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Code Issues Releases Wiki Activity

[#2249] Checkpoint: doc to finish

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This commit is contained in:
Francis Dupont
2022-02-06 17:54:00 +01:00
committed by Razvan Becheriu
parent 9df65becb2
commit 06be19c83e
25 changed files with 1029 additions and 232 deletions
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179
src/bin/dhcp4/dhcp4_srv.cc
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@@ -151,10 +151,11 @@ namespace dhcp {
Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
const Pkt4Ptr& query,
AllocEngine::ClientContext4Ptr& context,
const Subnet4Ptr& subnet,
bool& drop)
: alloc_engine_(alloc_engine), query_(query), resp_(),
context_(new AllocEngine::ClientContext4()) {
context_(context) {
if (!alloc_engine_) {
isc_throw(BadValue, "alloc_engine value must not be NULL"
@@ -165,31 +166,35 @@ Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
isc_throw(BadValue, "query value must not be NULL when"
" creating an instance of the Dhcpv4Exchange");
}
// Reset the given context argument.
context.reset();
// Create response message.
initResponse();
// Select subnet for the query message.
context_->subnet_ = subnet;
// Hardware address.
context_->hwaddr_ = query->getHWAddr();
// Pointer to client's query.
context_->query_ = query;
// If subnet found, retrieve client identifier which will be needed
// for allocations and search for reservations associated with a
// subnet/shared network.
SharedNetwork4Ptr sn;
if (subnet) {
if (subnet && !context_->early_global_reservations_lookup_) {
OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
if (opt_clientid) {
context_->clientid_.reset(new ClientId(opt_clientid->getData()));
}
}
if (subnet) {
// Find static reservations if not disabled for our subnet.
if (subnet->getReservationsInSubnet() ||
subnet->getReservationsGlobal()) {
// Before we can check for static reservations, we need to prepare a set
// of identifiers to be used for this.
setHostIdentifiers();
if (!context_->early_global_reservations_lookup_) {
setHostIdentifiers(context_);
}
// Check for static reservations.
alloc_engine->findReservation(*context_);
@@ -207,7 +212,8 @@ Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
// affect selection of a pool within the selected subnet.
auto global_host = context_->globalHost();
auto current_host = context_->currentHost();
if ((global_host && !global_host->getClientClasses4().empty()) ||
if ((!context_->early_global_reservations_lookup_ &&
global_host && !global_host->getClientClasses4().empty()) ||
(!sn && current_host && !current_host->getClientClasses4().empty())) {
// We have already evaluated client classes and some of them may
// be in conflict with the reserved classes. Suppose there are
@@ -223,19 +229,9 @@ Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
// a result, the first_class set via the host reservation will
// replace the second_class because the second_class will this
// time evaluate to false as desired.
const ClientClassDictionaryPtr& dict =
CfgMgr::instance().getCurrentCfg()->getClientClassDictionary();
const ClientClassDefListPtr& defs_ptr = dict->getClasses();
for (auto def : *defs_ptr) {
// Only remove evaluated classes. Other classes can be
// assigned via hooks libraries and we should not remove
// them because there is no way they can be added back.
if (def->getMatchExpr()) {
context_->query_->classes_.erase(def->getName());
}
}
removeDependentEvaluatedClasses(query);
setReservedClientClasses(context_);
evaluateClasses(context_->query_, false);
evaluateClasses(query, false);
}
// Set KNOWN builtin class if something was found, UNKNOWN if not.
@@ -392,7 +388,7 @@ Dhcpv4Exchange::copyDefaultOptions() {
}
void
Dhcpv4Exchange::setHostIdentifiers() {
Dhcpv4Exchange::setHostIdentifiers(AllocEngine::ClientContext4Ptr context) {
const ConstCfgHostOperationsPtr cfg =
CfgMgr::instance().getCurrentCfg()->getCfgHostOperations4();
@@ -402,23 +398,23 @@ Dhcpv4Exchange::setHostIdentifiers() {
cfg->getIdentifierTypes()) {
switch (id_type) {
case Host::IDENT_HWADDR:
if (context_->hwaddr_ && !context_->hwaddr_->hwaddr_.empty()) {
context_->addHostIdentifier(id_type, context_->hwaddr_->hwaddr_);
if (context->hwaddr_ && !context->hwaddr_->hwaddr_.empty()) {
context->addHostIdentifier(id_type, context->hwaddr_->hwaddr_);
}
break;
case Host::IDENT_DUID:
if (context_->clientid_) {
const std::vector<uint8_t>& vec = context_->clientid_->getDuid();
if (context->clientid_) {
const std::vector<uint8_t>& vec = context->clientid_->getDuid();
if (!vec.empty()) {
// Client identifier type = DUID? Client identifier holding a DUID
// comprises Type (1 byte), IAID (4 bytes), followed by the actual
// DUID. Thus, the minimal length is 6.
if ((vec[0] == CLIENT_ID_OPTION_TYPE_DUID) && (vec.size() > 5)) {
// Extract DUID, skip IAID.
context_->addHostIdentifier(id_type,
std::vector<uint8_t>(vec.begin() + 5,
vec.end()));
context->addHostIdentifier(id_type,
std::vector<uint8_t>(vec.begin() + 5,
vec.end()));
}
}
}
@@ -426,13 +422,13 @@ Dhcpv4Exchange::setHostIdentifiers() {
case Host::IDENT_CIRCUIT_ID:
{
OptionPtr rai = query_->getOption(DHO_DHCP_AGENT_OPTIONS);
OptionPtr rai = context->query_->getOption(DHO_DHCP_AGENT_OPTIONS);
if (rai) {
OptionPtr circuit_id_opt = rai->getOption(RAI_OPTION_AGENT_CIRCUIT_ID);
if (circuit_id_opt) {
const OptionBuffer& circuit_id_vec = circuit_id_opt->getData();
if (!circuit_id_vec.empty()) {
context_->addHostIdentifier(id_type, circuit_id_vec);
context->addHostIdentifier(id_type, circuit_id_vec);
}
}
}
@@ -440,10 +436,10 @@ Dhcpv4Exchange::setHostIdentifiers() {
break;
case Host::IDENT_CLIENT_ID:
if (context_->clientid_) {
const std::vector<uint8_t>& vec = context_->clientid_->getDuid();
if (context->clientid_) {
const std::vector<uint8_t>& vec = context->clientid_->getDuid();
if (!vec.empty()) {
context_->addHostIdentifier(id_type, vec);
context->addHostIdentifier(id_type, vec);
}
}
break;
@@ -453,7 +449,7 @@ Dhcpv4Exchange::setHostIdentifiers() {
break;
}
CalloutHandlePtr callout_handle = getCalloutHandle(context_->query_);
CalloutHandlePtr callout_handle = getCalloutHandle(context->query_);
Host::IdentifierType type = Host::IDENT_FLEX;
std::vector<uint8_t> id;
@@ -465,7 +461,7 @@ Dhcpv4Exchange::setHostIdentifiers() {
ScopedCalloutHandleState callout_handle_state(callout_handle);
// Pass incoming packet as argument
callout_handle->setArgument("query4", context_->query_);
callout_handle->setArgument("query4", context->query_);
callout_handle->setArgument("id_type", type);
callout_handle->setArgument("id_value", id);
@@ -482,7 +478,7 @@ Dhcpv4Exchange::setHostIdentifiers() {
LOG_DEBUG(packet4_logger, DBGLVL_TRACE_BASIC, DHCP4_FLEX_ID)
.arg(Host::getIdentifierAsText(type, &id[0], id.size()));
context_->addHostIdentifier(type, id);
context->addHostIdentifier(type, id);
}
break;
}
@@ -492,6 +488,21 @@ Dhcpv4Exchange::setHostIdentifiers() {
}
}
void
Dhcpv4Exchange::removeDependentEvaluatedClasses(const Pkt4Ptr& query) {
const ClientClassDictionaryPtr& dict =
CfgMgr::instance().getCurrentCfg()->getClientClassDictionary();
const ClientClassDefListPtr& defs_ptr = dict->getClasses();
for (auto def : *defs_ptr) {
// Only remove evaluated classes. Other classes can be
// assigned via hooks libraries and we should not remove
// them because there is no way they can be added back.
if (def->getMatchExpr()) {
query->classes_.erase(def->getName());
}
}
}
void
Dhcpv4Exchange::setReservedClientClasses(AllocEngine::ClientContext4Ptr context) {
if (context->currentHost() && context->query_) {
@@ -934,6 +945,79 @@ Dhcpv4Srv::sendPacket(const Pkt4Ptr& packet) {
IfaceMgr::instance().send(packet);
}
bool
Dhcpv4Srv::earlyGHRLookup(const Pkt4Ptr& query,
AllocEngine::ClientContext4Ptr ctx) {
// Pointer to client's query.
ctx->query_ = query;
// Hardware address.
ctx->hwaddr_ = query->getHWAddr();
// Get the early-global-reservations-lookup flag value.
data::ConstElementPtr egrl = CfgMgr::instance().getCurrentCfg()->
getConfiguredGlobal(CfgGlobals::EARLY_GLOBAL_RESERVATIONS_LOOKUP);
if (egrl) {
ctx->early_global_reservations_lookup_ = egrl->boolValue();
}
// Perform early global reservations lookup when wanted.
if (ctx->early_global_reservations_lookup_) {
// Retrieve retrieve client identifier.
OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
if (opt_clientid) {
ctx->clientid_.reset(new ClientId(opt_clientid->getData()));
}
// Get the host identifiers.
Dhcpv4Exchange::setHostIdentifiers(ctx);
// Check for global host reservations.
ConstHostPtr global_host = alloc_engine_->findGlobalReservation(*ctx);
if (global_host && !global_host->getClientClasses4().empty()) {
// Remove dependent evaluated classes.
Dhcpv4Exchange::removeDependentEvaluatedClasses(query);
// Add classes from the global reservations.
const ClientClasses& classes = global_host->getClientClasses4();
for (ClientClasses::const_iterator cclass = classes.cbegin();
cclass != classes.cend(); ++cclass) {
query->addClass(*cclass);
}
// Evaluate classes before KNOWN.
Dhcpv4Exchange::evaluateClasses(query, false);
}
if (global_host) {
// Add the KNOWN class;
query->addClass("KNOWN");
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED)
.arg(query->getLabel())
.arg("KNOWN");
// Evaluate classes after KNOWN.
Dhcpv4Exchange::evaluateClasses(query, true);
// Check the DROP special class.
if (query->inClass("DROP")) {
LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING,
DHCP4_PACKET_DROP_0014)
.arg(query->toText());
isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
return (false);
}
// Store the reservation.
ctx->hosts_[SUBNET_ID_GLOBAL] = global_host;
}
}
return (true);
}
int
Dhcpv4Srv::run() {
#ifdef ENABLE_AFL
@@ -1281,12 +1365,15 @@ Dhcpv4Srv::processDhcp4Query(Pkt4Ptr& query, Pkt4Ptr& rsp,
}
}
AllocEngine::ClientContext4Ptr ctx;
AllocEngine::ClientContext4Ptr ctx(new AllocEngine::ClientContext4());
if (!earlyGHRLookup(query, ctx)) {
return;
}
try {
switch (query->getType()) {
case DHCPDISCOVER:
rsp = processDiscover(query);
rsp = processDiscover(query, ctx);
break;
case DHCPREQUEST:
@@ -1305,7 +1392,7 @@ Dhcpv4Srv::processDhcp4Query(Pkt4Ptr& query, Pkt4Ptr& rsp,
break;
case DHCPINFORM:
rsp = processInform(query);
rsp = processInform(query, ctx);
break;
default:
@@ -1363,8 +1450,8 @@ Dhcpv4Srv::processDhcp4Query(Pkt4Ptr& query, Pkt4Ptr& rsp,
if (allow_packet_park) {
// Get the parking limit. Parsing should ensure the value is present.
uint32_t parked_packet_limit = 0;
data::ConstElementPtr ppl = CfgMgr::instance().
getCurrentCfg()->getConfiguredGlobal("parked-packet-limit");
data::ConstElementPtr ppl = CfgMgr::instance().getCurrentCfg()->
getConfiguredGlobal(CfgGlobals::PARKED_PACKET_LIMIT);
if (ppl) {
parked_packet_limit = ppl->intValue();
}
@@ -3047,7 +3134,7 @@ Dhcpv4Srv::getNetmaskOption(const Subnet4Ptr& subnet) {
}
Pkt4Ptr
Dhcpv4Srv::processDiscover(Pkt4Ptr& discover) {
Dhcpv4Srv::processDiscover(Pkt4Ptr& discover, AllocEngine::ClientContext4Ptr& context) {
// server-id is forbidden.
sanityCheck(discover, FORBIDDEN);
@@ -3059,7 +3146,7 @@ Dhcpv4Srv::processDiscover(Pkt4Ptr& discover) {
return (Pkt4Ptr());
}
Dhcpv4Exchange ex(alloc_engine_, discover, subnet, drop);
Dhcpv4Exchange ex(alloc_engine_, discover, context, subnet, drop);
// Stop here if Dhcpv4Exchange constructor decided to drop the packet
if (drop) {
@@ -3130,7 +3217,7 @@ Dhcpv4Srv::processRequest(Pkt4Ptr& request, AllocEngine::ClientContext4Ptr& cont
return (Pkt4Ptr());
}
Dhcpv4Exchange ex(alloc_engine_, request, subnet, drop);
Dhcpv4Exchange ex(alloc_engine_, request, context, subnet, drop);
// Stop here if Dhcpv4Exchange constructor decided to drop the packet
if (drop) {
@@ -3472,7 +3559,7 @@ Dhcpv4Srv::declineLease(const Lease4Ptr& lease, const Pkt4Ptr& decline,
}
Pkt4Ptr
Dhcpv4Srv::processInform(Pkt4Ptr& inform) {
Dhcpv4Srv::processInform(Pkt4Ptr& inform, AllocEngine::ClientContext4Ptr& context) {
// server-id is supposed to be forbidden (as is requested address)
// but ISC DHCP does not enforce either. So neither will we.
sanityCheck(inform, OPTIONAL);
@@ -3485,7 +3572,7 @@ Dhcpv4Srv::processInform(Pkt4Ptr& inform) {
return (Pkt4Ptr());
}
Dhcpv4Exchange ex(alloc_engine_, inform, subnet, drop);
Dhcpv4Exchange ex(alloc_engine_, inform, context, subnet, drop);
// Stop here if Dhcpv4Exchange constructor decided to drop the packet
if (drop) {