LXR linux/include/linux/sunrpc/svcauth.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * linux/include/linux/sunrpc/svcauth.h
   4 *
   5 * RPC server-side authentication stuff.
   6 *
   7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8 */
   9
  10#ifndef _LINUX_SUNRPC_SVCAUTH_H_
  11#define _LINUX_SUNRPC_SVCAUTH_H_
  12
  13#include <linux/string.h>
  14#include <linux/sunrpc/msg_prot.h>
  15#include <linux/sunrpc/cache.h>
  16#include <linux/sunrpc/gss_api.h>
  17#include <linux/hash.h>
  18#include <linux/stringhash.h>
  19#include <linux/cred.h>
  20
  21struct svc_cred {
  22        kuid_t                  cr_uid;
  23        kgid_t                  cr_gid;
  24        struct group_info       *cr_group_info;
  25        u32                     cr_flavor; /* pseudoflavor */
  26        /* name of form servicetype/hostname@REALM, passed down by
  27         * gss-proxy: */
  28        char                    *cr_raw_principal;
  29        /* name of form servicetype@hostname, passed down by
  30         * rpc.svcgssd, or computed from the above: */
  31        char                    *cr_principal;
  32        char                    *cr_targ_princ;
  33        struct gss_api_mech     *cr_gss_mech;
  34};
  35
  36static inline void init_svc_cred(struct svc_cred *cred)
  37{
  38        cred->cr_group_info = NULL;
  39        cred->cr_raw_principal = NULL;
  40        cred->cr_principal = NULL;
  41        cred->cr_targ_princ = NULL;
  42        cred->cr_gss_mech = NULL;
  43}
  44
  45static inline void free_svc_cred(struct svc_cred *cred)
  46{
  47        if (cred->cr_group_info)
  48                put_group_info(cred->cr_group_info);
  49        kfree(cred->cr_raw_principal);
  50        kfree(cred->cr_principal);
  51        kfree(cred->cr_targ_princ);
  52        gss_mech_put(cred->cr_gss_mech);
  53        init_svc_cred(cred);
  54}
  55
  56struct svc_rqst;                /* forward decl */
  57struct in6_addr;
  58
  59/* Authentication is done in the context of a domain.
  60 *
  61 * Currently, the nfs server uses the auth_domain to stand
  62 * for the "client" listed in /etc/exports.
  63 *
  64 * More generally, a domain might represent a group of clients using
  65 * a common mechanism for authentication and having a common mapping
  66 * between local identity (uid) and network identity.  All clients
  67 * in a domain have similar general access rights.  Each domain can
  68 * contain multiple principals which will have different specific right
  69 * based on normal Discretionary Access Control.
  70 *
  71 * A domain is created by an authentication flavour module based on name
  72 * only.  Userspace then fills in detail on demand.
  73 *
  74 * In the case of auth_unix and auth_null, the auth_domain is also
  75 * associated with entries in another cache representing the mapping
  76 * of ip addresses to the given client.
  77 */
  78struct auth_domain {
  79        struct kref             ref;
  80        struct hlist_node       hash;
  81        char                    *name;
  82        struct auth_ops         *flavour;
  83        struct rcu_head         rcu_head;
  84};
  85
  86/*
  87 * Each authentication flavour registers an auth_ops
  88 * structure.
  89 * name is simply the name.
  90 * flavour gives the auth flavour. It determines where the flavour is registered
  91 * accept() is given a request and should verify it.
  92 *   It should inspect the authenticator and verifier, and possibly the data.
  93 *    If there is a problem with the authentication *authp should be set.
  94 *    The return value of accept() can indicate:
  95 *      OK - authorised. client and credential are set in rqstp.
  96 *           reqbuf points to arguments
  97 *           resbuf points to good place for results.  verfier
  98 *             is (probably) already in place.  Certainly space is
  99 *             reserved for it.
 100 *      DROP - simply drop the request. It may have been deferred
 101 *      GARBAGE - rpc garbage_args error
 102 *      SYSERR - rpc system_err error
 103 *      DENIED - authp holds reason for denial.
 104 *      COMPLETE - the reply is encoded already and ready to be sent; no
 105 *              further processing is necessary.  (This is used for processing
 106 *              null procedure calls which are used to set up encryption
 107 *              contexts.)
 108 *
 109 *   accept is passed the proc number so that it can accept NULL rpc requests
 110 *   even if it cannot authenticate the client (as is sometimes appropriate).
 111 *
 112 * release() is given a request after the procedure has been run.
 113 *  It should sign/encrypt the results if needed
 114 * It should return:
 115 *    OK - the resbuf is ready to be sent
 116 *    DROP - the reply should be quitely dropped
 117 *    DENIED - authp holds a reason for MSG_DENIED
 118 *    SYSERR - rpc system_err
 119 *
 120 * domain_release()
 121 *   This call releases a domain.
 122 * set_client()
 123 *   Givens a pending request (struct svc_rqst), finds and assigns
 124 *   an appropriate 'auth_domain' as the client.
 125 */
 126struct auth_ops {
 127        char *  name;
 128        struct module *owner;
 129        int     flavour;
 130        int     (*accept)(struct svc_rqst *rq);
 131        int     (*release)(struct svc_rqst *rq);
 132        void    (*domain_release)(struct auth_domain *);
 133        int     (*set_client)(struct svc_rqst *rq);
 134};
 135
 136#define SVC_GARBAGE     1
 137#define SVC_SYSERR      2
 138#define SVC_VALID       3
 139#define SVC_NEGATIVE    4
 140#define SVC_OK          5
 141#define SVC_DROP        6
 142#define SVC_CLOSE       7       /* Like SVC_DROP, but request is definitely
 143                                 * lost so if there is a tcp connection, it
 144                                 * should be closed
 145                                 */
 146#define SVC_DENIED      8
 147#define SVC_PENDING     9
 148#define SVC_COMPLETE    10
 149
 150struct svc_xprt;
 151
 152extern int      svc_authenticate(struct svc_rqst *rqstp);
 153extern int      svc_authorise(struct svc_rqst *rqstp);
 154extern int      svc_set_client(struct svc_rqst *rqstp);
 155extern int      svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
 156extern void     svc_auth_unregister(rpc_authflavor_t flavor);
 157
 158extern struct auth_domain *unix_domain_find(char *name);
 159extern void auth_domain_put(struct auth_domain *item);
 160extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
 161extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
 162extern struct auth_domain *auth_domain_find(char *name);
 163extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
 164extern int auth_unix_forget_old(struct auth_domain *dom);
 165extern void svcauth_unix_purge(struct net *net);
 166extern void svcauth_unix_info_release(struct svc_xprt *xpt);
 167extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
 168
 169extern int unix_gid_cache_create(struct net *net);
 170extern void unix_gid_cache_destroy(struct net *net);
 171
 172/*
 173 * The <stringhash.h> functions are good enough that we don't need to
 174 * use hash_32() on them; just extracting the high bits is enough.
 175 */
 176static inline unsigned long hash_str(char const *name, int bits)
 177{
 178        return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
 179}
 180
 181static inline unsigned long hash_mem(char const *buf, int length, int bits)
 182{
 183        return full_name_hash(NULL, buf, length) >> (32 - bits);
 184}
 185
 186#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */
 187