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* $Id: ESIInclude.cc,v 1.14.2.2 2008/02/27 05:59:29 amosjeffries Exp $
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* DEBUG: section 86 ESI processing
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* AUTHOR: Robert Collins
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* SQUID Web Proxy Cache http://www.squid-cache.org/
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* ----------------------------------------------------------
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* Squid is the result of efforts by numerous individuals from
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* the Internet community; see the CONTRIBUTORS file for full
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* details. Many organizations have provided support for Squid's
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* development; see the SPONSORS file for full details. Squid is
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* Copyrighted (C) 2001 by the Regents of the University of
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* California; see the COPYRIGHT file for full details. Squid
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* incorporates software developed and/or copyrighted by other
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* sources; see the CREDITS file for full details.
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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; but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
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* Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
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/* MS Visual Studio Projects are monolithic, so we need the following
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* #if to exclude the ESI code from compile process when not needed.
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#if (USE_SQUID_ESI == 1)
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#include "ESIInclude.h"
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#include "ESIVarState.h"
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#include "client_side_request.h"
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#include "HttpReply.h"
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CBDATA_CLASS_INIT (ESIStreamContext);
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static CSCB esiBufferRecipient;
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static CSD esiBufferDetach;
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/* esiStreamContext */
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static ESIStreamContext *ESIStreamContextNew (ESIIncludePtr);
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* 1. retry failed upstream requests
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/* Detach from a buffering stream
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esiBufferDetach (clientStreamNode *node, ClientHttpRequest *http)
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/* Detach ourselves */
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clientStreamDetach (node, http);
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* Write a chunk of data to a client 'socket'.
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* If the reply is present, send the reply headers down the wire too.
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* The request is an internal ESI subrequest.
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* data context is not NULL
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* There are no more entries in the stream chain.
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* The caller is responsible for creation and deletion of the Reply headers.
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* Bug 975, bug 1566 : delete rep; 2006/09/02: TS, #975
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* This was causing double-deletes. Its possible that not deleting
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* it here will cause memory leaks, but if so, this delete should
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* not be reinstated or it will trigger bug #975 again - RBC 20060903
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esiBufferRecipient (clientStreamNode *node, ClientHttpRequest *http, HttpReply *rep, StoreIOBuffer receivedData)
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/* Test preconditions */
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assert (node != NULL);
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/* ESI TODO: handle thisNode rather than asserting
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* - it should only ever happen if we cause an
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* abort and the callback chain loops back to
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* here, so we can simply return. However, that
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* itself shouldn't happen, so it stays as an
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assert (cbdataReferenceValid (node));
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assert (node->node.next == NULL);
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assert (http->getConn().getRaw() == NULL);
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ESIStreamContext::Pointer esiStream = dynamic_cast<ESIStreamContext *>(node->data.getRaw());
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assert (esiStream.getRaw() != NULL);
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/* If segments become more flexible, ignore thisNode */
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assert (receivedData.length <= sizeof(esiStream->localbuffer->buf));
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assert (!esiStream->finished);
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debugs (86,5, HERE << "rep " << rep << " body " << receivedData.data << " len " << receivedData.length);
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assert (node->readBuffer.offset == receivedData.offset || receivedData.length == 0);
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if (http->out.offset != 0) {
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if (rep->sline.status != HTTP_OK) {
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esiStream->include->fail (esiStream);
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esiStream->finished = 1;
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httpRequestFree (http);
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/* should be done in the store rather than every recipient? */
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headersLog(0, 0, http->request->method, rep);
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if (receivedData.data && receivedData.length) {
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http->out.offset += receivedData.length;
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if (receivedData.data >= esiStream->localbuffer->buf &&
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receivedData.data < &esiStream->localbuffer->buf[sizeof(esiStream->localbuffer->buf)]) {
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/* original static buffer */
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if (receivedData.data != esiStream->localbuffer->buf) {
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/* But not the start of it */
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xmemmove (esiStream->localbuffer->buf, receivedData.data, receivedData.length);
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esiStream->localbuffer->len = receivedData.length;
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assert (esiStream->buffer.getRaw() != NULL);
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esiStream->buffer->len = receivedData.length;
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/* EOF / Read error / aborted entry */
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if (rep == NULL && receivedData.data == NULL && receivedData.length == 0) {
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/* TODO: get stream status to test the entry for aborts */
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debugs(86, 5, HERE << "Finished reading upstream data in subrequest");
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esiStream->include->subRequestDone (esiStream, true);
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esiStream->finished = 1;
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httpRequestFree (http);
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/* after the write to the user occurs, (ie here, or in a callback)
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if (clientHttpRequestStatus(-1, http)) {
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/* TODO: Does thisNode if block leak htto ? */
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/* XXX when reviewing ESI this is the first place to look */
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esiStream->finished = 1;
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esiStream->include->fail (esiStream);
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switch (clientStreamStatus (node, http)) {
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case STREAM_UNPLANNED_COMPLETE: /* fallthru ok */
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case STREAM_COMPLETE: /* ok */
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debugs(86, 3, "ESI subrequest finished OK");
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esiStream->include->subRequestDone (esiStream, true);
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esiStream->finished = 1;
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httpRequestFree (http);
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debugs(86, 1, "ESI subrequest failed transfer");
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esiStream->include->fail (esiStream);
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esiStream->finished = 1;
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httpRequestFree (http);
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StoreIOBuffer tempBuffer;
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if (!esiStream->buffer.getRaw()) {
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esiStream->buffer = esiStream->localbuffer;
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esiStream->buffer = esiStream->buffer->tail();
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if (esiStream->buffer->len) {
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esiStream->buffer->next = new ESISegment;
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esiStream->buffer = esiStream->buffer->next;
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tempBuffer.offset = http->out.offset;
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tempBuffer.length = sizeof (esiStream->buffer->buf);
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tempBuffer.data = esiStream->buffer->buf;
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/* now just read into 'buffer' */
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clientStreamRead (node, http, tempBuffer);
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debugs(86, 5, HERE << "Requested more data for ESI subrequest");
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fatal ("Hit unreachable code in esiBufferRecipient\n");
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/* esiStream functions */
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ESIStreamContext::~ESIStreamContext()
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ESIStreamContext::freeResources()
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debugs(86, 5, "Freeing stream context resources.");
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ESIStreamContext::operator new(size_t byteCount)
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assert (byteCount == sizeof (ESIStreamContext));
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CBDATA_INIT_TYPE(ESIStreamContext);
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ESIStreamContext *result = cbdataAlloc(ESIStreamContext);
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ESIStreamContext::operator delete (void *address)
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ESIStreamContext *t = static_cast<ESIStreamContext *>(address);
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ESIStreamContextNew (ESIIncludePtr include)
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ESIStreamContext *rv = new ESIStreamContext;
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rv->include = include;
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ESIInclude::~ESIInclude()
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debugs(86, 5, "ESIInclude::Free " << this);
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ESISegmentFreeList (srccontent);
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ESISegmentFreeList (altcontent);
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cbdataReferenceDone (varState);
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ESIInclude::makeCacheable() const
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return new ESIInclude (*this);
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ESIInclude::makeUsable(esiTreeParentPtr newParent, ESIVarState &newVarState) const
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ESIInclude *resultI = new ESIInclude (*this);
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ESIElement::Pointer result = resultI;
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resultI->parent = newParent;
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resultI->varState = cbdataReference (&newVarState);
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resultI->src = ESIStreamContextNew (resultI);
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resultI->alt = ESIStreamContextNew (resultI);
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ESIInclude::ESIInclude(ESIInclude const &old) : parent (NULL), started (false), sent (false)
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flags.onerrorcontinue = old.flags.onerrorcontinue;
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srcurl = xstrdup (old.srcurl);
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alturl = xstrdup (old.alturl);
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ESIInclude::prepareRequestHeaders(HttpHeader &tempheaders, ESIVarState *vars)
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tempheaders.update (&vars->header(), NULL);
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tempheaders.removeHopByHopEntries();
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ESIInclude::Start (ESIStreamContext::Pointer stream, char const *url, ESIVarState *vars)
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if (!stream.getRaw())
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HttpHeader tempheaders(hoRequest);
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prepareRequestHeaders(tempheaders, vars);
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/* Ensure variable state is clean */
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vars->feedData(url, strlen (url));
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/* tempUrl is eaten by the request */
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char const *tempUrl = vars->extractChar ();
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debugs(86, 5, "ESIIncludeStart: Starting subrequest with url '" << tempUrl <<
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if (clientBeginRequest(METHOD_GET, tempUrl, esiBufferRecipient, esiBufferDetach, stream.getRaw(), &tempheaders, stream->localbuffer->buf, HTTP_REQBUF_SZ)) {
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debugs(86, 0, "starting new ESI subrequest failed");
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ESIInclude::ESIInclude (esiTreeParentPtr aParent, int attrcount, char const **attr, ESIContext *aContext) : parent (aParent), started (false), sent (false)
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for (i = 0; i < attrcount && attr[i]; i += 2) {
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if (!strcmp(attr[i],"src")) {
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/* Start a request for thisNode url */
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debugs(86, 5, "ESIIncludeNew: Requesting source '" << attr[i+1] << "'");
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/* TODO: don't assert on thisNode, ignore the duplicate */
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assert (src.getRaw() == NULL);
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src = ESIStreamContextNew (this);
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assert (src.getRaw() != NULL);
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srcurl = xstrdup ( attr[i+1]);
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} else if (!strcmp(attr[i],"alt")) {
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/* Start a secondary request for thisNode url */
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/* TODO: make a config parameter to wait on requesting alt's
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* for the src to fail
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debugs(86, 5, "ESIIncludeNew: Requesting alternate '" << attr[i+1] << "'");
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assert (alt.getRaw() == NULL); /* TODO: FIXME */
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alt = ESIStreamContextNew (this);
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assert (alt.getRaw() != NULL);
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alturl = xstrdup (attr[i+1]);
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} else if (!strcmp(attr[i],"onerror")) {
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if (!strcmp(attr[i+1], "continue")) {
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flags.onerrorcontinue = 1;
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/* ignore mistyped attributes */
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debugs(86, 1, "invalid value for onerror='" << attr[i+1] << "'");
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/* ignore mistyped attributes. TODO:? error on these for user feedback - config parameter needed
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varState = cbdataReference(aContext->varState);
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/* prevent freeing ourselves */
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ESIIncludePtr foo(this);
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Start (src, srcurl, varState);
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Start (alt, alturl, varState);
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debugs(86, 1, "ESIIncludeNew: esi:include with no src attributes");
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ESIInclude::render(ESISegment::Pointer output)
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ESISegment::Pointer myout;
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debugs(86, 5, "ESIIncludeRender: Rendering include " << this);
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assert (flags.finished || (flags.failed && flags.onerrorcontinue));
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if (flags.failed && flags.onerrorcontinue) {
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/* Render the content */
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if (srccontent.getRaw()) {
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} else if (altcontent.getRaw()) {
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fatal ("ESIIncludeRender called with no content, and no failure!\n");
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assert (output->next == NULL);
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output->next = myout;
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ESIInclude::process (int dovars)
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/* Prevent refcount race leading to free */
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debugs(86, 5, "ESIIncludeRender: Processing include " << this);
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if (flags.onerrorcontinue)
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return ESI_PROCESS_COMPLETE;
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return ESI_PROCESS_FAILED;
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if (!flags.finished) {
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if (flags.onerrorcontinue)
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return ESI_PROCESS_PENDING_WONTFAIL;
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return ESI_PROCESS_PENDING_MAYFAIL;
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return ESI_PROCESS_COMPLETE;
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ESIInclude::fail (ESIStreamContext::Pointer stream)
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subRequestDone (stream, false);
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ESIInclude::dataNeeded() const
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return !(flags.finished || flags.failed);
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ESIInclude::subRequestDone (ESIStreamContext::Pointer stream, bool success)
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debugs(86, 3, "ESIInclude::subRequestDone: " << srcurl);
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/* copy the lead segment */
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debugs(86, 3, "ESIIncludeSubRequestDone: Src OK - include PASSED.");
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assert (!srccontent.getRaw());
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ESISegment::ListTransfer (stream->localbuffer, srccontent);
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/* Fail if there is no alt being retrieved */
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debugs(86, 3, "ESIIncludeSubRequestDone: Src FAILED");
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if (!(alt.getRaw() || altcontent.getRaw())) {
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debugs(86, 3, "ESIIncludeSubRequestDone: Include FAILED - No ALT");
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} else if (altcontent.getRaw()) {
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debugs(86, 3, "ESIIncludeSubRequestDone: Include PASSED - ALT already Complete");
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/* ALT was already retrieved, we are done */
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} else if (stream == alt) {
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debugs(86, 3, "ESIInclude::subRequestDone: " << alturl);
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debugs(86, 3, "ESIIncludeSubRequestDone: ALT OK.");
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/* copy the lead segment */
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assert (!altcontent.getRaw());
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ESISegment::ListTransfer (stream->localbuffer, altcontent);
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if (!(src.getRaw() || srccontent.getRaw())) {
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/* src already failed, kick ESI processor */
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debugs(86, 3, "ESIIncludeSubRequestDone: Include PASSED - SRC already failed.");
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if (!(src.getRaw() || srccontent.getRaw())) {
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debugs(86, 3, "ESIIncludeSubRequestDone: ALT FAILED, Include FAILED - SRC already failed");
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/* src already failed */
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fatal ("ESIIncludeSubRequestDone: non-owned stream found!\n");
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if (flags.finished || flags.failed) {
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/* Kick ESI Processor */
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debugs (86, 5, "ESIInclude " << this <<
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" SubRequest " << stream.getRaw() <<
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" completed, kicking processor , status " <<
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(flags.finished ? "OK" : "FAILED"));
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/* There is a race condition - and we have no reproducible test case -
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* during a subrequest the parent will get set to NULL, which is not
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* meant to be possible. Rather than killing squid, we let it leak
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* memory but complain in the log.
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* Someone wanting to debug this could well start by running squid with
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* a hardware breakpoint set to this location.
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* Its probably due to parent being set to null - by a call to
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* 'this.finish' while the subrequest is still not completed.
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if (parent.getRaw() == NULL) {
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debugs (86, 0, "ESIInclude::subRequestDone: Sub request completed "
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"after finish() called and parent unlinked. Unable to "
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"continue handling the request, and may be memory leaking. "
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"See http://www.squid-cache.org/bugs/show_bug.cgi?id=951 - we "
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"are looking for a reproducible test case. This will require "
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"an ESI template with includes, probably with alt-options, "
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"and we're likely to need traffic dumps to allow us to "
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"reconstruct the exact tcp handling sequences to trigger this "
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"rather elusive bug.");
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assert (parent.getRaw());
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parent->provideData (srccontent.getRaw() ? srccontent:altcontent,this);
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if (srccontent.getRaw())
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} else if (flags.onerrorcontinue) {
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/* render nothing but inform of completion */
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parent->provideData (new ESISegment, this);
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parent->fail(this, "esi:include could not be completed.");
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#endif /* USE_SQUID_ESI == 1 */
added
removed
src/ESIInclude.cc
