From 7d1e56dc90ebea1f14d06de5a6124d4ed186115f Mon Sep 17 00:00:00 2001
From: Noriko Hosoi <nhosoi@redhat.com>
Date: Fri, 19 Jul 2013 13:45:22 -0700
Subject: [PATCH 84/99] Ticket #47435 - Very large entryusn values after
 enabling the USN plugin and the lastusn value is negative.

1. Bug description: The initial value of lastusn is -1, but since
the entryusn has the unsigned long long integer type, the server
returns 18446744073709551615 == 0XFFFFFFFFFFFFFFFF.

Fix description: The initial value "-1" is returned as it is.

2. Bug description: Entryusn syntax is defined as an integer in
the schema.  If negative values are accidentally stored in the
entryusn value in the database, it was casted to the unsigned
integer in the entryusn initialization code (usn_get_last_usn).

Fix description: When an entryusn value is retrieved from the
database, it's checked as a singed integer once and if it is
negative, it's replaced with the initial value "-1".

https://fedorahosted.org/389/ticket/47435

Reviewed by Mark and Rich (Thank you!!)
(cherry picked from commit c94da991450da486b2032815b867bd2548a1614c)
(cherry picked from commit f54e44c138b0c56c2845d3614753d9ec5ebbdcba)
---
 ldap/servers/plugins/usn/usn.c           | 20 ++++++++++++++------
 ldap/servers/slapd/back-ldbm/back-ldbm.h |  1 +
 ldap/servers/slapd/back-ldbm/ldbm_usn.c  |  6 +++++-
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/ldap/servers/plugins/usn/usn.c b/ldap/servers/plugins/usn/usn.c
index 4473618..4eb6528 100644
--- a/ldap/servers/plugins/usn/usn.c
+++ b/ldap/servers/plugins/usn/usn.c
@@ -672,9 +672,13 @@ usn_rootdse_search(Slapi_PBlock *pb, Slapi_Entry* e, Slapi_Entry* entryAfter,
         }
         if (be && be->be_usn_counter) {
             /* get a next USN counter from be_usn_counter; 
-             * then minus 1 from it */
-            PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "%" NSPRIu64,
-                                slapi_counter_get_value(be->be_usn_counter)-1);
+             * then minus 1 from it (except if be_usn_counter has value 0) */
+            if (slapi_counter_get_value(be->be_usn_counter)) {
+                PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "%" NSPRIu64,
+                            slapi_counter_get_value(be->be_usn_counter)-1);
+            } else {
+                PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "-1");
+            }
             usn_berval.bv_len = strlen(usn_berval.bv_val);
             slapi_entry_attr_replace(e, attr, vals);
         }
@@ -691,9 +695,13 @@ usn_rootdse_search(Slapi_PBlock *pb, Slapi_Entry* e, Slapi_Entry* entryAfter,
                 continue;
             }
             /* get a next USN counter from be_usn_counter; 
-             * then minus 1 from it */
-            PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "%" NSPRIu64,
-                                slapi_counter_get_value(be->be_usn_counter)-1);
+             * then minus 1 from it (except if be_usn_counter has value 0) */
+            if (slapi_counter_get_value(be->be_usn_counter)) {
+                PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "%" NSPRIu64,
+                            slapi_counter_get_value(be->be_usn_counter)-1);
+            } else {
+                PR_snprintf(usn_berval.bv_val, USN_COUNTER_BUF_LEN, "-1");
+            }
             usn_berval.bv_len = strlen(usn_berval.bv_val);
     
             if (USN_LAST_USN_ATTR_CORE_LEN+strlen(be->be_name)+2 > attr_len) {
diff --git a/ldap/servers/slapd/back-ldbm/back-ldbm.h b/ldap/servers/slapd/back-ldbm/back-ldbm.h
index 3330449..61c7af9 100644
--- a/ldap/servers/slapd/back-ldbm/back-ldbm.h
+++ b/ldap/servers/slapd/back-ldbm/back-ldbm.h
@@ -868,6 +868,7 @@ typedef struct _back_search_result_set
 #define LDBM_ERROR_FOUND_DUPDN 9999
 
 /* Initial entryusn value */
+#define SIGNEDINITIALUSN (-1)
 #define INITIALUSN (PRUint64)(-1)
 
 /* changelog backup dir name 
diff --git a/ldap/servers/slapd/back-ldbm/ldbm_usn.c b/ldap/servers/slapd/back-ldbm/ldbm_usn.c
index 403e279..7c11a68 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_usn.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_usn.c
@@ -124,6 +124,7 @@ usn_get_last_usn(Slapi_Backend *be, PRUint64 *last_usn)
     DBC *dbc = NULL;
     DBT key;              /* For the last usn */
     DBT value;
+    PRInt64 signed_last_usn;
 
     if (NULL == last_usn) {
         return rc;
@@ -167,7 +168,10 @@ usn_get_last_usn(Slapi_Backend *be, PRUint64 *last_usn)
             p = (char *)key.data;
         }
         if (0 == rc) {
-            *last_usn = strtoll(++p, (char **)NULL, 0); /* key.data: =num */
+            signed_last_usn = strtoll(++p, (char **)NULL, 0); /* key.data: =num */
+            if (signed_last_usn > SIGNEDINITIALUSN) {
+                *last_usn = signed_last_usn;
+            }
         }
     } else if (DB_NOTFOUND == rc) {
         /* if empty, it's okay.  This is just a beginning. */
-- 
1.8.1.4