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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /netwerk/base/BackgroundFileSaver.cpp
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'netwerk/base/BackgroundFileSaver.cpp')
-rw-r--r--netwerk/base/BackgroundFileSaver.cpp1121
1 files changed, 1121 insertions, 0 deletions
diff --git a/netwerk/base/BackgroundFileSaver.cpp b/netwerk/base/BackgroundFileSaver.cpp
new file mode 100644
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+++ b/netwerk/base/BackgroundFileSaver.cpp
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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 "BackgroundFileSaver.h"
+
+#include "ScopedNSSTypes.h"
+#include "mozilla/ArrayAlgorithm.h"
+#include "mozilla/Casting.h"
+#include "mozilla/Logging.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Telemetry.h"
+#include "nsCOMArray.h"
+#include "nsComponentManagerUtils.h"
+#include "nsDependentSubstring.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIFile.h"
+#include "nsIMutableArray.h"
+#include "nsIPipe.h"
+#include "nsNetUtil.h"
+#include "nsThreadUtils.h"
+#include "pk11pub.h"
+#include "secoidt.h"
+
+#ifdef XP_WIN
+# include <windows.h>
+# include <softpub.h>
+# include <wintrust.h>
+#endif // XP_WIN
+
+namespace mozilla {
+namespace net {
+
+// MOZ_LOG=BackgroundFileSaver:5
+static LazyLogModule prlog("BackgroundFileSaver");
+#define LOG(args) MOZ_LOG(prlog, mozilla::LogLevel::Debug, args)
+#define LOG_ENABLED() MOZ_LOG_TEST(prlog, mozilla::LogLevel::Debug)
+
+////////////////////////////////////////////////////////////////////////////////
+//// Globals
+
+/**
+ * Buffer size for writing to the output file or reading from the input file.
+ */
+#define BUFFERED_IO_SIZE (1024 * 32)
+
+/**
+ * When this upper limit is reached, the original request is suspended.
+ */
+#define REQUEST_SUSPEND_AT (1024 * 1024 * 4)
+
+/**
+ * When this lower limit is reached, the original request is resumed.
+ */
+#define REQUEST_RESUME_AT (1024 * 1024 * 2)
+
+////////////////////////////////////////////////////////////////////////////////
+//// NotifyTargetChangeRunnable
+
+/**
+ * Runnable object used to notify the control thread that file contents will now
+ * be saved to the specified file.
+ */
+class NotifyTargetChangeRunnable final : public Runnable {
+ public:
+ NotifyTargetChangeRunnable(BackgroundFileSaver* aSaver, nsIFile* aTarget)
+ : Runnable("net::NotifyTargetChangeRunnable"),
+ mSaver(aSaver),
+ mTarget(aTarget) {}
+
+ NS_IMETHOD Run() override { return mSaver->NotifyTargetChange(mTarget); }
+
+ private:
+ RefPtr<BackgroundFileSaver> mSaver;
+ nsCOMPtr<nsIFile> mTarget;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaver
+
+uint32_t BackgroundFileSaver::sThreadCount = 0;
+uint32_t BackgroundFileSaver::sTelemetryMaxThreadCount = 0;
+
+BackgroundFileSaver::BackgroundFileSaver() {
+ LOG(("Created BackgroundFileSaver [this = %p]", this));
+}
+
+BackgroundFileSaver::~BackgroundFileSaver() {
+ LOG(("Destroying BackgroundFileSaver [this = %p]", this));
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::Init() {
+ MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+ NS_NewPipe2(getter_AddRefs(mPipeInputStream),
+ getter_AddRefs(mPipeOutputStream), true, true, 0,
+ HasInfiniteBuffer() ? UINT32_MAX : 0);
+
+ mControlEventTarget = GetCurrentSerialEventTarget();
+ NS_ENSURE_TRUE(mControlEventTarget, NS_ERROR_NOT_INITIALIZED);
+
+ nsresult rv = NS_CreateBackgroundTaskQueue("BgFileSaver",
+ getter_AddRefs(mBackgroundET));
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ sThreadCount++;
+ if (sThreadCount > sTelemetryMaxThreadCount) {
+ sTelemetryMaxThreadCount = sThreadCount;
+ }
+
+ return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::GetObserver(nsIBackgroundFileSaverObserver** aObserver) {
+ NS_ENSURE_ARG_POINTER(aObserver);
+ *aObserver = do_AddRef(mObserver).take();
+ return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::SetObserver(nsIBackgroundFileSaverObserver* aObserver) {
+ mObserver = aObserver;
+ return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::EnableAppend() {
+ MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+ MutexAutoLock lock(mLock);
+ mAppend = true;
+
+ return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::SetTarget(nsIFile* aTarget, bool aKeepPartial) {
+ NS_ENSURE_ARG(aTarget);
+ {
+ MutexAutoLock lock(mLock);
+ if (!mInitialTarget) {
+ aTarget->Clone(getter_AddRefs(mInitialTarget));
+ mInitialTargetKeepPartial = aKeepPartial;
+ } else {
+ aTarget->Clone(getter_AddRefs(mRenamedTarget));
+ mRenamedTargetKeepPartial = aKeepPartial;
+ }
+ }
+
+ // After the worker thread wakes up because attention is requested, it will
+ // rename or create the target file as requested, and start copying data.
+ return GetWorkerThreadAttention(true);
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::Finish(nsresult aStatus) {
+ nsresult rv;
+
+ // This will cause the NS_AsyncCopy operation, if it's in progress, to consume
+ // all the data that is still in the pipe, and then finish.
+ rv = mPipeOutputStream->Close();
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // Ensure that, when we get attention from the worker thread, if no pending
+ // rename operation is waiting, the operation will complete.
+ {
+ MutexAutoLock lock(mLock);
+ mFinishRequested = true;
+ if (NS_SUCCEEDED(mStatus)) {
+ mStatus = aStatus;
+ }
+ }
+
+ // After the worker thread wakes up because attention is requested, it will
+ // process the completion conditions, detect that completion is requested, and
+ // notify the main thread of the completion. If this function was called with
+ // a success code, we wait for the copy to finish before processing the
+ // completion conditions, otherwise we interrupt the copy immediately.
+ return GetWorkerThreadAttention(NS_FAILED(aStatus));
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::EnableSha256() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Can't enable sha256 or initialize NSS off the main thread");
+ // Ensure Personal Security Manager is initialized. This is required for
+ // PK11_* operations to work.
+ nsresult rv;
+ nsCOMPtr<nsISupports> nssDummy = do_GetService("@mozilla.org/psm;1", &rv);
+ NS_ENSURE_SUCCESS(rv, rv);
+ MutexAutoLock lock(mLock);
+ mSha256Enabled = true; // this will be read by the worker thread
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::GetSha256Hash(nsACString& aHash) {
+ MOZ_ASSERT(NS_IsMainThread(), "Can't inspect sha256 off the main thread");
+ // We acquire a lock because mSha256 is written on the worker thread.
+ MutexAutoLock lock(mLock);
+ if (mSha256.IsEmpty()) {
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+ aHash = mSha256;
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::EnableSignatureInfo() {
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Can't enable signature extraction off the main thread");
+ // Ensure Personal Security Manager is initialized.
+ nsresult rv;
+ nsCOMPtr<nsISupports> nssDummy = do_GetService("@mozilla.org/psm;1", &rv);
+ NS_ENSURE_SUCCESS(rv, rv);
+ MutexAutoLock lock(mLock);
+ mSignatureInfoEnabled = true;
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::GetSignatureInfo(
+ nsTArray<nsTArray<nsTArray<uint8_t>>>& aSignatureInfo) {
+ MOZ_ASSERT(NS_IsMainThread(), "Can't inspect signature off the main thread");
+ // We acquire a lock because mSignatureInfo is written on the worker thread.
+ MutexAutoLock lock(mLock);
+ if (!mComplete || !mSignatureInfoEnabled) {
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+ for (const auto& signatureChain : mSignatureInfo) {
+ aSignatureInfo.AppendElement(TransformIntoNewArray(
+ signatureChain, [](const auto& element) { return element.Clone(); }));
+ }
+ return NS_OK;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::GetWorkerThreadAttention(
+ bool aShouldInterruptCopy) {
+ nsresult rv;
+
+ MutexAutoLock lock(mLock);
+
+ // We only require attention one time. If this function is called two times
+ // before the worker thread wakes up, and the first has aShouldInterruptCopy
+ // false and the second true, we won't forcibly interrupt the copy from the
+ // control thread. However, that never happens, because calling Finish with a
+ // success code is the only case that may result in aShouldInterruptCopy being
+ // false. In that case, we won't call this function again, because consumers
+ // should not invoke other methods on the control thread after calling Finish.
+ // And in any case, Finish already closes one end of the pipe, causing the
+ // copy to finish properly on its own.
+ if (mWorkerThreadAttentionRequested) {
+ return NS_OK;
+ }
+
+ if (!mAsyncCopyContext) {
+ // Background event queues are not shutdown and could be called after
+ // the queue is reset to null. To match the behavior of nsIThread
+ // return NS_ERROR_UNEXPECTED
+ if (!mBackgroundET) {
+ return NS_ERROR_UNEXPECTED;
+ }
+
+ // Copy is not in progress, post an event to handle the change manually.
+ rv = mBackgroundET->Dispatch(
+ NewRunnableMethod("net::BackgroundFileSaver::ProcessAttention", this,
+ &BackgroundFileSaver::ProcessAttention),
+ NS_DISPATCH_EVENT_MAY_BLOCK);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ } else if (aShouldInterruptCopy) {
+ // Interrupt the copy. The copy will be resumed, if needed, by the
+ // ProcessAttention function, invoked by the AsyncCopyCallback function.
+ NS_CancelAsyncCopy(mAsyncCopyContext, NS_ERROR_ABORT);
+ }
+
+ // Indicate that attention has been requested successfully, there is no need
+ // to post another event until the worker thread processes the current one.
+ mWorkerThreadAttentionRequested = true;
+
+ return NS_OK;
+}
+
+// Called on the worker thread.
+// static
+void BackgroundFileSaver::AsyncCopyCallback(void* aClosure, nsresult aStatus) {
+ // We called NS_ADDREF_THIS when NS_AsyncCopy started, to keep the object
+ // alive even if other references disappeared. At the end of this method,
+ // we've finished using the object and can safely release our reference.
+ RefPtr<BackgroundFileSaver> self =
+ dont_AddRef((BackgroundFileSaver*)aClosure);
+ {
+ MutexAutoLock lock(self->mLock);
+
+ // Now that the copy was interrupted or terminated, any notification from
+ // the control thread requires an event to be posted to the worker thread.
+ self->mAsyncCopyContext = nullptr;
+
+ // When detecting failures, ignore the status code we use to interrupt.
+ if (NS_FAILED(aStatus) && aStatus != NS_ERROR_ABORT &&
+ NS_SUCCEEDED(self->mStatus)) {
+ self->mStatus = aStatus;
+ }
+ }
+
+ (void)self->ProcessAttention();
+}
+
+// Called on the worker thread.
+nsresult BackgroundFileSaver::ProcessAttention() {
+ nsresult rv;
+
+ // This function is called whenever the attention of the worker thread has
+ // been requested. This may happen in these cases:
+ // * We are about to start the copy for the first time. In this case, we are
+ // called from an event posted on the worker thread from the control thread
+ // by GetWorkerThreadAttention, and mAsyncCopyContext is null.
+ // * We have interrupted the copy for some reason. In this case, we are
+ // called by AsyncCopyCallback, and mAsyncCopyContext is null.
+ // * We are currently executing ProcessStateChange, and attention is requested
+ // by the control thread, for example because SetTarget or Finish have been
+ // called. In this case, we are called from from an event posted through
+ // GetWorkerThreadAttention. While mAsyncCopyContext was always null when
+ // the event was posted, at this point mAsyncCopyContext may not be null
+ // anymore, because ProcessStateChange may have started the copy before the
+ // event that called this function was processed on the worker thread.
+ // If mAsyncCopyContext is not null, we interrupt the copy and re-enter
+ // through AsyncCopyCallback. This allows us to check if, for instance, we
+ // should rename the target file. We will then restart the copy if needed.
+
+ // mAsyncCopyContext is only written on the worker thread (which we are on)
+ MOZ_ASSERT(!NS_IsMainThread());
+ {
+ // Even though we're the only thread that writes this, we have to take the
+ // lock
+ MutexAutoLock lock(mLock);
+ if (mAsyncCopyContext) {
+ NS_CancelAsyncCopy(mAsyncCopyContext, NS_ERROR_ABORT);
+ return NS_OK;
+ }
+ }
+ // Use the current shared state to determine the next operation to execute.
+ rv = ProcessStateChange();
+ if (NS_FAILED(rv)) {
+ // If something failed while processing, terminate the operation now.
+ {
+ MutexAutoLock lock(mLock);
+
+ if (NS_SUCCEEDED(mStatus)) {
+ mStatus = rv;
+ }
+ }
+ // Ensure we notify completion now that the operation failed.
+ CheckCompletion();
+ }
+
+ return NS_OK;
+}
+
+// Called on the worker thread.
+nsresult BackgroundFileSaver::ProcessStateChange() {
+ nsresult rv;
+
+ // We might have been notified because the operation is complete, verify.
+ if (CheckCompletion()) {
+ return NS_OK;
+ }
+
+ // Get a copy of the current shared state for the worker thread.
+ nsCOMPtr<nsIFile> initialTarget;
+ bool initialTargetKeepPartial;
+ nsCOMPtr<nsIFile> renamedTarget;
+ bool renamedTargetKeepPartial;
+ bool sha256Enabled;
+ bool append;
+ {
+ MutexAutoLock lock(mLock);
+
+ initialTarget = mInitialTarget;
+ initialTargetKeepPartial = mInitialTargetKeepPartial;
+ renamedTarget = mRenamedTarget;
+ renamedTargetKeepPartial = mRenamedTargetKeepPartial;
+ sha256Enabled = mSha256Enabled;
+ append = mAppend;
+
+ // From now on, another attention event needs to be posted if state changes.
+ mWorkerThreadAttentionRequested = false;
+ }
+
+ // The initial target can only be null if it has never been assigned. In this
+ // case, there is nothing to do since we never created any output file.
+ if (!initialTarget) {
+ return NS_OK;
+ }
+
+ // Determine if we are processing the attention request for the first time.
+ bool isContinuation = !!mActualTarget;
+ if (!isContinuation) {
+ // Assign the target file for the first time.
+ mActualTarget = initialTarget;
+ mActualTargetKeepPartial = initialTargetKeepPartial;
+ }
+
+ // Verify whether we have actually been instructed to use a different file.
+ // This may happen the first time this function is executed, if SetTarget was
+ // called two times before the worker thread processed the attention request.
+ bool equalToCurrent = false;
+ if (renamedTarget) {
+ rv = mActualTarget->Equals(renamedTarget, &equalToCurrent);
+ NS_ENSURE_SUCCESS(rv, rv);
+ if (!equalToCurrent) {
+ // If we were asked to rename the file but the initial file did not exist,
+ // we simply create the file in the renamed location. We avoid this check
+ // if we have already started writing the output file ourselves.
+ bool exists = true;
+ if (!isContinuation) {
+ rv = mActualTarget->Exists(&exists);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+ if (exists) {
+ // We are moving the previous target file to a different location.
+ nsCOMPtr<nsIFile> renamedTargetParentDir;
+ rv = renamedTarget->GetParent(getter_AddRefs(renamedTargetParentDir));
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ nsAutoString renamedTargetName;
+ rv = renamedTarget->GetLeafName(renamedTargetName);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // We must delete any existing target file before moving the current
+ // one.
+ rv = renamedTarget->Exists(&exists);
+ NS_ENSURE_SUCCESS(rv, rv);
+ if (exists) {
+ rv = renamedTarget->Remove(false);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+
+ // Move the file. If this fails, we still reference the original file
+ // in mActualTarget, so that it is deleted if requested. If this
+ // succeeds, the nsIFile instance referenced by mActualTarget mutates
+ // and starts pointing to the new file, but we'll discard the reference.
+ rv = mActualTarget->MoveTo(renamedTargetParentDir, renamedTargetName);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+
+ // We should not only update the mActualTarget with renameTarget when
+ // they point to the different files.
+ // In this way, if mActualTarget and renamedTarget point to the same file
+ // with different addresses, "CheckCompletion()" will return false
+ // forever.
+ }
+
+ // Update mActualTarget with renameTarget,
+ // even if they point to the same file.
+ mActualTarget = renamedTarget;
+ mActualTargetKeepPartial = renamedTargetKeepPartial;
+ }
+
+ // Notify if the target file name actually changed.
+ if (!equalToCurrent) {
+ // We must clone the nsIFile instance because mActualTarget is not
+ // immutable, it may change if the target is renamed later.
+ nsCOMPtr<nsIFile> actualTargetToNotify;
+ rv = mActualTarget->Clone(getter_AddRefs(actualTargetToNotify));
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ RefPtr<NotifyTargetChangeRunnable> event =
+ new NotifyTargetChangeRunnable(this, actualTargetToNotify);
+ NS_ENSURE_TRUE(event, NS_ERROR_FAILURE);
+
+ rv = mControlEventTarget->Dispatch(event, NS_DISPATCH_NORMAL);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+
+ if (isContinuation) {
+ // The pending rename operation might be the last task before finishing. We
+ // may return here only if we have already created the target file.
+ if (CheckCompletion()) {
+ return NS_OK;
+ }
+
+ // Even if the operation did not complete, the pipe input stream may be
+ // empty and may have been closed already. We detect this case using the
+ // Available property, because it never returns an error if there is more
+ // data to be consumed. If the pipe input stream is closed, we just exit
+ // and wait for more calls like SetTarget or Finish to be invoked on the
+ // control thread. However, we still truncate the file or create the
+ // initial digest context if we are expected to do that.
+ uint64_t available;
+ rv = mPipeInputStream->Available(&available);
+ if (NS_FAILED(rv)) {
+ return NS_OK;
+ }
+ }
+
+ // Create the digest if requested and NSS hasn't been shut down.
+ if (sha256Enabled && mDigest.isNothing()) {
+ mDigest.emplace(Digest());
+ mDigest->Begin(SEC_OID_SHA256);
+ }
+
+ // When we are requested to append to an existing file, we should read the
+ // existing data and ensure we include it as part of the final hash.
+ if (mDigest.isSome() && append && !isContinuation) {
+ nsCOMPtr<nsIInputStream> inputStream;
+ rv = NS_NewLocalFileInputStream(getter_AddRefs(inputStream), mActualTarget,
+ PR_RDONLY | nsIFile::OS_READAHEAD);
+ if (rv != NS_ERROR_FILE_NOT_FOUND) {
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // Try to clean up the inputStream if an error occurs.
+ auto closeGuard =
+ mozilla::MakeScopeExit([&] { Unused << inputStream->Close(); });
+
+ char buffer[BUFFERED_IO_SIZE];
+ while (true) {
+ uint32_t count;
+ rv = inputStream->Read(buffer, BUFFERED_IO_SIZE, &count);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ if (count == 0) {
+ // We reached the end of the file.
+ break;
+ }
+
+ rv = mDigest->Update(BitwiseCast<unsigned char*, char*>(buffer), count);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // The pending resume operation may have been cancelled by the control
+ // thread while the worker thread was reading in the existing file.
+ // Abort reading in the original file in that case, as the digest will
+ // be discarded anyway.
+ MutexAutoLock lock(mLock);
+ if (NS_FAILED(mStatus)) {
+ return NS_ERROR_ABORT;
+ }
+ }
+
+ // Close explicitly to handle any errors.
+ closeGuard.release();
+ rv = inputStream->Close();
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+ }
+
+ // We will append to the initial target file only if it was requested by the
+ // caller, but we'll always append on subsequent accesses to the target file.
+ int32_t creationIoFlags;
+ if (isContinuation) {
+ creationIoFlags = PR_APPEND;
+ } else {
+ creationIoFlags = (append ? PR_APPEND : PR_TRUNCATE) | PR_CREATE_FILE;
+ }
+
+ // Create the target file, or append to it if we already started writing it.
+ // The 0600 permissions are used while the file is being downloaded, and for
+ // interrupted downloads. Those may be located in the system temporary
+ // directory, as well as the target directory, and generally have a ".part"
+ // extension. Those part files should never be group or world-writable even
+ // if the umask allows it.
+ nsCOMPtr<nsIOutputStream> outputStream;
+ rv = NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mActualTarget,
+ PR_WRONLY | creationIoFlags, 0600);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ nsCOMPtr<nsIOutputStream> bufferedStream;
+ rv = NS_NewBufferedOutputStream(getter_AddRefs(bufferedStream),
+ outputStream.forget(), BUFFERED_IO_SIZE);
+ NS_ENSURE_SUCCESS(rv, rv);
+ outputStream = bufferedStream;
+
+ // Wrap the output stream so that it feeds the digest if needed.
+ if (mDigest.isSome()) {
+ // Constructing the DigestOutputStream cannot fail. Passing mDigest
+ // to DigestOutputStream is safe, because BackgroundFileSaver always
+ // outlives the outputStream. BackgroundFileSaver is reference-counted
+ // before the call to AsyncCopy, and mDigest is never destroyed
+ // before AsyncCopyCallback.
+ outputStream = new DigestOutputStream(outputStream, mDigest.ref());
+ }
+
+ // Start copying our input to the target file. No errors can be raised past
+ // this point if the copy starts, since they should be handled by the thread.
+ {
+ MutexAutoLock lock(mLock);
+
+ rv = NS_AsyncCopy(mPipeInputStream, outputStream, mBackgroundET,
+ NS_ASYNCCOPY_VIA_READSEGMENTS, 4096, AsyncCopyCallback,
+ this, false, true, getter_AddRefs(mAsyncCopyContext),
+ GetProgressCallback());
+ if (NS_FAILED(rv)) {
+ NS_WARNING("NS_AsyncCopy failed.");
+ mAsyncCopyContext = nullptr;
+ return rv;
+ }
+ }
+
+ // If the operation succeeded, we must ensure that we keep this object alive
+ // for the entire duration of the copy, since only the raw pointer will be
+ // provided as the argument of the AsyncCopyCallback function. We can add the
+ // reference now, after NS_AsyncCopy returned, because it always starts
+ // processing asynchronously, and there is no risk that the callback is
+ // invoked before we reach this point. If the operation failed instead, then
+ // AsyncCopyCallback will never be called.
+ NS_ADDREF_THIS();
+
+ return NS_OK;
+}
+
+// Called on the worker thread.
+bool BackgroundFileSaver::CheckCompletion() {
+ nsresult rv;
+
+ bool failed = true;
+ {
+ MutexAutoLock lock(mLock);
+ MOZ_ASSERT(!mAsyncCopyContext,
+ "Should not be copying when checking completion conditions.");
+
+ if (mComplete) {
+ return true;
+ }
+
+ // If an error occurred, we don't need to do the checks in this code block,
+ // and the operation can be completed immediately with a failure code.
+ if (NS_SUCCEEDED(mStatus)) {
+ failed = false;
+
+ // We did not incur in an error, so we must determine if we can stop now.
+ // If the Finish method has not been called, we can just continue now.
+ if (!mFinishRequested) {
+ return false;
+ }
+
+ // We can only stop when all the operations requested by the control
+ // thread have been processed. First, we check whether we have processed
+ // the first SetTarget call, if any. Then, we check whether we have
+ // processed any rename requested by subsequent SetTarget calls.
+ if ((mInitialTarget && !mActualTarget) ||
+ (mRenamedTarget && mRenamedTarget != mActualTarget)) {
+ return false;
+ }
+
+ // If we still have data to write to the output file, allow the copy
+ // operation to resume. The Available getter may return an error if one
+ // of the pipe's streams has been already closed.
+ uint64_t available;
+ rv = mPipeInputStream->Available(&available);
+ if (NS_SUCCEEDED(rv) && available != 0) {
+ return false;
+ }
+ }
+
+ mComplete = true;
+ }
+
+ // Ensure we notify completion now that the operation finished.
+ // Do a best-effort attempt to remove the file if required.
+ if (failed && mActualTarget && !mActualTargetKeepPartial) {
+ (void)mActualTarget->Remove(false);
+ }
+
+ // Finish computing the hash
+ if (!failed && mDigest.isSome()) {
+ nsTArray<uint8_t> outArray;
+ rv = mDigest->End(outArray);
+ if (NS_SUCCEEDED(rv)) {
+ MutexAutoLock lock(mLock);
+ mSha256 = nsDependentCSubstring(
+ BitwiseCast<char*, uint8_t*>(outArray.Elements()), outArray.Length());
+ }
+ }
+
+ // Compute the signature of the binary. ExtractSignatureInfo doesn't do
+ // anything on non-Windows platforms except return an empty nsIArray.
+ if (!failed && mActualTarget) {
+ nsString filePath;
+ mActualTarget->GetTarget(filePath);
+ nsresult rv = ExtractSignatureInfo(filePath);
+ if (NS_FAILED(rv)) {
+ LOG(("Unable to extract signature information [this = %p].", this));
+ } else {
+ LOG(("Signature extraction success! [this = %p]", this));
+ }
+ }
+
+ // Post an event to notify that the operation completed.
+ if (NS_FAILED(mControlEventTarget->Dispatch(
+ NewRunnableMethod("BackgroundFileSaver::NotifySaveComplete", this,
+ &BackgroundFileSaver::NotifySaveComplete),
+ NS_DISPATCH_NORMAL))) {
+ NS_WARNING("Unable to post completion event to the control thread.");
+ }
+
+ return true;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::NotifyTargetChange(nsIFile* aTarget) {
+ if (mObserver) {
+ (void)mObserver->OnTargetChange(this, aTarget);
+ }
+
+ return NS_OK;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::NotifySaveComplete() {
+ MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+ nsresult status;
+ {
+ MutexAutoLock lock(mLock);
+ status = mStatus;
+ }
+
+ if (mObserver) {
+ (void)mObserver->OnSaveComplete(this, status);
+ // If mObserver keeps alive an enclosure that captures `this`, we'll have a
+ // cycle that won't be caught by the cycle-collector, so we need to break it
+ // when we're done here (see bug 1444265).
+ mObserver = nullptr;
+ }
+
+ // At this point, the worker thread will not process any more events, and we
+ // can shut it down. Shutting down a thread may re-enter the event loop on
+ // this thread. This is not a problem in this case, since this function is
+ // called by a top-level event itself, and we have already invoked the
+ // completion observer callback. Re-entering the loop can only delay the
+ // final release and destruction of this saver object, since we are keeping a
+ // reference to it through the event object.
+ mBackgroundET = nullptr;
+
+ sThreadCount--;
+
+ // When there are no more active downloads, we consider the download session
+ // finished. We record the maximum number of concurrent downloads reached
+ // during the session in a telemetry histogram, and we reset the maximum
+ // thread counter for the next download session
+ if (sThreadCount == 0) {
+ Telemetry::Accumulate(Telemetry::BACKGROUNDFILESAVER_THREAD_COUNT,
+ sTelemetryMaxThreadCount);
+ sTelemetryMaxThreadCount = 0;
+ }
+
+ return NS_OK;
+}
+
+nsresult BackgroundFileSaver::ExtractSignatureInfo(const nsAString& filePath) {
+ MOZ_ASSERT(!NS_IsMainThread(), "Cannot extract signature on main thread");
+ {
+ MutexAutoLock lock(mLock);
+ if (!mSignatureInfoEnabled) {
+ return NS_OK;
+ }
+ }
+#ifdef XP_WIN
+ // Setup the file to check.
+ WINTRUST_FILE_INFO fileToCheck = {0};
+ fileToCheck.cbStruct = sizeof(WINTRUST_FILE_INFO);
+ fileToCheck.pcwszFilePath = filePath.Data();
+ fileToCheck.hFile = nullptr;
+ fileToCheck.pgKnownSubject = nullptr;
+
+ // We want to check it is signed and trusted.
+ WINTRUST_DATA trustData = {0};
+ trustData.cbStruct = sizeof(trustData);
+ trustData.pPolicyCallbackData = nullptr;
+ trustData.pSIPClientData = nullptr;
+ trustData.dwUIChoice = WTD_UI_NONE;
+ trustData.fdwRevocationChecks = WTD_REVOKE_NONE;
+ trustData.dwUnionChoice = WTD_CHOICE_FILE;
+ trustData.dwStateAction = WTD_STATEACTION_VERIFY;
+ trustData.hWVTStateData = nullptr;
+ trustData.pwszURLReference = nullptr;
+ // Disallow revocation checks over the network
+ trustData.dwProvFlags = WTD_CACHE_ONLY_URL_RETRIEVAL;
+ // no UI
+ trustData.dwUIContext = 0;
+ trustData.pFile = &fileToCheck;
+
+ // The WINTRUST_ACTION_GENERIC_VERIFY_V2 policy verifies that the certificate
+ // chains up to a trusted root CA and has appropriate permissions to sign
+ // code.
+ GUID policyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2;
+ // Check if the file is signed by something that is trusted. If the file is
+ // not signed, this is a no-op.
+ LONG ret = WinVerifyTrust(nullptr, &policyGUID, &trustData);
+ CRYPT_PROVIDER_DATA* cryptoProviderData = nullptr;
+ // According to the Windows documentation, we should check against 0 instead
+ // of ERROR_SUCCESS, which is an HRESULT.
+ if (ret == 0) {
+ cryptoProviderData = WTHelperProvDataFromStateData(trustData.hWVTStateData);
+ }
+ if (cryptoProviderData) {
+ // Lock because signature information is read on the main thread.
+ MutexAutoLock lock(mLock);
+ LOG(("Downloaded trusted and signed file [this = %p].", this));
+ // A binary may have multiple signers. Each signer may have multiple certs
+ // in the chain.
+ for (DWORD i = 0; i < cryptoProviderData->csSigners; ++i) {
+ const CERT_CHAIN_CONTEXT* certChainContext =
+ cryptoProviderData->pasSigners[i].pChainContext;
+ if (!certChainContext) {
+ break;
+ }
+ for (DWORD j = 0; j < certChainContext->cChain; ++j) {
+ const CERT_SIMPLE_CHAIN* certSimpleChain =
+ certChainContext->rgpChain[j];
+ if (!certSimpleChain) {
+ break;
+ }
+
+ nsTArray<nsTArray<uint8_t>> certList;
+ bool extractionSuccess = true;
+ for (DWORD k = 0; k < certSimpleChain->cElement; ++k) {
+ CERT_CHAIN_ELEMENT* certChainElement = certSimpleChain->rgpElement[k];
+ if (certChainElement->pCertContext->dwCertEncodingType !=
+ X509_ASN_ENCODING) {
+ continue;
+ }
+ nsTArray<uint8_t> cert;
+ cert.AppendElements(certChainElement->pCertContext->pbCertEncoded,
+ certChainElement->pCertContext->cbCertEncoded);
+ certList.AppendElement(std::move(cert));
+ }
+ if (extractionSuccess) {
+ mSignatureInfo.AppendElement(std::move(certList));
+ }
+ }
+ }
+ // Free the provider data if cryptoProviderData is not null.
+ trustData.dwStateAction = WTD_STATEACTION_CLOSE;
+ WinVerifyTrust(nullptr, &policyGUID, &trustData);
+ } else {
+ LOG(("Downloaded unsigned or untrusted file [this = %p].", this));
+ }
+#endif
+ return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverOutputStream
+
+NS_IMPL_ISUPPORTS(BackgroundFileSaverOutputStream, nsIBackgroundFileSaver,
+ nsIOutputStream, nsIAsyncOutputStream,
+ nsIOutputStreamCallback)
+
+BackgroundFileSaverOutputStream::BackgroundFileSaverOutputStream()
+ : BackgroundFileSaver(), mAsyncWaitCallback(nullptr) {}
+
+bool BackgroundFileSaverOutputStream::HasInfiniteBuffer() { return false; }
+
+nsAsyncCopyProgressFun BackgroundFileSaverOutputStream::GetProgressCallback() {
+ return nullptr;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Close() { return mPipeOutputStream->Close(); }
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Flush() { return mPipeOutputStream->Flush(); }
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::StreamStatus() {
+ return mPipeOutputStream->StreamStatus();
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Write(const char* aBuf, uint32_t aCount,
+ uint32_t* _retval) {
+ return mPipeOutputStream->Write(aBuf, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::WriteFrom(nsIInputStream* aFromStream,
+ uint32_t aCount, uint32_t* _retval) {
+ return mPipeOutputStream->WriteFrom(aFromStream, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::WriteSegments(nsReadSegmentFun aReader,
+ void* aClosure, uint32_t aCount,
+ uint32_t* _retval) {
+ return mPipeOutputStream->WriteSegments(aReader, aClosure, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::IsNonBlocking(bool* _retval) {
+ return mPipeOutputStream->IsNonBlocking(_retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::CloseWithStatus(nsresult reason) {
+ return mPipeOutputStream->CloseWithStatus(reason);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::AsyncWait(nsIOutputStreamCallback* aCallback,
+ uint32_t aFlags,
+ uint32_t aRequestedCount,
+ nsIEventTarget* aEventTarget) {
+ NS_ENSURE_STATE(!mAsyncWaitCallback);
+
+ mAsyncWaitCallback = aCallback;
+
+ return mPipeOutputStream->AsyncWait(this, aFlags, aRequestedCount,
+ aEventTarget);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::OnOutputStreamReady(
+ nsIAsyncOutputStream* aStream) {
+ NS_ENSURE_STATE(mAsyncWaitCallback);
+
+ nsCOMPtr<nsIOutputStreamCallback> asyncWaitCallback = nullptr;
+ asyncWaitCallback.swap(mAsyncWaitCallback);
+
+ return asyncWaitCallback->OnOutputStreamReady(this);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverStreamListener
+
+NS_IMPL_ISUPPORTS(BackgroundFileSaverStreamListener, nsIBackgroundFileSaver,
+ nsIRequestObserver, nsIStreamListener)
+
+bool BackgroundFileSaverStreamListener::HasInfiniteBuffer() { return true; }
+
+nsAsyncCopyProgressFun
+BackgroundFileSaverStreamListener::GetProgressCallback() {
+ return AsyncCopyProgressCallback;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnStartRequest(nsIRequest* aRequest) {
+ NS_ENSURE_ARG(aRequest);
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnStopRequest(nsIRequest* aRequest,
+ nsresult aStatusCode) {
+ // If an error occurred, cancel the operation immediately. On success, wait
+ // until the caller has determined whether the file should be renamed.
+ if (NS_FAILED(aStatusCode)) {
+ Finish(aStatusCode);
+ }
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnDataAvailable(nsIRequest* aRequest,
+ nsIInputStream* aInputStream,
+ uint64_t aOffset,
+ uint32_t aCount) {
+ nsresult rv;
+
+ NS_ENSURE_ARG(aRequest);
+
+ // Read the requested data. Since the pipe has an infinite buffer, we don't
+ // expect any write error to occur here.
+ uint32_t writeCount;
+ rv = mPipeOutputStream->WriteFrom(aInputStream, aCount, &writeCount);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ // If reading from the input stream fails for any reason, the pipe will return
+ // a success code, but without reading all the data. Since we should be able
+ // to read the requested data when OnDataAvailable is called, raise an error.
+ if (writeCount < aCount) {
+ NS_WARNING("Reading from the input stream should not have failed.");
+ return NS_ERROR_UNEXPECTED;
+ }
+
+ bool stateChanged = false;
+ {
+ MutexAutoLock lock(mSuspensionLock);
+
+ if (!mReceivedTooMuchData) {
+ uint64_t available;
+ nsresult rv = mPipeInputStream->Available(&available);
+ if (NS_SUCCEEDED(rv) && available > REQUEST_SUSPEND_AT) {
+ mReceivedTooMuchData = true;
+ mRequest = aRequest;
+ stateChanged = true;
+ }
+ }
+ }
+
+ if (stateChanged) {
+ NotifySuspendOrResume();
+ }
+
+ return NS_OK;
+}
+
+// Called on the worker thread.
+// static
+void BackgroundFileSaverStreamListener::AsyncCopyProgressCallback(
+ void* aClosure, uint32_t aCount) {
+ BackgroundFileSaverStreamListener* self =
+ (BackgroundFileSaverStreamListener*)aClosure;
+
+ // Wait if the control thread is in the process of suspending or resuming.
+ MutexAutoLock lock(self->mSuspensionLock);
+
+ // This function is called when some bytes are consumed by NS_AsyncCopy. Each
+ // time this happens, verify if a suspended request should be resumed, because
+ // we have now consumed enough data.
+ if (self->mReceivedTooMuchData) {
+ uint64_t available;
+ nsresult rv = self->mPipeInputStream->Available(&available);
+ if (NS_FAILED(rv) || available < REQUEST_RESUME_AT) {
+ self->mReceivedTooMuchData = false;
+
+ // Post an event to verify if the request should be resumed.
+ if (NS_FAILED(self->mControlEventTarget->Dispatch(
+ NewRunnableMethod(
+ "BackgroundFileSaverStreamListener::NotifySuspendOrResume",
+ self,
+ &BackgroundFileSaverStreamListener::NotifySuspendOrResume),
+ NS_DISPATCH_NORMAL))) {
+ NS_WARNING("Unable to post resume event to the control thread.");
+ }
+ }
+ }
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaverStreamListener::NotifySuspendOrResume() {
+ // Prevent the worker thread from changing state while processing.
+ MutexAutoLock lock(mSuspensionLock);
+
+ if (mReceivedTooMuchData) {
+ if (!mRequestSuspended) {
+ // Try to suspend the request. If this fails, don't try to resume later.
+ if (NS_SUCCEEDED(mRequest->Suspend())) {
+ mRequestSuspended = true;
+ } else {
+ NS_WARNING("Unable to suspend the request.");
+ }
+ }
+ } else {
+ if (mRequestSuspended) {
+ // Resume the request only if we succeeded in suspending it.
+ if (NS_SUCCEEDED(mRequest->Resume())) {
+ mRequestSuspended = false;
+ } else {
+ NS_WARNING("Unable to resume the request.");
+ }
+ }
+ }
+
+ return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// DigestOutputStream
+NS_IMPL_ISUPPORTS(DigestOutputStream, nsIOutputStream)
+
+DigestOutputStream::DigestOutputStream(nsIOutputStream* aStream,
+ Digest& aDigest)
+ : mOutputStream(aStream), mDigest(aDigest) {
+ MOZ_ASSERT(mOutputStream, "Can't have null output stream");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::Close() { return mOutputStream->Close(); }
+
+NS_IMETHODIMP
+DigestOutputStream::Flush() { return mOutputStream->Flush(); }
+
+NS_IMETHODIMP
+DigestOutputStream::StreamStatus() { return mOutputStream->StreamStatus(); }
+
+NS_IMETHODIMP
+DigestOutputStream::Write(const char* aBuf, uint32_t aCount, uint32_t* retval) {
+ nsresult rv = mDigest.Update(
+ BitwiseCast<const unsigned char*, const char*>(aBuf), aCount);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ return mOutputStream->Write(aBuf, aCount, retval);
+}
+
+NS_IMETHODIMP
+DigestOutputStream::WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
+ uint32_t* retval) {
+ // Not supported. We could read the stream to a buf, call DigestOp on the
+ // result, seek back and pass the stream on, but it's not worth it since our
+ // application (NS_AsyncCopy) doesn't invoke this on the sink.
+ MOZ_CRASH("DigestOutputStream::WriteFrom not implemented");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::WriteSegments(nsReadSegmentFun aReader, void* aClosure,
+ uint32_t aCount, uint32_t* retval) {
+ MOZ_CRASH("DigestOutputStream::WriteSegments not implemented");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::IsNonBlocking(bool* retval) {
+ return mOutputStream->IsNonBlocking(retval);
+}
+
+#undef LOG_ENABLED
+
+} // namespace net
+} // namespace mozilla