// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * NET4:        Sysctl interface to net af_unix subsystem.
 *
 * Authors:     Mike Shaver.
 */

#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysctl.h>
#include <net/af_unix.h>
#include <net/net_namespace.h>

#include "af_unix.h"

static struct ctl_table unix_table[] = {
        {
                .procname       = "max_dgram_qlen",
                .data           = &init_net.unx.sysctl_max_dgram_qlen,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
};

int __net_init unix_sysctl_register(struct net *net)
{
        struct ctl_table *table;

        if (net_eq(net, &init_net)) {
                table = unix_table;
        } else {
                table = kmemdup(unix_table, sizeof(unix_table), GFP_KERNEL);
                if (!table)
                        goto err_alloc;

                table[0].data = &net->unx.sysctl_max_dgram_qlen;
        }

        net->unx.ctl = register_net_sysctl_sz(net, "net/unix", table,
                                              ARRAY_SIZE(unix_table));
        if (net->unx.ctl == NULL)
                goto err_reg;

        return 0;

err_reg:
        if (!net_eq(net, &init_net))
                kfree(table);
err_alloc:
        return -ENOMEM;
}

void unix_sysctl_unregister(struct net *net)
{
        const struct ctl_table *table;

        table = net->unx.ctl->ctl_table_arg;
        unregister_net_sysctl_table(net->unx.ctl);
        if (!net_eq(net, &init_net))
                kfree(table);
}