1571. [bug] rbt:hash_node() could fail leaving the hash table

                        in an inconsistant state.  [RT #10208]

diff --git a/CHANGES b/CHANGES
index b8d52b9799c4331ad189d5a9f1b92f0f0fa767d9..f3557a23c4bd0355b36c8d3d2c63da148d7d309a 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -14,6 +14,9 @@
                        "make install DESTDIR=/xx" works with
                        "configure --with-libtool".  [RT #9941]
 
+1571.  [bug]           rbt:hash_node() could fail leaving the hash table
+                       in an inconsistant state.  [RT #10208]
+
 1567.  [bug]           B.ROOT-SERVERS.NET is now 192.228.79.201.
 
 1566.  [port]          Support for the cmsg framework on Solaris and HP/UX.

diff --git a/lib/dns/rbt.c b/lib/dns/rbt.c
index 1a688a374f9275b2c0457cd7f6c7ce06b155c228..febdcf6b0f5de96bf5f0f14dab2061db80221996 100644 (file)
--- a/lib/dns/rbt.c
+++ b/lib/dns/rbt.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: rbt.c,v 1.115.2.2 2003/07/22 04:03:42 marka Exp $ */
+/* $Id: rbt.c,v 1.115.2.3 2004/03/03 22:38:20 marka Exp $ */
 
 /* Principal Authors: DCL */
 
@@ -138,6 +138,11 @@ do { \
        (name)->attributes |= DNS_NAMEATTR_READONLY; \
 } while (0)
 
+#ifdef DNS_RBT_USEHASH
+static isc_result_t
+inithash(dns_rbt_t *rbt);
+#endif
+
 #ifdef DEBUG
 #define inline
 /*
@@ -220,7 +225,7 @@ static isc_result_t
 create_node(isc_mem_t *mctx, dns_name_t *name, dns_rbtnode_t **nodep);
 
 #ifdef DNS_RBT_USEHASH
-static inline isc_result_t
+static inline void
 hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node);
 static inline void
 unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node);
@@ -251,7 +256,11 @@ isc_result_t
 dns_rbt_create(isc_mem_t *mctx, void (*deleter)(void *, void *),
               void *deleter_arg, dns_rbt_t **rbtp)
 {
+#ifdef DNS_RBT_USEHASH
+       isc_result_t result;
+#endif
        dns_rbt_t *rbt;
+       
 
        REQUIRE(mctx != NULL);
        REQUIRE(rbtp != NULL && *rbtp == NULL);
@@ -268,6 +277,13 @@ dns_rbt_create(isc_mem_t *mctx, void (*deleter)(void *, void *),
        rbt->nodecount = 0;
        rbt->hashtable = NULL;
        rbt->hashsize = 0;
+#ifdef DNS_RBT_USEHASH
+       result = inithash(rbt);
+       if (result != ISC_R_SUCCESS) {
+               isc_mem_put(mctx, rbt, sizeof(*rbt));
+               return (result);
+       }
+#endif
        rbt->magic = RBT_MAGIC;
 
        *rbtp = rbt;
@@ -396,7 +412,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
                        new_current->is_root = 1;
                        rbt->root = new_current;
                        *nodep = new_current;
-                       result = hash_node(rbt, new_current);
+                       hash_node(rbt, new_current);
                }
                return (result);
        }
@@ -672,9 +688,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
                                ATTRS(current) &= ~DNS_NAMEATTR_ABSOLUTE;
 
                                rbt->nodecount++;
-                               result = hash_node(rbt, new_current);
-                               if (result != ISC_R_SUCCESS)
-                                       break;
+                               hash_node(rbt, new_current);
 
                                if (common_labels ==
                                    dns_name_countlabels(add_name) &&
@@ -726,18 +740,7 @@ dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) {
                dns_rbt_addonlevel(new_current, current, order, root);
                rbt->nodecount++;
                *nodep = new_current;
-               result = hash_node(rbt, new_current);
-               /*
-                * XXXDCL Ugh.  If hash_node failed, it was because
-                * there is not enough memory.  The node is now unfindable,
-                * and ideally should be removed.  This is kind of tricky,
-                * and all hell is probably going to break loose throughout
-                * the rest of the library because of the lack of memory,
-                * so fixing up the tree as though no addition had been
-                * made is skipped.  (Actually, this hash_node failing is
-                * not the only situation in this file where an unexpected
-                * error can leave things in an incorrect state.)
-                */
+               hash_node(rbt, new_current);
        }
 
        return (result);
@@ -1625,7 +1628,7 @@ inithash(dns_rbt_t *rbt) {
        return (ISC_R_SUCCESS);
 }
 
-static isc_result_t
+static void
 rehash(dns_rbt_t *rbt) {
        unsigned int oldsize;
        dns_rbtnode_t **oldtable;
@@ -1634,12 +1637,15 @@ rehash(dns_rbt_t *rbt) {
        unsigned int i;
 
        oldsize = rbt->hashsize;
-       rbt->hashsize *= 2;
        oldtable = rbt->hashtable;
+       rbt->hashsize *= 2 + 1;
        rbt->hashtable = isc_mem_get(rbt->mctx,
                                     rbt->hashsize * sizeof(dns_rbtnode_t *));
-       if (rbt->hashtable == NULL)
-               return (ISC_R_NOMEMORY);
+       if (rbt->hashtable == NULL) {
+               rbt->hashtable = oldtable;
+               rbt->hashsize = oldsize;
+               return;
+       }
 
        for (i = 0; i < rbt->hashsize; i++)
                rbt->hashtable[i] = NULL;
@@ -1654,26 +1660,17 @@ rehash(dns_rbt_t *rbt) {
                        node = oldtable[i];
                }
        }
-
-       isc_mem_put(rbt->mctx, oldtable,
-                   rbt->hashsize * sizeof(dns_rbtnode_t *) / 2);
-
-       return (ISC_R_SUCCESS);
+       
+       isc_mem_put(rbt->mctx, oldtable, oldsize * sizeof(dns_rbtnode_t *));
 }
 
-static inline isc_result_t
+static inline void
 hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node) {
-       isc_result_t result = ISC_R_SUCCESS;
 
-       if (rbt->hashtable == NULL)
-               result = inithash(rbt);
-       else if (rbt->nodecount >= rbt->hashsize)
-               result = rehash(rbt);
-
-       if (result == ISC_R_SUCCESS)
-               hash_add_node(rbt, node);
+       if (rbt->nodecount >= rbt->hashsize)
+               rehash(rbt);
 
-       return (result);
+       hash_add_node(rbt, node);
 }
 
 static inline void