/* * Copyright (c) 2020 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. */ #ifndef SRC_VNET_TCP_TCP_INLINES_H_ #define SRC_VNET_TCP_TCP_INLINES_H_ #include <vnet/tcp/tcp.h> always_inline tcp_header_t * tcp_buffer_hdr (vlib_buffer_t * b) { ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE); return (tcp_header_t *) (b->data + b->current_data + vnet_buffer (b)->tcp.hdr_offset); } always_inline tcp_connection_t * tcp_connection_get (u32 conn_index, u32 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); if (PREDICT_FALSE (pool_is_free_index (wrk->connections, conn_index))) return 0; return pool_elt_at_index (wrk->connections, conn_index); } always_inline tcp_connection_t * tcp_connection_get_if_valid (u32 conn_index, u32 thread_index) { tcp_worker_ctx_t *wrk; if (thread_index >= vec_len (tcp_main.wrk_ctx)) return 0; wrk = tcp_get_worker (thread_index); if (pool_is_free_index (wrk->connections, conn_index)) return 0; return pool_elt_at_index (wrk->connections, conn_index); } always_inline void tcp_connection_set_state (tcp_connection_t * tc, tcp_state_t state) { tc->state = state; TCP_EVT (TCP_EVT_STATE_CHANGE, tc); } always_inline tcp_connection_t * tcp_listener_get (u32 tli) { tcp_connection_t *tc = 0; if (!pool_is_free_index (tcp_main.listener_pool, tli)) tc = pool_elt_at_index (tcp_main.listener_pool, tli); return tc; } always_inline tcp_connection_t * tcp_half_open_connection_get (u32 conn_index) { return tcp_connection_get (conn_index, 0); } /** * Our estimate of the number of bytes that have left the network */ always_inline u32 tcp_bytes_out (const tcp_connection_t * tc) { if (tcp_opts_sack_permitted (&tc->rcv_opts)) return tc->sack_sb.sacked_bytes + tc->sack_sb.lost_bytes; else return clib_min (tc->rcv_dupacks * tc->snd_mss, tc->snd_nxt - tc->snd_una); } /** * Our estimate of the number of bytes in flight (pipe size) */ always_inline u32 tcp_flight_size (const tcp_connection_t * tc) { int flight_size; flight_size = (int) (tc->snd_nxt - tc->snd_una) - tcp_bytes_out (tc) + tc->snd_rxt_bytes - tc->rxt_delivered; ASSERT (flight_size >= 0); return flight_size; } /** * Initial cwnd as per RFC5681 */ always_inline u32 tcp_initial_cwnd (const tcp_connection_t * tc) { if (tcp_cfg.initial_cwnd_multiplier > 0) return tcp_cfg.initial_cwnd_multiplier * tc->snd_mss; if (tc->snd_mss > 2190) return 2 * tc->snd_mss; else if (tc->snd_mss > 1095) return 3 * tc->snd_mss; else return 4 * tc->snd_mss; } /* * Accumulate acked bytes for cwnd increase * * Once threshold bytes are accumulated, snd_mss bytes are added * to the cwnd. */ always_inline void tcp_cwnd_accumulate (tcp_connection_t * tc, u32 thresh, u32 bytes) { tc->cwnd_acc_bytes += bytes; if (tc->cwnd_acc_bytes >= thresh) { u32 inc = tc->cwnd_acc_bytes / thresh; tc->cwnd_acc_bytes -= inc * thresh; tc->cwnd += inc * tc->snd_mss; tc->cwnd = clib_min (tc->cwnd, tc->tx_fifo_size); } } always_inline u32 tcp_loss_wnd (const tcp_connection_t * tc) { /* Whatever we have in flight + the packet we're about to send */ return tcp_flight_size (tc) + tc->snd_mss; } always_inline u32 tcp_available_snd_wnd (const tcp_connection_t * tc) { return clib_min (tc->cwnd, tc->snd_wnd); } always_inline u32 tcp_available_output_snd_space (const tcp_connection_t * tc) { u32 available_wnd = tcp_available_snd_wnd (tc); int flight_size = (int) (tc->snd_nxt - tc->snd_una); if (available_wnd <= flight_size) return 0; return available_wnd - flight_size; } /** * Estimate of how many bytes we can still push into the network */ always_inline u32 tcp_available_cc_snd_space (const tcp_connection_t * tc) { u32 available_wnd = tcp_available_snd_wnd (tc); u32 flight_size = tcp_flight_size (tc); if (available_wnd <= flight_size) return 0; return available_wnd - flight_size; } always_inline u8 tcp_is_lost_fin (tcp_connection_t * tc) { if ((tc->flags & TCP_CONN_FINSNT) && (tc->snd_nxt - tc->snd_una == 1)) return 1; return 0; } /** * Time used to generate timestamps, not the timestamp */ always_inline u32 tcp_time_tstamp (u32 thread_index) { return tcp_main.wrk_ctx[thread_index].time_tstamp; } /** * Generate timestamp for tcp connection */ always_inline u32 tcp_tstamp (tcp_connection_t * tc) { return (tcp_main.wrk_ctx[tc->c_thread_index].time_tstamp - tc->timestamp_delta); } always_inline f64 tcp_time_now_us (u32 thread_index) { return tcp_main.wrk_ctx[thread_index].time_us; } always_inline void tcp_set_time_now (tcp_worker_ctx_t *wrk, f64 now) { /* TCP internal cache of time reference. Could use @ref transport_time_now * but because @ref tcp_time_now_us is used per packet, caching might * slightly improve efficiency. */ wrk->time_us = now; wrk->time_tstamp = (u64) (now * TCP_TSTP_HZ); } always_inline void tcp_update_time_now (tcp_worker_ctx_t *wrk) { f64 now = vlib_time_now (wrk->vm); /* Both pacer and tcp us time need to be updated */ transport_update_pacer_time (wrk->vm->thread_index, now); tcp_set_time_now (wrk, now); } always_inline tcp_connection_t * tcp_input_lookup_buffer (vlib_buffer_t * b, u8 thread_index, u32 * error, u8 is_ip4, u8 is_nolookup) { u32 fib_index = vnet_buffer (b)->ip.fib_index; int n_advance_bytes, n_data_bytes; transport_connection_t *tc; tcp_header_t *tcp; u8 result = 0; if (is_ip4) { ip4_header_t *ip4 = vlib_buffer_get_current (b); int ip_hdr_bytes = ip4_header_bytes (ip4); if (PREDICT_FALSE (b->current_length < ip_hdr_bytes + sizeof (*tcp))) { *error = TCP_ERROR_LENGTH; return 0; } tcp = ip4_next_header (ip4); vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip4; n_advance_bytes = (ip_hdr_bytes + tcp_header_bytes (tcp)); n_data_bytes = clib_net_to_host_u16 (ip4->length) - n_advance_bytes; /* Length check. Checksum computed by ipx_local no need to compute again */ if (PREDICT_FALSE (n_data_bytes < 0)) { *error = TCP_ERROR_LENGTH; return 0; } if (!is_nolookup) tc = session_lookup_connection_wt4 (fib_index, &ip4->dst_address, &ip4->src_address, tcp->dst_port, tcp->src_port, TRANSPORT_PROTO_TCP, thread_index, &result); } else { ip6_header_t *ip6 = vlib_buffer_get_current (b); if (PREDICT_FALSE (b->current_length < sizeof (*ip6) + sizeof (*tcp))) { *error = TCP_ERROR_LENGTH; return 0; } tcp = ip6_next_header (ip6); vnet_buffer (b)->tcp.hdr_offset = (u8 *) tcp - (u8 *) ip6; n_advance_bytes = tcp_header_bytes (tcp); n_data_bytes = clib_net_to_host_u16 (ip6->payload_length) - n_advance_bytes; n_advance_bytes += sizeof (ip6[0]); if (PREDICT_FALSE (n_data_bytes < 0)) { *error = TCP_ERROR_LENGTH; return 0; } if (!is_nolookup) { if (PREDICT_FALSE (ip6_address_is_link_local_unicast (&ip6->dst_address))) { ip6_main_t *im = &ip6_main; fib_index = vec_elt (im->fib_index_by_sw_if_index, vnet_buffer (b)->sw_if_index[VLIB_RX]); } tc = session_lookup_connection_wt6 (fib_index, &ip6->dst_address, &ip6->src_address, tcp->dst_port, tcp->src_port, TRANSPORT_PROTO_TCP, thread_index, &result); } } if (is_nolookup) tc = (transport_connection_t *) tcp_connection_get (vnet_buffer (b)-> tcp.connection_index, thread_index); vnet_buffer (b)->tcp.seq_number = clib_net_to_host_u32 (tcp->seq_number); vnet_buffer (b)->tcp.ack_number = clib_net_to_host_u32 (tcp->ack_number); vnet_buffer (b)->tcp.data_offset = n_advance_bytes; vnet_buffer (b)->tcp.data_len = n_data_bytes; vnet_buffer (b)->tcp.seq_end = vnet_buffer (b)->tcp.seq_number + n_data_bytes; *error = result ? TCP_ERROR_NONE + result : *error; return tcp_get_connection_from_transport (tc); } /** * Initialize connection by gleaning network and rcv params from buffer * * @param tc connection to initialize * @param b buffer whose current data is pointing at ip * @param is_ip4 flag set to 1 if using ip4 */ always_inline void tcp_init_w_buffer (tcp_connection_t * tc, vlib_buffer_t * b, u8 is_ip4) { tcp_header_t *th = tcp_buffer_hdr (b); tc->c_lcl_port = th->dst_port; tc->c_rmt_port = th->src_port; tc->c_is_ip4 = is_ip4; if (is_ip4) { ip4_header_t *ip4 = vlib_buffer_get_current (b); tc->c_lcl_ip4.as_u32 = ip4->dst_address.as_u32; tc->c_rmt_ip4.as_u32 = ip4->src_address.as_u32; } else { ip6_header_t *ip6 = vlib_buffer_get_current (b); clib_memcpy_fast (&tc->c_lcl_ip6, &ip6->dst_address, sizeof (ip6_address_t)); clib_memcpy_fast (&tc->c_rmt_ip6, &ip6->src_address, sizeof (ip6_address_t)); } tc->irs = vnet_buffer (b)->tcp.seq_number; tc->rcv_nxt = vnet_buffer (b)->tcp.seq_number + 1; tc->rcv_las = tc->rcv_nxt; tc->sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX]; tc->snd_wl1 = vnet_buffer (b)->tcp.seq_number; tc->snd_wl2 = vnet_buffer (b)->tcp.ack_number; /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK} * segments are used to initialize PAWS. */ if (tcp_opts_tstamp (&tc->rcv_opts)) { tc->tsval_recent = tc->rcv_opts.tsval; tc->tsval_recent_age = tcp_time_tstamp (tc->c_thread_index); } if (tcp_opts_wscale (&tc->rcv_opts)) tc->snd_wscale = tc->rcv_opts.wscale; tc->snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale; } always_inline void tcp_update_rto (tcp_connection_t * tc) { tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX); tc->rto = clib_max (tc->rto, TCP_RTO_MIN); } always_inline u8 tcp_is_descheduled (tcp_connection_t * tc) { return (transport_connection_is_descheduled (&tc->connection) ? 1 : 0); } /** * Push TCP header to buffer * * @param vm - vlib_main * @param b - buffer to write the header to * @param sp_net - source port net order * @param dp_net - destination port net order * @param seq - sequence number net order * @param ack - ack number net order * @param tcp_hdr_opts_len - header and options length in bytes * @param flags - header flags * @param wnd - window size * * @return - pointer to start of TCP header */ always_inline void * vlib_buffer_push_tcp_net_order (vlib_buffer_t * b, u16 sp, u16 dp, u32 seq, u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd) { tcp_header_t *th; th = vlib_buffer_push_uninit (b, tcp_hdr_opts_len); th->src_port = sp; th->dst_port = dp; th->seq_number = seq; th->ack_number = ack; th->data_offset_and_reserved = (tcp_hdr_opts_len >> 2) << 4; th->flags = flags; th->window = wnd; th->checksum = 0; th->urgent_pointer = 0; vnet_buffer (b)->l4_hdr_offset = (u8 *) th - b->data; b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID; return th; } /** * Push TCP header to buffer * * @param b - buffer to write the header to * @param sp_net - source port net order * @param dp_net - destination port net order * @param seq - sequence number host order * @param ack - ack number host order * @param tcp_hdr_opts_len - header and options length in bytes * @param flags - header flags * @param wnd - window size * * @return - pointer to start of TCP header */ always_inline void * vlib_buffer_push_tcp (vlib_buffer_t * b, u16 sp_net, u16 dp_net, u32 seq, u32 ack, u8 tcp_hdr_opts_len, u8 flags, u16 wnd) { return vlib_buffer_push_tcp_net_order (b, sp_net, dp_net, clib_host_to_net_u32 (seq), clib_host_to_net_u32 (ack), tcp_hdr_opts_len, flags, clib_host_to_net_u16 (wnd)); } #endif /* SRC_VNET_TCP_TCP_INLINES_H_ */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */