libinetutil/common/ifspec.c

	ifspec.c revision c7e4935f5b755b4bbeaec416f1ad24337aeac7a4
/*
 * 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"

/*
 * This file contains a routine used to validate a ifconfig-style interface
 * specification
 */

#include <stdlib.h>
#include <ctype.h>
#include <alloca.h>
#include <errno.h>
#include <string.h>
#include <libinetutil.h>

/*
 * Given a token with a logical unit spec, return the logical unit converted
 * to a uint_t.
 *
 * Returns: 0 for success, nonzero if an error occurred. errno is set if
 * necessary.
 */
static int
getlun(const char *bp, int bpsize, uint_t *lun)
{
    char    *ep = (char *)&bp[bpsize - 1];
    char    *sp = strchr(bp, ':'), *tp;

    /* A logical unit spec looks like: <token>:<unsigned int>\0 */
    if (isdigit(*bp) || !isdigit(*ep) || sp == NULL ||
        strchr(sp + 1, ':') != NULL) {
        errno = EINVAL;
        return (-1);
    }

    *sp++ = '\0';

    /* Lun must be all digits */
    for (tp = sp; tp < ep && isdigit(*tp); tp++)
        /* Null body */;
    if (tp != ep) {
        errno = EINVAL;
        return (-1);
    }

    *lun = atoi(sp);
    return (0);
}

/*
 * Given a single token ending with a ppa spec, return the ppa spec converted
 * to a uint_t.
 *
 * Returns: 0 for success, nonzero if an error occurred. errno is set if
 * necessary.
 */
static int
getppa(const char *bp, int bpsize, uint_t *ppa)
{
    char    *ep = (char *)&bp[bpsize - 1];
    char    *tp;

    if (!isdigit(*ep)) {
        errno = EINVAL;
        return (-1);
    }

    for (tp = ep; tp >= bp && isdigit(*tp); tp--)
        /* Null body */;

    if (*tp == '.' || *tp == ':') {
        errno = EINVAL;
        return (-1);
    }

    *ppa = atoi(tp + 1);
    return (0);
}

/*
 * Given an ifconfig-style inet relative-path interface specification
 * (e.g: hme.[module].[module][PPA]:2), validate its form and decompose the
 * contents into a dynamically allocated ifspec_t.
 *
 * Returns ifspec_t for success, NULL pointer if spec is malformed.
 */
boolean_t
ifparse_ifspec(const char *ifname, ifspec_t *ifsp)
{
    char        *mp, *ep, *lp, *tp;
    char        *ifnamecp;
    size_t      iflen;
    boolean_t   have_ppa = B_FALSE;

    iflen = strlen(ifname);
    if (iflen > LIFNAMSIZ) {
        errno = EINVAL;
        return (B_FALSE);
    }

    /* snag a copy we can modify */
    ifnamecp = alloca(iflen + 1);
    (void) strlcpy(ifnamecp, ifname, iflen + 1);

    ifsp->ifsp_lunvalid = B_FALSE;

    /*
     * An interface name must have the format of:
     * dev[.module[.module...]][ppa][:lun]
     *
     * where the ppa must be specified at the end of the interface name.
     * e.g. ip.foo.tun0
     *
     * lun - logical unit number.
     *
     * Produce substrings for each grouping, starting first with modules,
     * then lun, devname, and finally ppa.
     */

    /* Any modules? */
    mp = strchr(ifnamecp, '.');

    /* Any logical units? */
    lp = strchr(ifnamecp, ':');

    if (lp != NULL && mp != NULL && lp < mp) {
        errno = EINVAL;
        return (B_FALSE);
    }

    ifsp->ifsp_modcnt = 0;
    if (mp != NULL) {
        *mp++ = '\0';
        if (lp != NULL)
            *lp = '\0';
        while (mp != NULL && ifsp->ifsp_modcnt <= IFSP_MAXMODS) {
            if ((ep = strchr(mp, '.')) != NULL)
                *ep++ = '\0';
            (void) strlcpy(ifsp->ifsp_mods[ifsp->ifsp_modcnt++],
                mp, LIFNAMSIZ);
            mp = ep;
        }
        if (lp != NULL)
            *lp = ':';
        if (ifsp->ifsp_modcnt > IFSP_MAXMODS) {
            errno = E2BIG;
            return (B_FALSE);
        }
    }

    if (lp != NULL) {
        if (getlun(lp, strlen(lp), &ifsp->ifsp_lun) != 0)
            return (B_FALSE);
        ifsp->ifsp_lunvalid = B_TRUE;
    }

    (void) strlcpy(ifsp->ifsp_devnm, ifnamecp, LIFNAMSIZ);

    /*
     * Find ppa - has to be part of devname or if modules exist part of
     * last module name.
     */
    if (ifsp->ifsp_modcnt != 0 &&
        getppa(ifsp->ifsp_mods[ifsp->ifsp_modcnt - 1],
        strlen(ifsp->ifsp_mods[ifsp->ifsp_modcnt - 1]),
        &ifsp->ifsp_ppa) == 0) {
        have_ppa = B_TRUE;
    } else if (ifsp->ifsp_modcnt == 0 &&
        getppa(ifsp->ifsp_devnm, strlen(ifsp->ifsp_devnm),
        &ifsp->ifsp_ppa) == 0) {
        have_ppa = B_TRUE;

        /* strip the ppa off of the device name if present */
        for (tp = &ifsp->ifsp_devnm[strlen(ifsp->ifsp_devnm) - 1];
            tp >= ifsp->ifsp_devnm && isdigit(*tp); tp--)
            *tp = '\0';
    }

    return (have_ppa);
}