/*
* Copyright 2011, Christian Lamparter <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdbool.h>

#include <sys/types.h>
#include <sys/socket.h>

#include <linux/types.h>
#include <linux/if_ether.h> /* ETH_P_ALL */
#include <linux/if_packet.h> /* sockaddr_ll */
#include <linux/if.h> /* IFNAMSIZ */

static int monitor_init(const char *ifname)
{
struct sockaddr_ll ll;
int monitor_sock;

memset(&ll, 0, sizeof(ll));
ll.sll_family = AF_PACKET;
ll.sll_ifindex = if_nametoindex(ifname);
if (ll.sll_ifindex == 0) {
fprintf(stderr, "Monitor interface '%s' does not exist\n", ifname);
return -1;
}

monitor_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (monitor_sock < 0) {
fprintf(stderr, "socket(PF_PACKET,SOCK_RAW): %s\n", strerror(errno));
return -1;
}

if (bind(monitor_sock, (struct sockaddr *) &ll, sizeof(ll)) < 0) {
fprintf(stderr, "bind(PACKET): %s\n", strerror(errno));
close(monitor_sock);
return -1;
}

return monitor_sock;
}

static int inject_frame(int s, const void *data, size_t len)
{
#define IEEE80211_RADIOTAP_F_FRAG 0x08
unsigned char rtap_hdr[] = {
0x00, 0x00, /* radiotap version */
0x0e, 0x00, /* radiotap length */
0x02, 0xc0, 0x00, 0x00, /* bmap: flags, tx and rx flags */
IEEE80211_RADIOTAP_F_FRAG, /* F_FRAG (fragment if required) */
0x00, /* padding */
0x00, 0x00, /* RX and TX flags to indicate that */
0x00, 0x00, /* this is the injected frame directly */
};
struct iovec iov[2] = {
{
.iov_base = &rtap_hdr,
.iov_len = sizeof(rtap_hdr),
},
{
.iov_base = (void *) data,
.iov_len = len,
}
};
struct msghdr msg = {
.msg_name = NULL,
.msg_namelen = 0,
.msg_iov = iov,
.msg_iovlen = 2,
.msg_control = NULL,
.msg_controllen = 0,
.msg_flags = 0,
};
int ret;

ret = sendmsg(s, &msg, 0);
if (ret < 0)
perror("sendmsg");
return ret;
}

static unsigned char wol_magic_tmpl[30 + 6 + 16 * 6] = {
0x08, 0x00, 0x00, 0x00,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* RA */
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* TA */
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* SA */
0x00, 0x00,

0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

static void prepare_wol(unsigned char *wol_magic, unsigned char *mac)
{
int i;

for (i = 0; i < 16; i++)
memcpy(&wol_magic[30 + i * 6], mac, 6);
}

void usage(void)
{
fprintf(stderr, "Usage:\n");
fprintf(stderr, "\twol -i monitor_dev -m DE:VI:CE:MA:CW:OL -n #num -v\n");

fprintf(stderr, "\nDescription:\n");
fprintf(stderr, "\tThis utility generates a WOL packet for the"
"given [MAC] address and tries to injects"
"it into [monitor_dev]\n");

exit(EXIT_FAILURE);
}

#define MAC_STR "%2X:%2X:%2X:%2X:%2X:%2X"

#define M(a, i) ((unsigned int *)&a[i])
#define MAC_ARG(a) M(a, 0), M(a, 1), M(a, 2), M(a, 3), M(a, 4), M(a, 5)

#define M2(a, i) (a[i])
#define MAC_ARG2(a) M2(a, 0), M2(a, 1), M2(a, 2), M2(a, 3), M2(a, 4), M2(a, 5)

int main(int argc, char **args)
{
int sock, err = 0, opt, num = 10;
unsigned char mac[ETH_ALEN];
char dev_name[IFNAMSIZ + 1] = { 0 };
bool has_mac = false, has_dev = false, verbose = false;

while ((opt = getopt(argc, args, "m:i:n:v")) != -EXIT_FAILURE) {
switch (opt) {
case 'i':
has_dev = true;
strncpy(dev_name, optarg, IFNAMSIZ);
break;
case 'm':
has_mac = true;
err = sscanf(optarg, MAC_STR, MAC_ARG(mac)) != 6;
if (err)
fprintf(stderr, "invalid MAC: \"%s\"\n", optarg);
break;

case 'n':
err = sscanf(optarg, "%d", &num) != 1;
err |= num < 1 | num > 1000;
if (err)
fprintf(stderr, "invalid tries: \"%s\"\n", optarg);
break;

case 'v':
verbose = true;
break;

default:
err = -EINVAL;
break;
}

if (err)
break;
}

if (!has_mac || !has_dev || err)
usage();

if (verbose)
fprintf(stdout, "Opening monitor injection interface [%s].\n", dev_name);

sock = monitor_init(dev_name);
if (sock < 0)
return EXIT_FAILURE;

if (verbose)
fprintf(stdout, "Generating %d WOL packet for ["MAC_STR"].\n", num, MAC_ARG2(mac));

prepare_wol(wol_magic_tmpl, mac);

while (num--) {
err = inject_frame(sock, wol_magic_tmpl, sizeof(wol_magic_tmpl));
if (err < 0) {
fprintf(stderr, "failed to send WOL packet.\n");
break;
} else if (verbose) {
fprintf(stdout, "WOL packet sent.\n");
}
}

close(sock);
if (err < 0)
return EXIT_FAILURE;

return 0;
}