		memmove(&taglen, a.rmt_args.args + 4, 4);
		taglen = ntohl(taglen);
		off = 8 + (((taglen + 3) / 4) * 4);

		/* Get parent tag */
		memmove(&taglen, a.rmt_args.args + off, 4);
		taglen = ntohl(taglen);
		if (taglen >= MAXPATHLEN) return;

		off += 4;
		memmove(tag, a.rmt_args.args + off, taglen);
		tag[taglen] = '\0';

		/*
		 * If there was no network.nidb a few seconds ago, drop the requset.
		 */
		if (!strcmp(tag, NETINFO_TAG_NETWORK))
		{
			gettimeofday(&now, NULL);
			delta = now.tv_sec - last_network_stat.tv_sec;
			if (delta < NETINFO_STAT_LATENCY) return;

			if (stat(NETINFO_NETWORK_DIR_PATH, &sb) < 0)
			{
				last_network_stat = now;
				return;
			}

			have_tag_network = 1;
		}
	}

	if ((pml = find_service(a.rmt_prog, a.rmt_vers,
	    (u_long)IPPROTO_UDP)) == NULL)
		return;
	/*
	 * fork a child to do the work.  Parent immediately returns.
	 * Child exits upon completion.
	 */
	if ((pid = fork()) != 0) {
		if (pid < 0)
			syslog(LOG_ERR, "CALLIT (prog %lu): fork: %m",
			    a.rmt_prog);
		return;
	}
	port = pml->pml_map.pm_port;
	get_myaddress(&me);
	me.sin_port = htons(port);
	client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &so);
	if (client != (CLIENT *)NULL) {
		if (rqstp->rq_cred.oa_flavor == AUTH_UNIX) {
			client->cl_auth = authunix_create(au->aup_machname,
			   au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
		}
		a.rmt_port = (u_long)port;
		if (clnt_call(client, a.rmt_proc, xdr_opaque_parms, &a,
		    xdr_len_opaque_parms, &a, timeout) == RPC_SUCCESS) {
			svc_sendreply(xprt, xdr_rmtcall_result, (caddr_t)&a);
		}
		AUTH_DESTROY(client->cl_auth);
		clnt_destroy(client);
	}
	(void)close(so);
	exit(0);
}

void
reap()
{
	while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
}