3 * most of the swift's state machine
5 * Created by Victor Grishchenko on 3/6/09.
6 * Copyright 2009 Delft University of Technology. All rights reserved.
10 #include <algorithm> // kill it
12 using namespace swift;
18 - randomized testing of advanced ops (new testcase)
21 void Channel::AddPeakHashes (Datagram& dgram) {
22 for(int i=0; i<file().peak_count(); i++) {
23 bin64_t peak = file().peak(i);
24 dgram.Push8(SWIFT_HASH);
25 dgram.Push32((uint32_t)peak);
26 dgram.PushHash(file().peak_hash(i));
27 //DLOG(INFO)<<"#"<<id<<" +pHASH"<<file().peak(i);
28 dprintf("%s #%u +phash %s\n",tintstr(),id_,peak.str());
33 void Channel::AddUncleHashes (Datagram& dgram, bin64_t pos) {
34 bin64_t peak = file().peak_for(pos);
35 while (pos!=peak && ((NOW&3)==3 || !data_out_cap_.within(pos.parent())) &&
36 ack_in_.get(pos.parent())==binmap_t::EMPTY ) {
37 bin64_t uncle = pos.sibling();
38 dgram.Push8(SWIFT_HASH);
39 dgram.Push32((uint32_t)uncle);
40 dgram.PushHash( file().hash(uncle) );
41 //DLOG(INFO)<<"#"<<id<<" +uHASH"<<uncle;
42 dprintf("%s #%u +hash %s\n",tintstr(),id_,uncle.str());
48 bin64_t Channel::ImposeHint () {
49 uint64_t twist = peer_channel_id_; // got no hints, send something randomly
50 twist &= file().peak(0); // FIXME may make it semi-seq here
51 file().ack_out().twist(twist);
54 file().ack_out().find_filtered(ack_in_,bin64_t::ALL,binmap_t::FILLED);
55 while (my_pick.width()>max(1,(int)cwnd_))
56 my_pick = my_pick.left();
57 file().ack_out().twist(0);
59 return my_pick.twisted(twist);
63 bin64_t Channel::DequeueHint () {
64 if (hint_in_.empty() && last_recv_time_>NOW-rtt_avg_-TINT_SEC) {
65 bin64_t my_pick = ImposeHint(); // FIXME move to the loop
66 if (my_pick!=bin64_t::NONE) {
67 hint_in_.push_back(my_pick);
68 dprintf("%s #%u *hint %s\n",tintstr(),id_,my_pick.str());
71 bin64_t send = bin64_t::NONE;
72 while (!hint_in_.empty() && send==bin64_t::NONE) {
73 bin64_t hint = hint_in_.front().bin;
74 tint time = hint_in_.front().time;
76 while (!hint.is_base()) { // FIXME optimize; possible attack
77 hint_in_.push_front(tintbin(time,hint.right()));
80 //if (time < NOW-TINT_SEC*3/2 )
82 if (ack_in_.get(hint)!=binmap_t::FILLED)
86 for(int i=0; i<hint_in_.size(); i++)
87 mass += hint_in_[i].bin.width();
88 dprintf("%s #%u dequeued %s [%lli]\n",tintstr(),id_,send.str(),mass);
93 void Channel::AddHandshake (Datagram& dgram) {
94 if (!peer_channel_id_) { // initiating
95 dgram.Push8(SWIFT_HASH);
96 dgram.Push32(bin64_t::ALL32);
97 dgram.PushHash(file().root_hash());
98 dprintf("%s #%u +hash ALL %s\n",
99 tintstr(),id_,file().root_hash().hex().c_str());
101 dgram.Push8(SWIFT_HANDSHAKE);
102 int encoded = EncodeID(id_);
103 dgram.Push32(encoded);
104 dprintf("%s #%u +hs %x\n",tintstr(),id_,encoded);
110 void Channel::Send () {
111 Datagram dgram(socket_,peer());
112 dgram.Push32(peer_channel_id_);
113 bin64_t data = bin64_t::NONE;
114 if ( is_established() ) {
115 // FIXME: seeder check
117 if (!file().is_complete())
121 data = AddData(dgram);
126 dprintf("%s #%u sent %ib %s:%x\n",
127 tintstr(),id_,dgram.size(),peer().str(),peer_channel_id_);
128 if (dgram.size()==4) {// only the channel id; bare keep-alive
131 if (dgram.Send()==-1)
132 print_error("can't send datagram");
133 last_send_time_ = NOW;
139 void Channel::AddHint (Datagram& dgram) {
141 tint plan_for = max(TINT_SEC,rtt_avg_*4);
143 tint timed_out = NOW - plan_for*2;
144 while ( !hint_out_.empty() && hint_out_.front().time < timed_out ) {
145 hint_out_size_ -= hint_out_.front().bin.width();
146 hint_out_.pop_front();
149 int plan_pck = max ( (tint)1, plan_for / dip_avg_ );
151 if ( hint_out_size_ < plan_pck ) {
153 int diff = plan_pck - hint_out_size_; // TODO: aggregate
154 bin64_t hint = transfer().picker().Pick(ack_in_,diff,NOW+plan_for*2);
156 if (hint!=bin64_t::NONE) {
157 dgram.Push8(SWIFT_HINT);
159 dprintf("%s #%u +hint %s [%lli]\n",tintstr(),id_,hint.str(),hint_out_size_);
160 hint_out_.push_back(hint);
161 hint_out_size_ += hint.width();
163 dprintf("%s #%u Xhint\n",tintstr(),id_);
169 bin64_t Channel::AddData (Datagram& dgram) {
171 if (!file().size()) // know nothing
172 return bin64_t::NONE;
174 bin64_t tosend = bin64_t::NONE;
175 tint luft = send_interval_>>4; // may wake up a bit earlier
176 if (data_out_.size()<cwnd_ &&
177 last_data_out_time_+send_interval_<=NOW+luft) {
178 tosend = DequeueHint();
179 if (tosend==bin64_t::NONE) {
180 dprintf("%s #%u sendctrl no idea what to send\n",tintstr(),id_);
181 if (send_control_!=KEEP_ALIVE_CONTROL)
182 SwitchSendControl(KEEP_ALIVE_CONTROL);
185 dprintf("%s #%u sendctrl wait cwnd %f data_out %i next %s\n",
186 tintstr(),id_,cwnd_,data_out_.size(),tintstr(last_data_out_time_+NOW-send_interval_));
188 if (tosend==bin64_t::NONE)// && (last_data_out_time_>NOW-TINT_SEC || data_out_.empty()))
189 return bin64_t::NONE; // once in a while, empty data is sent just to check rtt FIXED
191 if (ack_in_.is_empty() && file().size())
192 AddPeakHashes(dgram);
193 AddUncleHashes(dgram,tosend);
194 if (!ack_in_.is_empty()) // TODO: cwnd_>1
195 data_out_cap_ = tosend;
197 if (dgram.size()>254) {
198 dgram.Send(); // kind of fragmentation
199 dgram.Push32(peer_channel_id_);
202 dgram.Push8(SWIFT_DATA);
203 dgram.Push32(tosend.to32());
206 size_t r = pread(file().file_descriptor(),buf,1024,tosend.base_offset()<<10);
207 // TODO: corrupted data, retries, caching
209 print_error("error on reading");
210 return bin64_t::NONE;
212 assert(dgram.space()>=r+4+1);
215 last_data_out_time_ = NOW;
216 data_out_.push_back(tosend);
217 dprintf("%s #%u +data %s\n",tintstr(),id_,tosend.str());
223 void Channel::AddAck (Datagram& dgram) {
224 if (data_in_==tintbin())
226 dgram.Push8(SWIFT_ACK);
227 dgram.Push32(data_in_.bin.to32());
228 dgram.Push32(data_in_.time);
229 ack_out_.set(data_in_.bin);
230 dprintf("%s #%u +ack %s %s\n",
231 tintstr(),id_,data_in_.bin.str(),tintstr(data_in_.time));
232 if (data_in_.bin.layer()>2)
233 data_in_dbl_ = data_in_.bin;
234 data_in_ = tintbin();
238 void Channel::AddHave (Datagram& dgram) {
239 if (data_in_dbl_!=bin64_t::NONE) { // TODO: do redundancy better
240 dgram.Push8(SWIFT_HAVE);
241 dgram.Push32(data_in_dbl_.to32());
242 data_in_dbl_=bin64_t::NONE;
244 for(int count=0; count<4; count++) {
245 bin64_t ack = file().ack_out().find_filtered // FIXME: do rotating queue
246 (ack_out_, bin64_t::ALL, binmap_t::FILLED);
247 if (ack==bin64_t::NONE)
249 ack = file().ack_out().cover(ack);
251 dgram.Push8(SWIFT_HAVE);
252 dgram.Push32(ack.to32());
253 dprintf("%s #%u +have %s\n",tintstr(),id_,ack.str());
258 void Channel::Recv (Datagram& dgram) {
259 dprintf("%s #%u recvd %i\n",tintstr(),id_,dgram.size()+4);
261 if (last_send_time_ && rtt_avg_==TINT_SEC && dev_avg_==0) {
262 rtt_avg_ = NOW - last_send_time_;
265 dprintf("%s #%u sendctrl rtt init %lli\n",tintstr(),id_,rtt_avg_);
267 bin64_t data = dgram.size() ? bin64_t::NONE : bin64_t::ALL;
268 while (dgram.size()) {
269 uint8_t type = dgram.Pull8();
271 case SWIFT_HANDSHAKE: OnHandshake(dgram); break;
272 case SWIFT_DATA: data=OnData(dgram); break;
273 case SWIFT_HAVE: OnHave(dgram); break;
274 case SWIFT_ACK: OnAck(dgram); break;
275 case SWIFT_HASH: OnHash(dgram); break;
276 case SWIFT_HINT: OnHint(dgram); break;
277 case SWIFT_PEX_ADD: OnPex(dgram); break;
279 eprintf("%s #%u ?msg id unknown %i\n",tintstr(),id_,(int)type);
283 last_recv_time_ = NOW;
284 sent_since_recv_ = 0;
288 void Channel::OnHash (Datagram& dgram) {
289 bin64_t pos = dgram.Pull32();
290 Sha1Hash hash = dgram.PullHash();
291 file().OfferHash(pos,hash);
292 dprintf("%s #%u -hash %s\n",tintstr(),id_,pos.str());
296 void Channel::CleanHintOut (bin64_t pos) {
298 while (hi<hint_out_.size() && !pos.within(hint_out_[hi].bin))
300 if (hi==hint_out_.size())
301 return; // something not hinted or hinted in far past
302 while (hi--) { // removing likely snubbed hints
303 hint_out_size_ -= hint_out_.front().bin.width();
304 hint_out_.pop_front();
306 while (hint_out_.front().bin!=pos) {
307 tintbin f = hint_out_.front();
308 f.bin = f.bin.towards(pos);
309 hint_out_.front().bin = f.bin.sibling();
310 hint_out_.push_front(f);
312 hint_out_.pop_front();
317 bin64_t Channel::OnData (Datagram& dgram) { // TODO: HAVE NONE for corrupted data
318 bin64_t pos = dgram.Pull32();
320 int length = dgram.Pull(&data,1024);
321 bool ok = (pos==bin64_t::NONE) || file().OfferData(pos, (char*)data, length) ;
322 dprintf("%s #%u %cdata %s\n",tintstr(),id_,ok?'-':'!',pos.str());
323 data_in_ = tintbin(NOW,bin64_t::NONE);
325 return bin64_t::NONE;
327 if (pos!=bin64_t::NONE) {
328 if (last_data_in_time_) {
329 tint dip = NOW - last_data_in_time_;
330 dip_avg_ = ( dip_avg_*3 + dip ) >> 2;
332 last_data_in_time_ = NOW;
339 void Channel::OnAck (Datagram& dgram) {
340 bin64_t ackd_pos = dgram.Pull32();
341 tint peer_time_ = dgram.Pull64();
342 if (ackd_pos==bin64_t::NONE)
343 return; // likely, brocken packet / insufficient hashes
344 if (file().size() && ackd_pos.base_offset()>=file().packet_size()) {
345 eprintf("invalid ack: %s\n",ackd_pos.str());
348 ack_in_.set(ackd_pos);
350 // find an entry for the send (data out) event
351 while ( di<data_out_.size() && ( data_out_[di]==tintbin() ||
352 !data_out_[di].bin.within(ackd_pos) ) )
354 // FUTURE: delayed acks
355 // rule out retransmits
356 while ( ri<data_out_tmo_.size() && !data_out_tmo_[ri].bin.within(ackd_pos) )
358 dprintf("%s #%u %cack %s %s\n",tintstr(),id_,
359 di==data_out_.size()?'?':'-',ackd_pos.str(),tintstr(peer_time_));
360 if (ri==data_out_tmo_.size()) { // not a retransmit
361 // round trip time calculations
362 tint rtt = NOW-data_out_[di].time;
363 rtt_avg_ = (rtt_avg_*7 + rtt) >> 3;
364 dev_avg_ = ( dev_avg_*3 + abs(rtt-rtt_avg_) ) >> 2;
365 assert(data_out_[di].time!=TINT_NEVER);
366 // one-way delay calculations
367 tint owd = peer_time_ - data_out_[di].time;
368 owd_cur_bin_ = (owd_cur_bin_+1) & 3;
369 owd_current_[owd_cur_bin_] = owd;
370 if ( owd_min_bin_start_+TINT_SEC*30 < NOW ) {
371 owd_min_bin_start_ = NOW;
372 owd_min_bin_ = (owd_min_bin_+1) & 3;
373 owd_min_bins_[owd_min_bin_] = TINT_NEVER;
375 if (owd_min_bins_[owd_min_bin_]>owd)
376 owd_min_bins_[owd_min_bin_] = owd;
377 dprintf("%s #%u sendctrl rtt %lli dev %lli based on %s\n",
378 tintstr(),id_,rtt_avg_,dev_avg_,data_out_[di].bin.str());
380 data_out_[di]=tintbin();
382 // early loss detection by packet reordering
383 for (int re=0; re<di-MAX_REORDERING; re++) {
384 if (data_out_[re]==tintbin())
386 ack_not_rcvd_recent_++;
387 data_out_tmo_.push_back(data_out_.front().bin);
388 dprintf("%s #%u Rdata %s\n",tintstr(),id_,data_out_.front().bin.str());
389 data_out_cap_ = bin64_t::ALL;
390 data_out_[ri] = tintbin();
392 // clear zeroed items
393 while (!data_out_.empty() && ( data_out_.front()==tintbin() ||
394 ack_in_.is_filled(data_out_.front().bin) ) )
395 data_out_.pop_front();
396 assert(data_out_.empty() || data_out_.front().time!=TINT_NEVER);
400 void Channel::TimeoutDataOut ( ) {
401 // losses: timeouted packets
402 tint timeout = NOW - ack_timeout();
403 for (int i=0; i<data_out_.size() && data_out_[i].time<timeout; i++) {
404 if (data_out_.front()!=tintbin() && ack_in_.is_empty(data_out_.front().bin)) {
405 ack_not_rcvd_recent_++;
406 data_out_cap_ = bin64_t::ALL;
407 data_out_tmo_.push_back(data_out_.front().bin);
408 dprintf("%s #%u Tdata %s\n",tintstr(),id_,data_out_.front().bin.str());
410 data_out_.pop_front();
412 // clear retransmit queue of older items
413 while (!data_out_tmo_.empty() && data_out_tmo_.front().time<NOW-MAX_POSSIBLE_RTT)
414 data_out_tmo_.pop_front();
418 void Channel::OnHave (Datagram& dgram) {
419 bin64_t ackd_pos = dgram.Pull32();
420 if (ackd_pos==bin64_t::NONE)
421 return; // wow, peer has hashes
422 ack_in_.set(ackd_pos);
423 dprintf("%s #%u -have %s\n",tintstr(),id_,ackd_pos.str());
427 void Channel::OnHint (Datagram& dgram) {
428 bin64_t hint = dgram.Pull32();
429 // FIXME: wake up here
430 hint_in_.push_back(hint);
431 dprintf("%s #%u -hint %s\n",tintstr(),id_,hint.str());
435 void Channel::OnHandshake (Datagram& dgram) {
436 peer_channel_id_ = dgram.Pull32();
437 dprintf("%s #%u -hs %x\n",tintstr(),id_,peer_channel_id_);
438 // self-connection check
440 uint32_t try_id = DecodeID(peer_channel_id_);
441 if (channel(try_id) && !channel(try_id)->peer_channel_id_) {
442 peer_channel_id_ = 0;
444 return; // this is a self-connection
447 // FUTURE: channel forking
451 void Channel::OnPex (Datagram& dgram) {
452 uint32_t ipv4 = dgram.Pull32();
453 uint16_t port = dgram.Pull16();
454 Address addr(ipv4,port);
455 dprintf("%s #%u -pex %s\n",tintstr(),id_,addr.str());
456 transfer().OnPexIn(addr);
460 void Channel::AddPex (Datagram& dgram) {
461 int chid = transfer().RevealChannel(pex_out_);
462 if (chid==-1 || chid==id_)
464 Address a = channels[chid]->peer();
465 dgram.Push8(SWIFT_PEX_ADD);
466 dgram.Push32(a.ipv4());
467 dgram.Push16(a.port());
468 dprintf("%s #%u +pex %s\n",tintstr(),id_,a.str());
472 Channel* Channel::RecvDatagram (int socket) {
473 Datagram data(socket);
475 const Address& addr = data.address();
476 #define return_log(...) { printf(__VA_ARGS__); return NULL; }
478 return_log("datagram shorter than 4 bytes %s\n",addr.str());
479 uint32_t mych = data.Pull32();
481 Channel* channel = NULL;
482 if (!mych) { // handshake initiated
483 if (data.size()<1+4+1+4+Sha1Hash::SIZE)
484 return_log ("%s #0 incorrect size %i initial handshake packet %s\n",
485 tintstr(),data.size(),addr.str());
486 uint8_t hashid = data.Pull8();
487 if (hashid!=SWIFT_HASH)
488 return_log ("%s #0 no hash in the initial handshake %s\n",
489 tintstr(),addr.str());
490 bin64_t pos = data.Pull32();
491 if (pos!=bin64_t::ALL)
492 return_log ("%s #0 that is not the root hash %s\n",tintstr(),addr.str());
493 hash = data.PullHash();
494 FileTransfer* file = FileTransfer::Find(hash);
496 return_log ("%s #0 hash %s unknown, no such file %s\n",tintstr(),hash.hex().c_str(),addr.str());
497 dprintf("%s #0 -hash ALL %s\n",tintstr(),hash.hex().c_str());
498 for(binqueue::iterator i=file->hs_in_.begin(); i!=file->hs_in_.end(); i++)
499 if (channels[*i] && channels[*i]->peer_==data.address() &&
500 channels[*i]->last_recv_time_>NOW-TINT_SEC*2)
501 return_log("%s #0 have a channel already to %s\n",tintstr(),addr.str());
502 channel = new Channel(file, socket, data.address());
504 mych = DecodeID(mych);
505 if (mych>=channels.size())
506 return_log("%s invalid channel #%u, %s\n",tintstr(),mych,addr.str());
507 channel = channels[mych];
509 return_log ("%s #%u is already closed\n",tintstr(),mych,addr.str());
510 if (channel->peer() != addr)
511 return_log ("%s #%u invalid peer address %s!=%s\n",
512 tintstr(),mych,channel->peer().str(),addr.str());
513 channel->own_id_mentioned_ = true;
515 //dprintf("recvd %i bytes for %i\n",data.size(),channel->id);
521 void Channel::Loop (tint howlong) {
523 tint limit = Datagram::Time() + howlong;
527 tint send_time(TINT_NEVER);
528 Channel* sender(NULL);
529 while (!sender && !send_queue.is_empty()) { // dequeue
530 tintbin next = send_queue.pop();
531 sender = channel((int)next.bin);
532 send_time = next.time;
533 if (sender && sender->next_send_time_!=send_time &&
534 sender->next_send_time_!=TINT_NEVER )
535 sender = NULL; // it was a stale entry
538 if ( sender!=NULL && send_time<=NOW ) { // it's time
540 dprintf("%s #%u sch_send %s\n",tintstr(),sender->id(),
543 sender->Reschedule();
545 } else { // it's too early, wait
547 tint towait = min(limit,send_time) - NOW;
548 dprintf("%s #0 waiting %lliusec\n",tintstr(),towait);
549 int rd = Datagram::Wait(socket_count,sockets,towait);
550 if (rd!=INVALID_SOCKET) { // in meantime, received something
551 Channel* receiver = RecvDatagram(rd);
552 if (receiver) // receiver's state may have changed
553 receiver->Reschedule();
555 if (sender) // get back to that later
556 send_queue.push(tintbin(send_time,sender->id()));
565 void Channel::Close () {
566 this->SwitchSendControl(CLOSE_CONTROL);
570 void Channel::Reschedule () {
571 TimeoutDataOut(); // precaution to know free cwnd
572 next_send_time_ = NextSendTime();
573 if (next_send_time_!=TINT_NEVER) {
574 assert(next_send_time_<NOW+TINT_MIN);
575 send_queue.push(tintbin(next_send_time_,id_));
576 dprintf("%s #%u requeue for %s\n",tintstr(),id_,tintstr(next_send_time_));
578 dprintf("%s #%u closed\n",tintstr(),id_);