[vhffs-dev] [2178] syslogger now truncates messages bigger than buffer

[subversion@xxxxxxxxxxxxx]

Revision: 2178
Author:   gradator
Date:     2012-05-07 21:19:35 +0200 (Mon, 07 May 2012)
Log Message:
-----------
syslogger now truncates messages bigger than buffer

Modified Paths:
--------------
    trunk/vhffs-syslogger/syslogger.c

Modified: trunk/vhffs-syslogger/syslogger.c
===================================================================
--- trunk/vhffs-syslogger/syslogger.c	2012-05-06 13:02:25 UTC (rev 2177)
+++ trunk/vhffs-syslogger/syslogger.c	2012-05-07 19:19:35 UTC (rev 2178)
@@ -37,6 +37,12 @@
 	int val;
 };
 
+enum {
+	SYSLOGGER_STATE_NORMALFLOW,	// Flow is normally flowing from standard input to syslog
+	SYSLOGGER_STATE_WAITFORNEWLINE	// We received a message which exceeded maxsize,
+					// we have to discard any input until we found a newline
+};
+
 static void usage_exit(int ret_code, char *progname);
 int syslog_facility_from_str(const char *facility);
 int syslog_priority_from_str(const char *priority);
@@ -45,8 +51,10 @@
 int main(int argc, char *argv[])  {
 	char *buffer, *ident = "httpd";
 	int facility = DEFAULT_FACILITY, priority = DEFAULT_PRIORITY, option = DEFAULT_OPTION;
-	size_t bufsiz = 32768;
+	size_t bufsize = 32768;
 	FILE *tee = NULL;
+	int state;
+	size_t overflowsize;
 
 	struct option long_options[] = {
 		{ "ident", required_argument, NULL, 'i' },
@@ -72,7 +80,7 @@
 				break;
 
 			case 's':
-				bufsiz = (size_t)(atoi(optarg));
+				bufsize = (size_t)(atoi(optarg));
 				break;
 
 			case 'f':
@@ -137,21 +145,62 @@
 	if(optind != argc)
 		usage_exit(1, argv[0]);
 
-	if(bufsiz < 1024)
-		bufsiz = 1024;
-	buffer = malloc(bufsiz);
+	if(bufsize < 1024)
+		bufsize = 1024;
+
+	buffer = malloc(bufsize+2); // + '\n' + '\0'
 	if(!buffer) {
 		fprintf(stderr, "Failed to allocated buffer, exiting.\n");
 		return -1;
 	}
 
+	state = SYSLOGGER_STATE_NORMALFLOW;
 	openlog(ident, option, facility);
-	while( fgets(buffer, bufsiz, stdin) ) {
-		syslog(priority, "%s", buffer);
+	while( fgets(buffer, bufsize+2, stdin) ) {
+		size_t len = strlen(buffer);
+
 		if(tee) {
-			fwrite(buffer, strlen(buffer), 1, tee);
+			fwrite(buffer, len, 1, tee);
 			fflush(tee);
 		}
+
+		switch( *(buffer+len-1) ) {
+
+			case '\n':
+				switch(state) {
+
+					// everything's good
+					case SYSLOGGER_STATE_NORMALFLOW:
+						syslog(priority, "%s", buffer);
+						break;
+
+					// overflow recovered
+					case SYSLOGGER_STATE_WAITFORNEWLINE:
+						overflowsize += len-1;
+						fprintf(stderr, "%s: too big message received: %d bytes long, truncated to %d bytes\n", argv[0], overflowsize, bufsize);
+						state = SYSLOGGER_STATE_NORMALFLOW;
+						break;
+				}
+				break;
+
+			default:
+				switch(state) {
+
+					// new overflow
+					case SYSLOGGER_STATE_NORMALFLOW:
+						*(buffer+len-1) = '\n';
+						overflowsize = len;
+						syslog(priority, "%s", buffer);
+						state = SYSLOGGER_STATE_WAITFORNEWLINE;
+						break;
+
+					// overflow continue
+					case SYSLOGGER_STATE_WAITFORNEWLINE:
+						overflowsize += len;
+						break;
+				}
+				break;
+		}
 	}
 	closelog();
 	if(tee) fclose(tee);