1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ip6_flowlabel.c IPv6 flowlabel manager. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 */ 7 8 #include <linux/capability.h> 9 #include <linux/errno.h> 10 #include <linux/types.h> 11 #include <linux/socket.h> 12 #include <linux/net.h> 13 #include <linux/netdevice.h> 14 #include <linux/in6.h> 15 #include <linux/proc_fs.h> 16 #include <linux/seq_file.h> 17 #include <linux/slab.h> 18 #include <linux/export.h> 19 #include <linux/pid_namespace.h> 20 #include <linux/jump_label_ratelimit.h> 21 22 #include <net/net_namespace.h> 23 #include <net/sock.h> 24 25 #include <net/ipv6.h> 26 #include <net/rawv6.h> 27 #include <net/transp_v6.h> 28 29 #include <linux/uaccess.h> 30 31 #define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified 32 in old IPv6 RFC. Well, it was reasonable value. 33 */ 34 #define FL_MAX_LINGER 150 /* Maximal linger timeout */ 35 36 /* FL hash table */ 37 38 #define FL_MAX_PER_SOCK 32 39 #define FL_MAX_SIZE 4096 40 #define FL_HASH_MASK 255 41 #define FL_HASH(l) (ntohl(l)&FL_HASH_MASK) 42 43 static atomic_t fl_size = ATOMIC_INIT(0); 44 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1]; 45 46 static void ip6_fl_gc(struct timer_list *unused); 47 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc); 48 49 /* FL hash table lock: it protects only of GC */ 50 51 static DEFINE_SPINLOCK(ip6_fl_lock); 52 53 /* Big socket sock */ 54 55 static DEFINE_SPINLOCK(ip6_sk_fl_lock); 56 57 DEFINE_STATIC_KEY_DEFERRED_FALSE(ipv6_flowlabel_exclusive, HZ); 58 EXPORT_SYMBOL(ipv6_flowlabel_exclusive); 59 60 #define for_each_fl_rcu(hash, fl) \ 61 for (fl = rcu_dereference_bh(fl_ht[(hash)]); \ 62 fl != NULL; \ 63 fl = rcu_dereference_bh(fl->next)) 64 #define for_each_fl_continue_rcu(fl) \ 65 for (fl = rcu_dereference_bh(fl->next); \ 66 fl != NULL; \ 67 fl = rcu_dereference_bh(fl->next)) 68 69 #define for_each_sk_fl_rcu(np, sfl) \ 70 for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \ 71 sfl != NULL; \ 72 sfl = rcu_dereference_bh(sfl->next)) 73 74 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label) 75 { 76 struct ip6_flowlabel *fl; 77 78 for_each_fl_rcu(FL_HASH(label), fl) { 79 if (fl->label == label && net_eq(fl->fl_net, net)) 80 return fl; 81 } 82 return NULL; 83 } 84 85 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label) 86 { 87 struct ip6_flowlabel *fl; 88 89 rcu_read_lock_bh(); 90 fl = __fl_lookup(net, label); 91 if (fl && !atomic_inc_not_zero(&fl->users)) 92 fl = NULL; 93 rcu_read_unlock_bh(); 94 return fl; 95 } 96 97 static bool fl_shared_exclusive(struct ip6_flowlabel *fl) 98 { 99 return fl->share == IPV6_FL_S_EXCL || 100 fl->share == IPV6_FL_S_PROCESS || 101 fl->share == IPV6_FL_S_USER; 102 } 103 104 static void fl_free_rcu(struct rcu_head *head) 105 { 106 struct ip6_flowlabel *fl = container_of(head, struct ip6_flowlabel, rcu); 107 108 if (fl->share == IPV6_FL_S_PROCESS) 109 put_pid(fl->owner.pid); 110 kfree(fl->opt); 111 kfree(fl); 112 } 113 114 115 static void fl_free(struct ip6_flowlabel *fl) 116 { 117 if (!fl) 118 return; 119 120 if (fl_shared_exclusive(fl) || fl->opt) 121 static_branch_slow_dec_deferred(&ipv6_flowlabel_exclusive); 122 123 call_rcu(&fl->rcu, fl_free_rcu); 124 } 125 126 static void fl_release(struct ip6_flowlabel *fl) 127 { 128 spin_lock_bh(&ip6_fl_lock); 129 130 fl->lastuse = jiffies; 131 if (atomic_dec_and_test(&fl->users)) { 132 unsigned long ttd = fl->lastuse + fl->linger; 133 if (time_after(ttd, fl->expires)) 134 fl->expires = ttd; 135 ttd = fl->expires; 136 if (fl->opt && fl->share == IPV6_FL_S_EXCL) { 137 struct ipv6_txoptions *opt = fl->opt; 138 fl->opt = NULL; 139 kfree(opt); 140 } 141 if (!timer_pending(&ip6_fl_gc_timer) || 142 time_after(ip6_fl_gc_timer.expires, ttd)) 143 mod_timer(&ip6_fl_gc_timer, ttd); 144 } 145 spin_unlock_bh(&ip6_fl_lock); 146 } 147 148 static void ip6_fl_gc(struct timer_list *unused) 149 { 150 int i; 151 unsigned long now = jiffies; 152 unsigned long sched = 0; 153 154 spin_lock(&ip6_fl_lock); 155 156 for (i = 0; i <= FL_HASH_MASK; i++) { 157 struct ip6_flowlabel *fl; 158 struct ip6_flowlabel __rcu **flp; 159 160 flp = &fl_ht[i]; 161 while ((fl = rcu_dereference_protected(*flp, 162 lockdep_is_held(&ip6_fl_lock))) != NULL) { 163 if (atomic_read(&fl->users) == 0) { 164 unsigned long ttd = fl->lastuse + fl->linger; 165 if (time_after(ttd, fl->expires)) 166 fl->expires = ttd; 167 ttd = fl->expires; 168 if (time_after_eq(now, ttd)) { 169 *flp = fl->next; 170 fl_free(fl); 171 atomic_dec(&fl_size); 172 continue; 173 } 174 if (!sched || time_before(ttd, sched)) 175 sched = ttd; 176 } 177 flp = &fl->next; 178 } 179 } 180 if (!sched && atomic_read(&fl_size)) 181 sched = now + FL_MAX_LINGER; 182 if (sched) { 183 mod_timer(&ip6_fl_gc_timer, sched); 184 } 185 spin_unlock(&ip6_fl_lock); 186 } 187 188 static void __net_exit ip6_fl_purge(struct net *net) 189 { 190 int i; 191 192 spin_lock_bh(&ip6_fl_lock); 193 for (i = 0; i <= FL_HASH_MASK; i++) { 194 struct ip6_flowlabel *fl; 195 struct ip6_flowlabel __rcu **flp; 196 197 flp = &fl_ht[i]; 198 while ((fl = rcu_dereference_protected(*flp, 199 lockdep_is_held(&ip6_fl_lock))) != NULL) { 200 if (net_eq(fl->fl_net, net) && 201 atomic_read(&fl->users) == 0) { 202 *flp = fl->next; 203 fl_free(fl); 204 atomic_dec(&fl_size); 205 continue; 206 } 207 flp = &fl->next; 208 } 209 } 210 spin_unlock_bh(&ip6_fl_lock); 211 } 212 213 static struct ip6_flowlabel *fl_intern(struct net *net, 214 struct ip6_flowlabel *fl, __be32 label) 215 { 216 struct ip6_flowlabel *lfl; 217 218 fl->label = label & IPV6_FLOWLABEL_MASK; 219 220 spin_lock_bh(&ip6_fl_lock); 221 if (label == 0) { 222 for (;;) { 223 fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK; 224 if (fl->label) { 225 lfl = __fl_lookup(net, fl->label); 226 if (!lfl) 227 break; 228 } 229 } 230 } else { 231 /* 232 * we dropper the ip6_fl_lock, so this entry could reappear 233 * and we need to recheck with it. 234 * 235 * OTOH no need to search the active socket first, like it is 236 * done in ipv6_flowlabel_opt - sock is locked, so new entry 237 * with the same label can only appear on another sock 238 */ 239 lfl = __fl_lookup(net, fl->label); 240 if (lfl) { 241 atomic_inc(&lfl->users); 242 spin_unlock_bh(&ip6_fl_lock); 243 return lfl; 244 } 245 } 246 247 fl->lastuse = jiffies; 248 fl->next = fl_ht[FL_HASH(fl->label)]; 249 rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl); 250 atomic_inc(&fl_size); 251 spin_unlock_bh(&ip6_fl_lock); 252 return NULL; 253 } 254 255 256 257 /* Socket flowlabel lists */ 258 259 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label) 260 { 261 struct ipv6_fl_socklist *sfl; 262 struct ipv6_pinfo *np = inet6_sk(sk); 263 264 label &= IPV6_FLOWLABEL_MASK; 265 266 rcu_read_lock_bh(); 267 for_each_sk_fl_rcu(np, sfl) { 268 struct ip6_flowlabel *fl = sfl->fl; 269 270 if (fl->label == label && atomic_inc_not_zero(&fl->users)) { 271 fl->lastuse = jiffies; 272 rcu_read_unlock_bh(); 273 return fl; 274 } 275 } 276 rcu_read_unlock_bh(); 277 return NULL; 278 } 279 EXPORT_SYMBOL_GPL(__fl6_sock_lookup); 280 281 void fl6_free_socklist(struct sock *sk) 282 { 283 struct ipv6_pinfo *np = inet6_sk(sk); 284 struct ipv6_fl_socklist *sfl; 285 286 if (!rcu_access_pointer(np->ipv6_fl_list)) 287 return; 288 289 spin_lock_bh(&ip6_sk_fl_lock); 290 while ((sfl = rcu_dereference_protected(np->ipv6_fl_list, 291 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) { 292 np->ipv6_fl_list = sfl->next; 293 spin_unlock_bh(&ip6_sk_fl_lock); 294 295 fl_release(sfl->fl); 296 kfree_rcu(sfl, rcu); 297 298 spin_lock_bh(&ip6_sk_fl_lock); 299 } 300 spin_unlock_bh(&ip6_sk_fl_lock); 301 } 302 303 /* Service routines */ 304 305 306 /* 307 It is the only difficult place. flowlabel enforces equal headers 308 before and including routing header, however user may supply options 309 following rthdr. 310 */ 311 312 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space, 313 struct ip6_flowlabel *fl, 314 struct ipv6_txoptions *fopt) 315 { 316 struct ipv6_txoptions *fl_opt = fl->opt; 317 318 if (!fopt || fopt->opt_flen == 0) 319 return fl_opt; 320 321 if (fl_opt) { 322 opt_space->hopopt = fl_opt->hopopt; 323 opt_space->dst0opt = fl_opt->dst0opt; 324 opt_space->srcrt = fl_opt->srcrt; 325 opt_space->opt_nflen = fl_opt->opt_nflen; 326 } else { 327 if (fopt->opt_nflen == 0) 328 return fopt; 329 opt_space->hopopt = NULL; 330 opt_space->dst0opt = NULL; 331 opt_space->srcrt = NULL; 332 opt_space->opt_nflen = 0; 333 } 334 opt_space->dst1opt = fopt->dst1opt; 335 opt_space->opt_flen = fopt->opt_flen; 336 opt_space->tot_len = fopt->tot_len; 337 return opt_space; 338 } 339 EXPORT_SYMBOL_GPL(fl6_merge_options); 340 341 static unsigned long check_linger(unsigned long ttl) 342 { 343 if (ttl < FL_MIN_LINGER) 344 return FL_MIN_LINGER*HZ; 345 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN)) 346 return 0; 347 return ttl*HZ; 348 } 349 350 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires) 351 { 352 linger = check_linger(linger); 353 if (!linger) 354 return -EPERM; 355 expires = check_linger(expires); 356 if (!expires) 357 return -EPERM; 358 359 spin_lock_bh(&ip6_fl_lock); 360 fl->lastuse = jiffies; 361 if (time_before(fl->linger, linger)) 362 fl->linger = linger; 363 if (time_before(expires, fl->linger)) 364 expires = fl->linger; 365 if (time_before(fl->expires, fl->lastuse + expires)) 366 fl->expires = fl->lastuse + expires; 367 spin_unlock_bh(&ip6_fl_lock); 368 369 return 0; 370 } 371 372 static struct ip6_flowlabel * 373 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq, 374 char __user *optval, int optlen, int *err_p) 375 { 376 struct ip6_flowlabel *fl = NULL; 377 int olen; 378 int addr_type; 379 int err; 380 381 olen = optlen - CMSG_ALIGN(sizeof(*freq)); 382 err = -EINVAL; 383 if (olen > 64 * 1024) 384 goto done; 385 386 err = -ENOMEM; 387 fl = kzalloc(sizeof(*fl), GFP_KERNEL); 388 if (!fl) 389 goto done; 390 391 if (olen > 0) { 392 struct msghdr msg; 393 struct flowi6 flowi6; 394 struct ipcm6_cookie ipc6; 395 396 err = -ENOMEM; 397 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL); 398 if (!fl->opt) 399 goto done; 400 401 memset(fl->opt, 0, sizeof(*fl->opt)); 402 fl->opt->tot_len = sizeof(*fl->opt) + olen; 403 err = -EFAULT; 404 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen)) 405 goto done; 406 407 msg.msg_controllen = olen; 408 msg.msg_control = (void *)(fl->opt+1); 409 memset(&flowi6, 0, sizeof(flowi6)); 410 411 ipc6.opt = fl->opt; 412 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6); 413 if (err) 414 goto done; 415 err = -EINVAL; 416 if (fl->opt->opt_flen) 417 goto done; 418 if (fl->opt->opt_nflen == 0) { 419 kfree(fl->opt); 420 fl->opt = NULL; 421 } 422 } 423 424 fl->fl_net = net; 425 fl->expires = jiffies; 426 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires); 427 if (err) 428 goto done; 429 fl->share = freq->flr_share; 430 addr_type = ipv6_addr_type(&freq->flr_dst); 431 if ((addr_type & IPV6_ADDR_MAPPED) || 432 addr_type == IPV6_ADDR_ANY) { 433 err = -EINVAL; 434 goto done; 435 } 436 fl->dst = freq->flr_dst; 437 atomic_set(&fl->users, 1); 438 switch (fl->share) { 439 case IPV6_FL_S_EXCL: 440 case IPV6_FL_S_ANY: 441 break; 442 case IPV6_FL_S_PROCESS: 443 fl->owner.pid = get_task_pid(current, PIDTYPE_PID); 444 break; 445 case IPV6_FL_S_USER: 446 fl->owner.uid = current_euid(); 447 break; 448 default: 449 err = -EINVAL; 450 goto done; 451 } 452 if (fl_shared_exclusive(fl) || fl->opt) 453 static_branch_deferred_inc(&ipv6_flowlabel_exclusive); 454 return fl; 455 456 done: 457 if (fl) { 458 kfree(fl->opt); 459 kfree(fl); 460 } 461 *err_p = err; 462 return NULL; 463 } 464 465 static int mem_check(struct sock *sk) 466 { 467 struct ipv6_pinfo *np = inet6_sk(sk); 468 struct ipv6_fl_socklist *sfl; 469 int room = FL_MAX_SIZE - atomic_read(&fl_size); 470 int count = 0; 471 472 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK) 473 return 0; 474 475 rcu_read_lock_bh(); 476 for_each_sk_fl_rcu(np, sfl) 477 count++; 478 rcu_read_unlock_bh(); 479 480 if (room <= 0 || 481 ((count >= FL_MAX_PER_SOCK || 482 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) && 483 !capable(CAP_NET_ADMIN))) 484 return -ENOBUFS; 485 486 return 0; 487 } 488 489 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl, 490 struct ip6_flowlabel *fl) 491 { 492 spin_lock_bh(&ip6_sk_fl_lock); 493 sfl->fl = fl; 494 sfl->next = np->ipv6_fl_list; 495 rcu_assign_pointer(np->ipv6_fl_list, sfl); 496 spin_unlock_bh(&ip6_sk_fl_lock); 497 } 498 499 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq, 500 int flags) 501 { 502 struct ipv6_pinfo *np = inet6_sk(sk); 503 struct ipv6_fl_socklist *sfl; 504 505 if (flags & IPV6_FL_F_REMOTE) { 506 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK; 507 return 0; 508 } 509 510 if (np->repflow) { 511 freq->flr_label = np->flow_label; 512 return 0; 513 } 514 515 rcu_read_lock_bh(); 516 517 for_each_sk_fl_rcu(np, sfl) { 518 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) { 519 spin_lock_bh(&ip6_fl_lock); 520 freq->flr_label = sfl->fl->label; 521 freq->flr_dst = sfl->fl->dst; 522 freq->flr_share = sfl->fl->share; 523 freq->flr_expires = (sfl->fl->expires - jiffies) / HZ; 524 freq->flr_linger = sfl->fl->linger / HZ; 525 526 spin_unlock_bh(&ip6_fl_lock); 527 rcu_read_unlock_bh(); 528 return 0; 529 } 530 } 531 rcu_read_unlock_bh(); 532 533 return -ENOENT; 534 } 535 536 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen) 537 { 538 int uninitialized_var(err); 539 struct net *net = sock_net(sk); 540 struct ipv6_pinfo *np = inet6_sk(sk); 541 struct in6_flowlabel_req freq; 542 struct ipv6_fl_socklist *sfl1 = NULL; 543 struct ipv6_fl_socklist *sfl; 544 struct ipv6_fl_socklist __rcu **sflp; 545 struct ip6_flowlabel *fl, *fl1 = NULL; 546 547 548 if (optlen < sizeof(freq)) 549 return -EINVAL; 550 551 if (copy_from_user(&freq, optval, sizeof(freq))) 552 return -EFAULT; 553 554 switch (freq.flr_action) { 555 case IPV6_FL_A_PUT: 556 if (freq.flr_flags & IPV6_FL_F_REFLECT) { 557 if (sk->sk_protocol != IPPROTO_TCP) 558 return -ENOPROTOOPT; 559 if (!np->repflow) 560 return -ESRCH; 561 np->flow_label = 0; 562 np->repflow = 0; 563 return 0; 564 } 565 spin_lock_bh(&ip6_sk_fl_lock); 566 for (sflp = &np->ipv6_fl_list; 567 (sfl = rcu_dereference_protected(*sflp, 568 lockdep_is_held(&ip6_sk_fl_lock))) != NULL; 569 sflp = &sfl->next) { 570 if (sfl->fl->label == freq.flr_label) { 571 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK)) 572 np->flow_label &= ~IPV6_FLOWLABEL_MASK; 573 *sflp = sfl->next; 574 spin_unlock_bh(&ip6_sk_fl_lock); 575 fl_release(sfl->fl); 576 kfree_rcu(sfl, rcu); 577 return 0; 578 } 579 } 580 spin_unlock_bh(&ip6_sk_fl_lock); 581 return -ESRCH; 582 583 case IPV6_FL_A_RENEW: 584 rcu_read_lock_bh(); 585 for_each_sk_fl_rcu(np, sfl) { 586 if (sfl->fl->label == freq.flr_label) { 587 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires); 588 rcu_read_unlock_bh(); 589 return err; 590 } 591 } 592 rcu_read_unlock_bh(); 593 594 if (freq.flr_share == IPV6_FL_S_NONE && 595 ns_capable(net->user_ns, CAP_NET_ADMIN)) { 596 fl = fl_lookup(net, freq.flr_label); 597 if (fl) { 598 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires); 599 fl_release(fl); 600 return err; 601 } 602 } 603 return -ESRCH; 604 605 case IPV6_FL_A_GET: 606 if (freq.flr_flags & IPV6_FL_F_REFLECT) { 607 struct net *net = sock_net(sk); 608 if (net->ipv6.sysctl.flowlabel_consistency) { 609 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n"); 610 return -EPERM; 611 } 612 613 if (sk->sk_protocol != IPPROTO_TCP) 614 return -ENOPROTOOPT; 615 616 np->repflow = 1; 617 return 0; 618 } 619 620 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK) 621 return -EINVAL; 622 623 if (net->ipv6.sysctl.flowlabel_state_ranges && 624 (freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG)) 625 return -ERANGE; 626 627 fl = fl_create(net, sk, &freq, optval, optlen, &err); 628 if (!fl) 629 return err; 630 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL); 631 632 if (freq.flr_label) { 633 err = -EEXIST; 634 rcu_read_lock_bh(); 635 for_each_sk_fl_rcu(np, sfl) { 636 if (sfl->fl->label == freq.flr_label) { 637 if (freq.flr_flags&IPV6_FL_F_EXCL) { 638 rcu_read_unlock_bh(); 639 goto done; 640 } 641 fl1 = sfl->fl; 642 if (!atomic_inc_not_zero(&fl1->users)) 643 fl1 = NULL; 644 break; 645 } 646 } 647 rcu_read_unlock_bh(); 648 649 if (!fl1) 650 fl1 = fl_lookup(net, freq.flr_label); 651 if (fl1) { 652 recheck: 653 err = -EEXIST; 654 if (freq.flr_flags&IPV6_FL_F_EXCL) 655 goto release; 656 err = -EPERM; 657 if (fl1->share == IPV6_FL_S_EXCL || 658 fl1->share != fl->share || 659 ((fl1->share == IPV6_FL_S_PROCESS) && 660 (fl1->owner.pid != fl->owner.pid)) || 661 ((fl1->share == IPV6_FL_S_USER) && 662 !uid_eq(fl1->owner.uid, fl->owner.uid))) 663 goto release; 664 665 err = -ENOMEM; 666 if (!sfl1) 667 goto release; 668 if (fl->linger > fl1->linger) 669 fl1->linger = fl->linger; 670 if ((long)(fl->expires - fl1->expires) > 0) 671 fl1->expires = fl->expires; 672 fl_link(np, sfl1, fl1); 673 fl_free(fl); 674 return 0; 675 676 release: 677 fl_release(fl1); 678 goto done; 679 } 680 } 681 err = -ENOENT; 682 if (!(freq.flr_flags&IPV6_FL_F_CREATE)) 683 goto done; 684 685 err = -ENOMEM; 686 if (!sfl1) 687 goto done; 688 689 err = mem_check(sk); 690 if (err != 0) 691 goto done; 692 693 fl1 = fl_intern(net, fl, freq.flr_label); 694 if (fl1) 695 goto recheck; 696 697 if (!freq.flr_label) { 698 if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label, 699 &fl->label, sizeof(fl->label))) { 700 /* Intentionally ignore fault. */ 701 } 702 } 703 704 fl_link(np, sfl1, fl); 705 return 0; 706 707 default: 708 return -EINVAL; 709 } 710 711 done: 712 fl_free(fl); 713 kfree(sfl1); 714 return err; 715 } 716 717 #ifdef CONFIG_PROC_FS 718 719 struct ip6fl_iter_state { 720 struct seq_net_private p; 721 struct pid_namespace *pid_ns; 722 int bucket; 723 }; 724 725 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private) 726 727 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq) 728 { 729 struct ip6_flowlabel *fl = NULL; 730 struct ip6fl_iter_state *state = ip6fl_seq_private(seq); 731 struct net *net = seq_file_net(seq); 732 733 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) { 734 for_each_fl_rcu(state->bucket, fl) { 735 if (net_eq(fl->fl_net, net)) 736 goto out; 737 } 738 } 739 fl = NULL; 740 out: 741 return fl; 742 } 743 744 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl) 745 { 746 struct ip6fl_iter_state *state = ip6fl_seq_private(seq); 747 struct net *net = seq_file_net(seq); 748 749 for_each_fl_continue_rcu(fl) { 750 if (net_eq(fl->fl_net, net)) 751 goto out; 752 } 753 754 try_again: 755 if (++state->bucket <= FL_HASH_MASK) { 756 for_each_fl_rcu(state->bucket, fl) { 757 if (net_eq(fl->fl_net, net)) 758 goto out; 759 } 760 goto try_again; 761 } 762 fl = NULL; 763 764 out: 765 return fl; 766 } 767 768 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos) 769 { 770 struct ip6_flowlabel *fl = ip6fl_get_first(seq); 771 if (fl) 772 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL) 773 --pos; 774 return pos ? NULL : fl; 775 } 776 777 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos) 778 __acquires(RCU) 779 { 780 struct ip6fl_iter_state *state = ip6fl_seq_private(seq); 781 782 state->pid_ns = proc_pid_ns(file_inode(seq->file)); 783 784 rcu_read_lock_bh(); 785 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; 786 } 787 788 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos) 789 { 790 struct ip6_flowlabel *fl; 791 792 if (v == SEQ_START_TOKEN) 793 fl = ip6fl_get_first(seq); 794 else 795 fl = ip6fl_get_next(seq, v); 796 ++*pos; 797 return fl; 798 } 799 800 static void ip6fl_seq_stop(struct seq_file *seq, void *v) 801 __releases(RCU) 802 { 803 rcu_read_unlock_bh(); 804 } 805 806 static int ip6fl_seq_show(struct seq_file *seq, void *v) 807 { 808 struct ip6fl_iter_state *state = ip6fl_seq_private(seq); 809 if (v == SEQ_START_TOKEN) { 810 seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n"); 811 } else { 812 struct ip6_flowlabel *fl = v; 813 seq_printf(seq, 814 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n", 815 (unsigned int)ntohl(fl->label), 816 fl->share, 817 ((fl->share == IPV6_FL_S_PROCESS) ? 818 pid_nr_ns(fl->owner.pid, state->pid_ns) : 819 ((fl->share == IPV6_FL_S_USER) ? 820 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) : 821 0)), 822 atomic_read(&fl->users), 823 fl->linger/HZ, 824 (long)(fl->expires - jiffies)/HZ, 825 &fl->dst, 826 fl->opt ? fl->opt->opt_nflen : 0); 827 } 828 return 0; 829 } 830 831 static const struct seq_operations ip6fl_seq_ops = { 832 .start = ip6fl_seq_start, 833 .next = ip6fl_seq_next, 834 .stop = ip6fl_seq_stop, 835 .show = ip6fl_seq_show, 836 }; 837 838 static int __net_init ip6_flowlabel_proc_init(struct net *net) 839 { 840 if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net, 841 &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state))) 842 return -ENOMEM; 843 return 0; 844 } 845 846 static void __net_exit ip6_flowlabel_proc_fini(struct net *net) 847 { 848 remove_proc_entry("ip6_flowlabel", net->proc_net); 849 } 850 #else 851 static inline int ip6_flowlabel_proc_init(struct net *net) 852 { 853 return 0; 854 } 855 static inline void ip6_flowlabel_proc_fini(struct net *net) 856 { 857 } 858 #endif 859 860 static void __net_exit ip6_flowlabel_net_exit(struct net *net) 861 { 862 ip6_fl_purge(net); 863 ip6_flowlabel_proc_fini(net); 864 } 865 866 static struct pernet_operations ip6_flowlabel_net_ops = { 867 .init = ip6_flowlabel_proc_init, 868 .exit = ip6_flowlabel_net_exit, 869 }; 870 871 int ip6_flowlabel_init(void) 872 { 873 return register_pernet_subsys(&ip6_flowlabel_net_ops); 874 } 875 876 void ip6_flowlabel_cleanup(void) 877 { 878 static_key_deferred_flush(&ipv6_flowlabel_exclusive); 879 del_timer(&ip6_fl_gc_timer); 880 unregister_pernet_subsys(&ip6_flowlabel_net_ops); 881 } 882