ZeroTierOne/osdep/LinuxNetLink.hpp

/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2023-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_LINUX_NETLINK_HPP
#define ZT_LINUX_NETLINK_HPP

#include <vector>

#include <sys/socket.h>
#include <asm/types.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <linux/if.h>

#include "../node/InetAddress.hpp"
#include "../node/MAC.hpp"
#include "Thread.hpp"
#include "../node/Hashtable.hpp"
#include "../node/Mutex.hpp"


namespace ZeroTier {

struct route_entry {
	InetAddress target;
	InetAddress via;
	int if_index;
	char iface[IFNAMSIZ];
};
typedef std::vector<route_entry> RouteList;

/**
 * Interface with Linux's RTNETLINK
 */
class LinuxNetLink
{
private:
    LinuxNetLink();
    ~LinuxNetLink();

public:
    static LinuxNetLink& getInstance()
    {
        static LinuxNetLink instance;
        return instance;
    }

    LinuxNetLink(LinuxNetLink const&) = delete;
    void operator=(LinuxNetLink const&) = delete;

    void addRoute(const InetAddress &target, const InetAddress &via, const InetAddress &src, const char *ifaceName);
    void delRoute(const InetAddress &target, const InetAddress &via, const InetAddress &src, const char *ifaceName);
    RouteList getIPV4Routes() const;
    RouteList getIPV6Routes() const;

    void addAddress(const InetAddress &addr, const char *iface);
    void removeAddress(const InetAddress &addr, const char *iface);

    void threadMain() throw();
private:
    int _doRecv(int fd);

    void _processMessage(struct nlmsghdr *nlp, int nll);
    void _routeAdded(struct nlmsghdr *nlp);
    void _routeDeleted(struct nlmsghdr *nlp);
    void _linkAdded(struct nlmsghdr *nlp);
    void _linkDeleted(struct nlmsghdr *nlp);
    void _ipAddressAdded(struct nlmsghdr *nlp);
    void _ipAddressDeleted(struct nlmsghdr *nlp);

    void _requestInterfaceList();
    void _requestIPv4Routes();
    void _requestIPv6Routes();

    int _indexForInterface(const char *iface);

    void _setSocketTimeout(int fd, int seconds = 1);

    Thread _t;
    bool _running;

    RouteList _routes_ipv4;
    Mutex _rv4_m;
    RouteList _routes_ipv6;
    Mutex _rv6_m;

    uint32_t _seq;

    struct iface_entry {
        int index;
        char ifacename[IFNAMSIZ];
        char mac[18];
        char mac_bin[6];
        unsigned int mtu;
    };
    Hashtable<int, iface_entry> _interfaces;
    Mutex _if_m;

    // socket communication vars;
    int _fd;
    struct sockaddr_nl _la;
};

}

#endif // ZT_LINUX_NETLINK_HPPS