common/ctf/ctf_labels.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2002-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <ctf_impl.h>

static int
extract_label_info(ctf_file_t *fp, const ctf_lblent_t **ctl, uint_t *num_labels)
{
    const ctf_header_t *h;

    /*
     * Labels are only supported in V2 or later
     */
    if (fp->ctf_version < CTF_VERSION_2)
        return (ctf_set_errno(fp, ECTF_NOTSUP));

    h = (const ctf_header_t *)fp->ctf_data.cts_data;

    /* LINTED - pointer alignment */
    *ctl = (const ctf_lblent_t *)(fp->ctf_buf + h->cth_lbloff);
    *num_labels = (h->cth_objtoff - h->cth_lbloff) / sizeof (ctf_lblent_t);

    return (0);
}

/*
 * Returns the topmost label, or NULL if any errors are encountered
 */
const char *
ctf_label_topmost(ctf_file_t *fp)
{
    const ctf_lblent_t *ctlp;
    const char *s;
    uint_t num_labels;

    if (extract_label_info(fp, &ctlp, &num_labels) == CTF_ERR)
        return (NULL); /* errno is set */

    if (num_labels == 0) {
        (void) ctf_set_errno(fp, ECTF_NOLABELDATA);
        return (NULL);
    }

    if ((s = ctf_strraw(fp, (ctlp + num_labels - 1)->ctl_label)) == NULL)
        (void) ctf_set_errno(fp, ECTF_CORRUPT);

    return (s);
}

/*
 * Iterate over all labels.  We pass the label string and the lblinfo_t struct
 * to the specified callback function.
 */
int
ctf_label_iter(ctf_file_t *fp, ctf_label_f *func, void *arg)
{
    const ctf_lblent_t *ctlp;
    uint_t i, num_labels;
    ctf_lblinfo_t linfo;
    const char *lname;
    int rc;

    if (extract_label_info(fp, &ctlp, &num_labels) == CTF_ERR)
        return (CTF_ERR); /* errno is set */

    if (num_labels == 0)
        return (ctf_set_errno(fp, ECTF_NOLABELDATA));

    for (i = 0; i < num_labels; i++, ctlp++) {
        if ((lname = ctf_strraw(fp, ctlp->ctl_label)) == NULL) {
            ctf_dprintf("failed to decode label %u with "
                "typeidx %u\n", ctlp->ctl_label, ctlp->ctl_typeidx);
            return (ctf_set_errno(fp, ECTF_CORRUPT));
        }

        linfo.ctb_typeidx = ctlp->ctl_typeidx;
        if ((rc = func(lname, &linfo, arg)) != 0)
            return (rc);
    }

    return (0);
}

typedef struct linfo_cb_arg {
    const char *lca_name;    /* Label we want to retrieve info for */
    ctf_lblinfo_t *lca_info; /* Where to store the info about the label */
} linfo_cb_arg_t;

static int
label_info_cb(const char *lname, const ctf_lblinfo_t *linfo, void *arg)
{
    /*
     * If lname matches the label we are looking for, copy the
     * lblinfo_t struct for the caller.
     */
    if (strcmp(lname, ((linfo_cb_arg_t *)arg)->lca_name) == 0) {
        /*
         * Allow caller not to allocate storage to test if label exists
         */
        if (((linfo_cb_arg_t *)arg)->lca_info != NULL)
            bcopy(linfo, ((linfo_cb_arg_t *)arg)->lca_info,
                sizeof (ctf_lblinfo_t));
        return (1); /* Indicate we found a match */
    }

    return (0);
}

/*
 * Retrieve information about the label with name "lname"
 */
int
ctf_label_info(ctf_file_t *fp, const char *lname, ctf_lblinfo_t *linfo)
{
    linfo_cb_arg_t cb_arg;
    int rc;

    cb_arg.lca_name = lname;
    cb_arg.lca_info = linfo;

    if ((rc = ctf_label_iter(fp, label_info_cb, &cb_arg)) == CTF_ERR)
        return (rc);

    if (rc != 1)
        return (ctf_set_errno(fp, ECTF_NOLABEL));

    return (0);
}