httpd: fix three small null-related bugs in accessing active transfer…

… fields

Motivation:

Patch 9258 introduced a UserInfo object and also somewhat restructured TransferObserverV1.
In so doing it introduced two minor bugs.  The first was an erroneous suppression
of a condition preventing the addition of nulls to an argument list in the creation
of the ascii context info.  The latter has to do with the handling of exceptions thrown by
the Subjects static methods (this was observed to occur using anonymous dccp).

Also, a method called by the webadmin version of this service also neglected to
check for a null value.

Modification:

1.  Restore the condition check (mover == null) for the ascii context info.
2.  Provide for the handling of NoSuchElement and IllegalArgument exceptions
3.  Handle the null value for bytesTransferred.

Result:

Errors are now handled gracefully rather than causing Wicket to crash or a log
full of stack traces.

Target: master
Require-notes: no
Require-book: no
Acked-by: Gerd

modules/common/src/main/java/org/dcache/auth/Subjects.java

@@ -249,7 +249,7 @@ public static String getDn(Subject subject)
      *         primary FQANs
      */
     public static FQAN getPrimaryFqan(Subject subject)
-        throws NoSuchElementException
+        throws IllegalArgumentException
     {
         Set<FQANPrincipal> principals =
             subject.getPrincipals(FQANPrincipal.class);

modules/dcache/src/main/java/diskCacheV111/cells/TransferObserverV1.java

@@ -216,12 +216,7 @@ void toHtmlRow(List<String> out) {
             if (moverStatus != null) {
                 out.add(moverStatus);
                 out.add(elapsedSinceSubmitted);
-                if (moverStart != null) {
-                    out.add(transferTimeStr);
-                    out.add(String.valueOf(bytesTransferred));
-                    out.add(transferRateStr);
-                    out.add(running);
-                }
+                addMoverInfo(out);
             }
         }
 
@@ -240,13 +235,25 @@ void toAsciiLine(StringBuilder builder) {
             args.add(replyHost);
             args.add(sessionStatus);
             args.add(waiting);
-            args.add(moverStatus == null ? "No-mover()-Found" : moverStatus);
-            args.add(transferTimeStr);
-            args.add(String.valueOf(bytesTransferred));
-            args.add(transferRateStr);
-            args.add(running);
+
+            if (moverStatus == null) {
+                args.add("No-mover()-Found");
+            } else {
+                args.add(moverStatus);
+                addMoverInfo(args);
+            }
+
             builder.append(new Args(args)).append('\n');
         }
+
+        private void addMoverInfo(List<String> list) {
+            if (moverStart != null) {
+                list.add(transferTimeStr);
+                list.add(String.valueOf(bytesTransferred));
+                list.add(transferRateStr);
+                list.add(running);
+            }
+        }
     }
 
     public TransferObserverV1(String name, String args) {

modules/dcache/src/main/java/diskCacheV111/util/TransferInfo.java

@@ -164,6 +164,14 @@ public Subject getSubject() {
     }
 
     public Long getTransferRate() {
+        if (bytesTransferred == null) {
+            return 0L;
+        }
+
+        if (transferTime == null) {
+            return 0L;
+        }
+
         long kB = bytesTransferred / 1024;
         long secs = transferTime / 1000;
         return secs > 0.0 ? kB / secs : 0L;

modules/dcache/src/main/java/diskCacheV111/util/UserInfo.java

@@ -59,8 +59,12 @@ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  */
 package diskCacheV111.util;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import javax.security.auth.Subject;
 import java.io.Serializable;
+import java.util.NoSuchElementException;
 
 import org.dcache.auth.FQAN;
 import org.dcache.auth.Subjects;
@@ -70,6 +74,7 @@ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  * between core dCache and webadmin modules.</p>
  */
 public final class UserInfo implements Serializable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(UserInfo.class);
     private String username;
     private Long   uid;
     private Long   gid;
@@ -80,9 +85,46 @@ public UserInfo() {
 
     public UserInfo(Subject subject) {
         username = Subjects.getUserName(subject);
-        uid = Subjects.getUid(subject);
-        gid = Subjects.getPrimaryGid(subject);
-        primaryFqan = Subjects.getPrimaryFqan(subject);
+
+        /*
+         *  The values may not be set by some protocols,
+         *  such as anonymous dcap.  We do not want to fail here
+         *  in that case.
+         *
+         *  In the case of an IllegalArgument, this is actually an
+         *  error which should be reported, but again we do not
+         *  want to fail the interface because of it.
+         */
+
+        if (Subjects.isNobody(subject)) {
+            uid = null;
+        } else {
+            try {
+                uid = Subjects.getUid(subject);
+            } catch (IllegalArgumentException e) {
+                uid = null;
+                LOGGER.warn("Error when fetching UID from {}: {}.",
+                            subject, e.toString());
+            }
+        }
+
+        try {
+            gid = Subjects.getPrimaryGid(subject);
+        } catch (NoSuchElementException e) {
+            gid = null;
+        } catch (IllegalArgumentException e) {
+            gid = null;
+            LOGGER.warn("Error when fetching GID from {}: {}.",
+                        subject, e.toString());
+        }
+
+        try {
+            primaryFqan = Subjects.getPrimaryFqan(subject);
+        } catch (IllegalArgumentException e) {
+            primaryFqan = null;
+            LOGGER.warn("Error when fetching primary FQAN from {}: {}.",
+                        subject, e.toString());
+        }
     }
 
     public String getGid() {