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         atomic_inc(&new->h.h.refcnt);
  59         new->h.name = strdup(name);
  60         new->h.flavour = RPC_AUTH_UNIX;
  61         new->addr_changes = 0;
  62         new->h.h.expiry_time = NEVER;
  63         new->h.h.flags = 0;
  64
  65         rv = auth_domain_lookup(&new->h, 2);
  66         if (rv == &new->h) {
  67                 if (atomic_dec_and_test(&new->h.h.refcnt)) BUG();
  68         } else {
  69                 auth_domain_put(&new->h);
  70                 goto foundit;
  71         }
  72
  73         return rv;
  74 }
  75
  76 static void svcauth_unix_domain_release(struct auth_domain *dom)
  77 {
  78         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
  79
  80         kfree(dom->name);
  81         kfree(ud);
  82 }
  83
  84
  85 /**************************************************
  86  * cache for IP address to unix_domain
  87  * as needed by AUTH_UNIX
  88  */
  89 #define IP_HASHBITS     8
  90 #define IP_HASHMAX      (1<<IP_HASHBITS)
  91 #define IP_HASHMASK     (IP_HASHMAX-1)
  92
  93 struct ip_map {
  94         struct cache_head       h;
  95         char                    *m_class; /* e.g. "nfsd" */
  96         struct in_addr          m_addr;
  97         struct unix_domain      *m_client;
  98         int                     m_add_change;
  99 };
 100 static struct cache_head        *ip_table[IP_HASHMAX];
 101
 102 void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 103 {
 104         struct ip_map *im = container_of(item, struct ip_map,h);
 105         if (cache_put(item, cd)) {
 106                 if (test_bit(CACHE_VALID, &item->flags) &&
 107                     !test_bit(CACHE_NEGATIVE, &item->flags))
 108                         auth_domain_put(&im->m_client->h);
 109                 kfree(im);
 110         }
 111 }
 112
 113 static inline int ip_map_hash(struct ip_map *item)
 114 {
 115         return hash_str(item->m_class, IP_HASHBITS) ^
 116                 hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
 117 }
 118 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 119 {
 120         return strcmp(tmp->m_class, item->m_class) == 0
 121                 && tmp->m_addr.s_addr == item->m_addr.s_addr;
 122 }
 123 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
 124 {
 125         new->m_class = item->m_class;
 126         item->m_class = NULL;
 127         new->m_addr.s_addr = item->m_addr.s_addr;
 128 }
 129 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
 130 {
 131         cache_get(&item->m_client->h.h);
 132         new->m_client = item->m_client;
 133         new->m_add_change = item->m_add_change;
 134 }
 135
 136 static void ip_map_request(struct cache_detail *cd,
 137                                   struct cache_head *h,
 138                                   char **bpp, int *blen)
 139 {
 140         char text_addr[20];
 141         struct ip_map *im = container_of(h, struct ip_map, h);
 142         __u32 addr = im->m_addr.s_addr;
 143
 144         snprintf(text_addr, 20, "%u.%u.%u.%u",
 145                  ntohl(addr) >> 24 & 0xff,
 146                  ntohl(addr) >> 16 & 0xff,
 147                  ntohl(addr) >>  8 & 0xff,
 148                  ntohl(addr) >>  0 & 0xff);
 149
 150         qword_add(bpp, blen, im->m_class);
 151         qword_add(bpp, blen, text_addr);
 152         (*bpp)[-1] = '\n';
 153 }
 154
 155 static struct ip_map *ip_map_lookup(struct ip_map *, int);
 156 static int ip_map_parse(struct cache_detail *cd,
 157                           char *mesg, int mlen)
 158 {
 159         /* class ipaddress [domainname] */
 160         char class[50], buf[50];
 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, class, 50);
 174         if (len <= 0) return -EINVAL;
 175
 176         /* ip address */
 177         len = qword_get(&mesg, buf, 50);
 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, 50);
 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_class = strdup(class);
 199         if (ipm.m_class == NULL)
 200                 return -ENOMEM;
 201         ipm.m_addr.s_addr =
 202                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
 203         ipm.h.flags = 0;
 204         if (dom) {
 205                 ipm.m_client = container_of(dom, struct unix_domain, h);
 206                 ipm.m_add_change = ipm.m_client->addr_changes;
 207         } else
 208                 set_bit(CACHE_NEGATIVE, &ipm.h.flags);
 209         ipm.h.expiry_time = expiry;
 210
 211         ipmp = ip_map_lookup(&ipm, 1);
 212         if (ipmp)
 213                 ip_map_put(&ipmp->h, &ip_map_cache);
 214         if (dom)
 215                 auth_domain_put(dom);
 216         if (ipm.m_class) kfree(ipm.m_class);
 217         if (!ipmp)
 218                 return -ENOMEM;
 219         cache_flush();
 220         return 0;
 221 }
 222
 223 static int ip_map_show(struct seq_file *m,
 224                        struct cache_detail *cd,
 225                        struct cache_head *h)
 226 {
 227         struct ip_map *im;
 228         struct in_addr addr;
 229         char *dom = "-no-domain-";
 230
 231         if (h == NULL) {
 232                 seq_puts(m, "#class IP domain\n");
 233                 return 0;
 234         }
 235         im = container_of(h, struct ip_map, h);
 236         /* class addr domain */
 237         addr = im->m_addr;
 238
 239         if (test_bit(CACHE_VALID, &h->flags) &&
 240             !test_bit(CACHE_NEGATIVE, &h->flags))
 241                 dom = im->m_client->h.name;
 242
 243         seq_printf(m, "%s %d.%d.%d.%d %s\n",
 244                    im->m_class,
 245                    htonl(addr.s_addr) >> 24 & 0xff,
 246                    htonl(addr.s_addr) >> 16 & 0xff,
 247                    htonl(addr.s_addr) >>  8 & 0xff,
 248                    htonl(addr.s_addr) >>  0 & 0xff,
 249                    dom
 250                    );
 251         return 0;
 252 }
 253
 254
 255 struct cache_detail ip_map_cache = {
 256         .hash_size      = IP_HASHMAX,
 257         .hash_table     = ip_table,
 258         .name           = "auth.unix.ip",
 259         .cache_put      = ip_map_put,
 260         .cache_request  = ip_map_request,
 261         .cache_parse    = ip_map_parse,
 262         .cache_show     = ip_map_show,
 263 };
 264
 265 static DefineSimpleCacheLookup(ip_map, 0)
 266
 267
 268 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 269 {
 270         struct unix_domain *udom;
 271         struct ip_map ip, *ipmp;
 272
 273         if (dom->flavour != RPC_AUTH_UNIX)
 274                 return -EINVAL;
 275         udom = container_of(dom, struct unix_domain, h);
 276         ip.m_class = strdup("nfsd");
 277         if (!ip.m_class)
 278                 return -ENOMEM;
 279         ip.m_addr = addr;
 280         ip.m_client = udom;
 281         ip.m_add_change = udom->addr_changes+1;
 282         ip.h.flags = 0;
 283         ip.h.expiry_time = NEVER;
 284
 285         ipmp = ip_map_lookup(&ip, 1);
 286         if (ip.m_class) kfree(ip.m_class);
 287         if (ipmp) {
 288                 ip_map_put(&ipmp->h, &ip_map_cache);
 289                 return 0;
 290         } else
 291                 return -ENOMEM;
 292 }
 293
 294 int auth_unix_forget_old(struct auth_domain *dom)
 295 {
 296         struct unix_domain *udom;
 297
 298         if (dom->flavour != RPC_AUTH_UNIX)
 299                 return -EINVAL;
 300         udom = container_of(dom, struct unix_domain, h);
 301         udom->addr_changes++;
 302         return 0;
 303 }
 304
 305 struct auth_domain *auth_unix_lookup(struct in_addr addr)
 306 {
 307         struct ip_map key, *ipm;
 308         struct auth_domain *rv;
 309
 310         key.m_class = "nfsd";
 311         key.m_addr = addr;
 312
 313         ipm = ip_map_lookup(&key, 0);
 314
 315         if (!ipm)
 316                 return NULL;
 317         if (cache_check(&ip_map_cache, &ipm->h, NULL))
 318                 return NULL;
 319
 320         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
 321                 set_bit(CACHE_NEGATIVE, &ipm->h.flags);
 322                 rv = NULL;
 323         } else {
 324                 rv = &ipm->m_client->h;
 325                 cache_get(&rv->h);
 326         }
 327         ip_map_put(&ipm->h, &ip_map_cache);
 328         return rv;
 329 }
 330
 331 void svcauth_unix_purge(void)
 332 {
 333         cache_purge(&ip_map_cache);
 334         cache_purge(&auth_domain_cache);
 335 }
 336
 337
 338 static int
 339 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
 340 {
 341         struct iovec    *argv = &rqstp->rq_arg.head[0];
 342         struct iovec    *resv = &rqstp->rq_res.head[0];
 343         int             rv=0;
 344         struct ip_map key, *ipm;
 345
 346         if (argv->iov_len < 3*4)
 347                 return SVC_GARBAGE;
 348
 349         if (svc_getu32(argv) != 0) {
 350                 dprintk("svc: bad null cred\n");
 351                 *authp = rpc_autherr_badcred;
 352                 return SVC_DENIED;
 353         }
 354         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 355                 dprintk("svc: bad null verf\n");
 356                 *authp = rpc_autherr_badverf;
 357                 return SVC_DENIED;
 358         }
 359
 360         /* Signal that mapping to nobody uid/gid is required */
 361         rqstp->rq_cred.cr_uid = (uid_t) -1;
 362         rqstp->rq_cred.cr_gid = (gid_t) -1;
 363         rqstp->rq_cred.cr_group_info = groups_alloc(0);
 364         if (rqstp->rq_cred.cr_group_info == NULL)
 365                 return SVC_DROP; /* kmalloc failure - client must retry */
 366
 367         /* Put NULL verifier */
 368         svc_putu32(resv, RPC_AUTH_NULL);
 369         svc_putu32(resv, 0);
 370
 371         key.m_class = rqstp->rq_server->sv_program->pg_class;
 372         key.m_addr = rqstp->rq_addr.sin_addr;
 373
 374         ipm = ip_map_lookup(&key, 0);
 375
 376         rqstp->rq_client = NULL;
 377
 378         if (ipm)
 379                 switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 380                 case -EAGAIN:
 381                         rv = SVC_DROP;
 382                         break;
 383                 case -ENOENT:
 384                         rv = SVC_OK; /* rq_client is NULL */
 385                         break;
 386                 case 0:
 387                         rqstp->rq_client = &ipm->m_client->h;
 388                         cache_get(&rqstp->rq_client->h);
 389                         ip_map_put(&ipm->h, &ip_map_cache);
 390                         rv = SVC_OK;
 391                         break;
 392                 default: BUG();
 393                 }
 394         else rv = SVC_DROP;
 395
 396         if (rqstp->rq_client == NULL && rqstp->rq_proc != 0)
 397                 *authp = rpc_autherr_badcred;
 398
 399         return rv;
 400 }
 401
 402 static int
 403 svcauth_null_release(struct svc_rqst *rqstp)
 404 {
 405         if (rqstp->rq_client)
 406                 auth_domain_put(rqstp->rq_client);
 407         rqstp->rq_client = NULL;
 408
 409         return 0; /* don't drop */
 410 }
 411
 412
 413 struct auth_ops svcauth_null = {
 414         .name           = "null",
 415         .owner          = THIS_MODULE,
 416         .flavour        = RPC_AUTH_NULL,
 417         .accept         = svcauth_null_accept,
 418         .release        = svcauth_null_release,
 419 };
 420
 421
 422 int
 423 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
 424 {
 425         struct iovec    *argv = &rqstp->rq_arg.head[0];
 426         struct iovec    *resv = &rqstp->rq_res.head[0];
 427         struct svc_cred *cred = &rqstp->rq_cred;
 428         u32             slen, i;
 429         int             len   = argv->iov_len;
 430         int             rv=0;
 431         struct ip_map key, *ipm;
 432
 433         cred->cr_group_info = NULL;
 434         rqstp->rq_client = NULL;
 435
 436         if ((len -= 3*4) < 0)
 437                 return SVC_GARBAGE;
 438
 439         svc_getu32(argv);                       /* length */
 440         svc_getu32(argv);                       /* time stamp */
 441         slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));    /* machname length */
 442         if (slen > 64 || (len -= (slen + 3)*4) < 0)
 443                 goto badcred;
 444         argv->iov_base = (void*)((u32*)argv->iov_base + slen);  /* skip machname */
 445         argv->iov_len -= slen*4;
 446
 447         cred->cr_uid = ntohl(svc_getu32(argv));         /* uid */
 448         cred->cr_gid = ntohl(svc_getu32(argv));         /* gid */
 449         slen = ntohl(svc_getu32(argv));                 /* gids length */
 450         if (slen > 16 || (len -= (slen + 2)*4) < 0)
 451                 goto badcred;
 452         cred->cr_group_info = groups_alloc(slen);
 453         if (cred->cr_group_info == NULL)
 454                 return SVC_DROP;
 455         for (i = 0; i < slen; i++)
 456                 GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
 457
 458         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 459                 *authp = rpc_autherr_badverf;
 460                 return SVC_DENIED;
 461         }
 462
 463
 464         key.m_class = rqstp->rq_server->sv_program->pg_class;
 465         key.m_addr = rqstp->rq_addr.sin_addr;
 466
 467
 468         ipm = ip_map_lookup(&key, 0);
 469
 470         if (ipm)
 471                 switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 472                 case -EAGAIN:
 473                         rv = SVC_DROP;
 474                         break;
 475                 case -ENOENT:
 476                         rv = SVC_OK; /* rq_client is NULL */
 477                         break;
 478                 case 0:
 479                         rqstp->rq_client = &ipm->m_client->h;
 480                         cache_get(&rqstp->rq_client->h);
 481                         ip_map_put(&ipm->h, &ip_map_cache);
 482                         rv = SVC_OK;
 483                         break;
 484                 default: BUG();
 485                 }
 486         else rv = SVC_DROP;
 487
 488         if (rv  == SVC_OK && rqstp->rq_client == NULL && rqstp->rq_proc != 0)
 489                 goto badcred;
 490
 491         /* Put NULL verifier */
 492         svc_putu32(resv, RPC_AUTH_NULL);
 493         svc_putu32(resv, 0);
 494
 495         return rv;
 496
 497 badcred:
 498         *authp = rpc_autherr_badcred;
 499         return SVC_DENIED;
 500 }
 501
 502 int
 503 svcauth_unix_release(struct svc_rqst *rqstp)
 504 {
 505         /* Verifier (such as it is) is already in place.
 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;
 515 }
 516
 517
 518 struct auth_ops svcauth_unix = {
 519         .name           = "unix",
 520         .owner          = THIS_MODULE,
 521         .flavour        = RPC_AUTH_UNIX,
 522         .accept         = svcauth_unix_accept,
 523         .release        = svcauth_unix_release,
 524         .domain_release = svcauth_unix_domain_release,
 525 };
 526