lib/ipmgmtd/ipmgmt_util.c

	ipmgmt_util.c revision 9b5bf10ab04b9be5564d70a57980cfb68b6372e7
/*
 * 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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * Utility functions used by the ipmgmtd daemon.
 */

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <syslog.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include "ipmgmt_impl.h"

#define IPMGMT_BUFSIZ   1024

void
ipmgmt_log(int pri, const char *fmt, ...)
{
    va_list alist;

    va_start(alist, fmt);
    vsyslog(pri, fmt, alist);
    va_end(alist);
}

/*
 * Copy a source file to a new destination. The source file will be
 * removed if rdonly is false (i.e., used when the source file resides
 * on a read-only file system).
 *
 * Returns 0 on success and errno on failure.
 */
int
ipmgmt_cpfile(const char *src, const char *dst, boolean_t rdonly)
{
    struct stat statbuf;
    FILE *sfp, *dfp;
    char buf[IPMGMT_BUFSIZ];
    size_t bytes;
    int err = 0;

    /*
     * Attempt to open the destination file first since we
     * want to optimize for the case where it is read-only
     * and will return EROFS.
     */
    if ((dfp = fopen(dst, "w+")) == NULL)
        return (errno);

    /*
     * Require that the source file exists.
     */
    if (stat(src, &statbuf) != 0) {
        err = errno;
        (void) fclose(dfp);
        return (err);
    }
    if ((sfp = fopen(src, "r")) == NULL) {
        err = errno;
        (void) fclose(dfp);
        return (err);
    }

    /*
     * Copy the file.
     */
    while (((bytes = fread(buf, 1, sizeof (buf), sfp)) != 0) &&
        (errno == 0)) {
        (void) fwrite(buf, bytes, 1, dfp);
        if (errno != 0)
            break;
    }
    if (errno != 0)
        err = errno;

    (void) fclose(sfp);
    (void) fclose(dfp);

    /*
     * If any error occurred, then remove the destination file.
     */
    if (err != 0) {
        (void) unlink(dst);
        return (err);
    }

    /*
     * Make sure the file attributes are correct.
     */
    if (chmod(dst, IPADM_FILE_MODE) != 0 ||
        chown(dst, UID_NETADM, GID_NETADM) != 0) {
        err = errno;
        (void) unlink(dst);
        return (err);
    }

    /*
     * If the source file does not reside on a read-only file system
     * then remove it.
     */
    if (!rdonly)
        (void) unlink(src);

    return (0);
}