On Fri, Aug 23, 2024 at 02:14:05PM -0400, Mike Snitzer wrote:
> From: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>
>
> Add new funtion rpcauth_map_clnt_to_svc_cred_local which maps a
> generic cred to a svc_cred suitable for use in nfsd.
>
> This is needed by the localio code to map nfs client creds to nfs
> server credentials.
>
> Following from net/sunrpc/auth_unix.c:unx_marshal() it is clear that
> ->fsuid and ->fsgid must be used (rather than ->uid and ->gid). In
> addition, these uid and gid must be translated with from_kuid_munged()
> so local client uses correct uid and gid when acting as local server.
>
> Suggested-by: NeilBrown <neilb@xxxxxxx> # to approximate unx_marshal()
> Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Co-developed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> ---
> include/linux/sunrpc/auth.h | 4 ++++
> net/sunrpc/auth.c | 22 ++++++++++++++++++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
> index 61e58327b1aa..4cfb68f511db 100644
> --- a/include/linux/sunrpc/auth.h
> +++ b/include/linux/sunrpc/auth.h
> @@ -11,6 +11,7 @@
> #define _LINUX_SUNRPC_AUTH_H
>
> #include <linux/sunrpc/sched.h>
> +#include <linux/sunrpc/svcauth.h>
> #include <linux/sunrpc/msg_prot.h>
> #include <linux/sunrpc/xdr.h>
>
> @@ -184,6 +185,9 @@ int rpcauth_uptodatecred(struct rpc_task *);
> int rpcauth_init_credcache(struct rpc_auth *);
> void rpcauth_destroy_credcache(struct rpc_auth *);
> void rpcauth_clear_credcache(struct rpc_cred_cache *);
> +void rpcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
> + const struct cred *,
> + struct svc_cred *);
> char * rpcauth_stringify_acceptor(struct rpc_cred *);
>
> static inline
> diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
> index 04534ea537c8..3b6d91b36589 100644
> --- a/net/sunrpc/auth.c
> +++ b/net/sunrpc/auth.c
> @@ -17,6 +17,7 @@
> #include <linux/sunrpc/clnt.h>
> #include <linux/sunrpc/gss_api.h>
> #include <linux/spinlock.h>
> +#include <linux/user_namespace.h>
>
> #include <trace/events/sunrpc.h>
>
> @@ -308,6 +309,27 @@ rpcauth_init_credcache(struct rpc_auth *auth)
> }
> EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
>
rpcauth_map_clnt_to_svc_cred_local() needs a kdoc comment.
Since it is called only from fs/nfsd/localio.c -- should this API
^^^^
reside in net/sunrpc/svcauth.c instead of net/sunrpc/auth.c ?
> +void
> +rpcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
> + const struct cred *cred,
> + struct svc_cred *svc)
> +{
> + struct user_namespace *userns = clnt->cl_cred ?
> + clnt->cl_cred->user_ns : &init_user_ns;
> +
> + memset(svc, 0, sizeof(struct svc_cred));
> +
> + svc->cr_uid = KUIDT_INIT(from_kuid_munged(userns, cred->fsuid));
> + svc->cr_gid = KGIDT_INIT(from_kgid_munged(userns, cred->fsgid));
> + svc->cr_flavor = clnt->cl_auth->au_flavor;
> + if (cred->group_info)
> + svc->cr_group_info = get_group_info(cred->group_info);
> + /* These aren't relevant for local (network is bypassed) */
> + svc->cr_principal = NULL;
> + svc->cr_gss_mech = NULL;
> +}
> +EXPORT_SYMBOL_GPL(rpcauth_map_clnt_to_svc_cred_local);
> +
> char *
> rpcauth_stringify_acceptor(struct rpc_cred *cred)
> {
> --
> 2.44.0
>
--
Chuck Lever
