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Diffstat (limited to 'src/msg/async/dpdk/TCP.h')
| -rw-r--r-- | src/msg/async/dpdk/TCP.h | 1506 |
1 files changed, 1506 insertions, 0 deletions
diff --git a/src/msg/async/dpdk/TCP.h b/src/msg/async/dpdk/TCP.h new file mode 100644 index 000000000..a0104fb44 --- /dev/null +++ b/src/msg/async/dpdk/TCP.h @@ -0,0 +1,1506 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +/* + * This file is open source software, licensed to you under the terms + * of the Apache License, Version 2.0 (the "License"). See the NOTICE file + * distributed with this work for additional information regarding copyright + * ownership. 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. + */ +/* + * Copyright (C) 2014 Cloudius Systems, Ltd. + */ + +#ifndef CEPH_DPDK_TCP_H_ +#define CEPH_DPDK_TCP_H_ + +#include <unordered_map> +#include <map> +#include <queue> +#include <functional> +#include <deque> +#include <chrono> +#include <stdexcept> +#include <system_error> + +#include "msg/async/dpdk/EventDPDK.h" + +#include "include/utime.h" +#include "common/Throttle.h" +#include "common/ceph_time.h" +#include "common/ceph_crypto.h" +#include "msg/async/Event.h" +#include "IPChecksum.h" +#include "IP.h" +#include "const.h" +#include "byteorder.h" +#include "shared_ptr.h" +#include "PacketUtil.h" + +#include "include/random.h" + +struct tcp_hdr; + +enum class tcp_state : uint16_t { + CLOSED = (1 << 0), + LISTEN = (1 << 1), + SYN_SENT = (1 << 2), + SYN_RECEIVED = (1 << 3), + ESTABLISHED = (1 << 4), + FIN_WAIT_1 = (1 << 5), + FIN_WAIT_2 = (1 << 6), + CLOSE_WAIT = (1 << 7), + CLOSING = (1 << 8), + LAST_ACK = (1 << 9), + TIME_WAIT = (1 << 10) +}; + +inline tcp_state operator|(tcp_state s1, tcp_state s2) { + return tcp_state(uint16_t(s1) | uint16_t(s2)); +} + +inline std::ostream & operator<<(std::ostream & str, const tcp_state& s) { + switch (s) { + case tcp_state::CLOSED: return str << "CLOSED"; + case tcp_state::LISTEN: return str << "LISTEN"; + case tcp_state::SYN_SENT: return str << "SYN_SENT"; + case tcp_state::SYN_RECEIVED: return str << "SYN_RECEIVED"; + case tcp_state::ESTABLISHED: return str << "ESTABLISHED"; + case tcp_state::FIN_WAIT_1: return str << "FIN_WAIT_1"; + case tcp_state::FIN_WAIT_2: return str << "FIN_WAIT_2"; + case tcp_state::CLOSE_WAIT: return str << "CLOSE_WAIT"; + case tcp_state::CLOSING: return str << "CLOSING"; + case tcp_state::LAST_ACK: return str << "LAST_ACK"; + case tcp_state::TIME_WAIT: return str << "TIME_WAIT"; + default: return str << "UNKNOWN"; + } +} + +struct tcp_option { + // The kind and len field are fixed and defined in TCP protocol + enum class option_kind: uint8_t { mss = 2, win_scale = 3, sack = 4, timestamps = 8, nop = 1, eol = 0 }; + enum class option_len: uint8_t { mss = 4, win_scale = 3, sack = 2, timestamps = 10, nop = 1, eol = 1 }; + struct mss { + option_kind kind = option_kind::mss; + option_len len = option_len::mss; + uint16_t mss; + struct mss hton() { + struct mss m = *this; + m.mss = ::hton(m.mss); + return m; + } + } __attribute__((packed)); + struct win_scale { + option_kind kind = option_kind::win_scale; + option_len len = option_len::win_scale; + uint8_t shift; + } __attribute__((packed)); + struct sack { + option_kind kind = option_kind::sack; + option_len len = option_len::sack; + } __attribute__((packed)); + struct timestamps { + option_kind kind = option_kind::timestamps; + option_len len = option_len::timestamps; + uint32_t t1; + uint32_t t2; + } __attribute__((packed)); + struct nop { + option_kind kind = option_kind::nop; + } __attribute__((packed)); + struct eol { + option_kind kind = option_kind::eol; + } __attribute__((packed)); + static const uint8_t align = 4; + + void parse(uint8_t* beg, uint8_t* end); + uint8_t fill(tcp_hdr* th, uint8_t option_size); + uint8_t get_size(bool syn_on, bool ack_on); + + // For option negotiattion + bool _mss_received = false; + bool _win_scale_received = false; + bool _timestamps_received = false; + bool _sack_received = false; + + // Option data + uint16_t _remote_mss = 536; + uint16_t _local_mss; + uint8_t _remote_win_scale = 0; + uint8_t _local_win_scale = 0; +}; +inline uint8_t*& operator+=(uint8_t*& x, tcp_option::option_len len) { x += uint8_t(len); return x; } +inline uint8_t& operator+=(uint8_t& x, tcp_option::option_len len) { x += uint8_t(len); return x; } + +struct tcp_sequence { + uint32_t raw; +}; + +tcp_sequence ntoh(tcp_sequence ts) { + return tcp_sequence { ::ntoh(ts.raw) }; +} + +tcp_sequence hton(tcp_sequence ts) { + return tcp_sequence { ::hton(ts.raw) }; +} + +inline std::ostream& operator<<(std::ostream& os, const tcp_sequence& s) { + return os << s.raw; +} + +inline tcp_sequence make_seq(uint32_t raw) { return tcp_sequence{raw}; } +inline tcp_sequence& operator+=(tcp_sequence& s, int32_t n) { s.raw += n; return s; } +inline tcp_sequence& operator-=(tcp_sequence& s, int32_t n) { s.raw -= n; return s; } +inline tcp_sequence operator+(tcp_sequence s, int32_t n) { return s += n; } +inline tcp_sequence operator-(tcp_sequence s, int32_t n) { return s -= n; } +inline int32_t operator-(tcp_sequence s, tcp_sequence q) { return s.raw - q.raw; } +inline bool operator==(tcp_sequence s, tcp_sequence q) { return s.raw == q.raw; } +inline bool operator!=(tcp_sequence s, tcp_sequence q) { return !(s == q); } +inline bool operator<(tcp_sequence s, tcp_sequence q) { return s - q < 0; } +inline bool operator>(tcp_sequence s, tcp_sequence q) { return q < s; } +inline bool operator<=(tcp_sequence s, tcp_sequence q) { return !(s > q); } +inline bool operator>=(tcp_sequence s, tcp_sequence q) { return !(s < q); } + +struct tcp_hdr { + uint16_t src_port; + uint16_t dst_port; + tcp_sequence seq; + tcp_sequence ack; + uint8_t rsvd1 : 4; + uint8_t data_offset : 4; + uint8_t f_fin : 1; + uint8_t f_syn : 1; + uint8_t f_rst : 1; + uint8_t f_psh : 1; + uint8_t f_ack : 1; + uint8_t f_urg : 1; + uint8_t rsvd2 : 2; + uint16_t window; + uint16_t checksum; + uint16_t urgent; + + tcp_hdr hton() { + tcp_hdr hdr = *this; + hdr.src_port = ::hton(src_port); + hdr.dst_port = ::hton(dst_port); + hdr.seq = ::hton(seq); + hdr.ack = ::hton(ack); + hdr.window = ::hton(window); + hdr.checksum = ::hton(checksum); + hdr.urgent = ::hton(urgent); + return hdr; + } + + tcp_hdr ntoh() { + tcp_hdr hdr = *this; + hdr.src_port = ::ntoh(src_port); + hdr.dst_port = ::ntoh(dst_port); + hdr.seq = ::ntoh(seq); + hdr.ack = ::ntoh(ack); + hdr.window = ::ntoh(window); + hdr.checksum = ::ntoh(checksum); + hdr.urgent = ::ntoh(urgent); + return hdr; + } +} __attribute__((packed)); + +struct tcp_tag {}; +using tcp_packet_merger = packet_merger<tcp_sequence, tcp_tag>; + +template <typename InetTraits> +class tcp { + public: + using ipaddr = typename InetTraits::address_type; + using inet_type = typename InetTraits::inet_type; + using connid = l4connid<InetTraits>; + using connid_hash = typename connid::connid_hash; + class connection; + class listener; + private: + class tcb; + + class C_handle_delayed_ack : public EventCallback { + tcb *tc; + + public: + C_handle_delayed_ack(tcb *t): tc(t) { } + void do_request(uint64_t r) { + tc->_delayed_ack_fd.destroy(); + tc->_nr_full_seg_received = 0; + tc->output(); + } + }; + + class C_handle_retransmit : public EventCallback { + tcb *tc; + + public: + C_handle_retransmit(tcb *t): tc(t) { } + void do_request(uint64_t r) { + tc->retransmit_fd.destroy(); + tc->retransmit(); + } + }; + + class C_handle_persist : public EventCallback { + tcb *tc; + + public: + C_handle_persist(tcb *t): tc(t) { } + void do_request(uint64_t r) { + tc->persist_fd.destroy(); + tc->persist(); + } + }; + + class C_all_data_acked : public EventCallback { + tcb *tc; + + public: + C_all_data_acked(tcb *t): tc(t) {} + void do_request(uint64_t fd_or_id) { + tc->close_final_cleanup(); + } + }; + + class C_actual_remove_tcb : public EventCallback { + lw_shared_ptr<tcb> tc; + public: + C_actual_remove_tcb(tcb *t): tc(t->shared_from_this()) {} + void do_request(uint64_t r) { + delete this; + } + }; + + class tcb : public enable_lw_shared_from_this<tcb> { + using clock_type = ceph::coarse_real_clock; + static constexpr tcp_state CLOSED = tcp_state::CLOSED; + static constexpr tcp_state LISTEN = tcp_state::LISTEN; + static constexpr tcp_state SYN_SENT = tcp_state::SYN_SENT; + static constexpr tcp_state SYN_RECEIVED = tcp_state::SYN_RECEIVED; + static constexpr tcp_state ESTABLISHED = tcp_state::ESTABLISHED; + static constexpr tcp_state FIN_WAIT_1 = tcp_state::FIN_WAIT_1; + static constexpr tcp_state FIN_WAIT_2 = tcp_state::FIN_WAIT_2; + static constexpr tcp_state CLOSE_WAIT = tcp_state::CLOSE_WAIT; + static constexpr tcp_state CLOSING = tcp_state::CLOSING; + static constexpr tcp_state LAST_ACK = tcp_state::LAST_ACK; + static constexpr tcp_state TIME_WAIT = tcp_state::TIME_WAIT; + tcp_state _state = CLOSED; + tcp& _tcp; + UserspaceEventManager &manager; + connection* _conn = nullptr; + bool _connect_done = false; + ipaddr _local_ip; + ipaddr _foreign_ip; + uint16_t _local_port; + uint16_t _foreign_port; + struct unacked_segment { + Packet p; + uint16_t data_len; + unsigned nr_transmits; + clock_type::time_point tx_time; + }; + struct send { + tcp_sequence unacknowledged; + tcp_sequence next; + uint32_t window; + uint8_t window_scale; + uint16_t mss; + tcp_sequence urgent; + tcp_sequence wl1; + tcp_sequence wl2; + tcp_sequence initial; + std::deque<unacked_segment> data; + std::deque<Packet> unsent; + uint32_t unsent_len = 0; + uint32_t queued_len = 0; + bool closed = false; + // Wait for all data are acked + int _all_data_acked_fd = -1; + // Limit number of data queued into send queue + Throttle user_queue_space; + // Round-trip time variation + std::chrono::microseconds rttvar; + // Smoothed round-trip time + std::chrono::microseconds srtt; + bool first_rto_sample = true; + clock_type::time_point syn_tx_time; + // Congestion window + uint32_t cwnd; + // Slow start threshold + uint32_t ssthresh; + // Duplicated ACKs + uint16_t dupacks = 0; + unsigned syn_retransmit = 0; + unsigned fin_retransmit = 0; + uint32_t limited_transfer = 0; + uint32_t partial_ack = 0; + tcp_sequence recover; + bool window_probe = false; + send(CephContext *c): user_queue_space(c, "DPDK::tcp::tcb::user_queue_space", 81920) {} + } _snd; + struct receive { + tcp_sequence next; + uint32_t window; + uint8_t window_scale; + uint16_t mss; + tcp_sequence urgent; + tcp_sequence initial; + std::deque<Packet> data; + tcp_packet_merger out_of_order; + } _rcv; + EventCenter *center; + int fd; + // positive means no errno, 0 means eof, nagetive means error + int16_t _errno = 1; + tcp_option _option; + EventCallbackRef delayed_ack_event; + Tub<uint64_t> _delayed_ack_fd; + // Retransmission timeout + std::chrono::microseconds _rto{1000*1000}; + std::chrono::microseconds _persist_time_out{1000*1000}; + static constexpr std::chrono::microseconds _rto_min{1000*1000}; + static constexpr std::chrono::microseconds _rto_max{60000*1000}; + // Clock granularity + static constexpr std::chrono::microseconds _rto_clk_granularity{1000}; + static constexpr uint16_t _max_nr_retransmit{5}; + EventCallbackRef retransmit_event; + Tub<uint64_t> retransmit_fd; + EventCallbackRef persist_event; + EventCallbackRef all_data_ack_event; + Tub<uint64_t> persist_fd; + uint16_t _nr_full_seg_received = 0; + struct isn_secret { + // 512 bits secretkey for ISN generating + uint32_t key[16]; + isn_secret () { + for (auto& k : key) { + k = ceph::util::generate_random_number<uint32_t>(0, std::numeric_limits<uint32_t>::max()); + } + } + }; + static isn_secret _isn_secret; + tcp_sequence get_isn(); + circular_buffer<typename InetTraits::l4packet> _packetq; + bool _poll_active = false; + public: + // callback + void close_final_cleanup(); + ostream& _prefix(std::ostream *_dout); + + public: + tcb(tcp& t, connid id); + ~tcb(); + void input_handle_listen_state(tcp_hdr* th, Packet p); + void input_handle_syn_sent_state(tcp_hdr* th, Packet p); + void input_handle_other_state(tcp_hdr* th, Packet p); + void output_one(bool data_retransmit = false); + bool is_all_data_acked(); + int send(Packet p); + void connect(); + Tub<Packet> read(); + void close(); + void remove_from_tcbs() { + auto id = connid{_local_ip, _foreign_ip, _local_port, _foreign_port}; + _tcp._tcbs.erase(id); + } + Tub<typename InetTraits::l4packet> get_packet(); + void output() { + if (!_poll_active) { + _poll_active = true; + + auto tcb = this->shared_from_this(); + _tcp._inet.wait_l2_dst_address(_foreign_ip, Packet(), [tcb] (const ethernet_address &dst, Packet p, int r) { + if (r == 0) { + tcb->_tcp.poll_tcb(dst, std::move(tcb)); + } else if (r == -ETIMEDOUT) { + // in other states connection should time out + if (tcb->in_state(SYN_SENT)) { + tcb->_errno = -ETIMEDOUT; + tcb->cleanup(); + } + } else if (r == -EBUSY) { + // retry later + tcb->_poll_active = false; + tcb->start_retransmit_timer(); + } + }); + } + } + + int16_t get_errno() const { + return _errno; + } + + tcp_state& state() { + return _state; + } + + uint64_t peek_sent_available() { + if (!in_state(ESTABLISHED)) + return 0; + uint64_t left = _snd.user_queue_space.get_max() - _snd.user_queue_space.get_current(); + return left; + } + + int is_connected() const { + if (_errno <= 0) + return _errno; + return _connect_done; + } + + private: + void respond_with_reset(tcp_hdr* th); + bool merge_out_of_order(); + void insert_out_of_order(tcp_sequence seq, Packet p); + void trim_receive_data_after_window(); + bool should_send_ack(uint16_t seg_len); + void clear_delayed_ack(); + Packet get_transmit_packet(); + void retransmit_one() { + bool data_retransmit = true; + output_one(data_retransmit); + } + void start_retransmit_timer() { + if (retransmit_fd) + center->delete_time_event(*retransmit_fd); + retransmit_fd.construct(center->create_time_event(_rto.count(), retransmit_event)); + }; + void stop_retransmit_timer() { + if (retransmit_fd) { + center->delete_time_event(*retransmit_fd); + retransmit_fd.destroy(); + } + }; + void start_persist_timer() { + if (persist_fd) + center->delete_time_event(*persist_fd); + persist_fd.construct(center->create_time_event(_persist_time_out.count(), persist_event)); + }; + void stop_persist_timer() { + if (persist_fd) { + center->delete_time_event(*persist_fd); + persist_fd.destroy(); + } + }; + void persist(); + void retransmit(); + void fast_retransmit(); + void update_rto(clock_type::time_point tx_time); + void update_cwnd(uint32_t acked_bytes); + void cleanup(); + uint32_t can_send() { + if (_snd.window_probe) { + return 1; + } + // Can not send more than advertised window allows + auto x = std::min(uint32_t(_snd.unacknowledged + _snd.window - _snd.next), _snd.unsent_len); + // Can not send more than congestion window allows + x = std::min(_snd.cwnd, x); + if (_snd.dupacks == 1 || _snd.dupacks == 2) { + // RFC5681 Step 3.1 + // Send cwnd + 2 * smss per RFC3042 + auto flight = flight_size(); + auto max = _snd.cwnd + 2 * _snd.mss; + x = flight <= max ? std::min(x, max - flight) : 0; + _snd.limited_transfer += x; + } else if (_snd.dupacks >= 3) { + // RFC5681 Step 3.5 + // Sent 1 full-sized segment at most + x = std::min(uint32_t(_snd.mss), x); + } + return x; + } + uint32_t flight_size() { + uint32_t size = 0; + std::for_each(_snd.data.begin(), _snd.data.end(), + [&] (unacked_segment& seg) { size += seg.p.len(); }); + return size; + } + uint16_t local_mss() { + return _tcp.get_hw_features().mtu - tcp_hdr_len_min - InetTraits::ip_hdr_len_min; + } + void queue_packet(Packet p) { + _packetq.emplace_back( + typename InetTraits::l4packet{_foreign_ip, std::move(p)}); + } + void signal_data_received() { + manager.notify(fd, EVENT_READABLE); + } + void signal_all_data_acked() { + if (_snd._all_data_acked_fd >= 0 && _snd.unsent_len == 0 && _snd.queued_len == 0) + manager.notify(_snd._all_data_acked_fd, EVENT_READABLE); + } + void do_syn_sent() { + _state = SYN_SENT; + _snd.syn_tx_time = clock_type::now(); + // Send <SYN> to remote + output(); + } + void do_syn_received() { + _state = SYN_RECEIVED; + _snd.syn_tx_time = clock_type::now(); + // Send <SYN,ACK> to remote + output(); + } + void do_established() { + _state = ESTABLISHED; + update_rto(_snd.syn_tx_time); + _connect_done = true; + manager.notify(fd, EVENT_READABLE|EVENT_WRITABLE); + } + void do_reset() { + _state = CLOSED; + // Free packets to be sent which are waiting for user_queue_space + _snd.user_queue_space.reset(); + cleanup(); + _errno = -ECONNRESET; + manager.notify(fd, EVENT_READABLE); + + if (_snd._all_data_acked_fd >= 0) + manager.notify(_snd._all_data_acked_fd, EVENT_READABLE); + } + void do_time_wait() { + // FIXME: Implement TIME_WAIT state timer + _state = TIME_WAIT; + cleanup(); + } + void do_closed() { + _state = CLOSED; + cleanup(); + } + void do_setup_isn() { + _snd.initial = get_isn(); + _snd.unacknowledged = _snd.initial; + _snd.next = _snd.initial + 1; + _snd.recover = _snd.initial; + } + void do_local_fin_acked() { + _snd.unacknowledged += 1; + _snd.next += 1; + } + bool syn_needs_on() { + return in_state(SYN_SENT | SYN_RECEIVED); + } + bool fin_needs_on() { + return in_state(FIN_WAIT_1 | CLOSING | LAST_ACK) && _snd.closed && + _snd.unsent_len == 0 && _snd.queued_len == 0; + } + bool ack_needs_on() { + return !in_state(CLOSED | LISTEN | SYN_SENT); + } + bool foreign_will_not_send() { + return in_state(CLOSING | TIME_WAIT | CLOSE_WAIT | LAST_ACK | CLOSED); + } + bool in_state(tcp_state state) { + return uint16_t(_state) & uint16_t(state); + } + void exit_fast_recovery() { + _snd.dupacks = 0; + _snd.limited_transfer = 0; + _snd.partial_ack = 0; + } + uint32_t data_segment_acked(tcp_sequence seg_ack); + bool segment_acceptable(tcp_sequence seg_seq, unsigned seg_len); + void init_from_options(tcp_hdr* th, uint8_t* opt_start, uint8_t* opt_end); + friend class connection; + + friend class C_handle_delayed_ack; + friend class C_handle_retransmit; + friend class C_handle_persist; + friend class C_all_data_acked; + }; + + CephContext *cct; + // ipv4_l4<ip_protocol_num::tcp> + inet_type& _inet; + EventCenter *center; + UserspaceEventManager &manager; + std::unordered_map<connid, lw_shared_ptr<tcb>, connid_hash> _tcbs; + std::unordered_map<uint16_t, listener*> _listening; + std::random_device _rd; + std::default_random_engine _e; + std::uniform_int_distribution<uint16_t> _port_dist{41952, 65535}; + circular_buffer<std::pair<lw_shared_ptr<tcb>, ethernet_address>> _poll_tcbs; + // queue for packets that do not belong to any tcb + circular_buffer<ipv4_traits::l4packet> _packetq; + Throttle _queue_space; + // Limit number of data queued into send queue + public: + class connection { + lw_shared_ptr<tcb> _tcb; + public: + explicit connection(lw_shared_ptr<tcb> tcbp) : _tcb(std::move(tcbp)) { _tcb->_conn = this; } + connection(const connection&) = delete; + connection(connection&& x) noexcept : _tcb(std::move(x._tcb)) { + _tcb->_conn = this; + } + ~connection(); + void operator=(const connection&) = delete; + connection& operator=(connection&& x) { + if (this != &x) { + this->~connection(); + new (this) connection(std::move(x)); + } + return *this; + } + int fd() const { + return _tcb->fd; + } + int send(Packet p) { + return _tcb->send(std::move(p)); + } + Tub<Packet> read() { + return _tcb->read(); + } + int16_t get_errno() const { + return _tcb->get_errno(); + } + void close_read(); + void close_write(); + entity_addr_t remote_addr() const { + entity_addr_t addr; + auto net_ip = _tcb->_foreign_ip.hton(); + memcpy((void*)&addr.in4_addr().sin_addr.s_addr, + &net_ip, sizeof(addr.in4_addr().sin_addr.s_addr)); + addr.set_family(AF_INET); + return addr; + } + uint64_t peek_sent_available() { + return _tcb->peek_sent_available(); + } + int is_connected() const { return _tcb->is_connected(); } + }; + class listener { + tcp& _tcp; + uint16_t _port; + int _fd = -1; + int16_t _errno; + queue<connection> _q; + size_t _q_max_length; + + private: + listener(tcp& t, uint16_t port, size_t queue_length) + : _tcp(t), _port(port), _errno(0), _q(), _q_max_length(queue_length) { + } + public: + listener(const listener&) = delete; + void operator=(const listener&) = delete; + listener(listener&& x) + : _tcp(x._tcp), _port(x._port), _fd(std::move(x._fd)), _errno(x._errno), + _q(std::move(x._q)) { + if (_fd >= 0) + _tcp._listening[_port] = this; + } + ~listener() { + abort_accept(); + } + int listen() { + if (_tcp._listening.find(_port) != _tcp._listening.end()) + return -EADDRINUSE; + _tcp._listening.emplace(_port, this); + _fd = _tcp.manager.get_eventfd(); + return 0; + } + Tub<connection> accept() { + Tub<connection> c; + if (!_q.empty()) { + c = std::move(_q.front()); + _q.pop(); + } + return c; + } + void abort_accept() { + while (!_q.empty()) + _q.pop(); + if (_fd >= 0) { + _tcp._listening.erase(_port); + _tcp.manager.close(_fd); + _fd = -1; + } + } + int16_t get_errno() const { + return _errno; + } + bool full() const { + return _q.size() == _q_max_length; + } + int fd() const { + return _fd; + } + friend class tcp; + }; + public: + explicit tcp(CephContext *c, inet_type& inet, EventCenter *cen); + void received(Packet p, ipaddr from, ipaddr to); + bool forward(forward_hash& out_hash_data, Packet& p, size_t off); + listener listen(uint16_t port, size_t queue_length = 100); + connection connect(const entity_addr_t &addr); + const hw_features& get_hw_features() const { return _inet._inet.get_hw_features(); } + void poll_tcb(const ethernet_address &dst, lw_shared_ptr<tcb> tcb) { + _poll_tcbs.emplace_back(std::move(tcb), dst); + } + bool push_listen_queue(uint16_t port, tcb *t) { + auto listener = _listening.find(port); + if (listener == _listening.end() || listener->second->full()) { + return false; + } + listener->second->_q.push(connection(t->shared_from_this())); + manager.notify(listener->second->_fd, EVENT_READABLE); + return true; + } + + private: + void send_packet_without_tcb(ipaddr from, ipaddr to, Packet p); + void respond_with_reset(tcp_hdr* rth, ipaddr local_ip, ipaddr foreign_ip); + friend class listener; +}; + +template <typename InetTraits> +tcp<InetTraits>::tcp(CephContext *c, inet_type& inet, EventCenter *cen) + : cct(c), _inet(inet), center(cen), + manager(static_cast<DPDKDriver*>(cen->get_driver())->manager), + _e(_rd()), _queue_space(cct, "DPDK::tcp::queue_space", 81920) { + int tcb_polled = 0u; + _inet.register_packet_provider([this, tcb_polled] () mutable { + Tub<typename InetTraits::l4packet> l4p; + auto c = _poll_tcbs.size(); + if (!_packetq.empty() && (!(tcb_polled % 128) || c == 0)) { + l4p = std::move(_packetq.front()); + _packetq.pop_front(); + _queue_space.put(l4p->p.len()); + } else { + while (c--) { + tcb_polled++; + lw_shared_ptr<tcb> tcb; + ethernet_address dst; + std::tie(tcb, dst) = std::move(_poll_tcbs.front()); + _poll_tcbs.pop_front(); + l4p = std::move(tcb->get_packet()); + if (l4p) { + l4p->e_dst = dst; + break; + } + } + } + return l4p; + }); +} + +template <typename InetTraits> +auto tcp<InetTraits>::listen(uint16_t port, size_t queue_length) -> listener { + return listener(*this, port, queue_length); +} + +template <typename InetTraits> +typename tcp<InetTraits>::connection tcp<InetTraits>::connect(const entity_addr_t &addr) { + uint16_t src_port; + connid id; + auto src_ip = _inet._inet.host_address(); + auto dst_ip = ipv4_address(addr); + auto dst_port = addr.get_port(); + + do { + src_port = _port_dist(_e); + id = connid{src_ip, dst_ip, src_port, (uint16_t)dst_port}; + if (_tcbs.find(id) == _tcbs.end()) { + if (_inet._inet.netif()->hw_queues_count() == 1 || + _inet._inet.netif()->hash2cpu( + id.hash(_inet._inet.netif()->rss_key())) == center->get_id()) + break; + } + } while (true); + + auto tcbp = make_lw_shared<tcb>(*this, id); + _tcbs.insert({id, tcbp}); + tcbp->connect(); + return connection(tcbp); +} + +template <typename InetTraits> +bool tcp<InetTraits>::forward(forward_hash& out_hash_data, Packet& p, size_t off) { + auto th = p.get_header<tcp_hdr>(off); + if (th) { + out_hash_data.push_back(th->src_port); + out_hash_data.push_back(th->dst_port); + } + return true; +} + +template <typename InetTraits> +void tcp<InetTraits>::received(Packet p, ipaddr from, ipaddr to) { + auto th = p.get_header<tcp_hdr>(0); + if (!th) { + return; + } + // th->data_offset is correct even before ntoh() + if (unsigned(th->data_offset * 4) < sizeof(*th)) { + return; + } + + if (!get_hw_features().rx_csum_offload) { + checksummer csum; + InetTraits::tcp_pseudo_header_checksum(csum, from, to, p.len()); + csum.sum(p); + if (csum.get() != 0) { + return; + } + } + auto h = th->ntoh(); + auto id = connid{to, from, h.dst_port, h.src_port}; + auto tcbi = _tcbs.find(id); + lw_shared_ptr<tcb> tcbp; + if (tcbi == _tcbs.end()) { + auto listener = _listening.find(id.local_port); + if (listener == _listening.end() || listener->second->full()) { + // 1) In CLOSE state + // 1.1 all data in the incoming segment is discarded. An incoming + // segment containing a RST is discarded. An incoming segment not + // containing a RST causes a RST to be sent in response. + // FIXME: + // if ACK off: <SEQ=0><ACK=SEG.SEQ+SEG.LEN><CTL=RST,ACK> + // if ACK on: <SEQ=SEG.ACK><CTL=RST> + return respond_with_reset(&h, id.local_ip, id.foreign_ip); + } else { + // 2) In LISTEN state + // 2.1 first check for an RST + if (h.f_rst) { + // An incoming RST should be ignored + return; + } + // 2.2 second check for an ACK + if (h.f_ack) { + // Any acknowledgment is bad if it arrives on a connection + // still in the LISTEN state. + // <SEQ=SEG.ACK><CTL=RST> + return respond_with_reset(&h, id.local_ip, id.foreign_ip); + } + // 2.3 third check for a SYN + if (h.f_syn) { + // check the security + // NOTE: Ignored for now + tcbp = make_lw_shared<tcb>(*this, id); + _tcbs.insert({id, tcbp}); + return tcbp->input_handle_listen_state(&h, std::move(p)); + } + // 2.4 fourth other text or control + // So you are unlikely to get here, but if you do, drop the + // segment, and return. + return; + } + } else { + tcbp = tcbi->second; + if (tcbp->state() == tcp_state::SYN_SENT) { + // 3) In SYN_SENT State + return tcbp->input_handle_syn_sent_state(&h, std::move(p)); + } else { + // 4) In other state, can be one of the following: + // SYN_RECEIVED, ESTABLISHED, FIN_WAIT_1, FIN_WAIT_2 + // CLOSE_WAIT, CLOSING, LAST_ACK, TIME_WAIT + return tcbp->input_handle_other_state(&h, std::move(p)); + } + } +} + +// Send packet does not belong to any tcb +template <typename InetTraits> +void tcp<InetTraits>::send_packet_without_tcb(ipaddr from, ipaddr to, Packet p) { + if (_queue_space.get_or_fail(p.len())) { // drop packets that do not fit the queue + _inet.wait_l2_dst_address(to, std::move(p), [this, to] (const ethernet_address &e_dst, Packet p, int r) mutable { + if (r == 0) + _packetq.emplace_back(ipv4_traits::l4packet{to, std::move(p), e_dst, ip_protocol_num::tcp}); + }); + } +} + +template <typename InetTraits> +tcp<InetTraits>::connection::~connection() { + if (_tcb) { + _tcb->_conn = nullptr; + close_read(); + close_write(); + } +} + +template <typename InetTraits> +tcp<InetTraits>::tcb::tcb(tcp& t, connid id) + : _tcp(t), manager(t.manager), _local_ip(id.local_ip) , _foreign_ip(id.foreign_ip), + _local_port(id.local_port), _foreign_port(id.foreign_port), + _snd(_tcp.cct), + center(t.center), + fd(t.manager.get_eventfd()), + delayed_ack_event(new tcp<InetTraits>::C_handle_delayed_ack(this)), + retransmit_event(new tcp<InetTraits>::C_handle_retransmit(this)), + persist_event(new tcp<InetTraits>::C_handle_persist(this)), + all_data_ack_event(new tcp<InetTraits>::C_all_data_acked(this)) {} + +template <typename InetTraits> +tcp<InetTraits>::tcb::~tcb() +{ + if (_delayed_ack_fd) + center->delete_time_event(*_delayed_ack_fd); + if (retransmit_fd) + center->delete_time_event(*retransmit_fd); + if (persist_fd) + center->delete_time_event(*persist_fd); + delete delayed_ack_event; + delete retransmit_event; + delete persist_event; + delete all_data_ack_event; + manager.close(fd); + fd = -1; +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::respond_with_reset(tcp_hdr* rth) +{ + _tcp.respond_with_reset(rth, _local_ip, _foreign_ip); +} + +template <typename InetTraits> +uint32_t tcp<InetTraits>::tcb::data_segment_acked(tcp_sequence seg_ack) { + uint32_t total_acked_bytes = 0; + // Full ACK of segment + while (!_snd.data.empty() + && (_snd.unacknowledged + _snd.data.front().p.len() <= seg_ack)) { + auto acked_bytes = _snd.data.front().p.len(); + _snd.unacknowledged += acked_bytes; + // Ignore retransmitted segments when setting the RTO + if (_snd.data.front().nr_transmits == 0) { + update_rto(_snd.data.front().tx_time); + } + update_cwnd(acked_bytes); + total_acked_bytes += acked_bytes; + _snd.user_queue_space.put(_snd.data.front().data_len); + manager.notify(fd, EVENT_WRITABLE); + _snd.data.pop_front(); + } + // Partial ACK of segment + if (_snd.unacknowledged < seg_ack) { + auto acked_bytes = seg_ack - _snd.unacknowledged; + if (!_snd.data.empty()) { + auto& unacked_seg = _snd.data.front(); + unacked_seg.p.trim_front(acked_bytes); + } + _snd.unacknowledged = seg_ack; + update_cwnd(acked_bytes); + total_acked_bytes += acked_bytes; + } + return total_acked_bytes; +} + +template <typename InetTraits> +bool tcp<InetTraits>::tcb::segment_acceptable(tcp_sequence seg_seq, unsigned seg_len) { + if (seg_len == 0 && _rcv.window == 0) { + // SEG.SEQ = RCV.NXT + return seg_seq == _rcv.next; + } else if (seg_len == 0 && _rcv.window > 0) { + // RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND + return (_rcv.next <= seg_seq) && (seg_seq < _rcv.next + _rcv.window); + } else if (seg_len > 0 && _rcv.window > 0) { + // RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND + // or + // RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND + bool x = (_rcv.next <= seg_seq) && seg_seq < (_rcv.next + _rcv.window); + bool y = (_rcv.next <= seg_seq + seg_len - 1) && (seg_seq + seg_len - 1 < _rcv.next + _rcv.window); + return x || y; + } else { + // SEG.LEN > 0 RCV.WND = 0, not acceptable + return false; + } +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::init_from_options(tcp_hdr* th, uint8_t* opt_start, uint8_t* opt_end) { + // Handle tcp options + _option.parse(opt_start, opt_end); + + // Remote receive window scale factor + _snd.window_scale = _option._remote_win_scale; + // Local receive window scale factor + _rcv.window_scale = _option._local_win_scale; + + // Maximum segment size remote can receive + _snd.mss = _option._remote_mss; + // Maximum segment size local can receive + _rcv.mss = _option._local_mss = local_mss(); + + // Linux's default window size + _rcv.window = 29200 << _rcv.window_scale; + _snd.window = th->window << _snd.window_scale; + + // Segment sequence number used for last window update + _snd.wl1 = th->seq; + // Segment acknowledgment number used for last window update + _snd.wl2 = th->ack; + + // Setup initial congestion window + if (2190 < _snd.mss) { + _snd.cwnd = 2 * _snd.mss; + } else if (1095 < _snd.mss && _snd.mss <= 2190) { + _snd.cwnd = 3 * _snd.mss; + } else { + _snd.cwnd = 4 * _snd.mss; + } + + // Setup initial slow start threshold + _snd.ssthresh = th->window << _snd.window_scale; +} + +template <typename InetTraits> +Packet tcp<InetTraits>::tcb::get_transmit_packet() { + // easy case: empty queue + if (_snd.unsent.empty()) { + return Packet(); + } + auto can_send = this->can_send(); + // Max number of TCP payloads we can pass to NIC + uint32_t len; + if (_tcp.get_hw_features().tx_tso) { + // FIXME: Info tap device the size of the split packet + len = _tcp.get_hw_features().max_packet_len - tcp_hdr_len_min - InetTraits::ip_hdr_len_min; + } else { + len = std::min(uint16_t(_tcp.get_hw_features().mtu - tcp_hdr_len_min - InetTraits::ip_hdr_len_min), _snd.mss); + } + can_send = std::min(can_send, len); + // easy case: one small packet + if (_snd.unsent.front().len() <= can_send) { + auto p = std::move(_snd.unsent.front()); + _snd.unsent.pop_front(); + _snd.unsent_len -= p.len(); + return p; + } + // moderate case: need to split one packet + if (_snd.unsent.front().len() > can_send) { + auto p = _snd.unsent.front().share(0, can_send); + _snd.unsent.front().trim_front(can_send); + _snd.unsent_len -= p.len(); + return p; + } + // hard case: merge some packets, possibly split last + auto p = std::move(_snd.unsent.front()); + _snd.unsent.pop_front(); + can_send -= p.len(); + while (!_snd.unsent.empty() + && _snd.unsent.front().len() <= can_send) { + can_send -= _snd.unsent.front().len(); + p.append(std::move(_snd.unsent.front())); + _snd.unsent.pop_front(); + } + // FIXME: this will result in calling "deleter" of packet which free managed objects + // will used later + // if (!_snd.unsent.empty() && can_send) { + // auto& q = _snd.unsent.front(); + // p.append(q.share(0, can_send)); + // q.trim_front(can_send); + // } + _snd.unsent_len -= p.len(); + return p; +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::output_one(bool data_retransmit) { + if (in_state(CLOSED)) { + return; + } + + Packet p = data_retransmit ? _snd.data.front().p.share() : get_transmit_packet(); + Packet clone = p.share(); // early clone to prevent share() from calling packet::unuse_internal_data() on header. + uint16_t len = p.len(); + bool syn_on = syn_needs_on(); + bool ack_on = ack_needs_on(); + + auto options_size = _option.get_size(syn_on, ack_on); + auto th = p.prepend_header<tcp_hdr>(options_size); + + th->src_port = _local_port; + th->dst_port = _foreign_port; + + th->f_syn = syn_on; + th->f_ack = ack_on; + if (ack_on) { + clear_delayed_ack(); + } + th->f_urg = false; + th->f_psh = false; + + tcp_sequence seq; + if (data_retransmit) { + seq = _snd.unacknowledged; + } else { + seq = syn_on ? _snd.initial : _snd.next; + _snd.next += len; + } + th->seq = seq; + th->ack = _rcv.next; + th->data_offset = (sizeof(*th) + options_size) / 4; + th->window = _rcv.window >> _rcv.window_scale; + th->checksum = 0; + + // FIXME: does the FIN have to fit in the window? + bool fin_on = fin_needs_on(); + th->f_fin = fin_on; + + // Add tcp options + _option.fill(th, options_size); + *th = th->hton(); + + offload_info oi; + checksummer csum; + uint16_t pseudo_hdr_seg_len = 0; + + oi.tcp_hdr_len = sizeof(tcp_hdr) + options_size; + + if (_tcp.get_hw_features().tx_csum_l4_offload) { + oi.needs_csum = true; + + // + // tx checksum offloading: both virtio-net's VIRTIO_NET_F_CSUM dpdk's + // PKT_TX_TCP_CKSUM - requires th->checksum to be initialized to ones' + // complement sum of the pseudo header. + // + // For TSO the csum should be calculated for a pseudo header with + // segment length set to 0. All the rest is the same as for a TCP Tx + // CSUM offload case. + // + if (_tcp.get_hw_features().tx_tso && len > _snd.mss) { + oi.tso_seg_size = _snd.mss; + } else { + pseudo_hdr_seg_len = sizeof(*th) + options_size + len; + } + } else { + pseudo_hdr_seg_len = sizeof(*th) + options_size + len; + oi.needs_csum = false; + } + + InetTraits::tcp_pseudo_header_checksum(csum, _local_ip, _foreign_ip, + pseudo_hdr_seg_len); + + if (_tcp.get_hw_features().tx_csum_l4_offload) { + th->checksum = ~csum.get(); + } else { + csum.sum(p); + th->checksum = csum.get(); + } + + oi.protocol = ip_protocol_num::tcp; + + p.set_offload_info(oi); + + if (!data_retransmit && (len || syn_on || fin_on)) { + auto now = clock_type::now(); + if (len) { + unsigned nr_transmits = 0; + _snd.data.emplace_back(unacked_segment{std::move(clone), + len, nr_transmits, now}); + } + if (!retransmit_fd) { + start_retransmit_timer(); + } + } + + queue_packet(std::move(p)); +} + +template <typename InetTraits> +bool tcp<InetTraits>::tcb::is_all_data_acked() { + if (_snd.data.empty() && _snd.unsent_len == 0 && _snd.queued_len == 0) { + return true; + } + return false; +} + +template <typename InetTraits> +Tub<Packet> tcp<InetTraits>::tcb::read() { + Tub<Packet> p; + if (_rcv.data.empty()) + return p; + + p.construct(); + for (auto&& q : _rcv.data) { + p->append(std::move(q)); + } + _rcv.data.clear(); + return p; +} + +template <typename InetTraits> +int tcp<InetTraits>::tcb::send(Packet p) { + // We can not send after the connection is closed + ceph_assert(!_snd.closed); + + if (in_state(CLOSED)) + return -ECONNRESET; + + auto len = p.len(); + if (!_snd.user_queue_space.get_or_fail(len)) { + // note: caller must ensure enough queue space to send + ceph_abort(); + } + // TODO: Handle p.len() > max user_queue_space case + _snd.queued_len += len; + _snd.unsent_len += len; + _snd.queued_len -= len; + _snd.unsent.push_back(std::move(p)); + if (can_send() > 0) { + output(); + } + return len; +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::close() { + if (in_state(CLOSED) || _snd.closed) { + return ; + } + // TODO: We should make this asynchronous + + _errno = -EPIPE; + center->delete_file_event(fd, EVENT_READABLE|EVENT_WRITABLE); + bool acked = is_all_data_acked(); + if (!acked) { + _snd._all_data_acked_fd = manager.get_eventfd(); + center->create_file_event(_snd._all_data_acked_fd, EVENT_READABLE, all_data_ack_event); + } else { + close_final_cleanup(); + } +} + +template <typename InetTraits> +bool tcp<InetTraits>::tcb::should_send_ack(uint16_t seg_len) { + // We've received a TSO packet, do ack immediately + if (seg_len > _rcv.mss) { + _nr_full_seg_received = 0; + if (_delayed_ack_fd) { + center->delete_time_event(*_delayed_ack_fd); + _delayed_ack_fd.destroy(); + } + return true; + } + + // We've received a full sized segment, ack for every second full sized segment + if (seg_len == _rcv.mss) { + if (_nr_full_seg_received++ >= 1) { + _nr_full_seg_received = 0; + if (_delayed_ack_fd) { + center->delete_time_event(*_delayed_ack_fd); + _delayed_ack_fd.destroy(); + } + return true; + } + } + + // If the timer is armed and its callback hasn't been run. + if (_delayed_ack_fd) { + return false; + } + + // If the timer is not armed, schedule a delayed ACK. + // The maximum delayed ack timer allowed by RFC1122 is 500ms, most + // implementations use 200ms. + _delayed_ack_fd.construct(center->create_time_event(200*1000, delayed_ack_event)); + return false; +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::clear_delayed_ack() { + if (_delayed_ack_fd) { + center->delete_time_event(*_delayed_ack_fd); + _delayed_ack_fd.destroy(); + } +} + +template <typename InetTraits> +bool tcp<InetTraits>::tcb::merge_out_of_order() { + bool merged = false; + if (_rcv.out_of_order.map.empty()) { + return merged; + } + for (auto it = _rcv.out_of_order.map.begin(); it != _rcv.out_of_order.map.end();) { + auto& p = it->second; + auto seg_beg = it->first; + auto seg_len = p.len(); + auto seg_end = seg_beg + seg_len; + if (seg_beg <= _rcv.next && seg_end > _rcv.next) { + // This segment has been received out of order and its previous + // segment has been received now + auto trim = _rcv.next - seg_beg; + if (trim) { + p.trim_front(trim); + seg_len -= trim; + } + _rcv.next += seg_len; + _rcv.data.push_back(std::move(p)); + // Since c++11, erase() always returns the value of the following element + it = _rcv.out_of_order.map.erase(it); + merged = true; + } else if (_rcv.next >= seg_end) { + // This segment has been receive already, drop it + it = _rcv.out_of_order.map.erase(it); + } else { + // seg_beg > _rcv.need, can not merge. Note, seg_beg can grow only, + // so we can stop looking here. + it++; + break; + } + } + return merged; +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::insert_out_of_order(tcp_sequence seg, Packet p) { + _rcv.out_of_order.merge(seg, std::move(p)); +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::trim_receive_data_after_window() { + abort(); +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::fast_retransmit() { + if (!_snd.data.empty()) { + auto& unacked_seg = _snd.data.front(); + unacked_seg.nr_transmits++; + retransmit_one(); + output(); + } +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::update_rto(clock_type::time_point tx_time) { + // Update RTO according to RFC6298 + auto R = std::chrono::duration_cast<std::chrono::microseconds>(clock_type::now() - tx_time); + if (_snd.first_rto_sample) { + _snd.first_rto_sample = false; + // RTTVAR <- R/2 + // SRTT <- R + _snd.rttvar = R / 2; + _snd.srtt = R; + } else { + // RTTVAR <- (1 - beta) * RTTVAR + beta * |SRTT - R'| + // SRTT <- (1 - alpha) * SRTT + alpha * R' + // where alpha = 1/8 and beta = 1/4 + auto delta = _snd.srtt > R ? (_snd.srtt - R) : (R - _snd.srtt); + _snd.rttvar = _snd.rttvar * 3 / 4 + delta / 4; + _snd.srtt = _snd.srtt * 7 / 8 + R / 8; + } + // RTO <- SRTT + max(G, K * RTTVAR) + _rto = _snd.srtt + std::max(_rto_clk_granularity, 4 * _snd.rttvar); + + // Make sure 1 sec << _rto << 60 sec + _rto = std::max(_rto, _rto_min); + _rto = std::min(_rto, _rto_max); +} + +template <typename InetTraits> +void tcp<InetTraits>::tcb::update_cwnd(uint32_t acked_bytes) { + uint32_t smss = _snd.mss; + if (_snd.cwnd < _snd.ssthresh) { + // In slow start phase + _snd.cwnd += std::min(acked_bytes, smss); + } else { + // In congestion avoidance phase + uint32_t round_up = 1; + _snd.cwnd += std::max(round_up, smss * smss / _snd.cwnd); + } +} + + +template <typename InetTraits> +void tcp<InetTraits>::tcb::cleanup() { + manager.notify(fd, EVENT_READABLE); + _snd.closed = true; + _snd.unsent.clear(); + _snd.data.clear(); + _rcv.out_of_order.map.clear(); + _rcv.data.clear(); + stop_retransmit_timer(); + clear_delayed_ack(); + center->dispatch_event_external(new tcp<InetTraits>::C_actual_remove_tcb(this)); + remove_from_tcbs(); +} + +template <typename InetTraits> +tcp_sequence tcp<InetTraits>::tcb::get_isn() { + // Per RFC6528, TCP SHOULD generate its Initial Sequence Numbers + // with the expression: + // ISN = M + F(localip, localport, remoteip, remoteport, secretkey) + // M is the 4 microsecond timer + using namespace std::chrono; + uint32_t hash[4]; + hash[0] = _local_ip.ip; + hash[1] = _foreign_ip.ip; + hash[2] = (_local_port << 16) + _foreign_port; + hash[3] = _isn_secret.key[15]; + ceph::crypto::MD5 md5; + md5.Update((const unsigned char*)_isn_secret.key, sizeof(_isn_secret.key)); + md5.Final((unsigned char*)hash); + auto seq = hash[0]; + auto m = duration_cast<microseconds>(clock_type::now().time_since_epoch()); + seq += m.count() / 4; + return make_seq(seq); +} + +template <typename InetTraits> +Tub<typename InetTraits::l4packet> tcp<InetTraits>::tcb::get_packet() { + _poll_active = false; + if (_packetq.empty()) { + output_one(); + } + + Tub<typename InetTraits::l4packet> p; + if (in_state(CLOSED)) { + return p; + } + + ceph_assert(!_packetq.empty()); + + p = std::move(_packetq.front()); + _packetq.pop_front(); + if (!_packetq.empty() || (_snd.dupacks < 3 && can_send() > 0)) { + // If there are packets to send in the queue or tcb is allowed to send + // more add tcp back to polling set to keep sending. In addition, dupacks >= 3 + // is an indication that an segment is lost, stop sending more in this case. + output(); + } + return p; +} + +template <typename InetTraits> +void tcp<InetTraits>::connection::close_read() { + // do nothing + // _tcb->manager.notify(_tcb->fd, EVENT_READABLE); +} + +template <typename InetTraits> +void tcp<InetTraits>::connection::close_write() { + _tcb->close(); +} + +template <typename InetTraits> +constexpr uint16_t tcp<InetTraits>::tcb::_max_nr_retransmit; + +template <typename InetTraits> +constexpr std::chrono::microseconds tcp<InetTraits>::tcb::_rto_min; + +template <typename InetTraits> +constexpr std::chrono::microseconds tcp<InetTraits>::tcb::_rto_max; + +template <typename InetTraits> +constexpr std::chrono::microseconds tcp<InetTraits>::tcb::_rto_clk_granularity; + +template <typename InetTraits> +typename tcp<InetTraits>::tcb::isn_secret tcp<InetTraits>::tcb::_isn_secret; + + +#endif /* TCP_HH_ */ |