root/net/ipv6/sysctl_net_ipv6.c
// SPDX-License-Identifier: GPL-2.0
/*
 * sysctl_net_ipv6.c: sysctl interface to net IPV6 subsystem.
 *
 * Changes:
 * YOSHIFUJI Hideaki @USAGI:    added icmp sysctl table.
 */

#include <linux/mm.h>
#include <linux/sysctl.h>
#include <linux/in6.h>
#include <linux/ipv6.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/ndisc.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/inet_frag.h>
#include <net/netevent.h>
#include <net/ip_fib.h>
#ifdef CONFIG_NETLABEL
#include <net/calipso.h>
#endif
#include <linux/ioam6.h>

static int flowlabel_reflect_max = 0x7;
static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX;
static u32 rt6_multipath_hash_fields_all_mask =
        FIB_MULTIPATH_HASH_FIELD_ALL_MASK;
static u32 ioam6_id_max = IOAM6_DEFAULT_ID;
static u64 ioam6_id_wide_max = IOAM6_DEFAULT_ID_WIDE;

static int proc_rt6_multipath_hash_policy(const struct ctl_table *table, int write,
                                          void *buffer, size_t *lenp, loff_t *ppos)
{
        struct net *net;
        int ret;

        net = container_of(table->data, struct net,
                           ipv6.sysctl.multipath_hash_policy);
        ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                call_netevent_notifiers(NETEVENT_IPV6_MPATH_HASH_UPDATE, net);

        return ret;
}

static int
proc_rt6_multipath_hash_fields(const struct ctl_table *table, int write, void *buffer,
                               size_t *lenp, loff_t *ppos)
{
        struct net *net;
        int ret;

        net = container_of(table->data, struct net,
                           ipv6.sysctl.multipath_hash_fields);
        ret = proc_douintvec_minmax(table, write, buffer, lenp, ppos);
        if (write && ret == 0)
                call_netevent_notifiers(NETEVENT_IPV6_MPATH_HASH_UPDATE, net);

        return ret;
}

static struct ctl_table ipv6_table_template[] = {
        {
                .procname       = "bindv6only",
                .data           = &init_net.ipv6.sysctl.bindv6only,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "anycast_src_echo_reply",
                .data           = &init_net.ipv6.sysctl.anycast_src_echo_reply,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "flowlabel_consistency",
                .data           = &init_net.ipv6.sysctl.flowlabel_consistency,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "auto_flowlabels",
                .data           = &init_net.ipv6.sysctl.auto_flowlabels,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra2         = &auto_flowlabels_max
        },
        {
                .procname       = "fwmark_reflect",
                .data           = &init_net.ipv6.sysctl.fwmark_reflect,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "idgen_retries",
                .data           = &init_net.ipv6.sysctl.idgen_retries,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "idgen_delay",
                .data           = &init_net.ipv6.sysctl.idgen_delay,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "flowlabel_state_ranges",
                .data           = &init_net.ipv6.sysctl.flowlabel_state_ranges,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "ip_nonlocal_bind",
                .data           = &init_net.ipv6.sysctl.ip_nonlocal_bind,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
        },
        {
                .procname       = "flowlabel_reflect",
                .data           = &init_net.ipv6.sysctl.flowlabel_reflect,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = &flowlabel_reflect_max,
        },
        {
                .procname       = "max_dst_opts_number",
                .data           = &init_net.ipv6.sysctl.max_dst_opts_cnt,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "max_hbh_opts_number",
                .data           = &init_net.ipv6.sysctl.max_hbh_opts_cnt,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "max_dst_opts_length",
                .data           = &init_net.ipv6.sysctl.max_dst_opts_len,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "max_hbh_length",
                .data           = &init_net.ipv6.sysctl.max_hbh_opts_len,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "fib_multipath_hash_policy",
                .data           = &init_net.ipv6.sysctl.multipath_hash_policy,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_rt6_multipath_hash_policy,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_THREE,
        },
        {
                .procname       = "fib_multipath_hash_fields",
                .data           = &init_net.ipv6.sysctl.multipath_hash_fields,
                .maxlen         = sizeof(u32),
                .mode           = 0644,
                .proc_handler   = proc_rt6_multipath_hash_fields,
                .extra1         = SYSCTL_ONE,
                .extra2         = &rt6_multipath_hash_fields_all_mask,
        },
        {
                .procname       = "seg6_flowlabel",
                .data           = &init_net.ipv6.sysctl.seg6_flowlabel,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "fib_notify_on_flag_change",
                .data           = &init_net.ipv6.sysctl.fib_notify_on_flag_change,
                .maxlen         = sizeof(u8),
                .mode           = 0644,
                .proc_handler   = proc_dou8vec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
        {
                .procname       = "ioam6_id",
                .data           = &init_net.ipv6.sysctl.ioam6_id,
                .maxlen         = sizeof(u32),
                .mode           = 0644,
                .proc_handler   = proc_douintvec_minmax,
                .extra2         = &ioam6_id_max,
        },
        {
                .procname       = "ioam6_id_wide",
                .data           = &init_net.ipv6.sysctl.ioam6_id_wide,
                .maxlen         = sizeof(u64),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
                .extra2         = &ioam6_id_wide_max,
        },
};

static struct ctl_table ipv6_rotable[] = {
        {
                .procname       = "mld_max_msf",
                .data           = &sysctl_mld_max_msf,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "mld_qrv",
                .data           = &sysctl_mld_qrv,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE
        },
#ifdef CONFIG_NETLABEL
        {
                .procname       = "calipso_cache_enable",
                .data           = &calipso_cache_enabled,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "calipso_cache_bucket_size",
                .data           = &calipso_cache_bucketsize,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif /* CONFIG_NETLABEL */
};

static int __net_init ipv6_sysctl_net_init(struct net *net)
{
        size_t table_size = ARRAY_SIZE(ipv6_table_template);
        struct ctl_table *ipv6_table;
        struct ctl_table *ipv6_route_table;
        struct ctl_table *ipv6_icmp_table;
        int err, i;

        err = -ENOMEM;
        ipv6_table = kmemdup(ipv6_table_template, sizeof(ipv6_table_template),
                             GFP_KERNEL);
        if (!ipv6_table)
                goto out;
        /* Update the variables to point into the current struct net */
        for (i = 0; i < table_size; i++)
                ipv6_table[i].data += (void *)net - (void *)&init_net;

        ipv6_route_table = ipv6_route_sysctl_init(net);
        if (!ipv6_route_table)
                goto out_ipv6_table;

        ipv6_icmp_table = ipv6_icmp_sysctl_init(net);
        if (!ipv6_icmp_table)
                goto out_ipv6_route_table;

        net->ipv6.sysctl.hdr = register_net_sysctl_sz(net, "net/ipv6",
                                                      ipv6_table, table_size);
        if (!net->ipv6.sysctl.hdr)
                goto out_ipv6_icmp_table;

        net->ipv6.sysctl.route_hdr = register_net_sysctl_sz(net,
                                                            "net/ipv6/route",
                                                            ipv6_route_table,
                                                            ipv6_route_sysctl_table_size(net));
        if (!net->ipv6.sysctl.route_hdr)
                goto out_unregister_ipv6_table;

        net->ipv6.sysctl.icmp_hdr = register_net_sysctl_sz(net,
                                                           "net/ipv6/icmp",
                                                           ipv6_icmp_table,
                                                           ipv6_icmp_sysctl_table_size());
        if (!net->ipv6.sysctl.icmp_hdr)
                goto out_unregister_route_table;

        err = 0;
out:
        return err;
out_unregister_route_table:
        unregister_net_sysctl_table(net->ipv6.sysctl.route_hdr);
out_unregister_ipv6_table:
        unregister_net_sysctl_table(net->ipv6.sysctl.hdr);
out_ipv6_icmp_table:
        kfree(ipv6_icmp_table);
out_ipv6_route_table:
        kfree(ipv6_route_table);
out_ipv6_table:
        kfree(ipv6_table);
        goto out;
}

static void __net_exit ipv6_sysctl_net_exit(struct net *net)
{
        const struct ctl_table *ipv6_table;
        const struct ctl_table *ipv6_route_table;
        const struct ctl_table *ipv6_icmp_table;

        ipv6_table = net->ipv6.sysctl.hdr->ctl_table_arg;
        ipv6_route_table = net->ipv6.sysctl.route_hdr->ctl_table_arg;
        ipv6_icmp_table = net->ipv6.sysctl.icmp_hdr->ctl_table_arg;

        unregister_net_sysctl_table(net->ipv6.sysctl.icmp_hdr);
        unregister_net_sysctl_table(net->ipv6.sysctl.route_hdr);
        unregister_net_sysctl_table(net->ipv6.sysctl.hdr);

        kfree(ipv6_table);
        kfree(ipv6_route_table);
        kfree(ipv6_icmp_table);
}

static struct pernet_operations ipv6_sysctl_net_ops = {
        .init = ipv6_sysctl_net_init,
        .exit = ipv6_sysctl_net_exit,
};

static struct ctl_table_header *ip6_header;

int ipv6_sysctl_register(void)
{
        int err = -ENOMEM;

        ip6_header = register_net_sysctl(&init_net, "net/ipv6", ipv6_rotable);
        if (!ip6_header)
                goto out;

        err = register_pernet_subsys(&ipv6_sysctl_net_ops);
        if (err)
                goto err_pernet;
out:
        return err;

err_pernet:
        unregister_net_sysctl_table(ip6_header);
        goto out;
}

void ipv6_sysctl_unregister(void)
{
        unregister_net_sysctl_table(ip6_header);
        unregister_pernet_subsys(&ipv6_sysctl_net_ops);
}