path: root/net/ipv4/inet_diag.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * inet_diag.c	Module for monitoring INET transport protocols sockets.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/time.h>

#include <net/icmp.h>
#include <net/tcp.h>
#include <net/ipv6.h>
#include <net/inet_common.h>
#include <net/inet_connection_sock.h>
#include <net/bpf_sk_storage.h>
#include <net/netlink.h>

#include <linux/inet.h>
#include <linux/stddef.h>

#include <linux/inet_diag.h>
#include <linux/sock_diag.h>

static const struct inet_diag_handler __rcu **inet_diag_table;

struct inet_diag_entry {
	const __be32 *saddr;
	const __be32 *daddr;
	u16 sport;
	u16 dport;
	u16 family;
	u16 userlocks;
	u32 ifindex;
	u32 mark;
#ifdef CONFIG_SOCK_CGROUP_DATA
	u64 cgroup_id;
#endif
};

static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
{
	const struct inet_diag_handler *handler;

	if (proto < 0 || proto >= IPPROTO_MAX)
		return NULL;

	if (!READ_ONCE(inet_diag_table[proto]))
		sock_load_diag_module(AF_INET, proto);

	rcu_read_lock();
	handler = rcu_dereference(inet_diag_table[proto]);
	if (handler && !try_module_get(handler->owner))
		handler = NULL;
	rcu_read_unlock();

	return handler;
}

static void inet_diag_unlock_handler(const struct inet_diag_handler *handler)
{
	module_put(handler->owner);
}

void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk)
{
	r->idiag_family = READ_ONCE(sk->sk_family);

	r->id.idiag_sport = htons(READ_ONCE(sk->sk_num));
	r->id.idiag_dport = READ_ONCE(sk->sk_dport);
	r->id.idiag_if = READ_ONCE(sk->sk_bound_dev_if);
	sock_diag_save_cookie(sk, r->id.idiag_cookie);

#if IS_ENABLED(CONFIG_IPV6)
	if (r->idiag_family == AF_INET6) {
		data_race(*(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr);
		data_race(*(struct in6_addr *)r->id.idiag_dst = sk->sk_v6_daddr);
	} else
#endif
	{
	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));

	r->id.idiag_src[0] = READ_ONCE(sk->sk_rcv_saddr);
	r->id.idiag_dst[0] = READ_ONCE(sk->sk_daddr);
	}
}
EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill);

int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
			     struct inet_diag_msg *r, int ext,
			     struct user_namespace *user_ns,
			     bool net_admin)
{
	const struct inet_sock *inet = inet_sk(sk);
	struct inet_diag_sockopt inet_sockopt;

	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
		goto errout;

	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
	 * hence this needs to be included regardless of socket family.
	 */
	if (ext & (1 << (INET_DIAG_TOS - 1)))
		if (nla_put_u8(skb, INET_DIAG_TOS,