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