gss/gssd/gssd.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Usermode daemon which assists the kernel when handling gssapi calls.
 * It is gssd that actually implements all gssapi calls.
 * Some calls, such as gss_sign, are implemented in the kernel on a per
 * mechanism basis.
 */

#include <stdio.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>
#include <sys/syslog.h>
#include <sys/termios.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <sys/systeminfo.h>
#include <stdlib.h>
#include <stropts.h>
#include <fcntl.h>
#include <strings.h>
#include <signal.h>
#include <syslog.h>
#include "gssd.h"

int gssd_debug = 0;     /* enable debugging printfs */
extern void gsscred_set_options(void);

void gssprog_1();
void gssd_setup(char *);
static void usage(void);
static void daemonize_start();
static void daemonize_ready(unsigned char status);
extern int  svc_create_local_service();

/* following declarations needed in rpcgen-generated code */
int _rpcpmstart = 0;        /* Started by a port monitor ? */
int _rpcfdtype;         /* Whether Stream or Datagram ? */
int _rpcsvcdirty;       /* Still serving ? */


static void
/* LINTED */
catch_hup(int sig_num)
{
    sigset_t mask_set;  /* used to set a signal masking set. */
    sigset_t old_set;   /* used to store the old mask set.   */

    /* re-set the signal handler again to catch_hup, for next time */
    (void) signal(SIGHUP, catch_hup);
    /* mask any further signals while we're inside the handler. */
    (void) sigfillset(&mask_set);
    (void) sigprocmask(SIG_SETMASK, &mask_set, &old_set);

    gsscred_set_options();

    /* let admin know the sighup was caught and conf file re-read */
    syslog(LOG_INFO,
        "catch_hup: read gsscred.conf opts");
    if (gssd_debug)
        (void) fprintf(stderr,
            "catch_hup: read gsscred.conf opts");

    (void) sigprocmask(SIG_SETMASK, &old_set, NULL);
}


int
main(argc, argv)
int argc;
char **argv;
{
    register SVCXPRT *transp;
    int maxrecsz = RPC_MAXDATASIZE;
    extern int optind;
    int c;
    char mname[FMNAMESZ + 1];

    /* set locale and domain for internationalization */
    setlocale(LC_ALL, "");
    textdomain(TEXT_DOMAIN);


    /*
     * Take special note that "getuid()" is called here.  This call is used
     * rather than app_krb5_user_uid(), to ensure gssd(1M) is running as
     * root.
     */
#ifdef DEBUG
    (void) setuid(0);       /* DEBUG: set ruid to root */
#endif /* DEBUG */
    if (getuid()) {
        (void) fprintf(stderr,
            gettext("[%s] must be run as root\n"), argv[0]);
#ifdef DEBUG
        (void) fprintf(stderr, gettext(" warning only\n"));
#else /* DEBUG */
        exit(1);
#endif /* DEBUG */
    }

    gssd_setup(argv[0]);

    while ((c = getopt(argc, argv, "d")) != -1)
        switch (c) {
            case 'd':
            /* turn on debugging */
            gssd_debug = 1;
            break;
            default:
            usage();
        }

    if (optind != argc) {
        usage();
    }

    gsscred_set_options();
    (void) signal(SIGHUP, catch_hup);

    /*
     * Started by inetd if name of module just below stream
     * head is either a sockmod or timod.
     */
    if (!ioctl(0, I_LOOK, mname) &&
        ((strcmp(mname, "sockmod") == 0) ||
            (strcmp(mname, "timod") == 0))) {

        char *netid;
        struct netconfig *nconf;

        openlog("gssd", LOG_PID, LOG_DAEMON);

        if ((netid = getenv("NLSPROVIDER")) ==  NULL) {
            netid = "ticotsord";
        }

        if ((nconf = getnetconfigent(netid)) == NULL) {
            syslog(LOG_ERR, gettext("cannot get transport info"));
            exit(1);
        }

        if (strcmp(mname, "sockmod") == 0) {
            if (ioctl(0, I_POP, 0) || ioctl(0, I_PUSH, "timod")) {
                syslog(LOG_ERR,
                    gettext("could not get the "
                        "right module"));
                exit(1);
            }
        }
        if (!rpc_control(RPC_SVC_CONNMAXREC_SET, &maxrecsz)) {
            syslog(LOG_ERR,
                gettext("unable to set RPC max record size"));
            exit(1);
        }
        /* XXX - is nconf even needed here? */
        if ((transp = svc_tli_create(0, nconf, NULL, 0, 0)) == NULL) {
            syslog(LOG_ERR, gettext("cannot create server handle"));
            exit(1);
        }

        /*
         * We use a NULL nconf because GSSPROG has already been
         * registered with rpcbind.
         */
        if (!svc_reg(transp, GSSPROG, GSSVERS, gssprog_1, NULL)) {
            syslog(LOG_ERR,
                gettext("unable to register "
                    "(GSSPROG, GSSVERS)"));
            exit(1);
        }

        if (nconf)
            freenetconfigent(nconf);
    } else {
        if (!gssd_debug)
            daemonize_start();

        openlog("gssd", LOG_PID, LOG_DAEMON);

        if (svc_create_local_service(gssprog_1, GSSPROG, GSSVERS,
            "netpath", "gssd") == 0) {
            syslog(LOG_ERR, gettext("unable to create service"));
            exit(1);
        }

        /* service created, now the daemon parent can exit */
        daemonize_ready(0);
    }


    if (gssd_debug) {
        fprintf(stderr,
            gettext("gssd start: \n"));
    }
    svc_run();
    abort();
    /*NOTREACHED*/
#ifdef  lint
    return (1);
#endif
}

static void
usage(void)
{
    (void) fprintf(stderr, gettext("usage: gssd [-dg]\n"));
    exit(1);
}


/*
 * Fork, detach from tty, etc...
 */
static int write_pipe_fd = -1;
static
void
daemonize_start()
{
    int pipe_fds[2];
    unsigned char status = 1;

    closefrom(0);

    /* Open stdin/out/err, chdir, get a pipe */
    if (open("/dev/null", O_RDONLY) < 0 ||
        open("/dev/null", O_WRONLY) < 0 || dup(1) < 0 ||
        chdir("/") < 0 || pipe(pipe_fds) < 0)
        exit(1);

    /* For daemonize_ready() */
    write_pipe_fd = pipe_fds[1];

    switch (fork()) {
    case -1:
        exit(1);
        /* NOTREACHED */
    case 0:
        break;
    default:
        /* Wait for child to be ready befor exiting */
        (void) close(pipe_fds[1]);
        (void) signal(SIGPIPE, SIG_DFL);
        (void) read(pipe_fds[0], &status, sizeof (status));
        exit(status);
    }

    (void) close(pipe_fds[0]);
    (void) setsid();
}

static
void
daemonize_ready(unsigned char status)
{
    if (write_pipe_fd == -1)
        return;

    (void) write(write_pipe_fd, &status, sizeof (status));
    (void) close(write_pipe_fd);
    write_pipe_fd = -1;
}

/*ARGSUSED*/
int
gssprog_1_freeresult(SVCXPRT *transport, xdrproc_t xdr_res, caddr_t res)
{
    xdr_free(xdr_res, res);
    return (1);
}