linux/include/linux/sunrpc/svcauth.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * linux/include/linux/sunrpc/svcauth.h
 *
 * RPC server-side authentication stuff.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
 */

#ifndef _LINUX_SUNRPC_SVCAUTH_H_
#define _LINUX_SUNRPC_SVCAUTH_H_

#include <linux/string.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/gss_api.h>
#include <linux/sunrpc/clnt.h>
#include <linux/hash.h>
#include <linux/stringhash.h>
#include <linux/cred.h>

struct svc_cred { … };

static inline void init_svc_cred(struct svc_cred *cred)
{ … }

static inline void free_svc_cred(struct svc_cred *cred)
{ … }

struct svc_rqst;		/* forward decl */
struct in6_addr;

/* Authentication is done in the context of a domain.
 *
 * Currently, the nfs server uses the auth_domain to stand
 * for the "client" listed in /etc/exports.
 *
 * More generally, a domain might represent a group of clients using
 * a common mechanism for authentication and having a common mapping
 * between local identity (uid) and network identity.  All clients
 * in a domain have similar general access rights.  Each domain can
 * contain multiple principals which will have different specific right
 * based on normal Discretionary Access Control.
 *
 * A domain is created by an authentication flavour module based on name
 * only.  Userspace then fills in detail on demand.
 *
 * In the case of auth_unix and auth_null, the auth_domain is also
 * associated with entries in another cache representing the mapping
 * of ip addresses to the given client.
 */
struct auth_domain { … };

enum svc_auth_status { … };

/*
 * Each authentication flavour registers an auth_ops
 * structure.
 * name is simply the name.
 * flavour gives the auth flavour. It determines where the flavour is registered
 * accept() is given a request and should verify it.
 *   It should inspect the authenticator and verifier, and possibly the data.
 *    If there is a problem with the authentication *authp should be set.
 *    The return value of accept() can indicate:
 *      OK - authorised. client and credential are set in rqstp.
 *           reqbuf points to arguments
 *           resbuf points to good place for results.  verfier
 *             is (probably) already in place.  Certainly space is
 *	       reserved for it.
 *      DROP - simply drop the request. It may have been deferred
 *      CLOSE - like SVC_DROP, but request is definitely lost.
 *		If there is a tcp connection, it should be closed.
 *      GARBAGE - rpc garbage_args error
 *      SYSERR - rpc system_err error
 *      DENIED - authp holds reason for denial.
 *      COMPLETE - the reply is encoded already and ready to be sent; no
 *		further processing is necessary.  (This is used for processing
 *		null procedure calls which are used to set up encryption
 *		contexts.)
 *
 *   accept is passed the proc number so that it can accept NULL rpc requests
 *   even if it cannot authenticate the client (as is sometimes appropriate).
 *
 * release() is given a request after the procedure has been run.
 *  It should sign/encrypt the results if needed
 *
 * domain_release()
 *   This call releases a domain.
 *
 * set_client()
 *   Given a pending request (struct svc_rqst), finds and assigns
 *   an appropriate 'auth_domain' as the client.
 *
 * pseudoflavor()
 *   Returns RPC_AUTH pseudoflavor in use by @rqstp.
 */
struct auth_ops { … };

struct svc_xprt;

extern rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp);
extern int	svc_authorise(struct svc_rqst *rqstp);
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);
extern struct auth_domain *auth_domain_find(char *name);
extern void svcauth_unix_purge(struct net *net);
extern void svcauth_unix_info_release(struct svc_xprt *xpt);
extern enum svc_auth_status svcauth_unix_set_client(struct svc_rqst *rqstp);

extern int unix_gid_cache_create(struct net *net);
extern void unix_gid_cache_destroy(struct net *net);

/*
 * The <stringhash.h> functions are good enough that we don't need to
 * use hash_32() on them; just extracting the high bits is enough.
 */
static inline unsigned long hash_str(char const *name, int bits)
{ … }

static inline unsigned long hash_mem(char const *buf, int length, int bits)
{ … }

#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */