Add Sequence Number Extension (SNE) extension 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 <fruggeri@xxxxxxxxxx> Signed-off-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx> Co-developed-by: Salam Noureddine <noureddine@xxxxxxxxxx> Signed-off-by: Salam Noureddine <noureddine@xxxxxxxxxx> Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx> --- net/ipv4/tcp_input.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 59d4e7b246a9..9727fef9f869 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3527,9 +3527,21 @@ static inline bool tcp_may_update_window(const struct tcp_sock *tp, static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack) { u32 delta = ack - tp->snd_una; +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao; +#endif sock_owned_by_me((struct sock *)tp); tp->bytes_acked += delta; +#ifdef CONFIG_TCP_AO + ao = rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held((struct sock *)tp)); + if (ao) { + if (ack < ao->snd_sne_seq) + ao->snd_sne++; + ao->snd_sne_seq = ack; + } +#endif tp->snd_una = ack; } @@ -3537,9 +3549,21 @@ static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack) static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq) { u32 delta = seq - tp->rcv_nxt; +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao; +#endif sock_owned_by_me((struct sock *)tp); tp->bytes_received += delta; +#ifdef CONFIG_TCP_AO + ao = rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held((struct sock *)tp)); + if (ao) { + if (seq < ao->rcv_sne_seq) + ao->rcv_sne++; + ao->rcv_sne_seq = seq; + } +#endif WRITE_ONCE(tp->rcv_nxt, seq); } @@ -6356,6 +6380,17 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, * simultaneous connect with crossed SYNs. * Particularly, it can be connect to self. */ +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao; + + ao = rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held(sk)); + if (ao) { + ao->risn = th->seq; + ao->rcv_sne = 0; + ao->rcv_sne_seq = ntohl(th->seq); + } +#endif tcp_set_state(sk, TCP_SYN_RECV); if (tp->rx_opt.saw_tstamp) { -- 2.37.2