src/PeerPoolMgr.cc

   1 /*
   2  * Copyright (C) 1996-2016 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "AccessLogEntry.h"
  11 #include "base/AsyncJobCalls.h"
  12 #include "base/RunnersRegistry.h"
  13 #include "CachePeer.h"
  14 #include "comm/Connection.h"
  15 #include "comm/ConnOpener.h"
  16 #include "Debug.h"
  17 #include "fd.h"
  18 #include "FwdState.h"
  19 #include "globals.h"
  20 #include "HttpRequest.h"
  21 #include "neighbors.h"
  22 #include "pconn.h"
  23 #include "PeerPoolMgr.h"
  24 #include "security/BlindPeerConnector.h"
  25 #include "SquidConfig.h"
  26 #include "SquidTime.h"
  27
  28 CBDATA_CLASS_INIT(PeerPoolMgr);
  29
  30 /// Gives Security::PeerConnector access to Answer in the PeerPoolMgr callback dialer.
  31 class MyAnswerDialer: public UnaryMemFunT<PeerPoolMgr, Security::EncryptorAnswer, Security::EncryptorAnswer&>,
  32     public Security::PeerConnector::CbDialer
  33 {
  34 public:
  35     MyAnswerDialer(const JobPointer &aJob, Method aMethod):
  36         UnaryMemFunT<PeerPoolMgr, Security::EncryptorAnswer, Security::EncryptorAnswer&>(aJob, aMethod, Security::EncryptorAnswer()) {}
  37
  38     /* Security::PeerConnector::CbDialer API */
  39     virtual Security::EncryptorAnswer &answer() { return arg1; }
  40 };
  41
  42 PeerPoolMgr::PeerPoolMgr(CachePeer *aPeer): AsyncJob("PeerPoolMgr"),
  43     peer(cbdataReference(aPeer)),
  44     request(),
  45     opener(),
  46     securer(),
  47     closer(),
  48     addrUsed(0)
  49 {
  50 }
  51
  52 PeerPoolMgr::~PeerPoolMgr()
  53 {
  54     cbdataReferenceDone(peer);
  55 }
  56
  57 void
  58 PeerPoolMgr::start()
  59 {
  60     AsyncJob::start();
  61
  62     // ErrorState, getOutgoingAddress(), and other APIs may require a request.
  63     // We fake one. TODO: Optionally send this request to peers?
  64     request = new HttpRequest(Http::METHOD_OPTIONS, AnyP::PROTO_HTTP, "*");
  65     request->url.host(peer->host);
  66
  67     checkpoint("peer initialized");
  68 }
  69
  70 void
  71 PeerPoolMgr::swanSong()
  72 {
  73     AsyncJob::swanSong();
  74 }
  75
  76 bool
  77 PeerPoolMgr::validPeer() const
  78 {
  79     return peer && cbdataReferenceValid(peer) && peer->standby.pool;
  80 }
  81
  82 bool
  83 PeerPoolMgr::doneAll() const
  84 {
  85     return !(validPeer() && peer->standby.limit) && AsyncJob::doneAll();
  86 }
  87
  88 void
  89 PeerPoolMgr::handleOpenedConnection(const CommConnectCbParams &params)
  90 {
  91     opener = NULL;
  92
  93     if (!validPeer()) {
  94         debugs(48, 3, "peer gone");
  95         if (params.conn != NULL)
  96             params.conn->close();
  97         return;
  98     }
  99
 100     if (params.flag != Comm::OK) {
 101         /* it might have been a timeout with a partially open link */
 102         if (params.conn != NULL)
 103             params.conn->close();
 104         peerConnectFailed(peer);
 105         checkpoint("conn opening failure"); // may retry
 106         return;
 107     }
 108
 109     Must(params.conn != NULL);
 110
 111     // Handle TLS peers.
 112     if (peer->secure.encryptTransport) {
 113         typedef CommCbMemFunT<PeerPoolMgr, CommCloseCbParams> CloserDialer;
 114         closer = JobCallback(48, 3, CloserDialer, this,
 115                              PeerPoolMgr::handleSecureClosure);
 116         comm_add_close_handler(params.conn->fd, closer);
 117
 118         securer = asyncCall(48, 4, "PeerPoolMgr::handleSecuredPeer",
 119                             MyAnswerDialer(this, &PeerPoolMgr::handleSecuredPeer));
 120
 121         const int peerTimeout = peer->connect_timeout > 0 ?
 122                                 peer->connect_timeout : Config.Timeout.peer_connect;
 123         const int timeUsed = squid_curtime - params.conn->startTime();
 124         // Use positive timeout when less than one second is left for conn.
 125         const int timeLeft = max(1, (peerTimeout - timeUsed));
 126         auto *connector = new Security::BlindPeerConnector(request, params.conn, securer, nullptr, timeLeft);
 127         AsyncJob::Start(connector); // will call our callback
 128         return;
 129     }
 130
 131     pushNewConnection(params.conn);
 132 }
 133
 134 void
 135 PeerPoolMgr::pushNewConnection(const Comm::ConnectionPointer &conn)
 136 {
 137     Must(validPeer());
 138     Must(Comm::IsConnOpen(conn));
 139     peer->standby.pool->push(conn, NULL /* domain */);
 140     // push() will trigger a checkpoint()
 141 }
 142
 143 void
 144 PeerPoolMgr::handleSecuredPeer(Security::EncryptorAnswer &answer)
 145 {
 146     Must(securer != NULL);
 147     securer = NULL;
 148
 149     if (closer != NULL) {
 150         if (answer.conn != NULL)
 151             comm_remove_close_handler(answer.conn->fd, closer);
 152         else
 153             closer->cancel("securing completed");
 154         closer = NULL;
 155     }
 156
 157     if (!validPeer()) {
 158         debugs(48, 3, "peer gone");
 159         if (answer.conn != NULL)
 160             answer.conn->close();
 161         return;
 162     }
 163
 164     if (answer.error.get()) {
 165         if (answer.conn != NULL)
 166             answer.conn->close();
 167         // PeerConnector calls peerConnectFailed() for us;
 168         checkpoint("conn securing failure"); // may retry
 169         return;
 170     }
 171
 172     pushNewConnection(answer.conn);
 173 }
 174
 175 void
 176 PeerPoolMgr::handleSecureClosure(const CommCloseCbParams &params)
 177 {
 178     Must(closer != NULL);
 179     Must(securer != NULL);
 180     securer->cancel("conn closed by a 3rd party");
 181     securer = NULL;
 182     closer = NULL;
 183     // allow the closing connection to fully close before we check again
 184     Checkpoint(this, "conn closure while securing");
 185 }
 186
 187 void
 188 PeerPoolMgr::openNewConnection()
 189 {
 190     // KISS: Do nothing else when we are already doing something.
 191     if (opener != NULL || securer != NULL || shutting_down) {
 192         debugs(48, 7, "busy: " << opener << '|' << securer << '|' << shutting_down);
 193         return; // there will be another checkpoint when we are done opening/securing
 194     }
 195
 196     // Do not talk to a peer until it is ready.
 197     if (!neighborUp(peer)) // provides debugging
 198         return; // there will be another checkpoint when peer is up
 199
 200     // Do not violate peer limits.
 201     if (!peerCanOpenMore(peer)) { // provides debugging
 202         peer->standby.waitingForClose = true; // may already be true
 203         return; // there will be another checkpoint when a peer conn closes
 204     }
 205
 206     // Do not violate global restrictions.
 207     if (fdUsageHigh()) {
 208         debugs(48, 7, "overwhelmed");
 209         peer->standby.waitingForClose = true; // may already be true
 210         // There will be another checkpoint when a peer conn closes OR when
 211         // a future pop() fails due to an empty pool. See PconnPool::pop().
 212         return;
 213     }
 214
 215     peer->standby.waitingForClose = false;
 216
 217     Comm::ConnectionPointer conn = new Comm::Connection;
 218     Must(peer->n_addresses); // guaranteed by neighborUp() above
 219     // cycle through all available IP addresses
 220     conn->remote = peer->addresses[addrUsed++ % peer->n_addresses];
 221     conn->remote.port(peer->http_port);
 222     conn->peerType = STANDBY_POOL; // should be reset by peerSelect()
 223     conn->setPeer(peer);
 224     getOutgoingAddress(request.getRaw(), conn);
 225     GetMarkingsToServer(request.getRaw(), *conn);
 226
 227     const int ctimeout = peer->connect_timeout > 0 ?
 228                          peer->connect_timeout : Config.Timeout.peer_connect;
 229     typedef CommCbMemFunT<PeerPoolMgr, CommConnectCbParams> Dialer;
 230     opener = JobCallback(48, 5, Dialer, this, PeerPoolMgr::handleOpenedConnection);
 231     Comm::ConnOpener *cs = new Comm::ConnOpener(conn, opener, ctimeout);
 232     AsyncJob::Start(cs);
 233 }
 234
 235 void
 236 PeerPoolMgr::closeOldConnections(const int howMany)
 237 {
 238     debugs(48, 8, howMany);
 239     peer->standby.pool->closeN(howMany);
 240 }
 241
 242 void
 243 PeerPoolMgr::checkpoint(const char *reason)
 244 {
 245     if (!validPeer()) {
 246         debugs(48, 3, reason << " and peer gone");
 247         return; // nothing to do after our owner dies; the job will quit
 248     }
 249
 250     const int count = peer->standby.pool->count();
 251     const int limit = peer->standby.limit;
 252     debugs(48, 7, reason << " with " << count << " ? " << limit);
 253
 254     if (count < limit)
 255         openNewConnection();
 256     else if (count > limit)
 257         closeOldConnections(count - limit);
 258 }
 259
 260 void
 261 PeerPoolMgr::Checkpoint(const Pointer &mgr, const char *reason)
 262 {
 263     CallJobHere1(48, 5, mgr, PeerPoolMgr, checkpoint, reason);
 264 }
 265
 266 /// launches PeerPoolMgrs for peers configured with standby.limit
 267 class PeerPoolMgrsRr: public RegisteredRunner
 268 {
 269 public:
 270     /* RegisteredRunner API */
 271     virtual void useConfig() { syncConfig(); }
 272     virtual void syncConfig();
 273 };
 274
 275 RunnerRegistrationEntry(PeerPoolMgrsRr);
 276
 277 void
 278 PeerPoolMgrsRr::syncConfig()
 279 {
 280     for (CachePeer *p = Config.peers; p; p = p->next) {
 281         // On reconfigure, Squid deletes the old config (and old peers in it),
 282         // so should always be dealing with a brand new configuration.
 283         assert(!p->standby.mgr);
 284         assert(!p->standby.pool);
 285         if (p->standby.limit) {
 286             p->standby.mgr = new PeerPoolMgr(p);
 287             p->standby.pool = new PconnPool(p->name, p->standby.mgr);
 288             AsyncJob::Start(p->standby.mgr.get());
 289         }
 290     }
 291 }
 292