portmap.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)portmap.c	4.1	ULTRIX	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/*
 *	Portions of this software have been licensed to 
 *	Digital Equipment Company, Maynard, MA.
 *	Copyright (c) 1986 Sun Microsystems, Inc.  ALL RIGHTS RESERVED.
 */
/*
 * portmap.c, Implements the program,version to port number mapping for
 * rpc.
 */

#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <stdio.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/ioctl.h>

char *malloc();
int reg_service();
static int debugging = 0;

main()
{
	SVCXPRT *xprt;
	int sock, pid, t;
	struct sockaddr_in addr;
	int len = sizeof(struct sockaddr_in);

	/*
	 * must be superuser to run 
	 */
	if (geteuid() != 0){
		(void) fprintf(stderr, "portmap:  must be super user\n");
		(void) fflush(stderr);
		exit(1);
	}

#ifndef DEBUG
	pid = fork();
	if (pid < 0) {
		perror("portmap: fork");
		exit(1);
	}
	if (pid != 0)
		exit(0);
	for (t = 0; t < 20; t++)
		close(t);
 	open("/", 0);
 	dup2(0, 1);
 	dup2(0, 2);
 	t = open("/dev/tty", 2);
 	if (t >= 0) {
 		ioctl(t, TIOCNOTTY, (char *)0);
 		close(t);
 	}
#endif
	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
		perror("portmap cannot create socket");
		exit(1);
	}

	addr.sin_addr.S_un.S_addr = 0;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PMAPPORT);
	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
		perror("portmap cannot bind");
		exit(1);
	}

	if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
		fprintf(stderr, "couldn't do udp_create\n");
		exit(1);
	}

	if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
		perror("portmap cannot create socket");
		exit(1);
	}
	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
		perror("portmap cannot bind");
		exit(1);
	}
	if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
	    == (SVCXPRT *)NULL) {
		fprintf(stderr, "couldn't do tcp_create\n");
		exit(1);
	}

        (void)svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE);
	svc_run();
	fprintf(stderr, "run_svc returned unexpectedly\n");
	abort();
}

struct pmaplist *pmaplist;

static struct pmaplist *
find_service(prog, vers, prot)
	u_long prog;
	u_long vers;
{
	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
 */
reg_service(rqstp, xprt)
	struct svc_req *rqstp;
	SVCXPRT *xprt;
{
	struct pmap reg;
	struct pmaplist *pml, *prevpml, *fnd;
	int ans, port;
	caddr_t t;
	
#ifdef DEBUG
	fprintf(stderr, "server: about do a switch\n");
#endif
	switch (rqstp->rq_proc) {

	case PMAPPROC_NULL:
		/*
		 * Null proc call
		 */
		if ((!svc_sendreply(xprt, xdr_void, NULL)) && 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) {
				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) {
				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) {
				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) {
				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

typedef 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), &(epp->arglen), ARGSIZE));
}

typedef 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 ...
 */
static
callit(rqstp, xprt)
	struct svc_req *rqstp;
	SVCXPRT *xprt;
{
	char buf[2000];
	struct rmtcallargs a;
	struct pmaplist *pml;
	u_short port;
	struct sockaddr_in me;
	int socket = -1;
	CLIENT *client;
	struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
	struct timeval timeout;

	timeout.tv_sec = 5;
	timeout.tv_usec = 0;
	a.rmt_args.args = buf;
	if (!svc_getargs(xprt, xdr_rmtcall_args, &a))
	    return;
	if ((pml = find_service(a.rmt_prog, a.rmt_vers, IPPROTO_UDP)) == NULL)
	    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, &socket);
	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, &a);
		}
		AUTH_DESTROY(client->cl_auth);
		clnt_destroy(client);
	}
	(void)close(socket);
}