Changeset 79865 in vbox for trunk/src/VBox/NetworkServices/Dhcpd

Timestamp:

Jul 18, 2019 8:31:15 PM (6 years ago)

Author:

vboxsync

Message:

Dhcpd: Implemented forcing and suppessing DHCP option. bugref:9288

Location:

trunk/src/VBox/NetworkServices/Dhcpd

Files:

• Config.cpp (modified) (6 diffs)
• Config.h (modified) (3 diffs)
• DhcpMessage.cpp (modified) (1 diff)
• DhcpOptions.cpp (modified) (2 diffs)
• DhcpOptions.h (modified) (1 diff)

trunk/src/VBox/NetworkServices/Dhcpd/Config.cpp

@@ -773 +773 @@
 
 /**
+ * Internal worker for parsing \<ForcedOption\> and \<SupressedOption\> elements
+ * found under /DHCPServer/Options/, /DHCPServer/Group/ and /DHCPServer/Config/.
+ *
+ * @param   pElmOption          The element.
+ * @param   fForced             Whether it's a ForcedOption (true) or
+ *                              SuppressedOption element.
+ * @throws  std::bad_alloc, ConfigFileError
+ */
+void ConfigLevelBase::i_parseForcedOrSuppressedOption(const xml::ElementNode *pElmOption, bool fForced)
+{
+    /* Only a name attribute: */
+    const char *pszName;
+    if (!pElmOption->getAttributeValue("name", &pszName))
+        throw ConfigFileError(pElmOption, "missing option name");
+
+    uint8_t u8Opt;
+    int rc = RTStrToUInt8Full(pszName, 10, &u8Opt);
+    if (rc != VINF_SUCCESS) /* no warnings either */
+        throw ConfigFileError(pElmOption, "Bad option name '%s': %Rrc", pszName, rc);
+
+    if (fForced)
+        m_vecForcedOptions.push_back(u8Opt);
+    else
+        m_vecSuppressedOptions.push_back(u8Opt);
+}
+
+
+/**
  * Final children parser, handling only \<Option\> and barfing at anything else.
  *
  * @param   pElmChild           The child element to handle.
  * @param   fStrict             Set if we're in strict mode, clear if we just
- *                              want to get on with it if we can.
+ *                              want to get on with it if we can.  That said,
+ *                              the caller will catch ConfigFileError exceptions
+ *                              and ignore them if @a fStrict is @c false.
  * @param   pConfig             The configuration object.
  * @throws  std::bad_alloc, ConfigFileError
@@ -783 +813 @@
 void ConfigLevelBase::i_parseChild(const xml::ElementNode *pElmChild, bool fStrict, Config const *pConfig)
 {
+    /*
+     * Options.
+     */
     if (pElmChild->nameEquals("Option"))
     {
-        try
-        {
-            i_parseOption(pElmChild);
-        }
-        catch (ConfigFileError &rXcpt)
-        {
-            if (fStrict)
-                throw rXcpt;
-            LogRelFunc(("Ignoring option: %s\n", rXcpt.what()));
-        }
-    }
-    else if (!fStrict)
-    {
-        ConfigFileError Dummy(pElmChild->getParent(), "Unexpected child '%s'", pElmChild->getName());
-        LogRelFunc(("%s\n", Dummy.what()));
-    }
-    else
-        throw ConfigFileError(pElmChild->getParent(), "Unexpected child '%s'", pElmChild->getName());
-    RT_NOREF(pConfig);
+        i_parseOption(pElmChild);
+        return;
+    }
+
+    /*
+     * Forced and supressed options.
+     */
+    bool const fForced = pElmChild->nameEquals("ForcedOption");
+    if (fForced || pElmChild->nameEquals("SuppressedOption"))
+    {
+        i_parseForcedOrSuppressedOption(pElmChild, fForced);
+        return;
+    }
+
+    /*
+     * What's this?
+     */
+    throw ConfigFileError(pElmChild->getParent(), "Unexpected child '%s'", pElmChild->getName());
+    RT_NOREF(fStrict, pConfig);
 }
 
@@ -845 +878 @@
     const xml::ElementNode *pElmChild;
     while ((pElmChild = it.forAllNodes()) != NULL)
-        i_parseChild(pElmChild, fStrict, pConfig);
+    {
+        try
+        {
+            i_parseChild(pElmChild, fStrict, pConfig);
+        }
+        catch (ConfigFileError &rXcpt)
+        {
+            if (fStrict)
+                throw rXcpt;
+            LogRelFunc(("Ignoring: %s\n", rXcpt.what()));
+        }
+    }
 }
 
@@ -1117 +1161 @@
 {
     /*
+     * The client typcially requests a list of options.  The list is subject to
+     * forced and supressed lists on each configuration level in a_rConfig.  To
+     * efficiently manage it without resorting to maps, the current code
+     * assembles a C-style array of options on the stack that should be returned
+     * to the client.
+     */
+    uint8_t abOptions[256];
+    size_t  cOptions = 0;
+    size_t  iFirstForced = 255;
+#define IS_OPTION_PRESENT(a_bOption)         (memchr(abOptions, (a_bOption), cOptions) != NULL)
+#define APPEND_NOT_PRESENT_OPTION(a_bOption) do { \
+            AssertLogRelMsgBreak(cOptions < sizeof(abOptions), \
+                                 ("a_bOption=%#x abOptions=%.*Rhxs\n", (a_bOption), sizeof(abOptions), &abOptions[0])); \
+            abOptions[cOptions++] = (a_bOption); \
+        } while (0)
+
+    const OptParameterRequest::value_t &reqValue = a_rReqOpts.value();
+    if (reqValue.size() != 0)
+    {
+        /* Copy the requested list and append any forced options from the configs: */
+        for (octets_t::const_iterator itOptReq = reqValue.begin(); itOptReq != reqValue.end(); ++itOptReq)
+            if (!IS_OPTION_PRESENT(*itOptReq))
+                APPEND_NOT_PRESENT_OPTION(*itOptReq);
+        iFirstForced = cOptions;
+        for (Config::ConfigVec::const_iterator itCfg = a_rConfigs.begin(); itCfg != a_rConfigs.end(); ++itCfg)
+        {
+            octets_t const &rForced = (*itCfg)->getForcedOptions();
+            for (octets_t::const_iterator itOpt = rForced.begin(); itOpt != rForced.end(); ++itOpt)
+                if (!IS_OPTION_PRESENT(*itOpt))
+                {
+                    LogRel3((">>> Forcing option %d (%s)\n", *itOpt, DhcpOption::name(*itOpt)));
+                    APPEND_NOT_PRESENT_OPTION(*itOpt);
+                }
+        }
+    }
+    else
+    {
+        /* No options requests, feed the client all available options: */
+        for (Config::ConfigVec::const_iterator itCfg = a_rConfigs.begin(); itCfg != a_rConfigs.end(); ++itCfg)
+        {
+            optmap_t const &rOptions = (*itCfg)->getOptions();
+            for (optmap_t::const_iterator itOpt = rOptions.begin(); itOpt != rOptions.end(); ++itOpt)
+                if (!IS_OPTION_PRESENT(itOpt->first))
+                    APPEND_NOT_PRESENT_OPTION(itOpt->first);
+
+        }
+    }
+
+    /*
      * Always supply the subnet:
      */
     a_rRetOpts << new OptSubnetMask(m_IPv4Netmask);
 
-    /** @todo If a_rReqOpts is not present, provide the sum of all options in
-     *        a_rConfigs like ics says it does. */
-    /** @todo Look thru a_rConfigs for forced options, maybe we do it by using
-     *        DHCP option 55, and merging these into a_rReqOpts. */
-    /** @todo Have a way to mute options, i.e. break out of the inner search
-     *        loop below. Maybe using 'Suppress' encoding? */
-
-    /*
-     * Try provide the requested options:
-     */
-    const OptParameterRequest::value_t &reqValue = a_rReqOpts.value();
-    for (octets_t::const_iterator itOptReq = reqValue.begin(); itOptReq != reqValue.end(); ++itOptReq)
-    {
-        uint8_t bOptReq = *itOptReq;
-        LogRel2((">>> requested option %d (%#x)\n", bOptReq, bOptReq));
+    /*
+     * Try provide the options we've decided to return.
+     */
+    for (size_t iOpt = 0; iOpt < cOptions; iOpt++)
+    {
+        uint8_t const bOptReq = abOptions[iOpt];
+        if (iOpt < iFirstForced)
+            LogRel2((">>> requested option %d (%s)\n", bOptReq, DhcpOption::name(bOptReq)));
+        else
+            LogRel2((">>> forced option %d (%s)\n", bOptReq, DhcpOption::name(bOptReq)));
 
         if (bOptReq != OptSubnetMask::optcode)
@@ -1142 +1230 @@
             for (size_t i = 0; i < a_rConfigs.size(); i++)
             {
-                optmap_t::const_iterator itFound;
-                if (a_rConfigs[i]->findOption(bOptReq, itFound)) /* crap interface */
+                if (!a_rConfigs[i]->isOptionSuppressed(bOptReq))
                 {
-                    LogRel2(("... found in %s (type %s)\n", a_rConfigs[i]->getName(), a_rConfigs[i]->getType()));
-                    a_rRetOpts << itFound->second;
+                    optmap_t::const_iterator itFound;
+                    if (a_rConfigs[i]->findOption(bOptReq, itFound)) /* crap interface */
+                    {
+                        LogRel2(("... found in %s (type %s)\n", a_rConfigs[i]->getName(), a_rConfigs[i]->getType()));
+                        a_rRetOpts << itFound->second;
+                        fFound = true;
+                        break;
+                    }
+                }
+                else
+                {
+                    LogRel2(("... suppressed by %s (type %s)\n", a_rConfigs[i]->getName(), a_rConfigs[i]->getType()));
                     fFound = true;
                     break;
@@ -1158 +1255 @@
     }
 
+#undef IS_OPTION_PRESENT
+#undef APPEND_NOT_PRESENT_OPTION
     return a_rRetOpts;
 }

trunk/src/VBox/NetworkServices/Dhcpd/Config.h

@@ -54 +54 @@
     uint32_t        m_secMaxLeaseTime;
 
+    /** Options forced unsolicited upon the client. */
+    octets_t        m_vecForcedOptions;
+    /** Options (typcially from higher up) that should be hidden from the client. */
+    octets_t        m_vecSuppressedOptions;
+
 public:
     ConfigLevelBase()
@@ -60 +65 @@
         , m_secDefaultLeaseTime(0)
         , m_secMaxLeaseTime(0)
+        , m_vecForcedOptions()
+        , m_vecSuppressedOptions()
     { }
 
@@ -79 +86 @@
     }
 
+    /** Checks if @a bOpt is suppressed or not. */
+    bool            isOptionSuppressed(uint8_t bOpt) const RT_NOEXCEPT
+    {
+        return m_vecSuppressedOptions.size() > 0
+            && memchr(&m_vecSuppressedOptions.front(), bOpt, m_vecSuppressedOptions.size()) != NULL;
+    }
+
     /** @name Accessors
      * @{ */
-    uint32_t        getMinLeaseTime()     const RT_NOEXCEPT { return m_secMinLeaseTime; }
-    uint32_t        getDefaultLeaseTime() const RT_NOEXCEPT { return m_secDefaultLeaseTime; }
-    uint32_t        getMaxLeaseTime()     const RT_NOEXCEPT { return m_secMaxLeaseTime; }
+    uint32_t        getMinLeaseTime()       const RT_NOEXCEPT { return m_secMinLeaseTime; }
+    uint32_t        getDefaultLeaseTime()   const RT_NOEXCEPT { return m_secDefaultLeaseTime; }
+    uint32_t        getMaxLeaseTime()       const RT_NOEXCEPT { return m_secMaxLeaseTime; }
+    octets_t const &getForcedOptions()      const RT_NOEXCEPT { return m_vecForcedOptions; }
+    octets_t const &getSuppressedOptions()  const RT_NOEXCEPT { return m_vecSuppressedOptions; }
+    optmap_t const &getOptions()            const RT_NOEXCEPT { return m_Options; }
     /** @} */
 
 protected:
     void            i_parseOption(const xml::ElementNode *pElmOption);
+    void            i_parseForcedOrSuppressedOption(const xml::ElementNode *pElmOption, bool fForced);
     virtual void    i_parseChild(const xml::ElementNode *pElmChild, bool fStrict, Config const *pConfig);
 };

trunk/src/VBox/NetworkServices/Dhcpd/DhcpMessage.cpp

@@ -400 +400 @@
     for (optmap_t::const_iterator it = m_optmap.begin(); it != m_optmap.end(); ++it)
     {
-        LogRel3(("encoding option %d\n", it->first));
+        LogRel3(("encoding option %d (%s)\n", it->first, DhcpOption::name(it->first)));
         DhcpOption &opt = *it->second;
         data << opt;

trunk/src/VBox/NetworkServices/Dhcpd/DhcpOptions.cpp

@@ -285 +285 @@
 
 
-DhcpOption *DhcpOption::parse(uint8_t aOptCode, int aEnc, const char *pcszValue, int *prc /*= NULL*/)
+/*static*/ DhcpOption *DhcpOption::parse(uint8_t aOptCode, int aEnc, const char *pcszValue, int *prc /*= NULL*/)
 {
     int rcIgn;
@@ -402 +402 @@
     }
 }
+
+
+/**
+ * Gets the option name (simply "unknown" if not known) for logging purposes.
+ */
+/*static*/ const char *DhcpOption::name(uint8_t aOptCode)
+{
+    switch (aOptCode)
+    {
+#define HANDLE(a_OptClass) \
+        case a_OptClass::optcode: \
+            return &#a_OptClass[3]
+
+        HANDLE(OptSubnetMask);                  // 1
+        HANDLE(OptTimeOffset);                  // 2
+        HANDLE(OptRouters);                     // 3
+        HANDLE(OptTimeServers);                 // 4
+        HANDLE(OptNameServers);                 // 5
+        HANDLE(OptDNSes);                       // 6
+        HANDLE(OptLogServers);                  // 7
+        HANDLE(OptCookieServers);               // 8
+        HANDLE(OptLPRServers);                  // 9
+        HANDLE(OptImpressServers);              // 10
+        HANDLE(OptResourceLocationServers);     // 11
+        HANDLE(OptHostName);                    // 12
+        HANDLE(OptBootFileSize);                // 13
+        HANDLE(OptMeritDumpFile);               // 14
+        HANDLE(OptDomainName);                  // 15
+        HANDLE(OptSwapServer);                  // 16
+        HANDLE(OptRootPath);                    // 17
+        HANDLE(OptExtensionPath);               // 18
+        HANDLE(OptIPForwarding);                // 19
+        HANDLE(OptNonLocalSourceRouting);       // 20
+        HANDLE(OptPolicyFilter);                // 21
+        HANDLE(OptMaxDgramReassemblySize);      // 22
+        HANDLE(OptDefaultIPTTL);                // 23
+        HANDLE(OptPathMTUAgingTimeout);         // 24
+        HANDLE(OptPathMTUPlateauTable);         // 25
+        HANDLE(OptInterfaceMTU);                // 26
+        HANDLE(OptAllSubnetsAreLocal);          // 27
+        HANDLE(OptBroadcastAddress);            // 28
+        HANDLE(OptPerformMaskDiscovery);        // 29
+        HANDLE(OptMaskSupplier);                // 30
+        HANDLE(OptPerformRouterDiscovery);      // 31
+        HANDLE(OptRouterSolicitationAddress);   // 32
+        HANDLE(OptStaticRoute);                 // 33
+        HANDLE(OptTrailerEncapsulation);        // 34
+        HANDLE(OptARPCacheTimeout);             // 35
+        HANDLE(OptEthernetEncapsulation);       // 36
+        HANDLE(OptTCPDefaultTTL);               // 37
+        HANDLE(OptTCPKeepaliveInterval);        // 38
+        HANDLE(OptTCPKeepaliveGarbage);         // 39
+        HANDLE(OptNISDomain);                   // 40
+        HANDLE(OptNISServers);                  // 41
+        HANDLE(OptNTPServers);                  // 42
+        HANDLE(OptVendorSpecificInfo);          // 43
+        HANDLE(OptNetBIOSNameServers);          // 44
+        HANDLE(OptNetBIOSDatagramServers);      // 45
+        HANDLE(OptNetBIOSNodeType);             // 46
+        HANDLE(OptNetBIOSScope);                // 47
+        HANDLE(OptXWindowsFontServers);         // 48
+        HANDLE(OptXWindowsDisplayManager);      // 49
+        HANDLE(OptRequestedAddress);            // 50
+        HANDLE(OptLeaseTime);                   // 51
+        //HANDLE(OptOptionOverload);              // 52
+        HANDLE(OptMessageType);                 // 53
+        HANDLE(OptServerId);                    // 54
+        HANDLE(OptParameterRequest);            // 55
+        HANDLE(OptMessage);                     // 56
+        HANDLE(OptMaxDHCPMessageSize);          // 57
+        HANDLE(OptRenewalTime);                 // 58
+        HANDLE(OptRebindingTime);               // 59
+        HANDLE(OptVendorClassId);               // 60
+        HANDLE(OptClientId);                    // 61
+        HANDLE(OptNetWareIPDomainName);         // 62
+        HANDLE(OptNetWareIPInformation);        // 63
+        HANDLE(OptNISPlusDomain);               // 64
+        HANDLE(OptNISPlusServers);              // 65
+        HANDLE(OptTFTPServerName);              // 66
+        HANDLE(OptBootfileName);                // 67
+        HANDLE(OptMobileIPHomeAgents);          // 68
+        HANDLE(OptSMTPServers);                 // 69
+        HANDLE(OptPOP3Servers);                 // 70
+        HANDLE(OptNNTPServers);                 // 71
+        HANDLE(OptWWWServers);                  // 72
+        HANDLE(OptFingerServers);               // 73
+        HANDLE(OptIRCServers);                  // 74
+        HANDLE(OptStreetTalkServers);           // 75
+        HANDLE(OptSTDAServers);                 // 76
+        HANDLE(OptUserClassId);                 // 77
+        HANDLE(OptSLPDirectoryAgent);           // 78 - Only DHCPOptionEncoding_hex
+        HANDLE(OptSLPServiceScope);             // 79 - Only DHCPOptionEncoding_hex
+        HANDLE(OptRapidCommit);                 // 80
+
+        HANDLE(OptDomainSearch);                // 119 - Only DHCPOptionEncoding_hex
+
+#undef HANDLE
+        default:
+            return "unknown";
+    }
+}
+

trunk/src/VBox/NetworkServices/Dhcpd/DhcpOptions.h

@@ -62 +62 @@
 public:
     static DhcpOption *parse(uint8_t aOptCode, int aEnc, const char *pcszValue, int *prc = NULL);
+    static const char *name(uint8_t bOptcode);
 
 public: