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
118 if (!file().is_complete())
122 data = AddData(dgram);
128 dprintf("%s #%u sent %ib %s:%x\n",
129 tintstr(),id_,dgram.size(),peer().str(),peer_channel_id_);
130 if (dgram.size()==4) {// only the channel id; bare keep-alive
133 if (dgram.Send()==-1)
134 print_error("can't send datagram");
135 last_send_time_ = NOW;
141 void Channel::AddHint (Datagram& dgram) {
143 tint plan_for = max(TINT_SEC,rtt_avg_*4);
145 tint timed_out = NOW - plan_for*2;
146 while ( !hint_out_.empty() && hint_out_.front().time < timed_out ) {
147 hint_out_size_ -= hint_out_.front().bin.width();
148 hint_out_.pop_front();
151 int plan_pck = max ( (tint)1, plan_for / dip_avg_ );
153 if ( hint_out_size_ < plan_pck ) {
155 int diff = plan_pck - hint_out_size_; // TODO: aggregate
156 bin64_t hint = transfer().picker().Pick(ack_in_,diff,NOW+plan_for*2);
158 if (hint!=bin64_t::NONE) {
159 dgram.Push8(SWIFT_HINT);
161 dprintf("%s #%u +hint %s [%lli]\n",tintstr(),id_,hint.str(),hint_out_size_);
162 hint_out_.push_back(hint);
163 hint_out_size_ += hint.width();
165 dprintf("%s #%u Xhint\n",tintstr(),id_);
171 bin64_t Channel::AddData (Datagram& dgram) {
173 if (!file().size()) // know nothing
174 return bin64_t::NONE;
176 bin64_t tosend = bin64_t::NONE;
177 tint luft = send_interval_>>4; // may wake up a bit earlier
178 if (data_out_.size()<cwnd_ &&
179 last_data_out_time_+send_interval_<=NOW+luft) {
180 tosend = DequeueHint();
181 if (tosend==bin64_t::NONE) {
182 dprintf("%s #%u sendctrl no idea what to send\n",tintstr(),id_);
183 if (send_control_!=KEEP_ALIVE_CONTROL)
184 SwitchSendControl(KEEP_ALIVE_CONTROL);
187 dprintf("%s #%u sendctrl wait cwnd %f data_out %i next %s\n",
188 tintstr(),id_,cwnd_,data_out_.size(),tintstr(last_data_out_time_+NOW-send_interval_));
190 if (tosend==bin64_t::NONE)// && (last_data_out_time_>NOW-TINT_SEC || data_out_.empty()))
191 return bin64_t::NONE; // once in a while, empty data is sent just to check rtt FIXED
193 if (ack_in_.is_empty() && file().size())
194 AddPeakHashes(dgram);
195 AddUncleHashes(dgram,tosend);
196 if (!ack_in_.is_empty()) // TODO: cwnd_>1
197 data_out_cap_ = tosend;
199 if (dgram.size()>254) {
200 dgram.Send(); // kind of fragmentation
201 dgram.Push32(peer_channel_id_);
204 dgram.Push8(SWIFT_DATA);
205 dgram.Push32(tosend.to32());
208 size_t r = pread(file().file_descriptor(),buf,1024,tosend.base_offset()<<10);
209 // TODO: corrupted data, retries, caching
211 print_error("error on reading");
212 return bin64_t::NONE;
214 assert(dgram.space()>=r+4+1);
217 last_data_out_time_ = NOW;
218 data_out_.push_back(tosend);
219 dprintf("%s #%u +data %s\n",tintstr(),id_,tosend.str());
225 void Channel::AddAck (Datagram& dgram) {
226 if (data_in_==tintbin())
228 dgram.Push8(SWIFT_ACK);
229 dgram.Push32(data_in_.bin.to32()); // FIXME not cover
230 dgram.Push64(data_in_.time); // FIXME 32
231 have_out_.set(data_in_.bin);
232 dprintf("%s #%u +ack %s %s\n",
233 tintstr(),id_,data_in_.bin.str(),tintstr(data_in_.time));
234 if (data_in_.bin.layer()>2)
235 data_in_dbl_ = data_in_.bin;
236 data_in_ = tintbin();
240 void Channel::AddHave (Datagram& dgram) {
241 if (data_in_dbl_!=bin64_t::NONE) { // TODO: do redundancy better
242 dgram.Push8(SWIFT_HAVE);
243 dgram.Push32(data_in_dbl_.to32());
244 data_in_dbl_=bin64_t::NONE;
246 for(int count=0; count<4; count++) {
247 bin64_t ack = file().ack_out().find_filtered // FIXME: do rotating queue
248 (have_out_, bin64_t::ALL, binmap_t::FILLED);
249 if (ack==bin64_t::NONE)
251 ack = file().ack_out().cover(ack);
253 dgram.Push8(SWIFT_HAVE);
254 dgram.Push32(ack.to32());
255 dprintf("%s #%u +have %s\n",tintstr(),id_,ack.str());
260 void Channel::Recv (Datagram& dgram) {
261 dprintf("%s #%u recvd %ib\n",tintstr(),id_,dgram.size()+4);
263 if (last_send_time_ && rtt_avg_==TINT_SEC && dev_avg_==0) {
264 rtt_avg_ = NOW - last_send_time_;
267 dprintf("%s #%u sendctrl rtt init %lli\n",tintstr(),id_,rtt_avg_);
269 bin64_t data = dgram.size() ? bin64_t::NONE : bin64_t::ALL;
270 while (dgram.size()) {
271 uint8_t type = dgram.Pull8();
273 case SWIFT_HANDSHAKE: OnHandshake(dgram); break;
274 case SWIFT_DATA: data=OnData(dgram); break;
275 case SWIFT_HAVE: OnHave(dgram); break;
276 case SWIFT_ACK: OnAck(dgram); break;
277 case SWIFT_HASH: OnHash(dgram); break;
278 case SWIFT_HINT: OnHint(dgram); break;
279 case SWIFT_PEX_ADD: OnPex(dgram); break;
281 eprintf("%s #%u ?msg id unknown %i\n",tintstr(),id_,(int)type);
285 last_recv_time_ = NOW;
286 sent_since_recv_ = 0;
290 void Channel::OnHash (Datagram& dgram) {
291 bin64_t pos = dgram.Pull32();
292 Sha1Hash hash = dgram.PullHash();
293 file().OfferHash(pos,hash);
294 dprintf("%s #%u -hash %s\n",tintstr(),id_,pos.str());
298 void Channel::CleanHintOut (bin64_t pos) {
300 while (hi<hint_out_.size() && !pos.within(hint_out_[hi].bin))
302 if (hi==hint_out_.size())
303 return; // something not hinted or hinted in far past
304 while (hi--) { // removing likely snubbed hints
305 hint_out_size_ -= hint_out_.front().bin.width();
306 hint_out_.pop_front();
308 while (hint_out_.front().bin!=pos) {
309 tintbin f = hint_out_.front();
310 f.bin = f.bin.towards(pos);
311 hint_out_.front().bin = f.bin.sibling();
312 hint_out_.push_front(f);
314 hint_out_.pop_front();
319 bin64_t Channel::OnData (Datagram& dgram) { // TODO: HAVE NONE for corrupted data
320 bin64_t pos = dgram.Pull32();
322 int length = dgram.Pull(&data,1024);
323 bool ok = (pos==bin64_t::NONE) || file().OfferData(pos, (char*)data, length) ;
324 dprintf("%s #%u %cdata %s\n",tintstr(),id_,ok?'-':'!',pos.str());
325 data_in_ = tintbin(NOW,bin64_t::NONE);
327 return bin64_t::NONE;
329 if (pos!=bin64_t::NONE) {
330 if (last_data_in_time_) {
331 tint dip = NOW - last_data_in_time_;
332 dip_avg_ = ( dip_avg_*3 + dip ) >> 2;
334 last_data_in_time_ = NOW;
341 void Channel::OnAck (Datagram& dgram) {
342 bin64_t ackd_pos = dgram.Pull32();
343 tint peer_time_ = dgram.Pull64(); // FIXME 32
344 // FIXME FIXME: wrap around here
345 if (ackd_pos==bin64_t::NONE)
346 return; // likely, brocken packet / insufficient hashes
347 if (file().size() && ackd_pos.base_offset()>=file().packet_size()) {
348 eprintf("invalid ack: %s\n",ackd_pos.str());
351 ack_in_.set(ackd_pos);
353 // find an entry for the send (data out) event
354 while ( di<data_out_.size() && ( data_out_[di]==tintbin() ||
355 !data_out_[di].bin.within(ackd_pos) ) )
357 // FUTURE: delayed acks
358 // rule out retransmits
359 while ( ri<data_out_tmo_.size() && !data_out_tmo_[ri].bin.within(ackd_pos) )
361 dprintf("%s #%u %cack %s %lli\n",tintstr(),id_,
362 di==data_out_.size()?'?':'-',ackd_pos.str(),peer_time_);
363 if (di!=data_out_.size() && ri==data_out_tmo_.size()) { // not a retransmit
364 // round trip time calculations
365 tint rtt = NOW-data_out_[di].time;
366 rtt_avg_ = (rtt_avg_*7 + rtt) >> 3;
367 dev_avg_ = ( dev_avg_*3 + abs(rtt-rtt_avg_) ) >> 2;
368 assert(data_out_[di].time!=TINT_NEVER);
369 // one-way delay calculations
370 tint owd = peer_time_ - data_out_[di].time;
371 owd_cur_bin_ = (owd_cur_bin_+1) & 3;
372 owd_current_[owd_cur_bin_] = owd;
373 if ( owd_min_bin_start_+TINT_SEC*30 < NOW ) {
374 owd_min_bin_start_ = NOW;
375 owd_min_bin_ = (owd_min_bin_+1) & 3;
376 owd_min_bins_[owd_min_bin_] = TINT_NEVER;
378 if (owd_min_bins_[owd_min_bin_]>owd)
379 owd_min_bins_[owd_min_bin_] = owd;
380 dprintf("%s #%u sendctrl rtt %lli dev %lli based on %s\n",
381 tintstr(),id_,rtt_avg_,dev_avg_,data_out_[di].bin.str());
383 // early loss detection by packet reordering
384 for (int re=0; re<di-MAX_REORDERING; re++) {
385 if (data_out_[re]==tintbin())
387 ack_not_rcvd_recent_++;
388 data_out_tmo_.push_back(data_out_[re].bin);
389 dprintf("%s #%u Rdata %s\n",tintstr(),id_,data_out_.front().bin.str());
390 data_out_cap_ = bin64_t::ALL;
391 data_out_[re] = tintbin();
394 if (di!=data_out_.size())
395 data_out_[di]=tintbin();
396 // clear zeroed items
397 while (!data_out_.empty() && ( data_out_.front()==tintbin() ||
398 ack_in_.is_filled(data_out_.front().bin) ) )
399 data_out_.pop_front();
400 assert(data_out_.empty() || data_out_.front().time!=TINT_NEVER);
404 void Channel::TimeoutDataOut ( ) {
405 // losses: timeouted packets
406 tint timeout = NOW - ack_timeout();
407 while (!data_out_.empty() &&
408 ( data_out_.front().time<timeout || data_out_.front()==tintbin() ) ) {
409 if (data_out_.front()!=tintbin() && ack_in_.is_empty(data_out_.front().bin)) {
410 ack_not_rcvd_recent_++;
411 data_out_cap_ = bin64_t::ALL;
412 data_out_tmo_.push_back(data_out_.front().bin);
413 dprintf("%s #%u Tdata %s\n",tintstr(),id_,data_out_.front().bin.str());
415 data_out_.pop_front();
417 // clear retransmit queue of older items
418 while (!data_out_tmo_.empty() && data_out_tmo_.front().time<NOW-MAX_POSSIBLE_RTT)
419 data_out_tmo_.pop_front();
423 void Channel::OnHave (Datagram& dgram) {
424 bin64_t ackd_pos = dgram.Pull32();
425 if (ackd_pos==bin64_t::NONE)
426 return; // wow, peer has hashes
427 ack_in_.set(ackd_pos);
428 dprintf("%s #%u -have %s\n",tintstr(),id_,ackd_pos.str());
432 void Channel::OnHint (Datagram& dgram) {
433 bin64_t hint = dgram.Pull32();
434 // FIXME: wake up here
435 hint_in_.push_back(hint);
436 dprintf("%s #%u -hint %s\n",tintstr(),id_,hint.str());
440 void Channel::OnHandshake (Datagram& dgram) {
441 peer_channel_id_ = dgram.Pull32();
442 dprintf("%s #%u -hs %x\n",tintstr(),id_,peer_channel_id_);
443 // self-connection check
445 uint32_t try_id = DecodeID(peer_channel_id_);
446 if (channel(try_id) && !channel(try_id)->peer_channel_id_) {
447 peer_channel_id_ = 0;
449 return; // this is a self-connection
452 // FUTURE: channel forking
456 void Channel::OnPex (Datagram& dgram) {
457 uint32_t ipv4 = dgram.Pull32();
458 uint16_t port = dgram.Pull16();
459 Address addr(ipv4,port);
460 dprintf("%s #%u -pex %s\n",tintstr(),id_,addr.str());
461 transfer().OnPexIn(addr);
465 void Channel::AddPex (Datagram& dgram) {
466 int chid = transfer().RevealChannel(pex_out_);
467 if (chid==-1 || chid==id_)
469 Address a = channels[chid]->peer();
470 dgram.Push8(SWIFT_PEX_ADD);
471 dgram.Push32(a.ipv4());
472 dgram.Push16(a.port());
473 dprintf("%s #%u +pex %s\n",tintstr(),id_,a.str());
477 Channel* Channel::RecvDatagram (int socket) {
478 Datagram data(socket);
480 const Address& addr = data.address();
481 #define return_log(...) { printf(__VA_ARGS__); return NULL; }
483 return_log("datagram shorter than 4 bytes %s\n",addr.str());
484 uint32_t mych = data.Pull32();
486 Channel* channel = NULL;
487 if (!mych) { // handshake initiated
488 if (data.size()<1+4+1+4+Sha1Hash::SIZE)
489 return_log ("%s #0 incorrect size %i initial handshake packet %s\n",
490 tintstr(),data.size(),addr.str());
491 uint8_t hashid = data.Pull8();
492 if (hashid!=SWIFT_HASH)
493 return_log ("%s #0 no hash in the initial handshake %s\n",
494 tintstr(),addr.str());
495 bin64_t pos = data.Pull32();
496 if (pos!=bin64_t::ALL)
497 return_log ("%s #0 that is not the root hash %s\n",tintstr(),addr.str());
498 hash = data.PullHash();
499 FileTransfer* file = FileTransfer::Find(hash);
501 return_log ("%s #0 hash %s unknown, no such file %s\n",tintstr(),hash.hex().c_str(),addr.str());
502 dprintf("%s #0 -hash ALL %s\n",tintstr(),hash.hex().c_str());
503 for(binqueue::iterator i=file->hs_in_.begin(); i!=file->hs_in_.end(); i++)
504 if (channels[*i] && channels[*i]->peer_==data.address() &&
505 channels[*i]->last_recv_time_>NOW-TINT_SEC*2)
506 return_log("%s #0 have a channel already to %s\n",tintstr(),addr.str());
507 channel = new Channel(file, socket, data.address());
509 mych = DecodeID(mych);
510 if (mych>=channels.size())
511 return_log("%s invalid channel #%u, %s\n",tintstr(),mych,addr.str());
512 channel = channels[mych];
514 return_log ("%s #%u is already closed\n",tintstr(),mych,addr.str());
515 if (channel->peer() != addr)
516 return_log ("%s #%u invalid peer address %s!=%s\n",
517 tintstr(),mych,channel->peer().str(),addr.str());
518 channel->own_id_mentioned_ = true;
520 //dprintf("recvd %i bytes for %i\n",data.size(),channel->id);
526 void Channel::Loop (tint howlong) {
528 tint limit = Datagram::Time() + howlong;
532 tint send_time(TINT_NEVER);
533 Channel* sender(NULL);
534 while (!sender && !send_queue.is_empty()) { // dequeue
535 tintbin next = send_queue.pop();
536 sender = channel((int)next.bin);
537 send_time = next.time;
538 if (sender && sender->next_send_time_!=send_time &&
539 sender->next_send_time_!=TINT_NEVER )
540 sender = NULL; // it was a stale entry
543 if ( sender!=NULL && send_time<=NOW ) { // it's time
545 dprintf("%s #%u sch_send %s\n",tintstr(),sender->id(),
548 sender->Reschedule();
550 } else { // it's too early, wait
552 tint towait = min(limit,send_time) - NOW;
553 dprintf("%s #0 waiting %lliusec\n",tintstr(),towait);
554 int rd = Datagram::Wait(socket_count,sockets,towait);
555 if (rd!=INVALID_SOCKET) { // in meantime, received something
556 Channel* receiver = RecvDatagram(rd);
557 if (receiver) // receiver's state may have changed
558 receiver->Reschedule();
560 if (sender) // get back to that later
561 send_queue.push(tintbin(send_time,sender->id()));
570 void Channel::Close () {
571 this->SwitchSendControl(CLOSE_CONTROL);
575 void Channel::Reschedule () {
576 next_send_time_ = NextSendTime();
577 if (next_send_time_!=TINT_NEVER) {
578 assert(next_send_time_<NOW+TINT_MIN);
579 send_queue.push(tintbin(next_send_time_,id_));
580 dprintf("%s #%u requeue for %s\n",tintstr(),id_,tintstr(next_send_time_));
582 dprintf("%s #%u closed\n",tintstr(),id_);