src/HttpReply.cc

   1 /*
   2  * Copyright (C) 1996-2017 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 /* DEBUG: section 58    HTTP Reply (Response) */
  10
  11 #include "squid.h"
  12 #include "acl/AclSizeLimit.h"
  13 #include "acl/FilledChecklist.h"
  14 #include "base/EnumIterator.h"
  15 #include "globals.h"
  16 #include "HttpBody.h"
  17 #include "HttpHdrCc.h"
  18 #include "HttpHdrContRange.h"
  19 #include "HttpHdrSc.h"
  20 #include "HttpReply.h"
  21 #include "HttpRequest.h"
  22 #include "MemBuf.h"
  23 #include "SquidConfig.h"
  24 #include "SquidTime.h"
  25 #include "Store.h"
  26 #include "StrList.h"
  27
  28 HttpReply::HttpReply() : Http::Message(hoReply), date (0), last_modified (0),
  29     expires (0), surrogate_control (NULL), content_range (NULL), keep_alive (0),
  30     protoPrefix("HTTP/"), bodySizeMax(-2)
  31 {
  32     init();
  33 }
  34
  35 HttpReply::~HttpReply()
  36 {
  37     if (do_clean)
  38         clean();
  39 }
  40
  41 void
  42 HttpReply::init()
  43 {
  44     hdrCacheInit();
  45     sline.init();
  46     pstate = Http::Message::psReadyToParseStartLine;
  47     do_clean = true;
  48 }
  49
  50 void HttpReply::reset()
  51 {
  52
  53     // reset should not reset the protocol; could have made protoPrefix a
  54     // virtual function instead, but it is not clear whether virtual methods
  55     // are allowed with MEMPROXY_CLASS() and whether some cbdata void*
  56     // conversions are not going to kill virtual tables
  57     const String pfx = protoPrefix;
  58     clean();
  59     init();
  60     protoPrefix = pfx;
  61 }
  62
  63 void
  64 HttpReply::clean()
  65 {
  66     // we used to assert that the pipe is NULL, but now the message only
  67     // points to a pipe that is owned and initiated by another object.
  68     body_pipe = NULL;
  69
  70     body.clear();
  71     hdrCacheClean();
  72     header.clean();
  73     sline.clean();
  74     bodySizeMax = -2; // hack: make calculatedBodySizeMax() false
  75 }
  76
  77 void
  78 HttpReply::packHeadersInto(Packable * p) const
  79 {
  80     sline.packInto(p);
  81     header.packInto(p);
  82     p->append("\r\n", 2);
  83 }
  84
  85 void
  86 HttpReply::packInto(Packable * p) const
  87 {
  88     packHeadersInto(p);
  89     body.packInto(p);
  90 }
  91
  92 /* create memBuf, create mem-based packer, pack, destroy packer, return MemBuf */
  93 MemBuf *
  94 HttpReply::pack() const
  95 {
  96     MemBuf *mb = new MemBuf;
  97     mb->init();
  98     packInto(mb);
  99     return mb;
 100 }
 101
 102 HttpReply *
 103 HttpReply::make304() const
 104 {
 105     static const Http::HdrType ImsEntries[] = {Http::HdrType::DATE, Http::HdrType::CONTENT_TYPE, Http::HdrType::EXPIRES, Http::HdrType::LAST_MODIFIED, /* eof */ Http::HdrType::OTHER};
 106
 107     HttpReply *rv = new HttpReply;
 108     int t;
 109     HttpHeaderEntry *e;
 110
 111     /* rv->content_length; */
 112     rv->date = date;
 113     rv->last_modified = last_modified;
 114     rv->expires = expires;
 115     rv->content_type = content_type;
 116     /* rv->content_range */
 117     /* rv->keep_alive */
 118     rv->sline.set(Http::ProtocolVersion(), Http::scNotModified, NULL);
 119
 120     for (t = 0; ImsEntries[t] != Http::HdrType::OTHER; ++t) {
 121         if ((e = header.findEntry(ImsEntries[t])))
 122             rv->header.addEntry(e->clone());
 123     }
 124
 125     rv->putCc(cache_control);
 126
 127     /* rv->body */
 128     return rv;
 129 }
 130
 131 MemBuf *
 132 HttpReply::packed304Reply() const
 133 {
 134     /* Not as efficient as skipping the header duplication,
 135      * but easier to maintain
 136      */
 137     HttpReply *temp = make304();
 138     MemBuf *rv = temp->pack();
 139     delete temp;
 140     return rv;
 141 }
 142
 143 void
 144 HttpReply::setHeaders(Http::StatusCode status, const char *reason,
 145                       const char *ctype, int64_t clen, time_t lmt, time_t expiresTime)
 146 {
 147     HttpHeader *hdr;
 148     sline.set(Http::ProtocolVersion(), status, reason);
 149     hdr = &header;
 150     hdr->putStr(Http::HdrType::SERVER, visible_appname_string);
 151     hdr->putStr(Http::HdrType::MIME_VERSION, "1.0");
 152     hdr->putTime(Http::HdrType::DATE, squid_curtime);
 153
 154     if (ctype) {
 155         hdr->putStr(Http::HdrType::CONTENT_TYPE, ctype);
 156         content_type = ctype;
 157     } else
 158         content_type = String();
 159
 160     if (clen >= 0)
 161         hdr->putInt64(Http::HdrType::CONTENT_LENGTH, clen);
 162
 163     if (expiresTime >= 0)
 164         hdr->putTime(Http::HdrType::EXPIRES, expiresTime);
 165
 166     if (lmt > 0)        /* this used to be lmt != 0 @?@ */
 167         hdr->putTime(Http::HdrType::LAST_MODIFIED, lmt);
 168
 169     date = squid_curtime;
 170
 171     content_length = clen;
 172
 173     expires = expiresTime;
 174
 175     last_modified = lmt;
 176 }
 177
 178 void
 179 HttpReply::redirect(Http::StatusCode status, const char *loc)
 180 {
 181     HttpHeader *hdr;
 182     sline.set(Http::ProtocolVersion(), status, NULL);
 183     hdr = &header;
 184     hdr->putStr(Http::HdrType::SERVER, APP_FULLNAME);
 185     hdr->putTime(Http::HdrType::DATE, squid_curtime);
 186     hdr->putInt64(Http::HdrType::CONTENT_LENGTH, 0);
 187     hdr->putStr(Http::HdrType::LOCATION, loc);
 188     date = squid_curtime;
 189     content_length = 0;
 190 }
 191
 192 /* compare the validators of two replies.
 193  * 1 = they match
 194  * 0 = they do not match
 195  */
 196 int
 197 HttpReply::validatorsMatch(HttpReply const * otherRep) const
 198 {
 199     String one,two;
 200     assert (otherRep);
 201     /* Numbers first - easiest to check */
 202     /* Content-Length */
 203     /* TODO: remove -1 bypass */
 204
 205     if (content_length != otherRep->content_length
 206             && content_length > -1 &&
 207             otherRep->content_length > -1)
 208         return 0;
 209
 210     /* ETag */
 211     one = header.getStrOrList(Http::HdrType::ETAG);
 212
 213     two = otherRep->header.getStrOrList(Http::HdrType::ETAG);
 214
 215     if (one.size()==0 || two.size()==0 || one.caseCmp(two)!=0 ) {
 216         one.clean();
 217         two.clean();
 218         return 0;
 219     }
 220
 221     if (last_modified != otherRep->last_modified)
 222         return 0;
 223
 224     /* MD5 */
 225     one = header.getStrOrList(Http::HdrType::CONTENT_MD5);
 226
 227     two = otherRep->header.getStrOrList(Http::HdrType::CONTENT_MD5);
 228
 229     if (one.size()==0 || two.size()==0 || one.caseCmp(two)!=0 ) {
 230         one.clean();
 231         two.clean();
 232         return 0;
 233     }
 234
 235     return 1;
 236 }
 237
 238 bool
 239 HttpReply::updateOnNotModified(HttpReply const * freshRep)
 240 {
 241     assert(freshRep);
 242
 243     /* update raw headers */
 244     if (!header.update(&freshRep->header))
 245         return false;
 246
 247     /* clean cache */
 248     hdrCacheClean();
 249
 250     header.compact();
 251     /* init cache */
 252     hdrCacheInit();
 253
 254     return true;
 255 }
 256
 257 /* internal routines */
 258
 259 time_t
 260 HttpReply::hdrExpirationTime()
 261 {
 262     /* The s-maxage and max-age directive takes priority over Expires */
 263
 264     if (cache_control) {
 265         int maxAge = -1;
 266         /*
 267          * Conservatively handle the case when we have a max-age
 268          * header, but no Date for reference?
 269          */
 270         if (cache_control->hasSMaxAge(&maxAge) || cache_control->hasMaxAge(&maxAge))
 271             return (date >= 0) ? date + maxAge : squid_curtime;
 272     }
 273
 274     if (Config.onoff.vary_ignore_expire &&
 275             header.has(Http::HdrType::VARY)) {
 276         const time_t d = header.getTime(Http::HdrType::DATE);
 277         const time_t e = header.getTime(Http::HdrType::EXPIRES);
 278
 279         if (d == e)
 280             return -1;
 281     }
 282
 283     if (header.has(Http::HdrType::EXPIRES)) {
 284         const time_t e = header.getTime(Http::HdrType::EXPIRES);
 285         /*
 286          * HTTP/1.0 says that robust implementations should consider
 287          * bad or malformed Expires header as equivalent to "expires
 288          * immediately."
 289          */
 290         return e < 0 ? squid_curtime : e;
 291     }
 292
 293     return -1;
 294 }
 295
 296 /* sync this routine when you update HttpReply struct */
 297 void
 298 HttpReply::hdrCacheInit()
 299 {
 300     Http::Message::hdrCacheInit();
 301
 302     http_ver = sline.version;
 303     content_length = header.getInt64(Http::HdrType::CONTENT_LENGTH);
 304     date = header.getTime(Http::HdrType::DATE);
 305     last_modified = header.getTime(Http::HdrType::LAST_MODIFIED);
 306     surrogate_control = header.getSc();
 307     content_range = header.getContRange();
 308     keep_alive = persistent() ? 1 : 0;
 309     const char *str = header.getStr(Http::HdrType::CONTENT_TYPE);
 310
 311     if (str)
 312         content_type.limitInit(str, strcspn(str, ";\t "));
 313     else
 314         content_type = String();
 315
 316     /* be sure to set expires after date and cache-control */
 317     expires = hdrExpirationTime();
 318 }
 319
 320 /* sync this routine when you update HttpReply struct */
 321 void
 322 HttpReply::hdrCacheClean()
 323 {
 324     content_type.clean();
 325
 326     if (cache_control) {
 327         delete cache_control;
 328         cache_control = NULL;
 329     }
 330
 331     if (surrogate_control) {
 332         delete surrogate_control;
 333         surrogate_control = NULL;
 334     }
 335
 336     if (content_range) {
 337         delete content_range;
 338         content_range = NULL;
 339     }
 340 }
 341
 342 /*
 343  * Returns the body size of a HTTP response
 344  */
 345 int64_t
 346 HttpReply::bodySize(const HttpRequestMethod& method) const
 347 {
 348     if (sline.version.major < 1)
 349         return -1;
 350     else if (method.id() == Http::METHOD_HEAD)
 351         return 0;
 352     else if (sline.status() == Http::scOkay)
 353         (void) 0;       /* common case, continue */
 354     else if (sline.status() == Http::scNoContent)
 355         return 0;
 356     else if (sline.status() == Http::scNotModified)
 357         return 0;
 358     else if (sline.status() < Http::scOkay)
 359         return 0;
 360
 361     return content_length;
 362 }
 363
 364 /**
 365  * Checks the first line of an HTTP Reply is valid.
 366  * currently only checks "HTTP/" exists.
 367  *
 368  * NP: not all error cases are detected yet. Some are left for detection later in parse.
 369  */
 370 bool
 371 HttpReply::sanityCheckStartLine(const char *buf, const size_t hdr_len, Http::StatusCode *error)
 372 {
 373     // hack warning: using psize instead of size here due to type mismatches with MemBuf.
 374
 375     // content is long enough to possibly hold a reply
 376     // 4 being magic size of a 3-digit number plus space delimiter
 377     if (hdr_len < (size_t)(protoPrefix.psize() + 4)) {
 378         if (hdr_len > 0) {
 379             debugs(58, 3, "Too small reply header (" << hdr_len << " bytes)");
 380             *error = Http::scInvalidHeader;
 381         }
 382         return false;
 383     }
 384
 385     int pos;
 386     // catch missing or mismatched protocol identifier
 387     // allow special-case for ICY protocol (non-HTTP identifier) in response to faked HTTP request.
 388     if (strncmp(buf, "ICY", 3) == 0) {
 389         protoPrefix = "ICY";
 390         pos = protoPrefix.psize();
 391     } else {
 392
 393         if (protoPrefix.cmp(buf, protoPrefix.size()) != 0) {
 394             debugs(58, 3, "missing protocol prefix (" << protoPrefix << ") in '" << buf << "'");
 395             *error = Http::scInvalidHeader;
 396             return false;
 397         }
 398
 399         // catch missing or negative status value (negative '-' is not a digit)
 400         pos = protoPrefix.psize();
 401
 402         // skip arbitrary number of digits and a dot in the verion portion
 403         while ((size_t)pos <= hdr_len && (*(buf+pos) == '.' || xisdigit(*(buf+pos)) ) ) ++pos;
 404
 405         // catch missing version info
 406         if (pos == protoPrefix.psize()) {
 407             debugs(58, 3, "missing protocol version numbers (ie. " << protoPrefix << "/1.0) in '" << buf << "'");
 408             *error = Http::scInvalidHeader;
 409             return false;
 410         }
 411     }
 412
 413     // skip arbitrary number of spaces...
 414     while ((size_t)pos <= hdr_len && (char)*(buf+pos) == ' ') ++pos;
 415
 416     if ((size_t)pos < hdr_len && !xisdigit(*(buf+pos))) {
 417         debugs(58, 3, "missing or invalid status number in '" << buf << "'");
 418         *error = Http::scInvalidHeader;
 419         return false;
 420     }
 421
 422     return true;
 423 }
 424
 425 bool
 426 HttpReply::parseFirstLine(const char *blk_start, const char *blk_end)
 427 {
 428     return sline.parse(protoPrefix, blk_start, blk_end);
 429 }
 430
 431 /* handy: resets and returns -1 */
 432 int
 433 HttpReply::httpMsgParseError()
 434 {
 435     int result(Http::Message::httpMsgParseError());
 436     /* indicate an error in the status line */
 437     sline.set(Http::ProtocolVersion(), Http::scInvalidHeader);
 438     return result;
 439 }
 440
 441 /*
 442  * Indicate whether or not we would usually expect an entity-body
 443  * along with this response
 444  */
 445 bool
 446 HttpReply::expectingBody(const HttpRequestMethod& req_method, int64_t& theSize) const
 447 {
 448     bool expectBody = true;
 449
 450     if (req_method == Http::METHOD_HEAD)
 451         expectBody = false;
 452     else if (sline.status() == Http::scNoContent)
 453         expectBody = false;
 454     else if (sline.status() == Http::scNotModified)
 455         expectBody = false;
 456     else if (sline.status() < Http::scOkay)
 457         expectBody = false;
 458     else
 459         expectBody = true;
 460
 461     if (expectBody) {
 462         if (header.chunked())
 463             theSize = -1;
 464         else if (content_length >= 0)
 465             theSize = content_length;
 466         else
 467             theSize = -1;
 468     }
 469
 470     return expectBody;
 471 }
 472
 473 bool
 474 HttpReply::receivedBodyTooLarge(HttpRequest& request, int64_t receivedSize)
 475 {
 476     calcMaxBodySize(request);
 477     debugs(58, 3, HERE << receivedSize << " >? " << bodySizeMax);
 478     return bodySizeMax >= 0 && receivedSize > bodySizeMax;
 479 }
 480
 481 bool
 482 HttpReply::expectedBodyTooLarge(HttpRequest& request)
 483 {
 484     calcMaxBodySize(request);
 485     debugs(58, 7, HERE << "bodySizeMax=" << bodySizeMax);
 486
 487     if (bodySizeMax < 0) // no body size limit
 488         return false;
 489
 490     int64_t expectedSize = -1;
 491     if (!expectingBody(request.method, expectedSize))
 492         return false;
 493
 494     debugs(58, 6, HERE << expectedSize << " >? " << bodySizeMax);
 495
 496     if (expectedSize < 0) // expecting body of an unknown length
 497         return false;
 498
 499     return expectedSize > bodySizeMax;
 500 }
 501
 502 void
 503 HttpReply::calcMaxBodySize(HttpRequest& request) const
 504 {
 505     // hack: -2 is used as "we have not calculated max body size yet" state
 506     if (bodySizeMax != -2) // already tried
 507         return;
 508     bodySizeMax = -1;
 509
 510     // short-circuit ACL testing if there are none configured
 511     if (!Config.ReplyBodySize)
 512         return;
 513
 514     ACLFilledChecklist ch(NULL, &request, NULL);
 515     // XXX: cont-cast becomes irrelevant when checklist is HttpReply::Pointer
 516     ch.reply = const_cast<HttpReply *>(this);
 517     HTTPMSGLOCK(ch.reply);
 518     for (AclSizeLimit *l = Config.ReplyBodySize; l; l = l -> next) {
 519         /* if there is no ACL list or if the ACLs listed match use this size value */
 520         if (!l->aclList || ch.fastCheck(l->aclList).allowed()) {
 521             debugs(58, 4, HERE << "bodySizeMax=" << bodySizeMax);
 522             bodySizeMax = l->size; // may be -1
 523             break;
 524         }
 525     }
 526 }
 527
 528 // XXX: check that this is sufficient for eCAP cloning
 529 HttpReply *
 530 HttpReply::clone() const
 531 {
 532     HttpReply *rep = new HttpReply();
 533     rep->sline = sline; // used in hdrCacheInit() call below
 534     rep->header.append(&header);
 535     rep->hdrCacheInit();
 536     rep->hdr_sz = hdr_sz;
 537     rep->http_ver = http_ver;
 538     rep->pstate = pstate;
 539     rep->body_pipe = body_pipe;
 540
 541     // keep_alive is handled in hdrCacheInit()
 542     return rep;
 543 }
 544
 545 bool
 546 HttpReply::inheritProperties(const Http::Message *aMsg)
 547 {
 548     const HttpReply *aRep = dynamic_cast<const HttpReply*>(aMsg);
 549     if (!aRep)
 550         return false;
 551     keep_alive = aRep->keep_alive;
 552     sources = aRep->sources;
 553     return true;
 554 }
 555
 556 void HttpReply::removeStaleWarnings()
 557 {
 558     String warning;
 559     if (header.getList(Http::HdrType::WARNING, &warning)) {
 560         const String newWarning = removeStaleWarningValues(warning);
 561         if (warning.size() && warning.size() == newWarning.size())
 562             return; // some warnings are there and none changed
 563         header.delById(Http::HdrType::WARNING);
 564         if (newWarning.size()) { // some warnings left
 565             HttpHeaderEntry *const e =
 566                 new HttpHeaderEntry(Http::HdrType::WARNING, SBuf(), newWarning.termedBuf());
 567             header.addEntry(e);
 568         }
 569     }
 570 }
 571
 572 /**
 573  * Remove warning-values with warn-date different from Date value from
 574  * a single header entry. Returns a string with all valid warning-values.
 575  */
 576 String HttpReply::removeStaleWarningValues(const String &value)
 577 {
 578     String newValue;
 579     const char *item = 0;
 580     int len = 0;
 581     const char *pos = 0;
 582     while (strListGetItem(&value, ',', &item, &len, &pos)) {
 583         bool keep = true;
 584         // Does warning-value have warn-date (which contains quoted date)?
 585         // We scan backwards, looking for two quoted strings.
 586         // warning-value = warn-code SP warn-agent SP warn-text [SP warn-date]
 587         const char *p = item + len - 1;
 588
 589         while (p >= item && xisspace(*p)) --p; // skip whitespace
 590
 591         // warning-value MUST end with quote
 592         if (p >= item && *p == '"') {
 593             const char *const warnDateEnd = p;
 594             --p;
 595             while (p >= item && *p != '"') --p; // find the next quote
 596
 597             const char *warnDateBeg = p + 1;
 598             --p;
 599             while (p >= item && xisspace(*p)) --p; // skip whitespace
 600
 601             if (p >= item && *p == '"' && warnDateBeg - p > 2) {
 602                 // found warn-text
 603                 String warnDate;
 604                 warnDate.append(warnDateBeg, warnDateEnd - warnDateBeg);
 605                 const time_t time = parse_rfc1123(warnDate.termedBuf());
 606                 keep = (time > 0 && time == date); // keep valid and matching date
 607             }
 608         }
 609
 610         if (keep) {
 611             if (newValue.size())
 612                 newValue.append(", ");
 613             newValue.append(item, len);
 614         }
 615     }
 616
 617     return newValue;
 618 }
 619
 620 bool
 621 HttpReply::olderThan(const HttpReply *them) const
 622 {
 623     if (!them || !them->date || !date)
 624         return false;
 625     return date < them->date;
 626 }
 627