ibrcommon/ibrcommon/net/NetLinkManager.cpp

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/*
 * NetLinkManager.cpp
 *
 *  Created on: 21.12.2010
 *      Author: morgenro
 */

#include "ibrcommon/net/NetLinkManager.h"
#include "ibrcommon/thread/MutexLock.h"
#include "ibrcommon/Logger.h"

#include <netlink/cache.h>
#include <netlink/route/addr.h>
#include <netlink/route/link.h>
#include <netlink/route/rtnl.h>
#include <net/if.h>

#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/tcp.h>
#include <sys/un.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h>
#include <arpa/inet.h>

#include <iostream>
#include <sstream>

namespace ibrcommon
{
        NetLinkManager::NetLinkManager()
         : _initialized(false), _sock(NULL), _refresh_cache(false)
        {
                ibrcommon::MutexLock l(_call_mutex);

                _handle = nl_handle_alloc();
                nl_connect(_handle, NETLINK_ROUTE);

                _link_cache = rtnl_link_alloc_cache(_handle);
                _addr_cache = rtnl_addr_alloc_cache(_handle);

                _initialized = true;

                // create a new socket for the netlink interface
                _sock = new ibrcommon::vsocket();
        }

        NetLinkManager::~NetLinkManager()
        {
                stop();
                join();

                // destroy the socket for the netlink interface
                _sock = new ibrcommon::vsocket();

                nl_close(_handle);
                nl_cache_free(_addr_cache);
                nl_cache_free(_link_cache);
                nl_handle_destroy(_handle);
        }

        void add_addr_to_list(struct nl_object *obj, void *data)
        {
                char buf[INET6_ADDRSTRLEN+5];
                std::list<vaddress> *list = static_cast<std::list<vaddress>*>(data);

                struct nl_addr *naddr = rtnl_addr_get_local((struct rtnl_addr *) obj);
                int ifindex = 0;
                int scope = rtnl_addr_get_scope((struct rtnl_addr *) obj);

                if (scope == rtnl_str2scope("link"))
                        ifindex = rtnl_addr_get_ifindex((struct rtnl_addr *) obj);

                if (naddr)
                {
                        int family = nl_addr_get_family(naddr);
                        nl_addr2str( naddr, buf, sizeof( buf ) );
                        vaddress vaddr(vaddress::Family(family), vaddress::strip_netmask(std::string(buf)), ifindex, false);
                        list->push_back( vaddr );
                }

                struct nl_addr *baddr = rtnl_addr_get_broadcast((struct rtnl_addr *) obj);

                if (baddr)
                {
                        int family = nl_addr_get_family(baddr);
                        nl_addr2str( baddr, buf, sizeof( buf ) );
                        vaddress vaddr(vaddress::Family(family), vaddress::strip_netmask(std::string(buf)), ifindex, true);
                        list->push_back( vaddr );
                }
        }

        bool NetLinkManager::__cancellation()
        {
                ibrcommon::MutexLock l(_call_mutex);
                _initialized = false;
                _sock->close();

                return true;
        }

        void NetLinkManager::run()
        {
                struct nl_handle *handle = nl_handle_alloc();
                nl_connect(handle, NETLINK_ROUTE);

                // init route messages
                nl_socket_add_membership(handle, RTNLGRP_IPV4_IFADDR);

//              IPv6 requires further support in the parsing procedures!
//              nl_socket_add_membership(handle, RTNLGRP_IPV6_IFADDR);
                nl_socket_add_membership(handle, RTNLGRP_LINK);

                // add netlink fd to vsocket
                _sock->add(nl_socket_get_fd(handle));

                try {
                        while (_initialized)
                        {
                                std::list<int> fds;
                                _sock->select(fds, NULL);
                                int fd = fds.front();

                                // create a new event object
                                NetLinkManagerEvent lme(fd);

                                // get the corresponding interface
                                const vinterface &iface = lme.getInterface();

                                // ignore if the event is unknown
                                if (lme.getType() == LinkManagerEvent::EVENT_UNKOWN) continue;

                                // ignore if this is an wireless extension event
                                if (lme.isWirelessExtension()) continue;

                                // need to refresh the cache
                                {
                                        ibrcommon::MutexLock l(_call_mutex);
                                        _refresh_cache = true;
                                }

                                // search for event subscriptions
                                ibrcommon::MutexLock l(_listener_mutex);
                                const std::set<LinkManager::EventCallback* > &ss = _listener[iface];

                                IBRCOMMON_LOGGER_DEBUG(10) << lme.toString() << IBRCOMMON_LOGGER_ENDL;

                                for (std::set<LinkManager::EventCallback* >::iterator iter = ss.begin(); iter != ss.end(); iter++)
                                {
                                        try {
                                                (*iter)->eventNotify((LinkManagerEvent&)lme);
                                        } catch (const std::exception&) { };
                                }
                        }
                } catch (const vsocket_exception&) {
                        // stopped / interrupted
                        IBRCOMMON_LOGGER(error) << "NetLink connection stopped" << IBRCOMMON_LOGGER_ENDL;
                }

                nl_close(handle);
                nl_handle_destroy(handle);
        }

        const std::list<vaddress> NetLinkManager::getAddressList(const vinterface &interface, const vaddress::Family f)
        {
                ibrcommon::MutexLock l(_call_mutex);

                if (_refresh_cache)
                {
                        nl_cache_free(_addr_cache);
                        nl_cache_free(_link_cache);

                        _link_cache = rtnl_link_alloc_cache(_handle);
                        _addr_cache = rtnl_addr_alloc_cache(_handle);
                }

                std::list<vaddress> addresses;

                struct rtnl_addr *filter = rtnl_addr_alloc();
                const std::string i = interface.toString();
                rtnl_addr_set_ifindex(filter, rtnl_link_name2i(_link_cache, i.c_str()));

                if (f == vaddress::VADDRESS_UNSPEC)
                {
                        rtnl_addr_set_family(filter, AF_INET6);
                        nl_cache_foreach_filter(_addr_cache, (struct nl_object *) filter,
                                                                        add_addr_to_list, &addresses);

                        rtnl_addr_set_family(filter, AF_INET);
                        nl_cache_foreach_filter(_addr_cache, (struct nl_object *) filter,
                                                                        add_addr_to_list, &addresses);
                }
                else
                {
                        rtnl_addr_set_family(filter, f);
                        nl_cache_foreach_filter(_addr_cache, (struct nl_object *) filter,
                                                                        add_addr_to_list, &addresses);
                }

                rtnl_addr_put(filter);

                return addresses;
        }

        const std::string NetLinkManager::getInterface(const int ifindex) const
        {
                char buf[256];
                rtnl_link_i2name(_link_cache, ifindex, (char*)&buf, sizeof buf);
                return std::string((char*)&buf);
        }

        NetLinkManagerEvent::NetLinkManagerEvent(int fd)
         : _type(EVENT_UNKOWN), _state(0), _wireless(false)
        {
                char buf[4096];
                int len = 0;
                struct nlmsghdr *nlh;

                // cast netlink message
                nlh = (struct nlmsghdr *) buf;

                // get local reference to the attributes list
                std::map<int, std::string> &attrlist = _attributes;

                while ((len = recv(fd, nlh, 4096, 0)) > 0)
                {
                        while ((NLMSG_OK(nlh, len)) && (nlh->nlmsg_type != NLMSG_DONE))
                        {
                                switch (nlh->nlmsg_type)
                                {
                                        case RTM_BASE:
                                        {
                                                int attrlen, nlmsg_len, rta_len;
                                                struct rtattr * attr;

                                                struct ifinfomsg *ifi = (struct ifinfomsg *) NLMSG_DATA(nlh);

                                                nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
                                                attrlen = nlh->nlmsg_len - nlmsg_len;

                                                if (attrlen < 0) break;

                                                attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);

                                                rta_len = RTA_ALIGN(sizeof(struct rtattr));
                                                while (RTA_OK(attr, attrlen))
                                                {
                                                        size_t rta_length = RTA_PAYLOAD(attr);

                                                        switch (attr->rta_type)
                                                        {
                                                        case IFLA_IFNAME:
                                                                _interface = ibrcommon::vinterface( std::string((char*)RTA_DATA(attr), rta_length) );
                                                                _type = EVENT_LINK_STATE;
                                                                break;

                                                        case IFLA_OPERSTATE:
                                                        {
                                                                char s;
                                                                ::memcpy(&s, (char*)RTA_DATA(attr), 1);
                                                                _state = s;
                                                                break;
                                                        }

                                                        case IFLA_WIRELESS:
                                                                _wireless = true;
                                                                break;

                                                        default:
                                                                attrlist[attr->rta_type] = std::string((char*)RTA_DATA(attr), rta_length);
                                                                break;
                                                        }

                                                        attr = RTA_NEXT(attr, attrlen);
                                                }
                                                break;
                                        }

                                        case RTM_NEWADDR:
                                        {
                                                struct ifaddrmsg *ifa = (struct ifaddrmsg *) NLMSG_DATA(nlh);
                                                struct rtattr *rth = IFA_RTA(ifa);
                                                int rtl = IFA_PAYLOAD(nlh);

                                                while (rtl && RTA_OK(rth, rtl)) {
                                                        if (rth->rta_type == IFA_LOCAL) {
                                                                uint32_t ipaddr = htonl(*((uint32_t *)RTA_DATA(rth)));
                                                                char name[IFNAMSIZ];
                                                                if_indextoname(ifa->ifa_index, name);
                                                                _interface = ibrcommon::vinterface(name);

                                                                char address[256];
                                                                sprintf(address, "%d.%d.%d.%d", (ipaddr >> 24) & 0xff, (ipaddr >> 16) & 0xff, (ipaddr >> 8) & 0xff, ipaddr & 0xff);

                                                                _address = ibrcommon::vaddress(ibrcommon::vaddress::VADDRESS_INET, std::string(address));

                                                                _type = EVENT_ADDRESS_ADDED;
                                                        }
                                                        rth = RTA_NEXT(rth, rtl);
                                                }
                                                break;
                                        }

                                        case RTM_DELADDR:
                                        {
                                                struct ifaddrmsg *ifa = (struct ifaddrmsg *) NLMSG_DATA(nlh);
                                                struct rtattr *rth = IFA_RTA(ifa);
                                                int rtl = IFA_PAYLOAD(nlh);

                                                while (rtl && RTA_OK(rth, rtl)) {
                                                        if (rth->rta_type == IFA_LOCAL) {
                                                                uint32_t ipaddr = htonl(*((uint32_t *)RTA_DATA(rth)));
                                                                char name[IFNAMSIZ];
                                                                if_indextoname(ifa->ifa_index, name);
                                                                _interface = ibrcommon::vinterface(name);

                                                                char address[256];
                                                                sprintf(address, "%d.%d.%d.%d", (ipaddr >> 24) & 0xff, (ipaddr >> 16) & 0xff, (ipaddr >> 8) & 0xff, ipaddr & 0xff);

                                                                _address = ibrcommon::vaddress(ibrcommon::vaddress::VADDRESS_INET, std::string(address));

                                                                _type = EVENT_ADDRESS_REMOVED;
                                                        }
                                                        rth = RTA_NEXT(rth, rtl);
                                                }
                                                break;
                                        }

                                        default:
                                                IBRCOMMON_LOGGER_DEBUG(10) << "unknown netlink type received: " << nlh->nlmsg_type << IBRCOMMON_LOGGER_ENDL;
                                                break;
                                }

                                nlh = NLMSG_NEXT(nlh, len);
                        }

                        return;
                }
        }

        NetLinkManagerEvent::~NetLinkManagerEvent()
        {
        }

        const ibrcommon::vinterface& NetLinkManagerEvent::getInterface() const
        {
                return _interface;
        }

        const ibrcommon::vaddress& NetLinkManagerEvent::getAddress() const
        {
                return _address;
        }

        unsigned int NetLinkManagerEvent::getState() const
        {
                return _state;
        }

        bool NetLinkManagerEvent::isWirelessExtension() const
        {
                return _wireless;
        }

        LinkManagerEvent::EventType NetLinkManagerEvent::getType() const
        {
                return _type;
        }

        const std::string NetLinkManagerEvent::toString() const
        {
                std::stringstream ss;
                ss << "NetLinkManagerEvent on " << getInterface().toString() << "; Type: " << getType();

                switch (getType())
                {
                case EVENT_LINK_STATE:
                        ss << "; State: " << getState();
                        break;

                case EVENT_ADDRESS_ADDED:
                        ss << "; Address added: " << getAddress().toString();
                        break;

                case EVENT_ADDRESS_REMOVED:
                        ss << "; Address removed: " << getAddress().toString();
                        break;

                default:
                        break;
                };

                return ss.str();
        }

        void NetLinkManagerEvent::debug() const
        {
//              for (std::map<int, std::string>::const_iterator iter = attr.begin(); iter != attr.end(); iter++)
//              {
//                      std::stringstream ss;
//                      const std::string &value = (*iter).second;
//
//                      for (std::string::const_iterator si = value.begin(); si != value.end(); si++)
//                      {
//                              const char &c = (*si);
//                              ss << std::hex << "0x" << (int)c << " ";
//                      }
//
//                      IBRCOMMON_LOGGER_DEBUG(10) << (*iter).first << ": " << ss.str() << IBRCOMMON_LOGGER_ENDL;
//              }
        }

        void NetLinkManager::registerInterfaceEvent(const vinterface &iface, LinkManager::EventCallback *cb)
        {
                if (cb == NULL) return;
                ibrcommon::MutexLock l(_listener_mutex);

                std::set<LinkManager::EventCallback* > &ss = _listener[iface];
                ss.insert(cb);
        }

        void NetLinkManager::unregisterInterfaceEvent(const vinterface &iface, LinkManager::EventCallback *cb)
        {
                if (cb == NULL) return;
                ibrcommon::MutexLock l(_listener_mutex);

                std::set<LinkManager::EventCallback* > &ss = _listener[iface];

                ss.erase(cb);

                if (ss.empty())
                {
                        _listener.erase(iface);
                }
        }

        void NetLinkManager::unregisterAllEvents(LinkManager::EventCallback *cb)
        {
                if (cb == NULL) return;

                try {
                        ibrcommon::MutexLock l(_listener_mutex);

                        for (std::map<vinterface, std::set<LinkManager::EventCallback* > >::iterator iter = _listener.begin(); iter != _listener.end(); iter++)
                        {
                                std::set<LinkManager::EventCallback* > &ss = iter->second;
                                ss.erase(cb);
                        }
                } catch (const ibrcommon::MutexException&) {
                        // this happens if this method is called after destroying the object
                        // and is normal at shutdown
                }
        }
}