| // 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> |
| |
| #define RPCDBG_FACILITY RPCDBG_AUTH |
| |
| |
| /* |
| * Table of authenticators |
| */ |
| extern struct auth_ops svcauth_null; |
| extern struct auth_ops svcauth_unix; |
| |
| 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, |
| }; |
| |
| 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); |
| } |
| |
| int |
| svc_authenticate(struct svc_rqst *rqstp, __be32 *authp) |
| { |
| rpc_authflavor_t flavor; |
| struct auth_ops *aops; |
| |
| *authp = rpc_auth_ok; |
| |
| flavor = svc_getnl(&rqstp->rq_arg.head[0]); |
| |
| dprintk("svc: svc_authenticate (%d)\n", flavor); |
| |
| aops = svc_get_auth_ops(flavor); |
| if (aops == NULL) { |
| *authp = 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, authp); |
| } |
| EXPORT_SYMBOL_GPL(svc_authenticate); |
| |
| int svc_set_client(struct svc_rqst *rqstp) |
| { |
| rqstp->rq_client = NULL; |
| return rqstp->rq_authop->set_client(rqstp); |
| } |
| EXPORT_SYMBOL_GPL(svc_set_client); |
| |
| /* A request, which was authenticated, has now executed. |
| * Time to finalise the credentials and verifier |
| * and release and resources |
| */ |
| 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); |