src/adaptation/icap/ModXact.h

   1
   2 /*
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  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
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  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  29  *
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  31
  32 #ifndef SQUID_ICAPMODXACT_H
  33 #define SQUID_ICAPMODXACT_H
  34
  35 #include "AccessLogEntry.h"
  36 #include "adaptation/icap/InOut.h"
  37 #include "adaptation/icap/Launcher.h"
  38 #include "adaptation/icap/Xaction.h"
  39 #include "BodyPipe.h"
  40
  41 /*
  42  * ICAPModXact implements ICAP REQMOD and RESPMOD transaction using
  43  * ICAPXaction as the base. The ICAPModXact receives a virgin HTTP message
  44  * from an ICAP vecoring point, (a.k.a., initiator), communicates with the
  45  * ICAP server, and sends the adapted HTTP message headers back.
  46  * Virgin/adapted HTTP message body is reveived/sent using BodyPipe
  47  * interface. The initiator (or its associate) is expected to send and/or
  48  * receive the HTTP body.
  49  */
  50
  51 class ChunkedCodingParser;
  52
  53 namespace Adaptation
  54 {
  55 namespace Icap
  56 {
  57
  58 // estimated future presence and size of something (e.g., HTTP body)
  59
  60 class SizedEstimate
  61 {
  62
  63 public:
  64     SizedEstimate(); // not expected by default
  65     void expect(int64_t aSize); // expect with any, even unknown size
  66     bool expected() const;
  67
  68     /* other members can be accessed iff expected() */
  69
  70     bool knownSize() const;
  71     uint64_t size() const; // can be accessed iff knownSize()
  72
  73 private:
  74     enum { dtUnexpected = -2, dtUnknown = -1 };
  75     int64_t theData; // combines expectation and size info to save RAM
  76 };
  77
  78 // Virgin body may be used for two activities: (a) writing preview or prime
  79 // body to the ICAP server and (b) sending the body back in the echo mode.
  80 // Both activities use the same BodyPipe and may be active at the same time.
  81 // This class is used to maintain the state of body writing or sending
  82 // activity and to coordinate consumption of the shared virgin body buffer.
  83 class VirginBodyAct
  84 {
  85
  86 public:
  87     VirginBodyAct();
  88
  89     void plan(); // the activity may happen; do not consume at or above offset
  90     void disable(); // the activity wont continue; no consumption restrictions
  91
  92     bool active() const { return theState == stActive; }
  93     bool disabled() const { return theState == stDisabled; }
  94
  95     // methods below require active()
  96
  97     uint64_t offset() const; // the absolute beginning of not-yet-acted-on data
  98     void progress(size_t size); // note processed body bytes
  99
 100 private:
 101     int64_t theStart; // unprocessed virgin body data offset
 102
 103     typedef enum { stUndecided, stActive, stDisabled } State;
 104     State theState;
 105 };
 106
 107 // maintains preview-related sizes
 108
 109 class Preview
 110 {
 111
 112 public:
 113     Preview();            // disabled
 114     void enable(size_t anAd); // enabled with advertised size
 115     bool enabled() const;
 116
 117     /* other members can be accessed iff enabled() */
 118
 119     size_t ad() const;      // advertised preview size
 120     size_t debt() const;    // remains to write
 121     bool done() const;      // wrote everything
 122     bool ieof() const;      // premature EOF
 123
 124     void wrote(size_t size, bool wroteEof);
 125
 126 private:
 127     size_t theWritten;
 128     size_t theAd;
 129     enum State { stDisabled, stWriting, stIeof, stDone } theState;
 130 };
 131
 132 class ModXact: public Xaction, public BodyProducer, public BodyConsumer
 133 {
 134
 135 public:
 136     ModXact(HttpMsg *virginHeader, HttpRequest *virginCause, AccessLogEntry::Pointer &alp, ServiceRep::Pointer &s);
 137     virtual ~ModXact();
 138
 139     // BodyProducer methods
 140     virtual void noteMoreBodySpaceAvailable(BodyPipe::Pointer);
 141     virtual void noteBodyConsumerAborted(BodyPipe::Pointer);
 142
 143     // BodyConsumer methods
 144     virtual void noteMoreBodyDataAvailable(BodyPipe::Pointer);
 145     virtual void noteBodyProductionEnded(BodyPipe::Pointer);
 146     virtual void noteBodyProducerAborted(BodyPipe::Pointer);
 147
 148     // comm handlers
 149     virtual void handleCommConnected();
 150     virtual void handleCommWrote(size_t size);
 151     virtual void handleCommRead(size_t size);
 152     void handleCommWroteHeaders();
 153     void handleCommWroteBody();
 154
 155     // service waiting
 156     void noteServiceReady();
 157     void noteServiceAvailable();
 158
 159 public:
 160     InOut virgin;
 161     InOut adapted;
 162
 163     // bypasses exceptions if needed and possible
 164     virtual void callException(const std::exception &e);
 165
 166     /// record error detail in the virgin request if possible
 167     virtual void detailError(int errDetail);
 168     // Icap::Xaction API
 169     virtual void clearError();
 170
 171 private:
 172     virtual void start();
 173
 174     /// locates the request, either as a cause or as a virgin message itself
 175     const HttpRequest &virginRequest() const; // Must always be available
 176
 177     void estimateVirginBody();
 178     void makeAdaptedBodyPipe(const char *what);
 179
 180     void waitForService();
 181
 182     // will not send anything [else] on the adapted pipe
 183     bool doneSending() const;
 184
 185     void startWriting();
 186     void writeMore();
 187     void writePreviewBody();
 188     void writePrimeBody();
 189     void writeSomeBody(const char *label, size_t size);
 190     void decideWritingAfterPreview(const char *previewKind);
 191
 192     void startReading();
 193     void readMore();
 194     virtual bool doneReading() const { return commEof || state.doneParsing(); }
 195     virtual bool doneWriting() const { return state.doneWriting(); }
 196
 197     size_t virginContentSize(const VirginBodyAct &act) const;
 198     const char *virginContentData(const VirginBodyAct &act) const;
 199     bool virginBodyEndReached(const VirginBodyAct &act) const;
 200
 201     void makeRequestHeaders(MemBuf &buf);
 202     void makeAllowHeader(MemBuf &buf);
 203     void makeUsernameHeader(const HttpRequest *request, MemBuf &buf);
 204     void addLastRequestChunk(MemBuf &buf);
 205     void openChunk(MemBuf &buf, size_t chunkSize, bool ieof);
 206     void closeChunk(MemBuf &buf);
 207     void virginConsume();
 208     void finishNullOrEmptyBodyPreview(MemBuf &buf);
 209
 210     void decideOnPreview();
 211     void decideOnRetries();
 212     bool shouldAllow204();
 213     bool shouldAllow206any();
 214     bool shouldAllow206in();
 215     bool shouldAllow206out();
 216     bool canBackupEverything() const;
 217
 218     void prepBackup(size_t expectedSize);
 219     void backup(const MemBuf &buf);
 220
 221     void parseMore();
 222
 223     void parseHeaders();
 224     void parseIcapHead();
 225     void parseHttpHead();
 226     bool parseHead(HttpMsg *head);
 227
 228     void decideOnParsingBody();
 229     void parseBody();
 230     void maybeAllocateHttpMsg();
 231
 232     void handle100Continue();
 233     bool validate200Ok();
 234     void handle200Ok();
 235     void handle204NoContent();
 236     void handle206PartialContent();
 237     void handleUnknownScode();
 238
 239     void bypassFailure();
 240
 241     void startSending();
 242     void disableBypass(const char *reason, bool includeGroupBypass);
 243
 244     void prepEchoing();
 245     void prepPartialBodyEchoing(uint64_t pos);
 246     void echoMore();
 247
 248     virtual bool doneAll() const;
 249     virtual void swanSong();
 250
 251     void stopReceiving();
 252     void stopSending(bool nicely);
 253     void stopWriting(bool nicely);
 254     void stopParsing();
 255     void stopBackup();
 256
 257     virtual void fillPendingStatus(MemBuf &buf) const;
 258     virtual void fillDoneStatus(MemBuf &buf) const;
 259     virtual bool fillVirginHttpHeader(MemBuf&) const;
 260
 261 private:
 262     void packHead(MemBuf &httpBuf, const HttpMsg *head);
 263     void encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head);
 264     bool gotEncapsulated(const char *section) const;
 265     void checkConsuming();
 266
 267     virtual void finalizeLogInfo();
 268
 269     SizedEstimate virginBody;
 270     VirginBodyAct virginBodyWriting; // virgin body writing state
 271     VirginBodyAct virginBodySending;  // virgin body sending state
 272     uint64_t virginConsumed;        // virgin data consumed so far
 273     Preview preview; // use for creating (writing) the preview
 274
 275     ChunkedCodingParser *bodyParser; // ICAP response body parser
 276
 277     bool canStartBypass; // enables bypass of transaction failures
 278     bool protectGroupBypass; // protects ServiceGroup-wide bypass of failures
 279
 280     /**
 281      * size of HTTP header in ICAP reply or -1 if there is not any encapsulated
 282      * message data
 283      */
 284     int64_t replyHttpHeaderSize;
 285     /**
 286      * size of dechunked HTTP body in ICAP reply or -1 if there is not any
 287      * encapsulated message data
 288      */
 289     int64_t replyHttpBodySize;
 290
 291     int adaptHistoryId; ///< adaptation history slot reservation
 292
 293     class State
 294     {
 295
 296     public:
 297         State();
 298
 299     public:
 300
 301         bool serviceWaiting; // waiting for ICAP service options
 302         bool allowedPostview204; // mmust handle 204 No Content outside preview
 303         bool allowedPostview206; // must handle 206 Partial Content outside preview
 304         bool allowedPreview206; // must handle 206 Partial Content inside preview
 305         bool readyForUob; ///< got a 206 response and expect a use-origin-body
 306         bool waitedForService; ///< true if was queued at least once
 307
 308         // will not write anything [else] to the ICAP server connection
 309         bool doneWriting() const { return writing == writingReallyDone; }
 310
 311         // will not use virgin.body_pipe
 312         bool doneConsumingVirgin() const {
 313             return writing >= writingAlmostDone
 314                    && ((sending == sendingAdapted && !readyForUob) ||
 315                        sending == sendingDone);
 316         }
 317
 318         // parsed entire ICAP response from the ICAP server
 319         bool doneParsing() const { return parsing == psDone; }
 320
 321         // is parsing ICAP or HTTP headers read from the ICAP server
 322         bool parsingHeaders() const {
 323             return parsing == psIcapHeader ||
 324                    parsing == psHttpHeader;
 325         }
 326
 327         enum Parsing { psIcapHeader, psHttpHeader, psBody, psDone } parsing;
 328
 329         // measures ICAP request writing progress
 330         enum Writing { writingInit, writingConnect, writingHeaders,
 331                        writingPreview, writingPaused, writingPrime,
 332                        writingAlmostDone, // waiting for the last write() call to finish
 333                        writingReallyDone
 334                      } writing;
 335
 336         enum Sending { sendingUndecided, sendingVirgin, sendingAdapted,
 337                        sendingDone
 338                      } sending;
 339     } state;
 340
 341     AccessLogEntry::Pointer alMaster; ///< Master transaction AccessLogEntry
 342     CBDATA_CLASS2(ModXact);
 343 };
 344
 345 // An Launcher that stores ModXact construction info and
 346 // creates ModXact when needed
 347 class ModXactLauncher: public Launcher
 348 {
 349 public:
 350     ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, AccessLogEntry::Pointer &alp, Adaptation::ServicePointer s);
 351
 352 protected:
 353     virtual Xaction *createXaction();
 354
 355     virtual void swanSong();
 356
 357     /// starts or stops transaction accounting in ICAP history
 358     void updateHistory(bool start);
 359
 360     InOut virgin;
 361
 362     AccessLogEntry::Pointer al;
 363
 364 private:
 365     CBDATA_CLASS2(ModXactLauncher);
 366 };
 367
 368 } // namespace Icap
 369 } // namespace Adaptation
 370
 371 #endif /* SQUID_ICAPMOD_XACT_H */