/*      $OpenBSD: w.c,v 1.70 2024/09/15 07:14:58 jsg 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.
 */

/*
 * w - print system status (who and what)
 *
 * This program is similar to the systat command on Tenex/Tops 10/20
 *
 */
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/signal.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/tty.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 <netdb.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <utmp.h>
#include <vis.h>

#include "extern.h"

struct utmp     utmp;
struct winsize  ws;
kvm_t          *kd;
time_t          now;            /* the current time of day */
int             ttywidth;       /* width of tty */
int             argwidth;       /* width of tty */
int             header = 1;     /* true if -h flag: don't print heading */
int             nflag = 1;      /* true if -n flag: don't convert addrs */
int             sortidle;       /* sort by idle time */
char           *sel_user;       /* login of particular user selected */
char            domain[HOST_NAME_MAX+1];

#define NAME_WIDTH      8
#define HOST_WIDTH      16

/*
 * One of these per active utmp entry.
 */
struct  entry {
        struct  entry *next;
        struct  utmp utmp;
        dev_t   tdev;                   /* dev_t of terminal */
        time_t  idle;                   /* idle time of terminal in seconds */
        struct  kinfo_proc *kp;         /* `most interesting' proc */
} *ep, *ehead = NULL, **nextp = &ehead;

static void      fmt_putc(int, int *);
static void      fmt_puts(const char *, int *);
static void      pr_args(struct kinfo_proc *);
static void      pr_header(time_t *, int);
static struct stat
                *ttystat(char *);
static void      usage(int);
static char     *hostlookup(char *, char *);

int
main(int argc, char *argv[])
{
        extern char *__progname;
        struct kinfo_proc *kp;
        struct stat *stp;
        FILE *ut;
        int ch, i, nentries, nusers, wcmd;
        char *memf, *nlistf, *p, *x;
        char buf[HOST_NAME_MAX+1], errbuf[_POSIX2_LINE_MAX];

        /* Are we w(1) or uptime(1)? */
        p = __progname;
        if (*p == '-')
                p++;
        if (p[0] == 'w' && p[1] == '\0') {
                wcmd = 1;
                p = "hiflM:N:asuw";
        } else if (!strcmp(p, "uptime")) {
                wcmd = 0;
                p = "";
        } else
                errx(1,
                 "this program should be invoked only as \"w\" or \"uptime\"");

        memf = nlistf = NULL;
        while ((ch = getopt(argc, argv, p)) != -1)
                switch (ch) {
                case 'h':
                        header = 0;
                        break;
                case 'i':
                        sortidle = 1;
                        break;
                case 'M':
                        header = 0;
                        memf = optarg;
                        break;
                case 'N':
                        nlistf = optarg;
                        break;
                case 'a':
                        nflag = 0;
                        break;
                case 'f': case 'l': case 's': case 'u': case 'w':
                        warnx("[-flsuw] no longer supported");
                        /* FALLTHROUGH */
                default:
                        usage(wcmd);
                }
        argc -= optind;
        argv += optind;

        if (nflag == 0) {
                if (pledge("stdio tty rpath dns ps vminfo", NULL) == -1)
                        err(1, "pledge");
        } else {
                if (pledge("stdio tty rpath ps vminfo", NULL) == -1)
                        err(1, "pledge");
        }

        if (nlistf == NULL && memf == NULL) {
                if ((kd = kvm_openfiles(nlistf, memf, NULL, KVM_NO_FILES,
                    errbuf)) == NULL)
                        errx(1, "%s", errbuf);
        } else {
                if ((kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf)) == NULL)
                        errx(1, "%s", errbuf);
        }

        (void)time(&now);
        if ((ut = fopen(_PATH_UTMP, "r")) == NULL)
                err(1, "%s", _PATH_UTMP);

        if (*argv)
                sel_user = *argv;

        for (nusers = 0; fread(&utmp, sizeof(utmp), 1, ut);) {
                if (utmp.ut_name[0] == '\0')
                        continue;
                ++nusers;
                if (wcmd == 0 || (sel_user &&
                    strncmp(utmp.ut_name, sel_user, UT_NAMESIZE) != 0))
                        continue;
                if ((ep = calloc(1, sizeof(*ep))) == NULL)
                        err(1, NULL);
                *nextp = ep;
                nextp = &(ep->next);
                memcpy(&(ep->utmp), &utmp, sizeof(utmp));
                if (!(stp = ttystat(ep->utmp.ut_line)))
                        continue;
                ep->tdev = stp->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);
                }

                if ((ep->idle = now - stp->st_atime) < 0)
                        ep->idle = 0;
        }
        (void)fclose(ut);

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

#define HEADER  "USER    TTY FROM              LOGIN@  IDLE WHAT"
#define WUSED   (sizeof(HEADER) - sizeof("WHAT"))
        if (header)
                (void)puts(HEADER);

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

        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;

        for (i = 0; i < nentries; i++, kp++) {
                if (kp->p_psflags & (PS_EMBRYO | PS_ZOMBIE))
                        continue;
                for (ep = ehead; ep != NULL; ep = ep->next) {
                        /* ftp is a special case. */
                        if (strncmp(ep->utmp.ut_line, "ftp", 3) == 0) {
                                char pidstr[UT_LINESIZE-2];
                                pid_t fp;

                                (void)strncpy(pidstr, &ep->utmp.ut_line[3],
                                    sizeof(pidstr) - 1);
                                pidstr[sizeof(pidstr) - 1] = '\0';
                                fp = (pid_t)strtol(pidstr, NULL, 10);
                                if (kp->p_pid == fp) {
                                        ep->kp = kp;
                                        break;
                                }
                        } else if (ep->tdev == kp->p_tdev &&
                            kp->p__pgid == kp->p_tpgid) {
                                /*
                                 * Proc is in foreground of this terminal
                                 */
                                if (proc_compare(ep->kp, kp))
                                        ep->kp = kp;
                                break;
                        }
                }
        }
        /* 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 (!nflag) {
                if (gethostname(domain, sizeof(domain)) == -1 ||
                    (p = strchr(domain, '.')) == 0)
                        domain[0] = '\0';
                else {
                        domain[sizeof(domain) - 1] = '\0';
                        memmove(domain, p, strlen(p) + 1);
                }
        }

        for (ep = ehead; ep != NULL; ep = ep->next) {
                p = *ep->utmp.ut_host ? ep->utmp.ut_host : "-";
                for (x = NULL, i = 0; p[i] != '\0' && i < UT_HOSTSIZE; i++) {
                        if (p[i] == ':') {
                                x = &p[i];
                                *x++ = '\0';
                                break;
                        }
                }

                if (x) {
                        (void)snprintf(buf, sizeof(buf), "%s:%.*s", p,
                            (int)(ep->utmp.ut_host + UT_HOSTSIZE - x), x);
                        p = buf;
                }

                if (!nflag) {
                        char *tmp;

                        if ((tmp = hostlookup(p, domain)) != NULL)
                                p = tmp;
                }

                (void)printf("%-*.*s %-2.2s %-*.*s ",
                    NAME_WIDTH, UT_NAMESIZE, ep->utmp.ut_name,
                    strncmp(ep->utmp.ut_line, "tty", 3) ?
                    ep->utmp.ut_line : ep->utmp.ut_line + 3,
                    HOST_WIDTH, HOST_WIDTH, *p ? p : "-");
                pr_attime(&ep->utmp.ut_time, &now);
                pr_idle(ep->idle);
                pr_args(ep->kp);
                printf("\n");
        }
        exit(0);
}

static void
fmt_putc(int c, int *leftp)
{

        if (*leftp == 0)
                return;
        if (*leftp != -1)
                *leftp -= 1;
        putchar(c);
}

static void
fmt_puts(const char *s, int *leftp)
{
        static char *v = NULL;
        static size_t maxlen = 0;
        size_t len;

        if (*leftp == 0)
                return;
        len = strlen(s) * 4 + 1;
        if (len > maxlen) {
                free(v);
                maxlen = 0;
                if (len < getpagesize())
                        len = getpagesize();
                v = malloc(len);
                if (v == NULL)
                        return;
                maxlen = len;
        }
        strvis(v, s, VIS_TAB | VIS_NL | VIS_CSTYLE);
        if (*leftp != -1) {
                len = strlen(v);
                if (len > *leftp) {
                        v[*leftp] = '\0';
                        *leftp = 0;
                } else
                        *leftp -= len;
        }
        printf("%s", v);
}


static void
pr_args(struct kinfo_proc *kp)
{
        char **argv, *str;
        int left;

        if (kp == NULL)
                goto nothing;           /* no matching process found */
        left = argwidth;
        argv = kvm_getargv(kd, kp, argwidth+60);  /* +60 for ftpd snip */
        if (argv == NULL)
                goto nothing;

        if (*argv == NULL || **argv == '\0') {
                /* Process has zeroed argv[0], display executable name. */
                fmt_putc('(', &left);
                fmt_puts(kp->p_comm, &left);
                fmt_putc(')', &left);
        }
        while (*argv) {
                /*
                 * ftp argv[0] is in the following format:
                 * ftpd: HOSTNAME: [USER/PASS: ]CMD args (ftpd)
                 */
                if (strncmp(*argv, "ftpd:", 5) == 0) {
                        if ((str = strchr(*argv + 5, ':')) != NULL)
                                str = strchr(str + 1, ':');
                        if (str != NULL) {
                                if ((str[0] == ':') &&
                                    isspace((unsigned char)str[1]))
                                        str += 2;
                                fmt_puts(str, &left);
                        } else
                                fmt_puts(*argv, &left);
                } else
                        fmt_puts(*argv, &left);
                argv++;
                fmt_putc(' ', &left);
        }
        return;
nothing:
        putchar('-');
}

static void
pr_header(time_t *nowp, int nusers)
{
        double avenrun[3];
        struct timespec boottime;
        time_t uptime;
        int days, hrs, i, mins;
        char buf[256];

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

        /*
         * Print how long system has been up.
         */
        if (clock_gettime(CLOCK_BOOTTIME, &boottime) != -1) {
                uptime = boottime.tv_sec;
                if (uptime > 59) {
                        uptime += 30;
                        days = uptime / SECSPERDAY;
                        uptime %= SECSPERDAY;
                        hrs = uptime / SECSPERHOUR;
                        uptime %= SECSPERHOUR;
                        mins = uptime / 60;
                        (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 || (days == 0 && hrs == 0))
                                        (void)printf(" %d min%s,",
                                            mins, mins != 1 ? "s" : "");
                        }
                } else
                        printf(" %d secs,", (int)uptime);
        }

        /* 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");
        }
}

static struct stat *
ttystat(char *line)
{
        static struct stat sb;
        char ttybuf[sizeof(_PATH_DEV) + UT_LINESIZE];

        /* Note, line may not be NUL-terminated */
        (void)strlcpy(ttybuf, _PATH_DEV, sizeof(ttybuf));
        (void)strncat(ttybuf, line, sizeof(ttybuf) - 1 - strlen(ttybuf));
        if (stat(ttybuf, &sb))
                return (NULL);
        return (&sb);
}

static void
usage(int wcmd)
{
        if (wcmd)
                (void)fprintf(stderr,
                    "usage: w [-ahi] [-M core] [-N system] [user]\n");
        else
                (void)fprintf(stderr,
                    "usage: uptime\n");
        exit (1);
}

static char*
hostlookup(char *host, char *domain)
{
        static char buf[NI_MAXHOST];
        struct addrinfo hints, *res;
        int error;
        char *p;

        memset(&hints, 0, sizeof(hints));
        if (getaddrinfo(host, NULL, &hints, &res) != 0)
                return NULL;

        error = getnameinfo(res->ai_addr, res->ai_addr->sa_len, buf,
            sizeof(buf), NULL, 0, 0);
        freeaddrinfo(res);

        if (error)
                return NULL;

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