image: add executable metadata to tag table entries

src/bin.h

@@ -52,6 +52,12 @@ enum ec3_tag_flags {
 	EC3_TAG_F_NONE = 0x00000000u,
 };
 
+enum ec3_executable_format {
+	EC3_EXEC_NONE = 0x0000u,
+	EC3_EXEC_ELF = 0x0001u,
+	EC3_EXEC_OTHER = 0x1000u,
+};
+
 enum ec3_vnode_mode {
 	EC3_V_REG = 0x0001u,
 	EC3_V_DIR = 0x0002u,
@@ -126,6 +132,27 @@ PACK(struct ec3_cluster_group {
 	uint8_t g_padding[20];
 });
 
+struct ec3_executable {
+	b_i16 exe_format;
+	b_i16 exe_reserved;
+
+	union {
+		struct {
+			b_i32 elf_data_offset;
+			b_i32 elf_data_filesz, elf_data_memsz;
+
+			b_i32 elf_text_offset;
+			b_i32 elf_text_filesz, elf_text_memsz;
+
+			b_i32 elf_data_align, elf_text_align;
+
+			b_i64 elf_data_vaddr;
+			b_i64 elf_text_vaddr;
+			b_i64 elf_entry;
+		} exe_elf;
+	};
+};
+
 struct ec3_tag_table_entry {
 	b_i32 tag_type;
 	b_i32 tag_flags;
@@ -133,6 +160,11 @@ struct ec3_tag_table_entry {
 	b_i32 tag_reserved1;
 	b_i64 tag_ident;
 	b_i64 tag_length;
+
+	union {
+		struct ec3_executable tag_exe;
+		char tag_reserved2[96];
+	};
 };
 
 /* Extents serve two purposes:

src/image.c

@@ -47,6 +47,43 @@ static enum ec3_status decode_header(
 	return EC3_SUCCESS;
 }
 
+static void decode_tag_executable_info(
+	const struct ec3_executable *in,
+	struct ec3_tag_executable_info *out)
+{
+	out->exe_format = b_i16_btoh(in->exe_format);
+
+	switch (out->exe_format) {
+	case EC3_EXEC_ELF:
+		out->exe_elf.elf_data_offset
+			= b_i32_btoh(in->exe_elf.elf_data_offset);
+		out->exe_elf.elf_data_filesz
+			= b_i32_btoh(in->exe_elf.elf_data_filesz);
+		out->exe_elf.elf_data_memsz
+			= b_i32_btoh(in->exe_elf.elf_data_memsz);
+		out->exe_elf.elf_data_align
+			= b_i32_btoh(in->exe_elf.elf_data_align);
+
+		out->exe_elf.elf_text_offset
+			= b_i32_btoh(in->exe_elf.elf_text_offset);
+		out->exe_elf.elf_text_filesz
+			= b_i32_btoh(in->exe_elf.elf_text_filesz);
+		out->exe_elf.elf_text_memsz
+			= b_i32_btoh(in->exe_elf.elf_text_memsz);
+		out->exe_elf.elf_text_align
+			= b_i32_btoh(in->exe_elf.elf_text_align);
+
+		out->exe_elf.elf_data_vaddr
+			= b_i64_btoh(in->exe_elf.elf_data_vaddr);
+		out->exe_elf.elf_text_vaddr
+			= b_i64_btoh(in->exe_elf.elf_text_vaddr);
+		out->exe_elf.elf_entry = b_i64_btoh(in->exe_elf.elf_entry);
+		break;
+	default:
+		break;
+	}
+}
+
 static void decode_tag(
 	const struct ec3_tag_table_entry *in,
 	struct ec3_tag_info *out)
@@ -56,6 +93,10 @@ static void decode_tag(
 	out->tag_checksum = b_i32_btoh(in->tag_checksum);
 	out->tag_ident = b_i64_btoh(in->tag_ident);
 	out->tag_total_length = b_i64_btoh(in->tag_length);
+
+	if (out->tag_type) {
+		decode_tag_executable_info(&in->tag_exe, &out->tag_exe);
+	}
 }
 
 static void decode_extent(
@@ -179,6 +220,12 @@ static enum ec3_status create_ioctx(struct ec3_image_ioctx **out)
 	return EC3_SUCCESS;
 }
 
+static struct ec3_tag_info *image_ioctx_get_tag_info(
+	struct ec3_image_ioctx *image)
+{
+	return b_buffer_ptr(image->io_tag_table);
+}
+
 static enum ec3_status open_image_ro(
 	b_path *image_path,
 	enum ec3_image_ioctx_mode mode,
@@ -430,7 +477,7 @@ enum ec3_status ec3_image_ioctx_close(struct ec3_image_ioctx *image)
 		return status;
 	}
 
-	const struct ec3_tag_info *tags = ec3_image_ioctx_get_tag_info(image);
+	struct ec3_tag_info *tags = image_ioctx_get_tag_info(image);
 	size_t nr_tags = image->io_header.img_nr_tags;
 
 	/* first set of tags to write are those that haven't been opened,
@@ -461,7 +508,7 @@ enum ec3_status ec3_image_ioctx_close(struct ec3_image_ioctx *image)
 	 * read into memory, encoded, and written to the dest image
 	 */
 	for (size_t i = 0; i < nr_tags; i++) {
-		const struct ec3_tag_info *tag = &tags[i];
+		struct ec3_tag_info *tag = &tags[i];
 
 		struct ec3_tag_ioctx *tag_io = get_opened_tag(
 			&image->io_opened_tags,
@@ -478,6 +525,12 @@ enum ec3_status ec3_image_ioctx_close(struct ec3_image_ioctx *image)
 			continue;
 		}
 
+		if (tag->tag_type == EC3_TAG_EXEC) {
+			memcpy(&tag->tag_exe,
+			       &tag_io->io_tag_info.tag_exe,
+			       sizeof tag->tag_exe);
+		}
+
 		status = shadow_image_write_tag(image, tag, tag_io, &shadow);
 		if (status != EC3_SUCCESS) {
 			shadow_image_cancel(&shadow);
@@ -494,7 +547,7 @@ enum ec3_status ec3_image_ioctx_close(struct ec3_image_ioctx *image)
 	 * the tag's cluster table with that of the dest image
 	 */
 	for (size_t i = 0; i < nr_tags; i++) {
-		const struct ec3_tag_info *tag = &tags[i];
+		struct ec3_tag_info *tag = &tags[i];
 
 		struct ec3_tag_ioctx *tag_io = get_opened_tag(
 			&image->io_opened_tags,
@@ -511,6 +564,12 @@ enum ec3_status ec3_image_ioctx_close(struct ec3_image_ioctx *image)
 			continue;
 		}
 
+		if (tag->tag_type == EC3_TAG_EXEC) {
+			memcpy(&tag->tag_exe,
+			       &tag_io->io_tag_info.tag_exe,
+			       sizeof tag->tag_exe);
+		}
+
 		status = shadow_image_write_tag(image, tag, tag_io, &shadow);
 		if (status != EC3_SUCCESS) {
 			shadow_image_cancel(&shadow);
@@ -586,7 +645,7 @@ static const struct ec3_tag_info *get_tag_info_by_id(
 const struct ec3_tag_info *ec3_image_ioctx_get_tag_info(
 	struct ec3_image_ioctx *image)
 {
-	return b_buffer_ptr(image->io_tag_table);
+	return image_ioctx_get_tag_info(image);
 }
 
 const struct ec3_tag_info *ec3_image_ioctx_get_tag_info_by_id(