From 64382c71a5575741933dfdb0cf7162c6e9b8854e Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Mon, 23 Oct 2023 20:22:06 +0100 Subject: net/tcp: Add TCP-AO SNE support Add Sequence Number Extension (SNE) for TCP-AO. This is needed to protect long-living TCP-AO connections from replaying attacks after sequence number roll-over, see RFC5925 (6.2). Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/tcp_minisocks.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp_minisocks.c') diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 8d941a6e066b..a9807eeb311c 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -51,6 +51,18 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw, return TCP_TW_SUCCESS; } +static void twsk_rcv_nxt_update(struct tcp_timewait_sock *tcptw, u32 seq) +{ +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao; + + ao = rcu_dereference(tcptw->ao_info); + if (unlikely(ao && seq < tcptw->tw_rcv_nxt)) + WRITE_ONCE(ao->rcv_sne, ao->rcv_sne + 1); +#endif + tcptw->tw_rcv_nxt = seq; +} + /* * * Main purpose of TIME-WAIT state is to close connection gracefully, * when one of ends sits in LAST-ACK or CLOSING retransmitting FIN @@ -136,7 +148,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, /* FIN arrived, enter true time-wait state. */ tw->tw_substate = TCP_TIME_WAIT; - tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq; + twsk_rcv_nxt_update(tcptw, TCP_SKB_CB(skb)->end_seq); + if (tmp_opt.saw_tstamp) { tcptw->tw_ts_recent_stamp = ktime_get_seconds(); tcptw->tw_ts_recent = tmp_opt.rcv_tsval; -- cgit v1.2.3