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dns_handler.cc
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dns_handler.cc
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/*
* Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
*/
#include "base/os.h"
#include "vr_defs.h"
#include "oper/interface_common.h"
#include "services/dns_proto.h"
#include "services/dhcp_proto.h"
#include "bind/bind_resolver.h"
#include "cmn/agent_cmn.h"
#include "controller/controller_dns.h"
#include "base/timer.h"
#include "oper/operdb_init.h"
#include "oper/global_vrouter.h"
#include "oper/vn.h"
DnsHandler::DnsHandler(Agent *agent, boost::shared_ptr<PktInfo> info,
boost::asio::io_service &io)
: ProtoHandler(agent, info, io), resp_ptr_(NULL), dns_resp_size_(0),
xid_(-1), retries_(0), action_(NONE), rkey_(NULL),
query_name_update_(false), pend_req_(0) {
dns_ = (dnshdr *) pkt_info_->data;
timer_ = TimerManager::CreateTimer(io, "DnsHandlerTimer",
TaskScheduler::GetInstance()->GetTaskId("Agent::Services"),
PktHandler::DNS);
}
DnsHandler::~DnsHandler() {
for (ResolvList::iterator it = resolv_list_.begin();
it != resolv_list_.end(); ++it) {
delete *it;
}
if (rkey_) {
delete rkey_;
}
timer_->Cancel();
TimerManager::DeleteTimer(timer_);
}
bool DnsHandler::Run() {
switch(pkt_info_->type) {
case PktType::MESSAGE:
return HandleMessage();
default:
return HandleRequest();
}
}
bool DnsHandler::HandleRequest() {
DnsProto *dns_proto = agent()->GetDnsProto();
dns_proto->IncrStatsReq();
uint16_t ret = DNS_ERR_NO_ERROR;
const Interface *itf =
agent()->interface_table()->FindInterface(GetInterfaceIndex());
if (!itf || (itf->type() != Interface::VM_INTERFACE) ||
dns_->flags.req) {
dns_proto->IncrStatsDrop();
DNS_BIND_TRACE(DnsBindError, "Received Invalid DNS request - dropping"
<< "; itf = " << itf << "; flags.req = "
<< dns_->flags.req << "; src addr = "
<< pkt_info_->ip->ip_src.s_addr <<";");
return true;
}
const VmInterface *vmitf = static_cast<const VmInterface *>(itf);
if (!vmitf->layer3_forwarding()) {
DNS_BIND_TRACE(DnsBindError, "DNS request on VM port with disabled"
"ipv4 service: " << itf);
dns_proto->IncrStatsDrop();
return true;
}
// Handle requests (req == 0), queries (op code == 0), updates, non auth
if ((dns_->flags.op && dns_->flags.op != DNS_OPCODE_UPDATE) ||
(dns_->flags.cd)) {
DNS_BIND_TRACE(DnsBindError, "Unimplemented DNS request"
<< "; flags.op = " << dns_->flags.op << "; flags.cd = "
<< dns_->flags.cd << ";");
ret = DNS_ERR_NO_IMPLEMENT;
goto error;
}
if (!vmitf->vn() ||
(pkt_info_->ip_saddr.is_v4() &&
!vmitf->vn()->GetIpamData(vmitf->ip_addr(),
&ipam_name_, &ipam_type_)) ||
(pkt_info_->ip_saddr.is_v6() &&
!vmitf->vn()->GetIpamData(vmitf->ip6_addr(),
&ipam_name_, &ipam_type_))) {
DNS_BIND_TRACE(DnsBindError, "Unable to find Ipam data; interface = "
<< vmitf->name());
ret = DNS_ERR_SERVER_FAIL;
goto error;
}
if (ipam_type_.ipam_dns_method == "default-dns-server" ||
ipam_type_.ipam_dns_method == "") {
if (dns_->flags.op == DNS_OPCODE_UPDATE) {
DNS_BIND_TRACE(DnsBindError, "Default DNS request : Update received, ignoring");
ret = DNS_ERR_NO_IMPLEMENT;
goto error;
}
GetDomainName(vmitf, &domain_name_);
return HandleDefaultDnsRequest(vmitf);
} else if (ipam_type_.ipam_dns_method == "virtual-dns-server") {
if (!agent()->domain_config_table()->GetVDns(ipam_type_.ipam_dns_server.
virtual_dns_server_name, &vdns_type_)) {
DNS_BIND_TRACE(DnsBindError, "Unable to find domain; interface = "
<< vmitf->vm_name());
ret = DNS_ERR_SERVER_FAIL;
goto error;
}
domain_name_ = vdns_type_.domain_name;
return HandleVirtualDnsRequest(vmitf);
}
ret = DNS_ERR_SERVER_FAIL;
error:
BindUtil::BuildDnsHeader(dns_, ntohs(dns_->xid), DNS_QUERY_RESPONSE,
DNS_OPCODE_QUERY, 0, 1, ret,
ntohs(dns_->ques_rrcount));
SendDnsResponse();
return true;
}
bool DnsHandler::HandleDefaultDnsRequest(const VmInterface *vmitf) {
tbb::mutex::scoped_lock lock(mutex_);
DnsProto *dns_proto = agent()->GetDnsProto();
rkey_ = new QueryKey(vmitf, dns_->xid);
if (dns_proto->IsVmRequestDuplicate(rkey_)) {
DNS_BIND_TRACE(DnsBindTrace,
"Retry DNS query from VM - dropping; interface = "
<< vmitf->vm_name() << " xid = " << dns_->xid);
dns_proto->IncrStatsRetransmitReq();
return true;
}
dns_proto->AddVmRequest(rkey_);
dns_resp_size_ = BindUtil::ParseDnsQuery((uint8_t *)dns_, items_);
resp_ptr_ = (uint8_t *)dns_ + dns_resp_size_;
action_ = DnsHandler::DNS_QUERY;
BindUtil::BuildDnsHeader(dns_, ntohs(dns_->xid), DNS_QUERY_RESPONSE,
DNS_OPCODE_QUERY, 0, 1, DNS_ERR_NO_ERROR,
ntohs(dns_->ques_rrcount));
ResolveAllLinkLocalRequests();
for (DnsItems::iterator it = items_.begin(); it != items_.end(); ++it) {
ResolveHandler resolv_handler =
boost::bind(&DnsHandler::DefaultDnsResolveHandler, this, _1, _2, it);
boost_udp::resolver *resolv = new boost_udp::resolver(io_);
switch(it->type) {
case DNS_A_RECORD:
resolv->async_resolve(
boost_udp::resolver::query(boost_udp::v4(),
it->name, "domain"), resolv_handler);
break;
case DNS_PTR_RECORD: {
uint32_t addr;
if (!BindUtil::GetAddrFromPtrName(it->name, addr)) {
DNS_BIND_TRACE(DnsBindError, "Default DNS request:"
" interface = " << vmitf->vm_name() <<
" Ignoring invalid IP in PTR type : " +
it->name);
delete resolv;
continue;
}
boost_udp::endpoint ep;
ep.address(boost::asio::ip::address_v4(addr));
resolv->async_resolve(ep, resolv_handler);
break;
}
case DNS_AAAA_RECORD:
resolv->async_resolve(
boost_udp::resolver::query(boost_udp::v6(),
it->name, "domain"), resolv_handler);
break;
default:
DNS_BIND_TRACE(DnsBindError, "Default DNS request:"
" interface = " << vmitf->vm_name() <<
" Ignoring unsupported type : " <<
it->type);
continue;
}
resolv_list_.push_back(resolv);
pend_req_++;
}
DNS_BIND_TRACE(DnsBindTrace, "Default DNS query received; "
"interface = " << vmitf->vm_name() << " xid = " <<
dns_->xid << " " << DnsItemsToString(items_));
if (pend_req_)
return false;
// Respond to requests needing only linklocal resolution.
// Requests needing both linklocal and non link local resolution are
// responded to when pending non linklocal items are resolved.
if (linklocal_items_.size()) {
dns_->ans_rrcount = htons(dns_->ans_rrcount);
DefaultDnsSendResponse();
}
dns_proto->DelVmRequest(rkey_);
return true;
}
void DnsHandler::DefaultDnsResolveHandler(const boost::system::error_code &error,
boost_udp::resolver::iterator it,
DnsItems::iterator item) {
{
tbb::mutex::scoped_lock lock(mutex_);
if (error) {
dns_->flags.ret = DNS_ERR_NO_SUCH_NAME;
} else {
bool resolved = true;
item->ttl = DEFAULT_DNS_TTL;
if (item->type == DNS_A_RECORD) {
boost_udp::resolver::iterator end;
while (it != end) {
boost_udp::endpoint ep = *it;
if (ep.address().is_v4() &&
!ep.address().to_v4().is_unspecified())
item->data = ep.address().to_v4().to_string();
else {
dns_->flags.ret = DNS_ERR_SERVER_FAIL;
resolved = false;
}
it++;
}
} else if (item->type == DNS_PTR_RECORD) {
item->data = it->host_name();
} else if (item->type == DNS_AAAA_RECORD) {
boost_udp::resolver::iterator end;
while (it != end) {
boost_udp::endpoint ep = *it;
if (ep.address().is_v6() &&
!ep.address().to_v6().is_unspecified())
item->data = ep.address().to_v6().to_string();
else {
dns_->flags.ret = DNS_ERR_SERVER_FAIL;
resolved = false;
}
it++;
}
}
if (resolved) {
resp_ptr_ = BindUtil::AddAnswerSection(resp_ptr_, *item,
dns_resp_size_);
dns_->ans_rrcount++;
}
}
pend_req_--;
if (pend_req_)
return;
dns_->ans_rrcount = htons(dns_->ans_rrcount);
}
agent()->GetDnsProto()->SendDnsIpc(DnsProto::DNS_DEFAULT_RESPONSE,
0, NULL, this);
}
void DnsHandler::DefaultDnsSendResponse() {
agent()->GetDnsProto()->DelVmRequest(rkey_);
if (dns_->flags.ret) {
DNS_BIND_TRACE(DnsBindError, "Query failed : " <<
BindUtil::DnsResponseCode(dns_->flags.ret) <<
" xid = " << dns_->xid << " " <<
DnsItemsToString(items_) <<
DnsItemsToString(linklocal_items_));
} else {
DNS_BIND_TRACE(DnsBindTrace, "Query successful : xid = " <<
dns_->xid << " " << DnsItemsToString(items_) <<
DnsItemsToString(linklocal_items_));
}
SendDnsResponse();
}
bool DnsHandler::HandleVirtualDnsRequest(const VmInterface *vmitf) {
rkey_ = new QueryKey(vmitf, dns_->xid);
DnsProto *dns_proto = agent()->GetDnsProto();
if (dns_proto->IsVmRequestDuplicate(rkey_)) {
DNS_BIND_TRACE(DnsBindTrace,
"Retry DNS query from VM - dropping; interface = " <<
vmitf->vm_name() << " xid = " << dns_->xid << " " <<
DnsItemsToString(items_) <<
DnsItemsToString(linklocal_items_));
dns_proto->IncrStatsRetransmitReq();
return true;
}
dns_proto->AddVmRequest(rkey_);
BindUtil::RemoveSpecialChars(ipam_type_.ipam_dns_server.
virtual_dns_server_name);
uint16_t ret = DNS_ERR_NO_ERROR;
switch (dns_->flags.op) {
case DNS_OPCODE_QUERY: {
dns_resp_size_ = BindUtil::ParseDnsQuery((uint8_t *)dns_, items_);
resp_ptr_ = (uint8_t *)dns_ + dns_resp_size_;
BindUtil::BuildDnsHeader(dns_, ntohs(dns_->xid), DNS_QUERY_RESPONSE,
DNS_OPCODE_QUERY, 0, 1, ret,
ntohs(dns_->ques_rrcount));
// Check for linklocal service name resolution
ResolveAllLinkLocalRequests();
if (!items_.size()) {
// no pending resolution, send response
dns_->ans_rrcount = htons(dns_->ans_rrcount);
SendDnsResponse();
break;
}
UpdateQueryNames();
xid_ = dns_proto->GetTransId();
action_ = DnsHandler::DNS_QUERY;
if (SendDnsQuery())
return false;
break;
}
case DNS_OPCODE_UPDATE: {
if (vdns_type_.dynamic_records_from_client) {
DnsUpdateData *update_data = new DnsUpdateData();
DnsProto::DnsUpdateIpc *update =
new DnsProto::DnsUpdateIpc(DnsAgentXmpp::Update,
update_data, vmitf, false);
if (BindUtil::ParseDnsUpdate((uint8_t *)dns_, *update_data)) {
update_data->virtual_dns = ipam_type_.ipam_dns_server.
virtual_dns_server_name;
Update(update);
} else {
delete update;
ret = DNS_ERR_NO_IMPLEMENT;
}
} else {
DNS_BIND_TRACE(DnsBindTrace, "Client not allowed to update "
"dynamic records : " << vmitf->vm_name() << " ;Ignoring "
"update for " << DnsItemsToString(items_));
ret = DNS_ERR_NOT_AUTH;
}
BindUtil::BuildDnsHeader(dns_, ntohs(dns_->xid), DNS_QUERY_RESPONSE,
DNS_OPCODE_UPDATE, 0, 1, ret,
ntohs(dns_->ques_rrcount));
SendDnsResponse();
break;
}
default: {
DNS_BIND_TRACE(DnsBindTrace, "Unsupported op : " << dns_->flags.op
<< "from vm : " << vmitf->vm_name());
break;
}
}
dns_proto->DelVmRequest(rkey_);
return true;
}
bool DnsHandler::SendDnsQuery() {
uint8_t *pkt = NULL;
std::size_t len = 0;
DnsProto *dns_proto = agent()->GetDnsProto();
bool in_progress = dns_proto->IsDnsQueryInProgress(xid_);
if (in_progress) {
if (retries_ >= dns_proto->max_retries()) {
DNS_BIND_TRACE(DnsBindTrace,
"Max retries reached for query; xid = " << xid_ <<
" " << DnsItemsToString(items_));
goto cleanup;
} else
retries_++;
} else {
dns_proto->AddDnsQuery(xid_, this);
}
pkt = new uint8_t[BindResolver::max_pkt_size];
len = BindUtil::BuildDnsQuery(pkt, xid_,
ipam_type_.ipam_dns_server.virtual_dns_server_name, items_);
if (BindResolver::Resolver()->DnsSend(pkt, agent()->dns_xmpp_server_index(),
len)) {
DNS_BIND_TRACE(DnsBindTrace, "DNS query sent to named server : " <<
agent()->dns_server(agent()->dns_xmpp_server_index()) <<
"; xid =" << xid_ << " " << DnsItemsToString(items_));
timer_->Start(dns_proto->timeout(),
boost::bind(&DnsHandler::TimerExpiry, this, xid_));
return true;
}
cleanup:
dns_proto->IncrStatsDrop();
dns_proto->DelDnsQuery(xid_);
return false;
}
// Check the request against configured link local services and
// update DnsItems, if found
bool DnsHandler::ResolveLinkLocalRequest(DnsItems::iterator &item,
DnsItems *linklocal_items) const {
GlobalVrouter *global_vrouter = agent_->oper_db()->global_vrouter();
switch (item->type) {
case DNS_A_RECORD: {
std::string base_name;
GetBaseName(item->name, &base_name);
std::set<Ip4Address> service_ips;
if (global_vrouter->FindLinkLocalService(item->name, &service_ips) ||
(!base_name.empty() &&
global_vrouter->FindLinkLocalService(base_name, &service_ips))) {
for (std::set<Ip4Address>::iterator it = service_ips.begin();
it != service_ips.end(); ++it) {
item->data = it->to_string();
linklocal_items->push_back(*item);
}
}
break;
}
case DNS_PTR_RECORD: {
std::set<std::string> service_names;
uint32_t addr;
if (!BindUtil::GetAddrFromPtrName(item->name, addr)) {
break;
}
if (global_vrouter->FindLinkLocalService(
boost::asio::ip::address_v4(addr), &service_names)) {
for (std::set<std::string>::iterator it = service_names.begin();
it != service_names.end(); ++it) {
item->data = *it;
linklocal_items->push_back(*item);
}
}
break;
}
case DNS_AAAA_RECORD:
break;
default:
break;
}
return (linklocal_items->size() > 0);
}
// Resolve link local service name requests locally
bool DnsHandler::ResolveAllLinkLocalRequests() {
bool linklocal_request = false;
for (DnsItems::iterator it = items_.begin(); it != items_.end(); ) {
DnsItems linklocal_items;
if (ResolveLinkLocalRequest(it, &linklocal_items)) {
linklocal_request = true;
for (DnsItems::iterator llit = linklocal_items.begin();
llit != linklocal_items.end(); ++llit) {
resp_ptr_ = BindUtil::AddAnswerSection(resp_ptr_, *llit,
dns_resp_size_);
dns_->ans_rrcount++;
}
// storing the link local items in a different list
linklocal_items_.splice(linklocal_items_.begin(), linklocal_items);
items_.erase(it++);
} else {
it++;
}
}
return linklocal_request;
}
bool DnsHandler::HandleMessage() {
switch (pkt_info_->ipc->cmd) {
case DnsProto::DNS_DEFAULT_RESPONSE:
return HandleDefaultDnsResponse();
case DnsProto::DNS_BIND_RESPONSE:
return HandleBindResponse();
case DnsProto::DNS_TIMER_EXPIRED:
return HandleRetryExpiry();
case DnsProto::DNS_XMPP_SEND_UPDATE:
return HandleUpdate();
case DnsProto::DNS_XMPP_MODIFY_VDNS:
return HandleModifyVdns();
case DnsProto::DNS_XMPP_UPDATE_RESPONSE:
return HandleUpdateResponse();
case DnsProto::DNS_XMPP_SEND_UPDATE_ALL:
return UpdateAll();
default:
DNS_BIND_TRACE(DnsBindError, "Invalid internal DNS message : " <<
pkt_info_->ipc->cmd);
return true;
}
}
bool DnsHandler::HandleDefaultDnsResponse() {
DnsProto::DnsIpc *ipc = static_cast<DnsProto::DnsIpc *>(pkt_info_->ipc);
ipc->handler->DefaultDnsSendResponse();
delete ipc;
return true;
}
bool DnsHandler::HandleBindResponse() {
DnsProto::DnsIpc *ipc = static_cast<DnsProto::DnsIpc *>(pkt_info_->ipc);
uint16_t xid = ntohs(*(uint16_t *)ipc->resp);
DnsProto *dns_proto = agent()->GetDnsProto();
DnsHandler *handler = dns_proto->GetDnsQueryHandler(xid);
if (handler) {
dns_flags flags;
DnsItems ques, ans, auth, add;
if (BindUtil::ParseDnsResponse(ipc->resp, xid, flags,
ques, ans, auth, add)) {
switch(handler->action_) {
case DnsHandler::DNS_QUERY:
handler->Resolve(flags, ques, ans, auth, add);
if (flags.ret) {
DNS_BIND_TRACE(DnsBindError, "Query failed : " <<
BindUtil::DnsResponseCode(flags.ret) <<
" xid = " << xid << " " <<
DnsItemsToString(items_) <<
DnsItemsToString(linklocal_items_));
} else {
DNS_BIND_TRACE(DnsBindTrace,
"Query successful : xid = " <<
xid << " " << DnsItemsToString(ans) <<
DnsItemsToString(linklocal_items_));
}
break;
default:
DNS_BIND_TRACE(DnsBindTrace,
"Invalid DNS action: xid = " << xid);
break;
}
} else {
DNS_BIND_TRACE(DnsBindTrace,
"Received invalid BIND response: xid = " << xid);
}
dns_proto->DelDnsQuery(xid);
dns_proto->DelVmRequest(handler->rkey_);
delete handler;
} else
DNS_BIND_TRACE(DnsBindError, "Invalid xid " << xid <<
"received from DNS server - dropping");
delete ipc;
return true;
}
bool DnsHandler::HandleRetryExpiry() {
DnsProto::DnsIpc *ipc = static_cast<DnsProto::DnsIpc *>(pkt_info_->ipc);
DnsProto *dns_proto = agent()->GetDnsProto();
DnsHandler *handler = dns_proto->GetDnsQueryHandler(ipc->xid);
if (handler && !handler->SendDnsQuery()) {
dns_proto->DelVmRequest(handler->rkey_);
delete handler;
}
delete ipc;
return true;
}
bool DnsHandler::HandleUpdateResponse() {
DnsProto::DnsUpdateIpc *ipc =
static_cast<DnsProto::DnsUpdateIpc *>(pkt_info_->ipc);
delete ipc;
return true;
}
bool DnsHandler::HandleUpdate() {
DnsProto::DnsUpdateIpc *ipc =
static_cast<DnsProto::DnsUpdateIpc *>(pkt_info_->ipc);
if (!ipc->xmpp_data) {
DelUpdate(ipc);
} else {
Update(ipc);
}
return true;
}
bool DnsHandler::HandleModifyVdns() {
DnsProto::DnsUpdateIpc *ipc =
static_cast<DnsProto::DnsUpdateIpc *>(pkt_info_->ipc);
DnsProto *dns_proto = agent()->GetDnsProto();
std::vector<DnsProto::DnsUpdateIpc *> change_list;
const DnsProto::DnsUpdateSet &update_set = dns_proto->update_set();
for (DnsProto::DnsUpdateSet::const_iterator it = update_set.begin();
it != update_set.end(); ++it) {
if ((ipc->itf &&
((*it)->itf != ipc->itf || (*it)->floatingIp != ipc->floatingIp)) ||
!((*it)->xmpp_data) || (*it)->xmpp_data->virtual_dns != ipc->old_vdns)
continue;
change_list.push_back(*it);
// if the server ttl changes, we only readd with the new values
if (!ipc->itf && ipc->new_vdns == ipc->old_vdns)
continue;
for (DnsItems::iterator item = (*it)->xmpp_data->items.begin();
item != (*it)->xmpp_data->items.end(); ++item) {
// in case of delete, set the class to NONE and ttl to 0
(*item).eclass = DNS_CLASS_NONE;
(*item).ttl = 0;
}
for (int i = 0; i < MAX_XMPP_SERVERS; i++) {
AgentDnsXmppChannel *channel = agent()->dns_xmpp_channel(i);
SendXmppUpdate(channel, (*it)->xmpp_data);
}
}
for (unsigned int i = 0; i < change_list.size(); i++) {
dns_proto->DelUpdateRequest(change_list[i]);
if (ipc->new_vdns.empty())
delete change_list[i];
}
if (ipc->new_vdns.empty())
goto done;
for (unsigned int i = 0; i < change_list.size(); i++) {
change_list[i]->xmpp_data->virtual_dns = ipc->new_vdns;
if (change_list[i]->xmpp_data->zone.find(".in-addr.arpa") ==
std::string::npos)
change_list[i]->xmpp_data->zone = ipc->new_domain;
for (DnsItems::iterator item = change_list[i]->xmpp_data->items.begin();
item != change_list[i]->xmpp_data->items.end(); ++item) {
(*item).eclass = DNS_CLASS_IN;
(*item).ttl = ipc->ttl;
}
Update(change_list[i]);
}
done:
delete ipc;
return true;
}
bool DnsHandler::UpdateAll() {
DnsProto::DnsUpdateAllIpc *ipc =
static_cast<DnsProto::DnsUpdateAllIpc *>(pkt_info_->ipc);
const DnsProto::DnsUpdateSet &update_set =
agent()->GetDnsProto()->update_set();
for (DnsProto::DnsUpdateSet::const_iterator it = update_set.begin();
it != update_set.end(); ++it) {
SendXmppUpdate(ipc->channel, (*it)->xmpp_data);
}
delete ipc;
return true;
}
void DnsHandler::SendXmppUpdate(AgentDnsXmppChannel *channel,
DnsUpdateData *xmpp_data) {
if (channel) {
// Split the request in case we have more data items
DnsItems done, store;
DnsItems::iterator first, last;
uint32_t size = xmpp_data->items.size();
store.swap(xmpp_data->items);
for (uint32_t i = 0; i <= size / max_items_per_xmpp_msg; i++) {
if (!store.size())
break;
first = last = store.begin();
if (store.size() > max_items_per_xmpp_msg)
std::advance(last, max_items_per_xmpp_msg);
else
last = store.end();
xmpp_data->items.splice(xmpp_data->items.begin(), store, first, last);
uint8_t *data = new uint8_t[DnsAgentXmpp::max_dns_xmpp_msg_len];
xid_ = agent()->GetDnsProto()->GetTransId();
std::size_t len = 0;
if ((len = DnsAgentXmpp::DnsAgentXmppEncode(channel->GetXmppChannel(),
DnsAgentXmpp::Update,
xid_, 0, xmpp_data,
data)) > 0) {
channel->SendMsg(data, len);
}
else
delete [] data;
done.splice(done.end(), xmpp_data->items, xmpp_data->items.begin(),
xmpp_data->items.end());
}
xmpp_data->items.swap(done);
}
}
void
DnsHandler::Resolve(dns_flags flags, const DnsItems &ques, DnsItems &ans,
DnsItems &auth, DnsItems &add) {
for (DnsItems::iterator it = ans.begin(); it != ans.end(); ++it) {
// find the matching entry in the request
bool name_update_required = true;
for (DnsItems::const_iterator item = items_.begin();
item != items_.end(); ++item) {
if (it->name == item->name && it->eclass == item->eclass) {
it->name_plen = item->name_plen;
it->name_offset = item->offset;
name_update_required = false;
break;
}
}
UpdateOffsets(*it, name_update_required);
UpdateGWAddress(*it);
resp_ptr_ = BindUtil::AddAnswerSection(resp_ptr_, *it, dns_resp_size_);
dns_->ans_rrcount++;
}
for (DnsItems::iterator it = auth.begin(); it != auth.end(); ++it) {
UpdateOffsets(*it, true);
UpdateGWAddress(*it);
resp_ptr_ = BindUtil::AddAnswerSection(resp_ptr_, *it, dns_resp_size_);
dns_->auth_rrcount++;
}
for (DnsItems::iterator it = add.begin(); it != add.end(); ++it) {
UpdateOffsets(*it, true);
UpdateGWAddress(*it);
resp_ptr_ = BindUtil::AddAnswerSection(resp_ptr_, *it, dns_resp_size_);
dns_->add_rrcount++;
}
dns_->flags.ret = flags.ret;
dns_->flags.auth = flags.auth;
dns_->flags.ad = flags.ad;
dns_->flags.ra = flags.ra;
dns_->ans_rrcount = htons(dns_->ans_rrcount);
dns_->auth_rrcount = htons(dns_->auth_rrcount);
dns_->add_rrcount = htons(dns_->add_rrcount);
SendDnsResponse();
}
void DnsHandler::SendDnsResponse() {
PktInfo in_pkt_info = *pkt_info_.get();
uint16_t buff_len = in_pkt_info.packet_buffer()->buffer_len();
pkt_info_->AllocPacketBuffer(agent(), PktHandler::DNS, buff_len, 0);
char *buff = (char *)pkt_info_->packet_buffer()->data();
memset(buff, 0, buff_len);
pkt_info_->vrf = in_pkt_info.vrf;
uint16_t eth_type = ETHERTYPE_IP;
if (in_pkt_info.ip == NULL)
eth_type = ETHERTYPE_IPV6;
MacAddress dest_mac(in_pkt_info.eth->ether_shost);
pkt_info_->eth = (struct ether_header *)(buff);
uint16_t eth_len = 0;
eth_len += EthHdr(buff, buff_len, in_pkt_info.GetAgentHdr().ifindex,
agent()->vhost_interface()->mac(), dest_mac, eth_type);
uint16_t data_len = dns_resp_size_;
// fill in the response
if (in_pkt_info.ip) {
// IPv4 request
in_addr_t src_ip = in_pkt_info.ip->ip_dst.s_addr;
in_addr_t dest_ip = in_pkt_info.ip->ip_src.s_addr;
pkt_info_->ip = (struct ip *)(buff + eth_len);
pkt_info_->transp.udp = (struct udphdr *)
((uint8_t *)pkt_info_->ip + sizeof(struct ip));
data_len += sizeof(udphdr);
UdpHdr(data_len, src_ip, DNS_SERVER_PORT,
dest_ip, ntohs(in_pkt_info.transp.udp->uh_sport));
data_len += sizeof(struct ip);
IpHdr(data_len, src_ip, dest_ip, IPPROTO_UDP,
DEFAULT_IP_ID, DEFAULT_IP_TTL);
} else {
// IPv6 request
Ip6Address src_ip = in_pkt_info.ip_daddr.to_v6();
Ip6Address dest_ip = in_pkt_info.ip_saddr.to_v6();
pkt_info_->ip6 = (struct ip6_hdr *)(buff + eth_len);
pkt_info_->transp.udp = (struct udphdr *)
((uint8_t *)pkt_info_->ip6 + sizeof(struct ip6_hdr));
data_len += sizeof(udphdr);
UdpHdr(data_len, src_ip.to_bytes().data(),
DNS_SERVER_PORT, dest_ip.to_bytes().data(),
ntohs(in_pkt_info.transp.udp->uh_sport), IPPROTO_UDP);
data_len += sizeof(struct ip6_hdr);
Ip6Hdr(pkt_info_->ip6, data_len, IPPROTO_UDP, 64,
src_ip.to_bytes().data(), dest_ip.to_bytes().data());
}
memcpy(((char *)pkt_info_->transp.udp + sizeof(udphdr)),
((char *)in_pkt_info.transp.udp + sizeof(udphdr)),
dns_resp_size_);
dns_resp_size_ += data_len + eth_len;
pkt_info_->set_len(dns_resp_size_);
PacketInterfaceKey key(nil_uuid(), agent()->pkt_interface_name());
Interface *pkt_itf = static_cast<Interface *>
(agent()->interface_table()->FindActiveEntry(&key));
if (pkt_itf) {
UpdateStats();
uint32_t interface =
(pkt_info_->agent_hdr.cmd == AgentHdr::TRAP_TOR_CONTROL_PKT) ?
pkt_info_->agent_hdr.cmd_param : GetInterfaceIndex();
uint16_t command =
(pkt_info_->agent_hdr.cmd == AgentHdr::TRAP_TOR_CONTROL_PKT) ?
(uint16_t)AgentHdr::TX_ROUTE : AgentHdr::TX_SWITCH;
Send(interface, pkt_info_->vrf, command, PktHandler::DNS);
} else {
agent()->GetDnsProto()->IncrStatsDrop();
}
}
void DnsHandler::UpdateQueryNames() {
for (DnsItems::iterator it = items_.begin(); it != items_.end(); ++it) {
if (it->name.find('.', 0) == std::string::npos) {
it->name.append(".");
it->name.append(vdns_type_.domain_name);
query_name_update_ = true;
}
}
}
// In case we added domain name to the queries, the response to the VM
// should not have the domain name. Update the offsets in the DnsItems
// accordingly.
void DnsHandler::UpdateOffsets(DnsItem &item, bool name_update_required) {
if (!query_name_update_)
return;
uint16_t msg_offset = (resp_ptr_ - (uint8_t *)dns_) | 0xC000;
if (name_update_required) {
name_encoder_.AddName(item.name, msg_offset, item.name_plen,
item.name_offset);
}
msg_offset += BindUtil::DataLength(item.name_plen, item.name_offset,
item.name.size()) + 10;
if (item.type == DNS_TYPE_SOA) {
name_encoder_.AddName(item.soa.primary_ns, msg_offset, item.soa.ns_plen,
item.soa.ns_offset);
msg_offset += BindUtil::DataLength(item.soa.ns_plen, item.soa.ns_offset,
item.soa.primary_ns.size());
name_encoder_.AddName(item.soa.mailbox, msg_offset,
item.soa.mailbox_plen, item.soa.mailbox_offset);
} else {
name_encoder_.AddName(item.data, msg_offset,
item.data_plen, item.data_offset);
}
}
void DnsHandler::UpdateGWAddress(DnsItem &item) {
boost::system::error_code ec;
if ((item.type == DNS_A_RECORD || item.type == DNS_AAAA_RECORD) &&
(item.data == agent()->dns_server(0) ||
item.data == agent()->dns_server(1))) {
item.data = pkt_info_->ip_daddr.to_string(ec);
}
}
void DnsHandler::Update(InterTaskMsg *msg) {
DnsProto::DnsUpdateIpc *update = static_cast<DnsProto::DnsUpdateIpc *>(msg);
bool free_update = true;
DnsProto *dns_proto = agent()->GetDnsProto();
DnsProto::DnsUpdateIpc *update_req = dns_proto->FindUpdateRequest(update);
if (update_req) {
DnsUpdateData *data = update_req->xmpp_data;
for (DnsItems::iterator item = update->xmpp_data->items.begin();
item != update->xmpp_data->items.end();) {
if ((*item).IsDelete()) {
if (!data->DelItem(*item))
update->xmpp_data->items.erase(item++);
else
++item;
} else {
if (!data->AddItem(*item))
update->xmpp_data->items.erase(item++);
else
++item;
}
}
if (!data->items.size()) {
dns_proto->DelUpdateRequest(update_req);
delete update_req;
}
if (!update->xmpp_data->items.size())
goto done;
} else {
dns_proto->AddUpdateRequest(update);
free_update = false;
}
for (int i = 0; i < MAX_XMPP_SERVERS; i++) {
AgentDnsXmppChannel *channel = agent()->dns_xmpp_channel(i);
SendXmppUpdate(channel, update->xmpp_data);
}
done:
if (free_update)
delete update;
}
void DnsHandler::DelUpdate(InterTaskMsg *msg) {
DnsProto::DnsUpdateIpc *update = static_cast<DnsProto::DnsUpdateIpc *>(msg);
DnsProto *dns_proto = agent()->GetDnsProto();
DnsProto::DnsUpdateIpc *update_req = dns_proto->FindUpdateRequest(update);
while (update_req) {
for (DnsItems::iterator item = update_req->xmpp_data->items.begin();
item != update_req->xmpp_data->items.end(); ++item) {
// in case of delete, set the class to NONE and ttl to 0
(*item).eclass = DNS_CLASS_NONE;
(*item).ttl = 0;
}
for (int i = 0; i < MAX_XMPP_SERVERS; i++) {
AgentDnsXmppChannel *channel =
agent()->dns_xmpp_channel(i);
SendXmppUpdate(channel, update_req->xmpp_data);
}
dns_proto->DelUpdateRequest(update_req);
delete update_req;
update_req = dns_proto->FindUpdateRequest(update);
}
delete update;
}
void DnsHandler::UpdateStats() {
DnsProto *dns_proto = agent()->GetDnsProto();
switch (dns_->flags.ret) {
case DNS_ERR_NO_ERROR:
dns_proto->IncrStatsRes();
break;
case DNS_ERR_NO_IMPLEMENT:
dns_proto->IncrStatsUnsupp();
break;
case DNS_ERR_FORMAT_ERROR:
case DNS_ERR_NO_SUCH_NAME:
case DNS_ERR_SERVER_FAIL:
case DNS_ERR_NOT_AUTH:
default:
dns_proto->IncrStatsFail();
break;
}
}
bool DnsHandler::TimerExpiry(uint16_t xid) {
agent()->GetDnsProto()->SendDnsIpc(DnsProto::DNS_TIMER_EXPIRED, xid,
NULL, NULL);
return false;
}
void DnsHandler::GetDomainName(const VmInterface *vm_itf,
std::string *domain_name) const {
std::vector<autogen::DhcpOptionType> options;
if (vm_itf->GetInterfaceDhcpOptions(&options)) {
if (GetDomainNameFromDhcp(options, domain_name))
return;
}
if (pkt_info_->ip_saddr.is_v4()) {
if (vm_itf->GetSubnetDhcpOptions(&options, false) ||
vm_itf->GetIpamDhcpOptions(&options, false)) {
GetDomainNameFromDhcp(options, domain_name);
return;
}
}
if (pkt_info_->ip_saddr.is_v6()) {
if (vm_itf->GetSubnetDhcpOptions(&options, true) ||
vm_itf->GetIpamDhcpOptions(&options, true)) {
GetDomainNameFromDhcp(options, domain_name);
return;
}
}
}
bool DnsHandler::GetDomainNameFromDhcp(
std::vector<autogen::DhcpOptionType> &options,
std::string *domain_name) const {
for (unsigned int i = 0; i < options.size(); ++i) {
uint32_t option_type;
std::stringstream str(options[i].dhcp_option_name);
str >> option_type;
if (option_type == DHCP_OPTION_DOMAIN_NAME) {
*domain_name = options[i].dhcp_option_value;
return true;
}
}
return false;
}
// remove domain name suffix from given name, if present
void DnsHandler::GetBaseName(const std::string &name, std::string *base) const {
if (domain_name_.empty())