net/sunrpc/svcauth_unix.c

   1 #include <linux/types.h>
   2 #include <linux/sched.h>
   3 #include <linux/sunrpc/types.h>
   4 #include <linux/sunrpc/xdr.h>
   5 #include <linux/sunrpc/svcsock.h>
   6 #include <linux/sunrpc/svcauth.h>
   7 #include <linux/err.h>
   8 #include <linux/seq_file.h>
   9 #include <linux/hash.h>
  10
  11 #define RPCDBG_FACILITY RPCDBG_AUTH
  12
  13
  14 /*
  15  * AUTHUNIX and AUTHNULL credentials are both handled here.
  16  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
  17  * are always nobody (-2).  i.e. we do the same IP address checks for
  18  * AUTHNULL as for AUTHUNIX, and that is done here.
  19  */
  20
  21
  22 static char *strdup(char *s)
  23 {
  24         char *rv = kmalloc(strlen(s)+1, GFP_KERNEL);
  25         if (rv)
  26                 strcpy(rv, s);
  27         return rv;
  28 }
  29
  30 struct unix_domain {
  31         struct auth_domain      h;
  32         int     addr_changes;
  33         /* other stuff later */
  34 };
  35
  36 struct auth_domain *unix_domain_find(char *name)
  37 {
  38         struct auth_domain *rv, ud;
  39         struct unix_domain *new;
  40
  41         ud.name = name;
  42
  43         rv = auth_domain_lookup(&ud, 0);
  44
  45  foundit:
  46         if (rv && rv->flavour != RPC_AUTH_UNIX) {
  47                 auth_domain_put(rv);
  48                 return NULL;
  49         }
  50         if (rv)
  51                 return rv;
  52
  53         new = kmalloc(sizeof(*new), GFP_KERNEL);
  54         if (new == NULL)
  55                 return NULL;
  56         cache_init(&new->h.h);
  57         atomic_inc(&new->h.h.refcnt);
  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         new->h.h.flags = 0;
  63
  64         rv = auth_domain_lookup(&new->h, 2);
  65         if (rv == &new->h) {
  66                 if (atomic_dec_and_test(&new->h.h.refcnt)) BUG();
  67         } else {
  68                 auth_domain_put(&new->h);
  69                 goto foundit;
  70         }
  71
  72         return rv;
  73 }
  74
  75 static void svcauth_unix_domain_release(struct auth_domain *dom)
  76 {
  77         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
  78
  79         kfree(dom->name);
  80         kfree(ud);
  81 }
  82
  83
  84 /**************************************************
  85  * cache for IP address to unix_domain
  86  * as needed by AUTH_UNIX
  87  */
  88 #define IP_HASHBITS     8
  89 #define IP_HASHMAX      (1<<IP_HASHBITS)
  90 #define IP_HASHMASK     (IP_HASHMAX-1)
  91
  92 struct ip_map {
  93         struct cache_head       h;
  94         char                    *m_class; /* e.g. "nfsd" */
  95         struct in_addr          m_addr;
  96         struct unix_domain      *m_client;
  97         int                     m_add_change;
  98 };
  99 static struct cache_head        *ip_table[IP_HASHMAX];
 100
 101 void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 102 {
 103         struct ip_map *im = container_of(item, struct ip_map,h);
 104         if (cache_put(item, cd)) {
 105                 if (test_bit(CACHE_VALID, &item->flags) &&
 106                     !test_bit(CACHE_NEGATIVE, &item->flags))
 107                         auth_domain_put(&im->m_client->h);
 108                 kfree(im);
 109         }
 110 }
 111
 112 static inline int ip_map_hash(struct ip_map *item)
 113 {
 114         return hash_str(item->m_class, IP_HASHBITS) ^
 115                 hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
 116 }
 117 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 118 {
 119         return strcmp(tmp->m_class, item->m_class) == 0
 120                 && tmp->m_addr.s_addr == item->m_addr.s_addr;
 121 }
 122 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
 123 {
 124         new->m_class = item->m_class;
 125         item->m_class = NULL;
 126         new->m_addr.s_addr = item->m_addr.s_addr;
 127 }
 128 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
 129 {
 130         cache_get(&item->m_client->h.h);
 131         new->m_client = item->m_client;
 132         new->m_add_change = item->m_add_change;
 133 }
 134
 135 static void ip_map_request(struct cache_detail *cd,
 136                                   struct cache_head *h,
 137                                   char **bpp, int *blen)
 138 {
 139         char text_addr[20];
 140         struct ip_map *im = container_of(h, struct ip_map, h);
 141         __u32 addr = im->m_addr.s_addr;
 142
 143         snprintf(text_addr, 20, "%u.%u.%u.%u",
 144                  ntohl(addr) >> 24 & 0xff,
 145                  ntohl(addr) >> 16 & 0xff,
 146                  ntohl(addr) >>  8 & 0xff,
 147                  ntohl(addr) >>  0 & 0xff);
 148
 149         qword_add(bpp, blen, im->m_class);
 150         qword_add(bpp, blen, text_addr);
 151         (*bpp)[-1] = '\n';
 152 }
 153
 154 static struct ip_map *ip_map_lookup(struct ip_map *, int);
 155 static int ip_map_parse(struct cache_detail *cd,
 156                           char *mesg, int mlen)
 157 {
 158         /* class ipaddress [domainname] */
 159         char class[50], buf[50];
 160         int len;
 161         int b1,b2,b3,b4;
 162         char c;
 163         struct ip_map ipm, *ipmp;
 164         struct auth_domain *dom;
 165         time_t expiry;
 166
 167         if (mesg[mlen-1] != '\n')
 168                 return -EINVAL;
 169         mesg[mlen-1] = 0;
 170
 171         /* class */
 172         len = qword_get(&mesg, class, 50);
 173         if (len <= 0) return -EINVAL;
 174
 175         /* ip address */
 176         len = qword_get(&mesg, buf, 50);
 177         if (len <= 0) return -EINVAL;
 178
 179         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
 180                 return -EINVAL;
 181
 182         expiry = get_expiry(&mesg);
 183         if (expiry ==0)
 184                 return -EINVAL;
 185
 186         /* domainname, or empty for NEGATIVE */
 187         len = qword_get(&mesg, buf, 50);
 188         if (len < 0) return -EINVAL;
 189
 190         if (len) {
 191                 dom = unix_domain_find(buf);
 192                 if (dom == NULL)
 193                         return -ENOENT;
 194         } else
 195                 dom = NULL;
 196
 197         ipm.m_class = strdup(class);
 198         if (ipm.m_class == NULL)
 199                 return -ENOMEM;
 200         ipm.m_addr.s_addr =
 201                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
 202         ipm.h.flags = 0;
 203         if (dom) {
 204                 ipm.m_client = container_of(dom, struct unix_domain, h);
 205                 ipm.m_add_change = ipm.m_client->addr_changes;
 206         } else
 207                 set_bit(CACHE_NEGATIVE, &ipm.h.flags);
 208         ipm.h.expiry_time = expiry;
 209
 210         ipmp = ip_map_lookup(&ipm, 1);
 211         if (ipmp)
 212                 ip_map_put(&ipmp->h, &ip_map_cache);
 213         if (dom)
 214                 auth_domain_put(dom);
 215         if (ipm.m_class) kfree(ipm.m_class);
 216         if (!ipmp)
 217                 return -ENOMEM;
 218         cache_flush();
 219         return 0;
 220 }
 221
 222 static int ip_map_show(struct seq_file *m,
 223                        struct cache_detail *cd,
 224                        struct cache_head *h)
 225 {
 226         struct ip_map *im;
 227         struct in_addr addr;
 228         char *dom = "-no-domain-";
 229
 230         if (h == NULL) {
 231                 seq_puts(m, "#class IP domain\n");
 232                 return 0;
 233         }
 234         im = container_of(h, struct ip_map, h);
 235         /* class addr domain */
 236         addr = im->m_addr;
 237
 238         if (test_bit(CACHE_VALID, &h->flags) &&
 239             !test_bit(CACHE_NEGATIVE, &h->flags))
 240                 dom = im->m_client->h.name;
 241
 242         seq_printf(m, "%s %d.%d.%d.%d %s\n",
 243                    im->m_class,
 244                    htonl(addr.s_addr) >> 24 & 0xff,
 245                    htonl(addr.s_addr) >> 16 & 0xff,
 246                    htonl(addr.s_addr) >>  8 & 0xff,
 247                    htonl(addr.s_addr) >>  0 & 0xff,
 248                    dom
 249                    );
 250         return 0;
 251 }
 252
 253
 254 struct cache_detail ip_map_cache = {
 255         .hash_size      = IP_HASHMAX,
 256         .hash_table     = ip_table,
 257         .name           = "auth.unix.ip",
 258         .cache_put      = ip_map_put,
 259         .cache_request  = ip_map_request,
 260         .cache_parse    = ip_map_parse,
 261         .cache_show     = ip_map_show,
 262 };
 263
 264 static DefineSimpleCacheLookup(ip_map, 0)
 265
 266
 267 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 268 {
 269         struct unix_domain *udom;
 270         struct ip_map ip, *ipmp;
 271
 272         if (dom->flavour != RPC_AUTH_UNIX)
 273                 return -EINVAL;
 274         udom = container_of(dom, struct unix_domain, h);
 275         ip.m_class = strdup("nfsd");
 276         if (!ip.m_class)
 277                 return -ENOMEM;
 278         ip.m_addr = addr;
 279         ip.m_client = udom;
 280         ip.m_add_change = udom->addr_changes+1;
 281         ip.h.flags = 0;
 282         ip.h.expiry_time = NEVER;
 283
 284         ipmp = ip_map_lookup(&ip, 1);
 285         if (ip.m_class) kfree(ip.m_class);
 286         if (ipmp) {
 287                 ip_map_put(&ipmp->h, &ip_map_cache);
 288                 return 0;
 289         } else
 290                 return -ENOMEM;
 291 }
 292
 293 int auth_unix_forget_old(struct auth_domain *dom)
 294 {
 295         struct unix_domain *udom;
 296
 297         if (dom->flavour != RPC_AUTH_UNIX)
 298                 return -EINVAL;
 299         udom = container_of(dom, struct unix_domain, h);
 300         udom->addr_changes++;
 301         return 0;
 302 }
 303
 304 struct auth_domain *auth_unix_lookup(struct in_addr addr)
 305 {
 306         struct ip_map key, *ipm;
 307         struct auth_domain *rv;
 308
 309         key.m_class = "nfsd";
 310         key.m_addr = addr;
 311
 312         ipm = ip_map_lookup(&key, 0);
 313
 314         if (!ipm)
 315                 return NULL;
 316         if (cache_check(&ip_map_cache, &ipm->h, NULL))
 317                 return NULL;
 318
 319         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
 320                 set_bit(CACHE_NEGATIVE, &ipm->h.flags);
 321                 rv = NULL;
 322         } else {
 323                 rv = &ipm->m_client->h;
 324                 cache_get(&rv->h);
 325         }
 326         ip_map_put(&ipm->h, &ip_map_cache);
 327         return rv;
 328 }
 329
 330 void svcauth_unix_purge(void)
 331 {
 332         cache_purge(&ip_map_cache);
 333         cache_purge(&auth_domain_cache);
 334 }
 335
 336
 337 static int
 338 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
 339 {
 340         struct iovec    *argv = &rqstp->rq_arg.head[0];
 341         struct iovec    *resv = &rqstp->rq_res.head[0];
 342         int             rv=0;
 343         struct ip_map key, *ipm;
 344
 345         if (argv->iov_len < 3*4)
 346                 return SVC_GARBAGE;
 347
 348         if (svc_getu32(argv) != 0) {
 349                 dprintk("svc: bad null cred\n");
 350                 *authp = rpc_autherr_badcred;
 351                 return SVC_DENIED;
 352         }
 353         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 354                 dprintk("svc: bad null verf\n");
 355                 *authp = rpc_autherr_badverf;
 356                 return SVC_DENIED;
 357         }
 358
 359         /* Signal that mapping to nobody uid/gid is required */
 360         rqstp->rq_cred.cr_uid = (uid_t) -1;
 361         rqstp->rq_cred.cr_gid = (gid_t) -1;
 362         rqstp->rq_cred.cr_group_info = groups_alloc(0);
 363         if (rqstp->rq_cred.cr_group_info == NULL)
 364                 return SVC_DROP; /* kmalloc failure - client must retry */
 365
 366         /* Put NULL verifier */
 367         svc_putu32(resv, RPC_AUTH_NULL);
 368         svc_putu32(resv, 0);
 369
 370         key.m_class = rqstp->rq_server->sv_program->pg_class;
 371         key.m_addr = rqstp->rq_addr.sin_addr;
 372
 373         ipm = ip_map_lookup(&key, 0);
 374
 375         rqstp->rq_client = NULL;
 376
 377         if (ipm)
 378                 switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 379                 case -EAGAIN:
 380                         rv = SVC_DROP;
 381                         break;
 382                 case -ENOENT:
 383                         rv = SVC_OK; /* rq_client is NULL */
 384                         break;
 385                 case 0:
 386                         rqstp->rq_client = &ipm->m_client->h;
 387                         cache_get(&rqstp->rq_client->h);
 388                         ip_map_put(&ipm->h, &ip_map_cache);
 389                         rv = SVC_OK;
 390                         break;
 391                 default: BUG();
 392                 }
 393         else rv = SVC_DROP;
 394
 395         if (rqstp->rq_client == NULL && rqstp->rq_proc != 0)
 396                 *authp = rpc_autherr_badcred;
 397
 398         return rv;
 399 }
 400
 401 static int
 402 svcauth_null_release(struct svc_rqst *rqstp)
 403 {
 404         if (rqstp->rq_client)
 405                 auth_domain_put(rqstp->rq_client);
 406         rqstp->rq_client = NULL;
 407
 408         return 0; /* don't drop */
 409 }
 410
 411
 412 struct auth_ops svcauth_null = {
 413         .name           = "null",
 414         .flavour        = RPC_AUTH_NULL,
 415         .accept         = svcauth_null_accept,
 416         .release        = svcauth_null_release,
 417 };
 418
 419
 420 int
 421 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
 422 {
 423         struct iovec    *argv = &rqstp->rq_arg.head[0];
 424         struct iovec    *resv = &rqstp->rq_res.head[0];
 425         struct svc_cred *cred = &rqstp->rq_cred;
 426         u32             slen, i;
 427         int             len   = argv->iov_len;
 428         int             rv=0;
 429         struct ip_map key, *ipm;
 430
 431         cred->cr_group_info = NULL;
 432         rqstp->rq_client = NULL;
 433
 434         if ((len -= 3*4) < 0)
 435                 return SVC_GARBAGE;
 436
 437         svc_getu32(argv);                       /* length */
 438         svc_getu32(argv);                       /* time stamp */
 439         slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));    /* machname length */
 440         if (slen > 64 || (len -= (slen + 3)*4) < 0)
 441                 goto badcred;
 442         argv->iov_base = (void*)((u32*)argv->iov_base + slen);  /* skip machname */
 443         argv->iov_len -= slen*4;
 444
 445         cred->cr_uid = ntohl(svc_getu32(argv));         /* uid */
 446         cred->cr_gid = ntohl(svc_getu32(argv));         /* gid */
 447         slen = ntohl(svc_getu32(argv));                 /* gids length */
 448         if (slen > 16 || (len -= (slen + 2)*4) < 0)
 449                 goto badcred;
 450         cred->cr_group_info = groups_alloc(slen);
 451         if (cred->cr_group_info == NULL)
 452                 return SVC_DROP;
 453         for (i = 0; i < slen; i++)
 454                 GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
 455
 456         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 457                 *authp = rpc_autherr_badverf;
 458                 return SVC_DENIED;
 459         }
 460
 461
 462         key.m_class = rqstp->rq_server->sv_program->pg_class;
 463         key.m_addr = rqstp->rq_addr.sin_addr;
 464
 465
 466         ipm = ip_map_lookup(&key, 0);
 467
 468         if (ipm)
 469                 switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 470                 case -EAGAIN:
 471                         rv = SVC_DROP;
 472                         break;
 473                 case -ENOENT:
 474                         rv = SVC_OK; /* rq_client is NULL */
 475                         break;
 476                 case 0:
 477                         rqstp->rq_client = &ipm->m_client->h;
 478                         cache_get(&rqstp->rq_client->h);
 479                         ip_map_put(&ipm->h, &ip_map_cache);
 480                         rv = SVC_OK;
 481                         break;
 482                 default: BUG();
 483                 }
 484         else rv = SVC_DROP;
 485
 486         if (rv  == SVC_OK && rqstp->rq_client == NULL && rqstp->rq_proc != 0)
 487                 goto badcred;
 488
 489         /* Put NULL verifier */
 490         svc_putu32(resv, RPC_AUTH_NULL);
 491         svc_putu32(resv, 0);
 492
 493         return rv;
 494
 495 badcred:
 496         *authp = rpc_autherr_badcred;
 497         return SVC_DENIED;
 498 }
 499
 500 int
 501 svcauth_unix_release(struct svc_rqst *rqstp)
 502 {
 503         /* Verifier (such as it is) is already in place.
 504          */
 505         if (rqstp->rq_client)
 506                 auth_domain_put(rqstp->rq_client);
 507         rqstp->rq_client = NULL;
 508         if (rqstp->rq_cred.cr_group_info)
 509                 put_group_info(rqstp->rq_cred.cr_group_info);
 510         rqstp->rq_cred.cr_group_info = NULL;
 511
 512         return 0;
 513 }
 514
 515
 516 struct auth_ops svcauth_unix = {
 517         .name           = "unix",
 518         .flavour        = RPC_AUTH_UNIX,
 519         .accept         = svcauth_unix_accept,
 520         .release        = svcauth_unix_release,
 521         .domain_release = svcauth_unix_domain_release,
 522 };
 523