/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993 The Regents of the University of California.
 * Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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/capsicum.h>
#include <sys/param.h>
#include <sys/file.h>

#include <protocols/rwhod.h>

#include <capsicum_helpers.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <langinfo.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <timeconv.h>
#include <unistd.h>

#define NUSERS          1000
#define WHDRSIZE        (ssize_t)(sizeof(wd) - sizeof(wd.wd_we))
/*
 * this macro should be shared with ruptime.
 */
#define down(w,now)     ((now) - (w)->wd_recvtime > 11 * 60)

static DIR      *dirp;
static struct   whod wd;
static int      nusers;
static struct   myutmp {
        char    myhost[sizeof(wd.wd_hostname)];
        int     myidle;
        struct  outmp myutmp;
} myutmp[NUSERS];

static time_t   now;
static int      aflg;

static void usage(void) __dead2;
static int utmpcmp(const void *, const void *);

int
main(int argc, char *argv[])
{
        int ch;
        struct dirent *dp;
        int width;
        ssize_t cc;
        struct whod *w;
        struct whoent *we;
        struct myutmp *mp;
        cap_rights_t rights;
        int f, n, i;
        int d_first;
        int dfd;
        time_t ct;

        w = &wd;
        (void) setlocale(LC_TIME, "");
        d_first = (*nl_langinfo(D_MD_ORDER) == 'd');

        while ((ch = getopt(argc, argv, "a")) != -1) {
                switch ((char)ch) {
                case 'a':
                        aflg = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 0)
                usage();

        if (chdir(_PATH_RWHODIR) < 0)
                err(1, "chdir(%s)", _PATH_RWHODIR);
        if ((dirp = opendir(".")) == NULL)
                err(1, "opendir(%s)", _PATH_RWHODIR);
        dfd = dirfd(dirp);
        mp = myutmp;
        cap_rights_init(&rights, CAP_READ, CAP_LOOKUP);
        if (caph_rights_limit(dfd, &rights) < 0)
                err(1, "cap_rights_limit failed: %s", _PATH_RWHODIR);
        /*
         * Cache files required for time(3) and localtime(3) before entering
         * capability mode.
         */
        (void) time(&ct);
        (void) localtime(&ct);
        if (caph_enter() < 0)
                err(1, "cap_enter");
        (void) time(&now);
        cap_rights_init(&rights, CAP_READ);
        while ((dp = readdir(dirp)) != NULL) {
                if (dp->d_ino == 0 || strncmp(dp->d_name, "whod.", 5) != 0)
                        continue;
                f = openat(dfd, dp->d_name, O_RDONLY);
                if (f < 0)
                        continue;
                if (caph_rights_limit(f, &rights) < 0)
                        err(1, "cap_rights_limit failed: %s", dp->d_name);
                cc = read(f, (char *)&wd, sizeof(struct whod));
                if (cc < WHDRSIZE) {
                        (void) close(f);
                        continue;
                }
                if (down(w, now) != 0) {
                        (void) close(f);
                        continue;
                }
                cc -= WHDRSIZE;
                we = w->wd_we;
                for (n = cc / sizeof(struct whoent); n > 0; n--) {
                        if (aflg == 0 && we->we_idle >= 60 * 60) {
                                we++;
                                continue;
                        }
                        if (nusers >= NUSERS)
                                errx(1, "too many users");
                        mp->myutmp = we->we_utmp;
                        mp->myidle = we->we_idle;
                        (void) strcpy(mp->myhost, w->wd_hostname);
                        nusers++;
                        we++;
                        mp++;
                }
                (void) close(f);
        }
        qsort((char *)myutmp, nusers, sizeof(struct myutmp), utmpcmp);
        mp = myutmp;
        width = 0;
        for (i = 0; i < nusers; i++) {
                /* append one for the blank and use 8 for the out_line */
                int j;

                j = strlen(mp->myhost) + 1 + sizeof(mp->myutmp.out_line);
                if (j > width)
                        width = j;
                mp++;
        }
        mp = myutmp;
        for (i = 0; i < nusers; i++) {
                char buf[BUFSIZ], cbuf[80];
                time_t t;

                t = _int_to_time(mp->myutmp.out_time);
                strftime(cbuf, sizeof(cbuf), d_first ? "%e %b %R" : "%b %e %R",
                    localtime(&t));
                (void) sprintf(buf, "%s:%-.*s", mp->myhost,
                    (int)sizeof(mp->myutmp.out_line), mp->myutmp.out_line);
                printf("%-*.*s %-*s %s",
                    (int)sizeof(mp->myutmp.out_name),
                    (int)sizeof(mp->myutmp.out_name),
                    mp->myutmp.out_name, width, buf, cbuf);
                mp->myidle /= 60;
                if (mp->myidle != 0) {
                        if (aflg != 0) {
                                if (mp->myidle >= 100 * 60)
                                        mp->myidle = 100 * 60 - 1;
                                if (mp->myidle >= 60)
                                        printf(" %2d", mp->myidle / 60);
                                else
                                        printf("   ");
                        } else {
                                printf(" ");
                        }
                        printf(":%02d", mp->myidle % 60);
                }
                printf("\n");
                mp++;
        }
        exit(0);
}


static void
usage(void)
{

        fprintf(stderr, "usage: rwho [-a]\n");
        exit(1);
}

#define MYUTMP(a) ((const struct myutmp *)(a))

static int
utmpcmp(const void *u1, const void *u2)
{
        int rc;

        rc = strncmp(MYUTMP(u1)->myutmp.out_name, MYUTMP(u2)->myutmp.out_name,
            sizeof(MYUTMP(u2)->myutmp.out_name));
        if (rc != 0)
                return (rc);
        rc = strcmp(MYUTMP(u1)->myhost, MYUTMP(u2)->myhost);
        if (rc != 0)
                return (rc);
        return (strncmp(MYUTMP(u1)->myutmp.out_line,
            MYUTMP(u2)->myutmp.out_line, sizeof(MYUTMP(u2)->myutmp.out_line)));
}