cmd/utmp_update/utmp_update.c

	utmp_update.c revision d2117003c7d0588abeea5ed1b925b77f025e2c96
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * CDDL HEADER START
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * The contents of this file are subject to the terms of the
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Common Development and Distribution License, Version 1.0 only
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * (the "License").  You may not use this file except in compliance
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * with the License.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * or http://www.opensolaris.org/os/licensing.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * See the License for the specific language governing permissions
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * and limitations under the License.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * When distributing Covered Code, include this CDDL HEADER in each
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * If applicable, add the following below this CDDL HEADER, with the
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * fields enclosed by brackets "[]" replaced with your own identifying
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * information: Portions Copyright [yyyy] [name of copyright owner]
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * CDDL HEADER END
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Use is subject to license terms.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#pragma ident   "%Z%%M% %I% %E% SMI"
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * utmp_update      - Update the /var/adm/utmpx file
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          As of on28, the utmp interface is obsolete,
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          so we only handle updating the utmpx file now.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          The utmpx routines in libc "simulate" calls
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          to manipulate utmp entries.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          This program runs set uid root on behalf of
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          non-privileged user programs.  Normal programs cannot
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          write to /var/adm/utmpx. Non-root callers of pututxline
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          will invoke this program to write the utmpx entry.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Header files
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <stdio.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <sys/param.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <sys/types.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <sys/stat.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <utmpx.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <errno.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <fcntl.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <string.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <stdlib.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <unistd.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <pwd.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <ctype.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <stropts.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <syslog.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Invocation argument definitions
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define UTMPX_NARGS 14
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Return codes
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define NORMAL_EXIT     0
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define BAD_ARGS        1
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define PUTUTXLINE_FAILURE  2
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define FORK_FAILURE        3
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define SETSID_FAILURE      4
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define ALREADY_DEAD        5
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define ENTRY_NOTFOUND      6
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define ILLEGAL_ARGUMENT    7
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Sizes
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define MAX_SYSLEN  257     /* From utmpx.h host length + nul */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define BUF_SIZE    256
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Other defines
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define ROOT_UID    0
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Debugging support
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifdef DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define dprintf printf
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define dprintf3 printf
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void display_args();
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#else /* DEBUG */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define dprintf(x, y)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define dprintf3(w, x, y, z)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * Local functions
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void load_utmpx_struct(struct utmpx *, char **);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void usage(void);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void check_utmpx(struct utmpx *);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int bad_hostname(char *, int);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int hex2bin(unsigned char);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int invalid_utmpx(struct utmpx *, struct utmpx *);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int bad_line(char *);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void check_id(char *, char *);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinmain(int argc, char *argv[])
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    struct utmpx *rutmpx;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    struct utmpx entryx;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#ifdef  DEBUG
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    int debugger = 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    printf("%d\n", getpid());
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /*  Uncomment the following for attaching with dbx(1)   */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /* while  (debugger) ; */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    display_args(argc, argv);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#endif  /*  DEBUG   */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * We will always be called by pututxline, so simply
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * verify the correct number of args
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if (argc != UTMPX_NARGS) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        usage();
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (BAD_ARGS);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * we should never be called by root the code in libc already
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * updates the file for root so no need to do it here. This
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * assumption simpilfies the rest of code since we nolonger
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * have to do special processing for the case when we are called
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * by root
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if (getuid() == ROOT_UID) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        usage();
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (ILLEGAL_ARGUMENT);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * Search for matching entry by line name before put operation
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * (scan over the whole file using getutxent(3C) to ensure
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * that the line name is the same. We can not use getutline(3C)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * because that will return LOGIN_PROCESS and USER_PROCESS
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * records. Also check that the entry is for either a dead
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * process or a current process that is valid (see
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     * invalid_utmpx() for details of validation criteria).
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin     */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    load_utmpx_struct(&entryx, argv);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    check_utmpx(&entryx);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    for (rutmpx = getutxent(); rutmpx != (struct utmpx *)NULL;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        rutmpx = getutxent()) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        if (strncmp(entryx.ut_line, rutmpx->ut_line,
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            sizeof (entryx.ut_line)) == 0) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if (rutmpx->ut_type == DEAD_PROCESS) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            if (rutmpx->ut_type == USER_PROCESS) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                if (invalid_utmpx(&entryx, rutmpx)) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    usage();
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    return (ILLEGAL_ARGUMENT);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                } else {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                    break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin                }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin            }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if (pututxline(&entryx) == (struct utmpx *)NULL) {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (PUTUTXLINE_FAILURE);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    return (NORMAL_EXIT);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic int
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinhex2bin(unsigned char c)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    if ('0' <= c && c <= '9')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (c - '0');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    else if ('A' <= c && c <= 'F')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (10 + c - 'A');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    else if ('a' <= c && c <= 'f')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        return (10 + c - 'a');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    dprintf("Bad hex character: 0x%x\n", c);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    exit(ILLEGAL_ARGUMENT);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    /* NOTREACHED */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * load_utmpx_struct    - Load up the utmpx structure with information supplied
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *          as arguments in argv.
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic void
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinload_utmpx_struct(struct utmpx *entryx, char *argv[])
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    char *user, *id, *line, *pid, *type, *term, *time_usec,
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin        *exitstatus, *xtime, *session, *pad, *syslen, *host;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    int temp, i;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    unsigned char *cp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    (void) memset(entryx, 0, sizeof (struct utmpx));
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    user    = argv[1];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    id  = argv[2];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    line    = argv[3];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    pid     = argv[4];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    type    = argv[5];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    term    = argv[6];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    exitstatus = argv[7];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    xtime   = argv[8];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin    time_usec = argv[9 ];
    session = argv[10];
    pad     = argv[11];
    syslen  = argv[12];
    host    = argv[13];

    (void) strncpy(entryx->ut_user, user, sizeof (entryx->ut_user));
    (void) strncpy(entryx->ut_id, id, sizeof (entryx->ut_id));
    (void) strncpy(entryx->ut_line, line, sizeof (entryx->ut_line));

    (void) sscanf(pid, "%d", &temp);
    entryx->ut_pid = temp;

    (void) sscanf(type, "%d", &temp);
    entryx->ut_type = temp;

    (void) sscanf(term, "%d", &temp);
    entryx->ut_exit.e_termination = temp;

    (void) sscanf(exitstatus, "%d", &temp);
    entryx->ut_exit.e_exit = temp;
    /*
     * Here's where we stamp the exit field of a USER_PROCESS
     * record so that we know it was written by a normal user.
     */

    if (entryx->ut_type == USER_PROCESS)
        setuserx(*entryx);

    (void) sscanf(xtime, "%d", &temp);
    entryx->ut_tv.tv_sec = temp;

    (void) sscanf(time_usec, "%d", &temp);
    entryx->ut_tv.tv_usec = temp;

    (void) sscanf(session, "%d", &temp);
    entryx->ut_session = temp;

    temp = strlen(pad);
    cp = (unsigned char *)entryx->pad;
    for (i = 0; i < temp && (i>>1) < sizeof (entryx->pad); i += 2)
        cp[i>>1] = hex2bin(pad[i]) << 4 | hex2bin(pad[i+1]);

    (void) sscanf(syslen, "%d", &temp);
    entryx->ut_syslen = temp;

    (void) strlcpy(entryx->ut_host, host, sizeof (entryx->ut_host));
}

/*
 * usage    - There's no need to say more.  This program isn't supposed to
 *      be executed by normal users directly.
 */

static void
usage()
{
    syslog(LOG_ERR, "Wrong number of arguments or invalid user \n");
}

/*
 * check_utmpx  - Verify the utmpx structure
 */

static void
check_utmpx(struct utmpx *entryx)
{
    char buf[BUF_SIZE];
    char *line = buf;
    struct passwd *pwd;
    int uid;
    int hostlen;
    char    *user;
    uid_t   ruid = getuid();

    (void) memset(buf, 0, BUF_SIZE);
    user = malloc(sizeof (entryx->ut_user) +1);
    (void) strncpy(user, entryx->ut_user, sizeof (entryx->ut_user));
    user[sizeof (entryx->ut_user)] = '\0';
    pwd = getpwnam(user);
    (void) free(user);

    (void) strlcat(strcpy(buf, "/dev/"), entryx->ut_line, sizeof (buf));

    if (pwd != (struct passwd *)NULL) {
        uid = pwd->pw_uid;
        /*
         * We nolonger permit the UID of the caller to be different
         * the UID to be written to the utmp file. This was thought
         * necessary to allow the utmp file to be updated when
         * logging out from an xterm(1) window after running
         * exec login. Instead we now rely upon utmpd(1) to update
         * the utmp file for us.
         *
         */

        if (ruid != uid) {
            dprintf3("Bad uid: user %s  = %d uid = %d \n",
                entryx->ut_user, uid, getuid());
            exit(ILLEGAL_ARGUMENT);
        }

    } else if (entryx->ut_type != DEAD_PROCESS) {
        dprintf("Bad user name: %s \n", entryx->ut_user);
        exit(ILLEGAL_ARGUMENT);
    }

    /*
     * Only USER_PROCESS and DEAD_PROCESS entries may be updated
     */
    if (!(entryx->ut_type == USER_PROCESS ||
        entryx->ut_type == DEAD_PROCESS)) {
        dprintf("Bad type type = %d\n", entryx->ut_type);
        exit(ILLEGAL_ARGUMENT);
    }

    /*
     * Verify that the pid of the entry field is the same pid as our
     * parent, who should be the guy writing the entry.  This is commented
     * out for now because this restriction is overkill.
     */
#ifdef  VERIFY_PID
    if (entryx->ut_type == USER_PROCESS && entryx->ut_pid != getppid()) {
        dprintf("Bad pid = %d\n", entryx->ut_pid);
        exit(ILLEGAL_ARGUMENT);
    }
#endif  /* VERIFY_PID */

    if (bad_line(line) == 1) {
        dprintf("Bad line = %s\n", line);
        exit(ILLEGAL_ARGUMENT);
    }

    hostlen = strlen(entryx->ut_host) + 1;
    if (entryx->ut_syslen != hostlen) {
        dprintf3("Bad syslen of \"%s\" = %d - correcting to %d\n",
            entryx->ut_host, entryx->ut_syslen, hostlen);
        entryx->ut_syslen = hostlen;
    }

    if (bad_hostname(entryx->ut_host, entryx->ut_syslen) == 1) {
        dprintf("Bad hostname name = %s\n", entryx->ut_host);
        exit(ILLEGAL_ARGUMENT);
    }
    check_id(entryx->ut_id, entryx->ut_line);
}

/*
 * bad_hostname     - Previously returned an error if a non alpha numeric
 *          was in the host field, but now just clears those so
 *          cmdtool entries will work.
 */

static int
bad_hostname(char *name, int len)
{
    int i;

    if (len < 0 || len > MAX_SYSLEN)
        return (1);
    /*
     * Scan for non-alpha numerics
     * Per utmpx.h, len includes the nul character.
     */
    for (i = 0; i < len; i++)
        if (name[i] != '\0' && isprint(name[i]) == 0)
            name[i] = ' ';
    return (0);
}

/*
 * Workaround until the window system gets fixed.  Look for id's with
 * a '/' in them.  That means they are probably from libxview.
 * Then create a new id that is unique using the last 4 chars in the line.
 */

static void
check_id(char *id, char *line)
{
    int i, len;

    if (id[1] == '/' && id[2] == 's' && id[3] == 't') {
        len = strlen(line);
        if (len > 0)
            len--;
        for (i = 0; i < 4; i++)
            id[i] = len - i < 0 ? 0 : line[len-i];
    }
}


/*
 * The function invalid_utmpx() enforces the requirement that the record
 * being updating in the utmpx file can not have been created by login(1)
 * or friends. Also that the id and username of the record to be written match
 * those found in the utmpx file. We need this both for security and to ensure
 * that pututxline(3C) will NOT reposition the file pointer in the utmpx file,
 * so that the record is updated in place.
 *
 */
static int
invalid_utmpx(struct utmpx *eutmpx, struct utmpx *rutmpx)
{
#define SUTMPX_ID   (sizeof (eutmpx->ut_id))
#define SUTMPX_USER (sizeof (eutmpx->ut_user))

    return (!nonuserx(*rutmpx) ||
        strncmp(eutmpx->ut_id, rutmpx->ut_id, SUTMPX_ID) != 0 ||
        strncmp(eutmpx->ut_user, rutmpx->ut_user, SUTMPX_USER) != 0);
}

static int
bad_line(char *line)
{
    struct stat statbuf;
    int fd;

    /*
     * The line field must be a device file that we can write to,
     * it should live under /dev which is enforced by requiring
     * its name not to contain "../" and opening it as the user for
     * writing.
     */
    if (strstr(line, "../") != 0) {
        dprintf("Bad line = %s\n", line);
        return (1);
    }

    /*
     * It has to be a tty. It can't be a bogus file, e.g. ../tmp/bogus.
     */
    if (seteuid(getuid()) != 0)
        return (1);

    /*
     * Check that the line refers to a character
     * special device see bugid: 1136978
     */
    if ((stat(line, &statbuf) < 0) || (statbuf.st_mode & S_IFCHR) == 0) {
        dprintf("Bad line (stat failed) (Not S_IFCHR) = %s\n", line);
        return (1);
    }

    /*
     * We need to open the line without blocking so that it does not hang
     */
    if ((fd = open(line, O_WRONLY|O_NOCTTY|O_NONBLOCK)) == -1) {
        dprintf("Bad line (Can't open/write) = %s\n", line);
        return (1);
    }

    /*
     * Check that fd is a tty, if this fails all is not lost see below
     */
    if (isatty(fd) == 1) {
        /*
         * It really is a tty, so return success
         */
        (void) close(fd);
        if (seteuid(ROOT_UID) != 0)
            return (1);
        return (0);
    }

    /*
     * Check that the line refers to a character
     * special device see bugid: 1136978
     */
    if ((fstat(fd, &statbuf) < 0) || (statbuf.st_mode & S_IFCHR) == 0) {
        dprintf("Bad line (fstat failed) (Not S_IFCHR) = %s\n", line);
        (void) close(fd);
        return (1);
    }

    /*
     * Check that the line refers to a streams device
     */
    if (isastream(fd) != 1) {
        dprintf("Bad line (isastream failed) = %s\n", line);
        (void) close(fd);
        return (1);
    }

    /*
     * if isatty(3C) failed above we assume that the ptem module has
     * been popped already and that caused the failure, so we push it
     * and try again
     */
    if (ioctl(fd, I_PUSH, "ptem") == -1) {
        dprintf("Bad line (I_PUSH of \"ptem\" failed) = %s\n", line);
        (void) close(fd);
        return (1);
    }

    if (isatty(fd) != 1) {
        dprintf("Bad line (isatty failed) = %s\n", line);
        (void) close(fd);
        return (1);
    }

    if (ioctl(fd, I_POP, 0) == -1) {
        dprintf("Bad line (I_POP of \"ptem\" failed) = %s\n", line);
        (void) close(fd);
        return (1);
    }

    (void) close(fd);

    if (seteuid(ROOT_UID) != 0)
        return (1);

    return (0);

}

#ifdef  DEBUG

/*
 * display_args     - This code prints out invocation arguments
 *          This is helpful since the program is called with
 *          up to 15 argumments.
 */

static void
display_args(argc, argv)
    int argc;
    char **argv;
{
    int i = 0;

    while (argc--) {
        printf("Argument #%d = %s\n", i, argv[i]);
        i++;
    }
}

fputmpx(struct utmpx *rutmpx)
{
    printf("ut_user = \"%-32.32s\" \n", rutmpx->ut_user);
    printf("ut_id = \"%-4.4s\" \n", rutmpx->ut_id);
    printf("ut_line = \"%-32.32s\" \n", rutmpx->ut_line);
    printf("ut_pid = \"%d\" \n", rutmpx->ut_pid);
    printf("ut_type = \"%d\" \n", rutmpx->ut_type);
    printf("ut_exit.e_termination = \"%d\" \n",
        rutmpx->ut_exit.e_termination);
    printf("ut_exit.e_exit = \"%d\" \n", rutmpx->ut_exit.e_exit);
}

#endif /* DEBUG */