1 /* 2 * net/sched/cls_api.c Packet classifier API. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Changes: 12 * 13 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 14 * 15 */ 16 17 #include <asm/uaccess.h> 18 #include <asm/system.h> 19 #include <linux/bitops.h> 20 #include <linux/config.h> 21 #include <linux/module.h> 22 #include <linux/types.h> 23 #include <linux/kernel.h> 24 #include <linux/sched.h> 25 #include <linux/string.h> 26 #include <linux/mm.h> 27 #include <linux/socket.h> 28 #include <linux/sockios.h> 29 #include <linux/in.h> 30 #include <linux/errno.h> 31 #include <linux/interrupt.h> 32 #include <linux/netdevice.h> 33 #include <linux/skbuff.h> 34 #include <linux/rtnetlink.h> 35 #include <linux/init.h> 36 #include <linux/kmod.h> 37 #include <net/sock.h> 38 #include <net/pkt_sched.h> 39 #include <net/pkt_cls.h> 40 41 #if 0 /* control */ 42 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) 43 #else 44 #define DPRINTK(format,args...) 45 #endif 46 47 /* The list of all installed classifier types */ 48 49 static struct tcf_proto_ops *tcf_proto_base; 50 51 /* Protects list of registered TC modules. It is pure SMP lock. */ 52 static DEFINE_RWLOCK(cls_mod_lock); 53 54 /* Find classifier type by string name */ 55 56 static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind) 57 { 58 struct tcf_proto_ops *t = NULL; 59 60 if (kind) { 61 read_lock(&cls_mod_lock); 62 for (t = tcf_proto_base; t; t = t->next) { 63 if (rtattr_strcmp(kind, t->kind) == 0) { 64 if (!try_module_get(t->owner)) 65 t = NULL; 66 break; 67 } 68 } 69 read_unlock(&cls_mod_lock); 70 } 71 return t; 72 } 73 74 /* Register(unregister) new classifier type */ 75 76 int register_tcf_proto_ops(struct tcf_proto_ops *ops) 77 { 78 struct tcf_proto_ops *t, **tp; 79 int rc = -EEXIST; 80 81 write_lock(&cls_mod_lock); 82 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next) 83 if (!strcmp(ops->kind, t->kind)) 84 goto out; 85 86 ops->next = NULL; 87 *tp = ops; 88 rc = 0; 89 out: 90 write_unlock(&cls_mod_lock); 91 return rc; 92 } 93 94 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) 95 { 96 struct tcf_proto_ops *t, **tp; 97 int rc = -ENOENT; 98 99 write_lock(&cls_mod_lock); 100 for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next) 101 if (t == ops) 102 break; 103 104 if (!t) 105 goto out; 106 *tp = t->next; 107 rc = 0; 108 out: 109 write_unlock(&cls_mod_lock); 110 return rc; 111 } 112 113 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, 114 struct tcf_proto *tp, unsigned long fh, int event); 115 116 117 /* Select new prio value from the range, managed by kernel. */ 118 119 static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp) 120 { 121 u32 first = TC_H_MAKE(0xC0000000U,0U); 122 123 if (tp) 124 first = tp->prio-1; 125 126 return first; 127 } 128 129 /* Add/change/delete/get a filter node */ 130 131 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 132 { 133 struct rtattr **tca; 134 struct tcmsg *t; 135 u32 protocol; 136 u32 prio; 137 u32 nprio; 138 u32 parent; 139 struct net_device *dev; 140 struct Qdisc *q; 141 struct tcf_proto **back, **chain; 142 struct tcf_proto *tp; 143 struct tcf_proto_ops *tp_ops; 144 struct Qdisc_class_ops *cops; 145 unsigned long cl; 146 unsigned long fh; 147 int err; 148 149 replay: 150 tca = arg; 151 t = NLMSG_DATA(n); 152 protocol = TC_H_MIN(t->tcm_info); 153 prio = TC_H_MAJ(t->tcm_info); 154 nprio = prio; 155 parent = t->tcm_parent; 156 cl = 0; 157 158 if (prio == 0) { 159 /* If no priority is given, user wants we allocated it. */ 160 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 161 return -ENOENT; 162 prio = TC_H_MAKE(0x80000000U,0U); 163 } 164 165 /* Find head of filter chain. */ 166 167 /* Find link */ 168 if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL) 169 return -ENODEV; 170 171 /* Find qdisc */ 172 if (!parent) { 173 q = dev->qdisc_sleeping; 174 parent = q->handle; 175 } else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL) 176 return -EINVAL; 177 178 /* Is it classful? */ 179 if ((cops = q->ops->cl_ops) == NULL) 180 return -EINVAL; 181 182 /* Do we search for filter, attached to class? */ 183 if (TC_H_MIN(parent)) { 184 cl = cops->get(q, parent); 185 if (cl == 0) 186 return -ENOENT; 187 } 188 189 /* And the last stroke */ 190 chain = cops->tcf_chain(q, cl); 191 err = -EINVAL; 192 if (chain == NULL) 193 goto errout; 194 195 /* Check the chain for existence of proto-tcf with this priority */ 196 for (back = chain; (tp=*back) != NULL; back = &tp->next) { 197 if (tp->prio >= prio) { 198 if (tp->prio == prio) { 199 if (!nprio || (tp->protocol != protocol && protocol)) 200 goto errout; 201 } else 202 tp = NULL; 203 break; 204 } 205 } 206 207 if (tp == NULL) { 208 /* Proto-tcf does not exist, create new one */ 209 210 if (tca[TCA_KIND-1] == NULL || !protocol) 211 goto errout; 212 213 err = -ENOENT; 214 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 215 goto errout; 216 217 218 /* Create new proto tcf */ 219 220 err = -ENOBUFS; 221 if ((tp = kmalloc(sizeof(*tp), GFP_KERNEL)) == NULL) 222 goto errout; 223 err = -EINVAL; 224 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]); 225 if (tp_ops == NULL) { 226 #ifdef CONFIG_KMOD 227 struct rtattr *kind = tca[TCA_KIND-1]; 228 char name[IFNAMSIZ]; 229 230 if (kind != NULL && 231 rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { 232 rtnl_unlock(); 233 request_module("cls_%s", name); 234 rtnl_lock(); 235 tp_ops = tcf_proto_lookup_ops(kind); 236 /* We dropped the RTNL semaphore in order to 237 * perform the module load. So, even if we 238 * succeeded in loading the module we have to 239 * replay the request. We indicate this using 240 * -EAGAIN. 241 */ 242 if (tp_ops != NULL) { 243 module_put(tp_ops->owner); 244 err = -EAGAIN; 245 } 246 } 247 #endif 248 kfree(tp); 249 goto errout; 250 } 251 memset(tp, 0, sizeof(*tp)); 252 tp->ops = tp_ops; 253 tp->protocol = protocol; 254 tp->prio = nprio ? : tcf_auto_prio(*back); 255 tp->q = q; 256 tp->classify = tp_ops->classify; 257 tp->classid = parent; 258 if ((err = tp_ops->init(tp)) != 0) { 259 module_put(tp_ops->owner); 260 kfree(tp); 261 goto errout; 262 } 263 264 qdisc_lock_tree(dev); 265 tp->next = *back; 266 *back = tp; 267 qdisc_unlock_tree(dev); 268 269 } else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind)) 270 goto errout; 271 272 fh = tp->ops->get(tp, t->tcm_handle); 273 274 if (fh == 0) { 275 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 276 qdisc_lock_tree(dev); 277 *back = tp->next; 278 qdisc_unlock_tree(dev); 279 280 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); 281 tcf_destroy(tp); 282 err = 0; 283 goto errout; 284 } 285 286 err = -ENOENT; 287 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 288 goto errout; 289 } else { 290 switch (n->nlmsg_type) { 291 case RTM_NEWTFILTER: 292 err = -EEXIST; 293 if (n->nlmsg_flags&NLM_F_EXCL) 294 goto errout; 295 break; 296 case RTM_DELTFILTER: 297 err = tp->ops->delete(tp, fh); 298 if (err == 0) 299 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); 300 goto errout; 301 case RTM_GETTFILTER: 302 err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); 303 goto errout; 304 default: 305 err = -EINVAL; 306 goto errout; 307 } 308 } 309 310 err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh); 311 if (err == 0) 312 tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); 313 314 errout: 315 if (cl) 316 cops->put(q, cl); 317 if (err == -EAGAIN) 318 /* Replay the request. */ 319 goto replay; 320 return err; 321 } 322 323 static int 324 tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh, 325 u32 pid, u32 seq, u16 flags, int event) 326 { 327 struct tcmsg *tcm; 328 struct nlmsghdr *nlh; 329 unsigned char *b = skb->tail; 330 331 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); 332 tcm = NLMSG_DATA(nlh); 333 tcm->tcm_family = AF_UNSPEC; 334 tcm->tcm_ifindex = tp->q->dev->ifindex; 335 tcm->tcm_parent = tp->classid; 336 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 337 RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind); 338 tcm->tcm_handle = fh; 339 if (RTM_DELTFILTER != event) { 340 tcm->tcm_handle = 0; 341 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0) 342 goto rtattr_failure; 343 } 344 nlh->nlmsg_len = skb->tail - b; 345 return skb->len; 346 347 nlmsg_failure: 348 rtattr_failure: 349 skb_trim(skb, b - skb->data); 350 return -1; 351 } 352 353 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, 354 struct tcf_proto *tp, unsigned long fh, int event) 355 { 356 struct sk_buff *skb; 357 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; 358 359 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 360 if (!skb) 361 return -ENOBUFS; 362 363 if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) { 364 kfree_skb(skb); 365 return -EINVAL; 366 } 367 368 return rtnetlink_send(skb, pid, RTMGRP_TC, n->nlmsg_flags&NLM_F_ECHO); 369 } 370 371 struct tcf_dump_args 372 { 373 struct tcf_walker w; 374 struct sk_buff *skb; 375 struct netlink_callback *cb; 376 }; 377 378 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg) 379 { 380 struct tcf_dump_args *a = (void*)arg; 381 382 return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid, 383 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER); 384 } 385 386 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 387 { 388 int t; 389 int s_t; 390 struct net_device *dev; 391 struct Qdisc *q; 392 struct tcf_proto *tp, **chain; 393 struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh); 394 unsigned long cl = 0; 395 struct Qdisc_class_ops *cops; 396 struct tcf_dump_args arg; 397 398 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) 399 return skb->len; 400 if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL) 401 return skb->len; 402 403 read_lock_bh(&qdisc_tree_lock); 404 if (!tcm->tcm_parent) 405 q = dev->qdisc_sleeping; 406 else 407 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 408 if (!q) 409 goto out; 410 if ((cops = q->ops->cl_ops) == NULL) 411 goto errout; 412 if (TC_H_MIN(tcm->tcm_parent)) { 413 cl = cops->get(q, tcm->tcm_parent); 414 if (cl == 0) 415 goto errout; 416 } 417 chain = cops->tcf_chain(q, cl); 418 if (chain == NULL) 419 goto errout; 420 421 s_t = cb->args[0]; 422 423 for (tp=*chain, t=0; tp; tp = tp->next, t++) { 424 if (t < s_t) continue; 425 if (TC_H_MAJ(tcm->tcm_info) && 426 TC_H_MAJ(tcm->tcm_info) != tp->prio) 427 continue; 428 if (TC_H_MIN(tcm->tcm_info) && 429 TC_H_MIN(tcm->tcm_info) != tp->protocol) 430 continue; 431 if (t > s_t) 432 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 433 if (cb->args[1] == 0) { 434 if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid, 435 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) { 436 break; 437 } 438 cb->args[1] = 1; 439 } 440 if (tp->ops->walk == NULL) 441 continue; 442 arg.w.fn = tcf_node_dump; 443 arg.skb = skb; 444 arg.cb = cb; 445 arg.w.stop = 0; 446 arg.w.skip = cb->args[1]-1; 447 arg.w.count = 0; 448 tp->ops->walk(tp, &arg.w); 449 cb->args[1] = arg.w.count+1; 450 if (arg.w.stop) 451 break; 452 } 453 454 cb->args[0] = t; 455 456 errout: 457 if (cl) 458 cops->put(q, cl); 459 out: 460 read_unlock_bh(&qdisc_tree_lock); 461 dev_put(dev); 462 return skb->len; 463 } 464 465 void 466 tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts) 467 { 468 #ifdef CONFIG_NET_CLS_ACT 469 if (exts->action) { 470 tcf_action_destroy(exts->action, TCA_ACT_UNBIND); 471 exts->action = NULL; 472 } 473 #elif defined CONFIG_NET_CLS_POLICE 474 if (exts->police) { 475 tcf_police_release(exts->police, TCA_ACT_UNBIND); 476 exts->police = NULL; 477 } 478 #endif 479 } 480 481 482 int 483 tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb, 484 struct rtattr *rate_tlv, struct tcf_exts *exts, 485 struct tcf_ext_map *map) 486 { 487 memset(exts, 0, sizeof(*exts)); 488 489 #ifdef CONFIG_NET_CLS_ACT 490 { 491 int err; 492 struct tc_action *act; 493 494 if (map->police && tb[map->police-1]) { 495 act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police", 496 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); 497 if (act == NULL) 498 return err; 499 500 act->type = TCA_OLD_COMPAT; 501 exts->action = act; 502 } else if (map->action && tb[map->action-1]) { 503 act = tcf_action_init(tb[map->action-1], rate_tlv, NULL, 504 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); 505 if (act == NULL) 506 return err; 507 508 exts->action = act; 509 } 510 } 511 #elif defined CONFIG_NET_CLS_POLICE 512 if (map->police && tb[map->police-1]) { 513 struct tcf_police *p; 514 515 p = tcf_police_locate(tb[map->police-1], rate_tlv); 516 if (p == NULL) 517 return -EINVAL; 518 519 exts->police = p; 520 } else if (map->action && tb[map->action-1]) 521 return -EOPNOTSUPP; 522 #else 523 if ((map->action && tb[map->action-1]) || 524 (map->police && tb[map->police-1])) 525 return -EOPNOTSUPP; 526 #endif 527 528 return 0; 529 } 530 531 void 532 tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, 533 struct tcf_exts *src) 534 { 535 #ifdef CONFIG_NET_CLS_ACT 536 if (src->action) { 537 struct tc_action *act; 538 tcf_tree_lock(tp); 539 act = xchg(&dst->action, src->action); 540 tcf_tree_unlock(tp); 541 if (act) 542 tcf_action_destroy(act, TCA_ACT_UNBIND); 543 } 544 #elif defined CONFIG_NET_CLS_POLICE 545 if (src->police) { 546 struct tcf_police *p; 547 tcf_tree_lock(tp); 548 p = xchg(&dst->police, src->police); 549 tcf_tree_unlock(tp); 550 if (p) 551 tcf_police_release(p, TCA_ACT_UNBIND); 552 } 553 #endif 554 } 555 556 int 557 tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts, 558 struct tcf_ext_map *map) 559 { 560 #ifdef CONFIG_NET_CLS_ACT 561 if (map->action && exts->action) { 562 /* 563 * again for backward compatible mode - we want 564 * to work with both old and new modes of entering 565 * tc data even if iproute2 was newer - jhs 566 */ 567 struct rtattr * p_rta = (struct rtattr*) skb->tail; 568 569 if (exts->action->type != TCA_OLD_COMPAT) { 570 RTA_PUT(skb, map->action, 0, NULL); 571 if (tcf_action_dump(skb, exts->action, 0, 0) < 0) 572 goto rtattr_failure; 573 p_rta->rta_len = skb->tail - (u8*)p_rta; 574 } else if (map->police) { 575 RTA_PUT(skb, map->police, 0, NULL); 576 if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0) 577 goto rtattr_failure; 578 p_rta->rta_len = skb->tail - (u8*)p_rta; 579 } 580 } 581 #elif defined CONFIG_NET_CLS_POLICE 582 if (map->police && exts->police) { 583 struct rtattr * p_rta = (struct rtattr*) skb->tail; 584 585 RTA_PUT(skb, map->police, 0, NULL); 586 587 if (tcf_police_dump(skb, exts->police) < 0) 588 goto rtattr_failure; 589 590 p_rta->rta_len = skb->tail - (u8*)p_rta; 591 } 592 #endif 593 return 0; 594 rtattr_failure: __attribute__ ((unused)) 595 return -1; 596 } 597 598 int 599 tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts, 600 struct tcf_ext_map *map) 601 { 602 #ifdef CONFIG_NET_CLS_ACT 603 if (exts->action) 604 if (tcf_action_copy_stats(skb, exts->action, 1) < 0) 605 goto rtattr_failure; 606 #elif defined CONFIG_NET_CLS_POLICE 607 if (exts->police) 608 if (tcf_police_dump_stats(skb, exts->police) < 0) 609 goto rtattr_failure; 610 #endif 611 return 0; 612 rtattr_failure: __attribute__ ((unused)) 613 return -1; 614 } 615 616 static int __init tc_filter_init(void) 617 { 618 struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC]; 619 620 /* Setup rtnetlink links. It is made here to avoid 621 exporting large number of public symbols. 622 */ 623 624 if (link_p) { 625 link_p[RTM_NEWTFILTER-RTM_BASE].doit = tc_ctl_tfilter; 626 link_p[RTM_DELTFILTER-RTM_BASE].doit = tc_ctl_tfilter; 627 link_p[RTM_GETTFILTER-RTM_BASE].doit = tc_ctl_tfilter; 628 link_p[RTM_GETTFILTER-RTM_BASE].dumpit = tc_dump_tfilter; 629 } 630 return 0; 631 } 632 633 subsys_initcall(tc_filter_init); 634 635 EXPORT_SYMBOL(register_tcf_proto_ops); 636 EXPORT_SYMBOL(unregister_tcf_proto_ops); 637 EXPORT_SYMBOL(tcf_exts_validate); 638 EXPORT_SYMBOL(tcf_exts_destroy); 639 EXPORT_SYMBOL(tcf_exts_change); 640 EXPORT_SYMBOL(tcf_exts_dump); 641 EXPORT_SYMBOL(tcf_exts_dump_stats); 642