From 199f2128741077087a2ab33889a6868830465033 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Thu, 5 Sep 2024 15:09:46 -0400 Subject: [PATCH] SUNRPC: add svcauth_map_clnt_to_svc_cred_local Add new funtion svcauth_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. Jeff Layton noted: This is where the magic happens. Since we're working in kuid_t/kgid_t, we don't need to worry about further idmapping. Suggested-by: NeilBrown # to approximate unx_marshal() Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust Co-developed-by: Mike Snitzer Signed-off-by: Mike Snitzer Reviewed-by: Chuck Lever Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Anna Schumaker --- include/linux/sunrpc/svcauth.h | 5 +++++ net/sunrpc/svcauth.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/include/linux/sunrpc/svcauth.h b/include/linux/sunrpc/svcauth.h index 63cf6fb26dcc..2e111153f7cd 100644 --- a/include/linux/sunrpc/svcauth.h +++ b/include/linux/sunrpc/svcauth.h @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -157,6 +158,10 @@ extern enum svc_auth_status svc_set_client(struct svc_rqst *rqstp); extern int svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops); extern void svc_auth_unregister(rpc_authflavor_t flavor); +extern void svcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt, + const struct cred *, + struct svc_cred *); + extern struct auth_domain *unix_domain_find(char *name); extern void auth_domain_put(struct auth_domain *item); extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new); diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c index 93d9e949e265..55b4d2874188 100644 --- a/net/sunrpc/svcauth.c +++ b/net/sunrpc/svcauth.c @@ -18,6 +18,7 @@ #include #include #include +#include #include @@ -175,6 +176,33 @@ rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp) } EXPORT_SYMBOL_GPL(svc_auth_flavor); +/** + * svcauth_map_clnt_to_svc_cred_local - maps a generic cred + * to a svc_cred suitable for use in nfsd. + * @clnt: rpc_clnt associated with nfs client + * @cred: generic cred associated with nfs client + * @svc: returned svc_cred that is suitable for use in nfsd + */ +void svcauth_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(svcauth_map_clnt_to_svc_cred_local); + /************************************************** * 'auth_domains' are stored in a hash table indexed by name. * When the last reference to an 'auth_domain' is dropped, -- 2.46.0