From: Sander Vanheule <sander@svanheule.net>
Date: Sat, 11 Jul 2020 20:58:07 +0000 (+0200)
Subject: firmware-utils/tplink-safeloader: soft-version magic is data length
X-Git-Url: http://git.openwrt.org/?a=commitdiff_plain;h=d583cca9e201f9b62baded2d1b8e75a60109159d;p=project%2Ffirmware-utils.git

firmware-utils/tplink-safeloader: soft-version magic is data length

The soft-version partition actually contains a header and trailing data:
* header: {data length, [zero]}
* data: {version, bcd encoded date, revision}

The data length is currently treated as a magic number, but should
contain the length of the partition data.

This header is also present the following partitions (non-exhaustive):
* string-based soft-version
* support-list

Signed-off-by: Sander Vanheule <sander@svanheule.net>
---

diff --git a/src/tplink-safeloader.c b/src/tplink-safeloader.c
index 501b396..145e808 100644
--- a/src/tplink-safeloader.c
+++ b/src/tplink-safeloader.c
@@ -84,7 +84,7 @@ struct device_info {
 
 /** The content of the soft-version structure */
 struct __attribute__((__packed__)) soft_version {
-	uint32_t magic;
+	uint32_t data_len;
 	uint32_t zero;
 	uint8_t pad1;
 	uint8_t version_major;
@@ -2153,7 +2153,8 @@ static struct image_partition_entry make_soft_version(uint32_t rev) {
 
 	struct tm *tm = gmtime(&t);
 
-	s->magic = htonl(0x0000000c);
+	/* Partition contents size, minus 8 byte header and trailing byte */
+	s->data_len = htonl(entry.size-9);
 	s->zero = 0;
 	s->pad1 = 0xff;