[PATCH 08/23] SUNRPC: remove machine_cred field from struct auth_cred

From: NeilBrown
Date: Tue Nov 06 2018 - 23:14:25 EST


The cred is a machine_cred iff ->principal is set, so there is no
need for the extra flag.

There is one case which deserves some
explanation. nfs4_root_machine_cred() calls rpc_lookup_machine_cred()
with a NULL principal name which results in not getting a machine
credential, but getting a root credential instead.
This appears to be what is expected of the caller, and is
clearly the result provided by both auth_unix and auth_gss
which already ignore the flag.

Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
include/linux/sunrpc/auth.h | 3 +--
net/sunrpc/auth_generic.c | 12 ++++++------
net/sunrpc/auth_gss/auth_gss.c | 5 +----
3 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 831ea65bd9f4..1c0468f39479 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -46,9 +46,8 @@ enum {

struct auth_cred {
const struct cred *cred;
- const char *principal;
+ const char *principal; /* If present, this is a machine credential */
unsigned long ac_flags;
- unsigned char machine_cred : 1;
};

/*
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index b9481f69ce7b..810d535c79b8 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -50,12 +50,13 @@ EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);

/*
* Public call interface for looking up machine creds.
+ * Note that if service_name is NULL, we actually look up
+ * "root" credential.
*/
struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
{
struct auth_cred acred = {
.principal = service_name,
- .machine_cred = 1,
.cred = get_task_cred(&init_task),
};
struct rpc_cred *ret;
@@ -108,11 +109,10 @@ generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, g

gcred->acred.cred = gcred->gc_base.cr_cred;
gcred->acred.ac_flags = 0;
- gcred->acred.machine_cred = acred->machine_cred;
gcred->acred.principal = acred->principal;

dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
- gcred->acred.machine_cred ? "machine" : "generic",
+ gcred->acred.principal ? "machine" : "generic",
gcred,
from_kuid(&init_user_ns, acred->cred->fsuid),
from_kgid(&init_user_ns, acred->cred->fsgid));
@@ -145,7 +145,7 @@ generic_destroy_cred(struct rpc_cred *cred)
static int
machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags)
{
- if (!gcred->acred.machine_cred ||
+ if (!gcred->acred.principal ||
gcred->acred.principal != acred->principal ||
!uid_eq(gcred->acred.cred->fsuid, acred->cred->fsuid) ||
!gid_eq(gcred->acred.cred->fsgid, acred->cred->fsgid))
@@ -163,12 +163,12 @@ generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
int i;
struct group_info *a, *g;

- if (acred->machine_cred)
+ if (acred->principal)
return machine_cred_match(acred, gcred, flags);

if (!uid_eq(gcred->acred.cred->fsuid, acred->cred->fsuid) ||
!gid_eq(gcred->acred.cred->fsgid, acred->cred->fsgid) ||
- gcred->acred.machine_cred != 0)
+ gcred->acred.principal != NULL)
goto out_nomatch;

a = acred->cred->group_info;
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 2501ac3cbdf4..feea8e65797c 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1372,9 +1372,7 @@ gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t
*/
cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
cred->gc_service = gss_auth->service;
- cred->gc_principal = NULL;
- if (acred->machine_cred)
- cred->gc_principal = acred->principal;
+ cred->gc_principal = acred->principal;
kref_get(&gss_auth->kref);
return &cred->gc_base;

@@ -1587,7 +1585,6 @@ static int gss_renew_cred(struct rpc_task *task)
struct auth_cred acred = {
.cred = oldcred->cr_cred,
.principal = gss_cred->gc_principal,
- .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
};
struct rpc_cred *new;