/*      $NetBSD: main.c,v 1.58 2024/06/16 22:44:01 kre Exp $    */

/*-
 * Copyright (c) 1980, 1992, 1993
 *      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, 1992, 1993\
 The Regents of the University of California.  All rights reserved.");
#if 0
static char sccsid[] = "@(#)main.c      8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: main.c,v 1.58 2024/06/16 22:44:01 kre Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <termios.h>

#include "systat.h"
#include "extern.h"
#include "drvstats.h"

static double   dellave;

kvm_t *kd;
char    *memf = NULL;
char    *nlistf = NULL;
sig_t   sigtstpdfl;
double avenrun[3];
int     col;
double  naptime = 1;
int     verbose = 1;                    /* to report kvm read errs */
int     hz, stathz, maxslp;
char    c;
char    *namp;
char    hostname[MAXHOSTNAMELEN + 1];
WINDOW  *wnd;
int     CMDLINE;
int     turns = 2;      /* stay how many refresh-turns in 'all' mode? */
int     allflag;
int     allcounter;
sig_atomic_t needsredraw = 0;
float   hertz;
double  etime;
bool    showzero = false;

static  WINDOW *wload;                  /* one line window for load average */

static void (*sv_stop_handler)(int);

static void stop(int);
__dead static void usage(void);

gid_t egid; /* XXX needed by initiostat() and initkre() */

int
main(int argc, char **argv)
{
        int ch;
        char errbuf[_POSIX2_LINE_MAX];
        const char *all;
        struct clockinfo clk;
        size_t len;
        int bflag = 0;

        all = "all";
        egid = getegid();
        (void)setegid(getgid());

        while ((ch = getopt(argc, argv, "M:N:bnw:t:z")) != -1)
                switch(ch) {
                case 'M':
                        memf = optarg;
                        break;
                case 'N':
                        nlistf = optarg;
                        break;
                case 'b':
                        bflag = !bflag;
                        break;
                case 'n':
                        nflag = !nflag;
                        break;
                case 't':
                        if ((turns = atoi(optarg)) <= 0)
                                errx(EXIT_FAILURE, "turns <= 0.");
                        break;
                case 'w':
                        if ((naptime = strtod(optarg, NULL)) <= 0)
                                errx(EXIT_FAILURE, "interval <= 0.");
                        break;
                case 'z':
                        showzero = true;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;


        for ( ; argc > 0; argc--, argv++) {
                struct mode *p;
                int modefound = 0;

                if (isdigit((unsigned char)argv[0][0])) {
                        naptime = strtod(argv[0], NULL);
                        if (naptime <= 0)
                                naptime = 5;
                        continue;
                }

                for (p = modes; p->c_name ; p++) {
                        if (strstr(p->c_name, argv[0]) == p->c_name) {
                                curmode = p;
                                modefound++;
                                break;
                        }

                        if (strstr(all, argv[0]) == all) {
                                allcounter=0;
                                allflag=1;
                        }
                }


                if (!modefound && !allflag)
                        error("%s: Unknown command.", argv[0]);
        }

        /*
         * Discard setgid privileges.  If not the running kernel, we toss
         * them away totally so that bad guys can't print interesting stuff
         * from kernel memory, otherwise switch back to kmem for the
         * duration of the kvm_openfiles() call.
         */
        if (nlistf != NULL || memf != NULL)
                (void)setgid(getgid());
        else
                (void)setegid(egid);

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

        /* Get rid of privs for now. */
        if (nlistf == NULL && memf == NULL)
                (void)setegid(getgid());

        signal(SIGINT, die);
        signal(SIGQUIT, die);
        signal(SIGTERM, die);
        sv_stop_handler = signal(SIGTSTP, stop);

        /*
         * Initialize display.  Load average appears in a one line
         * window of its own.  Current command's display appears in
         * an overlapping sub-window of stdscr configured by the display
         * routines to minimize update work by curses.
         */
        if (initscr() == NULL)
                errx(EXIT_FAILURE, "couldn't initialize screen");

        CMDLINE = LINES - 1;
        wnd = (*curmode->c_open)();
        if (wnd == NULL) {
                move(CMDLINE, 0);
                clrtoeol();
                refresh();
                endwin();
                warnx("couldn't initialize display");
                die(0);
        }
        wload = newwin(1, 0, 3, 20);
        if (wload == NULL) {
                move(CMDLINE, 0);
                clrtoeol();
                refresh();
                endwin();
                warnx("couldn't set up load average window");
                die(0);
        }
        gethostname(hostname, sizeof (hostname));
        hostname[sizeof(hostname) - 1] = '\0';

        len = sizeof(clk);
        if (sysctlbyname("kern.clockrate", &clk, &len, NULL, 0))
                error("can't get \"kern.clockrate\": %s", strerror(errno));
        hz = clk.hz;
        stathz = clk.stathz;

        len = sizeof(maxslp);
        if (sysctlbyname("vm.maxslp", &maxslp, &len, NULL, 0))
                error("can't get \"vm.maxslp\": %s", strerror(errno));

        (*curmode->c_init)();
        curmode->c_flags |= CF_INIT;
        labels();

        dellave = 0.0;

        display(0);
        if (!bflag) {
                noecho();
                cbreak();
                keyboard();
        } else
                die(0);
        /*NOTREACHED*/
}

static void
usage(void)
{
        fprintf(stderr, "usage: %s [-bnz] [-M core] [-N system] [-w wait] "
            "[-t turns]\n\t\t[display] [refresh-interval]\n", getprogname());
        exit(EXIT_FAILURE);
}


void
labels(void)
{
        if (curmode->c_flags & CF_LOADAV) {
                mvaddstr(2, 20,
                    "/0   /1   /2   /3   /4   /5   /6   /7   /8   /9   /10");
                mvaddstr(3, 5, "Load Average");
        }
        (*curmode->c_label)();
#ifdef notdef
        mvprintw(21, 25, "CPU usage on %s", hostname);
#endif
        refresh();
}

void
display(int signo)
{
        static int skip;
        int j;
        struct mode *p;
        int ms_delay;

        if (signo == SIGALRM && skip-- > 0)
                /* Don't display on this timeout */
                return;

        /* Get the load average over the last minute. */
        (void)getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0]));
        (*curmode->c_fetch)();
        if (curmode->c_flags & CF_LOADAV) {
                j = 5.0*avenrun[0] + 0.5;
                dellave -= avenrun[0];
                if (dellave >= 0.0)
                        c = '<';
                else {
                        c = '>';
                        dellave = -dellave;
                }
                if (dellave < 0.1)
                        c = '|';
                dellave = avenrun[0];
                wmove(wload, 0, 0);
                wclrtoeol(wload);
                whline(wload, c, (j > 50) ? 50 : j);
                if (j > 50)
                        wprintw(wload, " %4.1f", avenrun[0]);
        }
        (*curmode->c_refresh)();
        if (curmode->c_flags & CF_LOADAV)
                wrefresh(wload);
        wrefresh(wnd);
        move(CMDLINE, col);
        refresh();
        
        if (allflag && signo==SIGALRM) {
                if (allcounter >= turns){
                        p = curmode;
                        p++;
                        if (p->c_name == NULL)
                                p = modes;
                        switch_mode(p);
                        allcounter=0;
                } else
                        allcounter++;
        }

        /* curses timeout() uses VTIME, limited to 255 1/10th secs */
        ms_delay = naptime * 1000;
        if (ms_delay < 25500) {
                timeout(ms_delay);
                skip = 0;
        } else {
                skip = ms_delay / 25500;
                timeout(ms_delay / (skip + 1));
        }
}

void
redraw(void)
{
        CMDLINE = LINES - 1;
        labels();

        display(0);
        needsredraw = 0;
}

static void
stop(int signo)
{
        sigset_t set;

        signal(SIGTSTP, sv_stop_handler);
        /* unblock SIGTSTP */
        sigemptyset(&set);
        sigaddset(&set, SIGTSTP);
        sigprocmask(SIG_UNBLOCK, &set, NULL);
        /* stop ourselves */
        kill(0, SIGTSTP);
        /* must have been restarted */
        signal(SIGTSTP, stop);
        needsredraw = signo;
}

void
die(int signo)
{
        move(CMDLINE, 0);
        clrtoeol();
        refresh();
        endwin();
        exit(EXIT_SUCCESS);
}

void
error(const char *fmt, ...)
{
        va_list ap;
        char buf[255];
        int oy, ox;

        va_start(ap, fmt);

        if (wnd) {
                getyx(stdscr, oy, ox);
                (void) vsnprintf(buf, sizeof(buf), fmt, ap);
                clrtoeol();
                standout();
                mvaddstr(CMDLINE, 0, buf);
                standend();
                move(oy, ox);
                refresh();
        } else {
                (void) vfprintf(stderr, fmt, ap);
                fprintf(stderr, "\n");
        }
        va_end(ap);
}

void
clearerror(void)
{

        error("%s", "");
}

void
nlisterr(struct nlist name_list[])
{
        int i, n;

        n = 0;
        clear();
        mvprintw(2, 10, "systat: nlist: can't find following symbols:");
        for (i = 0;
            name_list[i].n_name != NULL && *name_list[i].n_name != '\0'; i++)
                if (name_list[i].n_value == 0)
                        mvprintw(2 + ++n, 10, "%s", name_list[i].n_name);
        move(CMDLINE, 0);
        clrtoeol();
        refresh();
        endwin();
        exit(EXIT_FAILURE);
}

bool
toofast(int *failcnt)
{
        static char pigs[] = "pigs";
        etime = cur.cp_etime;
        /* < 1 ticks - sleep for a tick */
        /* this is often triggered by repeated SIGWINCH */
        if ((etime * hertz) >= 1.0)
                return false;

        if ((*failcnt)++ <= MAXFAIL) {
                struct timespec interval = { 0, 1000000000L / hertz };
                while (nanosleep(&interval, &interval) == -1)
                        continue;
                return true;
        }
        clear();
        mvprintw(2, 10, "The alternate system clock has died!");
        mvprintw(3, 10, "Reverting to ``pigs'' display.");
        move(CMDLINE, 0);
        refresh();
        failcnt = 0;
        sleep(5);
        command(pigs);
        return true;
}