1 /*
2 * $smu-mark$
3 * $name: datafiller.c$
4 * $author: Salvatore Sanfilippo <antirez@invece.org>$
5 * $copyright: Copyright (C) 1999 by Salvatore Sanfilippo$
6 * $license: This software is under GPL version 2 of license$
7 * $date: Fri Nov 5 11:55:47 MET 1999$
8 * $rev: 8$
9 */
10
11 /* $Id: datafiller.c,v 1.2 2003/09/01 00:22:06 antirez Exp $ */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19 #include <string.h> /* memset */
20
21 #include "hping2.h"
22 #include "globals.h"
23
datafiller(char * p,int size)24 void datafiller(char *p, int size)
25 {
26 static int fd = 0;
27 int readed, diff;
28
29 if (!fd) {
30 fd = open(datafilename, O_RDONLY);
31 if (fd == -1) {
32 perror("[datafiller] open()");
33 fd = 0; /* will retry to open the file for
34 * the next packet */
35 memset(p, 'X', size);
36 return;
37 }
38 }
39
40 if (p == NULL && fd != -1) { /* seek operation */
41 /* size-1 because packet with id 1 start from 0 */
42 lseek(fd, (data_size-signlen)*(size-1), SEEK_SET);
43 return;
44 }
45
46 restart: /* if EOF occurs, after rewind, restart */
47
48 readed = read(fd, p, size);
49 if (readed == size)
50 return;
51 else if (readed == -1) {
52 perror("[datafiller] read()");
53 close(fd);
54 fd = 0; /* will retry to open the file for the next packet */
55 memset(p, 'X', size);
56 return;
57 }
58 else if (readed < size && opt_end == FALSE) {
59 lseek(fd, 0, SEEK_SET);
60 if (readed == 0)
61 goto restart;
62 }
63 else if (readed < size && opt_end == TRUE) {
64 fprintf(stderr, "EOF reached, wait some second than press "
65 "ctrl+c\n");
66 eof_reached = TRUE;
67 } else {
68 printf("[datafiller.c INTERNAL ERROR] readed = %d - "
69 "opt_end == %d\n", readed, opt_end);
70 exit(1);
71 }
72 diff = size - readed;
73 memset(p+readed, '\0', diff); /* padding */
74 lseek(fd, 0, SEEK_SET);
75 return;
76 }
77