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tcp: improve handling of snd_nxt

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- avoid changing snd_nxt when doing fast retransmits
- use snd_una_max only to keep track of the max seq number sent
- simplify future ack testing

Change-Id: I3580ad3aefe30128486c3375d0ac3f3f62c04c5e
Signed-off-by: Florin Coras <fcoras@cisco.com>
This commit is contained in:
Florin Coras
2019-03-12 18:58:54 -07:00
committed by Damjan Marion
parent 881d13ede7
commit 4759683744
5 changed files with 93 additions and 126 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/plugins/unittest/tcp_test.c
View File

@@ -239,7 +239,7 @@ tcp_test_sack_rx (vlib_main_t * vm, unformat_input_t * input)
*/
vec_reset_length (tc->rcv_opts.sacks);
tc->snd_una += sb->snd_una_adv;
tc->snd_una_max = 1900;
tc->snd_nxt = tc->snd_una_max = 1900;
for (i = 0; i < 5; i++)
{
block.start = i * 100 + 1200;
@@ -416,7 +416,7 @@ tcp_test_sack_rx (vlib_main_t * vm, unformat_input_t * input)
* snd_una = 1000 and snd_una_max = 1600
*/
tc->snd_una = 1000;
tc->snd_una_max = 1600;
tc->snd_nxt = tc->snd_una_max = 1600;
vec_reset_length (tc->rcv_opts.sacks);
block.start = 1200;
block.end = 1500;

4
src/vnet/tcp/tcp.c
View File

@@ -1164,7 +1164,7 @@ tcp_session_flush_data (transport_connection_t * tconn)
if (tc->flags & TCP_CONN_PSH_PENDING)
return;
tc->flags |= TCP_CONN_PSH_PENDING;
tc->psh_seq = tc->snd_una_max + transport_max_tx_dequeue (tconn) - 1;
tc->psh_seq = tc->snd_una + transport_max_tx_dequeue (tconn) - 1;
}
/* *INDENT-OFF* */
@@ -1296,7 +1296,7 @@ tcp_timer_waitclose_handler (u32 conn_index)
* and switch to LAST_ACK. */
tcp_cong_recovery_off (tc);
/* Make sure we don't try to send unsent data */
tc->snd_una_max = tc->snd_nxt = tc->snd_una;
tc->snd_nxt = tc->snd_una;
tcp_send_fin (tc);
tcp_connection_set_state (tc, TCP_STATE_LAST_ACK);

4
src/vnet/tcp/tcp.h
View File

@@ -680,7 +680,7 @@ tcp_flight_size (const tcp_connection_t * tc)
{
int flight_size;
flight_size = (int) (tc->snd_una_max - tc->snd_una) - tcp_bytes_out (tc)
flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc)
+ tc->snd_rxt_bytes;
if (flight_size < 0)
@@ -924,7 +924,7 @@ tcp_persist_timer_reset (tcp_connection_t * tc)
always_inline void
tcp_retransmit_timer_update (tcp_connection_t * tc)
{
if (tc->snd_una == tc->snd_una_max)
if (tc->snd_una == tc->snd_nxt)
{
tcp_retransmit_timer_reset (tc);
if (tc->snd_wnd < tc->snd_mss)

112
src/vnet/tcp/tcp_input.c
View File

@@ -409,7 +409,7 @@ tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0)
{
/* SND.UNA =< SEG.ACK =< SND.NXT */
return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number)
&& seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt));
&& seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_una_max));
}
/**
@@ -604,7 +604,7 @@ tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 prev_snd_wnd,
u32 prev_snd_una)
{
return ((vnet_buffer (b)->tcp.ack_number == prev_snd_una)
&& seq_gt (tc->snd_una_max, tc->snd_una)
&& seq_gt (tc->snd_nxt, tc->snd_una)
&& (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number)
&& (prev_snd_wnd == tc->snd_wnd));
}
@@ -913,7 +913,7 @@ tcp_scoreboard_is_sane_post_recovery (tcp_connection_t * tc)
sack_scoreboard_hole_t *hole;
hole = scoreboard_first_hole (&tc->sack_sb);
return (!hole || (seq_geq (hole->start, tc->snd_una)
&& seq_lt (hole->end, tc->snd_una_max)));
&& seq_lt (hole->end, tc->snd_nxt)));
}
#ifndef CLIB_MARCH_VARIANT
@@ -943,8 +943,8 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
if (seq_lt (blk->start, blk->end)
&& seq_gt (blk->start, tc->snd_una)
&& seq_gt (blk->start, ack)
&& seq_lt (blk->start, tc->snd_una_max)
&& seq_leq (blk->end, tc->snd_una_max))
&& seq_lt (blk->start, tc->snd_nxt)
&& seq_leq (blk->end, tc->snd_nxt))
{
blk++;
continue;
@@ -979,7 +979,7 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
{
/* If no holes, insert the first that covers all outstanding bytes */
last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
tc->snd_una, tc->snd_una_max);
tc->snd_una, tc->snd_nxt);
sb->tail = scoreboard_hole_index (sb, last_hole);
tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
sb->high_sacked = tmp.end;
@@ -990,17 +990,17 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
* last hole end */
tmp = tc->rcv_opts.sacks[vec_len (tc->rcv_opts.sacks) - 1];
last_hole = scoreboard_last_hole (sb);
if (seq_gt (tc->snd_una_max, last_hole->end))
if (seq_gt (tc->snd_nxt, last_hole->end))
{
if (seq_geq (last_hole->start, sb->high_sacked))
{
last_hole->end = tc->snd_una_max;
last_hole->end = tc->snd_nxt;
}
/* New hole after high sacked block */
else if (seq_lt (sb->high_sacked, tc->snd_una_max))
else if (seq_lt (sb->high_sacked, tc->snd_nxt))
{
scoreboard_insert_hole (sb, sb->tail, sb->high_sacked,
tc->snd_una_max);
tc->snd_nxt);
}
}
/* Keep track of max byte sacked for when the last hole
@@ -1078,8 +1078,7 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
if (pool_elts (sb->holes) == 1)
{
hole = scoreboard_first_hole (sb);
if (hole->start == ack + sb->snd_una_adv
&& hole->end == tc->snd_una_max)
if (hole->start == ack + sb->snd_una_adv && hole->end == tc->snd_nxt)
scoreboard_remove_hole (sb, hole);
}
@@ -1088,8 +1087,8 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
- (old_sacked_bytes - sb->last_bytes_delivered);
ASSERT (sb->last_sacked_bytes <= sb->sacked_bytes || tcp_in_recovery (tc));
ASSERT (sb->sacked_bytes == 0 || tcp_in_recovery (tc)
|| sb->sacked_bytes < tc->snd_una_max - seq_max (tc->snd_una, ack));
ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_una_max
|| sb->sacked_bytes < tc->snd_nxt - seq_max (tc->snd_una, ack));
ASSERT (sb->last_sacked_bytes + sb->lost_bytes <= tc->snd_nxt
- seq_max (tc->snd_una, ack) || tcp_in_recovery (tc));
ASSERT (sb->head == TCP_INVALID_SACK_HOLE_INDEX || tcp_in_recovery (tc)
|| sb->holes[sb->head].start == ack + sb->snd_una_adv);
@@ -1146,7 +1145,7 @@ void
tcp_cc_init_congestion (tcp_connection_t * tc)
{
tcp_fastrecovery_on (tc);
tc->snd_congestion = tc->snd_una_max;
tc->snd_congestion = tc->snd_nxt;
tc->cwnd_acc_bytes = 0;
tc->snd_rxt_bytes = 0;
tc->prev_ssthresh = tc->ssthresh;
@@ -1162,7 +1161,6 @@ tcp_cc_recovery_exit (tcp_connection_t * tc)
tc->rto_boff = 0;
tcp_update_rto (tc);
tc->snd_rxt_ts = 0;
tc->snd_nxt = tc->snd_una_max;
tc->rtt_ts = 0;
tcp_recovery_off (tc);
TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
@@ -1175,7 +1173,6 @@ tcp_cc_fastrecovery_exit (tcp_connection_t * tc)
tc->cc_algo->recovered (tc);
tc->snd_rxt_bytes = 0;
tc->rcv_dupacks = 0;
tc->snd_nxt = tc->snd_una_max;
tc->snd_rxt_bytes = 0;
tc->rtt_ts = 0;
@@ -1191,12 +1188,16 @@ tcp_cc_congestion_undo (tcp_connection_t * tc)
{
tc->cwnd = tc->prev_cwnd;
tc->ssthresh = tc->prev_ssthresh;
tc->snd_nxt = tc->snd_una_max;
tc->rcv_dupacks = 0;
if (tcp_in_recovery (tc))
tcp_cc_recovery_exit (tc);
{
tcp_cc_recovery_exit (tc);
tc->snd_nxt = seq_max (tc->snd_nxt, tc->snd_congestion);
}
else if (tcp_in_fastrecovery (tc))
tcp_cc_fastrecovery_exit (tc);
{
tcp_cc_fastrecovery_exit (tc);
}
ASSERT (tc->rto_boff == 0);
TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 5);
}
@@ -1374,8 +1375,7 @@ tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack)
else if (is_dack && !tcp_in_recovery (tc))
{
TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
ASSERT (tc->snd_una != tc->snd_una_max
|| tc->sack_sb.last_sacked_bytes);
ASSERT (tc->snd_una != tc->snd_nxt || tc->sack_sb.last_sacked_bytes);
tc->rcv_dupacks++;
@@ -1482,8 +1482,6 @@ partial_ack:
return;
}
tc->snd_nxt = tc->snd_una_max;
/* Treat as congestion avoidance ack */
tcp_cc_rcv_ack (tc);
return;
@@ -1565,38 +1563,18 @@ tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
/* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
if (PREDICT_FALSE (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)))
{
/* When we entered cong recovery, we reset snd_nxt to snd_una. Seems
* peer still has the data so accept the ack */
if (tcp_in_cong_recovery (tc)
&& seq_leq (vnet_buffer (b)->tcp.ack_number,
tc->snd_una + tc->snd_wnd))
/* We've probably entered recovery and the peer still has some
* of the data we've sent. Update snd_nxt and accept the ack */
if (seq_leq (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
{
tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
if (seq_gt (tc->snd_nxt, tc->snd_una_max))
tc->snd_una_max = tc->snd_nxt;
goto process_ack;
}
/* If we have outstanding data and this is within the window, accept it,
* probably retransmit has timed out. Otherwise ACK segment and then
* drop it */
if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max))
{
tcp_program_ack (wrk, tc);
*error = TCP_ERROR_ACK_FUTURE;
TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
vnet_buffer (b)->tcp.ack_number);
return -1;
}
TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2,
*error = TCP_ERROR_ACK_FUTURE;
TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0,
vnet_buffer (b)->tcp.ack_number);
tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
if (seq_gt (tc->snd_nxt, tc->snd_una_max))
tc->snd_una_max = tc->snd_nxt;
goto process_ack;
return -1;
}
/* If old ACK, probably it's an old dupack */
@@ -1611,10 +1589,11 @@ tcp_rcv_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b,
return 0;
}
process_ack:
/*
* Looks okay, process feedback
*/
process_ack:
if (tcp_opts_sack_permitted (&tc->rcv_opts))
tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
@@ -1767,13 +1746,7 @@ tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
/* Save to new SACK list if we have space. */
if (vec_len (new_list) < TCP_MAX_SACK_BLOCKS)
{
vec_add1 (new_list, tc->snd_sacks[i]);
}
else
{
clib_warning ("sack discarded");
}
vec_add1 (new_list, tc->snd_sacks[i]);
}
ASSERT (vec_len (new_list) <= TCP_MAX_SACK_BLOCKS);
@@ -2799,7 +2772,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
tcp_send_fin (tc0);
}
/* If FIN is ACKed */
else if (tc0->snd_una == tc0->snd_una_max)
else if (tc0->snd_una == tc0->snd_nxt)
{
tcp_connection_set_state (tc0, TCP_STATE_FIN_WAIT_2);
@@ -2845,8 +2818,21 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
/* In addition to the processing for the ESTABLISHED state, if
* the ACK acknowledges our FIN then enter the TIME-WAIT state,
* otherwise ignore the segment. */
if (tcp_rcv_ack (wrk, tc0, b0, tcp0, &error0))
goto drop;
if (!tcp_rcv_ack_is_acceptable (tc0, b0))
{
error0 = TCP_ERROR_ACK_INVALID;
goto drop;
}
error0 = TCP_ERROR_ACK_OK;
tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
/* Ack moved snd_una beyond snd_nxt so reprogram fin */
if (seq_gt (tc0->snd_una, tc0->snd_nxt))
{
tc0->snd_nxt = tc0->snd_una;
tc0->flags &= ~TCP_CONN_FINSNT;
goto drop;
}
tcp_connection_timers_reset (tc0);
tcp_connection_set_state (tc0, TCP_STATE_TIME_WAIT);
@@ -2867,7 +2853,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
error0 = TCP_ERROR_ACK_OK;
tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
/* Apparently our ACK for the peer's FIN was lost */
if (is_fin0 && tc0->snd_una != tc0->snd_una_max)
if (is_fin0 && tc0->snd_una != tc0->snd_nxt)
{
tcp_send_fin (tc0);
goto drop;
@@ -2971,7 +2957,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
tcp_fastrecovery_off (tc0);
tcp_recovery_off (tc0);
tcp_connection_timers_reset (tc0);
tc0->snd_nxt = tc0->snd_una_max = tc0->snd_una;
tc0->snd_nxt = tc0->snd_una;
}
tcp_send_fin (tc0);
}

95
src/vnet/tcp/tcp_output.c
View File

@@ -183,7 +183,7 @@ tcp_update_rcv_wnd (tcp_connection_t * tc)
/**
* Compute and return window to advertise, scaled as per RFC1323
*/
static u32
static inline u32
tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state)
{
if (state < TCP_STATE_ESTABLISHED)
@@ -1052,14 +1052,14 @@ tcp_send_fin (tcp_connection_t * tc)
fin_snt = tc->flags & TCP_CONN_FINSNT;
if (fin_snt)
tc->snd_nxt = tc->snd_una;
tc->snd_nxt -= 1;
if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
{
/* Out of buffers so program fin retransmit ASAP */
tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1);
if (fin_snt)
tc->snd_nxt = tc->snd_una_max;
tc->snd_nxt += 1;
else
/* Make sure retransmit retries a fin not data */
tc->flags |= TCP_CONN_FINSNT;
@@ -1072,18 +1072,13 @@ tcp_send_fin (tcp_connection_t * tc)
tcp_make_fin (tc, b);
tcp_enqueue_to_output_now (wrk, b, bi, tc->c_is_ip4);
TCP_EVT_DBG (TCP_EVT_FIN_SENT, tc);
/* Account for the FIN */
tc->snd_nxt += 1;
if (!fin_snt)
{
tc->flags |= TCP_CONN_FINSNT;
tc->flags &= ~TCP_CONN_FINPNDG;
/* Account for the FIN */
tc->snd_una_max += 1;
tc->snd_nxt = tc->snd_una_max;
}
else
{
tc->snd_nxt = tc->snd_una_max;
tc->snd_una_max = seq_max (tc->snd_una_max, tc->snd_nxt);
}
}
@@ -1092,8 +1087,8 @@ tcp_send_fin (tcp_connection_t * tc)
* for segments with data, not for 'control' packets.
*/
always_inline void
tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
tcp_state_t next_state, u8 compute_opts, u8 maybe_burst)
tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, u32 snd_nxt,
u8 compute_opts, u8 maybe_burst, u8 update_snd_nxt)
{
u8 tcp_hdr_opts_len, flags = TCP_FLAG_ACK;
u32 advertise_wnd, data_len;
@@ -1115,15 +1110,15 @@ tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
if (maybe_burst)
advertise_wnd = tc->rcv_wnd >> tc->rcv_wscale;
else
advertise_wnd = tcp_window_to_advertise (tc, next_state);
advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED);
if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
{
if (seq_geq (tc->psh_seq, tc->snd_nxt)
&& seq_lt (tc->psh_seq, tc->snd_nxt + data_len))
if (seq_geq (tc->psh_seq, snd_nxt)
&& seq_lt (tc->psh_seq, snd_nxt + data_len))
flags |= TCP_FLAG_PSH;
}
th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt,
th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, snd_nxt,
tc->rcv_nxt, tcp_hdr_opts_len, flags,
advertise_wnd);
@@ -1143,7 +1138,8 @@ tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
* Update connection variables
*/
tc->snd_nxt += data_len;
if (update_snd_nxt)
tc->snd_nxt += data_len;
tc->rcv_las = tc->rcv_nxt;
TCP_EVT_DBG (TCP_EVT_PKTIZE, tc);
@@ -1153,9 +1149,9 @@ u32
tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
{
tcp_connection_t *tc = (tcp_connection_t *) tconn;
tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, /* compute opts */ 0,
/* burst */ 1);
tc->snd_una_max = tc->snd_nxt;
tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0, /* burst */ 1,
/* update_snd_nxt */ 1);
tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
ASSERT (seq_leq (tc->snd_una_max, tc->snd_una + tc->snd_wnd));
tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
/* If not tracking an ACK, start tracking */
@@ -1322,9 +1318,8 @@ tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
max_deq_bytes);
ASSERT (n_bytes == max_deq_bytes);
b[0]->current_length = n_bytes;
tcp_push_hdr_i (tc, *b, tc->state, /* compute opts */ 0, /* burst */ 0);
if (seq_gt (tc->snd_nxt, tc->snd_una_max))
tc->snd_una_max = tc->snd_nxt;
tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
/* burst */ 0, /* update_snd_nxt */ 0);
}
/* Split mss into multiple buffers */
else
@@ -1381,9 +1376,8 @@ tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
b[0]->total_length_not_including_first_buffer += n_peeked;
}
tcp_push_hdr_i (tc, *b, tc->state, /* compute opts */ 0, /* burst */ 0);
if (seq_gt (tc->snd_nxt, tc->snd_una_max))
tc->snd_una_max = tc->snd_nxt;
tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
/* burst */ 0, /* update_snd_nxt */ 0);
if (PREDICT_FALSE (n_bufs))
{
@@ -1475,7 +1469,7 @@ tcp_rxt_timeout_cc (tcp_connection_t * tc)
/* Start again from the beginning */
tc->cc_algo->congestion (tc);
tc->cwnd = tcp_loss_wnd (tc);
tc->snd_congestion = tc->snd_una_max;
tc->snd_congestion = tc->snd_nxt;
tc->rtt_ts = 0;
tc->cwnd_acc_bytes = 0;
tcp_connection_tx_pacer_reset (tc, tc->cwnd, 2 * tc->snd_mss);
@@ -1527,7 +1521,7 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
/* Shouldn't be here. This condition is tricky because it has to take
* into account boff > 0 due to persist timeout. */
if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_una_max)
if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_nxt)
|| (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion)
&& !tcp_flight_size (tc)))
{
@@ -1555,10 +1549,9 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
scoreboard_clear (&tc->sack_sb);
/* If we've sent beyond snd_congestion, update it */
if (seq_gt (tc->snd_una_max, tc->snd_congestion))
tc->snd_congestion = tc->snd_una_max;
tc->snd_congestion = seq_max (tc->snd_nxt, tc->snd_congestion);
tc->snd_una_max = tc->snd_nxt = tc->snd_una;
tc->snd_nxt = tc->snd_una;
tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX);
/* Send one segment. Note that n_bytes may be zero due to buffer
@@ -1695,7 +1688,7 @@ tcp_timer_persist_handler (u32 index)
return;
available_bytes = transport_max_tx_dequeue (&tc->connection);
offset = tc->snd_una_max - tc->snd_una;
offset = tc->snd_nxt - tc->snd_una;
/* Reprogram persist if no new bytes available to send. We may have data
* next time */
@@ -1737,8 +1730,9 @@ tcp_timer_persist_handler (u32 index)
|| tc->snd_nxt == tc->snd_una_max
|| tc->rto_boff > 1));
tcp_push_hdr_i (tc, b, tc->state, /* compute opts */ 0, /* burst */ 0);
tc->snd_una_max = tc->snd_nxt;
tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0,
/* burst */ 0, /* update_snd_nxt */ 1);
tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
@@ -1752,12 +1746,9 @@ tcp_timer_persist_handler (u32 index)
int
tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
{
u32 bi, old_snd_nxt, n_bytes;
vlib_main_t *vm = wrk->vm;
vlib_buffer_t *b;
old_snd_nxt = tc->snd_nxt;
tc->snd_nxt = tc->snd_una;
u32 bi, n_bytes;
TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1);
@@ -1767,7 +1758,6 @@ tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
bi = vlib_get_buffer_index (vm, b);
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
tc->snd_nxt = old_snd_nxt;
return 0;
}
@@ -1780,8 +1770,7 @@ tcp_fast_retransmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
vlib_main_t *vm = wrk->vm;
vlib_buffer_t *b = 0;
tc->snd_nxt = tc->snd_una_max;
offset = tc->snd_una_max - tc->snd_una;
offset = tc->snd_nxt - tc->snd_una;
while (n_segs < burst_size)
{
n_written = tcp_prepare_segment (wrk, tc, offset, tc->snd_mss, &b);
@@ -1792,6 +1781,9 @@ tcp_fast_retransmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
offset += n_written;
n_segs += 1;
tc->snd_nxt += n_written;
tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max);
}
done:
@@ -1814,9 +1806,8 @@ tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
vlib_main_t *vm = wrk->vm;
vlib_buffer_t *b = 0;
sack_scoreboard_t *sb;
u32 bi, old_snd_nxt;
u32 bi, max_deq;
int snd_space;
u32 max_deq;
u8 snd_limited = 0, can_rescue = 0;
ASSERT (tcp_in_fastrecovery (tc));
@@ -1829,12 +1820,11 @@ tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
}
TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
old_snd_nxt = tc->snd_nxt;
sb = &tc->sack_sb;
hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
max_deq = transport_max_tx_dequeue (&tc->connection);
max_deq -= tc->snd_una_max - tc->snd_una;
max_deq -= tc->snd_nxt - tc->snd_una;
while (snd_space > 0 && n_segs < burst_size)
{
@@ -1867,7 +1857,6 @@ tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
max_bytes = clib_min (max_bytes, snd_space);
offset = tc->snd_congestion - tc->snd_una - max_bytes;
sb->rescue_rxt = tc->snd_congestion;
tc->snd_nxt = tc->snd_una + offset;
n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
max_bytes, &b);
if (!n_written)
@@ -1885,7 +1874,6 @@ tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
break;
offset = sb->high_rxt - tc->snd_una;
tc->snd_nxt = sb->high_rxt;
n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes,
&b);
ASSERT (n_written <= snd_space);
@@ -1906,8 +1894,6 @@ tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
tcp_program_fastretransmit (wrk, tc);
done:
/* If window allows, send 1 SMSS of new data */
tc->snd_nxt = old_snd_nxt;
return n_segs;
}
@@ -1918,14 +1904,13 @@ int
tcp_fast_retransmit_no_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
u32 burst_size)
{
u32 n_written = 0, offset = 0, bi, old_snd_nxt, max_deq, n_segs_now;
u32 n_written = 0, offset = 0, bi, max_deq, n_segs_now;
vlib_main_t *vm = wrk->vm;
int snd_space, n_segs = 0;
vlib_buffer_t *b;
ASSERT (tcp_in_fastrecovery (tc));
TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0);
old_snd_nxt = tc->snd_nxt;
if (!tcp_fastrecovery_first (tc))
goto send_unsent;
@@ -1933,7 +1918,6 @@ tcp_fast_retransmit_no_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
/* RFC 6582: [If a partial ack], retransmit the first unacknowledged
* segment. */
snd_space = tc->sack_sb.last_bytes_delivered;
tc->snd_nxt = tc->snd_una;
while (snd_space > 0 && n_segs < burst_size)
{
n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
@@ -1961,7 +1945,7 @@ send_unsent:
goto done;
max_deq = transport_max_tx_dequeue (&tc->connection);
max_deq -= tc->snd_una_max - tc->snd_una;
max_deq -= tc->snd_nxt - tc->snd_una;
if (max_deq)
{
snd_space = clib_min (max_deq, snd_space);
@@ -1972,9 +1956,6 @@ send_unsent:
n_segs += n_segs_now;
}
/* Restore snd_nxt */
tc->snd_nxt = old_snd_nxt;
done:
tcp_fastrecovery_first_off (tc);
return n_segs;