RCS_ID_C="$Id: portmap.c,v 3.9 1994/05/02 19:52:55 jraja Exp $";
/*
 * portmap.c -- implements the program, version to port number mapping for rpc
 */

#include "portmap_rev.h"

static const char version[] = VERSTAG
" Copyright © 1994 AmiTCP/IP Group, <amitcp-group@hut.fi>\n"
"Helsinki University of Technology, Finland.\n"
"Copyright © 1990 The Regents of the University of California.\n"
"All rights reserved.\n";

/****** netutil.doc/portmap *************************************************
    NAME
        portmap - DARPA port to RPC program number mapper

    SYNOPSIS
        AmiTCP:bin/portmap

    DESCRIPTION
        `portmap' is a server that converts RPC program numbers into DARPA
        protocol port numbers.  It must be running in order to make RPC
        calls.  When an RPC server is started, it will tell `portmap' what
        port number it is listening to, and what RPC program numbers it is
        prepared to serve.  When a client wishes to make an RPC call to a
        given program number, it will first contact `portmap' on the
        server machine to determine the port number where RPC packets
        should be sent.  Normally, standard RPC servers are started by
        `inetd', so `portmap' must be started before `inetd' is invoked.

    SEE ALSO
        netutil.doc/rpcinfo

    BUGS
        If `portmap' crashes, all servers must be restarted.

*****************************************************************************
* 
*/

/*
 * @(#)portmap.c 5.4 (Berkeley) 4/19/91
 * @(#)portmap.c 2.3 88/08/11 4.0 RPCSRC
 * @(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
 */

#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>

void reg_service(struct svc_req *rqstp, SVCXPRT *xprt);
static void callit(struct svc_req *rqstp, SVCXPRT *xprt);

struct pmaplist *pmaplist;
int debugging = 0;

main(int argc, char **argv)
{
	SVCXPRT *xprt;
	int sock, c;
	struct sockaddr_in addr = { 0 };
	int len = sizeof(struct sockaddr_in);
	register struct pmaplist *pml;

	signal(SIGINT, SIG_IGN); /* Prevent ANSI Signal handling */

	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);
		}
	}

	openlog("portmap", debugging ? LOG_PID | LOG_PERROR : LOG_PID,
	    LOG_DAEMON);
#ifndef amigados
	if (!debugging && daemon(0, 0)) {
		(void) fprintf(stderr, "portmap: fork: %s", strerror(errno));
		exit(1);
	}
#else
	/*
	 * We could probably detach here, but don't bother now...
	 */
#endif

	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);

	svc_run();
	syslog(LOG_ERR, "svc_run returned unexpectedly");
	exit(0);
}

/*
 * Overrides the strlib perror
 */
void
perror(const char *what)
{
	syslog(LOG_ERR, "%s: %m", what);
}

static struct pmaplist *
find_service(u_long prog, u_long vers, u_long 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(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) {
			exit(20);
		}
		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");
				exit(20);
			}
		}
		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");
				exit(20);
			}
		}
		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");
				exit(20);
			}
		}
		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");
				exit(20);
			}
		}
		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_int arglen;
	char *args;
};

static bool_t XDRFUN
xdr_encap_parms(XDR *xdrs, struct encap_parms *epp)
{

	return (xdr_bytes(xdrs, &(epp->args), &(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 XDRFUN
xdr_rmtcall_args(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 XDRFUN
xdr_rmtcall_result(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 XDRFUN
xdr_opaque_parms(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 parameters
 * and then calls xdr_opaque_parms.
 */
static bool_t XDRFUN 
xdr_len_opaque_parms(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(struct svc_req *rqstp, SVCXPRT *xprt)
{
	struct rmtcallargs a;
	struct pmaplist *pml;
	u_short port;
	struct sockaddr_in me;
#ifndef amigados /* forking not supported */
	int pid;
#endif
	int so = -1;
	CLIENT *client;
	struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
	struct timeval timeout;
	char buf[ARGSIZE];

	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,
	    (u_long)IPPROTO_UDP)) == NULL)
		return;
#ifndef amigados /* forking not supported */
	/*
	 * 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;
	}
#endif
	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)CloseSocket(so);
	exit(0);
}

#ifndef amigados /* forking not supported */
void
reap()
{
	while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
}
#endif