src/adaptation/ecap/Host.cc

   1 /*
   2  * DEBUG: section 93    eCAP Interface
   3  */
   4 #include "squid.h"
   5 #include <libecap/adapter/service.h>
   6 #include <libecap/common/names.h>
   7 #include <libecap/common/registry.h>
   8 #include "adaptation/ecap/Host.h"
   9 #include "adaptation/ecap/MessageRep.h"
  10 #include "adaptation/ecap/ServiceRep.h"
  11 #include "base/TextException.h"
  12 #include "HttpReply.h"
  13 #include "HttpRequest.h"
  14
  15 const libecap::Name Adaptation::Ecap::protocolInternal("internal", libecap::Name::NextId());
  16 const libecap::Name Adaptation::Ecap::protocolCacheObj("cache_object", libecap::Name::NextId());
  17 const libecap::Name Adaptation::Ecap::protocolIcp("ICP", libecap::Name::NextId());
  18 #if USE_HTCP
  19 const libecap::Name Adaptation::Ecap::protocolHtcp("Htcp", libecap::Name::NextId());
  20 #endif
  21 const libecap::Name Adaptation::Ecap::protocolIcy("ICY", libecap::Name::NextId());
  22 const libecap::Name Adaptation::Ecap::protocolUnknown("_unknown_", libecap::Name::NextId());
  23
  24 const libecap::Name Adaptation::Ecap::metaBypassable("bypassable", libecap::Name::NextId());
  25
  26 /// the host application (i.e., Squid) wrapper registered with libecap
  27 static libecap::shared_ptr<Adaptation::Ecap::Host> TheHost;
  28
  29 Adaptation::Ecap::Host::Host()
  30 {
  31     // assign our host-specific IDs to well-known names
  32     // this code can run only once
  33
  34     libecap::headerTransferEncoding.assignHostId(HDR_TRANSFER_ENCODING);
  35     libecap::headerReferer.assignHostId(HDR_REFERER);
  36     libecap::headerContentLength.assignHostId(HDR_CONTENT_LENGTH);
  37     libecap::headerVia.assignHostId(HDR_VIA);
  38     // TODO: libecap::headerXClientIp.assignHostId(HDR_X_CLIENT_IP);
  39     // TODO: libecap::headerXServerIp.assignHostId(HDR_X_SERVER_IP);
  40
  41     libecap::protocolHttp.assignHostId(AnyP::PROTO_HTTP);
  42     libecap::protocolHttps.assignHostId(AnyP::PROTO_HTTPS);
  43     libecap::protocolFtp.assignHostId(AnyP::PROTO_FTP);
  44     libecap::protocolGopher.assignHostId(AnyP::PROTO_GOPHER);
  45     libecap::protocolWais.assignHostId(AnyP::PROTO_WAIS);
  46     libecap::protocolUrn.assignHostId(AnyP::PROTO_URN);
  47     libecap::protocolWhois.assignHostId(AnyP::PROTO_WHOIS);
  48     protocolInternal.assignHostId(AnyP::PROTO_INTERNAL);
  49     protocolCacheObj.assignHostId(AnyP::PROTO_CACHE_OBJECT);
  50     protocolIcp.assignHostId(AnyP::PROTO_ICP);
  51 #if USE_HTCP
  52     protocolHtcp.assignHostId(AnyP::PROTO_HTCP);
  53 #endif
  54     protocolIcy.assignHostId(AnyP::PROTO_ICY);
  55     protocolUnknown.assignHostId(AnyP::PROTO_UNKNOWN);
  56
  57     // allows adapter to safely ignore this in adapter::Service::configure()
  58     metaBypassable.assignHostId(1);
  59 }
  60
  61 std::string
  62 Adaptation::Ecap::Host::uri() const
  63 {
  64     return "ecap://squid-cache.org/ecap/hosts/squid";
  65 }
  66
  67 void
  68 Adaptation::Ecap::Host::describe(std::ostream &os) const
  69 {
  70     os << PACKAGE_NAME << " v" << PACKAGE_VERSION;
  71 }
  72
  73 /// Strips libecap version components not affecting compatibility decisions.
  74 static SBuf
  75 EssentialVersion(const SBuf &raw)
  76 {
  77     // all libecap x.y.* releases are supposed to be compatible so we strip
  78     // everything after the second period
  79     const SBuf::size_type minorPos = raw.find('.');
  80     const SBuf::size_type microPos = minorPos == SBuf::npos ?
  81                                      SBuf::npos : raw.find('.', minorPos+1);
  82     return raw.substr(0, microPos); // becomes raw if microPos is npos
  83 }
  84
  85 /// If "their" libecap version is not compatible with what Squid has been built
  86 /// with, then complain and return false.
  87 static bool
  88 SupportedVersion(const char *vTheir, const char *them)
  89 {
  90     if (!vTheir || !*vTheir) {
  91         debugs(93, DBG_CRITICAL, "ERROR: Cannot use " << them <<
  92                " with libecap prior to v1.0.");
  93         return false;
  94     }
  95
  96     // we support what we are built with
  97     const SBuf vSupported(LIBECAP_VERSION);
  98     debugs(93, 2, them << " with libecap v" << vTheir << "; us: v" << vSupported);
  99
 100     if (EssentialVersion(SBuf(vTheir)) == EssentialVersion(vSupported))
 101         return true; // their version is supported
 102
 103     debugs(93, DBG_CRITICAL, "ERROR: Cannot use " << them <<
 104            " with libecap v" << vTheir <<
 105            ": incompatible with supported libecap v" << vSupported);
 106     return false;
 107 }
 108
 109 void
 110 Adaptation::Ecap::Host::noteVersionedService(const char *vGiven, const libecap::weak_ptr<libecap::adapter::Service> &weak)
 111 {
 112     /*
 113      * Check that libecap used to build the service is compatible with ours.
 114      * This has to be done using vGiven string and not Service object itself
 115      * because dereferencing a Service pointer coming from an unsupported
 116      * version is unsafe.
 117      */
 118     if (SupportedVersion(vGiven, "eCAP service built")) {
 119         Must(!weak.expired());
 120         RegisterAdapterService(weak.lock());
 121     }
 122 }
 123
 124 static int
 125 SquidLogLevel(libecap::LogVerbosity lv)
 126 {
 127     if (lv.critical())
 128         return DBG_CRITICAL; // is it a good idea to ignore other flags?
 129
 130     if (lv.large())
 131         return DBG_DATA; // is it a good idea to ignore other flags?
 132
 133     if (lv.application())
 134         return DBG_IMPORTANT; // is it a good idea to ignore other flags?
 135
 136     return 2 + 2*lv.debugging() + 3*lv.operation() + 2*lv.xaction();
 137 }
 138
 139 std::ostream *
 140 Adaptation::Ecap::Host::openDebug(libecap::LogVerbosity lv)
 141 {
 142     const int squidLevel = SquidLogLevel(lv);
 143     const int squidSection = 93; // XXX: this should be a global constant
 144     // XXX: Debug.h should provide this to us
 145     if ((Debug::level = squidLevel) <= Debug::Levels[squidSection])
 146         return &Debug::getDebugOut();
 147     else
 148         return NULL;
 149 }
 150
 151 void
 152 Adaptation::Ecap::Host::closeDebug(std::ostream *debug)
 153 {
 154     if (debug)
 155         Debug::finishDebug();
 156 }
 157
 158 Adaptation::Ecap::Host::MessagePtr
 159 Adaptation::Ecap::Host::newRequest() const
 160 {
 161     return MessagePtr(new Adaptation::Ecap::MessageRep(new HttpRequest));
 162 }
 163
 164 Adaptation::Ecap::Host::MessagePtr
 165 Adaptation::Ecap::Host::newResponse() const
 166 {
 167     return MessagePtr(new Adaptation::Ecap::MessageRep(new HttpReply));
 168 }
 169
 170 void
 171 Adaptation::Ecap::Host::Register()
 172 {
 173     if (!TheHost && SupportedVersion(libecap::VersionString(),
 174                                      "Squid executable dynamically linked")) {
 175         TheHost.reset(new Adaptation::Ecap::Host);
 176         libecap::RegisterHost(TheHost);
 177     }
 178 }