moved mysql action to its own code files

1 files changed, 275 insertions, 0 deletions

diff --git a/ommysql.c b/ommysql.c
new file mode 100644
index 00000000..eda2490a
--- /dev/null
+++ b/ommysql.c
@@ -0,0 +1,275 @@
+/* omusrmsg.c
+ * This is the implementation of the build-in output module for MySQL.
+ *
+ * File begun on 2007-07-20 by RGerhards (extracted from syslogd.c)
+ * This file is under development and has not yet arrived at being fully
+ * self-contained and a real object. So far, it is mostly an excerpt
+ * of the "old" message code without any modifications. However, it
+ * helps to have things at the right place one we go to the meat of it.
+ *
+ * Copyright 2007 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+#include "config.h"
+#ifdef	WITH_DB
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <signal.h>
+#include <errno.h>
+#include <time.h>
+#include "rsyslog.h"
+#include "syslogd.h"
+#include "syslogd-types.h"
+#include "srUtils.h"
+#include "ommysql.h"
+#include "mysql/mysql.h" 
+#include "mysql/errmsg.h"
+
+
+/**
+ * DBErrorHandler
+ *
+ * Call this function if an db error apears. It will initiate 
+ * the "delay" handling which stopped the db logging for some 
+ * time.  
+ *
+ * We now check if we have a valid MySQL handle. If not, we simply
+ * report an error, but can not be specific. RGerhards, 2007-01-30
+ */
+static void DBErrorHandler(register selector_t *f)
+{
+	char errMsg[512];
+
+	assert(f != NULL);
+
+	/* TODO:
+	 * NO DB connection -> Can not log to DB
+	 * -------------------- 
+	 * Case 1: db server unavailable
+	 * We can check after a specified time interval if the server is up.
+	 * Also a reason can be a down DNS service.
+	 * Case 2: uid, pwd or dbname are incorrect
+	 * If this is a fault in the syslog.conf we have no chance to recover. But
+	 * if it is a problem of the DB we can make a retry after some time. Possible
+	 * are that the admin has not already set up the database table. Or he has not
+	 * created the database user yet. 
+	 * Case 3: unkown error
+	 * If we get an unkowon error here, we should in any case try to recover after
+	 * a specified time interval.
+	 *
+	 * Insert failed -> Can not log to DB
+	 * -------------------- 
+	 * If the insert fails it is never a good idea to give up. Only an
+	 * invalid sql sturcture (wrong template) force us to disable db
+	 * logging. 
+	 *
+	 * Think about different "delay" for different errors!
+	 */
+	if(f->f_un.f_mysql.f_hmysql == NULL) {
+		logerror("unknown DB error occured - called error handler with NULL MySQL handle.");
+	} else { /* we can ask mysql for the error description... */
+		errno = 0;
+		snprintf(errMsg, sizeof(errMsg)/sizeof(char),
+			"db error (%d): %s\n", mysql_errno(f->f_un.f_mysql.f_hmysql),
+			mysql_error(f->f_un.f_mysql.f_hmysql));
+		f->f_un.f_mysql.f_iLastDBErrNo = mysql_errno(f->f_un.f_mysql.f_hmysql);
+		logerror(errMsg);
+	}
+		
+	/* Enable "delay" */
+	f->f_un.f_mysql.f_timeResumeOnError = time(&f->f_un.f_mysql.f_timeResumeOnError) + _DB_DELAYTIMEONERROR ;
+}
+
+
+/**
+ * checkDBErrorState
+ *
+ * Check if we can go on with database logging or if we should wait
+ * a little bit longer. It also check if the DB hanlde is still valid. 
+ * If it is necessary, it takes action to reinitiate the db connection.
+ *
+ * \ret int		Returns 0 if successful (no error)
+ */ 
+int checkDBErrorState(register selector_t *f)
+{
+	time_t now;
+	assert(f != NULL);
+	/* dprintf("in checkDBErrorState, timeResumeOnError: %d\n", f->f_timeResumeOnError); */
+
+	/* If timeResumeOnError == 0 no error occured, 
+	   we can return with 0 (no error) */
+	if (f->f_un.f_mysql.f_timeResumeOnError == 0)
+		return 0;
+	
+	(void) time(&now);
+	/* Now we know an error occured. We check timeResumeOnError
+	   if we can process. If we have not reach the resume time
+	   yet, we return an error status. */  
+	if (f->f_un.f_mysql.f_timeResumeOnError > now)
+	{
+		/* dprintf("Wait time is not over yet.\n"); */
+		return 1;
+	}
+	 	
+	/* Ok, we can try to resume the database logging. First
+	   we have to reset the status (timeResumeOnError) and
+	   the last error no. */
+	/* To improve this code it would be better to check 
+	   if we really need to reInit the db connection. If 
+	   only the insert failed and the db conncetcion is
+	   still valid, we need no reInit. 
+	   Of course, if an unkown error appeared, we should
+	   reInit. */
+	 /* rgerhards 2004-12-08: I think it is pretty unlikely
+	  * that we can re-use a connection after the error. So I guess
+	  * the connection must be closed and re-opened in all cases
+	  * (as it is done currently). When we come back to optimize
+	  * this code, we should anyhow see if there are cases where
+	  * we could keep it open. I just doubt this won't be the case.
+	  * I added this comment (and did not remove Michaels) just so
+	  * that we all know what we are looking for.
+	  */
+	f->f_un.f_mysql.f_timeResumeOnError = 0;
+	f->f_un.f_mysql.f_iLastDBErrNo = 0; 
+	reInitMySQL(f);
+	return 0;
+
+}
+
+/*
+ * The following function is responsible for initializing a
+ * MySQL connection.
+ * Initially added 2004-10-28 mmeckelein
+ */
+void initMySQL(register selector_t *f)
+{
+	int iCounter = 0;
+	assert(f != NULL);
+
+	if (checkDBErrorState(f))
+		return;
+	
+	f->f_un.f_mysql.f_hmysql = mysql_init(NULL);
+	if(f->f_un.f_mysql.f_hmysql == NULL) {
+		logerror("can not initialize MySQL handle - ignoring this action");
+		/* The next statement  causes a redundant message, but it is the
+		 * best thing we can do in this situation. -- rgerhards, 2007-01-30
+	     	 */
+		 f->f_type = F_UNUSED;
+	} else { /* we could get the handle, now on with work... */
+		do {
+			/* Connect to database */
+			if (!mysql_real_connect(f->f_un.f_mysql.f_hmysql, f->f_un.f_mysql.f_dbsrv, f->f_un.f_mysql.f_dbuid,
+			                        f->f_un.f_mysql.f_dbpwd, f->f_un.f_mysql.f_dbname, 0, NULL, 0)) {
+				/* if also the second attempt failed
+				   we call the error handler */
+				if(iCounter)
+					DBErrorHandler(f);
+			} else {
+				f->f_un.f_mysql.f_timeResumeOnError = 0; /* We have a working db connection */
+				dprintf("connected successfully to db\n");
+			}
+			iCounter++;
+		} while (mysql_errno(f->f_un.f_mysql.f_hmysql) && iCounter<2);
+	}
+}
+
+/*
+ * The following function is responsible for closing a
+ * MySQL connection.
+ * Initially added 2004-10-28
+ */
+void closeMySQL(register selector_t *f)
+{
+	assert(f != NULL);
+	dprintf("in closeMySQL\n");
+	if(f->f_un.f_mysql.f_hmysql != NULL)	/* just to be on the safe side... */
+		mysql_close(f->f_un.f_mysql.f_hmysql);	
+}
+
+/*
+ * Reconnect a MySQL connection.
+ * Initially added 2004-12-02
+ */
+void reInitMySQL(register selector_t *f)
+{
+	assert(f != NULL);
+
+	dprintf("reInitMySQL\n");
+	closeMySQL(f); /* close the current handle */
+	initMySQL(f); /* new connection */   
+}
+
+
+
+/* The following function writes the current log entry
+ * to an established MySQL session.
+ * Initially added 2004-10-28 mmeckelein
+ */
+void writeMySQL(register selector_t *f)
+{
+	char *psz;
+	int iCounter=0;
+	assert(f != NULL);
+
+	iovCreate(f);
+	psz = iovAsString(f);
+	
+	if (checkDBErrorState(f))
+		return;
+
+	/* Now we are trying to insert the data. 
+	 *
+	 * If the first attampt fails we simply try a second one. If that
+	 * fails too, we discard the message and enable "delay" error handling.
+	 */
+	do {
+		/* query */
+		if(mysql_query(f->f_un.f_mysql.f_hmysql, psz)) {
+			/* if the second attempt fails
+			   we call the error handler */
+			if(iCounter)
+				DBErrorHandler(f);
+		}
+		else {
+			/* dprintf("db insert sucessfully\n"); */
+		}
+		iCounter++;
+	} while (mysql_errno(f->f_un.f_mysql.f_hmysql) && iCounter<2);
+}
+
+/* call the shell action
+ * returns 0 if it succeeds, something else otherwise
+ */
+int doActionMySQL(selector_t *f, time_t now)
+{
+	assert(f != NULL);
+
+	f->f_time = now;
+	dprintf("\n");
+	writeMySQL(f);
+	return 0;
+}
+
+#endif /* #ifdef WITH_DB */
+/*
+ * vi:set ai:
+ */