Fixes to Coverity tasks : 73267, 72686, 72672

Cleaned up warnings, and added checks to malloc return values and error log writes in case of failures.

log_manager/log_manager.cc

@@ -273,7 +273,6 @@ static char* add_slash(char* str);
 
 static bool check_file_and_path(
 	char* filename,
-	bool* nameconflict,
 	bool* writable);
 
 static bool  file_is_symlink(char* filename);

log_manager/log_manager.h

@@ -15,7 +15,8 @@
  *
  * Copyright MariaDB Corporation Ab 2013-2014
  */
-
+#if !defined(LOG_MANAGER_H)
+# define LOG_MANAGER_H
 
 typedef struct filewriter_st  filewriter_t;
 typedef struct logfile_st     logfile_t;
@@ -90,3 +91,5 @@ const char* get_msg_suffix_default(void);
 const char* get_err_prefix_default(void);
 const char* get_err_suffix_default(void);
 const char* get_logpath_default(void);
+
+#endif /** LOG_MANAGER_H */

server/core/buffer.c

@@ -44,6 +44,10 @@
 #include <skygw_debug.h>
 #include <spinlock.h>
 #include <hint.h>
+#include <log_manager.h>
+#include <errno.h>
+
+extern int lm_enabled_logfiles_bitmask;
 
 static buffer_object_t* gwbuf_remove_buffer_object(
         GWBUF*           buf,
@@ -70,22 +74,23 @@ SHARED_BUF	*sbuf;
 	/* Allocate the buffer header */
 	if ((rval = (GWBUF *)malloc(sizeof(GWBUF))) == NULL)
 	{
-		return NULL;
+		goto retblock;;
 	}
 
 	/* Allocate the shared data buffer */
 	if ((sbuf = (SHARED_BUF *)malloc(sizeof(SHARED_BUF))) == NULL)
 	{
 		free(rval);
-		return NULL;
+		goto retblock;
 	}
 
 	/* Allocate the space for the actual data */
 	if ((sbuf->data = (unsigned char *)malloc(size)) == NULL)
 	{
+		ss_dassert(sbuf->data != NULL);
 		free(rval);
 		free(sbuf);
-		return NULL;
+		goto retblock;
 	}
 	spinlock_init(&rval->gwbuf_lock);
 	rval->start = sbuf->data;
@@ -100,6 +105,15 @@ SHARED_BUF	*sbuf;
         rval->gwbuf_info = GWBUF_INFO_NONE;
         rval->gwbuf_bufobj = NULL;
         CHK_GWBUF(rval);
+retblock:
+	if (rval == NULL || sbuf == NULL || sbuf->data == NULL)
+	{
+		ss_dassert(rval != NULL && sbuf != NULL && sbuf->data != NULL);
+		LOGIF(LE, (skygw_log_write_flush(
+			LOGFILE_ERROR,
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno))));
+	}
 	return rval;
 }
 
@@ -163,6 +177,11 @@ GWBUF	*rval;
 
 	if ((rval = (GWBUF *)malloc(sizeof(GWBUF))) == NULL)
 	{
+		ss_dassert(rval != NULL);
+		LOGIF(LE, (skygw_log_write_flush(
+			LOGFILE_ERROR,
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno))));
 		return NULL;
 	}
 
@@ -194,6 +213,11 @@ GWBUF *gwbuf_clone_portion(
         
         if ((clonebuf = (GWBUF *)malloc(sizeof(GWBUF))) == NULL)
         {
+		ss_dassert(clonebuf != NULL);
+		LOGIF(LE, (skygw_log_write_flush(
+			LOGFILE_ERROR,
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno))));
                 return NULL;
         }
         atomic_add(&buf->sbuf->refcount, 1);
@@ -438,6 +462,16 @@ void gwbuf_add_buffer_object(
         
         CHK_GWBUF(buf);
         newb = (buffer_object_t *)malloc(sizeof(buffer_object_t));
+	ss_dassert(newb != NULL);
+	
+	if (newb == NULL)
+	{
+		LOGIF(LE, (skygw_log_write_flush(
+			LOGFILE_ERROR,
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno))));
+		return;
+	}
         newb->bo_id = id;
         newb->bo_data = data;
         newb->bo_donefun_fp = donefun_fp;
@@ -518,8 +552,15 @@ gwbuf_add_property(GWBUF *buf, char *name, char *value)
 BUF_PROPERTY	*prop;
 
 	if ((prop = malloc(sizeof(BUF_PROPERTY))) == NULL)
+	{
+		ss_dassert(prop != NULL);
+		
+		LOGIF(LE, (skygw_log_write_flush(
+			LOGFILE_ERROR,
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno))));		
 		return 0;
-
+	}
 	prop->name = strdup(name);
 	prop->value = strdup(value);
 	spinlock_acquire(&buf->gwbuf_lock);

server/core/dcb.c

@@ -1891,7 +1891,6 @@ DCB_CALLBACK	*cb, *nextcb;
 int
 dcb_isvalid(DCB *dcb)
 {
-DCB	*ptr;
 int	rval = 0;
 
     if (dcb)

server/core/modutil.c

@@ -245,7 +245,7 @@ GWBUF *modutil_create_mysql_err_msg(
 	int		affected_rows,
 	int		merrno,
 	const char	*statemsg,
-	const char	* msg)
+	const char	*msg)
 {
 	uint8_t		*outbuf = NULL;
 	uint8_t		mysql_payload_size = 0;
@@ -259,6 +259,10 @@ GWBUF *modutil_create_mysql_err_msg(
 	const char	*mysql_state = NULL;
 	GWBUF		*errbuf = NULL;
 
+	if (statemsg == NULL || msg == NULL)
+	{
+		return NULL;
+	}
         mysql_errno = (unsigned int)merrno;
         mysql_error_msg = msg;
         mysql_state = statemsg;
@@ -270,9 +274,6 @@ GWBUF *modutil_create_mysql_err_msg(
         mysql_statemsg[0]='#';
         memcpy(mysql_statemsg+1, mysql_state, 5);
 
-        if (msg != NULL) {
-                mysql_error_msg = msg;
-        }
         mysql_payload_size = sizeof(field_count) +
                                 sizeof(mysql_err) +
                                 sizeof(mysql_statemsg) +
@@ -283,8 +284,9 @@ GWBUF *modutil_create_mysql_err_msg(
         ss_dassert(errbuf != NULL);
 
         if (errbuf == NULL)
+	{
                 return NULL;
-
+	}
         outbuf = GWBUF_DATA(errbuf);
 
         /** write packet header and packet number */

server/modules/protocol/mysql_backend.c

@@ -1300,14 +1300,33 @@ static int gw_change_user(
 						backend->session->client->remote,
 						password_set,
 						"");
+		if (message == NULL)
+		{
+			LOGIF(LE, (skygw_log_write_flush(
+				LOGFILE_ERROR,
+				"Error : Creating error message failed."))); 
+			rv = 0;
+			goto retblock;
+		}
 		/** TODO: Add custom message indicating that retry would probably help */
 		buf = modutil_create_mysql_err_msg(1, 0, 1045, "28000", message);
+		free(message);
+		
+		if (buf == NULL)
+		{
+			LOGIF(LE, (skygw_log_write_flush(
+				LOGFILE_ERROR,
+				"Error : Creating buffer for error message failed."))); 
+			rv = 0;
+			goto retblock;			
+		}
 		/** Set flags that help router to identify session commans reply */
 		gwbuf_set_type(buf, GWBUF_TYPE_MYSQL);
 		gwbuf_set_type(buf, GWBUF_TYPE_SESCMD_RESPONSE);
 		gwbuf_set_type(buf, GWBUF_TYPE_RESPONSE_END);
 		/** Create an incoming event for backend DCB */
-		poll_add_epollin_event_to_dcb(backend, buf);
+		poll_add_epollin_event_to_dcb(backend, gwbuf_clone(buf));
+		gwbuf_free(buf);
 		rv = 0;
         } else {
 		rv = gw_send_change_user_to_backend(database, username, client_sha1, backend_protocol);
@@ -1318,6 +1337,8 @@ static int gw_change_user(
 		strcpy(current_session->db, database);
 		memcpy(current_session->client_sha1, client_sha1, sizeof(current_session->client_sha1));
         }
+        
+retblock:
         gwbuf_free(queue);
 
 	return rv;

server/modules/protocol/mysql_common.c

@@ -2106,19 +2106,34 @@ char *create_auth_fail_str(
 	else
 		db_len = 0;
 
-	if (db_len>0)
+	if (db_len > 0)
+	{
 		ferrstr = "Access denied for user '%s'@'%s' (using password: %s) to database '%s'";
+	}
 	else
+	{
 		ferrstr = "Access denied for user '%s'@'%s' (using password: %s)";
-		
+	}	
 	errstr = (char *)malloc(strlen(username)+strlen(ferrstr)+strlen(hostaddr)+strlen("YES")-6 + db_len + ((db_len > 0) ? (strlen(" to database ") +2) : 0) + 1);
 	
-	if (errstr != NULL) {
+	if (errstr == NULL)
-		if (db_len>0)
+	{
-			sprintf(errstr, ferrstr, username, hostaddr, (*sha1 == '\0' ? "NO" : "YES"), db); 
+		LOGIF(LE, (skygw_log_write_flush(
-		else
+			LOGFILE_ERROR,
-			sprintf(errstr, ferrstr, username, hostaddr, (*sha1 == '\0' ? "NO" : "YES")); 
+			"Error : Memory allocation failed due to %s.", 
+			strerror(errno)))); 
+		goto retblock;
 	}
 
+	if (db_len > 0)
+	{
+		sprintf(errstr, ferrstr, username, hostaddr, (*sha1 == '\0' ? "NO" : "YES"), db); 
+	}
+	else
+	{
+		sprintf(errstr, ferrstr, username, hostaddr, (*sha1 == '\0' ? "NO" : "YES")); 
+	}
+	
+retblock:
 	return errstr;
 }

server/modules/routing/readconnroute.c

@@ -654,7 +654,7 @@ DCB*              backend_dcb;
  * @param instance		The router instance
  * @param router_session	The router session returned from the newSession call
  * @param queue			The queue of data buffers to route
- * @return The number of bytes sent
+ * @return if succeed 1, otherwise 0
  */
 static	int	
 routeQuery(ROUTER *instance, void *router_session, GWBUF *queue)
@@ -697,20 +697,22 @@ routeQuery(ROUTER *instance, void *router_session, GWBUF *queue)
                         "Error : Failed to route MySQL command %d to backend "
                         "server.",
                         mysql_command)));
+		rc = 0;
                 goto return_rc;
         }
         
 	switch(mysql_command) {
-        case MYSQL_COM_CHANGE_USER:
+		case MYSQL_COM_CHANGE_USER:
-                rc = backend_dcb->func.auth(
+			rc = backend_dcb->func.auth(
-                        backend_dcb,
+				backend_dcb,
-                        NULL,
+				NULL,
-                        backend_dcb->session,
+				backend_dcb->session,
-                        queue);
+				queue);
-		break;
+			break;
-        default:
+		
-                rc = backend_dcb->func.write(backend_dcb, queue);
+		default:
-                break;
+			rc = backend_dcb->func.write(backend_dcb, queue);
+			break;
         }
         
         CHK_PROTOCOL(((MySQLProtocol*)backend_dcb->protocol));

server/modules/routing/readwritesplit/readwritesplit.c

@@ -3829,7 +3829,6 @@ static bool route_session_write(
                                 {
                                         succp = false;
                                 }
-
                         }
                 }
                 rses_end_locked_router_action(router_cli_ses);
@@ -3842,6 +3841,12 @@ static bool route_session_write(
                 succp = false;
                 goto return_succp;
         }
+        
+        if (router_cli_ses->rses_nbackends <= 0)
+	{
+		succp = false;
+		goto return_succp;
+	}
         /** 
          * Additional reference is created to querybuf to 
          * prevent it from being released before properties
@@ -3909,6 +3914,10 @@ static bool route_session_write(
                                 }
                         }
                 }
+                else
+		{
+			succp = false;
+		}
         }
         /** Unlock router session */
         rses_end_locked_router_action(router_cli_ses);