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, u32 *authp) 39 { 40 rpc_authflavor_t flavor; 41 struct auth_ops *aops; 42 43 *authp = rpc_auth_ok; 44 45 flavor = ntohl(svc_getu32(&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 * cache for domain name to auth_domain 110 * Entries are only added by flavours which will normally 111 * have a structure that 'inherits' from auth_domain. 112 * e.g. when an IP -> domainname is given to auth_unix, 113 * and the domain name doesn't exist, it will create a 114 * auth_unix_domain and add it to this hash table. 115 * If it finds the name does exist, but isn't AUTH_UNIX, 116 * it will complain. 117 */ 118 119 /* 120 * Auth auth_domain cache is somewhat different to other caches, 121 * largely because the entries are possibly of different types: 122 * each auth flavour has it's own type. 123 * One consequence of this that DefineCacheLookup cannot 124 * allocate a new structure as it cannot know the size. 125 * Notice that the "INIT" code fragment is quite different 126 * from other caches. When auth_domain_lookup might be 127 * creating a new domain, the new domain is passed in 128 * complete and it is used as-is rather than being copied into 129 * another structure. 130 */ 131 #define DN_HASHBITS 6 132 #define DN_HASHMAX (1<<DN_HASHBITS) 133 #define DN_HASHMASK (DN_HASHMAX-1) 134 135 static struct cache_head *auth_domain_table[DN_HASHMAX]; 136 137 static void auth_domain_drop(struct cache_head *item, struct cache_detail *cd) 138 { 139 struct auth_domain *dom = container_of(item, struct auth_domain, h); 140 if (cache_put(item,cd)) 141 authtab[dom->flavour]->domain_release(dom); 142 } 143 144 145 struct cache_detail auth_domain_cache = { 146 .owner = THIS_MODULE, 147 .hash_size = DN_HASHMAX, 148 .hash_table = auth_domain_table, 149 .name = "auth.domain", 150 .cache_put = auth_domain_drop, 151 }; 152 153 void auth_domain_put(struct auth_domain *dom) 154 { 155 auth_domain_drop(&dom->h, &auth_domain_cache); 156 } 157 158 static inline int auth_domain_hash(struct auth_domain *item) 159 { 160 return hash_str(item->name, DN_HASHBITS); 161 } 162 static inline int auth_domain_match(struct auth_domain *tmp, struct auth_domain *item) 163 { 164 return strcmp(tmp->name, item->name) == 0; 165 } 166 167 struct auth_domain * 168 auth_domain_lookup(struct auth_domain *item, int set) 169 { 170 struct auth_domain *tmp = NULL; 171 struct cache_head **hp, **head; 172 head = &auth_domain_cache.hash_table[auth_domain_hash(item)]; 173 174 if (set) 175 write_lock(&auth_domain_cache.hash_lock); 176 else 177 read_lock(&auth_domain_cache.hash_lock); 178 for (hp=head; *hp != NULL; hp = &tmp->h.next) { 179 tmp = container_of(*hp, struct auth_domain, h); 180 if (!auth_domain_match(tmp, item)) 181 continue; 182 if (!set) { 183 cache_get(&tmp->h); 184 goto out_noset; 185 } 186 *hp = tmp->h.next; 187 tmp->h.next = NULL; 188 auth_domain_drop(&tmp->h, &auth_domain_cache); 189 goto out_set; 190 } 191 /* Didn't find anything */ 192 if (!set) 193 goto out_nada; 194 auth_domain_cache.entries++; 195 out_set: 196 item->h.next = *head; 197 *head = &item->h; 198 cache_get(&item->h); 199 write_unlock(&auth_domain_cache.hash_lock); 200 cache_fresh(&auth_domain_cache, &item->h, item->h.expiry_time); 201 cache_get(&item->h); 202 return item; 203 out_nada: 204 tmp = NULL; 205 out_noset: 206 read_unlock(&auth_domain_cache.hash_lock); 207 return tmp; 208 } 209 210 struct auth_domain *auth_domain_find(char *name) 211 { 212 struct auth_domain *rv, ad; 213 214 ad.name = name; 215 rv = auth_domain_lookup(&ad, 0); 216 return rv; 217 } 218