/*      $NetBSD: last.c,v 1.36 2012/03/15 03:04:05 dholland Exp $       */

/*
 * Copyright (c) 1987, 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) 1987, 1993, 1994\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)last.c      8.2 (Berkeley) 4/2/94";
#endif
__RCSID("$NetBSD: last.c,v 1.36 2012/03/15 03:04:05 dholland Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#include <arpa/inet.h>
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif
#ifdef SUPPORT_UTMP
#include <utmp.h>
#endif
#include <util.h>

#ifndef UT_NAMESIZE
#define UT_NAMESIZE 8
#define UT_LINESIZE 8
#define UT_HOSTSIZE 16
#endif
#ifndef SIGNATURE
#define SIGNATURE -1
#endif



#define NO      0                       /* false/no */
#define YES     1                       /* true/yes */

#define TBUFLEN 30                      /* length of time string buffer */
#define TFMT    "%a %b %d %R"           /* strftime format string */
#define LTFMT   "%a %b %d %Y %T"        /* strftime long format string */
#define TFMTS   "%R"                    /* strftime format string - time only */
#define LTFMTS  "%T"                    /* strftime long format string - " */

/* fmttime() flags */
#define FULLTIME        0x1             /* show year, seconds */
#define TIMEONLY        0x2             /* show time only, not date */
#define GMT             0x4             /* show time at GMT, for offsets only */

#define MAXUTMP         1024

typedef struct arg {
        const char      *name;          /* argument */
#define HOST_TYPE       -2
#define TTY_TYPE        -3
#define USER_TYPE       -4
        int             type;           /* type of arg */
        struct arg      *next;          /* linked list pointer */
} ARG;
static ARG      *arglist;               /* head of linked list */

typedef struct ttytab {
        time_t  logout;                 /* log out time */
        char    tty[128];               /* terminal name */
        struct ttytab   *next;          /* linked list pointer */
} TTY;
static TTY      *ttylist;               /* head of linked list */

static time_t   currentout;             /* current logout value */
static long     maxrec;                 /* records to display */
static int      fulltime = 0;           /* Display seconds? */
static int      xflag;                  /* Assume file is wtmpx format */

static void      addarg(int, const char *);
static TTY      *addtty(const char *);
static void      hostconv(char *);
static const char *ttyconv(char *);
#ifdef SUPPORT_UTMPX
static void      wtmpx(const char *, int, int, int, int);
#endif
#ifdef SUPPORT_UTMP
static void      wtmp(const char *, int, int, int, int);
#endif
static char     *fmttime(time_t, int);
__dead static void       usage(void);

static
void usage(void)
{
        (void)fprintf(stderr, "usage: %s [-#%s] [-nTx] [-f file]"
            " [-H hostsize] [-h host] [-L linesize]\n"
            "\t    [-N namesize] [-t tty] [user ...]\n", getprogname(),
#ifdef NOTYET_SUPPORT_UTMPX
            "w"
#else
            ""
#endif
        );
        exit(EXIT_FAILURE);
}

int
main(int argc, char *argv[])
{
        int ch;
        char *p;
        const char *file = NULL;
        int namesize = UT_NAMESIZE;
        int linesize = UT_LINESIZE;
        int hostsize = UT_HOSTSIZE;
        int numeric = 0;

        maxrec = -1;

        while ((ch = getopt(argc, argv, "0123456789f:H:h:L:nN:Tt:x")) != -1)
                switch (ch) {
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                        /*
                         * kludge: last was originally designed to take
                         * a number after a dash.
                         */
                        if (maxrec == -1) {
                                p = argv[optind - 1];
                                if (p[0] == '-' && p[1] == ch && !p[2])
                                        maxrec = atol(++p);
                                else if (optind < argc)
                                        maxrec = atol(argv[optind] + 1);
                                else
                                        usage();
                                if (!maxrec)
                                        return 0;
                        }
                        break;
                case 'f':
                        file = optarg;
                        if ('\0' == file[0])
                                usage();
                        break;
                case 'H':
                        hostsize = atoi(optarg);
                        if (hostsize < 1)
                                usage();
                        break;
                case 'h':
                        hostconv(optarg);
                        addarg(HOST_TYPE, optarg);
                        break;
                case 'L':
                        linesize = atoi(optarg);
                        if (linesize < 1)
                                usage();
                        break;
                case 'N':
                        namesize = atoi(optarg);
                        if (namesize < 1)
                                usage();
                        break;
                case 'n':
                        numeric = 1;
                        break;
                case 'T':
                        fulltime = 1;
                        break;
                case 't':
                        addarg(TTY_TYPE, ttyconv(optarg));
                        break;
                case 'x':
                        xflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }

        if (argc) {
                setlinebuf(stdout);
                for (argv += optind; *argv; ++argv) {
#define COMPATIBILITY
#ifdef  COMPATIBILITY
                        /* code to allow "last p5" to work */
                        addarg(TTY_TYPE, ttyconv(*argv));
#endif
                        addarg(USER_TYPE, *argv);
                }
        }
        if (file == NULL) {
#ifdef SUPPORT_UTMPX
                if (access(_PATH_WTMPX, R_OK) == 0)
                        file = _PATH_WTMPX;
                else
#endif
#ifdef SUPPORT_UTMP
                if (access(_PATH_WTMP, R_OK) == 0)
                        file = _PATH_WTMP;
#endif
                if (file == NULL)
#if defined(SUPPORT_UTMPX) && defined(SUPPORT_UTMP)
                        errx(EXIT_FAILURE, "Cannot access `%s' or `%s'", _PATH_WTMPX,
                            _PATH_WTMP);
#elif defined(SUPPORT_UTMPX)
                        errx(EXIT_FAILURE, "Cannot access `%s'", _PATH_WTMPX);
#elif defined(SUPPORT_UTMP)
                        errx(EXIT_FAILURE, "Cannot access `%s'", _PATH_WTMP);
#else
                        errx(EXIT_FAILURE, "No utmp or utmpx support compiled in.");
#endif
        }
#if defined(SUPPORT_UTMPX) && defined(SUPPORT_UTMP)
        if (file[strlen(file) - 1] == 'x' || xflag)
                wtmpx(file, namesize, linesize, hostsize, numeric);
        else
                wtmp(file, namesize, linesize, hostsize, numeric);
#elif defined(SUPPORT_UTMPX)
        wtmpx(file, namesize, linesize, hostsize, numeric);
#elif defined(SUPPORT_UTMP)
        wtmp(file, namesize, linesize, hostsize, numeric);
#else
        errx(EXIT_FAILURE, "No utmp or utmpx support compiled in.");
#endif
        exit(EXIT_SUCCESS);
}


/*
 * addarg --
 *      add an entry to a linked list of arguments
 */
static void
addarg(int type, const char *arg)
{
        ARG *cur;

        if (!(cur = (ARG *)malloc(sizeof(ARG))))
                err(EXIT_FAILURE, "malloc failure");
        cur->next = arglist;
        cur->type = type;
        cur->name = arg;
        arglist = cur;
}

/*
 * addtty --
 *      add an entry to a linked list of ttys
 */
static TTY *
addtty(const char *tty)
{
        TTY *cur;

        if (!(cur = (TTY *)malloc(sizeof(TTY))))
                err(EXIT_FAILURE, "malloc failure");
        cur->next = ttylist;
        cur->logout = currentout;
        memmove(cur->tty, tty, sizeof(cur->tty));
        return (ttylist = cur);
}

/*
 * hostconv --
 *      convert the hostname to search pattern; if the supplied host name
 *      has a domain attached that is the same as the current domain, rip
 *      off the domain suffix since that's what login(1) does.
 */
static void
hostconv(char *arg)
{
        static int first = 1;
        static char *hostdot, name[MAXHOSTNAMELEN + 1];
        char *argdot;

        if (!(argdot = strchr(arg, '.')))
                return;
        if (first) {
                first = 0;
                if (gethostname(name, sizeof(name)))
                        err(EXIT_FAILURE, "gethostname");
                name[sizeof(name) - 1] = '\0';
                hostdot = strchr(name, '.');
        }
        if (hostdot && !strcasecmp(hostdot, argdot))
                *argdot = '\0';
}

/*
 * ttyconv --
 *      convert tty to correct name.
 */
static const char *
ttyconv(char *arg)
{
        char *mval;

        if (!strcmp(arg, "co"))
                return ("console");
        /*
         * kludge -- we assume that all tty's end with
         * a two character suffix.
         */
        if (strlen(arg) == 2) {
                if (asprintf(&mval, "tty%s", arg) == -1)
                        err(EXIT_FAILURE, "malloc failure");
                return (mval);
        }
        if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
                return (&arg[sizeof(_PATH_DEV) - 1]);
        return (arg);
}

/*
 * fmttime --
 *      return pointer to (static) formatted time string.
 */
static char *
fmttime(time_t t, int flags)
{
        struct tm *tm;
        static char tbuf[TBUFLEN];

        tm = (flags & GMT) ? gmtime(&t) : localtime(&t);
        if (tm == NULL) {
                strcpy(tbuf, "????");
                return tbuf;
        }
        strftime(tbuf, sizeof(tbuf),
            (flags & TIMEONLY)
             ? (flags & FULLTIME ? LTFMTS : TFMTS)
             : (flags & FULLTIME ? LTFMT : TFMT),
            tm);
        return (tbuf);
}

#ifdef SUPPORT_UTMP
#define TYPE(a) 0
#define NAMESIZE UT_NAMESIZE
#define LINESIZE UT_LINESIZE
#define HOSTSIZE UT_HOSTSIZE
#define ut_timefld ut_time
#define HAS_UT_SS 0
#include "want.c"
#undef TYPE /*(a)*/
#undef NAMESIZE
#undef LINESIZE
#undef HOSTSIZE
#undef ut_timefld
#undef HAS_UT_SS
#endif

#ifdef SUPPORT_UTMPX
#define utmp utmpx
#define want wantx
#define wtmp wtmpx
#define gethost gethostx
#define buf bufx
#define onintr onintrx
#define TYPE(a) (a)->ut_type
#define NAMESIZE UTX_USERSIZE
#define LINESIZE UTX_LINESIZE
#define HOSTSIZE UTX_HOSTSIZE
#define ut_timefld ut_xtime
#define HAS_UT_SS 1
#include "want.c"
#endif