Refactor decoder functions

Author: Matsievskiy S.V

CMakeLists.txt

@@ -53,8 +53,8 @@ endfunction()
 
 add_executable(frugen frugen.c)
 add_executable(frugen-static frugen.c)
-add_library(fru-static STATIC fru.c fru_reader.c)
-add_library(fru-shared SHARED fru.c fru_reader.c)
+add_library(fru-static STATIC fru.c)
+add_library(fru-shared SHARED fru.c)
 find_library(JSON_LIB json-c)
 SET_TARGET_PROPERTIES(fru-static PROPERTIES OUTPUT_NAME fru CLEAN_DIRECT_OUTPUT 1)
 SET_TARGET_PROPERTIES(fru-shared PROPERTIES OUTPUT_NAME fru CLEAN_DIRECT_OUTPUT 1)

fatal.h

@@ -404,17 +404,9 @@ fru_field_t * fru_encode_data(int len, const uint8_t *data)
 	return out;
 }
 
-/**
- * Decode data from a buffer into another buffer.
- *
- * For binary data use FRU_FIELDDATALEN(field->typelen) to find
- * out the size of valid bytes in the returned buffer.
- *
- * Return false if there were errors during decoding and true otherwise.
- */
 bool fru_decode_data(fru_field_t *field,
-                     typed_field_t *out, //< [out] buffer to decode into
-                     size_t out_len) // <[in] length of output buffer
+                     typed_field_t *out,
+                     size_t out_len)
 {
 	if (!field) return false;
 
@@ -1225,6 +1217,57 @@ fru_t * fru_create(fru_area_t area[FRU_MAX_AREAS], size_t *size)
 	return out;
 }
 
+fru_t *find_fru_header(uint8_t *buffer, size_t size) {
+	if (size < 8) {
+		errno = ENOBUFS;
+		return NULL;
+	}
+	fru_t *header = (fru_t *) buffer;
+	if ((header->ver != FRU_VER_1) || (header->rsvd != 0) || (header->pad != 0)) {
+		errno = EPROTO;
+		return NULL;
+	}
+	if (header->hchecksum != calc_checksum(header, sizeof(fru_t) - 1)) {
+		errno = EPROTO;
+		return NULL;
+	}
+	return header;
+}
+
+#define AREAS \
+	X(chassis) \
+	X(board) \
+	X(product)
+#define X(AREA)                                                                    \
+fru_##AREA##_area_t *find_fru_##AREA##_area(uint8_t *buffer, size_t size) {        \
+	fru_t *header = find_fru_header(buffer, size);                             \
+	if ((header == NULL) || (header->AREA == 0)) {                             \
+		return NULL;                                                       \
+	}                                                                          \
+	if ((header->AREA + 3) > size) {                                           \
+		errno = ENOBUFS;                                                   \
+		return NULL;                                                       \
+	}                                                                          \
+	fru_##AREA##_area_t *area =                                                \
+	    (fru_##AREA##_area_t *)(buffer + FRU_BYTES(header->AREA));             \
+	if (area->ver != 1) {                                                      \
+		errno = EPROTO;                                                    \
+		return NULL;                                                       \
+	}                                                                          \
+	if (FRU_BYTES(header->AREA) + FRU_BYTES(area->blocks) > size) {            \
+		errno = ENOBUFS;                                                   \
+		return NULL;                                                       \
+	}                                                                          \
+	if (*(((uint8_t *)area) + FRU_BYTES(area->blocks) - 1) !=                  \
+	    calc_checksum(((uint8_t *)area), FRU_BYTES(area->blocks) - 1)) {       \
+		errno = EPROTO;                                                    \
+		return NULL;                                                       \
+	}                                                                          \
+	return area;                                                               \
+}
+AREAS
+#undef X
+#undef AREAS
 
 #ifdef __STANDALONE__
 

fru.c

@@ -327,13 +327,93 @@ fru_mr_reclist_t * add_mr_reclist(fru_mr_reclist_t **reclist);
 fru_mr_area_t * fru_mr_area(fru_mr_reclist_t *reclist, size_t *total);
 
 fru_chassis_area_t * fru_encode_chassis_info(const fru_exploded_chassis_t *chassis);
-bool fru_decode_chassis_info(const fru_chassis_area_t *area, fru_exploded_chassis_t *chassis_out);
 fru_board_area_t * fru_encode_board_info(const fru_exploded_board_t *board);
-bool fru_decode_board_info(const fru_board_area_t *area, fru_exploded_board_t *board_out);
 fru_product_area_t * fru_encode_product_info(const fru_exploded_product_t *product);
-bool fru_decode_product_info(const fru_product_area_t *area, fru_exploded_product_t *product_out);
 fru_field_t * fru_encode_data(int len, const uint8_t *data);
-bool fru_decode_data(fru_field_t *field, typed_field_t *out, size_t out_len);
 fru_t * fru_create(fru_area_t area[FRU_MAX_AREAS], size_t *size);
 
+/**
+ * @brief Find and validate FRU header in the byte buffer.
+ *
+ * @param[in] buffer Byte buffer.
+ * @param[in] size Byte buffer size.
+ * @return Pointer to the FRU header in the buffer.
+ * @retval NULL FRU header not found.
+ */
+fru_t *find_fru_header(uint8_t *buffer, size_t size);
+
+/**
+ * @brief Find and validate FRU chassis area in the byte buffer.
+ *
+ * @param[in] buffer Byte buffer.
+ * @param[in] size Byte buffer size.
+ * @return Pointer to the FRU chassis area in the buffer.
+ * @retval NULL FRU chassis area not found.
+ */
+fru_chassis_area_t *find_fru_chassis_area(uint8_t *buffer, size_t size);
+
+/**
+ * @brief Find and validate FRU board area in the byte buffer.
+ *
+ * @param[in] buffer Byte buffer.
+ * @param[in] size Byte buffer size.
+ * @return Pointer to the FRU board area in the buffer.
+ * @retval NULL FRU board area not found.
+ */
+fru_board_area_t *find_fru_board_area(uint8_t *buffer, size_t size);
+
+/**
+ * @brief Find and validate FRU product area in the byte buffer.
+ *
+ * @param[in] buffer Byte buffer.
+ * @param[in] size Byte buffer size.
+ * @return Pointer to the FRU product area in the buffer.
+ * @retval NULL FRU product area not found.
+ */
+fru_product_area_t *find_fru_product_area(uint8_t *buffer, size_t size);
+
+/**
+ * @brief Decode chassis area into \p fru_exploded_chassis_t.
+ *
+ * @param[in] area Encoded area.
+ * @param[out] chassis_out Decoded structure.
+ * @retval true Success.
+ * @retval false Failure.
+ */
+bool fru_decode_chassis_info(const fru_chassis_area_t *area, fru_exploded_chassis_t *chassis_out);
+
+/**
+ * @brief Decode board area into \p fru_exploded_board_t.
+ *
+ * @param[in] area Encoded area.
+ * @param[out] chassis_out Decoded structure.
+ * @retval true Success.
+ * @retval false Failure.
+ */
+bool fru_decode_board_info(const fru_board_area_t *area, fru_exploded_board_t *board_out);
+
+/**
+ * @brief Decode product area into \p fru_product_board_t.
+ *
+ * @param[in] area Encoded area.
+ * @param[out] chassis_out Decoded structure.
+ * @retval true Success.
+ * @retval false Failure.
+ */
+bool fru_decode_product_info(const fru_product_area_t *area, fru_exploded_product_t *product_out);
+
+/**
+ * Decode data from a buffer into another buffer.
+ *
+ * For binary data use FRU_FIELDDATALEN(field->typelen) to find
+ * out the size of valid bytes in the returned buffer.
+ *
+ * @param[in] field Encoded data field.
+ * @param[out] out Decoded field.
+ * @param[in] out_len Size of the decoded field region.
+ * @retval true Success.
+ * @retval false Failure.
+ */
+bool fru_decode_data(fru_field_t *field, typed_field_t *out, size_t out_len);
+
 #endif // __FRULIB_FRU_H__

fru.h

@@ -9,6 +9,7 @@
 #endif
 
 #define COPYRIGHT_YEARS "2016-2021"
+#define MAX_FILE_SIZE 1L * 1024L * 1024L
 
 #define _GNU_SOURCE
 #include <getopt.h>
@@ -23,14 +24,18 @@
 #include <time.h>
 #include <errno.h>
 #include "fru.h"
-#include "fru_reader.h"
 #include "smbios.h"
-#include "fatal.h"
 
 #ifdef __HAS_JSON__
 #include <json-c/json.h>
 #endif
 
+#define fatal(fmt, args...) do {  \
+	fprintf(stderr, fmt, ##args); \
+	fprintf(stderr, "\n");        \
+	exit(1);                      \
+} while(0)
+
 const char* type_names[] = {
 	"auto",
 	"binary",
@@ -749,54 +754,48 @@ int main(int argc, char *argv[])
 						fatal("Failed to open file: %s", strerror(errno));
 					}
 
-					fru_t *raw_fru = read_fru_header(fd);
-					if (!raw_fru)
-						fatal("Failed to read fru header");
+					struct stat statbuf = {0};
+					if (fstat(fd, &statbuf)) {
+						fatal("Failed to get file properties: %s", strerror(errno));
+					}
+					if (statbuf.st_size > MAX_FILE_SIZE) {
+						fatal("File too large");
+					}
 
-					if (raw_fru->chassis != 0) {
-						if (lseek(fd, 8 * raw_fru->chassis, SEEK_SET) < 0)
-							fatal("Failed to seek");
+					uint8_t *buffer = calloc(1, statbuf.st_size);
+					if (buffer == NULL) {
+						fatal("Cannot allocate buffer");
+					}
 
-						fru_chassis_area_t *chassis_raw =
-							read_fru_chassis_area(fd);
-						bool success = fru_decode_chassis_info(
-							chassis_raw, &chassis);
-						if (!success)
-							fatal("Failed to decode chassis");
+					if (read(fd, buffer, statbuf.st_size) != statbuf.st_size) {
+						fatal("Cannot read file");
+					}
+					close(fd);
 
-						free(chassis_raw);
+					fru_chassis_area_t *chassis_area =
+						find_fru_chassis_area(buffer, statbuf.st_size);
+					if (chassis_area) {
+						if (!fru_decode_chassis_info(chassis_area, &chassis))
+							fatal("Failed to decode chassis");
 						has_chassis = true;
 					}
-					if (raw_fru->board != 0) {
-						if(lseek(fd, 8 * raw_fru->board, SEEK_SET) < 0)
-							fatal("Failed to seek");
-
-						fru_board_area_t *board_raw = read_fru_board_area(fd);
-						bool success = fru_decode_board_info(board_raw, &board);
-						if (!success)
+					fru_board_area_t *board_area =
+						find_fru_board_area(buffer, statbuf.st_size);
+					if (board_area) {
+						if (!fru_decode_board_info(board_area, &board))
 							fatal("Failed to decode board");
-
-						free(board_raw);
 						has_board = true;
-						has_bdate = true;
 					}
-					if (raw_fru->product != 0) {
-						if (lseek(fd, 8 * raw_fru->product, SEEK_SET) < 0)
-							fatal("Failed to seek");
-
-						fru_product_area_t *product_raw =
-							read_fru_product_area(fd);
-						bool success =
-							fru_decode_product_info(product_raw, &product);
-						if (!success)
-							fatal("Failed to decode product");
 
-						free(product_raw);
+					fru_product_area_t *product_area =
+						find_fru_product_area(buffer, statbuf.st_size);
+					if (product_area) {
+						if (!fru_decode_product_info(product_area, &product))
+							fatal("Failed to decode product");
 						has_product = true;
 					}
 
-					free(raw_fru);
-					close(fd);
+					free(buffer);
 				}
 				else {
 					fatal("The requested input file format is not supported");