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