The new authentication flavor is used only to discover peer support
for RPC-over-TLS.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/auth.h | 1
net/sunrpc/Makefile | 2 -
net/sunrpc/auth.c | 2 -
net/sunrpc/auth_tls.c | 120 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 123 insertions(+), 2 deletions(-)
create mode 100644 net/sunrpc/auth_tls.c
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 3e6ce288a7fc..1f13d923f439 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -144,6 +144,7 @@ struct rpc_credops {
extern const struct rpc_authops authunix_ops;
extern const struct rpc_authops authnull_ops;
+extern const struct rpc_authops authtls_ops;
int __init rpc_init_authunix(void);
int __init rpcauth_init_module(void);
diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile
index 1c8de397d6ad..f89c10fe7e6a 100644
--- a/net/sunrpc/Makefile
+++ b/net/sunrpc/Makefile
@@ -9,7 +9,7 @@ obj-$(CONFIG_SUNRPC_GSS) += auth_gss/
obj-$(CONFIG_SUNRPC_XPRT_RDMA) += xprtrdma/
sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
- auth.o auth_null.o auth_unix.o \
+ auth.o auth_null.o auth_tls.o auth_unix.o \
svc.o svcsock.o svcauth.o svcauth_unix.o \
addr.o rpcb_clnt.o timer.o xdr.o \
sunrpc_syms.o cache.o rpc_pipe.o sysfs.o \
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 682fcd24bf43..91c21a1c7cdc 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -32,7 +32,7 @@ static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
static const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
[RPC_AUTH_NULL] = (const struct rpc_authops __force __rcu *)&authnull_ops,
[RPC_AUTH_UNIX] = (const struct rpc_authops __force __rcu *)&authunix_ops,
- NULL, /* others can be loadable modules */
+ [RPC_AUTH_TLS] = (const struct rpc_authops __force __rcu *)&authtls_ops,
};
static LIST_HEAD(cred_unused);
diff --git a/net/sunrpc/auth_tls.c b/net/sunrpc/auth_tls.c
new file mode 100644
index 000000000000..cf4185f188e9
--- /dev/null
+++ b/net/sunrpc/auth_tls.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, 2022 Oracle. All rights reserved.
+ *
+ * The AUTH_TLS credential is used only to probe a remote peer
+ * for RPC-over-TLS support.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sunrpc/clnt.h>
+
+static const char *starttls_token = "STARTTLS";
+static const size_t starttls_len = 8;
+
+static struct rpc_auth tls_auth;
+static struct rpc_cred tls_cred;
+
+static struct rpc_auth *tls_create(const struct rpc_auth_create_args *args,
+ struct rpc_clnt *clnt)
+{
+ refcount_inc(&tls_auth.au_count);
+ return &tls_auth;
+}
+
+static void tls_destroy(struct rpc_auth *auth)
+{
+}
+
+static struct rpc_cred *tls_lookup_cred(struct rpc_auth *auth,
+ struct auth_cred *acred, int flags)
+{
+ return get_rpccred(&tls_cred);
+}
+
+static void tls_destroy_cred(struct rpc_cred *cred)
+{
+}
+
+static int tls_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
+{
+ return 1;
+}
+
+static int tls_marshal(struct rpc_task *task, struct xdr_stream *xdr)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4 * XDR_UNIT);
+ if (!p)
+ return -EMSGSIZE;
+ /* Credential */
+ *p++ = rpc_auth_tls;
+ *p++ = xdr_zero;
+ /* Verifier */
+ *p++ = rpc_auth_null;
+ *p = xdr_zero;
+ return 0;
+}
+
+static int tls_refresh(struct rpc_task *task)
+{
+ set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
+ return 0;
+}
+
+static int tls_validate(struct rpc_task *task, struct xdr_stream *xdr)
+{
+ __be32 *p;
+ void *str;
+
+ p = xdr_inline_decode(xdr, XDR_UNIT);
+ if (!p)
+ return -EIO;
+ if (*p != rpc_auth_null)
+ return -EIO;
+ if (xdr_stream_decode_opaque_inline(xdr, &str, starttls_len) != starttls_len)
+ return -EIO;
+ if (memcmp(str, starttls_token, starttls_len))
+ return -EIO;
+ return 0;
+}
+
+const struct rpc_authops authtls_ops = {
+ .owner = THIS_MODULE,
+ .au_flavor = RPC_AUTH_TLS,
+ .au_name = "NULL",
+ .create = tls_create,
+ .destroy = tls_destroy,
+ .lookup_cred = tls_lookup_cred,
+};
+
+static struct rpc_auth tls_auth = {
+ .au_cslack = NUL_CALLSLACK,
+ .au_rslack = NUL_REPLYSLACK,
+ .au_verfsize = NUL_REPLYSLACK,
+ .au_ralign = NUL_REPLYSLACK,
+ .au_ops = &authtls_ops,
+ .au_flavor = RPC_AUTH_TLS,
+ .au_count = REFCOUNT_INIT(1),
+};
+
+static const struct rpc_credops tls_credops = {
+ .cr_name = "AUTH_TLS",
+ .crdestroy = tls_destroy_cred,
+ .crmatch = tls_match,
+ .crmarshal = tls_marshal,
+ .crwrap_req = rpcauth_wrap_req_encode,
+ .crrefresh = tls_refresh,
+ .crvalidate = tls_validate,
+ .crunwrap_resp = rpcauth_unwrap_resp_decode,
+};
+
+static struct rpc_cred tls_cred = {
+ .cr_lru = LIST_HEAD_INIT(tls_cred.cr_lru),
+ .cr_auth = &tls_auth,
+ .cr_ops = &tls_credops,
+ .cr_count = REFCOUNT_INIT(2),
+ .cr_flags = 1UL << RPCAUTH_CRED_UPTODATE,
+};
