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 #include <linux/vserver/network_cmd.h>
  22
  23 #include <asm/errno.h>
  24 #include <linux/vserver/base.h>
  25 #include <linux/vserver/network_cmd.h>
  26
  27
  28 atomic_t nx_global_ctotal       = ATOMIC_INIT(0);
  29 atomic_t nx_global_cactive      = ATOMIC_INIT(0);
  30
  31
  32 /*      __alloc_nx_info()
  33
  34         * allocate an initialized nx_info struct
  35         * doesn't make it visible (hash)                        */
  36
  37 static struct nx_info *__alloc_nx_info(nid_t nid)
  38 {
  39         struct nx_info *new = NULL;
  40
  41         vxdprintk(VXD_CBIT(nid, 1), "alloc_nx_info(%d)*", nid);
  42
  43         /* would this benefit from a slab cache? */
  44         new = kmalloc(sizeof(struct nx_info), GFP_KERNEL);
  45         if (!new)
  46                 return 0;
  47
  48         memset (new, 0, sizeof(struct nx_info));
  49         new->nx_id = nid;
  50         INIT_HLIST_NODE(&new->nx_hlist);
  51         atomic_set(&new->nx_usecnt, 0);
  52         atomic_set(&new->nx_tasks, 0);
  53         new->nx_state = 0;
  54
  55         new->nx_flags = NXF_INIT_SET;
  56
  57         /* rest of init goes here */
  58
  59         vxdprintk(VXD_CBIT(nid, 0),
  60                 "alloc_nx_info(%d) = %p", nid, new);
  61         atomic_inc(&nx_global_ctotal);
  62         return new;
  63 }
  64
  65 /*      __dealloc_nx_info()
  66
  67         * final disposal of nx_info                             */
  68
  69 static void __dealloc_nx_info(struct nx_info *nxi)
  70 {
  71         vxdprintk(VXD_CBIT(nid, 0),
  72                 "dealloc_nx_info(%p)", nxi);
  73
  74         nxi->nx_hlist.next = LIST_POISON1;
  75         nxi->nx_id = -1;
  76
  77         BUG_ON(atomic_read(&nxi->nx_usecnt));
  78         BUG_ON(atomic_read(&nxi->nx_tasks));
  79
  80         nxi->nx_state |= NXS_RELEASED;
  81         kfree(nxi);
  82         atomic_dec(&nx_global_ctotal);
  83 }
  84
  85 static void __shutdown_nx_info(struct nx_info *nxi)
  86 {
  87         nxi->nx_state |= NXS_SHUTDOWN;
  88         vs_net_change(nxi, VSC_NETDOWN);
  89 }
  90
  91 /*      exported stuff                                          */
  92
  93 void free_nx_info(struct nx_info *nxi)
  94 {
  95         /* context shutdown is mandatory */
  96         BUG_ON(nxi->nx_state != NXS_SHUTDOWN);
  97
  98         /* context must not be hashed */
  99         BUG_ON(nxi->nx_state & NXS_HASHED);
 100
 101         BUG_ON(atomic_read(&nxi->nx_usecnt));
 102         BUG_ON(atomic_read(&nxi->nx_tasks));
 103
 104         __dealloc_nx_info(nxi);
 105 }
 106
 107
 108 /*      hash table for nx_info hash */
 109
 110 #define NX_HASH_SIZE    13
 111
 112 struct hlist_head nx_info_hash[NX_HASH_SIZE];
 113
 114 static spinlock_t nx_info_hash_lock = SPIN_LOCK_UNLOCKED;
 115
 116
 117 static inline unsigned int __hashval(nid_t nid)
 118 {
 119         return (nid % NX_HASH_SIZE);
 120 }
 121
 122
 123
 124 /*      __hash_nx_info()
 125
 126         * add the nxi to the global hash table
 127         * requires the hash_lock to be held                     */
 128
 129 static inline void __hash_nx_info(struct nx_info *nxi)
 130 {
 131         struct hlist_head *head;
 132
 133         vxd_assert_lock(&nx_info_hash_lock);
 134         vxdprintk(VXD_CBIT(nid, 4),
 135                 "__hash_nx_info: %p[#%d]", nxi, nxi->nx_id);
 136
 137         /* context must not be hashed */
 138         BUG_ON(nx_info_state(nxi, NXS_HASHED));
 139
 140         nxi->nx_state |= NXS_HASHED;
 141         head = &nx_info_hash[__hashval(nxi->nx_id)];
 142         hlist_add_head(&nxi->nx_hlist, head);
 143         atomic_inc(&nx_global_cactive);
 144 }
 145
 146 /*      __unhash_nx_info()
 147
 148         * remove the nxi from the global hash table
 149         * requires the hash_lock to be held                     */
 150
 151 static inline void __unhash_nx_info(struct nx_info *nxi)
 152 {
 153         vxd_assert_lock(&nx_info_hash_lock);
 154         vxdprintk(VXD_CBIT(nid, 4),
 155                 "__unhash_nx_info: %p[#%d.%d.%d]", nxi, nxi->nx_id,
 156                 atomic_read(&nxi->nx_usecnt), atomic_read(&nxi->nx_tasks));
 157
 158         /* context must be hashed */
 159         BUG_ON(!nx_info_state(nxi, NXS_HASHED));
 160         /* but without tasks */
 161         BUG_ON(atomic_read(&nxi->nx_tasks));
 162
 163         nxi->nx_state &= ~NXS_HASHED;
 164         hlist_del(&nxi->nx_hlist);
 165         atomic_dec(&nx_global_cactive);
 166 }
 167
 168
 169 /*      __lookup_nx_info()
 170
 171         * requires the hash_lock to be held
 172         * doesn't increment the nx_refcnt                       */
 173
 174 static inline struct nx_info *__lookup_nx_info(nid_t nid)
 175 {
 176         struct hlist_head *head = &nx_info_hash[__hashval(nid)];
 177         struct hlist_node *pos;
 178         struct nx_info *nxi;
 179
 180         vxd_assert_lock(&nx_info_hash_lock);
 181         hlist_for_each(pos, head) {
 182                 nxi = hlist_entry(pos, struct nx_info, nx_hlist);
 183
 184                 if (nxi->nx_id == nid)
 185                         goto found;
 186         }
 187         nxi = NULL;
 188 found:
 189         vxdprintk(VXD_CBIT(nid, 0),
 190                 "__lookup_nx_info(#%u): %p[#%u]",
 191                 nid, nxi, nxi?nxi->nx_id:0);
 192         return nxi;
 193 }
 194
 195
 196 /*      __nx_dynamic_id()
 197
 198         * find unused dynamic nid
 199         * requires the hash_lock to be held                     */
 200
 201 static inline nid_t __nx_dynamic_id(void)
 202 {
 203         static nid_t seq = MAX_N_CONTEXT;
 204         nid_t barrier = seq;
 205
 206         vxd_assert_lock(&nx_info_hash_lock);
 207         do {
 208                 if (++seq > MAX_N_CONTEXT)
 209                         seq = MIN_D_CONTEXT;
 210                 if (!__lookup_nx_info(seq)) {
 211                         vxdprintk(VXD_CBIT(nid, 4),
 212                                 "__nx_dynamic_id: [#%d]", seq);
 213                         return seq;
 214                 }
 215         } while (barrier != seq);
 216         return 0;
 217 }
 218
 219 /*      __create_nx_info()
 220
 221         * create the requested context
 222         * get(), claim() and hash it                            */
 223
 224 static struct nx_info * __create_nx_info(int id)
 225 {
 226         struct nx_info *new, *nxi = NULL;
 227
 228         vxdprintk(VXD_CBIT(nid, 1), "create_nx_info(%d)*", id);
 229
 230         if (!(new = __alloc_nx_info(id)))
 231                 return ERR_PTR(-ENOMEM);
 232
 233         /* required to make dynamic xids unique */
 234         spin_lock(&nx_info_hash_lock);
 235
 236         /* dynamic context requested */
 237         if (id == NX_DYNAMIC_ID) {
 238 #ifdef  CONFIG_VSERVER_DYNAMIC_IDS
 239                 id = __nx_dynamic_id();
 240                 if (!id) {
 241                         printk(KERN_ERR "no dynamic context available.\n");
 242                         nxi = ERR_PTR(-EAGAIN);
 243                         goto out_unlock;
 244                 }
 245                 new->nx_id = id;
 246 #else
 247                 printk(KERN_ERR "dynamic contexts disabled.\n");
 248                 nxi = ERR_PTR(-EINVAL);
 249                 goto out_unlock;
 250 #endif
 251         }
 252         /* static context requested */
 253         else if ((nxi = __lookup_nx_info(id))) {
 254                 vxdprintk(VXD_CBIT(nid, 0),
 255                         "create_nx_info(%d) = %p (already there)", id, nxi);
 256                 if (nx_info_flags(nxi, NXF_STATE_SETUP, 0))
 257                         nxi = ERR_PTR(-EBUSY);
 258                 else
 259                         nxi = ERR_PTR(-EEXIST);
 260                 goto out_unlock;
 261         }
 262         /* dynamic nid creation blocker */
 263         else if (id >= MIN_D_CONTEXT) {
 264                 vxdprintk(VXD_CBIT(nid, 0),
 265                         "create_nx_info(%d) (dynamic rejected)", id);
 266                 nxi = ERR_PTR(-EINVAL);
 267                 goto out_unlock;
 268         }
 269
 270         /* new context */
 271         vxdprintk(VXD_CBIT(nid, 0),
 272                 "create_nx_info(%d) = %p (new)", id, new);
 273         claim_nx_info(new, NULL);
 274         __hash_nx_info(get_nx_info(new));
 275         nxi = new, new = NULL;
 276
 277 out_unlock:
 278         spin_unlock(&nx_info_hash_lock);
 279         if (new)
 280                 __dealloc_nx_info(new);
 281         return nxi;
 282 }
 283
 284
 285
 286 /*      exported stuff                                          */
 287
 288
 289 void unhash_nx_info(struct nx_info *nxi)
 290 {
 291         __shutdown_nx_info(nxi);
 292         spin_lock(&nx_info_hash_lock);
 293         __unhash_nx_info(nxi);
 294         spin_unlock(&nx_info_hash_lock);
 295 }
 296
 297 #ifdef  CONFIG_VSERVER_LEGACYNET
 298
 299 struct nx_info *create_nx_info(void)
 300 {
 301         return __create_nx_info(NX_DYNAMIC_ID);
 302 }
 303
 304 #endif
 305
 306 /*      lookup_nx_info()
 307
 308         * search for a nx_info and get() it
 309         * negative id means current                             */
 310
 311 struct nx_info *lookup_nx_info(int id)
 312 {
 313         struct nx_info *nxi = NULL;
 314
 315         if (id < 0) {
 316                 nxi = get_nx_info(current->nx_info);
 317         } else if (id > 1) {
 318                 spin_lock(&nx_info_hash_lock);
 319                 nxi = get_nx_info(__lookup_nx_info(id));
 320                 spin_unlock(&nx_info_hash_lock);
 321         }
 322         return nxi;
 323 }
 324
 325 /*      nid_is_hashed()
 326
 327         * verify that nid is still hashed                       */
 328
 329 int nid_is_hashed(nid_t nid)
 330 {
 331         int hashed;
 332
 333         spin_lock(&nx_info_hash_lock);
 334         hashed = (__lookup_nx_info(nid) != NULL);
 335         spin_unlock(&nx_info_hash_lock);
 336         return hashed;
 337 }
 338
 339
 340 #ifdef  CONFIG_PROC_FS
 341
 342 /*      get_nid_list()
 343
 344         * get a subset of hashed nids for proc
 345         * assumes size is at least one                          */
 346
 347 int get_nid_list(int index, unsigned int *nids, int size)
 348 {
 349         int hindex, nr_nids = 0;
 350
 351         /* only show current and children */
 352         if (!nx_check(0, VS_ADMIN|VS_WATCH)) {
 353                 if (index > 0)
 354                         return 0;
 355                 nids[nr_nids] = nx_current_nid();
 356                 return 1;
 357         }
 358
 359         for (hindex = 0; hindex < NX_HASH_SIZE; hindex++) {
 360                 struct hlist_head *head = &nx_info_hash[hindex];
 361                 struct hlist_node *pos;
 362
 363                 spin_lock(&nx_info_hash_lock);
 364                 hlist_for_each(pos, head) {
 365                         struct nx_info *nxi;
 366
 367                         if (--index > 0)
 368                                 continue;
 369
 370                         nxi = hlist_entry(pos, struct nx_info, nx_hlist);
 371                         nids[nr_nids] = nxi->nx_id;
 372                         if (++nr_nids >= size) {
 373                                 spin_unlock(&nx_info_hash_lock);
 374                                 goto out;
 375                         }
 376                 }
 377                 /* keep the lock time short */
 378                 spin_unlock(&nx_info_hash_lock);
 379         }
 380 out:
 381         return nr_nids;
 382 }
 383 #endif
 384
 385
 386 /*
 387  *      migrate task to new network
 388  *      gets nxi, puts old_nxi on change
 389  */
 390
 391 int nx_migrate_task(struct task_struct *p, struct nx_info *nxi)
 392 {
 393         struct nx_info *old_nxi;
 394         int ret = 0;
 395
 396         if (!p || !nxi)
 397                 BUG();
 398
 399         vxdprintk(VXD_CBIT(nid, 5),
 400                 "nx_migrate_task(%p,%p[#%d.%d.%d])",
 401                 p, nxi, nxi->nx_id,
 402                 atomic_read(&nxi->nx_usecnt),
 403                 atomic_read(&nxi->nx_tasks));
 404
 405         if (nx_info_flags(nxi, NXF_INFO_PRIVATE, 0) &&
 406                 !nx_info_flags(nxi, NXF_STATE_SETUP, 0))
 407                 return -EACCES;
 408
 409         if (nx_info_state(nxi, NXS_SHUTDOWN))
 410                 return -EFAULT;
 411
 412         /* maybe disallow this completely? */
 413         old_nxi = task_get_nx_info(p);
 414         if (old_nxi == nxi)
 415                 goto out;
 416
 417         task_lock(p);
 418         if (old_nxi)
 419                 clr_nx_info(&p->nx_info);
 420         claim_nx_info(nxi, p);
 421         set_nx_info(&p->nx_info, nxi);
 422         p->nid = nxi->nx_id;
 423         task_unlock(p);
 424
 425         vxdprintk(VXD_CBIT(nid, 5),
 426                 "moved task %p into nxi:%p[#%d]",
 427                 p, nxi, nxi->nx_id);
 428
 429         if (old_nxi)
 430                 release_nx_info(old_nxi, p);
 431         ret = 0;
 432 out:
 433         put_nx_info(old_nxi);
 434         return ret;
 435 }
 436
 437
 438 #ifdef CONFIG_INET
 439
 440 #include <linux/netdevice.h>
 441 #include <linux/inetdevice.h>
 442
 443 int ifa_in_nx_info(struct in_ifaddr *ifa, struct nx_info *nxi)
 444 {
 445         if (!nxi)
 446                 return 1;
 447         if (!ifa)
 448                 return 0;
 449         return addr_in_nx_info(nxi, ifa->ifa_local);
 450 }
 451
 452 int dev_in_nx_info(struct net_device *dev, struct nx_info *nxi)
 453 {
 454         struct in_device *in_dev;
 455         struct in_ifaddr **ifap;
 456         struct in_ifaddr *ifa;
 457         int ret = 0;
 458
 459         if (!nxi)
 460                 return 1;
 461
 462         if (!dev)
 463                 goto out;
 464         in_dev = in_dev_get(dev);
 465         if (!in_dev)
 466                 goto out;
 467
 468         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
 469                 ifap = &ifa->ifa_next) {
 470                 if (addr_in_nx_info(nxi, ifa->ifa_local)) {
 471                         ret = 1;
 472                         break;
 473                 }
 474         }
 475         in_dev_put(in_dev);
 476 out:
 477         return ret;
 478 }
 479
 480 /*
 481  *      check if address is covered by socket
 482  *
 483  *      sk:     the socket to check against
 484  *      addr:   the address in question (must be != 0)
 485  */
 486 static inline int __addr_in_socket(const struct sock *sk, uint32_t addr)
 487 {
 488         struct nx_info *nxi = sk->sk_nx_info;
 489         uint32_t saddr = inet_rcv_saddr(sk);
 490
 491         vxdprintk(VXD_CBIT(net, 5),
 492                 "__addr_in_socket(%p,%d.%d.%d.%d) %p:%d.%d.%d.%d %p;%lx",
 493                 sk, VXD_QUAD(addr), nxi, VXD_QUAD(saddr), sk->sk_socket,
 494                 (sk->sk_socket?sk->sk_socket->flags:0));
 495
 496         if (saddr) {
 497                 /* direct address match */
 498                 return (saddr == addr);
 499         } else if (nxi) {
 500                 /* match against nx_info */
 501                 return addr_in_nx_info(nxi, addr);
 502         } else {
 503                 /* unrestricted any socket */
 504                 return 1;
 505         }
 506 }
 507
 508
 509 int nx_addr_conflict(struct nx_info *nxi, uint32_t addr, const struct sock *sk)
 510 {
 511         vxdprintk(VXD_CBIT(net, 2),
 512                 "nx_addr_conflict(%p,%p) %d.%d,%d.%d",
 513                 nxi, sk, VXD_QUAD(addr));
 514
 515         if (addr) {
 516                 /* check real address */
 517                 return __addr_in_socket(sk, addr);
 518         } else if (nxi) {
 519                 /* check against nx_info */
 520                 int i, n = nxi->nbipv4;
 521
 522                 for (i=0; i<n; i++)
 523                         if (__addr_in_socket(sk, nxi->ipv4[i]))
 524                                 return 1;
 525                 return 0;
 526         } else {
 527                 /* check against any */
 528                 return 1;
 529         }
 530 }
 531
 532 #endif /* CONFIG_INET */
 533
 534 void nx_set_persistent(struct nx_info *nxi)
 535 {
 536         vxdprintk(VXD_CBIT(nid, 6),
 537                 "nx_set_persistent(%p[#%d])", nxi, nxi->nx_id);
 538
 539         get_nx_info(nxi);
 540         claim_nx_info(nxi, NULL);
 541 }
 542
 543 void nx_clear_persistent(struct nx_info *nxi)
 544 {
 545         vxdprintk(VXD_CBIT(nid, 6),
 546                 "nx_clear_persistent(%p[#%d])", nxi, nxi->nx_id);
 547
 548         release_nx_info(nxi, NULL);
 549         put_nx_info(nxi);
 550 }
 551
 552 void nx_update_persistent(struct nx_info *nxi)
 553 {
 554         if (nx_info_flags(nxi, NXF_PERSISTENT, 0))
 555                 nx_set_persistent(nxi);
 556         else
 557                 nx_clear_persistent(nxi);
 558 }
 559
 560 /* vserver syscall commands below here */
 561
 562 /* taks nid and nx_info functions */
 563
 564 #include <asm/uaccess.h>
 565
 566
 567 int vc_task_nid(uint32_t id, void __user *data)
 568 {
 569         nid_t nid;
 570
 571         if (id) {
 572                 struct task_struct *tsk;
 573
 574                 if (!nx_check(0, VS_ADMIN|VS_WATCH))
 575                         return -EPERM;
 576
 577                 read_lock(&tasklist_lock);
 578                 tsk = find_task_by_real_pid(id);
 579                 nid = (tsk) ? tsk->nid : -ESRCH;
 580                 read_unlock(&tasklist_lock);
 581         }
 582         else
 583                 nid = nx_current_nid();
 584         return nid;
 585 }
 586
 587
 588 int vc_nx_info(struct nx_info *nxi, void __user *data)
 589 {
 590         struct vcmd_nx_info_v0 vc_data;
 591
 592         vc_data.nid = nxi->nx_id;
 593
 594         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 595                 return -EFAULT;
 596         return 0;
 597 }
 598
 599
 600 /* network functions */
 601
 602 int vc_net_create(uint32_t nid, void __user *data)
 603 {
 604         struct vcmd_net_create vc_data = { .flagword = NXF_INIT_SET };
 605         struct nx_info *new_nxi;
 606         int ret;
 607
 608         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 609                 return -EFAULT;
 610
 611         if ((nid > MAX_S_CONTEXT) && (nid != NX_DYNAMIC_ID))
 612                 return -EINVAL;
 613         if (nid < 2)
 614                 return -EINVAL;
 615
 616         new_nxi = __create_nx_info(nid);
 617         if (IS_ERR(new_nxi))
 618                 return PTR_ERR(new_nxi);
 619
 620         /* initial flags */
 621         new_nxi->nx_flags = vc_data.flagword;
 622
 623         ret = -ENOEXEC;
 624         if (vs_net_change(new_nxi, VSC_NETUP))
 625                 goto out;
 626
 627         ret = nx_migrate_task(current, new_nxi);
 628         if (ret)
 629                 goto out;
 630
 631         /* return context id on success */
 632         ret = new_nxi->nx_id;
 633
 634         /* get a reference for persistent contexts */
 635         if ((vc_data.flagword & NXF_PERSISTENT))
 636                 nx_set_persistent(new_nxi);
 637 out:
 638         release_nx_info(new_nxi, NULL);
 639         put_nx_info(new_nxi);
 640         return ret;
 641 }
 642
 643
 644 int vc_net_migrate(struct nx_info *nxi, void __user *data)
 645 {
 646         return nx_migrate_task(current, nxi);
 647 }
 648
 649 int vc_net_add(struct nx_info *nxi, void __user *data)
 650 {
 651         struct vcmd_net_addr_v0 vc_data;
 652         int index, pos, ret = 0;
 653
 654         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 655                 return -EFAULT;
 656
 657         switch (vc_data.type) {
 658         case NXA_TYPE_IPV4:
 659                 if ((vc_data.count < 1) || (vc_data.count > 4))
 660                         return -EINVAL;
 661                 break;
 662
 663         default:
 664                 break;
 665         }
 666
 667         switch (vc_data.type) {
 668         case NXA_TYPE_IPV4:
 669                 index = 0;
 670                 while ((index < vc_data.count) &&
 671                         ((pos = nxi->nbipv4) < NB_IPV4ROOT)) {
 672                         nxi->ipv4[pos] = vc_data.ip[index];
 673                         nxi->mask[pos] = vc_data.mask[index];
 674                         index++;
 675                         nxi->nbipv4++;
 676                 }
 677                 ret = index;
 678                 break;
 679
 680         case NXA_TYPE_IPV4|NXA_MOD_BCAST:
 681                 nxi->v4_bcast = vc_data.ip[0];
 682                 ret = 1;
 683                 break;
 684
 685         default:
 686                 ret = -EINVAL;
 687                 break;
 688         }
 689         return ret;
 690 }
 691
 692 int vc_net_remove(struct nx_info * nxi, void __user *data)
 693 {
 694         struct vcmd_net_addr_v0 vc_data;
 695
 696         if (data && copy_from_user (&vc_data, data, sizeof(vc_data)))
 697                 return -EFAULT;
 698
 699         switch (vc_data.type) {
 700         case NXA_TYPE_ANY:
 701                 nxi->nbipv4 = 0;
 702                 break;
 703
 704         default:
 705                 return -EINVAL;
 706         }
 707         return 0;
 708 }
 709
 710 int vc_get_nflags(struct nx_info *nxi, void __user *data)
 711 {
 712         struct vcmd_net_flags_v0 vc_data;
 713
 714         vc_data.flagword = nxi->nx_flags;
 715
 716         /* special STATE flag handling */
 717         vc_data.mask = vs_mask_flags(~0UL, nxi->nx_flags, NXF_ONE_TIME);
 718
 719         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 720                 return -EFAULT;
 721         return 0;
 722 }
 723
 724 int vc_set_nflags(struct nx_info *nxi, void __user *data)
 725 {
 726         struct vcmd_net_flags_v0 vc_data;
 727         uint64_t mask, trigger;
 728
 729         if (copy_from_user (&vc_data, data, sizeof(vc_data)))
 730                 return -EFAULT;
 731
 732         /* special STATE flag handling */
 733         mask = vs_mask_mask(vc_data.mask, nxi->nx_flags, NXF_ONE_TIME);
 734         trigger = (mask & nxi->nx_flags) ^ (mask & vc_data.flagword);
 735
 736         nxi->nx_flags = vs_mask_flags(nxi->nx_flags,
 737                 vc_data.flagword, mask);
 738         if (trigger & NXF_PERSISTENT)
 739                 nx_update_persistent(nxi);
 740
 741         return 0;
 742 }
 743
 744 int vc_get_ncaps(struct nx_info *nxi, void __user *data)
 745 {
 746         struct vcmd_net_caps_v0 vc_data;
 747
 748         vc_data.ncaps = nxi->nx_ncaps;
 749         vc_data.cmask = ~0UL;
 750
 751         if (copy_to_user (data, &vc_data, sizeof(vc_data)))
 752                 return -EFAULT;
 753         return 0;
 754 }
 755
 756 int vc_set_ncaps(struct nx_info *nxi, void __user *data)
 757 {
 758         struct vcmd_net_caps_v0 vc_data;
 759
 760         if (copy_from_user (&vc_data, data, sizeof(vc_data)))
 761                 return -EFAULT;
 762
 763         nxi->nx_ncaps = vs_mask_flags(nxi->nx_ncaps,
 764                 vc_data.ncaps, vc_data.cmask);
 765         return 0;
 766 }
 767
 768
 769 #include <linux/module.h>
 770
 771 EXPORT_SYMBOL_GPL(free_nx_info);
 772 EXPORT_SYMBOL_GPL(unhash_nx_info);
 773