* or the rcv_nxt at last ack sent instead of rcv_nxt since that's the
* peer's reference when computing our receive window.
*
- * This accepts only segments within the window.
+ * This:
+ * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las)
+ * however, is too strict when we have retransmits. Instead we just check that
+ * the seq is not beyond the right edge and that the end of the segment is not
+ * less than the left edge.
+ *
+ * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so
+ * use rcv_nxt in the right edge window test instead of rcv_las.
+ *
*/
always_inline u8
tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq)
{
- return seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd)
- && seq_geq (seq, tc->rcv_nxt);
+ return (seq_geq (end_seq, tc->rcv_las)
+ && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd));
}
void
{
tcp_make_ack (tc0, b0);
*next0 = tcp_next_output (tc0->c_is_ip4);
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
return -1;
}
}
if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number,
vnet_buffer (b0)->tcp.seq_end))
{
- if (!tcp_rst (th0))
+ /* If our window is 0 and the packet is in sequence, let it pass
+ * through for ack processing. It should be dropped later.*/
+ if (tc0->rcv_wnd == 0
+ && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number)
{
- /* Send dup ack */
- tcp_make_ack (tc0, b0);
- *next0 = tcp_next_output (tc0->c_is_ip4);
+ /* TODO Should segment be tagged? */
+ }
+ else
+ {
+ /* If not RST, send dup ack */
+ if (!tcp_rst (th0))
+ {
+ tcp_make_ack (tc0, b0);
+ *next0 = tcp_next_output (tc0->c_is_ip4);
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0);
+ }
+ return -1;
}
- return -1;
}
/* 2nd: check the RST bit */
if (tcp_rst (th0))
{
- /* Notify session that connection has been reset. Switch
- * state to closed and await for session to do the cleanup. */
- stream_session_reset_notify (&tc0->connection);
- tc0->state = TCP_STATE_CLOSED;
+ tcp_connection_reset (tc0);
return -1;
}
/* XXX Drop in RTT results in RTTVAR increase and bigger RTO.
* The increase should be bound */
- tc->rttvar += (clib_abs (err) - tc->rttvar) >> 2;
+ tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2;
}
else
{
/* First measurement. */
tc->srtt = mrtt;
- tc->rttvar = mrtt << 1;
+ tc->rttvar = mrtt >> 1;
}
}
if (tc->rtt_seq && seq_gt (ack, tc->rtt_seq) && !tc->rto_boff)
{
mrtt = tcp_time_now () - tc->rtt_ts;
- tc->rtt_seq = 0;
}
/* As per RFC7323 TSecr can be used for RTTM only if the segment advances
tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX);
+ /* Allow measuring of RTT and make sure boff is 0 */
+ tc->rtt_seq = 0;
+ tc->rto_boff = 0;
+
return 1;
}
stream_session_dequeue_drop (&tc->connection, tc->bytes_acked);
/* Update rtt and rto */
- if (tcp_update_rtt (tc, ack))
- {
- /* Good ACK received and valid RTT, make sure retransmit backoff is 0 */
- tc->rto_boff = 0;
- }
+ tcp_update_rtt (tc, ack);
}
-/** Check if dupack as per RFC5681 Sec. 2 */
+/**
+ * Check if dupack as per RFC5681 Sec. 2
+ *
+ * This works only if called before updating snd_wnd.
+ * */
always_inline u8
tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd)
{
}
sack_scoreboard_hole_t *
-scoreboard_insert_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * prev,
+scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index,
u32 start, u32 end)
{
- sack_scoreboard_hole_t *hole, *next;
+ sack_scoreboard_hole_t *hole, *next, *prev;
u32 hole_index;
pool_get (sb->holes, hole);
hole->end = end;
hole_index = hole - sb->holes;
+ prev = scoreboard_get_hole (sb, prev_index);
if (prev)
{
hole->prev = prev - sb->holes;
return hole;
}
-static void
+void
tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
{
sack_scoreboard_t *sb = &tc->sack_sb;
sack_block_t *blk, tmp;
- sack_scoreboard_hole_t *hole, *next_hole;
- u32 blk_index = 0;
+ sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
+ u32 blk_index = 0, old_sacked_bytes, hole_index;
int i, j;
- if (!tcp_opts_sack (tc) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
+ sb->last_sacked_bytes = 0;
+ sb->snd_una_adv = 0;
+ old_sacked_bytes = sb->sacked_bytes;
+
+ if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
return;
/* Remove invalid blocks */
- vec_foreach (blk, tc->opt.sacks)
- {
- if (seq_lt (blk->start, blk->end)
- && seq_gt (blk->start, tc->snd_una)
- && seq_gt (blk->start, ack) && seq_lt (blk->end, tc->snd_nxt))
- continue;
-
- vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
- }
+ blk = tc->opt.sacks;
+ while (blk < vec_end (tc->opt.sacks))
+ {
+ if (seq_lt (blk->start, blk->end)
+ && seq_gt (blk->start, tc->snd_una)
+ && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt))
+ {
+ blk++;
+ continue;
+ }
+ vec_del1 (tc->opt.sacks, blk - tc->opt.sacks);
+ }
/* Add block for cumulative ack */
if (seq_gt (ack, tc->snd_una))
/* Make sure blocks are ordered */
for (i = 0; i < vec_len (tc->opt.sacks); i++)
- for (j = i; j < vec_len (tc->opt.sacks); j++)
+ for (j = i + 1; j < vec_len (tc->opt.sacks); j++)
if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start))
{
tmp = tc->opt.sacks[i];
tc->opt.sacks[j] = tmp;
}
- /* If no holes, insert the first that covers all outstanding bytes */
if (sb->head == TCP_INVALID_SACK_HOLE_INDEX)
{
- scoreboard_insert_hole (sb, 0, tc->snd_una, tc->snd_una_max);
+ /* 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);
+ sb->tail = scoreboard_hole_index (sb, last_hole);
+ }
+ else
+ {
+ /* If we have holes but snd_una_max is beyond the last hole, update
+ * last hole end */
+ tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
+ last_hole = scoreboard_last_hole (sb);
+ if (seq_gt (tc->snd_una_max, sb->max_byte_sacked)
+ && seq_gt (tc->snd_una_max, last_hole->end))
+ last_hole->end = tc->snd_una_max;
}
/* Walk the holes with the SACK blocks */
next_hole = scoreboard_next_hole (sb, hole);
/* Byte accounting */
- if (seq_lt (hole->end, ack))
+ if (seq_leq (hole->end, ack))
{
- /* Bytes lost because snd wnd left edge advances */
- if (seq_lt (next_hole->start, ack))
+ /* Bytes lost because snd_wnd left edge advances */
+ if (next_hole && seq_leq (next_hole->start, ack))
sb->sacked_bytes -= next_hole->start - hole->end;
else
sb->sacked_bytes -= ack - hole->end;
sb->sacked_bytes += scoreboard_hole_bytes (hole);
}
+ /* snd_una needs to be advanced */
+ if (seq_geq (ack, hole->end))
+ {
+ if (next_hole && seq_lt (ack, next_hole->start))
+ sb->snd_una_adv = next_hole->start - ack;
+ else
+ sb->snd_una_adv = sb->max_byte_sacked - ack;
+
+ /* all these can be delivered */
+ sb->sacked_bytes -= sb->snd_una_adv;
+ }
+
+ /* About to remove last hole */
+ if (hole == last_hole)
+ {
+ sb->tail = hole->prev;
+ last_hole = scoreboard_last_hole (sb);
+ /* keep track of max byte sacked in case the last hole
+ * is acked */
+ if (seq_gt (hole->end, sb->max_byte_sacked))
+ sb->max_byte_sacked = hole->end;
+ }
scoreboard_remove_hole (sb, hole);
hole = next_hole;
}
- /* Partial overlap */
+ /* Partial 'head' overlap */
else
{
- sb->sacked_bytes += blk->end - hole->start;
- hole->start = blk->end;
+ if (seq_gt (blk->end, hole->start))
+ {
+ sb->sacked_bytes += blk->end - hole->start;
+ hole->start = blk->end;
+ }
blk_index++;
}
}
else
{
/* Hole must be split */
- if (seq_leq (blk->end, hole->end))
+ if (seq_lt (blk->end, hole->end))
{
sb->sacked_bytes += blk->end - blk->start;
- scoreboard_insert_hole (sb, hole, blk->end, hole->end);
- hole->end = blk->start - 1;
+ hole_index = scoreboard_hole_index (sb, hole);
+ new_hole = scoreboard_insert_hole (sb, hole_index, blk->end,
+ hole->end);
+
+ /* Pool might've moved */
+ hole = scoreboard_get_hole (sb, hole_index);
+ hole->end = blk->start;
+
+ /* New or split of tail */
+ if ((last_hole->end == new_hole->end)
+ || seq_lt (last_hole->end, new_hole->start))
+ {
+ last_hole = new_hole;
+ sb->tail = scoreboard_hole_index (sb, new_hole);
+ }
+
blk_index++;
+ hole = scoreboard_next_hole (sb, hole);
}
else
{
- sb->sacked_bytes += hole->end - blk->start + 1;
- hole->end = blk->start - 1;
+ sb->sacked_bytes += hole->end - blk->start;
+ hole->end = blk->start;
hole = scoreboard_next_hole (sb, hole);
}
}
}
+
+ sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
+ - old_sacked_bytes;
}
/** Update snd_wnd
static void
tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd)
{
- if (tc->snd_wl1 < seq || (tc->snd_wl1 == seq && tc->snd_wl2 <= ack))
+ if (seq_lt (tc->snd_wl1, seq)
+ || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack)))
{
tc->snd_wnd = snd_wnd;
tc->snd_wl1 = seq;
tc->snd_wl2 = ack;
+ TCP_EVT_DBG (TCP_EVT_SND_WND, tc);
+
+ /* Set probe timer if we just got 0 wnd */
+ if (tc->snd_wnd < tc->snd_mss
+ && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST))
+ tcp_persist_timer_set (tc);
+ else
+ tcp_persist_timer_reset (tc);
}
}
-static void
+void
tcp_cc_congestion (tcp_connection_t * tc)
{
+ tc->snd_congestion = tc->snd_nxt;
tc->cc_algo->congestion (tc);
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4);
}
-static void
+void
tcp_cc_recover (tcp_connection_t * tc)
{
- if (tcp_in_fastrecovery (tc))
- {
- tc->cc_algo->recovered (tc);
- tcp_recovery_off (tc);
- }
- else if (tcp_in_recovery (tc))
- {
- tcp_recovery_off (tc);
- tc->cwnd = tcp_loss_wnd (tc);
- }
+ /* TODO: check if time to recover was small. It might be that RTO popped
+ * too soon.
+ */
+
+ tc->cc_algo->recovered (tc);
+
+ tc->rtx_bytes = 0;
+ tc->rcv_dupacks = 0;
+ tc->snd_nxt = tc->snd_una;
+
+ tc->cc_algo->rcv_ack (tc);
+ tc->tsecr_last_ack = tc->opt.tsecr;
+
+ tcp_cong_recovery_off (tc);
+
+ TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3);
}
static void
-tcp_cc_rcv_ack (tcp_connection_t * tc)
+tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b)
{
u8 partial_ack;
- if (tcp_in_recovery (tc))
+ if (tcp_in_cong_recovery (tc))
{
- partial_ack = seq_lt (tc->snd_una, tc->snd_una_max);
+ partial_ack = seq_lt (tc->snd_una, tc->snd_congestion);
if (!partial_ack)
{
/* Clear retransmitted bytes. */
- tc->rtx_bytes = 0;
tcp_cc_recover (tc);
}
else
{
+ TCP_EVT_DBG (TCP_EVT_CC_PACK, tc);
+
/* Clear retransmitted bytes. XXX should we clear all? */
tc->rtx_bytes = 0;
tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK);
- /* Retransmit first unacked segment */
- tcp_retransmit_first_unacked (tc);
+ /* In case snd_nxt is still in the past and output tries to
+ * shove some new bytes */
+ tc->snd_nxt = tc->snd_una_max;
+
+ /* XXX need proper RFC6675 support */
+ if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc))
+ {
+ tcp_fast_retransmit (tc);
+ }
+ else
+ {
+ /* Retransmit first unacked segment */
+ tcp_retransmit_first_unacked (tc);
+ }
}
}
else
{
tc->cc_algo->rcv_ack (tc);
+ tc->tsecr_last_ack = tc->opt.tsecr;
+ tc->rcv_dupacks = 0;
}
-
- tc->rcv_dupacks = 0;
- tc->tsecr_last_ack = tc->opt.tsecr;
}
static void
tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack)
{
- ASSERT (tc->snd_una == ack);
+// ASSERT (seq_geq(tc->snd_una, ack));
tc->rcv_dupacks++;
if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
{
u32 new_snd_wnd;
- /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) then send an
- * ACK, drop the segment, and return */
+ /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */
if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt))
{
- tcp_make_ack (tc, b);
- *next = tcp_next_output (tc->c_is_ip4);
- *error = TCP_ERROR_ACK_INVALID;
- return -1;
+ /* 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_make_ack (tc, b);
+ *next = tcp_next_output (tc->c_is_ip4);
+ *error = TCP_ERROR_ACK_INVALID;
+ 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,
+ vnet_buffer (b)->tcp.ack_number);
+
+ tc->snd_nxt = vnet_buffer (b)->tcp.ack_number;
+ *error = TCP_ERROR_ACK_FUTURE;
}
- /* If old ACK, discard */
+ /* If old ACK, probably it's an old dupack */
if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una))
{
*error = TCP_ERROR_ACK_OLD;
+ TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1,
+ vnet_buffer (b)->tcp.ack_number);
+ if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD)
+ {
+ TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc);
+ tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
+ }
return -1;
}
if (tcp_opts_sack_permitted (&tc->opt))
tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number);
- new_snd_wnd = clib_net_to_host_u32 (th->window) << tc->snd_wscale;
+ new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale;
if (tcp_ack_is_dupack (tc, b, new_snd_wnd))
{
+ TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1);
tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number);
*error = TCP_ERROR_ACK_DUP;
return -1;
}
- /* Valid ACK */
+ /*
+ * Valid ACK
+ */
+
tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una;
- tc->snd_una = vnet_buffer (b)->tcp.ack_number;
+ tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv;
- /* Dequeue ACKed packet and update RTT */
+ /* Dequeue ACKed data and update RTT */
tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number);
-
tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number,
vnet_buffer (b)->tcp.ack_number, new_snd_wnd);
- /* Updates congestion control (slow start/congestion avoidance) */
- tcp_cc_rcv_ack (tc);
+ /* If some of our sent bytes have been acked, update cc and retransmit
+ * timer. */
+ if (tc->bytes_acked)
+ {
+ TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc);
- /* If everything has been acked, stop retransmit timer
- * otherwise update */
- if (tc->snd_una == tc->snd_una_max)
- tcp_timer_reset (tc, TCP_TIMER_RETRANSMIT);
- else
- tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, tc->rto);
+ /* Updates congestion control (slow start/congestion avoidance) */
+ tcp_cc_rcv_ack (tc, b);
+
+ /* If everything has been acked, stop retransmit timer
+ * otherwise update */
+ if (tc->snd_una == tc->snd_una_max)
+ tcp_retransmit_timer_reset (tc);
+ else
+ tcp_retransmit_timer_update (tc);
+ }
return 0;
}
tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end)
{
sack_block_t *new_list = 0, block;
- u32 n_elts;
int i;
- u8 new_head = 0;
/* If the first segment is ooo add it to the list. Last write might've moved
* rcv_nxt over the first segment. */
block.start = start;
block.end = end;
vec_add1 (new_list, block);
- new_head = 1;
}
/* Find the blocks still worth keeping. */
|| seq_leq (tc->snd_sacks[i].start, end))
continue;
- /* Save subsequent segments to new SACK list. */
- n_elts = clib_min (vec_len (tc->snd_sacks) - i,
- TCP_MAX_SACK_BLOCKS - new_head);
- vec_insert_elts (new_list, &tc->snd_sacks[i], n_elts, new_head);
- break;
+ /* Save to new SACK list. */
+ vec_add1 (new_list, tc->snd_sacks[i]);
}
+ ASSERT (vec_len (new_list) < TCP_MAX_SACK_BLOCKS);
+
/* Replace old vector with new one */
vec_free (tc->snd_sacks);
tc->snd_sacks = new_list;
}
/** Enqueue data for delivery to application */
-always_inline u32
+always_inline int
tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
u16 data_len)
{
vlib_buffer_get_current (b),
data_len, 1 /* queue event */ );
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
+
/* Update rcv_nxt */
if (PREDICT_TRUE (written == data_len))
{
/* Send ACK confirming the update */
tc->flags |= TCP_CONN_SNDACK;
+ }
+ else if (written > 0)
+ {
+ /* We've written something but FIFO is probably full now */
+ tc->rcv_nxt += written;
+
+ /* Depending on how fast the app is, all remaining buffers in burst will
+ * not be enqueued. Inform peer */
+ tc->flags |= TCP_CONN_SNDACK;
- /* Update SACK list if need be */
- if (tcp_opts_sack_permitted (&tc->opt))
- {
- /* Remove SACK blocks that have been delivered */
- tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
- }
+ return TCP_ERROR_PARTIALLY_ENQUEUED;
}
else
{
- ASSERT (0);
+ tc->flags |= TCP_CONN_SNDACK;
return TCP_ERROR_FIFO_FULL;
}
+ /* Update SACK list if need be */
+ if (tcp_opts_sack_permitted (&tc->opt))
+ {
+ /* Remove SACK blocks that have been delivered */
+ tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt);
+ }
+
return TCP_ERROR_ENQUEUED;
}
/** Enqueue out-of-order data */
-always_inline u32
+always_inline int
tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
u16 data_len)
{
stream_session_t *s0;
u32 offset, seq;
+ int rv;
+
+ /* Pure ACK. Do nothing */
+ if (PREDICT_FALSE (data_len == 0))
+ {
+ return TCP_ERROR_PURE_ACK;
+ }
s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
seq = vnet_buffer (b)->tcp.seq_number;
offset = seq - tc->rcv_nxt;
- if (svm_fifo_enqueue_with_offset (s0->server_rx_fifo, s0->pid, offset,
- data_len, vlib_buffer_get_current (b)))
- return TCP_ERROR_FIFO_FULL;
+ rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo, s0->pid, offset,
+ data_len, vlib_buffer_get_current (b));
+
+ /* Nothing written */
+ if (rv)
+ {
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0);
+ return TCP_ERROR_FIFO_FULL;
+ }
+
+ TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len);
/* Update SACK list if in use */
if (tcp_opts_sack_permitted (&tc->opt))
}
/**
- * Check if ACK could be delayed. DELACK timer is set only after frame is
- * processed so this can return true for a full bursts of packets.
+ * Check if ACK could be delayed. If ack can be delayed, it should return
+ * true for a full frame. If we're always acking return 0.
*/
always_inline int
tcp_can_delack (tcp_connection_t * tc)
{
- /* If there's no DELACK timer set and the last window sent wasn't 0 we
- * can safely delay. */
- if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK)
- && (tc->flags & TCP_CONN_SENT_RCV_WND0) == 0
- && (tc->flags & TCP_CONN_SNDACK) == 0)
- return 1;
+ /* Send ack if ... */
+ if (TCP_ALWAYS_ACK
+ /* just sent a rcv wnd 0 */
+ || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0
+ /* constrained to send ack */
+ || (tc->flags & TCP_CONN_SNDACK) != 0
+ /* we're almost out of tx wnd */
+ || tcp_available_snd_space (tc) < 2 * tc->snd_mss)
+ return 0;
- return 0;
+ return 1;
}
static int
/* Handle out-of-order data */
if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt))
{
+ /* Old sequence numbers allowed through because they overlapped
+ * the rx window */
+ if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt))
+ {
+ error = TCP_ERROR_SEGMENT_OLD;
+ *next0 = TCP_NEXT_DROP;
+ goto done;
+ }
+
error = tcp_session_enqueue_ooo (tc, b, n_data_bytes);
- /* Don't send more than 3 dupacks per burst
- * XXX decide if this is good */
- if (tc->snt_dupacks < 3)
- {
- /* RFC2581: Send DUPACK for fast retransmit */
- tcp_make_ack (tc, b);
- *next0 = tcp_next_output (tc->c_is_ip4);
+ /* 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 eaten up all of it, so only the
+ * old ones could be filtered.
+ */
- /* Mark as DUPACK. We may filter these in output if
- * the burst fills the holes. */
- vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
+ /* RFC2581: Send DUPACK for fast retransmit */
+ tcp_make_ack (tc, b);
+ *next0 = tcp_next_output (tc->c_is_ip4);
- tc->snt_dupacks++;
- }
+ /* Mark as DUPACK. We may filter these in output if
+ * the burst fills the holes. */
+ if (n_data_bytes)
+ vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK;
+ TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc);
goto done;
}
* segments can be enqueued after fifo tail offset changes. */
error = tcp_session_enqueue_data (tc, b, n_data_bytes);
+ if (n_data_bytes == 0)
+ {
+ *next0 = TCP_NEXT_DROP;
+ goto done;
+ }
+
/* Check if ACK can be delayed */
if (tcp_can_delack (tc))
{
- /* Nothing to do for pure ACKs */
- if (n_data_bytes == 0)
- goto done;
-
- /* If connection has not been previously marked for delay ack
- * add it to the list and flag it */
- if (!tc->flags & TCP_CONN_DELACK)
- {
- vec_add1 (tm->delack_connections[tc->c_thread_index],
- tc->c_c_index);
- tc->flags |= TCP_CONN_DELACK;
- }
+ if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK))
+ tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME);
+ goto done;
}
- else
- {
- /* Check if a packet has already been enqueued to output for burst.
- * If yes, then drop this one, otherwise, let it pass through to
- * output */
- if ((tc->flags & TCP_CONN_BURSTACK) == 0)
- {
- *next0 = tcp_next_output (tc->c_is_ip4);
- tcp_make_ack (tc, b);
- error = TCP_ERROR_ENQUEUED;
- /* TODO: maybe add counter to ensure N acks will be sent/burst */
- tc->flags |= TCP_CONN_BURSTACK;
- }
- }
+ *next0 = tcp_next_output (tc->c_is_ip4);
+ tcp_make_ack (tc, b);
done:
return error;
}
-void
-delack_timers_init (tcp_main_t * tm, u32 thread_index)
+always_inline void
+tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val)
{
- tcp_connection_t *tc;
- u32 i, *conns;
- tw_timer_wheel_16t_2w_512sl_t *tw;
-
- tw = &tm->timer_wheels[thread_index];
- conns = tm->delack_connections[thread_index];
- for (i = 0; i < vec_len (conns); i++)
- {
- tc = pool_elt_at_index (tm->connections[thread_index], conns[i]);
- ASSERT (0 != tc);
+ if (PREDICT_TRUE (!val))
+ return;
- tc->timers[TCP_TIMER_DELACK]
- = tw_timer_start_16t_2w_512sl (tw, conns[i],
- TCP_TIMER_DELACK, TCP_DELACK_TIME);
- }
- vec_reset_length (tm->delack_connections[thread_index]);
+ if (is_ip4)
+ vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val);
+ else
+ vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val);
}
always_inline uword
vlib_frame_t * from_frame, int is_ip4)
{
u32 n_left_from, next_index, *from, *to_next;
- u32 my_thread_index = vm->cpu_index, errors = 0;
+ u32 my_thread_index = vm->thread_index, errors = 0;
tcp_main_t *tm = vnet_get_tcp_main ();
from = vlib_frame_vector_args (from_frame);
tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
my_thread_index);
+ if (PREDICT_FALSE (tc0 == 0))
+ {
+ error0 = TCP_ERROR_INVALID_CONNECTION;
+ goto done;
+ }
+
/* Checksum computed by ipx_local no need to compute again */
if (is_ip4)
if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0)))
{
error0 = TCP_ERROR_SEGMENT_INVALID;
- goto drop;
+ TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0,
+ vnet_buffer (b0)->tcp.seq_number,
+ vnet_buffer (b0)->tcp.seq_end);
+ goto done;
}
/* 5: check the ACK field */
if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0))
{
- goto drop;
+ goto done;
}
/* 6: check the URG bit TODO */
/* 7: process the segment text */
+
vlib_buffer_advance (b0, n_advance_bytes0);
error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0);
/* 8: check the FIN bit */
if (tcp_fin (th0))
{
- /* Send ACK and enter CLOSE-WAIT */
- tcp_make_ack (tc0, b0);
- tcp_connection_force_ack (tc0, b0);
- next0 = tcp_next_output (tc0->c_is_ip4);
+ /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead
+ * wait for session to call close. To avoid lingering
+ * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */
tc0->state = TCP_STATE_CLOSE_WAIT;
+ TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
stream_session_disconnect_notify (&tc0->connection);
+ tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
}
- drop:
+ done:
b0->error = node->errors[error0];
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
}
errors = session_manager_flush_enqueue_events (my_thread_index);
- if (errors)
- {
- if (is_ip4)
- vlib_node_increment_counter (vm, tcp4_established_node.index,
- TCP_ERROR_EVENT_FIFO_FULL, errors);
- else
- vlib_node_increment_counter (vm, tcp6_established_node.index,
- TCP_ERROR_EVENT_FIFO_FULL, errors);
- }
-
- delack_timers_init (tm, my_thread_index);
+ tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors);
return from_frame->n_vectors;
}
.name = "tcp4-established",
/* Takes a vector of packets. */
.vector_size = sizeof (u32),
- .n_errors = TCP_N_ERROR,.error_strings = tcp_error_strings,
+ .n_errors = TCP_N_ERROR,
+ .error_strings = tcp_error_strings,
.n_next_nodes = TCP_ESTABLISHED_N_NEXT,
.next_nodes =
{
{
tcp_main_t *tm = vnet_get_tcp_main ();
u32 n_left_from, next_index, *from, *to_next;
- u32 my_thread_index = vm->cpu_index, errors = 0;
+ u32 my_thread_index = vm->thread_index, errors = 0;
u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
from = vlib_frame_vector_args (from_frame);
/* Parse options */
tcp_options_parse (tcp0, &new_tc0->opt);
- tcp_connection_init_vars (new_tc0);
if (tcp_opts_tstamp (&new_tc0->opt))
{
if (tcp_opts_wscale (&new_tc0->opt))
new_tc0->snd_wscale = new_tc0->opt.wscale;
- new_tc0->snd_wnd = clib_net_to_host_u32 (tcp0->window)
- << new_tc0->snd_wscale;
+ /* No scaling */
+ new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window);
new_tc0->snd_wl1 = seq0;
new_tc0->snd_wl2 = ack0;
+ tcp_connection_init_vars (new_tc0);
+
/* SYN-ACK: See if we can switch to ESTABLISHED state */
if (tcp_ack (tcp0))
{
new_tc0->snd_una = ack0;
new_tc0->state = TCP_STATE_ESTABLISHED;
+ /* Make sure las is initialized for the wnd computation */
+ new_tc0->rcv_las = new_tc0->rcv_nxt;
+
/* Notify app that we have connection */
stream_session_connect_notify (&new_tc0->connection, sst, 0);
{
new_tc0->state = TCP_STATE_SYN_RCVD;
- /* Notify app that we have connection XXX */
+ /* Notify app that we have connection */
stream_session_connect_notify (&new_tc0->connection, sst, 0);
tcp_make_synack (new_tc0, b0);
VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv);
/**
- * Handles reception for all states except LISTEN, SYN-SEND and ESTABLISHED
+ * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED
* as per RFC793 p. 64
*/
always_inline uword
{
tcp_main_t *tm = vnet_get_tcp_main ();
u32 n_left_from, next_index, *from, *to_next;
- u32 my_thread_index = vm->cpu_index, errors = 0;
+ u32 my_thread_index = vm->thread_index, errors = 0;
from = vlib_frame_vector_args (from_frame);
n_left_from = from_frame->n_vectors;
b0 = vlib_get_buffer (vm, bi0);
tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index,
my_thread_index);
+ if (PREDICT_FALSE (tc0 == 0))
+ {
+ error0 = TCP_ERROR_INVALID_CONNECTION;
+ goto drop;
+ }
/* Checksum computed by ipx_local no need to compute again */
/* Initialize session variables */
tc0->snd_una = vnet_buffer (b0)->tcp.ack_number;
- tc0->snd_wnd = clib_net_to_host_u32 (tcp0->window)
+ tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window)
<< tc0->opt.wscale;
tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
/* Shoulder tap the server */
stream_session_accept_notify (&tc0->connection);
- tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN);
+ /* Reset SYN-ACK retransmit timer */
+ tcp_retransmit_timer_reset (tc0);
break;
case TCP_STATE_ESTABLISHED:
/* We can get packets in established state here because they
* continue processing in that state. */
if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0))
goto drop;
- tc0->state = TCP_STATE_FIN_WAIT_2;
- /* Stop all timers, 2MSL will be set lower */
- tcp_connection_timers_reset (tc0);
+
+ /* If FIN is ACKed */
+ if (tc0->snd_una == tc0->snd_una_max)
+ {
+ tc0->state = TCP_STATE_FIN_WAIT_2;
+ /* Stop all timers, 2MSL will be set lower */
+ tcp_connection_timers_reset (tc0);
+ }
break;
case TCP_STATE_FIN_WAIT_2:
/* In addition to the processing for the ESTABLISHED state, if
if (!tcp_rcv_ack_is_acceptable (tc0, b0))
goto drop;
- tcp_connection_del (tc0);
+ tc0->state = TCP_STATE_CLOSED;
+
+ /* Don't delete the connection/session yet. Instead, wait a
+ * reasonable amount of time until the pipes are cleared. In
+ * particular, this makes sure that we won't have dead sessions
+ * when processing events on the tx path */
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME);
+
+ /* Stop retransmit */
+ tcp_retransmit_timer_reset (tc0);
+
goto drop;
break;
case TCP_STATE_SYN_RCVD:
/* Send FIN-ACK notify app and enter CLOSE-WAIT */
tcp_connection_timers_reset (tc0);
- tcp_make_finack (tc0, b0);
+ tcp_make_fin (tc0, b0);
next0 = tcp_next_output (tc0->c_is_ip4);
stream_session_disconnect_notify (&tc0->connection);
tc0->state = TCP_STATE_CLOSE_WAIT;
case TCP_STATE_FIN_WAIT_1:
tc0->state = TCP_STATE_TIME_WAIT;
tcp_connection_timers_reset (tc0);
- tcp_timer_set (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME);
+ tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
break;
case TCP_STATE_FIN_WAIT_2:
/* Got FIN, send ACK! */
tc0->state = TCP_STATE_TIME_WAIT;
- tcp_timer_set (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME);
+ tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME);
tcp_make_ack (tc0, b0);
next0 = tcp_next_output (is_ip4);
break;
/* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait
* timeout.
*/
- tcp_timer_update (tc0, TCP_TIMER_2MSL, TCP_2MSL_TIME);
+ tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME);
break;
}
+ TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0);
b0->error = error0 ? node->errors[error0] : 0;
vlib_frame_t * from_frame, int is_ip4)
{
u32 n_left_from, next_index, *from, *to_next;
- u32 my_thread_index = vm->cpu_index;
+ u32 my_thread_index = vm->thread_index;
tcp_main_t *tm = vnet_get_tcp_main ();
u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP;
}
tcp_options_parse (th0, &child0->opt);
- tcp_connection_init_vars (child0);
child0->irs = vnet_buffer (b0)->tcp.seq_number;
child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1;
+ child0->rcv_las = child0->rcv_nxt;
child0->state = TCP_STATE_SYN_RCVD;
/* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK}
child0->tsval_recent_age = tcp_time_now ();
}
+ if (tcp_opts_wscale (&child0->opt))
+ child0->snd_wscale = child0->opt.wscale;
+
+ /* No scaling */
+ child0->snd_wnd = clib_net_to_host_u16 (th0->window);
+ child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number;
+ child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number;
+
+ tcp_connection_init_vars (child0);
+
+ TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0);
+
/* Reuse buffer to make syn-ack and send */
tcp_make_synack (child0, b0);
next0 = tcp_next_output (is_ip4);
}
- b0->error = error0 ? node->errors[error0] : 0;
+ b0->error = node->errors[error0];
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi0, next0);
u8 state;
} tcp_rx_trace_t;
-const char *tcp_fsm_states[] = {
-#define _(sym, str) str,
- foreach_tcp_fsm_state
-#undef _
-};
-
-u8 *
-format_tcp_state (u8 * s, va_list * args)
-{
- tcp_state_t *state = va_arg (*args, tcp_state_t *);
-
- if (state[0] < TCP_N_STATES)
- s = format (s, "%s", tcp_fsm_states[state[0]]);
- else
- s = format (s, "UNKNOWN");
-
- return s;
-}
-
u8 *
format_tcp_rx_trace (u8 * s, va_list * args)
{
vlib_frame_t * from_frame, int is_ip4)
{
u32 n_left_from, next_index, *from, *to_next;
- u32 my_thread_index = vm->cpu_index;
+ u32 my_thread_index = vm->thread_index;
tcp_main_t *tm = vnet_get_tcp_main ();
- session_manager_main_t *ssm = vnet_get_session_manager_main ();
from = vlib_frame_vector_args (from_frame);
n_left_from = from_frame->n_vectors;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
+ vnet_buffer (b0)->tcp.flags = 0;
if (is_ip4)
{
/* lookup session */
tc0 =
- (tcp_connection_t *) stream_session_lookup_transport4 (ssm,
- &ip40->dst_address,
- &ip40->src_address,
- tcp0->dst_port,
- tcp0->src_port,
- SESSION_TYPE_IP4_TCP,
- my_thread_index);
+ (tcp_connection_t *)
+ stream_session_lookup_transport4 (&ip40->dst_address,
+ &ip40->src_address,
+ tcp0->dst_port,
+ tcp0->src_port,
+ SESSION_TYPE_IP4_TCP,
+ my_thread_index);
}
else
{
ip60 = vlib_buffer_get_current (b0);
tcp0 = ip6_next_header (ip60);
tc0 =
- (tcp_connection_t *) stream_session_lookup_transport6 (ssm,
- &ip60->src_address,
- &ip60->dst_address,
- tcp0->src_port,
- tcp0->dst_port,
- SESSION_TYPE_IP6_TCP,
- my_thread_index);
+ (tcp_connection_t *)
+ stream_session_lookup_transport6 (&ip60->src_address,
+ &ip60->dst_address,
+ tcp0->src_port,
+ tcp0->dst_port,
+ SESSION_TYPE_IP6_TCP,
+ my_thread_index);
}
/* Session exists */
/* Send reset */
next0 = TCP_INPUT_NEXT_RESET;
error0 = TCP_ERROR_NO_LISTENER;
- vnet_buffer (b0)->tcp.flags = 0;
}
b0->error = error0 ? node->errors[error0] : 0;
_(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
_(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED,
TCP_ERROR_NONE);
+ _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE);
/* ACK or FIN-ACK to our FIN */
_(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
_(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS,
Code Review / vpp.git / blobdiff