// SPDX-License-Identifier: GPL-2.0-only
/*
 * sysctl.c: General linux system control interface
 */

#include <linux/printk.h>
#include <linux/capability.h>
#include <linux/ratelimit.h>
#include "internal.h"

static const int ten_thousand = 10000;

static int proc_dointvec_minmax_sysadmin(const struct ctl_table *table, int write,
                                void *buffer, size_t *lenp, loff_t *ppos)
{
        if (write && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
}

static const struct ctl_table printk_sysctls[] = {
        {
                .procname       = "printk",
                .data           = &console_loglevel,
                .maxlen         = 4*sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "printk_ratelimit",
                .data           = &printk_ratelimit_state.interval,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "printk_ratelimit_burst",
                .data           = &printk_ratelimit_state.burst,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "printk_delay",
                .data           = &printk_delay_msec,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&ten_thousand,
        },
        {
                .procname       = "printk_devkmsg",
                .data           = devkmsg_log_str,
                .maxlen         = DEVKMSG_STR_MAX_SIZE,
                .mode           = 0644,
                .proc_handler   = devkmsg_sysctl_set_loglvl,
        },
        {
                .procname       = "dmesg_restrict",
                .data           = &dmesg_restrict,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax_sysadmin,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "kptr_restrict",
                .data           = &kptr_restrict,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax_sysadmin,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
};

void __init printk_sysctl_init(void)
{
        register_sysctl_init("kernel", printk_sysctls);
}