[syslinux:lwip] implement fat_check_sb_fields()

[syslinux-bot for Paulo Alcantara]

Commit-ID:  4d086951a915d3e6faabbff0bd5214444a405658
Gitweb:     http://syslinux.zytor.com/commit/4d086951a915d3e6faabbff0bd5214444a405658
Author:     Paulo Alcantara <pcacjr at gmail.com>
AuthorDate: Tue, 5 Jul 2011 22:08:04 +0000
Committer:  Paulo Alcantara <pcacjr at gmail.com>
CommitDate: Tue, 5 Jul 2011 22:08:04 +0000

implement fat_check_sb_fields()

Sanity check for FAT volumes

Signed-off-by: Paulo Alcantara <pcacjr at gmail.com>


---
 libinstaller/syslxint.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/libinstaller/syslxint.h b/libinstaller/syslxint.h
index 80c40f7..7c9da51 100644
--- a/libinstaller/syslxint.h
+++ b/libinstaller/syslxint.h
@@ -247,4 +247,13 @@ struct boot_sector {
 #define bsCodeLen   (offsetof(struct boot_sector, bsSignature) - \
 		     offsetof(struct boot_sector, bsCode))
 
+static inline int fat_check_sb_fields(const struct boot_sector *sb)
+{
+    return sb->bsResSectors && sb->bsFATs &&
+            (!memcmp(sb->bs16.FileSysType, "FAT12   ", 8) ||
+             !memcmp(sb->bs16.FileSysType, "FAT16   ", 8) ||
+             !memcmp(sb->bs16.FileSysType, "FAT     ", 8) ||
+             !memcmp(sb->bs32.FileSysType, "FAT32   ", 8));
+}
+
 #endif /* SYSLXINT_H */