sexpr.c

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/*
 * Portions Copyright (C) 2004, 2005, 2007, 2014  Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (C) 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Portions Copyright (C) 2001  Nominum, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: sexpr.c,v 1.9 2007/08/28 07:20:43 tbox Exp $ */

/*! \file */

#include <config.h>

#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include <isc/assertions.h>
#include <isccc/sexpr.h>
#include <isccc/util.h>

static isccc_sexpr_t sexpr_t = { ISCCC_SEXPRTYPE_T, { NULL } };

#define CAR(s)                  (s)->value.as_dottedpair.car
#define CDR(s)                  (s)->value.as_dottedpair.cdr

isccc_sexpr_t *
isccc_sexpr_cons(isccc_sexpr_t *car, isccc_sexpr_t *cdr)
{
        isccc_sexpr_t *sexpr;

        sexpr = malloc(sizeof(*sexpr));
        if (sexpr == NULL)
                return (NULL);
        sexpr->type = ISCCC_SEXPRTYPE_DOTTEDPAIR;
        CAR(sexpr) = car;
        CDR(sexpr) = cdr;

        return (sexpr);
}

isccc_sexpr_t *
isccc_sexpr_tconst(void)
{
        return (&sexpr_t);
}

isccc_sexpr_t *
isccc_sexpr_fromstring(const char *str)
{
        isccc_sexpr_t *sexpr;

        sexpr = malloc(sizeof(*sexpr));
        if (sexpr == NULL)
                return (NULL);
        sexpr->type = ISCCC_SEXPRTYPE_STRING;
        sexpr->value.as_string = strdup(str);
        if (sexpr->value.as_string == NULL) {
                free(sexpr);
                return (NULL);
        }

        return (sexpr);
}

isccc_sexpr_t *
isccc_sexpr_frombinary(const isccc_region_t *region)
{
        isccc_sexpr_t *sexpr;
        unsigned int region_size;

        sexpr = malloc(sizeof(*sexpr));
        if (sexpr == NULL)
                return (NULL);
        sexpr->type = ISCCC_SEXPRTYPE_BINARY;
        region_size = REGION_SIZE(*region);
        /*
         * We add an extra byte when we malloc so we can NUL terminate
         * the binary data.  This allows the caller to use it as a C
         * string.  It's up to the caller to ensure this is safe.  We don't
         * add 1 to the length of the binary region, because the NUL is
         * not part of the binary data.
         */
        sexpr->value.as_region.rstart = malloc(region_size + 1);
        if (sexpr->value.as_region.rstart == NULL) {
                free(sexpr);
                return (NULL);
        }
        sexpr->value.as_region.rend = sexpr->value.as_region.rstart +
                region_size;
        memmove(sexpr->value.as_region.rstart, region->rstart, region_size);
        /*
         * NUL terminate.
         */
        sexpr->value.as_region.rstart[region_size] = '\0';

        return (sexpr);
}

void
isccc_sexpr_free(isccc_sexpr_t **sexprp)
{
        isccc_sexpr_t *sexpr;
        isccc_sexpr_t *item;

        sexpr = *sexprp;
        if (sexpr == NULL)
                return;
        switch (sexpr->type) {
        case ISCCC_SEXPRTYPE_STRING:
                free(sexpr->value.as_string);
                break;
        case ISCCC_SEXPRTYPE_DOTTEDPAIR:
                item = CAR(sexpr);
                if (item != NULL)
                        isccc_sexpr_free(&item);
                item = CDR(sexpr);
                if (item != NULL)
                        isccc_sexpr_free(&item);
                break;
        case ISCCC_SEXPRTYPE_BINARY:
                free(sexpr->value.as_region.rstart);
                break;
        }
        free(sexpr);

        *sexprp = NULL;
}

static isc_boolean_t
printable(isccc_region_t *r)
{
        unsigned char *curr;

        curr = r->rstart;
        while (curr != r->rend) {
                if (!isprint(*curr))
                        return (ISC_FALSE);
                curr++;
        }

        return (ISC_TRUE);
}

void
isccc_sexpr_print(isccc_sexpr_t *sexpr, FILE *stream)
{
        isccc_sexpr_t *cdr;
        unsigned int size, i;
        unsigned char *curr;

        if (sexpr == NULL) {
                fprintf(stream, "nil");
                return;
        }

        switch (sexpr->type) {
        case ISCCC_SEXPRTYPE_T:
                fprintf(stream, "t");
                break;
        case ISCCC_SEXPRTYPE_STRING:
                fprintf(stream, "\"%s\"", sexpr->value.as_string);
                break;
        case ISCCC_SEXPRTYPE_DOTTEDPAIR:
                fprintf(stream, "(");
                do {
                        isccc_sexpr_print(CAR(sexpr), stream);
                        cdr = CDR(sexpr);
                        if (cdr != NULL) {
                                fprintf(stream, " ");
                                if (cdr->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
                                        fprintf(stream, ". ");
                                        isccc_sexpr_print(cdr, stream);
                                        cdr = NULL;
                                }
                        }
                        sexpr = cdr;
                } while (sexpr != NULL);
                fprintf(stream, ")");
                break;
        case ISCCC_SEXPRTYPE_BINARY:
                size = REGION_SIZE(sexpr->value.as_region);
                curr = sexpr->value.as_region.rstart;
                if (printable(&sexpr->value.as_region)) {
                        fprintf(stream, "'%.*s'", (int)size, curr);
                } else {
                        fprintf(stream, "0x");
                        for (i = 0; i < size; i++)
                                fprintf(stream, "%02x", *curr++);
                }
                break;
        default:
                INSIST(0);
        }
}

isccc_sexpr_t *
isccc_sexpr_car(isccc_sexpr_t *list)
{
        REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);

        return (CAR(list));
}

isccc_sexpr_t *
isccc_sexpr_cdr(isccc_sexpr_t *list)
{
        REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);

        return (CDR(list));
}

void
isccc_sexpr_setcar(isccc_sexpr_t *pair, isccc_sexpr_t *car)
{
        REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);

        CAR(pair) = car;
}

void
isccc_sexpr_setcdr(isccc_sexpr_t *pair, isccc_sexpr_t *cdr)
{
        REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);

        CDR(pair) = cdr;
}

isccc_sexpr_t *
isccc_sexpr_addtolist(isccc_sexpr_t **l1p, isccc_sexpr_t *l2)
{
        isccc_sexpr_t *last, *elt, *l1;

        REQUIRE(l1p != NULL);
        l1 = *l1p;
        REQUIRE(l1 == NULL || l1->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);

        elt = isccc_sexpr_cons(l2, NULL);
        if (elt == NULL)
                return (NULL);
        if (l1 == NULL) {
                *l1p = elt;
                return (elt);
        }
        for (last = l1; CDR(last) != NULL; last = CDR(last))
                /* Nothing */;
        CDR(last) = elt;

        return (elt);
}

isc_boolean_t
isccc_sexpr_listp(isccc_sexpr_t *sexpr)
{
        if (sexpr == NULL || sexpr->type == ISCCC_SEXPRTYPE_DOTTEDPAIR)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
isccc_sexpr_emptyp(isccc_sexpr_t *sexpr)
{
        if (sexpr == NULL)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
isccc_sexpr_stringp(isccc_sexpr_t *sexpr)
{
        if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_STRING)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
isccc_sexpr_binaryp(isccc_sexpr_t *sexpr)
{
        if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

char *
isccc_sexpr_tostring(isccc_sexpr_t *sexpr)
{
        REQUIRE(sexpr != NULL &&
                (sexpr->type == ISCCC_SEXPRTYPE_STRING ||
                 sexpr->type == ISCCC_SEXPRTYPE_BINARY));

        if (sexpr->type == ISCCC_SEXPRTYPE_BINARY)
                return ((char *)sexpr->value.as_region.rstart);
        return (sexpr->value.as_string);
}

isccc_region_t *
isccc_sexpr_tobinary(isccc_sexpr_t *sexpr)
{
        REQUIRE(sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY);
        return (&sexpr->value.as_region);
}

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