src/client_side_reply.h

   1 /*
   2  * Copyright (C) 1996-2025 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 #ifndef SQUID_SRC_CLIENT_SIDE_REPLY_H
  10 #define SQUID_SRC_CLIENT_SIDE_REPLY_H
  11
  12 #include "acl/forward.h"
  13 #include "client_side_request.h"
  14 #include "ip/forward.h"
  15 #include "RequestFlags.h"
  16 #include "StoreClient.h"
  17
  18 class ErrorState;
  19
  20 /* XXX make static method */
  21
  22 class clientReplyContext : public RefCountable, public StoreClient
  23 {
  24     CBDATA_CLASS(clientReplyContext);
  25
  26 public:
  27     static STCB CacheHit;
  28     static STCB HandleIMSReply;
  29     static STCB SendMoreData;
  30
  31     clientReplyContext(ClientHttpRequest *);
  32     ~clientReplyContext() override;
  33
  34     void saveState();
  35     void restoreState();
  36     void purgeRequest ();
  37     void doGetMoreData();
  38     void identifyStoreObject();
  39     void identifyFoundObject(StoreEntry *entry, const char *detail);
  40     int storeOKTransferDone() const;
  41     int storeNotOKTransferDone() const;
  42     /// replaces current response store entry with the given one
  43     void setReplyToStoreEntry(StoreEntry *e, const char *reason);
  44     /// builds error using clientBuildError() and calls setReplyToError() below
  45     void setReplyToError(err_type, Http::StatusCode, char const *, const ConnStateData *, HttpRequest *, const char *,
  46 #if USE_AUTH
  47                          Auth::UserRequest::Pointer);
  48 #else
  49                          void * unused);
  50 #endif
  51     /// creates a store entry for the reply and appends err to it
  52     void setReplyToError(const HttpRequestMethod& method, ErrorState *err);
  53     /// creates a store entry for the reply and appends error reply to it
  54     void setReplyToReply(HttpReply *reply);
  55     void createStoreEntry(const HttpRequestMethod& m, RequestFlags flags);
  56     void removeStoreReference(store_client ** scp, StoreEntry ** ep);
  57     void removeClientStoreReference(store_client **scp, ClientHttpRequest *http);
  58     void startError(ErrorState * err);
  59     void processExpired();
  60     clientStream_status_t replyStatus();
  61     void processMiss();
  62     void traceReply();
  63     const char *storeId() const { return (http->store_id.size() > 0 ? http->store_id.termedBuf() : http->uri); }
  64
  65     Http::StatusCode purgeStatus;
  66
  67     /* StoreClient API */
  68     LogTags *loggingTags() const override;
  69
  70     ClientHttpRequest *http;
  71     store_client *sc;       /* The store_client we're using */
  72
  73     /// Buffer dedicated to receiving storeClientCopy() responses to generated
  74     /// revalidation requests. These requests cannot use next()->readBuffer
  75     /// because the latter keeps the contents of the stale HTTP response during
  76     /// revalidation. sendClientOldEntry() uses that contents.
  77     char tempbuf[HTTP_REQBUF_SZ];
  78
  79     struct Flags {
  80         Flags() : storelogiccomplete(0), complete(0), headersSent(false) {}
  81
  82         unsigned storelogiccomplete:1;
  83         unsigned complete:1;        ///< we have read all we can from upstream
  84         bool headersSent;
  85     } flags;
  86     clientStreamNode *ourNode;  /* This will go away if/when this file gets refactored some more */
  87
  88 private:
  89     /* StoreClient API */
  90     void fillChecklist(ACLFilledChecklist &) const override;
  91
  92     clientStreamNode *getNextNode() const;
  93     void makeThisHead();
  94     bool errorInStream(const StoreIOBuffer &result) const;
  95     bool matchesStreamBodyBuffer(const StoreIOBuffer &) const;
  96     void sendStreamError(StoreIOBuffer const &result);
  97     void pushStreamData(const StoreIOBuffer &);
  98     clientStreamNode * next() const;
  99     HttpReply *reply;
 100     void processReplyAccess();
 101     static ACLCB ProcessReplyAccessResult;
 102     void processReplyAccessResult(const Acl::Answer &accessAllowed);
 103     void cloneReply();
 104     void buildReplyHeader ();
 105     bool alwaysAllowResponse(Http::StatusCode sline) const;
 106     int checkTransferDone();
 107     void processOnlyIfCachedMiss();
 108     bool processConditional();
 109     void noteStreamBufferredBytes(const StoreIOBuffer &);
 110     void cacheHit(StoreIOBuffer result);
 111     void handleIMSReply(StoreIOBuffer result);
 112     void sendMoreData(StoreIOBuffer result);
 113     void triggerInitialStoreRead(STCB = SendMoreData);
 114     void requestMoreBodyFromStore();
 115     void sendClientOldEntry();
 116     void purgeAllCached();
 117     /// attempts to release the cached entry
 118     /// \returns whether the entry was released
 119     bool purgeEntry(StoreEntry &, const Http::MethodType, const char *descriptionPrefix = "");
 120     /// releases both cached GET and HEAD entries
 121     void purgeDoPurge();
 122     void forgetHit();
 123     bool blockedHit() const;
 124     const char *storeLookupString(bool found) const { return found ? "match" : "mismatch"; }
 125     void detailStoreLookup(const char *detail);
 126
 127     void sendBodyTooLargeError();
 128     void sendPreconditionFailedError();
 129     void sendNotModified();
 130     void sendNotModifiedOrPreconditionFailedError();
 131     void sendClientUpstreamResponse(const StoreIOBuffer &upstreamResponse);
 132
 133     /// Reduces a chance of an accidental direct storeClientCopy() call that
 134     /// (should but) forgets to invalidate our lastStreamBufferedBytes. This
 135     /// function is not defined; decltype() syntax prohibits "= delete", but
 136     /// function usage will trigger deprecation warnings and linking errors.
 137     static decltype(::storeClientCopy) storeClientCopy [[deprecated]];
 138
 139     /// Classification of the initial Store lookup.
 140     /// This very first lookup happens without the Vary-driven key augmentation.
 141     /// TODO: Exclude internal Store match bans from the "mismatch" category.
 142     const char *firstStoreLookup_ = nullptr;
 143
 144     /* (stale) cache hit information preserved during IMS revalidation */
 145     StoreEntry *old_entry;
 146     store_client *old_sc;
 147     time_t old_lastmod;
 148     String old_etag;
 149
 150     bool deleting;
 151
 152     typedef enum {
 153         crNone = 0, ///< collapsed revalidation is not allowed for this context
 154         crInitiator, ///< we initiated collapsed revalidation request
 155         crSlave ///< we collapsed on the existing revalidation request
 156     } CollapsedRevalidation;
 157
 158     CollapsedRevalidation collapsedRevalidation;
 159
 160     /// HTTP response body bytes stored in our Client Stream buffer (if any)
 161     StoreIOBuffer lastStreamBufferedBytes;
 162
 163     // TODO: Remove after moving the meat of this function into a method.
 164     friend CSR clientGetMoreData;
 165 };
 166
 167 // TODO: move to SideAgent parent, when we have one
 168 void purgeEntriesByUrl(HttpRequest *, const char *);
 169
 170 #endif /* SQUID_SRC_CLIENT_SIDE_REPLY_H */
 171