binarystore: Add ReadOnly Mode
Add Read Only mode to the binary store. In this mode,
all blobs are not writable, no new blobs can be created and
the storage protobuf can't be modified in any way.
Also added simple API for reading/examining blob store
without modifying it.
Signed-off-by: Maksym Sloyko <maxims@google.com>
Change-Id: I12e3473351be98820d8e5df1b71a6d43699aa671
diff --git a/binarystore.cpp b/binarystore.cpp
index 1307c3a..32547d7 100644
--- a/binarystore.cpp
+++ b/binarystore.cpp
@@ -9,6 +9,7 @@
#include <blobs-ipmid/blobs.hpp>
#include <boost/endian/arithmetic.hpp>
#include <cstdint>
+#include <ipmid/handler.hpp>
#include <memory>
#include <phosphor-logging/elog.hpp>
#include <string>
@@ -48,6 +49,25 @@
return std::move(store);
}
+std::unique_ptr<BinaryStoreInterface>
+ BinaryStore::createFromFile(std::unique_ptr<SysFile> file, bool readOnly)
+{
+ if (!file)
+ {
+ log<level::ERR>("Unable to create binarystore from invalid file");
+ return nullptr;
+ }
+
+ auto store = std::make_unique<BinaryStore>(std::move(file), readOnly);
+
+ if (!store->loadSerializedData())
+ {
+ return nullptr;
+ }
+
+ return std::move(store);
+}
+
bool BinaryStore::loadSerializedData()
{
/* Load blob from sysfile if we know it might not match what we have.
@@ -93,7 +113,7 @@
return true;
}
- if (blob_.blob_base_id() != baseBlobId_)
+ if (blob_.blob_base_id() != baseBlobId_ && !readOnly_)
{
/* Uh oh, stale data loaded. Clean it and commit. */
// TODO: it might be safer to add an option in config to error out
@@ -111,13 +131,18 @@
std::string BinaryStore::getBaseBlobId() const
{
- return baseBlobId_;
+ if (!baseBlobId_.empty())
+ {
+ return baseBlobId_;
+ }
+
+ return blob_.blob_base_id();
}
std::vector<std::string> BinaryStore::getBlobIds() const
{
std::vector<std::string> result;
- result.push_back(baseBlobId_);
+ result.push_back(getBaseBlobId());
for (const auto& blob : blob_.blobs())
{
@@ -144,6 +169,13 @@
return false;
}
+ if (readOnly_ && (flags & blobs::OpenFlags::write))
+ {
+ log<level::ERR>("Can't open the blob for writing: read-only store",
+ entry("BLOB_ID=%s", blobId.c_str()));
+ return false;
+ }
+
writable_ = flags & blobs::OpenFlags::write;
/* If there are uncommitted data, discard them. */
@@ -166,11 +198,20 @@
}
/* Otherwise, create the blob and append it */
- currentBlob_ = blob_.add_blobs();
- currentBlob_->set_blob_id(blobId);
+ if (readOnly_)
+ {
+ return false;
+ }
+ else
+ {
+ currentBlob_ = blob_.add_blobs();
+ currentBlob_->set_blob_id(blobId);
- commitState_ = CommitState::Dirty;
- log<level::NOTICE>("Created new blob", entry("BLOB_ID=%s", blobId.c_str()));
+ commitState_ = CommitState::Dirty;
+ log<level::NOTICE>("Created new blob",
+ entry("BLOB_ID=%s", blobId.c_str()));
+ }
+
return true;
}
@@ -208,6 +249,23 @@
return result;
}
+std::vector<uint8_t> BinaryStore::readBlob(const std::string& blobId) const
+{
+ const auto blobs = blob_.blobs();
+ const auto blobIt =
+ std::find_if(blobs.begin(), blobs.end(),
+ [&](const auto& b) { return b.blob_id() == blobId; });
+
+ if (blobIt == blobs.end())
+ {
+ throw ipmi::HandlerCompletion(ipmi::ccUnspecifiedError);
+ }
+
+ const auto blobData = blobIt->data();
+
+ return std::vector<uint8_t>(blobData.begin(), blobData.end());
+}
+
bool BinaryStore::write(uint32_t offset, const std::vector<uint8_t>& data)
{
if (!currentBlob_)
@@ -242,6 +300,12 @@
bool BinaryStore::commit()
{
+ if (readOnly_)
+ {
+ log<level::ERR>("ReadOnly blob, not committing");
+ return false;
+ }
+
/* Store as little endian to be platform agnostic. Consistent with read. */
auto blobData = blob_.SerializeAsString();
boost::endian::little_uint64_t sizeLE = blobData.size();