Merge pull request #59369 from aaronfranke/fixup-embedded-pck

1 files changed, 105 insertions, 0 deletions

diff --git a/platform/linuxbsd/export/export_plugin.cpp b/platform/linuxbsd/export/export_plugin.cpp
index 99f5b82b34..6300a37854 100644
--- a/platform/linuxbsd/export/export_plugin.cpp
+++ b/platform/linuxbsd/export/export_plugin.cpp
@@ -72,3 +72,108 @@ Error EditorExportPlatformLinuxBSD::export_project(const Ref<EditorExportPreset>
 
 	return err;
 }
+
+Error EditorExportPlatformLinuxBSD::fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size) const {
+	// Patch the header of the "pck" section in the ELF file so that it corresponds to the embedded data
+
+	FileAccess *f = FileAccess::open(p_path, FileAccess::READ_WRITE);
+	if (!f) {
+		return ERR_CANT_OPEN;
+	}
+
+	// Read and check ELF magic number
+	{
+		uint32_t magic = f->get_32();
+		if (magic != 0x464c457f) { // 0x7F + "ELF"
+			f->close();
+			return ERR_FILE_CORRUPT;
+		}
+	}
+
+	// Read program architecture bits from class field
+
+	int bits = f->get_8() * 32;
+
+	if (bits == 32 && p_embedded_size >= 0x100000000) {
+		f->close();
+		ERR_FAIL_V_MSG(ERR_INVALID_DATA, "32-bit executables cannot have embedded data >= 4 GiB.");
+	}
+
+	// Get info about the section header table
+
+	int64_t section_table_pos;
+	int64_t section_header_size;
+	if (bits == 32) {
+		section_header_size = 40;
+		f->seek(0x20);
+		section_table_pos = f->get_32();
+		f->seek(0x30);
+	} else { // 64
+		section_header_size = 64;
+		f->seek(0x28);
+		section_table_pos = f->get_64();
+		f->seek(0x3c);
+	}
+	int num_sections = f->get_16();
+	int string_section_idx = f->get_16();
+
+	// Load the strings table
+	uint8_t *strings;
+	{
+		// Jump to the strings section header
+		f->seek(section_table_pos + string_section_idx * section_header_size);
+
+		// Read strings data size and offset
+		int64_t string_data_pos;
+		int64_t string_data_size;
+		if (bits == 32) {
+			f->seek(f->get_position() + 0x10);
+			string_data_pos = f->get_32();
+			string_data_size = f->get_32();
+		} else { // 64
+			f->seek(f->get_position() + 0x18);
+			string_data_pos = f->get_64();
+			string_data_size = f->get_64();
+		}
+
+		// Read strings data
+		f->seek(string_data_pos);
+		strings = (uint8_t *)memalloc(string_data_size);
+		if (!strings) {
+			f->close();
+			return ERR_OUT_OF_MEMORY;
+		}
+		f->get_buffer(strings, string_data_size);
+	}
+
+	// Search for the "pck" section
+
+	bool found = false;
+	for (int i = 0; i < num_sections; ++i) {
+		int64_t section_header_pos = section_table_pos + i * section_header_size;
+		f->seek(section_header_pos);
+
+		uint32_t name_offset = f->get_32();
+		if (strcmp((char *)strings + name_offset, "pck") == 0) {
+			// "pck" section found, let's patch!
+
+			if (bits == 32) {
+				f->seek(section_header_pos + 0x10);
+				f->store_32(p_embedded_start);
+				f->store_32(p_embedded_size);
+			} else { // 64
+				f->seek(section_header_pos + 0x18);
+				f->store_64(p_embedded_start);
+				f->store_64(p_embedded_size);
+			}
+
+			found = true;
+			break;
+		}
+	}
+
+	memfree(strings);
+	f->close();
+
+	return found ? OK : ERR_FILE_CORRUPT;
+}