/*      $NetBSD: w.c,v 1.93 2022/05/26 06:48:36 wiz Exp $       */

/*-
 * Copyright (c) 1980, 1991, 1993, 1994
 *      The Regents of the University of California.  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/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1991, 1993, 1994\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)w.c 8.6 (Berkeley) 6/30/94";
#else
__RCSID("$NetBSD: w.c,v 1.93 2022/05/26 06:48:36 wiz Exp $");
#endif
#endif /* not lint */

/*
 * w - print system status (who and what)
 *
 * This program is similar to the systat command on Tenex/Tops 10/20
 *
 */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <netdb.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#ifdef SUPPORT_UTMP
#include <utmp.h>
#endif
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif
#include <vis.h>

#include "extern.h"

struct timespec boottime;
struct winsize  ws;
kvm_t          *kd;
time_t          now;            /* the current time of day */
int             ttywidth;       /* width of tty */
int             argwidth;       /* width of tty left to print process args */
int             header = 1;     /* true if -h flag: don't print heading */
int             nflag;          /* true if -n flag: don't convert addrs */
int             wflag;          /* true if -w flag: wide printout */
int             sortidle;       /* sort by idle time */
int             alphasort;      /* sort by tty alphabeta, not numeric */
char           *sel_user;       /* login of particular user selected */
char            domain[MAXHOSTNAMELEN + 1];
int maxname = 8, maxline = 3, maxhost = 16;

/*
 * One of these per active utmp entry.
 */
struct  entry {
        struct  entry *next;
        char name[UTX_USERSIZE + 1];
        char line[UTX_LINESIZE + 1];
        char host[UTX_HOSTSIZE + 1];
        char type[2];
        struct timeval tv;
        dev_t   tdev;                   /* dev_t of terminal */
        time_t  idle;                   /* idle time of terminal in seconds */
        struct  kinfo_proc2 *tp;        /* `most interesting' tty proc */
        struct  kinfo_proc2 *pp;        /* pid proc */
        pid_t   pid;                    /* pid or ~0 if not known */
} *ehead = NULL, **nextp = &ehead;

static void     pr_args(struct kinfo_proc2 *);
static void     pr_header(time_t *, int);
static int      proc_compare_wrapper(const struct kinfo_proc2 *,
    const struct kinfo_proc2 *);
#if defined(SUPPORT_UTMP) || defined(SUPPORT_UTMPX)
static int      ttystat(const char *, struct stat *);
static void     process(struct entry *);
#endif
static void     fixhost(struct entry *ep);
__dead static void      usage(int);

int
main(int argc, char **argv)
{
        struct kinfo_proc2 *kp;
        struct entry *ep;
        int ch, i, nentries, nusers, wcmd, curtain, use_sysctl;
        char *memf, *nlistf, *usrnp;
        const char *options;
        time_t then;
        size_t len;
#ifdef SUPPORT_UTMP
        struct utmp *ut;
#endif
#ifdef SUPPORT_UTMPX
        struct utmpx *utx;
#endif
        const char *progname;
        char errbuf[_POSIX2_LINE_MAX];

        setprogname(argv[0]);

        /* Are we w(1) or uptime(1)? */
        progname = getprogname();
        if (*progname == '-')
                progname++;
        if (*progname == 'u') {
                wcmd = 0;
                options = "";
        } else {
                wcmd = 1;
                options = "AhiM:N:nw";
        }

        memf = nlistf = NULL;
        while ((ch = getopt(argc, argv, options)) != -1)
                switch (ch) {
                case 'A':
                        alphasort = 1;
                        break;
                case 'h':
                        header = 0;
                        break;
                case 'i':
                        sortidle = 1;
                        break;
                case 'M':
                        header = 0;
                        memf = optarg;
                        break;
                case 'N':
                        nlistf = optarg;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 'w':
                        wflag = 1;
                        break;
                case '?':
                default:
                        usage(wcmd);
                }
        argc -= optind;
        argv += optind;

        use_sysctl = (memf == NULL && nlistf == NULL);

        if ((kd = kvm_openfiles(nlistf, memf, NULL,
            memf == NULL ? KVM_NO_FILES : O_RDONLY, errbuf)) == NULL)
                errx(1, "%s", errbuf);

        (void)time(&now);

        if (use_sysctl) {
                len = sizeof(curtain);
                if (sysctlbyname("security.curtain", &curtain, &len, 
                    NULL, 0) == -1)
                        curtain = 0;
        }

        if (!nflag) {
                int     rv;
                char    *p;

                rv = gethostname(domain, sizeof(domain));
                domain[sizeof(domain) - 1] = '\0';
                if (rv < 0 || (p = strchr(domain, '.')) == 0)
                        domain[0] = '\0';
                else
                        memmove(domain, p, strlen(p) + 1);
        }

#ifdef SUPPORT_UTMPX
        setutxent();
#endif
#ifdef SUPPORT_UTMP
        setutent();
#endif

        if (*argv)
                sel_user = *argv;

        nusers = 0;
#ifdef SUPPORT_UTMPX
        while ((utx = getutxent()) != NULL) {
                if (utx->ut_type != USER_PROCESS)
                        continue;
                ++nusers;

#ifndef SUPPORT_UTMP
                if (wcmd == 0)
                        continue;
#endif  /* !SUPPORT_UTMP */

                if (sel_user &&
                    strncmp(utx->ut_name, sel_user, sizeof(utx->ut_name)) != 0)
                        continue;
                if ((ep = calloc(1, sizeof(struct entry))) == NULL)
                        err(1, NULL);
                (void)memcpy(ep->line, utx->ut_line, sizeof(utx->ut_line));
                ep->line[sizeof(utx->ut_line)] = '\0';
                *nextp = ep;
                nextp = &(ep->next);

                if (wcmd == 0)
                        continue;

                (void)memcpy(ep->name, utx->ut_name, sizeof(utx->ut_name));
                ep->name[sizeof(utx->ut_name)] = '\0';
                if (!nflag || getnameinfo((struct sockaddr *)&utx->ut_ss,
                    utx->ut_ss.ss_len, ep->host, sizeof(ep->host), NULL, 0,
                    NI_NUMERICHOST) != 0) {
                        (void)memcpy(ep->host, utx->ut_host,
                            sizeof(utx->ut_host));
                        ep->host[sizeof(utx->ut_host)] = '\0';
                }
                fixhost(ep);
                ep->type[0] = 'x';
                ep->tv = utx->ut_tv;
                ep->pid = utx->ut_pid;
                process(ep);
        }
#endif

#ifdef SUPPORT_UTMP
        while ((ut = getutent()) != NULL) {
                if (ut->ut_name[0] == '\0')
                        continue;

                if (sel_user &&
                    strncmp(ut->ut_name, sel_user, sizeof(ut->ut_name)) != 0)
                        continue;

                /* Don't process entries that we have utmpx for */
                for (ep = ehead; ep != NULL; ep = ep->next) {
                        if (strncmp(ep->line, ut->ut_line,
                            sizeof(ut->ut_line)) == 0)
                                break;
                }
                if (ep != NULL)
                        continue;

                ++nusers;

                if (wcmd == 0)
                        continue;

                if ((ep = calloc(1, sizeof(struct entry))) == NULL)
                        err(1, NULL);
                (void)memcpy(ep->name, ut->ut_name, sizeof(ut->ut_name));
                (void)memcpy(ep->line, ut->ut_line, sizeof(ut->ut_line));
                (void)memcpy(ep->host, ut->ut_host, sizeof(ut->ut_host));
                ep->name[sizeof(ut->ut_name)] = '\0';
                ep->line[sizeof(ut->ut_line)] = '\0';
                ep->host[sizeof(ut->ut_host)] = '\0';
                fixhost(ep);
                ep->tv.tv_sec = ut->ut_time;
                *nextp = ep;
                nextp = &(ep->next);
                process(ep);
        }
#endif

#ifdef SUPPORT_UTMPX
        endutxent();
#endif
#ifdef SUPPORT_UTMP
        endutent();
#endif

        if (header || wcmd == 0) {
                pr_header(&now, nusers);
                if (wcmd == 0)
                        exit (0);
        }

        if ((kp = kvm_getproc2(kd, KERN_PROC_ALL, 0,
            sizeof(struct kinfo_proc2), &nentries)) == NULL)
                errx(1, "%s", kvm_geterr(kd));

        /* Include trailing space because TTY header starts one column early. */
        for (i = 0; i < nentries; i++, kp++) {

                for (ep = ehead; ep != NULL; ep = ep->next) {
                        if (ep->tdev != 0 && ep->tdev == kp->p_tdev &&
                            kp->p__pgid == kp->p_tpgid) {
                                /*
                                 * Proc is in foreground of this
                                 * terminal
                                 */
                                if (proc_compare_wrapper(ep->tp, kp))
                                        ep->tp = kp;
                                break;
                        } 
                        if (ep->pid != 0 && ep->pid == kp->p_pid) {
                                ep->pp = kp;
                                break;
                        }
                }
        }

        if ((ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 &&
            ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) == -1 &&
            ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == -1) || ws.ws_col == 0)
                ttywidth = 79;
        else
                ttywidth = ws.ws_col - 1;

        if (!wflag && maxhost > (ttywidth / 3))
                maxhost = ttywidth / 3;

        argwidth = printf("%-*s TTY     %-*s %*s  IDLE WHAT\n",
            maxname, "USER", maxhost, "FROM",
            7 /* "dddhhXm" */, "LOGIN@");
        argwidth -= sizeof("WHAT\n") - 1 /* NUL */;
        argwidth = ttywidth - argwidth;
        if (argwidth < 4)
                argwidth = 8;
        if (wflag)
                argwidth = -1;

        /* sort by idle time */
        if (sortidle && ehead != NULL) {
                struct entry *from = ehead, *save;

                ehead = NULL;
                while (from != NULL) {
                        for (nextp = &ehead;
                            (*nextp) && from->idle >= (*nextp)->idle;
                            nextp = &(*nextp)->next)
                                continue;
                        save = from;
                        from = from->next;
                        save->next = *nextp;
                        *nextp = save;
                }
        }
#if defined(SUPPORT_UTMP) || defined(SUPPORT_UTMPX)
        else if (ehead != NULL && alphasort) {
                struct entry *from = ehead, *save;

                ehead = NULL;
                while (from != NULL) {
                        for (nextp = &ehead;
                            (*nextp) && strcmp(from->line, (*nextp)->line) > 0;
                            nextp = &(*nextp)->next)
                                continue;
                        save = from;
                        from = from->next;
                        save->next = *nextp;
                        *nextp = save;
                }
        }
#endif

        for (ep = ehead; ep != NULL; ep = ep->next) {
                if (ep->tp != NULL)
                        kp = ep->tp;
                else if (ep->pp != NULL)
                        kp = ep->pp;
                else if (ep->pid != 0) {
                        if (curtain)
                                kp = NULL;
                        else {
                                warnx("Stale utmp%s entry: %s %s %s",
                                    ep->type, ep->name, ep->line, ep->host);
                                continue;
                        }
                }
                usrnp = (kp == NULL) ? ep->name : kp->p_login;
                (void)printf("%-*s %-7.7s %-*.*s ",
                    maxname, usrnp, ep->line,
                    maxhost, maxhost, ep->host);
                then = (time_t)ep->tv.tv_sec;
                pr_attime(&then, &now);
                pr_idle(ep->idle);
                pr_args(kp);
                (void)printf("\n");
        }
        exit(0);
}

static void
pr_args(struct kinfo_proc2 *kp)
{
        char **argv;
        int left;

        if (kp == 0)
                goto nothing;
        left = argwidth;
        argv = kvm_getargv2(kd, kp, (argwidth < 0) ? 0 : argwidth);
        if (argv == 0) {
                fmt_putc('(', &left);
                fmt_puts((char *)kp->p_comm, &left);
                fmt_putc(')', &left);
                return;
        }
        while (*argv) {
                fmt_puts(*argv, &left);
                argv++;
                fmt_putc(' ', &left);
        }
        return;
nothing:
        putchar('-');
}

static void
pr_header(time_t *nowp, int nusers)
{
        double avenrun[3];
        time_t uptime;
        int days, hrs, mins;
        int mib[2];
        size_t size, i;
        char buf[256];

        /*
         * Print time of day.
         */
        (void)strftime(buf, sizeof(buf), "%l:%M%p", localtime(nowp));
        buf[sizeof(buf) - 1] = '\0';
        (void)printf("%s ", buf);

        /*
         * Print how long system has been up.
         * (Found by looking getting "boottime" from the kernel)
         */
        mib[0] = CTL_KERN;
        mib[1] = KERN_BOOTTIME;
        size = sizeof(boottime);
        if (sysctl(mib, 2, &boottime, &size, NULL, 0) != -1 &&
            boottime.tv_sec != 0) {
                uptime = now - boottime.tv_sec;
                uptime += 30;
                if (uptime > SECSPERMIN) {
                        days = uptime / SECSPERDAY;
                        uptime %= SECSPERDAY;
                        hrs = uptime / SECSPERHOUR;
                        uptime %= SECSPERHOUR;
                        mins = uptime / SECSPERMIN;
                        (void)printf(" up");
                        if (days > 0)
                                (void)printf(" %d day%s,", days,
                                    days > 1 ? "s" : "");
                        if (hrs > 0 && mins > 0)
                                (void)printf(" %2d:%02d,", hrs, mins);
                        else {
                                if (hrs > 0)
                                        (void)printf(" %d hr%s,",
                                            hrs, hrs > 1 ? "s" : "");
                                if (mins > 0)
                                        (void)printf(" %d min%s,",
                                            mins, mins > 1 ? "s" : "");
                        }
                }
        }

        /* Print number of users logged in to system */
        (void)printf(" %d user%s", nusers, nusers != 1 ? "s" : "");

        /*
         * Print 1, 5, and 15 minute load averages.
         */
        if (getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0])) == -1)
                (void)printf(", no load average information available\n");
        else {
                (void)printf(", load averages:");
                for (i = 0; i < (sizeof(avenrun) / sizeof(avenrun[0])); i++) {
                        if (i > 0)
                                (void)printf(",");
                        (void)printf(" %.2f", avenrun[i]);
                }
                (void)printf("\n");
        }
}

#if defined(SUPPORT_UTMP) || defined(SUPPORT_UTMPX)
static int
ttystat(const char *line, struct stat *st)
{
        char ttybuf[MAXPATHLEN];

        (void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
        return stat(ttybuf, st);
}

static void
process(struct entry *ep)
{
        struct stat st;
        time_t touched;
        int max;

        if ((max = strlen(ep->name)) > maxname)
                maxname = max;
        if ((max = strlen(ep->line)) > maxline)
                maxline = max;
        if ((max = strlen(ep->host)) > maxhost)
                maxhost = max;

        ep->tdev = 0;
        ep->idle = (time_t)-1;

#ifdef SUPPORT_UTMP
        /*
         * Hack to recognize and correctly parse
         * ut entry made by ftpd. The "tty" used
         * by ftpd is not a real tty, just identifier in
         * form ftpPID. Pid parsed from the "tty name"
         * is used later to match corresponding process.
         * NB: This is only used for utmp entries. For utmpx,
         * we already have the pid.
         */
        if (ep->pid == 0 && strncmp(ep->line, "ftp", 3) == 0) {
                ep->pid = strtol(ep->line + 3, NULL, 10);
                return;
        }
#endif
        if (ttystat(ep->line, &st) == -1)
                return;

        ep->tdev = st.st_rdev;
        /*
         * If this is the console device, attempt to ascertain
         * the true console device dev_t.
         */
        if (ep->tdev == 0) {
                int mib[2];
                size_t size;

                mib[0] = CTL_KERN;
                mib[1] = KERN_CONSDEV;
                size = sizeof(dev_t);
                (void) sysctl(mib, 2, &ep->tdev, &size, NULL, 0);
        }

        touched = st.st_atime;
        if (touched < ep->tv.tv_sec) {
                /* tty untouched since before login */
                touched = ep->tv.tv_sec;
        }
        if ((ep->idle = now - touched) < 0)
                ep->idle = 0;
}
#endif

static int
proc_compare_wrapper(const struct kinfo_proc2 *p1,
    const struct kinfo_proc2 *p2)
{
        struct kinfo_lwp *l1, *l2;
        int cnt;

        if (p1 == NULL)
                return 1;

        l1 = kvm_getlwps(kd, p1->p_pid, 0, sizeof(*l1), &cnt);
        if (l1 == NULL || cnt == 0)
                return 1;

        l2 = kvm_getlwps(kd, p2->p_pid, 0, sizeof(*l1), &cnt);
        if (l2 == NULL || cnt == 0)
                return 0;

        return proc_compare(p1, l1, p2, l2);
}

static void
fixhost(struct entry *ep)
{
        char host_buf[sizeof(ep->host)];
        char *b, *m, *p, *r, *x;
        struct hostent *hp;
        union {
                struct in_addr l4;
                struct in6_addr l6;
        } l;

        strlcpy(host_buf, *ep->host ? ep->host : "-", sizeof(host_buf));
        p = host_buf;

        /*
         * One ':' in hostname means X display number, more is IPv6.
         */
        for (x = p; x < &host_buf[sizeof(host_buf)]; x++)
                if (*x == '\0' || *x == ':')
                        break;
        if (x == p + sizeof(host_buf) || *x != ':')
                m = x = NULL;
        else {
                for (m = x + 1; m < &host_buf[sizeof(host_buf)]; m++)
                        if (*m == '\0' || *m == ':')
                                break;
                if (m == p + sizeof(host_buf) || *m != ':') {
                        *x++ = '\0';
                        m = NULL;
                } else
                        x = NULL;
        }

        /*
         * Leading '[' indicates an IP address inside brackets.
         */
        b = NULL;
        if (!nflag && (*p == '[')) {
                for (b = p++; b < &host_buf[sizeof(host_buf)]; b++)
                        if (*b == '\0' || *b == ']')
                                break;
                if (b < &host_buf[sizeof(host_buf)] && *b == ']') {
                        *b = '\0';
                        for (x = b + 1; x < &host_buf[sizeof(host_buf)]; x++)
                                if (*x == '\0' || *x == ':')
                                        break;
                        if (x < &host_buf[sizeof(host_buf)] && *x == ':')
                                *x++ = '\0';
                } else
                        b = NULL;
        }

        int af = m ? AF_INET6 : AF_INET;
        size_t alen = m ? sizeof(l.l6) : sizeof(l.l4);
        if (!nflag && inet_pton(af, p, &l) &&
            (hp = gethostbyaddr((char *)&l, alen, af)))
                r = hp->h_name;
        else {
                if (b)
                        *b = ']';
                r = host_buf;
        }

        if (domain[0] != '\0') {
                p = r;
                p += strlen(r);
                p -= strlen(domain);
                if (p > r &&
                    strcasecmp(p, domain) == 0)
                        *p = '\0';
        }

        if (x)
                (void)snprintf(ep->host, sizeof(ep->host), "%s:%s", r, x);
        else
                strlcpy(ep->host, r, sizeof(ep->host));
}

static void
usage(int wcmd)
{

        if (wcmd)
                (void)fprintf(stderr,
                    "Usage: %s [-Ahinw] [-M core] [-N system] [user]\n",
                    getprogname());
        else
                (void)fprintf(stderr, "Usage: %s\n", getprogname());
        exit(1);
}