/*	$NetBSD: rusers.c,v 1.26 2019/02/03 10:48:47 mrg Exp $	*/

/*-
 *  Copyright (c) 1993 John Brezak
 *  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. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `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 AUTHOR 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: rusers.c,v 1.26 2019/02/03 10:48:47 mrg Exp $");
#endif /* not lint */

#include <sys/types.h>
#include <sys/socket.h>

#include <rpc/rpc.h>
#include <arpa/inet.h>

#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>

/*
 * For now we only try version 2 of the protocol. The current
 * version is 3 (rusers.h), but only Solaris and NetBSD seem
 * to support it currently.
 */
#include <rpcsvc/rnusers.h>	/* Old version */


#define MAX_INT 0x7fffffff

static struct timeval timeout = { 25, 0 };
static int longopt;
static int allopt;

static void	allhosts(void);
static void	onehost(char *);
static void	remember_host(struct sockaddr *);
static int	rusers_reply(char *, struct netbuf *, struct netconfig *);
static int	search_host(struct sockaddr *);
__dead static void	usage(void);

static struct host_list {
	struct host_list *next;
	int family;
	union {
		struct in6_addr _addr6;
		struct in_addr _addr4;
	} addr;
} *hosts;

#define addr6 addr._addr6
#define addr4 addr._addr4

static int
search_host(struct sockaddr *sa)
{
	struct host_list *hp;
	
	if (!hosts)
		return(0);

	for (hp = hosts; hp != NULL; hp = hp->next) {
		switch (hp->family) {
		case AF_INET6:
			if (!memcmp(&hp->addr6,
			    &((struct sockaddr_in6 *)sa)->sin6_addr,
			    sizeof (struct in6_addr)))
				return 1;
			break;
		case AF_INET:
			if (!memcmp(&hp->addr4,
			    &((struct sockaddr_in *)sa)->sin_addr,
			    sizeof (struct in_addr)))
				return 1;
			break;
		default:
			break;
		}
	}
	return(0);
}

static void
remember_host(struct sockaddr *sa)
{
	struct host_list *hp;

	if (!(hp = (struct host_list *)malloc(sizeof(struct host_list)))) {
		err(1, "malloc");
		/* NOTREACHED */
	}
	hp->family = sa->sa_family;
	hp->next = hosts;
	switch (sa->sa_family) {
	case AF_INET6:
		memcpy(&hp->addr6, &((struct sockaddr_in6 *)sa)->sin6_addr,
		    sizeof (struct in6_addr));
		break;
	case AF_INET:
		memcpy(&hp->addr4, &((struct sockaddr_in *)sa)->sin_addr,
		    sizeof (struct in_addr));
		break;
	default:
		err(1, "unknown address family");
		/* NOTREACHED */
	}
	hosts = hp;
}

static int
rusers_reply(char *replyp, struct netbuf *raddrp, struct netconfig *nconf)
{
	char host[NI_MAXHOST];
	int x;
	struct utmpidlearr *up = (struct utmpidlearr *)replyp;
	struct sockaddr *sa = raddrp->buf;
	
	if (search_host(sa))
		return(0);

	if (!allopt && !up->uia_cnt)
		return(0);

	if (getnameinfo(sa, sa->sa_len, host, sizeof host, NULL, 0, 0))
		return 0;

#define HOSTWID (int)sizeof(up->uia_arr[0]->ui_utmp.ut_host)
#define LINEWID (int)sizeof(up->uia_arr[0]->ui_utmp.ut_line)
#define NAMEWID (int)sizeof(up->uia_arr[0]->ui_utmp.ut_name)

	if (!longopt)
		printf("%-*.*s ", HOSTWID, HOSTWID, host);
	
	for (x = 0; x < up->uia_cnt; x++) {
		unsigned int minutes;
		char	date[26], idle[11];
		char	remote[HOSTWID + 3];		/* "(" host ")" \0 */
		char	local[HOSTWID + LINEWID + 2];	/* host ":" line \0 */
		time_t	uttime;

		if (!longopt) {
			printf("%.*s ", NAMEWID,
			    up->uia_arr[x]->ui_utmp.ut_name);
			continue;
		}

		snprintf(local, sizeof(local), "%.*s:%s",
		    HOSTWID, host, 
		    up->uia_arr[x]->ui_utmp.ut_line);

		uttime = up->uia_arr[x]->ui_utmp.ut_time;
		snprintf(date, sizeof(date), "%s",
		    &(ctime(&uttime))[4]);

		minutes = up->uia_arr[x]->ui_idle;
		if (minutes == MAX_INT)
			strcpy(idle, "??");
		else if (minutes == 0)
			strcpy(idle, "");
		else {
			unsigned int days, hours;

			days = minutes / (24 * 60);
			minutes %= (24 * 60);
			hours = minutes / 60;
			minutes %= 60;

			if (days > 0)
				snprintf(idle, sizeof(idle), "%d d ", days);
			else if (hours > 0)
				snprintf(idle, sizeof(idle), "%2d:%02d",
				    hours, minutes);
			else
				snprintf(idle, sizeof(idle), ":%02d", minutes);
		}

		if (up->uia_arr[x]->ui_utmp.ut_host[0] != '\0')
			snprintf(remote, sizeof(remote), "(%.*s)",
			    HOSTWID, up->uia_arr[x]->ui_utmp.ut_host);
		else
			remote[0] = '\0';

		printf("%-*.*s  %-*.*s  %-12.12s  %8.8s  %s\n",
		    NAMEWID, NAMEWID, up->uia_arr[x]->ui_utmp.ut_name,
		    HOSTWID+LINEWID+1, HOSTWID+LINEWID+1, local,
		    date, idle, remote);
	}
	if (!longopt)
		putchar('\n');
	
	remember_host(sa);
	return(0);
}

static void
onehost(char *host)
{
	struct utmpidlearr up;
	CLIENT *rusers_clnt;
	enum clnt_stat clnt_stat;
	struct netbuf nb;
	struct addrinfo *ai;
	int ecode;

	rusers_clnt = clnt_create(host, RUSERSPROG, RUSERSVERS_IDLE, "udp");
	if (rusers_clnt == NULL) {
		clnt_pcreateerror(getprogname());
		exit(1);
	}

	ecode = getaddrinfo(host, NULL, NULL, &ai);
	if (ecode != 0)
		err(1, "%s", gai_strerror(ecode));

	memset((char *)&up, 0, sizeof(up));
	clnt_stat = clnt_call(rusers_clnt, RUSERSPROC_NAMES, xdr_void, NULL,
	    xdr_utmpidlearr, &up, timeout);
	if (clnt_stat != RPC_SUCCESS)
		errx(1, "%s", clnt_sperrno(clnt_stat));
	nb.buf = ai->ai_addr;
	nb.len = nb.maxlen = ai->ai_addrlen;
	rusers_reply((char *)&up, &nb, NULL);
	freeaddrinfo(ai);
}

static void
allhosts(void)
{
	struct utmpidlearr up;
	enum clnt_stat clnt_stat;

	memset((char *)&up, 0, sizeof(up));
	clnt_stat = rpc_broadcast(RUSERSPROG, RUSERSVERS_IDLE,
	    RUSERSPROC_NAMES, (xdrproc_t)xdr_void, NULL,
	    (xdrproc_t)xdr_utmpidlearr, (char *)&up,
	    (resultproc_t)rusers_reply, "udp");
	if (clnt_stat != RPC_SUCCESS && clnt_stat != RPC_TIMEDOUT)
		errx(1, "%s", clnt_sperrno(clnt_stat));
}

static void
usage(void)
{
	fprintf(stderr, "usage: %s [-la] [hosts ...]\n", getprogname());
	exit(1);
}

int
main(int argc, char *argv[])
{
	int ch;
	
	while ((ch = getopt(argc, argv, "al")) != -1)
		switch (ch) {
		case 'a':
			allopt++;
			break;
		case 'l':
			longopt++;
			break;
		default:
			usage();
			/*NOTREACHED*/
		}

	setlinebuf(stdout);
	if (argc == optind)
		allhosts();
	else {
		for (; optind < argc; optind++)
			(void) onehost(argv[optind]);
	}
	exit(0);
}