ekanalyzer frushow: Fix internal area size calc

When there was no chassis and board areas, the internal use
are size was calculated incorrectly.

Additionally, it is possible that the internal area is actually
located after all other areas or that areas are arranged in
a different order than their offsets in the header. All those
cases weren't properly handled.

Now that is fixed.

Signed-off-by: Alexander Amelkin <alexander@amelkin.msk.ru>

1 files changed, 42 insertions, 6 deletions

diff --git a/lib/ipmi_ekanalyzer.c b/lib/ipmi_ekanalyzer.c
index be6b671..8a3e5a5 100644
--- a/lib/ipmi_ekanalyzer.c
+++ b/lib/ipmi_ekanalyzer.c
@@ -43,6 +43,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <fcntl.h>
+#include <sys/stat.h>
 
 #define NO_MORE_INFO_FIELD         0xc1
 #define TYPE_CODE 0xc0 /*Language code*/
@@ -2443,6 +2445,8 @@ ipmi_ek_display_fru_header_detail(char *filename)
 	if (header.offset.internal != 0) {
 		unsigned char format_version;
 		unsigned long len = 0;
+		uint8_t *area_offset;
+		uint8_t next_offset = UINT8_MAX;
 
 		printf("%s\n", EQUAL_LINE_LIMITER);
 		printf("FRU Internal Use Info\n");
@@ -2456,12 +2460,44 @@ ipmi_ek_display_fru_header_detail(char *filename)
 		}
 		printf("Format Version: %d\n", (format_version & 0x0f));
 
-		if (header.offset.chassis > 0) {
-			len = (header.offset.chassis * FACTOR_OFFSET)
-				- (header.offset.internal * FACTOR_OFFSET);
-		} else {
-			len = (header.offset.board * FACTOR_OFFSET)
-				- (header.offset.internal * FACTOR_OFFSET);
+		/* Internal use area doesn't contain the size byte.
+		 * We need to calculate its size by finding the area
+		 * that is next. Areas may not follow the same order
+		 * as their offsets listed in the header, so we need
+		 * to find the area that is physically next to the
+		 * internal use area.
+		 */
+		for (area_offset = &header.offset.internal + 1;
+			 area_offset <= &header.offset.multi;
+			 ++area_offset)
+		{
+			/* If the area is closer to us than the previously
+			 * checked one, make it our best candidate
+			 */
+			if (*area_offset < next_offset
+				&& *area_offset > header.offset.internal)
+			{
+				next_offset = *area_offset;
+			}
+		}
+
+		/* If there was at least one area after internal use one,
+		 * then we must have found it and can use it to calculate
+		 * length. Otherwise, everything till the end of file is
+		 * internal use area expect for the last (checksum) byte.
+		 */
+		if (next_offset < UINT8_MAX) {
+			len = (next_offset - header.offset.internal) * FACTOR_OFFSET;
+		}
+		else {
+			struct stat fs;
+			long curpos = ftell(input_file);
+			if (curpos < 0 || 0 > fstat(fileno(input_file), &fs)) {
+				lprintf(LOG_ERR, "Failed to determine FRU file size");
+				fclose(input_file);
+				return -1;
+			}
+			len = fs.st_size - curpos - 1; /* Last byte is checksum */
 		}
 		printf("Length: %ld\n", len);
 		printf("Data dump:\n");