NFSD/export: Add sign_fh export option

In order to signal that filehandles on this export should be signed, add a
"sign_fh" export option.  Filehandle signing can help the server defend
against certain filehandle guessing attacks.

Setting the "sign_fh" export option sets NFSEXP_SIGN_FH.  In a future patch
NFSD uses this signal to append a MAC onto filehandles for that export.

While we're in here, tidy a few stray expflags to more closely align to the
export flag order.

Link: https://lore.kernel.org/linux-nfs/cover.1772022373.git.bcodding@hammerspace.com
Signed-off-by: Benjamin Coddington <bcodding@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Benjamin Coddington
2026-02-25 07:51:37 -05:00
committed by Chuck Lever
parent 62346217fd
commit a002ad8a9b
2 changed files with 5 additions and 4 deletions

View File

@@ -1362,13 +1362,14 @@ static struct flags {
{ NFSEXP_ASYNC, {"async", "sync"}},
{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
{ NFSEXP_SIGN_FH, {"sign_fh", ""}},
{ NFSEXP_NOHIDE, {"nohide", ""}},
{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
{ NFSEXP_V4ROOT, {"v4root", ""}},
{ NFSEXP_PNFS, {"pnfs", ""}},
{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
{ 0, {"", ""}}
};

View File

@@ -34,7 +34,7 @@
#define NFSEXP_GATHERED_WRITES 0x0020
#define NFSEXP_NOREADDIRPLUS 0x0040
#define NFSEXP_SECURITY_LABEL 0x0080
/* 0x100 currently unused */
#define NFSEXP_SIGN_FH 0x0100
#define NFSEXP_NOHIDE 0x0200
#define NFSEXP_NOSUBTREECHECK 0x0400
#define NFSEXP_NOAUTHNLM 0x0800 /* Don't authenticate NLM requests - just trust */
@@ -55,7 +55,7 @@
#define NFSEXP_PNFS 0x20000
/* All flags that we claim to support. (Note we don't support NOACL.) */
#define NFSEXP_ALLFLAGS 0x3FEFF
#define NFSEXP_ALLFLAGS 0x3FFFF
/* The flags that may vary depending on security flavor: */
#define NFSEXP_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH \