[Server] Proide fallback when an IPv6 address is missing a ptr record.

src/Xrd/XrdLink.cc

@@ -285,6 +285,15 @@ int XrdLink::RecvAll(char *Buff, int Blen, int timeout)
               return linkXQ.RecvAll    (Buff, Blen, timeout);
 }
 
+/******************************************************************************/
+/*                              R e g i s t e r                               */
+/******************************************************************************/
+
+bool XrdLink::Register(const char *hName)
+{
+   return linkXQ.Register(hName);
+}
+
 /******************************************************************************/
 /*                                  S e n d                                   */
 /******************************************************************************/

src/Xrd/XrdLink.hh

@@ -326,6 +326,18 @@ int             Recv(char *buff, int blen, int timeout);
 
 int             RecvAll(char *buff, int blen, int timeout=-1);
 
+//------------------------------------------------------------------------------
+//! Register a host name with this IP address. This is not MT-safe!
+//!
+//! @param  hName    -> to a true host name which should be fully qualified.
+//!                     One of the IP addresses registered to this name must
+//!                     match the IP address associated with this object.
+//!
+//! @return True:    Specified name is now associated with this link.
+//!         False:   Nothing changed, registration could not be verified.
+//------------------------------------------------------------------------------
+
+bool        Register(const char *hName);
 //-----------------------------------------------------------------------------
 //! Send data on a link. This calls may block unless the socket was marked
 //! nonblocking. If a block would occur, the data is copied for later sending.

src/Xrd/XrdLinkXeq.cc

@@ -454,6 +454,25 @@ int XrdLinkXeq::RecvAll(char *Buff, int Blen, int timeout)
    return -1;
 }
 
+/******************************************************************************/
+/*                              R e g i s t e r                               */
+/******************************************************************************/
+
+bool XrdLinkXeq::Register(const char *hName)
+{
+
+// First see if we can register this name with the address object
+//
+   if (!Addr.Register(hName)) return false;
+
+// Make appropriate changes here
+//
+   if (HostName) free(HostName);
+   HostName = strdup(hName);
+   strlcpy(Lname, hName, sizeof(Lname));
+   return true;
+}
+
 /******************************************************************************/
 /*                                  S e n d                                   */
 /******************************************************************************/

src/Xrd/XrdLinkXeq.hh

@@ -91,6 +91,8 @@ int           Recv(char *buff, int blen, int timeout);
 
 int           RecvAll(char *buff, int blen, int timeout=-1);
 
+bool          Register(const char *hName);
+
 int           Send(const char *buff, int blen);
 int           Send(const struct iovec *iov, int iocnt, int bytes=0);
 

src/XrdCms/XrdCmsClientMan.cc

@@ -323,7 +323,8 @@ int XrdCmsClientMan::Hookup()
    EPNAME("Hookup");
    CmsLoginData Data;
    XrdLink *lp;
-   char buff[256];
+   char buff[256], hnBuff[264];
+   kXR_char *envData = 0;
    int rc, oldWait, tries = 12, opts = 0;
 
 // Turn off our debugging and version flags
@@ -332,6 +333,14 @@ int XrdCmsClientMan::Hookup()
    doDebug    &= ~manMask;
    manMutex.UnLock();
 
+// Report our hostname (there are better ways of doing this)
+//
+   const char *hn = getenv("XRDHOST");
+   if (hn)
+      {snprintf(hnBuff, sizeof(hnBuff), "myHN=%s", hn);
+       envData = (kXR_char *)hnBuff;
+      }
+
 // Keep trying to connect to the manager. Note that we bind the link to this
 // thread to make sure we get notified should another thread close the socket.
 //
@@ -343,6 +352,7 @@ int XrdCmsClientMan::Hookup()
             }
 //     lp->Bind(XrdSysThread::ID());
        memset(&Data, 0, sizeof(Data));
+       Data.envCGI = envData;
        Data.Mode = CmsLoginData::kYR_director;
        Data.HoldTime = static_cast<int>(getpid());
        if (!(rc = XrdCmsLogin::Login(lp, Data))) break;

src/XrdCms/XrdCmsConfig.cc

@@ -369,6 +369,11 @@ int XrdCmsConfig::Configure2()
    char *p, buff[512];
    std::string envData;
 
+// Add our host name to the env
+//
+   envData += "myHN=";
+   envData += myName;
+
 // Print herald
 //
    sprintf(buff, " phase 2 %s initialization started.", myRole);
@@ -414,7 +419,7 @@ int XrdCmsConfig::Configure2()
           else {if (QTRACE(Debug))
                    Say.Say("Config ", "Global System Identification: ", mySID);
                 if (Config.mySite)
-                   {envData += "site=";
+                   {envData += "&site=";
                     envData += mySite;
                    }
                }

src/XrdCms/XrdCmsProtocol.cc

@@ -365,6 +365,23 @@ void XrdCmsProtocol::Pander(const char *manager, int mport)
           }
        Netopts = 0; tries = waits = 6;
 
+       // Verify that this node has the real DNS name if it's IPv6
+       //
+       if (!(Link->AddrInfo()->isRegistered())
+       &&    Link->AddrInfo()->isIPType(XrdNetAddrInfo::IPv6))
+          {char *oldName = strdup(Link->Host());
+           Say.Emsg("Protocol", oldName, "is missing an IPv6 ptr record; "
+                               "attempting local registration as", manp);
+           if (!(Link->Register(manp)))
+              {Say.Emsg("Protocol", oldName,
+                        "registration failed; address mismatch.");
+              } else {
+               Say.Emsg("Protocol", oldName,
+                        "is now locally registered as", manp);
+              }
+           free(oldName);
+          }
+
        // Obtain a new node object for this connection
        //
        if (!(myNode = Manager->Add(Link, Lvl+1, terminate)))
@@ -557,7 +574,30 @@ int XrdCmsProtocol::Stats(char *buff, int blen, int do_sync)
 /******************************************************************************/
 /*                                 A d m i t                                  */
 /******************************************************************************/
-
+
+namespace
+{
+char *getAltName(char *sid, char *buff, int blen)
+{
+   char *atsign, *spacec, *retval = 0;
+   int  n;
+   if (sid)
+   if ((atsign = index(sid, '@')))
+      {atsign++;
+       if ((spacec = index(atsign, ' ')))
+          {*spacec = 0;
+           n = strlen(atsign);
+           if (n > 3 && n < blen)
+              {strcpy(buff, atsign);
+               retval = buff;
+              }
+           *spacec = ' ';
+          }
+      }
+   return retval;
+}
+}
+
 XrdCmsRouting *XrdCmsProtocol::Admit()
 {
    EPNAME("Admit");
@@ -590,6 +630,41 @@ XrdCmsRouting *XrdCmsProtocol::Admit()
 //
    if (!Source.Admit(Link, Data, Config.mySID, envP)) return 0;
 
+// Construct environment for incomming node
+//
+   XrdOucEnv cgiEnv((const char *)Data.envCGI);
+
+// We have this problem hat many times the IPv6 address is missing the ptr
+// record in DNS. If this node is IPv6 unregistered and the incomming node
+// supplied it's host name then we can attempt to register it locally.
+//
+   if (!(Link->AddrInfo()->isRegistered())
+   &&    Link->AddrInfo()->isIPType(XrdNetAddrInfo::IPv6))
+      {const char *altName = cgiEnv.Get("myHN");
+       const char *altType = "stated mapping";
+       char hBF[256], *oldName = strdup(Link->Host());
+       if (!altName) {altName = getAltName((char *)Data.SID, hBF, sizeof(hBF));
+                      altType = "inferred mapping";
+                     }
+       Say.Emsg("Protocol", "DNS lookup for", oldName, "failed; "
+                            "IPv6 ptr record missing!");
+       if (!altName)
+          {Say.Emsg("Protocol", oldName, "did not supply a fallback "
+                                         "mapping; using IPv6 address.");
+          } else {
+           char buff[512];
+           snprintf(buff, sizeof(buff), "%s -> %s", oldName, altName);
+           Say.Emsg("Protocol", "Attempting to use", altType, buff);
+           if (!(Link->Register(altName)))
+              {Say.Emsg("Protocol", buff, altType,"failed; address mismatch.");
+              } else {
+               Say.Emsg("Protocol", oldName,
+                        "is now locally registered as", altName);
+              }
+          }
+       free(oldName);
+      }
+
 // Handle Redirectors here (minimal stuff to do)
 //
    if (Data.Mode & CmsLoginData::kYR_director) 
@@ -736,7 +811,6 @@ XrdCmsRouting *XrdCmsProtocol::Admit()
 
 // Document the login
 //
-   XrdOucEnv cgiEnv((const char *)Data.envCGI);
    const char *sname = cgiEnv.Get("site");
    const char *lfmt  = (myNode->isMan > 1 ? "Standby%s%s" : "Primary%s%s");
    snprintf(envBuff,sizeof(envBuff),lfmt,(sname ? " ":""),(sname ? sname : ""));

src/XrdNet/XrdNetAddr.cc

@@ -164,6 +164,42 @@ int XrdNetAddr::Port(int pNum)
    return pNum;
 }
 
+/******************************************************************************/
+/*                              R e g i s t e r                               */
+/******************************************************************************/
+
+bool XrdNetAddr::Register(const char *hName)
+{
+   XrdNetAddr *aListVec = 0;
+   int i, aListNum;
+
+// Step one is to make sure the incomming name is not an address
+//
+   if (!isHostName(hName)) return false;
+
+// The next step is to get all of the IP addresses registered for this name
+//
+   if (XrdNetUtils::GetAddrs(hName, &aListVec, aListNum,
+                      XrdNetUtils::allIPMap, XrdNetUtils::NoPortRaw))
+      return false;
+
+// In order to use the given name, one of the IP addresses in the list must
+// match our address. This is about as secure we can get.
+//
+   for (i = 0; i < aListNum; i++) {if (Same(&aListVec[i])) break;}
+   delete [] aListVec;
+
+// If we didn't find a match, report it
+//
+   if (i >= aListNum) return false;
+
+// Replace current hostname with the wanted one
+//
+   if (hostName) free(hostName);
+   hostName = strdup(hName);
+   return true;
+}
+
 /******************************************************************************/
 /*                                   S e t                                    */
 /******************************************************************************/

src/XrdNet/XrdNetAddr.hh

@@ -72,6 +72,19 @@ static bool IPV4Set() {return useIPV4;}
 
 int         Port(int pNum=-1);
 
+//------------------------------------------------------------------------------
+//! Register a host name with this IP address. This is not MT-safe!
+//!
+//! @param  hName    -> to a true host name which should be fully qualified.
+//!                     One of the IP addresses registered to this name must
+//!                     match the IP address associated with this object.
+//!
+//! @return True:    Specified name is now associated with this address.
+//!         False:   Nothing changed, registration could not be verified.
+//------------------------------------------------------------------------------
+
+bool        Register(const char *hName);
+
 //------------------------------------------------------------------------------
 //! Set the IP address and possibly the port number.
 //!