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/*
*
* IPV4 Local Link library with GLib integration
*
* Copyright (C) 2009-2010 Aldebaran Robotics. All rights reserved.
*
* 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.
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
#include <glib.h>
#include "ipv4ll.h"
#include "common.h"
/**
* Return a random link local IP (in host byte order)
*/
uint32_t ipv4ll_random_ip(void)
{
unsigned tmp;
uint64_t rand;
do {
dhcp_get_random(&rand);
tmp = rand;
tmp = tmp & IN_CLASSB_HOST;
} while (tmp > (IN_CLASSB_HOST - 0x0200));
return ((LINKLOCAL_ADDR + 0x0100) + tmp);
}
/**
* Return a random delay in range of zero to secs*1000
*/
guint ipv4ll_random_delay_ms(guint secs)
{
uint64_t rand;
dhcp_get_random(&rand);
return rand % (secs * 1000);
}
int ipv4ll_send_arp_packet(uint8_t* source_eth, uint32_t source_ip,
uint32_t target_ip, int ifindex)
{
struct sockaddr_ll dest;
struct ether_arp p;
uint32_t ip_source;
uint32_t ip_target;
int fd, n;
fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (fd < 0)
return -errno;
memset(&dest, 0, sizeof(dest));
memset(&p, 0, sizeof(p));
dest.sll_family = AF_PACKET;
dest.sll_protocol = htons(ETH_P_ARP);
dest.sll_ifindex = ifindex;
dest.sll_halen = ETH_ALEN;
memset(dest.sll_addr, 0xFF, ETH_ALEN);
if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) {
int err = errno;
close(fd);
return -err;
}
ip_source = htonl(source_ip);
ip_target = htonl(target_ip);
p.arp_hrd = htons(ARPHRD_ETHER);
p.arp_pro = htons(ETHERTYPE_IP);
p.arp_hln = ETH_ALEN;
p.arp_pln = 4;
p.arp_op = htons(ARPOP_REQUEST);
memcpy(&p.arp_sha, source_eth, ETH_ALEN);
memcpy(&p.arp_spa, &ip_source, sizeof(p.arp_spa));
memcpy(&p.arp_tpa, &ip_target, sizeof(p.arp_tpa));
n = sendto(fd, &p, sizeof(p), 0,
(struct sockaddr*) &dest, sizeof(dest));
if (n < 0)
n = -errno;
close(fd);
return n;
}
int ipv4ll_arp_socket(int ifindex)
{
int fd;
struct sockaddr_ll sock;
fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (fd < 0)
return fd;
memset(&sock, 0, sizeof(sock));
sock.sll_family = AF_PACKET;
sock.sll_protocol = htons(ETH_P_ARP);
sock.sll_ifindex = ifindex;
if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) {
int err = errno;
close(fd);
return -err;
}
return fd;
}
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