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 59 rqstp->rq_authop = aops; 60 return aops->accept(rqstp, authp); 61 } 62 EXPORT_SYMBOL_GPL(svc_authenticate); 63 64 int svc_set_client(struct svc_rqst *rqstp) 65 { 66 return rqstp->rq_authop->set_client(rqstp); 67 } 68 EXPORT_SYMBOL_GPL(svc_set_client); 69 70 /* A request, which was authenticated, has now executed. 71 * Time to finalise the credentials and verifier 72 * and release and resources 73 */ 74 int svc_authorise(struct svc_rqst *rqstp) 75 { 76 struct auth_ops *aops = rqstp->rq_authop; 77 int rv = 0; 78 79 rqstp->rq_authop = NULL; 80 81 if (aops) { 82 rv = aops->release(rqstp); 83 module_put(aops->owner); 84 } 85 return rv; 86 } 87 88 int 89 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops) 90 { 91 int rv = -EINVAL; 92 spin_lock(&authtab_lock); 93 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) { 94 authtab[flavor] = aops; 95 rv = 0; 96 } 97 spin_unlock(&authtab_lock); 98 return rv; 99 } 100 EXPORT_SYMBOL_GPL(svc_auth_register); 101 102 void 103 svc_auth_unregister(rpc_authflavor_t flavor) 104 { 105 spin_lock(&authtab_lock); 106 if (flavor < RPC_AUTH_MAXFLAVOR) 107 authtab[flavor] = NULL; 108 spin_unlock(&authtab_lock); 109 } 110 EXPORT_SYMBOL_GPL(svc_auth_unregister); 111 112 /************************************************** 113 * 'auth_domains' are stored in a hash table indexed by name. 114 * When the last reference to an 'auth_domain' is dropped, 115 * the object is unhashed and freed. 116 * If auth_domain_lookup fails to find an entry, it will return 117 * it's second argument 'new'. If this is non-null, it will 118 * have been atomically linked into the table. 119 */ 120 121 #define DN_HASHBITS 6 122 #define DN_HASHMAX (1<<DN_HASHBITS) 123 124 static struct hlist_head auth_domain_table[DN_HASHMAX]; 125 static spinlock_t auth_domain_lock = 126 __SPIN_LOCK_UNLOCKED(auth_domain_lock); 127 128 void auth_domain_put(struct auth_domain *dom) 129 { 130 if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) { 131 hlist_del(&dom->hash); 132 dom->flavour->domain_release(dom); 133 spin_unlock(&auth_domain_lock); 134 } 135 } 136 EXPORT_SYMBOL_GPL(auth_domain_put); 137 138 struct auth_domain * 139 auth_domain_lookup(char *name, struct auth_domain *new) 140 { 141 struct auth_domain *hp; 142 struct hlist_head *head; 143 144 head = &auth_domain_table[hash_str(name, DN_HASHBITS)]; 145 146 spin_lock(&auth_domain_lock); 147 148 hlist_for_each_entry(hp, head, hash) { 149 if (strcmp(hp->name, name)==0) { 150 kref_get(&hp->ref); 151 spin_unlock(&auth_domain_lock); 152 return hp; 153 } 154 } 155 if (new) 156 hlist_add_head(&new->hash, head); 157 spin_unlock(&auth_domain_lock); 158 return new; 159 } 160 EXPORT_SYMBOL_GPL(auth_domain_lookup); 161 162 struct auth_domain *auth_domain_find(char *name) 163 { 164 return auth_domain_lookup(name, NULL); 165 } 166 EXPORT_SYMBOL_GPL(auth_domain_find); 167