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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* tcp_diag.c Module for monitoring TCP transport protocols sockets.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/sock_diag.h>
#include <linux/inet_diag.h>
#include <linux/tcp.h>
#include <net/netlink.h>
#include <net/tcp.h>
static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
void *_info)
{
struct tcp_info *info = _info;
if (inet_sk_state_load(sk) == TCP_LISTEN) {
r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
} else if (sk->sk_type == SOCK_STREAM) {
const struct tcp_sock *tp = tcp_sk(sk);
r->idiag_rqueue = max_t(int, READ_ONCE(tp->rcv_nxt) -
READ_ONCE(tp->copied_seq), 0);
r->idiag_wqueue = READ_ONCE(tp->write_seq) - tp->snd_una;
}
if (info)
tcp_get_info(sk, info);
}
#ifdef CONFIG_TCP_MD5SIG
static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info,
const struct tcp_md5sig_key *key)
{
info->tcpm_family = key->family;
info->tcpm_prefixlen = key->prefixlen;
info->tcpm_keylen = key->keylen;
memcpy(info->tcpm_key, key->key, key->keylen);
if (key->family == AF_INET)
info->tcpm_addr[0] = key->addr.a4.s_addr;
#if IS_ENABLED(CONFIG_IPV6)
else if (key->family == AF_INET6)
memcpy(&info->tcpm_addr, &key->addr.a6,
sizeof(info->tcpm_addr));
#endif
}
static int tcp_diag_put_md5sig(struct sk_buff *skb,
const struct tcp_md5sig_info *md5sig)
{
const struct tcp_md5sig_key *key;
struct tcp_diag_md5sig *info;
struct nlattr *attr;
int md5sig_count = 0;
hlist_for_each_entry_rcu(key, &md5sig->head, node)
md5sig_count++;
if (md5sig_count == 0)
return 0;
attr = nla_reserve(skb, INET_DIAG_MD5SIG,
md5sig_count * sizeof(struct tcp_diag_md5sig));
if (!attr)
return -EMSGSIZE;
info = nla_data(attr);
memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig));
hlist_for_each_entry_rcu(key, &md5sig->head, node) {
tcp_diag_md5sig_fill(info++, key);
if (--md5sig_count == 0)
break;
}
return 0;
}
#endif
static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk,
const struct tcp_ulp_ops *ulp_ops)
{
struct nlattr *nest;
int err;
nest = nla_nest_start_noflag(skb, INET_DIAG_ULP_INFO);
if (!nest)
return -EMSGSIZE;
err = nla_put_string(skb, INET_ULP_INFO_NAME, ulp_ops->name);
if (err)
goto nla_failure;
if (ulp_ops->get_info)
err = ulp_ops->get_info(sk, skb);
if (err)
goto nla_failure;
nla_nest_end(skb, nest);
return 0;
nla_failure:
nla_nest_cancel(skb, nest);
return err;
}
static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
struct sk_buff *skb)
{
struct inet_connection_sock *icsk = inet_csk(sk);
int err = 0;
#ifdef CONFIG_TCP_MD5SIG
if (net_admin) {
struct tcp_md5sig_info *md5sig;
rcu_read_lock();
md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
if (md5sig)
err = tcp_diag_put_md5sig(skb, md5sig);
rcu_read_unlock();
if (err < 0)
return err;
}
#endif
if (net_admin) {
const struct tcp_ulp_ops *ulp_ops;
ulp_ops = icsk->icsk_ulp_ops;
if (ulp_ops)
err = tcp_diag_put_ulp(skb, sk, ulp_ops);
if (err)
return err;
}
return 0;
}
static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
{
struct inet_connection_sock *icsk = inet_csk(sk);
size_t size = 0;
#ifdef CONFIG_TCP_MD5SIG
if (net_admin && sk_fullsock(sk)) {
const struct tcp_md5sig_info *md5sig;
const struct tcp_md5sig_key *key;
size_t md5sig_count = 0;
rcu_read_lock();
md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
if (md5sig) {
hlist_for_each_entry_rcu(key, &md5sig->head, node)
md5sig_count++;
}
rcu_read_unlock();
size += nla_total_size(md5sig_count *
sizeof(struct tcp_diag_md5sig));
}
#endif
if (net_admin && sk_fullsock(sk)) {
const struct tcp_ulp_ops *ulp_ops;
ulp_ops = icsk->icsk_ulp_ops;
if (ulp_ops) {
size += nla_total_size(0) +
nla_total_size(TCP_ULP_NAME_MAX);
if (ulp_ops->get_info_size)
size += ulp_ops->get_info_size(sk);
}
}
return size;
}
static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
const struct inet_diag_req_v2 *r)
{
struct inet_hashinfo *hinfo;
hinfo = sock_net(cb->skb->sk)->ipv4.tcp_death_row.hashinfo;
inet_diag_dump_icsk(hinfo, skb, cb, r);
}
static int tcp_diag_dump_one(struct netlink_callback *cb,
const struct inet_diag_req_v2 *req)
{
struct inet_hashinfo *hinfo;
hinfo = sock_net(cb->skb->sk)->ipv4.tcp_death_row.hashinfo;
return inet_diag_dump_one_icsk(hinfo, cb, req);
}
#ifdef CONFIG_INET_DIAG_DESTROY
static int tcp_diag_destroy(struct sk_buff *in_skb,
const struct inet_diag_req_v2 *req)
{
struct net *net = sock_net(in_skb->sk);
struct inet_hashinfo *hinfo;
struct sock *sk;
int err;
hinfo = net->ipv4.tcp_death_row.hashinfo;
sk = inet_diag_find_one_icsk(net, hinfo, req);
if (IS_ERR(sk))
return PTR_ERR(sk);
err = sock_diag_destroy(sk, ECONNABORTED);
sock_gen_put(sk);
return err;
}
#endif
static const struct inet_diag_handler tcp_diag_handler = {
.owner = THIS_MODULE,
.dump = tcp_diag_dump,
.dump_one = tcp_diag_dump_one,
.idiag_get_info = tcp_diag_get_info,
.idiag_get_aux = tcp_diag_get_aux,
.idiag_get_aux_size = tcp_diag_get_aux_size,
.idiag_type = IPPROTO_TCP,
.idiag_info_size = sizeof(struct tcp_info),
#ifdef CONFIG_INET_DIAG_DESTROY
.destroy = tcp_diag_destroy,
#endif
};
static int __init tcp_diag_init(void)
{
return inet_diag_register(&tcp_diag_handler);
}
static void __exit tcp_diag_exit(void)
{
inet_diag_unregister(&tcp_diag_handler);
}
module_init(tcp_diag_init);
module_exit(tcp_diag_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TCP socket monitoring via SOCK_DIAG");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
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