/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 2016-2018 Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.

 */

/*

 * This is an open source non-commercial project. Dear PVS-Studio, please check it.

 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

 */

#include <config.h>

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#include "sudo_compat.h"

#include "sudo_debug.h"

#include "sudo_util.h"

/* Trivial reference-counted strings. */

struct rcstr {

    int refcnt;

    char str[1];  /* actually bigger */

};

/*

 * Allocate a reference-counted string and copy src to it.

 * Returns the newly-created string with a refcnt of 1.

 */

char *

sudo_rcstr_dup(const char *src)

{

    size_t len = strlen(src);

    char *dst;

    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);

    dst = sudo_rcstr_alloc(len);

    if (dst != NULL) {

        memcpy(dst, src, len);

        dst[len] = '\0';

    }

    debug_return_ptr(dst);

}

char *

sudo_rcstr_alloc(size_t len)

{

    struct rcstr *rcs;

    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);

    /* Note: sizeof(struct rcstr) includes space for the NUL */

    rcs = malloc(sizeof(struct rcstr) + len);

    if (rcs == NULL)

  return NULL;

    rcs->refcnt = 1;

    rcs->str[0] = '\0';

    /* cppcheck-suppress memleak */

    debug_return_ptr(rcs->str); // -V773

}

char *

sudo_rcstr_addref(const char *s)

{

    struct rcstr *rcs;

    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);

    if (s == NULL)

  debug_return_ptr(NULL);

    rcs = __containerof((const void *)s, struct rcstr, str);

    rcs->refcnt++;

    debug_return_ptr(rcs->str);

}

void

sudo_rcstr_delref(const char *s)

{

    struct rcstr *rcs;

    debug_decl(sudo_rcstr_dup, SUDO_DEBUG_UTIL);

    if (s != NULL) {

  rcs = __containerof((const void *)s, struct rcstr, str);

  if (--rcs->refcnt == 0) {

      rcs->str[0] = '\0';

      free(rcs);

  }

    }

    debug_return;

}