/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 */

/*
 * 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/time.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <sys/sbuf.h>
#include <sys/socket.h>
#include <sys/tty.h>
#include <sys/types.h>

#include <machine/cpu.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <langinfo.h>
#include <libgen.h>
#include <libutil.h>
#include <limits.h>
#include <locale.h>
#include <netdb.h>
#include <nlist.h>
#include <paths.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <timeconv.h>
#include <unistd.h>
#include <utmpx.h>
#include <vis.h>
#include <libxo/xo.h>

#include "extern.h"

static struct utmpx *utmp;
static struct winsize ws;
static kvm_t   *kd;
static time_t   now;            /* the current time of day */
static size_t   ttywidth;       /* width of tty */
static size_t   fromwidth = 0;  /* max width of "from" field */
static size_t   argwidth;       /* width of arguments */
static int      header = 1;     /* true if -h flag: don't print heading */
static int      nflag;          /* true if -n flag: don't convert addrs */
static int      dflag;          /* true if -d flag: output debug info */
static int      sortidle;       /* sort by idle time */
int             use_ampm;       /* use AM/PM time */
static int      use_comma;      /* use comma as floats separator */
static char   **sel_users;      /* login array of particular users selected */

/*
 * One of these per active utmp entry.
 */
static struct entry {
        struct  entry *next;
        struct  utmpx utmp;
        dev_t   tdev;                   /* dev_t of terminal */
        time_t  idle;                   /* idle time of terminal in seconds */
        struct  kinfo_proc *kp;         /* `most interesting' proc */
        char    *args;                  /* arg list of interesting process */
        struct  kinfo_proc *dkp;        /* debug option proc list */
        char    *from;                  /* "from": name or addr */
        char    *save_from;             /* original "from": name or addr */
} *ep, *ehead = NULL, **nextp = &ehead;

#define debugproc(p) *(&((struct kinfo_proc *)p)->ki_udata)

#define W_XO_VERSION    "1"

#define W_DISPUSERSIZE  10
#define W_DISPLINESIZE  8
#define W_MAXHOSTSIZE   40

static void              pr_header(time_t *, int);
static struct stat      *ttystat(char *);
static void              usage(int);

char *fmt_argv(char **, char *, char *, size_t);        /* ../../bin/ps/fmt.c */

int
main(int argc, char *argv[])
{
        struct kinfo_proc *kp;
        struct kinfo_proc *dkp;
        struct stat *stp;
        time_t touched;
        size_t width;
        int ch, i, nentries, nusers, wcmd, longidle, longattime;
        const char *memf, *nlistf, *p, *save_p;
        char *x_suffix;
        char errbuf[_POSIX2_LINE_MAX];
        char buf[MAXHOSTNAMELEN], fn[MAXHOSTNAMELEN];
        char *dot;


        argc = xo_parse_args(argc, argv);
        if (argc < 0)
                exit(1);

        if (xo_get_style(NULL) == XO_STYLE_TEXT) {
                setlocale(LC_ALL, "");
        }
        use_ampm = (*nl_langinfo(T_FMT_AMPM) != '\0');
        use_comma = (*nl_langinfo(RADIXCHAR) != ',');
        /* Are we w(1) or uptime(1)? */
        if (strcmp(basename(argv[0]), "uptime") == 0) {
                wcmd = 0;
                p = "";
        } else {
                wcmd = 1;
                p = "dhiflM:N:nsuw";
        }

        memf = _PATH_DEVNULL;
        nlistf = NULL;
        while ((ch = getopt(argc, argv, p)) != -1)
                switch (ch) {
                case 'd':
                        dflag = 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 'f': case 'l': case 's': case 'u': case 'w':
                        xo_warnx("-%c no longer supported", ch);
                        /* FALLTHROUGH */
                case '?':
                default:
                        usage(wcmd);
                }
        argc -= optind;
        argv += optind;

        if (!(_res.options & RES_INIT))
                res_init();
        _res.retrans = 2;       /* resolver timeout to 2 seconds per try */
        _res.retry = 1;         /* only try once.. */

        if ((kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf)) == NULL)
                xo_errx(1, "%s", errbuf);

        (void)time(&now);

        if (*argv)
                sel_users = argv;

        setutxent();
        for (nusers = 0; (utmp = getutxent()) != NULL;) {
                struct addrinfo hints, *res;
                struct sockaddr_storage ss;
                struct sockaddr *sa = (struct sockaddr *)&ss;
                struct sockaddr_in *lsin = (struct sockaddr_in *)&ss;
                struct sockaddr_in6 *lsin6 = (struct sockaddr_in6 *)&ss;
                int isaddr;

                if (utmp->ut_type != USER_PROCESS)
                        continue;
                if (!(stp = ttystat(utmp->ut_line)))
                        continue;       /* corrupted record */
                ++nusers;
                if (wcmd == 0)
                        continue;
                if (sel_users) {
                        int usermatch;
                        char **user;

                        usermatch = 0;
                        for (user = sel_users; !usermatch && *user; user++)
                                if (!strcmp(utmp->ut_user, *user))
                                        usermatch = 1;
                        if (!usermatch)
                                continue;
                }
                if ((ep = calloc(1, sizeof(struct entry))) == NULL)
                        xo_errx(1, "calloc");
                *nextp = ep;
                nextp = &ep->next;
                memmove(&ep->utmp, utmp, sizeof *utmp);
                ep->tdev = stp->st_rdev;
                /*
                 * If this is the console device, attempt to ascertain
                 * the true console device dev_t.
                 */
                if (ep->tdev == 0) {
                        size_t size;

                        size = sizeof(dev_t);
                        (void)sysctlbyname("machdep.consdev", &ep->tdev, &size, NULL, 0);
                }
                touched = stp->st_atime;
                if (touched < ep->utmp.ut_tv.tv_sec) {
                        /* tty untouched since before login */
                        touched = ep->utmp.ut_tv.tv_sec;
                }
                if ((ep->idle = now - touched) < 0)
                        ep->idle = 0;

                save_p = p = *ep->utmp.ut_host ? ep->utmp.ut_host : "-";
                if ((x_suffix = strrchr(p, ':')) != NULL) {
                        if ((dot = strchr(x_suffix, '.')) != NULL &&
                            strchr(dot+1, '.') == NULL)
                                *x_suffix++ = '\0';
                        else
                                x_suffix = NULL;
                }

                isaddr = 0;
                memset(&ss, '\0', sizeof(ss));
                if (inet_pton(AF_INET6, p, &lsin6->sin6_addr) == 1) {
                        lsin6->sin6_len = sizeof(*lsin6);
                        lsin6->sin6_family = AF_INET6;
                        isaddr = 1;
                } else if (inet_pton(AF_INET, p, &lsin->sin_addr) == 1) {
                        lsin->sin_len = sizeof(*lsin);
                        lsin->sin_family = AF_INET;
                        isaddr = 1;
                }
                if (nflag == 0) {
                        /* Attempt to change an IP address into a name */
                        if (isaddr && realhostname_sa(fn, sizeof(fn), sa,
                            sa->sa_len) == HOSTNAME_FOUND)
                                p = fn;
                } else if (!isaddr && nflag > 1) {
                        /*
                         * If a host has only one A/AAAA RR, change a
                         * name into an IP address
                         */
                        memset(&hints, 0, sizeof(hints));
                        hints.ai_flags = AI_PASSIVE;
                        hints.ai_family = AF_UNSPEC;
                        hints.ai_socktype = SOCK_STREAM;
                        if (getaddrinfo(p, NULL, &hints, &res) == 0) {
                                if (res->ai_next == NULL &&
                                    getnameinfo(res->ai_addr, res->ai_addrlen,
                                        fn, sizeof(fn), NULL, 0,
                                        NI_NUMERICHOST) == 0)
                                        p = fn;
                                freeaddrinfo(res);
                        }
                }

                if (x_suffix) {
                        (void)snprintf(buf, sizeof(buf), "%s:%s", p, x_suffix);
                        p = buf;
                }
                ep->from = strdup(p);
                if ((width = strlen(p)) > fromwidth)
                        fromwidth = width;
                if (save_p != p)
                        ep->save_from = strdup(save_p);
        }
        endutxent();

#define HEADER_USER             "USER"
#define HEADER_TTY              "TTY"
#define HEADER_FROM             "FROM"
#define HEADER_LOGIN_IDLE       "LOGIN@  IDLE "
#define HEADER_WHAT             "WHAT\n"
#define WUSED  (W_DISPUSERSIZE + W_DISPLINESIZE + fromwidth + \
                sizeof(HEADER_LOGIN_IDLE) + 3)  /* header width incl. spaces */

        if (sizeof(HEADER_FROM) > fromwidth)
                fromwidth = sizeof(HEADER_FROM);
        fromwidth++;
        if (fromwidth > W_MAXHOSTSIZE)
                fromwidth = W_MAXHOSTSIZE;

        xo_set_version(W_XO_VERSION);
        xo_open_container("uptime-information");

        if (header || wcmd == 0) {
                pr_header(&now, nusers);
                if (wcmd == 0) {
                        xo_close_container("uptime-information");
                        if (xo_finish() < 0)
                                xo_err(1, "stdout");
                        (void)kvm_close(kd);
                        exit(0);
                }

                xo_emit("{T:/%-*.*s} {T:/%-*.*s} {T:/%-*.*s}  {T:/%s}",
                                W_DISPUSERSIZE, W_DISPUSERSIZE, HEADER_USER,
                                W_DISPLINESIZE, W_DISPLINESIZE, HEADER_TTY,
                                fromwidth, fromwidth, HEADER_FROM,
                                HEADER_LOGIN_IDLE HEADER_WHAT);
        }

        if ((kp = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nentries)) == NULL)
                xo_err(1, "%s", kvm_geterr(kd));
        for (i = 0; i < nentries; i++, kp++) {
                if (kp->ki_stat == SIDL || kp->ki_stat == SZOMB ||
                    kp->ki_tdev == NODEV)
                        continue;
                for (ep = ehead; ep != NULL; ep = ep->next) {
                        if (ep->tdev == kp->ki_tdev) {
                                /*
                                 * proc is associated with this terminal
                                 */
                                if (ep->kp == NULL && kp->ki_pgid == kp->ki_tpgid) {
                                        /*
                                         * Proc is 'most interesting'
                                         */
                                        if (proc_compare(ep->kp, kp))
                                                ep->kp = kp;
                                }
                                /*
                                 * Proc debug option info; add to debug
                                 * list using kinfo_proc ki_spare[0]
                                 * as next pointer; ptr to ptr avoids the
                                 * ptr = long assumption.
                                 */
                                dkp = ep->dkp;
                                ep->dkp = kp;
                                debugproc(kp) = dkp;
                        }
                }
        }
        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;
        argwidth = ttywidth - WUSED;
        if (argwidth < 4)
                argwidth = 8;
        /* Don't truncate if we're outputting json or XML. */
        if (xo_get_style(NULL) != XO_STYLE_TEXT)
                argwidth = ARG_MAX;
        for (ep = ehead; ep != NULL; ep = ep->next) {
                if (ep->kp == NULL) {
                        ep->args = strdup("-");
                        continue;
                }
                ep->args = fmt_argv(kvm_getargv(kd, ep->kp, argwidth),
                    ep->kp->ki_comm, NULL, MAXCOMLEN);
                if (ep->args == NULL)
                        xo_err(1, "fmt_argv");
        }
        /* sort by idle time */
        if (sortidle && ehead != NULL) {
                struct entry *from, *save;

                from = ehead;
                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;
                }
        }

        xo_open_container("user-table");
        xo_open_list("user-entry");

        for (ep = ehead; ep != NULL; ep = ep->next) {
                time_t t;

                xo_open_instance("user-entry");

                if (dflag) {
                        xo_open_container("process-table");
                        xo_open_list("process-entry");

                        for (dkp = ep->dkp; dkp != NULL; dkp = debugproc(dkp)) {
                                const char *ptr;

                                ptr = fmt_argv(kvm_getargv(kd, dkp, argwidth),
                                    dkp->ki_comm, NULL, MAXCOMLEN);
                                if (ptr == NULL)
                                        ptr = "-";
                                xo_open_instance("process-entry");
                                xo_emit("\t\t{:process-id/%-9d/%d} "
                                    "{:command/%hs}\n", dkp->ki_pid, ptr);
                                xo_close_instance("process-entry");
                        }
                        xo_close_list("process-entry");
                        xo_close_container("process-table");
                }
                xo_emit("{:user/%-*.*s/%@**@s} {:tty/%-*.*s/%@**@s} ",
                        W_DISPUSERSIZE, W_DISPUSERSIZE, ep->utmp.ut_user,
                        W_DISPLINESIZE, W_DISPLINESIZE,
                        *ep->utmp.ut_line ?
                        (strncmp(ep->utmp.ut_line, "tty", 3) &&
                         strncmp(ep->utmp.ut_line, "cua", 3) ?
                         ep->utmp.ut_line : ep->utmp.ut_line + 3) : "-");

                if (ep->save_from)
                    xo_attr("address", "%s", ep->save_from);
                xo_emit("{:from/%-*.*s/%@**@s} ",
                    (int)fromwidth, (int)fromwidth, ep->from);
                t = ep->utmp.ut_tv.tv_sec;
                longattime = pr_attime(&t, &now);
                longidle = pr_idle(ep->idle);
                xo_emit("{:command/%.*hs/%@*@hs}\n",
                    (int)argwidth - longidle - longattime,
                    ep->args);

                xo_close_instance("user-entry");
        }

        xo_close_list("user-entry");
        xo_close_container("user-table");
        xo_close_container("uptime-information");
        if (xo_finish() < 0)
                xo_err(1, "stdout");

        (void)kvm_close(kd);
        exit(0);
}

static void
pr_header(time_t *nowp, int nusers)
{
        char buf[64], *s, *e;
        struct sbuf upbuf;
        double avenrun[3];
        struct timespec tp;
        unsigned long days, hrs, mins, secs;
        unsigned int i;

        /*
         * Print time of day.
         */
        if (strftime(buf, sizeof(buf),
            use_ampm ? "%l:%M%p" : "%k:%M", localtime(nowp)) != 0) {
                s = buf;
                if (xo_get_style(NULL) != XO_STYLE_TEXT) {
                        /* trim leading whitespace */
                        while (isspace((unsigned char)*s))
                                s++;
                }
                xo_emit("{:time-of-day/%s} ", s);
        }
        /*
         * Print how long system has been up.
         */
        (void)sbuf_new(&upbuf, buf, sizeof(buf), SBUF_FIXEDLEN);
        if (clock_gettime(CLOCK_UPTIME, &tp) != -1) {
                xo_emit(" up");
                secs = tp.tv_sec;
                xo_emit("{e:uptime/%lu}", secs);
                mins = secs / 60;
                secs %= 60;
                hrs = mins / 60;
                mins %= 60;
                days = hrs / 24;
                hrs %= 24;
                xo_emit("{e:days/%ld}{e:hours/%ld}{e:minutes/%ld}{e:seconds/%ld}",
                    days, hrs, mins, secs);

                /* If we've been up longer than 60 s, round to nearest min */
                if (tp.tv_sec > 60) {
                        secs = tp.tv_sec + 30;
                        mins = secs / 60;
                        secs = 0;
                        hrs = mins / 60;
                        mins %= 60;
                        days = hrs / 24;
                        hrs %= 24;
                }

                if (days > 0)
                        sbuf_printf(&upbuf, " %ld day%s,",
                            days, days > 1 ? "s" : "");
                if (hrs > 0 && mins > 0)
                        sbuf_printf(&upbuf, " %2ld:%02ld,", hrs, mins);
                else if (hrs > 0)
                        sbuf_printf(&upbuf, " %ld hr%s,",
                            hrs, hrs > 1 ? "s" : "");
                else if (mins > 0)
                        sbuf_printf(&upbuf, " %ld min%s,",
                            mins, mins > 1 ? "s" : "");
                else
                        sbuf_printf(&upbuf, " %ld sec%s,",
                            secs, secs > 1 ? "s" : "");
                if (sbuf_finish(&upbuf) != 0)
                        xo_err(1, "Could not generate output");
                s = sbuf_data(&upbuf);
                if (xo_get_style(NULL) != XO_STYLE_TEXT) {
                        e = s + sbuf_len(&upbuf) - 1;
                        /* trim leading whitespace */
                        while (isspace((unsigned char)*s))
                                s++;
                        /* trim trailing comma */
                        if (e > s && *e == ',')
                                *e = '\0';
                }
                xo_emit("{:uptime-human/%s}", s);
                sbuf_delete(&upbuf);
        }

        /* Print number of users logged in to system */
        xo_emit(" {:users/%d} {Np:user,users}", nusers);

        /*
         * Print 1, 5, and 15 minute load averages.
         */
        if (getloadavg(avenrun, nitems(avenrun)) == -1)
                xo_emit(", no load average information available\n");
        else {
                static const char *format[] = {
                    " {:load-average-1/%.2f}",
                    " {:load-average-5/%.2f}",
                    " {:load-average-15/%.2f}",
                };
                xo_emit(", load averages:");
                for (i = 0; i < nitems(avenrun); i++) {
                        if (use_comma && i > 0)
                                xo_emit(",");
                        xo_emit(format[i], avenrun[i]);
                }
                xo_emit("\n");
        }
}

static struct stat *
ttystat(char *line)
{
        static struct stat sb;
        char ttybuf[MAXPATHLEN];

        (void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
        if (stat(ttybuf, &sb) == 0 && S_ISCHR(sb.st_mode))
                return (&sb);
        return (NULL);
}

static void
usage(int wcmd)
{
        if (wcmd)
                xo_error("usage: w [-dhin] [-M core] [-N system] [user ...]\n");
        else
                xo_error("usage: uptime\n");
        xo_finish();
        exit(1);
}