linux/net/ipv6/sysctl_net_ipv6.c
Joel Granados 1c106eb01c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

* Remove sentinel element from ctl_table structs.
* Remove the zeroing out of an array element (to make it look like a
  sentinel) in sysctl_route_net_init And ipv6_route_sysctl_init.
  This is not longer needed and is safe after commit c899710fe7
  ("networking: Update to register_net_sysctl_sz") added the array size
  to the ctl_table registration.
* Remove extra sentinel element in the declaration of devinet_vars.
* Removed the "-1" in __devinet_sysctl_register, sysctl_route_net_init,
  ipv6_sysctl_net_init and ipv4_sysctl_init_net that adjusted for having
  an extra empty element when looping over ctl_table arrays
* Replace the for loop stop condition in __addrconf_sysctl_register that
  tests for procname == NULL with one that depends on array size
* Removing the unprivileged user check in ipv6_route_sysctl_init is
  safe as it is replaced by calling ipv6_route_sysctl_table_size;
  introduced in commit c899710fe7 ("networking: Update to
  register_net_sysctl_sz")
* Use a table_size variable to keep the value of ARRAY_SIZE

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-05-03 13:29:42 +01:00

362 lines
9.0 KiB
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(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(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);
}