net/sunrpc/svcauth_unix.c

   1 #include <linux/types.h>
   2 #include <linux/sched.h>
   3 #include <linux/module.h>
   4 #include <linux/sunrpc/types.h>
   5 #include <linux/sunrpc/xdr.h>
   6 #include <linux/sunrpc/svcsock.h>
   7 #include <linux/sunrpc/svcauth.h>
   8 #include <linux/err.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/hash.h>
  11
  12 #define RPCDBG_FACILITY RPCDBG_AUTH
  13
  14
  15 /*
  16  * AUTHUNIX and AUTHNULL credentials are both handled here.
  17  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
  18  * are always nobody (-2).  i.e. we do the same IP address checks for
  19  * AUTHNULL as for AUTHUNIX, and that is done here.
  20  */
  21
  22
  23 static char *strdup(char *s)
  24 {
  25         char *rv = kmalloc(strlen(s)+1, GFP_KERNEL);
  26         if (rv)
  27                 strcpy(rv, s);
  28         return rv;
  29 }
  30
  31 struct unix_domain {
  32         struct auth_domain      h;
  33         int     addr_changes;
  34         /* other stuff later */
  35 };
  36
  37 struct auth_domain *unix_domain_find(char *name)
  38 {
  39         struct auth_domain *rv, ud;
  40         struct unix_domain *new;
  41
  42         ud.name = name;
  43
  44         rv = auth_domain_lookup(&ud, 0);
  45
  46  foundit:
  47         if (rv && rv->flavour != RPC_AUTH_UNIX) {
  48                 auth_domain_put(rv);
  49                 return NULL;
  50         }
  51         if (rv)
  52                 return rv;
  53
  54         new = kmalloc(sizeof(*new), GFP_KERNEL);
  55         if (new == NULL)
  56                 return NULL;
  57         cache_init(&new->h.h);
  58         new->h.name = strdup(name);
  59         new->h.flavour = RPC_AUTH_UNIX;
  60         new->addr_changes = 0;
  61         new->h.h.expiry_time = NEVER;
  62
  63         rv = auth_domain_lookup(&new->h, 2);
  64         if (rv == &new->h) {
  65                 if (atomic_dec_and_test(&new->h.h.refcnt)) BUG();
  66         } else {
  67                 auth_domain_put(&new->h);
  68                 goto foundit;
  69         }
  70
  71         return rv;
  72 }
  73
  74 static void svcauth_unix_domain_release(struct auth_domain *dom)
  75 {
  76         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
  77
  78         kfree(dom->name);
  79         kfree(ud);
  80 }
  81
  82
  83 /**************************************************
  84  * cache for IP address to unix_domain
  85  * as needed by AUTH_UNIX
  86  */
  87 #define IP_HASHBITS     8
  88 #define IP_HASHMAX      (1<<IP_HASHBITS)
  89 #define IP_HASHMASK     (IP_HASHMAX-1)
  90
  91 struct ip_map {
  92         struct cache_head       h;
  93         char                    m_class[8]; /* e.g. "nfsd" */
  94         struct in_addr          m_addr;
  95         struct unix_domain      *m_client;
  96         int                     m_add_change;
  97 };
  98 static struct cache_head        *ip_table[IP_HASHMAX];
  99
 100 static void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 101 {
 102         struct ip_map *im = container_of(item, struct ip_map,h);
 103         if (cache_put(item, cd)) {
 104                 if (test_bit(CACHE_VALID, &item->flags) &&
 105                     !test_bit(CACHE_NEGATIVE, &item->flags))
 106                         auth_domain_put(&im->m_client->h);
 107                 kfree(im);
 108         }
 109 }
 110
 111 static inline int ip_map_hash(struct ip_map *item)
 112 {
 113         return hash_str(item->m_class, IP_HASHBITS) ^
 114                 hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
 115 }
 116 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 117 {
 118         return strcmp(tmp->m_class, item->m_class) == 0
 119                 && tmp->m_addr.s_addr == item->m_addr.s_addr;
 120 }
 121 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
 122 {
 123         strcpy(new->m_class, item->m_class);
 124         new->m_addr.s_addr = item->m_addr.s_addr;
 125 }
 126 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
 127 {
 128         cache_get(&item->m_client->h.h);
 129         new->m_client = item->m_client;
 130         new->m_add_change = item->m_add_change;
 131 }
 132
 133 static void ip_map_request(struct cache_detail *cd,
 134                                   struct cache_head *h,
 135                                   char **bpp, int *blen)
 136 {
 137         char text_addr[20];
 138         struct ip_map *im = container_of(h, struct ip_map, h);
 139         __u32 addr = im->m_addr.s_addr;
 140
 141         snprintf(text_addr, 20, "%u.%u.%u.%u",
 142                  ntohl(addr) >> 24 & 0xff,
 143                  ntohl(addr) >> 16 & 0xff,
 144                  ntohl(addr) >>  8 & 0xff,
 145                  ntohl(addr) >>  0 & 0xff);
 146
 147         qword_add(bpp, blen, im->m_class);
 148         qword_add(bpp, blen, text_addr);
 149         (*bpp)[-1] = '\n';
 150 }
 151
 152 static struct ip_map *ip_map_lookup(struct ip_map *, int);
 153
 154 static int ip_map_parse(struct cache_detail *cd,
 155                           char *mesg, int mlen)
 156 {
 157         /* class ipaddress [domainname] */
 158         /* should be safe just to use the start of the input buffer
 159          * for scratch: */
 160         char *buf = mesg;
 161         int len;
 162         int b1,b2,b3,b4;
 163         char c;
 164         struct ip_map ipm, *ipmp;
 165         struct auth_domain *dom;
 166         time_t expiry;
 167
 168         if (mesg[mlen-1] != '\n')
 169                 return -EINVAL;
 170         mesg[mlen-1] = 0;
 171
 172         /* class */
 173         len = qword_get(&mesg, ipm.m_class, sizeof(ipm.m_class));
 174         if (len <= 0) return -EINVAL;
 175
 176         /* ip address */
 177         len = qword_get(&mesg, buf, mlen);
 178         if (len <= 0) return -EINVAL;
 179
 180         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
 181                 return -EINVAL;
 182
 183         expiry = get_expiry(&mesg);
 184         if (expiry ==0)
 185                 return -EINVAL;
 186
 187         /* domainname, or empty for NEGATIVE */
 188         len = qword_get(&mesg, buf, mlen);
 189         if (len < 0) return -EINVAL;
 190
 191         if (len) {
 192                 dom = unix_domain_find(buf);
 193                 if (dom == NULL)
 194                         return -ENOENT;
 195         } else
 196                 dom = NULL;
 197
 198         ipm.m_addr.s_addr =
 199                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
 200         ipm.h.flags = 0;
 201         if (dom) {
 202                 ipm.m_client = container_of(dom, struct unix_domain, h);
 203                 ipm.m_add_change = ipm.m_client->addr_changes;
 204         } else
 205                 set_bit(CACHE_NEGATIVE, &ipm.h.flags);
 206         ipm.h.expiry_time = expiry;
 207
 208         ipmp = ip_map_lookup(&ipm, 1);
 209         if (ipmp)
 210                 ip_map_put(&ipmp->h, &ip_map_cache);
 211         if (dom)
 212                 auth_domain_put(dom);
 213         if (!ipmp)
 214                 return -ENOMEM;
 215         cache_flush();
 216         return 0;
 217 }
 218
 219 static int ip_map_show(struct seq_file *m,
 220                        struct cache_detail *cd,
 221                        struct cache_head *h)
 222 {
 223         struct ip_map *im;
 224         struct in_addr addr;
 225         char *dom = "-no-domain-";
 226
 227         if (h == NULL) {
 228                 seq_puts(m, "#class IP domain\n");
 229                 return 0;
 230         }
 231         im = container_of(h, struct ip_map, h);
 232         /* class addr domain */
 233         addr = im->m_addr;
 234
 235         if (test_bit(CACHE_VALID, &h->flags) &&
 236             !test_bit(CACHE_NEGATIVE, &h->flags))
 237                 dom = im->m_client->h.name;
 238
 239         seq_printf(m, "%s %d.%d.%d.%d %s\n",
 240                    im->m_class,
 241                    htonl(addr.s_addr) >> 24 & 0xff,
 242                    htonl(addr.s_addr) >> 16 & 0xff,
 243                    htonl(addr.s_addr) >>  8 & 0xff,
 244                    htonl(addr.s_addr) >>  0 & 0xff,
 245                    dom
 246                    );
 247         return 0;
 248 }
 249
 250
 251 struct cache_detail ip_map_cache = {
 252         .hash_size      = IP_HASHMAX,
 253         .hash_table     = ip_table,
 254         .name           = "auth.unix.ip",
 255         .cache_put      = ip_map_put,
 256         .cache_request  = ip_map_request,
 257         .cache_parse    = ip_map_parse,
 258         .cache_show     = ip_map_show,
 259 };
 260
 261 static DefineSimpleCacheLookup(ip_map, 0)
 262
 263
 264 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 265 {
 266         struct unix_domain *udom;
 267         struct ip_map ip, *ipmp;
 268
 269         if (dom->flavour != RPC_AUTH_UNIX)
 270                 return -EINVAL;
 271         udom = container_of(dom, struct unix_domain, h);
 272         strcpy(ip.m_class, "nfsd");
 273         ip.m_addr = addr;
 274         ip.m_client = udom;
 275         ip.m_add_change = udom->addr_changes+1;
 276         ip.h.flags = 0;
 277         ip.h.expiry_time = NEVER;
 278
 279         ipmp = ip_map_lookup(&ip, 1);
 280
 281         if (ipmp) {
 282                 ip_map_put(&ipmp->h, &ip_map_cache);
 283                 return 0;
 284         } else
 285                 return -ENOMEM;
 286 }
 287
 288 int auth_unix_forget_old(struct auth_domain *dom)
 289 {
 290         struct unix_domain *udom;
 291
 292         if (dom->flavour != RPC_AUTH_UNIX)
 293                 return -EINVAL;
 294         udom = container_of(dom, struct unix_domain, h);
 295         udom->addr_changes++;
 296         return 0;
 297 }
 298
 299 struct auth_domain *auth_unix_lookup(struct in_addr addr)
 300 {
 301         struct ip_map key, *ipm;
 302         struct auth_domain *rv;
 303
 304         strcpy(key.m_class, "nfsd");
 305         key.m_addr = addr;
 306
 307         ipm = ip_map_lookup(&key, 0);
 308
 309         if (!ipm)
 310                 return NULL;
 311         if (cache_check(&ip_map_cache, &ipm->h, NULL))
 312                 return NULL;
 313
 314         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
 315                 if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
 316                         auth_domain_put(&ipm->m_client->h);
 317                 rv = NULL;
 318         } else {
 319                 rv = &ipm->m_client->h;
 320                 cache_get(&rv->h);
 321         }
 322         ip_map_put(&ipm->h, &ip_map_cache);
 323         return rv;
 324 }
 325
 326 void svcauth_unix_purge(void)
 327 {
 328         cache_purge(&ip_map_cache);
 329         cache_purge(&auth_domain_cache);
 330 }
 331
 332 static int
 333 svcauth_unix_set_client(struct svc_rqst *rqstp)
 334 {
 335         struct ip_map key, *ipm;
 336
 337         rqstp->rq_client = NULL;
 338         if (rqstp->rq_proc == 0)
 339                 return SVC_OK;
 340
 341         strcpy(key.m_class, rqstp->rq_server->sv_program->pg_class);
 342         key.m_addr = rqstp->rq_addr.sin_addr;
 343
 344         ipm = ip_map_lookup(&key, 0);
 345
 346         if (ipm == NULL)
 347                 return SVC_DENIED;
 348
 349         switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 350                 default:
 351                         BUG();
 352                 case -EAGAIN:
 353                         return SVC_DROP;
 354                 case -ENOENT:
 355                         return SVC_DENIED;
 356                 case 0:
 357                         rqstp->rq_client = &ipm->m_client->h;
 358                         cache_get(&rqstp->rq_client->h);
 359                         ip_map_put(&ipm->h, &ip_map_cache);
 360                         break;
 361         }
 362         return SVC_OK;
 363 }
 364
 365 static int
 366 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
 367 {
 368         struct kvec     *argv = &rqstp->rq_arg.head[0];
 369         struct kvec     *resv = &rqstp->rq_res.head[0];
 370         struct svc_cred *cred = &rqstp->rq_cred;
 371
 372         cred->cr_group_info = NULL;
 373         rqstp->rq_client = NULL;
 374
 375         if (argv->iov_len < 3*4)
 376                 return SVC_GARBAGE;
 377
 378         if (svc_getu32(argv) != 0) {
 379                 dprintk("svc: bad null cred\n");
 380                 *authp = rpc_autherr_badcred;
 381                 return SVC_DENIED;
 382         }
 383         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 384                 dprintk("svc: bad null verf\n");
 385                 *authp = rpc_autherr_badverf;
 386                 return SVC_DENIED;
 387         }
 388
 389         /* Signal that mapping to nobody uid/gid is required */
 390         cred->cr_uid = (uid_t) -1;
 391         cred->cr_gid = (gid_t) -1;
 392         cred->cr_group_info = groups_alloc(0);
 393         if (cred->cr_group_info == NULL)
 394                 return SVC_DROP; /* kmalloc failure - client must retry */
 395
 396         /* Put NULL verifier */
 397         svc_putu32(resv, RPC_AUTH_NULL);
 398         svc_putu32(resv, 0);
 399
 400         return SVC_OK;
 401 }
 402
 403 static int
 404 svcauth_null_release(struct svc_rqst *rqstp)
 405 {
 406         if (rqstp->rq_client)
 407                 auth_domain_put(rqstp->rq_client);
 408         rqstp->rq_client = NULL;
 409         if (rqstp->rq_cred.cr_group_info)
 410                 put_group_info(rqstp->rq_cred.cr_group_info);
 411         rqstp->rq_cred.cr_group_info = NULL;
 412
 413         return 0; /* don't drop */
 414 }
 415
 416
 417 struct auth_ops svcauth_null = {
 418         .name           = "null",
 419         .owner          = THIS_MODULE,
 420         .flavour        = RPC_AUTH_NULL,
 421         .accept         = svcauth_null_accept,
 422         .release        = svcauth_null_release,
 423         .set_client     = svcauth_unix_set_client,
 424 };
 425
 426
 427 static int
 428 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
 429 {
 430         struct kvec     *argv = &rqstp->rq_arg.head[0];
 431         struct kvec     *resv = &rqstp->rq_res.head[0];
 432         struct svc_cred *cred = &rqstp->rq_cred;
 433         u32             slen, i;
 434         int             len   = argv->iov_len;
 435
 436         cred->cr_group_info = NULL;
 437         rqstp->rq_client = NULL;
 438
 439         if ((len -= 3*4) < 0)
 440                 return SVC_GARBAGE;
 441
 442         svc_getu32(argv);                       /* length */
 443         svc_getu32(argv);                       /* time stamp */
 444         slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));    /* machname length */
 445         if (slen > 64 || (len -= (slen + 3)*4) < 0)
 446                 goto badcred;
 447         argv->iov_base = (void*)((u32*)argv->iov_base + slen);  /* skip machname */
 448         argv->iov_len -= slen*4;
 449
 450         cred->cr_uid = ntohl(svc_getu32(argv));         /* uid */
 451         cred->cr_gid = ntohl(svc_getu32(argv));         /* gid */
 452         slen = ntohl(svc_getu32(argv));                 /* gids length */
 453         if (slen > 16 || (len -= (slen + 2)*4) < 0)
 454                 goto badcred;
 455         cred->cr_group_info = groups_alloc(slen);
 456         if (cred->cr_group_info == NULL)
 457                 return SVC_DROP;
 458         for (i = 0; i < slen; i++)
 459                 GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
 460
 461         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 462                 *authp = rpc_autherr_badverf;
 463                 return SVC_DENIED;
 464         }
 465
 466         /* Put NULL verifier */
 467         svc_putu32(resv, RPC_AUTH_NULL);
 468         svc_putu32(resv, 0);
 469
 470         return SVC_OK;
 471
 472 badcred:
 473         *authp = rpc_autherr_badcred;
 474         return SVC_DENIED;
 475 }
 476
 477 static int
 478 svcauth_unix_release(struct svc_rqst *rqstp)
 479 {
 480         /* Verifier (such as it is) is already in place.
 481          */
 482         if (rqstp->rq_client)
 483                 auth_domain_put(rqstp->rq_client);
 484         rqstp->rq_client = NULL;
 485         if (rqstp->rq_cred.cr_group_info)
 486                 put_group_info(rqstp->rq_cred.cr_group_info);
 487         rqstp->rq_cred.cr_group_info = NULL;
 488
 489         return 0;
 490 }
 491
 492
 493 struct auth_ops svcauth_unix = {
 494         .name           = "unix",
 495         .owner          = THIS_MODULE,
 496         .flavour        = RPC_AUTH_UNIX,
 497         .accept         = svcauth_unix_accept,
 498         .release        = svcauth_unix_release,
 499         .domain_release = svcauth_unix_domain_release,
 500         .set_client     = svcauth_unix_set_client,
 501 };
 502