linux/net/ipv4/sysctl_net_ipv4.c
Josh Hunt c04b79b6cf tcp: add new tcp_mtu_probe_floor sysctl
The current implementation of TCP MTU probing can considerably
underestimate the MTU on lossy connections allowing the MSS to get down to
48. We have found that in almost all of these cases on our networks these
paths can handle much larger MTUs meaning the connections are being
artificially limited. Even though TCP MTU probing can raise the MSS back up
we have seen this not to be the case causing connections to be "stuck" with
an MSS of 48 when heavy loss is present.

Prior to pushing out this change we could not keep TCP MTU probing enabled
b/c of the above reasons. Now with a reasonble floor set we've had it
enabled for the past 6 months.

The new sysctl will still default to TCP_MIN_SND_MSS (48), but gives
administrators the ability to control the floor of MSS probing.

Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-09 13:03:30 -07:00

1397 lines
34 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
*
* Begun April 1, 1996, Mike Shaver.
* Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
*/
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/igmp.h>
#include <linux/inetdevice.h>
#include <linux/seqlock.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/nsproxy.h>
#include <linux/swap.h>
#include <net/snmp.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/cipso_ipv4.h>
#include <net/inet_frag.h>
#include <net/ping.h>
#include <net/protocol.h>
#include <net/netevent.h>
static int two = 2;
static int four = 4;
static int thousand = 1000;
static int gso_max_segs = GSO_MAX_SEGS;
static int tcp_retr1_max = 255;
static int ip_local_port_range_min[] = { 1, 1 };
static int ip_local_port_range_max[] = { 65535, 65535 };
static int tcp_adv_win_scale_min = -31;
static int tcp_adv_win_scale_max = 31;
static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
static int tcp_min_snd_mss_max = 65535;
static int ip_privileged_port_min;
static int ip_privileged_port_max = 65535;
static int ip_ttl_min = 1;
static int ip_ttl_max = 255;
static int tcp_syn_retries_min = 1;
static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
static int ip_ping_group_range_min[] = { 0, 0 };
static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
static int comp_sack_nr_max = 255;
static u32 u32_max_div_HZ = UINT_MAX / HZ;
static int one_day_secs = 24 * 3600;
/* obsolete */
static int sysctl_tcp_low_latency __read_mostly;
/* Update system visible IP port range */
static void set_local_port_range(struct net *net, int range[2])
{
bool same_parity = !((range[0] ^ range[1]) & 1);
write_seqlock_bh(&net->ipv4.ip_local_ports.lock);
if (same_parity && !net->ipv4.ip_local_ports.warned) {
net->ipv4.ip_local_ports.warned = true;
pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
}
net->ipv4.ip_local_ports.range[0] = range[0];
net->ipv4.ip_local_ports.range[1] = range[1];
write_sequnlock_bh(&net->ipv4.ip_local_ports.lock);
}
/* Validate changes from /proc interface. */
static int ipv4_local_port_range(struct ctl_table *table, int write,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
struct net *net =
container_of(table->data, struct net, ipv4.ip_local_ports.range);
int ret;
int range[2];
struct ctl_table tmp = {
.data = &range,
.maxlen = sizeof(range),
.mode = table->mode,
.extra1 = &ip_local_port_range_min,
.extra2 = &ip_local_port_range_max,
};
inet_get_local_port_range(net, &range[0], &range[1]);
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && ret == 0) {
/* Ensure that the upper limit is not smaller than the lower,
* and that the lower does not encroach upon the privileged
* port limit.
*/
if ((range[1] < range[0]) ||
(range[0] < net->ipv4.sysctl_ip_prot_sock))
ret = -EINVAL;
else
set_local_port_range(net, range);
}
return ret;
}
/* Validate changes from /proc interface. */
static int ipv4_privileged_ports(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = container_of(table->data, struct net,
ipv4.sysctl_ip_prot_sock);
int ret;
int pports;
int range[2];
struct ctl_table tmp = {
.data = &pports,
.maxlen = sizeof(pports),
.mode = table->mode,
.extra1 = &ip_privileged_port_min,
.extra2 = &ip_privileged_port_max,
};
pports = net->ipv4.sysctl_ip_prot_sock;
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && ret == 0) {
inet_get_local_port_range(net, &range[0], &range[1]);
/* Ensure that the local port range doesn't overlap with the
* privileged port range.
*/
if (range[0] < pports)
ret = -EINVAL;
else
net->ipv4.sysctl_ip_prot_sock = pports;
}
return ret;
}
static void inet_get_ping_group_range_table(struct ctl_table *table, kgid_t *low, kgid_t *high)
{
kgid_t *data = table->data;
struct net *net =
container_of(table->data, struct net, ipv4.ping_group_range.range);
unsigned int seq;
do {
seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
*low = data[0];
*high = data[1];
} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
}
/* Update system visible IP port range */
static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t high)
{
kgid_t *data = table->data;
struct net *net =
container_of(table->data, struct net, ipv4.ping_group_range.range);
write_seqlock(&net->ipv4.ping_group_range.lock);
data[0] = low;
data[1] = high;
write_sequnlock(&net->ipv4.ping_group_range.lock);
}
/* Validate changes from /proc interface. */
static int ipv4_ping_group_range(struct ctl_table *table, int write,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
struct user_namespace *user_ns = current_user_ns();
int ret;
gid_t urange[2];
kgid_t low, high;
struct ctl_table tmp = {
.data = &urange,
.maxlen = sizeof(urange),
.mode = table->mode,
.extra1 = &ip_ping_group_range_min,
.extra2 = &ip_ping_group_range_max,
};
inet_get_ping_group_range_table(table, &low, &high);
urange[0] = from_kgid_munged(user_ns, low);
urange[1] = from_kgid_munged(user_ns, high);
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && ret == 0) {
low = make_kgid(user_ns, urange[0]);
high = make_kgid(user_ns, urange[1]);
if (!gid_valid(low) || !gid_valid(high))
return -EINVAL;
if (urange[1] < urange[0] || gid_lt(high, low)) {
low = make_kgid(&init_user_ns, 1);
high = make_kgid(&init_user_ns, 0);
}
set_ping_group_range(table, low, high);
}
return ret;
}
static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
struct net *net;
int ret;
net = container_of(table->data, struct net,
ipv4.sysctl_ip_fwd_update_priority);
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (write && ret == 0)
call_netevent_notifiers(NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE,
net);
return ret;
}
static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = container_of(ctl->data, struct net,
ipv4.tcp_congestion_control);
char val[TCP_CA_NAME_MAX];
struct ctl_table tbl = {
.data = val,
.maxlen = TCP_CA_NAME_MAX,
};
int ret;
tcp_get_default_congestion_control(net, val);
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0)
ret = tcp_set_default_congestion_control(net, val);
return ret;
}
static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
int ret;
tbl.data = kmalloc(tbl.maxlen, GFP_USER);
if (!tbl.data)
return -ENOMEM;
tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
kfree(tbl.data);
return ret;
}
static int proc_allowed_congestion_control(struct ctl_table *ctl,
int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
int ret;
tbl.data = kmalloc(tbl.maxlen, GFP_USER);
if (!tbl.data)
return -ENOMEM;
tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0)
ret = tcp_set_allowed_congestion_control(tbl.data);
kfree(tbl.data);
return ret;
}
static int sscanf_key(char *buf, __le32 *key)
{
u32 user_key[4];
int i, ret = 0;
if (sscanf(buf, "%x-%x-%x-%x", user_key, user_key + 1,
user_key + 2, user_key + 3) != 4) {
ret = -EINVAL;
} else {
for (i = 0; i < ARRAY_SIZE(user_key); i++)
key[i] = cpu_to_le32(user_key[i]);
}
pr_debug("proc TFO key set 0x%x-%x-%x-%x <- 0x%s: %u\n",
user_key[0], user_key[1], user_key[2], user_key[3], buf, ret);
return ret;
}
static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
struct net *net = container_of(table->data, struct net,
ipv4.sysctl_tcp_fastopen);
/* maxlen to print the list of keys in hex (*2), with dashes
* separating doublewords and a comma in between keys.
*/
struct ctl_table tbl = { .maxlen = ((TCP_FASTOPEN_KEY_LENGTH *
2 * TCP_FASTOPEN_KEY_MAX) +
(TCP_FASTOPEN_KEY_MAX * 5)) };
struct tcp_fastopen_context *ctx;
u32 user_key[TCP_FASTOPEN_KEY_MAX * 4];
__le32 key[TCP_FASTOPEN_KEY_MAX * 4];
char *backup_data;
int ret, i = 0, off = 0, n_keys = 0;
tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
if (!tbl.data)
return -ENOMEM;
rcu_read_lock();
ctx = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
if (ctx) {
n_keys = tcp_fastopen_context_len(ctx);
memcpy(&key[0], &ctx->key[0], TCP_FASTOPEN_KEY_LENGTH * n_keys);
}
rcu_read_unlock();
if (!n_keys) {
memset(&key[0], 0, TCP_FASTOPEN_KEY_LENGTH);
n_keys = 1;
}
for (i = 0; i < n_keys * 4; i++)
user_key[i] = le32_to_cpu(key[i]);
for (i = 0; i < n_keys; i++) {
off += snprintf(tbl.data + off, tbl.maxlen - off,
"%08x-%08x-%08x-%08x",
user_key[i * 4],
user_key[i * 4 + 1],
user_key[i * 4 + 2],
user_key[i * 4 + 3]);
if (i + 1 < n_keys)
off += snprintf(tbl.data + off, tbl.maxlen - off, ",");
}
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
backup_data = strchr(tbl.data, ',');
if (backup_data) {
*backup_data = '\0';
backup_data++;
}
if (sscanf_key(tbl.data, key)) {
ret = -EINVAL;
goto bad_key;
}
if (backup_data) {
if (sscanf_key(backup_data, key + 4)) {
ret = -EINVAL;
goto bad_key;
}
}
tcp_fastopen_reset_cipher(net, NULL, key,
backup_data ? key + 4 : NULL);
}
bad_key:
kfree(tbl.data);
return ret;
}
static void proc_configure_early_demux(int enabled, int protocol)
{
struct net_protocol *ipprot;
#if IS_ENABLED(CONFIG_IPV6)
struct inet6_protocol *ip6prot;
#endif
rcu_read_lock();
ipprot = rcu_dereference(inet_protos[protocol]);
if (ipprot)
ipprot->early_demux = enabled ? ipprot->early_demux_handler :
NULL;
#if IS_ENABLED(CONFIG_IPV6)
ip6prot = rcu_dereference(inet6_protos[protocol]);
if (ip6prot)
ip6prot->early_demux = enabled ? ip6prot->early_demux_handler :
NULL;
#endif
rcu_read_unlock();
}
static int proc_tcp_early_demux(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int ret = 0;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
if (write && !ret) {
int enabled = init_net.ipv4.sysctl_tcp_early_demux;
proc_configure_early_demux(enabled, IPPROTO_TCP);
}
return ret;
}
static int proc_udp_early_demux(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int ret = 0;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
if (write && !ret) {
int enabled = init_net.ipv4.sysctl_udp_early_demux;
proc_configure_early_demux(enabled, IPPROTO_UDP);
}
return ret;
}
static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
int write,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
struct net *net = container_of(table->data, struct net,
ipv4.sysctl_tcp_fastopen_blackhole_timeout);
int ret;
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (write && ret == 0)
atomic_set(&net->ipv4.tfo_active_disable_times, 0);
return ret;
}
static int proc_tcp_available_ulp(struct ctl_table *ctl,
int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
int ret;
tbl.data = kmalloc(tbl.maxlen, GFP_USER);
if (!tbl.data)
return -ENOMEM;
tcp_get_available_ulp(tbl.data, TCP_ULP_BUF_MAX);
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
kfree(tbl.data);
return ret;
}
#ifdef CONFIG_IP_ROUTE_MULTIPATH
static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
struct net *net = container_of(table->data, struct net,
ipv4.sysctl_fib_multipath_hash_policy);
int ret;
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (write && ret == 0)
call_netevent_notifiers(NETEVENT_IPV4_MPATH_HASH_UPDATE, net);
return ret;
}
#endif
static struct ctl_table ipv4_table[] = {
{
.procname = "tcp_max_orphans",
.data = &sysctl_tcp_max_orphans,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "inet_peer_threshold",
.data = &inet_peer_threshold,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "inet_peer_minttl",
.data = &inet_peer_minttl,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "inet_peer_maxttl",
.data = &inet_peer_maxttl,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "tcp_mem",
.maxlen = sizeof(sysctl_tcp_mem),
.data = &sysctl_tcp_mem,
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "tcp_low_latency",
.data = &sysctl_tcp_low_latency,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
#ifdef CONFIG_NETLABEL
{
.procname = "cipso_cache_enable",
.data = &cipso_v4_cache_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "cipso_cache_bucket_size",
.data = &cipso_v4_cache_bucketsize,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "cipso_rbm_optfmt",
.data = &cipso_v4_rbm_optfmt,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "cipso_rbm_strictvalid",
.data = &cipso_v4_rbm_strictvalid,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#endif /* CONFIG_NETLABEL */
{
.procname = "tcp_available_congestion_control",
.maxlen = TCP_CA_BUF_MAX,
.mode = 0444,
.proc_handler = proc_tcp_available_congestion_control,
},
{
.procname = "tcp_allowed_congestion_control",
.maxlen = TCP_CA_BUF_MAX,
.mode = 0644,
.proc_handler = proc_allowed_congestion_control,
},
{
.procname = "tcp_available_ulp",
.maxlen = TCP_ULP_BUF_MAX,
.mode = 0444,
.proc_handler = proc_tcp_available_ulp,
},
{
.procname = "icmp_msgs_per_sec",
.data = &sysctl_icmp_msgs_per_sec,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
},
{
.procname = "icmp_msgs_burst",
.data = &sysctl_icmp_msgs_burst,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
},
{
.procname = "udp_mem",
.data = &sysctl_udp_mem,
.maxlen = sizeof(sysctl_udp_mem),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "fib_sync_mem",
.data = &sysctl_fib_sync_mem,
.maxlen = sizeof(sysctl_fib_sync_mem),
.mode = 0644,
.proc_handler = proc_douintvec_minmax,
.extra1 = &sysctl_fib_sync_mem_min,
.extra2 = &sysctl_fib_sync_mem_max,
},
{
.procname = "tcp_rx_skb_cache",
.data = &tcp_rx_skb_cache_key.key,
.mode = 0644,
.proc_handler = proc_do_static_key,
},
{
.procname = "tcp_tx_skb_cache",
.data = &tcp_tx_skb_cache_key.key,
.mode = 0644,
.proc_handler = proc_do_static_key,
},
{ }
};
static struct ctl_table ipv4_net_table[] = {
{
.procname = "icmp_echo_ignore_all",
.data = &init_net.ipv4.sysctl_icmp_echo_ignore_all,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "icmp_echo_ignore_broadcasts",
.data = &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "icmp_ignore_bogus_error_responses",
.data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "icmp_errors_use_inbound_ifaddr",
.data = &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "icmp_ratelimit",
.data = &init_net.ipv4.sysctl_icmp_ratelimit,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
{
.procname = "icmp_ratemask",
.data = &init_net.ipv4.sysctl_icmp_ratemask,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "ping_group_range",
.data = &init_net.ipv4.ping_group_range.range,
.maxlen = sizeof(gid_t)*2,
.mode = 0644,
.proc_handler = ipv4_ping_group_range,
},
#ifdef CONFIG_NET_L3_MASTER_DEV
{
.procname = "raw_l3mdev_accept",
.data = &init_net.ipv4.sysctl_raw_l3mdev_accept,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
#endif
{
.procname = "tcp_ecn",
.data = &init_net.ipv4.sysctl_tcp_ecn,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_ecn_fallback",
.data = &init_net.ipv4.sysctl_tcp_ecn_fallback,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "ip_dynaddr",
.data = &init_net.ipv4.sysctl_ip_dynaddr,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "ip_early_demux",
.data = &init_net.ipv4.sysctl_ip_early_demux,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "udp_early_demux",
.data = &init_net.ipv4.sysctl_udp_early_demux,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_udp_early_demux
},
{
.procname = "tcp_early_demux",
.data = &init_net.ipv4.sysctl_tcp_early_demux,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_tcp_early_demux
},
{
.procname = "ip_default_ttl",
.data = &init_net.ipv4.sysctl_ip_default_ttl,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &ip_ttl_min,
.extra2 = &ip_ttl_max,
},
{
.procname = "ip_local_port_range",
.maxlen = sizeof(init_net.ipv4.ip_local_ports.range),
.data = &init_net.ipv4.ip_local_ports.range,
.mode = 0644,
.proc_handler = ipv4_local_port_range,
},
{
.procname = "ip_local_reserved_ports",
.data = &init_net.ipv4.sysctl_local_reserved_ports,
.maxlen = 65536,
.mode = 0644,
.proc_handler = proc_do_large_bitmap,
},
{
.procname = "ip_no_pmtu_disc",
.data = &init_net.ipv4.sysctl_ip_no_pmtu_disc,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "ip_forward_use_pmtu",
.data = &init_net.ipv4.sysctl_ip_fwd_use_pmtu,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "ip_forward_update_priority",
.data = &init_net.ipv4.sysctl_ip_fwd_update_priority,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = ipv4_fwd_update_priority,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "ip_nonlocal_bind",
.data = &init_net.ipv4.sysctl_ip_nonlocal_bind,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "fwmark_reflect",
.data = &init_net.ipv4.sysctl_fwmark_reflect,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_fwmark_accept",
.data = &init_net.ipv4.sysctl_tcp_fwmark_accept,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#ifdef CONFIG_NET_L3_MASTER_DEV
{
.procname = "tcp_l3mdev_accept",
.data = &init_net.ipv4.sysctl_tcp_l3mdev_accept,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
#endif
{
.procname = "tcp_mtu_probing",
.data = &init_net.ipv4.sysctl_tcp_mtu_probing,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_base_mss",
.data = &init_net.ipv4.sysctl_tcp_base_mss,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_min_snd_mss",
.data = &init_net.ipv4.sysctl_tcp_min_snd_mss,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &tcp_min_snd_mss_min,
.extra2 = &tcp_min_snd_mss_max,
},
{
.procname = "tcp_mtu_probe_floor",
.data = &init_net.ipv4.sysctl_tcp_mtu_probe_floor,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &tcp_min_snd_mss_min,
.extra2 = &tcp_min_snd_mss_max,
},
{
.procname = "tcp_probe_threshold",
.data = &init_net.ipv4.sysctl_tcp_probe_threshold,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_probe_interval",
.data = &init_net.ipv4.sysctl_tcp_probe_interval,
.maxlen = sizeof(u32),
.mode = 0644,
.proc_handler = proc_douintvec_minmax,
.extra2 = &u32_max_div_HZ,
},
{
.procname = "igmp_link_local_mcast_reports",
.data = &init_net.ipv4.sysctl_igmp_llm_reports,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "igmp_max_memberships",
.data = &init_net.ipv4.sysctl_igmp_max_memberships,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "igmp_max_msf",
.data = &init_net.ipv4.sysctl_igmp_max_msf,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
#ifdef CONFIG_IP_MULTICAST
{
.procname = "igmp_qrv",
.data = &init_net.ipv4.sysctl_igmp_qrv,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE
},
#endif
{
.procname = "tcp_congestion_control",
.data = &init_net.ipv4.tcp_congestion_control,
.mode = 0644,
.maxlen = TCP_CA_NAME_MAX,
.proc_handler = proc_tcp_congestion_control,
},
{
.procname = "tcp_keepalive_time",
.data = &init_net.ipv4.sysctl_tcp_keepalive_time,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "tcp_keepalive_probes",
.data = &init_net.ipv4.sysctl_tcp_keepalive_probes,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_keepalive_intvl",
.data = &init_net.ipv4.sysctl_tcp_keepalive_intvl,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "tcp_syn_retries",
.data = &init_net.ipv4.sysctl_tcp_syn_retries,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &tcp_syn_retries_min,
.extra2 = &tcp_syn_retries_max
},
{
.procname = "tcp_synack_retries",
.data = &init_net.ipv4.sysctl_tcp_synack_retries,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
#ifdef CONFIG_SYN_COOKIES
{
.procname = "tcp_syncookies",
.data = &init_net.ipv4.sysctl_tcp_syncookies,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
#endif
{
.procname = "tcp_reordering",
.data = &init_net.ipv4.sysctl_tcp_reordering,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_retries1",
.data = &init_net.ipv4.sysctl_tcp_retries1,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra2 = &tcp_retr1_max
},
{
.procname = "tcp_retries2",
.data = &init_net.ipv4.sysctl_tcp_retries2,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_orphan_retries",
.data = &init_net.ipv4.sysctl_tcp_orphan_retries,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_fin_timeout",
.data = &init_net.ipv4.sysctl_tcp_fin_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "tcp_notsent_lowat",
.data = &init_net.ipv4.sysctl_tcp_notsent_lowat,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_douintvec,
},
{
.procname = "tcp_tw_reuse",
.data = &init_net.ipv4.sysctl_tcp_tw_reuse,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &two,
},
{
.procname = "tcp_max_tw_buckets",
.data = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_max_syn_backlog",
.data = &init_net.ipv4.sysctl_max_syn_backlog,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_fastopen",
.data = &init_net.ipv4.sysctl_tcp_fastopen,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_fastopen_key",
.mode = 0600,
.data = &init_net.ipv4.sysctl_tcp_fastopen,
/* maxlen to print the list of keys in hex (*2), with dashes
* separating doublewords and a comma in between keys.
*/
.maxlen = ((TCP_FASTOPEN_KEY_LENGTH *
2 * TCP_FASTOPEN_KEY_MAX) +
(TCP_FASTOPEN_KEY_MAX * 5)),
.proc_handler = proc_tcp_fastopen_key,
},
{
.procname = "tcp_fastopen_blackhole_timeout_sec",
.data = &init_net.ipv4.sysctl_tcp_fastopen_blackhole_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_tfo_blackhole_detect_timeout,
.extra1 = SYSCTL_ZERO,
},
#ifdef CONFIG_IP_ROUTE_MULTIPATH
{
.procname = "fib_multipath_use_neigh",
.data = &init_net.ipv4.sysctl_fib_multipath_use_neigh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "fib_multipath_hash_policy",
.data = &init_net.ipv4.sysctl_fib_multipath_hash_policy,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_fib_multipath_hash_policy,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
#endif
{
.procname = "ip_unprivileged_port_start",
.maxlen = sizeof(int),
.data = &init_net.ipv4.sysctl_ip_prot_sock,
.mode = 0644,
.proc_handler = ipv4_privileged_ports,
},
#ifdef CONFIG_NET_L3_MASTER_DEV
{
.procname = "udp_l3mdev_accept",
.data = &init_net.ipv4.sysctl_udp_l3mdev_accept,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
#endif
{
.procname = "tcp_sack",
.data = &init_net.ipv4.sysctl_tcp_sack,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_window_scaling",
.data = &init_net.ipv4.sysctl_tcp_window_scaling,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_timestamps",
.data = &init_net.ipv4.sysctl_tcp_timestamps,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_early_retrans",
.data = &init_net.ipv4.sysctl_tcp_early_retrans,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &four,
},
{
.procname = "tcp_recovery",
.data = &init_net.ipv4.sysctl_tcp_recovery,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_thin_linear_timeouts",
.data = &init_net.ipv4.sysctl_tcp_thin_linear_timeouts,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_slow_start_after_idle",
.data = &init_net.ipv4.sysctl_tcp_slow_start_after_idle,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_retrans_collapse",
.data = &init_net.ipv4.sysctl_tcp_retrans_collapse,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_stdurg",
.data = &init_net.ipv4.sysctl_tcp_stdurg,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_rfc1337",
.data = &init_net.ipv4.sysctl_tcp_rfc1337,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_abort_on_overflow",
.data = &init_net.ipv4.sysctl_tcp_abort_on_overflow,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_fack",
.data = &init_net.ipv4.sysctl_tcp_fack,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_max_reordering",
.data = &init_net.ipv4.sysctl_tcp_max_reordering,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_dsack",
.data = &init_net.ipv4.sysctl_tcp_dsack,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_app_win",
.data = &init_net.ipv4.sysctl_tcp_app_win,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_adv_win_scale",
.data = &init_net.ipv4.sysctl_tcp_adv_win_scale,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &tcp_adv_win_scale_min,
.extra2 = &tcp_adv_win_scale_max,
},
{
.procname = "tcp_frto",
.data = &init_net.ipv4.sysctl_tcp_frto,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_no_metrics_save",
.data = &init_net.ipv4.sysctl_tcp_nometrics_save,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_moderate_rcvbuf",
.data = &init_net.ipv4.sysctl_tcp_moderate_rcvbuf,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_tso_win_divisor",
.data = &init_net.ipv4.sysctl_tcp_tso_win_divisor,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "tcp_workaround_signed_windows",
.data = &init_net.ipv4.sysctl_tcp_workaround_signed_windows,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_limit_output_bytes",
.data = &init_net.ipv4.sysctl_tcp_limit_output_bytes,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_challenge_ack_limit",
.data = &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "tcp_min_tso_segs",
.data = &init_net.ipv4.sysctl_tcp_min_tso_segs,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &gso_max_segs,
},
{
.procname = "tcp_min_rtt_wlen",
.data = &init_net.ipv4.sysctl_tcp_min_rtt_wlen,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &one_day_secs
},
{
.procname = "tcp_autocorking",
.data = &init_net.ipv4.sysctl_tcp_autocorking,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "tcp_invalid_ratelimit",
.data = &init_net.ipv4.sysctl_tcp_invalid_ratelimit,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
{
.procname = "tcp_pacing_ss_ratio",
.data = &init_net.ipv4.sysctl_tcp_pacing_ss_ratio,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &thousand,
},
{
.procname = "tcp_pacing_ca_ratio",
.data = &init_net.ipv4.sysctl_tcp_pacing_ca_ratio,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &thousand,
},
{
.procname = "tcp_wmem",
.data = &init_net.ipv4.sysctl_tcp_wmem,
.maxlen = sizeof(init_net.ipv4.sysctl_tcp_wmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
},
{
.procname = "tcp_rmem",
.data = &init_net.ipv4.sysctl_tcp_rmem,
.maxlen = sizeof(init_net.ipv4.sysctl_tcp_rmem),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
},
{
.procname = "tcp_comp_sack_delay_ns",
.data = &init_net.ipv4.sysctl_tcp_comp_sack_delay_ns,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "tcp_comp_sack_nr",
.data = &init_net.ipv4.sysctl_tcp_comp_sack_nr,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &comp_sack_nr_max,
},
{
.procname = "udp_rmem_min",
.data = &init_net.ipv4.sysctl_udp_rmem_min,
.maxlen = sizeof(init_net.ipv4.sysctl_udp_rmem_min),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE
},
{
.procname = "udp_wmem_min",
.data = &init_net.ipv4.sysctl_udp_wmem_min,
.maxlen = sizeof(init_net.ipv4.sysctl_udp_wmem_min),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE
},
{ }
};
static __net_init int ipv4_sysctl_init_net(struct net *net)
{
struct ctl_table *table;
table = ipv4_net_table;
if (!net_eq(net, &init_net)) {
int i;
table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
if (!table)
goto err_alloc;
/* Update the variables to point into the current struct net */
for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
table[i].data += (void *)net - (void *)&init_net;
}
net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
if (!net->ipv4.ipv4_hdr)
goto err_reg;
net->ipv4.sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
if (!net->ipv4.sysctl_local_reserved_ports)
goto err_ports;
return 0;
err_ports:
unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
err_reg:
if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
static __net_exit void ipv4_sysctl_exit_net(struct net *net)
{
struct ctl_table *table;
kfree(net->ipv4.sysctl_local_reserved_ports);
table = net->ipv4.ipv4_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
kfree(table);
}
static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
.init = ipv4_sysctl_init_net,
.exit = ipv4_sysctl_exit_net,
};
static __init int sysctl_ipv4_init(void)
{
struct ctl_table_header *hdr;
hdr = register_net_sysctl(&init_net, "net/ipv4", ipv4_table);
if (!hdr)
return -ENOMEM;
if (register_pernet_subsys(&ipv4_sysctl_ops)) {
unregister_net_sysctl_table(hdr);
return -ENOMEM;
}
return 0;
}
__initcall(sysctl_ipv4_init);