/*      $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);
}