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-rw-r--r--net/sunrpc/svcauth.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
new file mode 100644
index 0000000000..aa4429d0b8
--- /dev/null
+++ b/net/sunrpc/svcauth.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/net/sunrpc/svcauth.c
+ *
+ * The generic interface for RPC authentication on the server side.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ *
+ * CHANGES
+ * 19-Apr-2000 Chris Evans - Security fix
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/svcauth.h>
+#include <linux/err.h>
+#include <linux/hash.h>
+
+#include <trace/events/sunrpc.h>
+
+#include "sunrpc.h"
+
+#define RPCDBG_FACILITY RPCDBG_AUTH
+
+
+/*
+ * Table of authenticators
+ */
+extern struct auth_ops svcauth_null;
+extern struct auth_ops svcauth_unix;
+extern struct auth_ops svcauth_tls;
+
+static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
+ [RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
+ [RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
+ [RPC_AUTH_TLS] = (struct auth_ops __force __rcu *)&svcauth_tls,
+};
+
+static struct auth_ops *
+svc_get_auth_ops(rpc_authflavor_t flavor)
+{
+ struct auth_ops *aops;
+
+ if (flavor >= RPC_AUTH_MAXFLAVOR)
+ return NULL;
+ rcu_read_lock();
+ aops = rcu_dereference(authtab[flavor]);
+ if (aops != NULL && !try_module_get(aops->owner))
+ aops = NULL;
+ rcu_read_unlock();
+ return aops;
+}
+
+static void
+svc_put_auth_ops(struct auth_ops *aops)
+{
+ module_put(aops->owner);
+}
+
+/**
+ * svc_authenticate - Initialize an outgoing credential
+ * @rqstp: RPC execution context
+ *
+ * Return values:
+ * %SVC_OK: XDR encoding of the result can begin
+ * %SVC_DENIED: Credential or verifier is not valid
+ * %SVC_GARBAGE: Failed to decode credential or verifier
+ * %SVC_COMPLETE: GSS context lifetime event; no further action
+ * %SVC_DROP: Drop this request; no further action
+ * %SVC_CLOSE: Like drop, but also close transport connection
+ */
+enum svc_auth_status svc_authenticate(struct svc_rqst *rqstp)
+{
+ struct auth_ops *aops;
+ u32 flavor;
+
+ rqstp->rq_auth_stat = rpc_auth_ok;
+
+ /*
+ * Decode the Call credential's flavor field. The credential's
+ * body field is decoded in the chosen ->accept method below.
+ */
+ if (xdr_stream_decode_u32(&rqstp->rq_arg_stream, &flavor) < 0)
+ return SVC_GARBAGE;
+
+ aops = svc_get_auth_ops(flavor);
+ if (aops == NULL) {
+ rqstp->rq_auth_stat = rpc_autherr_badcred;
+ return SVC_DENIED;
+ }
+
+ rqstp->rq_auth_slack = 0;
+ init_svc_cred(&rqstp->rq_cred);
+
+ rqstp->rq_authop = aops;
+ return aops->accept(rqstp);
+}
+EXPORT_SYMBOL_GPL(svc_authenticate);
+
+/**
+ * svc_set_client - Assign an appropriate 'auth_domain' as the client
+ * @rqstp: RPC execution context
+ *
+ * Return values:
+ * %SVC_OK: Client was found and assigned
+ * %SVC_DENY: Client was explicitly denied
+ * %SVC_DROP: Ignore this request
+ * %SVC_CLOSE: Ignore this request and close the connection
+ */
+enum svc_auth_status svc_set_client(struct svc_rqst *rqstp)
+{
+ rqstp->rq_client = NULL;
+ return rqstp->rq_authop->set_client(rqstp);
+}
+EXPORT_SYMBOL_GPL(svc_set_client);
+
+/**
+ * svc_authorise - Finalize credentials/verifier and release resources
+ * @rqstp: RPC execution context
+ *
+ * Returns zero on success, or a negative errno.
+ */
+int svc_authorise(struct svc_rqst *rqstp)
+{
+ struct auth_ops *aops = rqstp->rq_authop;
+ int rv = 0;
+
+ rqstp->rq_authop = NULL;
+
+ if (aops) {
+ rv = aops->release(rqstp);
+ svc_put_auth_ops(aops);
+ }
+ return rv;
+}
+
+int
+svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
+{
+ struct auth_ops *old;
+ int rv = -EINVAL;
+
+ if (flavor < RPC_AUTH_MAXFLAVOR) {
+ old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
+ if (old == NULL || old == aops)
+ rv = 0;
+ }
+ return rv;
+}
+EXPORT_SYMBOL_GPL(svc_auth_register);
+
+void
+svc_auth_unregister(rpc_authflavor_t flavor)
+{
+ if (flavor < RPC_AUTH_MAXFLAVOR)
+ rcu_assign_pointer(authtab[flavor], NULL);
+}
+EXPORT_SYMBOL_GPL(svc_auth_unregister);
+
+/**************************************************
+ * 'auth_domains' are stored in a hash table indexed by name.
+ * When the last reference to an 'auth_domain' is dropped,
+ * the object is unhashed and freed.
+ * If auth_domain_lookup fails to find an entry, it will return
+ * it's second argument 'new'. If this is non-null, it will
+ * have been atomically linked into the table.
+ */
+
+#define DN_HASHBITS 6
+#define DN_HASHMAX (1<<DN_HASHBITS)
+
+static struct hlist_head auth_domain_table[DN_HASHMAX];
+static DEFINE_SPINLOCK(auth_domain_lock);
+
+static void auth_domain_release(struct kref *kref)
+ __releases(&auth_domain_lock)
+{
+ struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
+
+ hlist_del_rcu(&dom->hash);
+ dom->flavour->domain_release(dom);
+ spin_unlock(&auth_domain_lock);
+}
+
+void auth_domain_put(struct auth_domain *dom)
+{
+ kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
+}
+EXPORT_SYMBOL_GPL(auth_domain_put);
+
+struct auth_domain *
+auth_domain_lookup(char *name, struct auth_domain *new)
+{
+ struct auth_domain *hp;
+ struct hlist_head *head;
+
+ head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+ spin_lock(&auth_domain_lock);
+
+ hlist_for_each_entry(hp, head, hash) {
+ if (strcmp(hp->name, name)==0) {
+ kref_get(&hp->ref);
+ spin_unlock(&auth_domain_lock);
+ return hp;
+ }
+ }
+ if (new)
+ hlist_add_head_rcu(&new->hash, head);
+ spin_unlock(&auth_domain_lock);
+ return new;
+}
+EXPORT_SYMBOL_GPL(auth_domain_lookup);
+
+struct auth_domain *auth_domain_find(char *name)
+{
+ struct auth_domain *hp;
+ struct hlist_head *head;
+
+ head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(hp, head, hash) {
+ if (strcmp(hp->name, name)==0) {
+ if (!kref_get_unless_zero(&hp->ref))
+ hp = NULL;
+ rcu_read_unlock();
+ return hp;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(auth_domain_find);
+
+/**
+ * auth_domain_cleanup - check that the auth_domain table is empty
+ *
+ * On module unload the auth_domain_table must be empty. To make it
+ * easier to catch bugs which don't clean up domains properly, we
+ * warn if anything remains in the table at cleanup time.
+ *
+ * Note that we cannot proactively remove the domains at this stage.
+ * The ->release() function might be in a module that has already been
+ * unloaded.
+ */
+
+void auth_domain_cleanup(void)
+{
+ int h;
+ struct auth_domain *hp;
+
+ for (h = 0; h < DN_HASHMAX; h++)
+ hlist_for_each_entry(hp, &auth_domain_table[h], hash)
+ pr_warn("svc: domain %s still present at module unload.\n",
+ hp->name);
+}