/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Auxiliary routines to shield off random internet hosts and to report
 * service requests (verbose mode only) or violations (always).
 *
 * This code was extensively modifed from a version authored by:
 *
 * Wietse Venema, Eindhoven University of Technology, The Netherlands
 * and distributed as "rpcbind 2.1".
 *
 * Sun was granted permission to use, modify, including make
 * derivatives of, copy, reproduce and distribute this code.c in both
 * binary and source forms, directly and indirectly.
 *
 * Modified for bundling with Solaris and IPv6.
 *
 * Solaris specific modifcations made are:
 *
 *	Double fork() logging replaced with qsyslog();
 *	Connection refusals are flagged with svcerr_auth(); this
 *	aids in quicker diagnosability of misconfigurations and quicker
 *	failures for /net automounts;
 *	Single function for pmap* and rpcb*;
 *	Local transport checks made using localxprt().
 *
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <errno.h>
#include <netconfig.h>
#include <netdb.h>
#include <netdir.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <rpc/rpcb_prot.h>

#include "rpcbind.h"

/*
 * These are globally visible so that they can be modified by the wrapper's
 * language extension routines.
 */
int allow_severity = LOG_INFO;
int deny_severity = LOG_WARNING;

extern int hosts_ctl();

/*
 * "inet_ntoa/inet_pton" for struct sockaddr_gen
 */
static const char *
sgen_toa(struct sockaddr_gen *addr)
{
	static char buf[INET6_ADDRSTRLEN];
	return (inet_ntop(SGFAM(addr), SGADDRP(addr), buf, sizeof (buf)));
}

/*
 * find_procname - map rpcb/pmap procedure number to name
 */
static const char *
find_procname(rpcproc_t procnum, boolean_t pm)
{
	static char procbuf[6 + 3 * sizeof (ulong_t)];
	struct proc_map {
		rpcproc_t code;
		const char *proc;
	};
	static struct proc_map pmapmap[] = {
		PMAPPROC_CALLIT,	"callit",
		PMAPPROC_DUMP,		"dump",
		PMAPPROC_GETPORT,	"getport",
		PMAPPROC_SET,		"set",
		PMAPPROC_UNSET,		"unset",
		NULLPROC,		"null",
	};
	static struct proc_map rpcbmap[] = {
		RPCBPROC_SET,		"set",
		RPCBPROC_UNSET,		"unset",
		RPCBPROC_GETADDR,	"getaddr",
		RPCBPROC_DUMP,		"dump",
		RPCBPROC_CALLIT,	"callit",
		RPCBPROC_GETTIME,	"gettime",
		RPCBPROC_UADDR2TADDR,	"uaddr2taddr",
		RPCBPROC_TADDR2UADDR,	"taddr2uaddr",
		RPCBPROC_GETVERSADDR,	"getversaddr",
		RPCBPROC_INDIRECT,	"indirect",
		RPCBPROC_GETADDRLIST,	"getaddrlist",
		RPCBPROC_GETSTAT,	"getstat",
		NULLPROC,		"null",
	};

	int nitems, i;
	struct proc_map *procp;

	if (pm) {
		procp = pmapmap;
		nitems = sizeof (pmapmap)/sizeof (struct proc_map);
	} else {
		procp = rpcbmap;
		nitems = sizeof (rpcbmap)/sizeof (struct proc_map);
	}

	for (i = 0; i < nitems; i++) {
		if (procp[i].code == procnum)
			return (procp[i].proc);
	}
	(void) snprintf(procbuf, sizeof (procbuf), "%s-%lu",
		pm ? "pmap" : "rpcb", (ulong_t)procnum);
	return (procbuf);
}

/*
 * find_progname - map rpc program number to name.
 */
static const char *
find_progname(rpcprog_t prognum)
{
	static char progbuf[1 + 3 * sizeof (ulong_t)];

	if (prognum == 0)
		return ("");

	/*
	 * The original code contained a call to "getrpcbynumber()";
	 * this call was removed because it may cause a call to a
	 * nameservice.
	 */

	(void) snprintf(progbuf, sizeof (progbuf), "%lu", (ulong_t)prognum);
	return (progbuf);
}

/*
 * rpcb_log - log request for service
 */
void
rpcb_log(boolean_t verdict, SVCXPRT *transp, rpcproc_t proc, rpcprog_t prog,
    boolean_t pm)
{
	struct netconfig *conf;
	const char *client = "unknown";
	char *uaddr;
	char buf[BUFSIZ];

	/*
	 * Transform the transport address into something printable.
	 */
	if ((conf = rpcbind_get_conf(transp->xp_netid)) == 0) {
		syslog(LOG_WARNING,
		    "unknown transport (rpcbind_get_conf failed)");
	} else if (strcmp(conf->nc_protofmly, "inet") == 0 ||
	    strcmp(conf->nc_protofmly, "inet6") == 0) {
		client = sgen_toa(svc_getgencaller(transp));
	} else if ((uaddr = taddr2uaddr(conf, &(transp->xp_rtaddr))) == NULL) {
		syslog(LOG_WARNING, "unknown address (taddr2uaddr failed)");
	} else {
		(void) snprintf(buf, sizeof (buf), "%s(%s)",
		    conf->nc_protofmly, uaddr);
		free(uaddr);
		client = buf;
	}
	qsyslog(verdict ? allow_severity : deny_severity,
	    "%sconnect from %s to %s(%s)", verdict ? "" : "refused ",
	    client, find_procname(proc, pm), find_progname(prog));
}

/*
 * rpcb_check; the rpcbind/portmap access check function.
 */
boolean_t
rpcb_check(SVCXPRT *transp, rpcproc_t procnum, boolean_t ispmap)
{
	struct netconfig *conf;
	boolean_t res = B_TRUE;

	if ((conf = rpcbind_get_conf(transp->xp_netid)) == 0) {
		syslog(LOG_ERR,
		    "rpcbind_get_conf failed: no client address checks");
		return (B_TRUE);
	}

	/*
	 * Require IPv4 for pmap calls; they're not defined for anything else.
	 */
	if (ispmap && strcmp(conf->nc_protofmly, "inet") != 0) {
		res = B_FALSE;
	} else if (strcmp(conf->nc_protofmly, "inet") == 0 ||
	    strcmp(conf->nc_protofmly, "inet6") == 0) {
		const char *addr_string = sgen_toa(svc_getgencaller(transp));

		if (!localxprt(transp, ispmap) &&
		    (local_only ||
		    hosts_ctl("rpcbind", addr_string, addr_string, "") == 0)) {
			res = B_FALSE;
		}
	}
out:
	if (!res)
		svcerr_auth(transp, AUTH_FAILED);

	if (verboselog || !res)
		rpcb_log(res, transp, procnum, 0, ispmap);

	return (res);
}