lib/libtnfprobe/tnf_args.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 (c) 1994, by Sun Microsytems, Inc.
 */

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

#ifndef DEBUG
#define NDEBUG  1
#endif

#include "tnf_trace.h"
#include "tnf_types.h"
#include "tnf_args.h"
#include <string.h>
#include <assert.h>

/*
 * tnf_probe_get_num_args: returns the number of arguments at probe site
 * probe_p.  This includes the first 2 args (tag and time delta) in the return
 * value.
 */
int
tnf_probe_get_num_args(tnf_probe_control_t *probe_p)
{
    int count = 0;
    tnf_tag_data_t ***tag_p;

    tag_p = probe_p->slot_types;
    while (*tag_p) {
        count++;
        tag_p++;
    }
    return (count);
}

/*
 * tnf_probe_get_arg_indexed: returns a pointer into the buffer where
 * argument i is stored.  Returns NULL on error.  Argument numbering is
 * zero based i.e. to get the 3rd argument, the input value should be 2.
 */

/* ALIGN_ROUNDUP: y has to be one less than a power of 2 eg. 3, 7, 15, etc. */
#define ALIGN_ROUNDUP(x, y) (((x) + (y)) & ~(y))

void *
tnf_probe_get_arg_indexed(tnf_probe_control_t *probe_p, int index, void *buffer)
{
    int count = 0;
    size_t align;
    size_t elem_size = 0;
    tnf_tag_data_t ***tag_ppp;
    tnf_tag_data_t   *tag_p;
    unsigned long offset = 0;

    tag_ppp = probe_p->slot_types;
    if (!tag_ppp)
        return (NULL);

    while (count <= index) {
        /* error checking. REMIND: Do we need it ? */
        if (!(*tag_ppp))
            return (NULL);
        tag_p = **tag_ppp;
        if (!tag_p)
            return (NULL);

        offset = offset + elem_size;
        align = tag_p->tag_align - 1;
        assert(align != 0);
        offset = ALIGN_ROUNDUP(offset, align);
        /* get size of current element */
        elem_size = tag_p->tag_ref_size;
        tag_ppp++;
        count++;
    }

    return ((void *)((char *)buffer + offset));
}

/*
 * tnf_probe_get_type_indexed: returns the type of the ith argument.
 * returns TNF_UNKNOWN on error.  Argument numbering is zero based
 * i.e. to get the 3rd argument, the input value should be 2.
 */

tnf_arg_kind_t
tnf_probe_get_type_indexed(tnf_probe_control_t *probe_p, int index)
{
    tnf_tag_data_t ***tag_ppp;
    tnf_tag_data_t   *tag_p;

    tag_ppp = probe_p->slot_types + index;
    if (!tag_ppp)
        return (TNF_UNKNOWN);
    if (!(*tag_ppp))
        return (TNF_UNKNOWN);
    tag_p = **tag_ppp;
    if (!tag_p)
        return (TNF_UNKNOWN);
    return (tag_p->tag_kind);
}


/*
 * tnf_probe_get_value: returns the start of the value string that is
 * associated with the input attribute.  The number of characters in the
 * value is also returned as the final argument.  The size return value
 * indicates the length of the string that is valid.  Returns NULL on no
 * match or error.
 */

const char *
tnf_probe_get_value(tnf_probe_control_t *probe_p, char *attribute,
ulong_t *size)
{

    const char  *attr_start, *attr_end, *str_end;
    const char  *val_start;
    int         separator;
    uint_t      attr_len;
    size_t      input_len;

    input_len = strlen(attribute);
    attr_start = probe_p->attrs;
    assert(attr_start);
    str_end = attr_start + strlen(attr_start);
    separator = ATTR_SEPARATOR;
    while (attr_start < str_end) {
        attr_end = strchr(attr_start, separator);
        if (!attr_end) {
            /* last attribute */
            attr_end = str_end;
        }
        /* LINTED - result <= string length */
        attr_len = attr_end - attr_start;

        /* skip over leading white space */
        while (*attr_start && ((*attr_start == ' ') ||
                        (*attr_start == '\t'))) {
            attr_start++;
        }
        /* search for match on attribute */
        if (strncmp(attr_start, attribute, input_len) == 0) {
            /* make sure next char is a space or semicolon */
            val_start = attr_start + input_len;
            if (*val_start == ATTR_SEPARATOR) {
                *size = 0;
                return (val_start);
            } else if (*val_start == VAL_SEPARATOR) {
                /* +1 for val separator */
                *size = attr_len - (input_len + 1);
                return (val_start + 1);
            }
            /* a false match - just continue */
        }
        /* skip to next attribute */
        attr_start = attr_end + 1;
    }

    /* no match */
    return (NULL);
}

/* used by in-process argument reader */
char *
tnf_probe_get_chars(void *slot)
{
    tnf_reference_t ref;
    char        *str_p;

    ref = *((tnf_reference_t *)slot);
    assert(TNF_REF32_IS_FWD(ref));
    str_p = (char *)slot + TNF_REF32_VALUE(ref);
    str_p += ARRAY_HDR_SIZE;
    return (str_p);
}