/*      $OpenBSD: pw_dup.c,v 1.9 2019/01/25 00:19:25 millert Exp $      */

/*
 * Copyright (c) 2000, 2002 Todd C. Miller <millert@openbsd.org>
 *
 * 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.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

#include <sys/types.h>

#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define PW_SIZE(name, size)                             \
do {                                                    \
        if (pw->name) {                                 \
                size = strlen(pw->name) + 1;            \
                total += size;                          \
        }                                               \
} while (0)

#define PW_COPY(name, size)                             \
do {                                                    \
        if (pw->name) {                                 \
                (void)memcpy(cp, pw->name, size);       \
                newpw->name = cp;                       \
                cp += size;                             \
        }                                               \
} while (0)

struct passwd *
pw_dup(const struct passwd *pw)
{
        char            *cp;
        size_t           nsize, psize, csize, gsize, dsize, ssize, total;
        struct passwd   *newpw;

        /* Allocate in one big chunk for easy freeing */
        total = sizeof(struct passwd);
        PW_SIZE(pw_name, nsize);
        PW_SIZE(pw_passwd, psize);
        PW_SIZE(pw_class, csize);
        PW_SIZE(pw_gecos, gsize);
        PW_SIZE(pw_dir, dsize);
        PW_SIZE(pw_shell, ssize);

        if ((cp = malloc(total)) == NULL)
                return (NULL);
        newpw = (struct passwd *)cp;

        /*
         * Copy in passwd contents and make strings relative to space
         * at the end of the buffer.
         */
        (void)memcpy(newpw, pw, sizeof(struct passwd));
        cp += sizeof(struct passwd);

        PW_COPY(pw_name, nsize);
        PW_COPY(pw_passwd, psize);
        PW_COPY(pw_class, csize);
        PW_COPY(pw_gecos, gsize);
        PW_COPY(pw_dir, dsize);
        PW_COPY(pw_shell, ssize);

        return (newpw);
}
DEF_WEAK(pw_dup);