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3494 lines
106 KiB
C++
3494 lines
106 KiB
C++
/*
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* Copyright (c) 2010-2013 BitTorrent, Inc.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdio.h>
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#include <assert.h>
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#include <string.h>
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#include <string.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <limits.h> // for UINT_MAX
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#include <time.h>
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#include "utp_types.h"
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#include "utp_packedsockaddr.h"
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#include "utp_internal.h"
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#include "utp_hash.h"
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#define TIMEOUT_CHECK_INTERVAL 500
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// number of bytes to increase max window size by, per RTT. This is
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// scaled down linearly proportional to off_target. i.e. if all packets
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// in one window have 0 delay, window size will increase by this number.
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// Typically it's less. TCP increases one MSS per RTT, which is 1500
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#define MAX_CWND_INCREASE_BYTES_PER_RTT 3000
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#define CUR_DELAY_SIZE 3
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// experiments suggest that a clock skew of 10 ms per 325 seconds
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// is not impossible. Reset delay_base every 13 minutes. The clock
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// skew is dealt with by observing the delay base in the other
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// direction, and adjusting our own upwards if the opposite direction
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// delay base keeps going down
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#define DELAY_BASE_HISTORY 13
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#define MAX_WINDOW_DECAY 100 // ms
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#define REORDER_BUFFER_SIZE 32
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#define REORDER_BUFFER_MAX_SIZE 1024
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#define OUTGOING_BUFFER_MAX_SIZE 1024
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#define PACKET_SIZE 1435
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// this is the minimum max_window value. It can never drop below this
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#define MIN_WINDOW_SIZE 10
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// if we receive 4 or more duplicate acks, we resend the packet
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// that hasn't been acked yet
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#define DUPLICATE_ACKS_BEFORE_RESEND 3
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// Allow a reception window of at least 3 ack_nrs behind seq_nr
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// A non-SYN packet with an ack_nr difference greater than this is
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// considered suspicious and ignored
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#define ACK_NR_ALLOWED_WINDOW DUPLICATE_ACKS_BEFORE_RESEND
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#define RST_INFO_TIMEOUT 10000
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#define RST_INFO_LIMIT 1000
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// 29 seconds determined from measuring many home NAT devices
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#define KEEPALIVE_INTERVAL 29000
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#define SEQ_NR_MASK 0xFFFF
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#define ACK_NR_MASK 0xFFFF
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#define TIMESTAMP_MASK 0xFFFFFFFF
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#define DIV_ROUND_UP(num, denom) ((num + denom - 1) / denom)
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// The totals are derived from the following data:
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// 45: IPv6 address including embedded IPv4 address
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// 11: Scope Id
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// 2: Brackets around IPv6 address when port is present
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// 6: Port (including colon)
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// 1: Terminating null byte
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char addrbuf[65];
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#define addrfmt(x, s) x.fmt(s, sizeof(s))
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#if (defined(__SVR4) && defined(__sun))
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#pragma pack(1)
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#else
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#pragma pack(push,1)
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#endif
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// these packet sizes are including the uTP header wich
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// is either 20 or 23 bytes depending on version
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#define PACKET_SIZE_EMPTY_BUCKET 0
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#define PACKET_SIZE_EMPTY 23
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#define PACKET_SIZE_SMALL_BUCKET 1
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#define PACKET_SIZE_SMALL 373
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#define PACKET_SIZE_MID_BUCKET 2
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#define PACKET_SIZE_MID 723
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#define PACKET_SIZE_BIG_BUCKET 3
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#define PACKET_SIZE_BIG 1400
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#define PACKET_SIZE_HUGE_BUCKET 4
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struct PACKED_ATTRIBUTE PacketFormatV1 {
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// packet_type (4 high bits)
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// protocol version (4 low bits)
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byte ver_type;
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byte version() const { return ver_type & 0xf; }
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byte type() const { return ver_type >> 4; }
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void set_version(byte v) { ver_type = (ver_type & 0xf0) | (v & 0xf); }
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void set_type(byte t) { ver_type = (ver_type & 0xf) | (t << 4); }
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// Type of the first extension header
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byte ext;
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// connection ID
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uint16_big connid;
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uint32_big tv_usec;
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uint32_big reply_micro;
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// receive window size in bytes
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uint32_big windowsize;
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// Sequence number
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uint16_big seq_nr;
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// Acknowledgment number
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uint16_big ack_nr;
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};
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struct PACKED_ATTRIBUTE PacketFormatAckV1 {
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PacketFormatV1 pf;
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byte ext_next;
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byte ext_len;
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byte acks[4];
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};
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#if (defined(__SVR4) && defined(__sun))
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#pragma pack(0)
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#else
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#pragma pack(pop)
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#endif
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enum {
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ST_DATA = 0, // Data packet.
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ST_FIN = 1, // Finalize the connection. This is the last packet.
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ST_STATE = 2, // State packet. Used to transmit an ACK with no data.
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ST_RESET = 3, // Terminate connection forcefully.
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ST_SYN = 4, // Connect SYN
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ST_NUM_STATES, // used for bounds checking
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};
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enum CONN_STATE {
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CS_UNINITIALIZED = 0,
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CS_IDLE,
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CS_SYN_SENT,
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CS_SYN_RECV,
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CS_CONNECTED,
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CS_CONNECTED_FULL,
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CS_RESET,
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CS_DESTROY
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};
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#if UTP_DEBUG_LOGGING
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static const cstr flagnames[] = {
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"ST_DATA","ST_FIN","ST_STATE","ST_RESET","ST_SYN"
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};
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static const cstr statenames[] = {
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"UNINITIALIZED", "IDLE","SYN_SENT", "SYN_RECV", "CONNECTED","CONNECTED_FULL","DESTROY_DELAY","RESET","DESTROY"
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};
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#endif
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struct OutgoingPacket {
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size_t length;
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size_t payload;
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uint64 time_sent; // microseconds
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uint transmissions:31;
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bool need_resend:1;
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byte data[1];
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};
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struct SizableCircularBuffer {
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// This is the mask. Since it's always a power of 2, adding 1 to this value will return the size.
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size_t mask;
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// This is the elements that the circular buffer points to
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void **elements;
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void *get(size_t i) const { assert(elements); return elements ? elements[i & mask] : NULL; }
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void put(size_t i, void *data) { assert(elements); elements[i&mask] = data; }
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void grow(size_t item, size_t index);
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void ensure_size(size_t item, size_t index) { if (index > mask) grow(item, index); }
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size_t size() { return mask + 1; }
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};
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// Item contains the element we want to make space for
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// index is the index in the list.
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void SizableCircularBuffer::grow(size_t item, size_t index)
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{
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// Figure out the new size.
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size_t size = mask + 1;
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do size *= 2; while (index >= size);
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// Allocate the new buffer
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void **buf = (void**)calloc(size, sizeof(void*));
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size--;
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// Copy elements from the old buffer to the new buffer
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for (size_t i = 0; i <= mask; i++) {
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buf[(item - index + i) & size] = get(item - index + i);
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}
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// Swap to the newly allocated buffer
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mask = size;
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free(elements);
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elements = buf;
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}
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// compare if lhs is less than rhs, taking wrapping
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// into account. if lhs is close to UINT_MAX and rhs
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// is close to 0, lhs is assumed to have wrapped and
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// considered smaller
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bool wrapping_compare_less(uint32 lhs, uint32 rhs, uint32 mask)
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{
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// distance walking from lhs to rhs, downwards
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const uint32 dist_down = (lhs - rhs) & mask;
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// distance walking from lhs to rhs, upwards
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const uint32 dist_up = (rhs - lhs) & mask;
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// if the distance walking up is shorter, lhs
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// is less than rhs. If the distance walking down
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// is shorter, then rhs is less than lhs
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return dist_up < dist_down;
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}
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struct DelayHist {
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uint32 delay_base;
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// this is the history of delay samples,
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// normalized by using the delay_base. These
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// values are always greater than 0 and measures
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// the queuing delay in microseconds
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uint32 cur_delay_hist[CUR_DELAY_SIZE];
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size_t cur_delay_idx;
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// this is the history of delay_base. It's
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// a number that doesn't have an absolute meaning
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// only relative. It doesn't make sense to initialize
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// it to anything other than values relative to
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// what's been seen in the real world.
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uint32 delay_base_hist[DELAY_BASE_HISTORY];
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size_t delay_base_idx;
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// the time when we last stepped the delay_base_idx
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uint64 delay_base_time;
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bool delay_base_initialized;
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void clear(uint64 current_ms)
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{
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delay_base_initialized = false;
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delay_base = 0;
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cur_delay_idx = 0;
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delay_base_idx = 0;
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delay_base_time = current_ms;
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for (size_t i = 0; i < CUR_DELAY_SIZE; i++) {
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cur_delay_hist[i] = 0;
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}
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for (size_t i = 0; i < DELAY_BASE_HISTORY; i++) {
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delay_base_hist[i] = 0;
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}
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}
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void shift(const uint32 offset)
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{
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// the offset should never be "negative"
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// assert(offset < 0x10000000);
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// increase all of our base delays by this amount
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// this is used to take clock skew into account
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// by observing the other side's changes in its base_delay
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for (size_t i = 0; i < DELAY_BASE_HISTORY; i++) {
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delay_base_hist[i] += offset;
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}
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delay_base += offset;
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}
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void add_sample(const uint32 sample, uint64 current_ms)
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{
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// The two clocks (in the two peers) are assumed not to
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// progress at the exact same rate. They are assumed to be
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// drifting, which causes the delay samples to contain
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// a systematic error, either they are under-
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// estimated or over-estimated. This is why we update the
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// delay_base every two minutes, to adjust for this.
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// This means the values will keep drifting and eventually wrap.
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// We can cross the wrapping boundry in two directions, either
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// going up, crossing the highest value, or going down, crossing 0.
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// if the delay_base is close to the max value and sample actually
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// wrapped on the other end we would see something like this:
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// delay_base = 0xffffff00, sample = 0x00000400
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// sample - delay_base = 0x500 which is the correct difference
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// if the delay_base is instead close to 0, and we got an even lower
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// sample (that will eventually update the delay_base), we may see
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// something like this:
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// delay_base = 0x00000400, sample = 0xffffff00
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// sample - delay_base = 0xfffffb00
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// this needs to be interpreted as a negative number and the actual
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// recorded delay should be 0.
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// It is important that all arithmetic that assume wrapping
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// is done with unsigned intergers. Signed integers are not guaranteed
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// to wrap the way unsigned integers do. At least GCC takes advantage
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// of this relaxed rule and won't necessarily wrap signed ints.
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// remove the clock offset and propagation delay.
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// delay base is min of the sample and the current
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// delay base. This min-operation is subject to wrapping
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// and care needs to be taken to correctly choose the
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// true minimum.
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// specifically the problem case is when delay_base is very small
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// and sample is very large (because it wrapped past zero), sample
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// needs to be considered the smaller
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if (!delay_base_initialized) {
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// delay_base being 0 suggests that we haven't initialized
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// it or its history with any real measurements yet. Initialize
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// everything with this sample.
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for (size_t i = 0; i < DELAY_BASE_HISTORY; i++) {
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// if we don't have a value, set it to the current sample
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delay_base_hist[i] = sample;
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continue;
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}
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delay_base = sample;
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delay_base_initialized = true;
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}
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if (wrapping_compare_less(sample, delay_base_hist[delay_base_idx], TIMESTAMP_MASK)) {
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// sample is smaller than the current delay_base_hist entry
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// update it
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delay_base_hist[delay_base_idx] = sample;
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}
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// is sample lower than delay_base? If so, update delay_base
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if (wrapping_compare_less(sample, delay_base, TIMESTAMP_MASK)) {
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// sample is smaller than the current delay_base
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// update it
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delay_base = sample;
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}
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// this operation may wrap, and is supposed to
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const uint32 delay = sample - delay_base;
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// sanity check. If this is triggered, something fishy is going on
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// it means the measured sample was greater than 32 seconds!
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//assert(delay < 0x2000000);
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cur_delay_hist[cur_delay_idx] = delay;
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cur_delay_idx = (cur_delay_idx + 1) % CUR_DELAY_SIZE;
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// once every minute
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if (current_ms - delay_base_time > 60 * 1000) {
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delay_base_time = current_ms;
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delay_base_idx = (delay_base_idx + 1) % DELAY_BASE_HISTORY;
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// clear up the new delay base history spot by initializing
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// it to the current sample, then update it
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delay_base_hist[delay_base_idx] = sample;
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delay_base = delay_base_hist[0];
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// Assign the lowest delay in the last 2 minutes to delay_base
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for (size_t i = 0; i < DELAY_BASE_HISTORY; i++) {
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if (wrapping_compare_less(delay_base_hist[i], delay_base, TIMESTAMP_MASK))
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delay_base = delay_base_hist[i];
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}
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}
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}
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uint32 get_value()
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{
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uint32 value = UINT_MAX;
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for (size_t i = 0; i < CUR_DELAY_SIZE; i++) {
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value = min<uint32>(cur_delay_hist[i], value);
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}
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// value could be UINT_MAX if we have no samples yet...
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return value;
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}
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};
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struct UTPSocket {
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~UTPSocket();
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PackedSockAddr addr;
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utp_context *ctx;
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int ida; //for ack socket list
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uint16 retransmit_count;
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uint16 reorder_count;
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byte duplicate_ack;
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// the number of packets in the send queue. Packets that haven't
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// yet been sent count as well as packets marked as needing resend
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// the oldest un-acked packet in the send queue is seq_nr - cur_window_packets
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uint16 cur_window_packets;
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// how much of the window is used, number of bytes in-flight
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// packets that have not yet been sent do not count, packets
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// that are marked as needing to be re-sent (due to a timeout)
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// don't count either
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size_t cur_window;
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// maximum window size, in bytes
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size_t max_window;
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// UTP_SNDBUF setting, in bytes
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size_t opt_sndbuf;
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// UTP_RCVBUF setting, in bytes
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size_t opt_rcvbuf;
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// this is the target delay, in microseconds
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// for this socket. defaults to 100000.
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size_t target_delay;
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// Is a FIN packet in the reassembly buffer?
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bool got_fin:1;
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// Have we reached the FIN?
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bool got_fin_reached:1;
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// Have we sent our FIN?
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bool fin_sent:1;
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// Has our fin been ACKed?
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bool fin_sent_acked:1;
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// Reading is disabled
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bool read_shutdown:1;
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// User called utp_close()
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bool close_requested:1;
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// Timeout procedure
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bool fast_timeout:1;
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// max receive window for other end, in bytes
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size_t max_window_user;
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CONN_STATE state;
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// TickCount when we last decayed window (wraps)
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int64 last_rwin_decay;
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// the sequence number of the FIN packet. This field is only set
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// when we have received a FIN, and the flag field has the FIN flag set.
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|
// it is used to know when it is safe to destroy the socket, we must have
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// received all packets up to this sequence number first.
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uint16 eof_pkt;
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// All sequence numbers up to including this have been properly received
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// by us
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uint16 ack_nr;
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// This is the sequence number for the next packet to be sent.
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uint16 seq_nr;
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uint16 timeout_seq_nr;
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// This is the sequence number of the next packet we're allowed to
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// do a fast resend with. This makes sure we only do a fast-resend
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// once per packet. We can resend the packet with this sequence number
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// or any later packet (with a higher sequence number).
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uint16 fast_resend_seq_nr;
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|
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uint32 reply_micro;
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uint64 last_got_packet;
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uint64 last_sent_packet;
|
|
uint64 last_measured_delay;
|
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|
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// timestamp of the last time the cwnd was full
|
|
// this is used to prevent the congestion window
|
|
// from growing when we're not sending at capacity
|
|
mutable uint64 last_maxed_out_window;
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|
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void *userdata;
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|
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// Round trip time
|
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uint rtt;
|
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// Round trip time variance
|
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uint rtt_var;
|
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// Round trip timeout
|
|
uint rto;
|
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DelayHist rtt_hist;
|
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uint retransmit_timeout;
|
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// The RTO timer will timeout here.
|
|
uint64 rto_timeout;
|
|
// When the window size is set to zero, start this timer. It will send a new packet every 30secs.
|
|
uint64 zerowindow_time;
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|
|
uint32 conn_seed;
|
|
// Connection ID for packets I receive
|
|
uint32 conn_id_recv;
|
|
// Connection ID for packets I send
|
|
uint32 conn_id_send;
|
|
// Last rcv window we advertised, in bytes
|
|
size_t last_rcv_win;
|
|
|
|
DelayHist our_hist;
|
|
DelayHist their_hist;
|
|
|
|
// extension bytes from SYN packet
|
|
byte extensions[8];
|
|
|
|
// MTU Discovery
|
|
// time when we should restart the MTU discovery
|
|
uint64 mtu_discover_time;
|
|
// ceiling and floor of binary search. last is the mtu size
|
|
// we're currently using
|
|
uint32 mtu_ceiling, mtu_floor, mtu_last;
|
|
// we only ever have a single probe in flight at any given time.
|
|
// this is the sequence number of that probe, and the size of
|
|
// that packet
|
|
uint32 mtu_probe_seq, mtu_probe_size;
|
|
|
|
// this is the average delay samples, as compared to the initial
|
|
// sample. It's averaged over 5 seconds
|
|
int32 average_delay;
|
|
// this is the sum of all the delay samples
|
|
// we've made recently. The important distinction
|
|
// of these samples is that they are all made compared
|
|
// to the initial sample, this is to deal with
|
|
// wrapping in a simple way.
|
|
int64 current_delay_sum;
|
|
// number of sample ins current_delay_sum
|
|
int current_delay_samples;
|
|
// initialized to 0, set to the first raw delay sample
|
|
// each sample that's added to current_delay_sum
|
|
// is subtracted from the value first, to make it
|
|
// a delay relative to this sample
|
|
uint32 average_delay_base;
|
|
// the next time we should add an average delay
|
|
// sample into average_delay_hist
|
|
uint64 average_sample_time;
|
|
// the estimated clock drift between our computer
|
|
// and the endpoint computer. The unit is microseconds
|
|
// per 5 seconds
|
|
int32 clock_drift;
|
|
// just used for logging
|
|
int32 clock_drift_raw;
|
|
|
|
SizableCircularBuffer inbuf, outbuf;
|
|
|
|
#ifdef _DEBUG
|
|
// Public per-socket statistics, returned by utp_get_stats()
|
|
utp_socket_stats _stats;
|
|
#endif
|
|
|
|
// true if we're in slow-start (exponential growth) phase
|
|
bool slow_start;
|
|
|
|
// the slow-start threshold, in bytes
|
|
size_t ssthresh;
|
|
|
|
void log(int level, char const *fmt, ...)
|
|
{
|
|
va_list va;
|
|
char buf[4096], buf2[4096];
|
|
|
|
// don't bother with vsnprintf() etc calls if we're not going to log.
|
|
if (!ctx->would_log(level)) {
|
|
return;
|
|
}
|
|
|
|
va_start(va, fmt);
|
|
vsnprintf(buf, 4096, fmt, va);
|
|
va_end(va);
|
|
buf[4095] = '\0';
|
|
|
|
snprintf(buf2, 4096, "%p %s %06u %s", this, addrfmt(addr, addrbuf), conn_id_recv, buf);
|
|
buf2[4095] = '\0';
|
|
|
|
ctx->log_unchecked(this, buf2);
|
|
}
|
|
|
|
void schedule_ack();
|
|
|
|
// called every time mtu_floor or mtu_ceiling are adjusted
|
|
void mtu_search_update();
|
|
void mtu_reset();
|
|
|
|
// Calculates the current receive window
|
|
size_t get_rcv_window()
|
|
{
|
|
// Trim window down according to what's already in buffer.
|
|
const size_t numbuf = utp_call_get_read_buffer_size(this->ctx, this);
|
|
assert((int)numbuf >= 0);
|
|
return opt_rcvbuf > numbuf ? opt_rcvbuf - numbuf : 0;
|
|
}
|
|
|
|
// Test if we're ready to decay max_window
|
|
// XXX this breaks when spaced by > INT_MAX/2, which is 49
|
|
// days; the failure mode in that case is we do an extra decay
|
|
// or fail to do one when we really shouldn't.
|
|
bool can_decay_win(int64 msec) const
|
|
{
|
|
return (msec - last_rwin_decay) >= MAX_WINDOW_DECAY;
|
|
}
|
|
|
|
// If we can, decay max window, returns true if we actually did so
|
|
void maybe_decay_win(uint64 current_ms)
|
|
{
|
|
if (can_decay_win(current_ms)) {
|
|
// TCP uses 0.5
|
|
max_window = (size_t)(max_window * .5);
|
|
last_rwin_decay = current_ms;
|
|
if (max_window < MIN_WINDOW_SIZE)
|
|
max_window = MIN_WINDOW_SIZE;
|
|
slow_start = false;
|
|
ssthresh = max_window;
|
|
}
|
|
}
|
|
|
|
size_t get_header_size() const
|
|
{
|
|
return sizeof(PacketFormatV1);
|
|
}
|
|
|
|
size_t get_udp_mtu()
|
|
{
|
|
socklen_t len;
|
|
SOCKADDR_STORAGE sa = addr.get_sockaddr_storage(&len);
|
|
return utp_call_get_udp_mtu(this->ctx, this, (const struct sockaddr *)&sa, len);
|
|
}
|
|
|
|
size_t get_udp_overhead()
|
|
{
|
|
socklen_t len;
|
|
SOCKADDR_STORAGE sa = addr.get_sockaddr_storage(&len);
|
|
return utp_call_get_udp_overhead(this->ctx, this, (const struct sockaddr *)&sa, len);
|
|
}
|
|
|
|
size_t get_overhead()
|
|
{
|
|
return get_udp_overhead() + get_header_size();
|
|
}
|
|
|
|
void send_data(byte* b, size_t length, bandwidth_type_t type, uint32 flags = 0);
|
|
|
|
void send_ack(bool synack = false);
|
|
|
|
void send_keep_alive();
|
|
|
|
static void send_rst(utp_context *ctx,
|
|
const PackedSockAddr &addr, uint32 conn_id_send,
|
|
uint16 ack_nr, uint16 seq_nr);
|
|
|
|
void send_packet(OutgoingPacket *pkt);
|
|
|
|
bool is_full(int bytes = -1);
|
|
bool flush_packets();
|
|
void write_outgoing_packet(size_t payload, uint flags, struct utp_iovec *iovec, size_t num_iovecs);
|
|
|
|
#ifdef _DEBUG
|
|
void check_invariant();
|
|
#endif
|
|
|
|
void check_timeouts();
|
|
int ack_packet(uint16 seq);
|
|
size_t selective_ack_bytes(uint base, const byte* mask, byte len, int64& min_rtt);
|
|
void selective_ack(uint base, const byte *mask, byte len);
|
|
void apply_ccontrol(size_t bytes_acked, uint32 actual_delay, int64 min_rtt);
|
|
size_t get_packet_size() const;
|
|
};
|
|
|
|
void removeSocketFromAckList(UTPSocket *conn)
|
|
{
|
|
if (conn->ida >= 0)
|
|
{
|
|
UTPSocket *last = conn->ctx->ack_sockets[conn->ctx->ack_sockets.GetCount() - 1];
|
|
|
|
assert(last->ida < (int)(conn->ctx->ack_sockets.GetCount()));
|
|
assert(conn->ctx->ack_sockets[last->ida] == last);
|
|
last->ida = conn->ida;
|
|
conn->ctx->ack_sockets[conn->ida] = last;
|
|
conn->ida = -1;
|
|
|
|
// Decrease the count
|
|
conn->ctx->ack_sockets.SetCount(conn->ctx->ack_sockets.GetCount() - 1);
|
|
}
|
|
}
|
|
|
|
static void utp_register_sent_packet(utp_context *ctx, size_t length)
|
|
{
|
|
if (length <= PACKET_SIZE_MID) {
|
|
if (length <= PACKET_SIZE_EMPTY) {
|
|
ctx->context_stats._nraw_send[PACKET_SIZE_EMPTY_BUCKET]++;
|
|
} else if (length <= PACKET_SIZE_SMALL) {
|
|
ctx->context_stats._nraw_send[PACKET_SIZE_SMALL_BUCKET]++;
|
|
} else
|
|
ctx->context_stats._nraw_send[PACKET_SIZE_MID_BUCKET]++;
|
|
} else {
|
|
if (length <= PACKET_SIZE_BIG) {
|
|
ctx->context_stats._nraw_send[PACKET_SIZE_BIG_BUCKET]++;
|
|
} else
|
|
ctx->context_stats._nraw_send[PACKET_SIZE_HUGE_BUCKET]++;
|
|
}
|
|
}
|
|
|
|
void send_to_addr(utp_context *ctx, const byte *p, size_t len, const PackedSockAddr &addr, int flags = 0)
|
|
{
|
|
socklen_t tolen;
|
|
SOCKADDR_STORAGE to = addr.get_sockaddr_storage(&tolen);
|
|
utp_register_sent_packet(ctx, len);
|
|
utp_call_sendto(ctx, NULL, p, len, (const struct sockaddr *)&to, tolen, flags);
|
|
}
|
|
|
|
void UTPSocket::schedule_ack()
|
|
{
|
|
if (ida == -1){
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "schedule_ack");
|
|
#endif
|
|
ida = ctx->ack_sockets.Append(this);
|
|
} else {
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "schedule_ack: already in list");
|
|
#endif
|
|
}
|
|
}
|
|
|
|
void UTPSocket::send_data(byte* b, size_t length, bandwidth_type_t type, uint32 flags)
|
|
{
|
|
// time stamp this packet with local time, the stamp goes into
|
|
// the header of every packet at the 8th byte for 8 bytes :
|
|
// two integers, check packet.h for more
|
|
uint64 time = utp_call_get_microseconds(ctx, this);
|
|
|
|
PacketFormatV1* b1 = (PacketFormatV1*)b;
|
|
b1->tv_usec = (uint32)time;
|
|
b1->reply_micro = reply_micro;
|
|
|
|
last_sent_packet = ctx->current_ms;
|
|
|
|
#ifdef _DEBUG
|
|
_stats.nbytes_xmit += length;
|
|
++_stats.nxmit;
|
|
#endif
|
|
|
|
if (ctx->callbacks[UTP_ON_OVERHEAD_STATISTICS]) {
|
|
size_t n;
|
|
if (type == payload_bandwidth) {
|
|
// if this packet carries payload, just
|
|
// count the header as overhead
|
|
type = header_overhead;
|
|
n = get_overhead();
|
|
} else {
|
|
n = length + get_udp_overhead();
|
|
}
|
|
utp_call_on_overhead_statistics(ctx, this, true, n, type);
|
|
}
|
|
#if UTP_DEBUG_LOGGING
|
|
int flags2 = b1->type();
|
|
uint16 seq_nr = b1->seq_nr;
|
|
uint16 ack_nr = b1->ack_nr;
|
|
log(UTP_LOG_DEBUG, "send %s len:%u id:%u timestamp:" I64u " reply_micro:%u flags:%s seq_nr:%u ack_nr:%u",
|
|
addrfmt(addr, addrbuf), (uint)length, conn_id_send, time, reply_micro, flagnames[flags2],
|
|
seq_nr, ack_nr);
|
|
#endif
|
|
send_to_addr(ctx, b, length, addr, flags);
|
|
removeSocketFromAckList(this);
|
|
}
|
|
|
|
void UTPSocket::send_ack(bool synack)
|
|
{
|
|
PacketFormatAckV1 pfa;
|
|
zeromem(&pfa);
|
|
|
|
size_t len;
|
|
last_rcv_win = get_rcv_window();
|
|
pfa.pf.set_version(1);
|
|
pfa.pf.set_type(ST_STATE);
|
|
pfa.pf.ext = 0;
|
|
pfa.pf.connid = conn_id_send;
|
|
pfa.pf.ack_nr = ack_nr;
|
|
pfa.pf.seq_nr = seq_nr;
|
|
pfa.pf.windowsize = (uint32)last_rcv_win;
|
|
len = sizeof(PacketFormatV1);
|
|
|
|
// we never need to send EACK for connections
|
|
// that are shutting down
|
|
if (reorder_count != 0 && !got_fin_reached) {
|
|
// if reorder count > 0, send an EACK.
|
|
// reorder count should always be 0
|
|
// for synacks, so this should not be
|
|
// as synack
|
|
assert(!synack);
|
|
pfa.pf.ext = 1;
|
|
pfa.ext_next = 0;
|
|
pfa.ext_len = 4;
|
|
uint m = 0;
|
|
|
|
// reorder count should only be non-zero
|
|
// if the packet ack_nr + 1 has not yet
|
|
// been received
|
|
assert(inbuf.get(ack_nr + 1) == NULL);
|
|
size_t window = min<size_t>(14+16, inbuf.size());
|
|
// Generate bit mask of segments received.
|
|
for (size_t i = 0; i < window; i++) {
|
|
if (inbuf.get(ack_nr + i + 2) != NULL) {
|
|
m |= 1 << i;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "EACK packet [%u]", ack_nr + i + 2);
|
|
#endif
|
|
}
|
|
}
|
|
pfa.acks[0] = (byte)m;
|
|
pfa.acks[1] = (byte)(m >> 8);
|
|
pfa.acks[2] = (byte)(m >> 16);
|
|
pfa.acks[3] = (byte)(m >> 24);
|
|
len += 4 + 2;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "Sending EACK %u [%u] bits:[%032b]", ack_nr, conn_id_send, m);
|
|
#endif
|
|
} else {
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "Sending ACK %u [%u]", ack_nr, conn_id_send);
|
|
#endif
|
|
}
|
|
|
|
send_data((byte*)&pfa, len, ack_overhead);
|
|
removeSocketFromAckList(this);
|
|
}
|
|
|
|
void UTPSocket::send_keep_alive()
|
|
{
|
|
ack_nr--;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "Sending KeepAlive ACK %u [%u]", ack_nr, conn_id_send);
|
|
#endif
|
|
|
|
send_ack();
|
|
ack_nr++;
|
|
}
|
|
|
|
void UTPSocket::send_rst(utp_context *ctx,
|
|
const PackedSockAddr &addr, uint32 conn_id_send, uint16 ack_nr, uint16 seq_nr)
|
|
{
|
|
PacketFormatV1 pf1;
|
|
zeromem(&pf1);
|
|
|
|
size_t len;
|
|
pf1.set_version(1);
|
|
pf1.set_type(ST_RESET);
|
|
pf1.ext = 0;
|
|
pf1.connid = conn_id_send;
|
|
pf1.ack_nr = ack_nr;
|
|
pf1.seq_nr = seq_nr;
|
|
pf1.windowsize = 0;
|
|
len = sizeof(PacketFormatV1);
|
|
|
|
// LOG_DEBUG("%s: Sending RST id:%u seq_nr:%u ack_nr:%u", addrfmt(addr, addrbuf), conn_id_send, seq_nr, ack_nr);
|
|
// LOG_DEBUG("send %s len:%u id:%u", addrfmt(addr, addrbuf), (uint)len, conn_id_send);
|
|
send_to_addr(ctx, (const byte*)&pf1, len, addr);
|
|
}
|
|
|
|
void UTPSocket::send_packet(OutgoingPacket *pkt)
|
|
{
|
|
// only count against the quota the first time we
|
|
// send the packet. Don't enforce quota when closing
|
|
// a socket. Only enforce the quota when we're sending
|
|
// at slow rates (max window < packet size)
|
|
|
|
//size_t max_send = min(max_window, opt_sndbuf, max_window_user);
|
|
time_t cur_time = utp_call_get_milliseconds(this->ctx, this);
|
|
|
|
if (pkt->transmissions == 0 || pkt->need_resend) {
|
|
cur_window += pkt->payload;
|
|
}
|
|
|
|
pkt->need_resend = false;
|
|
|
|
PacketFormatV1* p1 = (PacketFormatV1*)pkt->data;
|
|
p1->ack_nr = ack_nr;
|
|
pkt->time_sent = utp_call_get_microseconds(this->ctx, this);
|
|
|
|
//socklen_t salen;
|
|
//SOCKADDR_STORAGE sa = addr.get_sockaddr_storage(&salen);
|
|
bool use_as_mtu_probe = false;
|
|
|
|
// TODO: this is subject to nasty wrapping issues! Below as well
|
|
if (mtu_discover_time < (uint64)cur_time) {
|
|
// it's time to reset our MTU assupmtions
|
|
// and trigger a new search
|
|
mtu_reset();
|
|
}
|
|
|
|
// don't use packets that are larger then mtu_ceiling
|
|
// as probes, since they were probably used as probes
|
|
// already and failed, now we need it to fragment
|
|
// just to get it through
|
|
// if seq_nr == 1, the probe would end up being 0
|
|
// which is a magic number representing no-probe
|
|
// that why we don't send a probe for a packet with
|
|
// sequence number 0
|
|
if (mtu_floor < mtu_ceiling
|
|
&& pkt->length > mtu_floor
|
|
&& pkt->length <= mtu_ceiling
|
|
&& mtu_probe_seq == 0
|
|
&& seq_nr != 1
|
|
&& pkt->transmissions == 0) {
|
|
|
|
// we've already incremented seq_nr
|
|
// for this packet
|
|
mtu_probe_seq = (seq_nr - 1) & ACK_NR_MASK;
|
|
mtu_probe_size = pkt->length;
|
|
assert(pkt->length >= mtu_floor);
|
|
assert(pkt->length <= mtu_ceiling);
|
|
use_as_mtu_probe = true;
|
|
log(UTP_LOG_MTU, "MTU [PROBE] floor:%d ceiling:%d current:%d"
|
|
, mtu_floor, mtu_ceiling, mtu_probe_size);
|
|
}
|
|
|
|
pkt->transmissions++;
|
|
send_data((byte*)pkt->data, pkt->length,
|
|
(state == CS_SYN_SENT) ? connect_overhead
|
|
: (pkt->transmissions == 1) ? payload_bandwidth
|
|
: retransmit_overhead, use_as_mtu_probe ? UTP_UDP_DONTFRAG : 0);
|
|
}
|
|
|
|
bool UTPSocket::is_full(int bytes)
|
|
{
|
|
size_t packet_size = get_packet_size();
|
|
if (bytes < 0) bytes = packet_size;
|
|
else if (bytes > (int)packet_size) bytes = (int)packet_size;
|
|
size_t max_send = min(max_window, opt_sndbuf, max_window_user);
|
|
|
|
// subtract one to save space for the FIN packet
|
|
if (cur_window_packets >= OUTGOING_BUFFER_MAX_SIZE - 1) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "is_full:false cur_window_packets:%d MAX:%d", cur_window_packets, OUTGOING_BUFFER_MAX_SIZE - 1);
|
|
#endif
|
|
|
|
last_maxed_out_window = ctx->current_ms;
|
|
return true;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "is_full:%s. cur_window:%u pkt:%u max:%u cur_window_packets:%u max_window:%u"
|
|
, (cur_window + bytes > max_send) ? "true" : "false"
|
|
, cur_window, bytes, max_send, cur_window_packets
|
|
, max_window);
|
|
#endif
|
|
|
|
if (cur_window + bytes > max_send) {
|
|
last_maxed_out_window = ctx->current_ms;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool UTPSocket::flush_packets()
|
|
{
|
|
size_t packet_size = get_packet_size();
|
|
|
|
// send packets that are waiting on the pacer to be sent
|
|
// i has to be an unsigned 16 bit counter to wrap correctly
|
|
// signed types are not guaranteed to wrap the way you expect
|
|
for (uint16 i = seq_nr - cur_window_packets; i != seq_nr; ++i) {
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(i);
|
|
if (pkt == 0 || (pkt->transmissions > 0 && pkt->need_resend == false)) continue;
|
|
// have we run out of quota?
|
|
if (is_full()) return true;
|
|
|
|
// Nagle check
|
|
// don't send the last packet if we have one packet in-flight
|
|
// and the current packet is still smaller than packet_size.
|
|
if (i != ((seq_nr - 1) & ACK_NR_MASK) ||
|
|
cur_window_packets == 1 ||
|
|
pkt->payload >= packet_size) {
|
|
send_packet(pkt);
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// @payload: number of bytes to send
|
|
// @flags: either ST_DATA, or ST_FIN
|
|
// @iovec: base address of iovec array
|
|
// @num_iovecs: number of iovecs in array
|
|
void UTPSocket::write_outgoing_packet(size_t payload, uint flags, struct utp_iovec *iovec, size_t num_iovecs)
|
|
{
|
|
// Setup initial timeout timer
|
|
if (cur_window_packets == 0) {
|
|
retransmit_timeout = rto;
|
|
rto_timeout = ctx->current_ms + retransmit_timeout;
|
|
assert(cur_window == 0);
|
|
}
|
|
|
|
size_t packet_size = get_packet_size();
|
|
do {
|
|
assert(cur_window_packets < OUTGOING_BUFFER_MAX_SIZE);
|
|
assert(flags == ST_DATA || flags == ST_FIN);
|
|
|
|
size_t added = 0;
|
|
|
|
OutgoingPacket *pkt = NULL;
|
|
|
|
if (cur_window_packets > 0) {
|
|
pkt = (OutgoingPacket*)outbuf.get(seq_nr - 1);
|
|
}
|
|
|
|
const size_t header_size = get_header_size();
|
|
bool append = true;
|
|
|
|
// if there's any room left in the last packet in the window
|
|
// and it hasn't been sent yet, fill that frame first
|
|
if (payload && pkt && !pkt->transmissions && pkt->payload < packet_size) {
|
|
// Use the previous unsent packet
|
|
added = min(payload + pkt->payload, max<size_t>(packet_size, pkt->payload)) - pkt->payload;
|
|
pkt = (OutgoingPacket*)realloc(pkt,
|
|
(sizeof(OutgoingPacket) - 1) +
|
|
header_size +
|
|
pkt->payload + added);
|
|
outbuf.put(seq_nr - 1, pkt);
|
|
append = false;
|
|
assert(!pkt->need_resend);
|
|
} else {
|
|
// Create the packet to send.
|
|
added = payload;
|
|
pkt = (OutgoingPacket*)malloc((sizeof(OutgoingPacket) - 1) +
|
|
header_size +
|
|
added);
|
|
pkt->payload = 0;
|
|
pkt->transmissions = 0;
|
|
pkt->need_resend = false;
|
|
}
|
|
|
|
if (added) {
|
|
assert(flags == ST_DATA);
|
|
|
|
// Fill it with data from the upper layer.
|
|
unsigned char *p = pkt->data + header_size + pkt->payload;
|
|
size_t needed = added;
|
|
|
|
/*
|
|
while (needed) {
|
|
*p = *(char*)iovec[0].iov_base;
|
|
p++;
|
|
iovec[0].iov_base = (char *)iovec[0].iov_base + 1;
|
|
needed--;
|
|
}
|
|
*/
|
|
|
|
for (size_t i = 0; i < num_iovecs && needed; i++) {
|
|
if (iovec[i].iov_len == 0)
|
|
continue;
|
|
|
|
size_t num = min<size_t>(needed, iovec[i].iov_len);
|
|
memcpy(p, iovec[i].iov_base, num);
|
|
|
|
p += num;
|
|
|
|
iovec[i].iov_len -= num;
|
|
iovec[i].iov_base = (byte*)iovec[i].iov_base + num; // iovec[i].iov_base += num, but without void* pointers
|
|
needed -= num;
|
|
}
|
|
|
|
assert(needed == 0);
|
|
}
|
|
pkt->payload += added;
|
|
pkt->length = header_size + pkt->payload;
|
|
|
|
last_rcv_win = get_rcv_window();
|
|
|
|
PacketFormatV1* p1 = (PacketFormatV1*)pkt->data;
|
|
p1->set_version(1);
|
|
p1->set_type(flags);
|
|
p1->ext = 0;
|
|
p1->connid = conn_id_send;
|
|
p1->windowsize = (uint32)last_rcv_win;
|
|
p1->ack_nr = ack_nr;
|
|
|
|
if (append) {
|
|
// Remember the message in the outgoing queue.
|
|
outbuf.ensure_size(seq_nr, cur_window_packets);
|
|
outbuf.put(seq_nr, pkt);
|
|
p1->seq_nr = seq_nr;
|
|
seq_nr++;
|
|
cur_window_packets++;
|
|
}
|
|
|
|
payload -= added;
|
|
|
|
} while (payload);
|
|
|
|
flush_packets();
|
|
}
|
|
|
|
#ifdef _DEBUG
|
|
void UTPSocket::check_invariant()
|
|
{
|
|
if (reorder_count > 0) {
|
|
assert(inbuf.get(ack_nr + 1) == NULL);
|
|
}
|
|
|
|
size_t outstanding_bytes = 0;
|
|
for (int i = 0; i < cur_window_packets; ++i) {
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(seq_nr - i - 1);
|
|
if (pkt == 0 || pkt->transmissions == 0 || pkt->need_resend) continue;
|
|
outstanding_bytes += pkt->payload;
|
|
}
|
|
assert(outstanding_bytes == cur_window);
|
|
}
|
|
#endif
|
|
|
|
void UTPSocket::check_timeouts()
|
|
{
|
|
#ifdef _DEBUG
|
|
check_invariant();
|
|
#endif
|
|
|
|
// this invariant should always be true
|
|
assert(cur_window_packets == 0 || outbuf.get(seq_nr - cur_window_packets));
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "CheckTimeouts timeout:%d max_window:%u cur_window:%u "
|
|
"state:%s cur_window_packets:%u",
|
|
(int)(rto_timeout - ctx->current_ms), (uint)max_window, (uint)cur_window,
|
|
statenames[state], cur_window_packets);
|
|
#endif
|
|
|
|
if (state != CS_DESTROY) flush_packets();
|
|
|
|
switch (state) {
|
|
case CS_SYN_SENT:
|
|
case CS_SYN_RECV:
|
|
case CS_CONNECTED_FULL:
|
|
case CS_CONNECTED: {
|
|
|
|
// Reset max window...
|
|
if ((int)(ctx->current_ms - zerowindow_time) >= 0 && max_window_user == 0) {
|
|
max_window_user = PACKET_SIZE;
|
|
}
|
|
|
|
if ((int)(ctx->current_ms - rto_timeout) >= 0
|
|
&& rto_timeout > 0) {
|
|
|
|
bool ignore_loss = false;
|
|
|
|
if (cur_window_packets == 1
|
|
&& ((seq_nr - 1) & ACK_NR_MASK) == mtu_probe_seq
|
|
&& mtu_probe_seq != 0) {
|
|
// we only had a single outstanding packet that timed out, and it was the probe
|
|
mtu_ceiling = mtu_probe_size - 1;
|
|
mtu_search_update();
|
|
// this packet was most likely dropped because the packet size being
|
|
// too big and not because congestion. To accelerate the binary search for
|
|
// the MTU, resend immediately and don't reset the window size
|
|
ignore_loss = true;
|
|
log(UTP_LOG_MTU, "MTU [PROBE-TIMEOUT] floor:%d ceiling:%d current:%d"
|
|
, mtu_floor, mtu_ceiling, mtu_last);
|
|
}
|
|
// we dropepd the probe, clear these fields to
|
|
// allow us to send a new one
|
|
mtu_probe_seq = mtu_probe_size = 0;
|
|
log(UTP_LOG_MTU, "MTU [TIMEOUT]");
|
|
|
|
/*
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(seq_nr - cur_window_packets);
|
|
|
|
// If there were a lot of retransmissions, force recomputation of round trip time
|
|
if (pkt->transmissions >= 4)
|
|
rtt = 0;
|
|
*/
|
|
|
|
// Increase RTO
|
|
const uint new_timeout = ignore_loss ? retransmit_timeout : retransmit_timeout * 2;
|
|
|
|
// They initiated the connection but failed to respond before the rto.
|
|
// A malicious client can also spoof the destination address of a ST_SYN bringing us to this state.
|
|
// Kill the connection and do not notify the upper layer
|
|
if (state == CS_SYN_RECV) {
|
|
state = CS_DESTROY;
|
|
utp_call_on_error(ctx, this, UTP_ETIMEDOUT);
|
|
return;
|
|
}
|
|
|
|
// We initiated the connection but the other side failed to respond before the rto
|
|
if (retransmit_count >= 4 || (state == CS_SYN_SENT && retransmit_count >= 2)) {
|
|
// 4 consecutive transmissions have timed out. Kill it. If we
|
|
// haven't even connected yet, give up after only 2 consecutive
|
|
// failed transmissions.
|
|
if (close_requested)
|
|
state = CS_DESTROY;
|
|
else
|
|
state = CS_RESET;
|
|
utp_call_on_error(ctx, this, UTP_ETIMEDOUT);
|
|
return;
|
|
}
|
|
|
|
retransmit_timeout = new_timeout;
|
|
rto_timeout = ctx->current_ms + new_timeout;
|
|
|
|
if (!ignore_loss) {
|
|
// On Timeout
|
|
duplicate_ack = 0;
|
|
|
|
int packet_size = get_packet_size();
|
|
|
|
if ((cur_window_packets == 0) && ((int)max_window > packet_size)) {
|
|
// we don't have any packets in-flight, even though
|
|
// we could. This implies that the connection is just
|
|
// idling. No need to be aggressive about resetting the
|
|
// congestion window. Just let it decay by a 3:rd.
|
|
// don't set it any lower than the packet size though
|
|
max_window = max(max_window * 2 / 3, size_t(packet_size));
|
|
} else {
|
|
// our delay was so high that our congestion window
|
|
// was shrunk below one packet, preventing us from
|
|
// sending anything for one time-out period. Now, reset
|
|
// the congestion window to fit one packet, to start over
|
|
// again
|
|
max_window = packet_size;
|
|
slow_start = true;
|
|
}
|
|
}
|
|
|
|
// every packet should be considered lost
|
|
for (int i = 0; i < cur_window_packets; ++i) {
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(seq_nr - i - 1);
|
|
if (pkt == 0 || pkt->transmissions == 0 || pkt->need_resend) continue;
|
|
pkt->need_resend = true;
|
|
assert(cur_window >= pkt->payload);
|
|
cur_window -= pkt->payload;
|
|
}
|
|
|
|
if (cur_window_packets > 0) {
|
|
retransmit_count++;
|
|
// used in parse_log.py
|
|
log(UTP_LOG_NORMAL, "Packet timeout. Resend. seq_nr:%u. timeout:%u "
|
|
"max_window:%u cur_window_packets:%d"
|
|
, seq_nr - cur_window_packets, retransmit_timeout
|
|
, (uint)max_window, int(cur_window_packets));
|
|
|
|
fast_timeout = true;
|
|
timeout_seq_nr = seq_nr;
|
|
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(seq_nr - cur_window_packets);
|
|
assert(pkt);
|
|
|
|
// Re-send the packet.
|
|
send_packet(pkt);
|
|
}
|
|
}
|
|
|
|
// Mark the socket as writable. If the cwnd has grown, or if the number of
|
|
// bytes in-flight is lower than cwnd, we need to make the socket writable again
|
|
// in case it isn't
|
|
if (state == CS_CONNECTED_FULL && !is_full()) {
|
|
state = CS_CONNECTED;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "Socket writable. max_window:%u cur_window:%u packet_size:%u",
|
|
(uint)max_window, (uint)cur_window, (uint)get_packet_size());
|
|
#endif
|
|
utp_call_on_state_change(this->ctx, this, UTP_STATE_WRITABLE);
|
|
}
|
|
|
|
if (state >= CS_CONNECTED && !fin_sent) {
|
|
if ((int)(ctx->current_ms - last_sent_packet) >= KEEPALIVE_INTERVAL) {
|
|
send_keep_alive();
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
// prevent warning
|
|
case CS_UNINITIALIZED:
|
|
case CS_IDLE:
|
|
case CS_RESET:
|
|
case CS_DESTROY:
|
|
break;
|
|
}
|
|
}
|
|
|
|
// this should be called every time we change mtu_floor or mtu_ceiling
|
|
void UTPSocket::mtu_search_update()
|
|
{
|
|
assert(mtu_floor <= mtu_ceiling);
|
|
|
|
// binary search
|
|
mtu_last = (mtu_floor + mtu_ceiling) / 2;
|
|
|
|
// enable a new probe to be sent
|
|
mtu_probe_seq = mtu_probe_size = 0;
|
|
|
|
// if the floor and ceiling are close enough, consider the
|
|
// MTU binary search complete. We set the current value
|
|
// to floor since that's the only size we know can go through
|
|
// also set the ceiling to floor to terminate the searching
|
|
if (mtu_ceiling - mtu_floor <= 16) {
|
|
mtu_last = mtu_floor;
|
|
log(UTP_LOG_MTU, "MTU [DONE] floor:%d ceiling:%d current:%d"
|
|
, mtu_floor, mtu_ceiling, mtu_last);
|
|
mtu_ceiling = mtu_floor;
|
|
assert(mtu_floor <= mtu_ceiling);
|
|
// Do another search in 30 minutes
|
|
mtu_discover_time = utp_call_get_milliseconds(this->ctx, this) + 30 * 60 * 1000;
|
|
}
|
|
}
|
|
|
|
void UTPSocket::mtu_reset()
|
|
{
|
|
mtu_ceiling = get_udp_mtu();
|
|
// Less would not pass TCP...
|
|
mtu_floor = 576;
|
|
log(UTP_LOG_MTU, "MTU [RESET] floor:%d ceiling:%d current:%d"
|
|
, mtu_floor, mtu_ceiling, mtu_last);
|
|
assert(mtu_floor <= mtu_ceiling);
|
|
mtu_discover_time = utp_call_get_milliseconds(this->ctx, this) + 30 * 60 * 1000;
|
|
}
|
|
|
|
// returns:
|
|
// 0: the packet was acked.
|
|
// 1: it means that the packet had already been acked
|
|
// 2: the packet has not been sent yet
|
|
int UTPSocket::ack_packet(uint16 seq)
|
|
{
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(seq);
|
|
|
|
// the packet has already been acked (or not sent)
|
|
if (pkt == NULL) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "got ack for:%u (already acked, or never sent)", seq);
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
// can't ack packets that haven't been sent yet!
|
|
if (pkt->transmissions == 0) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "got ack for:%u (never sent, pkt_size:%u need_resend:%u)",
|
|
seq, (uint)pkt->payload, pkt->need_resend);
|
|
#endif
|
|
|
|
return 2;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "got ack for:%u (pkt_size:%u need_resend:%u)",
|
|
seq, (uint)pkt->payload, pkt->need_resend);
|
|
#endif
|
|
|
|
outbuf.put(seq, NULL);
|
|
|
|
// if we never re-sent the packet, update the RTT estimate
|
|
if (pkt->transmissions == 1) {
|
|
// Estimate the round trip time.
|
|
const uint32 ertt = (uint32)((utp_call_get_microseconds(this->ctx, this) - pkt->time_sent) / 1000);
|
|
if (rtt == 0) {
|
|
// First round trip time sample
|
|
rtt = ertt;
|
|
rtt_var = ertt / 2;
|
|
// sanity check. rtt should never be more than 6 seconds
|
|
// assert(rtt < 6000);
|
|
} else {
|
|
// Compute new round trip times
|
|
const int delta = (int)rtt - ertt;
|
|
rtt_var = rtt_var + (int)(abs(delta) - rtt_var) / 4;
|
|
rtt = rtt - rtt/8 + ertt/8;
|
|
// sanity check. rtt should never be more than 6 seconds
|
|
// assert(rtt < 6000);
|
|
rtt_hist.add_sample(ertt, ctx->current_ms);
|
|
}
|
|
rto = max<uint>(rtt + rtt_var * 4, 1000);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "rtt:%u avg:%u var:%u rto:%u",
|
|
ertt, rtt, rtt_var, rto);
|
|
#endif
|
|
|
|
}
|
|
retransmit_timeout = rto;
|
|
rto_timeout = ctx->current_ms + rto;
|
|
// if need_resend is set, this packet has already
|
|
// been considered timed-out, and is not included in
|
|
// the cur_window anymore
|
|
if (!pkt->need_resend) {
|
|
assert(cur_window >= pkt->payload);
|
|
cur_window -= pkt->payload;
|
|
}
|
|
free(pkt);
|
|
retransmit_count = 0;
|
|
return 0;
|
|
}
|
|
|
|
// count the number of bytes that were acked by the EACK header
|
|
size_t UTPSocket::selective_ack_bytes(uint base, const byte* mask, byte len, int64& min_rtt)
|
|
{
|
|
if (cur_window_packets == 0) return 0;
|
|
|
|
size_t acked_bytes = 0;
|
|
int bits = len * 8;
|
|
uint64 now = utp_call_get_microseconds(this->ctx, this);
|
|
|
|
do {
|
|
uint v = base + bits;
|
|
|
|
// ignore bits that haven't been sent yet
|
|
// see comment in UTPSocket::selective_ack
|
|
if (((seq_nr - v - 1) & ACK_NR_MASK) >= (uint16)(cur_window_packets - 1))
|
|
continue;
|
|
|
|
// ignore bits that represents packets we haven't sent yet
|
|
// or packets that have already been acked
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(v);
|
|
if (!pkt || pkt->transmissions == 0)
|
|
continue;
|
|
|
|
// Count the number of segments that were successfully received past it.
|
|
if (bits >= 0 && mask[bits>>3] & (1 << (bits & 7))) {
|
|
assert((int)(pkt->payload) >= 0);
|
|
acked_bytes += pkt->payload;
|
|
if (pkt->time_sent < now)
|
|
min_rtt = min<int64>(min_rtt, now - pkt->time_sent);
|
|
else
|
|
min_rtt = min<int64>(min_rtt, 50000);
|
|
continue;
|
|
}
|
|
} while (--bits >= -1);
|
|
return acked_bytes;
|
|
}
|
|
|
|
enum { MAX_EACK = 128 };
|
|
|
|
void UTPSocket::selective_ack(uint base, const byte *mask, byte len)
|
|
{
|
|
if (cur_window_packets == 0) return;
|
|
|
|
// the range is inclusive [0, 31] bits
|
|
int bits = len * 8 - 1;
|
|
|
|
int count = 0;
|
|
|
|
// resends is a stack of sequence numbers we need to resend. Since we
|
|
// iterate in reverse over the acked packets, at the end, the top packets
|
|
// are the ones we want to resend
|
|
int resends[MAX_EACK];
|
|
int nr = 0;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
char bitmask[1024] = {0};
|
|
int counter = bits;
|
|
for (int i = 0; i <= bits; ++i) {
|
|
bool bit_set = counter >= 0 && mask[counter>>3] & (1 << (counter & 7));
|
|
bitmask[i] = bit_set ? '1' : '0';
|
|
--counter;
|
|
}
|
|
|
|
log(UTP_LOG_DEBUG, "Got EACK [%s] base:%u", bitmask, base);
|
|
#endif
|
|
|
|
do {
|
|
// we're iterating over the bits from higher sequence numbers
|
|
// to lower (kind of in reverse order, wich might not be very
|
|
// intuitive)
|
|
uint v = base + bits;
|
|
|
|
// ignore bits that haven't been sent yet
|
|
// and bits that fall below the ACKed sequence number
|
|
// this can happen if an EACK message gets
|
|
// reordered and arrives after a packet that ACKs up past
|
|
// the base for thie EACK message
|
|
|
|
// this is essentially the same as:
|
|
// if v >= seq_nr || v <= seq_nr - cur_window_packets
|
|
// but it takes wrapping into account
|
|
|
|
// if v == seq_nr the -1 will make it wrap. if v > seq_nr
|
|
// it will also wrap (since it will fall further below 0)
|
|
// and be > cur_window_packets.
|
|
// if v == seq_nr - cur_window_packets, the result will be
|
|
// seq_nr - (seq_nr - cur_window_packets) - 1
|
|
// == seq_nr - seq_nr + cur_window_packets - 1
|
|
// == cur_window_packets - 1 which will be caught by the
|
|
// test. If v < seq_nr - cur_window_packets the result will grow
|
|
// fall furhter outside of the cur_window_packets range.
|
|
|
|
// sequence number space:
|
|
//
|
|
// rejected < accepted > rejected
|
|
// <============+--------------+============>
|
|
// ^ ^
|
|
// | |
|
|
// (seq_nr-wnd) seq_nr
|
|
|
|
if (((seq_nr - v - 1) & ACK_NR_MASK) >= (uint16)(cur_window_packets - 1))
|
|
continue;
|
|
|
|
// this counts as a duplicate ack, even though we might have
|
|
// received an ack for this packet previously (in another EACK
|
|
// message for instance)
|
|
bool bit_set = bits >= 0 && mask[bits>>3] & (1 << (bits & 7));
|
|
|
|
// if this packet is acked, it counts towards the duplicate ack counter
|
|
if (bit_set) count++;
|
|
|
|
// ignore bits that represents packets we haven't sent yet
|
|
// or packets that have already been acked
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(v);
|
|
if (!pkt || pkt->transmissions == 0) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "skipping %u. pkt:%08x transmissions:%u %s",
|
|
v, pkt, pkt?pkt->transmissions:0, pkt?"(not sent yet?)":"(already acked?)");
|
|
#endif
|
|
continue;
|
|
}
|
|
|
|
// Count the number of segments that were successfully received past it.
|
|
if (bit_set) {
|
|
// the selective ack should never ACK the packet we're waiting for to decrement cur_window_packets
|
|
assert((v & outbuf.mask) != ((seq_nr - cur_window_packets) & outbuf.mask));
|
|
ack_packet(v);
|
|
continue;
|
|
}
|
|
|
|
// Resend segments
|
|
// if count is less than our re-send limit, we haven't seen enough
|
|
// acked packets in front of this one to warrant a re-send.
|
|
// if count == 0, we're still going through the tail of zeroes
|
|
if (((v - fast_resend_seq_nr) & ACK_NR_MASK) <= OUTGOING_BUFFER_MAX_SIZE &&
|
|
count >= DUPLICATE_ACKS_BEFORE_RESEND) {
|
|
// resends is a stack, and we're mostly interested in the top of it
|
|
// if we're full, just throw away the lower half
|
|
if (nr >= MAX_EACK - 2) {
|
|
memmove(resends, &resends[MAX_EACK/2], MAX_EACK/2 * sizeof(resends[0]));
|
|
nr -= MAX_EACK / 2;
|
|
}
|
|
resends[nr++] = v;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "no ack for %u", v);
|
|
#endif
|
|
|
|
} else {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "not resending %u count:%d dup_ack:%u fast_resend_seq_nr:%u",
|
|
v, count, duplicate_ack, fast_resend_seq_nr);
|
|
#endif
|
|
}
|
|
} while (--bits >= -1);
|
|
|
|
if (((base - 1 - fast_resend_seq_nr) & ACK_NR_MASK) <= OUTGOING_BUFFER_MAX_SIZE &&
|
|
count >= DUPLICATE_ACKS_BEFORE_RESEND) {
|
|
// if we get enough duplicate acks to start
|
|
// resending, the first packet we should resend
|
|
// is base-1
|
|
resends[nr++] = (base - 1) & ACK_NR_MASK;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "no ack for %u", (base - 1) & ACK_NR_MASK);
|
|
#endif
|
|
|
|
} else {
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "not resending %u count:%d dup_ack:%u fast_resend_seq_nr:%u",
|
|
base - 1, count, duplicate_ack, fast_resend_seq_nr);
|
|
#endif
|
|
}
|
|
|
|
bool back_off = false;
|
|
int i = 0;
|
|
while (nr > 0) {
|
|
uint v = resends[--nr];
|
|
// don't consider the tail of 0:es to be lost packets
|
|
// only unacked packets with acked packets after should
|
|
// be considered lost
|
|
OutgoingPacket *pkt = (OutgoingPacket*)outbuf.get(v);
|
|
|
|
// this may be an old (re-ordered) packet, and some of the
|
|
// packets in here may have been acked already. In which
|
|
// case they will not be in the send queue anymore
|
|
if (!pkt) continue;
|
|
|
|
// used in parse_log.py
|
|
log(UTP_LOG_NORMAL, "Packet %u lost. Resending", v);
|
|
|
|
// On Loss
|
|
back_off = true;
|
|
|
|
#ifdef _DEBUG
|
|
++_stats.rexmit;
|
|
#endif
|
|
|
|
send_packet(pkt);
|
|
fast_resend_seq_nr = (v + 1) & ACK_NR_MASK;
|
|
|
|
// Re-send max 4 packets.
|
|
if (++i >= 4) break;
|
|
}
|
|
|
|
if (back_off)
|
|
maybe_decay_win(ctx->current_ms);
|
|
|
|
duplicate_ack = count;
|
|
}
|
|
|
|
void UTPSocket::apply_ccontrol(size_t bytes_acked, uint32 actual_delay, int64 min_rtt)
|
|
{
|
|
// the delay can never be greater than the rtt. The min_rtt
|
|
// variable is the RTT in microseconds
|
|
|
|
assert(min_rtt >= 0);
|
|
int32 our_delay = min<uint32>(our_hist.get_value(), uint32(min_rtt));
|
|
assert(our_delay != INT_MAX);
|
|
assert(our_delay >= 0);
|
|
|
|
utp_call_on_delay_sample(this->ctx, this, our_delay / 1000);
|
|
|
|
// This test the connection under heavy load from foreground
|
|
// traffic. Pretend that our delays are very high to force the
|
|
// connection to use sub-packet size window sizes
|
|
//our_delay *= 4;
|
|
|
|
// target is microseconds
|
|
int target = target_delay;
|
|
if (target <= 0) target = 100000;
|
|
|
|
// this is here to compensate for very large clock drift that affects
|
|
// the congestion controller into giving certain endpoints an unfair
|
|
// share of the bandwidth. We have an estimate of the clock drift
|
|
// (clock_drift). The unit of this is microseconds per 5 seconds.
|
|
// empirically, a reasonable cut-off appears to be about 200000
|
|
// (which is pretty high). The main purpose is to compensate for
|
|
// people trying to "cheat" uTP by making their clock run slower,
|
|
// and this definitely catches that without any risk of false positives
|
|
// if clock_drift < -200000 start applying a penalty delay proportional
|
|
// to how far beoynd -200000 the clock drift is
|
|
int32 penalty = 0;
|
|
if (clock_drift < -200000) {
|
|
penalty = (-clock_drift - 200000) / 7;
|
|
our_delay += penalty;
|
|
}
|
|
|
|
double off_target = target - our_delay;
|
|
|
|
// this is the same as:
|
|
//
|
|
// (min(off_target, target) / target) * (bytes_acked / max_window) * MAX_CWND_INCREASE_BYTES_PER_RTT
|
|
//
|
|
// so, it's scaling the max increase by the fraction of the window this ack represents, and the fraction
|
|
// of the target delay the current delay represents.
|
|
// The min() around off_target protects against crazy values of our_delay, which may happen when th
|
|
// timestamps wraps, or by just having a malicious peer sending garbage. This caps the increase
|
|
// of the window size to MAX_CWND_INCREASE_BYTES_PER_RTT per rtt.
|
|
// as for large negative numbers, this direction is already capped at the min packet size further down
|
|
// the min around the bytes_acked protects against the case where the window size was recently
|
|
// shrunk and the number of acked bytes exceeds that. This is considered no more than one full
|
|
// window, in order to keep the gain within sane boundries.
|
|
|
|
assert(bytes_acked > 0);
|
|
double window_factor = (double)min(bytes_acked, max_window) / (double)max(max_window, bytes_acked);
|
|
|
|
double delay_factor = off_target / target;
|
|
double scaled_gain = MAX_CWND_INCREASE_BYTES_PER_RTT * window_factor * delay_factor;
|
|
|
|
// since MAX_CWND_INCREASE_BYTES_PER_RTT is a cap on how much the window size (max_window)
|
|
// may increase per RTT, we may not increase the window size more than that proportional
|
|
// to the number of bytes that were acked, so that once one window has been acked (one rtt)
|
|
// the increase limit is not exceeded
|
|
// the +1. is to allow for floating point imprecision
|
|
assert(scaled_gain <= 1. + MAX_CWND_INCREASE_BYTES_PER_RTT * (double)min(bytes_acked, max_window) / (double)max(max_window, bytes_acked));
|
|
|
|
if (scaled_gain > 0 && ctx->current_ms - last_maxed_out_window > 1000) {
|
|
// if it was more than 1 second since we tried to send a packet
|
|
// and stopped because we hit the max window, we're most likely rate
|
|
// limited (which prevents us from ever hitting the window size)
|
|
// if this is the case, we cannot let the max_window grow indefinitely
|
|
scaled_gain = 0;
|
|
}
|
|
|
|
size_t ledbat_cwnd = (max_window + scaled_gain < MIN_WINDOW_SIZE) ? MIN_WINDOW_SIZE : (size_t)(max_window + scaled_gain);
|
|
|
|
if (slow_start) {
|
|
size_t ss_cwnd = (size_t)(max_window + window_factor*get_packet_size());
|
|
if (ss_cwnd > ssthresh) {
|
|
slow_start = false;
|
|
} else if (our_delay > target*0.9) {
|
|
// even if we're a little under the target delay, we conservatively
|
|
// discontinue the slow start phase
|
|
slow_start = false;
|
|
ssthresh = max_window;
|
|
} else {
|
|
max_window = max(ss_cwnd, ledbat_cwnd);
|
|
}
|
|
} else {
|
|
max_window = ledbat_cwnd;
|
|
}
|
|
|
|
|
|
// make sure that the congestion window is below max
|
|
// make sure that we don't shrink our window too small
|
|
max_window = clamp<size_t>(max_window, MIN_WINDOW_SIZE, opt_sndbuf);
|
|
|
|
// used in parse_log.py
|
|
log(UTP_LOG_NORMAL, "actual_delay:%u our_delay:%d their_delay:%u off_target:%d max_window:%u "
|
|
"delay_base:%u delay_sum:%d target_delay:%d acked_bytes:%u cur_window:%u "
|
|
"scaled_gain:%f rtt:%u rate:%u wnduser:%u rto:%u timeout:%d get_microseconds:" I64u " "
|
|
"cur_window_packets:%u packet_size:%u their_delay_base:%u their_actual_delay:%u "
|
|
"average_delay:%d clock_drift:%d clock_drift_raw:%d delay_penalty:%d current_delay_sum:" I64u
|
|
"current_delay_samples:%d average_delay_base:%d last_maxed_out_window:" I64u " opt_sndbuf:%d "
|
|
"current_ms:" I64u "",
|
|
actual_delay, our_delay / 1000, their_hist.get_value() / 1000,
|
|
int(off_target / 1000), uint(max_window), uint32(our_hist.delay_base),
|
|
int((our_delay + their_hist.get_value()) / 1000), int(target / 1000), uint(bytes_acked),
|
|
(uint)(cur_window - bytes_acked), (float)(scaled_gain), rtt,
|
|
(uint)(max_window * 1000 / (rtt_hist.delay_base?rtt_hist.delay_base:50)),
|
|
(uint)max_window_user, rto, (int)(rto_timeout - ctx->current_ms),
|
|
utp_call_get_microseconds(this->ctx, this), cur_window_packets, (uint)get_packet_size(),
|
|
their_hist.delay_base, their_hist.delay_base + their_hist.get_value(),
|
|
average_delay, clock_drift, clock_drift_raw, penalty / 1000,
|
|
current_delay_sum, current_delay_samples, average_delay_base,
|
|
uint64(last_maxed_out_window), int(opt_sndbuf), uint64(ctx->current_ms));
|
|
}
|
|
|
|
static void utp_register_recv_packet(UTPSocket *conn, size_t len)
|
|
{
|
|
#ifdef _DEBUG
|
|
++conn->_stats.nrecv;
|
|
conn->_stats.nbytes_recv += len;
|
|
#endif
|
|
|
|
if (len <= PACKET_SIZE_MID) {
|
|
if (len <= PACKET_SIZE_EMPTY) {
|
|
conn->ctx->context_stats._nraw_recv[PACKET_SIZE_EMPTY_BUCKET]++;
|
|
} else if (len <= PACKET_SIZE_SMALL) {
|
|
conn->ctx->context_stats._nraw_recv[PACKET_SIZE_SMALL_BUCKET]++;
|
|
} else
|
|
conn->ctx->context_stats._nraw_recv[PACKET_SIZE_MID_BUCKET]++;
|
|
} else {
|
|
if (len <= PACKET_SIZE_BIG) {
|
|
conn->ctx->context_stats._nraw_recv[PACKET_SIZE_BIG_BUCKET]++;
|
|
} else
|
|
conn->ctx->context_stats._nraw_recv[PACKET_SIZE_HUGE_BUCKET]++;
|
|
}
|
|
}
|
|
|
|
// returns the max number of bytes of payload the uTP
|
|
// connection is allowed to send
|
|
size_t UTPSocket::get_packet_size() const
|
|
{
|
|
int header_size = sizeof(PacketFormatV1);
|
|
size_t mtu = mtu_last ? mtu_last : mtu_ceiling;
|
|
return mtu - header_size;
|
|
}
|
|
|
|
// Process an incoming packet
|
|
// syn is true if this is the first packet received. It will cut off parsing
|
|
// as soon as the header is done
|
|
size_t utp_process_incoming(UTPSocket *conn, const byte *packet, size_t len, bool syn = false)
|
|
{
|
|
utp_register_recv_packet(conn, len);
|
|
|
|
conn->ctx->current_ms = utp_call_get_milliseconds(conn->ctx, conn);
|
|
|
|
const PacketFormatV1 *pf1 = (PacketFormatV1*)packet;
|
|
const byte *packet_end = packet + len;
|
|
|
|
uint16 pk_seq_nr = pf1->seq_nr;
|
|
uint16 pk_ack_nr = pf1->ack_nr;
|
|
uint8 pk_flags = pf1->type();
|
|
|
|
if (pk_flags >= ST_NUM_STATES) return 0;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Got %s. seq_nr:%u ack_nr:%u state:%s timestamp:" I64u " reply_micro:%u"
|
|
, flagnames[pk_flags], pk_seq_nr, pk_ack_nr, statenames[conn->state]
|
|
, uint64(pf1->tv_usec), (uint32)(pf1->reply_micro));
|
|
#endif
|
|
|
|
// mark receipt time
|
|
uint64 time = utp_call_get_microseconds(conn->ctx, conn);
|
|
|
|
// window packets size is used to calculate a minimum
|
|
// permissible range for received acks. connections with acks falling
|
|
// out of this range are dropped
|
|
const uint16 curr_window = max<uint16>(conn->cur_window_packets + ACK_NR_ALLOWED_WINDOW, ACK_NR_ALLOWED_WINDOW);
|
|
|
|
// ignore packets whose ack_nr is invalid. This would imply a spoofed address
|
|
// or a malicious attempt to attach the uTP implementation.
|
|
// acking a packet that hasn't been sent yet!
|
|
// SYN packets have an exception, since there are no previous packets
|
|
if ((pk_flags != ST_SYN || conn->state != CS_SYN_RECV) &&
|
|
(wrapping_compare_less(conn->seq_nr - 1, pk_ack_nr, ACK_NR_MASK)
|
|
|| wrapping_compare_less(pk_ack_nr, conn->seq_nr - 1 - curr_window, ACK_NR_MASK))) {
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Invalid ack_nr: %u. our seq_nr: %u last unacked: %u"
|
|
, pk_ack_nr, conn->seq_nr, (conn->seq_nr - conn->cur_window_packets) & ACK_NR_MASK);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
// RSTs are handled earlier, since the connid matches the send id not the recv id
|
|
assert(pk_flags != ST_RESET);
|
|
|
|
// TODO: maybe send a ST_RESET if we're in CS_RESET?
|
|
|
|
const byte *selack_ptr = NULL;
|
|
|
|
// Unpack UTP packet options
|
|
// Data pointer
|
|
const byte *data = (const byte*)pf1 + conn->get_header_size();
|
|
if (conn->get_header_size() > len) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Invalid packet size (less than header size)");
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
// Skip the extension headers
|
|
uint extension = pf1->ext;
|
|
if (extension != 0) {
|
|
do {
|
|
// Verify that the packet is valid.
|
|
data += 2;
|
|
|
|
if ((int)(packet_end - data) < 0 || (int)(packet_end - data) < data[-1]) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Invalid len of extensions");
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
switch(extension) {
|
|
case 1: // Selective Acknowledgment
|
|
selack_ptr = data;
|
|
break;
|
|
case 2: // extension bits
|
|
if (data[-1] != 8) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Invalid len of extension bits header");
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
memcpy(conn->extensions, data, 8);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "got extension bits:%02x%02x%02x%02x%02x%02x%02x%02x",
|
|
conn->extensions[0], conn->extensions[1], conn->extensions[2], conn->extensions[3],
|
|
conn->extensions[4], conn->extensions[5], conn->extensions[6], conn->extensions[7]);
|
|
#endif
|
|
}
|
|
extension = data[-2];
|
|
data += data[-1];
|
|
} while (extension);
|
|
}
|
|
|
|
if (conn->state == CS_SYN_SENT) {
|
|
// if this is a syn-ack, initialize our ack_nr
|
|
// to match the sequence number we got from
|
|
// the other end
|
|
conn->ack_nr = (pk_seq_nr - 1) & SEQ_NR_MASK;
|
|
}
|
|
|
|
conn->last_got_packet = conn->ctx->current_ms;
|
|
|
|
if (syn) {
|
|
return 0;
|
|
}
|
|
|
|
// seqnr is the number of packets past the expected
|
|
// packet this is. ack_nr is the last acked, seq_nr is the
|
|
// current. Subtracring 1 makes 0 mean "this is the next
|
|
// expected packet".
|
|
const uint seqnr = (pk_seq_nr - conn->ack_nr - 1) & SEQ_NR_MASK;
|
|
|
|
// Getting an invalid sequence number?
|
|
if (seqnr >= REORDER_BUFFER_MAX_SIZE) {
|
|
if (seqnr >= (SEQ_NR_MASK + 1) - REORDER_BUFFER_MAX_SIZE && pk_flags != ST_STATE) {
|
|
conn->schedule_ack();
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, " Got old Packet/Ack (%u/%u)=%u"
|
|
, pk_seq_nr, conn->ack_nr, seqnr);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
// Process acknowledgment
|
|
// acks is the number of packets that was acked
|
|
int acks = (pk_ack_nr - (conn->seq_nr - 1 - conn->cur_window_packets)) & ACK_NR_MASK;
|
|
|
|
// this happens when we receive an old ack nr
|
|
if (acks > conn->cur_window_packets) acks = 0;
|
|
|
|
// if we get the same ack_nr as in the last packet
|
|
// increase the duplicate_ack counter, otherwise reset
|
|
// it to 0.
|
|
// It's important to only count ACKs in ST_STATE packets. Any other
|
|
// packet (primarily ST_DATA) is likely to have been sent because of the
|
|
// other end having new outgoing data, not in response to incoming data.
|
|
// For instance, if we're receiving a steady stream of payload with no
|
|
// outgoing data, and we suddently have a few bytes of payload to send (say,
|
|
// a bittorrent HAVE message), we're very likely to see 3 duplicate ACKs
|
|
// immediately after sending our payload packet. This effectively disables
|
|
// the fast-resend on duplicate-ack logic for bi-directional connections
|
|
// (except in the case of a selective ACK). This is in line with BSD4.4 TCP
|
|
// implementation.
|
|
if (conn->cur_window_packets > 0) {
|
|
if (pk_ack_nr == ((conn->seq_nr - conn->cur_window_packets - 1) & ACK_NR_MASK)
|
|
&& conn->cur_window_packets > 0
|
|
&& pk_flags == ST_STATE) {
|
|
++conn->duplicate_ack;
|
|
if (conn->duplicate_ack == DUPLICATE_ACKS_BEFORE_RESEND && conn->mtu_probe_seq) {
|
|
// It's likely that the probe was rejected due to its size, but we haven't got an
|
|
// ICMP report back yet
|
|
if (pk_ack_nr == ((conn->mtu_probe_seq - 1) & ACK_NR_MASK)) {
|
|
conn->mtu_ceiling = conn->mtu_probe_size - 1;
|
|
conn->mtu_search_update();
|
|
conn->log(UTP_LOG_MTU, "MTU [DUPACK] floor:%d ceiling:%d current:%d"
|
|
, conn->mtu_floor, conn->mtu_ceiling, conn->mtu_last);
|
|
} else {
|
|
// A non-probe was blocked before our probe.
|
|
// Can't conclude much, send a new probe
|
|
conn->mtu_probe_seq = conn->mtu_probe_size = 0;
|
|
}
|
|
}
|
|
} else {
|
|
conn->duplicate_ack = 0;
|
|
}
|
|
|
|
// TODO: if duplicate_ack == DUPLICATE_ACK_BEFORE_RESEND
|
|
// and fast_resend_seq_nr <= ack_nr + 1
|
|
// resend ack_nr + 1
|
|
// also call maybe_decay_win()
|
|
}
|
|
|
|
// figure out how many bytes were acked
|
|
size_t acked_bytes = 0;
|
|
|
|
// the minimum rtt of all acks
|
|
// this is the upper limit on the delay we get back
|
|
// from the other peer. Our delay cannot exceed
|
|
// the rtt of the packet. If it does, clamp it.
|
|
// this is done in apply_ledbat_ccontrol()
|
|
int64 min_rtt = INT64_MAX;
|
|
|
|
uint64 now = utp_call_get_microseconds(conn->ctx, conn);
|
|
|
|
for (int i = 0; i < acks; ++i) {
|
|
int seq = (conn->seq_nr - conn->cur_window_packets + i) & ACK_NR_MASK;
|
|
OutgoingPacket *pkt = (OutgoingPacket*)conn->outbuf.get(seq);
|
|
if (pkt == 0 || pkt->transmissions == 0) continue;
|
|
assert((int)(pkt->payload) >= 0);
|
|
acked_bytes += pkt->payload;
|
|
if (conn->mtu_probe_seq && seq == static_cast< int >(conn->mtu_probe_seq)) {
|
|
conn->mtu_floor = conn->mtu_probe_size;
|
|
conn->mtu_search_update();
|
|
conn->log(UTP_LOG_MTU, "MTU [ACK] floor:%d ceiling:%d current:%d"
|
|
, conn->mtu_floor, conn->mtu_ceiling, conn->mtu_last);
|
|
}
|
|
|
|
// in case our clock is not monotonic
|
|
if (pkt->time_sent < now)
|
|
min_rtt = min<int64>(min_rtt, now - pkt->time_sent);
|
|
else
|
|
min_rtt = min<int64>(min_rtt, 50000);
|
|
}
|
|
|
|
// count bytes acked by EACK
|
|
if (selack_ptr != NULL) {
|
|
acked_bytes += conn->selective_ack_bytes((pk_ack_nr + 2) & ACK_NR_MASK,
|
|
selack_ptr, selack_ptr[-1], min_rtt);
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "acks:%d acked_bytes:%u seq_nr:%d cur_window:%u cur_window_packets:%u relative_seqnr:%u max_window:%u min_rtt:%u rtt:%u",
|
|
acks, (uint)acked_bytes, conn->seq_nr, (uint)conn->cur_window, conn->cur_window_packets,
|
|
seqnr, (uint)conn->max_window, (uint)(min_rtt / 1000), conn->rtt);
|
|
#endif
|
|
|
|
uint64 p = pf1->tv_usec;
|
|
|
|
conn->last_measured_delay = conn->ctx->current_ms;
|
|
|
|
// get delay in both directions
|
|
// record the delay to report back
|
|
const uint32 their_delay = (uint32)(p == 0 ? 0 : time - p);
|
|
conn->reply_micro = their_delay;
|
|
uint32 prev_delay_base = conn->their_hist.delay_base;
|
|
if (their_delay != 0) conn->their_hist.add_sample(their_delay, conn->ctx->current_ms);
|
|
|
|
// if their new delay base is less than their previous one
|
|
// we should shift our delay base in the other direction in order
|
|
// to take the clock skew into account
|
|
if (prev_delay_base != 0 &&
|
|
wrapping_compare_less(conn->their_hist.delay_base, prev_delay_base, TIMESTAMP_MASK)) {
|
|
// never adjust more than 10 milliseconds
|
|
if (prev_delay_base - conn->their_hist.delay_base <= 10000) {
|
|
conn->our_hist.shift(prev_delay_base - conn->their_hist.delay_base);
|
|
}
|
|
}
|
|
|
|
const uint32 actual_delay = (uint32(pf1->reply_micro)==INT_MAX?0:uint32(pf1->reply_micro));
|
|
|
|
// if the actual delay is 0, it means the other end
|
|
// hasn't received a sample from us yet, and doesn't
|
|
// know what it is. We can't update out history unless
|
|
// we have a true measured sample
|
|
if (actual_delay != 0) {
|
|
conn->our_hist.add_sample(actual_delay, conn->ctx->current_ms);
|
|
|
|
// this is keeping an average of the delay samples
|
|
// we've recevied within the last 5 seconds. We sum
|
|
// all the samples and increase the count in order to
|
|
// calculate the average every 5 seconds. The samples
|
|
// are based off of the average_delay_base to deal with
|
|
// wrapping counters.
|
|
if (conn->average_delay_base == 0) conn->average_delay_base = actual_delay;
|
|
int64 average_delay_sample = 0;
|
|
// distance walking from lhs to rhs, downwards
|
|
const uint32 dist_down = conn->average_delay_base - actual_delay;
|
|
// distance walking from lhs to rhs, upwards
|
|
const uint32 dist_up = actual_delay - conn->average_delay_base;
|
|
|
|
if (dist_down > dist_up) {
|
|
// assert(dist_up < INT_MAX / 4);
|
|
// average_delay_base < actual_delay, we should end up
|
|
// with a positive sample
|
|
average_delay_sample = dist_up;
|
|
} else {
|
|
// assert(-int64(dist_down) < INT_MAX / 4);
|
|
// average_delay_base >= actual_delay, we should end up
|
|
// with a negative sample
|
|
average_delay_sample = -int64(dist_down);
|
|
}
|
|
conn->current_delay_sum += average_delay_sample;
|
|
++conn->current_delay_samples;
|
|
|
|
if (conn->ctx->current_ms > conn->average_sample_time) {
|
|
|
|
int32 prev_average_delay = conn->average_delay;
|
|
|
|
assert(conn->current_delay_sum / conn->current_delay_samples < INT_MAX);
|
|
assert(conn->current_delay_sum / conn->current_delay_samples > -INT_MAX);
|
|
// write the new average
|
|
conn->average_delay = (int32)(conn->current_delay_sum / conn->current_delay_samples);
|
|
// each slot represents 5 seconds
|
|
conn->average_sample_time += 5000;
|
|
|
|
conn->current_delay_sum = 0;
|
|
conn->current_delay_samples = 0;
|
|
|
|
// this makes things very confusing when logging the average delay
|
|
//#if !g_log_utp
|
|
// normalize the average samples
|
|
// since we're only interested in the slope
|
|
// of the curve formed by the average delay samples,
|
|
// we can cancel out the actual offset to make sure
|
|
// we won't have problems with wrapping.
|
|
int min_sample = min(prev_average_delay, conn->average_delay);
|
|
int max_sample = max(prev_average_delay, conn->average_delay);
|
|
|
|
// normalize around zero. Try to keep the min <= 0 and max >= 0
|
|
int adjust = 0;
|
|
if (min_sample > 0) {
|
|
// adjust all samples (and the baseline) down by min_sample
|
|
adjust = -min_sample;
|
|
} else if (max_sample < 0) {
|
|
// adjust all samples (and the baseline) up by -max_sample
|
|
adjust = -max_sample;
|
|
}
|
|
if (adjust) {
|
|
conn->average_delay_base -= adjust;
|
|
conn->average_delay += adjust;
|
|
prev_average_delay += adjust;
|
|
}
|
|
//#endif
|
|
|
|
// update the clock drift estimate
|
|
// the unit is microseconds per 5 seconds
|
|
// what we're doing is just calculating the average of the
|
|
// difference between each slot. Since each slot is 5 seconds
|
|
// and the timestamps unit are microseconds, we'll end up with
|
|
// the average slope across our history. If there is a consistent
|
|
// trend, it will show up in this value
|
|
|
|
//int64 slope = 0;
|
|
int32 drift = conn->average_delay - prev_average_delay;
|
|
|
|
// clock_drift is a rolling average
|
|
conn->clock_drift = (int64(conn->clock_drift) * 7 + drift) / 8;
|
|
conn->clock_drift_raw = drift;
|
|
}
|
|
}
|
|
|
|
// if our new delay base is less than our previous one
|
|
// we should shift the other end's delay base in the other
|
|
// direction in order to take the clock skew into account
|
|
// This is commented out because it creates bad interactions
|
|
// with our adjustment in the other direction. We don't really
|
|
// need our estimates of the other peer to be very accurate
|
|
// anyway. The problem with shifting here is that we're more
|
|
// likely shift it back later because of a low latency. This
|
|
// second shift back would cause us to shift our delay base
|
|
// which then get's into a death spiral of shifting delay bases
|
|
/* if (prev_delay_base != 0 &&
|
|
wrapping_compare_less(conn->our_hist.delay_base, prev_delay_base)) {
|
|
// never adjust more than 10 milliseconds
|
|
if (prev_delay_base - conn->our_hist.delay_base <= 10000) {
|
|
conn->their_hist.Shift(prev_delay_base - conn->our_hist.delay_base);
|
|
}
|
|
}
|
|
*/
|
|
|
|
// if the delay estimate exceeds the RTT, adjust the base_delay to
|
|
// compensate
|
|
assert(min_rtt >= 0);
|
|
if (int64(conn->our_hist.get_value()) > min_rtt) {
|
|
conn->our_hist.shift((uint32)(conn->our_hist.get_value() - min_rtt));
|
|
}
|
|
|
|
// only apply the congestion controller on acks
|
|
// if we don't have a delay measurement, there's
|
|
// no point in invoking the congestion control
|
|
if (actual_delay != 0 && acked_bytes >= 1)
|
|
conn->apply_ccontrol(acked_bytes, actual_delay, min_rtt);
|
|
|
|
// sanity check, the other end should never ack packets
|
|
// past the point we've sent
|
|
if (acks <= conn->cur_window_packets) {
|
|
conn->max_window_user = pf1->windowsize;
|
|
|
|
// If max user window is set to 0, then we startup a timer
|
|
// That will reset it to 1 after 15 seconds.
|
|
if (conn->max_window_user == 0)
|
|
// Reset max_window_user to 1 every 15 seconds.
|
|
conn->zerowindow_time = conn->ctx->current_ms + 15000;
|
|
|
|
// Respond to connect message
|
|
// Switch to CONNECTED state.
|
|
// If this is an ack and we're in still handshaking
|
|
// transition over to the connected state.
|
|
|
|
// Incoming connection completion
|
|
if (pk_flags == ST_DATA && conn->state == CS_SYN_RECV) {
|
|
conn->state = CS_CONNECTED;
|
|
}
|
|
|
|
// Outgoing connection completion
|
|
if (pk_flags == ST_STATE && conn->state == CS_SYN_SENT) {
|
|
conn->state = CS_CONNECTED;
|
|
|
|
// If the user has defined the ON_CONNECT callback, use that to
|
|
// notify the user that the socket is now connected. If ON_CONNECT
|
|
// has not been defined, notify the user via ON_STATE_CHANGE.
|
|
if (conn->ctx->callbacks[UTP_ON_CONNECT])
|
|
utp_call_on_connect(conn->ctx, conn);
|
|
else
|
|
utp_call_on_state_change(conn->ctx, conn, UTP_STATE_CONNECT);
|
|
|
|
// We've sent a fin, and everything was ACKed (including the FIN).
|
|
// cur_window_packets == acks means that this packet acked all
|
|
// the remaining packets that were in-flight.
|
|
} else if (conn->fin_sent && conn->cur_window_packets == acks) {
|
|
conn->fin_sent_acked = true;
|
|
if (conn->close_requested) {
|
|
conn->state = CS_DESTROY;
|
|
}
|
|
}
|
|
|
|
// Update fast resend counter
|
|
if (wrapping_compare_less(conn->fast_resend_seq_nr
|
|
, (pk_ack_nr + 1) & ACK_NR_MASK, ACK_NR_MASK))
|
|
conn->fast_resend_seq_nr = (pk_ack_nr + 1) & ACK_NR_MASK;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "fast_resend_seq_nr:%u", conn->fast_resend_seq_nr);
|
|
#endif
|
|
|
|
for (int i = 0; i < acks; ++i) {
|
|
int ack_status = conn->ack_packet(conn->seq_nr - conn->cur_window_packets);
|
|
// if ack_status is 0, the packet was acked.
|
|
// if acl_stauts is 1, it means that the packet had already been acked
|
|
// if it's 2, the packet has not been sent yet
|
|
// We need to break this loop in the latter case. This could potentially
|
|
// happen if we get an ack_nr that does not exceed what we have stuffed
|
|
// into the outgoing buffer, but does exceed what we have sent
|
|
if (ack_status == 2) {
|
|
#ifdef _DEBUG
|
|
OutgoingPacket* pkt = (OutgoingPacket*)conn->outbuf.get(conn->seq_nr - conn->cur_window_packets);
|
|
assert(pkt->transmissions == 0);
|
|
#endif
|
|
|
|
break;
|
|
}
|
|
conn->cur_window_packets--;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "decementing cur_window_packets:%u", conn->cur_window_packets);
|
|
#endif
|
|
|
|
}
|
|
|
|
#ifdef _DEBUG
|
|
if (conn->cur_window_packets == 0)
|
|
assert(conn->cur_window == 0);
|
|
#endif
|
|
|
|
// packets in front of this may have been acked by a
|
|
// selective ack (EACK). Keep decreasing the window packet size
|
|
// until we hit a packet that is still waiting to be acked
|
|
// in the send queue
|
|
// this is especially likely to happen when the other end
|
|
// has the EACK send bug older versions of uTP had
|
|
while (conn->cur_window_packets > 0 && !conn->outbuf.get(conn->seq_nr - conn->cur_window_packets)) {
|
|
conn->cur_window_packets--;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "decementing cur_window_packets:%u", conn->cur_window_packets);
|
|
#endif
|
|
|
|
}
|
|
|
|
#ifdef _DEBUG
|
|
if (conn->cur_window_packets == 0)
|
|
assert(conn->cur_window == 0);
|
|
#endif
|
|
|
|
// this invariant should always be true
|
|
assert(conn->cur_window_packets == 0 || conn->outbuf.get(conn->seq_nr - conn->cur_window_packets));
|
|
|
|
// flush Nagle
|
|
if (conn->cur_window_packets == 1) {
|
|
OutgoingPacket *pkt = (OutgoingPacket*)conn->outbuf.get(conn->seq_nr - 1);
|
|
// do we still have quota?
|
|
if (pkt->transmissions == 0) {
|
|
conn->send_packet(pkt);
|
|
}
|
|
}
|
|
|
|
// Fast timeout-retry
|
|
if (conn->fast_timeout) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Fast timeout %u,%u,%u?", (uint)conn->cur_window, conn->seq_nr - conn->timeout_seq_nr, conn->timeout_seq_nr);
|
|
#endif
|
|
|
|
// if the fast_resend_seq_nr is not pointing to the oldest outstanding packet, it suggests that we've already
|
|
// resent the packet that timed out, and we should leave the fast-timeout mode.
|
|
if (((conn->seq_nr - conn->cur_window_packets) & ACK_NR_MASK) != conn->fast_resend_seq_nr) {
|
|
conn->fast_timeout = false;
|
|
} else {
|
|
// resend the oldest packet and increment fast_resend_seq_nr
|
|
// to not allow another fast resend on it again
|
|
OutgoingPacket *pkt = (OutgoingPacket*)conn->outbuf.get(conn->seq_nr - conn->cur_window_packets);
|
|
if (pkt && pkt->transmissions > 0) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Packet %u fast timeout-retry.", conn->seq_nr - conn->cur_window_packets);
|
|
#endif
|
|
|
|
#ifdef _DEBUG
|
|
++conn->_stats.fastrexmit;
|
|
#endif
|
|
|
|
conn->fast_resend_seq_nr++;
|
|
conn->send_packet(pkt);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Process selective acknowledgent
|
|
if (selack_ptr != NULL) {
|
|
conn->selective_ack(pk_ack_nr + 2, selack_ptr, selack_ptr[-1]);
|
|
}
|
|
|
|
// this invariant should always be true
|
|
assert(conn->cur_window_packets == 0 || conn->outbuf.get(conn->seq_nr - conn->cur_window_packets));
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "acks:%d acked_bytes:%u seq_nr:%u cur_window:%u cur_window_packets:%u ",
|
|
acks, (uint)acked_bytes, conn->seq_nr, (uint)conn->cur_window, conn->cur_window_packets);
|
|
#endif
|
|
|
|
// In case the ack dropped the current window below
|
|
// the max_window size, Mark the socket as writable
|
|
if (conn->state == CS_CONNECTED_FULL && !conn->is_full()) {
|
|
conn->state = CS_CONNECTED;
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Socket writable. max_window:%u cur_window:%u packet_size:%u",
|
|
(uint)conn->max_window, (uint)conn->cur_window, (uint)conn->get_packet_size());
|
|
#endif
|
|
utp_call_on_state_change(conn->ctx, conn, UTP_STATE_WRITABLE);
|
|
}
|
|
|
|
if (pk_flags == ST_STATE) {
|
|
// This is a state packet only.
|
|
return 0;
|
|
}
|
|
|
|
// The connection is not in a state that can accept data?
|
|
if (conn->state != CS_CONNECTED &&
|
|
conn->state != CS_CONNECTED_FULL) {
|
|
return 0;
|
|
}
|
|
|
|
// Is this a finalize packet?
|
|
if (pk_flags == ST_FIN && !conn->got_fin) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Got FIN eof_pkt:%u", pk_seq_nr);
|
|
#endif
|
|
|
|
conn->got_fin = true;
|
|
conn->eof_pkt = pk_seq_nr;
|
|
// at this point, it is possible for the
|
|
// other end to have sent packets with
|
|
// sequence numbers higher than seq_nr.
|
|
// if this is the case, our reorder_count
|
|
// is out of sync. This case is dealt with
|
|
// when we re-order and hit the eof_pkt.
|
|
// we'll just ignore any packets with
|
|
// sequence numbers past this
|
|
}
|
|
|
|
// Getting an in-order packet?
|
|
if (seqnr == 0) {
|
|
size_t count = packet_end - data;
|
|
if (count > 0 && !conn->read_shutdown) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Got Data len:%u (rb:%u)", (uint)count, (uint)utp_call_get_read_buffer_size(conn->ctx, conn));
|
|
#endif
|
|
|
|
// Post bytes to the upper layer
|
|
utp_call_on_read(conn->ctx, conn, data, count);
|
|
}
|
|
conn->ack_nr++;
|
|
|
|
// Check if the next packet has been received too, but waiting
|
|
// in the reorder buffer.
|
|
for (;;) {
|
|
|
|
if (!conn->got_fin_reached && conn->got_fin && conn->eof_pkt == conn->ack_nr) {
|
|
conn->got_fin_reached = true;
|
|
conn->rto_timeout = conn->ctx->current_ms + min<uint>(conn->rto * 3, 60);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Posting EOF");
|
|
#endif
|
|
|
|
utp_call_on_state_change(conn->ctx, conn, UTP_STATE_EOF);
|
|
|
|
// if the other end wants to close, ack
|
|
conn->send_ack();
|
|
|
|
// reorder_count is not necessarily 0 at this point.
|
|
// even though it is most of the time, the other end
|
|
// may have sent packets with higher sequence numbers
|
|
// than what later end up being eof_pkt
|
|
// since we have received all packets up to eof_pkt
|
|
// just ignore the ones after it.
|
|
conn->reorder_count = 0;
|
|
}
|
|
|
|
// Quick get-out in case there is nothing to reorder
|
|
if (conn->reorder_count == 0)
|
|
break;
|
|
|
|
// Check if there are additional buffers in the reorder buffers
|
|
// that need delivery.
|
|
byte *p = (byte*)conn->inbuf.get(conn->ack_nr+1);
|
|
if (p == NULL)
|
|
break;
|
|
conn->inbuf.put(conn->ack_nr+1, NULL);
|
|
count = *(uint*)p;
|
|
if (count > 0 && !conn->read_shutdown) {
|
|
// Pass the bytes to the upper layer
|
|
utp_call_on_read(conn->ctx, conn, p + sizeof(uint), count);
|
|
}
|
|
conn->ack_nr++;
|
|
|
|
// Free the element from the reorder buffer
|
|
free(p);
|
|
assert(conn->reorder_count > 0);
|
|
conn->reorder_count--;
|
|
}
|
|
|
|
conn->schedule_ack();
|
|
} else {
|
|
// Getting an out of order packet.
|
|
// The packet needs to be remembered and rearranged later.
|
|
|
|
// if we have received a FIN packet, and the EOF-sequence number
|
|
// is lower than the sequence number of the packet we just received
|
|
// something is wrong.
|
|
if (conn->got_fin && pk_seq_nr > conn->eof_pkt) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Got an invalid packet sequence number, past EOF "
|
|
"reorder_count:%u len:%u (rb:%u)",
|
|
conn->reorder_count, (uint)(packet_end - data), (uint)utp_call_get_read_buffer_size(conn->ctx, conn));
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
// if the sequence number is entirely off the expected
|
|
// one, just drop it. We can't allocate buffer space in
|
|
// the inbuf entirely based on untrusted input
|
|
if (seqnr > 0x3ff) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "0x%08x: Got an invalid packet sequence number, too far off "
|
|
"reorder_count:%u len:%u (rb:%u)",
|
|
conn->reorder_count, (uint)(packet_end - data), (uint)utp_call_get_read_buffer_size(conn->ctx, conn));
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
// we need to grow the circle buffer before we
|
|
// check if the packet is already in here, so that
|
|
// we don't end up looking at an older packet (since
|
|
// the indices wraps around).
|
|
conn->inbuf.ensure_size(pk_seq_nr + 1, seqnr + 1);
|
|
|
|
// Has this packet already been received? (i.e. a duplicate)
|
|
// If that is the case, just discard it.
|
|
if (conn->inbuf.get(pk_seq_nr) != NULL) {
|
|
#ifdef _DEBUG
|
|
++conn->_stats.nduprecv;
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
// Allocate memory to fit the packet that needs to re-ordered
|
|
byte *mem = (byte*)malloc((packet_end - data) + sizeof(uint));
|
|
*(uint*)mem = (uint)(packet_end - data);
|
|
memcpy(mem + sizeof(uint), data, packet_end - data);
|
|
|
|
// Insert into reorder buffer and increment the count
|
|
// of # of packets to be reordered.
|
|
// we add one to seqnr in order to leave the last
|
|
// entry empty, that way the assert in send_ack
|
|
// is valid. we have to add one to seqnr too, in order
|
|
// to make the circular buffer grow around the correct
|
|
// point (which is conn->ack_nr + 1).
|
|
assert(conn->inbuf.get(pk_seq_nr) == NULL);
|
|
assert((pk_seq_nr & conn->inbuf.mask) != ((conn->ack_nr+1) & conn->inbuf.mask));
|
|
conn->inbuf.put(pk_seq_nr, mem);
|
|
conn->reorder_count++;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "0x%08x: Got out of order data reorder_count:%u len:%u (rb:%u)",
|
|
conn->reorder_count, (uint)(packet_end - data), (uint)utp_call_get_read_buffer_size(conn->ctx, conn));
|
|
#endif
|
|
|
|
conn->schedule_ack();
|
|
}
|
|
|
|
return (size_t)(packet_end - data);
|
|
}
|
|
|
|
inline byte UTP_Version(PacketFormatV1 const* pf)
|
|
{
|
|
return (pf->type() < ST_NUM_STATES && pf->ext < 3 ? pf->version() : 0);
|
|
}
|
|
|
|
UTPSocket::~UTPSocket()
|
|
{
|
|
#if UTP_DEBUG_LOGGING
|
|
log(UTP_LOG_DEBUG, "Killing socket");
|
|
#endif
|
|
|
|
utp_call_on_state_change(ctx, this, UTP_STATE_DESTROYING);
|
|
|
|
if (ctx->last_utp_socket == this) {
|
|
ctx->last_utp_socket = NULL;
|
|
}
|
|
|
|
// Remove object from the global hash table
|
|
UTPSocketKeyData* kd = ctx->utp_sockets->Delete(UTPSocketKey(addr, conn_id_recv));
|
|
assert(kd);
|
|
|
|
// remove the socket from ack_sockets if it was there also
|
|
removeSocketFromAckList(this);
|
|
|
|
// Free all memory occupied by the socket object.
|
|
for (size_t i = 0; i <= inbuf.mask; i++) {
|
|
free(inbuf.elements[i]);
|
|
}
|
|
for (size_t i = 0; i <= outbuf.mask; i++) {
|
|
free(outbuf.elements[i]);
|
|
}
|
|
// TODO: The circular buffer should have a destructor
|
|
free(inbuf.elements);
|
|
free(outbuf.elements);
|
|
}
|
|
|
|
void UTP_FreeAll(struct UTPSocketHT *utp_sockets) {
|
|
utp_hash_iterator_t it;
|
|
UTPSocketKeyData* keyData;
|
|
while ((keyData = utp_sockets->Iterate(it))) {
|
|
delete keyData->socket;
|
|
}
|
|
}
|
|
|
|
void utp_initialize_socket( utp_socket *conn,
|
|
const struct sockaddr *addr,
|
|
socklen_t addrlen,
|
|
bool need_seed_gen,
|
|
uint32 conn_seed,
|
|
uint32 conn_id_recv,
|
|
uint32 conn_id_send)
|
|
{
|
|
PackedSockAddr psaddr = PackedSockAddr((const SOCKADDR_STORAGE*)addr, addrlen);
|
|
|
|
if (need_seed_gen) {
|
|
do {
|
|
conn_seed = utp_call_get_random(conn->ctx, conn);
|
|
// we identify v1 and higher by setting the first two bytes to 0x0001
|
|
conn_seed &= 0xffff;
|
|
} while (conn->ctx->utp_sockets->Lookup(UTPSocketKey(psaddr, conn_seed)));
|
|
|
|
conn_id_recv += conn_seed;
|
|
conn_id_send += conn_seed;
|
|
}
|
|
|
|
conn->state = CS_IDLE;
|
|
conn->conn_seed = conn_seed;
|
|
conn->conn_id_recv = conn_id_recv;
|
|
conn->conn_id_send = conn_id_send;
|
|
conn->addr = psaddr;
|
|
conn->ctx->current_ms = utp_call_get_milliseconds(conn->ctx, NULL);
|
|
conn->last_got_packet = conn->ctx->current_ms;
|
|
conn->last_sent_packet = conn->ctx->current_ms;
|
|
conn->last_measured_delay = conn->ctx->current_ms + 0x70000000;
|
|
conn->average_sample_time = conn->ctx->current_ms + 5000;
|
|
conn->last_rwin_decay = conn->ctx->current_ms - MAX_WINDOW_DECAY;
|
|
|
|
conn->our_hist.clear(conn->ctx->current_ms);
|
|
conn->their_hist.clear(conn->ctx->current_ms);
|
|
conn->rtt_hist.clear(conn->ctx->current_ms);
|
|
|
|
// initialize MTU floor and ceiling
|
|
conn->mtu_reset();
|
|
conn->mtu_last = conn->mtu_ceiling;
|
|
|
|
conn->ctx->utp_sockets->Add(UTPSocketKey(conn->addr, conn->conn_id_recv))->socket = conn;
|
|
|
|
// we need to fit one packet in the window when we start the connection
|
|
conn->max_window = conn->get_packet_size();
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP socket initialized");
|
|
#endif
|
|
}
|
|
|
|
utp_socket* utp_create_socket(utp_context *ctx)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return NULL;
|
|
|
|
UTPSocket *conn = new UTPSocket; // TODO: UTPSocket should have a constructor
|
|
|
|
conn->state = CS_UNINITIALIZED;
|
|
conn->ctx = ctx;
|
|
conn->userdata = NULL;
|
|
conn->reorder_count = 0;
|
|
conn->duplicate_ack = 0;
|
|
conn->timeout_seq_nr = 0;
|
|
conn->last_rcv_win = 0;
|
|
conn->got_fin = false;
|
|
conn->got_fin_reached = false;
|
|
conn->fin_sent = false;
|
|
conn->fin_sent_acked = false;
|
|
conn->read_shutdown = false;
|
|
conn->close_requested = false;
|
|
conn->fast_timeout = false;
|
|
conn->rtt = 0;
|
|
conn->retransmit_timeout = 0;
|
|
conn->rto_timeout = 0;
|
|
conn->zerowindow_time = 0;
|
|
conn->average_delay = 0;
|
|
conn->current_delay_samples = 0;
|
|
conn->cur_window = 0;
|
|
conn->eof_pkt = 0;
|
|
conn->last_maxed_out_window = 0;
|
|
conn->mtu_probe_seq = 0;
|
|
conn->mtu_probe_size = 0;
|
|
conn->current_delay_sum = 0;
|
|
conn->average_delay_base = 0;
|
|
conn->retransmit_count = 0;
|
|
conn->rto = 3000;
|
|
conn->rtt_var = 800;
|
|
conn->seq_nr = 1;
|
|
conn->ack_nr = 0;
|
|
conn->max_window_user = 255 * PACKET_SIZE;
|
|
conn->cur_window_packets = 0;
|
|
conn->fast_resend_seq_nr = conn->seq_nr;
|
|
conn->target_delay = ctx->target_delay;
|
|
conn->reply_micro = 0;
|
|
conn->opt_sndbuf = ctx->opt_sndbuf;
|
|
conn->opt_rcvbuf = ctx->opt_rcvbuf;
|
|
conn->slow_start = true;
|
|
conn->ssthresh = conn->opt_sndbuf;
|
|
conn->clock_drift = 0;
|
|
conn->clock_drift_raw = 0;
|
|
conn->outbuf.mask = 15;
|
|
conn->inbuf.mask = 15;
|
|
conn->outbuf.elements = (void**)calloc(16, sizeof(void*));
|
|
conn->inbuf.elements = (void**)calloc(16, sizeof(void*));
|
|
conn->ida = -1; // set the index of every new socket in ack_sockets to
|
|
// -1, which also means it is not in ack_sockets yet
|
|
|
|
memset(conn->extensions, 0, sizeof(conn->extensions));
|
|
|
|
#ifdef _DEBUG
|
|
memset(&conn->_stats, 0, sizeof(utp_socket_stats));
|
|
#endif
|
|
|
|
return conn;
|
|
}
|
|
|
|
int utp_context_set_option(utp_context *ctx, int opt, int val)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return -1;
|
|
|
|
switch (opt) {
|
|
case UTP_LOG_NORMAL:
|
|
ctx->log_normal = val ? true : false;
|
|
return 0;
|
|
|
|
case UTP_LOG_MTU:
|
|
ctx->log_mtu = val ? true : false;
|
|
return 0;
|
|
|
|
case UTP_LOG_DEBUG:
|
|
ctx->log_debug = val ? true : false;
|
|
return 0;
|
|
|
|
case UTP_TARGET_DELAY:
|
|
ctx->target_delay = val;
|
|
return 0;
|
|
|
|
case UTP_SNDBUF:
|
|
assert(val >= 1);
|
|
ctx->opt_sndbuf = val;
|
|
return 0;
|
|
|
|
case UTP_RCVBUF:
|
|
assert(val >= 1);
|
|
ctx->opt_rcvbuf = val;
|
|
return 0;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
int utp_context_get_option(utp_context *ctx, int opt)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return -1;
|
|
|
|
switch (opt) {
|
|
case UTP_LOG_NORMAL: return ctx->log_normal ? 1 : 0;
|
|
case UTP_LOG_MTU: return ctx->log_mtu ? 1 : 0;
|
|
case UTP_LOG_DEBUG: return ctx->log_debug ? 1 : 0;
|
|
case UTP_TARGET_DELAY: return ctx->target_delay;
|
|
case UTP_SNDBUF: return ctx->opt_sndbuf;
|
|
case UTP_RCVBUF: return ctx->opt_rcvbuf;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
|
|
int utp_setsockopt(UTPSocket* conn, int opt, int val)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
switch (opt) {
|
|
|
|
case UTP_SNDBUF:
|
|
assert(val >= 1);
|
|
conn->opt_sndbuf = val;
|
|
return 0;
|
|
|
|
case UTP_RCVBUF:
|
|
assert(val >= 1);
|
|
conn->opt_rcvbuf = val;
|
|
return 0;
|
|
|
|
case UTP_TARGET_DELAY:
|
|
conn->target_delay = val;
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
int utp_getsockopt(UTPSocket* conn, int opt)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
switch (opt) {
|
|
case UTP_SNDBUF: return conn->opt_sndbuf;
|
|
case UTP_RCVBUF: return conn->opt_rcvbuf;
|
|
case UTP_TARGET_DELAY: return conn->target_delay;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
// Try to connect to a specified host.
|
|
int utp_connect(utp_socket *conn, const struct sockaddr *to, socklen_t tolen)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
assert(conn->state == CS_UNINITIALIZED);
|
|
if (conn->state != CS_UNINITIALIZED) {
|
|
conn->state = CS_DESTROY;
|
|
return -1;
|
|
}
|
|
|
|
utp_initialize_socket(conn, to, tolen, true, 0, 0, 1);
|
|
|
|
assert(conn->cur_window_packets == 0);
|
|
assert(conn->outbuf.get(conn->seq_nr) == NULL);
|
|
assert(sizeof(PacketFormatV1) == 20);
|
|
|
|
conn->state = CS_SYN_SENT;
|
|
conn->ctx->current_ms = utp_call_get_milliseconds(conn->ctx, conn);
|
|
|
|
// Create and send a connect message
|
|
|
|
// used in parse_log.py
|
|
conn->log(UTP_LOG_NORMAL, "UTP_Connect conn_seed:%u packet_size:%u (B) "
|
|
"target_delay:%u (ms) delay_history:%u "
|
|
"delay_base_history:%u (minutes)",
|
|
conn->conn_seed, PACKET_SIZE, conn->target_delay / 1000,
|
|
CUR_DELAY_SIZE, DELAY_BASE_HISTORY);
|
|
|
|
// Setup initial timeout timer.
|
|
conn->retransmit_timeout = 3000;
|
|
conn->rto_timeout = conn->ctx->current_ms + conn->retransmit_timeout;
|
|
conn->last_rcv_win = conn->get_rcv_window();
|
|
|
|
// if you need compatibiltiy with 1.8.1, use this. it increases attackability though.
|
|
//conn->seq_nr = 1;
|
|
conn->seq_nr = utp_call_get_random(conn->ctx, conn);
|
|
|
|
// Create the connect packet.
|
|
const size_t header_size = sizeof(PacketFormatV1);
|
|
|
|
OutgoingPacket *pkt = (OutgoingPacket*)malloc(sizeof(OutgoingPacket) - 1 + header_size);
|
|
PacketFormatV1* p1 = (PacketFormatV1*)pkt->data;
|
|
|
|
memset(p1, 0, header_size);
|
|
// SYN packets are special, and have the receive ID in the connid field,
|
|
// instead of conn_id_send.
|
|
p1->set_version(1);
|
|
p1->set_type(ST_SYN);
|
|
p1->ext = 0;
|
|
p1->connid = conn->conn_id_recv;
|
|
p1->windowsize = (uint32)conn->last_rcv_win;
|
|
p1->seq_nr = conn->seq_nr;
|
|
pkt->transmissions = 0;
|
|
pkt->length = header_size;
|
|
pkt->payload = 0;
|
|
|
|
/*
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Sending connect %s [%u].",
|
|
addrfmt(conn->addr, addrbuf), conn_seed);
|
|
#endif
|
|
*/
|
|
|
|
// Remember the message in the outgoing queue.
|
|
conn->outbuf.ensure_size(conn->seq_nr, conn->cur_window_packets);
|
|
conn->outbuf.put(conn->seq_nr, pkt);
|
|
conn->seq_nr++;
|
|
conn->cur_window_packets++;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "incrementing cur_window_packets:%u", conn->cur_window_packets);
|
|
#endif
|
|
|
|
conn->send_packet(pkt);
|
|
return 0;
|
|
}
|
|
|
|
// Returns 1 if the UDP payload was recognized as a UTP packet, or 0 if it was not
|
|
int utp_process_udp(utp_context *ctx, const byte *buffer, size_t len, const struct sockaddr *to, socklen_t tolen)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return 0;
|
|
|
|
assert(buffer);
|
|
if (!buffer) return 0;
|
|
|
|
assert(to);
|
|
if (!to) return 0;
|
|
|
|
const PackedSockAddr addr((const SOCKADDR_STORAGE*)to, tolen);
|
|
|
|
if (len < sizeof(PacketFormatV1)) {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv %s len:%u too small", addrfmt(addr, addrbuf), (uint)len);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
const PacketFormatV1 *pf1 = (PacketFormatV1*)buffer;
|
|
const byte version = UTP_Version(pf1);
|
|
const uint32 id = uint32(pf1->connid);
|
|
|
|
if (version != 1) {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv %s len:%u version:%u unsupported version", addrfmt(addr, addrbuf), (uint)len, version);
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv %s len:%u id:%u", addrfmt(addr, addrbuf), (uint)len, id);
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv id:%u seq_nr:%u ack_nr:%u", id, (uint)pf1->seq_nr, (uint)pf1->ack_nr);
|
|
#endif
|
|
|
|
const byte flags = pf1->type();
|
|
|
|
if (flags == ST_RESET) {
|
|
// id is either our recv id or our send id
|
|
// if it's our send id, and we initiated the connection, our recv id is id + 1
|
|
// if it's our send id, and we did not initiate the connection, our recv id is id - 1
|
|
// we have to check every case
|
|
|
|
UTPSocketKeyData* keyData;
|
|
if ( (keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id))) ||
|
|
((keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id + 1))) && keyData->socket->conn_id_send == id) ||
|
|
((keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id - 1))) && keyData->socket->conn_id_send == id))
|
|
{
|
|
UTPSocket* conn = keyData->socket;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv RST for existing connection");
|
|
#endif
|
|
|
|
if (conn->close_requested)
|
|
conn->state = CS_DESTROY;
|
|
else
|
|
conn->state = CS_RESET;
|
|
|
|
utp_call_on_overhead_statistics(conn->ctx, conn, false, len + conn->get_udp_overhead(), close_overhead);
|
|
const int err = (conn->state == CS_SYN_SENT) ? UTP_ECONNREFUSED : UTP_ECONNRESET;
|
|
utp_call_on_error(conn->ctx, conn, err);
|
|
}
|
|
else {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv RST for unknown connection");
|
|
#endif
|
|
}
|
|
return 1;
|
|
}
|
|
else if (flags != ST_SYN) {
|
|
UTPSocket* conn = NULL;
|
|
|
|
if (ctx->last_utp_socket && ctx->last_utp_socket->addr == addr && ctx->last_utp_socket->conn_id_recv == id) {
|
|
conn = ctx->last_utp_socket;
|
|
} else {
|
|
UTPSocketKeyData* keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id));
|
|
if (keyData) {
|
|
conn = keyData->socket;
|
|
ctx->last_utp_socket = conn;
|
|
}
|
|
}
|
|
|
|
if (conn) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv processing");
|
|
#endif
|
|
|
|
const size_t read = utp_process_incoming(conn, buffer, len);
|
|
utp_call_on_overhead_statistics(conn->ctx, conn, false, (len - read) + conn->get_udp_overhead(), header_overhead);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
// We have not found a matching utp_socket, and this isn't a SYN. Reject it.
|
|
const uint32 seq_nr = pf1->seq_nr;
|
|
if (flags != ST_SYN) {
|
|
ctx->current_ms = utp_call_get_milliseconds(ctx, NULL);
|
|
|
|
for (size_t i = 0; i < ctx->rst_info.GetCount(); i++) {
|
|
if ((ctx->rst_info[i].connid == id) &&
|
|
(ctx->rst_info[i].addr == addr) &&
|
|
(ctx->rst_info[i].ack_nr == seq_nr))
|
|
{
|
|
ctx->rst_info[i].timestamp = ctx->current_ms;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv not sending RST to non-SYN (stored)");
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
if (ctx->rst_info.GetCount() > RST_INFO_LIMIT) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv not sending RST to non-SYN (limit at %u stored)", (uint)ctx->rst_info.GetCount());
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv send RST to non-SYN (%u stored)", (uint)ctx->rst_info.GetCount());
|
|
#endif
|
|
|
|
RST_Info &r = ctx->rst_info.Append();
|
|
r.addr = addr;
|
|
r.connid = id;
|
|
r.ack_nr = seq_nr;
|
|
r.timestamp = ctx->current_ms;
|
|
|
|
UTPSocket::send_rst(ctx, addr, id, seq_nr, utp_call_get_random(ctx, NULL));
|
|
return 1;
|
|
}
|
|
|
|
if (ctx->callbacks[UTP_ON_ACCEPT]) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "Incoming connection from %s", addrfmt(addr, addrbuf));
|
|
#endif
|
|
|
|
UTPSocketKeyData* keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id + 1));
|
|
if (keyData) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "rejected incoming connection, connection already exists");
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
if (ctx->utp_sockets->GetCount() > 3000) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "rejected incoming connection, too many uTP sockets %d", ctx->utp_sockets->GetCount());
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
// true means yes, block connection. false means no, don't block.
|
|
if (utp_call_on_firewall(ctx, to, tolen)) {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "rejected incoming connection, firewall callback returned true");
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
// Create a new UTP socket to handle this new connection
|
|
UTPSocket *conn = utp_create_socket(ctx);
|
|
utp_initialize_socket(conn, to, tolen, false, id, id+1, id);
|
|
conn->ack_nr = seq_nr;
|
|
conn->seq_nr = utp_call_get_random(ctx, NULL);
|
|
conn->fast_resend_seq_nr = conn->seq_nr;
|
|
conn->state = CS_SYN_RECV;
|
|
|
|
const size_t read = utp_process_incoming(conn, buffer, len, true);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "recv send connect ACK");
|
|
#endif
|
|
|
|
conn->send_ack(true);
|
|
|
|
utp_call_on_accept(ctx, conn, to, tolen);
|
|
|
|
// we report overhead after on_accept(), because the callbacks are setup now
|
|
utp_call_on_overhead_statistics(conn->ctx, conn, false, (len - read) + conn->get_udp_overhead(), header_overhead); // SYN
|
|
utp_call_on_overhead_statistics(conn->ctx, conn, true, conn->get_overhead(), ack_overhead); // SYNACK
|
|
}
|
|
else {
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "rejected incoming connection, UTP_ON_ACCEPT callback not set");
|
|
#endif
|
|
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
// Called by utp_process_icmp_fragmentation() and utp_process_icmp_error() below
|
|
static UTPSocket* parse_icmp_payload(utp_context *ctx, const byte *buffer, size_t len, const struct sockaddr *to, socklen_t tolen)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return NULL;
|
|
|
|
assert(buffer);
|
|
if (!buffer) return NULL;
|
|
|
|
assert(to);
|
|
if (!to) return NULL;
|
|
|
|
const PackedSockAddr addr((const SOCKADDR_STORAGE*)to, tolen);
|
|
|
|
// ICMP packets are only required to quote the first 8 bytes of the layer4
|
|
// payload. The UDP payload is 8 bytes, and the UTP header is another 20
|
|
// bytes. So, in order to find the entire UTP header, we need the ICMP
|
|
// packet to quote 28 bytes.
|
|
if (len < sizeof(PacketFormatV1)) {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "Ignoring ICMP from %s: runt length %d", addrfmt(addr, addrbuf), len);
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
const PacketFormatV1 *pf = (PacketFormatV1*)buffer;
|
|
const byte version = UTP_Version(pf);
|
|
const uint32 id = uint32(pf->connid);
|
|
|
|
if (version != 1) {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "Ignoring ICMP from %s: not UTP version 1", addrfmt(addr, addrbuf));
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
UTPSocketKeyData* keyData;
|
|
|
|
if ( (keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id))) ||
|
|
((keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id + 1))) && keyData->socket->conn_id_send == id) ||
|
|
((keyData = ctx->utp_sockets->Lookup(UTPSocketKey(addr, id - 1))) && keyData->socket->conn_id_send == id))
|
|
{
|
|
return keyData->socket;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "Ignoring ICMP from %s: No matching connection found for id %u", addrfmt(addr, addrbuf), id);
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
// Should be called when an ICMP Type 3, Code 4 packet (fragmentation needed) is received, to adjust the MTU
|
|
//
|
|
// Returns 1 if the UDP payload (delivered in the ICMP packet) was recognized as a UTP packet, or 0 if it was not
|
|
//
|
|
// @ctx: utp_context
|
|
// @buf: Contents of the original UDP payload, which the ICMP packet quoted. *Not* the ICMP packet itself.
|
|
// @len: buffer length
|
|
// @to: destination address of the original UDP pakcet
|
|
// @tolen: address length
|
|
// @next_hop_mtu:
|
|
int utp_process_icmp_fragmentation(utp_context *ctx, const byte* buffer, size_t len, const struct sockaddr *to, socklen_t tolen, uint16 next_hop_mtu)
|
|
{
|
|
UTPSocket* conn = parse_icmp_payload(ctx, buffer, len, to, tolen);
|
|
if (!conn) return 0;
|
|
|
|
// Constrain the next_hop_mtu to sane values. It might not be initialized or sent properly
|
|
if (next_hop_mtu >= 576 && next_hop_mtu < 0x2000) {
|
|
conn->mtu_ceiling = min<uint32>(next_hop_mtu, conn->mtu_ceiling);
|
|
conn->mtu_search_update();
|
|
// this is something of a speecial case, where we don't set mtu_last
|
|
// to the value in between the floor and the ceiling. We can update the
|
|
// floor, because there might be more network segments after the one
|
|
// that sent this ICMP with smaller MTUs. But we want to test this
|
|
// MTU size first. If the next probe gets through, mtu_floor is updated
|
|
conn->mtu_last = conn->mtu_ceiling;
|
|
} else {
|
|
// Otherwise, binary search. At this point we don't actually know
|
|
// what size the packet that failed was, and apparently we can't
|
|
// trust the next hop mtu either. It seems reasonably conservative
|
|
// to just lower the ceiling. This should not happen on working networks
|
|
// anyway.
|
|
conn->mtu_ceiling = (conn->mtu_floor + conn->mtu_ceiling) / 2;
|
|
conn->mtu_search_update();
|
|
}
|
|
|
|
conn->log(UTP_LOG_MTU, "MTU [ICMP] floor:%d ceiling:%d current:%d", conn->mtu_floor, conn->mtu_ceiling, conn->mtu_last);
|
|
return 1;
|
|
}
|
|
|
|
// Should be called when an ICMP message is received that should tear down the connection.
|
|
//
|
|
// Returns 1 if the UDP payload (delivered in the ICMP packet) was recognized as a UTP packet, or 0 if it was not
|
|
//
|
|
// @ctx: utp_context
|
|
// @buf: Contents of the original UDP payload, which the ICMP packet quoted. *Not* the ICMP packet itself.
|
|
// @len: buffer length
|
|
// @to: destination address of the original UDP pakcet
|
|
// @tolen: address length
|
|
int utp_process_icmp_error(utp_context *ctx, const byte *buffer, size_t len, const struct sockaddr *to, socklen_t tolen)
|
|
{
|
|
UTPSocket* conn = parse_icmp_payload(ctx, buffer, len, to, tolen);
|
|
if (!conn) return 0;
|
|
|
|
const int err = (conn->state == CS_SYN_SENT) ? UTP_ECONNREFUSED : UTP_ECONNRESET;
|
|
const PackedSockAddr addr((const SOCKADDR_STORAGE*)to, tolen);
|
|
|
|
switch(conn->state) {
|
|
// Don't pass on errors for idle/closed connections
|
|
case CS_IDLE:
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "ICMP from %s in state CS_IDLE, ignoring", addrfmt(addr, addrbuf));
|
|
#endif
|
|
return 1;
|
|
|
|
default:
|
|
if (conn->close_requested) {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "ICMP from %s after close, setting state to CS_DESTROY and causing error %d", addrfmt(addr, addrbuf), err);
|
|
#endif
|
|
conn->state = CS_DESTROY;
|
|
} else {
|
|
#if UTP_DEBUG_LOGGING
|
|
ctx->log(UTP_LOG_DEBUG, NULL, "ICMP from %s, setting state to CS_RESET and causing error %d", addrfmt(addr, addrbuf), err);
|
|
#endif
|
|
conn->state = CS_RESET;
|
|
}
|
|
break;
|
|
}
|
|
|
|
utp_call_on_error(conn->ctx, conn, err);
|
|
return 1;
|
|
}
|
|
|
|
// Write bytes to the UTP socket. Returns the number of bytes written.
|
|
// 0 indicates the socket is no longer writable, -1 indicates an error
|
|
ssize_t utp_writev(utp_socket *conn, struct utp_iovec *iovec_input, size_t num_iovecs)
|
|
{
|
|
static utp_iovec iovec[UTP_IOV_MAX];
|
|
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
assert(iovec_input);
|
|
if (!iovec_input) return -1;
|
|
|
|
assert(num_iovecs);
|
|
if (!num_iovecs) return -1;
|
|
|
|
if (num_iovecs > UTP_IOV_MAX)
|
|
num_iovecs = UTP_IOV_MAX;
|
|
|
|
memcpy(iovec, iovec_input, sizeof(struct utp_iovec)*num_iovecs);
|
|
|
|
size_t bytes = 0;
|
|
size_t sent = 0;
|
|
for (size_t i = 0; i < num_iovecs; i++)
|
|
bytes += iovec[i].iov_len;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
size_t param = bytes;
|
|
#endif
|
|
|
|
if (conn->state != CS_CONNECTED) {
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Write %u bytes = false (not CS_CONNECTED)", (uint)bytes);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
if (conn->fin_sent) {
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Write %u bytes = false (fin_sent already)", (uint)bytes);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
conn->ctx->current_ms = utp_call_get_milliseconds(conn->ctx, conn);
|
|
|
|
// don't send unless it will all fit in the window
|
|
size_t packet_size = conn->get_packet_size();
|
|
size_t num_to_send = min<size_t>(bytes, packet_size);
|
|
while (!conn->is_full(num_to_send)) {
|
|
// Send an outgoing packet.
|
|
// Also add it to the outgoing of packets that have been sent but not ACKed.
|
|
|
|
bytes -= num_to_send;
|
|
sent += num_to_send;
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Sending packet. seq_nr:%u ack_nr:%u wnd:%u/%u/%u rcv_win:%u size:%u cur_window_packets:%u",
|
|
conn->seq_nr, conn->ack_nr,
|
|
(uint)(conn->cur_window + num_to_send),
|
|
(uint)conn->max_window, (uint)conn->max_window_user,
|
|
(uint)conn->last_rcv_win, num_to_send,
|
|
conn->cur_window_packets);
|
|
#endif
|
|
conn->write_outgoing_packet(num_to_send, ST_DATA, iovec, num_iovecs);
|
|
num_to_send = min<size_t>(bytes, packet_size);
|
|
|
|
if (num_to_send == 0) {
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Write %u bytes = true", (uint)param);
|
|
#endif
|
|
return sent;
|
|
}
|
|
}
|
|
|
|
bool full = conn->is_full();
|
|
if (full) {
|
|
// mark the socket as not being writable.
|
|
conn->state = CS_CONNECTED_FULL;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Write %u bytes = %s", (uint)bytes, full ? "false" : "true");
|
|
#endif
|
|
|
|
// returns whether or not the socket is still writable
|
|
// if the congestion window is not full, we can still write to it
|
|
//return !full;
|
|
return sent;
|
|
}
|
|
|
|
void utp_read_drained(utp_socket *conn)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return;
|
|
|
|
assert(conn->state != CS_UNINITIALIZED);
|
|
if (conn->state == CS_UNINITIALIZED) return;
|
|
|
|
const size_t rcvwin = conn->get_rcv_window();
|
|
|
|
if (rcvwin > conn->last_rcv_win) {
|
|
// If last window was 0 send ACK immediately, otherwise should set timer
|
|
if (conn->last_rcv_win == 0) {
|
|
conn->send_ack();
|
|
} else {
|
|
conn->ctx->current_ms = utp_call_get_milliseconds(conn->ctx, conn);
|
|
conn->schedule_ack();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Should be called each time the UDP socket is drained
|
|
void utp_issue_deferred_acks(utp_context *ctx)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return;
|
|
|
|
for (size_t i = 0; i < ctx->ack_sockets.GetCount(); i++) {
|
|
UTPSocket *conn = ctx->ack_sockets[i];
|
|
conn->send_ack();
|
|
i--;
|
|
}
|
|
}
|
|
|
|
// Should be called every 500ms
|
|
void utp_check_timeouts(utp_context *ctx)
|
|
{
|
|
assert(ctx);
|
|
if (!ctx) return;
|
|
|
|
ctx->current_ms = utp_call_get_milliseconds(ctx, NULL);
|
|
|
|
if (ctx->current_ms - ctx->last_check < TIMEOUT_CHECK_INTERVAL)
|
|
return;
|
|
|
|
ctx->last_check = ctx->current_ms;
|
|
|
|
for (size_t i = 0; i < ctx->rst_info.GetCount(); i++) {
|
|
if ((int)(ctx->current_ms - ctx->rst_info[i].timestamp) >= RST_INFO_TIMEOUT) {
|
|
ctx->rst_info.MoveUpLast(i);
|
|
i--;
|
|
}
|
|
}
|
|
if (ctx->rst_info.GetCount() != ctx->rst_info.GetAlloc()) {
|
|
ctx->rst_info.Compact();
|
|
}
|
|
|
|
utp_hash_iterator_t it;
|
|
UTPSocketKeyData* keyData;
|
|
while ((keyData = ctx->utp_sockets->Iterate(it))) {
|
|
UTPSocket *conn = keyData->socket;
|
|
conn->check_timeouts();
|
|
|
|
// Check if the object was deleted
|
|
if (conn->state == CS_DESTROY) {
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "Destroying");
|
|
#endif
|
|
delete conn;
|
|
}
|
|
}
|
|
}
|
|
|
|
int utp_getpeername(utp_socket *conn, struct sockaddr *addr, socklen_t *addrlen)
|
|
{
|
|
assert(addr);
|
|
if (!addr) return -1;
|
|
|
|
assert(addrlen);
|
|
if (!addrlen) return -1;
|
|
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
assert(conn->state != CS_UNINITIALIZED);
|
|
if (conn->state == CS_UNINITIALIZED) return -1;
|
|
|
|
socklen_t len;
|
|
const SOCKADDR_STORAGE sa = conn->addr.get_sockaddr_storage(&len);
|
|
*addrlen = min(len, *addrlen);
|
|
memcpy(addr, &sa, *addrlen);
|
|
return 0;
|
|
}
|
|
|
|
int utp_get_delays(UTPSocket *conn, uint32 *ours, uint32 *theirs, uint32 *age)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return -1;
|
|
|
|
assert(conn->state != CS_UNINITIALIZED);
|
|
if (conn->state == CS_UNINITIALIZED) {
|
|
if (ours) *ours = 0;
|
|
if (theirs) *theirs = 0;
|
|
if (age) *age = 0;
|
|
return -1;
|
|
}
|
|
|
|
if (ours) *ours = conn->our_hist.get_value();
|
|
if (theirs) *theirs = conn->their_hist.get_value();
|
|
if (age) *age = (uint32)(conn->ctx->current_ms - conn->last_measured_delay);
|
|
return 0;
|
|
}
|
|
|
|
// Close the UTP socket.
|
|
// It is not valid for the upper layer to refer to socket after it is closed.
|
|
// Data will keep to try being delivered after the close.
|
|
void utp_close(UTPSocket *conn)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return;
|
|
|
|
assert(conn->state != CS_UNINITIALIZED
|
|
&& conn->state != CS_DESTROY);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Close in state:%s", statenames[conn->state]);
|
|
#endif
|
|
|
|
switch(conn->state) {
|
|
case CS_CONNECTED:
|
|
case CS_CONNECTED_FULL:
|
|
conn->read_shutdown = true;
|
|
conn->close_requested = true;
|
|
if (!conn->fin_sent) {
|
|
conn->fin_sent = true;
|
|
conn->write_outgoing_packet(0, ST_FIN, NULL, 0);
|
|
} else if (conn->fin_sent_acked) {
|
|
conn->state = CS_DESTROY;
|
|
}
|
|
break;
|
|
|
|
case CS_SYN_SENT:
|
|
conn->rto_timeout = utp_call_get_milliseconds(conn->ctx, conn) + min<uint>(conn->rto * 2, 60);
|
|
// fall through
|
|
case CS_SYN_RECV:
|
|
// fall through
|
|
default:
|
|
conn->state = CS_DESTROY;
|
|
break;
|
|
}
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_Close end in state:%s", statenames[conn->state]);
|
|
#endif
|
|
}
|
|
|
|
void utp_shutdown(UTPSocket *conn, int how)
|
|
{
|
|
assert(conn);
|
|
if (!conn) return;
|
|
|
|
assert(conn->state != CS_UNINITIALIZED
|
|
&& conn->state != CS_DESTROY);
|
|
|
|
#if UTP_DEBUG_LOGGING
|
|
conn->log(UTP_LOG_DEBUG, "UTP_shutdown(%d) in state:%s", how, statenames[conn->state]);
|
|
#endif
|
|
|
|
if (how != SHUT_WR) {
|
|
conn->read_shutdown = true;
|
|
}
|
|
if (how != SHUT_RD) {
|
|
switch(conn->state) {
|
|
case CS_CONNECTED:
|
|
case CS_CONNECTED_FULL:
|
|
if (!conn->fin_sent) {
|
|
conn->fin_sent = true;
|
|
conn->write_outgoing_packet(0, ST_FIN, NULL, 0);
|
|
}
|
|
break;
|
|
case CS_SYN_SENT:
|
|
conn->rto_timeout = utp_call_get_milliseconds(conn->ctx, conn) + min<uint>(conn->rto * 2, 60);
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
utp_context* utp_get_context(utp_socket *socket) {
|
|
assert(socket);
|
|
return socket ? socket->ctx : NULL;
|
|
}
|
|
|
|
void* utp_set_userdata(utp_socket *socket, void *userdata) {
|
|
assert(socket);
|
|
if (socket) socket->userdata = userdata;
|
|
return socket ? socket->userdata : NULL;
|
|
}
|
|
|
|
void* utp_get_userdata(utp_socket *socket) {
|
|
assert(socket);
|
|
return socket ? socket->userdata : NULL;
|
|
}
|
|
|
|
void struct_utp_context::log(int level, utp_socket *socket, char const *fmt, ...)
|
|
{
|
|
if (!would_log(level)) {
|
|
return;
|
|
}
|
|
|
|
va_list va;
|
|
va_start(va, fmt);
|
|
log_unchecked(socket, fmt, va);
|
|
va_end(va);
|
|
}
|
|
|
|
void struct_utp_context::log_unchecked(utp_socket *socket, char const *fmt, ...)
|
|
{
|
|
va_list va;
|
|
char buf[4096];
|
|
|
|
va_start(va, fmt);
|
|
vsnprintf(buf, 4096, fmt, va);
|
|
buf[4095] = '\0';
|
|
va_end(va);
|
|
|
|
utp_call_log(this, socket, (const byte *)buf);
|
|
}
|
|
|
|
inline bool struct_utp_context::would_log(int level)
|
|
{
|
|
if (level == UTP_LOG_NORMAL) return log_normal;
|
|
if (level == UTP_LOG_MTU) return log_mtu;
|
|
if (level == UTP_LOG_DEBUG) return log_debug;
|
|
return true;
|
|
}
|
|
|
|
utp_socket_stats* utp_get_stats(utp_socket *socket)
|
|
{
|
|
#ifdef _DEBUG
|
|
assert(socket);
|
|
if (!socket) return NULL;
|
|
socket->_stats.mtu_guess = socket->mtu_last ? socket->mtu_last : socket->mtu_ceiling;
|
|
return &socket->_stats;
|
|
#else
|
|
(void)socket;
|
|
return NULL;
|
|
#endif
|
|
}
|