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_NO_CRKEY_TIMEOUT = 0, /* underlying cred has no key timeout */ 41 RPC_CRED_KEY_EXPIRE_SOON = 1, /* underlying cred key will expire soon */ 42 RPC_CRED_NOTIFY_TIMEOUT = 2, /* nofity generic cred when underlying 43 key will expire soon */ 44 }; 45 46 /* Work around the lack of a VFS credential */ 47 struct auth_cred { 48 kuid_t uid; 49 kgid_t gid; 50 struct group_info *group_info; 51 const char *principal; 52 unsigned long ac_flags; 53 unsigned char machine_cred : 1; 54 }; 55 56 /* 57 * Client user credentials 58 */ 59 struct rpc_auth; 60 struct rpc_credops; 61 struct rpc_cred { 62 struct hlist_node cr_hash; /* hash chain */ 63 struct list_head cr_lru; /* lru garbage collection */ 64 struct rcu_head cr_rcu; 65 struct rpc_auth * cr_auth; 66 const struct rpc_credops *cr_ops; 67 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 68 unsigned long cr_magic; /* 0x0f4aa4f0 */ 69 #endif 70 unsigned long cr_expire; /* when to gc */ 71 unsigned long cr_flags; /* various flags */ 72 atomic_t cr_count; /* ref count */ 73 74 kuid_t cr_uid; 75 76 /* per-flavor data */ 77 }; 78 #define RPCAUTH_CRED_NEW 0 79 #define RPCAUTH_CRED_UPTODATE 1 80 #define RPCAUTH_CRED_HASHED 2 81 #define RPCAUTH_CRED_NEGATIVE 3 82 83 #define RPCAUTH_CRED_MAGIC 0x0f4aa4f0 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 atomic_t au_count; /* Reference counter */ 105 106 struct rpc_cred_cache * au_credcache; 107 /* per-flavor data */ 108 }; 109 110 struct rpc_auth_create_args { 111 rpc_authflavor_t pseudoflavor; 112 const char *target_name; 113 }; 114 115 /* Flags for rpcauth_lookupcred() */ 116 #define RPCAUTH_LOOKUP_NEW 0x01 /* Accept an uninitialised cred */ 117 #define RPCAUTH_LOOKUP_RCU 0x02 /* lock-less lookup */ 118 119 /* 120 * Client authentication ops 121 */ 122 struct rpc_authops { 123 struct module *owner; 124 rpc_authflavor_t au_flavor; /* flavor (RPC_AUTH_*) */ 125 char * au_name; 126 struct rpc_auth * (*create)(struct rpc_auth_create_args *, struct rpc_clnt *); 127 void (*destroy)(struct rpc_auth *); 128 129 struct rpc_cred * (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int); 130 struct rpc_cred * (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t); 131 int (*list_pseudoflavors)(rpc_authflavor_t *, int); 132 rpc_authflavor_t (*info2flavor)(struct rpcsec_gss_info *); 133 int (*flavor2info)(rpc_authflavor_t, 134 struct rpcsec_gss_info *); 135 int (*key_timeout)(struct rpc_auth *, 136 struct rpc_cred *); 137 }; 138 139 struct rpc_credops { 140 const char * cr_name; /* Name of the auth flavour */ 141 int (*cr_init)(struct rpc_auth *, struct rpc_cred *); 142 void (*crdestroy)(struct rpc_cred *); 143 144 int (*crmatch)(struct auth_cred *, struct rpc_cred *, int); 145 struct rpc_cred * (*crbind)(struct rpc_task *, struct rpc_cred *, int); 146 __be32 * (*crmarshal)(struct rpc_task *, __be32 *); 147 int (*crrefresh)(struct rpc_task *); 148 __be32 * (*crvalidate)(struct rpc_task *, __be32 *); 149 int (*crwrap_req)(struct rpc_task *, kxdreproc_t, 150 void *, __be32 *, void *); 151 int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t, 152 void *, __be32 *, void *); 153 int (*crkey_timeout)(struct rpc_cred *); 154 bool (*crkey_to_expire)(struct rpc_cred *); 155 char * (*crstringify_acceptor)(struct rpc_cred *); 156 }; 157 158 extern const struct rpc_authops authunix_ops; 159 extern const struct rpc_authops authnull_ops; 160 161 int __init rpc_init_authunix(void); 162 int __init rpc_init_generic_auth(void); 163 int __init rpcauth_init_module(void); 164 void rpcauth_remove_module(void); 165 void rpc_destroy_generic_auth(void); 166 void rpc_destroy_authunix(void); 167 168 struct rpc_cred * rpc_lookup_cred(void); 169 struct rpc_cred * rpc_lookup_cred_nonblock(void); 170 struct rpc_cred * rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t); 171 struct rpc_cred * rpc_lookup_machine_cred(const char *service_name); 172 int rpcauth_register(const struct rpc_authops *); 173 int rpcauth_unregister(const struct rpc_authops *); 174 struct rpc_auth * rpcauth_create(struct rpc_auth_create_args *, 175 struct rpc_clnt *); 176 void rpcauth_release(struct rpc_auth *); 177 rpc_authflavor_t rpcauth_get_pseudoflavor(rpc_authflavor_t, 178 struct rpcsec_gss_info *); 179 int rpcauth_get_gssinfo(rpc_authflavor_t, 180 struct rpcsec_gss_info *); 181 int rpcauth_list_flavors(rpc_authflavor_t *, int); 182 struct rpc_cred * rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t); 183 void rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *); 184 struct rpc_cred * rpcauth_lookupcred(struct rpc_auth *, int); 185 struct rpc_cred * rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int); 186 void put_rpccred(struct rpc_cred *); 187 __be32 * rpcauth_marshcred(struct rpc_task *, __be32 *); 188 __be32 * rpcauth_checkverf(struct rpc_task *, __be32 *); 189 int rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj); 190 int rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj); 191 int rpcauth_refreshcred(struct rpc_task *); 192 void rpcauth_invalcred(struct rpc_task *); 193 int rpcauth_uptodatecred(struct rpc_task *); 194 int rpcauth_init_credcache(struct rpc_auth *); 195 void rpcauth_destroy_credcache(struct rpc_auth *); 196 void rpcauth_clear_credcache(struct rpc_cred_cache *); 197 int rpcauth_key_timeout_notify(struct rpc_auth *, 198 struct rpc_cred *); 199 bool rpcauth_cred_key_to_expire(struct rpc_cred *); 200 char * rpcauth_stringify_acceptor(struct rpc_cred *); 201 202 static inline 203 struct rpc_cred * get_rpccred(struct rpc_cred *cred) 204 { 205 if (cred != NULL) 206 atomic_inc(&cred->cr_count); 207 return cred; 208 } 209 210 /** 211 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer 212 * @cred: cred of which to take a reference 213 * 214 * In some cases, we may have a pointer to a credential to which we 215 * want to take a reference, but don't already have one. Because these 216 * objects are freed using RCU, we can access the cr_count while its 217 * on its way to destruction and only take a reference if it's not already 218 * zero. 219 */ 220 static inline struct rpc_cred * 221 get_rpccred_rcu(struct rpc_cred *cred) 222 { 223 if (atomic_inc_not_zero(&cred->cr_count)) 224 return cred; 225 return NULL; 226 } 227 228 #endif /* __KERNEL__ */ 229 #endif /* _LINUX_SUNRPC_AUTH_H */ 230