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", clnt); 43 if (atomic_inc_return(&unix_auth.au_count) == 0) 44 unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1); 45 return &unix_auth; 46 } 47 48 static void 49 unx_destroy(struct rpc_auth *auth) 50 { 51 dprintk("RPC: destroying UNIX authenticator %p\n", auth); 52 rpcauth_free_credcache(auth); 53 } 54 55 /* 56 * Lookup AUTH_UNIX creds for current process 57 */ 58 static struct rpc_cred * 59 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 60 { 61 return rpcauth_lookup_credcache(auth, acred, flags); 62 } 63 64 static struct rpc_cred * 65 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 66 { 67 struct unx_cred *cred; 68 int i; 69 70 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", 71 acred->uid, acred->gid); 72 73 if (!(cred = (struct unx_cred *) kmalloc(sizeof(*cred), GFP_KERNEL))) 74 return ERR_PTR(-ENOMEM); 75 76 atomic_set(&cred->uc_count, 1); 77 cred->uc_flags = RPCAUTH_CRED_UPTODATE; 78 if (flags & RPC_TASK_ROOTCREDS) { 79 cred->uc_uid = 0; 80 cred->uc_gid = 0; 81 cred->uc_gids[0] = NOGROUP; 82 } else { 83 int groups = acred->group_info->ngroups; 84 if (groups > NFS_NGROUPS) 85 groups = NFS_NGROUPS; 86 87 cred->uc_uid = acred->uid; 88 cred->uc_gid = acred->gid; 89 for (i = 0; i < groups; i++) 90 cred->uc_gids[i] = GROUP_AT(acred->group_info, i); 91 if (i < NFS_NGROUPS) 92 cred->uc_gids[i] = NOGROUP; 93 } 94 cred->uc_base.cr_ops = &unix_credops; 95 96 return (struct rpc_cred *) cred; 97 } 98 99 static void 100 unx_destroy_cred(struct rpc_cred *cred) 101 { 102 kfree(cred); 103 } 104 105 /* 106 * Match credentials against current process creds. 107 * The root_override argument takes care of cases where the caller may 108 * request root creds (e.g. for NFS swapping). 109 */ 110 static int 111 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int taskflags) 112 { 113 struct unx_cred *cred = (struct unx_cred *) rcred; 114 int i; 115 116 if (!(taskflags & RPC_TASK_ROOTCREDS)) { 117 int groups; 118 119 if (cred->uc_uid != acred->uid 120 || cred->uc_gid != acred->gid) 121 return 0; 122 123 groups = acred->group_info->ngroups; 124 if (groups > NFS_NGROUPS) 125 groups = NFS_NGROUPS; 126 for (i = 0; i < groups ; i++) 127 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i)) 128 return 0; 129 return 1; 130 } 131 return (cred->uc_uid == 0 132 && cred->uc_gid == 0 133 && cred->uc_gids[0] == (gid_t) NOGROUP); 134 } 135 136 /* 137 * Marshal credentials. 138 * Maybe we should keep a cached credential for performance reasons. 139 */ 140 static u32 * 141 unx_marshal(struct rpc_task *task, u32 *p) 142 { 143 struct rpc_clnt *clnt = task->tk_client; 144 struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred; 145 u32 *base, *hold; 146 int i; 147 148 *p++ = htonl(RPC_AUTH_UNIX); 149 base = p++; 150 *p++ = htonl(jiffies/HZ); 151 152 /* 153 * Copy the UTS nodename captured when the client was created. 154 */ 155 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); 156 157 *p++ = htonl((u32) cred->uc_uid); 158 *p++ = htonl((u32) cred->uc_gid); 159 hold = p++; 160 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) 161 *p++ = htonl((u32) cred->uc_gids[i]); 162 *hold = htonl(p - hold - 1); /* gid array length */ 163 *base = htonl((p - base - 1) << 2); /* cred length */ 164 165 *p++ = htonl(RPC_AUTH_NULL); 166 *p++ = htonl(0); 167 168 return p; 169 } 170 171 /* 172 * Refresh credentials. This is a no-op for AUTH_UNIX 173 */ 174 static int 175 unx_refresh(struct rpc_task *task) 176 { 177 task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE; 178 return 0; 179 } 180 181 static u32 * 182 unx_validate(struct rpc_task *task, u32 *p) 183 { 184 rpc_authflavor_t flavor; 185 u32 size; 186 187 flavor = ntohl(*p++); 188 if (flavor != RPC_AUTH_NULL && 189 flavor != RPC_AUTH_UNIX && 190 flavor != RPC_AUTH_SHORT) { 191 printk("RPC: bad verf flavor: %u\n", flavor); 192 return NULL; 193 } 194 195 size = ntohl(*p++); 196 if (size > RPC_MAX_AUTH_SIZE) { 197 printk("RPC: giant verf size: %u\n", size); 198 return NULL; 199 } 200 task->tk_auth->au_rslack = (size >> 2) + 2; 201 p += (size >> 2); 202 203 return p; 204 } 205 206 struct rpc_authops authunix_ops = { 207 .owner = THIS_MODULE, 208 .au_flavor = RPC_AUTH_UNIX, 209 #ifdef RPC_DEBUG 210 .au_name = "UNIX", 211 #endif 212 .create = unx_create, 213 .destroy = unx_destroy, 214 .lookup_cred = unx_lookup_cred, 215 .crcreate = unx_create_cred, 216 }; 217 218 static 219 struct rpc_cred_cache unix_cred_cache = { 220 .expire = UNX_CRED_EXPIRE, 221 }; 222 223 static 224 struct rpc_auth unix_auth = { 225 .au_cslack = UNX_WRITESLACK, 226 .au_rslack = 2, /* assume AUTH_NULL verf */ 227 .au_ops = &authunix_ops, 228 .au_count = ATOMIC_INIT(0), 229 .au_credcache = &unix_cred_cache, 230 }; 231 232 static 233 struct rpc_credops unix_credops = { 234 .cr_name = "AUTH_UNIX", 235 .crdestroy = unx_destroy_cred, 236 .crmatch = unx_match, 237 .crmarshal = unx_marshal, 238 .crrefresh = unx_refresh, 239 .crvalidate = unx_validate, 240 }; 241