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