cmd/bnu/unknown.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


#pragma ident   "%Z%%M% %I% %E% SMI"
/*
 *  logs attempts by unknown remote machines to run uucico in FOREIGN
 *  ("/var/uucp/.Admin/Foreign").  if anything goes wrong,
 *  sends mail to login MAILTO ("uucp").  the executable should be
 *  placed in /usr/lib/uucp/remote.unknown, and should run setuid-uucp.
 */

#include    <stdio.h>
#include    <sys/types.h>
#include    <time.h>
#include    <errno.h>
#include    "uucp.h"

#define FOREIGN "/var/uucp/.Admin/Foreign"
#define MAILTO  "uucp"
#define LOGLEN  256

void fall_on_sword();

int
main(argc, argv)
int argc;
char    *argv[];
{
    char        buf[LOGLEN], *ctoday, *logname, tmpbuf[MAXBASENAME+1];
    FILE        *fp;
    time_t      today;
    extern char *ctime();
    extern FILE *fopen();

    if ( argc != 2 ) {
        (void) fprintf(stderr, "USAGE: %s remotename\n", argv[0]);
        exit(101);
    }

    if ( time(&today) != -1 ) {
        ctoday = ctime(&today);
        *(ctoday + strlen(ctoday) - 1) = '\0';  /* no ending \n */
    } else
        ctoday = "NO DATE";

    logname = cuserid((char *) NULL);
    (void) strncpy(tmpbuf, argv[1], MAXBASENAME);
    tmpbuf[MAXBASENAME] = '\0';
    (void) snprintf(buf, sizeof(buf), "%s: call from system %s login %s\n",
        ctoday, tmpbuf, (logname == NULL ? "<unknown>" : logname));

    errno = 0;
    if ( (fp = fopen(FOREIGN, "a+")) == (FILE *)NULL )
        fall_on_sword("cannot open", buf);
    if ( fputs(buf, fp) == EOF )
        fall_on_sword("cannot write", buf);
    if ( fclose(fp) != 0 )
        fall_on_sword("cannot close", buf);

    return (0);
}

/* don't return from here */
void
fall_on_sword(errmsg, logmsg)
char    *errmsg, *logmsg;
{
    char        ebuf[BUFSIZ+1];
    int     fds[2];
    size_t      sz;

    (void) snprintf(ebuf, BUFSIZ,
        "To: %s\nSubject: %s %s\n\n%s %s:\t%s (%d)\nlog msg:\t%s",
        MAILTO, errmsg, FOREIGN, errmsg, FOREIGN,
        strerror(errno), errno, logmsg);
    sz = strlen(ebuf);
    if (ebuf[sz-1] != '\n') {
        ebuf[sz] = '\n';
        ebuf[sz+1] = '\0';
    }

    /* reset to real uid. get a pipe. put error message on  */
    /* "write end" of pipe, close it. dup "read end" to */
    /* stdin and then execl mail (which will read the error */
    /* message we just wrote).              */

    if ( setuid(getuid()) == -1 || pipe(fds) != 0
    || write(fds[1], ebuf, strlen(ebuf)) != strlen(ebuf)
    || close(fds[1]) != 0 )
        exit(errno);

    if ( fds[0] != 0 ) {
        close(0);
        if ( dup(fds[0]) != 0 )
            exit(errno);
    }

    execl("/usr/bin/mail", "mail", MAILTO, (char *) 0);
    exit(errno);    /* shouldn't get here */
}