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 <[email protected]> 8 */ 9 10 #ifndef _LINUX_SUNRPC_AUTH_H 11 #define _LINUX_SUNRPC_AUTH_H 12 13 #ifdef __KERNEL__ 14 15 #include <linux/sunrpc/sched.h> 16 #include <linux/sunrpc/msg_prot.h> 17 #include <linux/sunrpc/xdr.h> 18 19 #include <linux/atomic.h> 20 #include <linux/rcupdate.h> 21 #include <linux/uidgid.h> 22 #include <linux/utsname.h> 23 24 /* 25 * Maximum size of AUTH_NONE authentication information, in XDR words. 26 */ 27 #define NUL_CALLSLACK (4) 28 #define NUL_REPLYSLACK (2) 29 30 /* 31 * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes, 32 * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes. 33 */ 34 #define UNX_MAXNODENAME __NEW_UTS_LEN 35 #define UNX_CALLSLACK (21 + XDR_QUADLEN(UNX_MAXNODENAME)) 36 #define UNX_NGROUPS 16 37 38 struct rpcsec_gss_info; 39 40 /* auth_cred ac_flags bits */ 41 enum { 42 RPC_CRED_KEY_EXPIRE_SOON = 1, /* underlying cred key will expire soon */ 43 RPC_CRED_NOTIFY_TIMEOUT = 2, /* nofity generic cred when underlying 44 key will expire soon */ 45 }; 46 47 /* Work around the lack of a VFS credential */ 48 struct auth_cred { 49 const struct cred *cred; 50 kuid_t uid; 51 kgid_t gid; 52 const char *principal; 53 unsigned long ac_flags; 54 unsigned char machine_cred : 1; 55 }; 56 57 /* 58 * Client user credentials 59 */ 60 struct rpc_auth; 61 struct rpc_credops; 62 struct rpc_cred { 63 struct hlist_node cr_hash; /* hash chain */ 64 struct list_head cr_lru; /* lru garbage collection */ 65 struct rcu_head cr_rcu; 66 struct rpc_auth * cr_auth; 67 const struct rpc_credops *cr_ops; 68 unsigned long cr_expire; /* when to gc */ 69 unsigned long cr_flags; /* various flags */ 70 refcount_t cr_count; /* ref count */ 71 const struct cred *cr_cred; 72 73 kuid_t cr_uid; 74 75 /* per-flavor data */ 76 }; 77 #define RPCAUTH_CRED_NEW 0 78 #define RPCAUTH_CRED_UPTODATE 1 79 #define RPCAUTH_CRED_HASHED 2 80 #define RPCAUTH_CRED_NEGATIVE 3 81 82 /* rpc_auth au_flags */ 83 #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT 0x0001 /* underlying cred has no key timeout */ 84 85 /* 86 * Client authentication handle 87 */ 88 struct rpc_cred_cache; 89 struct rpc_authops; 90 struct rpc_auth { 91 unsigned int au_cslack; /* call cred size estimate */ 92 /* guess at number of u32's auth adds before 93 * reply data; normally the verifier size: */ 94 unsigned int au_rslack; 95 /* for gss, used to calculate au_rslack: */ 96 unsigned int au_verfsize; 97 98 unsigned int au_flags; /* various flags */ 99 const struct rpc_authops *au_ops; /* operations */ 100 rpc_authflavor_t au_flavor; /* pseudoflavor (note may 101 * differ from the flavor in 102 * au_ops->au_flavor in gss 103 * case) */ 104 refcount_t au_count; /* Reference counter */ 105 106 struct rpc_cred_cache * au_credcache; 107 /* per-flavor data */ 108 }; 109 110 /* rpc_auth au_flags */ 111 #define RPCAUTH_AUTH_DATATOUCH 0x00000002 112 113 struct rpc_auth_create_args { 114 rpc_authflavor_t pseudoflavor; 115 const char *target_name; 116 }; 117 118 /* Flags for rpcauth_lookupcred() */ 119 #define RPCAUTH_LOOKUP_NEW 0x01 /* Accept an uninitialised cred */ 120 #define RPCAUTH_LOOKUP_RCU 0x02 /* lock-less lookup */ 121 122 /* 123 * Client authentication ops 124 */ 125 struct rpc_authops { 126 struct module *owner; 127 rpc_authflavor_t au_flavor; /* flavor (RPC_AUTH_*) */ 128 char * au_name; 129 struct rpc_auth * (*create)(const struct rpc_auth_create_args *, 130 struct rpc_clnt *); 131 void (*destroy)(struct rpc_auth *); 132 133 int (*hash_cred)(struct auth_cred *, unsigned int); 134 struct rpc_cred * (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int); 135 struct rpc_cred * (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t); 136 int (*list_pseudoflavors)(rpc_authflavor_t *, int); 137 rpc_authflavor_t (*info2flavor)(struct rpcsec_gss_info *); 138 int (*flavor2info)(rpc_authflavor_t, 139 struct rpcsec_gss_info *); 140 int (*key_timeout)(struct rpc_auth *, 141 struct rpc_cred *); 142 }; 143 144 struct rpc_credops { 145 const char * cr_name; /* Name of the auth flavour */ 146 int (*cr_init)(struct rpc_auth *, struct rpc_cred *); 147 void (*crdestroy)(struct rpc_cred *); 148 149 int (*crmatch)(struct auth_cred *, struct rpc_cred *, int); 150 struct rpc_cred * (*crbind)(struct rpc_task *, struct rpc_cred *, int); 151 __be32 * (*crmarshal)(struct rpc_task *, __be32 *); 152 int (*crrefresh)(struct rpc_task *); 153 __be32 * (*crvalidate)(struct rpc_task *, __be32 *); 154 int (*crwrap_req)(struct rpc_task *, kxdreproc_t, 155 void *, __be32 *, void *); 156 int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t, 157 void *, __be32 *, void *); 158 int (*crkey_timeout)(struct rpc_cred *); 159 bool (*crkey_to_expire)(struct rpc_cred *); 160 char * (*crstringify_acceptor)(struct rpc_cred *); 161 bool (*crneed_reencode)(struct rpc_task *); 162 }; 163 164 extern const struct rpc_authops authunix_ops; 165 extern const struct rpc_authops authnull_ops; 166 167 int __init rpc_init_authunix(void); 168 int __init rpc_init_generic_auth(void); 169 int __init rpcauth_init_module(void); 170 void rpcauth_remove_module(void); 171 void rpc_destroy_generic_auth(void); 172 void rpc_destroy_authunix(void); 173 174 struct rpc_cred * rpc_lookup_cred(void); 175 struct rpc_cred * rpc_lookup_cred_nonblock(void); 176 struct rpc_cred * rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t); 177 struct rpc_cred * rpc_lookup_machine_cred(const char *service_name); 178 int rpcauth_register(const struct rpc_authops *); 179 int rpcauth_unregister(const struct rpc_authops *); 180 struct rpc_auth * rpcauth_create(const struct rpc_auth_create_args *, 181 struct rpc_clnt *); 182 void rpcauth_release(struct rpc_auth *); 183 rpc_authflavor_t rpcauth_get_pseudoflavor(rpc_authflavor_t, 184 struct rpcsec_gss_info *); 185 int rpcauth_get_gssinfo(rpc_authflavor_t, 186 struct rpcsec_gss_info *); 187 int rpcauth_list_flavors(rpc_authflavor_t *, int); 188 struct rpc_cred * rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t); 189 void rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *); 190 struct rpc_cred * rpcauth_lookupcred(struct rpc_auth *, int); 191 struct rpc_cred * rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int); 192 void put_rpccred(struct rpc_cred *); 193 __be32 * rpcauth_marshcred(struct rpc_task *, __be32 *); 194 __be32 * rpcauth_checkverf(struct rpc_task *, __be32 *); 195 int rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj); 196 int rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj); 197 bool rpcauth_xmit_need_reencode(struct rpc_task *task); 198 int rpcauth_refreshcred(struct rpc_task *); 199 void rpcauth_invalcred(struct rpc_task *); 200 int rpcauth_uptodatecred(struct rpc_task *); 201 int rpcauth_init_credcache(struct rpc_auth *); 202 void rpcauth_destroy_credcache(struct rpc_auth *); 203 void rpcauth_clear_credcache(struct rpc_cred_cache *); 204 int rpcauth_key_timeout_notify(struct rpc_auth *, 205 struct rpc_cred *); 206 bool rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *); 207 char * rpcauth_stringify_acceptor(struct rpc_cred *); 208 209 static inline 210 struct rpc_cred *get_rpccred(struct rpc_cred *cred) 211 { 212 if (cred != NULL && refcount_inc_not_zero(&cred->cr_count)) 213 return cred; 214 return NULL; 215 } 216 217 /** 218 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer 219 * @cred: cred of which to take a reference 220 * 221 * In some cases, we may have a pointer to a credential to which we 222 * want to take a reference, but don't already have one. Because these 223 * objects are freed using RCU, we can access the cr_count while its 224 * on its way to destruction and only take a reference if it's not already 225 * zero. 226 */ 227 static inline struct rpc_cred * 228 get_rpccred_rcu(struct rpc_cred *cred) 229 { 230 return get_rpccred(cred); 231 } 232 233 #endif /* __KERNEL__ */ 234 #endif /* _LINUX_SUNRPC_AUTH_H */ 235