From 1f152cd6faf96b524b6b7071b5cffe1916f9c5cc Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Fri, 18 Aug 2017 19:28:03 -0700 Subject: tcp: retransmit and multi-buffer segment fixes and improvements - set session state as closed on session manager delete - enable retransmit as opposed to persist timer after persist timer completes - properly discard buffer chain bytes when new data overlaps ooo segments - don't use rxt bytes in snd space estimate used on tx path Change-Id: Id9cab686e532e5fe70c775d5440260e8eb890a9f Signed-off-by: Florin Coras --- src/vnet/tcp/tcp.c | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-) (limited to 'src/vnet/tcp/tcp.c') diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c index 6edf52af..197fff96 100644 --- a/src/vnet/tcp/tcp.c +++ b/src/vnet/tcp/tcp.c @@ -798,7 +798,8 @@ format_tcp_vars (u8 * s, va_list * args) s = format (s, "rtt_seq %u\n", tc->rtt_seq); s = format (s, " tsval_recent %u tsval_recent_age %u\n", tc->tsval_recent, tcp_time_now () - tc->tsval_recent_age); - s = format (s, " scoreboard: %U\n", format_tcp_scoreboard, &tc->sack_sb); + s = format (s, " scoreboard: %U\n", format_tcp_scoreboard, &tc->sack_sb, + tc); if (vec_len (tc->snd_sacks)) s = format (s, " sacks tx: %U\n", format_tcp_sacks, tc); @@ -858,7 +859,7 @@ format_tcp_session (u8 * s, va_list * args) if (tc) s = format (s, "%U", format_tcp_connection, tc, verbose); else - s = format (s, "empty"); + s = format (s, "empty\n"); return s; } @@ -930,7 +931,11 @@ u8 * format_tcp_sack_hole (u8 * s, va_list * args) { sack_scoreboard_hole_t *hole = va_arg (*args, sack_scoreboard_hole_t *); - s = format (s, "[%u, %u]", hole->start, hole->end); + tcp_connection_t *tc = va_arg (*args, tcp_connection_t *); + if (tc) + s = format (s, " [%u, %u]", hole->start - tc->iss, hole->end - tc->iss); + else + s = format (s, " [%u, %u]", hole->start, hole->end); return s; } @@ -938,6 +943,7 @@ u8 * format_tcp_scoreboard (u8 * s, va_list * args) { sack_scoreboard_t *sb = va_arg (*args, sack_scoreboard_t *); + tcp_connection_t *tc = va_arg (*args, tcp_connection_t *); sack_scoreboard_hole_t *hole; s = format (s, "sacked_bytes %u last_sacked_bytes %u lost_bytes %u\n", sb->sacked_bytes, sb->last_sacked_bytes, sb->lost_bytes); @@ -952,7 +958,7 @@ format_tcp_scoreboard (u8 * s, va_list * args) while (hole) { - s = format (s, "%U", format_tcp_sack_hole, hole); + s = format (s, "%U", format_tcp_sack_hole, hole, tc); hole = scoreboard_next_hole (sb, hole); } @@ -1001,13 +1007,10 @@ tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space) return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0; } - /* If we can't write at least a segment, don't try at all */ + /* If not snd_wnd constrained and we can't write at least a segment, + * don't try at all */ if (PREDICT_FALSE (snd_space < tc->snd_mss)) - { - if (snd_space > clib_min (tc->mss, tc->rcv_opts.mss) - TCP_HDR_LEN_MAX) - return snd_space; - return 0; - } + return 0; /* round down to mss multiple */ return snd_space - (snd_space % tc->snd_mss); @@ -1030,7 +1033,7 @@ tcp_snd_space (tcp_connection_t * tc) if (PREDICT_TRUE (tcp_in_cong_recovery (tc) == 0)) { - snd_space = tcp_available_snd_space (tc); + snd_space = tcp_available_output_snd_space (tc); /* If we haven't gotten dupacks or if we did and have gotten sacked * bytes then we can still send as per Limited Transmit (RFC3042) */ @@ -1051,17 +1054,20 @@ tcp_snd_space (tcp_connection_t * tc) if (tcp_in_recovery (tc)) { tc->snd_nxt = tc->snd_una_max; - snd_space = tcp_available_wnd (tc) - tc->snd_rxt_bytes + snd_space = tcp_available_snd_wnd (tc) - tc->snd_rxt_bytes - (tc->snd_una_max - tc->snd_congestion); if (snd_space <= 0 || (tc->snd_una_max - tc->snd_una) >= tc->snd_wnd) return 0; return tcp_round_snd_space (tc, snd_space); } - /* If in fast recovery, send 1 SMSS if wnd allows */ - if (tcp_in_fastrecovery (tc) - && tcp_available_snd_space (tc) && !tcp_fastrecovery_sent_1_smss (tc)) + /* RFC 5681: When previously unsent data is available and the new value of + * cwnd and the receiver's advertised window allow, a TCP SHOULD send 1*SMSS + * bytes of previously unsent data. */ + if (tcp_in_fastrecovery (tc) && !tcp_fastrecovery_sent_1_smss (tc)) { + if (tcp_available_output_snd_space (tc) < tc->snd_mss) + return 0; tcp_fastrecovery_1_smss_on (tc); return tc->snd_mss; } @@ -1073,7 +1079,8 @@ u32 tcp_session_send_space (transport_connection_t * trans_conn) { tcp_connection_t *tc = (tcp_connection_t *) trans_conn; - return tcp_snd_space (tc); + return clib_min (tcp_snd_space (tc), + tc->snd_wnd - (tc->snd_nxt - tc->snd_una)); } i32 -- cgit 1.2.3-korg