net/netlabel/netlabel_mgmt.c

   1 /*
   2  * NetLabel Management Support
   3  *
   4  * This file defines the management functions for the NetLabel system.  The
   5  * NetLabel system manages static and dynamic label mappings for network
   6  * protocols such as CIPSO and RIPSO.
   7  *
   8  * Author: Paul Moore <paul.moore@hp.com>
   9  *
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
  14  *
  15  * This program is free software;  you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  23  * the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program;  if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  28  *
  29  */
  30
  31 #include <linux/types.h>
  32 #include <linux/socket.h>
  33 #include <linux/string.h>
  34 #include <linux/skbuff.h>
  35 #include <net/sock.h>
  36 #include <net/netlink.h>
  37 #include <net/genetlink.h>
  38 #include <net/netlabel.h>
  39 #include <net/cipso_ipv4.h>
  40
  41 #include "netlabel_domainhash.h"
  42 #include "netlabel_user.h"
  43 #include "netlabel_mgmt.h"
  44
  45 /* Argument struct for netlbl_domhsh_walk() */
  46 struct netlbl_domhsh_walk_arg {
  47         struct netlink_callback *nl_cb;
  48         struct sk_buff *skb;
  49         u32 seq;
  50 };
  51
  52 /* NetLabel Generic NETLINK CIPSOv4 family */
  53 static struct genl_family netlbl_mgmt_gnl_family = {
  54         .id = GENL_ID_GENERATE,
  55         .hdrsize = 0,
  56         .name = NETLBL_NLTYPE_MGMT_NAME,
  57         .version = NETLBL_PROTO_VERSION,
  58         .maxattr = NLBL_MGMT_A_MAX,
  59 };
  60
  61 /* NetLabel Netlink attribute policy */
  62 static struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
  63         [NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
  64         [NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
  65         [NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
  66         [NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
  67 };
  68
  69 /*
  70  * NetLabel Command Handlers
  71  */
  72
  73 /**
  74  * netlbl_mgmt_add - Handle an ADD message
  75  * @skb: the NETLINK buffer
  76  * @info: the Generic NETLINK info block
  77  *
  78  * Description:
  79  * Process a user generated ADD message and add the domains from the message
  80  * to the hash table.  See netlabel.h for a description of the message format.
  81  * Returns zero on success, negative values on failure.
  82  *
  83  */
  84 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
  85 {
  86         int ret_val = -EINVAL;
  87         struct netlbl_dom_map *entry = NULL;
  88         size_t tmp_size;
  89         u32 tmp_val;
  90
  91         if (!info->attrs[NLBL_MGMT_A_DOMAIN] ||
  92             !info->attrs[NLBL_MGMT_A_PROTOCOL])
  93                 goto add_failure;
  94
  95         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  96         if (entry == NULL) {
  97                 ret_val = -ENOMEM;
  98                 goto add_failure;
  99         }
 100         tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
 101         entry->domain = kmalloc(tmp_size, GFP_KERNEL);
 102         if (entry->domain == NULL) {
 103                 ret_val = -ENOMEM;
 104                 goto add_failure;
 105         }
 106         entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
 107         nla_strlcpy(entry->domain, info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
 108
 109         switch (entry->type) {
 110         case NETLBL_NLTYPE_UNLABELED:
 111                 ret_val = netlbl_domhsh_add(entry);
 112                 break;
 113         case NETLBL_NLTYPE_CIPSOV4:
 114                 if (!info->attrs[NLBL_MGMT_A_CV4DOI])
 115                         goto add_failure;
 116
 117                 tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
 118                 /* We should be holding a rcu_read_lock() here while we hold
 119                  * the result but since the entry will always be deleted when
 120                  * the CIPSO DOI is deleted we aren't going to keep the
 121                  * lock. */
 122                 rcu_read_lock();
 123                 entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
 124                 if (entry->type_def.cipsov4 == NULL) {
 125                         rcu_read_unlock();
 126                         goto add_failure;
 127                 }
 128                 ret_val = netlbl_domhsh_add(entry);
 129                 rcu_read_unlock();
 130                 break;
 131         default:
 132                 goto add_failure;
 133         }
 134         if (ret_val != 0)
 135                 goto add_failure;
 136
 137         return 0;
 138
 139 add_failure:
 140         if (entry)
 141                 kfree(entry->domain);
 142         kfree(entry);
 143         return ret_val;
 144 }
 145
 146 /**
 147  * netlbl_mgmt_remove - Handle a REMOVE message
 148  * @skb: the NETLINK buffer
 149  * @info: the Generic NETLINK info block
 150  *
 151  * Description:
 152  * Process a user generated REMOVE message and remove the specified domain
 153  * mappings.  Returns zero on success, negative values on failure.
 154  *
 155  */
 156 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
 157 {
 158         char *domain;
 159
 160         if (!info->attrs[NLBL_MGMT_A_DOMAIN])
 161                 return -EINVAL;
 162
 163         domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
 164         return netlbl_domhsh_remove(domain);
 165 }
 166
 167 /**
 168  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
 169  * @entry: the domain mapping hash table entry
 170  * @arg: the netlbl_domhsh_walk_arg structure
 171  *
 172  * Description:
 173  * This function is designed to be used as a callback to the
 174  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
 175  * message.  Returns the size of the message on success, negative values on
 176  * failure.
 177  *
 178  */
 179 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
 180 {
 181         int ret_val = -ENOMEM;
 182         struct netlbl_domhsh_walk_arg *cb_arg = arg;
 183         void *data;
 184
 185         data = netlbl_netlink_hdr_put(cb_arg->skb,
 186                                       NETLINK_CB(cb_arg->nl_cb->skb).pid,
 187                                       cb_arg->seq,
 188                                       netlbl_mgmt_gnl_family.id,
 189                                       NLM_F_MULTI,
 190                                       NLBL_MGMT_C_LISTALL);
 191         if (data == NULL)
 192                 goto listall_cb_failure;
 193
 194         ret_val = nla_put_string(cb_arg->skb,
 195                                  NLBL_MGMT_A_DOMAIN,
 196                                  entry->domain);
 197         if (ret_val != 0)
 198                 goto listall_cb_failure;
 199         ret_val = nla_put_u32(cb_arg->skb, NLBL_MGMT_A_PROTOCOL, entry->type);
 200         if (ret_val != 0)
 201                 goto listall_cb_failure;
 202         switch (entry->type) {
 203         case NETLBL_NLTYPE_CIPSOV4:
 204                 ret_val = nla_put_u32(cb_arg->skb,
 205                                       NLBL_MGMT_A_CV4DOI,
 206                                       entry->type_def.cipsov4->doi);
 207                 if (ret_val != 0)
 208                         goto listall_cb_failure;
 209                 break;
 210         }
 211
 212         cb_arg->seq++;
 213         return genlmsg_end(cb_arg->skb, data);
 214
 215 listall_cb_failure:
 216         genlmsg_cancel(cb_arg->skb, data);
 217         return ret_val;
 218 }
 219
 220 /**
 221  * netlbl_mgmt_listall - Handle a LISTALL message
 222  * @skb: the NETLINK buffer
 223  * @cb: the NETLINK callback
 224  *
 225  * Description:
 226  * Process a user generated LISTALL message and dumps the domain hash table in
 227  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
 228  * on success, negative values on failure.
 229  *
 230  */
 231 static int netlbl_mgmt_listall(struct sk_buff *skb,
 232                                struct netlink_callback *cb)
 233 {
 234         struct netlbl_domhsh_walk_arg cb_arg;
 235         u32 skip_bkt = cb->args[0];
 236         u32 skip_chain = cb->args[1];
 237
 238         cb_arg.nl_cb = cb;
 239         cb_arg.skb = skb;
 240         cb_arg.seq = cb->nlh->nlmsg_seq;
 241
 242         netlbl_domhsh_walk(&skip_bkt,
 243                            &skip_chain,
 244                            netlbl_mgmt_listall_cb,
 245                            &cb_arg);
 246
 247         cb->args[0] = skip_bkt;
 248         cb->args[1] = skip_chain;
 249         return skb->len;
 250 }
 251
 252 /**
 253  * netlbl_mgmt_adddef - Handle an ADDDEF message
 254  * @skb: the NETLINK buffer
 255  * @info: the Generic NETLINK info block
 256  *
 257  * Description:
 258  * Process a user generated ADDDEF message and respond accordingly.  Returns
 259  * zero on success, negative values on failure.
 260  *
 261  */
 262 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
 263 {
 264         int ret_val = -EINVAL;
 265         struct netlbl_dom_map *entry = NULL;
 266         u32 tmp_val;
 267
 268         if (!info->attrs[NLBL_MGMT_A_PROTOCOL])
 269                 goto adddef_failure;
 270
 271         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 272         if (entry == NULL) {
 273                 ret_val = -ENOMEM;
 274                 goto adddef_failure;
 275         }
 276         entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
 277
 278         switch (entry->type) {
 279         case NETLBL_NLTYPE_UNLABELED:
 280                 ret_val = netlbl_domhsh_add_default(entry);
 281                 break;
 282         case NETLBL_NLTYPE_CIPSOV4:
 283                 if (!info->attrs[NLBL_MGMT_A_CV4DOI])
 284                         goto adddef_failure;
 285
 286                 tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
 287                 /* We should be holding a rcu_read_lock() here while we hold
 288                  * the result but since the entry will always be deleted when
 289                  * the CIPSO DOI is deleted we aren't going to keep the
 290                  * lock. */
 291                 rcu_read_lock();
 292                 entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
 293                 if (entry->type_def.cipsov4 == NULL) {
 294                         rcu_read_unlock();
 295                         goto adddef_failure;
 296                 }
 297                 ret_val = netlbl_domhsh_add_default(entry);
 298                 rcu_read_unlock();
 299                 break;
 300         default:
 301                 goto adddef_failure;
 302         }
 303         if (ret_val != 0)
 304                 goto adddef_failure;
 305
 306         return 0;
 307
 308 adddef_failure:
 309         kfree(entry);
 310         return ret_val;
 311 }
 312
 313 /**
 314  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
 315  * @skb: the NETLINK buffer
 316  * @info: the Generic NETLINK info block
 317  *
 318  * Description:
 319  * Process a user generated REMOVEDEF message and remove the default domain
 320  * mapping.  Returns zero on success, negative values on failure.
 321  *
 322  */
 323 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
 324 {
 325         return netlbl_domhsh_remove_default();
 326 }
 327
 328 /**
 329  * netlbl_mgmt_listdef - Handle a LISTDEF message
 330  * @skb: the NETLINK buffer
 331  * @info: the Generic NETLINK info block
 332  *
 333  * Description:
 334  * Process a user generated LISTDEF message and dumps the default domain
 335  * mapping in a form suitable for use in a kernel generated LISTDEF message.
 336  * Returns zero on success, negative values on failure.
 337  *
 338  */
 339 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
 340 {
 341         int ret_val = -ENOMEM;
 342         struct sk_buff *ans_skb = NULL;
 343         void *data;
 344         struct netlbl_dom_map *entry;
 345
 346         ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 347         if (ans_skb == NULL)
 348                 return -ENOMEM;
 349         data = netlbl_netlink_hdr_put(ans_skb,
 350                                       info->snd_pid,
 351                                       info->snd_seq,
 352                                       netlbl_mgmt_gnl_family.id,
 353                                       0,
 354                                       NLBL_MGMT_C_LISTDEF);
 355         if (data == NULL)
 356                 goto listdef_failure;
 357
 358         rcu_read_lock();
 359         entry = netlbl_domhsh_getentry(NULL);
 360         if (entry == NULL) {
 361                 ret_val = -ENOENT;
 362                 goto listdef_failure_lock;
 363         }
 364         ret_val = nla_put_u32(ans_skb, NLBL_MGMT_A_PROTOCOL, entry->type);
 365         if (ret_val != 0)
 366                 goto listdef_failure_lock;
 367         switch (entry->type) {
 368         case NETLBL_NLTYPE_CIPSOV4:
 369                 ret_val = nla_put_u32(ans_skb,
 370                                       NLBL_MGMT_A_CV4DOI,
 371                                       entry->type_def.cipsov4->doi);
 372                 if (ret_val != 0)
 373                         goto listdef_failure_lock;
 374                 break;
 375         }
 376         rcu_read_unlock();
 377
 378         genlmsg_end(ans_skb, data);
 379
 380         ret_val = genlmsg_unicast(ans_skb, info->snd_pid);
 381         if (ret_val != 0)
 382                 goto listdef_failure;
 383         return 0;
 384
 385 listdef_failure_lock:
 386         rcu_read_unlock();
 387 listdef_failure:
 388         kfree_skb(ans_skb);
 389         return ret_val;
 390 }
 391
 392 /**
 393  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
 394  * @skb: the skb to write to
 395  * @seq: the NETLINK sequence number
 396  * @cb: the NETLINK callback
 397  * @protocol: the NetLabel protocol to use in the message
 398  *
 399  * Description:
 400  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
 401  * answer a application's PROTOCOLS message.  Returns the size of the message
 402  * on success, negative values on failure.
 403  *
 404  */
 405 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
 406                                     struct netlink_callback *cb,
 407                                     u32 protocol)
 408 {
 409         int ret_val = -ENOMEM;
 410         void *data;
 411
 412         data = netlbl_netlink_hdr_put(skb,
 413                                       NETLINK_CB(cb->skb).pid,
 414                                       cb->nlh->nlmsg_seq,
 415                                       netlbl_mgmt_gnl_family.id,
 416                                       NLM_F_MULTI,
 417                                       NLBL_MGMT_C_PROTOCOLS);
 418         if (data == NULL)
 419                 goto protocols_cb_failure;
 420
 421         ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
 422         if (ret_val != 0)
 423                 goto protocols_cb_failure;
 424
 425         return genlmsg_end(skb, data);
 426
 427 protocols_cb_failure:
 428         genlmsg_cancel(skb, data);
 429         return ret_val;
 430 }
 431
 432 /**
 433  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
 434  * @skb: the NETLINK buffer
 435  * @cb: the NETLINK callback
 436  *
 437  * Description:
 438  * Process a user generated PROTOCOLS message and respond accordingly.
 439  *
 440  */
 441 static int netlbl_mgmt_protocols(struct sk_buff *skb,
 442                                  struct netlink_callback *cb)
 443 {
 444         u32 protos_sent = cb->args[0];
 445
 446         if (protos_sent == 0) {
 447                 if (netlbl_mgmt_protocols_cb(skb,
 448                                              cb,
 449                                              NETLBL_NLTYPE_UNLABELED) < 0)
 450                         goto protocols_return;
 451                 protos_sent++;
 452         }
 453         if (protos_sent == 1) {
 454                 if (netlbl_mgmt_protocols_cb(skb,
 455                                              cb,
 456                                              NETLBL_NLTYPE_CIPSOV4) < 0)
 457                         goto protocols_return;
 458                 protos_sent++;
 459         }
 460
 461 protocols_return:
 462         cb->args[0] = protos_sent;
 463         return skb->len;
 464 }
 465
 466 /**
 467  * netlbl_mgmt_version - Handle a VERSION message
 468  * @skb: the NETLINK buffer
 469  * @info: the Generic NETLINK info block
 470  *
 471  * Description:
 472  * Process a user generated VERSION message and respond accordingly.  Returns
 473  * zero on success, negative values on failure.
 474  *
 475  */
 476 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
 477 {
 478         int ret_val = -ENOMEM;
 479         struct sk_buff *ans_skb = NULL;
 480         void *data;
 481
 482         ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 483         if (ans_skb == NULL)
 484                 return -ENOMEM;
 485         data = netlbl_netlink_hdr_put(ans_skb,
 486                                       info->snd_pid,
 487                                       info->snd_seq,
 488                                       netlbl_mgmt_gnl_family.id,
 489                                       0,
 490                                       NLBL_MGMT_C_VERSION);
 491         if (data == NULL)
 492                 goto version_failure;
 493
 494         ret_val = nla_put_u32(ans_skb,
 495                               NLBL_MGMT_A_VERSION,
 496                               NETLBL_PROTO_VERSION);
 497         if (ret_val != 0)
 498                 goto version_failure;
 499
 500         genlmsg_end(ans_skb, data);
 501
 502         ret_val = genlmsg_unicast(ans_skb, info->snd_pid);
 503         if (ret_val != 0)
 504                 goto version_failure;
 505         return 0;
 506
 507 version_failure:
 508         kfree_skb(ans_skb);
 509         return ret_val;
 510 }
 511
 512
 513 /*
 514  * NetLabel Generic NETLINK Command Definitions
 515  */
 516
 517 static struct genl_ops netlbl_mgmt_genl_c_add = {
 518         .cmd = NLBL_MGMT_C_ADD,
 519         .flags = GENL_ADMIN_PERM,
 520         .policy = netlbl_mgmt_genl_policy,
 521         .doit = netlbl_mgmt_add,
 522         .dumpit = NULL,
 523 };
 524
 525 static struct genl_ops netlbl_mgmt_genl_c_remove = {
 526         .cmd = NLBL_MGMT_C_REMOVE,
 527         .flags = GENL_ADMIN_PERM,
 528         .policy = netlbl_mgmt_genl_policy,
 529         .doit = netlbl_mgmt_remove,
 530         .dumpit = NULL,
 531 };
 532
 533 static struct genl_ops netlbl_mgmt_genl_c_listall = {
 534         .cmd = NLBL_MGMT_C_LISTALL,
 535         .flags = 0,
 536         .policy = netlbl_mgmt_genl_policy,
 537         .doit = NULL,
 538         .dumpit = netlbl_mgmt_listall,
 539 };
 540
 541 static struct genl_ops netlbl_mgmt_genl_c_adddef = {
 542         .cmd = NLBL_MGMT_C_ADDDEF,
 543         .flags = GENL_ADMIN_PERM,
 544         .policy = netlbl_mgmt_genl_policy,
 545         .doit = netlbl_mgmt_adddef,
 546         .dumpit = NULL,
 547 };
 548
 549 static struct genl_ops netlbl_mgmt_genl_c_removedef = {
 550         .cmd = NLBL_MGMT_C_REMOVEDEF,
 551         .flags = GENL_ADMIN_PERM,
 552         .policy = netlbl_mgmt_genl_policy,
 553         .doit = netlbl_mgmt_removedef,
 554         .dumpit = NULL,
 555 };
 556
 557 static struct genl_ops netlbl_mgmt_genl_c_listdef = {
 558         .cmd = NLBL_MGMT_C_LISTDEF,
 559         .flags = 0,
 560         .policy = netlbl_mgmt_genl_policy,
 561         .doit = netlbl_mgmt_listdef,
 562         .dumpit = NULL,
 563 };
 564
 565 static struct genl_ops netlbl_mgmt_genl_c_protocols = {
 566         .cmd = NLBL_MGMT_C_PROTOCOLS,
 567         .flags = 0,
 568         .policy = netlbl_mgmt_genl_policy,
 569         .doit = NULL,
 570         .dumpit = netlbl_mgmt_protocols,
 571 };
 572
 573 static struct genl_ops netlbl_mgmt_genl_c_version = {
 574         .cmd = NLBL_MGMT_C_VERSION,
 575         .flags = 0,
 576         .policy = netlbl_mgmt_genl_policy,
 577         .doit = netlbl_mgmt_version,
 578         .dumpit = NULL,
 579 };
 580
 581 /*
 582  * NetLabel Generic NETLINK Protocol Functions
 583  */
 584
 585 /**
 586  * netlbl_mgmt_genl_init - Register the NetLabel management component
 587  *
 588  * Description:
 589  * Register the NetLabel management component with the Generic NETLINK
 590  * mechanism.  Returns zero on success, negative values on failure.
 591  *
 592  */
 593 int netlbl_mgmt_genl_init(void)
 594 {
 595         int ret_val;
 596
 597         ret_val = genl_register_family(&netlbl_mgmt_gnl_family);
 598         if (ret_val != 0)
 599                 return ret_val;
 600
 601         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 602                                     &netlbl_mgmt_genl_c_add);
 603         if (ret_val != 0)
 604                 return ret_val;
 605         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 606                                     &netlbl_mgmt_genl_c_remove);
 607         if (ret_val != 0)
 608                 return ret_val;
 609         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 610                                     &netlbl_mgmt_genl_c_listall);
 611         if (ret_val != 0)
 612                 return ret_val;
 613         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 614                                     &netlbl_mgmt_genl_c_adddef);
 615         if (ret_val != 0)
 616                 return ret_val;
 617         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 618                                     &netlbl_mgmt_genl_c_removedef);
 619         if (ret_val != 0)
 620                 return ret_val;
 621         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 622                                     &netlbl_mgmt_genl_c_listdef);
 623         if (ret_val != 0)
 624                 return ret_val;
 625         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 626                                     &netlbl_mgmt_genl_c_protocols);
 627         if (ret_val != 0)
 628                 return ret_val;
 629         ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
 630                                     &netlbl_mgmt_genl_c_version);
 631         if (ret_val != 0)
 632                 return ret_val;
 633
 634         return 0;
 635 }