/* * 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. */ /** * @file * @brief TCP host stack utilities */ #include <vnet/tcp/tcp.h> #include <vnet/tcp/tcp_inlines.h> #include <vnet/session/session.h> #include <vnet/fib/fib.h> #include <vnet/dpo/load_balance.h> #include <math.h> tcp_main_t tcp_main; typedef struct { fib_protocol_t nh_proto; vnet_link_t link_type; ip46_address_t ip; u32 sw_if_index; u8 is_add; } tcp_add_del_adj_args_t; static void tcp_add_del_adj_cb (tcp_add_del_adj_args_t * args) { u32 ai; if (args->is_add) { adj_nbr_add_or_lock (args->nh_proto, args->link_type, &args->ip, args->sw_if_index); } else { ai = adj_nbr_find (FIB_PROTOCOL_IP6, VNET_LINK_IP6, &args->ip, args->sw_if_index); if (ai != ADJ_INDEX_INVALID) adj_unlock (ai); } } static void tcp_add_del_adjacency (tcp_connection_t * tc, u8 is_add) { tcp_add_del_adj_args_t args = { .nh_proto = FIB_PROTOCOL_IP6, .link_type = VNET_LINK_IP6, .ip = tc->c_rmt_ip, .sw_if_index = tc->sw_if_index, .is_add = is_add }; vlib_rpc_call_main_thread (tcp_add_del_adj_cb, (u8 *) & args, sizeof (args)); } static void tcp_cc_init (tcp_connection_t * tc) { tc->cc_algo->init (tc); } static void tcp_cc_cleanup (tcp_connection_t * tc) { if (tc->cc_algo->cleanup) tc->cc_algo->cleanup (tc); } void tcp_cc_algo_register (tcp_cc_algorithm_type_e type, const tcp_cc_algorithm_t * vft) { tcp_main_t *tm = vnet_get_tcp_main (); vec_validate (tm->cc_algos, type); tm->cc_algos[type] = *vft; hash_set_mem (tm->cc_algo_by_name, vft->name, type); } tcp_cc_algorithm_t * tcp_cc_algo_get (tcp_cc_algorithm_type_e type) { tcp_main_t *tm = vnet_get_tcp_main (); return &tm->cc_algos[type]; } tcp_cc_algorithm_type_e tcp_cc_algo_new_type (const tcp_cc_algorithm_t * vft) { tcp_main_t *tm = vnet_get_tcp_main (); tcp_cc_algo_register (++tm->cc_last_type, vft); return tm->cc_last_type; } static u32 tcp_connection_bind (u32 session_index, transport_endpoint_t * lcl) { tcp_main_t *tm = &tcp_main; tcp_connection_t *listener; void *iface_ip; pool_get (tm->listener_pool, listener); clib_memset (listener, 0, sizeof (*listener)); listener->c_c_index = listener - tm->listener_pool; listener->c_lcl_port = lcl->port; /* If we are provided a sw_if_index, bind using one of its ips */ if (ip_is_zero (&lcl->ip, 1) && lcl->sw_if_index != ENDPOINT_INVALID_INDEX) { if ((iface_ip = ip_interface_get_first_ip (lcl->sw_if_index, lcl->is_ip4))) ip_set (&lcl->ip, iface_ip, lcl->is_ip4); } ip_copy (&listener->c_lcl_ip, &lcl->ip, lcl->is_ip4); listener->c_is_ip4 = lcl->is_ip4; listener->c_proto = TRANSPORT_PROTO_TCP; listener->c_s_index = session_index; listener->c_fib_index = lcl->fib_index; listener->state = TCP_STATE_LISTEN; listener->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo); tcp_connection_timers_init (listener); TCP_EVT (TCP_EVT_BIND, listener); return listener->c_c_index; } static u32 tcp_session_bind (u32 session_index, transport_endpoint_t * tep) { return tcp_connection_bind (session_index, tep); } static void tcp_connection_unbind (u32 listener_index) { tcp_main_t *tm = vnet_get_tcp_main (); tcp_connection_t *tc; tc = pool_elt_at_index (tm->listener_pool, listener_index); TCP_EVT (TCP_EVT_UNBIND, tc); /* Poison the entry */ if (CLIB_DEBUG > 0) clib_memset (tc, 0xFA, sizeof (*tc)); pool_put_index (tm->listener_pool, listener_index); } static u32 tcp_session_unbind (u32 listener_index) { tcp_connection_unbind (listener_index); return 0; } static transport_connection_t * tcp_session_get_listener (u32 listener_index) { tcp_main_t *tm = vnet_get_tcp_main (); tcp_connection_t *tc; tc = pool_elt_at_index (tm->listener_pool, listener_index); return &tc->connection; } /** * Cleanup half-open connection * */ static void tcp_half_open_connection_free (tcp_connection_t * tc) { tcp_main_t *tm = vnet_get_tcp_main (); clib_spinlock_lock_if_init (&tm->half_open_lock); if (CLIB_DEBUG) clib_memset (tc, 0xFA, sizeof (*tc)); pool_put (tm->half_open_connections, tc); clib_spinlock_unlock_if_init (&tm->half_open_lock); } /** * Try to cleanup half-open connection * * If called from a thread that doesn't own tc, the call won't have any * effect. * * @param tc - connection to be cleaned up * @return non-zero if cleanup failed. */ int tcp_half_open_connection_cleanup (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk; /* Make sure this is the owning thread */ if (tc->c_thread_index != vlib_get_thread_index ()) return 1; session_half_open_delete_notify (TRANSPORT_PROTO_TCP, tc->c_s_ho_handle); wrk = tcp_get_worker (tc->c_thread_index); tcp_timer_reset (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN); tcp_half_open_connection_free (tc); return 0; } static tcp_connection_t * tcp_half_open_connection_new (void) { tcp_main_t *tm = vnet_get_tcp_main (); tcp_connection_t *tc = 0; ASSERT (vlib_get_thread_index () == 0); pool_get (tm->half_open_connections, tc); clib_memset (tc, 0, sizeof (*tc)); tc->c_c_index = tc - tm->half_open_connections; return tc; } /** * Cleans up connection state. * * No notifications. */ void tcp_connection_cleanup (tcp_connection_t * tc) { TCP_EVT (TCP_EVT_DELETE, tc); /* Cleanup local endpoint if this was an active connect */ if (!(tc->cfg_flags & TCP_CFG_F_NO_ENDPOINT)) transport_endpoint_cleanup (TRANSPORT_PROTO_TCP, &tc->c_lcl_ip, tc->c_lcl_port); /* Check if connection is not yet fully established */ if (tc->state == TCP_STATE_SYN_SENT) { /* Try to remove the half-open connection. If this is not the owning * thread, tc won't be removed. Retransmit or establish timers will * eventually expire and call again cleanup on the right thread. */ if (tcp_half_open_connection_cleanup (tc)) tc->flags |= TCP_CONN_HALF_OPEN_DONE; } else { /* Make sure all timers are cleared */ tcp_connection_timers_reset (tc); if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6)) tcp_add_del_adjacency (tc, 0); tcp_cc_cleanup (tc); vec_free (tc->snd_sacks); vec_free (tc->snd_sacks_fl); vec_free (tc->rcv_opts.sacks); pool_free (tc->sack_sb.holes); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_cleanup (tc); tcp_connection_free (tc); } } /** * Connection removal. * * This should be called only once connection enters CLOSED state. Note * that it notifies the session of the removal event, so if the goal is to * just remove the connection, call tcp_connection_cleanup instead. */ void tcp_connection_del (tcp_connection_t * tc) { session_transport_delete_notify (&tc->connection); tcp_connection_cleanup (tc); } tcp_connection_t * tcp_connection_alloc (u8 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); tcp_connection_t *tc; pool_get (wrk->connections, tc); clib_memset (tc, 0, sizeof (*tc)); tc->c_c_index = tc - wrk->connections; tc->c_thread_index = thread_index; return tc; } tcp_connection_t * tcp_connection_alloc_w_base (u8 thread_index, tcp_connection_t * base) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); tcp_connection_t *tc; pool_get (wrk->connections, tc); clib_memcpy_fast (tc, base, sizeof (*tc)); tc->c_c_index = tc - wrk->connections; tc->c_thread_index = thread_index; return tc; } void tcp_connection_free (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); if (CLIB_DEBUG) { clib_memset (tc, 0xFA, sizeof (*tc)); pool_put (wrk->connections, tc); return; } pool_put (wrk->connections, tc); } void tcp_program_cleanup (tcp_worker_ctx_t * wrk, tcp_connection_t * tc) { tcp_cleanup_req_t *req; clib_time_type_t now; now = tcp_time_now_us (tc->c_thread_index); clib_fifo_add2 (wrk->pending_cleanups, req); req->connection_index = tc->c_c_index; req->free_time = now + tcp_cfg.cleanup_time; } /** * Begin connection closing procedure. * * If at the end the connection is not in CLOSED state, it is not removed. * Instead, we rely on on TCP to advance through state machine to either * 1) LAST_ACK (passive close) whereby when the last ACK is received * tcp_connection_del is called. This notifies session of the delete and * calls cleanup. * 2) TIME_WAIT (active close) whereby after 2MSL the 2MSL timer triggers * and cleanup is called. * * N.B. Half-close connections are not supported */ void tcp_connection_close (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); TCP_EVT (TCP_EVT_CLOSE, tc); /* Send/Program FIN if needed and switch state */ switch (tc->state) { case TCP_STATE_SYN_SENT: /* Try to cleanup. If not on the right thread, mark as half-open done. * Connection will be cleaned up when establish timer pops */ tcp_connection_cleanup (tc); break; case TCP_STATE_SYN_RCVD: tcp_connection_timers_reset (tc); tcp_send_fin (tc); tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1); tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time); break; case TCP_STATE_ESTABLISHED: /* If closing with unread data, reset the connection */ if (transport_max_rx_dequeue (&tc->connection)) { tcp_send_reset (tc); tcp_connection_timers_reset (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (tcp_get_worker (tc->c_thread_index), tc); tcp_worker_stats_inc (wrk, rst_unread, 1); break; } if (!transport_max_tx_dequeue (&tc->connection)) tcp_send_fin (tc); else tc->flags |= TCP_CONN_FINPNDG; tcp_connection_set_state (tc, TCP_STATE_FIN_WAIT_1); /* Set a timer in case the peer stops responding. Otherwise the * connection will be stuck here forever. */ ASSERT (tc->timers[TCP_TIMER_WAITCLOSE] == TCP_TIMER_HANDLE_INVALID); tcp_timer_set (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time); break; case TCP_STATE_CLOSE_WAIT: if (!transport_max_tx_dequeue (&tc->connection)) { tcp_send_fin (tc); tcp_connection_timers_reset (tc); tcp_connection_set_state (tc, TCP_STATE_LAST_ACK); tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time); } else tc->flags |= TCP_CONN_FINPNDG; break; case TCP_STATE_FIN_WAIT_1: tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.finwait1_time); break; case TCP_STATE_CLOSED: /* Cleanup should've been programmed already */ break; default: TCP_DBG ("state: %u", tc->state); } } static void tcp_session_close (u32 conn_index, u32 thread_index) { tcp_connection_t *tc; tc = tcp_connection_get (conn_index, thread_index); tcp_connection_close (tc); } static void tcp_session_cleanup (u32 conn_index, u32 thread_index) { tcp_connection_t *tc; tc = tcp_connection_get (conn_index, thread_index); if (!tc) return; tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_connection_cleanup (tc); } static void tcp_session_cleanup_ho (u32 conn_index) { tcp_worker_ctx_t *wrk; tcp_connection_t *tc; tc = tcp_half_open_connection_get (conn_index); wrk = tcp_get_worker (tc->c_thread_index); tcp_timer_reset (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN); tcp_half_open_connection_free (tc); } static void tcp_session_reset (u32 conn_index, u32 thread_index) { tcp_connection_t *tc; tc = tcp_connection_get (conn_index, thread_index); tcp_send_reset (tc); tcp_connection_timers_reset (tc); tcp_cong_recovery_off (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (tcp_get_worker (thread_index), tc); } /** * Initialize all connection timers as invalid */ void tcp_connection_timers_init (tcp_connection_t * tc) { int i; /* Set all to invalid */ for (i = 0; i < TCP_N_TIMERS; i++) { tc->timers[i] = TCP_TIMER_HANDLE_INVALID; } tc->rto = TCP_RTO_INIT; } /** * Stop all connection timers */ void tcp_connection_timers_reset (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); int i; for (i = 0; i < TCP_N_TIMERS; i++) tcp_timer_reset (&wrk->timer_wheel, tc, i); } #if 0 typedef struct ip4_tcp_hdr { ip4_header_t ip; tcp_header_t tcp; } ip4_tcp_hdr_t; typedef struct ip6_tcp_hdr { ip6_header_t ip; tcp_header_t tcp; } ip6_tcp_hdr_t; static void tcp_connection_select_lb_bucket (tcp_connection_t * tc, const dpo_id_t * dpo, dpo_id_t * result) { const dpo_id_t *choice; load_balance_t *lb; int hash; lb = load_balance_get (dpo->dpoi_index); if (tc->c_is_ip4) { ip4_tcp_hdr_t hdr; clib_memset (&hdr, 0, sizeof (hdr)); hdr.ip.protocol = IP_PROTOCOL_TCP; hdr.ip.address_pair.src.as_u32 = tc->c_lcl_ip.ip4.as_u32; hdr.ip.address_pair.dst.as_u32 = tc->c_rmt_ip.ip4.as_u32; hdr.tcp.src_port = tc->c_lcl_port; hdr.tcp.dst_port = tc->c_rmt_port; hash = ip4_compute_flow_hash (&hdr.ip, lb->lb_hash_config); } else { ip6_tcp_hdr_t hdr; clib_memset (&hdr, 0, sizeof (hdr)); hdr.ip.protocol = IP_PROTOCOL_TCP; clib_memcpy_fast (&hdr.ip.src_address, &tc->c_lcl_ip.ip6, sizeof (ip6_address_t)); clib_memcpy_fast (&hdr.ip.dst_address, &tc->c_rmt_ip.ip6, sizeof (ip6_address_t)); hdr.tcp.src_port = tc->c_lcl_port; hdr.tcp.dst_port = tc->c_rmt_port; hash = ip6_compute_flow_hash (&hdr.ip, lb->lb_hash_config); } choice = load_balance_get_bucket_i (lb, hash & lb->lb_n_buckets_minus_1); dpo_copy (result, choice); } fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc) { fib_prefix_t prefix; u32 fib_index; clib_memcpy_fast (&prefix.fp_addr, &tc->c_rmt_ip, sizeof (prefix.fp_addr)); prefix.fp_proto = tc->c_is_ip4 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6; prefix.fp_len = tc->c_is_ip4 ? 32 : 128; fib_index = fib_table_find (prefix.fp_proto, tc->c_fib_index); return fib_table_lookup (fib_index, &prefix); } static int tcp_connection_stack_on_fib_entry (tcp_connection_t * tc) { dpo_id_t choice = DPO_INVALID; u32 output_node_index; fib_entry_t *fe; fe = fib_entry_get (tc->c_rmt_fei); if (fe->fe_lb.dpoi_type != DPO_LOAD_BALANCE) return -1; tcp_connection_select_lb_bucket (tc, &fe->fe_lb, &choice); output_node_index = tc->c_is_ip4 ? tcp4_output_node.index : tcp6_output_node.index; dpo_stack_from_node (output_node_index, &tc->c_rmt_dpo, &choice); return 0; } /** Stack tcp connection on peer's fib entry. * * This ultimately populates the dpo the connection will use to send packets. */ static void tcp_connection_fib_attach (tcp_connection_t * tc) { tc->c_rmt_fei = tcp_lookup_rmt_in_fib (tc); ASSERT (tc->c_rmt_fei != FIB_NODE_INDEX_INVALID); tcp_connection_stack_on_fib_entry (tc); } #endif /* 0 */ /** * Generate random iss as per rfc6528 */ static u32 tcp_generate_random_iss (tcp_connection_t * tc) { tcp_main_t *tm = &tcp_main; u64 tmp; if (tc->c_is_ip4) tmp = (u64) tc->c_lcl_ip.ip4.as_u32 << 32 | (u64) tc->c_rmt_ip.ip4.as_u32; else tmp = tc->c_lcl_ip.ip6.as_u64[0] ^ tc->c_lcl_ip.ip6.as_u64[1] ^ tc->c_rmt_ip.ip6.as_u64[0] ^ tc->c_rmt_ip.ip6.as_u64[1]; tmp ^= tm->iss_seed.first | ((u64) tc->c_lcl_port << 16 | tc->c_rmt_port); tmp ^= tm->iss_seed.second; tmp = clib_xxhash (tmp) + clib_cpu_time_now (); return ((tmp >> 32) ^ (tmp & 0xffffffff)); } /** * Initialize max segment size we're able to process. * * The value is constrained by the output interface's MTU and by the size * of the IP and TCP headers (see RFC6691). It is also what we advertise * to our peer. */ static void tcp_init_rcv_mss (tcp_connection_t * tc) { u8 ip_hdr_len; /* Already provided at connection init time */ if (tc->mss) return; ip_hdr_len = tc->c_is_ip4 ? sizeof (ip4_header_t) : sizeof (ip6_header_t); tc->mss = tcp_cfg.default_mtu - sizeof (tcp_header_t) - ip_hdr_len; } static void tcp_init_mss (tcp_connection_t * tc) { u16 default_min_mss = 536; tcp_init_rcv_mss (tc); /* TODO consider PMTU discovery */ tc->snd_mss = clib_min (tc->rcv_opts.mss, tc->mss); if (tc->snd_mss < 45) { /* Assume that at least the min default mss works */ tc->snd_mss = default_min_mss; tc->rcv_opts.mss = default_min_mss; } /* We should have enough space for 40 bytes of options */ ASSERT (tc->snd_mss > 45); /* If we use timestamp option, account for it and make sure * the options are 4-byte aligned */ if (tcp_opts_tstamp (&tc->rcv_opts)) tc->snd_mss -= TCP_OPTION_LEN_TIMESTAMP + 2 /* alignment */; } /** * Initialize connection send variables. */ void tcp_init_snd_vars (tcp_connection_t * tc) { /* * We use the time to randomize iss and for setting up the initial * timestamp. Make sure it's updated otherwise syn and ack in the * handshake may make it look as if time has flown in the opposite * direction for us. */ tcp_update_time_now (tcp_get_worker (vlib_get_thread_index ())); tcp_init_rcv_mss (tc); tc->iss = tcp_generate_random_iss (tc); tc->snd_una = tc->iss; tc->snd_nxt = tc->iss + 1; tc->srtt = 0.1 * THZ; /* 100 ms */ if (!tcp_cfg.csum_offload) tc->cfg_flags |= TCP_CFG_F_NO_CSUM_OFFLOAD; } void tcp_enable_pacing (tcp_connection_t * tc) { u32 byte_rate; byte_rate = tc->cwnd / (tc->srtt * TCP_TICK); transport_connection_tx_pacer_init (&tc->connection, byte_rate, tc->cwnd); tc->mrtt_us = (u32) ~ 0; } /** Initialize tcp connection variables * * Should be called after having received a msg from the peer, i.e., a SYN or * a SYNACK, such that connection options have already been exchanged. */ void tcp_connection_init_vars (tcp_connection_t * tc) { tcp_connection_timers_init (tc); tcp_init_mss (tc); scoreboard_init (&tc->sack_sb); if (tc->state == TCP_STATE_SYN_RCVD) tcp_init_snd_vars (tc); tcp_cc_init (tc); if (!tc->c_is_ip4 && ip6_address_is_link_local_unicast (&tc->c_rmt_ip6)) tcp_add_del_adjacency (tc, 1); /* tcp_connection_fib_attach (tc); */ if (transport_connection_is_tx_paced (&tc->connection) || tcp_cfg.enable_tx_pacing) tcp_enable_pacing (tc); if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE) tcp_bt_init (tc); if (!tcp_cfg.allow_tso) tc->cfg_flags |= TCP_CFG_F_NO_TSO; tc->start_ts = tcp_time_now_us (tc->c_thread_index); } static int tcp_alloc_custom_local_endpoint (tcp_main_t * tm, ip46_address_t * lcl_addr, u16 * lcl_port, u8 is_ip4) { int index, port; if (is_ip4) { index = tm->last_v4_addr_rotor++; if (tm->last_v4_addr_rotor >= vec_len (tcp_cfg.ip4_src_addrs)) tm->last_v4_addr_rotor = 0; lcl_addr->ip4.as_u32 = tcp_cfg.ip4_src_addrs[index].as_u32; } else { index = tm->last_v6_addr_rotor++; if (tm->last_v6_addr_rotor >= vec_len (tcp_cfg.ip6_src_addrs)) tm->last_v6_addr_rotor = 0; clib_memcpy_fast (&lcl_addr->ip6, &tcp_cfg.ip6_src_addrs[index], sizeof (ip6_address_t)); } port = transport_alloc_local_port (TRANSPORT_PROTO_TCP, lcl_addr); if (port < 1) return SESSION_E_NOPORT; *lcl_port = port; return 0; } static int tcp_session_open (transport_endpoint_cfg_t * rmt) { tcp_main_t *tm = vnet_get_tcp_main (); tcp_connection_t *tc; ip46_address_t lcl_addr; u16 lcl_port; int rv; /* * Allocate local endpoint */ if ((rmt->is_ip4 && vec_len (tcp_cfg.ip4_src_addrs)) || (!rmt->is_ip4 && vec_len (tcp_cfg.ip6_src_addrs))) rv = tcp_alloc_custom_local_endpoint (tm, &lcl_addr, &lcl_port, rmt->is_ip4); else rv = transport_alloc_local_endpoint (TRANSPORT_PROTO_TCP, rmt, &lcl_addr, &lcl_port); if (rv) { if (rv != SESSION_E_PORTINUSE) return rv; if (session_lookup_connection (rmt->fib_index, &lcl_addr, &rmt->ip, lcl_port, rmt->port, TRANSPORT_PROTO_UDP, rmt->is_ip4)) return SESSION_E_PORTINUSE; /* 5-tuple is available so increase lcl endpoint refcount and proceed * with connection allocation */ transport_share_local_endpoint (TRANSPORT_PROTO_UDP, &lcl_addr, lcl_port); } /* * Create connection and send SYN */ clib_spinlock_lock_if_init (&tm->half_open_lock); tc = tcp_half_open_connection_new (); ip_copy (&tc->c_rmt_ip, &rmt->ip, rmt->is_ip4); ip_copy (&tc->c_lcl_ip, &lcl_addr, rmt->is_ip4); tc->c_rmt_port = rmt->port; tc->c_lcl_port = clib_host_to_net_u16 (lcl_port); tc->c_is_ip4 = rmt->is_ip4; tc->c_proto = TRANSPORT_PROTO_TCP; tc->c_fib_index = rmt->fib_index; tc->cc_algo = tcp_cc_algo_get (tcp_cfg.cc_algo); /* The other connection vars will be initialized after SYN ACK */ tcp_connection_timers_init (tc); tc->mss = rmt->mss; TCP_EVT (TCP_EVT_OPEN, tc); tc->state = TCP_STATE_SYN_SENT; tcp_init_snd_vars (tc); tcp_send_syn (tc); clib_spinlock_unlock_if_init (&tm->half_open_lock); return tc->c_c_index; } static u8 * format_tcp_session (u8 * s, va_list * args) { u32 tci = va_arg (*args, u32); u32 thread_index = va_arg (*args, u32); u32 verbose = va_arg (*args, u32); tcp_connection_t *tc; tc = tcp_connection_get (tci, thread_index); if (tc) s = format (s, "%U", format_tcp_connection, tc, verbose); else s = format (s, "empty\n"); return s; } static u8 * format_tcp_listener_session (u8 * s, va_list * args) { u32 tci = va_arg (*args, u32); u32 __clib_unused thread_index = va_arg (*args, u32); u32 verbose = va_arg (*args, u32); tcp_connection_t *tc = tcp_listener_get (tci); s = format (s, "%-" SESSION_CLI_ID_LEN "U", format_tcp_connection_id, tc); if (verbose) s = format (s, "%-" SESSION_CLI_STATE_LEN "U", format_tcp_state, tc->state); return s; } static u8 * format_tcp_half_open_session (u8 * s, va_list * args) { u32 tci = va_arg (*args, u32); u32 __clib_unused thread_index = va_arg (*args, u32); tcp_connection_t *tc = tcp_half_open_connection_get (tci); return format (s, "%U", format_tcp_connection_id, tc); } static transport_connection_t * tcp_session_get_transport (u32 conn_index, u32 thread_index) { tcp_connection_t *tc = tcp_connection_get (conn_index, thread_index); if (PREDICT_FALSE (!tc)) return 0; return &tc->connection; } static transport_connection_t * tcp_half_open_session_get_transport (u32 conn_index) { tcp_connection_t *tc = tcp_half_open_connection_get (conn_index); return &tc->connection; } static u16 tcp_session_cal_goal_size (tcp_connection_t * tc) { u16 goal_size = tc->snd_mss; goal_size = tcp_cfg.max_gso_size - tc->snd_mss % tcp_cfg.max_gso_size; goal_size = clib_min (goal_size, tc->snd_wnd / 2); return goal_size > tc->snd_mss ? goal_size : tc->snd_mss; } always_inline u32 tcp_round_snd_space (tcp_connection_t * tc, u32 snd_space) { if (PREDICT_FALSE (tc->snd_wnd < tc->snd_mss)) { return tc->snd_wnd <= snd_space ? tc->snd_wnd : 0; } /* If not snd_wnd constrained and we can't write at least a segment, * don't try at all */ if (PREDICT_FALSE (snd_space < tc->snd_mss)) return snd_space < tc->cwnd ? 0 : snd_space; /* round down to mss multiple */ return snd_space - (snd_space % tc->snd_mss); } /** * Compute tx window session is allowed to fill. * * Takes into account available send space, snd_mss and the congestion * state of the connection. If possible, the value returned is a multiple * of snd_mss. * * @param tc tcp connection * @return number of bytes session is allowed to write */ static inline u32 tcp_snd_space_inline (tcp_connection_t * tc) { int snd_space; /* Fast path is disabled when recovery is on. @ref tcp_session_custom_tx * controls both retransmits and the sending of new data while congested */ if (PREDICT_FALSE (tcp_in_cong_recovery (tc) || tc->state == TCP_STATE_CLOSED)) return 0; snd_space = tcp_available_output_snd_space (tc); /* If we got dupacks or sacked bytes but we're not yet in recovery, try * to force the peer to send enough dupacks to start retransmitting as * per Limited Transmit (RFC3042) */ if (PREDICT_FALSE (tc->rcv_dupacks || tc->sack_sb.sacked_bytes)) { int snt_limited, n_pkts; n_pkts = tcp_opts_sack_permitted (&tc->rcv_opts) ? tc->sack_sb.reorder - 1 : 2; if ((seq_lt (tc->limited_transmit, tc->snd_nxt - n_pkts * tc->snd_mss) || seq_gt (tc->limited_transmit, tc->snd_nxt))) tc->limited_transmit = tc->snd_nxt; ASSERT (seq_leq (tc->limited_transmit, tc->snd_nxt)); snt_limited = tc->snd_nxt - tc->limited_transmit; snd_space = clib_max (n_pkts * tc->snd_mss - snt_limited, 0); } return tcp_round_snd_space (tc, snd_space); } u32 tcp_snd_space (tcp_connection_t * tc) { return tcp_snd_space_inline (tc); } static int tcp_session_send_params (transport_connection_t * trans_conn, transport_send_params_t * sp) { tcp_connection_t *tc = (tcp_connection_t *) trans_conn; /* Ensure snd_mss does accurately reflect the amount of data we can push * in a segment. This also makes sure that options are updated according to * the current state of the connection. */ tcp_update_burst_snd_vars (tc); if (PREDICT_FALSE (tc->cfg_flags & TCP_CFG_F_TSO)) sp->snd_mss = tcp_session_cal_goal_size (tc); else sp->snd_mss = tc->snd_mss; sp->snd_space = clib_min (tcp_snd_space_inline (tc), tc->snd_wnd - (tc->snd_nxt - tc->snd_una)); ASSERT (seq_geq (tc->snd_nxt, tc->snd_una)); /* This still works if fast retransmit is on */ sp->tx_offset = tc->snd_nxt - tc->snd_una; sp->flags = sp->snd_space ? 0 : TRANSPORT_SND_F_DESCHED; return 0; } static void tcp_timer_waitclose_handler (tcp_connection_t * tc) { tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); switch (tc->state) { case TCP_STATE_CLOSE_WAIT: tcp_connection_timers_reset (tc); /* App never returned with a close */ if (!(tc->flags & TCP_CONN_FINPNDG)) { tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (wrk, tc); tcp_worker_stats_inc (wrk, to_closewait, 1); break; } /* Send FIN either way and switch to LAST_ACK. */ tcp_cong_recovery_off (tc); /* Make sure we don't try to send unsent data */ tc->snd_nxt = tc->snd_una; tcp_send_fin (tc); tcp_connection_set_state (tc, TCP_STATE_LAST_ACK); session_transport_closed_notify (&tc->connection); /* Make sure we don't wait in LAST ACK forever */ tcp_timer_set (&wrk->timer_wheel, tc, TCP_TIMER_WAITCLOSE, tcp_cfg.lastack_time); tcp_worker_stats_inc (wrk, to_closewait2, 1); /* Don't delete the connection yet */ break; case TCP_STATE_FIN_WAIT_1: tcp_connection_timers_reset (tc); if (tc->flags & TCP_CONN_FINPNDG) { /* If FIN pending, we haven't sent everything, but we did try. * Notify session layer that transport is closed. */ tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_send_reset (tc); tcp_program_cleanup (wrk, tc); } else { /* We've sent the fin but no progress. Close the connection and * to make sure everything is flushed, setup a cleanup timer */ tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_program_cleanup (wrk, tc); } session_transport_closed_notify (&tc->connection); tcp_worker_stats_inc (wrk, to_finwait1, 1); break; case TCP_STATE_LAST_ACK: tcp_connection_timers_reset (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (wrk, tc); tcp_worker_stats_inc (wrk, to_lastack, 1); break; case TCP_STATE_CLOSING: tcp_connection_timers_reset (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (wrk, tc); tcp_worker_stats_inc (wrk, to_closing, 1); break; case TCP_STATE_FIN_WAIT_2: tcp_send_reset (tc); tcp_connection_timers_reset (tc); tcp_connection_set_state (tc, TCP_STATE_CLOSED); session_transport_closed_notify (&tc->connection); tcp_program_cleanup (wrk, tc); tcp_worker_stats_inc (wrk, to_finwait2, 1); break; case TCP_STATE_TIME_WAIT: tcp_connection_set_state (tc, TCP_STATE_CLOSED); tcp_program_cleanup (wrk, tc); break; default: clib_warning ("waitclose in state: %U", format_tcp_state, tc->state); break; } } /* *INDENT-OFF* */ static timer_expiration_handler *timer_expiration_handlers[TCP_N_TIMERS] = { tcp_timer_retransmit_handler, tcp_timer_persist_handler, tcp_timer_waitclose_handler, tcp_timer_retransmit_syn_handler, }; /* *INDENT-ON* */ static void tcp_dispatch_pending_timers (tcp_worker_ctx_t * wrk) { u32 n_timers, connection_index, timer_id, thread_index, timer_handle; tcp_connection_t *tc; int i; if (!(n_timers = clib_fifo_elts (wrk->pending_timers))) return; thread_index = wrk->vm->thread_index; for (i = 0; i < clib_min (n_timers, wrk->max_timers_per_loop); i++) { clib_fifo_sub1 (wrk->pending_timers, timer_handle); connection_index = timer_handle & 0x0FFFFFFF; timer_id = timer_handle >> 28; if (PREDICT_TRUE (timer_id != TCP_TIMER_RETRANSMIT_SYN)) tc = tcp_connection_get (connection_index, thread_index); else tc = tcp_half_open_connection_get (connection_index); if (PREDICT_FALSE (!tc)) continue; /* Skip if the timer is not pending. Probably it was reset while * waiting for dispatch */ if (PREDICT_FALSE (!(tc->pending_timers & (1 << timer_id)))) continue; tc->pending_timers &= ~(1 << timer_id); /* Skip timer if it was rearmed while pending dispatch */ if (PREDICT_FALSE (tc->timers[timer_id] != TCP_TIMER_HANDLE_INVALID)) continue; (*timer_expiration_handlers[timer_id]) (tc); } if (thread_index == 0 && clib_fifo_elts (wrk->pending_timers)) session_queue_run_on_main_thread (wrk->vm); } static void tcp_handle_cleanups (tcp_worker_ctx_t * wrk, clib_time_type_t now) { u32 thread_index = wrk->vm->thread_index; tcp_cleanup_req_t *req; tcp_connection_t *tc; while (clib_fifo_elts (wrk->pending_cleanups)) { req = clib_fifo_head (wrk->pending_cleanups); if (req->free_time > now) break; clib_fifo_sub2 (wrk->pending_cleanups, req); tc = tcp_connection_get (req->connection_index, thread_index); if (PREDICT_FALSE (!tc)) continue; session_transport_delete_notify (&tc->connection); tcp_connection_cleanup (tc); } } static void tcp_update_time (f64 now, u8 thread_index) { tcp_worker_ctx_t *wrk = tcp_get_worker (thread_index); tcp_set_time_now (wrk, now); tcp_handle_cleanups (wrk, now); tcp_timer_expire_timers (&wrk->timer_wheel, now); tcp_dispatch_pending_timers (wrk); } static void tcp_session_flush_data (transport_connection_t * tconn) { tcp_connection_t *tc = (tcp_connection_t *) tconn; if (tc->flags & TCP_CONN_PSH_PENDING) return; tc->flags |= TCP_CONN_PSH_PENDING; tc->psh_seq = tc->snd_una + transport_max_tx_dequeue (tconn) - 1; } /* *INDENT-OFF* */ const static transport_proto_vft_t tcp_proto = { .enable = vnet_tcp_enable_disable, .start_listen = tcp_session_bind, .stop_listen = tcp_session_unbind, .push_header = tcp_session_push_header, .get_connection = tcp_session_get_transport, .get_listener = tcp_session_get_listener, .get_half_open = tcp_half_open_session_get_transport, .connect = tcp_session_open, .close = tcp_session_close, .cleanup = tcp_session_cleanup, .cleanup_ho = tcp_session_cleanup_ho, .reset = tcp_session_reset, .send_params = tcp_session_send_params, .update_time = tcp_update_time, .flush_data = tcp_session_flush_data, .custom_tx = tcp_session_custom_tx, .format_connection = format_tcp_session, .format_listener = format_tcp_listener_session, .format_half_open = format_tcp_half_open_session, .transport_options = { .name = "tcp", .short_name = "T", .tx_type = TRANSPORT_TX_PEEK, .service_type = TRANSPORT_SERVICE_VC, }, }; /* *INDENT-ON* */ void tcp_connection_tx_pacer_update (tcp_connection_t * tc) { if (!transport_connection_is_tx_paced (&tc->connection)) return; f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us); transport_connection_tx_pacer_update (&tc->connection, tcp_cc_get_pacing_rate (tc), srtt * CLIB_US_TIME_FREQ); } void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window, u32 start_bucket) { f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us); transport_connection_tx_pacer_reset (&tc->connection, tcp_cc_get_pacing_rate (tc), start_bucket, srtt * CLIB_US_TIME_FREQ); } void tcp_reschedule (tcp_connection_t * tc) { if (tcp_in_cong_recovery (tc) || tcp_snd_space_inline (tc)) transport_connection_reschedule (&tc->connection); } static void tcp_expired_timers_dispatch (u32 * expired_timers) { u32 thread_index = vlib_get_thread_index (), n_left, max_per_loop; u32 connection_index, timer_id, n_expired, max_loops; tcp_worker_ctx_t *wrk; tcp_connection_t *tc; int i; wrk = tcp_get_worker (thread_index); n_expired = vec_len (expired_timers); tcp_worker_stats_inc (wrk, timer_expirations, n_expired); n_left = clib_fifo_elts (wrk->pending_timers); /* * Invalidate all timer handles before dispatching. This avoids dangling * index references to timer wheel pool entries that have been freed. */ for (i = 0; i < n_expired; i++) { connection_index = expired_timers[i] & 0x0FFFFFFF; timer_id = expired_timers[i] >> 28; if (timer_id != TCP_TIMER_RETRANSMIT_SYN) tc = tcp_connection_get (connection_index, thread_index); else tc = tcp_half_open_connection_get (connection_index); TCP_EVT (TCP_EVT_TIMER_POP, connection_index, timer_id); tc->timers[timer_id] = TCP_TIMER_HANDLE_INVALID; tc->pending_timers |= (1 << timer_id); } clib_fifo_add (wrk->pending_timers, expired_timers, n_expired); max_loops = clib_max (1, 0.5 * TCP_TIMER_TICK * wrk->vm->loops_per_second); max_per_loop = clib_max ((n_left + n_expired) / max_loops, 10); max_per_loop = clib_min (max_per_loop, VLIB_FRAME_SIZE); wrk->max_timers_per_loop = clib_max (n_left ? wrk->max_timers_per_loop : 0, max_per_loop); if (thread_index == 0) session_queue_run_on_main_thread (wrk->vm); } static void tcp_initialize_iss_seed (tcp_main_t * tm) { u32 default_seed = random_default_seed (); u64 time_now = clib_cpu_time_now (); tm->iss_seed.first = (u64) random_u32 (&default_seed) << 32; tm->iss_seed.second = random_u64 (&time_now); } static clib_error_t * tcp_main_enable (vlib_main_t * vm) { vlib_thread_main_t *vtm = vlib_get_thread_main (); u32 num_threads, n_workers, prealloc_conn_per_wrk; tcp_connection_t *tc __attribute__ ((unused)); tcp_main_t *tm = vnet_get_tcp_main (); tcp_worker_ctx_t *wrk; clib_error_t *error = 0; int thread; if ((error = vlib_call_init_function (vm, ip_main_init))) return error; if ((error = vlib_call_init_function (vm, ip4_lookup_init))) return error; if ((error = vlib_call_init_function (vm, ip6_lookup_init))) return error; /* * Registrations */ ip4_register_protocol (IP_PROTOCOL_TCP, tcp4_input_node.index); ip6_register_protocol (IP_PROTOCOL_TCP, tcp6_input_node.index); /* * Initialize data structures */ num_threads = 1 /* main thread */ + vtm->n_threads; vec_validate (tm->wrk_ctx, num_threads - 1); n_workers = num_threads == 1 ? 1 : vtm->n_threads; prealloc_conn_per_wrk = tcp_cfg.preallocated_connections / n_workers; wrk = &tm->wrk_ctx[0]; wrk->tco_next_node[0] = vlib_node_get_next (vm, session_queue_node.index, tcp4_output_node.index); wrk->tco_next_node[1] = vlib_node_get_next (vm, session_queue_node.index, tcp6_output_node.index); for (thread = 0; thread < num_threads; thread++) { wrk = &tm->wrk_ctx[thread]; vec_validate (wrk->pending_deq_acked, 255); vec_validate (wrk->pending_disconnects, 255); vec_validate (wrk->pending_resets, 255); vec_reset_length (wrk->pending_deq_acked); vec_reset_length (wrk->pending_disconnects); vec_reset_length (wrk->pending_resets); wrk->vm = vlib_get_main_by_index (thread); wrk->max_timers_per_loop = 10; if (thread > 0) { wrk->tco_next_node[0] = tm->wrk_ctx[0].tco_next_node[0]; wrk->tco_next_node[1] = tm->wrk_ctx[0].tco_next_node[1]; } /* * Preallocate connections. Assume that thread 0 won't * use preallocated threads when running multi-core */ if ((thread > 0 || num_threads == 1) && prealloc_conn_per_wrk) pool_init_fixed (wrk->connections, prealloc_conn_per_wrk); tcp_timer_initialize_wheel (&wrk->timer_wheel, tcp_expired_timers_dispatch, vlib_time_now (vm)); } /* * Use a preallocated half-open connection pool? */ if (tcp_cfg.preallocated_half_open_connections) pool_init_fixed (tm->half_open_connections, tcp_cfg.preallocated_half_open_connections); if (num_threads > 1) { clib_spinlock_init (&tm->half_open_lock); } tcp_initialize_iss_seed (tm); tm->bytes_per_buffer = vlib_buffer_get_default_data_size (vm); tm->cc_last_type = TCP_CC_LAST; tm->ipl_next_node[0] = vlib_node_get_next (vm, session_queue_node.index, ip4_lookup_node.index); tm->ipl_next_node[1] = vlib_node_get_next (vm, session_queue_node.index, ip6_lookup_node.index); return error; } clib_error_t * vnet_tcp_enable_disable (vlib_main_t * vm, u8 is_en) { if (is_en) { if (tcp_main.is_enabled) return 0; return tcp_main_enable (vm); } else { tcp_main.is_enabled = 0; } return 0; } void tcp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add) { tcp_main_t *tm = &tcp_main; if (is_ip4) tm->punt_unknown4 = is_add; else tm->punt_unknown6 = is_add; } /** * Initialize default values for tcp parameters */ static void tcp_configuration_init (void) { /* Initial wnd for SYN. Fifos are not allocated at that point so use some * predefined value. For SYN-ACK we still want the scale to be computed in * the same way */ tcp_cfg.max_rx_fifo = 32 << 20; tcp_cfg.min_rx_fifo = 4 << 10; tcp_cfg.default_mtu = 1500; tcp_cfg.initial_cwnd_multiplier = 0; tcp_cfg.enable_tx_pacing = 1; tcp_cfg.allow_tso = 0; tcp_cfg.csum_offload = 1; tcp_cfg.cc_algo = TCP_CC_CUBIC; tcp_cfg.rwnd_min_update_ack = 1; tcp_cfg.max_gso_size = TCP_MAX_GSO_SZ; /* Time constants defined as timer tick (100us) multiples */ tcp_cfg.closewait_time = 20000; /* 2s */ tcp_cfg.timewait_time = 100000; /* 10s */ tcp_cfg.finwait1_time = 600000; /* 60s */ tcp_cfg.lastack_time = 300000; /* 30s */ tcp_cfg.finwait2_time = 300000; /* 30s */ tcp_cfg.closing_time = 300000; /* 30s */ /* This value is seconds */ tcp_cfg.cleanup_time = 0.1; /* 100ms */ } static clib_error_t * tcp_init (vlib_main_t * vm) { tcp_main_t *tm = vnet_get_tcp_main (); ip_main_t *im = &ip_main; ip_protocol_info_t *pi; /* Session layer, and by implication tcp, are disabled by default */ tm->is_enabled = 0; /* Register with IP for header parsing */ pi = ip_get_protocol_info (im, IP_PROTOCOL_TCP); if (pi == 0) return clib_error_return (0, "TCP protocol info AWOL"); pi->format_header = format_tcp_header; pi->unformat_pg_edit = unformat_pg_tcp_header; /* Register as transport with session layer */ transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto, FIB_PROTOCOL_IP4, tcp4_output_node.index); transport_register_protocol (TRANSPORT_PROTO_TCP, &tcp_proto, FIB_PROTOCOL_IP6, tcp6_output_node.index); tcp_configuration_init (); tm->cc_algo_by_name = hash_create_string (0, sizeof (uword)); return 0; } VLIB_INIT_FUNCTION (tcp_init); /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */