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|
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libnetlink.h>
#define BUFF_SIZE 1024
int main(int argc, char *argv[])
{
/* All the declarations and initializations relevant to the creation of the netlink socket to communicate with routing table */
int netlink_route_socket = 0;
/* All the declarations and initializations relevant to the binding of the socket to the local protocol address */
struct sockaddr_nl src_addr;
int bind_netlink_route_socket = 0;
/* All the declarations and initializations relevant to the creation and sending of the netlink message */
int m_nSeqNumber = 1;
int send_netlink_message = 0;
struct nlmsghdr *m_nlh;
struct iovec m_iov;
struct msghdr m_msghdr;
struct sockaddr_nl nladdr;
/* All the declarations and initializations relevant to the receiving of netlink messages */
int receive_netlink_message = 0;
int flag = 0;
int nb_addr_added = 0;
char buff[BUFF_SIZE];
char buf[4096];
struct nlmsghdr *p_netlink_message_header_received;
struct iovec iov;
struct msghdr msg;
struct sockaddr_nl sa;
struct ifinfomsg *p_ifinfomsg = NULL;
struct ifaddrmsg *p_ifaddrmsg = NULL;
struct rtattr *p_rtattr = NULL;
netlink_route_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if(netlink_route_socket < 0){
perror("socket");
exit(-1);
}
memset(&src_addr, 0, sizeof(src_addr));
src_addr.nl_family = AF_NETLINK;
src_addr.nl_pad = 0;
src_addr.nl_pid = getpid();
src_addr.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR; //RTMGRP_LINK (network interface create/delete/up/down events) and
//RTMGRP_IPV4_IFADDR (IPv4 addresses add/delete events) multicast groups
bind_netlink_route_socket = bind(netlink_route_socket, (struct sockaddr *)&src_addr, sizeof(src_addr));
if(bind_netlink_route_socket < 0){
perror("bind");
close(netlink_route_socket);
exit(-1);
}
m_msghdr.msg_name = (void *)&nladdr;
m_msghdr.msg_namelen = sizeof(nladdr);
m_msghdr.msg_iov = &m_iov;
m_msghdr.msg_iovlen = 1;
m_msghdr.msg_control = NULL;
m_msghdr.msg_controllen = 0;
m_msghdr.msg_flags = 0;
m_nlh = (struct nlmsghdr *)malloc NLMSG_SPACE(BUFF_SIZE);
m_nlh->nlmsg_pid = 0;
m_nlh->nlmsg_seq = m_nSeqNumber++;
m_nlh->nlmsg_len = NLMSG_SPACE(BUFF_SIZE);
m_nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST|NLM_F_ACK;
//m_nlh->nlmsg_type = RTM_GETLINK;
m_iov.iov_base = (void *) m_nlh;
m_iov.iov_len = m_nlh->nlmsg_len;
memset (&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
send_netlink_message = sendmsg(netlink_route_socket, &m_msghdr, 0);
if (send_netlink_message < 0){
perror("sendmsg");
close(netlink_route_socket);
exit(-1);
}
iov.iov_base = buf;
iov.iov_len = sizeof(buf);
msg.msg_name = (void *)&sa;
msg.msg_namelen = sizeof(sa);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
while(nb_addr_added < 3){
receive_netlink_message = recvmsg(netlink_route_socket, &msg, 0);
p_netlink_message_header_received = (struct nlmsghdr *)buff;
if(receive_netlink_message < 0){
perror("recvmsg");
close(netlink_route_socket);
exit(-1);
}
for(p_netlink_message_header_received = (struct nlmsghdr *) buf;
NLMSG_OK (p_netlink_message_header_received,
receive_netlink_message);
p_netlink_message_header_received = NLMSG_NEXT (p_netlink_message_header_received,receive_netlink_message))
{
switch(p_netlink_message_header_received->nlmsg_type)
{
case RTM_NEWLINK:
printf("***** case RTM_NEWLINK *****\n");
p_ifinfomsg = NLMSG_DATA(p_netlink_message_header_received);
printf("ifi_family %d\n",p_ifinfomsg->ifi_family);
printf("ifi_type %4x\n",p_ifinfomsg->ifi_type);
printf("ifi_index %d\n",p_ifinfomsg->ifi_index);
printf("ifi_flags %x\n",p_ifinfomsg->ifi_flags);
printf("ifi_change %x\n",p_ifinfomsg->ifi_change);
break;
case RTM_DELLINK:
printf("***** case RTM_DELLINK *****\n");
break;
case RTM_GETLINK:
printf("***** case RTM_GETLINK *****\n");
break;
case RTM_NEWADDR:
printf("***** case RTM_NEWADDR *****\n");
printf("A new address has been configured\n");
nb_addr_added++;
p_rtattr = NLMSG_DATA(p_netlink_message_header_received);
p_ifaddrmsg = NLMSG_DATA(p_netlink_message_header_received);
printf("=> Routing Attributes\n");
printf("rta_len %d\n",p_rtattr->rta_len);
printf("rta_type %d\n",p_rtattr->rta_type);
printf("=> Interface Address informations\n");
printf("ifa_family %d\n",p_ifaddrmsg->ifa_family);
printf("ifa_prefixlen %d\n",p_ifaddrmsg->ifa_prefixlen);
printf("ifa_flags %x\n",p_ifaddrmsg->ifa_flags);
printf("ifa_scope %d\n",p_ifaddrmsg->ifa_scope);
printf("ifa_index %d\n",p_ifaddrmsg->ifa_index);
break;
case RTM_DELADDR:
printf("***** case RTM_DELADDR *****\n");
printf("An address has been deleted ?\n");
break;
case RTM_GETADDR:
printf("***** case RTM_GETADDR *****\n");
break;
default:
printf("Message type %d received\n",
p_netlink_message_header_received->nlmsg_type);
break;
}
}
}
printf("Coming out\n");
return(0);
} |
