cmd/ttymon/tmexpress.c

	tmexpress.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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 2004 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"

#include    <stdio.h>
#include    <stdlib.h>
#include    <unistd.h>
#include    <fcntl.h>
#include    <errno.h>
#include    <ctype.h>
#include    <string.h>
#include    <signal.h>
#include    <sys/stat.h>
#include    <utmpx.h>
#include    <pwd.h>
#include    <dirent.h>
#include    <sys/param.h>
#include    <sys/acl.h>
#include    "ttymon.h"
#include    "tmextern.h"
#include    "tmstruct.h"

static  char    devbuf[BUFSIZ];
static  char    *devname;

static  int parse_args();
static  void    ttymon_options();
static  void    getty_options();
static  void    usage();
static  char    *find_ttyname();

extern  void    tmchild();
extern  int vml();

void        revokedevaccess(char *, uid_t, gid_t, mode_t);
/* cannot include libdevinfo.h */
extern int di_devperm_logout(const char *);

/*
 * ttymon_express - This is call when ttymon is invoked with args
 *          or invoked as getty
 *        - This special version of ttymon will monitor
 *          one port only
 *        - It is intended to be used when some process
 *          wants to have a login session on the fly
 */
void
ttymon_express(int argc, char **argv)
{
    struct  pmtab   *pmtab;
    struct  sigaction   sigact;
    extern  int Retry;
    extern  void    open_device();
    extern  void    read_ttydefs();
    extern  int checkut_line();
#ifdef  DEBUG
    extern  FILE    *Debugfp;
    extern  void    opendebug();
#endif

#ifdef  DEBUG
    opendebug(TRUE);
#endif

    sigact.sa_flags = 0;
    sigact.sa_handler = SIG_IGN;
    (void) sigemptyset(&sigact.sa_mask);
    (void) sigaction(SIGINT, &sigact, NULL);

    if ((pmtab = ALLOC_PMTAB) == PNULL) {
        log("ttymon_express: ALLOC_PMTAB failed");
        exit(1);
    }

    if (parse_args(argc, argv, pmtab) != 0) {
        log("ttymon_express: parse_args failed");
        exit(1);
    }

    read_ttydefs(NULL, FALSE);

    if ((pmtab->p_device != NULL) && (*(pmtab->p_device) != '\0') &&
        strcmp(pmtab->p_device, "/dev/console") == 0) {
        while (checkut_line(pmtab->p_device))
            sleep(15);
    }

    if ((pmtab->p_device == NULL) || (*(pmtab->p_device) == '\0')) {
        devname = find_ttyname(0);
        if ((devname == NULL) || (*devname == '\0')) {
            log("ttyname cannot find the device on fd 0");
            exit(1);
        }
        pmtab->p_device = devname;
#ifdef  DEBUG
        debug("ttymon_express: devname = %s", devname);
#endif
        /*
         * become session leader
         * fd 0 is closed and reopened just to make sure
         * controlling tty is set up right
         */
        (void) setsid();
        (void) close(0);
        revokedevaccess(pmtab->p_device, 0, 0, 0);
        if (open(pmtab->p_device, O_RDWR) < 0) {
            log("open %s failed: %s", pmtab->p_device,
                strerror(errno));
            exit(1);
        }
        if ((pmtab->p_modules != NULL) &&
            (*(pmtab->p_modules) != '\0')) {
            if (push_linedisc(0, pmtab->p_modules,
                pmtab->p_device) == -1)
                exit(1);
        }
        if (initial_termio(0, pmtab) == -1)
            exit(1);
        di_devperm_logout((const char *)pmtab->p_device);
    } else {
        (void) setsid();
        (void) close(0);
        Retry = FALSE;
        open_device(pmtab);
        if (Retry)      /* open failed */
            exit(1);
    }
    tmchild(pmtab);
    exit(1);    /*NOTREACHED*/
}

/*
 * parse_arg    - parse cmd line arguments
 */
static  int
parse_args(int argc, char **argv, struct pmtab *pmtab)
{
    static  char    p_server[] = "/usr/bin/login";
    extern  char    *lastname();
    extern  void    getty_account();

    /* initialize fields to some default first */
    pmtab->p_tag = "";
    pmtab->p_flags = 0;
    pmtab->p_identity = "root";
    pmtab->p_res1 = "reserved";
    pmtab->p_res2 = "reserved";
    pmtab->p_res3 = "reserved";
    pmtab->p_uid = 0;
    pmtab->p_gid = 0;
    pmtab->p_dir = "/";
    pmtab->p_ttyflags = 0;
    pmtab->p_count = 0;
    pmtab->p_server = p_server;
    pmtab->p_timeout = 0;
    pmtab->p_modules = "";
    pmtab->p_prompt = "login: ";
    pmtab->p_dmsg = "";
    pmtab->p_termtype = "";
    pmtab->p_device = "";
    pmtab->p_status = GETTY;
    if (strcmp(lastname(argv[0]), "getty") == 0) {
        pmtab->p_ttylabel = "300";
        getty_options(argc, argv, pmtab);
    } else {
        pmtab->p_ttylabel = "9600";
        ttymon_options(argc, argv, pmtab);
    }
    if ((pmtab->p_device != NULL) && (*(pmtab->p_device) != '\0'))
        getty_account(pmtab->p_device); /* utmp accounting */
    return (0);
}


/*
 *  ttymon_options - scan and check args for ttymon express
 */

static  void
ttymon_options(int argc, char **argv, struct pmtab *pmtab)
{
    int     c;          /* option letter */
    char    *timeout;
    int     gflag = 0;      /* -g seen */
    int size = 0;
    char    tbuf[BUFSIZ];

    extern  char    *optarg;
    extern  int optind;
    extern  void    copystr();
    extern  char    *strsave();
    extern  char    *getword();

    while ((c = getopt(argc, argv, "T:gd:ht:p:m:l:")) != -1) {
        switch (c) {
        case 'g':
            gflag = 1;
            break;
        case 'd':
            pmtab->p_device = optarg;
            break;
        case 'h':
            pmtab->p_ttyflags &= ~H_FLAG;
            break;

        case 'T':
            pmtab->p_termtype = optarg;
            break;
/*
 *      case 'b':
 *          pmtab->p_ttyflags |= B_FLAG;
 *          pmtab->p_ttyflags |= R_FLAG;
 *          break;
 */
        case 't':
            timeout = optarg;
            while (*optarg) {
                if (!isdigit(*optarg++)) {
                    log("Invalid argument for "
                        "\"-t\" -- number expected.");
                    usage();
                }
            }
            pmtab->p_timeout = atoi(timeout);
            break;
        case 'p':
            copystr(tbuf, optarg);
            pmtab->p_prompt = strsave(getword(tbuf, &size, TRUE));
            break;
        case 'm':
            pmtab->p_modules = optarg;
            if (vml(pmtab->p_modules) != 0)
                usage();
            break;
        case 'l':
            pmtab->p_ttylabel = optarg;
            break;
        case '?':
            usage();
            break;  /*NOTREACHED*/
        }
    }
    if (optind < argc)
        usage();

    if (!gflag)
        usage();
}

/*
 * usage - print out a usage message
 */

static  void
usage()
{
    char    *umsg = "Usage: ttymon\n  ttymon -g [-h] [-d device] "
        "[-l ttylabel] [-t timeout] [-p prompt] [-m modules]\n";

    if (isatty(STDERR_FILENO))
        (void) fprintf(stderr, "%s", umsg);
    else
        cons_printf(umsg);
    exit(1);
}

/*
 *  getty_options   - this is cut from getty.c
 *          - it scan getty cmd args
 *          - modification is made to stuff args in pmtab
 */
static  void
getty_options(argc, argv, pmtab)
int argc;
char **argv;
struct  pmtab   *pmtab;
{
    char    *ptr;

    /*
     * the pre-4.0 getty's hang_up_line() is a no-op.
     * For compatibility, H_FLAG cannot be set for this "getty".
     */
    pmtab->p_ttyflags &= ~(H_FLAG);

    while (--argc && **++argv == '-') {
        for (ptr = *argv + 1; *ptr; ptr++)
        switch (*ptr) {
        case 'h':
            break;
        case 't':
            if (isdigit(*++ptr)) {
                (void) sscanf(ptr, "%d", &(pmtab->p_timeout));
                while (isdigit(*++ptr));
                ptr--;
            } else if (--argc) {
                if (isdigit(*(ptr = *++argv)))
                    (void) sscanf(ptr, "%d",
                        &(pmtab->p_timeout));
                else {
                    log("getty: timeout argument <%s> "
                        "invalid", *argv);
                    exit(1);
                }
            }
            break;

        case 'c':
            log("Use \"sttydefs -l\" to check /etc/ttydefs.");
            exit(0);
        default:
            break;
        }
    }

    if (argc < 1) {
        log("getty: no terminal line specified.");
        exit(1);
    } else {
        (void) strcat(devbuf, "/dev/");
        (void) strcat(devbuf, *argv);
        pmtab->p_device = devbuf;
    }

    if (--argc > 0) {
        pmtab->p_ttylabel = *++argv;
    }

    /*
     * every thing after this will be ignored
     * i.e. termtype and linedisc are ignored
     */
}

/*
 * find_ttyname(fd)     - find the name of device associated with fd.
 *          - it first tries utmpx to see if an entry exists
 *          - with my pid and ut_line is defined. If ut_line
 *          - is defined, it will see if the major and minor
 *          - number of fd and devname from utmpx match.
 *          - If utmpx search fails, ttyname(fd) will be called.
 */
static  char    *
find_ttyname(fd)
int fd;
{
    pid_t ownpid;
    struct utmpx *u;
    static  struct  stat    statf, statu;
    static  char    buf[BUFSIZ];

    ownpid = getpid();
    setutxent();
    while ((u = getutxent()) != NULL) {
        if (u->ut_pid == ownpid) {
            if (strlen(u->ut_line) != 0) {
                if (*(u->ut_line) != '/') {
                    (void) strcpy(buf, "/dev/");
                    (void) strncat(buf, u->ut_line,
                        sizeof (u->ut_line));
                } else {
                    (void) strncat(buf, u->ut_line,
                        sizeof (u->ut_line));
                }
            }
            else
                u = NULL;
            break;
        }
    }
    endutxent();
    if ((u != NULL) &&
        (fstat(fd, &statf) == 0) &&
        (stat(buf, &statu) == 0) &&
        (statf.st_dev == statu.st_dev) &&
        (statf.st_rdev == statu.st_rdev)) {
#ifdef  DEBUG
            debug("ttymon_express: find device name from utmpx.");
#endif
            return (buf);
    } else {
#ifdef  DEBUG
        debug("ttymon_express: calling ttyname to find device name.");
#endif
        return (ttyname(fd));
    }
}

/*
 * Revoke all access to a device node and make sure that there are
 * no interposed streams devices attached.  Must be called before a
 * device is actually opened.
 * When fdetach is called, the underlying device node is revealed; it
 * will have the previous owner and that owner can re-attach; so we
 * retry until we win.
 * Ignore non-existent devices.
 */
void
revokedevaccess(char *dev, uid_t uid, gid_t gid, mode_t mode)
{
    do {
        if (chown(dev, uid, gid) == -1)
            return;
    } while (fdetach(dev) == 0);

    /* Remove ACLs */
    if (acl(dev, GETACLCNT, 0, NULL) > MIN_ACL_ENTRIES) {
        aclent_t acls[3];

        acls[0].a_type = USER_OBJ;
        acls[0].a_id = uid;
        acls[0].a_perm = 0;

        acls[1].a_type = GROUP_OBJ;
        acls[1].a_id = gid;
        acls[1].a_perm = 0;

        acls[2].a_type = OTHER_OBJ;
        acls[2].a_id = 0;
        acls[2].a_perm = 0;

        (void) acl(dev, SETACL, 3, acls);
    }

    (void) chmod(dev, mode);
}