Merge branch 'robust_listener'

Eric Dumazet says:

====================
tcp/dccp: make our listener code more robust

This patch series addresses request sockets leaks and listener dismantle
phase. This survives a stress test with listeners being added/removed
quite randomly.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-10-16 00:52:27 -07:00
Родитель 47ea032533 ebb516af60
Коммит a302afe980
7 изменённых файлов: 67 добавлений и 57 удалений

Просмотреть файл

@ -268,13 +268,8 @@ struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
struct sock *newsk,
const struct request_sock *req);
static inline void inet_csk_reqsk_queue_add(struct sock *sk,
struct request_sock *req,
struct sock *child)
{
reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);
}
void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,
struct sock *child);
void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
unsigned long timeout);
@ -299,6 +294,7 @@ static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
}
void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
void inet_csk_destroy_sock(struct sock *sk);
void inet_csk_prepare_forced_close(struct sock *sk);

Просмотреть файл

@ -186,25 +186,6 @@ static inline bool reqsk_queue_empty(const struct request_sock_queue *queue)
return queue->rskq_accept_head == NULL;
}
static inline void reqsk_queue_add(struct request_sock_queue *queue,
struct request_sock *req,
struct sock *parent,
struct sock *child)
{
spin_lock(&queue->rskq_lock);
req->sk = child;
sk_acceptq_added(parent);
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_head = req;
else
queue->rskq_accept_tail->dl_next = req;
queue->rskq_accept_tail = req;
req->dl_next = NULL;
spin_unlock(&queue->rskq_lock);
}
static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue,
struct sock *parent)
{

Просмотреть файл

@ -208,7 +208,6 @@ void dccp_req_err(struct sock *sk, u64 seq)
if (!between48(seq, dccp_rsk(req)->dreq_iss, dccp_rsk(req)->dreq_gss)) {
NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
reqsk_put(req);
} else {
/*
* Still in RESPOND, just remove it silently.
@ -218,6 +217,7 @@ void dccp_req_err(struct sock *sk, u64 seq)
*/
inet_csk_reqsk_queue_drop(req->rsk_listener, req);
}
reqsk_put(req);
}
EXPORT_SYMBOL(dccp_req_err);
@ -828,7 +828,7 @@ lookup:
if (likely(sk->sk_state == DCCP_LISTEN)) {
nsk = dccp_check_req(sk, skb, req);
} else {
inet_csk_reqsk_queue_drop(sk, req);
inet_csk_reqsk_queue_drop_and_put(sk, req);
goto lookup;
}
if (!nsk) {

Просмотреть файл

@ -686,7 +686,7 @@ lookup:
if (likely(sk->sk_state == DCCP_LISTEN)) {
nsk = dccp_check_req(sk, skb, req);
} else {
inet_csk_reqsk_queue_drop(sk, req);
inet_csk_reqsk_queue_drop_and_put(sk, req);
goto lookup;
}
if (!nsk) {

Просмотреть файл

@ -546,6 +546,13 @@ void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
}
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
{
inet_csk_reqsk_queue_drop(sk, req);
reqsk_put(req);
}
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
static void reqsk_timer_handler(unsigned long data)
{
struct request_sock *req = (struct request_sock *)data;
@ -608,8 +615,7 @@ static void reqsk_timer_handler(unsigned long data)
return;
}
drop:
inet_csk_reqsk_queue_drop(sk_listener, req);
reqsk_put(req);
inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
}
static void reqsk_queue_hash_req(struct request_sock *req,
@ -758,6 +764,53 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
}
EXPORT_SYMBOL_GPL(inet_csk_listen_start);
static void inet_child_forget(struct sock *sk, struct request_sock *req,
struct sock *child)
{
sk->sk_prot->disconnect(child, O_NONBLOCK);
sock_orphan(child);
percpu_counter_inc(sk->sk_prot->orphan_count);
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
BUG_ON(tcp_sk(child)->fastopen_rsk != req);
BUG_ON(sk != req->rsk_listener);
/* Paranoid, to prevent race condition if
* an inbound pkt destined for child is
* blocked by sock lock in tcp_v4_rcv().
* Also to satisfy an assertion in
* tcp_v4_destroy_sock().
*/
tcp_sk(child)->fastopen_rsk = NULL;
}
inet_csk_destroy_sock(child);
reqsk_put(req);
}
void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,
struct sock *child)
{
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
spin_lock(&queue->rskq_lock);
if (unlikely(sk->sk_state != TCP_LISTEN)) {
inet_child_forget(sk, req, child);
} else {
req->sk = child;
req->dl_next = NULL;
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_head = req;
else
queue->rskq_accept_tail->dl_next = req;
queue->rskq_accept_tail = req;
sk_acceptq_added(sk);
}
spin_unlock(&queue->rskq_lock);
}
EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
/*
* This routine closes sockets which have been at least partially
* opened, but not yet accepted.
@ -784,31 +837,11 @@ void inet_csk_listen_stop(struct sock *sk)
WARN_ON(sock_owned_by_user(child));
sock_hold(child);
sk->sk_prot->disconnect(child, O_NONBLOCK);
sock_orphan(child);
percpu_counter_inc(sk->sk_prot->orphan_count);
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
BUG_ON(tcp_sk(child)->fastopen_rsk != req);
BUG_ON(sk != req->rsk_listener);
/* Paranoid, to prevent race condition if
* an inbound pkt destined for child is
* blocked by sock lock in tcp_v4_rcv().
* Also to satisfy an assertion in
* tcp_v4_destroy_sock().
*/
tcp_sk(child)->fastopen_rsk = NULL;
}
inet_csk_destroy_sock(child);
inet_child_forget(sk, req, child);
bh_unlock_sock(child);
local_bh_enable();
sock_put(child);
reqsk_put(req);
cond_resched();
}
if (queue->fastopenq.rskq_rst_head) {
@ -823,7 +856,7 @@ void inet_csk_listen_stop(struct sock *sk)
req = next;
}
}
WARN_ON(sk->sk_ack_backlog);
WARN_ON_ONCE(sk->sk_ack_backlog);
}
EXPORT_SYMBOL_GPL(inet_csk_listen_stop);

Просмотреть файл

@ -324,7 +324,6 @@ void tcp_req_err(struct sock *sk, u32 seq)
if (seq != tcp_rsk(req)->snt_isn) {
NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
reqsk_put(req);
} else {
/*
* Still in SYN_RECV, just remove it silently.
@ -332,9 +331,10 @@ void tcp_req_err(struct sock *sk, u32 seq)
* created socket, and POSIX does not want network
* errors returned from accept().
*/
NET_INC_STATS_BH(net, LINUX_MIB_LISTENDROPS);
inet_csk_reqsk_queue_drop(req->rsk_listener, req);
NET_INC_STATS_BH(net, LINUX_MIB_LISTENDROPS);
}
reqsk_put(req);
}
EXPORT_SYMBOL(tcp_req_err);
@ -1591,7 +1591,7 @@ process:
if (likely(sk->sk_state == TCP_LISTEN)) {
nsk = tcp_check_req(sk, skb, req, false);
} else {
inet_csk_reqsk_queue_drop(sk, req);
inet_csk_reqsk_queue_drop_and_put(sk, req);
goto lookup;
}
if (!nsk) {

Просмотреть файл

@ -1386,7 +1386,7 @@ process:
if (likely(sk->sk_state == TCP_LISTEN)) {
nsk = tcp_check_req(sk, skb, req, false);
} else {
inet_csk_reqsk_queue_drop(sk, req);
inet_csk_reqsk_queue_drop_and_put(sk, req);
goto lookup;
}
if (!nsk) {