diff --git a/Documentation/networking/net_cachelines/tcp_sock.rst b/Documentation/networking/net_cachelines/tcp_sock.rst index 563daea10d6c..fecf61166a54 100644 --- a/Documentation/networking/net_cachelines/tcp_sock.rst +++ b/Documentation/networking/net_cachelines/tcp_sock.rst @@ -121,6 +121,7 @@ u64 delivered_mstamp read_write u32 rate_delivered read_mostly tcp_rate_gen u32 rate_interval_us read_mostly rate_delivered,rate_app_limited u32 rcv_wnd read_write read_mostly tcp_select_window,tcp_receive_window,tcp_fast_path_check +u32 rcv_mwnd_seq read_write tcp_select_window u32 write_seq read_write tcp_rate_check_app_limited,tcp_write_queue_empty,tcp_skb_entail,forced_push,tcp_mark_push u32 notsent_lowat read_mostly tcp_stream_memory_free u32 pushed_seq read_write tcp_mark_push,forced_push diff --git a/include/linux/tcp.h b/include/linux/tcp.h index bcebc4f07532..6982f10e826b 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -316,6 +316,9 @@ struct tcp_sock { */ u32 app_limited; /* limited until "delivered" reaches this val */ u32 rcv_wnd; /* Current receiver window */ + u32 rcv_mwnd_seq; /* Maximum window sequence number (RFC 7323, + * section 2.4, receiver requirements) + */ u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ /* * Options received (usually on last packet, some only on SYN packets). diff --git a/include/net/tcp.h b/include/net/tcp.h index 48dffcca0a71..f87bdacb5a69 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -934,6 +934,28 @@ static inline u32 tcp_receive_window(const struct tcp_sock *tp) return (u32) win; } +/* Compute the maximum receive window we ever advertised. + * Rcv_nxt can be after the window if our peer push more data + * than the offered window. + */ +static inline u32 tcp_max_receive_window(const struct tcp_sock *tp) +{ + s32 win = tp->rcv_mwnd_seq - tp->rcv_nxt; + + if (win < 0) + win = 0; + return (u32) win; +} + +/* Check if we need to update the maximum receive window sequence number */ +static inline void tcp_update_max_rcv_wnd_seq(struct tcp_sock *tp) +{ + u32 wre = tp->rcv_wup + tp->rcv_wnd; + + if (after(wre, tp->rcv_mwnd_seq)) + tp->rcv_mwnd_seq = wre; +} + /* Choose a new window, without checks for shrinking, and without * scaling applied to the result. The caller does these things * if necessary. This is a "raw" window selection. diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index ed6f6712f060..516087c622ad 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3561,6 +3561,7 @@ static int tcp_repair_set_window(struct tcp_sock *tp, sockptr_t optbuf, int len) tp->rcv_wnd = opt.rcv_wnd; tp->rcv_wup = opt.rcv_wup; + tp->rcv_mwnd_seq = opt.rcv_wup + opt.rcv_wnd; return 0; } @@ -5275,6 +5276,7 @@ static void __init tcp_struct_check(void) CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, received_ecn_bytes); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, app_limited); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_wnd); + CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_mwnd_seq); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_tstamp); CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rx_opt); diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 9fdc19accafd..4e389d609f91 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -377,6 +377,7 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk, tcp_rsk(req)->rcv_nxt = tp->rcv_nxt; tp->rcv_wup = tp->rcv_nxt; + tp->rcv_mwnd_seq = tp->rcv_wup + tp->rcv_wnd; /* tcp_conn_request() is sending the SYNACK, * and queues the child into listener accept queue. */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 71ac69b7b75e..2e1b23760815 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4808,20 +4808,18 @@ static enum skb_drop_reason tcp_sequence(const struct sock *sk, const struct tcphdr *th) { const struct tcp_sock *tp = tcp_sk(sk); - u32 seq_limit; if (before(end_seq, tp->rcv_wup)) return SKB_DROP_REASON_TCP_OLD_SEQUENCE; - seq_limit = tp->rcv_nxt + tcp_receive_window(tp); - if (unlikely(after(end_seq, seq_limit))) { + if (unlikely(after(end_seq, tp->rcv_nxt + tcp_max_receive_window(tp)))) { /* Some stacks are known to handle FIN incorrectly; allow the * FIN to extend beyond the window and check it in detail later. */ - if (!after(end_seq - th->fin, seq_limit)) + if (!after(end_seq - th->fin, tp->rcv_nxt + tcp_receive_window(tp))) return SKB_NOT_DROPPED_YET; - if (after(seq, seq_limit)) + if (after(seq, tp->rcv_nxt + tcp_max_receive_window(tp))) return SKB_DROP_REASON_TCP_INVALID_SEQUENCE; /* Only accept this packet if receive queue is empty. */ @@ -6903,6 +6901,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, */ WRITE_ONCE(tp->rcv_nxt, TCP_SKB_CB(skb)->seq + 1); tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1; + tp->rcv_mwnd_seq = tp->rcv_wup + tp->rcv_wnd; /* RFC1323: The window in SYN & SYN/ACK segments is * never scaled. @@ -7015,6 +7014,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, WRITE_ONCE(tp->rcv_nxt, TCP_SKB_CB(skb)->seq + 1); WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1; + tp->rcv_mwnd_seq = tp->rcv_wup + tp->rcv_wnd; /* RFC1323: The window in SYN & SYN/ACK segments is * never scaled. diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index dafb63b923d0..d350d794a959 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -604,6 +604,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, newtp->window_clamp = req->rsk_window_clamp; newtp->rcv_ssthresh = req->rsk_rcv_wnd; newtp->rcv_wnd = req->rsk_rcv_wnd; + newtp->rcv_mwnd_seq = newtp->rcv_wup + req->rsk_rcv_wnd; newtp->rx_opt.wscale_ok = ireq->wscale_ok; if (newtp->rx_opt.wscale_ok) { newtp->rx_opt.snd_wscale = ireq->snd_wscale; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 34a25ef61006..35c3b0ab5a0c 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -293,6 +293,7 @@ static u16 tcp_select_window(struct sock *sk) tp->pred_flags = 0; tp->rcv_wnd = 0; tp->rcv_wup = tp->rcv_nxt; + tcp_update_max_rcv_wnd_seq(tp); return 0; } @@ -316,6 +317,7 @@ static u16 tcp_select_window(struct sock *sk) tp->rcv_wnd = new_win; tp->rcv_wup = tp->rcv_nxt; + tcp_update_max_rcv_wnd_seq(tp); /* Make sure we do not exceed the maximum possible * scaled window. @@ -4165,6 +4167,7 @@ static void tcp_connect_init(struct sock *sk) else tp->rcv_tstamp = tcp_jiffies32; tp->rcv_wup = tp->rcv_nxt; + tp->rcv_mwnd_seq = tp->rcv_nxt + tp->rcv_wnd; WRITE_ONCE(tp->copied_seq, tp->rcv_nxt); inet_csk(sk)->icsk_rto = tcp_timeout_init(sk); diff --git a/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt b/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt index 6c0f32c40f19..12882be10f2e 100644 --- a/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt +++ b/tools/testing/selftests/net/packetdrill/tcp_rcv_big_endseq.pkt @@ -36,7 +36,7 @@ +0 read(4, ..., 100000) = 4000 -// If queue is empty, accept a packet even if its end_seq is above wup + rcv_wnd +// If queue is empty, accept a packet even if its end_seq is above rcv_mwnd_seq +0 < P. 4001:54001(50000) ack 1 win 257 * > . 1:1(0) ack 54001 win 0