/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#include <sys/param.h>
#include <stdio.h>
#include <dirent.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <fcntl.h>
#include <protocols/rwhod.h>

static DIR      *dirp;

#define HOSTLIM 100
static int      hostslim = HOSTLIM;
static int      nhosts;
struct  hs {
        struct  whod *hs_wd;
        int     hs_nusers;
};
static int      hscmp(), ucmp(), lcmp(), tcmp();

#define RWHODIR         "/var/spool/rwho"

static char     *interval();
static time_t   now;
static int      aflg;
static int      rflg = 1;

#define down(h)         (now - (h)->hs_wd->wd_recvtime > 11 * 60)

/* ARGSUSED */
int
main(int argc, char **argv)
{
        struct dirent *dp;
        int f, i;
        struct whod *buf;
        int cc;
        char *name;
        struct hs *hs;
        struct hs *hsp;
        struct whod *wd;
        struct whoent *we;
        int maxloadav = 0;
        int (*cmp)() = hscmp;
        ptrdiff_t hoff;

        name = *argv;
        while (*++argv)
                while (**argv)
                        switch (*(*argv)++) {
                        case 'a':
                                aflg++;
                                break;
                        case 'l':
                                cmp = lcmp;
                                break;
                        case 'u':
                                cmp = ucmp;
                                break;
                        case 't':
                                cmp = tcmp;
                                break;
                        case 'r':
                                rflg = -rflg;
                                break;
                        case '-':
                                break;
                        default:
                                (void) fprintf(stderr, "Usage: %s [ -alrtu ]"
                                    " (choose at most one of l, t, or u)\n",
                                    name);
                                exit(1);
                        }

        if ((hs = malloc(hostslim * sizeof (struct hs))) == NULL) {
                (void) fprintf(stderr, "initial hs malloc failed\n");
                exit(1);
        }
        hsp = hs;
        if ((buf = malloc(sizeof (struct whod))) == NULL) {
                (void) fprintf(stderr, "initial buf malloc failed\n");
                exit(1);
        }

        if (chdir(RWHODIR) < 0) {
                perror(RWHODIR);
                exit(1);
        }
        dirp = opendir(".");
        if (dirp == NULL) {
                perror(RWHODIR);
                exit(1);
        }
        while (dp = readdir(dirp)) {
                if (dp->d_ino == 0)
                        continue;
                if (strncmp(dp->d_name, "whod.", 5))
                        continue;
                if (nhosts == hostslim) {
                        /*
                         * We trust that the file system's limit on the number
                         * of files in a directory will kick in long before
                         * integer overflow.
                         */
                        hostslim = hostslim << 1;

                        /*
                         * hsp points into an area about to be moved,
                         * so we first remember its offset into hs[],
                         * then restore it after realloc() has moved
                         * the data.
                         */
                        hoff = hsp - hs;
                        hs = realloc(hs, hostslim * sizeof (struct hs));
                        if (hs == NULL) {
                                (void) fprintf(stderr, "too many hosts\n");
                                exit(1);
                        }
                        hsp = hs + hoff;
                }
                f = open(dp->d_name, 0);
                if (f > 0) {
                        int whdrsize = sizeof (*buf) - sizeof (buf->wd_we);

                        cc = read(f, buf, sizeof (struct whod));
                        if (cc >= whdrsize) {
                                hsp->hs_wd = malloc(whdrsize);
                                wd = buf;
                                bcopy((char *)buf, (char *)hsp->hs_wd,
                                    whdrsize);
                                hsp->hs_nusers = 0;
                                for (i = 0; i < 2; i++)
                                        if (wd->wd_loadav[i] > maxloadav)
                                                maxloadav = wd->wd_loadav[i];
                                /* LINTED:  pointer alignment */
                                we = (struct whoent *)(((char *)buf)+cc);
                                while (--we >= wd->wd_we)
                                        if (aflg || we->we_idle < 3600)
                                                hsp->hs_nusers++;
                                nhosts++; hsp++;
                        }
                }
                (void) close(f);
        }
        (void) time(&now);
        qsort((char *)hs, nhosts, sizeof (hs[0]), cmp);
        if (nhosts == 0) {
                (void) printf("no hosts!?!\n");
                exit(1);
        }
        for (i = 0; i < nhosts; i++) {
                hsp = &hs[i];
                if (down(hsp)) {
                        (void) printf("%-12s%s\n", hsp->hs_wd->wd_hostname,
                            interval((int)(now - hsp->hs_wd->wd_recvtime),
                                "down"));
                        continue;
                }
                (void) printf("%-12s%s,  %4d user%s  load %*.2f,"
                    " %*.2f, %*.2f\n",
                    hsp->hs_wd->wd_hostname,
                    interval(hsp->hs_wd->wd_sendtime -
                        hsp->hs_wd->wd_boottime, "  up"),
                    hsp->hs_nusers,
                    hsp->hs_nusers == 1 ? ", " : "s,",
                    maxloadav >= 1000 ? 5 : 4,
                        hsp->hs_wd->wd_loadav[0] / 100.0,
                    maxloadav >= 1000 ? 5 : 4,
                        hsp->hs_wd->wd_loadav[1] / 100.0,
                    maxloadav >= 1000 ? 5 : 4,
                        hsp->hs_wd->wd_loadav[2] / 100.0);
                free(hsp->hs_wd);
        }

        return (0);
}

static char *
interval(int time, char *updown)
{
        static char resbuf[32];
        int days, hours, minutes;

        if (time < 0 || time > 10*365*24*60*60) {
                (void) sprintf(resbuf, "   %s ??:??", updown);
                return (resbuf);
        }
        minutes = (time + 59) / 60;             /* round to minutes */
        hours = minutes / 60; minutes %= 60;
        days = hours / 24; hours %= 24;
        if (days)
                (void) sprintf(resbuf, "%s %2d+%02d:%02d",
                    updown, days, hours, minutes);
        else
                (void) sprintf(resbuf, "%s    %2d:%02d",
                    updown, hours, minutes);
        return (resbuf);
}

static int
hscmp(struct hs *h1, struct hs *h2)
{

        return (rflg * strcmp(h1->hs_wd->wd_hostname, h2->hs_wd->wd_hostname));
}

/*
 * Compare according to load average.
 */
static int
lcmp(struct hs *h1, struct hs *h2)
{

        if (down(h1))
                if (down(h2))
                        return (tcmp(h1, h2));
                else
                        return (rflg);
        else if (down(h2))
                return (-rflg);
        else
                return (rflg *
                        (h2->hs_wd->wd_loadav[0] - h1->hs_wd->wd_loadav[0]));
}

/*
 * Compare according to number of users.
 */
static int
ucmp(struct hs *h1, struct hs *h2)
{

        if (down(h1))
                if (down(h2))
                        return (tcmp(h1, h2));
                else
                        return (rflg);
        else if (down(h2))
                return (-rflg);
        else
                return (rflg * (h2->hs_nusers - h1->hs_nusers));
}

/*
 * Compare according to uptime.
 */
static int
tcmp(struct hs *h1, struct hs *h2)
{

        return (rflg * (
                (down(h2) ? h2->hs_wd->wd_recvtime - now :
                    h2->hs_wd->wd_sendtime - h2->hs_wd->wd_boottime)
                -
                (down(h1) ? h1->hs_wd->wd_recvtime - now :
                    h1->hs_wd->wd_sendtime - h1->hs_wd->wd_boottime)));
}