1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
#define MAX_NOTES 16
extern char edata;
extern char data_start;
static inline char *read_line(char **line_buf, size_t *size) {
*size = getdelim(line_buf, size, '\n', stdin);
if (*size == 0) {
puts("Invalid line");
exit(EXIT_FAILURE);
}
return *line_buf;
}
void add_note(size_t *sizes, char **notes) {
printf("Note: ");
for (size_t i = 0; i < MAX_NOTES; i++) {
if (sizes[i] == 0) {
notes[i] = NULL;
sizes[i] = getdelim(¬es[i], &sizes[i], '\n', stdin);
printf("Added note: %ld\n", i);
return;
}
}
puts("Too many notes");
exit(EXIT_FAILURE);
}
void remove_note(char **line_buf, size_t *size, size_t *sizes, char **notes) {
printf("Index: ");
char *line = read_line(line_buf, size);
unsigned long index = strtoul(line, NULL, 0);
if (index >= MAX_NOTES) {
puts("Invalid index");
exit(EXIT_FAILURE);
}
free(notes[index]);
sizes[index] = 0;
}
void edit_note(char **line_buf, size_t *size, size_t *sizes, char **notes) {
printf("Index: ");
char *line = read_line(line_buf, size);
unsigned long index = strtoul(line, NULL, 0);
if (index >= MAX_NOTES || sizes[index] == 0) {
puts("Invalid index");
exit(EXIT_FAILURE);
}
printf("Note: ");
line = read_line(line_buf, size);
if (*size - 2 > sizes[index]) {
puts("Invalid size");
exit(EXIT_FAILURE);
}
memcpy(notes[index], line, *size - 1);
}
void flip_bit(char **line_buf, size_t *size, char **notes, int *flips) {
if (*flips == 0) {
puts("The laser malfunctions and kills the program!");
exit(EXIT_FAILURE);
}
printf("Index: ");
unsigned long index = strtoul(read_line(line_buf, size), NULL, 0);
if (index >= MAX_NOTES || notes[index] == NULL) {
puts("Invalid index");
exit(EXIT_FAILURE);
}
printf("Offset: ");
char offset = (char)strtol(read_line(line_buf, size), NULL, 0);
size_t byte = offset / 8;
size_t bit = offset & 0b111;
puts("The laser is positioned and shoots at the selected memory location!");
notes[index][byte] ^= 0b1 << bit;
*flips = *flips - 1;
}
void exit_handler() {
mprotect(&data_start, (size_t)&edata - (size_t)&data_start,
PROT_READ | PROT_WRITE);
}
int main() {
char *notes[MAX_NOTES];
size_t sizes[MAX_NOTES];
char *line_buf = NULL;
size_t size = 0;
int flips = 2;
char buf[0x80];
memset(buf, 0, sizeof(buf));
memset(notes, 0, sizeof(notes));
memset(sizes, 0, sizeof(sizes));
setvbuf(stdin, buf, _IOFBF, sizeof(buf));
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
mprotect(&data_start, (size_t)&edata - (size_t)&data_start, PROT_READ);
on_exit(&exit_handler, NULL);
if (setuid(0)) {
puts("Not running as root :(");
}
puts("╭────────────────────────────────────────────────────╮");
puts("│ FlipNote │");
puts("│ │");
puts("│ Instructions: │");
puts("│ - Type 'a' or 'A' to add a note │");
puts("│ - Type 'e' or 'E' to edit a note │");
puts("│ - Type 'f' or 'F' to use a laser to flip a bit │");
puts("│ - Type 'r' or 'R' to remove a note │");
puts("│ - Type 'q' or 'Q' to quit the program │");
puts("│ │");
puts("╰────────────────────────────────────────────────────╯");
for (;;) {
printf("> ");
switch (read_line(&line_buf, &size)[0]) {
case 'a':
case 'A':
add_note(sizes, notes);
break;
case 'e':
case 'E':
edit_note(&line_buf, &size, sizes, notes);
break;
case 'f':
case 'F':
flip_bit(&line_buf, &size, notes, &flips);
break;
case 'r':
case 'R':
remove_note(&line_buf, &size, sizes, notes);
break;
case 'q':
case 'Q':
exit(EXIT_SUCCESS);
default:
printf("Invalid option: ");
puts(line_buf);
break;
}
}
free(line_buf);
return 0;
}
|
