From 77e5525436c180d70d417425f33317afb909891b Mon Sep 17 00:00:00 2001
From: VilhoRaatikka <vilho.raatikka@skysql.com>
Date: Thu, 14 Aug 2014 15:15:22 +0300
Subject: [PATCH] mysql_client.c:gw_error_client_event &
 gw_client_hangup_event: added session state check, if session is already
 closing, don't start redundant call to dcb_close.
 mysql_common.c:mysql_protocol_done: added protocol state check. Used not to
 check it which caused double free of allocated memory.

---
 server/core/dcb.c                             |  7 +++---
 server/modules/protocol/mysql_backend.c       | 25 +++++++++----------
 server/modules/protocol/mysql_client.c        | 14 +++++++++++
 server/modules/protocol/mysql_common.c        |  5 ++++
 .../routing/readwritesplit/readwritesplit.c   |  2 +-
 5 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/server/core/dcb.c b/server/core/dcb.c
index 1dfde0b58..090d57554 100644
--- a/server/core/dcb.c
+++ b/server/core/dcb.c
@@ -978,9 +978,10 @@ int	below_water;
                 }
                 if (dolog)
                 {
-                        LOGIF(LE, (skygw_log_write_flush(
-                                LOGFILE_ERROR,
-                                "Error : Writing to %s socket failed due %d, %s.",
+                        LOGIF(LD, (skygw_log_write(
+                                LOGFILE_DEBUG,
+                                "%lu [dcb_write] Writing to %s socket failed due %d, %s.",
+                                pthread_self(),
                                 dcb_isclient(dcb) ? "client" : "backend server",
                                 saved_errno,
                                 strerror(saved_errno))));
diff --git a/server/modules/protocol/mysql_backend.c b/server/modules/protocol/mysql_backend.c
index 903c17022..da00de083 100644
--- a/server/modules/protocol/mysql_backend.c
+++ b/server/modules/protocol/mysql_backend.c
@@ -777,11 +777,6 @@ static int gw_error_backend_event(DCB *dcb)
         router = session->service->router;
         router_instance = session->service->router_instance;
 
-#if defined(SS_DEBUG)                
-        LOGIF(LE, (skygw_log_write_flush(
-                LOGFILE_ERROR,
-                "Backend error event handling.")));
-#endif
         /**
          * Avoid running redundant error handling procedure.
          * dcb_close is already called for the DCB. Thus, either connection is
@@ -820,6 +815,11 @@ static int gw_error_backend_event(DCB *dcb)
                 goto retblock;
         }
         
+#if defined(SS_DEBUG)                
+        LOGIF(LE, (skygw_log_write_flush(
+                LOGFILE_ERROR,
+                "Backend error event handling.")));
+#endif
         router->handleError(router_instance,
                             rsession,
                             errbuf, 
@@ -963,14 +963,7 @@ gw_backend_hangup(DCB *dcb)
         
         rsession = session->router_session;
         router = session->service->router;
-        router_instance = session->service->router_instance;
-
-#if defined(SS_DEBUG)
-        LOGIF(LE, (skygw_log_write_flush(
-                LOGFILE_ERROR,
-                "Backend hangup error handling.")));
-#endif
-        
+        router_instance = session->service->router_instance;        
         
         errbuf = mysql_create_custom_error(
                 1, 
@@ -999,6 +992,12 @@ gw_backend_hangup(DCB *dcb)
                 gwbuf_free(errbuf);
                 goto retblock;
         }
+#if defined(SS_DEBUG)
+        LOGIF(LE, (skygw_log_write_flush(
+                LOGFILE_ERROR,
+                "Backend hangup error handling.")));
+#endif
+        
         router->handleError(router_instance,
                             rsession,
                             errbuf, 
diff --git a/server/modules/protocol/mysql_client.c b/server/modules/protocol/mysql_client.c
index fbe0589a5..0f243fb1d 100644
--- a/server/modules/protocol/mysql_client.c
+++ b/server/modules/protocol/mysql_client.c
@@ -1300,12 +1300,19 @@ static int gw_error_client_event(
                 STRDCBSTATE(dcb->state),
                 (session != NULL ? session : NULL))));
         
+        if (session != NULL && session->state == SESSION_STATE_STOPPING)
+        {
+                goto retblock;
+        }
+        
 #if defined(SS_DEBUG)
         LOGIF(LE, (skygw_log_write_flush(
                 LOGFILE_ERROR,
                 "Client error event handling.")));
 #endif
         dcb_close(dcb);
+        
+retblock:
         return 1;
 }
 
@@ -1380,12 +1387,19 @@ gw_client_hangup_event(DCB *dcb)
         {
                 CHK_SESSION(session);
         }
+        
+        if (session != NULL && session->state == SESSION_STATE_STOPPING)
+        {
+                goto retblock;
+        }
 #if defined(SS_DEBUG)
         LOGIF(LE, (skygw_log_write_flush(
                 LOGFILE_ERROR,
                 "Client hangup error handling.")));
 #endif
         dcb_close(dcb);
+ 
+retblock:
         return 1;
 }
 
diff --git a/server/modules/protocol/mysql_common.c b/server/modules/protocol/mysql_common.c
index ef9991554..cd1e5c5f9 100644
--- a/server/modules/protocol/mysql_common.c
+++ b/server/modules/protocol/mysql_common.c
@@ -117,6 +117,10 @@ void mysql_protocol_done (
         
         spinlock_acquire(&p->protocol_lock);
 
+        if (p->protocol_state != MYSQL_PROTOCOL_ACTIVE)
+        {
+                goto retblock;
+        }
         scmd = p->protocol_cmd_history;
         
         while (scmd != NULL)
@@ -127,6 +131,7 @@ void mysql_protocol_done (
         }
         p->protocol_state = MYSQL_PROTOCOL_DONE;
         
+retblock:
         spinlock_release(&p->protocol_lock);
 }
         
diff --git a/server/modules/routing/readwritesplit/readwritesplit.c b/server/modules/routing/readwritesplit/readwritesplit.c
index c10aca134..f09b29ae5 100644
--- a/server/modules/routing/readwritesplit/readwritesplit.c
+++ b/server/modules/routing/readwritesplit/readwritesplit.c
@@ -1548,7 +1548,7 @@ static void clientReply (
                                 (uint8_t *)GWBUF_DATA((scur->scmd_cur_cmd->my_sescmd_buf));
                         size_t   len = MYSQL_GET_PACKET_LEN(buf);
                         char*    cmdstr = (char *)malloc(len+1);
-
+                        /** data+termination character == len */
                         snprintf(cmdstr, len, "%s", &buf[5]);
                         
                         LOGIF(LE, (skygw_log_write_flush(