source: mainline/uspace/lib/posix/src/pwd.c

/*
 * Copyright (c) 2011 Jiri Zarevucky
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup libposix
 * @{
 */
/** @file Password handling.
 */

#include <stdbool.h>
#include <pwd.h>
#include <string.h>
#include <errno.h>
#include <assert.h>

static bool entry_read = false;

/* dummy user account */
static const struct passwd dummy_pwd = {
        .pw_name = (char *) "user",
        .pw_uid = 0,
        .pw_gid = 0,
        .pw_dir = (char *) "/",
        .pw_shell = (char *) "/app/bdsh"
};

/**
 * Retrieve next broken-down entry from the user database.
 *
 * Since HelenOS doesn't have user accounts, this always returns
 * the same made-up entry.
 *
 * @return Next user database entry or NULL if not possible. Since HelenOS
 *     doesn't have user accounts, this always returns the same made-up entry.
 */
struct passwd *getpwent(void)
{
        if (entry_read) {
                return NULL;
        }

        entry_read = true;
        return (struct passwd *) &dummy_pwd;
}

/**
 * Rewind the user list.
 */
void setpwent(void)
{
        entry_read = false;
}

/**
 * Ends enumerating and releases all resources. (Noop)
 */
void endpwent(void)
{
        /* noop */
}

/**
 * Find an entry by name.
 *
 * @param name Name of the entry.
 * @return Either found entry or NULL if no such entry exists.
 */
struct passwd *getpwnam(const char *name)
{
        assert(name != NULL);

        if (strcmp(name, "user") != 0) {
                return NULL;
        }

        return (struct passwd *) &dummy_pwd;
}

/**
 * Find an entry by name, thread safely.
 *
 * @param name Name of the entry.
 * @param pwd Original structure.
 * @param buffer Buffer for the strings referenced from the result structure.
 * @param bufsize Length of the buffer.
 * @param result Where to store updated structure.
 * @return Zero on success (either found or not found, but without an error),
 *     non-zero error number if error occured.
 */
int getpwnam_r(const char *name, struct passwd *pwd,
    char *buffer, size_t bufsize, struct passwd **result)
{
        assert(name != NULL);
        assert(pwd != NULL);
        assert(buffer != NULL);
        assert(result != NULL);

        if (strcmp(name, "user") != 0) {
                *result = NULL;
                return 0;
        }

        return getpwuid_r(0, pwd, buffer, bufsize, result);
}

/**
 * Find an entry by UID.
 *
 * @param uid UID of the entry.
 * @return Either found entry or NULL if no such entry exists.
 */
struct passwd *getpwuid(uid_t uid)
{
        if (uid != 0) {
                return NULL;
        }

        return (struct passwd *) &dummy_pwd;
}

/**
 * Find an entry by UID, thread safely.
 *
 * @param uid UID of the entry.
 * @param pwd Original structure.
 * @param buffer Buffer for the strings referenced from the result structure.
 * @param bufsize Length of the buffer.
 * @param result Where to store updated structure.
 * @return Zero on success (either found or not found, but without an error),
 *     non-zero error number if error occured.
 */
int getpwuid_r(uid_t uid, struct passwd *pwd,
    char *buffer, size_t bufsize, struct passwd **result)
{
        assert(pwd != NULL);
        assert(buffer != NULL);
        assert(result != NULL);

        static const char bf[] = { 'u', 's', 'e', 'r', '\0',
                '/', '\0', 'b', 'd', 's', 'h', '\0' };

        if (uid != 0) {
                *result = NULL;
                return 0;
        }
        if (bufsize < sizeof(bf)) {
                *result = NULL;
                return ERANGE;
        }

        memcpy(buffer, bf, sizeof(bf));

        pwd->pw_name = (char *) bf;
        pwd->pw_uid = 0;
        pwd->pw_gid = 0;
        pwd->pw_dir = (char *) bf + 5;
        pwd->pw_shell = (char *) bf + 7;
        *result = (struct passwd *) pwd;

        return 0;
}

/** @}
 */