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/*
* host_utils.c -- utils for host
*
* Author: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
* Author: Sukru Senli sukru.senli@inteno.se
* Author: Nevadita Chatterjee nevadita.chatterjee@iopsys.eu
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#define _GNU_SOURCE
#include "host_utils.h"
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
struct in_addr src;
struct in_addr dst;
struct sockaddr_ll me;
struct sockaddr_ll he;
int sock_fd;
typedef struct nl_req_s nl_req_t;
struct nl_req_s {
struct nlmsghdr hdr;
struct rtgenmsg gen;
};
static int
send_pack(struct in_addr *src_addr, struct in_addr *dst_addr, struct sockaddr_ll *ME, struct sockaddr_ll *HE)
{
int err;
unsigned char buf[256];
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
ah->ar_hrd = htons(ARPHRD_ETHER);
ah->ar_pro = htons(ETH_P_IP);
ah->ar_hln = ME->sll_halen;
ah->ar_pln = 4;
ah->ar_op = htons(ARPOP_REQUEST);
p = (unsigned char *)mempcpy((void *)p, (const void *)ME->sll_addr, (size_t)ah->ar_hln);
p = (unsigned char *)mempcpy((void *)p, (const void *)src_addr, 4);
p = (unsigned char *)mempcpy((void *)p, (const void *)HE->sll_addr, (size_t)ah->ar_hln);
p = (unsigned char *)mempcpy((void *)p, (const void *)dst_addr, 4);
err = sendto(sock_fd, buf, p - buf, 0, (struct sockaddr *) HE, sizeof(*HE));
return err;
}
static bool
recv_pack(char *buf, int len, struct sockaddr_ll *FROM)
{
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
struct in_addr src_ip, dst_ip;
/* Filter out wild packets */
if (FROM->sll_pkttype != PACKET_HOST
&& FROM->sll_pkttype != PACKET_BROADCAST
&& FROM->sll_pkttype != PACKET_MULTICAST)
return false;
/* Only these types are recognized */
if (ah->ar_op != htons(ARPOP_REPLY))
return false;
/* ARPHRD check and this darned FDDI hack here :-( */
if (ah->ar_hrd != htons(FROM->sll_hatype)
&& (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER)))
return false;
/* Protocol must be IP. */
if (ah->ar_pro != htons(ETH_P_IP)
|| (ah->ar_pln != 4)
|| (ah->ar_hln != me.sll_halen)
|| (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln))))
return false;
(src_ip.s_addr) = *(uint32_t *)(p + ah->ar_hln);
(dst_ip.s_addr) = *(uint32_t *)(p + ah->ar_hln + 4 + ah->ar_hln);
if (dst.s_addr != src_ip.s_addr)
return false;
if ((src.s_addr != dst_ip.s_addr) || (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln)))
return false;
return true;
}
bool
host_send_arping(const char *targetIP, const char *device, int toms, int is_recv)
{
struct sockaddr_in saddr;
struct ifreq ifr;
int probe_fd;
char packet[64];
struct sockaddr_ll from;
struct timeval timeout;
dbg("Inside %s %d\n", __func__, __LINE__);
sock_fd = socket(AF_PACKET, SOCK_DGRAM, 0);
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, device, IF_NAMESIZE);
if (ioctl(sock_fd, SIOCGIFINDEX, &ifr, sizeof(ifr)) < 0) {
close(sock_fd);
return false;
}
me.sll_family = AF_PACKET;
me.sll_ifindex = ifr.ifr_ifindex;
me.sll_protocol = htons(ETH_P_ARP);
bind(sock_fd, (struct sockaddr *) &me, sizeof(me));
socklen_t mlen = sizeof(me);
getsockname(sock_fd, (struct sockaddr *) &me, &mlen);
he = me;
memset(he.sll_addr, -1, he.sll_halen);
inet_pton(AF_INET, targetIP, &(dst.s_addr));
/* Get the sender IP address */
probe_fd = socket(AF_INET, SOCK_DGRAM, 0);
setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
memset(&saddr, 0, sizeof(saddr));
saddr.sin_family = AF_INET;
socklen_t slen = sizeof(saddr);
saddr.sin_port = htons(1025);
saddr.sin_addr = dst;
connect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
getsockname(probe_fd, (struct sockaddr *) &saddr, &slen);
src = saddr.sin_addr;
close(probe_fd);
send_pack(&src, &dst, &me, &he);
/*Here we are just sending the arp packet and returning*/
if (is_recv != 1)
return 1;
socklen_t alen = sizeof(from);
bool connected = false;
int cc = -1;
fd_set read_fds, write_fds, except_fds;
FD_ZERO(&read_fds);
FD_ZERO(&write_fds);
FD_ZERO(&except_fds);
FD_SET(sock_fd, &read_fds);
timeout.tv_sec = 0;
timeout.tv_usec = toms * 1000;
if (select(sock_fd + 1, &read_fds, &write_fds, &except_fds, &timeout) == 1)
cc = recvfrom(sock_fd, packet, sizeof(packet), 0, (struct sockaddr *) &from, &alen);
if (cc >= 0)
connected = recv_pack(packet, cc, &from);
close(sock_fd);
dbg("Inside %s %d connected %d\n", __func__, __LINE__, connected);
return connected;
}
int host_get_netlink_ip(uint8_t *mac_addr, char *ipv4_str, char *device)
{
struct rtnl_neigh *neigh;
struct nl_object *nobj;
struct nl_cache *cache;
uint32_t ifindex = 0;
struct nl_sock *sk;
int i, num;
int ret;
char *ifname = NULL;
dbg("Inside %s %d\n", __func__, __LINE__);
sk = nl_socket_alloc();
if (!sk) {
err("Unable to open nl event socket\n");
return -1;
}
if (nl_connect(sk, NETLINK_ROUTE) < 0) {
nl_socket_free(sk);
return -1;
}
ret = rtnl_neigh_alloc_cache(sk, &cache);
if (ret) {
nl_socket_free(sk);
return -1;
}
num = nl_cache_nitems(cache);
nobj = nl_cache_get_first(cache);
neigh = (struct rtnl_neigh *)nobj;
for (i = 0; i < num; i++) {
struct nl_addr *lladdr;
struct nl_addr *ipaddr;
struct ip_address ip = {0};
uint8_t hwaddr[6] = {0};
char addr_str[24];
nl_object_get((struct nl_object *) neigh);
ifindex = rtnl_neigh_get_ifindex(neigh);
lladdr = rtnl_neigh_get_lladdr(neigh);
if (lladdr)
memcpy(hwaddr, nl_addr_get_binary_addr(lladdr),
nl_addr_get_len(lladdr));
if (hwaddr_is_zero(hwaddr)) {
nl_object_put((struct nl_object *) neigh);
nobj = nl_cache_get_next(nobj);
neigh = (struct rtnl_neigh *)nobj;
continue;
}
ipaddr = rtnl_neigh_get_dst(neigh);
if (ipaddr) {
ip.family = nl_addr_get_family(ipaddr);
if (ip.family == AF_INET6 || ip.family == AF_INET) {
memcpy(&ip.addr, nl_addr_get_binary_addr(ipaddr),
nl_addr_get_len(ipaddr));
}
}
char *addr_s = nl_addr2str(ipaddr, addr_str, sizeof(addr_str));
if (addr_s == NULL) {
/* error */
err("nl_addr2str failed\n");
return -1;
}
ret = memcmp(hwaddr, mac_addr, 6);
if (ret == 0) {
strncpy(ipv4_str, addr_str, 24);
ifname = if_indextoname(ifindex, device);
if (ifname == NULL)
return -1;
dbg("intfname = [%s] ipv4addr= [%s] mac=["MACFMT"]\n", device, ipv4_str, MAC2STR(hwaddr));
break;
}
nl_object_put((struct nl_object *) neigh);
nobj = nl_cache_get_next(nobj);
neigh = (struct rtnl_neigh *)nobj;
}
nl_cache_free(cache);
nl_socket_free(sk);
return 0;
}