From: Cedric Le Goater <cl...@fr...>
The nvram is in big endian order. The partition length needs to be
byte-swapped when it is read or written on little endian machines.
Signed-off-by: Cedric Le Goater <cl...@fr...>
---
src/nvram.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/src/nvram.c b/src/nvram.c
index 8d567fa..d062c30 100644
--- a/src/nvram.c
+++ b/src/nvram.c
@@ -44,6 +44,8 @@
#include <getopt.h>
#include <inttypes.h>
#include <zlib.h>
+#include <endian.h>
+#include <byteswap.h>
#include "nvram.h"
@@ -407,6 +409,16 @@ parse_of_common(char *data, int data_len, char *outname, char *outval)
return p - data;
}
+static inline unsigned short
+nvram_swap_short(unsigned short length)
+{
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ return bswap_16(length);
+#else
+ return length;
+#endif
+}
+
/**
* nvram_parse_partitions
* @brief fill in the nvram structure with data from nvram
@@ -439,6 +451,7 @@ nvram_parse_partitions(struct nvram *nvram)
c_sum = checksum(phead);
if (c_sum != phead->checksum)
warn_msg("this partition checksum should be %02x!\n", c_sum);
+ phead->length = nvram_swap_short(phead->length);
p_start += phead->length * NVRAM_BLOCK_SIZE;
}
@@ -484,7 +497,8 @@ nvram_find_fd_partition(struct nvram *nvram, char *name)
if (! strncmp(phead.name, name, sizeof(phead.name)))
found = 1;
else {
- int offset = phead.length * NVRAM_BLOCK_SIZE - len;
+ int offset =
+ nvram_swap_short(phead.length) * NVRAM_BLOCK_SIZE - len;
if (lseek(nvram->fd, offset, SEEK_CUR) == -1) {
err_msg("seek error in file %s: %s\n", nvram->filename,
strerror(errno));
@@ -1337,6 +1351,7 @@ update_of_config_var(struct nvram *nvram, char *config_var, char *pname)
/* make sure the new config var will fit into the partition and add it */
new_phead = (struct partition_header *)new_part;
+ new_phead->length = nvram_swap_short(new_phead->length);
new_part_offset = new_part + (data_offset - (char *)phead);
new_part_end = new_part + part_size;
--
1.7.10.4
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