#include "open62541/config.h"

/* Service discovery TXT record parsing/generation

 *

 * Copyright (c) 2003  Jeremie Miller <jer@jabber.org>

 * Copyright (c) 2016-2026  Joachim Wiberg <troglobit@gmail.com>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above copyright

 *       notice, this list of conditions and the following disclaimer in the

 *       documentation and/or other materials provided with the distribution.

 *     * Neither the name of the copyright holders nor the names of its

 *       contributors may be used to endorse or promote products derived from

 *       this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#include "sdtxt.h"

#include <stdlib.h>

#include <string.h>

static size_t _sd2txt_len(const char *key, char *val)

{

  size_t ret = strlen(key);

  if (!*val)

    return ret;

  ret += strlen(val);

  ret++;

  return ret;

}

static void _sd2txt_count(xht_t *h __attribute__((unused)), const char *key, void *val, void *arg)

{

  int *const count = arg;

  *count += (int)_sd2txt_len(key, val) + 1;

}

static void _sd2txt_write(xht_t *h __attribute__((unused)), const char *key, void *val, void *arg)

{

  unsigned char **txtp = arg;

  char *const cval = val;

  /* Copy in lengths, then strings */

  **txtp = _sd2txt_len(key, val);

  (*txtp)++;

  memcpy(*txtp, key, strlen(key));

  *txtp += strlen(key);

  if (!*cval)

    return;

  **txtp = '=';

  (*txtp)++;

  memcpy(*txtp, cval, strlen(cval));

  *txtp += strlen(cval);

}

unsigned char *sd2txt(xht_t *h, int *len)

{

  unsigned char *buf, *raw;

  *len = 0;

  xht_walk(h, _sd2txt_count, len);

  if (!*len) {

    *len = 1;

    return (unsigned char *)strdup("");

  }

  raw = buf = malloc(*len);

  if (!buf)

    return NULL;

  xht_walk(h, _sd2txt_write, &buf);

  return raw;

}

xht_t *txt2sd(unsigned char *txt, int len)

{

  xht_t *h = 0;

  if (txt == 0 || len == 0 || *txt == 0)

    return 0;

  h = xht_new(23);

  /* Loop through data breaking out each block, storing into hashtable */

  for (; len > 0 && *txt < len; len -= *txt + 1, txt += *txt + 1) {

    char key[256], *val;

    if (*txt == 0)

      break;

    memcpy(key, txt + 1, *txt);

    key[*txt] = 0;

    /* RFC 6763 §6.4: keep a bare key (no '=') as a boolean

     * attribute with an empty value rather than drop it (#58) */

    val = strchr(key, '=');

    if (val)

      *val++ = 0;

    else

      val = "";

    xht_store(h, key, (int)strlen(key), val, (int)strlen(val));

  }

  return h;

}