// SPDX-License-Identifier: GPL-2.0

  /* -*- linux-c -*-
   * sysctl_net_core.c: sysctl interface to net core subsystem.
   *
   * Begun April 1, 1996, Mike Shaver.
   * Added /proc/sys/net/core directory entry (empty =) ). [MS]
   */
  
  #include <linux/mm.h>
  #include <linux/sysctl.h>

  #include <linux/module.h>

  #include <linux/socket.h>

  #include <linux/netdevice.h>

  #include <linux/ratelimit.h>

  #include <linux/vmalloc.h>

  #include <linux/init.h>

  #include <linux/slab.h>

  #include <net/ip.h>

  #include <net/sock.h>

  #include <net/net_ratelimit.h>

  #include <net/busy_poll.h>

  #include <net/pkt_sched.h>

  static int two __maybe_unused = 2;

  static int min_sndbuf = SOCK_MIN_SNDBUF;
  static int min_rcvbuf = SOCK_MIN_RCVBUF;

  static int max_skb_frags = MAX_SKB_FRAGS;

  static long long_one __maybe_unused = 1;
  static long long_max __maybe_unused = LONG_MAX;

  static int net_msg_warn;	/* Unused, but still a sysctl */

  int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
  EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);

  /* 0 - Keep current behavior:
   *     IPv4: inherit all current settings from init_net
   *     IPv6: reset all settings to default
   * 1 - Both inherit all current settings from init_net
   * 2 - Both reset all settings to default
   */
  int sysctl_devconf_inherit_init_net __read_mostly;
  EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);

  #ifdef CONFIG_RPS

  static int rps_sock_flow_sysctl(struct ctl_table *table, int write,

  				void __user *buffer, size_t *lenp, loff_t *ppos)
  {
  	unsigned int orig_size, size;
  	int ret, i;

  	struct ctl_table tmp = {

  		.data = &size,
  		.maxlen = sizeof(size),
  		.mode = table->mode
  	};
  	struct rps_sock_flow_table *orig_sock_table, *sock_table;
  	static DEFINE_MUTEX(sock_flow_mutex);
  
  	mutex_lock(&sock_flow_mutex);

  	orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
  					lockdep_is_held(&sock_flow_mutex));

  	size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
  
  	ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
  
  	if (write) {
  		if (size) {

  			if (size > 1<<29) {

  				/* Enforce limit to prevent overflow */
  				mutex_unlock(&sock_flow_mutex);
  				return -EINVAL;
  			}
  			size = roundup_pow_of_two(size);
  			if (size != orig_size) {
  				sock_table =
  				    vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
  				if (!sock_table) {
  					mutex_unlock(&sock_flow_mutex);
  					return -ENOMEM;
  				}

  				rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;

  				sock_table->mask = size - 1;
  			} else
  				sock_table = orig_sock_table;
  
  			for (i = 0; i < size; i++)
  				sock_table->ents[i] = RPS_NO_CPU;
  		} else
  			sock_table = NULL;
  
  		if (sock_table != orig_sock_table) {
  			rcu_assign_pointer(rps_sock_flow_table, sock_table);

  			if (sock_table) {

  				static_branch_inc(&rps_needed);
  				static_branch_inc(&rfs_needed);

  			}

  			if (orig_sock_table) {

  				static_branch_dec(&rps_needed);
  				static_branch_dec(&rfs_needed);

  				synchronize_rcu();
  				vfree(orig_sock_table);
  			}

  		}
  	}
  
  	mutex_unlock(&sock_flow_mutex);
  
  	return ret;
  }
  #endif /* CONFIG_RPS */

  #ifdef CONFIG_NET_FLOW_LIMIT
  static DEFINE_MUTEX(flow_limit_update_mutex);

  static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,

  				 void __user *buffer, size_t *lenp,
  				 loff_t *ppos)
  {
  	struct sd_flow_limit *cur;
  	struct softnet_data *sd;
  	cpumask_var_t mask;
  	int i, len, ret = 0;
  
  	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
  		return -ENOMEM;
  
  	if (write) {
  		ret = cpumask_parse_user(buffer, *lenp, mask);
  		if (ret)
  			goto done;
  
  		mutex_lock(&flow_limit_update_mutex);
  		len = sizeof(*cur) + netdev_flow_limit_table_len;
  		for_each_possible_cpu(i) {
  			sd = &per_cpu(softnet_data, i);
  			cur = rcu_dereference_protected(sd->flow_limit,
  				     lockdep_is_held(&flow_limit_update_mutex));
  			if (cur && !cpumask_test_cpu(i, mask)) {
  				RCU_INIT_POINTER(sd->flow_limit, NULL);
  				synchronize_rcu();
  				kfree(cur);
  			} else if (!cur && cpumask_test_cpu(i, mask)) {

  				cur = kzalloc_node(len, GFP_KERNEL,
  						   cpu_to_node(i));

  				if (!cur) {
  					/* not unwinding previous changes */
  					ret = -ENOMEM;
  					goto write_unlock;
  				}
  				cur->num_buckets = netdev_flow_limit_table_len;
  				rcu_assign_pointer(sd->flow_limit, cur);
  			}
  		}
  write_unlock:
  		mutex_unlock(&flow_limit_update_mutex);
  	} else {

  		char kbuf[128];

  		if (*ppos || !*lenp) {
  			*lenp = 0;
  			goto done;
  		}
  
  		cpumask_clear(mask);
  		rcu_read_lock();
  		for_each_possible_cpu(i) {
  			sd = &per_cpu(softnet_data, i);
  			if (rcu_dereference(sd->flow_limit))
  				cpumask_set_cpu(i, mask);
  		}
  		rcu_read_unlock();

  		len = min(sizeof(kbuf) - 1, *lenp);

  		len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));

  		if (!len) {
  			*lenp = 0;
  			goto done;
  		}
  		if (len < *lenp)
  			kbuf[len++] = '
  ';
  		if (copy_to_user(buffer, kbuf, len)) {
  			ret = -EFAULT;
  			goto done;
  		}
  		*lenp = len;
  		*ppos += len;

  	}
  
  done:
  	free_cpumask_var(mask);
  	return ret;
  }

  static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,

  				       void __user *buffer, size_t *lenp,
  				       loff_t *ppos)
  {
  	unsigned int old, *ptr;
  	int ret;
  
  	mutex_lock(&flow_limit_update_mutex);
  
  	ptr = table->data;
  	old = *ptr;
  	ret = proc_dointvec(table, write, buffer, lenp, ppos);
  	if (!ret && write && !is_power_of_2(*ptr)) {
  		*ptr = old;
  		ret = -EINVAL;
  	}
  
  	mutex_unlock(&flow_limit_update_mutex);
  	return ret;
  }
  #endif /* CONFIG_NET_FLOW_LIMIT */

  #ifdef CONFIG_NET_SCHED
  static int set_default_qdisc(struct ctl_table *table, int write,
  			     void __user *buffer, size_t *lenp, loff_t *ppos)
  {
  	char id[IFNAMSIZ];
  	struct ctl_table tbl = {
  		.data = id,
  		.maxlen = IFNAMSIZ,
  	};
  	int ret;
  
  	qdisc_get_default(id, IFNAMSIZ);
  
  	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
  	if (write && ret == 0)
  		ret = qdisc_set_default(id);
  	return ret;
  }
  #endif

  static int proc_do_dev_weight(struct ctl_table *table, int write,
  			   void __user *buffer, size_t *lenp, loff_t *ppos)
  {
  	int ret;
  
  	ret = proc_dointvec(table, write, buffer, lenp, ppos);
  	if (ret != 0)
  		return ret;
  
  	dev_rx_weight = weight_p * dev_weight_rx_bias;
  	dev_tx_weight = weight_p * dev_weight_tx_bias;
  
  	return ret;
  }

  static int proc_do_rss_key(struct ctl_table *table, int write,
  			   void __user *buffer, size_t *lenp, loff_t *ppos)
  {
  	struct ctl_table fake_table;
  	char buf[NETDEV_RSS_KEY_LEN * 3];
  
  	snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
  	fake_table.data = buf;
  	fake_table.maxlen = sizeof(buf);
  	return proc_dostring(&fake_table, write, buffer, lenp, ppos);
  }

  #ifdef CONFIG_BPF_JIT
  static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
  					   void __user *buffer, size_t *lenp,
  					   loff_t *ppos)
  {
  	int ret, jit_enable = *(int *)table->data;
  	struct ctl_table tmp = *table;
  
  	if (write && !capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	tmp.data = &jit_enable;
  	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
  	if (write && !ret) {
  		if (jit_enable < 2 ||
  		    (jit_enable == 2 && bpf_dump_raw_ok())) {
  			*(int *)table->data = jit_enable;
  			if (jit_enable == 2)
  				pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!
  ");
  		} else {
  			ret = -EPERM;
  		}
  	}
  	return ret;
  }

  # ifdef CONFIG_HAVE_EBPF_JIT

  static int
  proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
  				    void __user *buffer, size_t *lenp,
  				    loff_t *ppos)
  {
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
  }

  # endif /* CONFIG_HAVE_EBPF_JIT */

  
  static int
  proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
  				     void __user *buffer, size_t *lenp,
  				     loff_t *ppos)
  {
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
  }

  #endif

  static struct ctl_table net_core_table[] = {

  #ifdef CONFIG_NET
  	{

  		.procname	= "wmem_max",
  		.data		= &sysctl_wmem_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &min_sndbuf,

  	},
  	{

  		.procname	= "rmem_max",
  		.data		= &sysctl_rmem_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &min_rcvbuf,

  	},
  	{

  		.procname	= "wmem_default",
  		.data		= &sysctl_wmem_default,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &min_sndbuf,

  	},
  	{

  		.procname	= "rmem_default",
  		.data		= &sysctl_rmem_default,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &min_rcvbuf,

  	},
  	{

  		.procname	= "dev_weight",
  		.data		= &weight_p,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_do_dev_weight,
  	},
  	{
  		.procname	= "dev_weight_rx_bias",
  		.data		= &dev_weight_rx_bias,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_do_dev_weight,
  	},
  	{
  		.procname	= "dev_weight_tx_bias",
  		.data		= &dev_weight_tx_bias,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_do_dev_weight,

  	},
  	{

  		.procname	= "netdev_max_backlog",
  		.data		= &netdev_max_backlog,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{
  		.procname	= "netdev_rss_key",
  		.data		= &netdev_rss_key,
  		.maxlen		= sizeof(int),
  		.mode		= 0444,
  		.proc_handler	= proc_do_rss_key,
  	},

  #ifdef CONFIG_BPF_JIT
  	{
  		.procname	= "bpf_jit_enable",
  		.data		= &bpf_jit_enable,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax_bpf_enable,

  # ifdef CONFIG_BPF_JIT_ALWAYS_ON

  		.extra1		= SYSCTL_ONE,
  		.extra2		= SYSCTL_ONE,

  # else

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &two,
  # endif

  	},

  # ifdef CONFIG_HAVE_EBPF_JIT
  	{
  		.procname	= "bpf_jit_harden",
  		.data		= &bpf_jit_harden,
  		.maxlen		= sizeof(int),
  		.mode		= 0600,

  		.proc_handler	= proc_dointvec_minmax_bpf_restricted,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &two,

  	},

  	{
  		.procname	= "bpf_jit_kallsyms",
  		.data		= &bpf_jit_kallsyms,
  		.maxlen		= sizeof(int),
  		.mode		= 0600,

  		.proc_handler	= proc_dointvec_minmax_bpf_restricted,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},

  # endif

  	{
  		.procname	= "bpf_jit_limit",
  		.data		= &bpf_jit_limit,

  		.maxlen		= sizeof(long),

  		.mode		= 0600,

  		.proc_handler	= proc_dolongvec_minmax_bpf_restricted,
  		.extra1		= &long_one,
  		.extra2		= &long_max,

  	},

  #endif

  	{

  		.procname	= "netdev_tstamp_prequeue",
  		.data		= &netdev_tstamp_prequeue,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec
  	},
  	{

  		.procname	= "message_cost",

  		.data		= &net_ratelimit_state.interval,

  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_jiffies,

  	},
  	{

  		.procname	= "message_burst",

  		.data		= &net_ratelimit_state.burst,

  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "optmem_max",
  		.data		= &sysctl_optmem_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{
  		.procname	= "tstamp_allow_data",
  		.data		= &sysctl_tstamp_allow_data,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE

  	},

  #ifdef CONFIG_RPS
  	{
  		.procname	= "rps_sock_flow_entries",
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= rps_sock_flow_sysctl
  	},
  #endif

  #ifdef CONFIG_NET_FLOW_LIMIT
  	{
  		.procname	= "flow_limit_cpu_bitmap",
  		.mode		= 0644,
  		.proc_handler	= flow_limit_cpu_sysctl
  	},
  	{
  		.procname	= "flow_limit_table_len",
  		.data		= &netdev_flow_limit_table_len,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= flow_limit_table_len_sysctl
  	},
  #endif /* CONFIG_NET_FLOW_LIMIT */

  #ifdef CONFIG_NET_RX_BUSY_POLL

  	{

  		.procname	= "busy_poll",
  		.data		= &sysctl_net_busy_poll,

  		.maxlen		= sizeof(unsigned int),

  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  	},

  	{

  		.procname	= "busy_read",
  		.data		= &sysctl_net_busy_read,

  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  	},

  #endif
  #ifdef CONFIG_NET_SCHED
  	{
  		.procname	= "default_qdisc",
  		.mode		= 0644,
  		.maxlen		= IFNAMSIZ,
  		.proc_handler	= set_default_qdisc
  	},

  #endif

  #endif /* CONFIG_NET */
  	{

  		.procname	= "netdev_budget",
  		.data		= &netdev_budget,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{

  		.procname	= "warnings",
  		.data		= &net_msg_warn,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec

  	},

  	{
  		.procname	= "max_skb_frags",
  		.data		= &sysctl_max_skb_frags,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ONE,

  		.extra2		= &max_skb_frags,
  	},

  	{
  		.procname	= "netdev_budget_usecs",
  		.data		= &netdev_budget_usecs,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  	},

  	{
  		.procname	= "fb_tunnels_only_for_init_net",
  		.data		= &sysctl_fb_tunnels_only_for_init_net,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,
  		.extra2		= SYSCTL_ONE,

  	},

  	{
  		.procname	= "devconf_inherit_init_net",
  		.data		= &sysctl_devconf_inherit_init_net,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= SYSCTL_ZERO,

  		.extra2		= &two,
  	},

  	{
  		.procname	= "high_order_alloc_disable",
  		.data		= &net_high_order_alloc_disable_key.key,
  		.maxlen         = sizeof(net_high_order_alloc_disable_key),
  		.mode		= 0644,
  		.proc_handler	= proc_do_static_key,
  	},

  	{
  		.procname	= "gro_normal_batch",
  		.data		= &gro_normal_batch,
  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec_minmax,
  		.extra1		= SYSCTL_ONE,
  	},

  	{ }

  };

  static struct ctl_table netns_core_table[] = {
  	{

  		.procname	= "somaxconn",
  		.data		= &init_net.core.sysctl_somaxconn,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.extra1		= SYSCTL_ZERO,

  		.proc_handler	= proc_dointvec_minmax

  	},

  	{ }

  };

  static __net_init int sysctl_core_net_init(struct net *net)

  {

  	struct ctl_table *tbl;

  	tbl = netns_core_table;

  	if (!net_eq(net, &init_net)) {

  		tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);

  		if (tbl == NULL)
  			goto err_dup;

  		tbl[0].data = &net->core.sysctl_somaxconn;

  
  		/* Don't export any sysctls to unprivileged users */
  		if (net->user_ns != &init_user_ns) {
  			tbl[0].procname = NULL;
  		}

  	}

  	net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);

  	if (net->core.sysctl_hdr == NULL)

  		goto err_reg;

  	return 0;
  
  err_reg:

  	if (tbl != netns_core_table)

  		kfree(tbl);
  err_dup:
  	return -ENOMEM;
  }
  
  static __net_exit void sysctl_core_net_exit(struct net *net)
  {
  	struct ctl_table *tbl;

  	tbl = net->core.sysctl_hdr->ctl_table_arg;
  	unregister_net_sysctl_table(net->core.sysctl_hdr);

  	BUG_ON(tbl == netns_core_table);

  	kfree(tbl);
  }
  
  static __net_initdata struct pernet_operations sysctl_core_ops = {
  	.init = sysctl_core_net_init,
  	.exit = sysctl_core_net_exit,
  };
  
  static __init int sysctl_core_init(void)
  {

  	register_net_sysctl(&init_net, "net/core", net_core_table);

  	return register_pernet_subsys(&sysctl_core_ops);

  }

  fs_initcall(sysctl_core_init);