/*-
 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/usr.sbin/nscd/agents/group.c,v 1.3 2008/10/23 00:15:00 delphij Exp $
 */

#include <sys/param.h>
#include <sys/types.h>
#include <assert.h>
#include <nsswitch.h>
#include <grp.h>
#include <string.h>
#include <stdlib.h>
#include "../debug.h"
#include "passwd.h"

static int group_marshal_func(struct group *, char *, size_t *);
static int group_lookup_func(const char *, size_t, char **, size_t *);
static void *group_mp_init_func(void);
static int group_mp_lookup_func(char **, size_t *, void *);
static void group_mp_destroy_func(void *);

static int
group_marshal_func(struct group *grp, char *buffer, size_t *buffer_size)
{
        struct group new_grp;
        size_t desired_size, size, mem_size;
        char *p, **mem;

        TRACE_IN(group_marshal_func);
        desired_size = ALIGNBYTES + sizeof(struct group) + sizeof(char *);

        if (grp->gr_name != NULL)
                desired_size += strlen(grp->gr_name) + 1;
        if (grp->gr_passwd != NULL)
                desired_size += strlen(grp->gr_passwd) + 1;

        if (grp->gr_mem != NULL) {
                mem_size = 0;
                for (mem = grp->gr_mem; *mem; ++mem) {
                        desired_size += strlen(*mem) + 1;
                        ++mem_size;
                }

                desired_size += ALIGNBYTES + (mem_size + 1) * sizeof(char *);
        }

        if ((desired_size > *buffer_size) || (buffer == NULL)) {
                *buffer_size = desired_size;
                TRACE_OUT(group_marshal_func);
                return (NS_RETURN);
        }

        memcpy(&new_grp, grp, sizeof(struct group));
        memset(buffer, 0, desired_size);

        *buffer_size = desired_size;
        p = buffer + sizeof(struct group) + sizeof(char *);
        memcpy(buffer + sizeof(struct group), &p, sizeof(char *));
        p = (char *)ALIGN(p);

        if (new_grp.gr_name != NULL) {
                size = strlen(new_grp.gr_name);
                memcpy(p, new_grp.gr_name, size);
                new_grp.gr_name = p;
                p += size + 1;
        }

        if (new_grp.gr_passwd != NULL) {
                size = strlen(new_grp.gr_passwd);
                memcpy(p, new_grp.gr_passwd, size);
                new_grp.gr_passwd = p;
                p += size + 1;
        }

        if (new_grp.gr_mem != NULL) {
                p = (char *)ALIGN(p);
                memcpy(p, new_grp.gr_mem, sizeof(char *) * mem_size);
                new_grp.gr_mem = (char **)p;
                p += sizeof(char *) * (mem_size + 1);

                for (mem = new_grp.gr_mem; *mem; ++mem) {
                        size = strlen(*mem);
                        memcpy(p, *mem, size);
                        *mem = p;
                        p += size + 1;
                }
        }

        memcpy(buffer, &new_grp, sizeof(struct group));
        TRACE_OUT(group_marshal_func);
        return (NS_SUCCESS);
}

static int
group_lookup_func(const char *key, size_t key_size, char **buffer,
        size_t *buffer_size)
{
        enum nss_lookup_type lookup_type;
        char    *name;
        size_t  size;
        gid_t   gid;

        struct group *result;

        TRACE_IN(group_lookup_func);
        assert(buffer != NULL);
        assert(buffer_size != NULL);

        if (key_size < sizeof(enum nss_lookup_type)) {
                TRACE_OUT(group_lookup_func);
                return (NS_UNAVAIL);
        }
        memcpy(&lookup_type, key, sizeof(enum nss_lookup_type));

        switch (lookup_type) {
        case nss_lt_name:
                size = key_size - sizeof(enum nss_lookup_type)  + 1;
                name = (char *)calloc(1, size);
                assert(name != NULL);
                memcpy(name, key + sizeof(enum nss_lookup_type), size - 1);
                break;
        case nss_lt_id:
                if (key_size < sizeof(enum nss_lookup_type) +
                        sizeof(gid_t)) {
                        TRACE_OUT(passwd_lookup_func);
                        return (NS_UNAVAIL);
                }

                memcpy(&gid, key + sizeof(enum nss_lookup_type), sizeof(gid_t));
                break;
        default:
                TRACE_OUT(group_lookup_func);
                return (NS_UNAVAIL);
        }

        switch (lookup_type) {
        case nss_lt_name:
                TRACE_STR(name);
                result = getgrnam(name);
                free(name);
                break;
        case nss_lt_id:
                result = getgrgid(gid);
                break;
        default:
                /* SHOULD NOT BE REACHED */
                break;
        }

        if (result != NULL) {
                group_marshal_func(result, NULL, buffer_size);
                *buffer = (char *)malloc(*buffer_size);
                assert(*buffer != NULL);
                group_marshal_func(result, *buffer, buffer_size);
        }

        TRACE_OUT(group_lookup_func);
        return (result == NULL ? NS_NOTFOUND : NS_SUCCESS);
}

static void *
group_mp_init_func(void)
{
        TRACE_IN(group_mp_init_func);
        setgrent();
        TRACE_OUT(group_mp_init_func);

        return (NULL);
}

static int
group_mp_lookup_func(char **buffer, size_t *buffer_size, void *mdata)
{
        struct group *result;

        TRACE_IN(group_mp_lookup_func);
        result = getgrent();
        if (result != NULL) {
                group_marshal_func(result, NULL, buffer_size);
                *buffer = (char *)malloc(*buffer_size);
                assert(*buffer != NULL);
                group_marshal_func(result, *buffer, buffer_size);
        }

        TRACE_OUT(group_mp_lookup_func);
        return (result == NULL ? NS_NOTFOUND : NS_SUCCESS);
}

static void
group_mp_destroy_func(void *mdata)
{
        TRACE_IN(group_mp_destroy_func);
        TRACE_OUT(group_mp_destroy_func);
}

struct agent *
init_group_agent(void)
{
        struct common_agent     *retval;

        TRACE_IN(init_group_agent);
        retval = (struct common_agent *)calloc(1, sizeof(struct common_agent));
        assert(retval != NULL);

        retval->parent.name = strdup("group");
        assert(retval->parent.name != NULL);

        retval->parent.type = COMMON_AGENT;
        retval->lookup_func = group_lookup_func;

        TRACE_OUT(init_group_agent);
        return ((struct agent *)retval);
}

struct agent *
init_group_mp_agent(void)
{
        struct multipart_agent  *retval;

        TRACE_IN(init_group_mp_agent);
        retval = (struct multipart_agent *)calloc(1,
                sizeof(struct multipart_agent));
        assert(retval != NULL);

        retval->parent.name = strdup("group");
        retval->parent.type = MULTIPART_AGENT;
        retval->mp_init_func = group_mp_init_func;
        retval->mp_lookup_func = group_mp_lookup_func;
        retval->mp_destroy_func = group_mp_destroy_func;
        assert(retval->parent.name != NULL);

        TRACE_OUT(init_group_mp_agent);
        return ((struct agent *)retval);
}