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-rw-r--r--net/sunrpc/auth_unix.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
new file mode 100644
index 000000000..e7df1f782
--- /dev/null
+++ b/net/sunrpc/auth_unix.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/net/sunrpc/auth_unix.c
+ *
+ * UNIX-style authentication; no AUTH_SHORT support
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/mempool.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/user_namespace.h>
+
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY RPCDBG_AUTH
+#endif
+
+static struct rpc_auth unix_auth;
+static const struct rpc_credops unix_credops;
+static mempool_t *unix_pool;
+
+static struct rpc_auth *
+unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+ refcount_inc(&unix_auth.au_count);
+ return &unix_auth;
+}
+
+static void
+unx_destroy(struct rpc_auth *auth)
+{
+}
+
+/*
+ * Lookup AUTH_UNIX creds for current process
+ */
+static struct rpc_cred *
+unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+ struct rpc_cred *ret = mempool_alloc(unix_pool, GFP_NOFS);
+
+ rpcauth_init_cred(ret, acred, auth, &unix_credops);
+ ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
+ return ret;
+}
+
+static void
+unx_free_cred_callback(struct rcu_head *head)
+{
+ struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu);
+
+ put_cred(rpc_cred->cr_cred);
+ mempool_free(rpc_cred, unix_pool);
+}
+
+static void
+unx_destroy_cred(struct rpc_cred *cred)
+{
+ call_rcu(&cred->cr_rcu, unx_free_cred_callback);
+}
+
+/*
+ * Match credentials against current the auth_cred.
+ */
+static int
+unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
+{
+ unsigned int groups = 0;
+ unsigned int i;
+
+ if (cred->cr_cred == acred->cred)
+ return 1;
+
+ if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid))
+ return 0;
+
+ if (acred->cred->group_info != NULL)
+ groups = acred->cred->group_info->ngroups;
+ if (groups > UNX_NGROUPS)
+ groups = UNX_NGROUPS;
+ if (cred->cr_cred->group_info == NULL)
+ return groups == 0;
+ if (groups != cred->cr_cred->group_info->ngroups)
+ return 0;
+
+ for (i = 0; i < groups ; i++)
+ if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i]))
+ return 0;
+ return 1;
+}
+
+/*
+ * Marshal credentials.
+ * Maybe we should keep a cached credential for performance reasons.
+ */
+static int
+unx_marshal(struct rpc_task *task, struct xdr_stream *xdr)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+ __be32 *p, *cred_len, *gidarr_len;
+ int i;
+ struct group_info *gi = cred->cr_cred->group_info;
+ struct user_namespace *userns = clnt->cl_cred ?
+ clnt->cl_cred->user_ns : &init_user_ns;
+
+ /* Credential */
+
+ p = xdr_reserve_space(xdr, 3 * sizeof(*p));
+ if (!p)
+ goto marshal_failed;
+ *p++ = rpc_auth_unix;
+ cred_len = p++;
+ *p++ = xdr_zero; /* stamp */
+ if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename,
+ clnt->cl_nodelen) < 0)
+ goto marshal_failed;
+ p = xdr_reserve_space(xdr, 3 * sizeof(*p));
+ if (!p)
+ goto marshal_failed;
+ *p++ = cpu_to_be32(from_kuid_munged(userns, cred->cr_cred->fsuid));
+ *p++ = cpu_to_be32(from_kgid_munged(userns, cred->cr_cred->fsgid));
+
+ gidarr_len = p++;
+ if (gi)
+ for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++)
+ *p++ = cpu_to_be32(from_kgid_munged(userns, gi->gid[i]));
+ *gidarr_len = cpu_to_be32(p - gidarr_len - 1);
+ *cred_len = cpu_to_be32((p - cred_len - 1) << 2);
+ p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2);
+ if (!p)
+ goto marshal_failed;
+
+ /* Verifier */
+
+ p = xdr_reserve_space(xdr, 2 * sizeof(*p));
+ if (!p)
+ goto marshal_failed;
+ *p++ = rpc_auth_null;
+ *p = xdr_zero;
+
+ return 0;
+
+marshal_failed:
+ return -EMSGSIZE;
+}
+
+/*
+ * Refresh credentials. This is a no-op for AUTH_UNIX
+ */
+static int
+unx_refresh(struct rpc_task *task)
+{
+ set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
+ return 0;
+}
+
+static int
+unx_validate(struct rpc_task *task, struct xdr_stream *xdr)
+{
+ struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
+ __be32 *p;
+ u32 size;
+
+ p = xdr_inline_decode(xdr, 2 * sizeof(*p));
+ if (!p)
+ return -EIO;
+ switch (*p++) {
+ case rpc_auth_null:
+ case rpc_auth_unix:
+ case rpc_auth_short:
+ break;
+ default:
+ return -EIO;
+ }
+ size = be32_to_cpup(p);
+ if (size > RPC_MAX_AUTH_SIZE)
+ return -EIO;
+ p = xdr_inline_decode(xdr, size);
+ if (!p)
+ return -EIO;
+
+ auth->au_verfsize = XDR_QUADLEN(size) + 2;
+ auth->au_rslack = XDR_QUADLEN(size) + 2;
+ auth->au_ralign = XDR_QUADLEN(size) + 2;
+ return 0;
+}
+
+int __init rpc_init_authunix(void)
+{
+ unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred));
+ return unix_pool ? 0 : -ENOMEM;
+}
+
+void rpc_destroy_authunix(void)
+{
+ mempool_destroy(unix_pool);
+}
+
+const struct rpc_authops authunix_ops = {
+ .owner = THIS_MODULE,
+ .au_flavor = RPC_AUTH_UNIX,
+ .au_name = "UNIX",
+ .create = unx_create,
+ .destroy = unx_destroy,
+ .lookup_cred = unx_lookup_cred,
+};
+
+static
+struct rpc_auth unix_auth = {
+ .au_cslack = UNX_CALLSLACK,
+ .au_rslack = NUL_REPLYSLACK,
+ .au_verfsize = NUL_REPLYSLACK,
+ .au_ops = &authunix_ops,
+ .au_flavor = RPC_AUTH_UNIX,
+ .au_count = REFCOUNT_INIT(1),
+};
+
+static
+const struct rpc_credops unix_credops = {
+ .cr_name = "AUTH_UNIX",
+ .crdestroy = unx_destroy_cred,
+ .crmatch = unx_match,
+ .crmarshal = unx_marshal,
+ .crwrap_req = rpcauth_wrap_req_encode,
+ .crrefresh = unx_refresh,
+ .crvalidate = unx_validate,
+ .crunwrap_resp = rpcauth_unwrap_resp_decode,
+};