common/smbios/smb_open.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 2015 OmniTI Computer Consulting, Inc.  All rights reserved.
 * Copyright 2015 Joyent, Inc.
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/smbios_impl.h>

static const uint_t _smb_hashlen = 64;      /* hash length (must be Pof2) */
static const char _smb_emptystr[] = "";     /* empty string to return */
int _smb_debug = 0;             /* default debug mode */

/*
 * Strip out identification information for you privacy weenies.  This is quite
 * simple using our smbios_info_common() abstraction: we just locate any serial
 * numbers and asset tags for each record, and then zero out those strings.
 * Then we must handle two special cases: SMB_TYPE_SYSTEM holds a 16-byte UUID
 * and SMB_TYPE_BATTERY stores a Smart Battery Data Spec 16-bit serial number.
 * We use a literal '0' rather than '\0' for zeroing strings because \0\0 in
 * the SMBIOS string table has a special meaning (denotes end-of-record).
 */
static void
smb_strip(smbios_hdl_t *shp)
{
    uint_t i;

    for (i = 0; i < shp->sh_nstructs; i++) {
        const smb_header_t *hp = shp->sh_structs[i].smbst_hdr;
        smbios_info_t info;
        char *p;

        if (hp->smbh_type == SMB_TYPE_SYSTEM &&
            hp->smbh_len >= offsetof(smb_system_t, smbsi_wakeup)) {
            smb_system_t *sp = (smb_system_t *)(uintptr_t)hp;
            bzero(sp->smbsi_uuid, sizeof (sp->smbsi_uuid));
        }

        if (hp->smbh_type == SMB_TYPE_BATTERY &&
            hp->smbh_len >= offsetof(smb_battery_t, smbbat_sdate)) {
            smb_battery_t *bp = (smb_battery_t *)(uintptr_t)hp;
            bp->smbbat_ssn = 0;
        }

        if (smbios_info_common(shp, hp->smbh_hdl, &info) != SMB_ERR) {
            for (p = (char *)info.smbi_serial; *p != '\0'; p++)
                *p = '0';
            for (p = (char *)info.smbi_asset; *p != '\0'; p++)
                *p = '0';
        }
    }
}

smbios_hdl_t *
smbios_bufopen(const smbios_entry_t *ep, const void *buf, size_t len,
    int version, int flags, int *errp)
{
    smbios_hdl_t *shp = smb_zalloc(sizeof (smbios_hdl_t));
    const smb_header_t *hp, *nhp;
    const uchar_t *p, *q, *s;
    uint_t i, h;

    switch (version) {
    case SMB_VERSION_23:
    case SMB_VERSION_24:
    case SMB_VERSION_25:
    case SMB_VERSION_26:
    case SMB_VERSION_27:
    case SMB_VERSION_28:
    case SMB_VERSION_30:
        break;
    default:
        return (smb_open_error(shp, errp, ESMB_VERSION));
    }

    if (ep == NULL || buf == NULL || len == 0 || (flags & ~SMB_O_MASK))
        return (smb_open_error(shp, errp, ESMB_INVAL));

    if (shp == NULL)
        return (smb_open_error(shp, errp, ESMB_NOMEM));

    if (_smb_debug)
        shp->sh_flags |= SMB_FL_DEBUG;

    if (strncmp(ep->smbe_eanchor, SMB_ENTRY_EANCHOR, SMB_ENTRY_EANCHORLEN))
        return (smb_open_error(shp, errp, ESMB_HEADER));

    if (strncmp(ep->smbe_ianchor, SMB_ENTRY_IANCHOR, SMB_ENTRY_IANCHORLEN))
        return (smb_open_error(shp, errp, ESMB_HEADER));

    smb_dprintf(shp, "opening SMBIOS version %u.%u bcdrev 0x%x\n",
        ep->smbe_major, ep->smbe_minor, ep->smbe_bcdrev);

    if (!(flags & SMB_O_NOVERS)) {
        if (ep->smbe_major > SMB_MAJOR(SMB_VERSION))
            return (smb_open_error(shp, errp, ESMB_NEW));

        if (ep->smbe_major < SMB_MAJOR(SMB_VERSION_23) || (
            ep->smbe_major == SMB_MAJOR(SMB_VERSION_23) &&
            ep->smbe_minor < SMB_MINOR(SMB_VERSION_23)))
            return (smb_open_error(shp, errp, ESMB_OLD));
    }

    if (len < sizeof (smb_header_t) ||
        ep->smbe_stlen < sizeof (smb_header_t) || len < ep->smbe_stlen)
        return (smb_open_error(shp, errp, ESMB_SHORT));

    if (!(flags & SMB_O_NOCKSUM)) {
        uint8_t esum = 0, isum = 0;
        q = (uchar_t *)ep;

        for (p = q; p < q + ep->smbe_elen; p++)
            esum += *p;

        for (p = (uchar_t *)ep->smbe_ianchor; p < q + sizeof (*ep); p++)
            isum += *p;

        if (esum != 0 || isum != 0) {
            smb_dprintf(shp, "bad cksum: e=%x i=%x\n", esum, isum);
            return (smb_open_error(shp, errp, ESMB_CKSUM));
        }
    }

    /*
     * Copy the entry point into our handle.  The underlying entry point
     * may be larger than our structure definition, so reset smbe_elen
     * to our internal size and recompute good checksums for our copy.
     */
    bcopy(ep, &shp->sh_ent, sizeof (smbios_entry_t));
    shp->sh_ent.smbe_elen = sizeof (smbios_entry_t);
    smbios_checksum(shp, &shp->sh_ent);

    shp->sh_buf = buf;
    shp->sh_buflen = len;
    shp->sh_structs = smb_alloc(sizeof (smb_struct_t) * ep->smbe_stnum);
    shp->sh_nstructs = 0;
    shp->sh_hashlen = _smb_hashlen;
    shp->sh_hash = smb_zalloc(sizeof (smb_struct_t *) * shp->sh_hashlen);
    shp->sh_libvers = version;
    shp->sh_smbvers = SMB_MAJMIN(ep->smbe_major, ep->smbe_minor);

    if (shp->sh_structs == NULL || shp->sh_hash == NULL)
        return (smb_open_error(shp, errp, ESMB_NOMEM));

    hp = shp->sh_buf;
    q = (const uchar_t *)buf + MIN(ep->smbe_stlen, len);

    for (i = 0; i < ep->smbe_stnum; i++, hp = nhp) {
        smb_struct_t *stp = &shp->sh_structs[i];
        uint_t n = 0;

        if ((const uchar_t *)hp + sizeof (smb_header_t) > q) {
            shp->sh_flags |= SMB_FL_TRUNC;
            break;
        }

        smb_dprintf(shp, "struct [%u] type %u len %u hdl %u at %p\n",
            i, hp->smbh_type, hp->smbh_len, hp->smbh_hdl, (void *)hp);

        if (hp->smbh_type == SMB_TYPE_EOT)
            break; /* ignore any entries beyond end-of-table */

        if ((const uchar_t *)hp + hp->smbh_len > q - 2) {
            shp->sh_flags |= SMB_FL_TRUNC;
            break;
        }

        h = hp->smbh_hdl & (shp->sh_hashlen - 1);
        p = s = (const uchar_t *)hp + hp->smbh_len;

        while (p <= q - 2 && (p[0] != '\0' || p[1] != '\0')) {
            if (*p++ == '\0')
                n++; /* count strings until \0\0 delimiter */
        }

        if (p > q - 2) {
            shp->sh_flags |= SMB_FL_TRUNC;
            break;
        }

        if (p > s)
            n++; /* add one for final string in string table */

        stp->smbst_hdr = hp;
        stp->smbst_str = s;
        stp->smbst_end = p;
        stp->smbst_next = shp->sh_hash[h];
        stp->smbst_strtab = smb_alloc(sizeof (uint16_t) * n);
        stp->smbst_strtablen = n;

        if (n != 0 && stp->smbst_strtab == NULL)
            return (smb_open_error(shp, errp, ESMB_NOMEM));

        shp->sh_hash[h] = stp;
        nhp = (void *)(p + 2);
        shp->sh_nstructs++;

        for (n = 0, p = s; n < stp->smbst_strtablen; p++) {
            if (*p == '\0') {
                stp->smbst_strtab[n++] =
                    (uint16_t)(s - stp->smbst_str);
                s = p + 1;
            }
        }
    }

    /* error out if we couldn't find any complete entries in the table */
    if ((shp->sh_flags & SMB_FL_TRUNC) && i == 0)
        return (smb_open_error(shp, errp, ESMB_CORRUPT));

    if (flags & SMB_O_ZIDS)
        smb_strip(shp);

    return (shp);
}

void
smbios_close(smbios_hdl_t *shp)
{
    const smbios_entry_t *ep = &shp->sh_ent;
    uint_t i;

    for (i = 0; i < shp->sh_nstructs; i++) {
        smb_free(shp->sh_structs[i].smbst_strtab,
            sizeof (uint16_t) * shp->sh_structs[i].smbst_strtablen);
    }

    smb_free(shp->sh_structs, sizeof (smb_struct_t) * ep->smbe_stnum);
    smb_free(shp->sh_hash, sizeof (smb_struct_t *) * shp->sh_hashlen);

    if (shp->sh_flags & SMB_FL_BUFALLOC)
        smb_free((void *)shp->sh_buf, shp->sh_buflen);

    smb_free(shp, sizeof (smbios_hdl_t));
}

/*
 * Recompute the values of the entry point checksums based upon the content
 * of the specified SMBIOS entry point.  We don't need 'shp' but require it
 * anyway in case future versioning requires variations in the algorithm.
 */
/*ARGSUSED*/
void
smbios_checksum(smbios_hdl_t *shp, smbios_entry_t *ep)
{
    uchar_t *p, *q = (uchar_t *)ep;
    uint8_t esum = 0, isum = 0;

    ep->smbe_ecksum = ep->smbe_icksum = 0;

    for (p = (uchar_t *)ep->smbe_ianchor; p < q + sizeof (*ep); p++)
        isum += *p;

    ep->smbe_icksum = -isum;

    for (p = q; p < q + ep->smbe_elen; p++)
        esum += *p;

    ep->smbe_ecksum = -esum;
}

const void *
smbios_buf(smbios_hdl_t *shp)
{
    return (shp->sh_buf);
}

size_t
smbios_buflen(smbios_hdl_t *shp)
{
    return (shp->sh_buflen);
}

static smbios_struct_t *
smb_export(const smb_struct_t *stp, smbios_struct_t *sp)
{
    const smb_header_t *hdr = stp->smbst_hdr;

    sp->smbstr_id = hdr->smbh_hdl;
    sp->smbstr_type = hdr->smbh_type;
    sp->smbstr_data = hdr;
    sp->smbstr_size = (size_t)(stp->smbst_end - (uchar_t *)hdr);

    return (sp);
}

int
smbios_lookup_id(smbios_hdl_t *shp, id_t id, smbios_struct_t *sp)
{
    const smb_struct_t *stp = smb_lookup_id(shp, id);

    if (stp == NULL)
        return (-1); /* errno is set for us */

    if (sp != NULL)
        (void) smb_export(stp, sp);

    return (0);
}

int
smbios_lookup_type(smbios_hdl_t *shp, uint_t type, smbios_struct_t *sp)
{
    const smb_struct_t *stp = smb_lookup_type(shp, type);

    if (stp == NULL)
        return (-1); /* errno is set for us */

    if (sp != NULL)
        (void) smb_export(stp, sp);

    return (0);
}

int
smbios_iter(smbios_hdl_t *shp, smbios_struct_f *func, void *data)
{
    const smb_struct_t *sp = shp->sh_structs;
    smbios_struct_t s;
    int i, rv = 0;

    for (i = 0; i < shp->sh_nstructs; i++, sp++) {
        if (sp->smbst_hdr->smbh_type != SMB_TYPE_INACTIVE &&
            (rv = func(shp, smb_export(sp, &s), data)) != 0)
            break;
    }

    return (rv);
}

const smb_struct_t *
smb_lookup_type(smbios_hdl_t *shp, uint_t type)
{
    uint_t i;

    for (i = 0; i < shp->sh_nstructs; i++) {
        if (shp->sh_structs[i].smbst_hdr->smbh_type == type)
            return (&shp->sh_structs[i]);
    }

    (void) smb_set_errno(shp, ESMB_NOENT);
    return (NULL);
}

const smb_struct_t *
smb_lookup_id(smbios_hdl_t *shp, uint_t id)
{
    const smb_struct_t *stp = shp->sh_hash[id & (shp->sh_hashlen - 1)];

    switch (id) {
    case SMB_ID_NOTSUP:
        (void) smb_set_errno(shp, ESMB_NOTSUP);
        return (NULL);
    case SMB_ID_NONE:
        (void) smb_set_errno(shp, ESMB_NOENT);
        return (NULL);
    }

    for (; stp != NULL; stp = stp->smbst_next) {
        if (stp->smbst_hdr->smbh_hdl == id)
            break;
    }

    if (stp == NULL)
        (void) smb_set_errno(shp, ESMB_NOENT);

    return (stp);
}

const char *
smb_strptr(const smb_struct_t *stp, uint_t i)
{
    if (i == 0 || i > stp->smbst_strtablen)
        return (_smb_emptystr);
    else
        return ((char *)stp->smbst_str + stp->smbst_strtab[i - 1]);
}

int
smb_gteq(smbios_hdl_t *shp, int version)
{
    return (SMB_MAJOR(shp->sh_smbvers) > SMB_MAJOR(version) || (
        SMB_MAJOR(shp->sh_smbvers) == SMB_MAJOR(version) &&
        SMB_MINOR(shp->sh_smbvers) >= SMB_MINOR(version)));
}

boolean_t
smbios_truncated(smbios_hdl_t *shp)
{
    return ((shp->sh_flags & SMB_FL_TRUNC) != 0);
}