void route_table_mgr::rt_mgr_build_request(rt_req_type_t type, rt_req_info_t *req_info, struct nlmsghdr **nl_msg)
{
struct rtmsg *rt_msg;
memset(m_msg_buf, 0, m_buff_size);
// point the header and the msg structure pointers into the buffer
*nl_msg = (struct nlmsghdr *)m_msg_buf;
rt_msg = (struct rtmsg *)NLMSG_DATA(*nl_msg);
//Fill in the nlmsg header
(*nl_msg)->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
(*nl_msg)->nlmsg_seq = m_seq_num++;
(*nl_msg)->nlmsg_pid = m_pid;
rt_msg->rtm_family = AF_INET;
switch (type) {
case RT_TYPE_GET_RT:
(*nl_msg)->nlmsg_type = RTM_GETROUTE;
(*nl_msg)->nlmsg_flags = NLM_F_REQUEST;
if (req_info->dst.s_addr && req_info->dst_pref_len) {
rt_mgr_add_attr(*nl_msg, m_buff_size, RTA_DST, &req_info->dst, req_info->dst_pref_len);
}
if (req_info->src.s_addr && req_info->src_pref_len) {
rt_mgr_add_attr(*nl_msg, m_buff_size, RTA_SRC, &req_info->src, req_info->src_pref_len);
}
break;
case RT_TYPE_DUMP_RT:
(*nl_msg)->nlmsg_type = RTM_GETROUTE;
(*nl_msg)->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
break;
BULLSEYE_EXCLUDE_BLOCK_START
default:
rt_mgr_logwarn("Unknown netlink route request type.");
break;
BULLSEYE_EXCLUDE_BLOCK_END
}
}
void route_table_mgr::rt_mgr_update_source_ip()
{
route_val *p_val;
//for route entries which still have no src ip and no gw
for (int i = 0; i < m_tab.entries_num; i++) {
p_val = &m_tab.value[i];
if (p_val->get_src_addr() || p_val->get_gw_addr()) continue;
if (g_p_net_device_table_mgr) { //try to get src ip from net_dev list of the interface
in_addr_t longest_prefix = 0;
in_addr_t correct_src = 0;
net_dev_lst_t* nd_lst = g_p_net_device_table_mgr->get_net_device_val_lst_from_index(p_val->get_if_index());
if (nd_lst) {
net_dev_lst_t::iterator iter = nd_lst->begin();
while (iter != nd_lst->end()) {
if((p_val->get_dst_addr() & (*iter)->get_netmask()) == ((*iter)->get_local_addr() & (*iter)->get_netmask())) { //found a match in routing table
if(((*iter)->get_netmask() | longest_prefix) != longest_prefix){
longest_prefix = (*iter)->get_netmask(); // this is the longest prefix match
correct_src = (*iter)->get_local_addr();
}
}
iter++;
}
if (correct_src) {
p_val->set_src_addr(correct_src);
continue;
}
}
}
// if still no src ip, get it from ioctl
struct sockaddr_in src_addr;
char *if_name = (char *)p_val->get_if_name();
if (!get_ipv4_from_ifname(if_name, &src_addr)) {
p_val->set_src_addr(src_addr.sin_addr.s_addr);
}
else {
// Failed mapping if_name to IPv4 address
rt_mgr_logwarn("could not figure out source ip for rtv = %s", p_val->to_str());
}
}
//for route entries with gateway, do recursive search for src ip
int num_unresolved_src = m_tab.entries_num;
int prev_num_unresolved_src = 0;
do {
prev_num_unresolved_src = num_unresolved_src;
num_unresolved_src = 0;
for (int i = 0; i < m_tab.entries_num; i++) {
p_val = &m_tab.value[i];
if (p_val->get_gw_addr() && !p_val->get_src_addr()) {
route_val* p_val_dst;
in_addr_t in_addr = p_val->get_gw_addr();
unsigned char table_id = p_val->get_table_id();
if (find_route_val(in_addr, table_id, p_val_dst)) {
if (p_val_dst->get_src_addr()) {
p_val->set_src_addr(p_val_dst->get_src_addr());
} else if (p_val == p_val_dst) { //gateway of the entry lead to same entry
net_dev_lst_t* nd_lst = g_p_net_device_table_mgr->get_net_device_val_lst_from_index(p_val->get_if_index());
if (nd_lst) {
net_dev_lst_t::iterator iter = nd_lst->begin();
while (iter != nd_lst->end()) {
if(p_val->get_gw_addr() == (*iter)->get_local_addr()) {
p_val->set_gw(0);
p_val->set_src_addr((*iter)->get_local_addr());
break;
}
iter++;
}
}
if (!p_val->get_src_addr())
num_unresolved_src++;
} else {
num_unresolved_src++;
}
// gateway and source are equal, no need of gw.
if (p_val->get_src_addr() == p_val->get_gw_addr()) {
p_val->set_gw(0);
}
} else {
num_unresolved_src++;
}
}
}
} while (num_unresolved_src && prev_num_unresolved_src > num_unresolved_src);
//for route entries which still have no src ip
for (int i = 0; i < m_tab.entries_num; i++) {
p_val = &m_tab.value[i];
if (p_val->get_src_addr()) continue;
if (p_val->get_gw_addr()) {
rt_mgr_logdbg("could not figure out source ip for gw address. rtv = %s", p_val->to_str());
}
// if still no src ip, get it from ioctl
struct sockaddr_in src_addr;
char *if_name = (char *)p_val->get_if_name();
if (!get_ipv4_from_ifname(if_name, &src_addr)) {
p_val->set_src_addr(src_addr.sin_addr.s_addr);
}
else {
// Failed mapping if_name to IPv4 address
rt_mgr_logwarn("could not figure out source ip for rtv = %s", p_val->to_str());
}
}
}