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 #ifdef __KERNEL__
  14
  15 #include <linux/string.h>
  16 #include <linux/sunrpc/msg_prot.h>
  17 #include <linux/sunrpc/cache.h>
  18 #include <linux/sunrpc/gss_api.h>
  19 #include <linux/hash.h>
  20 #include <linux/stringhash.h>
  21 #include <linux/cred.h>
  22
  23 struct svc_cred {
  24         kuid_t                  cr_uid;
  25         kgid_t                  cr_gid;
  26         struct group_info       *cr_group_info;
  27         u32                     cr_flavor; /* pseudoflavor */
  28         /* name of form servicetype/hostname@REALM, passed down by
  29          * gss-proxy: */
  30         char                    *cr_raw_principal;
  31         /* name of form servicetype@hostname, passed down by
  32          * rpc.svcgssd, or computed from the above: */
  33         char                    *cr_principal;
  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_gss_mech = NULL;
  43 }
  44
  45 static 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         gss_mech_put(cred->cr_gss_mech);
  52         init_svc_cred(cred);
  53 }
  54
  55 struct svc_rqst;                /* forward decl */
  56 struct in6_addr;
  57
  58 /* Authentication is done in the context of a domain.
  59  *
  60  * Currently, the nfs server uses the auth_domain to stand
  61  * for the "client" listed in /etc/exports.
  62  *
  63  * More generally, a domain might represent a group of clients using
  64  * a common mechanism for authentication and having a common mapping
  65  * between local identity (uid) and network identity.  All clients
  66  * in a domain have similar general access rights.  Each domain can
  67  * contain multiple principals which will have different specific right
  68  * based on normal Discretionary Access Control.
  69  *
  70  * A domain is created by an authentication flavour module based on name
  71  * only.  Userspace then fills in detail on demand.
  72  *
  73  * In the case of auth_unix and auth_null, the auth_domain is also
  74  * associated with entries in another cache representing the mapping
  75  * of ip addresses to the given client.
  76  */
  77 struct auth_domain {
  78         struct kref             ref;
  79         struct hlist_node       hash;
  80         char                    *name;
  81         struct auth_ops         *flavour;
  82 };
  83
  84 /*
  85  * Each authentication flavour registers an auth_ops
  86  * structure.
  87  * name is simply the name.
  88  * flavour gives the auth flavour. It determines where the flavour is registered
  89  * accept() is given a request and should verify it.
  90  *   It should inspect the authenticator and verifier, and possibly the data.
  91  *    If there is a problem with the authentication *authp should be set.
  92  *    The return value of accept() can indicate:
  93  *      OK - authorised. client and credential are set in rqstp.
  94  *           reqbuf points to arguments
  95  *           resbuf points to good place for results.  verfier
  96  *             is (probably) already in place.  Certainly space is
  97  *             reserved for it.
  98  *      DROP - simply drop the request. It may have been deferred
  99  *      GARBAGE - rpc garbage_args error
 100  *      SYSERR - rpc system_err error
 101  *      DENIED - authp holds reason for denial.
 102  *      COMPLETE - the reply is encoded already and ready to be sent; no
 103  *              further processing is necessary.  (This is used for processing
 104  *              null procedure calls which are used to set up encryption
 105  *              contexts.)
 106  *
 107  *   accept is passed the proc number so that it can accept NULL rpc requests
 108  *   even if it cannot authenticate the client (as is sometimes appropriate).
 109  *
 110  * release() is given a request after the procedure has been run.
 111  *  It should sign/encrypt the results if needed
 112  * It should return:
 113  *    OK - the resbuf is ready to be sent
 114  *    DROP - the reply should be quitely dropped
 115  *    DENIED - authp holds a reason for MSG_DENIED
 116  *    SYSERR - rpc system_err
 117  *
 118  * domain_release()
 119  *   This call releases a domain.
 120  * set_client()
 121  *   Givens a pending request (struct svc_rqst), finds and assigns
 122  *   an appropriate 'auth_domain' as the client.
 123  */
 124 struct auth_ops {
 125         char *  name;
 126         struct module *owner;
 127         int     flavour;
 128         int     (*accept)(struct svc_rqst *rq, __be32 *authp);
 129         int     (*release)(struct svc_rqst *rq);
 130         void    (*domain_release)(struct auth_domain *);
 131         int     (*set_client)(struct svc_rqst *rq);
 132 };
 133
 134 #define SVC_GARBAGE     1
 135 #define SVC_SYSERR      2
 136 #define SVC_VALID       3
 137 #define SVC_NEGATIVE    4
 138 #define SVC_OK          5
 139 #define SVC_DROP        6
 140 #define SVC_CLOSE       7       /* Like SVC_DROP, but request is definitely
 141                                  * lost so if there is a tcp connection, it
 142                                  * should be closed
 143                                  */
 144 #define SVC_DENIED      8
 145 #define SVC_PENDING     9
 146 #define SVC_COMPLETE    10
 147
 148 struct svc_xprt;
 149
 150 extern int      svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
 151 extern int      svc_authorise(struct svc_rqst *rqstp);
 152 extern int      svc_set_client(struct svc_rqst *rqstp);
 153 extern int      svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
 154 extern void     svc_auth_unregister(rpc_authflavor_t flavor);
 155
 156 extern struct auth_domain *unix_domain_find(char *name);
 157 extern void auth_domain_put(struct auth_domain *item);
 158 extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
 159 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
 160 extern struct auth_domain *auth_domain_find(char *name);
 161 extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
 162 extern int auth_unix_forget_old(struct auth_domain *dom);
 163 extern void svcauth_unix_purge(struct net *net);
 164 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
 165 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
 166
 167 extern int unix_gid_cache_create(struct net *net);
 168 extern void unix_gid_cache_destroy(struct net *net);
 169
 170 /*
 171  * The <stringhash.h> functions are good enough that we don't need to
 172  * use hash_32() on them; just extracting the high bits is enough.
 173  */
 174 static inline unsigned long hash_str(char const *name, int bits)
 175 {
 176         return hashlen_hash(hashlen_string(NULL, name)) >> (32 - bits);
 177 }
 178
 179 static inline unsigned long hash_mem(char const *buf, int length, int bits)
 180 {
 181         return full_name_hash(NULL, buf, length) >> (32 - bits);
 182 }
 183
 184 #endif /* __KERNEL__ */
 185
 186 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */