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/sunrpc/clnt.h>
  18 #include <linux/hash.h>
  19 #include <linux/stringhash.h>
  20 #include <linux/cred.h>
  21
  22 struct svc_cred {
  23         kuid_t                  cr_uid;
  24         kgid_t                  cr_gid;
  25         struct group_info       *cr_group_info;
  26         u32                     cr_flavor; /* pseudoflavor */
  27         /* name of form servicetype/hostname@REALM, passed down by
  28          * gss-proxy: */
  29         char                    *cr_raw_principal;
  30         /* name of form servicetype@hostname, passed down by
  31          * rpc.svcgssd, or computed from the above: */
  32         char                    *cr_principal;
  33         char                    *cr_targ_princ;
  34         struct gss_api_mech     *cr_gss_mech;
  35 };
  36
  37 static inline void init_svc_cred(struct svc_cred *cred)
  38 {
  39         cred->cr_group_info = NULL;
  40         cred->cr_raw_principal = NULL;
  41         cred->cr_principal = NULL;
  42         cred->cr_targ_princ = NULL;
  43         cred->cr_gss_mech = NULL;
  44 }
  45
  46 static inline void free_svc_cred(struct svc_cred *cred)
  47 {
  48         if (cred->cr_group_info)
  49                 put_group_info(cred->cr_group_info);
  50         kfree(cred->cr_raw_principal);
  51         kfree(cred->cr_principal);
  52         kfree(cred->cr_targ_princ);
  53         gss_mech_put(cred->cr_gss_mech);
  54         init_svc_cred(cred);
  55 }
  56
  57 struct svc_rqst;                /* forward decl */
  58 struct in6_addr;
  59
  60 /* Authentication is done in the context of a domain.
  61  *
  62  * Currently, the nfs server uses the auth_domain to stand
  63  * for the "client" listed in /etc/exports.
  64  *
  65  * More generally, a domain might represent a group of clients using
  66  * a common mechanism for authentication and having a common mapping
  67  * between local identity (uid) and network identity.  All clients
  68  * in a domain have similar general access rights.  Each domain can
  69  * contain multiple principals which will have different specific right
  70  * based on normal Discretionary Access Control.
  71  *
  72  * A domain is created by an authentication flavour module based on name
  73  * only.  Userspace then fills in detail on demand.
  74  *
  75  * In the case of auth_unix and auth_null, the auth_domain is also
  76  * associated with entries in another cache representing the mapping
  77  * of ip addresses to the given client.
  78  */
  79 struct auth_domain {
  80         struct kref             ref;
  81         struct hlist_node       hash;
  82         char                    *name;
  83         struct auth_ops         *flavour;
  84         struct rcu_head         rcu_head;
  85 };
  86
  87 enum svc_auth_status {
  88         SVC_GARBAGE = 1,
  89         SVC_SYSERR,
  90         SVC_VALID,
  91         SVC_NEGATIVE,
  92         SVC_OK,
  93         SVC_DROP,
  94         SVC_CLOSE,
  95         SVC_DENIED,
  96         SVC_PENDING,
  97         SVC_COMPLETE,
  98 };
  99
 100 /*
 101  * Each authentication flavour registers an auth_ops
 102  * structure.
 103  * name is simply the name.
 104  * flavour gives the auth flavour. It determines where the flavour is registered
 105  * accept() is given a request and should verify it.
 106  *   It should inspect the authenticator and verifier, and possibly the data.
 107  *    If there is a problem with the authentication *authp should be set.
 108  *    The return value of accept() can indicate:
 109  *      OK - authorised. client and credential are set in rqstp.
 110  *           reqbuf points to arguments
 111  *           resbuf points to good place for results.  verfier
 112  *             is (probably) already in place.  Certainly space is
 113  *             reserved for it.
 114  *      DROP - simply drop the request. It may have been deferred
 115  *      CLOSE - like SVC_DROP, but request is definitely lost.
 116  *              If there is a tcp connection, it should be closed.
 117  *      GARBAGE - rpc garbage_args error
 118  *      SYSERR - rpc system_err error
 119  *      DENIED - authp holds reason for denial.
 120  *      COMPLETE - the reply is encoded already and ready to be sent; no
 121  *              further processing is necessary.  (This is used for processing
 122  *              null procedure calls which are used to set up encryption
 123  *              contexts.)
 124  *
 125  *   accept is passed the proc number so that it can accept NULL rpc requests
 126  *   even if it cannot authenticate the client (as is sometimes appropriate).
 127  *
 128  * release() is given a request after the procedure has been run.
 129  *  It should sign/encrypt the results if needed
 130  *
 131  * domain_release()
 132  *   This call releases a domain.
 133  *
 134  * set_client()
 135  *   Given a pending request (struct svc_rqst), finds and assigns
 136  *   an appropriate 'auth_domain' as the client.
 137  *
 138  * pseudoflavor()
 139  *   Returns RPC_AUTH pseudoflavor in use by @rqstp.
 140  */
 141 struct auth_ops {
 142         char *  name;
 143         struct module *owner;
 144         int     flavour;
 145
 146         enum svc_auth_status    (*accept)(struct svc_rqst *rqstp);
 147         int                     (*release)(struct svc_rqst *rqstp);
 148         void                    (*domain_release)(struct auth_domain *dom);
 149         enum svc_auth_status    (*set_client)(struct svc_rqst *rqstp);
 150         rpc_authflavor_t        (*pseudoflavor)(struct svc_rqst *rqstp);
 151 };
 152
 153 struct svc_xprt;
 154
 155 extern rpc_authflavor_t svc_auth_flavor(struct svc_rqst *rqstp);
 156 extern int      svc_authorise(struct svc_rqst *rqstp);
 157 extern enum svc_auth_status svc_set_client(struct svc_rqst *rqstp);
 158 extern int      svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
 159 extern void     svc_auth_unregister(rpc_authflavor_t flavor);
 160
 161 extern void     svcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
 162                                                    const struct cred *,
 163                                                    struct svc_cred *);
 164
 165 extern struct auth_domain *unix_domain_find(char *name);
 166 extern void auth_domain_put(struct auth_domain *item);
 167 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
 168 extern struct auth_domain *auth_domain_find(char *name);
 169 extern void svcauth_unix_purge(struct net *net);
 170 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
 171 extern enum svc_auth_status svcauth_unix_set_client(struct svc_rqst *rqstp);
 172
 173 extern int unix_gid_cache_create(struct net *net);
 174 extern void unix_gid_cache_destroy(struct net *net);
 175
 176 /*
 177  * The <stringhash.h> functions are good enough that we don't need to
 178  * use hash_32() on them; just extracting the high bits is enough.
 179  */
 180 static inline unsigned long hash_str(char const *name, int bits)
 181 {
 182         return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
 183 }
 184
 185 static inline unsigned long hash_mem(char const *buf, int length, int bits)
 186 {
 187         return full_name_hash(NULL, buf, length) >> (32 - bits);
 188 }
 189
 190 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */