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