lib/libdevinfo/devinfo_dli.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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

/*
 * Interfaces for getting device configuration data from kernel
 * through the devinfo driver.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdarg.h>
#include <unistd.h>
#include <libgen.h>
#include "libdevinfo.h"

/* Function Prototypes */
static int di_dli_open(char *, int, short, int);

#define DLI_NAME    0x1

/*
 * Private hotplug interfaces to be used between cfgadm pci plugin and
 * devfsadm link generator.
 */


/*
 * returns a devlink info file name derived from <path>
 * callers need to free the returned string
 */
char *
di_dli_name(char *path)
{
#define dliroot     "/etc/devices/dli/info."
#define dliroot_len (sizeof (dliroot) - 1)

    char *dlipath;
    int dlipathsz;
    char *basep;

    basep = basename(path);
    dlipathsz = strlen(basep) + dliroot_len + 1;
    dlipath = malloc(sizeof (char) * dlipathsz);

    (void) snprintf(dlipath, dlipathsz, "%s%s", dliroot, basep);
    dlipath[dlipathsz - 1] = '\0';
    return (dlipath);

#undef  dlipre
#undef  dlipre_len
#undef  dliroot
#undef  dliroot_len
}


static int
di_dli_open(char *path, int oflag, short l_type, int flags)
{
    int fd;
    char *dlipath, *dlipath_dir, *dlipath_dup;
    struct stat statbuf;
    int mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
    flock_t lock;

    dlipath = (flags & DLI_NAME) ? di_dli_name(path) : (char *)path;
    dlipath_dup = strdup(dlipath);
    dlipath_dir = dirname(dlipath_dup);

    if (stat(dlipath_dir, &statbuf) < 0) {
        if (mkdirp(dlipath_dir,
            S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0) {
            fd = -1;
            goto OUT;
        }
    }

    fd = open(dlipath, oflag, mode);
    if (fd < 0)
        goto OUT;

    if (fchmod(fd, mode) < 0) {
        (void) close(fd);
        fd = -1;
        goto OUT;
    }

    bzero(&lock, sizeof (lock));
    lock.l_type = l_type;
    if (fcntl(fd, F_SETLKW, &lock) < 0) {
        (void) close(fd);
        fd = -1;
    }
OUT:
    free(dlipath_dup);
    if (flags & DLI_NAME)
        free(dlipath);
    return (fd);
}


int
di_dli_openr(char *path)
{
    return (di_dli_open(path, O_RDONLY, F_RDLCK, DLI_NAME));
}


int
di_dli_openw(char *path)
{
    return (di_dli_open(path, O_RDWR | O_SYNC | O_TRUNC | O_CREAT,
        F_WRLCK, DLI_NAME));
}


void
di_dli_close(int fd)
{
    flock_t lock;
    if (fd < 0)
        return;

    bzero(&lock, sizeof (lock));
    lock.l_type = F_UNLCK;
    (void) fcntl(fd, F_SETLK, &lock);
    (void) close(fd);
}