mesg.c

Firestorm NIDS是一个性能非常高的网络入侵检测系统 (NIDS)。目前

#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <sys/time.h>
#include <fcntl.h>

#include <cleanup.h>
#include <firestorm.h>

char *mesg_str[]={"undefined","critical","error","warning","info","debug"};

#define MESG_INITBUF_LEN 8192
char *init_buf;
char *init_buf_p;
size_t init_buflen;

/* print out messages stored in the internal buffer */
void mesg_flush(int code, void *u)
{
	if ( !init_buf ) return;
	printf("%s", init_buf);
	free(init_buf);
	init_buf=NULL;
	init_buflen=0;
}

/* Initialise the logging code */
void mesg_init(void)
{
	init_buflen=MESG_INITBUF_LEN;
	if ( !(init_buf=init_buf_p=malloc(init_buflen)) )
		cperror("calloc");
	cleanup_add(mesg_flush, NULL);
}

/* Print a message to the internal text buffer */
/* We know at this point how the user wants us to log
 * from the config file, so lets do it */
void mesg_logfile(char *fn)
{
	int fd;

	fflush(stdout);

	if ( !fn )
		goto no_open;

	if ( (fd=open(fn, O_WRONLY|O_CREAT|O_TRUNC, 00640))<0 ) {
		cleanup(EXIT_ERR, "%s: open(): %s", fn, get_err());
	}

	if ( fd!=1 ) {
		if ( dup2(fd, 1)<0 )
			cleanup(EXIT_ERR, "%s: dup2(): %s", fn, get_err());
		close(fd);
	}

no_open:
	mesg_flush(0,NULL);
}

/* put a message in to the initial buffer */
void mesg_initlog(struct timeval *tv, int code, char *buf)
{
	int ret;

	if ( !init_buflen ) {
		printf("warning: internal message buffer overflow\n");
		return;
	}

	ret=snprintf(init_buf_p, init_buflen,
		"%.8lu.%.6lu %s: %s\n",
		tv->tv_sec, tv->tv_usec, mesg_str[code], buf);

	init_buf_p+=ret;

	if ( ret > init_buflen ) {
		init_buflen=0;
	}else{
		init_buflen-=ret;
	}
}

/* Print out a firestorm internal system log message */
void mesg(unsigned char code, char *fmt, ...)
{
	static char buf[1024];
	struct timeval tv;
	va_list va;

	if ( code > M_MAX )
		code=0;

	gettimeofday(&tv, NULL);

	va_start(va, fmt);
	vsnprintf(buf, sizeof(buf), fmt, va);
	va_end(va);

	if ( !init_buflen ) {
		/* No point checking for errors, what are we gonna do
		 * print them to screen? ;) */
		printf("%.8lu.%.6lu %s: %s\n", tv.tv_sec,
			tv.tv_usec, mesg_str[code], buf);
		fflush(stdout);
		return;
	}else{
		mesg_initlog(&tv, code, buf);
	}
}