include/linux/sunrpc/auth.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * linux/include/linux/sunrpc/auth.h
   4  *
   5  * Declarations for the RPC client authentication machinery.
   6  *
   7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #ifndef _LINUX_SUNRPC_AUTH_H
  11 #define _LINUX_SUNRPC_AUTH_H
  12
  13 #include <linux/sunrpc/sched.h>
  14 #include <linux/sunrpc/msg_prot.h>
  15 #include <linux/sunrpc/xdr.h>
  16
  17 #include <linux/atomic.h>
  18 #include <linux/rcupdate.h>
  19 #include <linux/uidgid.h>
  20 #include <linux/utsname.h>
  21
  22 /*
  23  * Maximum size of AUTH_NONE authentication information, in XDR words.
  24  */
  25 #define NUL_CALLSLACK   (4)
  26 #define NUL_REPLYSLACK  (2)
  27
  28 /*
  29  * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes,
  30  * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes.
  31  */
  32 #define UNX_MAXNODENAME __NEW_UTS_LEN
  33 #define UNX_CALLSLACK   (21 + XDR_QUADLEN(UNX_MAXNODENAME))
  34 #define UNX_NGROUPS     16
  35
  36 struct rpcsec_gss_info;
  37
  38 struct auth_cred {
  39         const struct cred *cred;
  40         const char *principal;  /* If present, this is a machine credential */
  41 };
  42
  43 /*
  44  * Client user credentials
  45  */
  46 struct rpc_auth;
  47 struct rpc_credops;
  48 struct rpc_cred {
  49         struct hlist_node       cr_hash;        /* hash chain */
  50         struct list_head        cr_lru;         /* lru garbage collection */
  51         struct rcu_head         cr_rcu;
  52         struct rpc_auth *       cr_auth;
  53         const struct rpc_credops *cr_ops;
  54         unsigned long           cr_expire;      /* when to gc */
  55         unsigned long           cr_flags;       /* various flags */
  56         refcount_t              cr_count;       /* ref count */
  57         const struct cred       *cr_cred;
  58
  59         /* per-flavor data */
  60 };
  61 #define RPCAUTH_CRED_NEW        0
  62 #define RPCAUTH_CRED_UPTODATE   1
  63 #define RPCAUTH_CRED_HASHED     2
  64 #define RPCAUTH_CRED_NEGATIVE   3
  65
  66 const struct cred *rpc_machine_cred(void);
  67
  68 /*
  69  * Client authentication handle
  70  */
  71 struct rpc_cred_cache;
  72 struct rpc_authops;
  73 struct rpc_auth {
  74         unsigned int            au_cslack;      /* call cred size estimate */
  75         unsigned int            au_rslack;      /* reply cred size estimate */
  76         unsigned int            au_verfsize;    /* size of reply verifier */
  77         unsigned int            au_ralign;      /* words before UL header */
  78
  79         unsigned long           au_flags;
  80         const struct rpc_authops *au_ops;
  81         rpc_authflavor_t        au_flavor;      /* pseudoflavor (note may
  82                                                  * differ from the flavor in
  83                                                  * au_ops->au_flavor in gss
  84                                                  * case) */
  85         refcount_t              au_count;       /* Reference counter */
  86
  87         struct rpc_cred_cache * au_credcache;
  88         /* per-flavor data */
  89 };
  90
  91 /* rpc_auth au_flags */
  92 #define RPCAUTH_AUTH_DATATOUCH          (1)
  93 #define RPCAUTH_AUTH_UPDATE_SLACK       (2)
  94
  95 struct rpc_auth_create_args {
  96         rpc_authflavor_t pseudoflavor;
  97         const char *target_name;
  98 };
  99
 100 /* Flags for rpcauth_lookupcred() */
 101 #define RPCAUTH_LOOKUP_NEW              0x01    /* Accept an uninitialised cred */
 102 #define RPCAUTH_LOOKUP_ASYNC            0x02    /* Don't block waiting for memory */
 103
 104 /*
 105  * Client authentication ops
 106  */
 107 struct rpc_authops {
 108         struct module           *owner;
 109         rpc_authflavor_t        au_flavor;      /* flavor (RPC_AUTH_*) */
 110         char *                  au_name;
 111         struct rpc_auth *       (*create)(const struct rpc_auth_create_args *,
 112                                           struct rpc_clnt *);
 113         void                    (*destroy)(struct rpc_auth *);
 114
 115         int                     (*hash_cred)(struct auth_cred *, unsigned int);
 116         struct rpc_cred *       (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
 117         struct rpc_cred *       (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t);
 118         rpc_authflavor_t        (*info2flavor)(struct rpcsec_gss_info *);
 119         int                     (*flavor2info)(rpc_authflavor_t,
 120                                                 struct rpcsec_gss_info *);
 121         int                     (*key_timeout)(struct rpc_auth *,
 122                                                 struct rpc_cred *);
 123         int                     (*ping)(struct rpc_clnt *clnt);
 124 };
 125
 126 struct rpc_credops {
 127         const char *            cr_name;        /* Name of the auth flavour */
 128         int                     (*cr_init)(struct rpc_auth *, struct rpc_cred *);
 129         void                    (*crdestroy)(struct rpc_cred *);
 130
 131         int                     (*crmatch)(struct auth_cred *, struct rpc_cred *, int);
 132         int                     (*crmarshal)(struct rpc_task *task,
 133                                              struct xdr_stream *xdr);
 134         int                     (*crrefresh)(struct rpc_task *);
 135         int                     (*crvalidate)(struct rpc_task *task,
 136                                               struct xdr_stream *xdr);
 137         int                     (*crwrap_req)(struct rpc_task *task,
 138                                               struct xdr_stream *xdr);
 139         int                     (*crunwrap_resp)(struct rpc_task *task,
 140                                                  struct xdr_stream *xdr);
 141         int                     (*crkey_timeout)(struct rpc_cred *);
 142         char *                  (*crstringify_acceptor)(struct rpc_cred *);
 143         bool                    (*crneed_reencode)(struct rpc_task *);
 144 };
 145
 146 extern const struct rpc_authops authunix_ops;
 147 extern const struct rpc_authops authnull_ops;
 148 extern const struct rpc_authops authtls_ops;
 149
 150 int __init              rpc_init_authunix(void);
 151 int __init              rpcauth_init_module(void);
 152 void                    rpcauth_remove_module(void);
 153 void                    rpc_destroy_authunix(void);
 154
 155 int                     rpcauth_register(const struct rpc_authops *);
 156 int                     rpcauth_unregister(const struct rpc_authops *);
 157 struct rpc_auth *       rpcauth_create(const struct rpc_auth_create_args *,
 158                                 struct rpc_clnt *);
 159 void                    rpcauth_release(struct rpc_auth *);
 160 rpc_authflavor_t        rpcauth_get_pseudoflavor(rpc_authflavor_t,
 161                                 struct rpcsec_gss_info *);
 162 int                     rpcauth_get_gssinfo(rpc_authflavor_t,
 163                                 struct rpcsec_gss_info *);
 164 struct rpc_cred *       rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t);
 165 void                    rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
 166 struct rpc_cred *       rpcauth_lookupcred(struct rpc_auth *, int);
 167 void                    put_rpccred(struct rpc_cred *);
 168 int                     rpcauth_marshcred(struct rpc_task *task,
 169                                           struct xdr_stream *xdr);
 170 int                     rpcauth_checkverf(struct rpc_task *task,
 171                                           struct xdr_stream *xdr);
 172 int                     rpcauth_wrap_req_encode(struct rpc_task *task,
 173                                                 struct xdr_stream *xdr);
 174 int                     rpcauth_wrap_req(struct rpc_task *task,
 175                                          struct xdr_stream *xdr);
 176 int                     rpcauth_unwrap_resp_decode(struct rpc_task *task,
 177                                                    struct xdr_stream *xdr);
 178 int                     rpcauth_unwrap_resp(struct rpc_task *task,
 179                                             struct xdr_stream *xdr);
 180 bool                    rpcauth_xmit_need_reencode(struct rpc_task *task);
 181 int                     rpcauth_refreshcred(struct rpc_task *);
 182 void                    rpcauth_invalcred(struct rpc_task *);
 183 int                     rpcauth_uptodatecred(struct rpc_task *);
 184 int                     rpcauth_init_credcache(struct rpc_auth *);
 185 void                    rpcauth_destroy_credcache(struct rpc_auth *);
 186 void                    rpcauth_clear_credcache(struct rpc_cred_cache *);
 187 char *                  rpcauth_stringify_acceptor(struct rpc_cred *);
 188
 189 static inline
 190 struct rpc_cred *get_rpccred(struct rpc_cred *cred)
 191 {
 192         if (cred != NULL && refcount_inc_not_zero(&cred->cr_count))
 193                 return cred;
 194         return NULL;
 195 }
 196
 197 #endif /* _LINUX_SUNRPC_AUTH_H */