kernel/vserver/network.c

   1 /*
   2  *  linux/kernel/vserver/network.c
   3  *
   4  *  Virtual Server: Network Support
   5  *
   6  *  Copyright (C) 2003-2007  Herbert Pötzl
   7  *
   8  *  V0.01  broken out from vcontext V0.05
   9  *  V0.02  cleaned up implementation
  10  *  V0.03  added equiv nx commands
  11  *  V0.04  switch to RCU based hash
  12  *  V0.05  and back to locking again
  13  *  V0.06  changed vcmds to nxi arg
  14  *  V0.07  have __create claim() the nxi
  15  *
  16  */
  17
  18 #include <linux/slab.h>
  19 #include <linux/rcupdate.h>
  20 #include <net/tcp.h>
  21
  22 #include <asm/errno.h>
  23 #include <linux/vserver/base.h>
  24 #include <linux/vserver/network_cmd.h>
  25
  26
  27 atomic_t nx_global_ctotal       = ATOMIC_INIT(0);
  28 atomic_t nx_global_cactive      = ATOMIC_INIT(0);
  29
  30
  31 /*      __alloc_nx_info()
  32
  33         * allocate an initialized nx_info struct
  34         * doesn't make it visible (hash)                        */
  35
  36 static struct nx_info *__alloc_nx_info(nid_t nid)
  37 {
  38         struct nx_info *new = NULL;
  39
  40         vxdprintk(VXD_CBIT(nid, 1), "alloc_nx_info(%d)*", nid);
  41
  42         /* would this benefit from a slab cache? */
  43         new = kmalloc(sizeof(struct nx_info), GFP_KERNEL);
  44         if (!new)
  45                 return 0;
  46
  47         memset (new, 0, sizeof(struct nx_info));
  48         new->nx_id = nid;
  49         INIT_HLIST_NODE(&new->nx_hlist);
  50         atomic_set(&new->nx_usecnt, 0);
  51         atomic_set(&new->nx_tasks, 0);
  52         new->nx_state = 0;
  53
  54         new->nx_flags = NXF_INIT_SET;
  55
  56         /* rest of init goes here */
  57
  58         vxdprintk(VXD_CBIT(nid, 0),
  59                 "alloc_nx_info(%d) = %p", nid, new);
  60         atomic_inc(&nx_global_ctotal);
  61         return new;
  62 }
  63
  64 /*      __dealloc_nx_info()
  65
  66         * final disposal of nx_info                             */
  67
  68 static void __dealloc_nx_info(struct nx_info *nxi)
  69 {
  70         vxdprintk(VXD_CBIT(nid, 0),
  71                 "dealloc_nx_info(%p)", nxi);
  72
  73         nxi->nx_hlist.next = LIST_POISON1;
  74         nxi->nx_id = -1;
  75
  76         BUG_ON(atomic_read(&nxi->nx_usecnt));
  77         BUG_ON(atomic_read(&nxi->nx_tasks));
  78
  79         nxi->nx_state |= NXS_RELEASED;
  80         kfree(nxi);
  81         atomic_dec(&nx_global_ctotal);
  82 }
  83
  84 static void __shutdown_nx_info(struct nx_info *nxi)
  85 {
  86         nxi->nx_state |= NXS_SHUTDOWN;
  87         vs_net_change(nxi, VSC_NETDOWN);
  88 }
  89
  90 /*      exported stuff                                          */
  91
  92 void free_nx_info(struct nx_info *nxi)
  93 {
  94         /* context shutdown is mandatory */
  95         BUG_ON(nxi->nx_state != NXS_SHUTDOWN);
  96
  97         /* context must not be hashed */
  98         BUG_ON(nxi->nx_state & NXS_HASHED);
  99
 100         BUG_ON(atomic_read(&nxi->nx_usecnt));
 101         BUG_ON(atomic_read(&nxi->nx_tasks));
 102
 103         __dealloc_nx_info(nxi);
 104 }
 105
 106
 107 /*      hash table for nx_info hash */
 108
 109 #define NX_HASH_SIZE    13
 110
 111 struct hlist_head nx_info_hash[NX_HASH_SIZE];
 112
 113 static spinlock_t nx_info_hash_lock = SPIN_LOCK_UNLOCKED;
 114
 115
 116 static inline unsigned int __hashval(nid_t nid)
 117 {
 118         return (nid % NX_HASH_SIZE);
 119 }
 120
 121
 122
 123 /*      __hash_nx_info()
 124
 125         * add the nxi to the global hash table
 126         * requires the hash_lock to be held                     */
 127
 128 static inline void __hash_nx_info(struct nx_info *nxi)
 129 {
 130         struct hlist_head *head;
 131
 132         vxd_assert_lock(&nx_info_hash_lock);
 133         vxdprintk(VXD_CBIT(nid, 4),
 134                 "__hash_nx_info: %p[#%d]", nxi, nxi->nx_id);
 135
 136         /* context must not be hashed */
 137         BUG_ON(nx_info_state(nxi, NXS_HASHED));
 138
 139         nxi->nx_state |= NXS_HASHED;
 140         head = &nx_info_hash[__hashval(nxi->nx_id)];
 141         hlist_add_head(&nxi->nx_hlist, head);
 142         atomic_inc(&nx_global_cactive);
 143 }
 144
 145 /*      __unhash_nx_info()
 146
 147         * remove the nxi from the global hash table
 148         * requires the hash_lock to be held                     */
 149
 150 static inline void __unhash_nx_info(struct nx_info *nxi)
 151 {
 152         vxd_assert_lock(&nx_info_hash_lock);
 153         vxdprintk(VXD_CBIT(nid, 4),
 154                 "__unhash_nx_info: %p[#%d.%d.%d]", nxi, nxi->nx_id,
 155                 atomic_read(&nxi->nx_usecnt), atomic_read(&nxi->nx_tasks));
 156
 157         /* context must be hashed */
 158         BUG_ON(!nx_info_state(nxi, NXS_HASHED));
 159         /* but without tasks */
 160         BUG_ON(atomic_read(&nxi->nx_tasks));
 161
 162         nxi->nx_state &= ~NXS_HASHED;
 163         hlist_del(&nxi->nx_hlist);
 164         atomic_dec(&nx_global_cactive);
 165 }
 166
 167
 168 /*      __lookup_nx_info()
 169
 170         * requires the hash_lock to be held
 171         * doesn't increment the nx_refcnt                       */
 172
 173 static inline struct nx_info *__lookup_nx_info(nid_t nid)
 174 {
 175         struct hlist_head *head = &nx_info_hash[__hashval(nid)];
 176         struct hlist_node *pos;
 177         struct nx_info *nxi;
 178
 179         vxd_assert_lock(&nx_info_hash_lock);
 180         hlist_for_each(pos, head) {
 181                 nxi = hlist_entry(pos, struct nx_info, nx_hlist);
 182
 183                 if (nxi->nx_id == nid)
 184                         goto found;
 185         }
 186         nxi = NULL;
 187 found:
 188         vxdprintk(VXD_CBIT(nid, 0),
 189                 "__lookup_nx_info(#%u): %p[#%u]",
 190                 nid, nxi, nxi?nxi->nx_id:0);
 191         return nxi;
 192 }
 193
 194
 195 /*      __nx_dynamic_id()
 196
 197         * find unused dynamic nid
 198         * requires the hash_lock to be held                     */
 199
 200 static inline nid_t __nx_dynamic_id(void)
 201 {
 202         static nid_t seq = MAX_N_CONTEXT;
 203         nid_t barrier = seq;
 204
 205         vxd_assert_lock(&nx_info_hash_lock);
 206         do {
 207                 if (++seq > MAX_N_CONTEXT)
 208                         seq = MIN_D_CONTEXT;
 209                 if (!__lookup_nx_info(seq)) {
 210                         vxdprintk(VXD_CBIT(nid, 4),
 211                                 "__nx_dynamic_id: [#%d]", seq);
 212                         return seq;
 213                 }
 214         } while (barrier != seq);
 215         return 0;
 216 }
 217
 218 /*      __create_nx_info()
 219
 220         * create the requested context
 221         * get(), claim() and hash it                            */
 222
 223 static struct nx_info * __create_nx_info(int id)
 224 {
 225         struct nx_info *new, *nxi = NULL;
 226
 227         vxdprintk(VXD_CBIT(nid, 1), "create_nx_info(%d)*", id);
 228
 229         if (!(new = __alloc_nx_info(id)))
 230                 return ERR_PTR(-ENOMEM);
 231
 232         /* required to make dynamic xids unique */
 233         spin_lock(&nx_info_hash_lock);
 234
 235         /* dynamic context requested */
 236         if (id == NX_DYNAMIC_ID) {
 237 #ifdef  CONFIG_VSERVER_DYNAMIC_IDS
 238                 id = __nx_dynamic_id();
 239                 if (!id) {
 240                         printk(KERN_ERR "no dynamic context available.\n");
 241                         nxi = ERR_PTR(-EAGAIN);
 242                         goto out_unlock;
 243                 }
 244                 new->nx_id = id;
 245 #else
 246                 printk(KERN_ERR "dynamic contexts disabled.\n");
 247                 nxi = ERR_PTR(-EINVAL);
 248                 goto out_unlock;
 249 #endif
 250         }
 251         /* static context requested */
 252         else if ((nxi = __lookup_nx_info(id))) {
 253                 vxdprintk(VXD_CBIT(nid, 0),
 254                         "create_nx_info(%d) = %p (already there)", id, nxi);
 255                 if (nx_info_flags(nxi, NXF_STATE_SETUP, 0))
 256                         nxi = ERR_PTR(-EBUSY);
 257                 else
 258                         nxi = ERR_PTR(-EEXIST);
 259                 goto out_unlock;
 260         }
 261         /* dynamic nid creation blocker */
 262         else if (id >= MIN_D_CONTEXT) {
 263                 vxdprintk(VXD_CBIT(nid, 0),
 264                         "create_nx_info(%d) (dynamic rejected)", id);
 265                 nxi = ERR_PTR(-EINVAL);
 266                 goto out_unlock;
 267         }
 268
 269         /* new context */
 270         vxdprintk(VXD_CBIT(nid, 0),
 271                 "create_nx_info(%d) = %p (new)", id, new);
 272         claim_nx_info(new, NULL);
 273         __hash_nx_info(get_nx_info(new));
 274         nxi = new, new = NULL;
 275
 276 out_unlock:
 277         spin_unlock(&nx_info_hash_lock);
 278         if (new)
 279                 __dealloc_nx_info(new);
 280         return nxi;
 281 }
 282
 283
 284
 285 /*      exported stuff                                          */
 286
 287
 288 void unhash_nx_info(struct nx_info *nxi)
 289 {
 290         __shutdown_nx_info(nxi);
 291         spin_lock(&nx_info_hash_lock);
 292         __unhash_nx_info(nxi);
 293         spin_unlock(&nx_info_hash_lock);
 294 }
 295
 296 #ifdef  CONFIG_VSERVER_LEGACYNET
 297
 298 struct nx_info *create_nx_info(void)
 299 {
 300         return __create_nx_info(NX_DYNAMIC_ID);
 301 }
 302
 303 #endif
 304
 305 /*      lookup_nx_info()
 306
 307         * search for a nx_info and get() it
 308         * negative id means current                             */
 309
 310 struct nx_info *lookup_nx_info(int id)
 311 {
 312         struct nx_info *nxi = NULL;
 313
 314         if (id < 0) {
 315                 nxi = get_nx_info(current->nx_info);
 316         } else if (id > 1) {
 317                 spin_lock(&nx_info_hash_lock);
 318                 nxi = get_nx_info(__lookup_nx_info(id));
 319                 spin_unlock(&nx_info_hash_lock);
 320         }
 321         return nxi;
 322 }
 323
 324 /*      nid_is_hashed()
 325
 326         * verify that nid is still hashed                       */
 327
 328 int nid_is_hashed(nid_t nid)
 329 {
 330         int hashed;
 331
 332         spin_lock(&nx_info_hash_lock);
 333         hashed = (__lookup_nx_info(nid) != NULL);
 334         spin_unlock(&nx_info_hash_lock);
 335         return hashed;
 336 }
 337
 338
 339 #ifdef  CONFIG_PROC_FS
 340
 341 /*      get_nid_list()
 342
 343         * get a subset of hashed nids for proc
 344         * assumes size is at least one                          */
 345
 346 int get_nid_list(int index, unsigned int *nids, int size)
 347 {
 348         int hindex, nr_nids = 0;
 349
 350         /* only show current and children */
 351         if (!nx_check(0, VS_ADMIN|VS_WATCH)) {
 352                 if (index > 0)
 353                         return 0;
 354                 nids[nr_nids] = nx_current_nid();
 355                 return 1;
 356         }
 357
 358         for (hindex = 0; hindex < NX_HASH_SIZE; hindex++) {
 359                 struct hlist_head *head = &nx_info_hash[hindex];
 360                 struct hlist_node *pos;
 361
 362                 spin_lock(&nx_info_hash_lock);
 363                 hlist_for_each(pos, head) {
 364                         struct nx_info *nxi;
 365
 366                         if (--index > 0)
 367                                 continue;
 368
 369                         nxi = hlist_entry(pos, struct nx_info, nx_hlist);
 370                         nids[nr_nids] = nxi->nx_id;
 371                         if (++nr_nids >= size) {
 372                                 spin_unlock(&nx_info_hash_lock);
 373                                 goto out;
 374                         }
 375                 }
 376                 /* keep the lock time short */
 377                 spin_unlock(&nx_info_hash_lock);
 378         }
 379 out:
 380         return nr_nids;
 381 }
 382 #endif
 383
 384
 385 /*
 386  *      migrate task to new network
 387  *      gets nxi, puts old_nxi on change
 388  */
 389
 390 int nx_migrate_task(struct task_struct *p, struct nx_info *nxi)
 391 {
 392         struct nx_info *old_nxi;
 393         int ret = 0;
 394
 395         if (!p || !nxi)
 396                 BUG();
 397
 398         vxdprintk(VXD_CBIT(nid, 5),
 399                 "nx_migrate_task(%p,%p[#%d.%d.%d])",
 400                 p, nxi, nxi->nx_id,
 401                 atomic_read(&nxi->nx_usecnt),
 402                 atomic_read(&nxi->nx_tasks));
 403
 404         if (nx_info_flags(nxi, NXF_INFO_PRIVATE, 0) &&
 405                 !nx_info_flags(nxi, NXF_STATE_SETUP, 0))
 406                 return -EACCES;
 407
 408         if (nx_info_state(nxi, NXS_SHUTDOWN))
 409                 return -EFAULT;
 410
 411         /* maybe disallow this completely? */
 412         old_nxi = task_get_nx_info(p);
 413         if (old_nxi == nxi)
 414                 goto out;
 415
 416         task_lock(p);
 417         if (old_nxi)
 418                 clr_nx_info(&p->nx_info);
 419         claim_nx_info(nxi, p);
 420         set_nx_info(&p->nx_info, nxi);
 421         p->nid = nxi->nx_id;
 422         task_unlock(p);
 423
 424         vxdprintk(VXD_CBIT(nid, 5),
 425                 "moved task %p into nxi:%p[#%d]",
 426                 p, nxi, nxi->nx_id);
 427
 428         if (old_nxi)
 429                 release_nx_info(old_nxi, p);
 430         ret = 0;
 431 out:
 432         put_nx_info(old_nxi);
 433         return ret;
 434 }
 435
 436
 437 #ifdef CONFIG_INET
 438
 439 #include <linux/netdevice.h>
 440 #include <linux/inetdevice.h>
 441
 442 int ifa_in_nx_info(struct in_ifaddr *ifa, struct nx_info *nxi)
 443 {
 444         if (!nxi)
 445                 return 1;
 446         if (!ifa)
 447                 return 0;
 448         return addr_in_nx_info(nxi, ifa->ifa_local);
 449 }
 450
 451 int dev_in_nx_info(struct net_device *dev, struct nx_info *nxi)
 452 {
 453         struct in_device *in_dev;
 454         struct in_ifaddr **ifap;
 455         struct in_ifaddr *ifa;
 456         int ret = 0;
 457
 458         if (!nxi)
 459                 return 1;
 460
 461         if (!dev)
 462                 goto out;
 463         in_dev = in_dev_get(dev);
 464         if (!in_dev)
 465                 goto out;
 466
 467         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
 468                 ifap = &ifa->ifa_next) {
 469                 if (addr_in_nx_info(nxi, ifa->ifa_local)) {
 470                         ret = 1;
 471                         break;
 472                 }
 473         }
 474         in_dev_put(in_dev);
 475 out:
 476         return ret;
 477 }
 478
 479 /*
 480  *      check if address is covered by socket
 481  *
 482  *      sk:     the socket to check against
 483  *      addr:   the address in question (must be != 0)
 484  */
 485 static inline int __addr_in_socket(const struct sock *sk, uint32_t addr)
 486 {
 487         struct nx_info *nxi = sk->sk_nx_info;
 488         uint32_t saddr = inet_rcv_saddr(sk);
 489
 490         vxdprintk(VXD_CBIT(net, 5),
 491                 "__addr_in_socket(%p,%d.%d.%d.%d) %p:%d.%d.%d.%d %p;%lx",
 492                 sk, VXD_QUAD(addr), nxi, VXD_QUAD(saddr), sk->sk_socket,
 493                 (sk->sk_socket?sk->sk_socket->flags:0));
 494
 495         if (saddr) {
 496                 /* direct address match */
 497                 return (saddr == addr);
 498         } else if (nxi) {
 499                 /* match against nx_info */
 500                 return addr_in_nx_info(nxi, addr);
 501         } else {
 502                 /* unrestricted any socket */
 503                 return 1;
 504         }
 505 }
 506
 507
 508 int nx_addr_conflict(struct nx_info *nxi, uint32_t addr, const struct sock *sk)
 509 {
 510         vxdprintk(VXD_CBIT(net, 2),
 511                 "nx_addr_conflict(%p,%p) %d.%d,%d.%d",
 512                 nxi, sk, VXD_QUAD(addr));
 513
 514         if (addr) {
 515                 /* check real address */
 516                 return __addr_in_socket(sk, addr);
 517         } else if (nxi) {
 518                 /* check against nx_info */
 519                 int i, n = nxi->nbipv4;
 520
 521                 for (i=0; i<n; i++)
 522                         if (__addr_in_socket(sk, nxi->ipv4[i]))
 523                                 return 1;
 524                 return 0;
 525         } else {
 526                 /* check against any */
 527                 return 1;
 528         }
 529 }
 530
 531 #endif /* CONFIG_INET */
 532
 533 void nx_set_persistent(struct nx_info *nxi)
 534 {
 535         vxdprintk(VXD_CBIT(nid, 6),
 536                 "nx_set_persistent(%p[#%d])", nxi, nxi->nx_id);
 537
 538         get_nx_info(nxi);
 539         claim_nx_info(nxi, NULL);
 540 }
 541
 542 void nx_clear_persistent(struct nx_info *nxi)
 543 {
 544         vxdprintk(VXD_CBIT(nid, 6),
 545                 "nx_clear_persistent(%p[#%d])", nxi, nxi->nx_id);
 546
 547         release_nx_info(nxi, NULL);
 548         put_nx_info(nxi);
 549 }
 550
 551 void nx_update_persistent(struct nx_info *nxi)
 552 {
 553         if (nx_info_flags(nxi, NXF_PERSISTENT, 0))
 554                 nx_set_persistent(nxi);
 555         else
 556                 nx_clear_persistent(nxi);
 557 }
 558
 559 /* vserver syscall commands below here */
 560
 561 /* taks nid and nx_info functions */
 562
 563 #include <asm/uaccess.h>
 564
 565
 566 int vc_task_nid(uint32_t id, void __user *data)
 567 {
 568         nid_t nid;
 569
 570         if (id) {
 571                 struct task_struct *tsk;
 572
 573                 if (!nx_check(0, VS_ADMIN|VS_WATCH))
 574                         return -EPERM;
 575
 576                 read_lock(&tasklist_lock);
 577                 tsk = find_task_by_real_pid(id);
 578                 nid = (tsk) ? tsk->nid : -ESRCH;
 579                 read_unlock(&tasklist_lock);
 580         }
 581         else
 582                 nid = nx_current_nid();
 583         return nid;
 584 }
 585
 586
 587 int vc_nx_info(struct nx_info *nxi, void __user *data)
 588 {
 589         struct vcmd_nx_info_v0 vc_data;
 590
 591         vc_data.nid = nxi->nx_id;
 592
 593         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 594                 return -EFAULT;
 595         return 0;
 596 }
 597
 598
 599 /* network functions */
 600
 601 int vc_net_create(uint32_t nid, void __user *data)
 602 {
 603         struct vcmd_net_create vc_data = { .flagword = NXF_INIT_SET };
 604         struct nx_info *new_nxi;
 605         int ret;
 606
 607         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 608                 return -EFAULT;
 609
 610         if ((nid > MAX_S_CONTEXT) && (nid != NX_DYNAMIC_ID))
 611                 return -EINVAL;
 612         if (nid < 2)
 613                 return -EINVAL;
 614
 615         new_nxi = __create_nx_info(nid);
 616         if (IS_ERR(new_nxi))
 617                 return PTR_ERR(new_nxi);
 618
 619         /* initial flags */
 620         new_nxi->nx_flags = vc_data.flagword;
 621
 622         ret = -ENOEXEC;
 623         if (vs_net_change(new_nxi, VSC_NETUP))
 624                 goto out;
 625
 626         ret = nx_migrate_task(current, new_nxi);
 627         if (ret)
 628                 goto out;
 629
 630         /* return context id on success */
 631         ret = new_nxi->nx_id;
 632
 633         /* get a reference for persistent contexts */
 634         if ((vc_data.flagword & NXF_PERSISTENT))
 635                 nx_set_persistent(new_nxi);
 636 out:
 637         release_nx_info(new_nxi, NULL);
 638         put_nx_info(new_nxi);
 639         return ret;
 640 }
 641
 642
 643 int vc_net_migrate(struct nx_info *nxi, void __user *data)
 644 {
 645         return nx_migrate_task(current, nxi);
 646 }
 647
 648 int vc_net_add(struct nx_info *nxi, void __user *data)
 649 {
 650         struct vcmd_net_addr_v0 vc_data;
 651         int index, pos, ret = 0;
 652
 653         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 654                 return -EFAULT;
 655
 656         switch (vc_data.type) {
 657         case NXA_TYPE_IPV4:
 658                 if ((vc_data.count < 1) || (vc_data.count > 4))
 659                         return -EINVAL;
 660                 break;
 661
 662         default:
 663                 break;
 664         }
 665
 666         switch (vc_data.type) {
 667         case NXA_TYPE_IPV4:
 668                 index = 0;
 669                 while ((index < vc_data.count) &&
 670                         ((pos = nxi->nbipv4) < NB_IPV4ROOT)) {
 671                         nxi->ipv4[pos] = vc_data.ip[index];
 672                         nxi->mask[pos] = vc_data.mask[index];
 673                         index++;
 674                         nxi->nbipv4++;
 675                 }
 676                 ret = index;
 677                 break;
 678
 679         case NXA_TYPE_IPV4|NXA_MOD_BCAST:
 680                 nxi->v4_bcast = vc_data.ip[0];
 681                 ret = 1;
 682                 break;
 683
 684         default:
 685                 ret = -EINVAL;
 686                 break;
 687         }
 688         return ret;
 689 }
 690
 691 int vc_net_remove(struct nx_info * nxi, void __user *data)
 692 {
 693         struct vcmd_net_addr_v0 vc_data;
 694
 695         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 696                 return -EFAULT;
 697
 698         switch (vc_data.type) {
 699         case NXA_TYPE_ANY:
 700                 nxi->nbipv4 = 0;
 701                 break;
 702
 703         default:
 704                 return -EINVAL;
 705         }
 706         return 0;
 707 }
 708
 709 int vc_get_nflags(struct nx_info *nxi, void __user *data)
 710 {
 711         struct vcmd_net_flags_v0 vc_data;
 712
 713         vc_data.flagword = nxi->nx_flags;
 714
 715         /* special STATE flag handling */
 716         vc_data.mask = vs_mask_flags(~0UL, nxi->nx_flags, NXF_ONE_TIME);
 717
 718         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 719                 return -EFAULT;
 720         return 0;
 721 }
 722
 723 int vc_set_nflags(struct nx_info *nxi, void __user *data)
 724 {
 725         struct vcmd_net_flags_v0 vc_data;
 726         uint64_t mask, trigger;
 727
 728         if (copy_from_user (&vc_data, data, sizeof(vc_data)))
 729                 return -EFAULT;
 730
 731         /* special STATE flag handling */
 732         mask = vs_mask_mask(vc_data.mask, nxi->nx_flags, NXF_ONE_TIME);
 733         trigger = (mask & nxi->nx_flags) ^ (mask & vc_data.flagword);
 734
 735         nxi->nx_flags = vs_mask_flags(nxi->nx_flags,
 736                 vc_data.flagword, mask);
 737         if (trigger & NXF_PERSISTENT)
 738                 nx_update_persistent(nxi);
 739
 740         return 0;
 741 }
 742
 743 int vc_get_ncaps(struct nx_info *nxi, void __user *data)
 744 {
 745         struct vcmd_net_caps_v0 vc_data;
 746
 747         vc_data.ncaps = nxi->nx_ncaps;
 748         vc_data.cmask = ~0UL;
 749
 750         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 751                 return -EFAULT;
 752         return 0;
 753 }
 754
 755 int vc_set_ncaps(struct nx_info *nxi, void __user *data)
 756 {
 757         struct vcmd_net_caps_v0 vc_data;
 758
 759         if (copy_from_user (&vc_data, data, sizeof(vc_data)))
 760                 return -EFAULT;
 761
 762         nxi->nx_ncaps = vs_mask_flags(nxi->nx_ncaps,
 763                 vc_data.ncaps, vc_data.cmask);
 764         return 0;
 765 }
 766
 767
 768 #include <linux/module.h>
 769
 770 EXPORT_SYMBOL_GPL(free_nx_info);
 771 EXPORT_SYMBOL_GPL(unhash_nx_info);
 772