1 /* 2 * linux/net/sunrpc/svcauth.c 3 * 4 * The generic interface for RPC authentication on the server side. 5 * 6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> 7 * 8 * CHANGES 9 * 19-Apr-2000 Chris Evans - Security fix 10 */ 11 12 #include <linux/types.h> 13 #include <linux/module.h> 14 #include <linux/sunrpc/types.h> 15 #include <linux/sunrpc/xdr.h> 16 #include <linux/sunrpc/svcsock.h> 17 #include <linux/sunrpc/svcauth.h> 18 #include <linux/err.h> 19 #include <linux/hash.h> 20 21 #define RPCDBG_FACILITY RPCDBG_AUTH 22 23 24 /* 25 * Table of authenticators 26 */ 27 extern struct auth_ops svcauth_null; 28 extern struct auth_ops svcauth_unix; 29 30 static DEFINE_SPINLOCK(authtab_lock); 31 static struct auth_ops *authtab[RPC_AUTH_MAXFLAVOR] = { 32 [0] = &svcauth_null, 33 [1] = &svcauth_unix, 34 }; 35 36 int 37 svc_authenticate(struct svc_rqst *rqstp, __be32 *authp) 38 { 39 rpc_authflavor_t flavor; 40 struct auth_ops *aops; 41 42 *authp = rpc_auth_ok; 43 44 flavor = svc_getnl(&rqstp->rq_arg.head[0]); 45 46 dprintk("svc: svc_authenticate (%d)\n", flavor); 47 48 spin_lock(&authtab_lock); 49 if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) || 50 !try_module_get(aops->owner)) { 51 spin_unlock(&authtab_lock); 52 *authp = rpc_autherr_badcred; 53 return SVC_DENIED; 54 } 55 spin_unlock(&authtab_lock); 56 57 rqstp->rq_auth_slack = 0; 58 init_svc_cred(&rqstp->rq_cred); 59 60 rqstp->rq_authop = aops; 61 return aops->accept(rqstp, authp); 62 } 63 EXPORT_SYMBOL_GPL(svc_authenticate); 64 65 int svc_set_client(struct svc_rqst *rqstp) 66 { 67 rqstp->rq_client = NULL; 68 return rqstp->rq_authop->set_client(rqstp); 69 } 70 EXPORT_SYMBOL_GPL(svc_set_client); 71 72 /* A request, which was authenticated, has now executed. 73 * Time to finalise the credentials and verifier 74 * and release and resources 75 */ 76 int svc_authorise(struct svc_rqst *rqstp) 77 { 78 struct auth_ops *aops = rqstp->rq_authop; 79 int rv = 0; 80 81 rqstp->rq_authop = NULL; 82 83 if (aops) { 84 rv = aops->release(rqstp); 85 module_put(aops->owner); 86 } 87 return rv; 88 } 89 90 int 91 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops) 92 { 93 int rv = -EINVAL; 94 spin_lock(&authtab_lock); 95 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) { 96 authtab[flavor] = aops; 97 rv = 0; 98 } 99 spin_unlock(&authtab_lock); 100 return rv; 101 } 102 EXPORT_SYMBOL_GPL(svc_auth_register); 103 104 void 105 svc_auth_unregister(rpc_authflavor_t flavor) 106 { 107 spin_lock(&authtab_lock); 108 if (flavor < RPC_AUTH_MAXFLAVOR) 109 authtab[flavor] = NULL; 110 spin_unlock(&authtab_lock); 111 } 112 EXPORT_SYMBOL_GPL(svc_auth_unregister); 113 114 /************************************************** 115 * 'auth_domains' are stored in a hash table indexed by name. 116 * When the last reference to an 'auth_domain' is dropped, 117 * the object is unhashed and freed. 118 * If auth_domain_lookup fails to find an entry, it will return 119 * it's second argument 'new'. If this is non-null, it will 120 * have been atomically linked into the table. 121 */ 122 123 #define DN_HASHBITS 6 124 #define DN_HASHMAX (1<<DN_HASHBITS) 125 126 static struct hlist_head auth_domain_table[DN_HASHMAX]; 127 static spinlock_t auth_domain_lock = 128 __SPIN_LOCK_UNLOCKED(auth_domain_lock); 129 130 void auth_domain_put(struct auth_domain *dom) 131 { 132 if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) { 133 hlist_del(&dom->hash); 134 dom->flavour->domain_release(dom); 135 spin_unlock(&auth_domain_lock); 136 } 137 } 138 EXPORT_SYMBOL_GPL(auth_domain_put); 139 140 struct auth_domain * 141 auth_domain_lookup(char *name, struct auth_domain *new) 142 { 143 struct auth_domain *hp; 144 struct hlist_head *head; 145 146 head = &auth_domain_table[hash_str(name, DN_HASHBITS)]; 147 148 spin_lock(&auth_domain_lock); 149 150 hlist_for_each_entry(hp, head, hash) { 151 if (strcmp(hp->name, name)==0) { 152 kref_get(&hp->ref); 153 spin_unlock(&auth_domain_lock); 154 return hp; 155 } 156 } 157 if (new) 158 hlist_add_head(&new->hash, head); 159 spin_unlock(&auth_domain_lock); 160 return new; 161 } 162 EXPORT_SYMBOL_GPL(auth_domain_lookup); 163 164 struct auth_domain *auth_domain_find(char *name) 165 { 166 return auth_domain_lookup(name, NULL); 167 } 168 EXPORT_SYMBOL_GPL(auth_domain_find); 169