first draft

datafiller.c

@@ -0,0 +1,74 @@
+/* 
+ * $smu-mark$ 
+ * $name: datafiller.c$ 
+ * $author: Salvatore Sanfilippo <antirez@invece.org>$ 
+ * $copyright: Copyright (C) 1999 by Salvatore Sanfilippo$ 
+ * $license: This software is under GPL version 2 of license$ 
+ * $date: Fri Nov  5 11:55:47 MET 1999$ 
+ * $rev: 8$ 
+ */ 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h> /* memset */
+
+#include "hping2.h"
+#include "globals.h"
+
+void datafiller(char *p, int size)
+{
+	static int fd = 0;
+	int readed, diff;
+
+	if (!fd) {
+		fd = open(datafilename, O_RDONLY);
+		if (fd == -1) {
+			perror("[datafiller] open()");
+			fd = 0; /* will retry to open the file for
+				 * the next packet */
+			memset(p, 'X', size);
+			return;
+		}
+	}
+
+	if (p == NULL && fd != -1) { /* seek operation */
+		/* size-1 because packet with id 1 start from 0 */
+		lseek(fd, (data_size-signlen)*(size-1), SEEK_SET);
+		return;
+	}
+
+restart: /* if EOF occurs, after rewind, restart */
+
+	readed = read(fd, p, size);
+	if (readed == size)
+		return;
+	else if (readed == -1) {
+		perror("[datafiller] read()");
+		close(fd);
+		fd = 0; /* will retry to open the file for the next packet */
+		memset(p, 'X', size);
+		return;
+	}
+	else if (readed < size && opt_end == FALSE) {
+		lseek(fd, 0, SEEK_SET);
+		if (readed == 0)
+			goto restart;
+	}
+	else if (readed < size && opt_end == TRUE) {
+		fprintf(stderr, "EOF reached, wait some second than press "
+				"ctrl+c\n");
+		eof_reached = TRUE;
+	} else {
+		printf("[datafiller.c INTERNAL ERROR] readed = %d - "
+			"opt_end == %d\n", readed, opt_end);
+		exit(1);
+	}
+	diff = size - readed;
+	memset(p+readed, '\0', diff); /* padding */
+	lseek(fd, 0, SEEK_SET);
+	return;
+}