cmd/modload/modunload.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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <strings.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/modctl.h>
#include <zone.h>

void    usage();
void    exec_userfile(char *execfile, int id, char **envp);

extern void fatal(char *fmt, ...);
extern void error(char *fmt, ...);

/*
 * Unload a loaded module.
 */
int
main(int argc, char *argv[], char *envp[])
{
    int child;
    int status;
    int id;
    char *execfile = NULL;
    int opt;
    extern char *optarg;

    if (argc < 3)
        usage();

    while ((opt = getopt(argc, argv, "i:e:")) != -1) {
        switch (opt) {
        case 'i':
            if (sscanf(optarg, "%d", &id) != 1)
                fatal("Invalid id %s\n", optarg);
            break;
        case 'e':
            execfile = optarg;
        }
    }

    if (getzoneid() != GLOBAL_ZONEID) {
        fatal("modunload can only be run from the global zone\n");
    }

    if (execfile) {
        child = fork();
        if (child == -1)
            error("can't fork %s", execfile);
        else if (child == 0)
            exec_userfile(execfile, id, envp);
        else {
            (void) wait(&status);
            if (status != 0) {
                (void) printf("%s returned error %d.\n",
                    execfile, status);
                (void) exit(status >> 8);
            }
        }
    }

    /*
     * Unload the module.
     */
    if (modctl(MODUNLOAD, id) < 0) {
        if (errno == EPERM)
            fatal("Insufficient privileges to unload a module\n");
        else if (id != 0)
            error("can't unload the module");
    }

    return (0);         /* success */
}

/*
 * exec the user file.
 */
void
exec_userfile(char *execfile, int id, char **envp)
{
    struct modinfo modinfo;

    char modid[8];
    char mod0[8];

    modinfo.mi_id = modinfo.mi_nextid = id;
    modinfo.mi_info = MI_INFO_ONE;
    if (modctl(MODINFO, id, &modinfo) < 0)
        error("can't get module information");

    (void) sprintf(modid, "%d", id);
    (void) sprintf(mod0, "%d", modinfo.mi_msinfo[0].msi_p0);

    (void) execle(execfile, execfile, modid, mod0, NULL, envp);

    error("couldn't exec %s\n", execfile);
}


void
usage()
{
    fatal("usage:  modunload -i <module_id> [-e <exec_file>]\n");
}