From 4eeeaaf5e822718eb222e6c49abd82e1bcb566fd Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Tue, 5 Sep 2017 14:03:37 -0400 Subject: tcp: horizontal scaling improvments - do not scale syn-ack window - fix the max number of outstanding syns in builtin client - fix syn-sent ack validation to use modulo arithmetic - improve retransmit timer handler - fix output buffer allocator leakeage - improved debugging Change-Id: Iac3bc0eadf7d0b494a93e22d210a3153b61b3273 Signed-off-by: Florin Coras --- src/vnet/tcp/tcp_input.c | 204 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 146 insertions(+), 58 deletions(-) (limited to 'src/vnet/tcp/tcp_input.c') diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index 1d903453..841e72a5 100644 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -275,6 +275,7 @@ tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0, if (PREDICT_FALSE (tcp_options_parse (th0, &tc0->rcv_opts))) { + clib_warning ("options parse error"); return -1; } @@ -350,9 +351,12 @@ tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0, if (tcp_syn (th0)) { /* TODO implement RFC 5961 */ - tcp_make_ack (tc0, b0); + if (tc0->state != TCP_STATE_SYN_RCVD) + tcp_make_ack (tc0, b0); + else + tcp_make_synack (tc0, b0); *next0 = tcp_next_output (tc0->c_is_ip4); - TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0); + TCP_EVT_DBG (TCP_EVT_SYN_RCVD, tc0, 0); return -1; } @@ -1842,6 +1846,74 @@ VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established); vlib_node_registration_t tcp4_syn_sent_node; vlib_node_registration_t tcp6_syn_sent_node; +static u8 +tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr) +{ + transport_connection_t *tmp; + if (!tc) + return 1; + + u8 is_valid = (tc->c_lcl_port == hdr->dst_port + && (tc->state == TCP_STATE_LISTEN + || tc->c_rmt_port == hdr->src_port)); + + if (!is_valid) + { + if ((tmp = + stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip, + tc->c_lcl_port, tc->c_rmt_port, + tc->c_transport_proto))) + { + if (tmp->lcl_port == hdr->dst_port + && tmp->rmt_port == hdr->src_port) + { + clib_warning ("half-open is valid!"); + } + } + } + return is_valid; +} + +/** + * Lookup transport connection + */ +static tcp_connection_t * +tcp_lookup_connection (vlib_buffer_t * b, u8 thread_index, u8 is_ip4) +{ + tcp_header_t *tcp; + transport_connection_t *tconn; + tcp_connection_t *tc; + if (is_ip4) + { + ip4_header_t *ip4; + ip4 = vlib_buffer_get_current (b); + tcp = ip4_next_header (ip4); + tconn = stream_session_lookup_transport_wt4 (&ip4->dst_address, + &ip4->src_address, + tcp->dst_port, + tcp->src_port, + SESSION_TYPE_IP4_TCP, + thread_index); + tc = tcp_get_connection_from_transport (tconn); + ASSERT (tcp_lookup_is_valid (tc, tcp)); + } + else + { + ip6_header_t *ip6; + ip6 = vlib_buffer_get_current (b); + tcp = ip6_next_header (ip6); + tconn = stream_session_lookup_transport_wt6 (&ip6->dst_address, + &ip6->src_address, + tcp->dst_port, + tcp->src_port, + SESSION_TYPE_IP6_TCP, + thread_index); + tc = tcp_get_connection_from_transport (tconn); + ASSERT (tcp_lookup_is_valid (tc, tcp)); + } + return tc; +} + always_inline uword tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, int is_ip4) @@ -1888,6 +1960,15 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, goto drop; } + /* Half-open completed recently but the connection was't removed + * yet by the owning thread */ + if (PREDICT_FALSE (tc0->flags & TCP_CONN_HALF_OPEN_DONE)) + { + /* Make sure the connection actually exists */ + ASSERT (tcp_lookup_connection (b0, my_thread_index, is_ip4)); + goto drop; + } + ack0 = vnet_buffer (b0)->tcp.ack_number; seq0 = vnet_buffer (b0)->tcp.seq_number; tcp0 = tcp_buffer_hdr (b0); @@ -1914,16 +1995,20 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, */ if (tcp_ack (tcp0)) { - if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt) + if (seq_leq (ack0, tc0->iss) || seq_gt (ack0, tc0->snd_nxt)) { + clib_warning ("ack not in rcv wnd"); if (!tcp_rst (tcp0)) tcp_send_reset_w_pkt (tc0, b0, is_ip4); goto drop; } /* Make sure ACK is valid */ - if (tc0->snd_una > ack0) - goto drop; + if (seq_gt (tc0->snd_una, ack0)) + { + clib_warning ("ack invalid"); + goto drop; + } } /* @@ -1949,11 +2034,17 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* No SYN flag. Drop. */ if (!tcp_syn (tcp0)) - goto drop; + { + clib_warning ("not synack"); + goto drop; + } /* Parse options */ if (tcp_options_parse (tcp0, &tc0->rcv_opts)) - goto drop; + { + clib_warning ("options parse fail"); + goto drop; + } /* Valid SYN or SYN-ACK. Move connection from half-open pool to * current thread pool. */ @@ -1981,8 +2072,8 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, if (tcp_opts_wscale (&new_tc0->rcv_opts)) new_tc0->snd_wscale = new_tc0->rcv_opts.wscale; - new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window) - << new_tc0->snd_wscale; + /* RFC1323: SYN and SYN-ACK wnd not scaled */ + new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window); new_tc0->snd_wl1 = seq0; new_tc0->snd_wl2 = ack0; @@ -2004,6 +2095,7 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, * allocate session send reset */ if (stream_session_connect_notify (&new_tc0->connection, 0)) { + clib_warning ("connect notify fail"); tcp_send_reset_w_pkt (new_tc0, b0, is_ip4); tcp_connection_cleanup (new_tc0); goto drop; @@ -2032,6 +2124,7 @@ tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, } tc0->rtt_ts = 0; + tcp_init_snd_vars (tc0); tcp_make_synack (new_tc0, b0); next0 = tcp_next_output (is_ip4); @@ -2196,6 +2289,18 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) + vnet_buffer (b0)->tcp.data_len; + if (CLIB_DEBUG) + { + tcp_connection_t *tmp; + tmp = tcp_lookup_connection (b0, my_thread_index, is_ip4); + if (tmp->state != tc0->state) + { + clib_warning ("state changed"); + ASSERT (0); + goto drop; + } + } + /* * Special treatment for CLOSED */ @@ -2211,8 +2316,8 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, */ /* 1-4: check SEQ, RST, SYN */ - if (PREDICT_FALSE - (tcp_segment_validate (vm, tc0, b0, tcp0, &next0))) + if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, tcp0, + &next0))) { error0 = TCP_ERROR_SEGMENT_INVALID; goto drop; @@ -2230,6 +2335,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, */ if (!tcp_rcv_ack_is_acceptable (tc0, b0)) { + clib_warning ("connection not accepted"); tcp_send_reset_w_pkt (tc0, b0, is_ip4); goto drop; } @@ -2252,6 +2358,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* Reset SYN-ACK retransmit and SYN_RCV establish timers */ tcp_retransmit_timer_reset (tc0); tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH); + TCP_EVT_DBG (TCP_EVT_STATE_CHANGE, tc0); break; case TCP_STATE_ESTABLISHED: /* We can get packets in established state here because they @@ -2400,6 +2507,7 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* Send FIN-ACK notify app and enter CLOSE-WAIT */ tcp_connection_timers_reset (tc0); tcp_make_fin (tc0, b0); + tc0->snd_nxt += 1; next0 = tcp_next_output (tc0->c_is_ip4); stream_session_disconnect_notify (&tc0->connection); tc0->state = TCP_STATE_CLOSE_WAIT; @@ -2598,6 +2706,14 @@ tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node, /* 3. check for a SYN (did that already) */ + /* Make sure connection wasn't just created */ + child0 = tcp_lookup_connection (b0, my_thread_index, is_ip4); + if (PREDICT_FALSE (child0->state != TCP_STATE_LISTEN)) + { + error0 = TCP_ERROR_CREATE_EXISTS; + goto drop; + } + /* Create child session and send SYN-ACK */ child0 = tcp_connection_new (my_thread_index); child0->c_lcl_port = lc0->c_lcl_port; @@ -2621,12 +2737,15 @@ tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node, if (stream_session_accept (&child0->connection, lc0->c_s_index, sst, 0 /* notify */ )) { + clib_warning ("session accept fail"); + tcp_connection_cleanup (child0); error0 = TCP_ERROR_CREATE_SESSION_FAIL; goto drop; } if (tcp_options_parse (th0, &child0->rcv_opts)) { + clib_warning ("options parse fail"); goto drop; } @@ -2651,7 +2770,7 @@ tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node, child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number; tcp_connection_init_vars (child0); - TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0); + TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0, 1); /* Reuse buffer to make syn-ack and send */ tcp_make_synack (child0, b0); @@ -2768,34 +2887,6 @@ typedef enum _tcp_input_next #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN) -static u8 -tcp_lookup_is_valid (tcp_connection_t * tc, tcp_header_t * hdr) -{ - transport_connection_t *tmp; - if (!tc) - return 1; - - u8 is_valid = (tc->c_lcl_port == hdr->dst_port - && (tc->state == TCP_STATE_LISTEN - || tc->c_rmt_port == hdr->src_port)); - - if (!is_valid) - { - if ((tmp = - stream_session_half_open_lookup (&tc->c_lcl_ip, &tc->c_rmt_ip, - tc->c_lcl_port, tc->c_rmt_port, - tc->c_transport_proto))) - { - if (tmp->lcl_port == hdr->dst_port - && tmp->rmt_port == hdr->src_port) - { - clib_warning ("half-open is valid!"); - } - } - } - return is_valid; -} - always_inline uword tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, int is_ip4) @@ -2822,6 +2913,7 @@ tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t *b0; tcp_header_t *tcp0 = 0; tcp_connection_t *tc0; + transport_connection_t *tconn; ip4_header_t *ip40; ip6_header_t *ip60; u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP; @@ -2847,15 +2939,13 @@ tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, + tcp_header_bytes (tcp0)); n_data_bytes0 = clib_net_to_host_u16 (ip40->length) - n_advance_bytes0; - - tc0 = - (tcp_connection_t *) - stream_session_lookup_transport_wt4 (&ip40->dst_address, - &ip40->src_address, - tcp0->dst_port, - tcp0->src_port, - SESSION_TYPE_IP4_TCP, - my_thread_index); + tconn = stream_session_lookup_transport_wt4 (&ip40->dst_address, + &ip40->src_address, + tcp0->dst_port, + tcp0->src_port, + SESSION_TYPE_IP4_TCP, + my_thread_index); + tc0 = tcp_get_connection_from_transport (tconn); ASSERT (tcp_lookup_is_valid (tc0, tcp0)); } else @@ -2866,15 +2956,13 @@ tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length) - n_advance_bytes0; n_advance_bytes0 += sizeof (ip60[0]); - - tc0 = - (tcp_connection_t *) - stream_session_lookup_transport_wt6 (&ip60->dst_address, - &ip60->src_address, - tcp0->dst_port, - tcp0->src_port, - SESSION_TYPE_IP6_TCP, - my_thread_index); + tconn = stream_session_lookup_transport_wt6 (&ip60->dst_address, + &ip60->src_address, + tcp0->dst_port, + tcp0->src_port, + SESSION_TYPE_IP6_TCP, + my_thread_index); + tc0 = tcp_get_connection_from_transport (tconn); ASSERT (tcp_lookup_is_valid (tc0, tcp0)); } -- cgit 1.2.3-korg