From 360336fa56ae913ceb17a8e0b010e96bed78cfc3 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Thu, 13 Feb 2020 18:46:18 +0000 Subject: [PATCH] tcp: improve reset generation in reset node Type: improvement Signed-off-by: Florin Coras Change-Id: I7a4a4a52c3e4ad47aabb2ef5f53a0e0bb7e71690 --- src/vnet/tcp/tcp_input.c | 6 +--- src/vnet/tcp/tcp_output.c | 92 +++++++++++++++++++++-------------------------- 2 files changed, 41 insertions(+), 57 deletions(-) diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index f907750bccc..14f427cf1e8 100755 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -3705,14 +3705,10 @@ tcp_input_dispatch_buffer (tcp_main_t * tm, tcp_connection_t * tc, if (PREDICT_FALSE (error != TCP_ERROR_NONE)) { - /* Overload tcp flags to store state */ - tcp_state_t state = tc->state; - vnet_buffer (b)->tcp.flags = tc->state; - b->error = error_node->errors[error]; if (error == TCP_ERROR_DISPATCH) clib_warning ("tcp conn %u disp error state %U flags %U", - tc->c_c_index, format_tcp_state, state, + tc->c_c_index, format_tcp_state, tc->state, format_tcp_flags, (int) flags); } } diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c index 1b9530b4e1a..69b34cc595f 100644 --- a/src/vnet/tcp/tcp_output.c +++ b/src/vnet/tcp/tcp_output.c @@ -690,78 +690,76 @@ tcp_enqueue_to_output (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi, #endif /* CLIB_MARCH_VARIANT */ static int -tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b0, - tcp_state_t state, u8 thread_index, u8 is_ip4) +tcp_make_reset_in_place (vlib_main_t * vm, vlib_buffer_t * b, u8 is_ip4) { ip4_header_t *ih4; ip6_header_t *ih6; - tcp_header_t *th0; - ip4_address_t src_ip40, dst_ip40; - ip6_address_t src_ip60, dst_ip60; + tcp_header_t *th; + ip4_address_t src_ip4, dst_ip4; + ip6_address_t src_ip6, dst_ip6; u16 src_port, dst_port; - u32 tmp; - u32 seq, ack; + u32 tmp, len, seq, ack; u8 flags; /* Find IP and TCP headers */ - th0 = tcp_buffer_hdr (b0); + th = tcp_buffer_hdr (b); /* Save src and dst ip */ if (is_ip4) { - ih4 = vlib_buffer_get_current (b0); + ih4 = vlib_buffer_get_current (b); ASSERT ((ih4->ip_version_and_header_length & 0xF0) == 0x40); - src_ip40.as_u32 = ih4->src_address.as_u32; - dst_ip40.as_u32 = ih4->dst_address.as_u32; + src_ip4.as_u32 = ih4->src_address.as_u32; + dst_ip4.as_u32 = ih4->dst_address.as_u32; } else { - ih6 = vlib_buffer_get_current (b0); + ih6 = vlib_buffer_get_current (b); ASSERT ((ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60); - clib_memcpy_fast (&src_ip60, &ih6->src_address, sizeof (ip6_address_t)); - clib_memcpy_fast (&dst_ip60, &ih6->dst_address, sizeof (ip6_address_t)); + clib_memcpy_fast (&src_ip6, &ih6->src_address, sizeof (ip6_address_t)); + clib_memcpy_fast (&dst_ip6, &ih6->dst_address, sizeof (ip6_address_t)); } - src_port = th0->src_port; - dst_port = th0->dst_port; + src_port = th->src_port; + dst_port = th->dst_port; + flags = TCP_FLAG_RST; - /* Try to determine what/why we're actually resetting */ - if (state == TCP_STATE_CLOSED) + /* + * RFC 793. If the ACK bit is off, sequence number zero is used, + * + * If the ACK bit is on, + * + */ + if (tcp_ack (th)) { - if (!tcp_syn (th0)) - return -1; - - tmp = clib_net_to_host_u32 (th0->seq_number); - - /* Got a SYN for no listener. */ - flags = TCP_FLAG_RST | TCP_FLAG_ACK; - ack = clib_host_to_net_u32 (tmp + 1); - seq = 0; + seq = th->ack_number; + ack = 0; } else { - flags = TCP_FLAG_RST; - seq = th0->ack_number; - ack = 0; + flags |= TCP_FLAG_ACK; + tmp = clib_net_to_host_u32 (th->seq_number); + len = vnet_buffer (b)->tcp.data_len + tcp_is_syn (th) + tcp_is_fin (th); + ack = clib_host_to_net_u32 (tmp + len); + seq = 0; } - tcp_reuse_buffer (vm, b0); - tcp_trajectory_add_start (b0, 4); - th0 = vlib_buffer_push_tcp_net_order (b0, dst_port, src_port, seq, ack, - sizeof (tcp_header_t), flags, 0); + tcp_reuse_buffer (vm, b); + tcp_trajectory_add_start (b, 4); + th = vlib_buffer_push_tcp_net_order (b, dst_port, src_port, seq, ack, + sizeof (tcp_header_t), flags, 0); if (is_ip4) { - ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40, + ih4 = vlib_buffer_push_ip4 (vm, b, &dst_ip4, &src_ip4, IP_PROTOCOL_TCP, 1); - th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ih4); + th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4); } else { int bogus = ~0; - ih6 = vlib_buffer_push_ip6 (vm, b0, &dst_ip60, &src_ip60, - IP_PROTOCOL_TCP); - th0->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b0, ih6, &bogus); + ih6 = vlib_buffer_push_ip6 (vm, b, &dst_ip6, &src_ip6, IP_PROTOCOL_TCP); + th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus); ASSERT (!bogus); } @@ -2515,8 +2513,8 @@ static uword tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, u8 is_ip4) { + u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP; u32 n_left_from, next_index, *from, *to_next; - u32 my_thread_index = vm->thread_index; from = vlib_frame_vector_args (from_frame); n_left_from = from_frame->n_vectors; @@ -2531,11 +2529,10 @@ tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node, while (n_left_from > 0 && n_left_to_next > 0) { - u32 bi0; vlib_buffer_t *b0; tcp_tx_trace_t *t0; tcp_header_t *th0; - u32 error0 = TCP_ERROR_RST_SENT, next0 = TCP_RESET_NEXT_IP_LOOKUP; + u32 bi0; bi0 = from[0]; to_next[0] = bi0; @@ -2545,20 +2542,11 @@ tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node, n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); - - if (tcp_make_reset_in_place (vm, b0, vnet_buffer (b0)->tcp.flags, - my_thread_index, is_ip4)) - { - error0 = TCP_ERROR_LOOKUP_DROPS; - next0 = TCP_RESET_NEXT_DROP; - goto done; - } + tcp_make_reset_in_place (vm, b0, is_ip4); /* Prepare to send to IP lookup */ vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0; - next0 = TCP_RESET_NEXT_IP_LOOKUP; - done: b0->error = node->errors[error0]; b0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) -- 2.16.6