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 struct auth_cred { 41 const struct cred *cred; 42 const char *principal; /* If present, this is a machine credential */ 43 }; 44 45 /* 46 * Client user credentials 47 */ 48 struct rpc_auth; 49 struct rpc_credops; 50 struct rpc_cred { 51 struct hlist_node cr_hash; /* hash chain */ 52 struct list_head cr_lru; /* lru garbage collection */ 53 struct rcu_head cr_rcu; 54 struct rpc_auth * cr_auth; 55 const struct rpc_credops *cr_ops; 56 unsigned long cr_expire; /* when to gc */ 57 unsigned long cr_flags; /* various flags */ 58 refcount_t cr_count; /* ref count */ 59 const struct cred *cr_cred; 60 61 kuid_t cr_uid; 62 63 /* per-flavor data */ 64 }; 65 #define RPCAUTH_CRED_NEW 0 66 #define RPCAUTH_CRED_UPTODATE 1 67 #define RPCAUTH_CRED_HASHED 2 68 #define RPCAUTH_CRED_NEGATIVE 3 69 70 struct rpc_cred *rpc_machine_cred(void); 71 72 /* rpc_auth au_flags */ 73 #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT 0x0001 /* underlying cred has no key timeout */ 74 75 /* 76 * Client authentication handle 77 */ 78 struct rpc_cred_cache; 79 struct rpc_authops; 80 struct rpc_auth { 81 unsigned int au_cslack; /* call cred size estimate */ 82 /* guess at number of u32's auth adds before 83 * reply data; normally the verifier size: */ 84 unsigned int au_rslack; 85 /* for gss, used to calculate au_rslack: */ 86 unsigned int au_verfsize; 87 88 unsigned int au_flags; /* various flags */ 89 const struct rpc_authops *au_ops; /* operations */ 90 rpc_authflavor_t au_flavor; /* pseudoflavor (note may 91 * differ from the flavor in 92 * au_ops->au_flavor in gss 93 * case) */ 94 refcount_t au_count; /* Reference counter */ 95 96 struct rpc_cred_cache * au_credcache; 97 /* per-flavor data */ 98 }; 99 100 /* rpc_auth au_flags */ 101 #define RPCAUTH_AUTH_DATATOUCH 0x00000002 102 103 struct rpc_auth_create_args { 104 rpc_authflavor_t pseudoflavor; 105 const char *target_name; 106 }; 107 108 /* Flags for rpcauth_lookupcred() */ 109 #define RPCAUTH_LOOKUP_NEW 0x01 /* Accept an uninitialised cred */ 110 #define RPCAUTH_LOOKUP_RCU 0x02 /* lock-less lookup */ 111 112 /* 113 * Client authentication ops 114 */ 115 struct rpc_authops { 116 struct module *owner; 117 rpc_authflavor_t au_flavor; /* flavor (RPC_AUTH_*) */ 118 char * au_name; 119 struct rpc_auth * (*create)(const struct rpc_auth_create_args *, 120 struct rpc_clnt *); 121 void (*destroy)(struct rpc_auth *); 122 123 int (*hash_cred)(struct auth_cred *, unsigned int); 124 struct rpc_cred * (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int); 125 struct rpc_cred * (*crcreate)(struct rpc_auth*, struct auth_cred *, int, gfp_t); 126 int (*list_pseudoflavors)(rpc_authflavor_t *, int); 127 rpc_authflavor_t (*info2flavor)(struct rpcsec_gss_info *); 128 int (*flavor2info)(rpc_authflavor_t, 129 struct rpcsec_gss_info *); 130 int (*key_timeout)(struct rpc_auth *, 131 struct rpc_cred *); 132 }; 133 134 struct rpc_credops { 135 const char * cr_name; /* Name of the auth flavour */ 136 int (*cr_init)(struct rpc_auth *, struct rpc_cred *); 137 void (*crdestroy)(struct rpc_cred *); 138 139 int (*crmatch)(struct auth_cred *, struct rpc_cred *, int); 140 struct rpc_cred * (*crbind)(struct rpc_task *, struct rpc_cred *, int); 141 __be32 * (*crmarshal)(struct rpc_task *, __be32 *); 142 int (*crrefresh)(struct rpc_task *); 143 __be32 * (*crvalidate)(struct rpc_task *, __be32 *); 144 int (*crwrap_req)(struct rpc_task *, kxdreproc_t, 145 void *, __be32 *, void *); 146 int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t, 147 void *, __be32 *, void *); 148 int (*crkey_timeout)(struct rpc_cred *); 149 char * (*crstringify_acceptor)(struct rpc_cred *); 150 bool (*crneed_reencode)(struct rpc_task *); 151 }; 152 153 extern const struct rpc_authops authunix_ops; 154 extern const struct rpc_authops authnull_ops; 155 156 int __init rpc_init_authunix(void); 157 int __init rpc_init_generic_auth(void); 158 int __init rpcauth_init_module(void); 159 void rpcauth_remove_module(void); 160 void rpc_destroy_generic_auth(void); 161 void rpc_destroy_authunix(void); 162 163 struct rpc_cred * rpc_lookup_cred(void); 164 struct rpc_cred * rpc_lookup_cred_nonblock(void); 165 struct rpc_cred * rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t); 166 int rpcauth_register(const struct rpc_authops *); 167 int rpcauth_unregister(const struct rpc_authops *); 168 struct rpc_auth * rpcauth_create(const struct rpc_auth_create_args *, 169 struct rpc_clnt *); 170 void rpcauth_release(struct rpc_auth *); 171 rpc_authflavor_t rpcauth_get_pseudoflavor(rpc_authflavor_t, 172 struct rpcsec_gss_info *); 173 int rpcauth_get_gssinfo(rpc_authflavor_t, 174 struct rpcsec_gss_info *); 175 int rpcauth_list_flavors(rpc_authflavor_t *, int); 176 struct rpc_cred * rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int, gfp_t); 177 void rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *); 178 struct rpc_cred * rpcauth_lookupcred(struct rpc_auth *, int); 179 struct rpc_cred * rpcauth_generic_bind_cred(struct rpc_task *, struct rpc_cred *, int); 180 void put_rpccred(struct rpc_cred *); 181 __be32 * rpcauth_marshcred(struct rpc_task *, __be32 *); 182 __be32 * rpcauth_checkverf(struct rpc_task *, __be32 *); 183 int rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp, __be32 *data, void *obj); 184 int rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp, __be32 *data, void *obj); 185 bool rpcauth_xmit_need_reencode(struct rpc_task *task); 186 int rpcauth_refreshcred(struct rpc_task *); 187 void rpcauth_invalcred(struct rpc_task *); 188 int rpcauth_uptodatecred(struct rpc_task *); 189 int rpcauth_init_credcache(struct rpc_auth *); 190 void rpcauth_destroy_credcache(struct rpc_auth *); 191 void rpcauth_clear_credcache(struct rpc_cred_cache *); 192 char * rpcauth_stringify_acceptor(struct rpc_cred *); 193 194 static inline 195 struct rpc_cred *get_rpccred(struct rpc_cred *cred) 196 { 197 if (cred != NULL && refcount_inc_not_zero(&cred->cr_count)) 198 return cred; 199 return NULL; 200 } 201 202 /** 203 * get_rpccred_rcu - get a reference to a cred using rcu-protected pointer 204 * @cred: cred of which to take a reference 205 * 206 * In some cases, we may have a pointer to a credential to which we 207 * want to take a reference, but don't already have one. Because these 208 * objects are freed using RCU, we can access the cr_count while its 209 * on its way to destruction and only take a reference if it's not already 210 * zero. 211 */ 212 static inline struct rpc_cred * 213 get_rpccred_rcu(struct rpc_cred *cred) 214 { 215 return get_rpccred(cred); 216 } 217 218 #endif /* __KERNEL__ */ 219 #endif /* _LINUX_SUNRPC_AUTH_H */ 220