Re: [libvirt] [PATCH v2 06/15] util: Modify the FileTypeInfo to add a version size

On Thu, Jun 23, 2016 at 13:29:02 -0400, John Ferlan wrote: > The version field historically has been a 4 byte data; however, an upcoming > new type will use a 2 byte version. So let's adjust for that now. > > Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; > --- > src/util/virstoragefile.c | 60 +++++++++++++++++++++++++++++------------------ > 1 file changed, 37 insertions(+), 23 deletions(-) > > diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c > index de4955b..37e9798 100644 > --- a/src/util/virstoragefile.c > +++ b/src/util/virstoragefile.c > @@ -1,7 +1,7 @@ > /* > * virstoragefile.c: file utility functions for FS storage backend > * > - * Copyright (C) 2007-2014 Red Hat, Inc. > + * Copyright (C) 2007-2014, 2016 Red Hat, Inc. > * Copyright (C) 2007-2008 Daniel P. Berrange > * > * This library is free software; you can redistribute it and/or > @@ -120,10 +120,12 @@ struct FileTypeInfo { > * to check at head of file */ > const char *extension; /* Optional file extension to check */ > enum lv_endian endian; /* Endianness of file format */ > + > int versionOffset; /* Byte offset from start of file > * where we find version number, > * -1 to always fail the version test, > * -2 to always pass the version test */ > + int versionSize; /* Size in bytes of version data (0, 2, or 4) */ If the size is 0 ... > int versionNumbers[FILE_TYPE_VERSIONS_LAST]; > /* Version numbers to validate. Zeroes are ignored. */ > int sizeOffset; /* Byte offset from start of file [...] > @@ -635,13 +637,25 @@ virStorageFileMatchesVersion(int format, > if (fileTypeInfo[format].versionOffset == -2) > return true;

> > - if ((fileTypeInfo[format].versionOffset + 4) > buflen) > + if ((fileTypeInfo[format].versionOffset + > + fileTypeInfo[format].versionSize) > buflen) > return false; > > - if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN) > - version = virReadBufInt32LE(buf + fileTypeInfo[format].versionOffset); > - else > - version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset); > + if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN) { ... code below shouldn't be executed at all.

> + if (fileTypeInfo[format].versionSize == 4) > + version = virReadBufInt32LE(buf + > + fileTypeInfo[format].versionOffset); > + else > + version = virReadBufInt16LE(buf + > + fileTypeInfo[format].versionOffset); > + } else { > + if (fileTypeInfo[format].versionSize == 4) > + version = virReadBufInt32BE(buf + > + fileTypeInfo[format].versionOffset); > + else > + version = virReadBufInt16BE(buf + > + fileTypeInfo[format].versionOffset); > + } ACK with the change.