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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
/*
* MAC address manupulation utility
*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
*/
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#define MAC_ADDRESS_LEN 6
#define ERR_INVALID 1
#define ERR_IO 2
static void usage(void);
char *maccalc_name;
static int parse_mac(const char *mac_str, unsigned char *buf)
{
int t;
t = sscanf(mac_str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
&buf[0], &buf[1], &buf[2], &buf[3], &buf[4], &buf[5]);
if (t != MAC_ADDRESS_LEN)
return ERR_INVALID;
return 0;
}
static void print_mac(unsigned char *buf)
{
printf("%02x:%02x:%02x:%02x:%02x:%02x\n",
buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
}
static int maccalc_do_add(int argc, const char *argv[])
{
unsigned char mac[MAC_ADDRESS_LEN];
uint32_t t;
int err;
int i;
if (argc != 2) {
usage();
return ERR_INVALID;
}
err = parse_mac(argv[0], mac);
if (err)
return err;
i = atoi(argv[1]);
t = (mac[3] << 16) | (mac[4] << 8) | mac[5];
t += i;
mac[3] = (t >> 16) & 0xff;
mac[4] = (t >> 8) & 0xff;
mac[5] = t & 0xff;
print_mac(mac);
return 0;
}
static int maccalc_do_logical(int argc, const char *argv[],
unsigned char (*op)(unsigned char n1,
unsigned char n2))
{
unsigned char mac1[MAC_ADDRESS_LEN];
unsigned char mac2[MAC_ADDRESS_LEN];
int err;
int i;
if (argc != 2) {
usage();
return ERR_INVALID;
}
err = parse_mac(argv[0], mac1);
if (err)
return err;
err = parse_mac(argv[1], mac2);
if (err)
return err;
for (i = 0; i < MAC_ADDRESS_LEN; i++)
mac1[i] = op(mac1[i],mac2[i]);
print_mac(mac1);
return 0;
}
static int maccalc_do_mac2bin(int argc, const char *argv[])
{
unsigned char mac[MAC_ADDRESS_LEN];
ssize_t c;
int err;
if (argc != 1) {
usage();
return ERR_INVALID;
}
err = parse_mac(argv[0], mac);
if (err)
return err;
c = write(STDOUT_FILENO, mac, sizeof(mac));
if (c != sizeof(mac)) {
fprintf(stderr, "failed to write to stdout\n");
return ERR_IO;
}
return 0;
}
static ssize_t read_safe(int fd, void *buf, size_t count)
{
ssize_t total = 0;
ssize_t r;
while(count > 0) {
r = read(fd, buf, count);
if (r == 0)
/* EOF */
break;
if (r < 0) {
if (errno == EINTR)
/* interrupted by a signal, restart */
continue;
/* error */
total = -1;
break;
}
/* ok */
total += r;
count -= r;
buf += r;
}
return total;
}
static int maccalc_do_bin2mac(int argc, const char *argv[])
{
unsigned char mac[MAC_ADDRESS_LEN];
ssize_t c;
if (argc != 0) {
usage();
return ERR_INVALID;
}
c = read_safe(STDIN_FILENO, mac, sizeof(mac));
if (c != sizeof(mac)) {
fprintf(stderr, "failed to read from stdin\n");
return ERR_IO;
}
print_mac(mac);
return 0;
}
static unsigned char op_or(unsigned char n1, unsigned char n2)
{
return n1 | n2;
}
static int maccalc_do_or(int argc, const char *argv[])
{
return maccalc_do_logical(argc, argv, op_or);
}
static unsigned char op_and(unsigned char n1, unsigned char n2)
{
return n1 & n2;
}
static int maccalc_do_and(int argc, const char *argv[])
{
return maccalc_do_logical(argc, argv, op_and);
}
static unsigned char op_xor(unsigned char n1, unsigned char n2)
{
return n1 ^ n2;
}
static int maccalc_do_xor(int argc, const char *argv[])
{
return maccalc_do_logical(argc, argv, op_xor);
}
static void usage(void)
{
fprintf(stderr,
"Usage: %s <command>\n"
"valid commands:\n"
" add <mac> <number>\n"
" and|or|xor <mac1> <mac2>\n"
" mac2bin <mac>\n"
" bin2mac\n",
maccalc_name);
}
int main(int argc, const char *argv[])
{
int (*op)(int argc, const char *argv[]);
int ret;
maccalc_name = (char *) argv[0];
if (argc < 2) {
usage();
return EXIT_FAILURE;
}
if (strcmp(argv[1], "add") == 0) {
op = maccalc_do_add;
} else if (strcmp(argv[1], "and") == 0) {
op = maccalc_do_and;
} else if (strcmp(argv[1], "or") == 0) {
op = maccalc_do_or;
} else if (strcmp(argv[1], "xor") == 0) {
op = maccalc_do_xor;
} else if (strcmp(argv[1], "mac2bin") == 0) {
op = maccalc_do_mac2bin;
} else if (strcmp(argv[1], "bin2mac") == 0) {
op = maccalc_do_bin2mac;
} else {
fprintf(stderr, "unknown command '%s'\n", argv[1]);
usage();
return EXIT_FAILURE;
}
argc -= 2;
argv += 2;
ret = op(argc, argv);
if (ret)
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
|
