1 /* 2 * linux/include/linux/sunrpc/auth.h 3 * 4 * Declarations for the RPC client authentication machinery. 5 * 6 * Copyright (C) 1996, Olaf Kirch <[email protected]> 7 */ 8 9 #ifndef _LINUX_SUNRPC_AUTH_H 10 #define _LINUX_SUNRPC_AUTH_H 11 12 #ifdef __KERNEL__ 13 14 #include <linux/sunrpc/sched.h> 15 #include <linux/sunrpc/msg_prot.h> 16 #include <linux/sunrpc/xdr.h> 17 18 #include <linux/atomic.h> 19 #include <linux/rcupdate.h> 20 #include <linux/uidgid.h> 21 #include <linux/utsname.h> 22 23 /* 24 * Maximum size of AUTH_NONE authentication information, in XDR words. 25 */ 26 #define NUL_CALLSLACK (4) 27 #define NUL_REPLYSLACK (2) 28 29 /* 30 * Size of the nodename buffer. RFC1831 specifies a hard limit of 255 bytes, 31 * but Linux hostnames are actually limited to __NEW_UTS_LEN bytes. 32 */ 33 #define UNX_MAXNODENAME __NEW_UTS_LEN 34 #define UNX_CALLSLACK (21 + XDR_QUADLEN(UNX_MAXNODENAME)) 35 36 struct rpcsec_gss_info; 37 38 /* auth_cred ac_flags bits */ 39 enum { 40 RPC_CRED_KEY_EXPIRE_SOON = 1, /* underlying cred key will expire soon */ 41 RPC_CRED_NOTIFY_TIMEOUT = 2, /* nofity generic cred when underlying 42 key will expire soon */ 43 }; 44 45 /* Work around the lack of a VFS credential */ 46 struct auth_cred { 47 kuid_t uid; 48 kgid_t gid; 49 struct group_info *group_info; 50 const char *principal; 51 unsigned long ac_flags; 52 unsigned char machine_cred : 1; 53 }; 54 55 /* 56 * Client user credentials 57 */ 58 struct rpc_auth; 59 struct rpc_credops; 60 struct rpc_cred { 61 struct hlist_node cr_hash; /* hash chain */ 62 struct list_head cr_lru; /* lru garbage collection */ 63 struct rcu_head cr_rcu; 64 struct rpc_auth * cr_auth; 65 const struct rpc_credops *cr_ops; 66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 67 unsigned long cr_magic; /* 0x0f4aa4f0 */ 68 #endif 69 unsigned long cr_expire; /* when to gc */ 70 unsigned long cr_flags; /* various flags */ 71 atomic_t cr_count; /* ref count */ 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 #define RPCAUTH_CRED_MAGIC 0x0f4aa4f0 83 84 /* rpc_auth au_flags */ 85 #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT 0x0001 /* underlying cred has no key timeout */ 86 87 /* 88 * Client authentication handle 89 */ 90 struct rpc_cred_cache; 91 struct rpc_authops; 92 struct rpc_auth { 93 unsigned int au_cslack; /* call cred size estimate */ 94 /* guess at number of u32's auth adds before 95 * reply data; normally the verifier size: */ 96 unsigned int au_rslack; 97 /* for gss, used to calculate au_rslack: */ 98 unsigned int au_verfsize; 99 100 unsigned int au_flags; /* various flags */ 101 const struct rpc_authops *au_ops; /* operations */ 102 rpc_authflavor_t au_flavor; /* pseudoflavor (note may 103 * differ from the flavor in 104 * au_ops->au_flavor in gss 105 * case) */ 106 atomic_t au_count; /* Reference counter */ 107 108 struct rpc_cred_cache * au_credcache; 109 /* per-flavor data */ 110 }; 111 112 /* rpc_auth au_flags */ 113 #define RPCAUTH_AUTH_DATATOUCH 0x00000002 114 115 struct rpc_auth_create_args { 116 rpc_authflavor_t pseudoflavor; 117 const char *target_name; 118 }; 119 120 /* Flags for rpcauth_lookupcred() */ 121 #define RPCAUTH_LOOKUP_NEW 0x01 /* Accept an uninitialised cred */ 122 #define RPCAUTH_LOOKUP_RCU 0x02 /* lock-less lookup */ 123 124 /* 125 * Client authentication ops 126 */ 127 struct rpc_authops { 128 struct module *owner; 129 rpc_authflavor_t au_flavor; /* flavor (RPC_AUTH_*) */ 130 char * au_name; 131 struct rpc_auth * (*create)(struct rpc_auth_create_args *, struct rpc_clnt *); 132 void (*destroy)(struct rpc_auth *); 133 134 int (*hash_cred)(struct auth_cred *, unsigned int); 135 struct rpc_cred * (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int); 136 struct rpc_cred * (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t); 137 int (*list_pseudoflavors)(rpc_authflavor_t *, int); 138 rpc_authflavor_t (*info2flavor)(struct rpcsec_gss_info *); 139 int (*flavor2info)(rpc_authflavor_t, 140 struct rpcsec_gss_info *); 141 int (*key_timeout)(struct rpc_auth *, 142 struct rpc_cred *); 143 }; 144 145 struct rpc_credops { 146 const char * cr_name; /* Name of the auth flavour */ 147 int (*cr_init)(struct rpc_auth *, struct rpc_cred *); 148 void (*crdestroy)(struct rpc_cred *); 149 150 int (*crmatch)(struct auth_cred *, struct rpc_cred *, int); 151 struct rpc_cred * (*crbind)(struct rpc_task *, struct rpc_cred *, int); 152 __be32 * (*crmarshal)(struct rpc_task *, __be32 *); 153 int (*crrefresh)(struct rpc_task *); 154 __be32 * (*crvalidate)(struct rpc_task *, __be32 *); 155 int (*crwrap_req)(struct rpc_task *, kxdreproc_t, 156 void *, __be32 *, void *); 157 int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t, 158 void *, __be32 *, void *); 159 int (*crkey_timeout)(struct rpc_cred *); 160 bool (*crkey_to_expire)(struct rpc_cred *); 161 char * (*crstringify_acceptor)(struct rpc_cred *); 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(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 int rpcauth_refreshcred(struct rpc_task *); 198 void rpcauth_invalcred(struct rpc_task *); 199 int rpcauth_uptodatecred(struct rpc_task *); 200 int rpcauth_init_credcache(struct rpc_auth *); 201 void rpcauth_destroy_credcache(struct rpc_auth *); 202 void rpcauth_clear_credcache(struct rpc_cred_cache *); 203 int rpcauth_key_timeout_notify(struct rpc_auth *, 204 struct rpc_cred *); 205 bool rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *); 206 char * rpcauth_stringify_acceptor(struct rpc_cred *); 207 208 static inline 209 struct rpc_cred * get_rpccred(struct rpc_cred *cred) 210 { 211 if (cred != NULL) 212 atomic_inc(&cred->cr_count); 213 return cred; 214 } 215 216 /** 217 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer 218 * @cred: cred of which to take a reference 219 * 220 * In some cases, we may have a pointer to a credential to which we 221 * want to take a reference, but don't already have one. Because these 222 * objects are freed using RCU, we can access the cr_count while its 223 * on its way to destruction and only take a reference if it's not already 224 * zero. 225 */ 226 static inline struct rpc_cred * 227 get_rpccred_rcu(struct rpc_cred *cred) 228 { 229 if (atomic_inc_not_zero(&cred->cr_count)) 230 return cred; 231 return NULL; 232 } 233 234 #endif /* __KERNEL__ */ 235 #endif /* _LINUX_SUNRPC_AUTH_H */ 236