src/PeerPoolMgr.cc

   1 /*
   2  * Copyright (C) 1996-2014 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 "base/AsyncJobCalls.h"
  11 #include "base/RunnersRegistry.h"
  12 #include "CachePeer.h"
  13 #include "comm/Connection.h"
  14 #include "comm/ConnOpener.h"
  15 #include "Debug.h"
  16 #include "fd.h"
  17 #include "FwdState.h"
  18 #include "globals.h"
  19 #include "HttpRequest.h"
  20 #include "neighbors.h"
  21 #include "pconn.h"
  22 #include "PeerPoolMgr.h"
  23 #include "SquidConfig.h"
  24 #include "SquidTime.h"
  25 #if USE_OPENSSL
  26 #include "ssl/PeerConnector.h"
  27 #endif
  28
  29 CBDATA_CLASS_INIT(PeerPoolMgr);
  30
  31 #if USE_OPENSSL
  32 /// Gives Ssl::PeerConnector access to Answer in the PeerPoolMgr callback dialer.
  33 class MyAnswerDialer: public UnaryMemFunT<PeerPoolMgr, Ssl::PeerConnectorAnswer, Ssl::PeerConnectorAnswer&>,
  34         public Ssl::PeerConnector::CbDialer
  35 {
  36 public:
  37     MyAnswerDialer(const JobPointer &aJob, Method aMethod):
  38             UnaryMemFunT<PeerPoolMgr, Ssl::PeerConnectorAnswer, Ssl::PeerConnectorAnswer&>(aJob, aMethod, Ssl::PeerConnectorAnswer()) {}
  39
  40     /* Ssl::PeerConnector::CbDialer API */
  41     virtual Ssl::PeerConnectorAnswer &answer() { return arg1; }
  42 };
  43 #endif
  44
  45 PeerPoolMgr::PeerPoolMgr(CachePeer *aPeer): AsyncJob("PeerPoolMgr"),
  46         peer(cbdataReference(aPeer)),
  47         request(),
  48         opener(),
  49         securer(),
  50         closer(),
  51         addrUsed(0)
  52 {
  53 }
  54
  55 PeerPoolMgr::~PeerPoolMgr()
  56 {
  57     cbdataReferenceDone(peer);
  58 }
  59
  60 void
  61 PeerPoolMgr::start()
  62 {
  63     AsyncJob::start();
  64
  65     // ErrorState, getOutgoingAddress(), and other APIs may require a request.
  66     // We fake one. TODO: Optionally send this request to peers?
  67     request = new HttpRequest(Http::METHOD_OPTIONS, AnyP::PROTO_HTTP, "*");
  68     request->SetHost(peer->host);
  69
  70     checkpoint("peer initialized");
  71 }
  72
  73 void
  74 PeerPoolMgr::swanSong()
  75 {
  76     AsyncJob::swanSong();
  77 }
  78
  79 bool
  80 PeerPoolMgr::validPeer() const
  81 {
  82     return peer && cbdataReferenceValid(peer) && peer->standby.pool;
  83 }
  84
  85 bool
  86 PeerPoolMgr::doneAll() const
  87 {
  88     return !(validPeer() && peer->standby.limit) && AsyncJob::doneAll();
  89 }
  90
  91 void
  92 PeerPoolMgr::handleOpenedConnection(const CommConnectCbParams &params)
  93 {
  94     opener = NULL;
  95
  96     if (!validPeer()) {
  97         debugs(48, 3, "peer gone");
  98         if (params.conn != NULL)
  99             params.conn->close();
 100         return;
 101     }
 102
 103     if (params.flag != Comm::OK) {
 104         /* it might have been a timeout with a partially open link */
 105         if (params.conn != NULL)
 106             params.conn->close();
 107         peerConnectFailed(peer);
 108         checkpoint("conn opening failure"); // may retry
 109         return;
 110     }
 111
 112     Must(params.conn != NULL);
 113
 114 #if USE_OPENSSL
 115     // Handle SSL peers.
 116     if (peer->use_ssl) {
 117         typedef CommCbMemFunT<PeerPoolMgr, CommCloseCbParams> CloserDialer;
 118         closer = JobCallback(48, 3, CloserDialer, this,
 119                              PeerPoolMgr::handleSecureClosure);
 120         comm_add_close_handler(params.conn->fd, closer);
 121
 122         securer = asyncCall(48, 4, "PeerPoolMgr::handleSecuredPeer",
 123                             MyAnswerDialer(this, &PeerPoolMgr::handleSecuredPeer));
 124
 125         const int peerTimeout = peer->connect_timeout > 0 ?
 126                                 peer->connect_timeout : Config.Timeout.peer_connect;
 127         const int timeUsed = squid_curtime - params.conn->startTime();
 128         // Use positive timeout when less than one second is left for conn.
 129         const int timeLeft = max(1, (peerTimeout - timeUsed));
 130         Ssl::PeerConnector *connector =
 131             new Ssl::PeerConnector(request, params.conn, NULL, securer, timeLeft);
 132         AsyncJob::Start(connector); // will call our callback
 133         return;
 134     }
 135 #endif
 136
 137     pushNewConnection(params.conn);
 138 }
 139
 140 void
 141 PeerPoolMgr::pushNewConnection(const Comm::ConnectionPointer &conn)
 142 {
 143     Must(validPeer());
 144     Must(Comm::IsConnOpen(conn));
 145     peer->standby.pool->push(conn, NULL /* domain */);
 146     // push() will trigger a checkpoint()
 147 }
 148
 149 #if USE_OPENSSL
 150 void
 151 PeerPoolMgr::handleSecuredPeer(Ssl::PeerConnectorAnswer &answer)
 152 {
 153     Must(securer != NULL);
 154     securer = NULL;
 155
 156     if (closer != NULL) {
 157         if (answer.conn != NULL)
 158             comm_remove_close_handler(answer.conn->fd, closer);
 159         else
 160             closer->cancel("securing completed");
 161         closer = NULL;
 162     }
 163
 164     if (!validPeer()) {
 165         debugs(48, 3, "peer gone");
 166         if (answer.conn != NULL)
 167             answer.conn->close();
 168         return;
 169     }
 170
 171     if (answer.error.get()) {
 172         if (answer.conn != NULL)
 173             answer.conn->close();
 174         // PeerConnector calls peerConnectFailed() for us;
 175         checkpoint("conn securing failure"); // may retry
 176         return;
 177     }
 178
 179     pushNewConnection(answer.conn);
 180 }
 181
 182 void
 183 PeerPoolMgr::handleSecureClosure(const CommCloseCbParams &params)
 184 {
 185     Must(closer != NULL);
 186     Must(securer != NULL);
 187     securer->cancel("conn closed by a 3rd party");
 188     securer = NULL;
 189     closer = NULL;
 190     // allow the closing connection to fully close before we check again
 191     Checkpoint(this, "conn closure while securing");
 192 }
 193 #endif
 194
 195 void
 196 PeerPoolMgr::openNewConnection()
 197 {
 198     // KISS: Do nothing else when we are already doing something.
 199     if (opener != NULL || securer != NULL || shutting_down) {
 200         debugs(48, 7, "busy: " << opener << '|' << securer << '|' << shutting_down);
 201         return; // there will be another checkpoint when we are done opening/securing
 202     }
 203
 204     // Do not talk to a peer until it is ready.
 205     if (!neighborUp(peer)) // provides debugging
 206         return; // there will be another checkpoint when peer is up
 207
 208     // Do not violate peer limits.
 209     if (!peerCanOpenMore(peer)) { // provides debugging
 210         peer->standby.waitingForClose = true; // may already be true
 211         return; // there will be another checkpoint when a peer conn closes
 212     }
 213
 214     // Do not violate global restrictions.
 215     if (fdUsageHigh()) {
 216         debugs(48, 7, "overwhelmed");
 217         peer->standby.waitingForClose = true; // may already be true
 218         // There will be another checkpoint when a peer conn closes OR when
 219         // a future pop() fails due to an empty pool. See PconnPool::pop().
 220         return;
 221     }
 222
 223     peer->standby.waitingForClose = false;
 224
 225     Comm::ConnectionPointer conn = new Comm::Connection;
 226     Must(peer->n_addresses); // guaranteed by neighborUp() above
 227     // cycle through all available IP addresses
 228     conn->remote = peer->addresses[addrUsed++ % peer->n_addresses];
 229     conn->remote.port(peer->http_port);
 230     conn->peerType = STANDBY_POOL; // should be reset by peerSelect()
 231     conn->setPeer(peer);
 232     getOutgoingAddress(request.getRaw(), conn);
 233     GetMarkingsToServer(request.getRaw(), *conn);
 234
 235     const int ctimeout = peer->connect_timeout > 0 ?
 236                          peer->connect_timeout : Config.Timeout.peer_connect;
 237     typedef CommCbMemFunT<PeerPoolMgr, CommConnectCbParams> Dialer;
 238     opener = JobCallback(48, 5, Dialer, this, PeerPoolMgr::handleOpenedConnection);
 239     Comm::ConnOpener *cs = new Comm::ConnOpener(conn, opener, ctimeout);
 240     AsyncJob::Start(cs);
 241 }
 242
 243 void
 244 PeerPoolMgr::closeOldConnections(const int howMany)
 245 {
 246     debugs(48, 8, howMany);
 247     peer->standby.pool->closeN(howMany);
 248 }
 249
 250 void
 251 PeerPoolMgr::checkpoint(const char *reason)
 252 {
 253     if (!validPeer()) {
 254         debugs(48, 3, reason << " and peer gone");
 255         return; // nothing to do after our owner dies; the job will quit
 256     }
 257
 258     const int count = peer->standby.pool->count();
 259     const int limit = peer->standby.limit;
 260     debugs(48, 7, reason << " with " << count << " ? " << limit);
 261
 262     if (count < limit)
 263         openNewConnection();
 264     else if (count > limit)
 265         closeOldConnections(count - limit);
 266 }
 267
 268 void
 269 PeerPoolMgr::Checkpoint(const Pointer &mgr, const char *reason)
 270 {
 271     CallJobHere1(48, 5, mgr, PeerPoolMgr, checkpoint, reason);
 272 }
 273
 274 /// launches PeerPoolMgrs for peers configured with standby.limit
 275 class PeerPoolMgrsRr: public RegisteredRunner
 276 {
 277 public:
 278     /* RegisteredRunner API */
 279     virtual void useConfig() { syncConfig(); }
 280     virtual void syncConfig();
 281 };
 282
 283 RunnerRegistrationEntry(PeerPoolMgrsRr);
 284
 285 void
 286 PeerPoolMgrsRr::syncConfig()
 287 {
 288     for (CachePeer *p = Config.peers; p; p = p->next) {
 289         // On reconfigure, Squid deletes the old config (and old peers in it),
 290         // so should always be dealing with a brand new configuration.
 291         assert(!p->standby.mgr);
 292         assert(!p->standby.pool);
 293         if (p->standby.limit) {
 294             p->standby.mgr = new PeerPoolMgr(p);
 295             p->standby.pool = new PconnPool(p->name, p->standby.mgr);
 296             AsyncJob::Start(p->standby.mgr.get());
 297         }
 298     }
 299 }