xmpp_message_builder.cc

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/*
 * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
 */

#include "bgp/xmpp_message_builder.h"

#include <boost/foreach.hpp>

#include <algorithm>

#include "bgp/ipeer.h"
#include "bgp/bgp_server.h"
#include "bgp/bgp_table.h"
#include "bgp/extended-community/etree.h"
#include "bgp/extended-community/mac_mobility.h"
#include "bgp/ermvpn/ermvpn_route.h"
#include "bgp/evpn/evpn_route.h"
#include "bgp/mvpn/mvpn_route.h"
#include "bgp/routing-instance/routing_instance.h"
#include "bgp/security_group/security_group.h"
#include "db/db.h"
#include "net/community_type.h"
#include "schema/xmpp_multicast_types.h"
#include "schema/xmpp_mvpn_types.h"
#include "schema/xmpp_enet_types.h"
#include "xmpp/xmpp_init.h"

using pugi::xml_attribute;
using pugi::xml_document;
using pugi::xml_node;
using std::ostringstream;
using std::copy;
using std::fill;
using std::string;
using std::stringstream;
using std::vector;

static inline const char *AfiName(uint16_t afi) {
    switch (afi) {
    case BgpAf::IPv4:
        return "1";
        break;
    case BgpAf::IPv6:
        return "2";
        break;
    case BgpAf::L2Vpn:
        return "25";
        break;
    }
    assert(false);
    return NULL;
}

static inline const char *XmppSafiName(uint8_t safi) {
    switch (safi) {
    case BgpAf::Unicast:
        return "1";
        break;
    case BgpAf::Mpls:
        return "4";
        break;
    case BgpAf::MVpn:
        return "5";
        break;
    case BgpAf::Mcast:
        return "241";
        break;
    case BgpAf::Enet:
        return "242";
        break;
    }
    assert(false);
    return NULL;
}

BgpXmppMessage::BgpXmppMessage()
    : table_(NULL),
      writer_(XmlWriter(&repr_)),
      is_reachable_(false),
      cache_routes_(false),
      repr_valid_(false),
      mobility_(0, false),
      etree_leaf_(false) {
    msg_begin_.reserve(kMaxFromToLength);
}

BgpXmppMessage::~BgpXmppMessage() {
}

void BgpXmppMessage::Reset() {
    Message::Reset();
    table_ = NULL;
    is_reachable_ = false;
    cache_routes_ = false;
    repr_valid_ = false;
    repr_.clear();
}

bool BgpXmppMessage::Start(const RibOut *ribout, bool cache_routes,
    const RibOutAttr *roattr, const BgpRoute *route) {
    Reset();
    table_ = ribout->table();
    is_reachable_ = roattr->IsReachable();
    cache_routes_ = cache_routes;
    Address::Family family = table_->family();

    if (is_reachable_) {
        const BgpAttr *attr = roattr->attr();
        ProcessCommunity(attr->community());
        ProcessExtCommunity(attr->ext_community());
    }

    // Reserve space for the begin line that contains the message opening tag
    // with from and to attributes. Actual value gets patched in when GetData
    // is called.
    repr_.append(kMaxFromToLength, ' ');

    // Add opening tags for event and items. The closing tags are added when
    // GetData is called.
    repr_ += "\n\t<event xmlns=\"http://jabber.org/protocol/pubsub\">";
    repr_ += "\n\t\t<items node=\"";
    repr_ += AfiName(BgpAf::FamilyToAfi(family));
    repr_ += "/";
    repr_ += XmppSafiName(BgpAf::FamilyToXmppSafi(family));
    repr_ += "/";
    repr_ += table_->routing_instance()->name();
    repr_ += "\">\n";

    if (table_->family() == Address::ERMVPN) {
        AddMcastRoute(route, roattr);
    } else if (table_->family() == Address::EVPN) {
        AddEnetRoute(route, roattr);
    } else if (table_->family() == Address::INET6) {
        AddInet6Route(route, roattr);
    } else if (table_->family() == Address::MVPN) {
        AddMvpnRoute(route, roattr);
    } else {
        AddInetRoute(route, roattr);
    }
    return true;
}

void BgpXmppMessage::Finish() {
}

bool BgpXmppMessage::AddRoute(const BgpRoute *route, const RibOutAttr *roattr) {
    assert(is_reachable_ == roattr->IsReachable());
    if (is_reachable_ && num_reach_route_ >= kMaxReachCount)
        return false;
    if (!is_reachable_ && num_unreach_route_ >= kMaxUnreachCount)
        return false;

    if (is_reachable_) {
        const BgpAttr *attr = roattr->attr();
        ProcessCommunity(attr->community());
        ProcessExtCommunity(attr->ext_community());
    }

    if (table_->family() == Address::ERMVPN) {
        return AddMcastRoute(route, roattr);
    } else if (table_->family() == Address::EVPN) {
        return AddEnetRoute(route, roattr);
    } else if (table_->family() == Address::INET6) {
        return AddInet6Route(route, roattr);
    } else if (table_->family() == Address::MVPN) {
        return AddMvpnRoute(route, roattr);
    } else {
        return AddInetRoute(route, roattr);
    }
}

void BgpXmppMessage::EncodeNextHop(const BgpRoute *route,
                                   const RibOutAttr::NextHop &nexthop,
                                   autogen::ItemType *item) {
    autogen::NextHopType item_nexthop;

    const IpAddress &address = nexthop.address();
    if (address.is_v4()) {
        item_nexthop.af = BgpAf::IPv4;
        item_nexthop.address = address.to_v4().to_string();
    } else {
        item_nexthop.af = BgpAf::IPv6;
        item_nexthop.address = address.to_v6().to_string();
    }
    item_nexthop.label = nexthop.label();
    item_nexthop.virtual_network = GetVirtualNetwork(nexthop);
    item_nexthop.tag_list.tag = nexthop.tag_list();

    // If there's a non-zero label and encap list is empty use mpls over gre
    // as default encap.
    if (item_nexthop.label) {
        vector<string> &encap_list =
            item_nexthop.tunnel_encapsulation_list.tunnel_encapsulation;
        if (nexthop.encap().empty()) {
            encap_list.push_back(string("gre"));
        } else {
            encap_list = nexthop.encap();
        }
    }

    item->entry.next_hops.next_hop.push_back(item_nexthop);
}

void BgpXmppMessage::AddIpReach(const BgpRoute *route,
                                const RibOutAttr *roattr) {
    if (!roattr->repr().empty()) {
        repr_ += roattr->repr();
        return;
    }
    Address::Family family = table_->family();

    autogen::ItemType item;
    item.entry.nlri.af = BgpAf::FamilyToAfi(family);
    item.entry.nlri.safi = BgpAf::FamilyToXmppSafi(family);
    item.entry.nlri.address = route->ToString();
    item.entry.version = 1;
    item.entry.virtual_network = GetVirtualNetwork(route, roattr);
    item.entry.local_preference = roattr->attr()->local_pref();
    item.entry.med = roattr->attr()->med();
    item.entry.sequence_number = mobility_.sequence_number;
    item.entry.mobility.seqno = mobility_.sequence_number;
    item.entry.mobility.sticky = mobility_.sticky;

    assert(!roattr->nexthop_list().empty());

    // Encode all next-hops in the list.
    BOOST_FOREACH(const RibOutAttr::NextHop &nexthop, roattr->nexthop_list()) {
        EncodeNextHop(route, nexthop, &item);
    }

    for (vector<int>::const_iterator it = security_group_list_.begin();
         it != security_group_list_.end(); ++it) {
        item.entry.security_group_list.security_group.push_back(*it);
    }

    for (vector<string>::const_iterator it = community_list_.begin();
         it != community_list_.end(); ++it) {
        item.entry.community_tag_list.community_tag.push_back(*it);
    }

    // Encode load balance attribute.
    if (!load_balance_attribute_.IsDefault())
        load_balance_attribute_.Encode(&item.entry.load_balance);

    xml_node node = doc_.append_child("item");
    node.append_attribute("id") = route->ToXmppIdString().c_str();

    // Remember the previous size.
    // Using remove_child instead of reset allows memory pages allocated for
    // the xml_document to be reused during the lifetime of the xml_document.
    size_t pos = repr_.size();
    item.Encode(&node);
    doc_.print(writer_, "\t", pugi::format_default, pugi::encoding_auto, 3);
    doc_.remove_child(node);

    // Cache the substring starting at the previous size.
    if (cache_routes_)
        roattr->set_repr(repr_, pos);
}

void BgpXmppMessage::AddIpUnreach(const BgpRoute *route) {
    repr_ += "\t\t\t<retract id=\"" + route->ToXmppIdString() + "\" />\n";
}

bool BgpXmppMessage::AddInetRoute(const BgpRoute *route,
                                  const RibOutAttr *roattr) {
    if (is_reachable_) {
        num_reach_route_++;
        AddIpReach(route, roattr);
    } else {
        num_unreach_route_++;
        AddIpUnreach(route);
    }
    return true;
}

bool BgpXmppMessage::AddInet6Route(const BgpRoute *route,
                                   const RibOutAttr *roattr) {
    if (is_reachable_) {
        num_reach_route_++;
        AddIpReach(route, roattr);
    } else {
        num_unreach_route_++;
        AddIpUnreach(route);
    }
    return true;
}

void BgpXmppMessage::EncodeEnetNextHop(const BgpRoute *route,
                                       const RibOutAttr::NextHop &nexthop,
                                       autogen::EnetItemType *item) {
    autogen::EnetNextHopType item_nexthop;

    item_nexthop.af = BgpAf::IPv4;
    item_nexthop.address = nexthop.address().to_v4().to_string();
    item_nexthop.label = nexthop.label();
    item_nexthop.l3_label = nexthop.l3_label();
    if (!nexthop.mac().IsZero())
        item_nexthop.mac = nexthop.mac().ToString();

    // If encap list is empty use mpls over gre as default encap.
    vector<string> &encap_list =
        item_nexthop.tunnel_encapsulation_list.tunnel_encapsulation;
    if (nexthop.encap().empty()) {
        encap_list.push_back(string("gre"));
    } else {
        encap_list = nexthop.encap();
    }
    item_nexthop.tag_list.tag = nexthop.tag_list();
    item->entry.next_hops.next_hop.push_back(item_nexthop);
}

void BgpXmppMessage::AddEnetReach(const BgpRoute *route,
                                  const RibOutAttr *roattr) {
    if (!roattr->repr().empty()) {
        repr_ += roattr->repr();
        return;
    }
    Address::Family family = table_->family();

    autogen::EnetItemType item;
    item.entry.nlri.af = BgpAf::FamilyToAfi(family);
    item.entry.nlri.safi = BgpAf::FamilyToXmppSafi(family);

    EvpnRoute *evpn_route =
        static_cast<EvpnRoute *>(const_cast<BgpRoute *>(route));
    const EvpnPrefix &evpn_prefix = evpn_route->GetPrefix();
    item.entry.nlri.ethernet_tag = evpn_prefix.tag();
    item.entry.nlri.mac = evpn_prefix.mac_addr().ToString();
    item.entry.nlri.address = evpn_prefix.ip_address().to_string() + "/" +
        integerToString(evpn_prefix.ip_address_length());
    item.entry.nlri.source = evpn_prefix.source().to_string();
    item.entry.nlri.group = evpn_prefix.group().to_string();

    item.entry.virtual_network = GetVirtualNetwork(route, roattr);
    item.entry.local_preference = roattr->attr()->local_pref();
    item.entry.med = roattr->attr()->med();
    item.entry.sequence_number = mobility_.sequence_number;
    item.entry.mobility.seqno = mobility_.sequence_number;
    item.entry.mobility.sticky = mobility_.sticky;
    item.entry.etree_leaf = etree_leaf_;

    for (vector<int>::const_iterator it = security_group_list_.begin();
         it != security_group_list_.end(); ++it) {
        item.entry.security_group_list.security_group.push_back(*it);
    }

    const BgpOList *olist = roattr->attr()->olist().get();
    assert((olist == NULL) != roattr->nexthop_list().empty());

    if (olist) {
        assert(olist->olist().subcode == BgpAttribute::OList);
        BOOST_FOREACH(const BgpOListElem *elem, olist->elements()) {
            autogen::EnetNextHopType nh;
            nh.af = BgpAf::IPv4;
            nh.address = elem->address.to_string();
            nh.label = elem->label;
            nh.tunnel_encapsulation_list.tunnel_encapsulation = elem->encap;
            item.entry.olist.next_hop.push_back(nh);
        }
    }

    const BgpOList *leaf_olist = roattr->attr()->leaf_olist().get();
    assert((leaf_olist == NULL) != roattr->nexthop_list().empty());

    if (leaf_olist) {
        assert(leaf_olist->olist().subcode == BgpAttribute::LeafOList);
        BOOST_FOREACH(const BgpOListElem *elem, leaf_olist->elements()) {
            autogen::EnetNextHopType nh;
            nh.af = BgpAf::IPv4;
            nh.address = elem->address.to_string();
            nh.label = elem->label;
            nh.tunnel_encapsulation_list.tunnel_encapsulation = elem->encap;
            item.entry.leaf_olist.next_hop.push_back(nh);
        }
    }

    BOOST_FOREACH(const RibOutAttr::NextHop &nexthop, roattr->nexthop_list()) {
        EncodeEnetNextHop(route, nexthop, &item);
    }

    xml_node node = doc_.append_child("item");
    node.append_attribute("id") = route->ToXmppIdString().c_str();

    // Remember the previous size.
    // Using remove_child instead of reset allows memory pages allocated for
    // the xml_document to be reused during the lifetime of the xml_document.
    size_t pos = repr_.size();
    item.Encode(&node);
    doc_.print(writer_, "\t", pugi::format_default, pugi::encoding_auto, 3);
    doc_.remove_child(node);

    // Cache the substring starting at the previous size.
    if (cache_routes_)
        roattr->set_repr(repr_, pos);
}

void BgpXmppMessage::AddEnetUnreach(const BgpRoute *route) {
    repr_ += "\t\t\t<retract id=\"" + route->ToXmppIdString() + "\" />\n";
}

bool BgpXmppMessage::AddEnetRoute(const BgpRoute *route,
    const RibOutAttr *roattr) {
    if (is_reachable_) {
        num_reach_route_++;
        AddEnetReach(route, roattr);
    } else {
        num_unreach_route_++;
        AddEnetUnreach(route);
    }
    return true;
}

//
// Note that there's no need to cache the string representation since a given
// mcast route is sent to exactly one xmpp peer.
//
void BgpXmppMessage::AddMcastReach(const BgpRoute *route,
                                   const RibOutAttr *roattr) {
    Address::Family family = table_->family();
    autogen::McastItemType item;
    item.entry.nlri.af = BgpAf::FamilyToAfi(family);
    item.entry.nlri.safi = BgpAf::FamilyToXmppSafi(family);

    ErmVpnRoute *ermvpn_route =
        static_cast<ErmVpnRoute *>(const_cast<BgpRoute *>(route));
    item.entry.nlri.group = ermvpn_route->GetPrefix().group().to_string();
    item.entry.nlri.source =  ermvpn_route->GetPrefix().source().to_string();
    item.entry.nlri.source_label = roattr->label();
    if (!roattr->source_address().is_unspecified()) {
        item.entry.nlri.source_address =
           roattr->source_address().to_string();
    }

    const BgpOList *olist = roattr->attr()->olist().get();
    assert(olist->olist().subcode == BgpAttribute::OList);
    BOOST_FOREACH(const BgpOListElem *elem, olist->elements()) {
        autogen::McastNextHopType nh;
        nh.af = BgpAf::IPv4;
        nh.address = elem->address.to_string();
        nh.label = integerToString(elem->label);
        nh.tunnel_encapsulation_list.tunnel_encapsulation = elem->encap;
        item.entry.olist.next_hop.push_back(nh);
    }

    // Using remove_child instead of reset allows memory pages allocated for
    // the xml_document to be reused during the lifetime of the xml_document.
    xml_node node = doc_.append_child("item");
    node.append_attribute("id") = route->ToXmppIdString().c_str();
    item.Encode(&node);
    doc_.print(writer_, "\t", pugi::format_default, pugi::encoding_auto, 3);
    doc_.remove_child(node);
}

void BgpXmppMessage::AddMcastUnreach(const BgpRoute *route) {
    repr_ += "\t\t\t<retract id=\"" + route->ToXmppIdString() + "\" />\n";
}

bool BgpXmppMessage::AddMcastRoute(const BgpRoute *route,
                                   const RibOutAttr *roattr) {
    if (is_reachable_) {
        num_reach_route_++;
        AddMcastReach(route, roattr);
    } else {
        num_unreach_route_++;
        AddMcastUnreach(route);
    }
    return true;
}

void BgpXmppMessage::AddMvpnReach(const BgpRoute *route,
                                  const RibOutAttr *roattr) {
    Address::Family family = table_->family();
    autogen::MvpnItemType item;
    item.entry.nlri.af = BgpAf::FamilyToAfi(family);
    item.entry.nlri.safi = BgpAf::FamilyToXmppSafi(family);

    MvpnRoute *mvpn_route =
        static_cast<MvpnRoute *>(const_cast<BgpRoute *>(route));
    item.entry.nlri.group = mvpn_route->GetPrefix().group().to_string();
    item.entry.nlri.source =  mvpn_route->GetPrefix().source().to_string();
    item.entry.nlri.route_type = mvpn_route->GetPrefix().type();
    assert((item.entry.nlri.route_type == MvpnPrefix::SourceActiveADRoute) ||
            (item.entry.nlri.route_type == MvpnPrefix::SourceTreeJoinRoute));

    if (item.entry.nlri.route_type == MvpnPrefix::SourceActiveADRoute) {
        const BgpOList *olist = roattr->attr()->olist().get();
        assert(olist->olist().subcode == BgpAttribute::OList);
        BOOST_FOREACH(const BgpOListElem *elem, olist->elements()) {
            autogen::MvpnNextHopType nh;
            nh.af = BgpAf::IPv4;
            nh.address = elem->address.to_string();
            nh.label = elem->label;
            nh.tunnel_encapsulation_list.tunnel_encapsulation = elem->encap;
            item.entry.olist.next_hop.push_back(nh);
        }
    }

    // Using remove_child instead of reset allows memory pages allocated for
    // the xml_document to be reused during the lifetime of the xml_document.
    xml_node node = doc_.append_child("item");
    node.append_attribute("id") = route->ToXmppIdString().c_str();
    item.Encode(&node);
    doc_.print(writer_, "\t", pugi::format_default, pugi::encoding_auto, 3);
    doc_.remove_child(node);
}

void BgpXmppMessage::AddMvpnUnreach(const BgpRoute *route) {
    repr_ += "\t\t\t<retract id=\"" + route->ToXmppIdString() + "\" />\n";
}

bool BgpXmppMessage::AddMvpnRoute(const BgpRoute *route,
                                   const RibOutAttr *roattr) {
    if (is_reachable_) {
        num_reach_route_++;
        AddMvpnReach(route, roattr);
    } else {
        num_unreach_route_++;
        AddMvpnUnreach(route);
    }
    return true;
}

const uint8_t *BgpXmppMessage::GetData(IPeerUpdate *peer, size_t *lenp,
    const string **msg_str, string *temp) {
    // Build begin line that contains message opening tag with from and to
    // attributes.
    msg_begin_.clear();
    msg_begin_ += "\n<message from=\"";
    msg_begin_ += XmppInit::kControlNodeJID;
    msg_begin_ += "\" to=\"";
    msg_begin_ += peer->ToString();
    msg_begin_ += "/";
    msg_begin_ += XmppInit::kBgpPeer;
    msg_begin_ += "\">";

    // Add closing tags if this is the first peer to which the message will
    // be sent.
    if (!repr_valid_) {
        repr_ += "\t\t</items>\n\t</event>\n</message>\n";
        repr_valid_ = true;
    }

    // Replace the begin line if it fits in the space reserved at the start
    // of repr_. Use fill and copy instead of string::replace as the latter
    // seems to construct a new temporary string to hold the input data to
    // be copied.
    // Otherwise build a new string with the begin line and the rest of the
    // message in repr_.
    size_t begin_size = msg_begin_.size();
    if (begin_size <= kMaxFromToLength) {
        size_t extra = kMaxFromToLength - begin_size;
        char *data = const_cast<char *>(repr_.c_str());
        fill(data, data + extra, ' ');
        copy(msg_begin_.c_str(), msg_begin_.c_str() + begin_size, data + extra);
        *lenp = repr_.size() - extra;
        *msg_str = &repr_;
        return reinterpret_cast<const uint8_t *>(repr_.c_str()) + extra;
    } else {
        *temp = msg_begin_ + string(repr_, kMaxFromToLength);
        *lenp = temp->size();
        *msg_str = NULL;
        return reinterpret_cast<const uint8_t *>(temp->c_str());
    }
}

void BgpXmppMessage::ProcessCommunity(const Community *community) {
    community_list_.clear();
    if (community == NULL)
        return;
    BOOST_FOREACH(uint32_t value, community->communities()) {
        community_list_.push_back(CommunityType::CommunityToString(value));
    }
}

void BgpXmppMessage::ProcessExtCommunity(const ExtCommunity *ext_community) {
    mobility_.sequence_number = 0;
    mobility_.sticky = false;
    etree_leaf_ = false;
    security_group_list_.clear();
    load_balance_attribute_ = LoadBalance::LoadBalanceAttribute();
    if (ext_community == NULL)
        return;

    as_t as_number =  table_->server()->autonomous_system();
    bool sg_asn_match = true;
    for (ExtCommunity::ExtCommunityList::const_iterator iter =
        ext_community->communities().begin();
        iter != ext_community->communities().end(); ++iter) {
        if (ExtCommunity::is_security_group(*iter)) {
            SecurityGroup sg(*iter);
            if (as_number <= AS2_MAX)
                if (sg.as_number() != as_number && !sg.IsGlobal())
                    continue;
            security_group_list_.push_back(sg.security_group_id());
        } else if (ExtCommunity::is_security_group4(*iter)) {
            SecurityGroup4ByteAs sg(*iter);
            if (sg.as_number() != as_number)
                sg_asn_match = false;
        } else if (ExtCommunity::is_mac_mobility(*iter)) {
            MacMobility mm(*iter);
            mobility_.sequence_number = mm.sequence_number();
            mobility_.sticky = mm.sticky();
        } else if (ExtCommunity::is_load_balance(*iter)) {
            LoadBalance load_balance(*iter);
            load_balance.FillAttribute(&load_balance_attribute_);
        } else if (ExtCommunity::is_etree(*iter)) {
            ETree etree(*iter);
            etree_leaf_ = etree.leaf();
        }
    }
    if (!sg_asn_match)
        security_group_list_.clear();
}

string BgpXmppMessage::GetVirtualNetwork(
    const RibOutAttr::NextHop &nexthop) const {
    int index = nexthop.origin_vn_index();
    if (index > 0) {
        const RoutingInstanceMgr *manager =
            table_->routing_instance()->manager();
        return manager->GetVirtualNetworkByVnIndex(index);
    } else if (index == 0) {
        return table_->routing_instance()->GetVirtualNetworkName();
    } else {
        return "unresolved";
    }
}

string BgpXmppMessage::GetVirtualNetwork(const BgpRoute *route,
    const RibOutAttr *roattr) const {
    if (!is_reachable_) {
        return "unresolved";
    } else if (roattr->nexthop_list().empty()) {
        if (roattr->vrf_originated()) {
            return table_->routing_instance()->GetVirtualNetworkName();
        } else {
            return "unresolved";
        }
    } else {
        return GetVirtualNetwork(roattr->nexthop_list().front());
    }
}

BgpXmppMessageBuilder::BgpXmppMessageBuilder() {
}

Message *BgpXmppMessageBuilder::Create() const {
    return new BgpXmppMessage;
}