/*

 * Copyright (c) 2001-2020 Mellanox Technologies, Ltd. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the

 * BSD license below:

 *

 *     Redistribution and use in source and binary forms, with or

 *     without modification, are permitted provided that the following

 *     conditions are met:

 *

 *      - Redistributions of source code must retain the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer.

 *

 *      - Redistributions in binary form must reproduce the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer in the documentation and/or other materials

 *        provided with the distribution.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#include <stdio.h>

#include <stdint.h>

#include <string.h>

#include <stdlib.h>

#include <sys/ioctl.h>

#include <sys/socket.h>

#include <linux/rtnetlink.h>

#include <linux/netlink.h>

#include <netinet/in.h>

#include <netinet/ether.h>

#include <arpa/inet.h>

#include "utils/bullseye.h"

#include "utils/lock_wrapper.h"

#include "vlogger/vlogger.h"

#include "vma/util/vtypes.h"

#include "vma/util/utils.h"

#include "route_table_mgr.h"

#include "vma/sock/socket_fd_api.h"

#include "vma/sock/sock-redirect.h"

#include "vma/dev/net_device_table_mgr.h"

#include "ip_address.h"

// debugging macros

#define MODULE_NAME 		"rtm:"

#define rt_mgr_if_logpanic	__log_panic

#define	rt_mgr_logerr		__log_err

#define rt_mgr_logwarn		__log_warn

#define rt_mgr_loginfo		__log_info

#define rt_mgr_logdbg		__log_dbg

#define rt_mgr_logfunc		__log_func

#define rt_mgr_logfuncall	__log_funcall

route_table_mgr* g_p_route_table_mgr = NULL;

route_table_mgr::route_table_mgr() : netlink_socket_mgr<route_val>(ROUTE_DATA_TYPE), cache_table_mgr<route_rule_table_key, route_val*>("route_table_mgr")

{

	rt_mgr_logdbg("");

	//Read Route table from kernel and save it in local variable. 

	update_tbl();

	// create route_entry for each net_dev- needed for receiving port up/down events for net_dev_entry

	route_val *p_val;

	for (int i = 0; i < m_tab.entries_num; i++)

	{

		p_val = &m_tab.value[i];

		in_addr_t src_addr = p_val->get_src_addr();

		in_addr_route_entry_map_t::iterator iter = m_rte_list_for_each_net_dev.find(src_addr);

		// if src_addr of interface exists in the map, no need to create another route_entry

		if (iter == m_rte_list_for_each_net_dev.end()) {

			in_addr_t dst_ip	= src_addr;

			in_addr_t src_ip	= 0;

			uint8_t tos		= 0;

			m_rte_list_for_each_net_dev.insert(pair<in_addr_t, route_entry*> (src_addr, create_new_entry(route_rule_table_key(dst_ip, src_ip, tos), NULL)));

		}

	}

	//Print table

	print_val_tbl();

	// register to netlink event

	g_p_netlink_handler->register_event(nlgrpROUTE, this);

	rt_mgr_logdbg("Registered to g_p_netlink_handler");

	rt_mgr_logdbg("Done");

}

route_table_mgr::~route_table_mgr()

{

	rt_mgr_logdbg("");

	// clear all route_entrys created in the constructor

	in_addr_route_entry_map_t::iterator iter;

	while ((iter = m_rte_list_for_each_net_dev.begin()) != m_rte_list_for_each_net_dev.end()) {

		delete(iter->second);

		m_rte_list_for_each_net_dev.erase(iter);

	}

	rt_tbl_cach_entry_map_t::iterator cache_itr;

	while ((cache_itr = m_cache_tbl.begin()) != m_cache_tbl.end()) {

		delete(cache_itr->second);

		m_cache_tbl.erase(cache_itr);

	}

	rt_mgr_logdbg("Done");

}

void route_table_mgr::update_tbl()

{

	auto_unlocker lock(m_lock);

	netlink_socket_mgr<route_val>::update_tbl();

	rt_mgr_update_source_ip();

	return;

}

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;

			local_ip_list_t::iterator lip_iter;

			local_ip_list_t lip_offloaded_list = g_p_net_device_table_mgr->get_ip_list(p_val->get_if_index());

			if (!lip_offloaded_list.empty()) {

				for (lip_iter = lip_offloaded_list.begin(); lip_offloaded_list.end() != lip_iter; lip_iter++)

				{

					ip_data_t ip = *lip_iter;

					if((p_val->get_dst_addr() & ip.netmask) == (ip.local_addr & ip.netmask)) { //found a match in routing table

						if((ip.netmask | longest_prefix) != longest_prefix){

							longest_prefix = ip.netmask; // this is the longest prefix match

							correct_src = ip.local_addr;

						}

					}

				}

				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

						local_ip_list_t::iterator lip_iter;

						local_ip_list_t lip_offloaded_list = g_p_net_device_table_mgr->get_ip_list(p_val->get_if_index());

						for (lip_iter = lip_offloaded_list.begin(); lip_offloaded_list.end() != lip_iter; lip_iter++)

						{

							ip_data_t ip = *lip_iter;

							if(p_val->get_gw_addr() == ip.local_addr) {

								p_val->set_gw(0);

								p_val->set_src_addr(ip.local_addr);

								break;

							}

						}

						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_logdbg("could not figure out source ip for rtv = %s", p_val->to_str());

		}

	}

}

bool route_table_mgr::parse_enrty(nlmsghdr *nl_header, route_val *p_val)

{

	int len;

	struct rtmsg *rt_msg;

	struct rtattr *rt_attribute;

	// get route entry header

	rt_msg = (struct rtmsg *) NLMSG_DATA(nl_header);

	// we are not concerned about the local and default route table

	if (rt_msg->rtm_family != AF_INET || rt_msg->rtm_table == RT_TABLE_LOCAL)

		return false;

	p_val->set_protocol(rt_msg->rtm_protocol);

	p_val->set_scope(rt_msg->rtm_scope);

	p_val->set_type(rt_msg->rtm_type);

	p_val->set_table_id(rt_msg->rtm_table);

	in_addr_t dst_mask = htonl(VMA_NETMASK(rt_msg->rtm_dst_len));

	p_val->set_dst_mask(dst_mask);

	p_val->set_dst_pref_len(rt_msg->rtm_dst_len);

	len = RTM_PAYLOAD(nl_header);

	rt_attribute = (struct rtattr *) RTM_RTA(rt_msg);

	for (;RTA_OK(rt_attribute, len);rt_attribute=RTA_NEXT(rt_attribute,len)) {

		parse_attr(rt_attribute, p_val);

	}

	p_val->set_state(true);

	p_val->set_str();

	return true;

}

void route_table_mgr::parse_attr(struct rtattr *rt_attribute, route_val *p_val)

{

	switch (rt_attribute->rta_type) {

	case RTA_DST:

		p_val->set_dst_addr(*(in_addr_t *)RTA_DATA(rt_attribute));

		break;

	// next hop IPv4 address

	case RTA_GATEWAY:

		p_val->set_gw(*(in_addr_t *)RTA_DATA(rt_attribute));

		break;

	// unique ID associated with the network interface

	case RTA_OIF:

		p_val->set_if_index(*(int *)RTA_DATA(rt_attribute));

		char if_name[IFNAMSIZ];

		if_indextoname(p_val->get_if_index(),if_name);

		p_val->set_if_name(if_name);

		break;

	case RTA_SRC:

	case RTA_PREFSRC:

		p_val->set_src_addr(*(in_addr_t *)RTA_DATA(rt_attribute));

		break;

	case RTA_TABLE:

		p_val->set_table_id(*(uint32_t *)RTA_DATA(rt_attribute));

		break;

	case RTA_METRICS:

	{

		struct rtattr *rta = (struct rtattr *)RTA_DATA(rt_attribute);

		int len = RTA_PAYLOAD(rt_attribute);

		uint16_t type;

		while (RTA_OK(rta, len)) {

			type = rta->rta_type;

			switch (type) {

			case RTAX_MTU:

				p_val->set_mtu(*(uint32_t *)RTA_DATA(rta));

				break;

			default:

				rt_mgr_logdbg("got unexpected METRICS %d %x",

					type, *(uint32_t *)RTA_DATA(rta));

				break;

			}

			rta = RTA_NEXT(rta, len);

		}

		break;

	}

	default:

		rt_mgr_logdbg("got unexpected type %d %x", rt_attribute->rta_type,

				*(uint32_t *)RTA_DATA(rt_attribute));

		break;

	}

}

bool route_table_mgr::find_route_val(in_addr_t &dst, unsigned char table_id, route_val* &p_val)

{

	ip_address dst_addr = dst;

	rt_mgr_logfunc("dst addr '%s'", dst_addr.to_str().c_str());

	route_val *correct_route_val = NULL;

	int longest_prefix = -1;

	for (int i = 0; i < m_tab.entries_num; i++) {

		route_val* p_val_from_tbl = &m_tab.value[i];

		if (!p_val_from_tbl->is_deleted() && p_val_from_tbl->is_if_up()) { // value was not deleted

			if(p_val_from_tbl->get_table_id() == table_id) { //found a match in routing table ID

				if(p_val_from_tbl->get_dst_addr() == (dst & p_val_from_tbl->get_dst_mask())) { //found a match in routing table

					if(p_val_from_tbl->get_dst_pref_len() > longest_prefix) { // this is the longest prefix match

						longest_prefix = p_val_from_tbl->get_dst_pref_len();

						correct_route_val = p_val_from_tbl;

					}

				}

			}

		}	

	}

	if (correct_route_val) {

		ip_address dst_gw = correct_route_val->get_dst_addr();

		p_val = correct_route_val;

		rt_mgr_logdbg("found route val[%p]: %s", p_val, p_val->to_str());

		return true;

	}

	rt_mgr_logdbg("destination gw wasn't found");

	return false;

}

bool route_table_mgr::route_resolve(IN route_rule_table_key key, OUT route_result &res)

{

	in_addr_t dst = key.get_dst_ip();

	ip_address dst_addr = dst;

	rt_mgr_logdbg("dst addr '%s'", dst_addr.to_str().c_str());

	route_val *p_val = NULL;

	std::deque<unsigned char> table_id_list;

	g_p_rule_table_mgr->rule_resolve(key, table_id_list);

	auto_unlocker lock(m_lock);

	std::deque<unsigned char>::iterator table_id_iter = table_id_list.begin();

	for (; table_id_iter != table_id_list.end(); table_id_iter++) {

		if (find_route_val(dst, *table_id_iter, p_val)) {

			res.p_src = p_val->get_src_addr();

			rt_mgr_logdbg("dst ip '%s' resolved to src addr "

					"'%d.%d.%d.%d'", dst_addr.to_str().c_str(),

					NIPQUAD(res.p_src));

			res.p_gw = p_val->get_gw_addr();

			rt_mgr_logdbg("dst ip '%s' resolved to gw addr '%d.%d.%d.%d'",

					dst_addr.to_str().c_str(), NIPQUAD(res.p_gw));

			res.mtu = p_val->get_mtu();

			rt_mgr_logdbg("found route mtu %d", res.mtu);

			return true;

		}

	}

	/* prevent usage on false return */

	return false;

}

void route_table_mgr::update_entry(INOUT route_entry* p_ent, bool b_register_to_net_dev /*= false*/)

{

	rt_mgr_logdbg("entry [%p]", p_ent);

	auto_unlocker lock(m_lock);

	if (p_ent && !p_ent->is_valid()) { //if entry is found in the collection and is not valid

		rt_mgr_logdbg("route_entry is not valid-> update value");

		rule_entry* p_rr_entry = p_ent->get_rule_entry();

		std::deque<rule_val*>* p_rr_val;

		if (p_rr_entry && p_rr_entry->get_val(p_rr_val)) {

			route_val* p_val = NULL;

			in_addr_t peer_ip = p_ent->get_key().get_dst_ip();

			unsigned char table_id;

			for (std::deque<rule_val*>::iterator p_rule_val = p_rr_val->begin(); p_rule_val != p_rr_val->end(); p_rule_val++) {

				table_id = (*p_rule_val)->get_table_id();

				if (find_route_val(peer_ip, table_id, p_val)) {

					p_ent->set_val(p_val);

					if (b_register_to_net_dev) {

						//in_addr_t src_addr = p_val->get_src_addr();

						//net_device_val* p_ndv = g_p_net_device_table_mgr->get_net_device_val(src_addr);

						// Check if broadcast IP which is NOT supported

						if (IS_BROADCAST_N(peer_ip)) {

							rt_mgr_logdbg("Disabling Offload for route_entry '%s' - this is BC address", p_ent->to_str().c_str());

							// Need to route traffic to/from OS

							// Prevent registering of net_device to route entry

						}

						// Check if: Local loopback over Ethernet case which was not supported before OFED 2.1

						/*else if (p_ndv && (p_ndv->get_transport_type() == VMA_TRANSPORT_ETH) &&  (peer_ip == src_addr)) {

							rt_mgr_logdbg("Disabling Offload for route_entry '%s' - this is an Ethernet unicast loopback route", p_ent->to_str().c_str());

							// Need to route traffic to/from OS

							// Prevent registering of net_device to route entry

						}*/

						else {

							// register to net device for bonding events

							p_ent->register_to_net_device();

						}

					}

					// All good, validate the new route entry

					p_ent->set_entry_valid();

					break;

				} else {

					rt_mgr_logdbg("could not find route val for route_entry '%s in table %u'", p_ent->to_str().c_str(), table_id);

				}

			}

		}

		else {

			rt_mgr_logdbg("rule entry is not valid");

		}

	}

}

route_entry* route_table_mgr::create_new_entry(route_rule_table_key key, const observer *obs)

{

	// no need for lock - lock is activated in cache_collection_mgr::register_observer

	rt_mgr_logdbg("");

	NOT_IN_USE(obs);

	route_entry* p_ent = new route_entry(key);

	update_entry(p_ent, true);

	rt_mgr_logdbg("new entry %p created successfully", p_ent);

	return p_ent;

}

void route_table_mgr::new_route_event(route_val* netlink_route_val)

{

	if (!netlink_route_val) {

		rt_mgr_logdbg("Invalid route entry");

		return;

	}

	if (m_tab.entries_num >= MAX_TABLE_SIZE) {

		rt_mgr_logwarn("No available space for new route entry");	

		return;

	}

	auto_unlocker lock(m_lock);	

	route_val* p_route_val = &m_tab.value[m_tab.entries_num];

	p_route_val->set_dst_addr(netlink_route_val->get_dst_addr());

	p_route_val->set_dst_mask(netlink_route_val->get_dst_mask());

	p_route_val->set_dst_pref_len(netlink_route_val->get_dst_pref_len());

	p_route_val->set_src_addr(netlink_route_val->get_src_addr());

	p_route_val->set_gw(netlink_route_val->get_gw_addr());

	p_route_val->set_protocol(netlink_route_val->get_protocol());

	p_route_val->set_scope(netlink_route_val->get_scope()); 

	p_route_val->set_type(netlink_route_val->get_type());

	p_route_val->set_table_id(netlink_route_val->get_table_id());

	p_route_val->set_if_index(netlink_route_val->get_if_index());

	p_route_val->set_if_name(const_cast<char*> (netlink_route_val->get_if_name()));

	p_route_val->set_mtu((netlink_route_val->get_mtu()));

	p_route_val->set_state(true);

	p_route_val->set_str();

	p_route_val->print_val();

	++m_tab.entries_num;

}

void route_table_mgr::notify_cb(event *ev)

{

	rt_mgr_logdbg("received route event from netlink");

	route_nl_event *route_netlink_ev = dynamic_cast <route_nl_event*>(ev);

	if (!route_netlink_ev) {

		rt_mgr_logwarn("Received non route event!!!");

		return;

	}

	netlink_route_info* p_netlink_route_info = route_netlink_ev->get_route_info();

	if (!p_netlink_route_info) {

		rt_mgr_logdbg("Received invalid route event!!!");

		return;

	}

	switch(route_netlink_ev->nl_type) {

		case RTM_NEWROUTE:

			new_route_event(p_netlink_route_info->get_route_val());

			break;

#if 0

		case RTM_DELROUTE:

			del_route_event(p_netlink_route_info->get_route_val());

			break;

#endif

		default:

			rt_mgr_logdbg("Route event (%u) is not handled", route_netlink_ev->nl_type);

			break;

	}

}