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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "IPCFuzzController.h"
#include "mozilla/Fuzzing.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "mozilla/SyncRunnable.h"
#include "nsIThread.h"
#include "nsThreadUtils.h"
#include "mozilla/ipc/MessageChannel.h"
#include "mozilla/ipc/MessageLink.h"
#include "mozilla/ipc/ProtocolUtils.h"
#include "mozilla/ipc/NodeChannel.h"
#include "mozilla/ipc/NodeController.h"
#include "mozilla/ipc/PIdleScheduler.h"
#include "mozilla/ipc/PBackground.h"
#include "mozilla/dom/PContent.h"
#include <fstream>
#include <set>
#include <sstream>
#include <algorithm>
using namespace mojo::core::ports;
using namespace mozilla::ipc;
// Sync inject means that the actual fuzzing takes place on the I/O thread
// and hence it injects directly into the target NodeChannel. In async mode,
// we run the fuzzing on a separate thread and dispatch the runnable that
// injects the message back to the I/O thread. Both approaches seem to work
// and have advantages and disadvantages. Blocking the I/O thread means no
// IPC between other processes will interfere with our fuzzing in the meantime
// but blocking could also cause hangs when such IPC is required during the
// fuzzing runtime for some reason.
// #define MOZ_FUZZ_IPC_SYNC_INJECT 1
// Synchronize after each message rather than just after every constructor
// or at the end of the iteration. Doing so costs us some performance because
// we have to wait for each packet and process events on the main thread,
// but it is necessary when using `OnMessageError` to release on early errors.
#define MOZ_FUZZ_IPC_SYNC_AFTER_EACH_MSG 1
namespace mozilla {
namespace fuzzing {
const uint32_t ipcDefaultTriggerMsg = dom::PContent::Msg_SignalFuzzingReady__ID;
IPCFuzzController::IPCFuzzController()
: useLastPortName(false),
useLastPortNameAlways(false),
protoFilterTargetExcludeToplevel(false),
useLastActor(0),
mMutex("IPCFuzzController"),
mIPCTriggerMsg(ipcDefaultTriggerMsg) {
InitializeIPCTypes();
// We use 6 bits for port index selection without wrapping, so we just
// create 64 empty rows in our port matrix. Not all of these rows will
// be used though.
portNames.resize(64);
// This is our port / toplevel actor ordering. Add new toplevel actors
// here to support them in the fuzzer. Do *NOT* change the order of
// these, as it will invalidate our fuzzing corpus.
portNameToIndex["PContent"] = 0;
portNameToIndex["PBackground"] = 1;
portNameToIndex["PBackgroundStarter"] = 2;
portNameToIndex["PCompositorManager"] = 3;
portNameToIndex["PImageBridge"] = 4;
portNameToIndex["PProcessHangMonitor"] = 5;
portNameToIndex["PProfiler"] = 6;
portNameToIndex["PVRManager"] = 7;
portNameToIndex["PCanvasManager"] = 8;
portNameToIndex["PRemoteLazyInputStream"] = 9;
portNameToIndex["PRemoteWorkerService"] = 10;
// Used to select the n-th trigger message as a starting point for fuzzing
// in single message mode. A value of 1 will skip the first matching message
// and start fuzzing on the second message, and so on.
if (!!getenv("MOZ_FUZZ_IPC_TRIGGER_SINGLEMSG_WAIT")) {
mIPCTriggerSingleMsgWait =
atoi(getenv("MOZ_FUZZ_IPC_TRIGGER_SINGLEMSG_WAIT"));
}
// When set, dump all IPC message at or above the specified size to files.
// Useful to collect samples of different types in one run.
if (!!getenv("MOZ_FUZZ_IPC_DUMP_ALL_MSGS_SIZE")) {
mIPCDumpAllMsgsSize.emplace(
atoi(getenv("MOZ_FUZZ_IPC_DUMP_ALL_MSGS_SIZE")));
}
}
// static
IPCFuzzController& IPCFuzzController::instance() {
static IPCFuzzController ifc;
return ifc;
}
void IPCFuzzController::InitializeIPCTypes() {
const char* cons = "Constructor";
size_t cons_len = strlen(cons);
const char* targetNameTrigger = getenv("MOZ_FUZZ_IPC_TRIGGER");
const char* targetNameDump = getenv("MOZ_FUZZ_IPC_DUMPMSG");
for (uint32_t start = 0; start < LastMsgIndex; ++start) {
uint32_t i;
for (i = (start << 16) + 1; i < ((start + 1) << 16); ++i) {
const char* name = IPC::StringFromIPCMessageType(i);
if (name[0] == '<') break;
if (targetNameTrigger && !strcmp(name, targetNameTrigger)) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [InitializeIPCTypes] Located trigger message (%s, %d)\n",
targetNameTrigger, i);
mIPCTriggerMsg = i;
}
if (targetNameDump && !strcmp(name, targetNameDump)) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [InitializeIPCTypes] Located dump message (%s, %d)\n",
targetNameDump, i);
mIPCDumpMsg.emplace(i);
}
size_t len = strlen(name);
if (len > cons_len && !memcmp(cons, name + len - cons_len, cons_len)) {
constructorTypes.insert(i);
}
}
uint32_t msgCount = i - ((start << 16) + 1);
if (msgCount) {
validMsgTypes[(ProtocolId)start] = msgCount;
}
}
// Resolve potentially disallowed messages now that we have initialized IPC
// types.
InitDisallowedIPCTypes();
}
bool IPCFuzzController::GetRandomIPCMessageType(ProtocolId pId,
uint16_t typeOffset,
uint32_t* type) {
if (actorAllowedMessages.size() > 0) {
// We are fixed to a single actor with a particular message set allowed.
*type = actorAllowedMessages[typeOffset % actorAllowedMessages.size()];
return true;
}
auto pIdEntry = validMsgTypes.find(pId);
if (pIdEntry == validMsgTypes.end()) {
return false;
}
*type =
((uint32_t)pIdEntry->first << 16) + 1 + (typeOffset % pIdEntry->second);
if (strstr(IPC::StringFromIPCMessageType(*type), "::Reply_")) {
*type = *type - 1;
}
// Check if we are allowed to send this message type.
if (actorDisallowedMessages.find(*type) != actorDisallowedMessages.end()) {
return false;
}
return true;
}
void IPCFuzzController::InitDisallowedIPCTypes() {
const char* targetMsgName = getenv("MOZ_FUZZ_IPC_MSGFILTER_DISALLOW");
if (!targetMsgName) {
// Nothing to do.
return;
}
std::vector<std::string> targetMsgNames;
std::istringstream targetMsgNameStream(targetMsgName);
for (std::string msg; getline(targetMsgNameStream, msg, ';');) {
targetMsgNames.push_back(msg);
}
for (auto pIdEntry : validMsgTypes) {
for (uint16_t typeOffset = 0; typeOffset < pIdEntry.second; ++typeOffset) {
uint32_t type = ((uint32_t)pIdEntry.first << 16) + 1 + typeOffset;
const char* msgName = IPC::StringFromIPCMessageType(type);
if (strstr(msgName, "::Reply_")) {
continue;
}
for (std::string msg : targetMsgNames) {
if (strstr(msgName, msg.c_str())) {
actorDisallowedMessages.insert(type);
break;
}
}
}
}
}
void IPCFuzzController::InitAllowedIPCTypes() {
const char* targetMsgName = getenv("MOZ_FUZZ_IPC_MSGFILTER_ALLOW");
if (!targetMsgName) {
// Nothing to do.
return;
}
std::vector<std::string> targetMsgNames;
std::istringstream targetMsgNameStream(targetMsgName);
for (std::string msg; getline(targetMsgNameStream, msg, ';');) {
targetMsgNames.push_back(msg);
}
if (!maybeLastActorId) {
// We only want to call this if we are actually pinning to an actor.
// This also means that calling this is only valid with a PROTOID_FILTER
// set.
MOZ_FUZZING_NYX_ABORT("InitAllowedIPCTypes called without actor pinned?!");
}
auto result = actorIds.find(lastActorPortName);
if (result == actorIds.end()) {
MOZ_FUZZING_NYX_ABORT("ERROR: Couldn't find port in actors map?!\n");
}
auto actors = result->second;
bool found = false;
size_t actorIndex;
for (actorIndex = 0; actorIndex < actors.size(); ++actorIndex) {
if (actors[actorIndex].first == maybeLastActorId ||
(maybeLastActorId == MSG_ROUTING_CONTROL &&
!actors[actorIndex].first)) {
found = true;
break;
}
}
if (!found) {
MOZ_FUZZING_NYX_ABORT(
"ERROR: Pinned to actor that's not in actors map!?\n");
}
ActorIdPair ids = actors[actorIndex];
ProtocolId pId = ids.second;
auto pIdEntry = validMsgTypes.find(pId);
if (pIdEntry == validMsgTypes.end()) {
MOZ_FUZZING_NYX_ABORT("ERROR: Pinned actor has no valid message types!?\n");
}
for (uint16_t typeOffset = 0; typeOffset < pIdEntry->second; ++typeOffset) {
uint32_t type = ((uint32_t)pIdEntry->first << 16) + 1 + typeOffset;
const char* msgName = IPC::StringFromIPCMessageType(type);
if (strstr(msgName, "::Reply_")) {
continue;
}
for (std::string msg : targetMsgNames) {
if (strstr(msgName, msg.c_str())) {
actorAllowedMessages.push_back(type);
break;
}
}
}
if (!actorAllowedMessages.size()) {
MOZ_FUZZING_NYX_ABORT("ERROR: Empty actorAllowedMessages!?\n");
}
}
static bool IsManagedByTargetActor(IProtocol* protocol,
std::string& protoIdFilter) {
while (protocol) {
if (!strcmp(protocol->GetProtocolName(), protoIdFilter.c_str())) {
return true;
}
protocol = protocol->Manager();
}
return false;
}
void IPCFuzzController::OnActorConnected(IProtocol* protocol) {
if (!XRE_IsParentProcess()) {
return;
}
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::OnActorConnected() Mutex try\n");
// Called on background threads and modifies `actorIds`.
MutexAutoLock lock(mMutex);
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::OnActorConnected() Mutex locked\n");
static bool protoIdFilterInitialized = false;
static bool allowSubActors =
!!getenv("MOZ_FUZZ_PROTOID_FILTER_ALLOW_SUBACTORS");
static std::string protoIdFilter;
if (!protoIdFilterInitialized) {
const char* protoIdFilterStr = getenv("MOZ_FUZZ_PROTOID_FILTER");
if (protoIdFilterStr) {
protoIdFilter = std::string(protoIdFilterStr);
}
protoIdFilterInitialized = true;
}
MessageChannel* channel = protocol->ToplevelProtocol()->GetIPCChannel();
Maybe<PortName> portName = channel->GetPortName();
if (!portName) {
MOZ_FUZZING_NYX_PRINTF("INFO: [OnActorConnected] ActorID %d Protocol: %s\n",
protocol->Id(), protocol->GetProtocolName());
}
if (portName) {
if (!protoIdFilter.empty()) {
if (!strcmp(protocol->GetProtocolName(), protoIdFilter.c_str())) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [OnActorConnected] ActorID %d Protocol: %s matches "
"target.\n",
protocol->Id(), protocol->GetProtocolName());
// If our matching protocol is not a toplevel actor, then we need to
// exclude the toplevel protocol later in `MakeTargetDecision` because
// the actor will always be added to the map.
protoFilterTargetExcludeToplevel = protocol->Manager() != nullptr;
} else if (actorIds[*portName].empty()) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [OnActorConnected] ActorID %d Protocol: %s is toplevel "
"actor.\n",
protocol->Id(), protocol->GetProtocolName());
} else if (allowSubActors &&
IsManagedByTargetActor(protocol, protoIdFilter)) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [OnActorConnected] ActorID %d Protocol: %s is managed by "
"target actor.\n",
protocol->Id(), protocol->GetProtocolName());
} else {
// Not a toplevel actor, not matching the filter and also either not a
// sub actor of our target or we are focusing only on the target. Ignore
// this actor.
if (!!getenv("MOZ_FUZZ_DEBUG")) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [OnActorConnected] ActorID %d Protocol: %s ignored due to "
"filter.\n",
protocol->Id(), protocol->GetProtocolName());
}
return;
}
}
if (!!getenv("MOZ_FUZZ_DEBUG")) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [OnActorConnected] ActorID %d Protocol: %s Port: %lu %lu\n",
protocol->Id(), protocol->GetProtocolName(), portName->v1,
portName->v2);
}
actorIds[*portName].emplace_back(protocol->Id(), protocol->GetProtocolId());
if (Nyx::instance().started()) {
if (!useLastPortNameAlways) {
// Fix the port we will be using for at least the next 5 messages
useLastPortName = true;
lastActorPortName = *portName;
}
// Use this actor for the next 5 messages
useLastActor = 5;
}
} else {
MOZ_FUZZING_NYX_DEBUG("WARNING: No port name on actor?!\n");
}
}
void IPCFuzzController::OnActorDestroyed(IProtocol* protocol) {
if (!XRE_IsParentProcess()) {
return;
}
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF("INFO: [OnActorDestroyed] ActorID %d Protocol: %s\n",
protocol->Id(), protocol->GetProtocolName());
#endif
MessageChannel* channel = protocol->ToplevelProtocol()->GetIPCChannel();
Maybe<PortName> portName = channel->GetPortName();
if (portName) {
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::OnActorDestroyed() Mutex try\n");
// Called on background threads and modifies `actorIds`.
MutexAutoLock lock(mMutex);
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::OnActorDestroyed() Mutex locked\n");
if (maybeLastActorId &&
(maybeLastActorId == protocol->Id() ||
(maybeLastActorId == MSG_ROUTING_CONTROL && !protocol->Id())) &&
lastActorPortName == *portName) {
MOZ_FUZZING_NYX_DEBUG("INFO: Actor pinning released.\n");
// We destroyed the actor we were focusing on, unpin.
maybeLastActorId = 0;
useLastActor = 0;
}
for (auto iter = actorIds[*portName].begin();
iter != actorIds[*portName].end();) {
if (iter->first == protocol->Id() &&
iter->second == protocol->GetProtocolId()) {
iter = actorIds[*portName].erase(iter);
} else {
++iter;
}
}
} else {
MOZ_FUZZING_NYX_DEBUG("WARNING: No port name on destroyed actor?!\n");
}
}
void IPCFuzzController::AddToplevelActor(PortName name, ProtocolId protocolId) {
const char* protocolName = ProtocolIdToName(protocolId);
auto result = portNameToIndex.find(protocolName);
if (result == portNameToIndex.end()) {
MOZ_FUZZING_NYX_PRINTF(
"ERROR: [OnActorConnected] Unknown Top-Level Protocol: %s\n",
protocolName);
MOZ_FUZZING_NYX_ABORT("Unknown Top-Level Protocol\n");
}
uint8_t portIndex = result->second;
portNames[portIndex].push_back(name);
portNameToProtocolName[name] = std::string(protocolName);
}
bool IPCFuzzController::ObserveIPCMessage(mozilla::ipc::NodeChannel* channel,
IPC::Message& aMessage) {
if (!mozilla::fuzzing::Nyx::instance().is_enabled("IPC_Generic")) {
// Fuzzer is not enabled.
return true;
}
if (!XRE_IsParentProcess()) {
// For now we only care about things in the parent process.
return true;
}
if (aMessage.IsFuzzMsg()) {
// Don't observe our own messages. If this is the first fuzzing message,
// we also block further non-fuzzing communication on that node.
if (!channel->mBlockSendRecv) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [NodeChannel::OnMessageReceived] Blocking further "
"communication on node %lu %lu (seen fuzz msg)\n",
channel->GetName().v1, channel->GetName().v2);
channel->mBlockSendRecv = true;
}
return true;
} else if (aMessage.type() == mIPCTriggerMsg && !Nyx::instance().started()) {
MOZ_FUZZING_NYX_PRINTF("DEBUG: Ready message detected on actor %d.\n",
aMessage.routing_id());
if (!haveTargetNodeName && !!getenv("MOZ_FUZZ_PROTOID_FILTER")) {
// With a protocol filter set, we want to pin to the actor that
// received the ready message and stay there. We should do this here
// because OnActorConnected can be called even after the ready message
// has been received and potentially override the correct actor.
// Get the port name associated with this message
Vector<char, 256, InfallibleAllocPolicy> footer;
if (!footer.initLengthUninitialized(aMessage.event_footer_size()) ||
!aMessage.ReadFooter(footer.begin(), footer.length(), false)) {
MOZ_FUZZING_NYX_ABORT("ERROR: Failed to read message footer.\n");
}
UniquePtr<Event> event =
Event::Deserialize(footer.begin(), footer.length());
if (!event || event->type() != Event::kUserMessage) {
MOZ_FUZZING_NYX_ABORT("ERROR: Trigger message is not kUserMessage?!\n");
}
lastActorPortName = event->port_name();
useLastPortNameAlways = true;
if (!getenv("MOZ_FUZZ_PROTOID_FILTER_ALLOW_SUBACTORS")) {
// In this mode, we really want to focus on a single actor.
useLastActor = 1024;
maybeLastActorId = aMessage.routing_id();
MOZ_FUZZING_NYX_PRINTF("DEBUG: Pinned to actor %d forever.\n",
aMessage.routing_id());
} else {
// In this mode, we want to focus on a particular actor and all of its
// sub actors. This means we have to pin the port at least. Undesired
// other actors are filtered out already in OnActorConnected *except*
// for the toplevel actor belonging to this port. This exception is
// handled separately in MakeTargetDecision.
MOZ_FUZZING_NYX_PRINTF("DEBUG: Pinned to port %lu %lu forever.\n",
lastActorPortName.v1, lastActorPortName.v2);
}
InitAllowedIPCTypes();
}
// TODO: This is specific to PContent fuzzing. If we later want to fuzz
// a different process pair, we need additional signals here.
OnChildReady();
// The ready message indicates the right node name for us to work with
// and we should only ever receive it once.
if (!haveTargetNodeName) {
targetNodeName = channel->GetName();
haveTargetNodeName = true;
// We can also use this message as the base template for other messages
if (!this->sampleHeader.initLengthUninitialized(
sizeof(IPC::Message::Header))) {
MOZ_FUZZING_NYX_ABORT("sampleHeader.initLengthUninitialized failed\n");
}
memcpy(sampleHeader.begin(), aMessage.header(),
sizeof(IPC::Message::Header));
}
} else if (haveTargetNodeName && targetNodeName != channel->GetName()) {
// Not our node, no need to observe
return true;
} else if (Nyx::instance().started()) {
// When fuzzing is already started, we shouldn't observe messages anymore.
if (!channel->mBlockSendRecv) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [NodeChannel::OnMessageReceived] Blocking further "
"communication on node %lu %lu (fuzzing started)\n",
channel->GetName().v1, channel->GetName().v2);
channel->mBlockSendRecv = true;
}
return false;
}
Vector<char, 256, InfallibleAllocPolicy> footer;
if (!footer.initLengthUninitialized(aMessage.event_footer_size())) {
MOZ_FUZZING_NYX_ABORT("footer.initLengthUninitialized failed\n");
}
if (!aMessage.ReadFooter(footer.begin(), footer.length(), false)) {
MOZ_FUZZING_NYX_ABORT("ERROR: ReadFooter() failed?!\n");
}
UniquePtr<Event> event = Event::Deserialize(footer.begin(), footer.length());
if (!event) {
MOZ_FUZZING_NYX_ABORT("ERROR: Failed to deserialize observed message?!\n");
}
if (event->type() == Event::kUserMessage) {
if (haveTargetNodeName && !fuzzingStartPending) {
bool missingActor = false;
// Check if we have any entries in our port map that we haven't seen yet
// though `OnActorConnected`. That method is called on a background
// thread and this call will race with the I/O thread.
//
// However, with a custom MOZ_FUZZ_IPC_TRIGGER we assume we want to keep
// the port pinned so we don't have to wait at all.
if (mIPCTriggerMsg == ipcDefaultTriggerMsg) {
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::ObserveIPCMessage() Mutex try\n");
// Called on the I/O thread and reads `portSeqNos`.
//
// IMPORTANT: We must give up any locks before entering `StartFuzzing`,
// as we will never return. This would cause a deadlock with new actors
// being created and `OnActorConnected` being called.
MutexAutoLock lock(mMutex);
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: IPCFuzzController::ObserveIPCMessage() Mutex locked\n");
for (auto iter = portSeqNos.begin(); iter != portSeqNos.end(); ++iter) {
auto result = actorIds.find(iter->first);
if (result == actorIds.end()) {
// Make sure we only wait for actors that belong to us.
auto result = portNodeName.find(iter->first);
if (result->second == targetNodeName) {
missingActor = true;
break;
}
}
}
}
if (missingActor) {
MOZ_FUZZING_NYX_PRINT(
"INFO: Delaying fuzzing start, missing actors...\n");
} else if (!childReady) {
MOZ_FUZZING_NYX_PRINT(
"INFO: Delaying fuzzing start, waiting for child...\n");
} else {
fuzzingStartPending = true;
StartFuzzing(channel, aMessage);
// In the async case, we return and can already block the relevant
// communication.
if (targetNodeName == channel->GetName()) {
if (!channel->mBlockSendRecv) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: [NodeChannel::OnMessageReceived] Blocking further "
"communication on node %lu %lu (fuzzing start pending)\n",
channel->GetName().v1, channel->GetName().v2);
channel->mBlockSendRecv = true;
}
return false;
}
MOZ_FUZZING_NYX_ABORT("Unreachable");
return true;
}
}
// Add/update sequence numbers. We need to make sure to do this after our
// call to `StartFuzzing` because once we start fuzzing, the message will
// never actually be processed, so we run into a sequence number desync.
{
// Get the port name associated with this message
UserMessageEvent* userMsgEv = static_cast<UserMessageEvent*>(event.get());
PortName name = event->port_name();
// Called on the I/O thread and modifies `portSeqNos`.
MutexAutoLock lock(mMutex);
portSeqNos.insert_or_assign(
name, std::pair<int32_t, uint64_t>(aMessage.seqno(),
userMsgEv->sequence_num()));
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF(
"DEBUG: Port %lu %lu updated sequence number to %lu\n", name.v1,
name.v2, userMsgEv->sequence_num());
#endif
portNodeName.insert_or_assign(name, channel->GetName());
}
}
return true;
}
void IPCFuzzController::OnMessageError(
mozilla::ipc::HasResultCodes::Result code, const IPC::Message& aMsg) {
if (!mozilla::fuzzing::Nyx::instance().is_enabled("IPC_Generic")) {
// Fuzzer is not enabled.
return;
}
if (!XRE_IsParentProcess()) {
// For now we only care about things in the parent process.
return;
}
if (!aMsg.IsFuzzMsg()) {
// We should only act upon fuzzing messages.
return;
}
switch (code) {
case ipc::HasResultCodes::MsgNotKnown:
// Seeing this error should be rare - one potential reason is if a sync
// message is sent as async and vice versa. Other than that, we shouldn't
// be generating this error at all.
Nyx::instance().handle_event("MOZ_IPC_UNKNOWN_TYPE", nullptr, 0, nullptr);
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF(
"WARNING: MOZ_IPC_UNKNOWN_TYPE for message type %s (%u) routed to "
"actor %d (sync %d)\n",
IPC::StringFromIPCMessageType(aMsg.type()), aMsg.type(),
aMsg.routing_id(), aMsg.is_sync());
#endif
break;
case ipc::HasResultCodes::MsgNotAllowed:
Nyx::instance().handle_event("MOZ_IPC_NOTALLOWED_ERROR", nullptr, 0,
nullptr);
break;
case ipc::HasResultCodes::MsgPayloadError:
case ipc::HasResultCodes::MsgValueError:
Nyx::instance().handle_event("MOZ_IPC_DESERIALIZE_ERROR", nullptr, 0,
nullptr);
break;
case ipc::HasResultCodes::MsgProcessingError:
Nyx::instance().handle_event("MOZ_IPC_PROCESS_ERROR", nullptr, 0,
nullptr);
break;
case ipc::HasResultCodes::MsgRouteError:
Nyx::instance().handle_event("MOZ_IPC_ROUTE_ERROR", nullptr, 0, nullptr);
break;
default:
MOZ_FUZZING_NYX_ABORT("unknown Result code");
}
// Count this message as one iteration as well.
Nyx::instance().release(IPCFuzzController::instance().getMessageStopCount() +
1);
}
bool IPCFuzzController::MakeTargetDecision(
uint8_t portIndex, uint8_t portInstanceIndex, uint8_t actorIndex,
uint8_t actorProtocolIndex, uint16_t typeOffset, PortName* name,
int32_t* seqno, uint64_t* fseqno, int32_t* actorId, uint32_t* type,
bool* is_cons, bool update) {
if (useLastActor) {
useLastActor--;
*name = lastActorPortName;
MOZ_FUZZING_NYX_PRINT("DEBUG: MakeTargetDecision: Pinned to last actor.\n");
// Once we stop pinning to the last actor, we need to decide if we
// want to keep the pinning on the port itself. We use one of the
// unused upper bits of portIndex for this purpose.
if (!useLastActor && !useLastPortNameAlways && (portIndex & (1 << 7))) {
MOZ_FUZZING_NYX_PRINT(
"DEBUG: MakeTargetDecision: Released pinning on last port.\n");
useLastPortName = false;
}
} else if (useLastPortName || useLastPortNameAlways) {
*name = lastActorPortName;
MOZ_FUZZING_NYX_PRINT("DEBUG: MakeTargetDecision: Pinned to last port.\n");
} else {
// Every possible toplevel actor type has a fixed number that
// we assign to it in the constructor of this class. Here, we
// use the lower 6 bits to select this toplevel actor type.
// This approach has the advantage that the tests will always
// select the same toplevel actor type deterministically,
// independent of the order they appeared and independent
// of the type of fuzzing we are doing.
auto portInstances = portNames[portIndex & 0x3f];
if (!portInstances.size()) {
return false;
}
*name = portInstances[portInstanceIndex % portInstances.size()];
}
// We should always have at least one actor per port
auto result = actorIds.find(*name);
if (result == actorIds.end()) {
MOZ_FUZZING_NYX_PRINT("ERROR: Couldn't find port in actors map?!\n");
return false;
}
// Find a random actor on this port
auto actors = result->second;
if (actors.empty()) {
MOZ_FUZZING_NYX_PRINT(
"ERROR: Couldn't find an actor for selected port?!\n");
return false;
}
auto seqNos = portSeqNos[*name];
// Hand out the correct sequence numbers
*seqno = seqNos.first - 1;
*fseqno = seqNos.second + 1;
// If a type is already specified, we must be in preserveHeaderMode.
bool isPreserveHeader = *type;
if (useLastActor) {
if (maybeLastActorId) {
bool found = false;
for (actorIndex = 0; actorIndex < actors.size(); ++actorIndex) {
// Toplevel actors have a discrepancy here: Routing ID is -1 but the
// actor id provided through protocol->Id() is 0.
if (actors[actorIndex].first == maybeLastActorId ||
(maybeLastActorId == MSG_ROUTING_CONTROL &&
!actors[actorIndex].first)) {
found = true;
break;
}
}
if (!found) {
MOZ_FUZZING_NYX_ABORT(
"ERROR: Pinned to actor that's not in actors map!?\n");
}
} else {
actorIndex = actors.size() - 1;
}
} else if (isPreserveHeader) {
// In preserveHeaderMode, we need to find an actor that matches the
// requested message type instead of any random actor.
uint16_t maybeProtocolId = *type >> 16;
if (maybeProtocolId >= IPCMessageStart::LastMsgIndex) {
// Not a valid protocol.
return false;
}
ProtocolId wantedProtocolId = static_cast<ProtocolId>(maybeProtocolId);
std::vector<uint32_t> allowedIndices;
for (uint32_t i = 0; i < actors.size(); ++i) {
if (protoFilterTargetExcludeToplevel && !i) {
// Filter out the toplevel protocol at index 0
continue;
}
if (actors[i].second == wantedProtocolId) {
allowedIndices.push_back(i);
}
}
if (allowedIndices.empty()) {
return false;
}
actorIndex = allowedIndices[actorIndex % allowedIndices.size()];
} else {
std::set<ProtocolId> seenProtocol;
std::vector<ProtocolId> availableProtocols;
if (protoFilterTargetExcludeToplevel && actors.size() < 2) {
// We likely destroyed all other actors
return false;
}
for (auto actor : actors) {
if (protoFilterTargetExcludeToplevel && seenProtocol.empty()) {
// Skip the toplevel protocol.
seenProtocol.insert(actor.second);
continue;
}
if (seenProtocol.find(actor.second) == seenProtocol.end()) {
seenProtocol.insert(actor.second);
availableProtocols.push_back(actor.second);
}
}
// Instead of directly selecting a random actor, we select the protocol
// first and then out of all available actors matching this protocol,
// we select the destination actor. This makes sure that we are uniformly
// fuzzing protocols and not biasing towards protocols with lots of actor
// instances.
ProtocolId wantedProtocolId =
availableProtocols[actorProtocolIndex % availableProtocols.size()];
std::vector<uint32_t> allowedIndices;
for (uint32_t i = 0; i < actors.size(); ++i) {
if (actors[i].second == wantedProtocolId) {
allowedIndices.push_back(i);
}
}
actorIndex = allowedIndices[actorIndex % allowedIndices.size()];
}
ActorIdPair ids = actors[actorIndex];
*actorId = ids.first;
// If the actor ID is 0, then we are talking to the toplevel actor
// of this port. Hence we must set the ID to MSG_ROUTING_CONTROL.
if (!*actorId) {
*actorId = MSG_ROUTING_CONTROL;
}
if (!isPreserveHeader || actorAllowedMessages.size() > 0) {
// If msgType is already set, then we are in preserveHeaderMode
if (!this->GetRandomIPCMessageType(ids.second, typeOffset, type)) {
MOZ_FUZZING_NYX_PRINT("ERROR: GetRandomIPCMessageType failed?!\n");
return false;
}
*is_cons = false;
if (constructorTypes.find(*type) != constructorTypes.end()) {
*is_cons = true;
}
}
if (isPreserveHeader &&
actorDisallowedMessages.find(*type) != actorDisallowedMessages.end()) {
// If we have messages that aren't allowed to be sent, we need to
// confirm that the type set in the header is still allowed.
return false;
}
MOZ_FUZZING_NYX_PRINTF(
"DEBUG: MakeTargetDecision: Top-Level Protocol: %s Protocol: %s msgType: "
"%s (%u), Actor Instance %u of %zu, actor ID: %d, PreservedHeader: %d\n",
portNameToProtocolName[*name].c_str(), ProtocolIdToName(ids.second),
IPC::StringFromIPCMessageType(*type), *type, actorIndex, actors.size(),
*actorId, isPreserveHeader);
if (update) {
portSeqNos.insert_or_assign(*name,
std::pair<int32_t, uint64_t>(*seqno, *fseqno));
}
return true;
}
void IPCFuzzController::OnMessageTaskStart() { messageStartCount++; }
void IPCFuzzController::OnMessageTaskStop() { messageStopCount++; }
void IPCFuzzController::OnPreFuzzMessageTaskRun() { messageTaskCount++; }
void IPCFuzzController::OnPreFuzzMessageTaskStop() { messageTaskCount--; }
void IPCFuzzController::OnDropPeer(const char* reason = nullptr,
const char* file = nullptr, int line = 0) {
if (!XRE_IsParentProcess()) {
return;
}
if (!Nyx::instance().started()) {
// It's possible to close a connection to some peer before we have even
// started fuzzing. We ignore these events until we are actually fuzzing.
return;
}
MOZ_FUZZING_NYX_PRINT(
"ERROR: ======== END OF ITERATION (DROP_PEER) ========\n");
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF("DEBUG: ======== %s:%d ========\n", file, line);
#endif
Nyx::instance().handle_event("MOZ_IPC_DROP_PEER", file, line, reason);
if (Nyx::instance().is_replay()) {
// In replay mode, let's ignore drop peer to avoid races with it.
return;
}
Nyx::instance().release(IPCFuzzController::instance().getMessageStopCount());
}
void IPCFuzzController::StartFuzzing(mozilla::ipc::NodeChannel* channel,
IPC::Message& aMessage) {
nodeChannel = channel;
RefPtr<IPCFuzzLoop> runnable = new IPCFuzzLoop();
#if MOZ_FUZZ_IPC_SYNC_INJECT
runnable->Run();
#else
nsCOMPtr<nsIThread> newThread;
nsresult rv =
NS_NewNamedThread("IPCFuzzLoop", getter_AddRefs(newThread), runnable);
if (NS_FAILED(rv)) {
MOZ_FUZZING_NYX_ABORT("ERROR: [StartFuzzing] NS_NewNamedThread failed?!\n");
}
#endif
}
IPCFuzzController::IPCFuzzLoop::IPCFuzzLoop()
: mozilla::Runnable("IPCFuzzLoop") {}
NS_IMETHODIMP IPCFuzzController::IPCFuzzLoop::Run() {
MOZ_FUZZING_NYX_DEBUG("DEBUG: BEGIN IPCFuzzLoop::Run()\n");
const size_t maxMsgSize = 2048;
const size_t controlLen = 16;
Vector<char, 256, InfallibleAllocPolicy> buffer;
RefPtr<NodeController> controller = NodeController::GetSingleton();
// TODO: The following code is full of data races. We need synchronization
// on the `IPCFuzzController` instance, because the I/O thread can call into
// this class via ObserveIPCMessages. The problem is that any such call
// must either be observed to update the sequence numbers, or the packet
// must be dropped already.
if (!IPCFuzzController::instance().haveTargetNodeName) {
MOZ_FUZZING_NYX_ABORT("ERROR: I don't have the target NodeName?!\n");
}
{
MOZ_FUZZING_NYX_DEBUG("DEBUG: IPCFuzzLoop::Run() Mutex try\n");
// Called on the I/O thread and modifies `portSeqNos` and `actorIds`.
MutexAutoLock lock(IPCFuzzController::instance().mMutex);
MOZ_FUZZING_NYX_DEBUG("DEBUG: IPCFuzzLoop::Run() Mutex locked\n");
// The wait/delay logic in ObserveIPCMessage should ensure that we haven't
// seen any packets on ports for which we haven't received actor information
// yet, if those ports belong to our channel. However, we might also have
// seen ports not belonging to our channel, which we have to remove now.
for (auto iter = IPCFuzzController::instance().portSeqNos.begin();
iter != IPCFuzzController::instance().portSeqNos.end();) {
auto result = IPCFuzzController::instance().actorIds.find(iter->first);
if (result == IPCFuzzController::instance().actorIds.end()) {
auto portNameResult =
IPCFuzzController::instance().portNodeName.find(iter->first);
if (portNameResult->second ==
IPCFuzzController::instance().targetNodeName &&
IPCFuzzController::instance().mIPCTriggerMsg ==
ipcDefaultTriggerMsg) {
MOZ_FUZZING_NYX_PRINTF(
"ERROR: We should not have port map entries without a "
"corresponding "
"entry in our actors map (Port %lu %lu)\n",
iter->first.v1, iter->first.v2);
MOZ_REALLY_CRASH(__LINE__);
} else {
iter = IPCFuzzController::instance().portSeqNos.erase(iter);
}
} else {
++iter;
}
}
// TODO: Technically, at this point we only know that PContent (or whatever
// toplevel protocol we decided to synchronize on), is present. It might
// be possible that others aren't created yet and we are racing on this.
//
// Note: The delay logic mentioned above makes this less likely. Only actors
// which are created on-demand and which have not been referenced yet at all
// would be affected by such a race.
for (auto iter = IPCFuzzController::instance().actorIds.begin();
iter != IPCFuzzController::instance().actorIds.end(); ++iter) {
bool isValidTarget = false;
Maybe<PortStatus> status;
PortRef ref = controller->GetPort(iter->first);
if (ref.is_valid()) {
status = controller->GetStatus(ref);
if (status) {
isValidTarget = status->peer_node_name ==
IPCFuzzController::instance().targetNodeName;
}
}
auto result = IPCFuzzController::instance().portSeqNos.find(iter->first);
if (result == IPCFuzzController::instance().portSeqNos.end()) {
if (isValidTarget) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: Using Port %lu %lu for protocol %s (*)\n", iter->first.v1,
iter->first.v2, ProtocolIdToName(iter->second[0].second));
// Normally the start sequence numbers would be -1 and 1, but our map
// does not record the next numbers, but the "last seen" state. So we
// have to adjust these so the next calculated sequence number pair
// matches the start sequence numbers.
IPCFuzzController::instance().portSeqNos.insert_or_assign(
iter->first, std::pair<int32_t, uint64_t>(0, 0));
IPCFuzzController::instance().AddToplevelActor(
iter->first, iter->second[0].second);
} else {
MOZ_FUZZING_NYX_PRINTF(
"INFO: Removing Port %lu %lu for protocol %s (*)\n",
iter->first.v1, iter->first.v2,
ProtocolIdToName(iter->second[0].second));
// This toplevel actor does not belong to us, but we haven't added
// it to `portSeqNos`, so we don't have to remove it.
}
} else {
if (isValidTarget) {
MOZ_FUZZING_NYX_PRINTF("INFO: Using Port %lu %lu for protocol %s\n",
iter->first.v1, iter->first.v2,
ProtocolIdToName(iter->second[0].second));
IPCFuzzController::instance().AddToplevelActor(
iter->first, iter->second[0].second);
} else {
MOZ_FUZZING_NYX_PRINTF(
"INFO: Removing Port %lu %lu for protocol %s\n", iter->first.v1,
iter->first.v2, ProtocolIdToName(iter->second[0].second));
// This toplevel actor does not belong to us, so remove it.
IPCFuzzController::instance().portSeqNos.erase(result);
}
}
}
}
IPCFuzzController::instance().runnableDone = false;
SyncRunnable::DispatchToThread(
GetMainThreadSerialEventTarget(),
NS_NewRunnableFunction("IPCFuzzController::StartFuzzing", [&]() -> void {
MOZ_FUZZING_NYX_PRINT("INFO: Main thread runnable start.\n");
NS_ProcessPendingEvents(NS_GetCurrentThread());
MOZ_FUZZING_NYX_PRINT("INFO: Main thread runnable done.\n");
}));
MOZ_FUZZING_NYX_PRINT("INFO: Performing snapshot...\n");
Nyx::instance().start();
uint32_t expected_messages = 0;
if (!buffer.initLengthUninitialized(maxMsgSize)) {
MOZ_FUZZING_NYX_ABORT("ERROR: Failed to initialize buffer!\n");
}
for (int i = 0; i < 3; ++i) {
// Grab enough data to potentially fill our everything except the footer.
uint32_t bufsize =
Nyx::instance().get_data((uint8_t*)buffer.begin(), buffer.length());
if (bufsize == 0xFFFFFFFF) {
// Done constructing
MOZ_FUZZING_NYX_DEBUG("Iteration complete: Out of data.\n");
break;
}
// Payload must be int aligned
bufsize -= bufsize % 4;
// Need at least a header and the control bytes.
if (bufsize < sizeof(IPC::Message::Header) + controlLen) {
MOZ_FUZZING_NYX_DEBUG("INFO: Not enough data to craft IPC message.\n");
continue;
}
const uint8_t* controlData = (uint8_t*)buffer.begin();
char* ipcMsgData = buffer.begin() + controlLen;
size_t ipcMsgLen = bufsize - controlLen;
bool preserveHeader = controlData[15] == 0xFF;
if (!preserveHeader) {
// Copy the header of the original message
memcpy(ipcMsgData, IPCFuzzController::instance().sampleHeader.begin(),
sizeof(IPC::Message::Header));
}
IPC::Message::Header* ipchdr = (IPC::Message::Header*)ipcMsgData;
ipchdr->payload_size = ipcMsgLen - sizeof(IPC::Message::Header);
PortName new_port_name;
int32_t new_seqno;
uint64_t new_fseqno;
int32_t actorId;
uint32_t msgType = 0;
bool isConstructor = false;
// Control Data Layout (16 byte)
// Byte 0 - Port Index (selects out of the valid ports seen)
// Byte 1 - Actor Index (selects one of the actors for that port)
// Byte 2 - Type Offset (select valid type for the specified actor)
// Byte 3 - ^- continued
// Byte 4 - Actor Protocol Index (selects the protocol on that port)
// Byte 5 - Optionally select a particular instance of the selected
// port type. Some toplevel protocols can have multiple
// instances running at the same time.
//
// Byte 15 - If set to 0xFF, skip overwriting the header, leave fields
// like message type intact and only set target actor and
// other fields that are dynamic.
uint8_t portIndex = controlData[0];
uint8_t actorIndex = controlData[1];
uint16_t typeOffset = *(uint16_t*)(&controlData[2]);
uint8_t actorProtocolIndex = controlData[4];
uint8_t portInstanceIndex = controlData[5];
UniquePtr<IPC::Message> msg(new IPC::Message(ipcMsgData, ipcMsgLen));
if (preserveHeader) {
isConstructor = msg->is_constructor();
msgType = msg->header()->type;
if (!msgType) {
// msgType == 0 is used to indicate to MakeTargetDecision that we are
// not in preserve header mode. It's not a valid message type in any
// case and we can error out early.
Nyx::instance().release(
IPCFuzzController::instance().getMessageStopCount());
}
}
if (!IPCFuzzController::instance().MakeTargetDecision(
portIndex, portInstanceIndex, actorIndex, actorProtocolIndex,
typeOffset, &new_port_name, &new_seqno, &new_fseqno, &actorId,
&msgType, &isConstructor)) {
MOZ_FUZZING_NYX_DEBUG("DEBUG: MakeTargetDecision returned false.\n");
continue;
}
if (Nyx::instance().is_replay()) {
MOZ_FUZZING_NYX_PRINT("INFO: Replaying IPC packet with payload:\n");
for (uint32_t i = 0; i < ipcMsgLen - sizeof(IPC::Message::Header); ++i) {
if (i % 16 == 0) {
MOZ_FUZZING_NYX_PRINT("\n ");
}
MOZ_FUZZING_NYX_PRINTF(
"0x%02X ",
(unsigned char)(ipcMsgData[sizeof(IPC::Message::Header) + i]));
}
MOZ_FUZZING_NYX_PRINT("\n");
}
if (isConstructor) {
MOZ_FUZZING_NYX_DEBUG("DEBUG: Sending constructor message...\n");
msg->header()->flags.SetConstructor();
}
if (IPC::IPCMessageTypeIsSync(msgType)) {
MOZ_FUZZING_NYX_DEBUG("INFO: Sending sync message...\n");
msg->header()->flags.SetSync();
}
msg->set_seqno(new_seqno);
msg->set_routing_id(actorId);
if (!preserveHeader) {
// TODO: There is no setter for this.
msg->header()->type = msgType;
}
// Make sure we're not sending with LAZY_SEND
msg->header()->flags.mFlags &= ~IPC::Message::HeaderFlags::LAZY_SEND_BIT;
// Create the footer
auto messageEvent = MakeUnique<UserMessageEvent>(0);
messageEvent->set_port_name(new_port_name);
messageEvent->set_sequence_num(new_fseqno);
Vector<char, 256, InfallibleAllocPolicy> footerBuffer;
(void)footerBuffer.initLengthUninitialized(
messageEvent->GetSerializedSize());
messageEvent->Serialize(footerBuffer.begin());
msg->WriteFooter(footerBuffer.begin(), footerBuffer.length());
msg->set_event_footer_size(footerBuffer.length());
// This marks the message as a fuzzing message. Without this, it will
// be ignored by MessageTask and also not even scheduled by NodeChannel
// in asynchronous mode. We use this to ignore any IPC activity that
// happens just while we are fuzzing.
msg->SetFuzzMsg();
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF(
"DEBUG: OnEventMessage iteration %d, EVS: %u Payload: %u.\n", i,
ipchdr->event_footer_size, ipchdr->payload_size);
#endif
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF("DEBUG: OnEventMessage: Port %lu %lu. Actor %d\n",
new_port_name.v1, new_port_name.v2, actorId);
MOZ_FUZZING_NYX_PRINTF(
"DEBUG: OnEventMessage: Flags: %u TxID: %d Handles: %u\n",
msg->header()->flags, msg->header()->txid, msg->header()->num_handles);
#endif
if (!!getenv("MOZ_FUZZ_DEBUG")) {
MOZ_FUZZING_NYX_PRINTF(
"INFO: Flags: IsSync: %d IsReply: %d IsReplyError: %d IsConstructor: "
"%d IsRelay: %d IsLazySend: %d\n",
msg->is_sync(), msg->is_reply(), msg->is_reply_error(),
msg->is_constructor(), msg->is_relay(), msg->is_lazy_send());
}
// The number of messages we expect to see stopped.
expected_messages++;
#if MOZ_FUZZ_IPC_SYNC_INJECT
// For synchronous injection, we just call OnMessageReceived directly.
IPCFuzzController::instance().nodeChannel->OnMessageReceived(
std::move(msg));
#else
// For asynchronous injection, we have to post to the I/O thread instead.
XRE_GetIOMessageLoop()->PostTask(NS_NewRunnableFunction(
"NodeChannel::OnMessageReceived",
[msg = std::move(msg),
nodeChannel =
RefPtr{IPCFuzzController::instance().nodeChannel}]() mutable {
int32_t msgType = msg->header()->type;
// By default, we sync on the target thread of the receiving actor.
bool syncOnIOThread = false;
switch (msgType) {
case DATA_PIPE_CLOSED_MESSAGE_TYPE:
case DATA_PIPE_BYTES_CONSUMED_MESSAGE_TYPE:
case ACCEPT_INVITE_MESSAGE_TYPE:
case REQUEST_INTRODUCTION_MESSAGE_TYPE:
case INTRODUCE_MESSAGE_TYPE:
case BROADCAST_MESSAGE_TYPE:
// This set of special messages will not be routed to actors and
// therefore we won't see these as stopped messages later. These
// messages are either used by NodeChannel, DataPipe or
// MessageChannel without creating MessageTasks. As such, the best
// we can do is synchronize on this thread. We do this by
// emulating the MessageTaskStart/Stop behavior that normal event
// messages have.
syncOnIOThread = true;
break;
default:
// Synchronization will happen in MessageChannel. Note that this
// also applies to certain special message types, as long as they
// are received by actors and not intercepted earlier.
break;
}
if (syncOnIOThread) {
mozilla::fuzzing::IPCFuzzController::instance()
.OnMessageTaskStart();
}
nodeChannel->OnMessageReceived(std::move(msg));
if (syncOnIOThread) {
mozilla::fuzzing::IPCFuzzController::instance().OnMessageTaskStop();
// Don't continue for now after sending such a special message.
// It can cause ports to go away and further messages can time out.
Nyx::instance().release(
IPCFuzzController::instance().getMessageStopCount());
}
}));
#endif
#ifdef MOZ_FUZZ_IPC_SYNC_AFTER_EACH_MSG
MOZ_FUZZING_NYX_DEBUG("DEBUG: Synchronizing after message...\n");
IPCFuzzController::instance().SynchronizeOnMessageExecution(
expected_messages);
SyncRunnable::DispatchToThread(
GetMainThreadSerialEventTarget(),
NS_NewRunnableFunction(
"IPCFuzzController::StartFuzzing", [&]() -> void {
MOZ_FUZZING_NYX_DEBUG("DEBUG: Main thread runnable start.\n");
NS_ProcessPendingEvents(NS_GetCurrentThread());
MOZ_FUZZING_NYX_DEBUG("DEBUG: Main thread runnable done.\n");
}));
#else
if (isConstructor) {
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: Synchronizing due to constructor message...\n");
IPCFuzzController::instance().SynchronizeOnMessageExecution(
expected_messages);
}
#endif
}
#ifndef MOZ_FUZZ_IPC_SYNC_AFTER_EACH_MSG
MOZ_FUZZING_NYX_DEBUG("DEBUG: Synchronizing due to end of iteration...\n");
IPCFuzzController::instance().SynchronizeOnMessageExecution(
expected_messages);
SyncRunnable::DispatchToThread(
GetMainThreadSerialEventTarget(),
NS_NewRunnableFunction("IPCFuzzController::StartFuzzing", [&]() -> void {
MOZ_FUZZING_NYX_DEBUG("DEBUG: Main thread runnable start.\n");
NS_ProcessPendingEvents(NS_GetCurrentThread());
MOZ_FUZZING_NYX_DEBUG("DEBUG: Main thread runnable done.\n");
}));
#endif
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: ======== END OF ITERATION (RELEASE) ========\n");
Nyx::instance().release(IPCFuzzController::instance().getMessageStopCount());
// Never reached.
return NS_OK;
}
void IPCFuzzController::SynchronizeOnMessageExecution(
uint32_t expected_messages) {
// This synchronization will work in both the sync and async case.
// For the async case, it is important to wait for the exact stop count
// because the message task is not even started potentially when we
// read this loop.
int hang_timeout = 10 * 1000;
while (IPCFuzzController::instance().getMessageStopCount() !=
expected_messages) {
#ifdef FUZZ_DEBUG
uint32_t count_stopped =
IPCFuzzController::instance().getMessageStopCount();
uint32_t count_live = IPCFuzzController::instance().getMessageStartCount();
MOZ_FUZZING_NYX_PRINTF(
"DEBUG: Post Constructor: %d stopped messages (%d live, %d "
"expected)!\n",
count_stopped, count_live, expected_messages);
#endif
PR_Sleep(PR_MillisecondsToInterval(50));
hang_timeout -= 50;
if (hang_timeout <= 0) {
Nyx::instance().handle_event("MOZ_TIMEOUT", nullptr, 0, nullptr);
MOZ_FUZZING_NYX_PRINT(
"ERROR: ======== END OF ITERATION (TIMEOUT) ========\n");
if (!!getenv("MOZ_FUZZ_CRASH_ON_TIMEOUT")) {
MOZ_DIAGNOSTIC_ASSERT(false, "IPCFuzzController Timeout");
}
Nyx::instance().release(
IPCFuzzController::instance().getMessageStopCount());
}
}
}
static void dumpIPCMessageToFile(const UniquePtr<IPC::Message>& aMsg,
uint32_t aDumpCount, bool aUseNyx = false) {
if (Nyx::instance().is_replay()) {
return;
}
std::stringstream dumpFilename;
std::string msgName(IPC::StringFromIPCMessageType(aMsg->type()));
std::replace(msgName.begin(), msgName.end(), ':', '_');
if (aUseNyx) {
dumpFilename << "seeds/";
}
dumpFilename << msgName << aDumpCount << ".bin";
Pickle::BufferList::IterImpl iter(aMsg->Buffers());
Vector<char, 256, InfallibleAllocPolicy> dumpBuffer;
if (!dumpBuffer.initLengthUninitialized(sizeof(IPC::Message::Header) +
aMsg->Buffers().Size())) {
MOZ_FUZZING_NYX_ABORT("dumpBuffer.initLengthUninitialized failed\n");
}
if (!aMsg->Buffers().ReadBytes(
iter,
reinterpret_cast<char*>(dumpBuffer.begin() +
sizeof(IPC::Message::Header)),
dumpBuffer.length() - sizeof(IPC::Message::Header))) {
MOZ_FUZZING_NYX_ABORT("ReadBytes failed\n");
}
memcpy(dumpBuffer.begin(), aMsg->header(), sizeof(IPC::Message::Header));
if (aUseNyx) {
MOZ_FUZZING_NYX_PRINTF("INFO: Calling dump_file: %s Size: %zu\n",
dumpFilename.str().c_str(), dumpBuffer.length());
Nyx::instance().dump_file(reinterpret_cast<char*>(dumpBuffer.begin()),
dumpBuffer.length(), dumpFilename.str().c_str());
} else {
std::fstream file;
file.open(dumpFilename.str(), std::ios::out | std::ios::binary);
file.write(reinterpret_cast<char*>(dumpBuffer.begin()),
dumpBuffer.length());
file.close();
}
}
UniquePtr<IPC::Message> IPCFuzzController::replaceIPCMessage(
UniquePtr<IPC::Message> aMsg) {
if (!mozilla::fuzzing::Nyx::instance().is_enabled("IPC_SingleMessage")) {
// Fuzzer is not enabled.
return aMsg;
}
if (!XRE_IsParentProcess()) {
// For now we only care about things in the parent process.
return aMsg;
}
static bool dumpFilterInitialized = false;
static std::string dumpFilter;
if (!dumpFilterInitialized) {
const char* dumpFilterStr = getenv("MOZ_FUZZ_DUMP_FILTER");
if (dumpFilterStr) {
dumpFilter = std::string(dumpFilterStr);
}
dumpFilterInitialized = true;
}
if (aMsg->type() != mIPCTriggerMsg) {
if ((mIPCDumpMsg && aMsg->type() == mIPCDumpMsg.value()) ||
(mIPCDumpAllMsgsSize.isSome() &&
aMsg->Buffers().Size() >= mIPCDumpAllMsgsSize.value())) {
if (!dumpFilter.empty()) {
std::string msgName(IPC::StringFromIPCMessageType(aMsg->type()));
if (msgName.find(dumpFilter) != std::string::npos) {
dumpIPCMessageToFile(aMsg, mIPCDumpCount);
mIPCDumpCount++;
}
} else {
dumpIPCMessageToFile(aMsg, mIPCDumpCount);
mIPCDumpCount++;
}
}
// Not the trigger message. Output additional information here for
// automation purposes. This shouldn't be an issue as we will only
// output these messages until we take a snapshot.
MOZ_FUZZING_NYX_PRINTF("INFO: [OnIPCMessage] Message: %s Size: %u\n",
IPC::StringFromIPCMessageType(aMsg->type()),
aMsg->header()->payload_size);
return aMsg;
} else {
// Dump the trigger message through Nyx in case we want to use it
// as a seed to AFL++ outside of the VM.
dumpIPCMessageToFile(aMsg, mIPCDumpCount, true /* aUseNyx */);
mIPCDumpCount++;
if (mIPCTriggerSingleMsgWait > 0) {
mIPCTriggerSingleMsgWait--;
return aMsg;
}
}
const size_t maxMsgSize = 4096;
Vector<char, 256, InfallibleAllocPolicy> buffer;
if (!buffer.initLengthUninitialized(maxMsgSize)) {
MOZ_FUZZING_NYX_ABORT("ERROR: Failed to initialize buffer!\n");
}
char* ipcMsgData = buffer.begin();
// //
// *** Snapshot Point *** //
// //
MOZ_FUZZING_NYX_PRINT("INFO: Performing snapshot...\n");
Nyx::instance().start();
IPCFuzzController::instance().useLastActor = 0;
IPCFuzzController::instance().useLastPortName = false;
IPCFuzzController::instance().useLastPortNameAlways = false;
MOZ_FUZZING_NYX_DEBUG("DEBUG: Requesting data...\n");
// Grab enough data to send at most `maxMsgSize` bytes
uint32_t bufsize =
Nyx::instance().get_raw_data((uint8_t*)buffer.begin(), buffer.length());
if (bufsize == 0xFFFFFFFF) {
MOZ_FUZZING_NYX_DEBUG("Nyx: Out of data.\n");
Nyx::instance().release(0);
}
#ifdef FUZZ_DEBUG
MOZ_FUZZING_NYX_PRINTF("DEBUG: Got buffer of size %u...\n", bufsize);
#endif
// Payload must be int aligned
bufsize -= bufsize % 4;
// Need at least a header and the control bytes.
if (bufsize < sizeof(IPC::Message::Header)) {
MOZ_FUZZING_NYX_DEBUG("INFO: Not enough data to craft IPC message.\n");
Nyx::instance().release(0);
}
buffer.shrinkTo(bufsize);
// Copy the header of the original message
memcpy(ipcMsgData, aMsg->header(), sizeof(IPC::Message::Header));
IPC::Message::Header* ipchdr = (IPC::Message::Header*)ipcMsgData;
size_t ipcMsgLen = buffer.length();
ipchdr->payload_size = ipcMsgLen - sizeof(IPC::Message::Header);
if (Nyx::instance().is_replay()) {
MOZ_FUZZING_NYX_PRINT("INFO: Replaying single IPC packet with payload:\n");
for (uint32_t i = 0; i < ipcMsgLen - sizeof(IPC::Message::Header); ++i) {
if (i % 16 == 0) {
MOZ_FUZZING_NYX_PRINT("\n ");
}
MOZ_FUZZING_NYX_PRINTF(
"0x%02X ",
(unsigned char)(ipcMsgData[sizeof(IPC::Message::Header) + i]));
}
MOZ_FUZZING_NYX_PRINT("\n");
}
UniquePtr<IPC::Message> msg(new IPC::Message(ipcMsgData, ipcMsgLen));
if (!!getenv("MOZ_FUZZ_DEBUG")) {
MOZ_FUZZING_NYX_PRINTF("INFO: Name: %s Target: %d\n", msg->name(),
msg->routing_id());
}
// This marks the message as a fuzzing message. Without this, it will
// be ignored by MessageTask and also not even scheduled by NodeChannel
// in asynchronous mode. We use this to ignore any IPC activity that
// happens just while we are fuzzing.
msg->SetFuzzMsg();
return msg;
}
void IPCFuzzController::syncAfterReplace() {
if (!mozilla::fuzzing::Nyx::instance().is_enabled("IPC_SingleMessage")) {
// Fuzzer is not enabled.
return;
}
if (!XRE_IsParentProcess()) {
// For now we only care about things in the parent process.
return;
}
if (!Nyx::instance().started()) {
// Not started yet
return;
}
MOZ_FUZZING_NYX_DEBUG(
"DEBUG: ======== END OF ITERATION (RELEASE) ========\n");
Nyx::instance().release(1);
}
} // namespace fuzzing
} // namespace mozilla