/*-
 * 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.
 *
 * @(#) Copyright (c) 1980, 1991, 1993, 1994 The Regents of the University of California.  All rights reserved.
 * @(#)w.c      8.4 (Berkeley) 4/16/94
 * $FreeBSD: src/usr.bin/w/w.c,v 1.38.2.6 2002/03/12 19:51:51 phantom Exp $
 */

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

#include <machine/cpu.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 <langinfo.h>
#include <locale.h>
#include <netdb.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utmpx.h>
#include <vis.h>

#include <arpa/nameser.h>
#include <resolv.h>

#include "extern.h"

static struct winsize   ws;
static kvm_t    *kd;
static time_t   now;            /* the current time of day */
static time_t   then;
static int      ttywidth;       /* width of tty */
static int      argwidth;       /* width of tty */
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 */
static char     domain[MAXHOSTNAMELEN];
static int      maxname = 8, maxline = 3, maxhost = 16;

struct kplist {
        struct kplist *next;
        struct kinfo_proc *kp;
};

/*
 * One of these per active utmpx entry.
 */
static 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_proc *kp;         /* `most interesting' proc */
        char    *args;                  /* arg list of interesting process */
        struct  kplist *list;           /* debug option proc list */
        pid_t   pid;                    /* pid or ~0 if not known */
} *ep, *ehead = NULL, **nextp = &ehead;

static void              pr_header(time_t *, int);
static struct stat      *ttystat(char *, int);
static void              process(struct entry *);
static void              usage(int);
static int               this_is_uptime(const char *s);

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

int
main(int argc, char **argv)
{
        struct kinfo_proc *kp;
        struct kplist *scan;
        struct hostent *hp;
        in_addr_t l;
        int ch, i, nentries, nusers, wcmd, longidle, dropgid;
        char *memf, *nlistf, *p, *x;
        struct utmpx *utx;
        char buf[MAXHOSTNAMELEN], errbuf[_POSIX2_LINE_MAX];

        (void)setlocale(LC_ALL, "");
        use_ampm = (*nl_langinfo(T_FMT_AMPM) != '\0');
        use_comma = (*nl_langinfo(RADIXCHAR) != ',');

        /* Are we w(1) or uptime(1)? */
        if (this_is_uptime(argv[0]) == 0) {
                wcmd = 0;
                p = "";
        } else {
                wcmd = 1;
                p = "dhiflM:N:nsuw";
        }

        dropgid = 0;
        memf = nlistf = _PATH_DEVNULL;
        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;
                        dropgid = 1;
                        break;
                case 'N':
                        nlistf = optarg;
                        dropgid = 1;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 'f': case 'l': case 's': case 'u': case 'w':
                        warnx("[-flsuw] no longer supported");
                        /* 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.. */

        /*
         * Discard setgid privileges if not the running kernel so that bad
         * guys can't print interesting stuff from kernel memory.
         */
        if (dropgid)
                setgid(getgid());

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

        (void)time(&now);
        setutxent();

        if (*argv)
                sel_users = argv;

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

                if (sel_users) {
                        int usermatch;
                        char **user;

                        usermatch = 0;
                        for (user = sel_users; !usermatch && *user; user++)
                                if (!strncmp(utx->ut_name, *user, UTX_USERSIZE))
                                        usermatch = 1;
                        if (!usermatch)
                                continue;
                }

                if ((ep = calloc(1, sizeof(struct entry))) == NULL)
                        err(1, NULL);
                (void)memcpy(ep->name, utx->ut_name, sizeof(utx->ut_name));
                (void)memcpy(ep->line, utx->ut_line, sizeof(utx->ut_line));
                (void)memcpy(ep->host, utx->ut_host, sizeof(utx->ut_host));
                ep->name[sizeof(utx->ut_name)] = '\0';
                ep->line[sizeof(utx->ut_line)] = '\0';
                ep->host[sizeof(utx->ut_host)] = '\0';
#if 1
                /* XXX: Actually we don't support the utx->ut_ss stuff yet */
                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';
                }
#endif
                ep->type[0] = 'x';
                ep->tv = utx->ut_tv;
                ep->pid = utx->ut_pid;

                *nextp = ep;
                nextp = &(ep->next);
                if (wcmd != 0)
                        process(ep);
        }
        endutxent();
        
        if (header || wcmd == 0) {
                pr_header(&now, nusers);
                if (wcmd == 0) {
                        (void)kvm_close(kd);
                        exit(0);
                }

#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  (maxname + maxline + maxhost + \
                sizeof(HEADER_LOGIN_IDLE) + 3)  /* header width incl. spaces */ 
                (void)printf("%-*.*s %-*.*s %-*.*s  %s", 
                                maxname, maxname, HEADER_USER,
                                maxline, maxline, HEADER_TTY,
                                maxhost, maxhost, HEADER_FROM,
                                HEADER_LOGIN_IDLE HEADER_WHAT);
        }

        if ((kp = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nentries)) == NULL)
                err(1, "%s", kvm_geterr(kd));
        for (i = 0; i < nentries; i++, kp++) {
                /*
                 * login(1) is a special case.
                 */
                if (strcmp(kp->kp_comm, "login") == 0)
                        continue;
                if (kp->kp_stat == SIDL || kp->kp_stat == SZOMB)
                        continue;
                if (kp->kp_sid != kp->kp_tsid)
                        continue;
                for (ep = ehead; ep != NULL; ep = ep->next) {
                        if (ep->tdev == kp->kp_tdev) {
                                /*
                                 * proc is associated with this terminal
                                 */
                                if (ep->kp == NULL &&
                                    kp->kp_pgid == kp->kp_tpgid)
                                {
                                        /*
                                         * Proc is 'most interesting'
                                         */
                                        if (proc_compare(ep->kp, kp))
                                                ep->kp = kp;
                                }
                                /*
                                 * Retain list of kinfo_proc's for -d
                                 * option.
                                 */
                                scan = malloc(sizeof(*scan));
                                scan->kp = kp;
                                scan->next = ep->list;
                                ep->list = scan;
                        }
                        if (ep->pid != 0 && ep->pid == kp->kp_pid) {
                                ep->kp = 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;
        argwidth = ttywidth - WUSED;
        if (argwidth < 4)
                argwidth = 8;
        for (ep = ehead; ep != NULL; ep = ep->next) {
                if (ep->kp == NULL) {
                        ep->args = "-";
                        continue;
                }
                ep->args = fmt_argv(kvm_getargv(kd, ep->kp, argwidth),
                    ep->kp->kp_comm, MAXCOMLEN);
                if (ep->args == NULL)
                        err(1, NULL);
        }
        /* 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;
                }
        } else if (ehead != NULL) {
                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;
                }
        }

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

        for (ep = ehead; ep != NULL; ep = ep->next) {
                char host_buf[UTX_HOSTSIZE + 1];

                host_buf[UTX_HOSTSIZE] = '\0';
                strncpy(host_buf, ep->host, maxhost);
                p = *host_buf ? host_buf : "-";
                if ((x = strchr(p, ':')) != NULL)
                        *x++ = '\0';
                if (!nflag && isdigit(*p) &&
                    (l = inet_addr(p)) != INADDR_NONE &&
                    (hp = gethostbyaddr(&l, sizeof(l), AF_INET))) {
                        if (domain[0] != '\0') {
                                p = hp->h_name;
                                p += strlen(hp->h_name);
                                p -= strlen(domain);
                                if (p > hp->h_name &&
                                    strcasecmp(p, domain) == 0)
                                        *p = '\0';
                        }
                        p = hp->h_name;
                }
                if (nflag && *p && strcmp(p, "-") &&
                    inet_addr(p) == INADDR_NONE) {
                        hp = gethostbyname(p);

                        if (hp != NULL) {
                                struct in_addr in;

                                memmove(&in, hp->h_addr, sizeof(in));
                                p = inet_ntoa(in);
                        }
                }
                if (x) {
                        (void)snprintf(buf, sizeof(buf), "%s:%s", p, x);
                        p = buf;
                }
                if (dflag) {
                        for (scan = ep->list; scan; scan = scan->next) {
                                char *ptr;

                                ptr = fmt_argv(kvm_getargv(kd, scan->kp,
                                                           argwidth),
                                               scan->kp->kp_comm,
                                               MAXCOMLEN);
                                if (ptr == NULL)
                                        ptr = "-";
                                printf("\t\t%-9d %s\n", scan->kp->kp_pid, ptr);
                        }
                }
                (void)printf("%-*.*s %-*.*s %-*.*s ",
                    maxname, maxname, ep->name,
                    maxline, maxline,
                    strncmp(ep->line, "tty", 3) &&
                    strncmp(ep->line, "cua", 3) ?
                    ep->line : ep->line + 3,
                    maxhost, maxhost, *p ? p : "-");
                then = (time_t)ep->tv.tv_sec;
                pr_attime(&then, &now);
                longidle = pr_idle(ep->idle);
                (void)printf("%.*s\n", argwidth - longidle, ep->args);
        }
        (void)kvm_close(kd);
        exit(0);
}

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

        /*
         * Print time of day. (use "AM"/"PM" for all locales)
         */
        (void)strftime_l(buf, sizeof(buf) - 1,
                       use_ampm ? "%l:%M%p" : "%k:%M",
                       localtime(nowp), NULL);
        buf[sizeof(buf) - 1] = '\0';
        (void)printf("%s ", buf);

        /*
         * Print how long system has been up.
         *
         * Use clock_gettime() rather than trying to calculate
         * a realtime delta that would be subject to time and date
         * changes.
         */
        if (clock_gettime(CLOCK_UPTIME, &boot_ts) == 0) {
                uptime = boot_ts.tv_sec;
                if (uptime > 60)
                        uptime += 30;
                days = uptime / 86400;
                uptime %= 86400;
                hrs = uptime / 3600;
                uptime %= 3600;
                mins = uptime / 60;
                secs = 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" : "");
                else if (mins > 0)
                        (void)printf(" %d min%s,", mins, mins > 1 ? "s" : "");
                else
                        (void)printf(" %d sec%s,", secs, secs > 1 ? "s" : "");
        }

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

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

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

        (void)snprintf(ttybuf, sizeof(ttybuf), "%s%.*s", _PATH_DEV, sz, line);
        if (stat(ttybuf, &sb)) {
                warn("%s", ttybuf);
                return (NULL);
        }
        return (&sb);
}

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

static int 
this_is_uptime(const char *s)
{
        const char *u;

        if ((u = strrchr(s, '/')) != NULL)
                ++u;
        else
                u = s;
        if (strcmp(u, "uptime") == 0)
                return (0);
        return (-1);
}

static void
process(struct entry *ep)
{
        struct stat *stp;
        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;

        if (!(stp = ttystat(ep->line, maxline)))
                return; /* corrupted record */

        ep->tdev = stp->st_rdev;
#ifdef CPU_CONSDEV
        /*
         * 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_MACHDEP;
                mib[1] = CPU_CONSDEV;
                size = sizeof(dev_t);
                (void)sysctl(mib, 2, &ep->tdev, &size, NULL, 0);
        }
#endif

        touched = stp->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;
}