1 files changed, 115 insertions, 0 deletions
diff --git a/view/macho/chained_fixups.h b/view/macho/chained_fixups.h
new file mode 100644
index 00000000..9a26a1f5
--- /dev/null
+++ b/view/macho/chained_fixups.h
@@ -0,0 +1,115 @@
+#pragma once
+
+#include "machoview.h"
+
+#include <functional>
+#include <stdint.h>
+#include <string_view>
+#include <vector>
+
+namespace BinaryNinja
+{
+	
+enum class FixupType : uint8_t
+{
+	Bind,
+	Rebase,
+};
+
+enum class AuthKeyType : uint8_t
+{
+	IA,
+	IB,
+	DA,
+	DB,
+	None,
+};
+
+struct FixupInfo
+{
+	union
+	{
+		struct
+		{
+			uint32_t ordinal = 0;
+			int32_t addend = 0;
+		} bind;
+		struct
+		{
+			uint64_t target = 0;
+		} rebase;
+	};
+	FixupType type : 1;
+	bool isAuthenticated : 1 = false;
+	AuthKeyType authKeyType : 3 = AuthKeyType::None;
+	bool usesAddressDiversity : 1 = false;
+	uint16_t addressDiversity = 0;
+	uint16_t next = 0;
+};
+
+struct ImportEntry
+{
+	std::string_view name;
+	uint64_t addend;
+	int32_t libraryOrdinal;
+	bool weakImport = false;
+};
+
+class ChainedFixupProcessor
+{
+public:
+	ChainedFixupProcessor(Ref<BinaryView> raw, Ref<Logger> logger, uint64_t machOStartOffset, uint64_t preferredLoadAddress,
+		const linkedit_data_command& chainedFixupCommand, std::unordered_map<uint64_t, uint64_t> segmentVMAddrToFileOffset)
+		: m_raw(std::move(raw))
+		, m_logger(std::move(logger))
+		, m_machOStartOffset(machOStartOffset)
+		, m_fixupsStartOffset(OffsetInRaw(chainedFixupCommand.dataoff))
+		, m_fixupsSize(chainedFixupCommand.datasize)
+		, m_preferredLoadAddress(preferredLoadAddress)
+		, m_segmentVMAddrToFileOffset(std::move(segmentVMAddrToFileOffset))
+	{}
+
+	std::vector<ImportEntry> ProcessImports() const;
+
+	// Calls the provided handler for each fixup found. `offset` is relative to `machOStartOffset`.
+	//
+	// Note that `FixupInfo` references data owned by this object and so should not be used outside
+	// of the handler function.
+	void ProcessFixups(std::function<void(uint64_t offset, const FixupInfo&)> fixupHandler) const;
+
+private:
+	dyld_chained_fixups_header ReadHeader(BinaryReader&) const;
+
+	void ProcessChainedFixups(const dyld_chained_fixups_header&, BinaryReader&) const;
+	void ProcessChainsInSegment(const dyld_chained_starts_in_segment&, BinaryReader&) const;
+
+	// Returns a vector of pairs of (page index, offset in page) representing the start of each fixup chain.
+	std::vector<std::pair<uint64_t, uint16_t>> ReadChainStartsInSegment(const dyld_chained_starts_in_segment&, BinaryReader&) const;
+
+	uint64_t OffsetInRaw(uint64_t offset) const { return m_machOStartOffset + offset; }
+	uint64_t OffsetInFixups(uint64_t offset) const { return m_fixupsStartOffset + offset; }
+
+	Ref<BinaryView> m_raw;
+	Ref<Logger> m_logger;
+
+	// Offset to the start of the Mach-O file within the BinaryView.
+	// This will be non-zero for Mach-O files within a universal binary.
+	uint64_t m_machOStartOffset;
+
+	// Offset to the start of the chained fixups data within the BinaryView.
+	uint64_t m_fixupsStartOffset;
+
+	// Total size of the chained fixups data.
+	uint64_t m_fixupsSize;
+
+	// The preferred load address of the __TEXT segment. Used for translating
+	// address-based fixups into offset-based fixups.
+	uint64_t m_preferredLoadAddress;
+
+	std::unordered_map<uint64_t, uint64_t> m_segmentVMAddrToFileOffset;
+
+	mutable std::function<void(uint64_t offset, const FixupInfo&)> m_fixupHandler;
+	mutable std::vector<char> m_symbolData;
+};
+
+} // namespace BinaryNinja