/* * Copyright (c) 2016-2019 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include typedef enum _tcp_output_next { TCP_OUTPUT_NEXT_DROP, TCP_OUTPUT_NEXT_IP_LOOKUP, TCP_OUTPUT_NEXT_IP_REWRITE, TCP_OUTPUT_NEXT_IP_ARP, TCP_OUTPUT_N_NEXT } tcp_output_next_t; #define foreach_tcp4_output_next \ _ (DROP, "error-drop") \ _ (IP_LOOKUP, "ip4-lookup") \ _ (IP_REWRITE, "ip4-rewrite") \ _ (IP_ARP, "ip4-arp") #define foreach_tcp6_output_next \ _ (DROP, "error-drop") \ _ (IP_LOOKUP, "ip6-lookup") \ _ (IP_REWRITE, "ip6-rewrite") \ _ (IP_ARP, "ip6-discover-neighbor") static char *tcp_error_strings[] = { #define tcp_error(n,s) s, #include #undef tcp_error }; typedef struct { tcp_header_t tcp_header; tcp_connection_t tcp_connection; } tcp_tx_trace_t; static u8 * format_tcp_tx_trace (u8 * s, va_list * args) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); tcp_tx_trace_t *t = va_arg (*args, tcp_tx_trace_t *); tcp_connection_t *tc = &t->tcp_connection; u32 indent = format_get_indent (s); s = format (s, "%U state %U\n%U%U", format_tcp_connection_id, tc, format_tcp_state, tc->state, format_white_space, indent, format_tcp_header, &t->tcp_header, 128); return s; } #ifndef CLIB_MARCH_VARIANT static u8 tcp_window_compute_scale (u32 window) { u8 wnd_scale = 0; while (wnd_scale < TCP_MAX_WND_SCALE && (window >> wnd_scale) > TCP_WND_MAX) wnd_scale++; return wnd_scale; } /** * TCP's initial window */ always_inline u32 tcp_initial_wnd_unscaled (tcp_connection_t * tc) { /* RFC 6928 recommends the value lower. However at the time our connections * are initialized, fifos may not be allocated. Therefore, advertise the * smallest possible unscaled window size and update once fifos are * assigned to the session. */ /* tcp_update_rcv_mss (tc); TCP_IW_N_SEGMENTS * tc->mss; */ return tcp_cfg.min_rx_fifo; } /** * Compute initial window and scale factor. As per RFC1323, window field in * SYN and SYN-ACK segments is never scaled. */ u32 tcp_initial_window_to_advertise (tcp_connection_t * tc) { /* Compute rcv wscale only if peer advertised support for it */ if (tc->state != TCP_STATE_SYN_RCVD || tcp_opts_wscale (&tc->rcv_opts)) tc->rcv_wscale = tcp_window_compute_scale (tcp_cfg.max_rx_fifo); tc->rcv_wnd = tcp_initial_wnd_unscaled (tc); return clib_min (tc->rcv_wnd, TCP_WND_MAX); } static inline void tcp_update_rcv_wnd (tcp_connection_t * tc) { u32 available_space, wnd; i32 observed_wnd; ASSERT (tc->rcv_opts.mss < transport_rx_fifo_size (&tc->connection)); /* * Figure out how much space we have available */ available_space = transport_max_rx_enqueue (&tc->connection); if (PREDICT_FALSE (available_space < tc->rcv_opts.mss)) { tc->rcv_wnd = 0; return; } /* * Use the above and what we know about what we've previously advertised * to compute the new window */ observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las); /* Bad. Thou shalt not shrink */ if (PREDICT_FALSE ((i32) available_space < observed_wnd)) { wnd = clib_max (observed_wnd, 0); TCP_EVT (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space); } else { wnd = available_space; } /* Make sure we have a multiple of rcv_wscale */ if (wnd && tc->rcv_wscale) { wnd &= ~((1 << tc->rcv_wscale) - 1); if (wnd == 0) wnd = 1 << tc->rcv_wscale; } tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale); } /** * Compute and return window to advertise, scaled as per RFC1323 */ static inline u32 tcp_window_to_advertise (tcp_connection_t * tc, tcp_state_t state) { if (state < TCP_STATE_ESTABLISHED) return tcp_initial_window_to_advertise (tc); tcp_update_rcv_wnd (tc); return tc->rcv_wnd >> tc->rcv_wscale; } /** * Write TCP options to segment. */ static u32 tcp_options_write (u8 * data, tcp_options_t * opts) { u32 opts_len = 0; u32 buf, seq_len = 4; if (tcp_opts_mss (opts)) { *data++ = TCP_OPTION_MSS; *data++ = TCP_OPTION_LEN_MSS; buf = clib_host_to_net_u16 (opts->mss); clib_memcpy_fast (data, &buf, sizeof (opts->mss)); data += sizeof (opts->mss); opts_len += TCP_OPTION_LEN_MSS; } if (tcp_opts_wscale (opts)) { *data++ = TCP_OPTION_WINDOW_SCALE; *data++ = TCP_OPTION_LEN_WINDOW_SCALE; *data++ = opts->wscale; opts_len += TCP_OPTION_LEN_WINDOW_SCALE; } if (tcp_opts_sack_permitted (opts)) { *data++ = TCP_OPTION_SACK_PERMITTED; *data++ = TCP_OPTION_LEN_SACK_PERMITTED; opts_len += TCP_OPTION_LEN_SACK_PERMITTED; } if (tcp_opts_tstamp (opts)) { *data++ = TCP_OPTION_TIMESTAMP; *data++ = TCP_OPTION_LEN_TIMESTAMP; buf = clib_host_to_net_u32 (opts->tsval); clib_memcpy_fast (data, &buf, sizeof (opts->tsval)); data += sizeof (opts->tsval); buf = clib_host_to_net_u32 (opts->tsecr); clib_memcpy_fast (data, &buf, sizeof (opts->tsecr)); data += sizeof (opts->tsecr); opts_len += TCP_OPTION_LEN_TIMESTAMP; } if (tcp_opts_sack (opts)) { int i; if (opts->n_sack_blocks != 0) { *data++ = TCP_OPTION_SACK_BLOCK; *data++ = 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK; for (i = 0; i < opts->n_sack_blocks; i++) { buf = clib_host_to_net_u32 (opts->sacks[i].start); clib_memcpy_fast (data, &buf, seq_len); data += seq_len; buf = clib_host_to_net_u32 (opts->sacks[i].end); clib_memcpy_fast (data, &buf, seq_len); data += seq_len; } opts_len += 2 + opts->n_sack_blocks * TCP_OPTION_LEN_SACK_BLOCK; } } /* Terminate TCP options */ if (opts_len % 4) { *data++ = TCP_OPTION_EOL; opts_len += TCP_OPTION_LEN_EOL; } /* Pad with zeroes to a u32 boundary */ while (opts_len % 4) { *data++ = TCP_OPTION_NOOP; opts_len += TCP_OPTION_LEN_NOOP; } return opts_len; } static int tcp_make_syn_options (tcp_connection_t * tc, tcp_options_t * opts) { u8 len = 0; opts->flags |= TCP_OPTS_FLAG_MSS; opts->mss = tc->mss; len += TCP_OPTION_LEN_MSS; opts->flags |= TCP_OPTS_FLAG_WSCALE; opts->wscale = tc->rcv_wscale; len += TCP_OPTION_LEN_WINDOW_SCALE; opts->flags |= TCP_OPTS_FLAG_TSTAMP; opts->tsval = tcp_time_now (); opts->tsecr = 0; len += TCP_OPTION_LEN_TIMESTAMP; if (TCP_USE_SACKS) { opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED; len += TCP_OPTION_LEN_SACK_PERMITTED; } /* Align to needed boundary */ len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN; return len; } static int tcp_make_synack_options (tcp_connection_t * tc, tcp_options_t * opts) { u8 len = 0; opts->flags |= TCP_OPTS_FLAG_MSS; opts->mss = tc->mss; len += TCP_OPTION_LEN_MSS; if (tcp_opts_wscale (&tc->rcv_opts)) { opts->flags |= TCP_OPTS_FLAG_WSCALE; opts->wscale = tc->rcv_wscale; len += TCP_OPTION_LEN_WINDOW_SCALE; } if (tcp_opts_tstamp (&tc->rcv_opts)) { opts->flags |= TCP_OPTS_FLAG_TSTAMP; opts->tsval = tcp_time_now (); opts->tsecr = tc->tsval_recent; len += TCP_OPTION_LEN_TIMESTAMP; } if (tcp_opts_sack_permitted (&tc->rcv_opts)) { opts->flags |= TCP_OPTS_FLAG_SACK_PERMITTED; len += TCP_OPTION_LEN_SACK_PERMITTED; } /* Align to needed boundary */ len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN; return len; } static int tcp_make_established_options (tcp_connection_t * tc, tcp_options_t * opts) { u8 len = 0; opts->flags = 0; if (tcp_opts_tstamp (&tc->rcv_opts)) { opts->flags |= TCP_OPTS_FLAG_TSTAMP; opts->tsval = tcp_tstamp (tc); opts->tsecr = tc->tsval_recent; len += TCP_OPTION_LEN_TIMESTAMP; } if (tcp_opts_sack_permitted (&tc->rcv_opts)) { if (vec_len (tc->snd_sacks)) { opts->flags |= TCP_OPTS_FLAG_SACK; if (tc->snd_sack_pos >= vec_len (tc->snd_sacks)) tc->snd_sack_pos = 0; opts->sacks = &tc->snd_sacks[tc->snd_sack_pos]; opts->n_sack_blocks = vec_len (tc->snd_sacks) - tc->snd_sack_pos; opts->n_sack_blocks = clib_min (opts->n_sack_blocks, TCP_OPTS_MAX_SACK_BLOCKS); tc->snd_sack_pos += opts->n_sack_blocks; len += 2 + TCP_OPTION_LEN_SACK_BLOCK * opts->n_sack_blocks; } } /* Align to needed boundary */ len += (TCP_OPTS_ALIGN - len % TCP_OPTS_ALIGN) % TCP_OPTS_ALIGN; return len; } always_inline int tcp_make_options (tcp_connection_t * tc, tcp_options_t * opts, tcp_state_t state) { switch (state) { case TCP_STATE_ESTABLISHED: case TCP_STATE_CLOSE_WAIT: case TCP_STATE_FIN_WAIT_1: case TCP_STATE_LAST_ACK: case TCP_STATE_CLOSING: case TCP_STATE_FIN_WAIT_2: case TCP_STATE_TIME_WAIT: case TCP_STATE_CLOSED: return tcp_make_established_options (tc, opts); case TCP_STATE_SYN_RCVD: return tcp_make_synack_options (tc, opts); case TCP_STATE_SYN_SENT: return tcp_make_syn_options (tc, opts); default: clib_warning ("State not handled! %d", state); return 0; } } /** * Update burst send vars * * - Updates snd_mss to reflect the effective segment size that we can send * by taking into account all TCP options, including SACKs. * - Cache 'on the wire' options for reuse * - Updates receive window which can be reused for a burst. * * This should *only* be called when doing bursts */ void tcp_update_burst_snd_vars (tcp_connection_t * tc) { tcp_main_t *tm = &tcp_main; /* 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->rcv_opts.mss) - tc->snd_opts_len; ASSERT (tc->snd_mss > 0); tcp_options_write (tm->wrk_ctx[tc->c_thread_index].cached_opts, &tc->snd_opts); tcp_update_rcv_wnd (tc); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_check_app_limited (tc); if (tc->snd_una == tc->snd_nxt) { tcp_cc_event (tc, TCP_CC_EVT_START_TX); tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_MSS); } } #endif /* CLIB_MARCH_VARIANT */ static void * tcp_reuse_buffer (vlib_main_t * vm, vlib_buffer_t * b) { if (b->flags & VLIB_BUFFER_NEXT_PRESENT) vlib_buffer_free_one (vm, b->next_buffer); /* Zero all flags but free list index and trace flag */ b->flags &= VLIB_BUFFER_NEXT_PRESENT - 1; b->current_data = 0; b->current_length = 0; b->total_length_not_including_first_buffer = 0; vnet_buffer (b)->tcp.flags = 0; /* Leave enough space for headers */ return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN); } #ifndef CLIB_MARCH_VARIANT static void * tcp_init_buffer (vlib_main_t * vm, vlib_buffer_t * b) { ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0); b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; b->total_length_not_including_first_buffer = 0; b->current_data = 0; vnet_buffer (b)->tcp.flags = 0; VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b); /* Leave enough space for headers */ return vlib_buffer_make_headroom (b, TRANSPORT_MAX_HDRS_LEN); } /* Compute TCP checksum in software when offloading is disabled for a connection */ u16 ip6_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0, ip46_address_t * src, ip46_address_t * dst) { ip_csum_t sum0; u16 payload_length_host_byte_order; u32 i; /* Initialize checksum with ip header. */ sum0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, p0)) + clib_host_to_net_u16 (IP_PROTOCOL_TCP); payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0); for (i = 0; i < ARRAY_LEN (src->ip6.as_uword); i++) { sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&src->ip6.as_uword[i], uword)); sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&dst->ip6.as_uword[i], uword)); } return ip_calculate_l4_checksum (vm, p0, sum0, payload_length_host_byte_order, NULL, 0, NULL); } u16 ip4_tcp_compute_checksum_custom (vlib_main_t * vm, vlib_buffer_t * p0, ip46_address_t * src, ip46_address_t * dst) { ip_csum_t sum0; u32 payload_length_host_byte_order; payload_length_host_byte_order = vlib_buffer_length_in_chain (vm, p0); sum0 = clib_host_to_net_u32 (payload_length_host_byte_order + (IP_PROTOCOL_TCP << 16)); sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&src->ip4, u32)); sum0 = ip_csum_with_carry (sum0, clib_mem_unaligned (&dst->ip4, u32)); return ip_calculate_l4_checksum (vm, p0, sum0, payload_length_host_byte_order, NULL, 0, NULL); } static inline u16 tcp_compute_checksum (tcp_connection_t * tc, vlib_buffer_t * b) { u16 checksum = 0; if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_NO_CSUM_OFFLOAD)) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; if (tc->c_is_ip4) checksum = ip4_tcp_compute_checksum_custom (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip); else checksum = ip6_tcp_compute_checksum_custom (vm, b, &tc->c_lcl_ip, &tc->c_rmt_ip); } else { b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM; } return checksum; } /** * Prepare ACK */ static inline void tcp_make_ack_i (tcp_connection_t * tc, vlib_buffer_t * b, tcp_state_t state, u8 flags) { tcp_options_t _snd_opts, *snd_opts = &_snd_opts; u8 tcp_opts_len, tcp_hdr_opts_len; tcp_header_t *th; u16 wnd; wnd = tcp_window_to_advertise (tc, state); /* Make and write options */ tcp_opts_len = tcp_make_established_options (tc, snd_opts); tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t); th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt, tc->rcv_nxt, tcp_hdr_opts_len, flags, wnd); tcp_options_write ((u8 *) (th + 1), snd_opts); th->checksum = tcp_compute_checksum (tc, b); vnet_buffer (b)->tcp.connection_index = tc->c_c_index; if (wnd == 0) tcp_zero_rwnd_sent_on (tc); else tcp_zero_rwnd_sent_off (tc); } /** * Convert buffer to ACK */ static inline void tcp_make_ack (tcp_connection_t * tc, vlib_buffer_t * b) { tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_ACK); TCP_EVT (TCP_EVT_ACK_SENT, tc); tc->rcv_las = tc->rcv_nxt; } /** * Convert buffer to FIN-ACK */ void tcp_make_fin (tcp_connection_t * tc, vlib_buffer_t * b) { tcp_make_ack_i (tc, b, TCP_STATE_ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK); } /** * Convert buffer to SYN */ void tcp_make_syn (tcp_connection_t * tc, vlib_buffer_t * b) { u8 tcp_hdr_opts_len, tcp_opts_len; tcp_header_t *th; u16 initial_wnd; tcp_options_t snd_opts; initial_wnd = tcp_initial_window_to_advertise (tc); /* Make and write options */ clib_memset (&snd_opts, 0, sizeof (snd_opts)); tcp_opts_len = tcp_make_syn_options (tc, &snd_opts); tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t); th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss, tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN, initial_wnd); vnet_buffer (b)->tcp.connection_index = tc->c_c_index; tcp_options_write ((u8 *) (th + 1), &snd_opts); th->checksum = tcp_compute_checksum (tc, b); } /** * Convert buffer to SYN-ACK */ void tcp_make_synack (tcp_connection_t * tc, vlib_buffer_t * b) { tcp_options_t _snd_opts, *snd_opts = &_snd_opts; u8 tcp_opts_len, tcp_hdr_opts_len; tcp_header_t *th; u16 initial_wnd; clib_memset (snd_opts, 0, sizeof (*snd_opts)); initial_wnd = tcp_initial_window_to_advertise (tc); tcp_opts_len = tcp_make_synack_options (tc, snd_opts); tcp_hdr_opts_len = tcp_opts_len + sizeof (tcp_header_t); th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->iss, tc->rcv_nxt, tcp_hdr_opts_len, TCP_FLAG_SYN | TCP_FLAG_ACK, initial_wnd); tcp_options_write ((u8 *) (th + 1), snd_opts); vnet_buffer (b)->tcp.connection_index = tc->c_c_index; th->checksum = tcp_compute_checksum (tc, b); } always_inline void tcp_enqueue_to_ip_lookup_i (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi, u8 is_ip4, u32 fib_index, u8 flush) { vlib_main_t *vm = wrk->vm; u32 *to_next, next_index; vlib_frame_t *f; b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; b->error = 0; vnet_buffer (b)->sw_if_index[VLIB_TX] = fib_index; vnet_buffer (b)->sw_if_index[VLIB_RX] = 0; /* Send to IP lookup */ next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index; tcp_trajectory_add_start (b, 1); f = wrk->ip_lookup_tx_frames[!is_ip4]; if (!f) { f = vlib_get_frame_to_node (vm, next_index); ASSERT (f); wrk->ip_lookup_tx_frames[!is_ip4] = f; } to_next = vlib_frame_vector_args (f); to_next[f->n_vectors] = bi; f->n_vectors += 1; if (flush || f->n_vectors == VLIB_FRAME_SIZE) { vlib_put_frame_to_node (vm, next_index, f); wrk->ip_lookup_tx_frames[!is_ip4] = 0; } } static void tcp_enqueue_to_ip_lookup_now (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi, u8 is_ip4, u32 fib_index) { tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 1); } static void tcp_enqueue_to_ip_lookup (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi, u8 is_ip4, u32 fib_index) { tcp_enqueue_to_ip_lookup_i (wrk, b, bi, is_ip4, fib_index, 0); if (wrk->vm->thread_index == 0 && vlib_num_workers ()) session_flush_frames_main_thread (wrk->vm); } static void tcp_enqueue_to_output (tcp_worker_ctx_t * wrk, vlib_buffer_t * b, u32 bi, u8 is_ip4) { session_type_t st; b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; b->error = 0; st = session_type_from_proto_and_ip (TRANSPORT_PROTO_TCP, is_ip4); session_add_pending_tx_buffer (st, wrk->vm->thread_index, 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) { 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; u16 src_port, dst_port; u32 tmp; u32 seq, ack; u8 flags; /* Find IP and TCP headers */ th0 = tcp_buffer_hdr (b0); /* Save src and dst ip */ if (is_ip4) { ih4 = vlib_buffer_get_current (b0); 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; } else { ih6 = vlib_buffer_get_current (b0); 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)); } src_port = th0->src_port; dst_port = th0->dst_port; /* Try to determine what/why we're actually resetting */ if (state == TCP_STATE_CLOSED) { 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; } else { flags = TCP_FLAG_RST; seq = th0->ack_number; ack = 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); if (is_ip4) { ih4 = vlib_buffer_push_ip4 (vm, b0, &dst_ip40, &src_ip40, IP_PROTOCOL_TCP, 1); th0->checksum = ip4_tcp_udp_compute_checksum (vm, b0, 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); ASSERT (!bogus); } return 0; } #ifndef CLIB_MARCH_VARIANT /** * Send reset without reusing existing buffer * * It extracts connection info out of original packet */ void tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt, u32 thread_index, u8 is_ip4) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi, sw_if_index, fib_index; u8 tcp_hdr_len, flags = 0; tcp_header_t *th, *pkt_th; u32 seq, ack; ip4_header_t *ih4, *pkt_ih4; ip6_header_t *ih6, *pkt_ih6; fib_protocol_t fib_proto; if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) return; b = vlib_get_buffer (vm, bi); sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX]; fib_proto = is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6; fib_index = fib_table_get_index_for_sw_if_index (fib_proto, sw_if_index); tcp_init_buffer (vm, b); /* Make and write options */ tcp_hdr_len = sizeof (tcp_header_t); if (is_ip4) { pkt_ih4 = vlib_buffer_get_current (pkt); pkt_th = ip4_next_header (pkt_ih4); } else { pkt_ih6 = vlib_buffer_get_current (pkt); pkt_th = ip6_next_header (pkt_ih6); } if (tcp_ack (pkt_th)) { flags = TCP_FLAG_RST; seq = pkt_th->ack_number; ack = (tc->state >= TCP_STATE_SYN_RCVD) ? tc->rcv_nxt : 0; } else { flags = TCP_FLAG_RST | TCP_FLAG_ACK; seq = 0; ack = clib_host_to_net_u32 (vnet_buffer (pkt)->tcp.seq_end); } th = vlib_buffer_push_tcp_net_order (b, pkt_th->dst_port, pkt_th->src_port, seq, ack, tcp_hdr_len, flags, 0); /* Swap src and dst ip */ if (is_ip4) { ASSERT ((pkt_ih4->ip_version_and_header_length & 0xF0) == 0x40); ih4 = vlib_buffer_push_ip4 (vm, b, &pkt_ih4->dst_address, &pkt_ih4->src_address, IP_PROTOCOL_TCP, tcp_csum_offload (tc)); th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih4); } else { int bogus = ~0; ASSERT ((pkt_ih6->ip_version_traffic_class_and_flow_label & 0xF0) == 0x60); ih6 = vlib_buffer_push_ip6 (vm, b, &pkt_ih6->dst_address, &pkt_ih6->src_address, IP_PROTOCOL_TCP); th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih6, &bogus); ASSERT (!bogus); } tcp_enqueue_to_ip_lookup_now (wrk, b, bi, is_ip4, fib_index); TCP_EVT (TCP_EVT_RST_SENT, tc); vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4), TCP_ERROR_RST_SENT, 1); } /** * Build and set reset packet for connection */ void tcp_send_reset (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi; tcp_header_t *th; u16 tcp_hdr_opts_len, advertise_wnd, opts_write_len; u8 flags; if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) return; b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t); advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED); flags = TCP_FLAG_RST; th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, tc->snd_nxt, tc->rcv_nxt, tcp_hdr_opts_len, flags, advertise_wnd); opts_write_len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts); th->checksum = tcp_compute_checksum (tc, b); ASSERT (opts_write_len == tc->snd_opts_len); vnet_buffer (b)->tcp.connection_index = tc->c_c_index; tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); TCP_EVT (TCP_EVT_RST_SENT, tc); vlib_node_increment_counter (vm, tcp_node_index (output, tc->c_is_ip4), TCP_ERROR_RST_SENT, 1); } static void tcp_push_ip_hdr (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, vlib_buffer_t * b) { tcp_header_t *th = vlib_buffer_get_current (b); vlib_main_t *vm = wrk->vm; if (tc->c_is_ip4) { ip4_header_t *ih; ih = vlib_buffer_push_ip4 (vm, b, &tc->c_lcl_ip4, &tc->c_rmt_ip4, IP_PROTOCOL_TCP, tcp_csum_offload (tc)); th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ih); } else { ip6_header_t *ih; int bogus = ~0; ih = vlib_buffer_push_ip6 (vm, b, &tc->c_lcl_ip6, &tc->c_rmt_ip6, IP_PROTOCOL_TCP); th->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ih, &bogus); ASSERT (!bogus); } } /** * Send SYN * * Builds a SYN packet for a half-open connection and sends it to ipx_lookup. * The packet is not forwarded through tcpx_output to avoid doing lookups * in the half_open pool. */ void tcp_send_syn (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi; /* * Setup retransmit and establish timers before requesting buffer * such that we can return if we've ran out. */ tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK); if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1); return; } b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_syn (tc, b); /* Measure RTT with this */ tc->rtt_ts = tcp_time_now_us (vlib_num_workers ()? 1 : 0); tc->rtt_seq = tc->snd_nxt; tc->rto_boff = 0; tcp_push_ip_hdr (wrk, tc, b); tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index); TCP_EVT (TCP_EVT_SYN_SENT, tc); } void tcp_send_synack (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi; tcp_retransmit_timer_force_update (tc); if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); return; } tc->rtt_ts = tcp_time_now_us (tc->c_thread_index); b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_synack (tc, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); TCP_EVT (TCP_EVT_SYNACK_SENT, tc); } /** * Flush ip lookup tx frames populated by timer pops */ static void tcp_flush_frame_to_ip_lookup (tcp_worker_ctx_t * wrk, u8 is_ip4) { if (wrk->ip_lookup_tx_frames[!is_ip4]) { u32 next_index; next_index = is_ip4 ? ip4_lookup_node.index : ip6_lookup_node.index; vlib_put_frame_to_node (wrk->vm, next_index, wrk->ip_lookup_tx_frames[!is_ip4]); wrk->ip_lookup_tx_frames[!is_ip4] = 0; } } /** * Flush v4 and v6 tcp and ip-lookup tx frames for thread index */ void tcp_flush_frames_to_output (tcp_worker_ctx_t * wrk) { tcp_flush_frame_to_ip_lookup (wrk, 1); tcp_flush_frame_to_ip_lookup (wrk, 0); } /** * Send FIN */ void tcp_send_fin (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi; u8 fin_snt = 0; fin_snt = tc->flags & TCP_CONN_FINSNT; if (fin_snt) tc->snd_nxt -= 1; if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { /* Out of buffers so program fin retransmit ASAP */ tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); if (fin_snt) tc->snd_nxt += 1; else /* Make sure retransmit retries a fin not data */ tc->flags |= TCP_CONN_FINSNT; return; } /* If we have non-dupacks programmed, no need to send them */ if ((tc->flags & TCP_CONN_SNDACK) && !tc->pending_dupacks) tc->flags &= ~TCP_CONN_SNDACK; tcp_retransmit_timer_force_update (tc); b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_fin (tc, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); TCP_EVT (TCP_EVT_FIN_SENT, tc); /* Account for the FIN */ tc->snd_nxt += 1; if (!fin_snt) { tc->flags |= TCP_CONN_FINSNT; tc->flags &= ~TCP_CONN_FINPNDG; tc->snd_una_max = seq_max (tc->snd_una_max, tc->snd_nxt); } } /** * Push TCP header and update connection variables. Should only be called * for segments with data, not for 'control' packets. */ always_inline void tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b, u32 snd_nxt, u8 compute_opts, u8 maybe_burst, u8 update_snd_nxt) { u8 tcp_hdr_opts_len, flags = TCP_FLAG_ACK; u32 advertise_wnd, data_len; tcp_main_t *tm = &tcp_main; tcp_header_t *th; data_len = b->current_length; if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT)) data_len += b->total_length_not_including_first_buffer; vnet_buffer (b)->tcp.flags = 0; vnet_buffer (b)->tcp.connection_index = tc->c_c_index; if (compute_opts) tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); tcp_hdr_opts_len = tc->snd_opts_len + sizeof (tcp_header_t); if (maybe_burst) advertise_wnd = tc->rcv_wnd >> tc->rcv_wscale; else advertise_wnd = tcp_window_to_advertise (tc, TCP_STATE_ESTABLISHED); if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING)) { if (seq_geq (tc->psh_seq, snd_nxt) && seq_lt (tc->psh_seq, snd_nxt + data_len)) flags |= TCP_FLAG_PSH; } th = vlib_buffer_push_tcp (b, tc->c_lcl_port, tc->c_rmt_port, snd_nxt, tc->rcv_nxt, tcp_hdr_opts_len, flags, advertise_wnd); if (maybe_burst) { clib_memcpy_fast ((u8 *) (th + 1), tm->wrk_ctx[tc->c_thread_index].cached_opts, tc->snd_opts_len); } else { u8 len = tcp_options_write ((u8 *) (th + 1), &tc->snd_opts); ASSERT (len == tc->snd_opts_len); } /* * Update connection variables */ if (update_snd_nxt) tc->snd_nxt += data_len; tc->rcv_las = tc->rcv_nxt; tc->bytes_out += data_len; tc->data_segs_out += 1; th->checksum = tcp_compute_checksum (tc, b); TCP_EVT (TCP_EVT_PKTIZE, tc); } always_inline u32 tcp_buffer_len (vlib_buffer_t * b) { u32 data_len = b->current_length; if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT)) data_len += b->total_length_not_including_first_buffer; return data_len; } u32 tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b) { tcp_connection_t *tc = (tcp_connection_t *) tconn; if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_track_tx (tc, tcp_buffer_len (b)); tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0, /* burst */ 1, /* update_snd_nxt */ 1); tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max); tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una); /* If not tracking an ACK, start tracking */ if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc)) { tc->rtt_ts = tcp_time_now_us (tc->c_thread_index); tc->rtt_seq = tc->snd_nxt; } if (PREDICT_FALSE (!tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT))) { tcp_retransmit_timer_set (tc); tc->rto_boff = 0; } tcp_trajectory_add_start (b, 3); return 0; } void tcp_send_ack (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi; if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_update_rcv_wnd (tc); return; } b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_ack (tc, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); } void tcp_program_ack (tcp_connection_t * tc) { if (!(tc->flags & TCP_CONN_SNDACK)) { session_add_self_custom_tx_evt (&tc->connection, 1); tc->flags |= TCP_CONN_SNDACK; } } void tcp_program_dupack (tcp_connection_t * tc) { if (!(tc->flags & TCP_CONN_SNDACK)) { session_add_self_custom_tx_evt (&tc->connection, 1); tc->flags |= TCP_CONN_SNDACK; } if (tc->pending_dupacks < 255) tc->pending_dupacks += 1; } void tcp_program_retransmit (tcp_connection_t * tc) { if (!(tc->flags & TCP_CONN_RXT_PENDING)) { session_add_self_custom_tx_evt (&tc->connection, 0); tc->flags |= TCP_CONN_RXT_PENDING; } } /** * Delayed ack timer handler * * Sends delayed ACK when timer expires */ void tcp_timer_delack_handler (u32 index, u32 thread_index) { tcp_connection_t *tc; tc = tcp_connection_get (index, thread_index); tcp_send_ack (tc); } /** * Send window update ack * * Ensures that it will be sent only once, after a zero rwnd has been * advertised in a previous ack, and only if rwnd has grown beyond a * configurable value. */ void tcp_send_window_update_ack (tcp_connection_t * tc) { if (tcp_zero_rwnd_sent (tc)) { tcp_update_rcv_wnd (tc); if (tc->rcv_wnd >= tcp_cfg.rwnd_min_update_ack * tc->snd_mss) { tcp_zero_rwnd_sent_off (tc); tcp_program_ack (tc); } } } /** * Allocate a new buffer and build a new tcp segment * * @param wrk tcp worker * @param tc connection for which the segment will be allocated * @param offset offset of the first byte in the tx fifo * @param max_deq_byte segment size * @param[out] b pointer to buffer allocated * * @return the number of bytes in the segment or 0 if buffer cannot be * allocated or no data available */ static int tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, u32 offset, u32 max_deq_bytes, vlib_buffer_t ** b) { u32 bytes_per_buffer = vnet_get_tcp_main ()->bytes_per_buffer; vlib_main_t *vm = wrk->vm; u32 bi, seg_size; int n_bytes = 0; u8 *data; seg_size = max_deq_bytes + TRANSPORT_MAX_HDRS_LEN; /* * Prepare options */ tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); /* * Allocate and fill in buffer(s) */ /* Easy case, buffer size greater than mss */ if (PREDICT_TRUE (seg_size <= bytes_per_buffer)) { if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) return 0; *b = vlib_get_buffer (vm, bi); data = tcp_init_buffer (vm, *b); n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset, max_deq_bytes); ASSERT (n_bytes == max_deq_bytes); b[0]->current_length = n_bytes; tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0, /* burst */ 0, /* update_snd_nxt */ 0); } /* Split mss into multiple buffers */ else { u32 chain_bi = ~0, n_bufs_per_seg, n_bufs; u16 n_peeked, len_to_deq; vlib_buffer_t *chain_b, *prev_b; int i; /* Make sure we have enough buffers */ n_bufs_per_seg = ceil ((double) seg_size / bytes_per_buffer); vec_validate_aligned (wrk->tx_buffers, n_bufs_per_seg - 1, CLIB_CACHE_LINE_BYTES); n_bufs = vlib_buffer_alloc (vm, wrk->tx_buffers, n_bufs_per_seg); if (PREDICT_FALSE (n_bufs != n_bufs_per_seg)) { if (n_bufs) vlib_buffer_free (vm, wrk->tx_buffers, n_bufs); return 0; } *b = vlib_get_buffer (vm, wrk->tx_buffers[--n_bufs]); data = tcp_init_buffer (vm, *b); n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset, bytes_per_buffer - TRANSPORT_MAX_HDRS_LEN); b[0]->current_length = n_bytes; b[0]->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID; b[0]->total_length_not_including_first_buffer = 0; max_deq_bytes -= n_bytes; chain_b = *b; for (i = 1; i < n_bufs_per_seg; i++) { prev_b = chain_b; len_to_deq = clib_min (max_deq_bytes, bytes_per_buffer); chain_bi = wrk->tx_buffers[--n_bufs]; chain_b = vlib_get_buffer (vm, chain_bi); chain_b->current_data = 0; data = vlib_buffer_get_current (chain_b); n_peeked = session_tx_fifo_peek_bytes (&tc->connection, data, offset + n_bytes, len_to_deq); ASSERT (n_peeked == len_to_deq); n_bytes += n_peeked; chain_b->current_length = n_peeked; chain_b->next_buffer = 0; /* update previous buffer */ prev_b->next_buffer = chain_bi; prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT; max_deq_bytes -= n_peeked; b[0]->total_length_not_including_first_buffer += n_peeked; } tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0, /* burst */ 0, /* update_snd_nxt */ 0); if (PREDICT_FALSE (n_bufs)) { clib_warning ("not all buffers consumed"); vlib_buffer_free (vm, wrk->tx_buffers, n_bufs); } } ASSERT (n_bytes > 0); ASSERT (((*b)->current_data + (*b)->current_length) <= bytes_per_buffer); return n_bytes; } /** * Build a retransmit segment * * @return the number of bytes in the segment or 0 if there's nothing to * retransmit */ static u32 tcp_prepare_retransmit_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, u32 offset, u32 max_deq_bytes, vlib_buffer_t ** b) { u32 start, available_bytes; int n_bytes = 0; ASSERT (tc->state >= TCP_STATE_ESTABLISHED); ASSERT (max_deq_bytes != 0); /* * Make sure we can retransmit something */ available_bytes = transport_max_tx_dequeue (&tc->connection); ASSERT (available_bytes >= offset); available_bytes -= offset; if (!available_bytes) return 0; max_deq_bytes = clib_min (tc->snd_mss, max_deq_bytes); max_deq_bytes = clib_min (available_bytes, max_deq_bytes); start = tc->snd_una + offset; ASSERT (seq_leq (start + max_deq_bytes, tc->snd_nxt)); n_bytes = tcp_prepare_segment (wrk, tc, offset, max_deq_bytes, b); if (!n_bytes) return 0; tc->snd_rxt_bytes += n_bytes; if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_track_rxt (tc, start, start + n_bytes); tc->bytes_retrans += n_bytes; tc->segs_retrans += 1; TCP_EVT (TCP_EVT_CC_RTX, tc, offset, n_bytes); return n_bytes; } static void tcp_check_sack_reneging (tcp_connection_t * tc) { sack_scoreboard_t *sb = &tc->sack_sb; sack_scoreboard_hole_t *hole; hole = scoreboard_first_hole (sb); if (!sb->is_reneging && (!hole || hole->start == tc->snd_una)) return; scoreboard_clear_reneging (sb, tc->snd_una, tc->snd_nxt); } /** * Reset congestion control, switch cwnd to loss window and try again. */ static void tcp_cc_init_rxt_timeout (tcp_connection_t * tc) { TCP_EVT (TCP_EVT_CC_EVT, tc, 6); tc->prev_ssthresh = tc->ssthresh; tc->prev_cwnd = tc->cwnd; /* If we entrered loss without fast recovery, notify cc algo of the * congestion event such that it can update ssthresh and its state */ if (!tcp_in_fastrecovery (tc)) tcp_cc_congestion (tc); /* Let cc algo decide loss cwnd and ssthresh post unrecovered loss */ tcp_cc_loss (tc); tc->rtt_ts = 0; tc->cwnd_acc_bytes = 0; tc->tr_occurences += 1; tcp_recovery_on (tc); } void tcp_timer_retransmit_handler (u32 tc_index, u32 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); vlib_main_t *vm = wrk->vm; tcp_connection_t *tc; vlib_buffer_t *b = 0; u32 bi, n_bytes; tc = tcp_connection_get (tc_index, thread_index); /* Note: the connection may have been closed and pool_put */ if (PREDICT_FALSE (tc == 0 || tc->state == TCP_STATE_SYN_SENT)) return; /* Wait-close and retransmit could pop at the same time */ if (tc->state == TCP_STATE_CLOSED) return; if (tc->state >= TCP_STATE_ESTABLISHED) { TCP_EVT (TCP_EVT_CC_EVT, tc, 2); /* Lost FIN, retransmit and return */ if (tc->flags & TCP_CONN_FINSNT) { tcp_send_fin (tc); tc->rto_boff += 1; tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); return; } /* Shouldn't be here. This condition is tricky because it has to take * into account boff > 0 due to persist timeout. */ if ((tc->rto_boff == 0 && tc->snd_una == tc->snd_nxt) || (tc->rto_boff > 0 && seq_geq (tc->snd_una, tc->snd_congestion) && !tcp_flight_size (tc))) { ASSERT (!tcp_in_recovery (tc)); tc->rto_boff = 0; return; } /* We're not in recovery so make sure rto_boff is 0. Can be non 0 due * to persist timer timeout */ if (!tcp_in_recovery (tc) && tc->rto_boff > 0) { tc->rto_boff = 0; tcp_update_rto (tc); } /* Peer is dead or network connectivity is lost. Close connection. * RFC 1122 section 4.2.3.5 recommends a value of at least 100s. For * a min rto of 0.2s we need to retry about 8 times. */ if (tc->rto_boff >= TCP_RTO_BOFF_MAX) { tcp_send_reset (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closing_notify (&tc->connection); session_transport_closed_notify (&tc->connection); tcp_connection_timers_reset (tc); tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.closewait_time); return; } if (tcp_opts_sack_permitted (&tc->rcv_opts)) tcp_check_sack_reneging (tc); /* Update send congestion to make sure that rxt has data to send */ tc->snd_congestion = tc->snd_nxt; /* Send the first unacked segment. If we're short on buffers, return * as soon as possible */ n_bytes = clib_min (tc->snd_mss, tc->snd_nxt - tc->snd_una); n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, n_bytes, &b); if (!n_bytes) { tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); return; } bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); tcp_retransmit_timer_force_update (tc); tc->rto_boff += 1; if (tc->rto_boff == 1) { tcp_cc_init_rxt_timeout (tc); /* Record timestamp. Eifel detection algorithm RFC3522 */ tc->snd_rxt_ts = tcp_tstamp (tc); } if (tcp_opts_sack_permitted (&tc->rcv_opts)) scoreboard_init_rxt (&tc->sack_sb, tc->snd_una + n_bytes); tcp_program_retransmit (tc); } /* Retransmit SYN-ACK */ else if (tc->state == TCP_STATE_SYN_RCVD) { TCP_EVT (TCP_EVT_CC_EVT, tc, 2); tc->rtt_ts = 0; /* Passive open establish timeout */ if (tc->rto > TCP_ESTABLISH_TIME >> 1) { tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_connection_timers_reset (tc); tcp_timer_update (tc, TCP_TIMER_WAITCLOSE, tcp_cfg.cleanup_time); return; } if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_timer_update (tc, TCP_TIMER_RETRANSMIT, 1); return; } tc->rto_boff += 1; if (tc->rto_boff > TCP_RTO_SYN_RETRIES) tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); tcp_retransmit_timer_force_update (tc); b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_synack (tc, b); TCP_EVT (TCP_EVT_SYN_RXT, tc, 1); /* Retransmit timer already updated, just enqueue to output */ tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); } else { ASSERT (tc->state == TCP_STATE_CLOSED); return; } } /** * SYN retransmit timer handler. Active open only. */ void tcp_timer_retransmit_syn_handler (u32 tc_index, u32 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); vlib_main_t *vm = wrk->vm; tcp_connection_t *tc; vlib_buffer_t *b = 0; u32 bi; tc = tcp_half_open_connection_get (tc_index); /* Note: the connection may have transitioned to ESTABLISHED... */ if (PREDICT_FALSE (tc == 0 || tc->state != TCP_STATE_SYN_SENT)) return; /* Half-open connection actually moved to established but we were * waiting for syn retransmit to pop to call cleanup from the right * thread. */ if (tc->flags & TCP_CONN_HALF_OPEN_DONE) { if (tcp_half_open_connection_cleanup (tc)) TCP_DBG ("could not remove half-open connection"); return; } TCP_EVT (TCP_EVT_CC_EVT, tc, 2); tc->rtt_ts = 0; /* Active open establish timeout */ if (tc->rto >= TCP_ESTABLISH_TIME >> 1) { session_stream_connect_notify (&tc->connection, 1 /* fail */ ); tcp_connection_cleanup (tc); return; } if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, 1); return; } /* Try without increasing RTO a number of times. If this fails, * start growing RTO exponentially */ tc->rto_boff += 1; if (tc->rto_boff > TCP_RTO_SYN_RETRIES) tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); b = vlib_get_buffer (vm, bi); tcp_init_buffer (vm, b); tcp_make_syn (tc, b); TCP_EVT (TCP_EVT_SYN_RXT, tc, 0); /* This goes straight to ipx_lookup */ tcp_push_ip_hdr (wrk, tc, b); tcp_enqueue_to_ip_lookup (wrk, b, bi, tc->c_is_ip4, tc->c_fib_index); tcp_timer_update (tc, TCP_TIMER_RETRANSMIT_SYN, tc->rto * TCP_TO_TIMER_TICK); } /** * Got 0 snd_wnd from peer, try to do something about it. * */ void tcp_timer_persist_handler (u32 index, u32 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); u32 bi, max_snd_bytes, available_bytes, offset; tcp_main_t *tm = vnet_get_tcp_main (); vlib_main_t *vm = wrk->vm; tcp_connection_t *tc; vlib_buffer_t *b; int n_bytes = 0; u8 *data; tc = tcp_connection_get_if_valid (index, thread_index); if (!tc) return; /* Problem already solved or worse */ if (tc->state == TCP_STATE_CLOSED || tc->snd_wnd > tc->snd_mss || (tc->flags & TCP_CONN_FINSNT)) return; available_bytes = transport_max_tx_dequeue (&tc->connection); offset = tc->snd_nxt - tc->snd_una; /* Reprogram persist if no new bytes available to send. We may have data * next time */ if (!available_bytes) { tcp_persist_timer_set (tc); return; } if (available_bytes <= offset) return; /* Increment RTO backoff */ tc->rto_boff += 1; tc->rto = clib_min (tc->rto << 1, TCP_RTO_MAX); /* * Try to force the first unsent segment (or buffer) */ if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1))) { tcp_persist_timer_set (tc); return; } b = vlib_get_buffer (vm, bi); data = tcp_init_buffer (vm, b); tcp_validate_txf_size (tc, offset); tc->snd_opts_len = tcp_make_options (tc, &tc->snd_opts, tc->state); max_snd_bytes = clib_min (tc->snd_mss, tm->bytes_per_buffer - TRANSPORT_MAX_HDRS_LEN); n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset, max_snd_bytes); b->current_length = n_bytes; ASSERT (n_bytes != 0 && (tcp_timer_is_active (tc, TCP_TIMER_RETRANSMIT) || tc->snd_nxt == tc->snd_una_max || tc->rto_boff > 1)); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) { tcp_bt_check_app_limited (tc); tcp_bt_track_tx (tc, n_bytes); } tcp_push_hdr_i (tc, b, tc->snd_nxt, /* compute opts */ 0, /* burst */ 0, /* update_snd_nxt */ 1); tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max); tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); /* Just sent new data, enable retransmit */ tcp_retransmit_timer_update (tc); } /** * Retransmit first unacked segment */ int tcp_retransmit_first_unacked (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { vlib_main_t *vm = wrk->vm; vlib_buffer_t *b; u32 bi, n_bytes; TCP_EVT (TCP_EVT_CC_EVT, tc, 1); n_bytes = tcp_prepare_retransmit_segment (wrk, tc, 0, tc->snd_mss, &b); if (!n_bytes) return -1; bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); return 0; } static int tcp_transmit_unsent (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, u32 burst_size) { u32 offset, n_segs = 0, n_written, bi, available_wnd; vlib_main_t *vm = wrk->vm; vlib_buffer_t *b = 0; offset = tc->snd_nxt - tc->snd_una; available_wnd = tc->snd_wnd - offset; burst_size = clib_min (burst_size, available_wnd / tc->snd_mss); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_check_app_limited (tc); while (n_segs < burst_size) { n_written = tcp_prepare_segment (wrk, tc, offset, tc->snd_mss, &b); if (!n_written) goto done; bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); offset += n_written; n_segs += 1; if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_track_tx (tc, n_written); tc->snd_nxt += n_written; tc->snd_una_max = seq_max (tc->snd_nxt, tc->snd_una_max); } done: return n_segs; } /** * Estimate send space using proportional rate reduction (RFC6937) */ int tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc) { u32 pipe, prr_out; int space; pipe = tcp_flight_size (tc); prr_out = tc->snd_rxt_bytes + (tc->snd_nxt - tc->snd_congestion); if (pipe > tc->ssthresh) { space = ((int) tc->prr_delivered * ((f64) tc->ssthresh / tc->prev_cwnd)) - prr_out; } else { int limit; limit = clib_max ((int) (tc->prr_delivered - prr_out), 0) + tc->snd_mss; space = clib_min (tc->ssthresh - pipe, limit); } space = clib_max (space, prr_out ? 0 : tc->snd_mss); return space; } static inline u8 tcp_retransmit_should_retry_head (tcp_connection_t * tc, sack_scoreboard_t * sb) { u32 tx_adv_sack = sb->high_sacked - tc->snd_congestion; f64 rr = (f64) tc->ssthresh / tc->prev_cwnd; if (tcp_fastrecovery_first (tc)) return 1; return (tx_adv_sack > (tc->snd_una - tc->prr_start) * rr); } static inline u8 tcp_max_tx_deq (tcp_connection_t * tc) { return (transport_max_tx_dequeue (&tc->connection) - (tc->snd_nxt - tc->snd_una)); } #define scoreboard_rescue_rxt_valid(_sb, _tc) \ (seq_geq (_sb->rescue_rxt, _tc->snd_una) \ && seq_leq (_sb->rescue_rxt, _tc->snd_congestion)) /** * Do retransmit with SACKs */ static int tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, u32 burst_size) { u8 snd_limited = 0, can_rescue = 0, reset_pacer = 0; u32 n_written = 0, offset, max_bytes, n_segs = 0; u32 bi, max_deq, burst_bytes, sent_bytes; sack_scoreboard_hole_t *hole; vlib_main_t *vm = wrk->vm; vlib_buffer_t *b = 0; sack_scoreboard_t *sb; int snd_space; ASSERT (tcp_in_cong_recovery (tc)); burst_bytes = transport_connection_tx_pacer_burst (&tc->connection); burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss); if (!burst_size) { tcp_program_retransmit (tc); return 0; } if (tcp_in_recovery (tc)) snd_space = tcp_available_cc_snd_space (tc); else snd_space = tcp_fastrecovery_prr_snd_space (tc); if (snd_space < tc->snd_mss) { reset_pacer = burst_bytes > tc->snd_mss; goto done; } reset_pacer = snd_space < burst_bytes; sb = &tc->sack_sb; /* Check if snd_una is a lost retransmit */ if (pool_elts (sb->holes) && seq_gt (sb->high_sacked, tc->snd_congestion) && tc->rxt_head != tc->snd_una && tcp_retransmit_should_retry_head (tc, sb)) { max_bytes = clib_min (tc->snd_mss, tc->snd_congestion - tc->snd_una); n_written = tcp_prepare_retransmit_segment (wrk, tc, 0, max_bytes, &b); if (!n_written) { tcp_program_retransmit (tc); goto done; } bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); n_segs = 1; tc->rxt_head = tc->snd_una; tc->rxt_delivered += n_written; tc->prr_delivered += n_written; ASSERT (tc->rxt_delivered <= tc->snd_rxt_bytes); } tcp_fastrecovery_first_off (tc); TCP_EVT (TCP_EVT_CC_EVT, tc, 0); hole = scoreboard_get_hole (sb, sb->cur_rxt_hole); max_deq = transport_max_tx_dequeue (&tc->connection); max_deq -= tc->snd_nxt - tc->snd_una; while (snd_space > 0 && n_segs < burst_size) { hole = scoreboard_next_rxt_hole (sb, hole, max_deq != 0, &can_rescue, &snd_limited); if (!hole) { /* We are out of lost holes to retransmit so send some new data. */ if (max_deq > tc->snd_mss) { u32 n_segs_new; int av_wnd; /* Make sure we don't exceed available window and leave space * for one more packet, to avoid zero window acks */ av_wnd = (int) tc->snd_wnd - (tc->snd_nxt - tc->snd_una); av_wnd = clib_max (av_wnd - tc->snd_mss, 0); snd_space = clib_min (snd_space, av_wnd); snd_space = clib_min (max_deq, snd_space); burst_size = clib_min (burst_size - n_segs, snd_space / tc->snd_mss); burst_size = clib_min (burst_size, TCP_RXT_MAX_BURST); n_segs_new = tcp_transmit_unsent (wrk, tc, burst_size); if (max_deq > n_segs_new * tc->snd_mss) tcp_program_retransmit (tc); n_segs += n_segs_new; goto done; } if (tcp_in_recovery (tc) || !can_rescue || scoreboard_rescue_rxt_valid (sb, tc)) break; /* If rescue rxt undefined or less than snd_una then one segment of * up to SMSS octets that MUST include the highest outstanding * unSACKed sequence number SHOULD be returned, and RescueRxt set to * RecoveryPoint. HighRxt MUST NOT be updated. */ hole = scoreboard_last_hole (sb); max_bytes = clib_min (tc->snd_mss, hole->end - hole->start); max_bytes = clib_min (max_bytes, snd_space); offset = hole->end - tc->snd_una - max_bytes; n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes, &b); if (!n_written) goto done; sb->rescue_rxt = tc->snd_congestion; bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); n_segs += 1; break; } max_bytes = clib_min (hole->end - sb->high_rxt, snd_space); max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes; if (max_bytes == 0) break; offset = sb->high_rxt - tc->snd_una; n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes, &b); ASSERT (n_written <= snd_space); /* Nothing left to retransmit */ if (n_written == 0) break; bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); sb->high_rxt += n_written; ASSERT (seq_leq (sb->high_rxt, tc->snd_nxt)); snd_space -= n_written; n_segs += 1; } if (hole) tcp_program_retransmit (tc); done: if (reset_pacer) { transport_connection_tx_pacer_reset_bucket (&tc->connection); } else { sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes); transport_connection_tx_pacer_update_bytes (&tc->connection, sent_bytes); } return n_segs; } /** * Fast retransmit without SACK info */ static int tcp_retransmit_no_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc, u32 burst_size) { u32 n_written = 0, offset = 0, bi, max_deq, n_segs_now, max_bytes; u32 burst_bytes, sent_bytes; vlib_main_t *vm = wrk->vm; int snd_space, n_segs = 0; u8 cc_limited = 0; vlib_buffer_t *b; ASSERT (tcp_in_cong_recovery (tc)); TCP_EVT (TCP_EVT_CC_EVT, tc, 0); burst_bytes = transport_connection_tx_pacer_burst (&tc->connection); burst_size = clib_min (burst_size, burst_bytes / tc->snd_mss); if (!burst_size) { tcp_program_retransmit (tc); return 0; } snd_space = tcp_available_cc_snd_space (tc); cc_limited = snd_space < burst_bytes; if (!tcp_fastrecovery_first (tc)) goto send_unsent; /* RFC 6582: [If a partial ack], retransmit the first unacknowledged * segment. */ while (snd_space > 0 && n_segs < burst_size) { max_bytes = clib_min (tc->snd_mss, tc->snd_congestion - tc->snd_una - offset); if (!max_bytes) break; n_written = tcp_prepare_retransmit_segment (wrk, tc, offset, max_bytes, &b); /* Nothing left to retransmit */ if (n_written == 0) break; bi = vlib_get_buffer_index (vm, b); tcp_enqueue_to_output (wrk, b, bi, tc->c_is_ip4); snd_space -= n_written; offset += n_written; n_segs += 1; } if (n_segs == burst_size) goto done; send_unsent: /* RFC 6582: Send a new segment if permitted by the new value of cwnd. */ if (snd_space < tc->snd_mss || tc->snd_mss == 0) goto done; max_deq = transport_max_tx_dequeue (&tc->connection); max_deq -= tc->snd_nxt - tc->snd_una; if (max_deq) { snd_space = clib_min (max_deq, snd_space); burst_size = clib_min (burst_size - n_segs, snd_space / tc->snd_mss); n_segs_now = tcp_transmit_unsent (wrk, tc, burst_size); if (n_segs_now && max_deq > n_segs_now * tc->snd_mss) tcp_program_retransmit (tc); n_segs += n_segs_now; } done: tcp_fastrecovery_first_off (tc); sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes); sent_bytes = cc_limited ? burst_bytes : sent_bytes; transport_connection_tx_pacer_update_bytes (&tc->connection, sent_bytes); return n_segs; } static int tcp_send_acks (tcp_connection_t * tc, u32 max_burst_size) { int j, n_acks; if (!tc->pending_dupacks) { if (tcp_in_cong_recovery (tc) || !tcp_max_tx_deq (tc) || tc->state != TCP_STATE_ESTABLISHED) { tcp_send_ack (tc); return 1; } return 0; } /* If we're supposed to send dupacks but have no ooo data * send only one ack */ if (!vec_len (tc->snd_sacks)) { tcp_send_ack (tc); tc->pending_dupacks = 0; return 1; } /* Start with first sack block */ tc->snd_sack_pos = 0; /* Generate enough dupacks to cover all sack blocks. Do not generate * more sacks than the number of packets received. But do generate at * least 3, i.e., the number needed to signal congestion, if needed. */ n_acks = vec_len (tc->snd_sacks) / TCP_OPTS_MAX_SACK_BLOCKS; n_acks = clib_min (n_acks, tc->pending_dupacks); n_acks = clib_max (n_acks, clib_min (tc->pending_dupacks, 3)); for (j = 0; j < clib_min (n_acks, max_burst_size); j++) tcp_send_ack (tc); if (n_acks < max_burst_size) { tc->pending_dupacks = 0; tc->snd_sack_pos = 0; tc->dupacks_out += n_acks; return n_acks; } else { TCP_DBG ("constrained by burst size"); tc->pending_dupacks = n_acks - max_burst_size; tc->dupacks_out += max_burst_size; tcp_program_dupack (tc); return max_burst_size; } } static int tcp_do_retransmit (tcp_connection_t * tc, u32 max_burst_size) { tcp_worker_ctx_t *wrk; u32 n_segs; if (PREDICT_FALSE (tc->state == TCP_STATE_CLOSED)) return 0; wrk = tcp_get_worker (tc->c_thread_index); if (tcp_opts_sack_permitted (&tc->rcv_opts)) n_segs = tcp_retransmit_sack (wrk, tc, max_burst_size); else n_segs = tcp_retransmit_no_sack (wrk, tc, max_burst_size); return n_segs; } int tcp_session_custom_tx (void *conn, u32 max_burst_size) { tcp_connection_t *tc = (tcp_connection_t *) conn; u32 n_segs = 0; if (tcp_in_cong_recovery (tc) && (tc->flags & TCP_CONN_RXT_PENDING)) { tc->flags &= ~TCP_CONN_RXT_PENDING; n_segs = tcp_do_retransmit (tc, max_burst_size); max_burst_size -= n_segs; } if (!(tc->flags & TCP_CONN_SNDACK)) return n_segs; tc->flags &= ~TCP_CONN_SNDACK; /* We have retransmitted packets and no dupack */ if (n_segs && !tc->pending_dupacks) return n_segs; if (!max_burst_size) { tcp_program_ack (tc); return max_burst_size; } n_segs += tcp_send_acks (tc, max_burst_size); return n_segs; } #endif /* CLIB_MARCH_VARIANT */ static void tcp_output_handle_link_local (tcp_connection_t * tc0, vlib_buffer_t * b0, u16 * next0, u32 * error0) { ip_adjacency_t *adj; adj_index_t ai; /* Not thread safe but as long as the connection exists the adj should * not be removed */ ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &tc0->c_rmt_ip, tc0->sw_if_index); if (ai == ADJ_INDEX_INVALID) { vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0; *next0 = TCP_OUTPUT_NEXT_DROP; *error0 = TCP_ERROR_LINK_LOCAL_RW; return; } adj = adj_get (ai); if (PREDICT_TRUE (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE)) *next0 = TCP_OUTPUT_NEXT_IP_REWRITE; else if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP) *next0 = TCP_OUTPUT_NEXT_IP_ARP; else { *next0 = TCP_OUTPUT_NEXT_DROP; *error0 = TCP_ERROR_LINK_LOCAL_RW; } vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ai; } static void tcp46_output_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node, u32 * to_next, u32 n_bufs) { tcp_connection_t *tc; tcp_tx_trace_t *t; vlib_buffer_t *b; tcp_header_t *th; int i; for (i = 0; i < n_bufs; i++) { b = vlib_get_buffer (vm, to_next[i]); if (!(b->flags & VLIB_BUFFER_IS_TRACED)) continue; th = vlib_buffer_get_current (b); tc = tcp_connection_get (vnet_buffer (b)->tcp.connection_index, vm->thread_index); t = vlib_add_trace (vm, node, b, sizeof (*t)); clib_memcpy_fast (&t->tcp_header, th, sizeof (t->tcp_header)); clib_memcpy_fast (&t->tcp_connection, tc, sizeof (t->tcp_connection)); } } always_inline void tcp_output_push_ip (vlib_main_t * vm, vlib_buffer_t * b0, tcp_connection_t * tc0, u8 is_ip4) { u8 __clib_unused *ih0; tcp_header_t __clib_unused *th0 = vlib_buffer_get_current (b0); TCP_EVT (TCP_EVT_OUTPUT, tc0, th0->flags, b0->current_length); if (is_ip4) ih0 = vlib_buffer_push_ip4 (vm, b0, &tc0->c_lcl_ip4, &tc0->c_rmt_ip4, IP_PROTOCOL_TCP, tcp_csum_offload (tc0)); else ih0 = vlib_buffer_push_ip6 (vm, b0, &tc0->c_lcl_ip6, &tc0->c_rmt_ip6, IP_PROTOCOL_TCP); } always_inline void tcp_check_if_gso (tcp_connection_t * tc, vlib_buffer_t * b) { if (PREDICT_TRUE (!(tc->cfg_flags & TCP_CFG_F_TSO))) return; u16 data_len = b->current_length - sizeof (tcp_header_t) - tc->snd_opts_len; if (PREDICT_FALSE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID)) data_len += b->total_length_not_including_first_buffer; if (PREDICT_TRUE (data_len <= tc->snd_mss)) return; else { ASSERT ((b->flags & VNET_BUFFER_F_L3_HDR_OFFSET_VALID) != 0); ASSERT ((b->flags & VNET_BUFFER_F_L4_HDR_OFFSET_VALID) != 0); b->flags |= VNET_BUFFER_F_GSO; vnet_buffer2 (b)->gso_l4_hdr_sz = sizeof (tcp_header_t) + tc->snd_opts_len; vnet_buffer2 (b)->gso_size = tc->snd_mss; } } always_inline void tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0, vlib_node_runtime_t * error_node, u16 * next0, u8 is_ip4) { /* If next_index is not drop use it */ if (tc0->next_node_index) { *next0 = tc0->next_node_index; vnet_buffer (b0)->tcp.next_node_opaque = tc0->next_node_opaque; } else { *next0 = TCP_OUTPUT_NEXT_IP_LOOKUP; } vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index; vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0; if (!is_ip4) { u32 error0 = 0; if (PREDICT_FALSE (ip6_address_is_link_local_unicast (&tc0->c_rmt_ip6))) tcp_output_handle_link_local (tc0, b0, next0, &error0); if (PREDICT_FALSE (error0)) { b0->error = error_node->errors[error0]; return; } } if (!TCP_ALWAYS_ACK) tcp_timer_reset (tc0, TCP_TIMER_DELACK); tc0->segs_out += 1; } always_inline uword tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, int is_ip4) { u32 n_left_from, *from, thread_index = vm->thread_index; vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b; u16 nexts[VLIB_FRAME_SIZE], *next; vlib_node_runtime_t *error_node; error_node = vlib_node_get_runtime (vm, tcp_node_index (output, is_ip4)); from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; tcp_set_time_now (tcp_get_worker (thread_index)); if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE)) tcp46_output_trace_frame (vm, node, from, n_left_from); vlib_get_buffers (vm, from, bufs, n_left_from); b = bufs; next = nexts; while (n_left_from >= 4) { tcp_connection_t *tc0, *tc1; { vlib_prefetch_buffer_header (b[2], STORE); CLIB_PREFETCH (b[2]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE); vlib_prefetch_buffer_header (b[3], STORE); CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE); } tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index, thread_index); tc1 = tcp_connection_get (vnet_buffer (b[1])->tcp.connection_index, thread_index); if (PREDICT_TRUE (!tc0 + !tc1 == 0)) { tcp_output_push_ip (vm, b[0], tc0, is_ip4); tcp_output_push_ip (vm, b[1], tc1, is_ip4); tcp_check_if_gso (tc0, b[0]); tcp_check_if_gso (tc1, b[1]); tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4); tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4); } else { if (tc0 != 0) { tcp_output_push_ip (vm, b[0], tc0, is_ip4); tcp_check_if_gso (tc0, b[0]); tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4); } else { b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION]; next[0] = TCP_OUTPUT_NEXT_DROP; } if (tc1 != 0) { tcp_output_push_ip (vm, b[1], tc1, is_ip4); tcp_check_if_gso (tc1, b[1]); tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4); } else { b[1]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION]; next[1] = TCP_OUTPUT_NEXT_DROP; } } b += 2; next += 2; n_left_from -= 2; } while (n_left_from > 0) { tcp_connection_t *tc0; if (n_left_from > 1) { vlib_prefetch_buffer_header (b[1], STORE); CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE); } tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index, thread_index); if (PREDICT_TRUE (tc0 != 0)) { tcp_output_push_ip (vm, b[0], tc0, is_ip4); tcp_check_if_gso (tc0, b[0]); tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4); } else { b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION]; next[0] = TCP_OUTPUT_NEXT_DROP; } b += 1; next += 1; n_left_from -= 1; } vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors); vlib_node_increment_counter (vm, tcp_node_index (output, is_ip4), TCP_ERROR_PKTS_SENT, frame->n_vectors); return frame->n_vectors; } VLIB_NODE_FN (tcp4_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_output_inline (vm, node, from_frame, 1 /* is_ip4 */ ); } VLIB_NODE_FN (tcp6_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_output_node) = { .name = "tcp4-output", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .protocol_hint = VLIB_NODE_PROTO_HINT_TCP, .error_strings = tcp_error_strings, .n_next_nodes = TCP_OUTPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n, foreach_tcp4_output_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_tx_trace, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_output_node) = { .name = "tcp6-output", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .protocol_hint = VLIB_NODE_PROTO_HINT_TCP, .error_strings = tcp_error_strings, .n_next_nodes = TCP_OUTPUT_N_NEXT, .next_nodes = { #define _(s,n) [TCP_OUTPUT_NEXT_##s] = n, foreach_tcp6_output_next #undef _ }, .format_buffer = format_tcp_header, .format_trace = format_tcp_tx_trace, }; /* *INDENT-ON* */ typedef enum _tcp_reset_next { TCP_RESET_NEXT_DROP, TCP_RESET_NEXT_IP_LOOKUP, TCP_RESET_N_NEXT } tcp_reset_next_t; #define foreach_tcp4_reset_next \ _(DROP, "error-drop") \ _(IP_LOOKUP, "ip4-lookup") #define foreach_tcp6_reset_next \ _(DROP, "error-drop") \ _(IP_LOOKUP, "ip6-lookup") static uword tcp46_send_reset_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame, u8 is_ip4) { 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; next_index = node->cached_next_index; while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); 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; bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; 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; } /* 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)) { th0 = vlib_buffer_get_current (b0); if (is_ip4) th0 = ip4_next_header ((ip4_header_t *) th0); else th0 = ip6_next_header ((ip6_header_t *) th0); t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); clib_memcpy_fast (&t0->tcp_header, th0, sizeof (t0->tcp_header)); } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, next0); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } return from_frame->n_vectors; } VLIB_NODE_FN (tcp4_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_send_reset_inline (vm, node, from_frame, 1); } VLIB_NODE_FN (tcp6_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return tcp46_send_reset_inline (vm, node, from_frame, 0); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp4_reset_node) = { .name = "tcp4-reset", .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_RESET_N_NEXT, .next_nodes = { #define _(s,n) [TCP_RESET_NEXT_##s] = n, foreach_tcp4_reset_next #undef _ }, .format_trace = format_tcp_tx_trace, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (tcp6_reset_node) = { .name = "tcp6-reset", .vector_size = sizeof (u32), .n_errors = TCP_N_ERROR, .error_strings = tcp_error_strings, .n_next_nodes = TCP_RESET_N_NEXT, .next_nodes = { #define _(s,n) [TCP_RESET_NEXT_##s] = n, foreach_tcp6_reset_next #undef _ }, .format_trace = format_tcp_tx_trace, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */