From 5903123f662ed18483f05cac3f9e800a074c29ff Mon Sep 17 00:00:00 2001 From: Akhmat Karakotov Date: Fri, 28 Jan 2022 22:26:21 +0300 Subject: [PATCH] tcp: Use BPF timeout setting for SYN ACK RTO When setting RTO through BPF program, some SYN ACK packets were unaffected and continued to use TCP_TIMEOUT_INIT constant. This patch adds timeout option to struct request_sock. Option is initialized with TCP_TIMEOUT_INIT and is reassigned through BPF using tcp_timeout_init call. SYN ACK retransmits now use newly added timeout option. Signed-off-by: Akhmat Karakotov Acked-by: Martin KaFai Lau v2: - Add timeout option to struct request_sock. Do not call tcp_timeout_init on every syn ack retransmit. v3: - Use unsigned long for min. Bound tcp_timeout_init to TCP_RTO_MAX. v4: - Refactor duplicate code by adding reqsk_timeout function. Signed-off-by: David S. Miller --- include/net/inet_connection_sock.h | 8 ++++++++ include/net/request_sock.h | 2 ++ include/net/tcp.h | 2 +- net/ipv4/inet_connection_sock.c | 5 +---- net/ipv4/tcp_input.c | 8 +++++--- net/ipv4/tcp_minisocks.c | 5 ++--- 6 files changed, 19 insertions(+), 11 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 4ad47d9f9d27..3908296d103f 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -285,6 +285,14 @@ static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) bool 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); +static inline unsigned long +reqsk_timeout(struct request_sock *req, unsigned long max_timeout) +{ + u64 timeout = (u64)req->timeout << req->num_timeout; + + return (unsigned long)min_t(u64, timeout, max_timeout); +} + static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) { /* The below has to be done to allow calling inet_csk_destroy_sock */ diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 29e41ff3ec93..144c39db9898 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -70,6 +70,7 @@ struct request_sock { struct saved_syn *saved_syn; u32 secid; u32 peer_secid; + u32 timeout; }; static inline struct request_sock *inet_reqsk(const struct sock *sk) @@ -104,6 +105,7 @@ reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener, sk_node_init(&req_to_sk(req)->sk_node); sk_tx_queue_clear(req_to_sk(req)); req->saved_syn = NULL; + req->timeout = 0; req->num_timeout = 0; req->num_retrans = 0; req->sk = NULL; diff --git a/include/net/tcp.h b/include/net/tcp.h index b9fc978fb2ca..eff2487d972d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2358,7 +2358,7 @@ static inline u32 tcp_timeout_init(struct sock *sk) if (timeout <= 0) timeout = TCP_TIMEOUT_INIT; - return timeout; + return min_t(int, timeout, TCP_RTO_MAX); } static inline u32 tcp_rwnd_init_bpf(struct sock *sk) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index b81fb13fc5f4..1e5b53c2bb26 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -866,12 +866,9 @@ static void reqsk_timer_handler(struct timer_list *t) (!resend || !inet_rtx_syn_ack(sk_listener, req) || inet_rsk(req)->acked)) { - unsigned long timeo; - if (req->num_timeout++ == 0) atomic_dec(&queue->young); - timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); - mod_timer(&req->rsk_timer, jiffies + timeo); + mod_timer(&req->rsk_timer, jiffies + reqsk_timeout(req, TCP_RTO_MAX)); if (!nreq) return; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index dc49a3d551eb..302744bec59e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6723,6 +6723,7 @@ struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops, ireq->ireq_state = TCP_NEW_SYN_RECV; write_pnet(&ireq->ireq_net, sock_net(sk_listener)); ireq->ireq_family = sk_listener->sk_family; + req->timeout = TCP_TIMEOUT_INIT; } return req; @@ -6939,9 +6940,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, sock_put(fastopen_sk); } else { tcp_rsk(req)->tfo_listener = false; - if (!want_cookie) - inet_csk_reqsk_queue_hash_add(sk, req, - tcp_timeout_init((struct sock *)req)); + if (!want_cookie) { + req->timeout = tcp_timeout_init((struct sock *)req); + inet_csk_reqsk_queue_hash_add(sk, req, req->timeout); + } af_ops->send_synack(sk, dst, &fl, req, &foc, !want_cookie ? TCP_SYNACK_NORMAL : TCP_SYNACK_COOKIE, diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 3977257f80d9..6366df7aaf2a 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -583,7 +583,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, * it can be estimated (approximately) * from another data. */ - tmp_opt.ts_recent_stamp = ktime_get_seconds() - ((TCP_TIMEOUT_INIT/HZ)<num_timeout); + tmp_opt.ts_recent_stamp = ktime_get_seconds() - reqsk_timeout(req, TCP_RTO_MAX) / HZ; paws_reject = tcp_paws_reject(&tmp_opt, th->rst); } } @@ -622,8 +622,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, !inet_rtx_syn_ack(sk, req)) { unsigned long expires = jiffies; - expires += min(TCP_TIMEOUT_INIT << req->num_timeout, - TCP_RTO_MAX); + expires += reqsk_timeout(req, TCP_RTO_MAX); if (!fastopen) mod_timer_pending(&req->rsk_timer, expires); else