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/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/inet6_hashtables.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 = sk->sk_family;

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

#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == AF_INET6) {
		*(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr;
		*(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] = sk->sk_rcv_saddr;
	r->id.idiag_dst[0] = sk->sk_daddr;
	}
}
EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill);

static size_t inet_sk_attr_size(struct sock *sk,
				const struct inet_diag_req_v2 *req,
				bool net_admin)
{
	const struct inet_diag_handler *handler;
	size_t aux = 0;

	rcu_read_lock();
	handler = rcu_dereference(inet_diag_table[req->sdiag_protocol]);
	DEBUG_NET_WARN_ON_ONCE(!handler);
	if (handler && handler->idiag_get_aux_size)
		aux = handler->idiag_get_aux_size(sk, net_admin);
	rcu_read_unlock();

	return	  nla_total_size(sizeof(struct tcp_info))
		+ nla_total_size(sizeof(struct inet_diag_msg))
		+ inet_diag_msg_attrs_size()
		+ nla_total_size(sizeof(struct inet_diag_meminfo))
		+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
		+ nla_total_size(TCP_CA_NAME_MAX)
		+ nla_total_size(sizeof(struct tcpvegas_info))
		+ aux
		+ 64;
}

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, READ_ONCE(inet->tos)) < 0)
			goto errout;

#if IS_ENABLED(CONFIG_IPV6)
	if (r->idiag_family == AF_INET6) {
		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
			if (nla_put_u8(skb, INET_DIAG_TCLASS,
				       inet6_sk(sk)->tclass) < 0)
				goto errout;

		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
			goto errout;
	}
#endif

	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, READ_ONCE(sk->sk_mark)))
		goto errout;

	if (ext & (1 << (INET_DIAG_CLASS_ID - 1)) ||
	    ext & (1 << (INET_DIAG_TCLASS - 1))) {
		u32 classid = 0;

#ifdef CONFIG_CGROUP_NET_CLASSID
		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
#endif
		/* Fallback to socket priority if class id isn't set.
		 * Classful qdiscs use it as direct reference to class.
		 * For cgroup2 classid is always zero.
		 */
		if (!classid)
			classid = READ_ONCE(sk->sk_priority);

		if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid))
			goto errout;
	}

#ifdef CONFIG_SOCK_CGROUP_DATA
	if (nla_put_u64_64bit(skb, INET_DIAG_CGROUP_ID,
			      cgroup_id(sock_cgroup_ptr(&sk->sk_cgrp_data)),
			      INET_DIAG_PAD))
		goto errout;
#endif

	r->idiag_uid = from_kuid_munged(user_ns, sk_uid(sk));
	r->idiag_inode = sock_i_ino(sk);

	memset(&inet_sockopt, 0, sizeof(inet_sockopt));
	inet_sockopt.recverr	= inet_test_bit(RECVERR, sk);
	inet_sockopt.is_icsk	= inet_test_bit(IS_ICSK, sk);
	inet_sockopt.freebind	= inet_test_bit(FREEBIND, sk);
	inet_sockopt.hdrincl	= inet_test_bit(HDRINCL, sk);
	inet_sockopt.mc_loop	= inet_test_bit(MC_LOOP, sk);
	inet_sockopt.transparent = inet_test_bit(TRANSPARENT, sk);
	inet_sockopt.mc_all	= inet_test_bit(MC_ALL, sk);
	inet_sockopt.nodefrag	= inet_test_bit(NODEFRAG, sk);
	inet_sockopt.bind_address_no_port = inet_test_bit(BIND_ADDRESS_NO_PORT, sk);
	inet_sockopt.recverr_rfc4884 = inet_test_bit(RECVERR_RFC4884, sk);
	inet_sockopt.defer_connect = inet_test_bit(DEFER_CONNECT, sk);
	if (nla_put(skb, INET_DIAG_SOCKOPT, sizeof(inet_sockopt),
		    &inet_sockopt))
		goto errou