diff options
Diffstat (limited to 'src/vnet/tcp/tcp_output.c')
| -rw-r--r-- | src/vnet/tcp/tcp_output.c | 295 |
1 files changed, 202 insertions, 93 deletions
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c index 114a5b9e..a671f728 100644 --- a/src/vnet/tcp/tcp_output.c +++ b/src/vnet/tcp/tcp_output.c @@ -125,15 +125,33 @@ tcp_initial_window_to_advertise (tcp_connection_t * tc) u32 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state) { - u32 available_space, max_fifo, observed_wnd; - if (state < TCP_STATE_ESTABLISHED) return tcp_initial_window_to_advertise (tc); + tcp_update_rcv_wnd (tc); + + if (tc->rcv_wnd == 0) + { + tc->flags |= TCP_CONN_SENT_RCV_WND0; + } + else + { + tc->flags &= ~TCP_CONN_SENT_RCV_WND0; + } + + return tc->rcv_wnd >> tc->rcv_wscale; +} + +void +tcp_update_rcv_wnd (tcp_connection_t * tc) +{ + i32 observed_wnd; + u32 available_space, max_fifo, wnd; + /* * Figure out how much space we have available */ - available_space = stream_session_max_enqueue (&tc->connection); + available_space = stream_session_max_rx_enqueue (&tc->connection); max_fifo = stream_session_fifo_size (&tc->connection); ASSERT (tc->opt.mss < max_fifo); @@ -145,23 +163,25 @@ tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state) * Use the above and what we know about what we've previously advertised * to compute the new window */ - observed_wnd = tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las); + observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las); + if (observed_wnd < 0) + observed_wnd = 0; /* Bad. Thou shalt not shrink */ if (available_space < observed_wnd) { - if (available_space == 0) - clib_warning ("Didn't shrink rcv window despite not having space"); + /* Does happen! */ + wnd = observed_wnd; } - - tc->rcv_wnd = clib_min (available_space, TCP_WND_MAX << tc->rcv_wscale); - - if (tc->rcv_wnd == 0) + else { - tc->flags |= TCP_CONN_SENT_RCV_WND0; + wnd = available_space; } - return tc->rcv_wnd >> tc->rcv_wscale; + if (wnd && ((wnd << tc->rcv_wscale) >> tc->rcv_wscale != wnd)) + wnd += 1 << tc->rcv_wscale; + + tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale); } /** @@ -363,7 +383,7 @@ tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts, #define tcp_get_free_buffer_index(tm, bidx) \ do { \ u32 *my_tx_buffers, n_free_buffers; \ - u32 cpu_index = tm->vlib_main->cpu_index; \ + u32 cpu_index = os_get_cpu_number(); \ my_tx_buffers = tm->tx_buffers[cpu_index]; \ if (PREDICT_FALSE(vec_len (my_tx_buffers) == 0)) \ { \ @@ -381,6 +401,14 @@ do { \ _vec_len (my_tx_buffers) -= 1; \ } while (0) +#define tcp_return_buffer(tm) \ +do { \ + u32 *my_tx_buffers; \ + u32 cpu_index = os_get_cpu_number(); \ + my_tx_buffers = tm->tx_buffers[cpu_index]; \ + _vec_len (my_tx_buffers) +=1; \ +} while (0) + always_inline void tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b) { @@ -421,8 +449,6 @@ tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state, tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd); tcp_options_write ((u8 *) (th + 1), snd_opts); - - /* Mark as ACK */ vnet_buffer (b)->tcp.connection_index = tc->c_c_index; } @@ -432,12 +458,12 @@ tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state, void tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b) { - tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); tcp_reuse_buffer (vm, b); tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK); vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_ACK; + TCP_EVT_DBG (TCP_EVT_ACK_SENT, tc); } /** @@ -446,8 +472,7 @@ tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b) void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b) { - tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); u8 flags = 0; tcp_reuse_buffer (vm, b); @@ -467,8 +492,7 @@ tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b) void tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b) { - tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); tcp_options_t _snd_opts, *snd_opts = &_snd_opts; u8 tcp_opts_len, tcp_hdr_opts_len; tcp_header_t *th; @@ -631,7 +655,7 @@ tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4) vlib_buffer_t *b; u32 bi; tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); u8 tcp_hdr_len, flags = 0; tcp_header_t *th, *pkt_th; u32 seq, ack; @@ -736,7 +760,7 @@ tcp_send_syn (tcp_connection_t * tc) vlib_buffer_t *b; u32 bi; tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); u8 tcp_hdr_opts_len, tcp_opts_len; tcp_header_t *th; u32 time_now; @@ -795,9 +819,9 @@ tcp_enqueue_to_output (vlib_main_t * vm, vlib_buffer_t * b, u32 bi, u8 is_ip4) /* Decide where to send the packet */ next_index = is_ip4 ? tcp4_output_node.index : tcp6_output_node.index; - f = vlib_get_frame_to_node (vm, next_index); /* Enqueue the packet */ + f = vlib_get_frame_to_node (vm, next_index); to_next = vlib_frame_vector_args (f); to_next[0] = bi; f->n_vectors = 1; @@ -813,7 +837,7 @@ tcp_send_fin (tcp_connection_t * tc) vlib_buffer_t *b; u32 bi; tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); tcp_get_free_buffer_index (tm, &bi); b = vlib_get_buffer (vm, bi); @@ -884,22 +908,21 @@ tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, vnet_buffer (b)->tcp.connection_index = tc->c_c_index; tc->snd_nxt += data_len; + /* TODO this is updated in output as well ... */ + if (tc->snd_nxt > tc->snd_una_max) + tc->snd_una_max = tc->snd_nxt; TCP_EVT_DBG (TCP_EVT_PKTIZE, tc); } -/* Send delayed ACK when timer expires */ void -tcp_timer_delack_handler (u32 index) +tcp_send_ack (tcp_connection_t * tc) { tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; - u32 thread_index = os_get_cpu_number (); - tcp_connection_t *tc; + vlib_main_t *vm = vlib_get_main (); + vlib_buffer_t *b; u32 bi; - tc = tcp_connection_get (index, thread_index); - /* Get buffer */ tcp_get_free_buffer_index (tm, &bi); b = vlib_get_buffer (vm, bi); @@ -907,12 +930,22 @@ tcp_timer_delack_handler (u32 index) /* Fill in the ACK */ tcp_make_ack (tc, b); - tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID; - tc->flags &= ~TCP_CONN_DELACK; - tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4); } +/* Send delayed ACK when timer expires */ +void +tcp_timer_delack_handler (u32 index) +{ + u32 thread_index = os_get_cpu_number (); + tcp_connection_t *tc; + + tc = tcp_connection_get (index, thread_index); + tc->timers[TCP_TIMER_DELACK] = TCP_TIMER_HANDLE_INVALID; +// tc->flags &= ~TCP_CONN_DELACK; + tcp_send_ack (tc); +} + /** Build a retransmit segment * * @return the number of bytes in the segment or 0 if there's nothing to @@ -920,59 +953,74 @@ tcp_timer_delack_handler (u32 index) * */ u32 tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b, - u32 max_bytes) + u32 offset, u32 max_bytes) { - tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; - u32 n_bytes, offset = 0; - sack_scoreboard_hole_t *hole; - u32 hole_size; + vlib_main_t *vm = vlib_get_main (); + u32 n_bytes = 0; tcp_reuse_buffer (vm, b); ASSERT (tc->state >= TCP_STATE_ESTABLISHED); ASSERT (max_bytes != 0); - if (tcp_opts_sack_permitted (&tc->opt)) - { - /* XXX get first hole not retransmitted yet */ - hole = scoreboard_first_hole (&tc->sack_sb); - if (!hole) - return 0; - - offset = hole->start - tc->snd_una; - hole_size = hole->end - hole->start; + max_bytes = clib_min (tc->snd_mss, max_bytes); - ASSERT (hole_size); + /* Start is beyond snd_congestion */ + if (seq_geq (tc->snd_una + offset, tc->snd_congestion)) + goto done; - if (hole_size < max_bytes) - max_bytes = hole_size; - } - else + /* Don't overshoot snd_congestion */ + if (seq_gt (tc->snd_nxt + max_bytes, tc->snd_congestion)) { - if (seq_geq (tc->snd_nxt, tc->snd_una_max)) - return 0; + max_bytes = tc->snd_congestion - tc->snd_nxt; + if (max_bytes == 0) + goto done; } + ASSERT (max_bytes <= tc->snd_mss); + n_bytes = stream_session_peek_bytes (&tc->connection, vlib_buffer_get_current (b), offset, max_bytes); ASSERT (n_bytes != 0); - + b->current_length = n_bytes; tcp_push_hdr_i (tc, b, tc->state); +done: + TCP_EVT_DBG (TCP_EVT_CC_RTX, tc, offset, n_bytes); return n_bytes; } +/** + * Reset congestion control, switch cwnd to loss window and try again. + */ +static void +tcp_rtx_timeout_cc_recover (tcp_connection_t * tc) +{ + /* Cleanly recover cc (also clears up fast retransmit) */ + if (tcp_in_fastrecovery (tc)) + { + tcp_cc_recover (tc); + } + else + { + tc->ssthresh = clib_max (tcp_flight_size (tc) / 2, 2 * tc->snd_mss); + } + + /* Start again from the beginning */ + tc->cwnd = tcp_loss_wnd (tc); + tc->snd_congestion = tc->snd_una_max; +} + static void tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) { tcp_main_t *tm = vnet_get_tcp_main (); - vlib_main_t *vm = tm->vlib_main; + vlib_main_t *vm = vlib_get_main (); u32 thread_index = os_get_cpu_number (); tcp_connection_t *tc; vlib_buffer_t *b; - u32 bi, max_bytes, snd_space; + u32 bi, snd_space, n_bytes; if (is_syn) { @@ -998,26 +1046,43 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) if (tc->state >= TCP_STATE_ESTABLISHED) { - tcp_fastrecovery_off (tc); + /* First retransmit timeout */ + if (tc->rto_boff == 1) + tcp_rtx_timeout_cc_recover (tc); /* Exponential backoff */ tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); /* Figure out what and how many bytes we can send */ snd_space = tcp_available_snd_space (tc); - max_bytes = clib_min (tc->snd_mss, snd_space); - if (max_bytes == 0) + TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 1); + + if (snd_space == 0) { clib_warning ("no wnd to retransmit"); + tcp_return_buffer (tm); + + /* Force one segment */ + tcp_retransmit_first_unacked (tc); + + /* Re-enable retransmit timer. Output may be unwilling + * to do it for us */ + tcp_retransmit_timer_set (tc); + return; } - tcp_prepare_retransmit_segment (tc, b, max_bytes); + else + { + /* No fancy recovery for now! */ + n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, snd_space); + scoreboard_clear (&tc->sack_sb); - tc->rtx_bytes += max_bytes; + if (n_bytes == 0) + return; - /* No fancy recovery for now! */ - scoreboard_clear (&tc->sack_sb); + tc->rtx_bytes += n_bytes; + } } else { @@ -1072,63 +1137,110 @@ tcp_timer_retransmit_syn_handler (u32 index) } /** - * Retansmit first unacked segment */ + * Retransmit first unacked segment + */ void tcp_retransmit_first_unacked (tcp_connection_t * tc) { tcp_main_t *tm = vnet_get_tcp_main (); - u32 snd_nxt = tc->snd_nxt; + vlib_main_t *vm = vlib_get_main (); vlib_buffer_t *b; - u32 bi; + u32 bi, n_bytes; tc->snd_nxt = tc->snd_una; /* Get buffer */ tcp_get_free_buffer_index (tm, &bi); - b = vlib_get_buffer (tm->vlib_main, bi); + b = vlib_get_buffer (vm, bi); + + TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 2); - tcp_prepare_retransmit_segment (tc, b, tc->snd_mss); - tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4); + n_bytes = tcp_prepare_retransmit_segment (tc, b, 0, tc->snd_mss); + if (n_bytes == 0) + return; - tc->snd_nxt = snd_nxt; - tc->rtx_bytes += tc->snd_mss; + tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4); + tc->rtx_bytes += n_bytes; +} + +sack_scoreboard_hole_t * +scoreboard_first_rtx_hole (sack_scoreboard_t * sb) +{ + sack_scoreboard_hole_t *hole = 0; + +// hole = scoreboard_first_hole (&tc->sack_sb); +// if (hole) +// { +// +// offset = hole->start - tc->snd_una; +// hole_size = hole->end - hole->start; +// +// ASSERT(hole_size); +// +// if (hole_size < max_bytes) +// max_bytes = hole_size; +// } + return hole; } +/** + * Do fast retransmit. + */ void tcp_fast_retransmit (tcp_connection_t * tc) { tcp_main_t *tm = vnet_get_tcp_main (); - u32 snd_space, max_bytes, n_bytes, bi; + vlib_main_t *vm = vlib_get_main (); + u32 bi; + int snd_space; + u32 n_written = 0, offset = 0; vlib_buffer_t *b; + u8 use_sacks = 0; ASSERT (tcp_in_fastrecovery (tc)); - clib_warning ("fast retransmit!"); - /* Start resending from first un-acked segment */ tc->snd_nxt = tc->snd_una; snd_space = tcp_available_snd_space (tc); + TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 0); + + /* If we have SACKs use them */ + if (tcp_opts_sack_permitted (&tc->opt) + && scoreboard_first_hole (&tc->sack_sb)) + use_sacks = 0; - while (snd_space) + while (snd_space > 0) { tcp_get_free_buffer_index (tm, &bi); - b = vlib_get_buffer (tm->vlib_main, bi); + b = vlib_get_buffer (vm, bi); + + if (use_sacks) + { + scoreboard_first_rtx_hole (&tc->sack_sb); + } + else + { + offset += n_written; + } - max_bytes = clib_min (tc->snd_mss, snd_space); - n_bytes = tcp_prepare_retransmit_segment (tc, b, max_bytes); + n_written = tcp_prepare_retransmit_segment (tc, b, offset, snd_space); /* Nothing left to retransmit */ - if (n_bytes == 0) - return; - - tcp_enqueue_to_output (tm->vlib_main, b, bi, tc->c_is_ip4); + if (n_written == 0) + { + tcp_return_buffer (tm); + break; + } - snd_space -= n_bytes; + tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4); + tc->rtx_bytes += n_written; + snd_space -= n_written; } - /* If window allows, send new data */ - tc->snd_nxt = tc->snd_una_max; + /* If window allows, send 1 SMSS of new data */ + if (seq_lt (tc->snd_nxt, tc->snd_congestion)) + tc->snd_nxt = tc->snd_congestion; } always_inline u32 @@ -1209,8 +1321,6 @@ tcp46_output_inline (vlib_main_t * vm, if (PREDICT_FALSE (vnet_buffer (b0)->tcp.flags & TCP_BUF_FLAG_DUPACK)) { - ASSERT (tc0->snt_dupacks > 0); - tc0->snt_dupacks--; if (!tcp_session_has_ooo_data (tc0)) { error0 = TCP_ERROR_FILTERED_DUPACKS; @@ -1223,8 +1333,7 @@ tcp46_output_inline (vlib_main_t * vm, tc0->rcv_las = tc0->rcv_nxt; /* Stop DELACK timer and fix flags */ - tc0->flags &= - ~(TCP_CONN_SNDACK | TCP_CONN_DELACK | TCP_CONN_BURSTACK); + tc0->flags &= ~(TCP_CONN_SNDACK); if (tcp_timer_is_active (tc0, TCP_TIMER_DELACK)) { tcp_timer_reset (tc0, TCP_TIMER_DELACK); |