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mtd: fix reading of image magic bytes in smaller chunks

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The image_check currently fails when it cannot read all magic bytes in a
single chunk. But this can happen when the data are read from a pipe. This
currently breaks the openmesh.sh upgrade script with musl because it uses
dd with a blocksize of 1 to copy the image file to the mtd process.

The read can simply be repeated until enough bytes are read for the magic
byte check. It only stops when either an error was returned or 0 bytes were
read.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>

SVN-Revision: 48891
This commit is contained in:
John Crispin 2016-03-03 20:24:38 +00:00
parent 8fb8b78bb2
commit 4a4c324cd2
1 changed files with 12 additions and 5 deletions
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17
package/system/mtd/src/mtd.c
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@ -179,14 +179,21 @@ image_check(int imagefd, const char *mtd)
{
uint32_t magic;
int ret = 1;
int bufread;
while (buflen < sizeof(magic)) {
bufread = read(imagefd, buf + buflen, sizeof(magic) - buflen);
if (bufread < 1)
break;
buflen += bufread;
}
if (buflen < sizeof(magic)) {
buflen += read(imagefd, buf + buflen, sizeof(magic) - buflen);
if (buflen < sizeof(magic)) {
fprintf(stdout, "Could not get image magic\n");
return 0;
}
fprintf(stdout, "Could not get image magic\n");
return 0;
}
magic = ((uint32_t *)buf)[0];
if (be32_to_cpu(magic) == TRX_MAGIC)