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/slab.h> 10 #include <linux/types.h> 11 #include <linux/sched.h> 12 #include <linux/module.h> 13 #include <linux/sunrpc/clnt.h> 14 #include <linux/sunrpc/auth.h> 15 16 #define NFS_NGROUPS 16 17 18 struct unx_cred { 19 struct rpc_cred uc_base; 20 gid_t uc_gid; 21 gid_t uc_gids[NFS_NGROUPS]; 22 }; 23 #define uc_uid uc_base.cr_uid 24 25 #define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) 26 27 #ifdef RPC_DEBUG 28 # define RPCDBG_FACILITY RPCDBG_AUTH 29 #endif 30 31 static struct rpc_auth unix_auth; 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 if (groups < NFS_NGROUPS && 133 cred->uc_gids[groups] != NOGROUP) 134 return 0; 135 return 1; 136 } 137 138 /* 139 * Marshal credentials. 140 * Maybe we should keep a cached credential for performance reasons. 141 */ 142 static __be32 * 143 unx_marshal(struct rpc_task *task, __be32 *p) 144 { 145 struct rpc_clnt *clnt = task->tk_client; 146 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base); 147 __be32 *base, *hold; 148 int i; 149 150 *p++ = htonl(RPC_AUTH_UNIX); 151 base = p++; 152 *p++ = htonl(jiffies/HZ); 153 154 /* 155 * Copy the UTS nodename captured when the client was created. 156 */ 157 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); 158 159 *p++ = htonl((u32) cred->uc_uid); 160 *p++ = htonl((u32) cred->uc_gid); 161 hold = p++; 162 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) 163 *p++ = htonl((u32) cred->uc_gids[i]); 164 *hold = htonl(p - hold - 1); /* gid array length */ 165 *base = htonl((p - base - 1) << 2); /* cred length */ 166 167 *p++ = htonl(RPC_AUTH_NULL); 168 *p++ = htonl(0); 169 170 return p; 171 } 172 173 /* 174 * Refresh credentials. This is a no-op for AUTH_UNIX 175 */ 176 static int 177 unx_refresh(struct rpc_task *task) 178 { 179 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags); 180 return 0; 181 } 182 183 static __be32 * 184 unx_validate(struct rpc_task *task, __be32 *p) 185 { 186 rpc_authflavor_t flavor; 187 u32 size; 188 189 flavor = ntohl(*p++); 190 if (flavor != RPC_AUTH_NULL && 191 flavor != RPC_AUTH_UNIX && 192 flavor != RPC_AUTH_SHORT) { 193 printk("RPC: bad verf flavor: %u\n", flavor); 194 return NULL; 195 } 196 197 size = ntohl(*p++); 198 if (size > RPC_MAX_AUTH_SIZE) { 199 printk("RPC: giant verf size: %u\n", size); 200 return NULL; 201 } 202 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2; 203 p += (size >> 2); 204 205 return p; 206 } 207 208 int __init rpc_init_authunix(void) 209 { 210 return rpcauth_init_credcache(&unix_auth); 211 } 212 213 void rpc_destroy_authunix(void) 214 { 215 rpcauth_destroy_credcache(&unix_auth); 216 } 217 218 const struct rpc_authops authunix_ops = { 219 .owner = THIS_MODULE, 220 .au_flavor = RPC_AUTH_UNIX, 221 .au_name = "UNIX", 222 .create = unx_create, 223 .destroy = unx_destroy, 224 .lookup_cred = unx_lookup_cred, 225 .crcreate = unx_create_cred, 226 }; 227 228 static 229 struct rpc_auth unix_auth = { 230 .au_cslack = UNX_WRITESLACK, 231 .au_rslack = 2, /* assume AUTH_NULL verf */ 232 .au_ops = &authunix_ops, 233 .au_flavor = RPC_AUTH_UNIX, 234 .au_count = ATOMIC_INIT(0), 235 }; 236 237 static 238 const struct rpc_credops unix_credops = { 239 .cr_name = "AUTH_UNIX", 240 .crdestroy = unx_destroy_cred, 241 .crbind = rpcauth_generic_bind_cred, 242 .crmatch = unx_match, 243 .crmarshal = unx_marshal, 244 .crrefresh = unx_refresh, 245 .crvalidate = unx_validate, 246 }; 247