diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 52 |
1 files changed, 31 insertions, 21 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ff10be8c76..1054a44033 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1164,7 +1164,7 @@ static void tcp_count_delivered(struct tcp_sock *tp, u32 delivered, * L|R 1 - orig is lost, retransmit is in flight. * S|R 1 - orig reached receiver, retrans is still in flight. * (L|S|R is logically valid, it could occur when L|R is sacked, - * but it is equivalent to plain S and code short-curcuits it to S. + * but it is equivalent to plain S and code short-circuits it to S. * L|S is logically invalid, it would mean -1 packet in flight 8)) * * These 6 states form finite state machine, controlled by the following events: @@ -6289,6 +6289,7 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, skb_rbtree_walk_from(data) tcp_mark_skb_lost(sk, data); tcp_xmit_retransmit_queue(sk); + tp->retrans_stamp = 0; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVEFAIL); return true; @@ -6361,6 +6362,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, TCP_TIMEOUT_MIN, TCP_RTO_MAX); + SKB_DR_SET(reason, TCP_INVALID_ACK_SEQUENCE); goto reset_and_undo; } @@ -6369,6 +6371,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, tcp_time_stamp_ts(tp))) { NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSACTIVEREJECTED); + SKB_DR_SET(reason, TCP_RFC7323_PAWS); goto reset_and_undo; } @@ -6572,7 +6575,8 @@ discard_and_undo: reset_and_undo: tcp_clear_options(&tp->rx_opt); tp->rx_opt.mss_clamp = saved_clamp; - return 1; + /* we can reuse/return @reason to its caller to handle the exception */ + return reason; } static void tcp_rcv_synrecv_state_fastopen(struct sock *sk) @@ -6616,14 +6620,14 @@ static void tcp_rcv_synrecv_state_fastopen(struct sock *sk) * address independent. */ -int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) +enum skb_drop_reason +tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); const struct tcphdr *th = tcp_hdr(skb); struct request_sock *req; int queued = 0; - bool acceptable; SKB_DR(reason); switch (sk->sk_state) { @@ -6633,7 +6637,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) case TCP_LISTEN: if (th->ack) - return 1; + return SKB_DROP_REASON_TCP_FLAGS; if (th->rst) { SKB_DR_SET(reason, TCP_RESET); @@ -6649,12 +6653,10 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) */ rcu_read_lock(); local_bh_disable(); - acceptable = icsk->icsk_af_ops->conn_request(sk, skb) >= 0; + icsk->icsk_af_ops->conn_request(sk, skb); local_bh_enable(); rcu_read_unlock(); - if (!acceptable) - return 1; consume_skb(skb); return 0; } @@ -6699,17 +6701,25 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) return 0; /* step 5: check the ACK field */ - acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH | - FLAG_UPDATE_TS_RECENT | - FLAG_NO_CHALLENGE_ACK) > 0; - - if (!acceptable) { - if (sk->sk_state == TCP_SYN_RECV) - return 1; /* send one RST */ - tcp_send_challenge_ack(sk); - SKB_DR_SET(reason, TCP_OLD_ACK); - goto discard; + reason = tcp_ack(sk, skb, FLAG_SLOWPATH | + FLAG_UPDATE_TS_RECENT | + FLAG_NO_CHALLENGE_ACK); + + if ((int)reason <= 0) { + if (sk->sk_state == TCP_SYN_RECV) { + /* send one RST */ + if (!reason) + return SKB_DROP_REASON_TCP_OLD_ACK; + return -reason; + } + /* accept old ack during closing */ + if ((int)reason < 0) { + tcp_send_challenge_ack(sk); + reason = -reason; + goto discard; + } } + SKB_DR_SET(reason, NOT_SPECIFIED); switch (sk->sk_state) { case TCP_SYN_RECV: tp->delivered++; /* SYN-ACK delivery isn't tracked in tcp_ack */ @@ -6779,7 +6789,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (READ_ONCE(tp->linger2) < 0) { tcp_done(sk); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); - return 1; + return SKB_DROP_REASON_TCP_ABORT_ON_DATA; } if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq && after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) { @@ -6788,7 +6798,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) tcp_fastopen_active_disable(sk); tcp_done(sk); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); - return 1; + return SKB_DROP_REASON_TCP_ABORT_ON_DATA; } tmo = tcp_fin_time(sk); @@ -6853,7 +6863,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA); tcp_reset(sk, skb); - return 1; + return SKB_DROP_REASON_TCP_ABORT_ON_DATA; } } fallthrough; |