diff options
| -rw-r--r-- | include/linux/tcp.h | 4 | ||||
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 29 |
2 files changed, 28 insertions, 5 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 66d85a8..1a7adb4 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -342,6 +342,10 @@ struct tcp_timewait_sock { u32 tw_rcv_wnd; u32 tw_ts_offset; u32 tw_ts_recent; + + /* The time we sent the last out-of-window ACK: */ + u32 tw_last_oow_ack_time; + long tw_ts_recent_stamp; #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *tw_md5_key; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 98a8405..dd11ac7 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -58,6 +58,25 @@ static bool tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win) return seq == e_win && seq == end_seq; } +static enum tcp_tw_status +tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw, + const struct sk_buff *skb, int mib_idx) +{ + struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); + + if (!tcp_oow_rate_limited(twsk_net(tw), skb, mib_idx, + &tcptw->tw_last_oow_ack_time)) { + /* Send ACK. Note, we do not put the bucket, + * it will be released by caller. + */ + return TCP_TW_ACK; + } + + /* We are rate-limiting, so just release the tw sock and drop skb. */ + inet_twsk_put(tw); + return TCP_TW_SUCCESS; +} + /* * * Main purpose of TIME-WAIT state is to close connection gracefully, * when one of ends sits in LAST-ACK or CLOSING retransmitting FIN @@ -116,7 +135,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt, tcptw->tw_rcv_nxt + tcptw->tw_rcv_wnd)) - return TCP_TW_ACK; + return tcp_timewait_check_oow_rate_limit( + tw, skb, LINUX_MIB_TCPACKSKIPPEDFINWAIT2); if (th->rst) goto kill; @@ -250,10 +270,8 @@ kill: inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN, TCP_TIMEWAIT_LEN); - /* Send ACK. Note, we do not put the bucket, - * it will be released by caller. - */ - return TCP_TW_ACK; + return tcp_timewait_check_oow_rate_limit( + tw, skb, LINUX_MIB_TCPACKSKIPPEDTIMEWAIT); } inet_twsk_put(tw); return TCP_TW_SUCCESS; @@ -289,6 +307,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) tcptw->tw_ts_recent = tp->rx_opt.ts_recent; tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp; tcptw->tw_ts_offset = tp->tsoffset; + tcptw->tw_last_oow_ack_time = 0; #if IS_ENABLED(CONFIG_IPV6) if (tw->tw_family == PF_INET6) { |