/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * 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 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: naptr_35.c,v 1.14 2022/12/26 19:24:11 jmc Exp $ */

/* Reviewed: Thu Mar 16 16:52:50 PST 2000 by bwelling */

/* RFC2915 */

#ifndef RDATA_GENERIC_NAPTR_35_C
#define RDATA_GENERIC_NAPTR_35_C

#include <isc/regex.h>

/*
 * Check the wire format of the Regexp field.
 * Don't allow embedded NUL's.
 */
static inline isc_result_t
txt_valid_regex(const unsigned char *txt) {
        unsigned int nsub = 0;
        char regex[256];
        char *cp;
        int flags = 0;
        int replace = 0;
        unsigned char c;
        unsigned char delim;
        unsigned int len;
        int n;

        len = *txt++;
        if (len == 0U)
                return (ISC_R_SUCCESS);

        delim = *txt++;
        len--;

        /*
         * Digits, backslash and flags can't be delimiters.
         */
        switch (delim) {
        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
        case '\\': case 'i': case 0:
                return (DNS_R_SYNTAX);
        }

        cp = regex;
        while (len-- > 0) {
                c = *txt++;
                if (c == 0)
                        return (DNS_R_SYNTAX);
                if (c == delim && !replace) {
                        replace = 1;
                        continue;
                } else if (c == delim && !flags) {
                        flags = 1;
                        continue;
                } else if (c == delim)
                        return (DNS_R_SYNTAX);
                /*
                 * Flags are not escaped.
                 */
                if (flags) {
                        switch (c) {
                        case 'i':
                                continue;
                        default:
                                return (DNS_R_SYNTAX);
                        }
                }
                if (!replace)
                        *cp++ = c;
                if (c == '\\') {
                        if (len == 0)
                                return (DNS_R_SYNTAX);
                        c = *txt++;
                        if (c == 0)
                                return (DNS_R_SYNTAX);
                        len--;
                        if (replace)
                                switch (c) {
                                case '0': return (DNS_R_SYNTAX);
                                case '1': if (nsub < 1) nsub = 1; break;
                                case '2': if (nsub < 2) nsub = 2; break;
                                case '3': if (nsub < 3) nsub = 3; break;
                                case '4': if (nsub < 4) nsub = 4; break;
                                case '5': if (nsub < 5) nsub = 5; break;
                                case '6': if (nsub < 6) nsub = 6; break;
                                case '7': if (nsub < 7) nsub = 7; break;
                                case '8': if (nsub < 8) nsub = 8; break;
                                case '9': if (nsub < 9) nsub = 9; break;
                                }
                        if (!replace)
                                *cp++ = c;
                }
        }
        if (!flags)
                return (DNS_R_SYNTAX);
        *cp = '\0';
        n = isc_regex_validate(regex);
        if (n < 0 || nsub > (unsigned int)n)
                return (DNS_R_SYNTAX);
        return (ISC_R_SUCCESS);
}

static inline isc_result_t
totext_naptr(ARGS_TOTEXT) {
        isc_region_t region;
        dns_name_t name;
        dns_name_t prefix;
        int sub;
        char buf[sizeof("64000")];
        unsigned short num;

        REQUIRE(rdata->type == dns_rdatatype_naptr);
        REQUIRE(rdata->length != 0);

        dns_name_init(&name, NULL);
        dns_name_init(&prefix, NULL);

        dns_rdata_toregion(rdata, &region);

        /*
         * Order.
         */
        num = uint16_fromregion(&region);
        isc_region_consume(&region, 2);
        snprintf(buf, sizeof(buf), "%u", num);
        RETERR(isc_str_tobuffer(buf, target));
        RETERR(isc_str_tobuffer(" ", target));

        /*
         * Preference.
         */
        num = uint16_fromregion(&region);
        isc_region_consume(&region, 2);
        snprintf(buf, sizeof(buf), "%u", num);
        RETERR(isc_str_tobuffer(buf, target));
        RETERR(isc_str_tobuffer(" ", target));

        /*
         * Flags.
         */
        RETERR(txt_totext(&region, 1, target));
        RETERR(isc_str_tobuffer(" ", target));

        /*
         * Service.
         */
        RETERR(txt_totext(&region, 1, target));
        RETERR(isc_str_tobuffer(" ", target));

        /*
         * Regexp.
         */
        RETERR(txt_totext(&region, 1, target));
        RETERR(isc_str_tobuffer(" ", target));

        /*
         * Replacement.
         */
        dns_name_fromregion(&name, &region);
        sub = name_prefix(&name, tctx->origin, &prefix);
        return (dns_name_totext(&prefix, sub, target));
}

static inline isc_result_t
fromwire_naptr(ARGS_FROMWIRE) {
        dns_name_t name;
        isc_region_t sr;
        unsigned char *regex;

        REQUIRE(type == dns_rdatatype_naptr);

        UNUSED(type);
        UNUSED(rdclass);

        dns_decompress_setmethods(dctx, DNS_COMPRESS_NONE);

        dns_name_init(&name, NULL);

        /*
         * Order, preference.
         */
        isc_buffer_activeregion(source, &sr);
        if (sr.length < 4)
                return (ISC_R_UNEXPECTEDEND);
        RETERR(isc_mem_tobuffer(target, sr.base, 4));
        isc_buffer_forward(source, 4);

        /*
         * Flags.
         */
        RETERR(txt_fromwire(source, target));

        /*
         * Service.
         */
        RETERR(txt_fromwire(source, target));

        /*
         * Regexp.
         */
        regex = isc_buffer_used(target);
        RETERR(txt_fromwire(source, target));
        RETERR(txt_valid_regex(regex));

        /*
         * Replacement.
         */
        return (dns_name_fromwire(&name, source, dctx, options, target));
}

static inline isc_result_t
towire_naptr(ARGS_TOWIRE) {
        dns_name_t name;
        dns_offsets_t offsets;
        isc_region_t sr;

        REQUIRE(rdata->type == dns_rdatatype_naptr);
        REQUIRE(rdata->length != 0);

        dns_compress_setmethods(cctx, DNS_COMPRESS_NONE);
        /*
         * Order, preference.
         */
        dns_rdata_toregion(rdata, &sr);
        RETERR(isc_mem_tobuffer(target, sr.base, 4));
        isc_region_consume(&sr, 4);

        /*
         * Flags.
         */
        RETERR(isc_mem_tobuffer(target, sr.base, sr.base[0] + 1));
        isc_region_consume(&sr, sr.base[0] + 1);

        /*
         * Service.
         */
        RETERR(isc_mem_tobuffer(target, sr.base, sr.base[0] + 1));
        isc_region_consume(&sr, sr.base[0] + 1);

        /*
         * Regexp.
         */
        RETERR(isc_mem_tobuffer(target, sr.base, sr.base[0] + 1));
        isc_region_consume(&sr, sr.base[0] + 1);

        /*
         * Replacement.
         */
        dns_name_init(&name, offsets);
        dns_name_fromregion(&name, &sr);
        return (dns_name_towire(&name, cctx, target));
}

#endif  /* RDATA_GENERIC_NAPTR_35_C */