Signal temporary host lookup errors in nscd as such to the requester.

(cherry picked from commit bc425b339b067bebe3d49907e63b0e81eb261bd2)

diff --git a/ChangeLog b/ChangeLog
index 68fec19b03eccb4b6b8f3354883c780e4ad758f4..76eb85882b0fe63cb074aa080d7d43524d677fb1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-01-15  Ulrich Drepper  <drepper@gmail.com>
+
+       [BZ #6812]
+       * nscd/hstcache.c (tryagain): Define.
+       (cache_addhst): Return tryagain not notfound for temporary errors.
+       (addhstbyX): Also set h_errno to TRY_AGAIN when memory allocation
+       failed.
+
 2011-01-13  Ulrich Drepper  <drepper@gmail.com>
 
        [BZ #12397]

diff --git a/nscd/hstcache.c b/nscd/hstcache.c
index 228f6fd8ab1a7f54ac6644f702eec19d118bb5ab..a6055cf998329b0db0de237fa42aa6f7a2dd96e0 100644 (file)
--- a/nscd/hstcache.c
+++ b/nscd/hstcache.c
@@ -1,5 +1,5 @@
 /* Cache handling for host lookup.
-   Copyright (C) 1998-2008, 2009 Free Software Foundation, Inc.
+   Copyright (C) 1998-2008, 2009, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -77,6 +77,20 @@ static const hst_response_header notfound =
 };
 
 
+/* This is the standard reply in case there are temporary problems.  */
+static const hst_response_header tryagain =
+{
+  .version = NSCD_VERSION,
+  .found = 0,
+  .h_name_len = 0,
+  .h_aliases_cnt = 0,
+  .h_addrtype = -1,
+  .h_length = -1,
+  .h_addr_list_cnt = 0,
+  .error = TRY_AGAIN
+};
+
+
 static void
 cache_addhst (struct database_dyn *db, int fd, request_header *req,
              const void *key, struct hostent *hst, uid_t owner,
@@ -111,11 +125,15 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req,
       else
        {
          /* We have no data.  This means we send the standard reply for this
-            case.  */
+            case.  Possibly this is only temporary.  */
          ssize_t total = sizeof (notfound);
+         assert (sizeof (notfound) == sizeof (tryagain));
+
+         const hst_response_header *resp = (errval == EAGAIN
+                                            ? &tryagain : &notfound);
 
          if (fd != -1 &&
-             TEMP_FAILURE_RETRY (send (fd, &notfound, total,
+             TEMP_FAILURE_RETRY (send (fd, resp, total,
                                        MSG_NOSIGNAL)) != total)
            all_written = false;
 
@@ -135,7 +153,7 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req,
                                           ? db->negtimeout : ttl);
 
              /* This is the reply.  */
-             memcpy (&dataset->resp, &notfound, total);
+             memcpy (&dataset->resp, resp, total);
 
              /* Copy the key data.  */
              memcpy (dataset->strdata, key, req->key_len);
@@ -490,6 +508,7 @@ addhstbyX (struct database_dyn *db, int fd, request_header *req,
              /* We set the error to indicate this is (possibly) a
                 temporary error and that it does not mean the entry
                 is not available at all.  */
+             h_errno = TRY_AGAIN;
              errval = EAGAIN;
              break;
            }