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 kuid_t uid; 50 kgid_t gid; 51 struct group_info *group_info; 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 atomic_t cr_count; /* ref count */ 71 72 kuid_t cr_uid; 73 74 /* per-flavor data */ 75 }; 76 #define RPCAUTH_CRED_NEW 0 77 #define RPCAUTH_CRED_UPTODATE 1 78 #define RPCAUTH_CRED_HASHED 2 79 #define RPCAUTH_CRED_NEGATIVE 3 80 81 /* rpc_auth au_flags */ 82 #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT 0x0001 /* underlying cred has no key timeout */ 83 84 /* 85 * Client authentication handle 86 */ 87 struct rpc_cred_cache; 88 struct rpc_authops; 89 struct rpc_auth { 90 unsigned int au_cslack; /* call cred size estimate */ 91 /* guess at number of u32's auth adds before 92 * reply data; normally the verifier size: */ 93 unsigned int au_rslack; 94 /* for gss, used to calculate au_rslack: */ 95 unsigned int au_verfsize; 96 97 unsigned int au_flags; /* various flags */ 98 const struct rpc_authops *au_ops; /* operations */ 99 rpc_authflavor_t au_flavor; /* pseudoflavor (note may 100 * differ from the flavor in 101 * au_ops->au_flavor in gss 102 * case) */ 103 atomic_t au_count; /* Reference counter */ 104 105 struct rpc_cred_cache * au_credcache; 106 /* per-flavor data */ 107 }; 108 109 /* rpc_auth au_flags */ 110 #define RPCAUTH_AUTH_DATATOUCH 0x00000002 111 112 struct rpc_auth_create_args { 113 rpc_authflavor_t pseudoflavor; 114 const char *target_name; 115 }; 116 117 /* Flags for rpcauth_lookupcred() */ 118 #define RPCAUTH_LOOKUP_NEW 0x01 /* Accept an uninitialised cred */ 119 #define RPCAUTH_LOOKUP_RCU 0x02 /* lock-less lookup */ 120 121 /* 122 * Client authentication ops 123 */ 124 struct rpc_authops { 125 struct module *owner; 126 rpc_authflavor_t au_flavor; /* flavor (RPC_AUTH_*) */ 127 char * au_name; 128 struct rpc_auth * (*create)(struct rpc_auth_create_args *, struct rpc_clnt *); 129 void (*destroy)(struct rpc_auth *); 130 131 int (*hash_cred)(struct auth_cred *, unsigned int); 132 struct rpc_cred * (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int); 133 struct rpc_cred * (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t); 134 int (*list_pseudoflavors)(rpc_authflavor_t *, int); 135 rpc_authflavor_t (*info2flavor)(struct rpcsec_gss_info *); 136 int (*flavor2info)(rpc_authflavor_t, 137 struct rpcsec_gss_info *); 138 int (*key_timeout)(struct rpc_auth *, 139 struct rpc_cred *); 140 }; 141 142 struct rpc_credops { 143 const char * cr_name; /* Name of the auth flavour */ 144 int (*cr_init)(struct rpc_auth *, struct rpc_cred *); 145 void (*crdestroy)(struct rpc_cred *); 146 147 int (*crmatch)(struct auth_cred *, struct rpc_cred *, int); 148 struct rpc_cred * (*crbind)(struct rpc_task *, struct rpc_cred *, int); 149 __be32 * (*crmarshal)(struct rpc_task *, __be32 *); 150 int (*crrefresh)(struct rpc_task *); 151 __be32 * (*crvalidate)(struct rpc_task *, __be32 *); 152 int (*crwrap_req)(struct rpc_task *, kxdreproc_t, 153 void *, __be32 *, void *); 154 int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t, 155 void *, __be32 *, void *); 156 int (*crkey_timeout)(struct rpc_cred *); 157 bool (*crkey_to_expire)(struct rpc_cred *); 158 char * (*crstringify_acceptor)(struct rpc_cred *); 159 }; 160 161 extern const struct rpc_authops authunix_ops; 162 extern const struct rpc_authops authnull_ops; 163 164 int __init rpc_init_authunix(void); 165 int __init rpc_init_generic_auth(void); 166 int __init rpcauth_init_module(void); 167 void rpcauth_remove_module(void); 168 void rpc_destroy_generic_auth(void); 169 void rpc_destroy_authunix(void); 170 171 struct rpc_cred * rpc_lookup_cred(void); 172 struct rpc_cred * rpc_lookup_cred_nonblock(void); 173 struct rpc_cred * rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t); 174 struct rpc_cred * rpc_lookup_machine_cred(const char *service_name); 175 int rpcauth_register(const struct rpc_authops *); 176 int rpcauth_unregister(const struct rpc_authops *); 177 struct rpc_auth * rpcauth_create(struct rpc_auth_create_args *, 178 struct rpc_clnt *); 179 void rpcauth_release(struct rpc_auth *); 180 rpc_authflavor_t rpcauth_get_pseudoflavor(rpc_authflavor_t, 181 struct rpcsec_gss_info *); 182 int rpcauth_get_gssinfo(rpc_authflavor_t, 183 struct rpcsec_gss_info *); 184 int rpcauth_list_flavors(rpc_authflavor_t *, int); 185 struct rpc_cred * rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t); 186 void rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *); 187 struct rpc_cred * rpcauth_lookupcred(struct rpc_auth *, int); 188 struct rpc_cred * rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int); 189 void put_rpccred(struct rpc_cred *); 190 __be32 * rpcauth_marshcred(struct rpc_task *, __be32 *); 191 __be32 * rpcauth_checkverf(struct rpc_task *, __be32 *); 192 int rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj); 193 int rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj); 194 int rpcauth_refreshcred(struct rpc_task *); 195 void rpcauth_invalcred(struct rpc_task *); 196 int rpcauth_uptodatecred(struct rpc_task *); 197 int rpcauth_init_credcache(struct rpc_auth *); 198 void rpcauth_destroy_credcache(struct rpc_auth *); 199 void rpcauth_clear_credcache(struct rpc_cred_cache *); 200 int rpcauth_key_timeout_notify(struct rpc_auth *, 201 struct rpc_cred *); 202 bool rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *); 203 char * rpcauth_stringify_acceptor(struct rpc_cred *); 204 205 static inline 206 struct rpc_cred * get_rpccred(struct rpc_cred *cred) 207 { 208 if (cred != NULL) 209 atomic_inc(&cred->cr_count); 210 return cred; 211 } 212 213 /** 214 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer 215 * @cred: cred of which to take a reference 216 * 217 * In some cases, we may have a pointer to a credential to which we 218 * want to take a reference, but don't already have one. Because these 219 * objects are freed using RCU, we can access the cr_count while its 220 * on its way to destruction and only take a reference if it's not already 221 * zero. 222 */ 223 static inline struct rpc_cred * 224 get_rpccred_rcu(struct rpc_cred *cred) 225 { 226 if (atomic_inc_not_zero(&cred->cr_count)) 227 return cred; 228 return NULL; 229 } 230 231 #endif /* __KERNEL__ */ 232 #endif /* _LINUX_SUNRPC_AUTH_H */ 233