portmap.c

当你重新编译了EM85XX的交叉编译工具以支持SUNRPC时

	deny_severity = LOG_WARNING;

	if (debugging)
		(void) fprintf(stderr, "server: about do a switch\n");
	switch (rqstp->rq_proc) {

	case PMAPPROC_NULL:
		/*
		 * Null proc call
		 */
		/* remote host authorization check */
		check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
		if (!svc_sendreply(xprt, (xdrproc_t) xdr_void, (caddr_t)0)
		    && debugging) {
			abort();
		}
		break;

	case PMAPPROC_SET:
		/*
		 * Set a program,version to port mapping
		 */
		if (!svc_getargs(xprt, (xdrproc_t) xdr_pmap, (caddr_t)&reg))
			svcerr_decode(xprt);
		else {
			/* reject non-local requests, protect priv. ports */
			if (!CHECK_SETUNSET(xprt, ludpxprt, ltcpxprt,
			    rqstp->rq_proc, reg.pm_prog, reg.pm_port)) {
				ans = 0;
				goto done;
			} 
			/*
			 * 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
				 */
				fpml = (struct flagged_pml *)
				    malloc((u_int)sizeof(struct flagged_pml));
				pml = &fpml->pml;
				fpml->priv =
					(ntohs(svc_getcaller(xprt)->sin_port)
					 < IPPORT_RESERVED);
				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;
				dump_table();
			}
		done:
			if ((!svc_sendreply(xprt, (xdrproc_t)xdr_int,
					    (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, (xdrproc_t)xdr_pmap, (caddr_t)&reg))
			svcerr_decode(xprt);
		else {
			ans = 0;
			/* reject non-local requests */
			if (!CHECK_SETUNSET(xprt, ludpxprt, ltcpxprt,
			    rqstp->rq_proc, reg.pm_prog, (u_long) 0))
				goto done;
			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 */
				/* privileged port check */
				if (!check_privileged_port(svc_getcaller(xprt), 
				    rqstp->rq_proc, 
				    reg.pm_prog, 
				    pml->pml_map.pm_port)) {
					ans = 0;
					break;
				}
				fpml = (struct flagged_pml*)pml;
				if (fpml->priv &&
				    (ntohs(svc_getcaller(xprt)->sin_port)
				     >= IPPORT_RESERVED)) {
					ans = 0;
					break;
				}

				ans = 1;
				t = (caddr_t)pml;
				pml = pml->pml_next;
				if (prevpml == NULL)
					pmaplist = pml;
				else
					prevpml->pml_next = pml;
				free(t);
				dump_table();
			}
			if ((!svc_sendreply(xprt, (xdrproc_t)xdr_int,
					    (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, (xdrproc_t)xdr_pmap, (caddr_t)&reg))
			svcerr_decode(xprt);
		else {
			/* remote host authorization check */
			if (!check_default(svc_getcaller(xprt), 
			    rqstp->rq_proc, 
			    reg.pm_prog)) {
				ans = 0;
				goto done;
			}
			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, (xdrproc_t)xdr_int,
					    (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, (xdrproc_t)xdr_void, NULL))
			svcerr_decode(xprt);
		else {
			/* remote host authorization check */
			struct pmaplist *p;
			if (!check_default(svc_getcaller(xprt), 
			    rqstp->rq_proc, (u_long) 0)) {
				p = 0;	/* send empty list */
			} else {
				p = pmaplist;
			}
			if ((!svc_sendreply(xprt, (xdrproc_t)xdr_pmaplist,
			    (caddr_t)&p)) && 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:
		/* remote host authorization check */
		check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
		svcerr_noproc(xprt);
		break;
	}
}


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

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

static bool_t
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
xdr_rmtcall_args(XDR *xdrs, 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(XDR *xdrs, 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(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(XDR *xdrs, struct rmtcallargs *cap)
{
	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;
	int pid, 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, (xdrproc_t)xdr_rmtcall_args, (caddr_t)&a))
		return;
	/* host and service access control */
	if (!check_callit(svc_getcaller(xprt), 
	    rqstp->rq_proc, a.rmt_prog, a.rmt_proc))
		return;
	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, (xdrproc_t)xdr_opaque_parms,
			      (caddr_t)&a, (xdrproc_t)xdr_len_opaque_parms,
			      (caddr_t)&a, timeout) == RPC_SUCCESS) {
			svc_sendreply(xprt, (xdrproc_t)xdr_rmtcall_result,
				      (caddr_t)&a);
		}
		AUTH_DESTROY(client->cl_auth);
		clnt_destroy(client);
	}
	(void)close(so);
	exit(0);
}

#ifndef IGNORE_SIGCHLD			/* Lionel Cons <[e-mail]> */
static void reap(int ignore)
{
	int save_errno = errno;
	while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
	errno = save_errno;
}
#endif

/* Dump and restore mapping table so that we can survive kill/restart.
 * To cope with chroot, an fd is opened early and we just write to that.
 * If we are killed while writing the file, we lose, but that isn't
 * very likely...
 */

static void dump_table(void)
{
	FILE *f;
	struct pmaplist *pml;

	if (store_fd < 0)
		return;
	ftruncate(store_fd, 0);
	lseek(store_fd, 0, 0);
	f = fdopen(dup(store_fd), "w");
	if (!f)
		return;

	for (pml = pmaplist ; pml ; pml = pml->pml_next) {
		struct flagged_pml *fpml = (struct flagged_pml*)pml;

		fprintf(f, "%lu %lu %lu %lu %d\n",
			pml->pml_map.pm_prog,
			pml->pml_map.pm_vers,
			pml->pml_map.pm_prot,
			pml->pml_map.pm_port,
			fpml->priv);
	}
	fclose(f);
}

static void load_table(void)
{
	FILE *f;
	struct pmaplist **ep;
	struct flagged_pml fpml, *fpmlp;

	ep = &pmaplist;
	while ((*ep)->pml_next)
		ep = & (*ep)->pml_next;

	if (store_fd < 0)
		return;
	lseek(store_fd, 0, 0);
	f = fdopen(dup(store_fd), "r");
	if (f == NULL)
		return;

	while (fscanf(f, "%lu %lu %lu %lu %d\n",
		      &fpml.pml.pml_map.pm_prog,
		      &fpml.pml.pml_map.pm_vers,
		      &fpml.pml.pml_map.pm_prot,
		      &fpml.pml.pml_map.pm_port,
		      &fpml.priv) == 5) {
		if (fpml.pml.pml_map.pm_port == PMAPPORT)
			continue;
		fpmlp = malloc(sizeof(struct flagged_pml));
		if (!fpmlp)
			break;
		*fpmlp = fpml;
		*ep = &fpmlp->pml;
		ep = &fpmlp->pml.pml_next;
		*ep = NULL;
	}
	fclose(f);
}