src/adaptation/AccessCheck.cc

   1 #include "squid.h"
   2 #include "structs.h"
   3
   4 #include "ConfigParser.h"
   5 #include "HttpRequest.h"
   6 #include "HttpReply.h"
   7 #include "acl/FilledChecklist.h"
   8 #include "adaptation/Service.h"
   9 #include "adaptation/ServiceGroups.h"
  10 #include "adaptation/AccessRule.h"
  11 #include "adaptation/Config.h"
  12 #include "adaptation/AccessCheck.h"
  13
  14
  15 /** \cond AUTODOCS-IGNORE */
  16 cbdata_type Adaptation::AccessCheck::CBDATA_AccessCheck = CBDATA_UNKNOWN;
  17 /** \endcond */
  18
  19 bool
  20 Adaptation::AccessCheck::Start(Method method, VectPoint vp,
  21                                HttpRequest *req, HttpReply *rep, AccessCheckCallback *cb, void *cbdata)
  22 {
  23
  24     if (Config::Enabled) {
  25         // the new check will call the callback and delete self, eventually
  26         return AsyncStart(new AccessCheck(
  27             ServiceFilter(method, vp, req, rep), cb, cbdata));
  28     }
  29
  30     debugs(83, 3, HERE << "adaptation off, skipping");
  31     return false;
  32 }
  33
  34 Adaptation::AccessCheck::AccessCheck(const ServiceFilter &aFilter,
  35                                      AccessCheckCallback *aCallback,
  36                                      void *aCallbackData):
  37     AsyncJob("AccessCheck"), filter(aFilter),
  38     callback(aCallback),
  39     callback_data(cbdataReference(aCallbackData)),
  40     acl_checklist(NULL)
  41 {
  42 #if ICAP_CLIENT
  43     Adaptation::Icap::History::Pointer h = filter.request->icapHistory();
  44     if (h != NULL)
  45         h->start("ACL");
  46 #endif
  47
  48     debugs(93, 5, HERE << "AccessCheck constructed for " <<
  49         methodStr(filter.method) << " " << vectPointStr(filter.point));
  50 }
  51
  52 Adaptation::AccessCheck::~AccessCheck()
  53 {
  54 #if ICAP_CLIENT
  55     Adaptation::Icap::History::Pointer h = filter.request->icapHistory();
  56     if (h != NULL)
  57         h->stop("ACL");
  58 #endif
  59     if (callback_data)
  60         cbdataReferenceDone(callback_data);
  61 }
  62
  63 void
  64 Adaptation::AccessCheck::start() {
  65         AsyncJob::start();
  66         check();
  67 }
  68
  69 /// Walk the access rules list to find rules with applicable service groups
  70 void
  71 Adaptation::AccessCheck::check()
  72 {
  73     debugs(93, 4, HERE << "start checking");
  74
  75     typedef AccessRules::iterator ARI;
  76     for (ARI i = AllRules().begin(); i != AllRules().end(); ++i) {
  77         AccessRule *r = *i;
  78         if (isCandidate(*r)) {
  79             debugs(93, 5, HERE << "check: rule '" << r->id << "' is a candidate");
  80             candidates += r->id;
  81         }
  82     }
  83
  84     checkCandidates();
  85 }
  86
  87 // XXX: Here and everywhere we call FindRule(topCandidate()):
  88 // Once we identified the candidate, we should not just ignore it
  89 // if reconfigure changes rules. We should either lock the rule to
  90 // prevent reconfigure from stealing it or restart the check with
  91 // new rules. Throwing an exception may also be appropriate.
  92 void
  93 Adaptation::AccessCheck::checkCandidates()
  94 {
  95     debugs(93, 4, HERE << "has " << candidates.size() << " rules");
  96
  97     while (!candidates.empty()) {
  98         if (AccessRule *r = FindRule(topCandidate())) {
  99             /* BUG 2526: what to do when r->acl is empty?? */
 100             // XXX: we do not have access to conn->rfc931 here.
 101             acl_checklist = new ACLFilledChecklist(r->acl, filter.request, dash_str);
 102             acl_checklist->reply = filter.reply ? HTTPMSGLOCK(filter.reply) : NULL;
 103             acl_checklist->nonBlockingCheck(AccessCheckCallbackWrapper, this);
 104             return;
 105         }
 106
 107         candidates.shift(); // the rule apparently went away (reconfigure)
 108     }
 109
 110     debugs(93, 4, HERE << "NO candidates left");
 111     callBack(NULL);
 112     Must(done());
 113 }
 114
 115 void
 116 Adaptation::AccessCheck::AccessCheckCallbackWrapper(int answer, void *data)
 117 {
 118     debugs(93, 8, HERE << "callback answer=" << answer);
 119     AccessCheck *ac = (AccessCheck*)data;
 120
 121     /** \todo AYJ 2008-06-12: If answer == ACCESS_REQ_PROXY_AUTH
 122      * we should be kicking off an authentication before continuing
 123      * with this request. see bug 2400 for details.
 124      */
 125     ac->noteAnswer(answer==ACCESS_ALLOWED);
 126 }
 127
 128 /// process the results of the ACL check
 129 void
 130 Adaptation::AccessCheck::noteAnswer(int answer)
 131 {
 132     Must(!candidates.empty()); // the candidate we were checking must be there
 133     debugs(93,5, HERE << topCandidate() << " answer=" << answer);
 134
 135     if (answer) { // the rule matched
 136         ServiceGroupPointer g = topGroup();
 137         if (g != NULL) { // the corresponding group found
 138             callBack(g);
 139             Must(done());
 140             return;
 141         }
 142     }
 143
 144     // no match or the group disappeared during reconfiguration
 145     candidates.shift();
 146     checkCandidates();
 147 }
 148
 149 /// call back with a possibly nil group; the job ends here because all failures
 150 /// at this point are fatal to the access check process
 151 void
 152 Adaptation::AccessCheck::callBack(const ServiceGroupPointer &g)
 153 {
 154     debugs(93,3, HERE << g);
 155
 156     void *validated_cbdata;
 157     if (cbdataReferenceValidDone(callback_data, &validated_cbdata)) {
 158         callback(g, validated_cbdata);
 159     }
 160     mustStop("done"); // called back or will never be able to call back
 161 }
 162
 163 Adaptation::ServiceGroupPointer
 164 Adaptation::AccessCheck::topGroup() const
 165 {
 166     ServiceGroupPointer g;
 167     if (candidates.size()) {
 168         if (AccessRule *r = FindRule(topCandidate())) {
 169             g = FindGroup(r->groupId);
 170             debugs(93,5, HERE << "top group for " << r->id << " is " << g);
 171         } else {
 172             debugs(93,5, HERE << "no rule for " << topCandidate());
 173         }
 174     } else {
 175         debugs(93,5, HERE << "no candidates"); // should not happen
 176     }
 177
 178     return g;
 179 }
 180
 181 /** Returns true iff the rule's service group will be used after ACL matches.
 182     Used to detect rules worth ACl-checking. */
 183 bool
 184 Adaptation::AccessCheck::isCandidate(AccessRule &r)
 185 {
 186     debugs(93,7,HERE << "checking candidacy of " << r.id << ", group " <<
 187         r.groupId);
 188
 189     ServiceGroupPointer g = FindGroup(r.groupId);
 190
 191     if (!g) {
 192         debugs(93,7,HERE << "lost " << r.groupId << " group in rule" << r.id);
 193         return false;
 194     }
 195
 196     const bool wants = g->wants(filter);
 197     debugs(93,7,HERE << r.groupId << (wants ? " wants" : " ignores"));
 198     return wants;
 199 }