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         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
  63         rv = auth_domain_lookup(&new->h, 2);
  64         if (rv == &new->h) {
  65                 if (atomic_dec_and_test(&new->h.h.refcnt)) BUG();
  66         } else {
  67                 auth_domain_put(&new->h);
  68                 goto foundit;
  69         }
  70
  71         return rv;
  72 }
  73
  74 static void svcauth_unix_domain_release(struct auth_domain *dom)
  75 {
  76         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
  77
  78         kfree(dom->name);
  79         kfree(ud);
  80 }
  81
  82
  83 /**************************************************
  84  * cache for IP address to unix_domain
  85  * as needed by AUTH_UNIX
  86  */
  87 #define IP_HASHBITS     8
  88 #define IP_HASHMAX      (1<<IP_HASHBITS)
  89 #define IP_HASHMASK     (IP_HASHMAX-1)
  90
  91 struct ip_map {
  92         struct cache_head       h;
  93         char                    m_class[8]; /* e.g. "nfsd" */
  94         struct in_addr          m_addr;
  95         struct unix_domain      *m_client;
  96         int                     m_add_change;
  97 };
  98 static struct cache_head        *ip_table[IP_HASHMAX];
  99
 100 void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 101 {
 102         struct ip_map *im = container_of(item, struct ip_map,h);
 103         if (cache_put(item, cd)) {
 104                 if (test_bit(CACHE_VALID, &item->flags) &&
 105                     !test_bit(CACHE_NEGATIVE, &item->flags))
 106                         auth_domain_put(&im->m_client->h);
 107                 kfree(im);
 108         }
 109 }
 110
 111 static inline int ip_map_hash(struct ip_map *item)
 112 {
 113         return hash_str(item->m_class, IP_HASHBITS) ^
 114                 hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
 115 }
 116 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 117 {
 118         return strcmp(tmp->m_class, item->m_class) == 0
 119                 && tmp->m_addr.s_addr == item->m_addr.s_addr;
 120 }
 121 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
 122 {
 123         strcpy(new->m_class, item->m_class);
 124         new->m_addr.s_addr = item->m_addr.s_addr;
 125 }
 126 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
 127 {
 128         cache_get(&item->m_client->h.h);
 129         new->m_client = item->m_client;
 130         new->m_add_change = item->m_add_change;
 131 }
 132
 133 static void ip_map_request(struct cache_detail *cd,
 134                                   struct cache_head *h,
 135                                   char **bpp, int *blen)
 136 {
 137         char text_addr[20];
 138         struct ip_map *im = container_of(h, struct ip_map, h);
 139         __u32 addr = im->m_addr.s_addr;
 140
 141         snprintf(text_addr, 20, "%u.%u.%u.%u",
 142                  ntohl(addr) >> 24 & 0xff,
 143                  ntohl(addr) >> 16 & 0xff,
 144                  ntohl(addr) >>  8 & 0xff,
 145                  ntohl(addr) >>  0 & 0xff);
 146
 147         qword_add(bpp, blen, im->m_class);
 148         qword_add(bpp, blen, text_addr);
 149         (*bpp)[-1] = '\n';
 150 }
 151
 152 static struct ip_map *ip_map_lookup(struct ip_map *, int);
 153
 154 static int ip_map_parse(struct cache_detail *cd,
 155                           char *mesg, int mlen)
 156 {
 157         /* class ipaddress [domainname] */
 158         /* should be safe just to use the start of the input buffer
 159          * for scratch: */
 160         char *buf = mesg;
 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, ipm.m_class, sizeof(ipm.m_class));
 174         if (len <= 0) return -EINVAL;
 175         if (len >= sizeof(ipm.m_class))
 176                 return -EINVAL;
 177
 178         /* ip address */
 179         len = qword_get(&mesg, buf, mlen);
 180         if (len <= 0) return -EINVAL;
 181
 182         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
 183                 return -EINVAL;
 184
 185         expiry = get_expiry(&mesg);
 186         if (expiry ==0)
 187                 return -EINVAL;
 188
 189         /* domainname, or empty for NEGATIVE */
 190         len = qword_get(&mesg, buf, mlen);
 191         if (len < 0) return -EINVAL;
 192
 193         if (len) {
 194                 dom = unix_domain_find(buf);
 195                 if (dom == NULL)
 196                         return -ENOENT;
 197         } else
 198                 dom = NULL;
 199
 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 (!ipmp)
 216                 return -ENOMEM;
 217         cache_flush();
 218         return 0;
 219 }
 220
 221 static int ip_map_show(struct seq_file *m,
 222                        struct cache_detail *cd,
 223                        struct cache_head *h)
 224 {
 225         struct ip_map *im;
 226         struct in_addr addr;
 227         char *dom = "-no-domain-";
 228
 229         if (h == NULL) {
 230                 seq_puts(m, "#class IP domain\n");
 231                 return 0;
 232         }
 233         im = container_of(h, struct ip_map, h);
 234         /* class addr domain */
 235         addr = im->m_addr;
 236
 237         if (test_bit(CACHE_VALID, &h->flags) &&
 238             !test_bit(CACHE_NEGATIVE, &h->flags))
 239                 dom = im->m_client->h.name;
 240
 241         seq_printf(m, "%s %d.%d.%d.%d %s\n",
 242                    im->m_class,
 243                    htonl(addr.s_addr) >> 24 & 0xff,
 244                    htonl(addr.s_addr) >> 16 & 0xff,
 245                    htonl(addr.s_addr) >>  8 & 0xff,
 246                    htonl(addr.s_addr) >>  0 & 0xff,
 247                    dom
 248                    );
 249         return 0;
 250 }
 251
 252
 253 struct cache_detail ip_map_cache = {
 254         .hash_size      = IP_HASHMAX,
 255         .hash_table     = ip_table,
 256         .name           = "auth.unix.ip",
 257         .cache_put      = ip_map_put,
 258         .cache_request  = ip_map_request,
 259         .cache_parse    = ip_map_parse,
 260         .cache_show     = ip_map_show,
 261 };
 262
 263 static DefineSimpleCacheLookup(ip_map, 0)
 264
 265
 266 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 267 {
 268         struct unix_domain *udom;
 269         struct ip_map ip, *ipmp;
 270
 271         if (dom->flavour != RPC_AUTH_UNIX)
 272                 return -EINVAL;
 273         udom = container_of(dom, struct unix_domain, h);
 274         strcpy(ip.m_class, "nfsd");
 275         ip.m_addr = addr;
 276         ip.m_client = udom;
 277         ip.m_add_change = udom->addr_changes+1;
 278         ip.h.flags = 0;
 279         ip.h.expiry_time = NEVER;
 280
 281         ipmp = ip_map_lookup(&ip, 1);
 282
 283         if (ipmp) {
 284                 ip_map_put(&ipmp->h, &ip_map_cache);
 285                 return 0;
 286         } else
 287                 return -ENOMEM;
 288 }
 289
 290 int auth_unix_forget_old(struct auth_domain *dom)
 291 {
 292         struct unix_domain *udom;
 293
 294         if (dom->flavour != RPC_AUTH_UNIX)
 295                 return -EINVAL;
 296         udom = container_of(dom, struct unix_domain, h);
 297         udom->addr_changes++;
 298         return 0;
 299 }
 300
 301 struct auth_domain *auth_unix_lookup(struct in_addr addr)
 302 {
 303         struct ip_map key, *ipm;
 304         struct auth_domain *rv;
 305
 306         strcpy(key.m_class, "nfsd");
 307         key.m_addr = addr;
 308
 309         ipm = ip_map_lookup(&key, 0);
 310
 311         if (!ipm)
 312                 return NULL;
 313         if (cache_check(&ip_map_cache, &ipm->h, NULL))
 314                 return NULL;
 315
 316         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
 317                 if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
 318                         auth_domain_put(&ipm->m_client->h);
 319                 rv = NULL;
 320         } else {
 321                 rv = &ipm->m_client->h;
 322                 cache_get(&rv->h);
 323         }
 324         ip_map_put(&ipm->h, &ip_map_cache);
 325         return rv;
 326 }
 327
 328 void svcauth_unix_purge(void)
 329 {
 330         cache_purge(&ip_map_cache);
 331         cache_purge(&auth_domain_cache);
 332 }
 333
 334
 335 static int
 336 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
 337 {
 338         struct kvec     *argv = &rqstp->rq_arg.head[0];
 339         struct kvec     *resv = &rqstp->rq_res.head[0];
 340         int             rv=0;
 341         struct ip_map key, *ipm;
 342
 343         if (argv->iov_len < 3*4)
 344                 return SVC_GARBAGE;
 345
 346         if (svc_getu32(argv) != 0) {
 347                 dprintk("svc: bad null cred\n");
 348                 *authp = rpc_autherr_badcred;
 349                 return SVC_DENIED;
 350         }
 351         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
 352                 dprintk("svc: bad null verf\n");
 353                 *authp = rpc_autherr_badverf;
 354                 return SVC_DENIED;
 355         }
 356
 357         /* Signal that mapping to nobody uid/gid is required */
 358         rqstp->rq_cred.cr_uid = (uid_t) -1;
 359         rqstp->rq_cred.cr_gid = (gid_t) -1;
 360         rqstp->rq_cred.cr_group_info = groups_alloc(0);
 361         if (rqstp->rq_cred.cr_group_info == NULL)
 362                 return SVC_DROP; /* kmalloc failure - client must retry */
 363
 364         /* Put NULL verifier */
 365         svc_putu32(resv, RPC_AUTH_NULL);
 366         svc_putu32(resv, 0);
 367
 368         strcpy(key.m_class, rqstp->rq_server->sv_program->pg_class);
 369         key.m_addr = rqstp->rq_addr.sin_addr;
 370
 371         ipm = ip_map_lookup(&key, 0);
 372
 373         rqstp->rq_client = NULL;
 374
 375         if (ipm)
 376                 switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 377                 case -EAGAIN:
 378                         rv = SVC_DROP;
 379                         break;
 380                 case -ENOENT:
 381                         rv = SVC_OK; /* rq_client is NULL */
 382                         break;
 383                 case 0:
 384                         rqstp->rq_client = &ipm->m_client->h;
 385                         cache_get(&rqstp->rq_client->h);
 386                         ip_map_put(&ipm->h, &ip_map_cache);
 387                         rv = SVC_OK;
 388                         break;
 389                 default: BUG();
 390                 }
 391         else rv = SVC_DROP;
 392
 393         if (rqstp->rq_client == NULL && rqstp->rq_proc != 0)
 394                 *authp = rpc_autherr_badcred;
 395
 396         return rv;
 397 }
 398
 399 static int
 400 svcauth_null_release(struct svc_rqst *rqstp)
 401 {
 402         if (rqstp->rq_client)
 403                 auth_domain_put(rqstp->rq_client);
 404         rqstp->rq_client = NULL;
 405         if (rqstp->rq_cred.cr_group_info)
 406                 put_group_info(rqstp->rq_cred.cr_group_info);
 407         rqstp->rq_cred.cr_group_info = 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 kvec     *argv = &rqstp->rq_arg.head[0];
 426         struct kvec     *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         strcpy(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