tcp_reuse_buffer (vm, b);
tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK);
TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc);
- vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
tc->rcv_las = tc->rcv_nxt;
}
tcp_options_write ((u8 *) (th + 1), snd_opts);
vnet_buffer (b)->tcp.connection_index = tc->c_c_index;
- vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK;
/* Init retransmit timer. Use update instead of set because of
* retransmissions */
{
flags = TCP_FLAG_RST;
seq = pkt_th->ack_number;
- ack = (tc && tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
+ ack = (tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0;
}
else
{
TCP_EVT_DBG (TCP_EVT_SYN_SENT, tc);
}
+void
+tcp_send_synack (tcp_connection_t * tc)
+{
+ tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index);
+ vlib_main_t *vm = wrk->vm;
+ vlib_buffer_t *b;
+ u32 bi;
+
+ /* Get buffer */
+ if (PREDICT_FALSE (tcp_get_free_buffer_index (wrk, &bi)))
+ return;
+
+ b = vlib_get_buffer (vm, bi);
+ tcp_make_synack (tc, b);
+ tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
+}
+
/**
* Flush tx frame populated by retransmits and timer pops
*/
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
}
+void
+tcp_program_ack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
+{
+ if (!(tc->flags & TCP_CONN_SNDACK))
+ {
+ vec_add1 (wrk->pending_acks, tc->c_c_index);
+ tc->flags |= TCP_CONN_SNDACK;
+ }
+}
+
+void
+tcp_program_dupack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc)
+{
+ if (!(tc->flags & TCP_CONN_SNDACK))
+ {
+ vec_add1 (wrk->pending_acks, tc->c_c_index);
+ tc->flags |= TCP_CONN_SNDACK;
+ }
+ if (tc->pending_dupacks < 255)
+ tc->pending_dupacks += 1;
+}
+
+void
+tcp_send_acks (tcp_worker_ctx_t * wrk)
+{
+ u32 thread_index, *pending_acks;
+ tcp_connection_t *tc;
+ int i, j, n_acks;
+
+ if (!vec_len (wrk->pending_acks))
+ return;
+
+ thread_index = wrk->vm->thread_index;
+ pending_acks = wrk->pending_acks;
+ for (i = 0; i < vec_len (pending_acks); i++)
+ {
+ tc = tcp_connection_get (pending_acks[i], thread_index);
+ tc->flags &= ~TCP_CONN_SNDACK;
+ n_acks = clib_max (1, tc->pending_dupacks);
+ /* If we're supposed to send dupacks but have no ooo data
+ * send only one ack */
+ if (tc->pending_dupacks && !vec_len (tc->snd_sacks))
+ n_acks = 1;
+ for (j = 0; j < n_acks; j++)
+ tcp_send_ack (tc);
+ tc->pending_dupacks = 0;
+ }
+ _vec_len (wrk->pending_acks) = 0;
+}
+
/**
* Delayed ack timer handler
*
}
/**
- * Build a retransmit segment
+ * Allocate a new buffer and build a new tcp segment
*
- * @return the number of bytes in the segment or 0 if there's nothing to
- * retransmit
+ * @param wrk tcp worker
+ * @param tc connection for which the segment will be allocated
+ * @param offset offset of the first byte in the tx fifo
+ * @param max_deq_byte segment size
+ * @param[out] b pointer to buffer allocated
+ *
+ * @return the number of bytes in the segment or 0 if buffer cannot be
+ * allocated or no data available
*/
-static u32
-tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk,
- tcp_connection_t * tc, u32 offset,
- u32 max_deq_bytes, vlib_buffer_t ** b)
+static int
+tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
+ u32 offset, u32 max_deq_bytes, vlib_buffer_t ** b)
{
u32 bytes_per_buffer = vnet_get_tcp_main ()->bytes_per_buffer;
+ u32 bi, seg_size;
vlib_main_t *vm = wrk->vm;
int n_bytes = 0;
- u32 start, bi, available_bytes, seg_size;
u8 *data;
- ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
- ASSERT (max_deq_bytes != 0);
-
- /*
- * Make sure we can retransmit something
- */
- available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
- ASSERT (available_bytes >= offset);
- available_bytes -= offset;
- if (!available_bytes)
- return 0;
- max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
- max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
-
- /* Start is beyond snd_congestion */
- start = tc->snd_una + offset;
- if (seq_geq (start, tc->snd_congestion))
- goto done;
-
- /* Don't overshoot snd_congestion */
- if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
- {
- max_deq_bytes = tc->snd_congestion - start;
- if (max_deq_bytes == 0)
- goto done;
- }
-
seg_size = max_deq_bytes + MAX_HDRS_LEN;
/*
}
}
- tcp_get_free_buffer_index (wrk, &bi);
+ (void) tcp_get_free_buffer_index (wrk, &bi);
ASSERT (bi != (u32) ~ 0);
*b = vlib_get_buffer (vm, bi);
data = tcp_init_buffer (vm, *b);
ASSERT (n_bytes > 0);
ASSERT (((*b)->current_data + (*b)->current_length) <= bytes_per_buffer);
+ return n_bytes;
+}
+
+/**
+ * Build a retransmit segment
+ *
+ * @return the number of bytes in the segment or 0 if there's nothing to
+ * retransmit
+ */
+static u32
+tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk,
+ tcp_connection_t * tc, u32 offset,
+ u32 max_deq_bytes, vlib_buffer_t ** b)
+{
+ u32 start, available_bytes;
+ int n_bytes = 0;
+
+ ASSERT (tc->state >= TCP_STATE_ESTABLISHED);
+ ASSERT (max_deq_bytes != 0);
+
+ /*
+ * Make sure we can retransmit something
+ */
+ available_bytes = session_tx_fifo_max_dequeue (&tc->connection);
+ ASSERT (available_bytes >= offset);
+ available_bytes -= offset;
+ if (!available_bytes)
+ return 0;
+
+ max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes);
+ max_deq_bytes = clib_min (available_bytes, max_deq_bytes);
+
+ /* Start is beyond snd_congestion */
+ start = tc->snd_una + offset;
+ if (seq_geq (start, tc->snd_congestion))
+ goto done;
+
+ /* Don't overshoot snd_congestion */
+ if (seq_gt (start + max_deq_bytes, tc->snd_congestion))
+ {
+ max_deq_bytes = tc->snd_congestion - start;
+ if (max_deq_bytes == 0)
+ goto done;
+ }
+
+ n_bytes = tcp_prepare_segment (wrk, tc, offset, max_deq_bytes, b);
+ if (!n_bytes)
+ return 0;
+
if (tcp_in_fastrecovery (tc))
tc->snd_rxt_bytes += n_bytes;
return 0;
}
+static int
+tcp_fast_retransmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
+ u32 burst_size)
+{
+ u32 offset, n_segs = 0, n_written, bi;
+ 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;
+ while (n_segs < burst_size)
+ {
+ n_written = tcp_prepare_segment (wrk, tc, offset, tc->snd_mss, &b);
+ if (!n_written)
+ goto done;
+
+ bi = vlib_get_buffer_index (vm, b);
+ tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
+ offset += n_written;
+ n_segs += 1;
+ }
+
+done:
+ return n_segs;
+}
+
+#define scoreboard_rescue_rxt_valid(_sb, _tc) \
+ (seq_geq (_sb->rescue_rxt, _tc->snd_una) \
+ && seq_leq (_sb->rescue_rxt, _tc->snd_congestion))
+
/**
* Do fast retransmit with SACKs
*/
tcp_fast_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
u32 burst_size)
{
+ u32 n_written = 0, offset, max_bytes, n_segs = 0, n_segs_now;
+ sack_scoreboard_hole_t *hole;
vlib_main_t *vm = wrk->vm;
- u32 n_written = 0, offset, max_bytes, n_segs = 0;
vlib_buffer_t *b = 0;
- sack_scoreboard_hole_t *hole;
sack_scoreboard_t *sb;
u32 bi, old_snd_nxt;
int snd_space;
+ u32 max_deq;
u8 snd_limited = 0, can_rescue = 0;
ASSERT (tcp_in_fastrecovery (tc));
- old_snd_nxt = tc->snd_nxt;
- sb = &tc->sack_sb;
snd_space = tcp_available_cc_snd_space (tc);
- hole = scoreboard_get_hole (sb, sb->cur_rxt_hole);
-
if (snd_space < tc->snd_mss)
{
tcp_program_fastretransmit (wrk, tc);
- goto done;
+ return 0;
}
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 = session_tx_fifo_max_dequeue (&tc->connection);
+ max_deq -= tc->snd_una_max - tc->snd_una;
+
while (snd_space > 0 && n_segs < burst_size)
{
- hole = scoreboard_next_rxt_hole (sb, hole,
- tcp_fastrecovery_sent_1_smss (tc),
- &can_rescue, &snd_limited);
+ hole = scoreboard_next_rxt_hole (sb, hole, max_deq, &can_rescue,
+ &snd_limited);
if (!hole)
{
- if (!can_rescue || !(seq_lt (sb->rescue_rxt, tc->snd_una)
- || seq_gt (sb->rescue_rxt,
- tc->snd_congestion)))
+ if (max_deq)
{
- if (tcp_fastrecovery_first (tc))
- break;
-
- /* We tend to lose the first segment. Try re-resending
- * it but only once and after we've tried everything */
- hole = scoreboard_first_hole (sb);
- if (hole && hole->start == tc->snd_una)
- {
- tcp_retransmit_first_unacked (wrk, tc);
- tcp_fastrecovery_first_on (tc);
- n_segs += 1;
- }
- break;
+ snd_space = clib_min (max_deq, snd_space);
+ burst_size = clib_min (burst_size - n_segs,
+ snd_space / tc->snd_mss);
+ n_segs_now = tcp_fast_retransmit_unsent (wrk, tc, burst_size);
+ if (max_deq > n_segs_now * tc->snd_mss)
+ tcp_program_fastretransmit (wrk, tc);
+ n_segs += n_segs_now;
+ goto done;
}
+ if (!can_rescue || scoreboard_rescue_rxt_valid (sb, tc))
+ break;
+
/* If rescue rxt undefined or less than snd_una then one segment of
* up to SMSS octets that MUST include the highest outstanding
* unSACKed sequence number SHOULD be returned, and RescueRxt set to
max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
if (max_bytes == 0)
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);
/* Nothing left to retransmit */
if (n_written == 0)
break;
bi = vlib_get_buffer_index (vm, b);
- sb->high_rxt += n_written;
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
- ASSERT (n_written <= snd_space);
+
+ sb->high_rxt += n_written;
snd_space -= n_written;
n_segs += 1;
}
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;
+ u32 n_written = 0, offset = 0, bi, old_snd_nxt, 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);
-
- /* Start resending from first un-acked segment */
old_snd_nxt = tc->snd_nxt;
- tc->snd_nxt = tc->snd_una;
- snd_space = tcp_available_cc_snd_space (tc);
+ if (!tcp_fastrecovery_first (tc))
+ goto send_unsent;
+
+ /* 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)
{
- offset += n_written;
- n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, snd_space,
- &b);
+ n_written = tcp_prepare_retransmit_segment (wrk, tc, offset,
+ tc->snd_mss, &b);
/* Nothing left to retransmit */
if (n_written == 0)
bi = vlib_get_buffer_index (vm, b);
tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4);
snd_space -= n_written;
+ offset += n_written;
n_segs += 1;
}
- /* More data to resend */
- if (seq_lt (tc->snd_nxt, tc->snd_congestion))
- tcp_program_fastretransmit (wrk, tc);
+ if (n_segs == burst_size)
+ goto done;
+
+send_unsent:
+
+ /* RFC 6582: Send a new segment if permitted by the new value of cwnd. */
+ snd_space = tcp_available_cc_snd_space (tc);
+ if (snd_space < tc->snd_mss || tc->snd_mss == 0)
+ goto done;
+
+ max_deq = session_tx_fifo_max_dequeue (&tc->connection);
+ max_deq -= tc->snd_una_max - tc->snd_una;
+ if (max_deq)
+ {
+ snd_space = clib_min (max_deq, snd_space);
+ burst_size = clib_min (burst_size - n_segs, snd_space / tc->snd_mss);
+ n_segs_now = tcp_fast_retransmit_unsent (wrk, tc, burst_size);
+ if (max_deq > n_segs_now * tc->snd_mss)
+ tcp_program_fastretransmit (wrk, tc);
+ n_segs += n_segs_now;
+ }
- /* Restore snd_nxt. If window allows, send 1 SMSS of new data */
+ /* Restore snd_nxt */
tc->snd_nxt = old_snd_nxt;
+done:
+ tcp_fastrecovery_first_off (tc);
return n_segs;
}
return tcp_fast_retransmit_no_sack (wrk, tc, burst_size);
}
-static u32
-tcp_session_has_ooo_data (tcp_connection_t * tc)
-{
- stream_session_t *s = session_get (tc->c_s_index, tc->c_thread_index);
- return svm_fifo_has_ooo_data (s->server_rx_fifo);
-}
-
static void
tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0,
u16 * next0, u32 * error0)
tcp_output_handle_link_local (tc0, b0, next0, error0);
}
- /* Filter out DUPACKs if there are no OOO segments left */
- if (PREDICT_FALSE (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK))
- {
- /* N.B. Should not filter burst of dupacks. Two issues:
- * 1) dupacks open cwnd on remote peer when congested
- * 2) acks leaving should have the latest rcv_wnd since the
- * burst may have eaten up all of it, so only the old ones
- * could be filtered.
- */
- if (!tcp_session_has_ooo_data (tc0))
- {
- *error0 = TCP_ERROR_FILTERED_DUPACKS;
- *next0 = TCP_OUTPUT_NEXT_DROP;
- return;
- }
- }
-
- /* Stop DELACK timer and fix flags */
- tc0->flags &= ~(TCP_CONN_SNDACK);
if (!TCP_ALWAYS_ACK)
tcp_timer_reset (tc0, TCP_TIMER_DELACK);
}
Code Review / vpp.git / blobdiff