base/SOURCES/net-snmp-5.7.2-agentx-disconnect-crash.patch

969061 - net-snmpd crash on time out

ABI breaking upstream patch.

commit 793d596838ff7cb48a73b675d62897c56c9e62df
Author: Jan Safranek <jsafranek@users.sourceforge.net>
Date:   Tue Jul 2 14:32:56 2013 +0200

    From: Jiri Cervenka: snmpd: Fixed agentx crashing and/or freezing on timeout.
    
    Queued requests are dropped gracefuly.

diff --git a/agent/mibgroup/agentx/master_admin.c b/agent/mibgroup/agentx/master_admin.c
index 999128a..4b42104 100644
--- a/agent/mibgroup/agentx/master_admin.c
+++ b/agent/mibgroup/agentx/master_admin.c
@@ -158,6 +158,7 @@ close_agentx_session(netsnmp_session * session, int sessid)
     for (sp = session->subsession; sp != NULL; sp = sp->next) {
 
         if (sp->sessid == sessid) {
+            netsnmp_remove_delegated_requests_for_session(sp);
             unregister_mibs_by_session(sp);
             unregister_index_by_session(sp);
             unregister_sysORTable_by_session(sp);
diff --git a/agent/snmp_agent.c b/agent/snmp_agent.c
index 1261c53..51eb287 100644
--- a/agent/snmp_agent.c
+++ b/agent/snmp_agent.c
@@ -1415,6 +1415,7 @@ init_agent_snmp_session(netsnmp_session * session, netsnmp_pdu *pdu)
     asp->treecache_num = -1;
     asp->treecache_len = 0;
     asp->reqinfo = SNMP_MALLOC_TYPEDEF(netsnmp_agent_request_info);
+    asp->flags = SNMP_AGENT_FLAGS_NONE;
     DEBUGMSGTL(("verbose:asp", "asp %p reqinfo %p created\n",
                 asp, asp->reqinfo));
 
@@ -1463,6 +1464,9 @@ netsnmp_check_for_delegated(netsnmp_agent_session *asp)
 
     if (NULL == asp->treecache)
         return 0;
+
+    if (asp->flags & SNMP_AGENT_FLAGS_CANCEL_IN_PROGRESS)
+        return 0;
     
     for (i = 0; i <= asp->treecache_num; i++) {
         for (request = asp->treecache[i].requests_begin; request;
@@ -1541,39 +1545,48 @@ int
 netsnmp_remove_delegated_requests_for_session(netsnmp_session *sess)
 {
     netsnmp_agent_session *asp;
-    int count = 0;
+    int total_count = 0;
     
     for (asp = agent_delegated_list; asp; asp = asp->next) {
         /*
          * check each request
          */
+        int i;
+        int count = 0;
         netsnmp_request_info *request;
-        for(request = asp->requests; request; request = request->next) {
-            /*
-             * check session
-             */
-            netsnmp_assert(NULL!=request->subtree);
-            if(request->subtree->session != sess)
-                continue;
+        for (i = 0; i <= asp->treecache_num; i++) {
+            for (request = asp->treecache[i].requests_begin; request;
+                 request = request->next) {
+                /*
+                 * check session
+                 */
+                netsnmp_assert(NULL!=request->subtree);
+                if(request->subtree->session != sess)
+                    continue;
 
-            /*
-             * matched! mark request as done
-             */
-            netsnmp_request_set_error(request, SNMP_ERR_GENERR);
-            ++count;
+                /*
+                 * matched! mark request as done
+                 */
+                netsnmp_request_set_error(request, SNMP_ERR_GENERR);
+                ++count;
+            }
+        }
+        if (count) {
+            asp->flags |= SNMP_AGENT_FLAGS_CANCEL_IN_PROGRESS;
+            total_count += count;
         }
     }
 
     /*
      * if we found any, that request may be finished now
      */
-    if(count) {
+    if(total_count) {
         DEBUGMSGTL(("snmp_agent", "removed %d delegated request(s) for session "
-                    "%8p\n", count, sess));
-        netsnmp_check_outstanding_agent_requests();
+                    "%8p\n", total_count, sess));
+        netsnmp_check_delegated_requests();
     }
     
-    return count;
+    return total_count;
 }
 
 int
@@ -2745,19 +2758,11 @@ handle_var_requests(netsnmp_agent_session *asp)
     return final_status;
 }
 
-/*
- * loop through our sessions known delegated sessions and check to see
- * if they've completed yet. If there are no more delegated sessions,
- * check for and process any queued requests
- */
 void
-netsnmp_check_outstanding_agent_requests(void)
+netsnmp_check_delegated_requests(void)
 {
     netsnmp_agent_session *asp, *prev_asp = NULL, *next_asp = NULL;
 
-    /*
-     * deal with delegated requests
-     */
     for (asp = agent_delegated_list; asp; asp = next_asp) {
         next_asp = asp->next;   /* save in case we clean up asp */
         if (!netsnmp_check_for_delegated(asp)) {
@@ -2796,6 +2801,22 @@ netsnmp_check_outstanding_agent_requests(void)
             prev_asp = asp;
         }
     }
+}
+
+/*
+ * loop through our sessions known delegated sessions and check to see
+ * if they've completed yet. If there are no more delegated sessions,
+ * check for and process any queued requests
+ */
+void
+netsnmp_check_outstanding_agent_requests(void)
+{
+    netsnmp_agent_session *asp;
+
+    /*
+     * deal with delegated requests
+     */
+    netsnmp_check_delegated_requests();
 
     /*
      * if we are processing a set and there are more delegated
@@ -2825,7 +2846,8 @@ netsnmp_check_outstanding_agent_requests(void)
 
             netsnmp_processing_set = netsnmp_agent_queued_list;
             DEBUGMSGTL(("snmp_agent", "SET request remains queued while "
-                        "delegated requests finish, asp = %8p\n", asp));
+                        "delegated requests finish, asp = %8p\n",
+                        agent_delegated_list));
             break;
         }
 #endif /* NETSNMP_NO_WRITE_SUPPORT */
@@ -2886,6 +2908,10 @@ check_delayed_request(netsnmp_agent_session *asp)
     case SNMP_MSG_GETBULK:
     case SNMP_MSG_GETNEXT:
         netsnmp_check_all_requests_status(asp, 0);
+        if (asp->flags & SNMP_AGENT_FLAGS_CANCEL_IN_PROGRESS) {
+            DEBUGMSGTL(("snmp_agent","canceling next walk for asp %p\n", asp));
+            break;
+        }
         handle_getnext_loop(asp);
         if (netsnmp_check_for_delegated(asp) &&
             netsnmp_check_transaction_id(asp->pdu->transid) !=
diff --git a/include/net-snmp/agent/snmp_agent.h b/include/net-snmp/agent/snmp_agent.h
index aad8837..43f4fff 100644
--- a/include/net-snmp/agent/snmp_agent.h
+++ b/include/net-snmp/agent/snmp_agent.h
@@ -32,6 +32,9 @@ extern          "C" {
 #define SNMP_MAX_PDU_SIZE 64000 /* local constraint on PDU size sent by agent
                                  * (see also SNMP_MAX_MSG_SIZE in snmp_api.h) */
 
+#define SNMP_AGENT_FLAGS_NONE                   0x0
+#define SNMP_AGENT_FLAGS_CANCEL_IN_PROGRESS     0x1
+
     /*
      * If non-zero, causes the addresses of peers to be logged when receptions
      * occur.  
@@ -205,6 +208,7 @@ extern          "C" {
         int             treecache_num;  /* number of current cache entries */
         netsnmp_cachemap *cache_store;
         int             vbcount;
+        int             flags;
     } netsnmp_agent_session;
 
     /*
@@ -240,6 +244,7 @@ extern          "C" {
     int             init_master_agent(void);
     void            shutdown_master_agent(void);
     int             agent_check_and_process(int block);
+    void            netsnmp_check_delegated_requests(void);
     void            netsnmp_check_outstanding_agent_requests(void);
 
     int             netsnmp_request_set_error(netsnmp_request_info *request,