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_authop = aops; 58 return aops->accept(rqstp, authp); 59 } 60 EXPORT_SYMBOL_GPL(svc_authenticate); 61 62 int svc_set_client(struct svc_rqst *rqstp) 63 { 64 return rqstp->rq_authop->set_client(rqstp); 65 } 66 EXPORT_SYMBOL_GPL(svc_set_client); 67 68 /* A request, which was authenticated, has now executed. 69 * Time to finalise the credentials and verifier 70 * and release and resources 71 */ 72 int svc_authorise(struct svc_rqst *rqstp) 73 { 74 struct auth_ops *aops = rqstp->rq_authop; 75 int rv = 0; 76 77 rqstp->rq_authop = NULL; 78 79 if (aops) { 80 rv = aops->release(rqstp); 81 module_put(aops->owner); 82 } 83 return rv; 84 } 85 86 int 87 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops) 88 { 89 int rv = -EINVAL; 90 spin_lock(&authtab_lock); 91 if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) { 92 authtab[flavor] = aops; 93 rv = 0; 94 } 95 spin_unlock(&authtab_lock); 96 return rv; 97 } 98 EXPORT_SYMBOL_GPL(svc_auth_register); 99 100 void 101 svc_auth_unregister(rpc_authflavor_t flavor) 102 { 103 spin_lock(&authtab_lock); 104 if (flavor < RPC_AUTH_MAXFLAVOR) 105 authtab[flavor] = NULL; 106 spin_unlock(&authtab_lock); 107 } 108 EXPORT_SYMBOL_GPL(svc_auth_unregister); 109 110 /************************************************** 111 * 'auth_domains' are stored in a hash table indexed by name. 112 * When the last reference to an 'auth_domain' is dropped, 113 * the object is unhashed and freed. 114 * If auth_domain_lookup fails to find an entry, it will return 115 * it's second argument 'new'. If this is non-null, it will 116 * have been atomically linked into the table. 117 */ 118 119 #define DN_HASHBITS 6 120 #define DN_HASHMAX (1<<DN_HASHBITS) 121 122 static struct hlist_head auth_domain_table[DN_HASHMAX]; 123 static spinlock_t auth_domain_lock = 124 __SPIN_LOCK_UNLOCKED(auth_domain_lock); 125 126 void auth_domain_put(struct auth_domain *dom) 127 { 128 if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) { 129 hlist_del(&dom->hash); 130 dom->flavour->domain_release(dom); 131 spin_unlock(&auth_domain_lock); 132 } 133 } 134 EXPORT_SYMBOL_GPL(auth_domain_put); 135 136 struct auth_domain * 137 auth_domain_lookup(char *name, struct auth_domain *new) 138 { 139 struct auth_domain *hp; 140 struct hlist_head *head; 141 142 head = &auth_domain_table[hash_str(name, DN_HASHBITS)]; 143 144 spin_lock(&auth_domain_lock); 145 146 hlist_for_each_entry(hp, head, hash) { 147 if (strcmp(hp->name, name)==0) { 148 kref_get(&hp->ref); 149 spin_unlock(&auth_domain_lock); 150 return hp; 151 } 152 } 153 if (new) 154 hlist_add_head(&new->hash, head); 155 spin_unlock(&auth_domain_lock); 156 return new; 157 } 158 EXPORT_SYMBOL_GPL(auth_domain_lookup); 159 160 struct auth_domain *auth_domain_find(char *name) 161 { 162 return auth_domain_lookup(name, NULL); 163 } 164 EXPORT_SYMBOL_GPL(auth_domain_find); 165