diff options
| -rw-r--r-- | src/vnet/session/node.c | 2 | ||||
| -rw-r--r-- | src/vnet/tcp/tcp.c | 17 | ||||
| -rw-r--r-- | src/vnet/tcp/tcp.h | 10 | ||||
| -rw-r--r-- | src/vnet/tcp/tcp_input.c | 6 | ||||
| -rw-r--r-- | src/vnet/tcp/tcp_output.c | 104 |
5 files changed, 97 insertions, 42 deletions
diff --git a/src/vnet/session/node.c b/src/vnet/session/node.c index 210754fa723..2d12ee2bac9 100644 --- a/src/vnet/session/node.c +++ b/src/vnet/session/node.c @@ -95,8 +95,8 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node, tc0 = transport_vft->get_connection (s0->connection_index, thread_index); /* Make sure we have space to send and there's something to dequeue */ - snd_space0 = transport_vft->send_space (tc0); snd_mss0 = transport_vft->send_mss (tc0); + snd_space0 = transport_vft->send_space (tc0); /* Can't make any progress */ if (snd_space0 == 0 || snd_mss0 == 0) diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c index e80e2ec9b7c..224ee0dd160 100644 --- a/src/vnet/tcp/tcp.c +++ b/src/vnet/tcp/tcp.c @@ -331,7 +331,7 @@ void tcp_connection_init_vars (tcp_connection_t * tc) { tcp_connection_timers_init (tc); - tcp_set_snd_mss (tc); + tcp_init_mss (tc); scoreboard_init (&tc->sack_sb); tcp_cc_init (tc); } @@ -560,10 +560,23 @@ tcp_half_open_session_get_transport (u32 conn_index) return &tc->connection; } +/** + * Compute maximum segment size for session layer. + * + * Since the result needs to be the actual data length, it first computes + * the tcp options to be used in the next burst and subtracts their + * length from the connection's snd_mss. + */ u16 tcp_session_send_mss (transport_connection_t * trans_conn) { tcp_connection_t *tc = (tcp_connection_t *) trans_conn; + + /* Ensure snd_mss does accurately reflect the amount of data we can push + * in a segment. This also makes sure that options are updated according to + * the current state of the connection. */ + tcp_update_snd_mss (tc); + return tc->snd_mss; } @@ -607,7 +620,7 @@ tcp_session_send_space (transport_connection_t * trans_conn) tc->snd_nxt = tc->snd_una_max; snd_space = tcp_available_wnd (tc) - tc->rtx_bytes - (tc->snd_una_max - tc->snd_congestion); - if (snd_space <= 0) + if (snd_space <= 0 || (tc->snd_una_max - tc->snd_una) >= tc->snd_wnd) return 0; return tcp_round_snd_space (tc, snd_space); } diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h index c75479dce5c..8212ada785e 100644 --- a/src/vnet/tcp/tcp.h +++ b/src/vnet/tcp/tcp.h @@ -211,7 +211,9 @@ typedef struct _tcp_connection u32 irs; /**< initial remote sequence */ /* Options */ - tcp_options_t opt; /**< TCP connection options parsed */ + tcp_options_t opt; /**< TCP connection options parsed */ + tcp_options_t snd_opts; /**< Tx options for connection */ + u8 snd_opts_len; /**< Tx options len */ u8 rcv_wscale; /**< Window scale to advertise to peer */ u8 snd_wscale; /**< Window scale to use when sending */ u32 tsval_recent; /**< Last timestamp received */ @@ -241,7 +243,8 @@ typedef struct _tcp_connection u32 rtt_ts; /**< Timestamp for tracked ACK */ u32 rtt_seq; /**< Sequence number for tracked ACK */ - u16 snd_mss; /**< Send MSS */ + u16 snd_mss; /**< Effective send max seg (data) size */ + u16 mss; /**< Our max seg size that includes options */ } tcp_connection_t; struct _tcp_cc_algorithm @@ -405,7 +408,8 @@ void tcp_make_synack (tcp_connection_t * ts, vlib_buffer_t * b); void tcp_send_reset (vlib_buffer_t * pkt, u8 is_ip4); void tcp_send_syn (tcp_connection_t * tc); void tcp_send_fin (tcp_connection_t * tc); -void tcp_set_snd_mss (tcp_connection_t * tc); +void tcp_init_mss (tcp_connection_t * tc); +void tcp_update_snd_mss (tcp_connection_t * tc); always_inline u32 tcp_end_seq (tcp_header_t * th, u32 len) diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index e9c52c5e27f..d268251cb38 100644 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -389,10 +389,14 @@ static int tcp_update_rtt (tcp_connection_t * tc, u32 ack) { u32 mrtt = 0; + u8 rtx_acked; + + /* Determine if only rtx bytes are acked. TODO fast retransmit */ + rtx_acked = tc->rto_boff && (tc->bytes_acked <= tc->snd_mss); /* Karn's rule, part 1. Don't use retransmitted segments to estimate * RTT because they're ambiguous. */ - if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !tc->rto_boff) + if (tc->rtt_ts && seq_geq (ack, tc->rtt_seq) && !rtx_acked) { mrtt = tcp_time_now () - tc->rtt_ts; } diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c index 7ee930c61af..2a1b140750c 100644 --- a/src/vnet/tcp/tcp_output.c +++ b/src/vnet/tcp/tcp_output.c @@ -64,26 +64,6 @@ format_tcp_tx_trace (u8 * s, va_list * args) return s; } -void -tcp_set_snd_mss (tcp_connection_t * tc) -{ - u16 snd_mss; - - /* TODO find our iface MTU */ - snd_mss = dummy_mtu; - - /* TODO cache mss and consider PMTU discovery */ - snd_mss = clib_min (tc->opt.mss, snd_mss); - - tc->snd_mss = snd_mss; - - if (tc->snd_mss == 0) - { - clib_warning ("snd mss is 0"); - tc->snd_mss = dummy_mtu; - } -} - static u8 tcp_window_compute_scale (u32 available_space) { @@ -100,7 +80,7 @@ tcp_window_compute_scale (u32 available_space) always_inline u32 tcp_initial_wnd_unscaled (tcp_connection_t * tc) { - return TCP_IW_N_SEGMENTS * dummy_mtu; + return TCP_IW_N_SEGMENTS * tc->mss; } /** @@ -310,7 +290,7 @@ tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts) u8 len = 0; opts->flags |= TCP_OPTS_FLAG_MSS; - opts->mss = dummy_mtu; /*XXX discover that */ + opts->mss = tc->mss; len += TCP_OPTION_LEN_MSS; if (tcp_opts_wscale (&tc->opt)) @@ -389,6 +369,57 @@ tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts, } } +/** + * Update max segment size we're able to process. + * + * The value is constrained by our interface's MTU and IP options. It is + * also what we advertise to our peer. + */ +void +tcp_update_rcv_mss (tcp_connection_t * tc) +{ + /* TODO find our iface MTU */ + tc->mss = dummy_mtu; +} + +/** + * Update snd_mss to reflect the effective segment size that we can send + * by taking into account all TCP options, including SACKs + */ +void +tcp_update_snd_mss (tcp_connection_t * tc) +{ + /* Compute options to be used for connection. These may be reused when + * sending data or to compute the effective mss (snd_mss) */ + tc->snd_opts_len = + tcp_make_options (tc, &tc->snd_opts, TCP_STATE_ESTABLISHED); + + /* XXX check if MTU has been updated */ + tc->snd_mss = clib_min (tc->mss, tc->opt.mss) - tc->snd_opts_len; +} + +void +tcp_init_mss (tcp_connection_t * tc) +{ + tcp_update_rcv_mss (tc); + + /* TODO cache mss and consider PMTU discovery */ + tc->snd_mss = clib_min (tc->opt.mss, tc->mss); + + if (tc->snd_mss == 0) + { + clib_warning ("snd mss is 0"); + tc->snd_mss = tc->mss; + } + + /* We should have enough space for 40 bytes of options */ + ASSERT (tc->snd_mss > 45); + + /* If we use timestamp option, account for it */ + if (tcp_opts_tstamp (&tc->opt)) + tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP; +} + #define tcp_get_free_buffer_index(tm, bidx) \ do { \ u32 *my_tx_buffers, n_free_buffers; \ @@ -886,20 +917,20 @@ tcp_make_state_flags (tcp_state_t next_state) */ static void tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, - tcp_state_t next_state) + tcp_state_t next_state, u8 compute_opts) { u32 advertise_wnd, data_len; - u8 tcp_opts_len, tcp_hdr_opts_len, opts_write_len, flags; - tcp_options_t _snd_opts, *snd_opts = &_snd_opts; + u8 tcp_hdr_opts_len, opts_write_len, flags; tcp_header_t *th; data_len = b->current_length; vnet_buffer (b)->tcp.flags = 0; - /* Make and write options */ - memset (snd_opts, 0, sizeof (*snd_opts)); - tcp_opts_len = tcp_make_options (tc, snd_opts, next_state); - tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t); + if (compute_opts) + tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); + + /* Write pre-computed options */ + tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t); /* Get rcv window to advertise */ advertise_wnd = tcp_window_to_advertise (tc, next_state); @@ -910,9 +941,9 @@ tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, tc->rcv_nxt, tcp_hdr_opts_len, flags, advertise_wnd); - opts_write_len = tcp_options_write ((u8 *) (th + 1), snd_opts); + opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts); - ASSERT (opts_write_len == tcp_opts_len); + ASSERT (opts_write_len == tc->snd_opts_len); /* Tag the buffer with the connection index */ vnet_buffer (b)->tcp.connection_index = tc->c_c_index; @@ -993,6 +1024,8 @@ tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b, goto done; } + tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); + ASSERT (max_bytes <= tc->snd_mss); n_bytes = stream_session_peek_bytes (&tc->connection, @@ -1000,7 +1033,7 @@ tcp_prepare_retransmit_segment (tcp_connection_t * tc, vlib_buffer_t * b, max_bytes); ASSERT (n_bytes != 0); b->current_length = n_bytes; - tcp_push_hdr_i (tc, b, tc->state); + tcp_push_hdr_i (tc, b, tc->state, 0); tc->rtx_bytes += n_bytes; done: @@ -1097,7 +1130,7 @@ tcp_timer_retransmit_handler_i (u32 index, u8 is_syn) vlib_buffer_make_headroom (b, MAX_HDRS_LEN); - tcp_push_hdr_i (tc, b, tc->state); + tcp_push_hdr_i (tc, b, tc->state, 1); /* Account for the SYN */ tc->snd_nxt += 1; @@ -1168,6 +1201,7 @@ tcp_timer_persist_handler (u32 index) /* Try to force the first unsent segment */ tcp_get_free_buffer_index (tm, &bi); b = vlib_get_buffer (vm, bi); + tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); n_bytes = stream_session_peek_bytes (&tc->connection, vlib_buffer_get_current (b), tc->snd_una_max - tc->snd_una, @@ -1180,7 +1214,7 @@ tcp_timer_persist_handler (u32 index) } b->current_length = n_bytes; - tcp_push_hdr_i (tc, b, tc->state); + tcp_push_hdr_i (tc, b, tc->state, 0); tcp_enqueue_to_output (vm, b, bi, tc->c_is_ip4); /* Re-enable persist timer */ @@ -1507,7 +1541,7 @@ tcp_push_header (transport_connection_t * tconn, vlib_buffer_t * b) tcp_connection_t *tc; tc = (tcp_connection_t *) tconn; - tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED); + tcp_push_hdr_i (tc, b, TCP_STATE_ESTABLISHED, 0); return 0; } |