1 /* 2 * linux/net/sunrpc/auth_unix.c 3 * 4 * UNIX-style authentication; no AUTH_SHORT support 5 * 6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #include <linux/types.h> 10 #include <linux/sched.h> 11 #include <linux/module.h> 12 #include <linux/sunrpc/clnt.h> 13 #include <linux/sunrpc/auth.h> 14 15 #define NFS_NGROUPS 16 16 17 struct unx_cred { 18 struct rpc_cred uc_base; 19 gid_t uc_gid; 20 gid_t uc_gids[NFS_NGROUPS]; 21 }; 22 #define uc_uid uc_base.cr_uid 23 24 #define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) 25 26 #ifdef RPC_DEBUG 27 # define RPCDBG_FACILITY RPCDBG_AUTH 28 #endif 29 30 static struct rpc_auth unix_auth; 31 static struct rpc_cred_cache unix_cred_cache; 32 static const struct rpc_credops unix_credops; 33 34 static struct rpc_auth * 35 unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 36 { 37 dprintk("RPC: creating UNIX authenticator for client %p\n", 38 clnt); 39 atomic_inc(&unix_auth.au_count); 40 return &unix_auth; 41 } 42 43 static void 44 unx_destroy(struct rpc_auth *auth) 45 { 46 dprintk("RPC: destroying UNIX authenticator %p\n", auth); 47 rpcauth_clear_credcache(auth->au_credcache); 48 } 49 50 /* 51 * Lookup AUTH_UNIX creds for current process 52 */ 53 static struct rpc_cred * 54 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 55 { 56 return rpcauth_lookup_credcache(auth, acred, flags); 57 } 58 59 static struct rpc_cred * 60 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 61 { 62 struct unx_cred *cred; 63 unsigned int groups = 0; 64 unsigned int i; 65 66 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", 67 acred->uid, acred->gid); 68 69 if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS))) 70 return ERR_PTR(-ENOMEM); 71 72 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops); 73 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; 74 75 if (acred->group_info != NULL) 76 groups = acred->group_info->ngroups; 77 if (groups > NFS_NGROUPS) 78 groups = NFS_NGROUPS; 79 80 cred->uc_gid = acred->gid; 81 for (i = 0; i < groups; i++) 82 cred->uc_gids[i] = GROUP_AT(acred->group_info, i); 83 if (i < NFS_NGROUPS) 84 cred->uc_gids[i] = NOGROUP; 85 86 return &cred->uc_base; 87 } 88 89 static void 90 unx_free_cred(struct unx_cred *unx_cred) 91 { 92 dprintk("RPC: unx_free_cred %p\n", unx_cred); 93 kfree(unx_cred); 94 } 95 96 static void 97 unx_free_cred_callback(struct rcu_head *head) 98 { 99 struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu); 100 unx_free_cred(unx_cred); 101 } 102 103 static void 104 unx_destroy_cred(struct rpc_cred *cred) 105 { 106 call_rcu(&cred->cr_rcu, unx_free_cred_callback); 107 } 108 109 /* 110 * Match credentials against current process creds. 111 * The root_override argument takes care of cases where the caller may 112 * request root creds (e.g. for NFS swapping). 113 */ 114 static int 115 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags) 116 { 117 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base); 118 unsigned int groups = 0; 119 unsigned int i; 120 121 122 if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid) 123 return 0; 124 125 if (acred->group_info != NULL) 126 groups = acred->group_info->ngroups; 127 if (groups > NFS_NGROUPS) 128 groups = NFS_NGROUPS; 129 for (i = 0; i < groups ; i++) 130 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i)) 131 return 0; 132 return 1; 133 } 134 135 /* 136 * Marshal credentials. 137 * Maybe we should keep a cached credential for performance reasons. 138 */ 139 static __be32 * 140 unx_marshal(struct rpc_task *task, __be32 *p) 141 { 142 struct rpc_clnt *clnt = task->tk_client; 143 struct unx_cred *cred = container_of(task->tk_msg.rpc_cred, struct unx_cred, uc_base); 144 __be32 *base, *hold; 145 int i; 146 147 *p++ = htonl(RPC_AUTH_UNIX); 148 base = p++; 149 *p++ = htonl(jiffies/HZ); 150 151 /* 152 * Copy the UTS nodename captured when the client was created. 153 */ 154 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); 155 156 *p++ = htonl((u32) cred->uc_uid); 157 *p++ = htonl((u32) cred->uc_gid); 158 hold = p++; 159 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) 160 *p++ = htonl((u32) cred->uc_gids[i]); 161 *hold = htonl(p - hold - 1); /* gid array length */ 162 *base = htonl((p - base - 1) << 2); /* cred length */ 163 164 *p++ = htonl(RPC_AUTH_NULL); 165 *p++ = htonl(0); 166 167 return p; 168 } 169 170 /* 171 * Refresh credentials. This is a no-op for AUTH_UNIX 172 */ 173 static int 174 unx_refresh(struct rpc_task *task) 175 { 176 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_msg.rpc_cred->cr_flags); 177 return 0; 178 } 179 180 static __be32 * 181 unx_validate(struct rpc_task *task, __be32 *p) 182 { 183 rpc_authflavor_t flavor; 184 u32 size; 185 186 flavor = ntohl(*p++); 187 if (flavor != RPC_AUTH_NULL && 188 flavor != RPC_AUTH_UNIX && 189 flavor != RPC_AUTH_SHORT) { 190 printk("RPC: bad verf flavor: %u\n", flavor); 191 return NULL; 192 } 193 194 size = ntohl(*p++); 195 if (size > RPC_MAX_AUTH_SIZE) { 196 printk("RPC: giant verf size: %u\n", size); 197 return NULL; 198 } 199 task->tk_msg.rpc_cred->cr_auth->au_rslack = (size >> 2) + 2; 200 p += (size >> 2); 201 202 return p; 203 } 204 205 void __init rpc_init_authunix(void) 206 { 207 spin_lock_init(&unix_cred_cache.lock); 208 } 209 210 const struct rpc_authops authunix_ops = { 211 .owner = THIS_MODULE, 212 .au_flavor = RPC_AUTH_UNIX, 213 .au_name = "UNIX", 214 .create = unx_create, 215 .destroy = unx_destroy, 216 .lookup_cred = unx_lookup_cred, 217 .crcreate = unx_create_cred, 218 }; 219 220 static 221 struct rpc_cred_cache unix_cred_cache = { 222 }; 223 224 static 225 struct rpc_auth unix_auth = { 226 .au_cslack = UNX_WRITESLACK, 227 .au_rslack = 2, /* assume AUTH_NULL verf */ 228 .au_ops = &authunix_ops, 229 .au_flavor = RPC_AUTH_UNIX, 230 .au_count = ATOMIC_INIT(0), 231 .au_credcache = &unix_cred_cache, 232 }; 233 234 static 235 const struct rpc_credops unix_credops = { 236 .cr_name = "AUTH_UNIX", 237 .crdestroy = unx_destroy_cred, 238 .crbind = rpcauth_generic_bind_cred, 239 .crmatch = unx_match, 240 .crmarshal = unx_marshal, 241 .crrefresh = unx_refresh, 242 .crvalidate = unx_validate, 243 }; 244