netlink.h

/*
 * Copyright (C) 2016-2017 Pelagicore AB
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
 * BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 *
 * For further information see LICENSE
 *
 */

#include "softwarecontainer-common.h"

#include <linux/rtnetlink.h>
#include <arpa/inet.h>

#include <string>
#include <vector>

namespace softwarecontainer {

class Netlink
{
public:
    LOG_DECLARE_CLASS_CONTEXT("NETL", "Netlink");

    typedef std::pair<rtattr, void*> AttributeInfo;
    typedef std::vector<AttributeInfo> AttributeList;
    typedef std::pair<ifinfomsg, AttributeList> LinkInfo;
    typedef std::pair<ifaddrmsg, AttributeList> AddressInfo;
    typedef std::pair<rtmsg, AttributeList> RouteInfo;

    Netlink();

    virtual ~Netlink();

    bool getKernelDump();

    virtual bool checkKernelDump();

    bool setDefaultGateway(const char *gatewayAddress);

    bool linkUp(const int ifaceIndex);

    bool linkDown(const int ifaceIndex);

    bool setIP(const int ifaceIndex, const in_addr ip, const unsigned char netmask);

    bool findLink(const char *ifaceName, LinkInfo &linkInfo);

    bool findAddresses(const unsigned int interfaceIndex, std::vector<AddressInfo> &result);

    bool hasAddress(const std::vector<AddressInfo> &haystack, const int addressFamily, const char *needle);

private:
    bool setupNetlink();

    void clearCache();

    template<typename msgtype, typename InfoType>
    bool saveMessage(const struct nlmsghdr &header, std::vector<InfoType> &result);

    template<typename msgtype>
    bool getAttributes(const struct nlmsghdr &header, AttributeList &result);

    template<typename payload>struct netlink_request {
        nlmsghdr hdr;
        payload pay;
        char attr[2048];
    };

    template<typename payload>
    netlink_request<payload> createMessage(const int type, const int flags);

    template<typename payload>
    bool addAttribute(netlink_request<payload> &req, const int type, const size_t length, const void *data);

    template<typename payload>
    bool sendMessage(netlink_request<payload> &request);

    int readMessage();

    void freeAttributes(AttributeList &attrList);

    // Netlink communication variables
    struct sockaddr_nl m_local;
    struct sockaddr_nl m_kernel;
    int m_fd;
    pid_t m_pid;
    unsigned int m_sequenceNumber;

    // The local cache of links, addresses and routes
    std::vector< LinkInfo > m_links;
    std::vector< AddressInfo > m_addresses;
    std::vector< RouteInfo > m_routes;

    // Status flags
    bool m_hasKernelDump;
    bool m_netlinkInitialized;
};

} // namespace softwarecontainer