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 #define uc_count uc_base.cr_count 24 #define uc_flags uc_base.cr_flags 25 #define uc_expire uc_base.cr_expire 26 27 #define UNX_CRED_EXPIRE (60 * HZ) 28 29 #define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) 30 31 #ifdef RPC_DEBUG 32 # define RPCDBG_FACILITY RPCDBG_AUTH 33 #endif 34 35 static struct rpc_auth unix_auth; 36 static struct rpc_cred_cache unix_cred_cache; 37 static struct rpc_credops unix_credops; 38 39 static struct rpc_auth * 40 unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 41 { 42 dprintk("RPC: creating UNIX authenticator for client %p\n", 43 clnt); 44 if (atomic_inc_return(&unix_auth.au_count) == 0) 45 unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1); 46 return &unix_auth; 47 } 48 49 static void 50 unx_destroy(struct rpc_auth *auth) 51 { 52 dprintk("RPC: destroying UNIX authenticator %p\n", auth); 53 rpcauth_free_credcache(auth); 54 } 55 56 /* 57 * Lookup AUTH_UNIX creds for current process 58 */ 59 static struct rpc_cred * 60 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 61 { 62 return rpcauth_lookup_credcache(auth, acred, flags); 63 } 64 65 static struct rpc_cred * 66 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 67 { 68 struct unx_cred *cred; 69 int i; 70 71 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", 72 acred->uid, acred->gid); 73 74 if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL))) 75 return ERR_PTR(-ENOMEM); 76 77 atomic_set(&cred->uc_count, 1); 78 cred->uc_flags = RPCAUTH_CRED_UPTODATE; 79 if (flags & RPCAUTH_LOOKUP_ROOTCREDS) { 80 cred->uc_uid = 0; 81 cred->uc_gid = 0; 82 cred->uc_gids[0] = NOGROUP; 83 } else { 84 int groups = acred->group_info->ngroups; 85 if (groups > NFS_NGROUPS) 86 groups = NFS_NGROUPS; 87 88 cred->uc_uid = acred->uid; 89 cred->uc_gid = acred->gid; 90 for (i = 0; i < groups; i++) 91 cred->uc_gids[i] = GROUP_AT(acred->group_info, i); 92 if (i < NFS_NGROUPS) 93 cred->uc_gids[i] = NOGROUP; 94 } 95 cred->uc_base.cr_ops = &unix_credops; 96 97 return (struct rpc_cred *) cred; 98 } 99 100 static void 101 unx_destroy_cred(struct rpc_cred *cred) 102 { 103 kfree(cred); 104 } 105 106 /* 107 * Match credentials against current process creds. 108 * The root_override argument takes care of cases where the caller may 109 * request root creds (e.g. for NFS swapping). 110 */ 111 static int 112 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags) 113 { 114 struct unx_cred *cred = (struct unx_cred *) rcred; 115 int i; 116 117 if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) { 118 int groups; 119 120 if (cred->uc_uid != acred->uid 121 || cred->uc_gid != acred->gid) 122 return 0; 123 124 groups = acred->group_info->ngroups; 125 if (groups > NFS_NGROUPS) 126 groups = NFS_NGROUPS; 127 for (i = 0; i < groups ; i++) 128 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i)) 129 return 0; 130 return 1; 131 } 132 return (cred->uc_uid == 0 133 && cred->uc_gid == 0 134 && cred->uc_gids[0] == (gid_t) NOGROUP); 135 } 136 137 /* 138 * Marshal credentials. 139 * Maybe we should keep a cached credential for performance reasons. 140 */ 141 static __be32 * 142 unx_marshal(struct rpc_task *task, __be32 *p) 143 { 144 struct rpc_clnt *clnt = task->tk_client; 145 struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred; 146 __be32 *base, *hold; 147 int i; 148 149 *p++ = htonl(RPC_AUTH_UNIX); 150 base = p++; 151 *p++ = htonl(jiffies/HZ); 152 153 /* 154 * Copy the UTS nodename captured when the client was created. 155 */ 156 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); 157 158 *p++ = htonl((u32) cred->uc_uid); 159 *p++ = htonl((u32) cred->uc_gid); 160 hold = p++; 161 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) 162 *p++ = htonl((u32) cred->uc_gids[i]); 163 *hold = htonl(p - hold - 1); /* gid array length */ 164 *base = htonl((p - base - 1) << 2); /* cred length */ 165 166 *p++ = htonl(RPC_AUTH_NULL); 167 *p++ = htonl(0); 168 169 return p; 170 } 171 172 /* 173 * Refresh credentials. This is a no-op for AUTH_UNIX 174 */ 175 static int 176 unx_refresh(struct rpc_task *task) 177 { 178 task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE; 179 return 0; 180 } 181 182 static __be32 * 183 unx_validate(struct rpc_task *task, __be32 *p) 184 { 185 rpc_authflavor_t flavor; 186 u32 size; 187 188 flavor = ntohl(*p++); 189 if (flavor != RPC_AUTH_NULL && 190 flavor != RPC_AUTH_UNIX && 191 flavor != RPC_AUTH_SHORT) { 192 printk("RPC: bad verf flavor: %u\n", flavor); 193 return NULL; 194 } 195 196 size = ntohl(*p++); 197 if (size > RPC_MAX_AUTH_SIZE) { 198 printk("RPC: giant verf size: %u\n", size); 199 return NULL; 200 } 201 task->tk_auth->au_rslack = (size >> 2) + 2; 202 p += (size >> 2); 203 204 return p; 205 } 206 207 struct rpc_authops authunix_ops = { 208 .owner = THIS_MODULE, 209 .au_flavor = RPC_AUTH_UNIX, 210 #ifdef RPC_DEBUG 211 .au_name = "UNIX", 212 #endif 213 .create = unx_create, 214 .destroy = unx_destroy, 215 .lookup_cred = unx_lookup_cred, 216 .crcreate = unx_create_cred, 217 }; 218 219 static 220 struct rpc_cred_cache unix_cred_cache = { 221 .expire = UNX_CRED_EXPIRE, 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 struct rpc_credops unix_credops = { 236 .cr_name = "AUTH_UNIX", 237 .crdestroy = unx_destroy_cred, 238 .crmatch = unx_match, 239 .crmarshal = unx_marshal, 240 .crrefresh = unx_refresh, 241 .crvalidate = unx_validate, 242 }; 243