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 #include <linux/string.h>
  12 #include <net/sock.h>
  13
  14 #define RPCDBG_FACILITY RPCDBG_AUTH
  15
  16
  17 /*
  18  * AUTHUNIX and AUTHNULL credentials are both handled here.
  19  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
  20  * are always nobody (-2).  i.e. we do the same IP address checks for
  21  * AUTHNULL as for AUTHUNIX, and that is done here.
  22  */
  23
  24
  25 struct unix_domain {
  26         struct auth_domain      h;
  27         int     addr_changes;
  28         /* other stuff later */
  29 };
  30
  31 extern struct auth_ops svcauth_unix;
  32
  33 struct auth_domain *unix_domain_find(char *name)
  34 {
  35         struct auth_domain *rv;
  36         struct unix_domain *new = NULL;
  37
  38         rv = auth_domain_lookup(name, NULL);
  39         while(1) {
  40                 if (rv) {
  41                         if (new && rv != &new->h)
  42                                 auth_domain_put(&new->h);
  43
  44                         if (rv->flavour != &svcauth_unix) {
  45                                 auth_domain_put(rv);
  46                                 return NULL;
  47                         }
  48                         return rv;
  49                 }
  50
  51                 new = kmalloc(sizeof(*new), GFP_KERNEL);
  52                 if (new == NULL)
  53                         return NULL;
  54                 kref_init(&new->h.ref);
  55                 new->h.name = kstrdup(name, GFP_KERNEL);
  56                 if (new->h.name == NULL) {
  57                         kfree(new);
  58                         return NULL;
  59                 }
  60                 new->h.flavour = &svcauth_unix;
  61                 new->addr_changes = 0;
  62                 rv = auth_domain_lookup(name, &new->h);
  63         }
  64 }
  65
  66 static void svcauth_unix_domain_release(struct auth_domain *dom)
  67 {
  68         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
  69
  70         kfree(dom->name);
  71         kfree(ud);
  72 }
  73
  74
  75 /**************************************************
  76  * cache for IP address to unix_domain
  77  * as needed by AUTH_UNIX
  78  */
  79 #define IP_HASHBITS     8
  80 #define IP_HASHMAX      (1<<IP_HASHBITS)
  81 #define IP_HASHMASK     (IP_HASHMAX-1)
  82
  83 struct ip_map {
  84         struct cache_head       h;
  85         char                    m_class[8]; /* e.g. "nfsd" */
  86         struct in_addr          m_addr;
  87         struct unix_domain      *m_client;
  88         int                     m_add_change;
  89 };
  90 static struct cache_head        *ip_table[IP_HASHMAX];
  91
  92 static void ip_map_put(struct kref *kref)
  93 {
  94         struct cache_head *item = container_of(kref, struct cache_head, ref);
  95         struct ip_map *im = container_of(item, struct ip_map,h);
  96
  97         if (test_bit(CACHE_VALID, &item->flags) &&
  98             !test_bit(CACHE_NEGATIVE, &item->flags))
  99                 auth_domain_put(&im->m_client->h);
 100         kfree(im);
 101 }
 102
 103 #if IP_HASHBITS == 8
 104 /* hash_long on a 64 bit machine is currently REALLY BAD for
 105  * IP addresses in reverse-endian (i.e. on a little-endian machine).
 106  * So use a trivial but reliable hash instead
 107  */
 108 static inline int hash_ip(__be32 ip)
 109 {
 110         int hash = (__force u32)ip ^ ((__force u32)ip>>16);
 111         return (hash ^ (hash>>8)) & 0xff;
 112 }
 113 #endif
 114 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
 115 {
 116         struct ip_map *orig = container_of(corig, struct ip_map, h);
 117         struct ip_map *new = container_of(cnew, struct ip_map, h);
 118         return strcmp(orig->m_class, new->m_class) == 0
 119                 && orig->m_addr.s_addr == new->m_addr.s_addr;
 120 }
 121 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
 122 {
 123         struct ip_map *new = container_of(cnew, struct ip_map, h);
 124         struct ip_map *item = container_of(citem, struct ip_map, h);
 125
 126         strcpy(new->m_class, item->m_class);
 127         new->m_addr.s_addr = item->m_addr.s_addr;
 128 }
 129 static void update(struct cache_head *cnew, struct cache_head *citem)
 130 {
 131         struct ip_map *new = container_of(cnew, struct ip_map, h);
 132         struct ip_map *item = container_of(citem, struct ip_map, h);
 133
 134         kref_get(&item->m_client->h.ref);
 135         new->m_client = item->m_client;
 136         new->m_add_change = item->m_add_change;
 137 }
 138 static struct cache_head *ip_map_alloc(void)
 139 {
 140         struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
 141         if (i)
 142                 return &i->h;
 143         else
 144                 return NULL;
 145 }
 146
 147 static void ip_map_request(struct cache_detail *cd,
 148                                   struct cache_head *h,
 149                                   char **bpp, int *blen)
 150 {
 151         char text_addr[20];
 152         struct ip_map *im = container_of(h, struct ip_map, h);
 153         __be32 addr = im->m_addr.s_addr;
 154
 155         snprintf(text_addr, 20, "%u.%u.%u.%u",
 156                  ntohl(addr) >> 24 & 0xff,
 157                  ntohl(addr) >> 16 & 0xff,
 158                  ntohl(addr) >>  8 & 0xff,
 159                  ntohl(addr) >>  0 & 0xff);
 160
 161         qword_add(bpp, blen, im->m_class);
 162         qword_add(bpp, blen, text_addr);
 163         (*bpp)[-1] = '\n';
 164 }
 165
 166 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
 167 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
 168
 169 static int ip_map_parse(struct cache_detail *cd,
 170                           char *mesg, int mlen)
 171 {
 172         /* class ipaddress [domainname] */
 173         /* should be safe just to use the start of the input buffer
 174          * for scratch: */
 175         char *buf = mesg;
 176         int len;
 177         int b1,b2,b3,b4;
 178         char c;
 179         char class[8];
 180         struct in_addr addr;
 181         int err;
 182
 183         struct ip_map *ipmp;
 184         struct auth_domain *dom;
 185         time_t expiry;
 186
 187         if (mesg[mlen-1] != '\n')
 188                 return -EINVAL;
 189         mesg[mlen-1] = 0;
 190
 191         /* class */
 192         len = qword_get(&mesg, class, sizeof(class));
 193         if (len <= 0) return -EINVAL;
 194
 195         /* ip address */
 196         len = qword_get(&mesg, buf, mlen);
 197         if (len <= 0) return -EINVAL;
 198
 199         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
 200                 return -EINVAL;
 201
 202         expiry = get_expiry(&mesg);
 203         if (expiry ==0)
 204                 return -EINVAL;
 205
 206         /* domainname, or empty for NEGATIVE */
 207         len = qword_get(&mesg, buf, mlen);
 208         if (len < 0) return -EINVAL;
 209
 210         if (len) {
 211                 dom = unix_domain_find(buf);
 212                 if (dom == NULL)
 213                         return -ENOENT;
 214         } else
 215                 dom = NULL;
 216
 217         addr.s_addr =
 218                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
 219
 220         ipmp = ip_map_lookup(class,addr);
 221         if (ipmp) {
 222                 err = ip_map_update(ipmp,
 223                              container_of(dom, struct unix_domain, h),
 224                              expiry);
 225         } else
 226                 err = -ENOMEM;
 227
 228         if (dom)
 229                 auth_domain_put(dom);
 230
 231         cache_flush();
 232         return err;
 233 }
 234
 235 static int ip_map_show(struct seq_file *m,
 236                        struct cache_detail *cd,
 237                        struct cache_head *h)
 238 {
 239         struct ip_map *im;
 240         struct in_addr addr;
 241         char *dom = "-no-domain-";
 242
 243         if (h == NULL) {
 244                 seq_puts(m, "#class IP domain\n");
 245                 return 0;
 246         }
 247         im = container_of(h, struct ip_map, h);
 248         /* class addr domain */
 249         addr = im->m_addr;
 250
 251         if (test_bit(CACHE_VALID, &h->flags) &&
 252             !test_bit(CACHE_NEGATIVE, &h->flags))
 253                 dom = im->m_client->h.name;
 254
 255         seq_printf(m, "%s %d.%d.%d.%d %s\n",
 256                    im->m_class,
 257                    ntohl(addr.s_addr) >> 24 & 0xff,
 258                    ntohl(addr.s_addr) >> 16 & 0xff,
 259                    ntohl(addr.s_addr) >>  8 & 0xff,
 260                    ntohl(addr.s_addr) >>  0 & 0xff,
 261                    dom
 262                    );
 263         return 0;
 264 }
 265
 266
 267 struct cache_detail ip_map_cache = {
 268         .owner          = THIS_MODULE,
 269         .hash_size      = IP_HASHMAX,
 270         .hash_table     = ip_table,
 271         .name           = "auth.unix.ip",
 272         .cache_put      = ip_map_put,
 273         .cache_request  = ip_map_request,
 274         .cache_parse    = ip_map_parse,
 275         .cache_show     = ip_map_show,
 276         .match          = ip_map_match,
 277         .init           = ip_map_init,
 278         .update         = update,
 279         .alloc          = ip_map_alloc,
 280 };
 281
 282 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
 283 {
 284         struct ip_map ip;
 285         struct cache_head *ch;
 286
 287         strcpy(ip.m_class, class);
 288         ip.m_addr = addr;
 289         ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
 290                                  hash_str(class, IP_HASHBITS) ^
 291                                  hash_ip(addr.s_addr));
 292
 293         if (ch)
 294                 return container_of(ch, struct ip_map, h);
 295         else
 296                 return NULL;
 297 }
 298
 299 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
 300 {
 301         struct ip_map ip;
 302         struct cache_head *ch;
 303
 304         ip.m_client = udom;
 305         ip.h.flags = 0;
 306         if (!udom)
 307                 set_bit(CACHE_NEGATIVE, &ip.h.flags);
 308         else {
 309                 ip.m_add_change = udom->addr_changes;
 310                 /* if this is from the legacy set_client system call,
 311                  * we need m_add_change to be one higher
 312                  */
 313                 if (expiry == NEVER)
 314                         ip.m_add_change++;
 315         }
 316         ip.h.expiry_time = expiry;
 317         ch = sunrpc_cache_update(&ip_map_cache,
 318                                  &ip.h, &ipm->h,
 319                                  hash_str(ipm->m_class, IP_HASHBITS) ^
 320                                  hash_ip(ipm->m_addr.s_addr));
 321         if (!ch)
 322                 return -ENOMEM;
 323         cache_put(ch, &ip_map_cache);
 324         return 0;
 325 }
 326
 327 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 328 {
 329         struct unix_domain *udom;
 330         struct ip_map *ipmp;
 331
 332         if (dom->flavour != &svcauth_unix)
 333                 return -EINVAL;
 334         udom = container_of(dom, struct unix_domain, h);
 335         ipmp = ip_map_lookup("nfsd", addr);
 336
 337         if (ipmp)
 338                 return ip_map_update(ipmp, udom, NEVER);
 339         else
 340                 return -ENOMEM;
 341 }
 342
 343 int auth_unix_forget_old(struct auth_domain *dom)
 344 {
 345         struct unix_domain *udom;
 346
 347         if (dom->flavour != &svcauth_unix)
 348                 return -EINVAL;
 349         udom = container_of(dom, struct unix_domain, h);
 350         udom->addr_changes++;
 351         return 0;
 352 }
 353
 354 struct auth_domain *auth_unix_lookup(struct in_addr addr)
 355 {
 356         struct ip_map *ipm;
 357         struct auth_domain *rv;
 358
 359         ipm = ip_map_lookup("nfsd", addr);
 360
 361         if (!ipm)
 362                 return NULL;
 363         if (cache_check(&ip_map_cache, &ipm->h, NULL))
 364                 return NULL;
 365
 366         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
 367                 if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
 368                         auth_domain_put(&ipm->m_client->h);
 369                 rv = NULL;
 370         } else {
 371                 rv = &ipm->m_client->h;
 372                 kref_get(&rv->ref);
 373         }
 374         cache_put(&ipm->h, &ip_map_cache);
 375         return rv;
 376 }
 377
 378 void svcauth_unix_purge(void)
 379 {
 380         cache_purge(&ip_map_cache);
 381 }
 382
 383 static inline struct ip_map *
 384 ip_map_cached_get(struct svc_rqst *rqstp)
 385 {
 386         struct ip_map *ipm;
 387         struct svc_sock *svsk = rqstp->rq_sock;
 388         spin_lock_bh(&svsk->sk_defer_lock);
 389         ipm = svsk->sk_info_authunix;
 390         if (ipm != NULL) {
 391                 if (!cache_valid(&ipm->h)) {
 392                         /*
 393                          * The entry has been invalidated since it was
 394                          * remembered, e.g. by a second mount from the
 395                          * same IP address.
 396                          */
 397                         svsk->sk_info_authunix = NULL;
 398                         spin_unlock_bh(&svsk->sk_defer_lock);
 399                         cache_put(&ipm->h, &ip_map_cache);
 400                         return NULL;
 401                 }
 402                 cache_get(&ipm->h);
 403         }
 404         spin_unlock_bh(&svsk->sk_defer_lock);
 405         return ipm;
 406 }
 407
 408 static inline void
 409 ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
 410 {
 411         struct svc_sock *svsk = rqstp->rq_sock;
 412
 413         spin_lock_bh(&svsk->sk_defer_lock);
 414         if (svsk->sk_sock->type == SOCK_STREAM &&
 415             svsk->sk_info_authunix == NULL) {
 416                 /* newly cached, keep the reference */
 417                 svsk->sk_info_authunix = ipm;
 418                 ipm = NULL;
 419         }
 420         spin_unlock_bh(&svsk->sk_defer_lock);
 421         if (ipm)
 422                 cache_put(&ipm->h, &ip_map_cache);
 423 }
 424
 425 void
 426 svcauth_unix_info_release(void *info)
 427 {
 428         struct ip_map *ipm = info;
 429         cache_put(&ipm->h, &ip_map_cache);
 430 }
 431
 432 static int
 433 svcauth_unix_set_client(struct svc_rqst *rqstp)
 434 {
 435         struct ip_map *ipm;
 436
 437         rqstp->rq_client = NULL;
 438         if (rqstp->rq_proc == 0)
 439                 return SVC_OK;
 440
 441         ipm = ip_map_cached_get(rqstp);
 442         if (ipm == NULL)
 443                 ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
 444                                     rqstp->rq_addr.sin_addr);
 445
 446         if (ipm == NULL)
 447                 return SVC_DENIED;
 448
 449         switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 450                 default:
 451                         BUG();
 452                 case -EAGAIN:
 453                 case -ETIMEDOUT:
 454                         return SVC_DROP;
 455                 case -ENOENT:
 456                         return SVC_DENIED;
 457                 case 0:
 458                         rqstp->rq_client = &ipm->m_client->h;
 459                         kref_get(&rqstp->rq_client->ref);
 460                         ip_map_cached_put(rqstp, ipm);
 461                         break;
 462         }
 463         return SVC_OK;
 464 }
 465
 466 static int
 467 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
 468 {
 469         struct kvec     *argv = &rqstp->rq_arg.head[0];
 470         struct kvec     *resv = &rqstp->rq_res.head[0];
 471         struct svc_cred *cred = &rqstp->rq_cred;
 472
 473         cred->cr_group_info = NULL;
 474         rqstp->rq_client = NULL;
 475
 476         if (argv->iov_len < 3*4)
 477                 return SVC_GARBAGE;
 478
 479         if (svc_getu32(argv) != 0) {
 480                 dprintk("svc: bad null cred\n");
 481                 *authp = rpc_autherr_badcred;
 482                 return SVC_DENIED;
 483         }
 484         if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
 485                 dprintk("svc: bad null verf\n");
 486                 *authp = rpc_autherr_badverf;
 487                 return SVC_DENIED;
 488         }
 489
 490         /* Signal that mapping to nobody uid/gid is required */
 491         cred->cr_uid = (uid_t) -1;
 492         cred->cr_gid = (gid_t) -1;
 493         cred->cr_group_info = groups_alloc(0);
 494         if (cred->cr_group_info == NULL)
 495                 return SVC_DROP; /* kmalloc failure - client must retry */
 496
 497         /* Put NULL verifier */
 498         svc_putnl(resv, RPC_AUTH_NULL);
 499         svc_putnl(resv, 0);
 500
 501         return SVC_OK;
 502 }
 503
 504 static int
 505 svcauth_null_release(struct svc_rqst *rqstp)
 506 {
 507         if (rqstp->rq_client)
 508                 auth_domain_put(rqstp->rq_client);
 509         rqstp->rq_client = NULL;
 510         if (rqstp->rq_cred.cr_group_info)
 511                 put_group_info(rqstp->rq_cred.cr_group_info);
 512         rqstp->rq_cred.cr_group_info = NULL;
 513
 514         return 0; /* don't drop */
 515 }
 516
 517
 518 struct auth_ops svcauth_null = {
 519         .name           = "null",
 520         .owner          = THIS_MODULE,
 521         .flavour        = RPC_AUTH_NULL,
 522         .accept         = svcauth_null_accept,
 523         .release        = svcauth_null_release,
 524         .set_client     = svcauth_unix_set_client,
 525 };
 526
 527
 528 static int
 529 svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
 530 {
 531         struct kvec     *argv = &rqstp->rq_arg.head[0];
 532         struct kvec     *resv = &rqstp->rq_res.head[0];
 533         struct svc_cred *cred = &rqstp->rq_cred;
 534         u32             slen, i;
 535         int             len   = argv->iov_len;
 536
 537         cred->cr_group_info = NULL;
 538         rqstp->rq_client = NULL;
 539
 540         if ((len -= 3*4) < 0)
 541                 return SVC_GARBAGE;
 542
 543         svc_getu32(argv);                       /* length */
 544         svc_getu32(argv);                       /* time stamp */
 545         slen = XDR_QUADLEN(svc_getnl(argv));    /* machname length */
 546         if (slen > 64 || (len -= (slen + 3)*4) < 0)
 547                 goto badcred;
 548         argv->iov_base = (void*)((__be32*)argv->iov_base + slen);       /* skip machname */
 549         argv->iov_len -= slen*4;
 550
 551         cred->cr_uid = svc_getnl(argv);         /* uid */
 552         cred->cr_gid = svc_getnl(argv);         /* gid */
 553         slen = svc_getnl(argv);                 /* gids length */
 554         if (slen > 16 || (len -= (slen + 2)*4) < 0)
 555                 goto badcred;
 556         cred->cr_group_info = groups_alloc(slen);
 557         if (cred->cr_group_info == NULL)
 558                 return SVC_DROP;
 559         for (i = 0; i < slen; i++)
 560                 GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);
 561
 562         if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
 563                 *authp = rpc_autherr_badverf;
 564                 return SVC_DENIED;
 565         }
 566
 567         /* Put NULL verifier */
 568         svc_putnl(resv, RPC_AUTH_NULL);
 569         svc_putnl(resv, 0);
 570
 571         return SVC_OK;
 572
 573 badcred:
 574         *authp = rpc_autherr_badcred;
 575         return SVC_DENIED;
 576 }
 577
 578 static int
 579 svcauth_unix_release(struct svc_rqst *rqstp)
 580 {
 581         /* Verifier (such as it is) is already in place.
 582          */
 583         if (rqstp->rq_client)
 584                 auth_domain_put(rqstp->rq_client);
 585         rqstp->rq_client = NULL;
 586         if (rqstp->rq_cred.cr_group_info)
 587                 put_group_info(rqstp->rq_cred.cr_group_info);
 588         rqstp->rq_cred.cr_group_info = NULL;
 589
 590         return 0;
 591 }
 592
 593
 594 struct auth_ops svcauth_unix = {
 595         .name           = "unix",
 596         .owner          = THIS_MODULE,
 597         .flavour        = RPC_AUTH_UNIX,
 598         .accept         = svcauth_unix_accept,
 599         .release        = svcauth_unix_release,
 600         .domain_release = svcauth_unix_domain_release,
 601         .set_client     = svcauth_unix_set_client,
 602 };
 603